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It is often desirable to package sheet materials in roll form, and to provide a cutting mechanism for severing the sheets into desired lengths; depending upon intended use. It is quite common to package such rolls in cartons that are intended to be disposed of after the rolls have been depleted. Obviously any cutting mechanism employed as part of such a carton must be sufficiently economical to manufacture to justify its disposal along with the package. Although inexpensive mechanisms, such as serrated cutting bars, are known, they generally are not capable of accurately and easily cutting strong flexible sheet materials of the type that tend to stretch or flex as they are being subjected to a cutting force. Moreover, in the case of serrated cutting bars, it is quite easy for a person handling the package to inadvertently cut himself.
Although other types of cutters have been disclosed for use on boxes or cartons in which roll materials are packaged, a need does exist for improved low cost cutters which can be easily fabricated, which are reliable and safe in operation, and which are capable of cutting a wide variety of different sheet materials; particularly those that are strong, stretchable and flexible.
One prior art approach to cutting flexible sheet materials is to include the cutting element on a moveable assembly that has rotatable elements, such as wheels, to press the sheet material against a stationary plate or track for locally immobilizing the material as it is being cut. These devices have been found to work quite well; however, they are believed to be too expensive for the limited use encountered on packages of disposable products. The following patents disclose representative devices of the type employing rotatable elements as part of the cutter: U.S. Pat. Nos. 1,745,476 (Cohn); 2,503,353 (Pugh); 3,277,760 (Keene et al); 3,463,040 (Pouilloux) and 3,791,246 (Lazickas).
A different type of cutting assembly employs a clamping arrangement that is operated independently of a sliding cutter to immobilize the sheet prior to the cutting operation. In this type of device the clamping action is achieved between a stationary surface and a hinged, moveable surface. The use of relatively moveable clamping elements increases the overall cost and complexity of the cutting assembly, as compared to assemblies in which separate clamping bars, independent of the cutter slide, are not utilized. The following patents disclose representative devices of the type employing moveable clamping elements: U.S. Pat. Nos. 3,142,217 and 3,370,497 (Busse) and 3,222,972 (Fulton).
A fairly simple cutting assembly is disclosed in U.S. Pat. No. Re 22,565, issued to Gillanders et al. This device is designed for use in cutting adhesive tape, and employs a cutter knife that is adapted to move along an elongated slot in a cylindrical bore. A handle is secured to the upper end of the knife to aid in moving the knife along the slot, and the handle is provided with laterally spaced-apart wings to prevent accidental contact of the blade by the user. The wings also are employed to press the adhesive surface of the tape against a bead adjacent the slot to adhesively attach the tape to said bead. Although this cutter may be suitable for immobilizing adhesive tape by pressing its adhesive surface against the guide in which the knife is slid, there is no mechanism, either provided or suggested, for adequately immobilizing non-adhesive sheet materials during a cutting operation.
An improvement over the Gillanders et al construction has been invented by Balbir Singh and Ernest M. Pinhak, and is disclosed in co-pending U.S. Pat. application Ser. No. 959,359, entitled "Cutting Assembly", and filed on even date herewith. In the Singh et al assembly a top surface of a track is roughened, and a cutter slide, moveable in the track, includes an extremely smooth stationary lower surface overlying the roughened track surface to press the sheet material to be cut against said roughened track surface as the cutting operation is performed. Although this type of system represents a very economical approach to immobilizing non-adhesive sheet materials during a cutting operation, it may not provide the desired degree of immobilization and tensioning for reliably cutting extremely strong and stretchable sheets.
Applicants' cutting assembly is an improvement over that disclosed in the Singh et al patent application.
In order to economically manufacture the cutting assembly it is highly desirable to form it of a minimum number of components. To this end it is highly desirable to be able to form the elongate track as a single unit, and in a form that will permit the cutter slide to be mounted and retained within an interior compartment thereof.
It is known to mold two sections of an article as a single unit with a hinge section between them to permit the sections to be moved together to form a closed interior compartment, as is exemplified in U.S. Pat. No. 3,834,007, issued to Lambiris. In order to mold an elongate track or article having a split upper wall capable of defining a slot that communicates with an interior compartment, the split upper wall sections should initially be moldable in an opened position to permit insertion of the cutter slide. This type of forming technique is not suggested by Lambiris. Thereafter, the upper wall sections should be moveable into, and retained in the position they assume in the final track configuration to both trap the cutter slide in the interior compartment and form the slot in which the cutter slide is moveable. Clearly this type of forming technique is not suggested by Lambiris.
The instant invention relates to a simple and reliable cutting assembly, and to a unique method that can be employed to form, as a one-piece unit, the track of the cutting assembly.
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The present invention relates to one-part formulations which rapidly cure on exposure to moisture and are useful for forming films in personal and healthcare applications. The formulations comprise an alkylene trialkoxy terminated siloxane; a catalyst; a diluent; and, optionally, an alkoxysilane and/or a filler.
Many formulations for forming films are known in the pharmaceutical art. These include, for example, ointments, salves, creams, lotions, gels, elastomers and the like. Some of these formulations use silicone-based materials as key components. Silicone based materials are desirable in these formulations since they are generally inert to the body.
One example of silicon-based materials in film forming formulations is provided in European publication number 465,744. This publication teaches the use of a multi-part formulation including an active agent, a Si-H containing polymer, a polymer having unsaturated groups bound to silicon, a catalyst and a hydrophilic component. This formulation is mixed and applied to the body where it cures and forms a controlled release gel.
The prior art methods such as those described in EP 465,744, however, have several disadvantages. For instance, in such methods the person utilizing the formulation must be skilled so as to ensure adequate mixing of the appropriate amounts of component materials in the formulation and then applying the correct amount of the mixed formulation to the desired site before it gels. Similarly, such a method can be an inconvenience and messy for the user. Finally, these methods involve ingredients that may not be desirable for healthcare applications.
WO 90/03809 teaches a coating material for forming bandages comprising a siloxane containing bandage material diluted in a volatile polydimethylsiloxane. The materials described in this reference, however, are different than those described and claimed herein.
Finally, patent such as U.S. Pat. Nos. 3,175,993, 4,772,675, 4,871,827, 4,888,380, 4,898,910, and 4,906,719 teach silicone sealants comprising an alkylene trialkoxysilyl terminated polysiloxane; an alkoxysilane; and a catalyst. Such references, however, do not teach the compositions or the uses described and claimed herein.
We have now discovered a formulation for making a film which can avoid many of the above prior art problems.
The present invention relates to a formulation comprising 5 to 79.99 wt. % of an alkylene trialkoxysilyl terminated polysiloxane; 0 to 5 wt. % of an alkoxysilane; 0.01 to 5 wt. % of a catalyst; 0 to 25 wt % of a filler; and 20 to 94.99 wt % of a volatile diluent.
The present invention also relates to a method for forming a film on a substrate comprising mixing the above components and applying the formulation onto the desired site, wherein said formulation cures in situ on the desired site to form the film.
The present invention relates to formulations which are useful for forming films on substrates, preferably biological substrates, where they can serve, for example, as barrier films, cosmetic films, drug delivery mechanisms and the like.
The first component in the formulations of the present invention comprises alkylene alkoxy terminated polysiloxanes. The polymers may be linear or branched and may be homopolymers, copolymers, or terpolymers. Moreover, the polymers may be a single species or a mixture of different polymers. Typically, it is preferred that these polymers have, on average, at least 1.2 alkylene trialkoxysilyl chain terminations per molecule.
The monomeric units of these polymers may include organic units, such as ethylene, butylene, or oxyalkylene units, but preferably a majority of the monomeric units are siloxy units such as those described by the formula R9sSiO(4xe2x88x92s)/2, where each R9 is independently selected from the group consisting of alkyl groups comprising 1 to about 6 carbon atoms, phenyl, and fluorinated alkyl groups, and s is 0, 1, 2 or 3. Examples of the alkyl groups described by R9 include methyl, ethyl, propyl, butyl and hexyl. An example of the fluorinated alkyl groups described by R9 includes 3,3,3-trifluoropropyl. The preferred polymers comprise polydiorganosiloxanes having repeating units described by the formula xe2x80x94(R92SiO2)fxe2x80x94, wherein each R9 is as described above, preferably methyl, and f is a value such that the polymer has a viscosity within a range of about 0.5 to 3000 Paxc2x7s at 25xc2x0 C. and preferably within a range of about 5 to 150 Paxc2x7s at 25xc2x0 C.
These polymers preferably comprise, on average, at least 1.2 alkylene trialkoxysilyl chain terminations per molecule described by formula xe2x80x94ZSiR1x(OR)3xe2x88x92x, wherein each R is independently selected from the group consisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and isobutyl, R1 is selected from the group consisting of methyl and ethyl, and x is 0 or 1. In preferred embodiments, each R is independently selected from the group consisting of methyl and ethyl, and x is zero. Z in the above formula is independently selected from the group consisting of divalent hydrocarbon radicals free of aliphatic unsaturation comprising about 2 to 18 carbon atoms and a combination of divalent hydrocarbon radicals and siloxane segments described by the formula
wherein R9 is as defined above, each G is a divalent hydrocarbon radical free of aliphatic unsaturation comprising about 2 to 18 carbon atoms, and c is a whole number from 1 to about 6. Examples of the divalent hydrocarbon radicals describing Z and G include alkylene radicals such as ethylene, propylene, butylene, pentylene, and hexylene; and arylene radicals including phenylene. Preferably, Z is alkylene with ethylene being particularly preferred.
These polymers typically have, on average, at least 1.2 alkylene trialkoxysilyl chain terminations per molecule, and preferably, have, on average, at least 1.5 alkylene trialkoxysilyl chain terminations per molecule. Since these polymers may have on average at least 1.2 alkylene trialkoxysilyl chain terminations per molecule, some polymers may contain other types of chain terminations. Preferably, this other type of chain termination comprises organosilyl chain terminations selected from the group consisting of CH2xe2x95x90CHxe2x80x94SiR92xe2x80x94 and R63xe2x80x94Sixe2x80x94, where R9 is as defined above and each R6 is independently selected from the group consisting of R9 and vinyl. Examples of organosilyl chain terminations include trimethylsilyl, triethylsilyl, vinyldimethylsilyl, and vinylmethylphenylsilyl.
Polysiloxanes useful herein include those described in U.S. Pat. Nos. 3,175,993, 4,772,675, 4,871,827, 4,888,380, 4,898,910, 4,906,719, and 4,962,174, which are hereby incorporated by reference, and can be described, for example, by the formula
wherein R, R1, R9, Z, x, and f are as described above. These polymers can be made as described in the above patents.
Other polymers useful in this invention are mixtures of the polysiloxanes described by this formula (I) with trialkyl terminated siloxanes and/or the polysiloxanes described by Kamis et al., U.S. Pat. No. 4,898,910, which is hereby incorporated by reference, and described, for example, by the formula
wherein R, R1, R9, Z, x and f are as defined above.
When the polymer comprises mixtures of polysiloxanes described by the above formulas, typically the polysiloxanes will be present in an amount such that 40 percent or less of the chain terminations will be organosilyl chain terminations, and preferably in an amount such that less than 25 percent of the chain terminations are organosilyl chain terminations.
The most preferred polymers useful in this invention are those polymers described by the polysiloxane formula (I).
The polymers useful herein can also include organic units. One type of organic polymer useful in the invention is the polyoxyalkylene, described by Okawa et al., U.S. Pat. No. 5,403,881, and hereby incorporated by reference to show polyoxyalkylene polymers comprising on average at least 1.2 alkylene trialkoxysilyl chain terminations per molecule and methods of preparing these polymers. Other organic units such as polyisobutylenes, polyethylenes, acrylics, amides and the like can also be included.
The amount of polymer useful in formulations of the present invention is dependent on the amounts of other components added but is typically in the range of about 5 to about 79.99 weight percent based on the total weight of the formulation. Preferably, the polymer is added in amounts from about 15 to 50 weight percent on the same basis.
The present formulation also includes a catalyst. Although nearly any suitable catalyst (e.g., metal containing materials) will work herein, the preferred agent is a titanium containing material. A preferred titanium material comprises a tetraalkoxytitanium compound described by average formula Ti(OR2)y(OR3)4xe2x88x92y, where each R2 is independently selected from the group consisting of tertiary alkyl radicals and 2,4-dimethyl-3-pentyl; each R3 is an independently selected alkyl radical comprising from 1 to about 6 carbon atoms; and y is an average value of from 3 to 4.
Examples of tertiary alkyl radicals represented by R2 include tertiary butyl and tertiary amyl. Preferably, each R2 is an independently selected tertiary alkyl radical. More preferably each R2 is independently selected from the group consisting of a tertiary butyl radical and a tertiary arnyl radical.
Examples of alkyl radicals comprising from 1 to about 6 carbon atoms represented by R3 include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and hexyl.
In this formula, y is an average value of from 3 to 4. Preferably, y is an average value of from about 3.4 to 4, with an average value from about 3.6 to 4 being most preferred.
The amount of catalyst useful in the present formulations is dependent on the amounts of other components added, but is typically used in amounts in the range of about 0.01 to 5 weight percent based on the total weight of the formulation. Preferably, the catalyst is a tetraalkoxytitanium compound and it is added in amounts in the range of about 0.3 to 2.3 weight percent on the same basis. The tetraalkoxytitanium compound may be a single species or a mixture of two or more species.
The formulations of the present invention also include diluents. Such diluents are often necessary to decrease the viscosity of the formulation sufficiently for application. Examples of diluents include silicon containing diluents such as hexamethyldisiloxane, octamethyltrisiloxane, and other short chain linear siloxanes, cyclic siloxanes such as octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, organic diluents such as alkanes, alcohols, ketones, esters, hydrofluorocarbons or any other material which can dilute the formulation without adversely affecting any of the component materials of the formulation or the curing time.
The above diluents are often used in amounts of up 94.99 wt. % of the formulation. Preferably, the diluent is used in an amount of between about 30 and 90 wt % and more preferably between about 45 and 80 wt % of the formulation. On application, however, the diluent often substantially volatilizes leaving the other component materials on the desired site.
The present formulations can also comprise an alkoxysilane described by formula R4zSi(OR5)4xe2x88x92z, where each R4 is independently selected from the group consisting of alkyl radicals comprising from 1 to about 12 carbon atoms and alkenyl radicals comprising from 1 to about 12 carbon atoms; each R5 is independently selected from the group consisting of methyl and ethyl, and z is 1 or 2. Preferably z is 1.
The alkyl radicals comprising 1 to about 12 carbon atoms represented by R4 include, for example, methyl, ethyl, isobutyl, hexyl, octyl, and dodecyl. The alkenyl radicals comprising 1 to about 12 carbon atoms represented by R4 include for example vinyl, allyl, butadienyl, and hexenyl. Preferably, each R4 is independently selected from the group consisting of methyl, ethyl, isobutyl and vinyl. More preferably each R4 is methyl.
Examples of useful alkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, octyltriethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, dimethyldiethoxysilane, isobutyltrimethoxysilane, and ethylmethyldiethoxysilane. The partial hydrolyzates of these alkoxysilanes can also be used in the present formulation. Preferred alkoxysilanes include methyltrimethoxysilane and dimethyldimethoxysilane.
If used, the amount of alkoxysilane is dependent on the amounts of other components added, but is typically in the range of 0.1 to 5 weight percent based on the total weight of the formulation, with amounts in the range of about 0.1 to 2 weight percent on the same basis being preferred. The alkoxysilane may be a single species or a mixture of two or more species.
The present formulations can also comprise fillers. The fillers can include, but are not limited to, ground, precipitated, and colloidal calcium carbonates which can be untreated or treated with stearate or stearic acid; reinforcing silicas such as fumed silicas, precipitated silicas, and hydrophobed silicas; crushed quartz, ground quartz, alumina, aluminum hydroxide, titanium dioxide, diatomaceous earth, iron oxide, carbon black, and graphite. One class of preferred fillers are synthetic silicas where the surfaces of the silica are modified with silicon compounds to produce a hydrophobic behavior. These materials differ from one another in surface area, the silicon compound used to treat the silica, and the extent of surface treatment. Such materials are surprisingly able to reduce the viscosity of the film forming formulation. In addition, resinous reinforcing fillers can be used herein to form transparent films. Silica, calcium carbonate and resinous fillers are especially preferred. Specific examples include Cab-O-Sil(copyright) TS-530 treated filler, Aerosil(copyright) R8200 treated filler, and Wacker(copyright) HDX H2000 treated filler.
If used, the amount of filler in the formulation is generally that amount which provides the desired properties to the uncured formulation such as viscosity, thixotropy, pigmentation, and UV protection. The amount of filler also depends upon the cured physical properties desired such as tensile strength, elongation, and durometer. Finally, the amount of filler also depends on the amounts of other components added, as well as the hydroxyl content of the specific filler used. Typically, this is an amount in the range of about 0.1 to 25 weight percent based on the total weight of the formulation. Preferably, the filler is added in amounts from about 2 to 15 weight percent on the same basis. The filler may be a single filler or a mixture of two or more fillers.
Other materials such as active agents can also be added to formulations of the present invention. The active agents used in the present invention are generally not critical. They can comprise any solid or liquid material which can be bound in the composition and subsequently released at the desired rate. The active agent should also not interfere with the curing of the silicone formulation to an unacceptable extent. Suitable active agents include cosmetics, therapeutic or diagnostic materials, pesticides, herbicides, and the like.
Therapeutic active agents which may be employed include, for example, antibiotic, antiseptic, antifungal, antibacterial, antiinflammatory, hormones, anticancer agents, smoking cessation compositions, cardiovascular, histamine blocker, bronchodilator, analgesic, antiarrythmic, antihistamine, alpha-1 blocker, beta blocker, ACE inhibitor, diuretic, antiaggregant, sedative, tranquillizer, anticonvulsant, anticoagulant agents, vitamins, antiaging agents, agents for treating gastric and duodenal ulcers, anticellulites, proteolytic enzymes, healing factors, cell growth nutrients, peptides and others. Specific examples of suitable therapeutic active agents include penicillins, cephalosporins, tetracyclines, macrolides, epinephrine, amphetamines, aspirin, barbiturates, catecholamines, benzodiazepine, thiopental, codeine, morphine, procaine, lidocaine, benzocaine, sulphonamides, ticonazole, perbuterol, furosamide, prazosin, prostaglandins, salbutamol, indomethicane, diclofenac, glafenine, dipyridamole, theophylline and retinol.
In addition to the therapeutic or diagnostic materials, active agents could be cosmetics such as perfumes, UV protectors, shaving products, deodorants or the like. Suitable cosmetics are known to those skilled in the art.
The proportion of the active agent employed in the present invention is chosen in accordance with the concentration of the active agent required in the composition to deliver the dosage required at the proposed delivery rate. This may vary within a wide range such as from 0.1 to about 70 weight percent, preferably 0.1 to 20 weight percent, of the final composition.
If desired the formulation may also contain other additional ingredients. One advantageous additive is a water scavenger to prevent early curing of the formulation. Other optional ingredients include colorants, coloured indicators, other diluents, extenders such as silicone fluids, silicone resins, excipients employed in pharmacy, compounds intended to perform as pH buffers in controlling the environment immediately in and around the formulation, stabilizers, preservatives, surfactants for cellular formulations such as fluorinated silicones, processing aids such as cyclic or linear polydiorganosiloxanes, bioadhesive materials, and hydrophilic, modulating and swellable components or polymers as set forth in EP Publication 465,744. Still other additional ingredients include absorbents for wounds, alginate, polysaccharides, gelatin, collagen, and materials that can decrease the friction on the surface of the cured film and/or change its gloss.
Since mixing of the component materials in the formulation causes curing at room temperature in the presence of moisture, the component materials can be mixed and stored in a moisture proof container or they can be stored in a plurality of containers prior to use to inhibit curing prior to use. Moisture proof containers include, for example, single use containers (e.g., foil packets). When using a plurality of containers, one container could, for example, contain the silane and a second could contain the polysiloxanes. Each of the additional components in the formulation is put in the container that is most desirable depending on factors such as stability, viscosity, and interactions. Often, however, it is preferable to include an active agent, if used, in only one of the parts of the formulation in order to preserve its effectiveness. Similarly, it is often desirable to put a diluent in both containers.
According to the method of the invention, the mixed formulation is applied to the desired site or, alternatively, the component materials of the invention can be applied onto the desired site in a manner that causes mixing. The formulation reacts in the presence of moisture and results in a cured composition. Preferably, the formulations are applied on a biological surface including, but not limited to animal bodies (eg., human or other animal) and flora.
The formulations of the invention can be applied, for example, by rubbing, painting, spraying, or any other conventional method of applying thin films.
As noted above, when the formulation is mixed, it cures rapidly at room temperature in the presence of moisture (e.g., within 10 minutes, usually within 1-2 minutes). For example, the formulation will cure rapidly on a human or other animal body. If used on an animal, this can minimize the amount time necessary to keep the area immobile while curing takes place.
The final composition can be in the form of a gel or an elastomer and it can have pores (e.g., foams) or it can be pore-free.
The present invention offers numerous advantages over the prior art. The method described herein allows for a simple method of forming a film on a substrate. As such, a skilled practitioner is not required for application. Moreover, the composition can be formed into a wide variety of shapes and have selected combinations of properties (e.g. bioadhesion, release rate and release profile). Similarly, the formulations and processes described herein don""t involve severe conditions (e.g. high temperatures or pressures) that might damage any active agents or substrates used.
The formulations and resultant compositions herein are generally acceptable on many biological membranes. The composition may be formed on intact or damaged skin or in a natural or artificial cavity of the body. The cavity may be, for example, the ocular, buccal, nasal, aural, vaginal or rectal cavity or a cavity formed, for example, in a tooth or an open wound.
The resultant films are typically thin and non-tacky. Films on the order of up to 20 mils (e.g., 1 to 15 mils) are often obtained. These films can have many physical properties from gels to elastomers so that they are able to withstand many of the pressures exerted during normal activities of a patient.
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1. Field of the Invention
This invention relates to tow cables for underwater applications and more particularly to a termination device and a method for terminating braided ropes or cables of aramid fiber to increase the reliability of such cables.
2. State of Prior Art
As described in U.S. Pat. No. 4,184,784 to Killian the introduction of aramid fibers having great tensile strength has made possible a number of applications for lightweight high strength cables for underwater applications and arrays. The major advantage of using aramid cables is that they are light-weight compared to cables made of steel and provide extra strength. It is to be noted that such cables have been marketed under the trade name "KEVLAR" which is a trademark of Dupont Corporation and they require special handling. One of the characteristics of aramid fibers is that they retain their tensile strength right up to the breaking point. Consequently, it has been found to be a very difficult problem to provide a satisfactory termination for such cables since any significant variation in strand length causes the load to be carried to the shortest length strand until it breaks and then the load being transferred to the next available shortest piece, etc. with each strand failing under load until all are broken. It is thus quite important that terminating a cable or rope of KEVLAR is done carefully to maximize the strength of the rope at termination. Various techniques have been used in the prior art with limited success. As an example, Killian, as described in U.S. Pat. No. 4,184,784 which is incorporated herein by reference, uses a tapered coupling having a central sleeve passing through the axis of that coupling. KEVLAR strands or braids or fibers are passed through the annular space between the coupling and the central sleeve and a wedge is inserted from the opposite end to secure the position of the KEVLAR cable after it has passed through the sleeve. However, it has been reported that the results obtained with the termination procedure described and claimed in the above mentioned patent to Killian meets partial success in that the strength of the termination of the KEVLAR cable is up to about 50% to 70% of its original strength. There is thus still a need to improve the termination device and a terminating procedure so as to improve the strength of the cable up to its normal strength at the termination point.
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Field of the Invention
Embodiments of the invention generally relate to a straddle packer system for use in a wellbore.
Description of the Related Art
A straddle packer system is used to sealingly isolate a section of a wellbore to conduct a treatment operation (for example a fracking operation) that helps increase oil and/or gas production from an underground reservoir that is in fluid communication with the isolated wellbore section. The straddle packer system is lowered into the wellbore on a work string and located adjacent to the wellbore section that is to be isolated. An upper packer of the straddle packer system is actuated into a sealed engagement with the wellbore above the wellbore section to be isolated, and a lower packer of the straddle packer system is actuated into a sealed engagement with the wellbore below the wellbore section to be isolated, thereby “straddling” the section of the wellbore to sealingly isolate the wellbore section from the sections of the wellbore above and below the upper and lower packers.
To conduct the treatment operation, pressurized fluid is supplied down through the work string and injected out of a port of the straddle packer system that is positioned between the upper and lower packers. The upper packer prevents the pressurized fluid from flowing up the wellbore past the upper packer, and the lower packer prevents the pressurized fluid from flowing down the wellbore past the lower packer. The pressurized fluid is forced into the underground reservoir that is in fluid communication with the isolated wellbore section between the upper and lower packers. The pressurized fluid is supplied at a pressure that is greater than the underground reservoir to effectively treat the underground reservoir through which oil and/or gas previously trapped in the underground reservoir can now flow.
After conducting the treatment operation, the straddle packer system can be removed from the wellbore or moved to another location within the wellbore to isolate another wellbore section. To remove or move the straddle packer system, the upper and lower packers first have to be unset from the sealed engagement with the wellbore by applying a force to the straddle packer system by pulling or pushing on the work string that is used to lower or raise the straddle packers system into the wellbore. Unsetting of the upper and lower packers of straddle packer systems, however, is difficult because a pressure differential formed across the upper and lower packers during the treatment operation continues to force the upper and lower packers into engagement with the wellbore after the treatment operation is complete.
The pressure difference is formed by the pressure on the side of the upper and lower packers that is exposed to the pressurized fluid from the treatment operation being greater than the pressure on the opposite side of the upper and lower packers that is isolated from the pressurized fluid from the treatment operation. The pressure differential forces the upper and lower packers into engagement with the wellbore and acts against the force that is applied to unset the upper and lower packers from engagement with the wellbore. Pulling or pushing on the straddle packer system via the work string while the upper and lower packers are forced into engagement with the wellbore either requires a force so large that the force will break or collapse the work string before unsetting the upper and lower packers, or causes the upper and lower packers to move while sealing against the wellbore, also known as “swabbing”, which can tear and damage the upper and lower packers.
Therefore, there is a need for new and improved straddle packer systems and methods of use.
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Several publications are referenced in this application within parentheses. Full citation to these references is found at the end of the specification immediately preceding the claims. These references describe the state of the art to which this invention pertains, and are incorporated herein by reference.
The consumption of foods rich in antioxidant compounds is well-known to be inversely correlated with the incidence of many chronic disease states (Halliwell, 1994; Thomas, 1994; Ziegler, 1989). Intake of certain of these compounds, such as vitamins C, E and A, is in fact essential for human life. However, most of the natural compounds present in food possessing antioxidant potential are currently considered to be "non-nutritive". Given the preponderant accumulation of epidemiological data and increasing amount of mechanistic data which support an important role for antioxidants in the maintenance of long-term health, their status as "non-nutritive" food components may have to be reconsidered in the future.
The importance of oxidant defense systems in humans is demonstrated by the essential in vivo presence of both enzymatic as well as non-enzymatic antioxidant components (Thomas, 1994). Oxidative stress and resultant oxidative damage may occur as a result of oxidative insults such as air pollution or the "oxidative burst" characteristic of activated neutrophils mediated by the immune response. A constant source of oxidative stress results from formation of superoxide anion via "electron leakage" in the mitochondria during production of adenosine triphosphate (ATP). Although superoxide anion is not exceedingly reactive in and of itself, it can initiate a chain of events that eventually results in the formation of the highly reactive free radicals and other oxidants. If these reactive oxygen species are not controlled by enzymatic and/or non-enzymatic antioxidant systems, in vivo oxidation of critical cellular components such as membranes, DNA and proteins will result, eventually leading to tissue damage and dysfunction.
Intense exercise can contribute significantly to oxidative stress in a number of ways. Most individuals have at some time in their lives experienced soreness and fatigue after physical exertion. For individuals that desire intense, frequent exercising, the effects of oxidative stress can often inhibit the intensity and/or reduce the frequency of workout routines.
Intense exercise results in a number of physiological changes in the body. First, aerobic respiration is dramatically increased, thereby increasing superoxide anion generation as much as 10-fold or more (Halliwell, 1994) in addition to increasing exposure to environmental oxidative insults such as air pollution. Second, muscle and joint inflammation often result from intense exercise, thus triggering tissue infiltration of neutrophils and subsequent release of reactive oxygen species during the "oxidative burst".
It would therefore be desirable to provide a shelf-stable, visually appealing and flavorful food product comprising carbohydrate and/or fat and/or protein, and other nutritive and non-nutritive compounds, that provides energy and alleviates the effects of oxidative stress and other damage resulting from intense exercise.
The following references, each of which are also incorporated herein by reference, further disclose the state of the art.
U.S. Pat. No. 4,451,488 to Cooke et al. discloses a shelf-stable, intermediate moisture, food bar having a soft and chewy texture, and low sugar content formed from a combination of at least two polyhydric alcohols in varying ratios, one of which comprises a sugar alcohol and the other either glycerol or propylene glycol (abstract). The food bar may additionally contain a mixture of dry ingredients selected from the group consisting of grains, fruits, nuts, chocolate chips and vegetables (column 3, lines 51-57).
U.S. Pat. No. 5,290,605 to Shapira discloses a nutritional soft drink for protecting against the danger of exposure to UV light comprising a mixture of carotenoids, optionally together with vitamin C and/or vitamin E and/or other physiologically acceptable antioxidants (abstract).
U.S. Pat. No. 5,234,702 to Katz discloses the incorporation of an antioxidant system of natural ingredients to minimize the oxidation of a powdered nutritional product (abstract). The antioxidant system is made up of ascorbyl palmitate, beta carotene and/or mixed tocopherols, and citrate (abstract and column 2, lines 56-59).
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It is well known in the art to equip vacuum cleaners with filter bags for filtering dust and dirt particles out of a particle laden air stream created by a vacuum cleaner blower. These filter bags may comprise a single bag element or multiple bag elements of a porous paper or fiber material defining a matrix which traps particulate matter suspended in the air stream while allowing clean air to pass through each bag element and into the environment. Such filter bags are generally disposable and may be detached from a vacuum cleaner and discarded when they have become full of dirt or the openings therethrough have become clogged with dirt.
The efficiency of a vacuum cleaner is affected, in part, by the resistance to air flow imposed by the vacuum cleaner filter bag attached thereto. The more porous the bag elements of the filter bag, the less effort is needed to force air through the filter bag to filter particulate matter from the air. However, if a bag element is too porous, much of the dirt and dust picked up by the vacuum cleaner will pass through the bag element or elements and return to the environment, thus reducing the utility and efficiency of the vacuum cleaner. If bag elements with a tight fiber matrix are used, however, a great amount of force will be needed by the vacuum motor to force air therethrough. Thus, when very tightly woven bag elements are used, the vacuum cleaner must have a fairly powerful motor. Even when a powerful motor is used, its efficiency is decreased by the resistance to air flow imposed by the bag elements of the filter bag. Also, when bag elements having very small openings are employed, these openings quickly become clogged with dirt, decreasing the efficiency of the vacuum and straining the vacuum cleaner motor. Such a filter bag must be replaced frequently adding to the operating cost of the vacuum cleaner. An acceptable balance must therefore be reached between the size of the motor used, the frequency with which the filter bag must be changed, and the percentage of dust and dirt which will be removed from the air by the bag elements. Most attempts to improve vacuum cleaner filter bag design in one of these three areas result in a worsening of the other problems. Thus a filter bag having bag elements with a very fine matrix for use in settings where removing substantially all dust from the discharge is imperative generally must be changed frequently and be used with a vacuum cleaner having a relatively large motor. When a small motor is to be used for reasons of economy, only a lesser degree of dirt removal can be obtained. No known filter bag design adequately addresses all of these problems simultaneously.
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The information processing terminal such as mobile phone, personal digital assistant (PDA) or the like can be connected to a network for sending and receiving an electronic mail (e-mail), and also to the so-called Internet. Also, the mobile phone and PDA have become amazingly prevalent, and there has become more popular the sending and reception of an e-mail by direct communications between the information processing terminals than that by the conventional communications, namely, indirect communications, between stationary personal computers (PC) via the Internet.
Along with the diversification of the electronic mail, various manners of e-mail sending and reception have been proposed. Normally, an e-mail is sent or received simply by clicking the ‘Send and Receive’ button. As one of such various e-mail sending and receiving manners, there is already available, for example, software which is to be used in the apparatus to display a virtual world in which a character such as a fictional pet or the like appearing on the screen of the apparatus carries a mail from or to the user in order to alarm the user of the e-mail sending or reception. This software provides such a function that the user can communicate with the pet or can occasionally receive a message from the pet.
Also, other manners of e-mail sending and reception are available. For example, simple “pictures” are provided which can be depicted with combinations of symbols to make text data that reflects user's emotion as much as possible. Further, pictographic characters are provided which are represented by special codes which are effective only between apparatuses suitable for exclusive use. Since these manners of e-mail sending and reception need not any dedicated software, they are simplest to use and are widely accepted.
Although an e-mail can be accompanied by video data and audio data, it is basically expressed with text data and thus is limited in incorporating “mood” and “user's sentiment” in a sentence.
On the other hand, there have been proposed techniques to control an apparatus in response to an internal state, such as emotion, of the apparatus user or the like. The conventional techniques are different from the e-mail sending and receiving method. For example, the Japanese Patent Application Laid Open No. 2001-34410 (Patent Document No. 1) has proposed a technique for safe handling of an apparatus, with which a sensor provided at an interface of the apparatus, such as a so-called mouse of a PC, joystick of an airplane or control stick of a crane vehicle, through which the user (pilot or operator) makes input of an intended operation to the apparatus, is used to detect a phenomenon of the user or operator, such as “unconscious straining”, “cliff-hanging” or the like and estimate the emotion or sensitiveness of the user, pilot or operator, such as upsurge of sentiment, on the basis of the detected phenomenon for the purpose of safe handling of the apparatus.
Taking the electronic mail (e-mail) as an example, however, communication with a software-controlled character or mail from the character will not be in dialogue form in many cases because the response from the character is just a selected one of, for example, formulaic expressions or keywords prepared in advance. Also, a response can only be made in a predetermined pattern, and hence the e-mail is still limited in making an expression corresponding to “mood” or “user's sentiment”.
Also, with the technique disclosed in the above Patent Document No. 1, the emotion or sensitiveness of the operator is detected. However, the detected operator's emotion or sensitiveness is fed back to the control of the apparatus being operated by the user, but not used as any communication tool responsive to the operator's emotion or sensitiveness.
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1. Field of the Invention
The present invention is in the fields of molecular biology and cellular biology. The invention is directed generally to activation of gene expression or causing over-expression of a gene by recombination methods in situ. More specifically, the invention is directed to activation of endogenous genes by non-targeted integration of specialized activation vectors, which are provided by the invention, into the genome of a host cell. The invention also is directed to methods for the identification, activation, and isolation of genes that were heretofore undiscoverable, and to host cells and vectors comprising such isolated genes. The invention also is directed to isolated genes, gene products, nucleic acid molecules, and compositions comprising such genes, gene products and nucleic acid molecules, that may be used in a variety of therapeutic and diagnostic applications. Thus, by the present invention, endogenous genes, including those associated with human disease and development, may be identified, activated, and isolated without prior knowledge of the sequence, structure, function, or expression profile of the genes.
2. Related Art
Identification and over-expression of novel genes associated with human disease is an important step towards developing new therapeutic drugs. Current approaches to creating libraries of cells for protein over-expression are based on the production and cloning of cDNA. Thus, in order to identify a new gene using this approach, the gene must be expressed in the cells that were used to make the library. The gene also must be expressed at sufficient levels to be adequately represented in the library. This is problematic because many genes are expressed only in very low quantities, in a rare population of cells, or during short developmental periods.
Furthermore, because of the large size of some mRNAs, it is difficult or impossible to produce full length cDNA molecules capable of expressing the biologically active protein. Lack of full-length cDNA molecules has also been observed for small mRNAs and is thought to be related to sequences in the message that are difficult to produce by reverse transcription or that are unstable during propagation in bacteria. As a result, even the most complete cDNA libraries express only a fraction of the entire set of possible genes.
Finally, many cDNA libraries are produced in bacterial vectors. Use of these vectors to express biologically active mammalian proteins is severely limited since most mammalian proteins do not fold correctly and/or are improperly glycosylated in bacteria.
Therefore, a method for creating a more representative library for protein expression, capable of facilitating faithful expression of biologically active proteins, would be extremely valuable.
Current methods for over-expressing proteins involve cloning the gene of interest and placing it, in a construct, next to a suitable promoter/enhancer, polyadenylation signal, and splice site, and introducing the construct into an appropriate host cell.
An alternative approach involves the use of homologous recombination to activate gene expression by targeting a strong promoter or other regulatory sequence to a previously identified gene.
WO 90/14092 describes in situ modification of genes, in mammalian cells, encoding proteins of interest. This application describes single-stranded oligonucleotides for site-directed modification of genes encoding proteins of interest. A marker may also be included. However, the methods are limited to providing an oligonucleotide sequence substantially homologous to a target site. Thus, the method requires knowledge of the site required for activation by site-directed modification and homologous recombination. Novel genes are not discoverable by such methods.
WO 91/06667 describes methods for expressing a mammalian gene in situ. With this method, an amplifiable gene is introduced next to a target gene by homologous recombination. When the cell is then grown in the appropriate medium, both the amplifiable gene and the target gene are amplified and there is enhanced expression of the target gene. As above, methods of introducing the amplifiable gene are limited to homologous recombination, and are not useful for activating novel genes whose sequence (or existence) is unknown.
WO 91/01140 describes the inactivation of endogenous genes by modification of cells by homologous recombination. By these methods, homologous recombination is used to modify and inactivate genes and to produce cells which can serve as donors in gene therapy.
WO 92/20808 describes methods for modifying genomic target sites in situ. The modifications are described as being small, for example, changing single bases in DNA. The method relies upon genomic modification using homologous DNA for targeting.
WO 92/19255 describes a method for enhancing the expression of a target gene, achieved by homologous recombination in which a DNA sequence is integrated into the genome or large genomic fragment. This modified sequence can then be transferred to a secondary host for expression. An amplifiable gene can be integrated next to the target gene so that the target region can be amplified for enhanced expression. Homologous recombination is necessary to this targeted approach.
WO 93/09222 describes methods of making proteins by activating an endogenous gene encoding a desired product. A regulatory region is targeted by homologous recombination and replacing or disabling the region normally associated with the gene whose expression is desired. This disabling or replacement causes the gene to be expressed at levels higher than normal.
WO 94/12650 describes a method for activating expression of and amplifying an endogenous gene in situ in a cell, which gene is not expressed or is not expressed at desired levels in the cell. The cell is transfected with exogenous DNA sequences which repair, alter, delete, or replace a sequence present in the cell or which are regulatory sequences not normally functionally linked to the endogenous gene in the cell. In order to do this, DNA sequences homologous to genomic DNA sequences at a preselected site are used to target the endogenous gene. In addition, amplifiable DNA encoding a selectable marker can be included. By culturing the homologously recombinant cells under conditions that select for amplification, both the endogenous gene and the amplifiable marker are co-amplified and expression of the gene increased.
WO 95/31560 describes DNA constructs for homologous recombination. The constructs include a targeting sequence, a regulatory sequence, an exon, and an unpaired splice donor site. The targeting is achieved by homologous recombination of the construct with genomic sequences in the cell and allows the production of a protein in vitro or in vivo.
WO 96/29411 describes methods using an exogenous regulatory sequence, an exogenous exon, either coding or non-coding, and a splice donor site introduced into a preselected site in the genome by homologous recombination. In this application, the introduced DNA is positioned so that the transcripts under control of the exogenous regulatory region include both the exogenous exon and endogenous exons present in either the thrombopoietin, DNase I, or xcex2-interferon genes, resulting in transcripts in which the exogenous and exogenous exons are operably linked. The novel transcription units are produced by homologous recombination.
U.S. Pat. No. 5,272,071 describes the transcriptional activation of transcriptionally silent genes in a cell by inserting a DNA regulatory element capable of promoting the expression of a gene normally expressed in that cell. The regulatory element is inserted so that it is operably linked to the normally silent gene. The insertion is accomplished by means of homologous recombination by creating a DNA construct with a segment of the normally silent gene (the target DNA) and the DNA regulatory element used to induce the desired transcription.
U.S. Pat. No. 5, 578,461 discusses activating expression of mammalian target genes by homologous recombination. A DNA sequence is integrated into the genome or a large genomic fragment to enhance the expression of the target gene. The modified construct can then be transferred to a secondary host. An amplifiable gene can be integrated adjacent to the target gene so that the target region is amplified for enhanced expression.
Both of the above approaches (construction of an over-expressing construct by cloning or by homologous recombination in vivo) require the gene to be cloned and sequenced before it can be over-expressed. Furthermore, using homologous recombination, the genomic sequence and structure must also be known.
Unfortunately, many genes have not yet been identified and/or sequenced. Thus, a method for over-expressing a gene of interest, whether or not it has been previously cloned, and whether or not its sequence and structure are known, would be useful.
The invention is, therefore, generally directed to methods for over-expressing an endogenous gene in a cell, comprising introducing a vector containing a transcriptional regulatory sequence into the cell, allowing the vector to integrate into the genome of the cell by non-homologous recombination, and allowing over-expression of the endogenous gene in the cell. The method does not require previous knowledge of the sequence of the endogenous gene or even of the existence of the gene. Hence, the invention is directed to non-targeted gene activation, which as used herein means the activation of endogenous genes by non-targeted or non-homologous (as opposed to targeted or homologous) integration of specialized activation vectors into the genome of a host cell.
The invention also encompasses novel vector constructs for activating gene expression or over-expressing a gene through non-homologous recombination. The novel construct lacks homologous targeting sequences. That is, it does not contain nucleotide sequences that target host cell DNA and promote homologous recombination at the target site, causing over-expressing of a cellular gene via the introduced transcriptional regulatory sequence.
Novel vector constructs include a vector containing a transcriptional regulatory sequence operably linked to an unpaired splice donor sequence and further contains one or more amplifiable markers.
Novel vector constructs include constructs with a transcriptional regulatory sequence operably linked to a translational start codon, a signal secretion sequence, and an unpaired splice donor site; constructs with a transcriptional regulatory sequence, operably linked to a translation start codon, an epitope tag, and an unpaired splice donor site; constructs containing a transcriptional regulatory sequence operably linked to a translational start codon, a signal sequence and an epitope tag, and an unpaired splice donor site; constructs containing a transcriptional regulatory sequence operably linked to a translation start codon, a signal secretion sequence, an epitope tag, and a sequence-specific protease site, and an unpaired splice donor site.
The vector construct can contain one or more selectable markers for recombinant host cell selection. Alternatively, selection can be effected by phenotypic selection for a trait provided by the activated endogenous gene product.
These vectors, and indeed any of the vectors disclosed herein, and variants of the vectors that will be readily recognized by one of ordinary skill in the art, can be used in any of the methods described herein to form any of the compositions producible by these methods.
The transcriptional regulatory sequence used in the vector constructs of the invention includes, but is not limited to, a promoter. In preferred embodiments, the promoter is a viral promoter. In highly preferred embodiments, the viral promoter is the cytomegalovirus immediate early promoter. In alternative embodiments, the promoter is a cellular, non-viral promoter or inducible promoter.
The transcriptional regulatory sequence used in the vector construct of the invention may also include, but is not limited to, an enhancer. In preferred embodiments, the enhancer is a viral enhancer. In highly preferred embodiments, the viral enhancer is the cytomegalovirus immediate early enhancer. In alternative embodiments, the enhancer is a cellular non-viral enhancer.
In preferred embodiments of the methods described herein, the vector construct be, or may contain, linear RNA or DNA.
The cell containing the vector may be screened for expression of the gene.
The cell over-expressing the gene can be cultured in vitro under conditions favoring the production, by the cell, of desired amounts of the gene product (also referred to interchangeably herein as the xe2x80x9cexpression productxe2x80x9d) of the endogenous gene that has been activated or whose expression has been increased. The expression product can then be isolated and purified to use, for example, in protein therapy or drug discovery.
Alternatively, the cell expressing the desired gene product can be allowed to express the gene product in vivo. In certain such aspects of the invention, the cell containing a vector construct of the invention integrated into its genome may be introduced into a eukaryote (such as a vertebrate, particularly a mammal, more particularly a human) under conditions favoring the overexpression or activation of the gene by the cell in vivo in the eukaryote. In related such aspects of the invention, the cell may be isolated and cloned prior to being introduced into the eukaryote.
The invention is also directed to methods for over-expressing an endogenous gene in a cell, comprising introducing a vector containing a transcriptional regulatory sequence and one or more amplifiable markers into the cell, allowing the vector to integrate into the genome of the cell by non-homologous recombination, and allowing over-expression of the endogenous gene in the cell.
The cell containing the vector may be screened for over-expression of the gene.
The cell over-expressing the gene is cultured such that amplification of the endogenous gene is obtained. The cell can then be cultured in vitro so as to produce desired amounts of the gene product of the amplified endogenous gene that has been activated or whose expression has been increased. The gene product can then be isolated and purified.
Alternatively, following amplification, the cell can be allowed to express the endogenous gene and produce desired amounts of the gene product in vivo.
It is to be understood, however, that any vector used in the methods described herein can include one or more amplifiable markers. Thereby, amplification of both the vector and the DNA of interest (i.e., containing the over-expressed gene) occurs in the cell, and further enhanced expression of the endogenous gene is obtained. Accordingly, methods can include a step in which the endogenous gene is amplified.
The invention is also directed to methods for over-expressing an endogenous gene in a cell comprising introducing a vector containing a transcriptional regulatory sequence and an unpaired splice donor sequence into the cell, allowing the vector to integrate into the genome of the cell by non-homologous recombination, and allowing over-expression of the endogenous gene in the cell.
The cell containing the vector may be screened for expression of the gene.
The cell over-expressing the gene can be cultured in vitro so as to produce desirable amounts of the gene product of the endogenous gene whose expression has been activated or increased. The gene product can then be isolated and purified.
Alternatively, the cell can be allowed to express the desired gene product in vivo.
The vector construct can consist essentially of the transcriptional regulatory sequence.
The vector construct can consist essentially of the transcriptional regulatory sequence and one or more amplifiable markers.
The vector construct can consist essentially of the transcriptional regulatory sequence and the splice donor sequence.
Any of the vector constructs of the invention can also include a secretion signal sequence. The secretion signal sequence is arranged in the construct so that it will be operably linked to the activated endogenous protein. Thereby, secretion of the protein of interest occurs in the cell, and purification of that protein is facilitated. Accordingly, methods can include a step in which the protein expression product is secreted from the cell.
The invention also encompasses cells made by any of the above methods. The invention encompasses cells containing the vector constructs, cells in which the vector constructs have integrated into the cellular genome, and cells which are over-expressing desired gene products from an endogenous gene, over-expression being driven by the introduced transcriptional regulatory sequence.
The cells can be isolated and cloned.
The methods can be carried out in any cell of eukaryotic origin, such as fungal, plant or animal. In preferred embodiments, the methods of the invention may be carried out in vertebrate cells, and particularly mammalian cells including but not limited to rat, mouse, bovine, porcine, sheep, goat and human cells, and more particularly in human cells.
A single cell made by the methods described above can over-express a single gene or more than one gene. More than one gene in a cell can be activated by the integration of a single type of construct into multiple locations in the genome. Similarly, more than one gene in a cell can be activated by the integration of multiple constructs (i.e., more than one type of construct) into multiple locations in the genome. Therefore, a cell can contain only one type of vector construct or different types of constructs, each capable of activating an endogenous gene.
The invention is also directed to methods for making the cells described above by one or more of the following: introducing one or more of the vector constructs of the invention into a cell; allowing the introduced construct(s) to integrate into the genome of the cell by non-homologous recombination; allowing over-expression of one or more endogenous genes in the cell; and isolating and cloning the cell. The invention is also directed to cells produced by such methods, which may be isolated cells.
The invention also encompasses methods for using the cells described above to over-express a gene, such as an endogenous cellular gene, that has been characterized (for example, sequenced), uncharacterized (for example, a gene whose function is known but which has not been cloned or sequenced), or a gene whose existence was, prior to over-expression, unknown. The cells can be used to produce desired amounts of an expression product in vitro or in vivo. If desired, this expression product can then be isolated and purified, for example by cell lysis or by isolation from the growth medium (as when the vector contains a secretion signal sequence).
The invention also encompasses libraries of cells made by the above described methods. A library can encompass all of the clones from a single transfection experiment or a subset of clones from a single transfection experiment. The subset can over-express the same gene or more than one gene, for example, a class of genes. The transfection can have been done with a single construct or with more than one construct.
A library can also be formed by combining all of the recombinant cells from two or more transfection experiments, by combining one or more subsets of cells from a single transfection experiment or by combining subsets of cells from separate transfection experiments. The resulting library can express the same gene, or more than one gene, for example, a class of genes. Again, in each of these individual transfections, a unique construct or more than one construct can be used.
Libraries can be formed from the same cell type or different cell types.
The invention is also directed to methods for making libraries by selecting various subsets of cells from the same or different transfection experiments.
The invention is also directed to methods of using the above-described cells or libraries of cells to over-express or activate endogenous genes, or to obtain the gene expression products of such over-expressed or activated genes. According to this aspect of the invention, the cell or library may be screened for the expression of the gene and cells that express the desired gene product may be selected. The cell can then be used to isolate or purify the gene product for subsequent use. Expression in the cell can occur by culturing the cell in vitro, under conditions favoring the production of the expression product of the endogenous gene by the cell, or by allowing the cell to express the gene in vivo.
In preferred embodiments of the invention, the methods include a process wherein the expression product is isolated or purified. In highly preferred embodiments, the cells expressing the endogenous gene product are cultured under conditions favoring production of sufficient amounts of gene product for commercial application, and especially for diagnostic, therapeutic and drug discovery uses.
Any of the methods can further comprise introducing double-strand breaks into the genomic DNA in the cell prior to or simultaneously with vector integration.
The invention also is directed to vector constructs that are useful for activating expression of endogenous genes and for isolating the mRNA and cDNA corresponding to the activated genes.
In one such embodiment, the vector construct may comprise (a) a first transcriptional regulatory sequence operably linked to a first unpaired splice donor sequence; (b) a second transcriptional regulatory sequence operably linked to a second unpaired splice donor sequence; and (c) a linearization site, which may be located between the first and second transcriptional regulatory sequences. According to the invention, when the vector construct is transformed into a host cell and then integrates into the genome of the host cell, the first transcriptional regulatory sequence is preferably in an inverted orientation relative to the orientation of the second transcriptional regulatory sequence. In certain preferred such embodiments, the vector may be rendered linear by cleavage at the linearization site.
In another embodiment, the invention provides a linear vector construct having a 3xe2x80x2 end and a 5xe2x80x2 end, comprising a transcriptional regulatory sequence operably linked to an unpaired spliced donor site, wherein the transcriptional regulatory sequence is oriented in the linear vector construct in an orientation that directs transcription towards the 3xe2x80x2 end or the 5xe2x80x2 end of the linear vector construct.
In another embodiment, the invention provides a vector construct comprising, in sequential order, (a) a transcriptional regulatory sequence, (b) an unpaired splice donor site, (c) a rare cutting restriction site, and (d) a linearization site.
In another embodiment, the invention provides a vector construct comprising (a) a first transcriptional regulatory sequence operably linked to a selectable marker lacking a polyadenylation signal; and (b) a second transcriptional regulatory sequence operably linked to an exon-splice donor site complex, wherein the first transcriptional regulatory sequence is in the same orientation in the vector construct as is the second transcriptional regulatory sequence, and wherein the first transcriptional regulatory sequence is upstream of the second transcriptional regulatory sequence in the vector construct.
In additional embodiments, the invention provides vector constructs comprising a transcriptional regulatory sequence operably linked to a selectable marker lacking a polyadenylation signal, and further comprising an unpaired splice donor site.
In another embodiment, the invention provides vector constructs comprising a first transcriptional regulatory sequence operably linked to a selectable marker lacking a polyadenylation signal, and further comprising a second transcriptional regulatory sequence operably linked to an unpaired splice donor site.
According to the invention, the transcriptional regulatory sequence (or first or second transcriptional regulatory sequence, in vector constructs having more than one transcriptional regulatory sequence) may be a promoter, an enhancer, or a repressor, and is preferably a promoter, including an animal cell promoter, a plant cell promoter, or a fungal cell promoter, most preferably a promoter selected from the group consisting of a CMV immediate early gene promoter, an SV40 T antigen promoter, and a xcex2-actin promoter. Other promoters of animal, plant, or fungal cell origin that may be used in accordance with the invention are known in the art and will be familiar to one of ordinary skill in view of the teachings herein.
The selectable marker used in the vector constructs of the invention may be any marker or marker gene that, upon integration of a vector containing the selectable marker into the host cell genome, permits the selection of a cell containing or expressing the marker gene. Suitable such selectable markers include, but are not limited to, a neomycin gene, a hypoxanthine phosphribosyl transferase gene, a puromycin gene, a dihydrooratase gene, a glutamine synthetase gene, a histidine D gene, a carbamyl phosphate synthase gene, a dihydrofolate reductase gene, a multidrug resistance 1 gene, an aspartate transcarbamylase gene, a xanthine-guanine phosphoribosyl transferase gene, an adenosine deaminase gene, and a thymidine kinase gene.
In related embodiments, the invention provides vector constructs comprising a positive selectable marker, a negative selectable marker, and an unpaired splice donor site, wherein the positive and negative selectable markers and the splice donor site are oriented in the vector construct in an orientation that results in expression of the positive selectable marker in active form, and either non-expression of said negative selectable marker or expression of the negative selectable marker in inactive form, when the vector construct is integrated into the genome of a eukaryotic host cell and activates an endogenous gene in the genome. In certain preferred such embodiments, either the positive selection marker, the negative selection marker, or both, may lack a polyadenylation signal. The positive selection marker used in these aspects of the invention may be any selection marker that, upon expression, produces a protein capable of facilitating the isolation of cells expressing the marker, including but not limited to a neomycin gene, a hypoxanthine phosphribosyl transferase gene, a puromycin gene, a dihydrooratase gene, a glutamine synthetase gene, a histidine D gene, a carbamyl phosphate synthase gene, a dihydrofolate reductase gene, a multidrug resistance 1 gene, an aspartate transcarbamylase gene, a xanthine-guanine phosphoribosyl transferase gene, or an adenosine deaminase gene. Analogously, the negative selection marker used in these aspects of the invention may be any selection marker that, upon expression, produces a protein capable of facilitating removal of cells expressing the marker, including but not limited to a hypoxanthine phosphribosyl transferase gene, a thymidine kinase gene, or a diphtheria toxin gene.
The invention also is directed to eukaryotic host cells, which may be isolated host cells, comprising one or more of the vector constructs of the invention. Preferred such eukaryotic host cells include, but are not limited to, animal cells (including, but not limited to, mammalian (particularly human) cells, insect cells, avian cells, annelid cells, amphibian cells, reptilian cells, and fish cells), plant cells, and fungal (particularly yeast) cells. In certain such host cells, the vector construct may be integrated into the genome of the host cell.
The invention also is directed to primer molecules comprising a PCR-amplifiable sequence and a degenerate 3xe2x80x2 terminus. Primer molecules according to this aspect of the invention preferably have the general structure:
5xe2x80x2-(dT)a-X-Nb-TTTATT-3xe2x80x2,
wherein a is a whole number from 1 to 100 (preferably from 10 to 30), X is a PCR-amplifiable sequence consisting of a nucleic acid sequence of about 10-20 nucleotides in length, N is any nucleotide, and b is a whole number from 0 to 6. One preferred such primer has the nucleotide sequence 5xe2x80x2-TTTTTTTTTTTTCGTCAGCGGCCGCATCNNNNTTTATT-3xe2x80x2(SEQ ID NO:10). In related embodiments, the primer molecules according to this aspect of the invention may be biotinylated.
The invention also is directed to methods for first strand cDNA synthesis comprising (a) annealing a first primer of the invention (such as the primer described above) to an RNA template molecule to form an first primer-RNA complex, and (b) treating this first primer-RNA complex with reverse transcriptase and one or more deoxynucleoside triphosphate molecules under conditions favoring the reverse transcription of the first primer-RNA complex to synthesize a first strand cDNA.
The invention also is directed to methods for isolating activated genes, particularly from a host cell genome. These methods of the invention exploit the structure of the m-RNA molecules produced using the non-targeted gene activation vectors of the invention. One such method of the invention comprises, for example, (a) introducing a vector construct comprising a transcriptional regulatory sequence and an unpaired splice donor site into a host cell (preferably one of the eukaryotic host cells described above), (b) allowing the vector construct to integrate into the genome of the host cell by non-homologous recombination, under conditions such that the vector activates an endogenous gene comprising an exon in the genome, (c) isolating RNA from the host cell, (d) synthesizing first strand cDNA according to the method of the invention described above, (e) annealing a second primer specific for the vector-encoded exon to the first strand cDNA to create a second primer-first strand cDNA complex, and (f) contacting the second primer-first strand cDNA complex with a DNA polymerase under conditions favoring the production of a second strand cDNA substantially complementary to the first strand cDNA. Methods according to this aspect of the invention may comprise one or more additional steps, such as treating the second strand cDNA with a restriction enzyme that cleaves at a restriction site located on the vector downstream of the unpaired splice donor site, or amplifying the second strand cDNA using a third primer specific for the vector-encoded exon and a fourth primer specific for the second primer. The invention also is directed to isolated genes produced according to these methods, and to vectors (which may be expression vectors) and host cells comprising these isolated genes. The invention also is directed to methods of producing a polypeptide, comprising cultivating a host cell comprising the isolated gene (or a vector, particularly an expression vector, comprising the isolated gene), and culturing the host cell under conditions favoring the expression by the host cell of a polypeptide encoded by the isolated gene. The invention also provides additional methods of producing a polypeptide, comprising introducing into a host cell a vector comprising a transcriptional regulatory sequence operably linked to an exonic region followed by an unpaired splice donor site, and culturing the host cell under conditions favoring the expression by said host cell of a polypeptide encoded by the exonic region, wherein the exon contains a translational start site positioned at any of the open reading frame positions relative to the 5xe2x80x2-most base of the unpaired splice donor site (e.g., the xe2x80x9cAxe2x80x9d in the ATG start codon may be at position xe2x88x923 or at an increment of 3 bases upstream therefrom (e.g., xe2x88x926, xe2x88x929, xe2x88x9212, xe2x88x9215, xe2x88x9218, etc.), at position xe2x88x922 or at an increment of 3 bases upstream therefrom (e.g., xe2x88x925, xe2x88x928, xe2x88x9211, xe2x88x9214, xe2x88x9217, xe2x88x9220, etc.), or at position xe2x88x921 or at an increment of 3 bases upstream therefrom (e.g., xe2x88x924, xe2x88x927, xe2x88x9210, xe2x88x9213, xe2x88x9216, xe2x88x9219, etc.), relative to the 5xe2x80x2-most base of the splice donor site). In related embodiments, the methods of the invention may further comprise isolating the polypeptide. The invention also is directed to polypeptides, which may or may not be isolated polypeptides, produced according to these methods.
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The subject of the present invention is a percussive hydraulic apparatus.
A percussive hydraulic apparatus comprises a body inside which there is mounted a cylinder in which there is guided an impact piston driven back and forth by an incompressible fluid and which strikes a tool held at the lower end of the body. The distribution of the fluid which moves the piston is performed by a distributor housed in a distribution box mounted in the body.
Document EP 0 638 013 relates to a percussive apparatus in which the cylinder of the impact piston and the various liners forming the cylinder guiding the latter and the distributor are held in a body by a top cover, itself fixed to the body by screws. These screws mechanically immobilize the various parts, but give rise to the following disadvantages:
the distribution of the pressure exerted by the cover is entirely dependent upon the clamping force transmitted by each screw. Now, tensioning short screws on a civil engineering works apparatus is generally performed by torquing, with all the uncertainties associated with this type of stressing: non-uniform friction in the threads of the screws, precision of the tightening equipment, etc. Deformation of the impact-piston guide assembly may therefore be caused by the tightening of the cover.
the cover cannot simultaneously be in contact with the liners and the body of the apparatus as the functional clearance needed might then cause the cover to bend and this would result in bending on the screws, which is detrimental to their fatigue strength.
a slight backing-off of the cover fixing screws results, through a relative movement of the liners with respect to one another, in wear of the bearing surfaces, and gradual misalignment which may detract from the hydraulic guidance of the impact piston.
The object of the invention is to provide a percussive hydraulic apparatus in which the various parts intended to be mounted in an enclosure of the body are not subjected to the constraints resulting from screw-tightening, with the ensuing disadvantages defined above.
To this end, the percussive hydraulic apparatus to which it relates comprising a body inside which there is mounted a cylinder in which there is guided an impact piston driven back and forth by an incompressible fluid and which strikes a tool held at the lower end of the body, the distribution of the fluid which moves the piston being performed by a distributor housed in a distribution box mounted in the body, is characterized in that the cylinder and the distribution box are entirely contained in the enclosure delimited by the body, in that the cylinder bears axially on the body, in that the distribution box is mounted coaxially with respect to the cylinder and bears mechanically thereon and in that the surfaces perpendicular to the axis of the apparatus, subjected to pressure, are arranged and dimensioned in such a way that the resultants of the hydraulic forces applied to the parts, cylinder and distribution box, are directed in the same direction toward a support situated in the body of the apparatus, throughout all the phases of the operating cycle thereof.
According to one embodiment, this apparatus also comprises a distribution cover arranged coaxially with respect to the distribution box and bearing axially thereon, of which the surfaces perpendicular to the axis of the apparatus and subjected to pressure are arranged and dimensioned in such a way that the resultant of the hydraulic forces applied to the cover is directed in the same direction as the resultant of the forces applied to the other parts, cylinder and distribution box, throughout all the phases of the operating cycle of the apparatus.
It is apparent from this structure that the parts which consist of the cylinder, the distribution box and the distribution cover are not fixed mechanically by the cover of the body, as they usually would be. The degree to which the cover is tightened down onto the body therefore has absolutely no influence on the integrity of the various parts inside the body, on the one hand, and relative to one another, on the other hand, because these parts are firmly pressed against one another and against the body by hydraulic forces. This results in the possibility of having far broader manufacturing tolerances than in the conventional case of assembly by screw-fastening, while at the same time enjoying better apparatus behavior since the risks of deformation of the cylinder and of misalignment of the guidance of the impact piston which are known from the prior art are avoided.
According to one feature of the invention, the support of the body, against which the various parts are hydraulically pushed, consists of the end wall of the enclosure, on the tool side, in which enclosure the cylinder is mounted.
According to another feature, each part, cylinder, distribution box, distribution cover, has two antagonist surfaces the first of which is subjected alternately to the high and to the low pressure and the second of which, of a larger surface area than the first, is constantly subjected to the high pressure.
According to one embodiment of this apparatus, the end face of the cylinder bearing against the end wall of the enclosure of the body is at atmospheric pressure while its opposite face is always subjected to the high pressure. The cylinder is thus firmly pressed into the end wall of the enclosure of the body.
According to one possibility, the distribution box has two successive cylindrical portions of which the one facing toward the piston is closed off by an end wall delimiting, with the piston, a chamber connected alternately to the high and to the low pressure, and of which the other portion, which has a larger cross section than the first, is situated in a chamber constantly supplied with high-pressure fluid.
Advantageously, the distribution cover has a circular wall the outer face of which bears against the interior face of the distribution box, the interior face of which serves, in part, to guide the distributor, the lower face of which delimits, in part, an annular chamber which is constantly connected to the low-pressure circuit, this circular wall ending in a part of larger cross section resting on the end of the distribution box and situated in a chamber constantly supplied with high-pressure fluid.
According to another embodiment, the distribution cover has a circular wall the outer face of which bears in a bore of the body, the lower face of which bears against the upper face of the distribution box, the interior face of which serves, in part, to guide the distributor and delimits therewith an annular chamber which is constantly connected to the low-pressure circuit, this circular wall ending, at its upper end, in a part of larger cross section situated in a chamber constantly supplied with high-pressure fluid.
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This application contains material relating to medical services and medical information. The provision and handling of some medical services and medical information are regulated, as for example, by the United States Government, the various state governments, and other governmental agencies within the United States and elsewhere. The disclosure herein is made solely in terms of logical and financial possibility and advantage, without regard to possible statutory, regulatory, or other legal considerations. Nothing herein is intended as a statement or representation of any kind that any method or process proposed or discussed herein does or does not comply with any statute, law, regulation, or other legal requirement whatsoever, in any jurisdiction; nor should it be taken or construed as doing so.
Sometimes, keeping track of people and things is a matter of life and death.
Consider severe food allergies, for example. An allergic reaction to food can affect the skin, the gastrointestinal tract, the respiratory tract, and in the most serious cases, the cardiovascular system. Reactions can range from mild to severe, including the potentially life-threatening condition of anaphylaxis. During an anaphylactic event, an individual may have difficulty breathing and experience a drop in blood pressure. Anaphylaxis can result in death if not treated immediately with an epinephrine injection.
And food allergies are not particularly rare. To the contrary, according to the World Allergy Organization, the burden of food allergies is on the rise in both developed and developing countries. Worldwide, 240-550 million people have food allergies, and it is estimated that, in the United States, up to 15 million Americans have food allergies. This affects roughly 1 in every 13 children, which averages to about 2 children in every classroom. Further, food allergies in children increased at an alarming rate of approximately 50% between 1997 and 2011.
As of this writing, children's food allergies cost nearly S25 billion per year. Among children under the age of 18 in the United States, this life threatening medical condition has caused more than 200,000 visits to the emergency room and more than 300,000 ambulatory care visits each year. A food allergy reaction sends someone to the emergency room every 3 minutes.
Notwithstanding the seriousness of the condition and the immense cost, no clear cause of food allergies has been identified, much less a cure for this medical condition. The only known way to prevent anaphylaxis is a total avoidance of foods that contain the allergen, which is an endless, anxious challenge for the allergic individual.
Once an allergen is consumed, leading to anaphylaxis, epinephrine is the only life-saving form of treatment. Thus, individuals with food allergies are advised to carry 2 doses of epinephrine with them at all times, but it is often a burden for them and their families or other caregivers. For example, parents of young children need to make sure there are epinephrine injectors at school and with all daycare providers. Teenagers may not want to carry the injectors with them due to inconvenience, shame, bullying, or simple adolescent rebellion. And people forget things.
Further, epinephrine is worthless in an anaphylactic emergency if it is not administered. A person who may be experiencing signs of an allergic reaction may nonetheless hesitate to administer the epinephrine, maybe out of uncertainty that an anaphylactic reaction has begun or for fear of administering the injection. Individuals with allergies are sometimes not quite sure when they need to administer epinephrine, especially if they have not (to their knowledge) ingested an allergen, and they may hesitate because they do not want to deal with going to the hospital after injecting themselves with epinephrine. Those who do not have allergies may fear to use an epinephrine injector on someone else.
A number of U.S. patents relate to monitoring locations of portable medical devices, including U.S. Pat. No. 6,937,150 issued to Medema, et al., on Aug. 30, 2005, which discusses a remote locating service situated in an emergency response central dispatch. U.S. Patent Application Publication 2014/0155827, assigned to Mylan, Inc., discusses an application server configured to periodically receive location information of a medicament device from a mobile device. U.S. Patent Application Publication 2014/0243749, assigned to Intelliject, Inc., discusses a monitoring device that assists a patient in determining the location of a medicament delivery device and an alarm on the monitoring device to alert users of separation from the medicament delivery device.
Nevertheless, none of these patents and patent applications provides a reliable and integrated system that provides different levels of alerts and reminders for assisting an individual to manage and use his or her medication delivery devices across different day-to-day settings.
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The present invention relates to foliage trimmers designed for cutting the leaves and branches of asymmetrically convex plants, bushes, shrubs, hedges and the like. Trimming asymmetrically convex shrubs, or the like, manually to a desired shape is very arduous and time consuming operation.
There have been attempts in the past to invent a device to cut convex shapes. Examples of such foliage trimming devices are shown in U.S. Pat. No. 3,487,614, invented by E. Uhor; and U.S. Pat. No. 3,913,304, invented by Paul Jodoin; and U.S. Pat. No. 4,970,791, invented by Florentino S. Vergara; and U.S. Pat. No. 6,151,876, invented by William Van Der Burg; and U.S. Pat. Application No. US 2004/0103631 A1, invented by Jan Pontianus Ezendam and Nicodemus Assisius Ezendam. Unfortunately all these inventions are designed to cut symmetrically convex shapes, thus they are useless in everyday gardens that are made up of asymmetrically convex bushes and furthermore the gardens are not created to accommodate the machinery associated with these trimmers.
Therefore landscapers and others still use conventional linear trimmers that cut in a flat linear plane to trim asymmetrically convex shrubs and the like. Conventional linear foliage trimmers comprise of two straight flat blades situated in facial engagement, with overlapped teeth protruding along their registering edges. A motor means is arranged at one end of the blade assembly to move one of the blades reciprocally or both blades counter reciprocally so the registering teeth slide across one another to cut the foliage projecting through the spaces between the teeth.
In order to cut asymmetrically convex shapes, it is necessary to periodically adjust the angle between the conventional linear trimmer blade assembly and the foliage surface. And multiple passes have to be made to create an asymmetrically convex contour. In many cases the conventional linear trimmer cuts into the foliage contour or creates a flat spot, thus requiring removal of more foliage than is desired. The final condition of the foliage is often not what was initially intended.
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1. Field of the Invention
This invention relates to an optical organic material, particularly an optical organic material having distinct absorption in Infra Red (IR) range and no absorption in visible range.
2. Description of the Prior Art
Materials having distinct absorption in IR range and no absorption in visible range are very important in the field of optical materials, particularly optical sensors consisting of CdS or Si very sensitive to red. Many types of materials were tried to overcome the problem in optical sensors. However, materials consisting of glass are very poor in water resistivity and durability. Materials consisting of synthetic resins have disadvantage in color deterioration. Thus, satisfactory filter materials are not known in the prior art.
Recently, it is proposed to disperse metal ions homogeneously in resin materials. However, it is very difficult to obtain a transparent material of excellent transmittancy through homogeneous and stable dispersion of metal ion in resin material without disturbing the ionic characteristics.
Accordingly, it is an object of the present invention to provide an optical organic material having excellent transmittancy without disturbing the ionic characteristics incorporated.
It is another object of the present invention to provide a process for dispersing metal ions in matrix resin easily and effectively.
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1. Field of the Invention
The present invention relates to a magneto-optical device using the Faraday effect, and to an optical magnetic field sensor probe for detecting a magnetic field by using the same to measure the intensity of the magnetic field.
2. Related art of the Invention
As a method of measuring the magnetic field intensity generated around an electric current by using light, an optical magnetic field sensor combining a magneto-optical device having the Faraday effect and optical fiber is known. Such an optical magnetic field sensor provides high insulation and is free from the effects of electromagnetic induction noise, and owing to such advantages, already, it is realized as a sensor for detecting accidents of high voltage distribution lines in the electric power field (Journal of the Institute of Electrical Engineers of Japan, Section B, Vol. 115, No. 12, p. 1447, 1995). Recently, moreover, there is a mounting need for higher performance for this instrument, and an optical magnetic field sensor of high precision and small size is demanded.
As the optical magnetic sensor making use of the Faraday effect, hitherto, the sensor heads as shown in FIGS. 16(a) and 16(b) have been disclosed (see Journal of Japan Society of Applied Magnetics, Vol. 19, No. 2, p. 209, 1995, and IEEE Transactions on Magnetics, Vol. 31, p. 3191, 1995). In FIGS. 16(a) and 16(b), magneto-optical devices 1 of rare earth iron garnet material are disposed in a magnetic field H. The sensor head in FIG. 16(a) constitutes a collimated optical system using collimated lenses 24a, 24b. Herein, the rare earth iron garnet material used as the magneto-optical device 1 measures 3 mm square and 60 .mu.m in film thickness. Optical fibers 6a and 6b are multi-mode optical fibers with a core diameter of 200 .mu.m. In a polarizer 2 and an analyzer 3a, polarizing beam splitters of a 5 mm cube are used, and the polarizer 2 and analyzer 3a are disposed so that the direction of polarization may be mutually different by 45 degrees. The light entering from an input optical fiber 6a is transformed into a parallel light beam by the collimated lens 24a. It is further transformed into a straight polarized light beam by the polarizer 2, and passes through the magneto-optical device 1, and the plane of polarization is rotated in proportion to the intensity of the magnetic field by the Faraday effect. The rotated straight polarized light passes through the analyzer 3a different by 45 degrees in the transmission and polarization direction with respect to the polarizer 2, and is reflected by a total reflection mirror 4, condensed by the collimated lens 24b, and is focused on the output optical fiber 6b. In such an optical system, the analyzer 3a is fixed, the light output from the polarizer 3a is utilized in one port only, and hence it is called the non-differential fixed analyzer method, in which the change in the magnetic field intensity is converted into a change in quantity of light so as to be measurable. In the optical magnetic field sensor shown in FIG. 16(a), of the light diffracted by the multiple-domain structure of rare earth iron garnet material serving as the magneto-optical device 1, only the 0th-order light is received, and therefore it is hitherto unveiled that the increases as the magnetic field becomes higher.
On the other hand, the sensor head in FIG. 16(b) constitutes a confocal optical system using spherical lenses 25a, 25b as the lenses, and forming a beam waist at the position of the magneto-optical device 1. Thus, the light diffracted by the rare earth iron garnet material can be received up to a high order, so that the linearity is improved. In FIG. 16(b), in order to shorten the optical path length so as to form a beam waist at the position of the magneto-optical device 1, a 3 mm square glass polarizing plate is used in the analyzer 3b. The spherical lenses 25a, 25b, are 3 mm in diameter, being made of material BK-7 with a refractive index of 1.517, and the sensor head measures 12 mm in width and 20 mm in length. These optical magnetic field sensors are installed in the gap of an iron core 16 as shown in FIG. 9 (a block diagram of an optical transformer using the optical magnetic field sensor probe of the invention), and used as optical transformers. Therefore, the smaller the width of the sensor head, the narrower the gap that may be formed, so that an optical transformer of high sensitivity may be realized.
As the magneto-optical device 1 used in such a sensor, the rare earth iron garnet material as shown in formula 2 is disclosed (see Technical Research Report of Electronics, Information and Communication Society of Japan, OQE92-105, 1992). In this prior art, by replacing Y with Bi or Gd, a magneto-optical device of excellent temperature characteristic is realized. The chemical formula of the crystal used in this prior art is shown in formula 2. EQU Bi.sub.1.3 Gd.sub.0.1 La.sub.0.1 Y.sub.1.5 Fe.sub.4.4 Ga.sub.0.6 O.sub.12 (Formula 2)
The linearity and temperature characteristic of the optical magnetic field sensor shown in FIG. 16(b) fabricated by using this magneto-optical device are shown in FIG. 17 and FIG. 18. As shown in FIG. 17, a favorable linearity of 1.0% or less is realized in a magnetic field range of about 25 Oe to 300 Oe. However, to measure a weak magnetic field of less than 25 Oe, the linearity error is large, and a practical problem is noted. The measuring range is narrow, only up to 300 Oe, and an optical magnetic field sensor having a wider measuring range is desired. FIG. 18 shows the result of measuring changes of sensitivity depending on temperature by using two kinds of sensor optical systems, that is, the collimated optical system shown in FIG. 16(a) and the confocal optical system shown in FIG. 16(b), by using the magneto-optical device shown in formula 2. The change rate of sensitivity is normalized by room temperature, and the applied magnetic field is an alternating-current magnetic field of 50 Oe and 60 Hz. In the optical magnetic field sensor shown in FIG. 16(a) composed of the collimated optical system for receiving 0th-order diffracted light only as indicated by bullet marks in FIG. 18, the temperature dependent change of sensitivity of 1.0% or less is obtained. However, in the case of using the magneto-optical device shown in formula 2 in the optical magnetic field sensor shown in FIG. 16(b), a positive characteristic of about 10% of temperature dependent sensitivity change rate is shown as indicated by blank circle marks in FIG. 18. That is, the optical magnetic field sensor in FIG. 16(b) is excellent in linearity, but has a serious problem in the temperature characteristic of the sensitivity.
Therefore, in the prior art, an optical magnetic field sensor satisfying the contradictory problems of favorable linearity and favorable temperature characteristic cannot be realized. Accordingly, an optical magnetic field sensor of smaller size and higher precision is demanded.
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Ceramic matrix composite (CMC) structures may be used in aerospace and other applications because of their ability to withstand high operating temperatures. For example, CMC structures may be used where parts are subjected to high temperature exhaust gases in aircraft applications. Generally, laminated CMC composite structures may have relatively low impact resistance, particularly where the impact is localized as a result of sudden point loads. This low impact resistance stems in part from the fact that these CMC laminates may be formed from fibers held in a ceramic matrix, which may have less than optimal ability to absorb or dampen the energy resulting from localized impacts.
One solution to the problem mentioned above consists of adding additional layers of CMC laminate materials in order to strengthen the structure, however this solution may be undesirable in some applications because of the additional weight it adds to the aircraft component.
Hybrid laminate materials are known in which composite layers comprising continuous fibers in a resin matrix are interspersed with layers containing metal. For example, TiGr laminates have been developed comprising interspersed layers of graphite composite and titanium. Similarly, laminates having glass composite layers interspersed with aluminum layers are also known. However, none of these prior material systems is readily adaptable for use in strengthening CMC structures.
Accordingly, there is a need for a hybrid metal-ceramic matrix composite structure in which the CMC laminates are reinforced to resist localized impact loads, but yet avoid materials that add substantial weight to the structure. There is also a need for a method of making the hybrid structures mentioned above that is both repeatable and well suited for production environments.
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1. Field of the Invention.
This invention relates to condensation proof or fog-free mirrors and more particularly to a fog-free mirror suitable for use during normal ablution in conventional shower stalls or in standard steam baths. This invention operates through heating of its rear surface by means of a flow of the shower water or steam across its rear surface, heating that surface to the approximate temperature of the shower water or steam, and conducting heat to the front reflective surface so that said reflective surface is maintained at a temperature higher than that of the ambient, moisture laden air in the shower stall or steam bath proper, preventing condensation of that moisture on the reflective surface.
2. Description of Prior Art
Individuals often have need for use of mirrors during showers or steam baths, the most common examples of such need being males with particularly tough beards which are softened greatly by the hot water or steam and so rendered yieldable to safety razor shaving, and females with facial blemishes, or situations requiring adjustment or care best given during immersion in shower water or during steam baths. High temperatures of the moisture filled air in shower stalls or steam baths results in condensation of moisture on conventional reflective surfaces used, normally requiring that a hand held mirror have its surface frequently splashed into the shower spray, or wiped free of condensation with wash cloths and towels, while the user usually requires both hands for the operation involving said mirror.
Prevention of condensate formation on automobile windshields and special viewing windows has been achieved in a variety of ways, as noted in U.S. Pat. Nos. 1,702,877, (CLEAR VISION DEVICE FOR WINDSHIELDS) 2,059,990, (WINDSHIELD DEFROSTER) and 1,843,828, (MEANS FOR KEEPING WINDOWS, WINDSHIELDS, etc. CLEAR OF MOISTURE). U.S. Pat. No. 3,530,275, (CONDENSATION CONTROL FOR MIRRORS) a 1968 patent, provides for reflective surface heating by means of a resistive element mounted in the mirror proper and controlled by sensing of shower use through a heat sensitive switch mounted on the shower water supply line. U.S. Pat. No. 2,815,433 provides for heating a mirror's surface by means of an incandescent light bulb's radiated heat.
The device proposed herein operates on the same general principle of heating the optical surface but achieves its results in a novel and much more effective manner. In this invention, a portion of the high temperature material (viz. shower water or steam) creating the high humidity environment is directed to a manifold on the rear surface of the mirror to be acted on and is sprayed or distributed over that rear surface, heating both the rear, and, consequently, the front surface, of that mirror to the approximate temperature of the material. Since the environment of the shower stall will be cooler than the hot water being used for the shower and since steam baths are always cooler than the steam itself, the mirror's front surface will be warmer than that environment and condensation of moisture out of that environment, onto the mirror, will be positively inhibited.
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This invention is generally directed to drogues and or sea anchors which are used as devices which are towed from the stern of water craft to act as a brake to reduce excessive and dangerous speed in conditions of high following winds and more specifically to drogues which are constructed so as to be compactly stored but which, when deployed, automatically assume an orientation which promotes the opening of the drogues as they are pulled through water. The invention more directly relates to open belted type drogues which are formed so as to create a plurality of open spaces between each of the belts through which fluid may pass and wherein the drogues act to control the speed of a vessel to thereby aid in stabilizing the vessel especially in rough seas.
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The present invention relates to an improved hoop clamp for a bass drum, or the like.
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1. Technical Field
The present disclosure relates to an electro-optical device and an electronic apparatus.
2. Related Art
Recently, an electro-optical device which uses an organic light emitting diode (OLED) as a light emitting element has been used in an electronic apparatus which can form a virtual image, such as a head mounted display. In such an electro-optical device, as disclosed in JP-A-2013-211147, a technology using a color filter is proposed as one of technologies which realize color display.
In this technology, emitted light beams of the red color, the greed color, and the blue color are obtained through color filters of three primary colors, that is, red, green, and blue, by using an OLED of emitting white light as a light source. A combination of an OLED and a filter for any color of the three primary colors is assumed to be a subpixel, and a combination of subpixels of the three primary colors is assumed to be a pixel. Such pixels are arranged in matrix so as to constitute a screen of a display device. However, a method in which subpixels for the same colors are arranged in a vertical direction (up-and-down direction) or in a transverse direction (right-and-left direction) is known as an arrangement method of the pixels.
However, the light emitted from the OLED of emitting white light is diffused light. A certain transparent layer having a thickness which is formed by an inorganic film or a resin film for sealing the OLED is provided between the OLED and the color filter. Thus, in the electro-optical device of a color filter type, there is a problem that a portion of light emitted from an OLED of a certain subpixel is transmitted through a color filter of an adjacent subpixel, and thus color mixing occurs depending on an angle at which a screen is observed.
In a technology in which subpixels of the same color are arranged in a vertical direction (up-and-down direction) of a screen, even though the screen is observed at a tilted angle, color shift hardly occurs regarding the vertical direction. Regarding a transverse (right-and-left) direction, in a case where a panel is observed at an inclined angle, color-mixed light such as light of mixed color of red and green, light of mixed color of red and blue, and light of mixed color of green and blue is visually recognized. Thus, the color shift occurs in comparison to a case of being observed from the front.
JP-A-2013-211147 proposes that reflection electrodes of subpixels of red and green are arranged in the transverse direction (right-and-left direction), and a reflection electrode of a subpixel of blue is disposed in a direction (up-and-down direction) perpendicular to the reflection electrodes of subpixels of red and green.
However, in the electro-optical device disclosed in JP-A-2013-211147, scanning lines for subpixels of color are arranged in the vertical direction (up-and-down direction), and thus the number of scanning lines selected for one horizontal scanning period is increased. As a result, a time to select each of the scanning line in the one horizontal scanning period becomes shorter, and thus writing from a data transfer line to a pixel may be difficult.
As in JP-A-2013-211147, the width of a reflective layer in a transverse direction (right-and-left direction) in a subpixel of blue is shorter than the width of the reflective layer in the transverse direction (right-and-left direction) in one pixel obtained by combining a subpixel of red and a subpixel of green. Thus, blue light is applied to a transistor, and thus transistor characteristics may be changed.
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The invention relates generally to direct current machines and more particularly to direct current machine monitoring systems.
A degraded commutator of a direct current (dc) machine will show excessive sparking as brushes bounce over the rough surface and the conduction period for a particular segment ends prematurely or as a winding remains shorted for too long by a spark region which extends between segments. Ultimately a short circuit will develop, through an extended spark region over the commutator bars, between opposite-polarity brushes. This xe2x80x9cflashoverxe2x80x9d is often severe enough to destroy the machine. Sparking can additionally be caused by factors such as worn down brushes, improper brush positioning, or load or supply problems, for example.
On-line monitoring of commutation quality degradation as a measure of brush and/or commutator degradation or wear, for example, or as a precursor to flashover in dc machines can provide a significant advantage in steel mill, paper mill, and locomotive applications, for example, wherein visual inspection during operation is unsafe or otherwise impractical. As described in Michael P. Treanor and Gerald B. Kliman, xe2x80x9cINCIPIENT FAULT DETECTION IN LOCOMOTIVE DC TRACTION MOTORS,xe2x80x9d Proceedings of the 49th Meeting of the Society for Machinery Failure Prevention Technology, Virginia Beach, Va., April 1995, pp. 221-230, machine condition monitoring for poor commutation can be achieved by frequency-domain analysis of machine current at the frequency of bar passing. The bar-passing frequency can be determined by multiplying the number of commutator bars by the speed (rotation frequency) of the motor. The magnitude of the peak at the bar-passing frequency increased by a factor of at least two when the commutation quality was degraded by incorrectly aligning the brushes. To provide an unambiguous determination of the bar passing frequency, the speed of the motor needs to be obtained with sufficient certainty and precision.
Additionally, once an assessment of commutation quality has been made, it would further be advantageous to assess whether the cause of any degradation resulted from commutator roughness or distortion as compared with non-commutator factors such as brush wear, improper positioning of brushes, or load or supply problems. By identifying the cause, proper maintenance and/or repair can be initiated.
Briefly, in accordance with one embodiment of the present invention, a system for determining a rotation frequency of a direct current machine comprises (a) a sensor for monitoring load current of the machine; and (b) a computer for (i) obtaining a first power spectrum of the load current, (ii) identifying significant peaks of the power spectrum, (iii) identifying one of the significant peaks as indicative of rotation frequency, and (iv) identifying a frequency of the identified peak as the rotation frequency.
In accordance with another embodiment of the present invention, a direct current machine monitoring system comprises (a) a current sensor for monitoring load current of the machine; and (b) a computer for (i) obtaining a power spectrum in a range including a machine trait-passing frequency, (ii) determining a magnitude of a maximum peak in the power spectrum in a range including the trait-passing frequency plus or minus an uncertainty frequency, and (iii) evaluating the magnitude of the maximum peak to assess a condition of the machine.
In accordance with another embodiment of the present invention, a direct current machine monitoring system comprises (a) a current sensor for monitoring load current of the machine; and (b) a computer for (i) obtaining a low frequency power spectrum of the load current, (ii) obtaining at least one magnitude of a component of the power spectrum at a respective predicted frequency, and (iii) evaluating the at least one magnitude of the component to assess a condition of th machine.
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The present invention relates to a charging circuit for an electrical energy storage device, a drive system having a charging circuit, and a method for operating a charging circuit.
Motor vehicles that are completely or at least in part electrically driven such as for example hybrid vehicles and electric vehicles are becoming increasingly more important. The desire for greater driving ranges and capacities of the electrically driven vehicles is also increasing simultaneously. The charging technology for electric vehicles is also becoming increasingly more important in this connection. Present-day electric vehicles typically use conductive charging concepts that represent units that are self-sufficient and spatially separate from the electronic drive system. Furthermore, charging concepts that function in a contact-less and generally inductive manner are also already known. These charging concepts are typically likewise embodied as stand-alone systems.
The European patent application EP 0 768 774 A2 discloses a device for charging batteries in electric vehicles. The electric vehicle comprises an electronic regulation system that has a recovery facility. A DC current source provides a direct current that charges the battery by way of this electronic regulation system so as to charge the battery.
Owing to the increasing battery capacities and the endeavors to achieve ever-reducing charging time periods, it is desirable that the magnitude of energy that is transferred per unit of time in the charging operation is approximately equal to the magnitude of energy that is drawn off from the traction battery during the driving operation or is even greater than the magnitude of said drawn-off energy. This requires that the components that participate in the charging procedure are embodied to cope with the high currents. The electrical energy storage device in an electric vehicle is generally charged by means of the electrical energy that is provided by means of an alternating current supply.
There is therefore a requirement for a cost-effective and efficient charging circuit for an electrical energy storage device for charging the electrical energy storage device from an AC voltage supply.
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Resources such as oil, gas, water and other materials may be extracted from geologic formations, such as deep shale formations, by creating fracture zones and resulting permeability within the formation, thereby enabling flow pathways for fluids (including liquids and/or gasses). For hydrocarbon based materials encased within geologic formations, this fracturing is typically achieved by a process known as hydraulic fracturing. Hydraulic fracturing is the propagation of fractures in a rock layer using a pressurized fracturing fluid. This type of fracturing is done from a wellbore drilled into reservoir rock formations. The energy from the injection of a pressurized fracturing fluid creates new channels in the rock which can increase the extraction rates and ultimate recovery of hydrocarbons. The fracture width may be maintained after the injection is stopped by introducing a proppant, such as grains of sand, ceramic, or other particulates into the injected fluid. Additionally, by its nature, the direction and distance a hydraulic fracture travels is mainly dependent on the direction of the maximum principle (in-situ) stress in the reservoir. Although this technology has the potential to provide access to large amounts of efficient energy resources, the practice of hydraulic fracturing has been restricted in parts of the world due to logistical or regulatory constraints. Therefore, a need exists for alternative fracturing methods.
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As technology continues to advance, people are increasingly more likely to consume content via a computer, as opposed to via traditional printed publications. Oftentimes, when consuming such content, the consumer's interest may be piqued concerning something that they would like to do in the future (e.g. dine at the top of the Eiffel Tower, take a white water rafting ride through the Grand Canyon, ski the Andes Mountains in Chile). Quite often, these ideas would be stashed away in a person's mind and quickly forgotten, especially when they concern discrete details that are difficult to recall (e.g. eating a chocolate croissant at a certain French bakery in New York City). Alternatively, people may attempt to compile a to do list concerning these experiences that they would like to someday experience. However, unless this to do list is readily available, it will oftentimes not be used or, alternatively, may grow to an unmanageable size/complexity.
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Semiconductor memory devices are usually characterized as either volatile or non-volatile devices. In volatile memory devices, logic information is stored either by setting up the logic state of a bistable flip-flop, such as in a static random access memory, or through the charging of a capacitor as in a dynamic random access memory. In volatile memory devices, the data is lost whenever there is a power interruption; hence, the name volatile memories.
Non-volatile semiconductor memory devices such as mask read-only memory (MROM), programmable read-only memory (PROM), erasable read-only memory (EPROM), electrically erasable read-only memory (EEPROM), etc. are capable of storing data even during a power interruption. The nonvolatile memory data storage mode may be permanent or reprogrammable, depending upon the fabrication technology used. Nonvolatile memories may be used for program and microcode storage in a wide variety of applications in various industries, including the computer, avionics, telecommunications, and consumer electronics industries. A combination of single-chip volatile as well as nonvolatile memory storage modes is also available in devices such as nonvolatile SRAM (nvRAM) for systems that require fast, reprogrammable nonvolatile memories. In addition, numerous special memory architectures have evolved which contain some additional logic circuitry to optimize their performance for application-specific tasks.
In some nonvolatile semiconductor memory devices like MROM, PROM and EPROM, due to problems associated with electrical erasing and writing, it is not easy for general users to update the stored contents. On the other hand, since electrical erasing and writing for EEPROM can be readily accomplished, it is widely used in applications that need continuous updating. A flash EEPROM (hereinafter, referred to as a flash memory) has a higher integrity degree than a conventional EEPROM. Flash EEPROM is suitable for a large volume auxiliary storage device. Among flash memories, a NAND flash memory has a higher integrity degree as compared to a NOR flash memory. Generally, a NAND flash memory is used to store a large volume of data, and a NOR flash memory is used to store code data such as boot code.
With an increase in the use of flash memories, issues like operating time and power consumption of flash memories become critical design factors.
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1. Field of the Invention
The instant invention relates generally to animal traps and more specifically it relates to a humane animal trap.
2. Description of the Prior Art
Numerous animal traps have been provided in prior art that are adapted to catch and in most cases injure or kill the animals. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as heretofore described.
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This invention relates generally to pinball games and, more particularly, to a play feature for such games.
Pinball games generally consist of an inclined playfield and a plurality of targets and other play features arranged on the playfield. A player uses flippers to direct a moving ball at desired targets thereby scoring points. A spring loaded plunger is used to project the ball onto the playfield.
The players of pinball machines are selective as to the machines they choose to play and base their selections on the various types of play features offered. Therefore, the popularity of a pinball game is, in part, a function of its player appeal.
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1. Field of the Invention
The present invention relates generally to controlling light propagating in a wave guide. More particularly, the present invention relates to using gratings to cause mode coupling of light propagating in a wave guide.
2. Description of Related Art
Devices used in optical systems, such as in fiber optic communication systems and sensing systems, often benefit from the filtering or control of light propagating in a wave guide. Examples of such devices include, but are not limited to, source lasers, optical amplifiers, filters and other integrated-optical components. One method of controlling and filtering light utilizes diffraction gratings. Descriptions of such devices and how they benefit from diffraction gratings are described in T. Erdogan and V. Mizrahi, xe2x80x9cFiber Phase Gratings Reflect Advances in Lightwave Technology,xe2x80x9d February 1994 edition of Laser Focus World.
There are three techniques typically used to create a diffraction grating in a wave guide to induce mode coupling or Bragg reflection. The most common method uses ultraviolet light to induce a refractive index change in an optical fiber. A system for producing a periodic refractive index change in the optical fiber is illustrated in FIG. 1. In FIG. 1 a first beam 104 of coherent ultraviolet xe2x80x9cUVxe2x80x9d light and a second beam 108 of coherent UV light are directed at a photosensitive optical fiber 112. At the intersection of the first beam 104 and the second beam 108, an interference pattern 116 is generated. The refractive index of the photosensitive optical fiber 112 changes with the intensity of the UV exposure, thus an index grating with a periodicity determined by the interference pattern 116 forms where the first coherent beam 104 and the second coherent beam 108 intersect.
A second technique for creating a grating in an optical fiber involves etching a periodic pattern directly onto an optical fiber. In one embodiment, a photomask is used to generate a periodic pattern in a photolithographic process. An acid etch etches the grating or periodic pattern into the optical fiber. Such photomasks and etching are commonly used in semiconductor processes.
A third technique to control light in a waveguide is used in semiconductor waveguides. In one embodiment, a layered growth is formed on the semiconductor wave guide to generate light reflection in the wave guide.
The described techniques for creating a grating on or in a wave guide are permanent. The gratings have a fixed periodicity at a fixed location on the waveguide that cannot be easily changed. Thus, a particular wave guide and grating combination will have a predetermined transmission characteristic. In order to change the characteristic, the entire wave guide segment containing the grating is typically replaced with a wave guide segment having a different transmission characteristic. Replacing wave guide segments is a cumbersome process requiring that each end be properly coupled to the light source and the light receiving device.
Thus, an improved system and method to control light propagating in a wave guide is needed.
The present invention relates to a method and apparatus of controlling light transmitted in a wave guide. The apparatus uses a holder to fix a wave guide in a fixed position relative to an adjustable periodic grating. The periodic grating is movable to at least two positions, in one position the periodic grating induces mode coupling in the wave guide, and in the second position the periodic grating does not induce mode coupling in the wave guide.
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1. Field of the Invention
This invention relates to production machines for slicing and/or perforating of baked goods such as English muffins, bagels, buns, rolls or the like in a controlled manner, and more particularly to a new and improved self-contained machine for simultaneously slicing and perforating of baked goods, such as English muffins, bagels, buns, rolls or the like.
2. Description of the Prior Art
It long has been recognized that consumers generally prefer pre-sliced and/or perforated English muffins, bagels, buns, rolls or similar baked goods, because slicing by hand causes an inconvenience to the consumer, and very often uneven slices are made, particularly when toasting the sliced baked goods, the goods either will not fit into a conventional toaster aperture or the product may be charred in one part and underdone in another. Machines for pre-slicing or perforating muffins and similar bakery products are described in the prior art, but they are usually complex in structure and often pre-slice or perforate the bakery product in an unsatisfactory manner.
Basically, such prior art devices are divided into two groups, the first group being muffin slicing machines, the second group being muffin perforating machines.
Examples of the slicing machines are as follows:
Ost, U.S. Pat. No. 1,766,450, issued 6/24/30, discloses a muffin cutting machine, which is self-contained, and does utilize a single drive motor for partially or completely slicing muffins, with a straight line passthrough. However there is no provision for perforating the muffins (as opposed to slicing the same), and the patented cutting wheel is located in a vertical plane, as opposed to a horizontal plane.
Ahrndt, U.S. Pat. No. 2,235,546, issued March 18, 1941, discloses a muffin slicing machine wherein the muffins are sliced as they slide down an inclined shute into which the cutting wheel projects. This patent does not disclose a conveyor, it being necessary to push the muffins down by hand, and clearly there is no suggestion of any simultaneous slicing and perforating operations either.
Dettman, U.S. Pat. No. 2,520,000, issued 8/22/50, merely discloses a hot dog slicer wherein the sliding knife protruding down through the slot in the inverted channel frame slices the frankfurter held within such frame.
Schmidt, U.S. Pat. No. 2,686,542, issued Aug. 17, 1954, discloses a machine for simultaneously partially slicing adjacent rows of rolls spread apart by a cutter wheel guide. Once again, there is no provision for perforating such buns or rolls.
Jovis, U.S. Pat. No. 2,979,095, issued Apr. 11, 1961 also shows a fully automatic muffin splitting machine which likewise delivers a separated muffin to the consumer.
Swedish Pat. No. 145,284 (1961) discloses a rusk roll slicing device that splits the roll into two separate and distinct pieces and then separates the top half of the roll from the bottom half to complete the split, for delivery of both halves as separate units to the consumer.
Tobey, U.S. Pat. No. 3,669,175, issued 6/13/72, describes a machine for making pre-sliced English muffins wherein the muffin is pre-sliced by means of a plurality of series arranged rotating cutter disks so that the slicing of the muffin is made in a series of successive cuts, this device being complicated in structure and expensive to manufacture and, because the muffins must pass through a series of rotating blades, often resulting in uneven slices.
Chipchase, U.S. Pat. No. 4,237,763, issued 12/9/80, relates to a rather complex muffin slicing or scoring machine having oppositely driven belts for rotating the muffins as the same are fed to a cutting wheel. There is no disclosure of slicing and perforating muffins, the split belts are located on the same edge of the muffin, which could possibly cause skewing thereof during travel, and separate and complicated takeup devices are necessary for such split belts.
The second group of patents, is directed to perforating machines, as follows:
Weckel, U.S. Pat. No. 2,783,803, issued 3/5/57, merely discloses a cranberry puncturing machine, wherein radially outwardly projecting tines are located on a rotating cylinder. This patented device is otherwise not pertinent.
Clock, U.S. Pat. No. 3,192,976, issued 7/6/65, is directed to a muffin perforating apparatus employing chain driven tines, somewhat similar to Hanson, below, but the Clock tines converge along an arcuate, rather than a diamond shape path, as in Hanson, below.
Noel, U.S. Pat. No. 3,733,942, issued 5/22/73, relates to a muffin perforating machine but does not provide for pre-slicing of muffins or similar baked goods. In this patent, the tines are reciprocated transversely of the muffins while traveling along the muffin conveyor.
Noel, U.S. Pat. No. 3,737,084, issued 6/5/73, also discloses a muffin perforating machine, wherein the tines are reciprocated transversely of the muffins, as in the patent just mentioned above, but this patented device also splits the perforated muffins by elevating one of the two transversely movable tine sections. Even so, this patent is no more pertinent than the first mentioned Noel patent.
Hanson, U.S. Pat. No. 4,287,801, issued 9/8/81, discloses a somewhat complex muffin perforating machine wherein the chain driven blades or tines travel along an elongated diamond shaped path, while at the same time being oscillated transversely of such path for penetration into and removal from the belt driven muffins. Clearly, there is no suggestion of simultaneously slicing a separate row of muffins.
There is, then, an obvious need in the marketplace for a production muffin slicer and perforater that is not only economical to manufacture, but also will produce a uniformly pre-sliced or perforated muffin for use by the consumer. This need has, until now, been fulfilled by the inventor's prior U.S. Pat. No. 4,015,492, issued 4/5/77, wherein the patented device is useful in production operations for slicing or perforating muffins in an even and uniform manner, to provide a uniform top and bottom section thereof, but without separating the top from the bottom of the muffin. The patented device is capable of both slicing and perforating; it is easy to use and reliable and efficient in operation; it also is of a rugged and durable construction, and which, therefore may be quaranteed by the manufacturer to withstand rough and continual usage. In addition, it is simple in construction, and therefore may be economically produced by the manufacturer.
At the same time, the patented device does have limitations. The slicing and perforating operations only can be performed alternately, not simultaneously. More than one drive motor is required to operate the machine; the muffins follow a sequential straight line, arcuate path and then straight line passthrough, increasing the likelihood of jamming, and the patented machine is not self-contained, but rather designed to be mounted over an existing bakery conveyor belt.
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The present invention relates to a control architecture for asynchronous transfer mode (ATM) networks, and specifically relates to a burst-level control for controlling access in an ATM network.
While the following description describes the invention in conjunction with a LAN, the invention is not so limited and is applicable to any ATM network.
There is tremendous interest in the development of ATM based LANs that provide connectivity between local work-stations and servers and are also suitable for use as a hub.
Current LAN technologies have media access control which ensures that once a station gains access to the medium, no frame loss results (except due to random noise). Many ATM-based switch architectures, on the other hand, do not have such control. Moreover, because of the limited amount of high speed memory that is provided in a switch, it is possible for there to be significant cell loss, especially when there is hot spot traffic from several bursty sources all directed to a single output port. For example, such a condition occurs in a client server model. The resulting cell loss leads to large frame loss when compared to systems having media access control. Therefore, it is essential that during periods of overload the bandwidth at a hot-spot output port be shared in a manner similar to that in a shared medium network.
A solution to implementing media access control and shared bandwidth at a hot-spot output port is to institute a burst-level control that manages media access in an ATM LAN. Burst level control is preferable in an ATM LAN when the following conditions are met: sources generate large bursts (compared to the amount of buffer memory in the switch) that will result in buffer overflows in the absence of any control; blocking a burst at the beginning of the burst is preferable to having retransmissions of bursts already in progress and frequent retransmissions due to cell loss increases the effective load on the system, resulting in an end-to-end throughput that is several times slower than that of a shared medium network.
However, it is important that the burst level control be done in real time so that the latencies in admitting new bursts do not become a significant bottleneck.
The present invention describes a burst level control method and apparatus for use in an ATM LAN. The burst level provides both a media access control and a fast and efficient call admission control.
By using such a burst level control, not only can ATM LAN performance be comparable to the performance of media access based technologies, e.g., FDDI, with respect to hot spot traffic, but the ATM LAN is able to provide a total bandwidth that is N times the bandwidth of a shared media system (where N is the number of ports). Moreover, the burst level control is scalable to wide area networks because the control does not rely on reactive mechanisms as a primary method of congestion control and is a small add-on function that is useful for Public Networks.
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In the design of shoes, in particular sports shoes, there are a number of contradicting design goals to be realized. On the one hand, a sports shoe should cushion the loads arising on the body and be capable of permanently resisting the arising forces. On the other hand, a sports shoe should be lightweight in order to hinder, as little as possible, the course of movement of the athlete.
Known sports shoes typically use foamed materials in the sole area to meet the above described requirements. For example, foams made out of ethylene vinyl acetate (EVA) have deformation properties that are well suited for cushioning ground reaction forces. Using different densities and modifying other parameters, the dynamic properties of such foams can be varied over wide ranges to take into account the different loads in different types of sports shoes, or in different parts of a single sports shoe, or both.
Shoe soles with foamed elements, however, have a number of disadvantages. For example, the cushioning properties of an EVA foam depend significantly on the surrounding temperature. Further, the lifetime of a foamed cushioning element is limited. Due to the repeated compressions, the cell structure of the foam degrades over time, such that the sole element loses its original dynamic properties. In the case of running shoes, this effect can occur after approximately 250 km. In addition, manufacturing a shoe with foamed sole elements having different densities is so costly that shoes are often produced only with a continuous midsole made from a homogeneous EVA-foam. The comparatively high weight is a further disadvantage, in particular with hard foams having greater densities. Further, sole elements of foamed materials are difficult to adapt to different shoe sizes since larger designs can result in undesired changes of the dynamic properties.
It has, therefore, been tried for many years to replace known foamed materials with other sole constructions that provide similar or better cushioning properties at a lower weight, where the sole constructions are unaffected by temperature, can be cost-efficiently produced, and have a long lifetime. For example, German Patent Application Nos. DE 41 14 551 A1, DE 40 35 416 A1, DE 102 34 913 A1, and DE 38 10 930 A1, German Utility Model No. DE 210 113 U, and European Patent No. EP 0 741 529 B1, the entire disclosures of which are hereby incorporated herein by reference, disclose constructions of this type. The foam-free sole designs of the prior art, however, have until now not gained acceptance. One reason is that the excellent cushioning properties of EVA foams have not been sufficiently achieved in these foam-free designs. This applies in particular for the heel area where the ground reaction forces acting on the sole reach their maximum values, which can exceed several times the weight of an athlete.
It is, therefore, an object of the present invention to provide a shoe sole that can be cost-efficiently manufactured and provide good cushioning properties in a heel area without using foamed materials so that, if desired, the use of a foamed material is no longer necessary.
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This disclosure relates to a touch detection device, in particular, to a touch detection device detecting touch events based on a change of an electrostatic capacitance in response to an external proximity object, a display device with a touch detection function including such a touch detection device, and an electronic unit.
In recent years, a display device capable of inputting information by mounting a contact detection device, which is a so-called touch panel, on a display device such as a liquid crystal display device, or integrating the touch panel and the display device, and displaying various button images and the like on the display device instead of typical mechanical buttons has attracted attention. The display device including such a touch panel does not require input devices such as a keyboard, a mouse, and a keypad, and therefore there is a tendency to expand the use of such a display device to portable information terminals such as mobile phones, in addition to computers.
Some methods are included in the touch detection methods, and one of them is an electrostatic capacitance method. For example, Japanese Unexamined Patent Application Publication No. 2008-129708 discloses a touch panel including a plurality of X-direction electrodes and a plurality of Y-direction electrodes arranged to face the X-direction electrodes, and detecting touch events by using a change of an electrostatic capacitance formed in the intersections of the X-direction electrodes and the Y-direction electrodes in response to an external proximity object. These electrodes are formed of a translucent material, however, light transmittance is different between a portion with the electrode and a portion without the electrode, and therefore, these electrodes are possibly viewed from outside. Accordingly, in the touch panel, dummy electrodes are provided between the X-direction electrodes, or between the Y-direction electrodes to reduce the difference of the light transmittance between the electrode region formed with the X-direction electrodes and the Y-direction electrodes and the inter-electrode region arranged with the dummy electrodes, and therefore the X-direction electrodes and Y-direction electrodes are allowed to be hardly viewed from outside.
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1. Field of Invention
The present invention relates to a polymer material, and an ophthalmic lens and a contact lens constituted with the same. More particularly, the present invention relates to a polymer material which has high oxygen permeability and is superior in water wettability and lubricity of the surface as well as flexibility, and which is suited for ophthalmic lenses and contact lenses.
2. Description of the Related Art
Silicone hydrogels have been used as a material and the like of ophthalmic lenses such as contact lenses owing to high oxygen permeability. However, since silicone hydrogels have low water wettability and lubricity of the surface in general, various efforts such as surface treatments, blending of a hydrophilic polymer and the like have been made in attempts to improve these regards.
Techniques for improving lubricity and water wettability of the surface of contact lenses produced using such a silicone hydrogel were developed which include: (1) a technique of blending polyvinylpyrrolidone that is a hydrophilic polymer in a mixture of monomer components (see PCT International Publication No. 01/70837); (2) a technique of soaking a contact lens in a stock solution containing a surfactant and hydrophilic polymers to allow the surfactant and the like to attach on the surface of the contact lens (JP-A No. S61-69023); (3) a technique of allowing surfactant molecules to be covalently bonded directly on the surface of the lens of a silicone hydrogel (see U.S. Pat. No. 4,546,123); (4) a technique in producing a contact lens constituted with a silicone-containing monomer and a hydrophilic monomer as monomer components in which the monomers are homogeneously dissolved by using a surfactant and/or an organic solvent as additive(s) (U.S. Pat. No. 4,534,916); (5) a technique of permitting containments of a surfactant in a polymer by bringing a polymeric substrate into contact with a mixture of a carrier liquid and an impregnating agent containing a surfactant in a supercritical fluid such as carbon dioxide gas (JP-TA (Translation of PCT Application) No. H8-506612); and the like.
However, in the aforementioned Prior Art (1), it is difficult to homogeneously dissolve a silicone-containing monomer having hydrophobicity and a hydrophilic polymer in a monomer mixture; therefore, favorable water wettability and lubricity for a contact lens cannot be easily attained. In addition, persistence of water wettability and lubricity of a contact lens for a long period of time is impossible in the aforementioned Prior Art (2). In the aforementioned Prior Arts (3) and (4), the amount of the surfactant used is comparatively great; therefore, the surfactant aggregated on the surface of the contact lens, and the surfactant contained within the contact lens are gradually released, thereby leading to failure in persistence of water wettability and lubricity for a long period of time, and possibility of occurrence of eye irritation during use of the contact lens.
Moreover, in the aforementioned Prior Art (5), since a surfactant that substantially poorly interacts with a polymer is used, the surfactant is likely to be eluted from the polymer in a solvent such as water or buffer, leading to failure in persistence of water wettability and lubricity for a long period of time. In addition, when the surfactant is contained in a polymer material of a contact lens or the like, the polymer material per se is likely to be deformed due to the behavior in incorporation and gradual release of the surfactant, resulting in a disadvantage of impaired stability.
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The present invention relates to a vibration damper for preventing vibration occurring on a vibration transmitting member such as various function members, frame members or the like.
For example, in a vehicle such as a motorcar, vibration of a vibration source such as an internal combustion engine or vibration caused by a road surface is transmitted to the whole vehicle body, and if a vibration transmitting member such as a function instrument attached to a body frame resonates, lowering of function or noise occurs.
Therefore, in order to suppress vibration transmitted to the vibration transmitting member, usually the vibration transmitting member is attached with a mass damper, a dynamic damper or a vibration damping device.
In the mass damper, a weight is added to the vibration transmitting member to change the natural frequency, therefore it is necessary to increase weight of the weight in order to obtain sufficient vibration reducing effect, so that weight of the vehicle body increases.
In the dynamic damper, a frequency to be suppressed is specified by spring constant of an elastic body and weight of a weight. Therefore, the dynamic damper is not effective to vibration having a plurality of resonance frequencies.
The vibration damping device comprises a plate-like vibration transmitting member and a layer or several layers of sheet-like elastic member stuck on the vibration transmitting member. In this device, the elastic member must be stuck over a somewhat large area to obtain an effect, vibration reducing function is dependent on temperature largely and sometimes the vibration damping function is lowered owing to temperature.
In a vibration damper of a former application (International Application PCT/JP98/05530), a filling at least partly made of an elastic material is inserted in an internal space of a housing fixed to a vibration transmitting member with a gap not bonded to the housing. According to this vibration damper, since vibration is reduced owing to energy loss caused by sliding friction and impact when the filling touches an inner surface of the housing, plural resonance vibrations of different frequencies can be suppressed effectively. Further, the vibration damping owing to energy loss by sliding friction and impact is little influenced by temperature. The vibration damping effect becomes larger as the impact speed increases, therefore the damping effect is obtainable especially at a resonance region of high frequency. Accordingly, regarding a low resonance frequency, the vibration damping effect can not be expected so much. Also the vibration damper is not effective when it is intended that plural resonance vibrations are damped and a specific frequency is damped particularly largely.
Japanese Laid-Open Patent Publication Hei 8-127347 discloses an example for suppressing vibration of a steering wheel by a dynamic damper. However, management of resonance frequency deviation on mass-production is not easy.
The present invention has been accomplished in view of the foregoing and an object of the invention is to provide a vibration damper little depending on temperature capable of damping plural resonance vibrations over a wide frequency region as well as damping a specific frequency vibration. Another object of the invention is to provide a vibration damper capable of reducing deviation of resonance frequencies on mass-production and suppressing vibration of a steering wheel effectively.
In order to achieve the above objects, the present invention provides a vibration damper, comprising: a housing formed of a rigid material, having an internal space and fixed to a vibration transmitting member; an elastic body inserted in the internal space not bonded to the housing with a gap in a direction of vibration of the housing; and a weight integrally supported by the elastic body so as not to touch the housing, thereby the elastic body and the weight form a dynamic damper.
Owing to the construction that the elastic body is inserted in the inner space of the housing, vibration is damped based on energy loss caused by sliding friction and impact occurring when the elastic body touches the inner surface of the housing. Therefore, vibration damping effect is obtainable regarding plural resonance vibrations of different frequencies and dependence on temperature is small.
A resonance vibration in a specific frequency region which can not be damped by the above construction or a resonance vibration wanted to be cancelled especially can be damped by the construction that the weight is supported by the elastic body to form a dynamic damper. Thus, vibration damping effect can be obtained regarding plural resonance vibrations in a wide frequency range.
The weight may be provided within the elastic body. The weight can be supported by the elastic body integrally not touching the housing by the simple construction and the vibration damper can be made small and light.
Spring constant of the elastic body and weight of the weight may be set so that the dynamic damper cancels a specific frequency vibration. Owing to the construction that the elastic body is inserted within the housing fixed to the vibration transmitting member not bonded to the housing with a gap in a direction of vibration of the housing, vibration damping effect is obtainable regarding plural resonance vibrations of different frequencies, and also vibration in a frequency region which can not be damped by the construction or vibration of a specific frequency to be damped especially can be damped by the dynamic damper.
The above-mentioned specific frequency vibration may be a low frequency vibration. According to the construction that the elastic body is inserted within the housing fixed to the vibration transmitting member not bonded to the housing with a gap in a direction of vibration of the housing, vibration is damped based on energy loss caused by sliding friction and impact, therefore the vibration damping effect is larger especially in a high frequency resonance region.
Therefore, regarding a low frequency resonance region, vibration damping property is obtained by suitably setting spring constant of the elastic body and weight of the weight in the dynamic damper. Thus, vibration damping effect can be obtained regarding plural resonance vibrations in substantially overall frequency region.
According to another aspect of the invention, there is provided a vibration damper, comprising a housing formed in a cylinder from a rigid material, having an internal space, and fixed to a steering wheel with axis of the cylinder directed substantially in parallel with a steering shaft; an elastic body inserted in the internal space not bonded to the housing with a gap in a direction of vibration of the housing; and a weight integrally supported by the elastic body so as not to touch the housing.
Owing to the construction that the housing is fixed to the steering wheel with axis of the cylinder directed substantially in parallel with the steering shaft and the elastic body is inserted in the internal space not bonded to the housing with a gap in a direction of vibration of the housing, the elastic body touches an inner surface of the housing corresponding to vibration in the direction perpendicular to the steering shaft of the steering wheel to suppress the vibration based on energy loss caused by sliding friction and impact. Therefore, vibration damping effect is obtained regarding plural resonance vibrations of different frequencies. An exact setting of the resonance frequency, which is necessary in a dynamic damper, is not necessary so that deviation of the resonance frequency on mass-production can be reduced. Since vibration damping effect is obtained effectively by the weight of relatively small mass, the vibration damper can be applied to a steering wheel easily.
In the last-mentioned vibration damper, a plurality of the weights may be provided. Even if the total mass of the weights is the same as a mass of a weight in a case having single weight, vibration is damped more and degree of freedom for layout of the weight is improved.
In the above-mentioned vibration damper, a plurality of the elastic bodies each supporting the weight may be provided. Each elastic body integrally supporting the weight is small, so that degree of freedom of layout and shape of the housing is high.
The elastic body and the weight may form a dynamic damper. While plural resonance vibrations of different frequencies can be damped generally, the dynamic damper is capable of damping a specific frequency necessitating to be damped especially, therefore vibrations in a wide frequency region can be damped more effectively.
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1. Technical Field
The present disclosure relates to field emission cathode devices, and particularly, to a field emission cathode device using carbon nanotubes.
2. Description of Related Art
Generally, field emission displays (FEDs) can be roughly classified into diode and triode structures. In particular, carbon nanotube-based FEDs have attracted much attention in recent years.
Carbon nanotubes (CNTs) produced by means of arc discharge between graphite rods were first discovered and reported in an article by Sumio Iijima, entitled “Helical Microtubules of Graphitic Carbon” (Nature, Vol. 354, Nov. 7, 1991, pp. 56-58). Carbon nanotubes are electrically conductive along longitudinal directions of the carbon nanotubes, chemically stable, and can each have a very small diameter (much less than 100 nanometers) and a large aspect ratio (length/diameter). Due to at least the above described properties, carbon nanotubes may play an important role in field of field emission devices.
Generally, a CNTs field emission cathode includes a substrate, a cathode electrode and a CNTs electron emitter. The cathode electrode is located on the substrate, and the CNTs electron emitter is located on the cathode electrode, perpendicular to the substrate. One known method is to fix the CNT electron emitter on the conductive cathode electrode via a conductive paste or adhesive, and make the CNTs electron emitter perpendicular to the substrate.
However, precision and efficiency of the known method for making the CNTs field emission cathode may be low. Therefore, an improved field emission cathode device using carbon nanotubes may be desired within the art.
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1. Field of the Invention
The invention relates to a video compression method, and especially to a video compression method that is intended to be applied in the transmission of a video picture as a digital video signal at very low transmission rates.
2. Description of the Prior Art
A video picture is digitized by dividing it into pixels and by giving the pixels digitized values. In a black and white picture, the value of a pixel can simply be the value of brightness of the corresponding pixel in digital form, for example, given in 8 bits. Several signals are required in order to show a color picture, and thus, the digital presentation requires, for example, Y, U and V pixels and their digitized values, which contain the information about the brightness and colors of the picture. The invention is applied in the same way in the compression of all pixel information, and that is why this application primarily refers to pixels, pixel values and value information in general.
Because of the limited capacity of the channels used specifically for transferring digital picture information, the information must be compressed before transfer. For example, in practice, when transferring a normal television picture on a UHF channel, which has a transfer capacity of 32 Mbit/s, a compression of picture information is required in a ratio of 1:10-1:20. When a video picture is transferred on a channel, which has a very low transfer rate, for example, 8 kbit/s, a very efficient compression is required even if some of the picture quality is sacrificed.
Several different techniques have been developed for compressing a video picture. These techniques are used in coding the picture information in the transmission encoder and, correspondingly, in decoding the picture information and reconstructing the picture at the receiving end. These methods include, for example, variable length coding (VLC), predictive coding, movement compensation, run-length coding, and transform coding, such as discrete cosine transform coding (DCT). To make calculations easier, a picture is usually coded in blocks. A generally used block size in 8.times.8 pixels. The above-mentioned methods are familiar to the persons skilled in the art, and even though some of the methods, for example, variable length coding, can also be used in the video compression method of the invention to enhance the compression, they are not described in detail here, because it is not necessary in order to understand the invention.
When transferring a video picture as a digital video signal at low transfer rates, a generally used compression method is one, in which the picture is divided in blocks of n.times.m pixels. The blocks are compared to the corresponding blocks of the previously processed picture. The changed blocks are identified, and their coded information and the address data, which indicate their location, are transferred. At the receiving end, this information and the information of the said previously processed picture are used to reconstruct the picture. This compression method is very economical when transferring a video picture at low transfer rates, and that is why the method of the invention is considered to be preferably applied, but not in any way limited, to this application.
The next explains the conditions of transferring a video picture in a case, in which the available capacity of the transfer channel is very low, and in which it is economical to apply the method of the invention. The QCIF resolution of the picture is 176 pixels/line, and the picture has 144 lines. The picture is divided into macro blocks of 16.times.16 pixels, the total amount of which is 9.times.11, that is 99. Each macro block contains four Y blocks (8.times.8 pixels) and one U block and one V block (8.times.8 pixels). So, the picture has a total of 4.times.99+2.times.99=594 blocks. If we assume that the capacity of the channel is 8 kbit/s and the frequency of the picture is 8.3 pictures per second, there are 963 bits available per picture. If we assume further, that the share of the changed macro blocks is 10% of the picture, there are 0.1.times.594, that is, about 60 blocks to be coded. Of the available 963 bits, about 50 are used to address the changed macro blocks, for example, by use of a binary run-length coded bit map. The other 910 bits are left for the picture information, so there are 910/60, that is, 15 bits available per block.
At very low transfer rates, or if the amount of changes in the picture is greater than the 10% assumed previously, one generally used method is to reduce the picture rate so that the amount of transferred picture information and, in that way, the resolution can be retained. The reduction in the picture rate is known to reduce the quality of the motion the eye can see. An alternative to reducing the picture rate is a more efficient compression, in which the aim is to present the information contained in a picture block with a smaller amount of information than previously.
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1. Field
The present invention generally relates to wireless communication systems and, in particular, to methods and systems for providing effective signal reconstruction from spatially and temporally correlated received samples.
2. Background
A communication system may provide communication between base stations and access terminals (ATs). Forward link or downlink refers to transmission from a base station to an access terminal. Reverse link or uplink refers to transmission from an access terminal to a base station. Each access terminal may communicate with one or more base stations on the forward and reverse links at a given moment, depending on whether the access terminal is active and whether the access terminal is in soft handoff.
Wireless communication systems are widely deployed to provide various types of communication (e.g., voice, data, etc.) to multiple users. Such systems may be based on Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or other multiple access techniques. CDMA systems offer some desirable features, including increased system capacity. A CDMA system may be designed to implement one or more standards, such as IS-95, CDMA2000®, IS-856, W-CDMA, TD-SCDMA, and other standards.
As wireless communication systems strive to provide diverse services at ever higher data rates to a growing number of users, there lies a challenge to effectively mitigate interference and other artifacts so as to ensure the quality of service and maintain a desired throughput.
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Air entering a turbine compressor and similar devices should be treated before compression or other use. Air treatment includes removing solid or liquid particulates from the air, cooling or heating the air to the optimum temperature, and minimizing the pressure loss of the air during this process.
Impure air laden with dust particles, salt, and other contaminants may damage the compressor blades and other types of power plant equipment via corrosion and erosion. Such damage may reduce the life expectancy and the performance of the equipment. To avoid this problem, the turbine inlet air generally passes through a series of air filters to remove the contaminants. Known air filters generally are located at an elevated height so as to minimize the entry of ground contaminants. These known filtration systems, however, are generally complicated and costly.
The performance of a turbine is very sensitive to the inlet air temperature. At higher temperatures, the power output of the turbine is significantly lower due to lower air density and mass flow. High ambient temperature also is detrimental to efficiency while too low a temperature may cause icing and compressor damage.
Pressure loss of the inlet air reduces the power output and the efficiency of the gas turbine. Minimizing the pressure loss of the inlet air, however, is very difficult and costly. Conventional inlet air filters generally have limitations on the maximum air velocity so as to maintain filtration and limit the pressure loss of the inlet air. Known air filters also may be clogged by environmental conditions such as rain and snow. Such clogging may reduce filtration and cooling efficiency while increasing the overall pressure drop.
Thus, there is a desire for an improved turbine inlet air system. Such an improved system preferably would provide adequate filtering while chilling the intake temperature of the air with limited or no pressure loss. Specifically, such a system would increase the output of the turbine system as a whole and increase overall efficiency.
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Holograms are those in which the wave front of an object light beam is recorded as interference fringes in a photosensitive material by the interference between two beams (object light beam and reference light beam) having the same wavelength. When a light beam having the same conditions as a reference light beam used at the time of recording interference fringes is applied, a diffraction phenomenon by the interference fringes is caused, and whereby the same wave front as that of the original object light beam can be regenerated. Such a hologram can be divided into some types (surface relief type hologram and a volume type hologram) by the recording form of interference fringes.
Here, the surface relief type hologram is a type in which fine convexo-concave pattern is engraved on the surface of a hologram layer to record a hologram. The volume type hologram, on the other hand, is a type in which interference fringes produced by the interference of light are depicted three-dimensionally in the direction of the thickness as fringes differing in refractive index to record a hologram.
The volume type hologram can be mass-produced by using the hologram original master, and therefore has an advantage of being better in technical production compare to the relief type hologram. However, reality is that the laser beam used for technical production is limited in their wavelengths. Therefore, the wavelengths of the light which regenerate the hologram image of the volume type hologram mass-produced are also limited and it has been difficult to regenerate bright hologram images in embodiments commonly using the holograms.
To respond to such problem, methods of changing the regenerated wavelengths of the hologram images to the wavelengths different from the wavelengths of lights used at the time of recording the interference fringes are recently used. In such method, an after-treatment to the volume hologram layer where the interference fringes are recorded is carried out, and thereby the period of interference fringes initially recorded is changed.
In other words, since the regenerated wavelengths of the volume hologram are the same to the period of interference fringes recorded on the hologram layer, by changing the period of interference fringes recorded to the hologram layer afterwards, it is possible to change the period of interference fringes identical to the wavelengths of lights which are frequently used in daily bases. Such methods to change the period of interference fringes recorded to the hologram layer afterwards is useful in that it is possible to produce the volume hologram layers which can regenerate bright hologram images in common embodiments.
As such methods to change the period of interference fringes recorded to the hologram layer afterwards, various methods are known. As a more common method, a method disclosed in the Patent Document 1 is introduced here as an example. The Patent Document 1 discloses a method to enlarge the period of interference fringe by moving a monomer and/or a plasticizer contained in a layer to a volume hologram layer by carrying out a treatment such as a heating treatment through contacting the layer containing the monomer and/or the plasticizer to the volume hologram layer where the interference fringes are recorded. Such a method is certainly effective in enlarging the period of interference fringes and to shift the regenerated wavelength to the long-wavelength side. However, on the other hand, it has problems such as offering few variable amounts in the period of interference fringe or making the process complicating.
Further, since the volume holograms can record information to the thickness direction, is means to record/regenerate the three-dimension images, and is expressed by light interference colors, it has an appearance not easily obtained by other image-forming means. The producing methods of the volume hologram are known, but copying of the volume hologram is difficult because producing thereof requires a sophisticated work using optical devices. Using such characteristics of the volume holograms, the volume holograms are used for prevention of copying the identification cards, bank card and others. The present inventors have been discussing various methods as shown in Patent Documents 2 and 3 to prevent forgery by making the peeling of volume hologram layer from the adhered identification card impossible so that peeling of which results in the breakage of the attached volume hologram. However, there is a possibility of allowing a copy of the volume hologram when a contact copy by a single wavelength laser using the volume hologram laminate with a volume hologram recorded as an original master is tried. Thus, a development of a volume hologram laminate which makes a copy of the volume hologram difficult has been called for. Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 3-46687 Patent Document 2: JP-A No. 63-284586 Patent Document 3: JP-A No. 2002-358018
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Among currently employed processes for synthesizing acetic acid, one of the most used commercially is the catalyzed carbonylation of methanol with carbon monoxide. Preferred methods of practicing this technology include so-called “low water” processes catalyzed with rhodium or iridium of the class seen in U.S. Pat. No. 5,001,259, issued Mar. 19, 1991; U.S. Pat. No. 5,026,908, issued Jun. 25, 1991; and U.S. Pat. No. 5,144,068, issued Sep. 1, 1992; as well as European Patent No. EP 0 161 874 B2, published Jul. 1, 1992. The features involved in practicing a low water carbonylation process may include maintaining in the reaction medium, along with a catalytically effective amount of rhodium and at least a finite concentration of water, an elevated concentration of inorganic iodide anion over and above the iodide ion that is present due to hydrogen iodide in the system. This iodide ion may be a simple salt, with lithium iodide being preferred in most cases. U.S. Pat. Nos. 5,001,259, 5,026,908, 5,144,068 and European Patent No. EP 0 161 874 B2 are herein incorporated by reference.
Generally speaking, a methanol carbonylation production line includes a reaction section, a purification section, light ends recovery and a catalyst reservoir system. In the reaction section, methanol and carbon monoxide are contacted with a rhodium or iridium catalyst in a homogenous stirred liquid phase reaction medium in a reactor to produce acetic acid. Methanol is pumped into the reactor from a methanol surge tank. The process is highly efficient, having a conversion of methanol to acetic acid of typically greater than 99 percent. The reaction section also generally includes a flash vessel coupled to the reactor which flashes a draw stream in order to remove crude product from the reaction section. The crude product is fed to a purification section which includes generally a light ends or stripper column, a drying column, auxiliary purification and optionally a finishing column. In the process, various uncondensible vent streams containing light ends, notably methyl iodide, carbon monoxide and methyl acetate are generated and fed to the light ends recovery section. These vent streams are scrubbed with a solvent to remove the light ends which are returned to the system or discarded.
Despite advances in the art, catalyst deactivation and vent losses, especially carbon monoxide losses, remain persistent inefficiencies in methanol carbonylation systems. So also, there is always a need to reduce capital and operating expense associated with vent scrubbing and product purification.
In a traditional methanol carbonylation plant, a high pressure and low pressure absorber are included wherein acetic acid is used as the scrubber solvent. The acetic acid solvent must subsequently be stripped of light ends, usually in another purification column so that the acid is not wasted. Such columns are expensive because they must be made of a highly corrosion resistant material such as zirconium alloys and so forth. Moreover, stripping light ends from the acid requires steam and contributes to operating expense. Methanol has been suggested for use as a scrubber solvent in connection with a methanol carbonylation processes as well. In this regard, see U.S. Pat. No. 5,416,237 to Aubigne et al., entitled “Process for the Production of Acetic Acid”. It is noted in the '237 patent that noncondensibles from a flash tank vapor overhead may be scrubbed countercurrently with chilled methanol. The methanol scrubber solvent residual stream is added to pure methanol and then used as feed to the reactor. See Col. 9, lines 30-42. Chinese Patent Application Publication No. 200410016120.7 discloses a method for recovering light components in vent gas from production of acetic acid/acetic anhydride by way of scrubbing with methanol and acetic acid. Another system is seen in an industrial publication entitled “Process of 200 ktpa Methanol Low Press Oxo Synthesis AA” (SWRDICI 2006) (China) (referred to as SWRDICI below). In this research publication, there is shown a vent gas treatment system including a high pressure absorber as well as a low pressure absorber. Both absorbers of this system are described as being operated utilizing methanol as a scrub fluid.
European Patent No. EP 0 759 419 proposes to reduce vent losses by injecting methanol into the reactor vent stream and catalytically producing more product in a secondary reactor, which optionally contains heterogeneous catalyst.
Catalyst deactivation and loss is generally believed due to carbon monoxide-depleted or low pressure environments in the carbonylation system as are seen in the flasher. As carbon monoxide levels fall in the catalyst solution, rhodium increasingly takes the form of rhodium triiodide which precipitates. Various modifications have been proposed in the art to address this aspect of conventional processes, perhaps the most successful being the use of lithium iodide to enhance catalyst stability and reaction rates under low water conditions. Other proposed modifications are discussed below.
U.S. Pat. No. 5,770,768 to Denis et al. discloses carbonylation systems where recycle catalyst solution from the flasher is treated with additional carbon monoxide prior to return to the reactor to increase catalyst stability.
A high pressure “converter” reactor is proposed in Chinese Patent No. ZL92108244.4 as well as SWRDICI (noted above). The converter reactor illustrated in SWRDICI is coupled to the high pressure vent scrubber and is reported to allow the reaction to proceed to a greater extent prior to flashing.
In accordance with the present invention, there is provided an improved carbonylation system with staged reaction and pre-flash removal of light ends to increase productivity and operating efficiencies.
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Display cases are used in many stores to display items for sale, particulary small and valuable items which some members of the public might otherwise be tempted to misappropriate. As is well known, both floor mounted and counter mounted display cases are known. The present invention is directed to a counter mounted display case for displaying relatively small items for sale such as small items of jewelry.
In the prior art, counter mounted display cases have been utilized which are fully capable of displaying several items of jewelry or other small items and keeping them relatively secure. For example, prior art display cases are known which are formed of an upright cylindar of transparent plastic of about one foot in diameter and eighteen inches in heigth. An axially arranged rod holds two end caps securely in place and the displayed jewelry is supported from the rod.
The jewlry displayed in the case is preferably changed from time to time as the store changes its stock with the seasons. Usually the case remains the property of the distributor who sells the jewelry to the store. Typically the entire case is returned to the distributor for updating its contents while the distributor's sales force substitutes an updated case for the case presently being used at the store.
This requires the distributor to maintain a number of display cases merely to support the aforedescribed process of substitution and updating the contents of the cases. Of course, these display cases are not then being used to market jewelry. As might be expected, this prior art display case system requires considerable capital investment for (1) the display cases actively being used in the retail stores, (2) the jewelry sealed in those display cases, (3) the display cases reserved to support the substitution and updating process and (4) the jewelry in the last mentioned display cases.
It was therefore one object of the present invention to provide an improved display case for jewelry or the like items requiring less capital investment than the prior art designs and being relatively easy to update with new design items, yet secure.
It was another object to provide a case having modular display units.
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Samples such as solid (bulk), liquid, wipe or an air filter are routinely analyzed for a variety of metallic contaminations. Solid samples such as dust and soil are collected and subjected to a dissolution solution to dissolve the metal or metal compound of interest. Liquid samples such as water may also be analyzed, but in this case dissolution process is not necessary. Wipes are used to determine surface contamination of articles and after wiping a specific amount of area these are subjected to dissolution. Similarly, the air-sampling device comprises of a filter through which a specific volume of air is passed and then the filter is analyzed to determine airborne pollution from the metal of interest after subjecting the filter to dissolution. Most of the quantitative test methods to analyze metals go through a dissolution process and then an analytical procedure to quantify the metal. Some examples of the analytical test methods where dissolution and then an analysis are carried out are NIOSH 7301 (NIOSH is National Institute of Occupational Health and Safety, Atlanta, Ga.), where the material is dissoluted using aqua regia, EPA procedure SW-846-3051 (EPA is US Environmental Protection Agency, Washington D.C.) uses microwave digestion with nitric acid. In all these test methods the samples are then analyzed using plasma methods, which typically are not affected by organic impurities. Organic impurities are usually colored, may bind to other molecules that result in color or fluoresce, or can have strong fluorescence signals. In either case all of these may interact with optical detection methods. For those methods that rely on fluorescence, this interference can be two fold, first it can absorb the excitation energy and thus lowering the excitation signal available for the intended fluorophore, and secondly if the impurities emit in the same wavelength region as the intended fluorophore then the analysis may falsely provide elevated levels of metal when only low concentrations of metal are present. Thus in test methods such as NIOSH 7704, 9110 and ASTM D7202 for beryllium analysis by fluorescence such interferences can be severe. Such interferences can also influence optical analytical methods for a variety of other metals, e.g., NIOSH 7703 and EPA SW846-7196 for hexavalent chromium, and NIOSH 7700 for lead. Thus it is desirable to reduce or eliminate interferences due to the organic impurities that will interfere with the results.
Although this invention is applicable to all types of optical analysis for metals, it will be mainly illustrated for analysis of beryllium by fluorescence. Beryllium is a metal that is used in a wide variety of industries including electronics, aerospace, defense, and the US Department of Energy (DOE) complexes. Exposure to beryllium containing particles can lead to a lung disease called Chronic Beryllium Disease (CBD). CBD involves an uncontrolled immune response in the lungs that can lead to deterioration in breathing capacity and ultimately death. It is clear that even in processes where beryllium dust has been controlled to very low levels, cases of disease still persist. In fact, there have been cases of CBD reported in people that have had no obvious direct contact with beryllium operations. Despite the fact that very low exposure levels can lead to CBD, the onset of disease can take decades. Thus it is important that any analytical method provide an accurate assessment of the beryllium or any other metal where this information is used further to make decisions. Optical fluorescence is used to determine beryllium in several standard test methods, e.g., NIOSH 7704, NIOSH 9110, ASTM D7202 and ASTM D7458. These methods follow steps where a sample comprising beryllium or its compound is dissoluted in an aqueous solution of ammonium bifluoride. An aliquot of this solution is added to a buffered solution of an indicator solution comprising 10-hydroxybenzo[h]quinoline-7-sulfonate (10-HBQS) dye. This solution is measured for fluorescence signal to quantify beryllium. An organic impurity in the sample that may have fluorescence characteristics similar to 10-HBQS can result in a significant error.
One object of the present invention is to demonstrate practical methods of removing the effects of organic impurities from analytes that are analyzed for metal content using optical methods.
Yet another objective of this invention is to demonstrate practical methods of removing the effect of the organic impurities from analytes that are analyzed for beryllium by fluorescence.
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1. Field of the Invention
This invention relates to nucleators for generating magnetic domains, and more particularly to a magnetic bubble domain generator which can be integrated into circuitry used to perform other functions with the magnetic bubble domains.
2. Description of the Prior Art
Many devices have been proposed in the prior art for generating magnetic bubble domains in a magnetic bubble domain material. These devices can be divided into two classes: those which generate bubble domains by replication from an existing bubble domain, and those which initially nucleate a bubble domain in the magnetic bubble material. Although many designs have been proposed for bubble domain replicator generators, such bubble generators have limitations when used at high frequencies. Therefore, bubble domain nucleators have been thought to be more preferable as the operating frequency of bubble devices has increased.
U.S. Pat. No. 3,662,359 describes a bubble domain nucleator which comprises a magnetic element for creating a localized magnetic field as well as a current carrying loop for creation of the localized magnetic field. Additionally, U.S. Pat. No. 3,706,081 describes a bubble domain nucleator in which permalloy is adjacent to the magnetic bubble material in order to produce a more intense magnetic field for nucleation of bubbles. In this latter reference, an opening is created in the insulating layer located over the bubble domain material in order to have the permalloy elements be closer to the bubble domain material.
In order to have stable bubble domain devices using bubble domains of two microns diameter or less, current carrying bubble domain nucleators become impractical due to a high current density requirement for nucleation. That is, for smaller bubble sizes, the anisotrophy of the bubble material has to be large and this in turn requires larger magnetic fields for nucleation of bubble domains in the bubble domain material. However, the need for larger magnetic fields means that larger currents will be required in the current carrying conductor of the bubble nucleator. As an example, it has been found that current carrying conductors would not nucleate two micron bubble domains in amorphous magnetic GdCoMo films at currents up to about 30 ma. This corresponds to a current density of approximately 10.sup.7 amps/cm.sup.2. The need for large currents in the current carrying conductors comprising the bubble domain nucleators leads to electromigration problems.
The present invention seeks to provide bubble domain nucleators comprising current carrying conductors which do not suffer the problems of adverse effects due to electromigration when very small magnetic bubbles are to be nucleated. Accordingly, it has been discovered that when the nucleating current passes through the amorphous magnetic medium the current required for bubble domain nucleation is significantly less than would be if there were no current passage through the amorphous bubble medium.
Accordingly, it is a primary object of this invention to provide improved magnetic bubble domain nucleators comprised of current carrying conductors.
It is another object of this invention to provide nucleators for nucleating magnetic bubble domains in amorphous magnetic materials which are not hampered by adverse effects of electromigration.
It is another object of this invention to provide an improved bubble domain nucleator using current carrying conductors which utilizes the magnetic bubble material as a current conducting medium.
It is another object of the present invention to provide an improved bubble domain nucleator for nucleating very small bubble domains in amorphous magnetic media.
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The Arkansas serotype of infectious bronchitis virus (IBV) is the most isolated type of IBV from commercial poultry. This is due to the heavy use of the currently available Ark-type vaccine in use in the industry, ArkDPI. The ArkDPI vaccine was developed from an isolate from the DelMarVa peninsula in the late 1970's and has been the only available Ark-type vaccine since that time. It has previously been shown that this vaccine is not efficacious at protecting chickens from a pathogenic Ark-type challenge, it does not infect and replicate well in chicks when mass applied and contains multiple genetic subpopulations that cause the vaccine to erratically reappear in vaccinated flocks and transmit to non-vaccinated flocks. For these reasons, new Arkansas type IBV vaccines are needed in the commercial poultry industry.
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1. Field of the Invention
The present invention relates to a field of machines and more particularly to compressors of a vortex type.
2. Description of the Prior Art
A vortex compressor is known comprising a casing with an annular working channel having suction and discharge ports and a stripper seal is arranged in the channel between the ports. An impeller is mounted in the casing, a disc of the impeller having blades thereon to form a blade set and the stripper seal has an orifice for gas removal (see DE-A-2409184).
In this known design, gas, contained in the space between the blades is heated as it is compressed and is partially released from the stripper seal through the orifice. This reduces the undesirable transfer of hot gas from the compressor suction side to the discharge side and increases the machine efficiency. The gas is removed from the stripper seal back to the annular working channel through the orifice along a special pipeline to a zone of an intermediate pressure. Although this design reduces the harmful impact of ballast gas, it is not sufficient since hot gas under some intermediate pressure appears at the compressor suction side from the space between the blades.
Another vortex compressor is known comprising a casing in which are formed an annular working channel, suction and discharge ports communicating with the annular channel, a stripper seal arranged between the suction and discharge ports, an impeller mounted in the casing, a ring of blades, mounted on a disc of the impeller, is located in the annular working channel, and wherein the casing and stripper seal comprise regions having arched shapes, communicating therebetween and equidistant from the blade edges (see SU-A-328265).
In this latter design, ballast hot gas from the space between the blades is almost completely removed to the ambient air and excluded from the compression process in the compressor. This design provides a blowing effect which, owing to a specific arched shape and arrangement of the region, the hot gas in the space between the blades is replaced by cold gas entering from the atmosphere. Such blowing effect ensures an increase of the machine efficiency, reduction of the gas temperature at the suction side due to lack of replenishment by the ballast hot gas, raising the amount of compression at this stage and improvement of weight output.
In such design, the amount of blowing depends substantially on the size of the arched region. On the one hand, the reduction of an arched region results in incomplete blowing with all resulting consequences. On the other hand, although the increase of the arched region intensifies the blowing, it can be attained only by increasing a portion of the annular channel occupied by the stripper seal since the arc is arranged within the margins of this portion. This results in reduction of the remaining portion of the working channel wherein the compression takes place thereby reducing the efficiency of the compressor. Therefore, the efficiency of this design is limited by the blowing.
3. Summary of the Invention
It is an object of present invention to provide a vortex compressor combining two gas dynamic blowing processes, namely, a removal of hot gas from a stripper seal, and a suction, and thereby to intensify the flow at the vortex compressor input and to extend a zone of an efficient compression process in an annular working channel, and thus, to raise the efficiency of the vortex compressor.
The object is attained by providing a vortex compressor for compressing a fluid and comprising a casing having an annular working channel adapted to have fluid compressed therein. A blade set having a plurality of blades rotatably mounted in the casing is provided and adapted to compress fluid in the channel. The compressor includes an inlet for the channel disposed radially inward of the blade set, an outlet for the channel disposed radially outward of the blade set, a two-piece stripper seal arranged in the channel and having a first radially inward member and a second radially outward member, in which the first and second members of the stripper seal are circumferentially offset from each other. The inlet and outlet of the compressor being circumferentially offset from each other, the radially outward member of the stripper seal being circumferentially closer to the outlet than the radially inward member of the stripper seal and the radially inward member of the stripper seal being circumferentially closer to the inlet than the radially outward member of the stripper seal. The stripper seal has an orifice for fluid removal, whereby fluid introduced into the inlet of the channel is compressed and emitted from the outlet of the channel and the orifice of the stripper seal.
Alternatively, a vortex compressor can be provided wherein the members of the stripper seal are two concentric annular members, the radially outward member being shorter than the radially inward member circumferentially along the annular channel.
Alternatively, a vortex compressor can be provided wherein the inlet of the channel is disposed adjacent an edge of the radially inward member of the stripper seal and the radially outward member of the stripper seal is circumferentially offset towards the other edge of the radially inward member.
Further a vortex compressor can be provided wherein the orifice of the stripper seal has a length in the circumferential direction of the channel longer than the combined length of the inlet and the radially inward member of the stripper seal and at least a portion of the inlet of the channel lies along a common radius with the orifice of the stripper seal.
Alternatively, a vortex compressor can be provided with a baffle arranged in the working annular channel at an end of the orifice of the stripper seal for removing compressed fluid more efficiently.
The disclosed advantages of the present invention will become more apparent from further description of the preferred embodiment of the invention with references to the accompanying drawings.
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The present invention relates to an air cleaner for filtering air taken inside an internal combustion engine of a vehicle, and more particularly, to an air cleaner provided with a cylindrical filter element.
A conventional air cleaner of this kind is shown, for example, in FIG. 7. The shown air cleaner is provided with a cylindrical outer case 1, and the case 1 is formed with an integrally formed bottom 1b and an opened end. An air inlet 1a is formed to a side wall section of the case 1, and inside the case 1, there is disposed a cylindrical filter element 2. The opened end is covered by a cover 3 which is formed with an air outlet 3a being coaxial with the cylindrical filter element 2 in an assembled state. When the cover 3 is fitted to the opened end of the case 1, the filter element 2 is pressed and secured in the axial direction between the cover 3 and the bottom 1b of the case 1.
The air introduced inside the case 1 through the air inlet 1a passes the cylindrical filter element 2 thereinto in its radial direction as shown with an arrow. The air passing through the filter element 2 flows in an inner space of the filter element 2 along the central axial direction thereof and then flows out of the case 1 through the outlet 3a formed to the cover 3.
When such air cleaner has been used for a long time, much dust or dirt adheres to a filter or filter paper wound around the filter element, and an intake resistance is increased and air intake performance will be hence deteriorated. For this reason, it is necessary to periodically carry out a maintenance work such as cleaning of a soiled filter element 2 or exchanging of the soiled filter element 2 with a new one. In the case of carrying out such maintenance work, the cover 3 is first removed sideways from the body of the case 1, and the filter element 2 is moved transversely (i.e. axially) in the case 1 and then removed therefrom.
In an internal combustion engine, generally, various elements or equipments are arranged around an air cleaner in an engine room. In an air cleaner of a conventional structure, it is necessary to provide a space around the air cleaner for transversely removing the cover from the case and moving the filter element in the transverse direction. There is a possibility of interference of the filter element with the other elements or equipments disposed around the filter element, thus providing a problem in the maintenance work.
An object of the present invention is to substantially eliminate defects or problems encountered in the prior art mentioned above and to provide an air cleaner capable of requiring no specific space for maintenance work around the air cleaner and easily carrying out the maintenance work.
This and other objects of the present invention can be achieved according to the present invention by providing, in one aspect, an air cleaner comprising:
a case;
a cover detachably mounted to the case;
a filter element accommodated in the case, said filter element having a cylindrical shape having a central axis therealong; and
a pair of support members provided for the cover,
wherein said the pair of support members can be engaged with both end portions of the filter element in an axial direction thereof so as to hold the filter element between the support members,
and wherein removing said cover from the case removes the filter element from the case together with the cover and disengaging said filter element from the support members removes the filter element from the cover.
According to the structure of this aspect, when the cover is removed from the case, the filter element is also removed together with the cover. The filter element can be disengaged from the cover after removing the cover upward from an engine room of a vehicle, for example, so as not to interfere with peripheral elements or parts. Accordingly, it is not necessary to specifically form a space around the air cleaner for maintenance, and hence, the maintenance itself can be easily performed.
In a preferred embodiment of the above aspect, one of the paired support members is mounted to the cover to be rotatable through a hinge device, and the paired support members can be engaged with the filter element by rotating (pivoting) the one of the paired support members in one direction and disengaged therefrom by rotating the same in another direction. This one of the paired support members comprises a disc plate section, a rotatable (pivotal) shaft attached to the disc plate section and a connection pin connected to the rotatable shaft, and the cover is provided with a pin receiver to receive the connection pin, the connection pin and the pin receiver constituting the hinge device about which the above-mentioned one of the support members is rotated. The pin receiver may be formed with a groove into which the connection pin is fitted when rotated.
The cover is provided with a support member holding rib for holding that one of the paired support members at a predetermined angle with respect to the case to hold the filter element between the paired support members.
According to the location of the hinge device and the pivotal motion of one of the support members, the filter element can be surely supported by the cover, with substantially no shifting of position, when the cover is removed from the case, and the filter element can be thereafter easily disengaged from the cover, improving a maintenance work. Furthermore, when the filter element is assembled in the case and supported by the support members at both ends, the filter element can be placed to the predetermined position with no tilting from a predetermined axial line.
Furthermore, the location of the support member holding rib can ensure the axial holding force, so that the filter element can be surely supported at its both ends by the support members, thus achieving a sealing performance.
In a modified aspect of the present invention, there is also provided an air cleaner for an engine of a vehicle comprising:
a case;
a cover detachably mounted to the case, said cover having an air outlet through which air flows out;
a filter element accommodated in the case, said filter element having a cylindrical shape having a central axis therealong, said central axis of the filter element being directed in a direction other than a vertical direction with respect to a body of the vehicle to which the engine is mounted; and
a pair of support members provided for the cover,
wherein said the pair of support members can be engaged with both end portions of the filter element in an axial direction thereof so as to hold the filter element between the support members to be coaxial with an axis of said air outlet,
and wherein removing said cover from the case removes the filter element from the case and disengaging said filter element from the support members removes the filter element from the cover.
The structure of this modified aspect will be preferably applied to a transverse-setting type air cleaner in which the central axis of the filter element directs in a direction, for example, horizontal direction, other than the vertical direction with respect to the vehicle body. This is because, in the case of the transverse-setting type air cleaner, it is required to set a space for maintenance in the axial direction of the filter element, i.e., approximately horizontal direction of the vehicle body. Further, in such transverse-setting type air cleaner, the air cleaner can be rectilinearly connected in a direction of a throttle body of the engine without bending an air outlet provided coaxially with the axis of the filter element, so that the air resistance becomes not so large. On the contrary, in the structure of the vertical arrangement of the axis of the filter element, it is required to bend the air outlet for connecting to the engine throttle body or like, thus increasing air resistance. Furthermore, a tire house is generally provided in the engine room. However, according to this embodiment, since the filter element is directed to the direction other than the vertical direction to the vehicle body and an arc section of the air cleaner is effectively utilized, the interference of the tire house with the air cleaner can be prevented, and hence, the layout or arrangement of the air cleaner can be made more free.
The nature and further characteristic features of the present invention will be made more clear from the following descriptions with reference to the accompanying drawings.
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It is known to examine and measure the extent of the deformation of an object with the aid of holography. Double exposure of hologram plates enables changes in shape to be made visible on a hologram, in the form of images having a larger or smaller number of stripes in different configurations. This enables extremely small changes in shape, e.g. deformations as small as 0.3 micron, to be measured, which is highly significant when monitoring the quality of or load testing mechanical constructions. In view of the very small dimensions concerned in this regard, it is important that shaking between objects being examined and hologram plates used to take the two exposures be prevented to the maximum extent possible. Previously, certain difficulties have been experienced in fulfilling these conditions without the use of excessively complicated and expensive arrangements.
An object of the present invention is to provide means which will enable two objects, e.g. industrial products and hologram plates, to be mounted in a manner which will substantially prevent shaking from occurring and which will enable the same relative positions between the objects to be re-established subsequent to having moved one of said objects.
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1. Field of the Invention
The present invention relates to a cooling structure for an internal combustion engine in which: a spacer is fitted inside a water jacket which is formed to surround peripheries of three or more cylinder bores arranged one after another on a cylinder row line of a cylinder block of the internal combustion engine; and a cooling condition of the cylinder bores is controlled by regulating a flow of cooling water in the water jacket by use of the spacer.
2. Description of the Related Art
Japanese Patent No. 3596438 has made publicly known such a cooling structure for an internal combustion engine in which: the heat transfer coefficient of the spacer fitted inside the water jacket is made different between the thrust/reverse-thrust sides of the cylinder bores (portions distant from the cylinder row line) and the inter-bore portions of the cylinder bores (portions close to the cylinder row line); and thereby, the cylinder bores are uniformly cooled throughout their whole peripheries.
Meanwhile, in a cylinder block in which three or more cylinder bores are arranged one after another along the cylinder row line, each of the two cylinder bores (end-portion cylinder bores) in the respective two end portions in the cylinder row line direction has only one adjacent cylinder bore. For this reason, each end-portion cylinder bore receives a smaller quantity of heat from its adjacent cylinder bore, and reaches a lower temperature. On the other hand, since each of the cylinder bores (intermediate cylinder bores) other than the end-portion cylinder bores has two adjacent cylinder bores, the intermediate cylinder bore receives a larger quantity of heat from the adjacent cylinder bores and reaches a higher temperature.
As described above, the temperature difference occurs between the end-portion cylinder bores and the intermediate cylinder bores. Even though the end-portion cylinder bores and the intermediate cylinder bores are thermally insulated equally by the spacer, all the temperatures of the cylinder bores cannot be made uniform. This leads to a problem that variations occur among the clearances between the pistons and the corresponding cylinder bores.
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This invention is in the field of microprocessor and other integrated logic circuits, and is more specifically directed to fault detection circuitry therein.
A common function performed by conventional microprocessors in preparing an instruction for execution is referred to as fault detection. Fault detection, in general, determines whether a register or memory location is available for use in connection with the instruction. For example, a read fault occurs if an instruction that is about to be executed (or, in simple cases, is being executed) includes a read of data from a register or memory location that does not contain valid data; conversely, a write fault occurs if an instruction includes a write of data to a register or memory location that is already in use (i.e., contains valid data from a different operation). In the event that a fault is detected, the fault detection circuitry may issue an exception, causing the microprocessor to process certain control operations to dear the exception.
Fault detection is especially important in microprocessors of the pipelined type, in which multiple instructions are processed simultaneously along various stages of execution. The effective rate at which instructions are executed by a pipelined microprocessor can approach one instruction per machine cycle per pipeline, even though the processing of each individual instruction may require multiple machine cycles from fetch through execution. In a pipelined microprocessor, fault detection is typically performed during the scheduling pipeline stage, so that an instruction involving a read or write fault is not issued to execution. Fault detection may be performed not only relative to previously executed and completed instructions, but also relative to instructions that are not yet executed but which are further along in the pipeline. Handling of faults in pipelined microprocessors generally involves the flushing and refilling of the pipeline, and thus involve significant delay.
According to prior techniques, fault detection is performed in a relatively simple manner by straightforward logic. Attention is directed, in this regard, to FIG. 1, which illustrates conventional fault detection logic, as is typically implemented into the scheduling circuitry of the microprocessor. In this conventional arrangement, write fault detection is being performed upon an instruction that includes a three-bit address indicating one of eight possible registers to which a write is to be effected upon execution of the instruction. Selection information, such as register and memory addresses, are typically contained within instructions in encoded form, to save word width and thus chip area. In the conventional fault detection logic of FIG. 1, the register address is communicated on three lines REGADR to the input of 3:8 decoder 2 which, in turn, drives one of eight output lines SEL to an active state in response to the address on lines REGADR. Lines SEL from decoder 2 are applied to inputs of AND function 4. Mask register M, according to this conventional arrangement, includes eight bit positions M.sub.0 through M.sub.7 corresponding to the eight registers; each of bit positions M.sub.0 through M.sub.7 indicate, when set, that its corresponding register contains valid data, such that the execution of a write thereto would constitute a write fault. State or condition information, such as the valid data information stored in bit positions M.sub.0 through M.sub.7 of mask register M, is generally stored in decoded form, to eliminate the need for decoder circuitry and considering that the extent to which the state information is to be communicated within the integrated circuit is relatively small. The contents of mask register M are also applied to inputs of AND function 4.
AND function 4 performs eight bit-by-bit logical AND operations between each of lines SEL from decoder 2 and a corresponding one of the bit positions M.sub.0 through M.sub.7 communicated thereto; as such, AND function 4 has eight outputs, on lines CHECK, at which the results of the eight logical ANDs are presented. In this example, assuming active and set states are at a high logic level, AND function 4 will drive a high logic level at one of lines CHECK if the register location addressed by the instruction under test (as indicated by lines REGADR) already contains valid data (as indicated by the corresponding one of bit positions M.sub.0 through M.sub.7 of mask register M). The states of lines CHECK from the output of AND function 4 are combined by OR function 6 to drive line FLT that indicates, when high, that a write fault is detected.
The conventional logic of FIG. 1 is thus operable to detect write faults in microprocessor instructions; similar logic will also be used to detect read faults, in which case the fault will be indicated if the addressed register does not contain valid data. In either case, significant delay is encountered in this conventional logic realization of the fault detection logic. For example, 3:8 decoder 2 is generally realized with a gate depth of three, and eight-input OR function 6 is generally realized with a gate depth of two. As such, the overall gate depth of the conventional logic realization of FIG. 1 is about six, considering one gate delay for AND function 4.
While six gate delays may be considered to be insignificant in modern VLSI microprocessors, it has been observed, in connection with the present invention, that fault detection may be part of a critical path in the instruction flow, such that any additional delay in fault detection directly affects the microprocessor performance. For example, fault detection performance has been observed to be particularly critical in the performance of on-chip floating-point units (FPU), where the performance of the microprocessor in executing complex computational routines is directly affected by the time required for scheduling of instructions, particularly in the repetitive instruction loops often encountered in floating-point computational routines.
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1. Field of the Invention
This invention generally relates to methods for reducing the vulnerability of election procedures to rigging and hacking. Specifically, it relates to election procedures that avoid the use of electronic voting and vote tabulation that have both been shown to be extremely easy to manipulate because they are driven by computer programs that can readily be altered by putting “patches” onto the computer source code.
2. Description of Related Art
Applicant knows of no prior art that teaches the method of dividing the full-page ballot into a large number of small cards, each of which lists the candidates for a single office or a single initiative proposition, while the voting booth provides separate ballot boxes for each candidate and proposition choice.
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This invention relates to processes for the phosphate conversion treatment of metals wherein said processes employ a nickel ion-free phosphate conversion treatment bath and produce a uniform, strongly paint-adherent, and highly post-painting corrosion-resistant coating on such metals as steel sheet, zinc-plated steel sheet, aluminum alloys, and magnesium alloys.
Phosphate conversion treatments are currently executed as a pre-paint treatment on automotive body components in order to enhance corrosion resistance and improve the steel sheet-to-paint adherence. In these phosphate conversion treatments, the metal is first brought into contact with a colloidal titanium surface conditioning bath and is then brought into contact with an acidic solution containing phosphate ions, zinc ions, nickel ions, and manganese ions in order to precipitate a phosphate coating on the metal.
However, in association with today""s heightened concern with environmental protection, the regulatory situation with regard to nickel in wastewater has become increasingly stringent, particularly in Europe. It is certainly prudent to anticipate that regulations on nickel in wastewater might also become much more demanding in other countries in the future. These considerations make it desirable to eliminate the nickel from the conversion treatment baths used in zinc phosphate treatments.
Unfortunately, a number of negative effects are caused by removal of the nickel from many phosphate treatment baths used in the aforementioned phosphate treatment processes: The crystals in the phosphate coating undergo coarsening: the phosphate coating suffers from a loss of uniformity, the post-painting corrosion resistance declines, and the secondary (water-resistant) adherence of paint to zinc-plated material also declines,
Japanese Laid Open Patent Application (PCT) Number Hei 7-505445 (505,445/1995) teaches a nickel-free phosphate treatment process in order to solve the problems referenced above. This treatment process involves formation of a nickel-free phosphate coating by treatment with a phosphate conversion bath containing 0.2 to 2 grams of zinc ions per liter of bath (this unit of concentration being freely used hereinafter for any constituent of any liquid and being usually abbreviated as xe2x80x9cg/lxe2x80x9d), 0.5 to 25 milligrams of copper ions per liter, and 5 to 30 g/l phosphate ions. This process uses copper as a substitute metal for nickel, but still suffers from several problems. Since the allowable copper level in this conversion treatment bath is so very low, management of the copper concentration in real-world lines is exceedingly difficult. Another concern is with electrolytic corrosion of the equipment accompanied by displacement copper plating on parts of the equipment.
Given this background, there is a desire for development of a phosphate conversion treatment process that does not use nickel but nevertheless affords a post-painting adherence and post-painting corrosion resistance that are the equal of those afforded by existing phosphate conversion treatments that use nickel. One major object of this invention is to provide a phosphate conversion treatment process that treats metal surfaces with a nickel-free conversion treatment bath and produces a phosphate conversion coating that evidences an excellent post-painting corrosion resistance and excellent paint adherence.
It has been found that most or all of the problems caused by the removal of nickel from previous phosphating treatments can be eliminated by using a surface conditioning composition that contains very fine, dispersed solid phosphate particles.
More specifically, a process according to the invention for forming a phosphate conversion on a metal substrate surface comprises, preferably consists essentially of, or more preferably consists of the following operations:
(I) contacting the metal substrate surface with an aqueous liquid surface conditioning composition (hereinafter for brevity often called a xe2x80x9cbathxe2x80x9d without intending any implication that it must be contacted with the metal substrate by immersion of the metal substrate in a volume of the aqueous liquid surface conditioning composition) that comprises, preferably consists essentially of, or more preferably consists of, water and the following components:
(I.A) dispersed solid phosphate particles that:
(i) have a diameter no greater than 5 micrometres, this unit of length being hereinafter usually abbreviated as xe2x80x9cxcexcmxe2x80x9d; and
(ii) comprise, preferably consist essentially of, or more preferably consist of, at least one substance selected from the group consisting of phosphates that contain at least one divalent or trivalent metal cation; and
(I.B) as adhesion-promoting component, at least one selection from the group consisting of the following subgroups:
(1) monosaccharides, polysaccharides, and derivatives thereof;
(2) phosphorus containing solutes selected from the group consisting of orthophosphoric acid, condensed phosphoric acids, and organophosphonic acid compounds;
(3) water-soluble polymers that are homopolymers or copolymers of vinyl acetate and derivatives of these homopolymers and copolymers; and
(4) copolymers and polymers as afforded by the polymerization of:
(a) at least one selection from:
monomers, exclusive of vinyl acetate, that conform to general chemical formula (I):
xe2x80x83where R1=H or CH3 and R2=H, C1 to C5 alkyl or C1 to C5 hydroxyalkyl; and
other xcex1,xcex2-unsaturated carboxylic acid monomers; and, optionally,
(b) not more than 50 % by weight of monomers that are not vinyl acetate and are not within the description of part (a) immediately above but are copolymerizable with said monomers that are within the description of said part (a); and
(II) contacting the metal substrate surface as conditioned in operation (I) as described above with a nickel-free phosphate conversion treatment bath that comprises, preferably consists essentially of, or more preferably consists of water and the following amounts of the following components:
(II.A) from 0.5 to 5 g/l of zinc cations;
(II.B) from 5 to 30 g/l of phosphate ions; and
(II.C) a component of conversion accelerator.
In a preferred embodiment, the above-specified conversion treatment baths also contain from 0.1 to 3.0 g/l of at least one type of metal containing ions selected from the group consisting of magnesium ions, cobalt ions, manganese ions, calcium ions, tungstate ions, and strontium ions.
The features of this invention are explained in greater detail hereinbelow. Whenever a group of materials from which a constituent can be selected is specified, whether by a specific list, use of generic chemical terms, and/or conformance to a general chemical formula, any two or more of the group may be selected instead of a single member with equal preference unless explicitly stated otherwise.
While no particular limitations apply to the metal on which the inventive phosphate-treatment process may be executed, this metal is preferably steel sheet, zinc-plated steel sheet, zinc alloy-plated steel sheet, magnesium alloy, or aluminum alloy.
It is preferred in the practice of the invention that the metal substrate surface be clean prior to the phosphate conversion treatment. Metal whose surface is already clean can be brought without further treatment into contact with the surface conditioning bath. However, in the case of treatment of metal whose surface is contaminated with adherent materials such as iron particles, dust, and oil, the contaminants adhering on the surface should be removed by cleaning, for example, by cleaning with a water-based alkaline degreaser or an emulsion degreaser or by solvent degreasing. When a water-based cleaner is used, the cleaning bath remaining on the metal surface is preferably removed by the provision of, for example, a water rinse step after the cleaning step.
At least some of the particles of divalent and/or trivalent metal phosphate present in a surface conditioning bath in a process according to the invention must have a particle size or diameter no greater than 5 xcexcm. (Insolubles of larger size are undesirable becausexe2x80x94depending on the particular circumstancesxe2x80x94they often cannot be stably maintained in the aqueous bath.) These phosphate particles are believed to function as nuclei during phosphate crystal deposition and also to promote the deposition reaction itself, by undergoing partial dissolution in the phosphate conversion treatment bath and inducing a substantial acceleration of the initial phosphate crystal deposition reactions by supplying one or more main components of the phosphate crystals to the region immediately adjacent to the metal surface.
The divalent and trivalent metals used here are not critical, but preferably comprise at least one selection from Zn, Fe, Mn, Co, Ca, Mg, and Al. The divalent and/or trivalent metal phosphate particles are preferably present at a concentration from 0.001 to 30 g/l. Acceleration of the initial phosphate crystal deposition reactions does not normally occur at a divalent and/or trivalent metal phosphate particle concentration below 0.001 g/l due to the small amount of divalent and/or trivalent metal phosphate particles that become adsorbed on the metal surface at such low concentrations. Concentrations below 0.001 g/l also prevent acceleration of the crystal deposition reactions due to the small number of divalent and/or trivalent metal phosphate particles available to act as crystal nuclei. Divalent and/or trivalent metal phosphate particle concentrations in excess of 30 g/l cannot be expected to provide additional promotion of the phosphate conversion reactions and hence will be uneconomical.
The adhesion-promoting component that must be present in the inventive surface conditioning bath functions to improve the dispersion stability of the divalent and/or trivalent metal phosphate particles and to accelerate adsorption of the divalent and/or trivalent metal phosphate particles onto the metal surface. More specifically, the adhesion promoting component is believed to adsorb on the surface of the divalent and/or trivalent metal phosphate particles and, through a steric hindrance activity and repulsive forces arising from its electrical charge, to prevent collisions among the divalent and/or trivalent metal phosphate particles in the surface conditioning bath and thereby inhibit their aggregation and sedirmentation. In addition, due to its structure, the adhesion-promotng component itself is believed to have an ability to adsorb to metal surfaces and thereby to accelerate adsorption to metal surfaces by the divalent and/or trivalent metal phosphate particles, so that the surface conditioning activity. manifests upon contact between the metal workpiece and surface conditioning bath.
The adhesion-promoting component concentration is preferably from 1 to 2,000 parts by weight of the adhesion promoting component per 1000 parts by weight of the total conditioning composition, this unit of concentration being hereinafter usually abbreviated as xe2x80x9cppmxe2x80x9d. At concentrations below 1 ppm a surface conditioning activity can not usually be produced just by contact between the metal workpiece and the surface conditioning bath. Not only can no additional benefit be expected at concentrations in excess of 2,000 ppm, but such concentrations can impair the phosphate conversion coating formed, perhaps as a result of excessive adsorption of the adhesion promoting component on the metal substrate surface.
A saccharide type of adhesion-promoting component for the surface conditioning operation in a process according to the invention may be exemplified by fructose, tagatose, psicose, sorbose, erythrose, threose, ribose, arabinose, xylose, lyxose, allose, altrose, glucose, mannose, gulose, idose, galactose, talose, and the sodium and ammonium salts of all of these saccharides.
A phosphorus containing acid type of adhesion-promoting component in the surface conditioning process is exemplified by orthophosphoric acid, polyphosphoric acids, and organophosphonic acid compounds, or more individually by pyrophosphoric acid, triphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, aminotrimethylenephosphonic acid, 1-hydrbxyethylidene-1,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, and the sodium and ammonium salts of all of the preceding acids. Sodium salts are preferred for the organophosphonic acids if they are to be used in salt form.
Polymeric adhesion promoting components derived from polyvinylacetate in a surface conditioning operation in a process according to the invention are exemplified by polyvinyl alcohols afforded by the hydrolysis of vinyl acetate polymers, cyanoethylated polyvinyl alcohols afforded by the cyanoethylation of polyvinyl alcohol with acrylonitrile, formalated polyvinyl alcohols afforded by the acetalation of polyvinyl alcohol with formaldehyde, urethanized polyvinyl alcohols afforded by the urethanation of polyvinyl alcohol with urea, and water-soluble polymers afforded by the introduction of carboxyl moieties, sulfonic moieties, or amide moieties into polyvinyl alcohol. Suitable vinyl acetate-copolymerizable monomers are exemplified by acrylic acid, crotonic acid, and maleic anhydride. The effects associated with the present invention will be fully manifested as long as the vinyl acetate polymer or derivative thereof or the copolymer of vinyl acetate and vinyl acetate-copolymerizable monomer is soluble in water. Within this limitation, these effects are independent of the degree of polymerization and the degree of functional group introduction of the subject polymers.
Suitable monomers for other polymeric adhesion promoting components for the surface conditioning operation are exemplifed by: methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, hydroxypentyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, and hydroxypentyl methacrylate as examples of polymers according to formula (I); acrylic acid, methacrylic acid, and maleic acid as unsaturated adds; and styrene, vinyl chloride, and vinylsulfonic acid as optional comonomers.
A surface conditioning bath used by the inventive phosphate treatment processes can also optionally contain an alkali metal salt or ammonium salt or a mixture thereof, selected from the group consisting of orthophosphate salts, metaphosphate salts, orthosilicate salts, metasilicate salts, carbonate salts, bicarbonate salts, nitrate salts, nitrite salts, sulfate salts, borate salts, organic acid salts, and combinations of two or more selections from the aforesaid alkali metal and ammonium salts. The concentration of this component is not critical, but when used is preferably from 0.5 to 20 g/l. The surface conditioning bath may also contain a surfactant to promote uniform wetting of the surface being treated.
The phosphate conversion treatment process of this invention will now be considered in greater detail. A zinc ions concentration below 0.5 g/l, because it can prevent the formation of a coating of acceptable weight and can result in a diminished coverage ratio by the deposited phosphate crystals, can produce an inadequate post-painting corrosion resistance. A zinc ions concentration in excess of 5.0 g/l can cause a coarsening of the coating crystals, resulting in particular in a decline in the post-painting adherence. The use of a phosphate ions concentration below 5.0 g/l strongly impairs the production of a normal conversion coating. Concentrations in excess of 30.0 g/l are uneconomical since they provide no additional effect. Phosphate ions can be supplied by the addition of phosphoric acid or its aqueous solution to the phosphate conversion treatment bath or by the dissolution of, for example, sodium, magnesium, or zinc phosphate in the phosphate conversion treatment bath.
The conversion treatment bath also contains a component known as a xe2x80x9cconversion acceleratorxe2x80x9d or simply xe2x80x9cacceleratorxe2x80x9d. The accelerator acts to restrain gaseous hydrogen production during etching, an action sometimes called xe2x80x9cdepolarizingxe2x80x9d the metal substrate surface. Otherwise, however, no particular limitations apply to the accelerator; and any material or combination of materials recognized as a conversion accelerator in prior art may be used.
The phosphate conversion treatment bath of this invention can also contain from 0.1 to 3.0 g/l of at least one type of metal containing ions selected from the group consisting of magnesium cations, cobalt cations, manganese cations, calcium cations, tungstate anions, and strontium cations. The presence of this component in the phosphate conversion treatment bath, through its incorporation into the phosphate coating and through its precipitation in a form separate from the phosphate, provides additional performance enhancements in the post-painting corrosion resistance and post-painting adherence, respectively. The use of a concentration below 0.1 g/l usually does not effect any improvement in painting performance. A concentration above 3.0 g/l is economically wasteful, since no additional improvements in painting performance usually results; a high concentration can actually hinder deposition of the zinc phosphate that is the main component of an effectively protective conversion coating produced according to this invention. The source of one of the types of metal cations can be, for example, an oxide, hydroxide, carbonate, sulfate, nitrate, or phosphate of the particular metal. The source of tungstate can be, for example, the sodium or potassium salt.
An etchant may be added to the phosphate conversion treatment bath in order to induce a uniform etch of the surface of the metal workpiece. Usable as this etchant are, for example, fluoride ions and complex fluoride ions such as fluorosilicate ions. The fluorine compound used here can be, for example, hydrofluoric acid, fluorosilicic acid, or a water soluble metal saft (e.g., sodium salt, potassium salt) of the preceding.
The phosphate conversion treatment can be carried out by immersion or spraying or some combination thereof. Treatment for about 1 to 5 minutes can form a conversion coating satisfactorily robust for practical applications. The temperature of the phosphate conversion treatment bath is preferably from 30 to 60xc2x0 C.
The phosphate conversion treatment is preferably followed by at least one water rinse, and deionized water is preferably used in the final water rinse.
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1. Field of the Invention
This invention relates to a disc cartridge having accommodated therein a disc on which predetermined information signals are recordable or have been recorded, such as a magneto-optical disc or an optical disc. More particularly, it relates to a disc cartridge provided with a shutter for opening and closing an aperture by means of which at least a part of a signal recording area of the disc may be radially exposed to an exterior environment.
2. Description of Related Art
There has previously been proposed a disc for recording and/or reproducing information signals, such as a magneto-optical disc or an optical disc. This disc is comprised of a disc-shaped base plate and a recording layer formed on at least one major surface of the base plate. The central portion of the disc is formed as a clamp area which is to be retained by a disc driving unit of a disc recording and/or reproducing apparatus adapted for recording and/or reproducing information signals on or from the disc. The portion of the disc lying around the clamp area is reserved as a signal recording area on or from which the information signals are recorded of read.
Referring to FIG. 1, there has hitherto been proposed a disc cartridge comprised of a cartridge body 103 and a shutter member 110 which is accommodated within the cartridge body 103 and the shutter member 110 with a view to preventing deposition of dust and dirt on a disc 102 or injuries thereto due to contact especially with user's hands or fingers as well as to facilitating handling of the disc 102. The disc 102 accommodated within the cartridge body 103 may be rotated therein by disc rotating means. Referring to FIG. 2, the major surface of the cartridge body 103 is formed with an aperture 107 by means of which at least a part of the signal recording area of the disc may be exposed to an exterior environment across its inner and outer peripheries. The information signals may be recorded and/or reproduced on or from the signal recording surface by means of the disc recording and/or reproducing apparatus, through the aperture 107.
The disc cartridge is provided with the shutter member 110 adapted for closing the aperture 107 during non-use the disc cartridge as shown in FIG. 1 for protecting the disc 101 by preventing intrusion of dust and dirt into the inside of the cartridge body 103. The shutter member 110 is provided with a shutter portion or plate portion 111 of a size large enough to close the aperture 107. The shutter portion 105 is formed with a opening 109 corresponding in size and shape to the aperture 107. The shutter member 110 is mounted by the cartridge body 103 for sliding along a lateral side of the cartridge body 103 by having its end face 113 supported by a corresponding lateral side of the cartridge body 103. The shutter member 110 is supported in this manner for sliding between a first position of closing the aperture 107 by the shutter portion 111 as shown in FIG. 1 and a second position of opening the aperture 107 with the aperture 109 then being in register with the aperture 107 as shown in FIG. 2, as disclosed for example in U.S. Pat. Nos. 4,714,973 and 4,685,017.
A recess 115 for guiding the shutter portion 111 is formed on a major surface of the cartridge body 103 in an area thereof corresponding to the travel passage of the shutter portion 105. The recess 115 is of a depth corresponding to the thickness of the shutter portion 111. Thus the upper surface of the shutter portion 111 is substantially flush with the major surface of the cartridge body 103 for the entire sliding stroke of the shutter member 110 with respect to the cartridge body 103.
Meanwhile, the shutter member 110 is constituted by bending a substantially rectangular metallic plate. The shutter member 110 may also be formed by bending a plate of synthetic resin or by integral molding of synthetic resin.
It is noted that, when the disc cartridge is loaded into the disc recording and/or reproducing apparatus, the shutter member 110 has its proximal end 113, supported by the corresponding lateral side of the cartridge body 103, thrust by shutter opening means, not shown, provided in the disc recording and/or reproducing apparatus, so that the shutter member 110 is slid from the above mentioned first position to the second position, as indicted by arrow c in FIG. 2.
When the shutter member 110 is slid in this manner by the disc recording and/or reproducing apparatus, the shutter member 111 is subjected to a tilting force relative to the sliding direction under a force of friction between the cartridge body 103 and the distal free end of the shutter portion 111. If the shutter portion 111 is shorter in length in a direction along a lateral side of the cartridge body 103 indicated by double-headed arrow a in FIG. 1 than in a direction normal to the aforementioned lateral side indicated by double-headed arrow b in FIG. 1, the shutter portion 11 tends to be tilted with respect to the sliding direction as indicated by arrow d in FIG. 1. Should the shutter portion 111 be tilted with respect to the sliding direction, the shutter member 110 can not be slid smoothly with respect to the cartridge body 103.
On the other hand, if the shutter portion 111 is shorter in length in the direction along the aforementioned one lateral side of the cartridge body 103 than in the direction normal thereto, the shutter portion 111 is extended a longer distance from its proximal end 113 towards its distal end, so that it becomes difficult to form the shutter portion 111 as a flat plate.
For this reason, the shutter portion 111 is longer in the direction along the aforementioned one lateral side of the cartridge body 103, that is, in the sliding direction of the shutter member 110, than in the direction normal to the sliding direction of the shutter member 110. Above all, if the shutter portion 111 iS formed of synthetic resin, since the shutter portion 111 is lower in toughness than if the shutter portion is formed of metal , it becomes more necessary that the shutter portion 111 be longer in the direction along its sliding direction than in the direction normal thereto.
However, if the shutter portion 111 has a longer length in its sliding direction, the proportion of the area taken up by the shutter section guide recess 115 to the entire area of the major surface of the cartridge body 103 is necessarily increased. If the proportion of the area taken up by the shutter guide recess 115 is increased in this manner, it becomes difficult to provide the major surface with a so-called positioning holes or to apply a label on the major surface. These positioning holes are used for securing the disc cartridge in position within the disc recording and/or reproducing apparatus, while the label are used for indicating the contents of information signals recorded on the disc 102.
On the other hand, if the length in the sliding direction of the shutter portion 111 is increased as described above, there may arise a risk that the cartridge body 103 be correspondingly increased in size. That is, since the distance by which the shutter member 110 can be slid relative to the cartridge body 103 is determined by the size of the aperture 107 formed in the cartridge body 103, if the shutter portion 111 is of a longer length in the sliding direction of the shutter member 110, there may arise the risk that, when the shutter member 110 is slid relative to the cartridge body 103, the shutter portion 111 be protruded beyond the corresponding lateral side of the cartridge body 103.
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1. Field of the Invention
This invention relates to an acoustic baffle for an automobile cavity. In one of its aspects, the invention relates to a composite integral baffle which includes a heat expandable sealing material and rigid support of predetermined shape that can be mounted in a cavity such as a hollow pillar of an automobile or similar vehicle. In another of its aspects, the invention relates to a method for manufacturing the composite integral baffle that includes a heat expandable sealing material and rigid support of predetermined shape.
2. Description of the Related Art
With increased focus on interior "noise quality" for automobiles, many new and existing material applications are being investigated. One existing application is the use of heat reactive, expanding sealing materials used in the vehicle body structures known as pillars. One particular problem to the acoustical engineer is the nuisance noise the "pillars", or hollow channels in the vehicle body structures, transmit to the passenger compartment. The pillars are linked together to define the body structure from front to back of the automobile. Blocking these channels and the noise path has proven to help a vehicle's perceived sound quality.
The nuisance noise that occurs in these pillars is related to power train, wind, tire, and road noise. Over the years, various solutions have been used to minimize the energy level of noise that flows from these sources to these pillars. A current approach is to block the path of noise with heat reactive, expandable sealing materials mounted to support plates to create a "baffle". Baffles are strategically located within the body structure in a pattern that helps to eliminate propagation of noise into the vehicle passenger compartment.
The varying vehicle body styles in the automotive industry has lead to the development of numerous baffle constructions, particularly since pillar definition is becoming more complex. This complexity has required designs to become more precise, yet flexible for easy installation. Further, because sealing effectiveness of any baffle design is critical to acoustic performance, the presence of any holes in the sealed out perimeter of the baffle within the channel drastically reduces the acoustic response.
Many attempts have been made to seal these cavities, including spraying of a sealant into the cavity, introducing foreign products into the cavity, and using fiberglass matting and the like. These past efforts have not been entirely satisfactory because of the inefficiency of the sealing and baffling methods, the relatively high cost of the sealing process, and the fact that erratic sealing has resulted in many instances.
Foaming in place has not been totally satisfactory because of the difficulty in controlling where the foam travels upon introduction of the foam into a vehicle body cavity, and the fact that more foam than is actually needed is usually introduced into the body cavity to provide some degree of redundancy in preventing the passage of moisture into and the blockage of noise within the cavity during use of the vehicle. Furthermore, foams have a finite life insofar as they become rigid with time, thus limiting the time period available in which the foam may be introduced in the vehicle cavity. In addition, if the interior surface of the cavity has a somewhat oily surface, the foams would not adequately adhere to that surface, thereby resulting in an ineffective seal.
It is also known to use an expandable baffle for sealing the cavity of an automobile pillar with a sheet of heat expandable sealing material mounted on a rigid plastic or metal support that is formed in the shape corresponding to the shape of the cross-section of the cavity to be sealed. The heat expandable material has been mounted to a single support sheet of has been sandwiched between two rigid support sheets. The composite material is mounted inside the cavity and the sealing material is expanded when the automobile is subjected to a high temperature, often during the paint baking cycle, at which point the sealing material expands to seal the cavity at the cross-section. This method generally produces a superior acoustic seal, but the manufacture of the combined heat activated sealing material and support plate is costly. In the case of the use of a single support sheet, the heat expandable material tends to form a dome shape while the sealing occurs only at the edges of the dome. Much heat expandable material is wasted. In the case of the use of a sandwich construction, the expansion tends to be directional but there is significant excess material between the two support sheets. Thus, there is much wasted sealing material. Furthermore, depending upon the dimensions of the cross-section or space restrictions for mounting the expandable material and support plate, it may not be possible to seal a pillar cavity at the preferred point. That is, the direction of expansion cannot be controlled.
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1. Technical Field
The present invention relates to a brushless motor and, more particularly, to a motor for an electric power steering device which supports steering effort of a steering wheel of a vehicle.
2. Description of the Related Art
In recent years, electric power steering (EPS) system that supports steering operation by rotating a motor with a vehicle battery is employed. The EPS system is attracting attention as an efficient system with smaller power loss of an engine as compared with the case of generating an oil pressure by rotation of the engine. On a motor used for such an EPS system, a part as position detecting structure is mounted in order to realize high-precision control.
Since the rotary shaft of a motor used for the EPS system is connected to the driver indirectly via a steering wheel, cogging and torque ripple generated from the motor is directly transmitted as an abnormal state of the steering wheel to the driver. Consequently, it is necessary to reduce the cogging and the torque ripple. To solve the problem, a method of accurately disposing position detecting structure has been devised.
Next, conventional structures of the EPS will be described with reference to FIGS. 7 and 8.
FIG. 7 shows a first conventional structure in which a resolver 1 as position detecting structure is disposed on an axial outside of an inner space of ball bearings 2 axially apart from each other.
In the first conventional structure, however, since the resolver 1 is disposed on the axial outside of a space between a ball bearings 2 axially apart from each other, the space between the ball bearings 2 axially apart from each other has to be narrowed only by a space 3 in the axial direction in which the resolver 1 is disposed. As a result, when the distance between the ball bearings 2 is shortened, accuracy of a shaft 4 attached to the ball bearings 2 cannot be assured. Therefore, the shaft 4 swings and it may cause vibration of the motor. Moreover, in the first conventional structure, the resolver 1 is exposed to the axial outside, so that a circumferential position adjustment of the resolver 1 is performed after the motor is assembled. There is consequently the possibility that a member other than the motor comes into contact with the resolver 1 and the resolver 1 is damaged.
FIG. 8 shows a second conventional structure in which a board holder 5 including a rotation position detecting board 5b on which a hall device 5a as position detecting structure is mounted is disposed on an axial inside of the space between ball bearings 7 axially apart from each other. A sensor magnet 6 is axially disposed so as to face the rotation position detecting board 5b. The board holder 5 is disposed under a bracket 8 and is fixed to the bracket 8 by only three screws 9 screwed from an upper side of the bracket 8. Insertion holes 8a of the screws 9 in the bracket 8 are circumferentially formed in an arc shape. By moving the screws 9 among the insertion holes 8a in the circumferential direction, the circumferential position adjustment of the board holder 5 is performed.
In the second conventional structure, however, after the motor is assembled, there is no member supporting the board holder 5 below the board holder 5. Consequently, the board holder 5 cannot be fixed by being axially sandwiched. The board holder 5 cannot be fixed with reliability, and a low-reliability motor is produced in which the board holder 5 may come off due to motor vibrations, an external collision, or the like. Moreover, since the circumferential position adjustment of the board holder 5 is performed by moving the screw 9 in the circumferential direction, the board holder 5 has to be circumferentially moved by holding the head of the screw 9. It is difficult to move the board holder 5 by holding only the head of the screw 9 and a problem of low workability arises.
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Presently available in-vitro diagnostic (IVD) devices are used in various medical settings to detect the presence of numerous types of biological conditions, such as the presence of infection antibodies, quickly and reliably. Known IVD devices are used in hospitals, clinics, doctors' offices, and other patient care facilities to enable rapid detection and identification of potentially harmful conditions in patients presenting at these facilities.
One type of IVD device is configured to read or otherwise analyze lateral flow assays, which can test for a wide variety of medical and environmental conditions or compounds. For example, lateral flow tests can rely on a form of immunoassay in which the test sample flows along a solid substrate via capillary action. Known IVD devices can read lateral flow assay strips to detect the existence of a hormone, metabolite, toxin, or pathogen-derived antigen. This reading can be accomplished with the use of an imager, such as a CMOS imager or a CCD-based imaging device, which is configured to detect the presence or absence of a line on the lateral flow assay based on the presence or absence of a visual line on the assay. Some tests, implemented by IVD devices, are designed to make a quantitative determination, but in many circumstances the tests are designed to return or indicate a positive/negative qualitative indication. Examples of assays that enable such qualitative analysis include blood typing, most types of urinalysis, pregnancy tests, and AIDS tests.
Certain known IVD devices (including known assay test strip reader devices) are configured to report, store, and/or transmit diagnostic information determined solely resulting from a diagnostic test and not provided by a source external to the IVD device. That is, certain known IVD devices are configured to report, store, or transmit information related to, the infection or other condition tested for, as well as to report, store, or transmit additional information manually entered by patient care personnel assisting in the use of the IVD devices. Some IVD devices are provided as stand-alone devices—that is, they perform infection detection by autonomously following a pre-programmed decision-making process or rule. For each test performed by such an IVD device, the same process is undertaken, and a result is generated in the same way. Moreover, in known IVD devices, a built-in or integrated display is used to display the results of the test, and the results may also be printed using a built-in or attached printer.
Many known IVD devices are not configured to send of receive data to or from any source external to the IVD device. In such devices, the only output enabled by the IVD devices is to display the results of a test on an integrated display. Certain other known IVD devices are configured to exchange data with another device, remote from the IVD device, through a short-range wired or wireless connection. For example, known IVD devices may exchange data with another device through a USB, serial, or proprietary wired connection, or through a Bluetooth, Wireless USB, or proprietary wireless connection. Finally, certain known IVD devices are configured to connect to a local area network (e.g., LAN) through a wired (e.g., Ethernet) or wireless (e.g., WiFi or ZigBee) connection.
Known IVD devices suffer from many drawbacks. First, known IVD devices suffer from drawbacks in that any data used by known WD devices to generate outcomes or test results must either be determined by the device as a part of the analysis of the test results, or must be manually entered by medical personnel or other users of the IVD device. This manual entry is frequently limited, and involves the use of a keyboard or a barcode scanner. Even if such data is manually entered, known IVD devices suffer from drawbacks in that the correctness of the entered data is questionable, and in fact may be in jeopardy, depending upon the mechanism for entering data and/or the care given to the correct entry of data by the user of the IVD device. Finally, known IVD devices suffer from drawbacks in that they are limited to receiving and utilizing only that data and/or information known to the individual entering the information into the device. Other information (such as information obtainable from medical or other databases or information repositories, or from a device manufacturer) is not available for use by the IVD device in generating its results.
Further, known IVD devices suffer from drawbacks in that the limited connectivity options provided with such IVD devices prevents the devices from forming ad-hoc networks and connecting directly to other IVD devices or network elements. To the extent that network capabilities are provided, data generated by IVD devices is limited to transmission within a given patient care facility. Moreover, a patient care facility which enables connection of IVD devices to a network must operate an appropriate LAN or other network, and must provide infrastructure for integrating and maintaining IVD devices within the network, both of which can be costly endeavors. Finally, even with known network-enabled IVD devices, manual interaction is required to access the test results generated by an IVD device and to store it electronically in an appropriate medical facility database. For example, manual intervention is required in known IVD devices to upload data indicative of an outcome of a diagnostic test from an IVD device and store it in an appropriate Hospital Information System (HIS) or Laboratory Information System (LIS) database.
Known IVD devices do not provide a mechanism to enable near-patient testing results to be provided to a centralized server for analysis, aggregation, and distribution using an established public network, such as a public telephone network. Moreover, known IVD devices do not provide a mechanism by which a centralized server can track, manage, and determine characteristics of those IVD devices to ensure appropriate use of the devices and appropriate use of environmental data detected by the IVD devices.
Thus, it is desirable to create IVD devices that are configured to receive and store data from sources external to the individuals utilizing the IVD devices, in addition to data currently gathered by known IVD devices, and to utilize the data received from external sources to supplement the analysis capabilities of the WD device, such as by confirming or verifying part of the diagnostic information generated by the IVD device. It is further desirable to create IVD devices that are network-ready, such that the devices can connect to a network (such as the Internet) and obtain external data independent from the actual test being performed. It is also desirable to create an IVD device that is capable of sending or uploading data to a remote repository via a network, such that data about the tests performed with such IVD devices can be stored and analyzed, alone or in the aggregate, by remote devices or personnel. Finally, it is desirable to provide an IVD device that includes a built-in mechanism for accessing publicly available networks, such as telephone or cellular networks, to enable direct communication by the IVD device with network elements or other IVD devices to enable electronic test result transmission, storage, analysis and/or dissemination without requiring separate intervention or action by the user of the IVD device.
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The present invention relates to an electrical simulator of a plectrum instrument.
It is known that in the field of musical instruments there are instruments which include a keyboard connected to electronic equipment by means of which it is possible to imitate the sounds of many instruments: thus, by playing a certain chord on the keyboard, that chord will be heard as if it were played by a flute, a saxophone, or any instrument, according to the selection made by the user by pressing different buttons.
Commercially available instruments are all standardized, most of them according to a system known as MIDI: a chord played on the keyboard corresponds to the external output of a standardized signal and to a simultaneous signal to a sound card which is suitable to emit the sound and is contained within the instrument; external signals may also reach the sound card, and it is furthermore possible to interrupt communication between the keyboard and the sound card.
Instruments known as "sequencers" are also commercially available: these instruments emit standardized signals which are suitable for being received by a sound card to create an entire piece of music, and each emitted signal corresponds to a recorded chord originally set up on a keyboard.
The above described instruments allow to imitate excellently the sound of a vast number of different instruments but not of plectrum instruments such as the guitar or the mandolin, because in these instruments a chord is produced by a fingering, i.e. an action of the fingers, which is very different from the action used at the keyboard (it is enough merely to consider, for example, that the same chord is formed by pressing three keys on the keyboard and six strings on a guitar neck), and because the strings of plectrum instruments form the chord by acting at a very short time interval from each other due to contact with the user's descending and ascending hand.
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1. Field of the Invention
The present invention relates to a buffer architecture, and more specifically to a buffer architecture with multiple buffers allocated storage within a common storage area where the allocation is reconfigurable.
2. Description of the Related Art
Buffers are used within systems to provide temporary storage for data. Buffers are either FIFO (First-In-First-Out) or LIFO (Last-In-First-Out). In a FIFO buffer, data is written to the front end of the buffer and is read from the back end of the buffer. In a LIFO buffer, data is written and read from the front end of the buffer. Data in a FIFO buffer “Marches” through the buffer and is read in the strict ordering in which it was written. Data in a LIFO buffer is stacked on the buffer and the most recently written data is read before less recently written data.
FIFO buffers are generally implemented as a circular queue having a read pointer which points to the “next” location in the buffer storage to be read and a write pointer which points to the “next” location to be written. The write pointer is used by the control logic of the buffer to access a location where data is to be written in the buffer storage and the read pointer used by the control logic of the buffer to access a location whose data is to be read from buffer storage. A device which is connected to the buffer sends data to the buffer and the control logic writes the data to the buffer storage location corresponding to the write pointer. A device which reads from the buffer reads data presented to it by the control logic which reads the data from the buffer storage location corresponding to the read pointer.
LIFO buffers are generally implemented as a stack with a pointer to the bottom of the stack and a stack pointer to the location in buffer storage where data was last written. The stack pointer is usually both a read pointer and a write pointer. The stack pointer is used by the control logic of the buffer to point to the location in buffer storage where the most recently written data was stored. A device connected to the buffer reads from data presented to it by the control logic which reads the data from the buffer storage location corresponding to the stack pointer, then moves the stack pointer to the location in buffer storage previously written. A device writes data to the buffer and the control logic moves the stack pointer to the next free location in buffer storage and writes the data to the location in buffer storage corresponding to the pointer.
In a conventional buffer mechanism, the size of each buffer storage area is determined in advance and is fixed thereafter, especially in ASIC applications. This fixed allocation can be inefficient and has a larger memory requirement if multiple buffers are required by the system, not all of which will be simultaneously busy or active to the same degree. For example, in a system with two devices or applications needing buffer support, only one of which is active at any time, all of the buffers associated with the inactive device or application may be in an idle state, while the buffers for the active device or application may be of insufficient size for optimal performance.
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The present invention relates to a method of producing reflectors from glass or glass ceramics wherein a reflector being open to the outside having a closed bottom is molded in a mold at a temperature above the transformation temperature and an opening is then punched out from the bottom.
A method of that kind is known from US 2004/0264200 A1.
A reflector consisting of glass is initially produced in this case by molding a gob in a mold whereafter its bottom area is heated up locally using a burner so that an opening can then be punched out from the bottom, in the softened state of the glass, using a ram and a die. The reflector is then fire-polished to make the surface sufficiently smooth.
Alternatively, the opening in the bottom area can be produced by drilling. In that case as well, a fire-polishing step is carried out subsequently in order to produce a smooth surface.
It has been found that while a smooth surface is guaranteed in the bottom area of reflectors that have been produced according to the known method, the tolerances regarding the opening produced frequently cannot be maintained without a secondary treatment.
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Many enterprise data processing systems rely on multi-node database servers to store and manage data. Such enterprise data processing systems typically follow a multi-tier model that has a multi-node database server in the first tier, and one or more computers in the middle tier and outer tiers.
FIG. 1 depicts multi-node database server mds11, which is implemented on multi-tier architecture 10. A server, such as multi-node database server mds11, is a combination of integrated software components and an allocation of computational resources, such as memory, a node, and processes on the node for executing the integrated software components on a processor, the combination of the software and computational resources being dedicated to performing a particular function on behalf of one or more clients. Resources from multiple nodes in a multi-node computer system can be allocated to run a particular server's software. A particular combination of the software on a node and the allocation of the resources from the node is a server that is referred to herein as a server instance or instance. Thus, a multi-node server comprises multiple server instances that can run on multiple nodes. Several instances of a multi-node server can even run on the same node.
A database server governs and facilitates access to a particular database, processing requests by clients to access the database. A multi-node database server, such as multi-node database server mds11, comprises multiple “database instances”, each database instance running on a node. Multi-node database server mds11 governs access to database db11. A multi-node database server can govern and facilitate access to one or more databases.
The middle-tier of multi-tier architecture 10 includes middle-tier computer cmp11 and the outer-tier includes user computer cmp12. User computer cmp12 executes browser br11, which interacts with an end-user. The end-user's interaction with browser br11 causes the browser to transmit requests over a network, such as the Internet, to middle-tier computer cmp11. The request causes a process on middle-tier computer cmp11, client c11, to execute application appl11. Execution of application appl11 by the client c11 causes client c11 to connect to multi-node database server mds11. For example, application appl11 may be an order entry application that is configured to receive order requests from browser br11. Data for the order entry application is stored in db11. To process the requests, execution of application appl11 by client c11 causes client c11 to connect to database db11. Once connected, client c11 issues database statements to retrieve and manipulate data stored in database db11.
The tier that directly connects to a server, relative to other tiers in a multi-tier architecture, is referred to herein as containing the client of the server. Thus, client process c11 is referred to herein as the client of multi-node database server mds11.
An application, as the term is used herein, is a unit of software that is configured to interact with and use the functions of a server. In general, applications are comprised of integrated functions and software modules (e.g. programs comprised of machine executable code or interpretable code, dynamically linked libraries) that perform a set of related functions.
An application, such application appl11, interacts with a multi-node database server mds11 via client-side interface component intcomp11. Execution of application appl11 causes client c11 to execute client-side interface component intcomp11 to interact with multi-node database server mds11. Application appl11 includes invocations of routines (e.g. functions, procedures, object methods, remote procedures) of client-side interface component intcomp11. Applications are typically developed by vendors and development teams different from those that develop servers and interfaces to servers, such as multi-node database server mds11 and client-side component intcomp11.
In order for a client to interact with multi-node database server mds11, a session is established for the client on a database instance of multi-node database server mds11. A session, such as a database session, is a particular connection established for a client to a server, such as a database instance, through which the client issues a series of requests (e.g., requests for execution of database statements).
For each database session established on a database instance, session state is maintained for the session. Session state includes the data stored for a database session for the duration of the database session. Such data includes, for example, the identity of the client for which the session is established, and temporary variable values generated by processes and database components executing software within the database session. A database component is a set of software modules that provide specialized and related functions for a database server, and shall be described later in greater detail. An example of a database component is a Java execution engine.
The beginning and end of a session demarcates a unit of work. Often, the beginning of a database session corresponds to an end-user establishing an interactive session with an application via, for example, a browser, and ends when the end-user logs off. Thus, the beginning and ending of the database session depend on application logic and end-user action, and may not be controlled by a server on which the session is established.
Client-Side Interface Components
Client-side interface components, such as client-side interface component intcomp11, are software components that reside and are executed on the same computer of a client of a server, and that are configured to provide an interface between the client and the server. The client-side interface component intcomp11 is configured for performing the detailed operations needed to interface with multi-node database server mds11. For example, an application appl11 invokes a function of client-side interface component intcomp11 to establish a connection to multi-node database server mds11. The client-side interface component then handles the details of a connection on a particular instance of multi-node database server mds11. To make requests of multi-node database server mds11, such as a request for execution of a query, application appl11 is configured to invoke functions of client-side interface component intcomp11, which then transmits a request for the same to the node and database instance on which the session is established.
Client-side interface component intcomp11 may generate and/or access state that is hidden from other software modules, that is, is not or may not be referenced and accessed by other software modules, and in particular, by application appl11. Such state is referred to as being internal or private to client-side interface component intcomp11.
For example, to create a database session on a multi-node database server mds11, application appl11 invokes a routine of client-side interface component intcomp11. The client-side interface component establishes a database session on a particular database instance within multi-node database server mds11, and stores details about the database session within internal data structures or objects. Such data structures and objects define, for example, the session established for an application, and specify such values as an identity of a session on a database instance, the name of the database instance, and a network address and port number for the connection to the database instance.
Such details of the session are not returned to application appl11, nor may application appl11 access the details. Instead, what is provided to application appl11 is an “external identifier” for the session, such as a value that internal data of client-side interface component intcomp11 maps to the session, or a reference to an object generated by client-side interface component intcomp11 to store some details of the session in private attributes of the object that are inaccessible to application appl11. In this way, application appl11 does not “know” of the specific details of the session that has been established for it; however, application appl11 has the information needed to be able to identify to client-side interface component intcomp11 the particular session that has been established for application appl11.
Distributing Workload
An important capability needed to manage multi-node database servers is to distribute work load between the nodes. Distributing work load is used to improve performance, by optimally balancing workload between nodes. Distributing workload also allows work to be shifted from a node that is being taken off-line for maintenance operations to another node.
To improve performance, work load on a multi-node database server is distributed using connection-time balancing. Under connection-time balancing, work load is distributed at connection-time, when a database session for a client is created. Specifically, when a client requests to establish a database session on a multi-node database server, the session is placed on an instance or node based on work load considerations. For example, a client transmits a request for a session to a multi-node database server. The multi-node database server determines that a node is less busy than other nodes, and establishes a session for the client on that node.
A drawback to connection-time balancing is that it cannot rebalance existing sessions; it only balances sessions when they created. The work load created by existing sessions cannot be shifted and does not abate until a client, on its own accord, reduces or ceases to make requests and/or terminates the sessions. As a result, the timing of work load shifting is subject to events not under the control of a multi-node database server.
Based on the foregoing, it is clearly desirable to provide a way to shift work load of clients of sessions after the sessions have been created.
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1. Field
Embodiments of the present disclosure relate to a motor to generate rotating force and a washing machine having the same.
2. Description of the Related Art
A washing machine, which washes clothes using electricity, generally includes a tub to retain wash water, a drum rotatably installed in the tub and a motor to rotate the drum.
The motor, which produces rotating power from electric energy, is provided with a stator and a rotor. The rotor is configured to electromagnetically interact with the stator, and is rotated by force acting between a magnetic field and current flowing through a coil.
The motor is generally mounted to rear wall of the tub. The motor mounted to the rear wall of the tub is exposed to moisture formed on the outer surface of the cabinet or tub.
If the moisture reaches the motor due to gravity or vibration caused by rotation of the drum infiltrates the motor, a short circuit may occur, causing the motor to malfunction or stop.
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{
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I. Field
The present disclosure relates to card games, and in particular, to a method and apparatus for playing a dice-less Craps game.
II. Background
Craps is one of the most popular dice games played in the casinos of Nevada and New Jersey. Players and spectators alike enjoy the fast-paced action provided by Craps.
However, in some areas of the country dice games are prohibited, while other types of games, such as card games, slot machines, or keno, may be permitted. In such jurisdictions, the absence of Craps on the casino floor may be missed.
Card games designed to replicate dice games are known in the art. For example, the Official World Encyclopedia of Sport and Games, 1979, discloses a craps game that is played with a deck of cards.
The game uses a special deck of 48 cards, consisting of two sets of each of the denominations Ace, 2, 3, 4, 5 and 6. The numerical value of the cards correspond to the indicia on the faces of two dice.
The shooter deals two cards from the top of the deck face up onto the table, constituting a throw. The value of the two cards added together is a xe2x80x9crollxe2x80x9d in the same way as the two dice in dice craps. Play follows the basic rules for Craps, where the first two cards on a come-out give either a natural (7 or 11), a craps (2, 3, or 12), or a point (4, 5, 6, 8, 9 or 10).
After every come-out throw the two cards are shuffled back into the deck by the shooter, and the deck is cut. This happens even if no decision has been reached (e.g. if a point has been thrown), If the shooter then still has to make a point, he deals further throws, but does not shuffle these back into the deck.
This continues until he makes the point or sevens out. The entire deck is then shuffled together and cut. If, on a point, the entire deck is exhausted, the deck is reshuffled and cut by the shooter; he then continues, trying for the same point.
The prior art card games suffers from certain disadvantages, however. For example, since cards are not returned to the deck while the shooter is trying to make a point, the odds of the game are not equivalent to a true Craps dice game since the rolls represented by the used cards are not available.
A novel and improved dice-less Craps game is disclosed. In one disclosed aspect, a method for playing a dice-less Craps game with a deck of cards is disclosed, comprising: dealing, by a dealer, a pair of cards having numerical indicia thereon; determining whether the pair of cards are of a like suit; if the cards are not of a like suit, then adding the numerical indicia together to determine a roll in accordance with the rules of Craps; and if the pair of cards are of a like suit, then arriving at a predetermined result other than a roll in accordance with the rules of Craps. In a further disclosed aspect, the first predetermined result comprises a NoCall.
An apparatus for playing a dice-less Craps game is disclosed comprising: a Craps playing surface for receiving a pair of dealt playing cards, the playing surface having indicia thereon for wagering on a predetermined result other than a roll in accordance with the rules of Craps.
In a further disclosed aspect an apparatus for playing a dice-less Craps game is disclosed, comprising a deck of cards comprising 48 cards having numerical indicia thereon including four like-suited pairs each of Aces, Twos, Threes, Fours, Fives, and Sixes; and a Craps playing surface having additional indicia thereon for wagering on a predetermined result if a pair of dealt cards are of a like suit.
In additional aspect of a disclosed dice-less Craps game, a pair of dealt cards may be drawn from a deck consisting of 48 cards including four like-suited pairs each of Aces, Twos, Threes, Fours, Fives, and Sixes. The dealt pair of cards may be returned to the deck prior to the dealer dealing a subsequent pair of cards.
It is contemplated that the disclosed game may be embodied in computerized gaming equipment.
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Thermal tiles are installed on space vehicles, such as the Orbiter, to protect the space vehicle from overheating during reentry into the Earth's atmosphere. Such tiles are usually installed in such a way that gaps are maintained between each tile on the vehicle. However, high pressure gradients can exist along the vehicle surface and adverse thermal effects may then result from the flow of gasses through these gaps, particularly during reentry through the Earth's atmosphere. To minimize adverse gap heating, gap fillers are presently installed in these critical gaps during vehicle assembly after the tiles have been installed. Gap fillers may also be installed at any time after vehicle assembly when additional critical areas are identified.
Gap fillers may be made of various materials and configurations. An example of such a gap filler may be seen in U.S. Pat. No. 4,308,309. Currently, such gap fillers are secured by bonding them with room temperature vulcanizing (RTV) polymer to the filler bar located underneath and between the tiles. RTV, e.g. composition of silicone rubber, is placed between the tiles along the filler bar and then the gap filler is inserted between the tiles to form a bond. This type of installation is described in the aforementioned U.S. Pat. No. 4,308,309.
There is a significant disadvantage associated with RTV installation of gap fillers between tiles. Installing the gap filler with RTV is an operation which is difficult to perform properly in a time efficient manner. RTV is often smeared along the sides of the tiles because the gaps are small, e.g. 0.030 to 0.060 inches. During ascent and reentry of the space vehicle to which the tiles and gap fillers are attached, high tile temperatures causes the RTV to burn off the sides of the tiles and the RTV no longer provides an adequate bond to the vehicle. This is why the gap filler is intended to be bonded to the filler bar instead of the tile. As the gap fillers are currently installed, it is difficult to verify whether the gap filler is being held in place by an RTV bond to the side of the tiles or by a bond established with the filler bar. Since the structural integrity of each installation is unreliable, as described above, many gap fillers have become detached and lost during flight. As a result, increased heating of the vehicle may occur, increasing the possibility of large scale structural repair.
Thus, the current methods of installing gap fillers in the gap between tiles or, for that mutter, installing any structure in gaps or narrow spaces, are not satisfactory for many applications. Retaining apparatus and methods for such gap fillers can be improved in reliability, installation time, and structural integrity.
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{
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1. Field of the Invention
This invention relates to locks for releasably maintaining a hinged closure in a closed state and, more particularly, to a lock assembly having a plunger that is guidingly moved within a housing between a latched and unlatched position.
2. Background Art
A wide variety of locks/latches are currently present in the art to maintain a hinged closure member in a closed state with respect to a frame to which it is mounted. It is common practice to assemble the lock by providing two separate subassemblies and to operatively interconnect these subassemblies, one each from the opposite sides of the closure.
One exemplary environment for such locks is on doors for travel trailers and motor homes. Typically, the external subassembly is operable by a flat paddle. Operation of the paddle effects repositioning of a plunger from a latched position to an unlatched position on the internal subassembly. Most commonly, pivoting of the paddle is converted into translatory movement of the plunger.
It is desirable to incorporate the plunger into a housing to define a self-contained unit/module in which the plunger is guided by the housing between latched and unlatched positions. Heretofore, various structures have been devised to maintain the plunger and the housing in assembled relationship. Most typically, the plunger is preassembled to the housing after which a separately attached part maintains the plunger captive in assembled relationship with the housing. The extra part(s) might be held in place by fasteners or welded in place.
The need to assemble separate fasteners and/or to carry out the welding step contributes to the complexity of manufacture, which results in an increase in the attendant cost for the locks.
Another problem with the conventional locks is that the construction of some of the interior subassemblies does not lend itself to being actuated from the inside of the closure. While in some applications, this feature is not necessary, it is necessary when the lock is part of a closure, such as a door on a motor home.
A further problem with conventional locks is that it may be difficult with some of these locks to effect mounting on a closure. Separate mounting structure may be provided to connect the housing to the closure. Multiplication of parts, as in most manufacturing processes, increases inventorying problems and complicates manufacture.
A still further problem with conventional locks is that it is often difficult in constructing these locks to maintain all the parts in desired relationship. In most of these locks, a coil spring is used to bias the plunger towards a latched position. The assembler must put the spring in place, which may in itself be a delicate operation, and thereafter complete the assembly to captively hold the plunger and spring within the housing. The spring has a tendency to fall out and may be improperly located if not held in place by the assemblers as the lock is constructed.
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{
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1. Field of the Invention
The present invention relates to communication systems, and more particularly, to an apparatus that allows random access to information pertaining to the number of output ports that have transmitted copies of designated data frames.
2. Description of the Related Art
Modern communication systems, such as computer networking systems or communication networks, provide constant transmission of data between end stations and/or intermediate stations such as routers and signal amplifiers. Computer networking systems, such as packet switched networks (e.g., Ethernet networks), often require transmission of data to a single end station or to multiple end stations within the network. The data originates from a user program and is segmented into multiple data frames, and subsequently transmitted in order to simplify processing and minimize the retransmission time required for error recovery. For example, in a conventional e-mail system, a user may desire to send the same e-mail message to four different users that are connected to the e-mail system. Accordingly, the identical data would be directed to multiple end stations.
Packet switched computer networks typically employ a network switch that receives and forwards data frames to individual and/or multiple end stations. The network switch makes forwarding decisions upon receipt of data frames based on information contained in a header of the data frame. For example, if a received data frame is to be transmitted to a number of end stations, the switch must make the forwarding decision to forward the data frame to the ports of the correct end stations. Depending on the specific implementation and/or characteristic of the networking system (i.e., data transfer rate, traffic intensity, etc.), buffers must be provided for temporary storage of the data frames, received by the switch, until forwarding decisions can be made. The buffers used to store the data frames are often implemented as first in, first out (FIFO) queues.
Buffering the data as it is received allows, for example, robust error checking to be performed on the data frames, and also permits rate matching between transmitting and receiving ports. When data frames arrive at a network switch, only buffers that are currently available (i.e., xe2x80x9cfreexe2x80x9d) may be used to store the data frames, in order to prevent overwriting of a first data frame by a second data frame prior to transmission.
In systems that employ multiple buffers to store a single data frame, the network switch monitors the transmission of all data frames. In addition, it is often necessary to transmit multiple copies of the same data frame to different network stations. Such situations require that the network switch closely monitor the system to ensure that all copies of the data frame have been either transmitted or accounted for. The network switch may also include various components that maintain information regarding the number of copies of data frames that have been successfully transmitted. Therefore, it is necessary to continually update the status of all data frames that must be transmitted by multiple output ports. Depending on the specific implementation of the system, updating the status of such data frames can often be very time consuming, particularly when multiple components of the network switch maintain or use information pertaining to the number of output ports that have completed transmission of their copy of the data frame.
Based on the foregoing, a primary disadvantage associated with current methods of transmitting multiple copies of the same data within communication systems, such as a packet switched computer networking system, is the amount of time required to update multiple components of the switch with copy number information for multicast data frames.
There is a need for an arrangement that allows various components of a network switch to quickly obtain information regarding the number of copies of a received data frame remaining to be transmitted by various output ports of a network switch.
These and other needs are addressed by the present invention, wherein a multiport switch maintains copy information, pertaining to the number of copies of a received data frame that have been transmitted, in a random access storage area that may be accessed by various components of the multiport switch.
In accordance with one aspect of the present invention, an apparatus for maintaining copy information pertaining to data frames received by a multiport switch that forwards received data frames to plural output ports comprises: a random access storage area and a control logic, both of which are located on the chip. The random access storage area stores a copy information that indicates the number of output ports that have not yet transmitted their copy of a designated data frame. The control logic addresses locations within the random access storage area using frame pointers that identify where the received data frames are stored in an external memory. Each frame pointer includes at least two portions that are used by the control logic to address a specific row location and specific column location of a cell within the random access storage area where the copy number value of a designated data frame is stored. Depending on the specific implementation, the random access storage area can be configured to provide read access to all components of the multiport switch, while additionally providing write access to the control logic. The present arrangement advantageously minimizes the amount of time required to update copy number information for the multiport switch by storing the information in a random access storage area.
According to one embodiment of the present invention, the random access storage area is physically configured as a matrix containing 1,024 rows, and 8 columns that are 4-bits wide. In addition, each frame pointer is thirteen (13) bits long. The control logic uses the ten (10) most significant bits of the frame pointer to address the specific row location of cells within the random access storage area, and the three (3) least significant bits to address specific column location of cells within the random access storage area.
In accordance with another aspect of the present invention, a method of randomly accessing copy information for received data frames from a random access storage area of a multiport switch comprises the steps: retrieving a frame pointer that identifies the location of a designated data within an external memory area; decoding the retrieved pointer to indicate a specific row and specific column of the decoded cell of the random access storage area where a copy number value for the designated data frame is stored; and reading the copy number value stored in the decoded cell of the random access storage area. The present arrangement provides an efficient method for any and all components of the multiport switch to determine copy information regarding multicast data frames.
Additional advantages and novel features of the present invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
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1. Field of Invention
The present invention relates generally to power supplies and more particularly to air ventilation cooling systems for a portable power device.
2. Description of Related Art
Portable power devices, such as power converters and fuel cells, can become very hot when used for an extended period of time. In a portable power device, which is typically rectangular, heat is transferred through all side surfaces of the device except for the largest bottom surface. The bottom surface in a conventional portable power device is an ineffective surface for the purpose of heat dissipation.
One conventional solution provides a portable power device with an external enclosure in which a number of open air vents exist on the top and bottom covers. Another conventional solution provides an external enclosure that supports an inner thermally conductive enclosure with a gap between them to facilitate ventilation. These ventilation constructions, however, possess several disadvantages. First, liquid may enter into a sealed enclosure through openings on the top of the enclosure. Second, the temperature rise inside of an enclosure needs to create sufficient pressure difference to generate air movement. Third, spaces that are utilized for air passages may reduce the overall package usable volume as well as increase the thermal resistance to ambient.
Accordingly, there is a need for an air ventilation cooling structure for a portable power device that produces a more efficient heat dissipation effect.
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As a main part of an LCD device, an LCD module includes an LCD panel and a backlight module. At present, most LCD panels of the LCD panels in production are supported by the buffer rubber strips on rubber frames. As shown in FIG. 1, a manufacturer uses raw material rubber and an additive to conduct mixing, presses the mixed rubber into a strip, pastes a double sided adhesive tape on the rubber strip surface, attaches a buffer rubber strip 1 with double sided adhesive tape to a rubber frame 2, and assemblies LC (liquid crystal) glass and other components after assembling the rubber frame 2 on the backlight module. Furthermore, the accuracy that the buffer rubber strip 1 generally pasted by manual work is low and the buffer rubber strip 1 is often not correctly pasted, causing the product yield to be reduced.
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{
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1. Field of the Invention
The present invention relates to the field of fabrication of semiconductor devices, and, more particularly, to packaging circuit chips by attaching a carrier substrate to a chip using an underfill material.
2. Description of the Related Art
As semiconductor manufacturers continue to scale down on-chip features, the need to contact those reduced size features becomes a more significant constraint. The number of scaled features provided for increased functionality, i.e., in general, the number of inputs and outputs (I/O count) of an integrated circuit, may be increased while maintaining the chip size or, on the other hand, the chip size may be reduced while maintaining the functionality (and the I/O count) of the integrated circuit. In both cases, however, the density of inputs and outputs (I/Os) is increased. For a conventional peripheral bond pad arrangement, the resulting bond pad pitch, i.e., the distance between the center of two adjacent bond pads, is accordingly reduced.
Semiconductor devices including integrated circuitry are typically formed on appropriate substrates or wafers, such as silicon wafers, silicon-on-insulator (SOI) wafers, glass wafers and the like, wherein usually a large number of individual semiconductor devices, such as CPUs, memory chips, ASICs (application specific ICs) and the like, are formed simultaneously on the wafer. Depending on the complexity of the semiconductor devices under consideration, up to 500 or more interrelated processes may be required to complete the semiconductor devices on wafer level. Due to economical constraints, feature sizes of individual circuit elements, such as transistors, are continuously being scaled, thereby increasing package density per unit area of the wafer, while, at the same time, wafers of increased surface area are employed to enhance production yield, since most of the highly complex manufacturing processes may be performed on wafer basis rather than die basis. Typically, as package densities of the individual circuit elements increase, the complexity of the individual semiconductor devices may also increase, thereby frequently requiring an increased number of input/output terminals for contacting the periphery.
Packaging of the individual semiconductor devices after dicing the wafer also plays an important role in view of cost efficiency of the overall manufacturing process, as well as with respect to device performance and reliability. A packaging technique has recently become a standard procedure, at least for highly complex semiconductor devices, in which each semiconductor device is provided with a specifically designed contact layer, also often referred to as a “bump layer.” The bump layer typically includes a plurality of contact pads, with adhesive bumps or solder bumps which may provide thermal or electrical contact to underlying circuit elements or which may be provided in view of mechanical stability of the semiconductor device in the package. The semiconductor device may then be directly attached to an appropriate carrier substrate or printed wiring board, which has a contact pad array that matches the layout of the bump layer of the semiconductor device, wherein the bonding of the carrier substrate and the semiconductor device may be accomplished by reflowing the bump material or adhesive, thereby substantially simultaneously contacting all of the solder bumps with the respective contact pads on the carrier substrate.
Thus, contrary to traditional wire bonding techniques, extremely short electrical connections between the semiconductor device and the carrier substrate are accomplished in a highly efficient manner, thereby providing low ohmic connections with low parasitic inductance, wherein additionally, the entire semiconductor surface is substantially available for providing contact areas, contrary to the traditional wire bonding techniques that are substantially restricted to the chip perimeter.
Despite the many advantages of this packaging technique compared to, for instance, conventional wire bonding techniques, problems may arise from the fact that the characteristics of the substrate material may significantly influence the overall performance of the packaged semiconductor device. In particular, the coefficient of thermal expansion (CTE), the conductor resistivity, the dielectric constant, the dielectric loss tangent and the thermal conductivity of the carrier substrate material may have to be taken into consideration when selecting appropriate carrier materials to appropriately balance material costs against device performance and reliability. For example, a mismatch in the coefficient of thermal expansion between the package or the printed wiring board and the die has a significant influence on product reliability. The mismatch in thermal expansion may generate shear stresses, which, in turn, may cause failure in the electrical connections.
FIG. 1 schematically shows a cross-sectional view of a semiconductor device 100 including a semiconductor chip 110 that is directly connected to a carrier substrate 120. The semiconductor chip 110 may comprise a plurality of contact pads 111 arranged in a corresponding pattern which matches a corresponding pattern of contact pads 121 formed on the carrier substrate 120. Corresponding contact pads 111 and 121 may be connected by a solder material 130 or a conductive adhesive material, thereby providing an electrical connection, also referred to as 130, between the semiconductor chip 110 and the carrier substrate 120. Moreover, in many semiconductor devices, including a semiconductor chip and a carrier substrate that are directly attached to each other, a fill material may be provided between the two components to enhance thermal and mechanical characteristics, as well as the integrity with respect to environmental influences.
In the example shown, a fill material, also referred to as underfill material 140, is provided between the semiconductor chip 110 and the carrier substrate 120. The underfill material 140 may comprise particles 141, which may substantially determine the thermal and mechanical characteristics of the underfill material 140, such as the thermal conductivity and the coefficient of thermal expansion. The underfill material 140 is provided in many applications to compensate for the differences in coefficients of thermal expansion between the semiconductor chip 110 and the carrier substrate 120. For example, the semiconductor chip 110 may be substantially comprised of a semiconductive material, such as silicon, and may have a coefficient of thermal expansion of approximately three parts per million per degree Celsius (ppm/C.), while the carrier substrate 120 may have a different coefficient, such as a difference of a few ppm/C. for an alumina ceramic substrate and may be as high as approximately 17-22 ppm/C. for an organic substrate comprised of FR4, which is frequently used due to its high cost efficiency and superior high frequency characteristics. Consequently, by coupling substantially the entire area of the semiconductor chip 110 to the substrate carrier 120, the effective thermal mechanical stress created during the operation of the semiconductor device 110 creates a “gradient” of the effective composite coefficient of thermal expansion between the semiconductor chip 110 and the carrier substrate 120, thereby increasing the reliability of the device 110, because the probability of a premature failure in one of the electrical connections 130 is significantly reduced.
A typical process flow for forming the device 110 may be carried out as follows. After the completion of the semiconductor chip 110 by forming circuit elements (not shown) and respective metallization layers (not shown), which are electrically connected to at least some of the contact pads 111, including solder bumps or solder balls, the corresponding chips 110 are diced to provide the individual semiconductor chip 110. Thereafter, the carrier substrate 120 and the semiconductor chip 110 are aligned to each other, contacted and heat treated to reflow the solder bumps or solder balls or any other bumps comprised of conductive adhesive to form the electric connections 130. Next, a precursor of the underfill material 140, for instance, in the form of a viscous epoxy containing the particles 141, which may be provided in the form of silica particles, is applied by dispensing a liquid precursor material along a single edge or along two adjacent edges of the gap between the semiconductor chip 110 and the carrier substrate 120. Surface tension then draws the liquid precursor material under the chip and through the array of electrical connections 130. Since the liquid flow is substantially governed by capillary flow, the entire process of distributing the liquid precursor material between the semiconductor chip 110 and the carrier substrate 120 may take several minutes, wherein the fluid flow is affected by the gap width, the pattern configuration of the electrical connections 130, the substrate temperature and gradients, the viscosity of the liquid precursor material, flux contamination, the dispense pattern used for applying the liquid precursor material, and the like. Thereafter, the device 110 may be heat-treated, for instance, in an oven, at temperatures from approximately 130-175° C. to cure the liquid precursor material and to form the underfill material 140. During the process of filling in the liquid precursor material, as well as during the heat treatment for curing the liquid, the particles 141 may move and accumulate at an interface 122 between the material 140 and the underlying carrier substrate 120. Since the particles 141 may significantly affect the thermal and mechanical characteristics of the underfill material 140, for instance, the coefficient of thermal expansion, undue thermomechanical stress may be created during the operation of the device 110, since the coefficient of thermal expansion of the underfill material 140 may be low at the interface 122 due to the accumulated particles 141, whereas the coefficient of thermal expansion of the underlying carrier substrate 120 may be significantly higher, thereby deteriorating the capability of thermal and mechanical stress “redistribution” of the underfill material 140.
In view of the situation described above, a need exists for an enhanced technique that enables the formation of packaged semiconductor devices having an underfill material, wherein one or more of the problems identified above, or at least the effects thereof, may be avoided or reduced.
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Electronic devices have been reduced in size and weight in recent years, and there has been an increasing market demand for switching power supplies with increased efficiency and reduced size and weight. For example, in the market for flat screen television sets or the like, in which output current ripple characteristics are relatively moderate, a current resonant half bridge converter in which a sinusoidal resonant current is made to flow in a transformer to cause the transformer to operate while utilizing an LC resonance phenomenon is being put to practical use while taking advantage of its feature of being highly efficient.
For example, Japanese Unexamined Patent Application Publication No. 9-308243 discloses an LC series resonant DC-DC converter. FIG. 13 is a basic circuit diagram of a switching power supply device described in Japanese Unexamined Patent Application Publication No. 9-308243. This switching power supply device is a current resonant half bridge DC-DC converter, in which an LC resonant circuit that is formed by an inductor Lr and a capacitor Cr and two switching elements Q1 and Q2 are connected to a primary winding np of a transformer T. A rectifying smoothing circuit that is formed by diodes D3 and D4 and a capacitor Co is formed on secondary windings ns1 and ns2 of the transformer T.
With the configuration described above, the switching elements Q1 and Q2 are complementarily turned on and off with a dead time, and the waveform of a current that flows through the transformer T thus has a sinusoidal resonant waveform. In addition, electric power is transmitted from the primary side to the secondary side during both on periods and off periods of the two switching elements Q1 and Q2.
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Burst Mode optical receivers are typically located in the Optical Line Termination (OLT), or service node, or Local exchange, of an optical access network. Such an optical access network typically consists of a number of Optical Network Units (ONUs) located at a subscriber's premises and connected using a tree-like fibre plant to the OLT. The prior art has implemented burst mode receivers in which amplifiers are used whose output voltage is clamped at a fixed value once the input signal strength (voltage or current) exceeds a given value (so-called limiting amplifiers). This behaviour however is highly non-linear, which prevents the use of electronic equalization techniques to mitigate distortion in the input signal and certain classes of advanced modulation formats, which also require a linear receiver.
As all of the ONUs share the same fibre on the same wavelength, time division multiple access (TDMA) is used to transmit data upstream (from the ONUs towards the OLT). In TDMA, each ONU is assigned specific time slots during which it may send a burst of data upstream. As the bursts from different ONUs have undergone different amounts of attenuation while travelling towards the OLT, the signal at the OLT consists of a rapid sequence of bursts whose amplitude can differ greatly from burst to burst. To recover the transmitted data from this signal, a burst mode receiver is needed which quickly adapts its settings (gain and decision threshold) from one burst to the next. Similarly, in optical burst switched networks bursts may arrive at the receiver that have travelled along different paths, and hence have undergone different amounts of attenuation or amplification.
Today, there is significant Industry interest in increasing the bit rate over optical access networks towards 10 Gb/s and beyond. Burst-mode receivers operating at 10 Gb/s have been demonstrated, but still exhibit several problems:
1) Operation at sufficiently high bitrates implies that the properties of the optical fibre, such as chromatic dispersion, may severely distort the transmitted signal. This distortion can be compensated using techniques such as electronic dispersion compensation, but require that the optical receiver is linear with respect to the detected photocurrent. In today's, state-of-the-art, burst-mode receivers use limiting amplifiers which are highly non-linear and prevent the use of e.g. electronic dispersion compensation.
2) Burst-mode receivers today employ gain switching front-ends. This is needed to ensure that the burst-mode receiver does not distort the signal for strong input signals. For these strong input signals, the gain of the burst-mode receiver front-end is switched to a lower value. These gain switching front-ends enable fast (typically in a few nanoseconds) adjustment of the gain during the preamble at the start of each burst. However these gain switching architectures show severe problems for input signal strengths close to the switching points, for example, as late switching may occur resulting in significant numbers of errors or the loss of entire bursts.
3) A burst-mode receiver typically needs a control signal that indicates the start of a new burst. As it is not known a priori when a new burst will arrive, the burst-mode receiver detects the arrival of a new burst itself. This is done by detecting the transition of the input from its zero level towards the level of the incoming burst. However, if detected from the first rising edge of the burst, the detected moment of arrival of the new burst may be highly inaccurate. Indeed this first rising edge may exhibit a high amount of jitter as the transmitter is still turning on (e.g. in case of a directly modulated laser there may be a significant turn-on delay). This is problematic for any receiver circuitry that relies on an accurate detection of the start of a new burst.
A number of attempted solutions to these problems have been proposed in the prior art. For example, a first publication (S. Nishihara et. al., ‘A burst-mode 3R receiver for 10-Gbit/s PON systems with high sensitivity, wide dynamic range, and fast response’, IEEE Journal of Lightwave Technology, vol. 26, pp. 99-107, January 2008) describes the concept of a 10 Gb/s burst-mode receiver, that uses gain switching to enlarge its dynamic range. There are two main problems with the solution proposed in this paper:—
1) The burst-mode receiver disclosed in the paper uses gain-switching to reduce its gain from a high state to a low state for sufficiently strong input bursts. This is done by comparing the strength of the burst with a fixed reference. If the strength of the burst is greater than this reference, the gain of the burst-mode receiver is switched to its Low state. This gain-switching however has a serious problem, in that a burst with strength close to this reference, may cause gain switching to occur too late, for example during the data portion of the burst.
2) The burst-mode receiver disclosed in the paper uses a limiting amplifier to amplify the signals to a level that is compatible with a given logical format (such as e.g. current-mode logic). Such Limiting action is highly non-linear, thus preventing the use of electronic dispersion compensation to mitigate transmission impairments due to e.g. chromatic dispersion.
A second publication (T. De Ridder, P. Ossieur et. al., ‘A 2.7V 9.8-Gb/s burst-mode transimpedance amplifier with fast automatic threshold locking and coarse threshold extraction’, pp. 220-221, in Technical Digest International Solid-State Circuits Conference (ISSCC), February 2008) describes the concept of a 10 Gb/s burst-mode receiver front-end that quickly switches gain again by comparing the strength of the incoming burst to a reference. In variance from the first publication, an additional gain locking mechanism has been added in an effort to solve the problem of late gain switching. The described gain locking mechanism has two disadvantages however. First, it relies upon the use of a flip-flop. If this flip-flop exhibits metastability, again late gain switching may occur. Secondly, the described gain locking mechanism only works for a transimpedance amplifier front-end whose gain can be switched to a limited number of discrete gain settings. This excludes implementation of the described mechanism, whereby its gain should scale inversely with the input signal strength.
European Patent Publication number EP1357665 describes an automatic gain control method for a burst-mode optical receiver. U.S. Pat. No. 7,539,424 describes an automatic gain control method for a burst-mode optical receiver. However these patents do not solve the problems of automatic gain control accuracy, non-linearity of the burst mode receiver and do not implement any method to extract timing signals from the data bursts. European Patent Publication number EP1032145, assigned to NEC corporation, discloses an automatic gain control method for a burst-mode optical receiver. A means is disclosed to monitor the strength of the incoming burst, and based upon this strength to adjust the gain of a transimpedance amplifier so that the voltage signal outputted from said transimpedance amplifier is not saturated. However a problem with this approach is that it does not provide a method to ensure that the swing of the transimpedance amplifier equals a given reference, and that avoiding saturation in the transimpedance amplifier is not sufficient to ensure linearity. This is an important feature that is required for a linear burst-mode receiver, as the reference (and hence output swing) can then be optimized to ensure the linearity of the burst-mode receiver; for example by minimising total harmonic distortion.
An additional problem with today's state-of-the-art conventional linear optical receivers is that they rely on slow feedback automatic gain control loops with settling times exceeding hundreds of microseconds. Such long settling times are clearly not suitable for optical access networks or optical burst switched networks where the receivers need to respond to a new incoming burst during a few nanoseconds at the start (commonly known as the preamble) of each burst.
Further, referring to today's state-of-the-art, European Patent Publication number EP1935091 describes a method to derive a signal from a new incoming burst that indicates the start of this new burst. However, as the derived signal uses the very first rising edge of this new incoming burst, the signal that indicates the start of this burst is potentially inaccurate. Indeed at the start of the burst, the transmitter may not be fully switched on which results in a high amount of jitter at the start of the burst. US Patent Publication number US2009/0142074/A1 describes a method to detect the start of an incoming burst, and subsequently delays this signal. The detection of the start of the burst is performed using a relatively low-speed determinator. This time has to be added to the settling time of the first amplifier (2), which will result in unacceptable delays and jitter in detecting the start of the burst.
It is clear from the state of the art that there is a need to provide a solution to the problems associated with utilising gain switching and limiting amplifiers in burst mode optical receivers. It is further clear from the state of the art that there is a need to provide a solution to the problem of generating a signal that precisely indicates the start of a new incoming burst.
An object of the present invention is to provide a linear burst mode receiver to overcome the above mentioned problems.
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The present invention relates to methods and systems for receiving direct-sequence code division multiple access signals, in general and to methods and systems for adaptively receiving such signals, in particular.
In recent years, direct-sequence (DS) code division multiple access (CDMA) spread spectrum communication systems and methods experience growing attention worldwide. The IS-95 cellular communication standard is one example for application of DS-CDMA communications, which are described in TIA/EIA/IS-95-A, xe2x80x9cMobile Station-Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System,xe2x80x9d Feb. 27, 1996.
Other implementations of CDMA can be found in third generation cellular systems, wireless multimedia systems, personal satellite mobile systems, and more. The basic principle of direct sequence code division multiple access communications, is that each user is assigned with a distinct spreading code, which is often referred to as a pseudo noise (PN) sequence. The spreading code bits (also called chips), are used to modulate the user data. The number of chips used to modulate one data symbol is known as the spreading factor (processing gain) of the system, and it is related to the spreading in bandwidth between the (unmodulated) user data and the CDMA signal.
In its simplest form, the base-band equivalent of the transmitted CDMA signal is, T [ n ] = ∑ i = 1 K xe2x80x83 a i [ ⌊ n / SF ⌋ ] · PN i [ n ] Equation 1
where SF is the spreading factor, └n/SF┘ denotes the integer part of n/SF, ai[└n/SF┘] and PNi[n] are the data symbol and spreading code of the i-th user, respectively, and K is the number of active users. Note that by the definition of └n/SF┘, ai[└n/SF┘] is fixed for SF consecutive chips, in accordance with the definition above that each data symbol is modulated by SF chips.
If TS and TC denote the symbol and chip intervals in seconds, respectively, then TS=SFxc2x7TC. The chip rate is defined as 1/TC, and the symbol rate is defined as 1/TS. Accordingly, the chip rate is SF times greater than the symbol rate.
In a DS-CDMA system, all of the users are continuously transmitting over the same frequency band. Thus, at the receiver end, each user is distinguishable from all other users, only through his spreading code. The spreading codes are therefore designed to minimize cross-talk effects between the different users. Conventional systems often use orthogonal spreading sequences.
In practice, however, channel distortions and asynchronicity modify the transmitted signals, and as a consequence, cross-talks between the users exist even when orthogonal spreading codes are utilized by the transmitter.
A plurality of receiver structures are known in the art for DS-CDMA signals, including single-user (SU) and multi-user (MU) receivers, interference cancellation (IC) receivers, and more.
A conventional single-user receiver correlates the received signal with the spreading code of the desired user (user no. 1), as follows y 1 [ m ] = 1 2 · SF ∑ n = 1 SF xe2x80x83 R [ m · SF + n ] · PN 1 [ m · SF + n ] * Equation 2
where R[n] denotes the received signal after down conversion and sampling and xe2x80x9c*xe2x80x9d denotes the complex conjugation. For simplicity we assume QPSK signaling in Equation 2. A simplistic example is provided, by setting K=2 (i.e. a system which includes two users) and discarding channel degradation (i.e. R[n]=T[n]). Hence, the following expression is obtained by substituting Equation 1 into Equation 2,
y1[m]=a1[m]+CrossCorr1,2[m]xc2x7a2[m]xe2x80x83xe2x80x83Equation 3
where CrossCorr i , j [ m ] = xe2x80x83 1 2 · SF · ∑ l = 1 SF xe2x80x83 PN i [ m · SF + l ] * · xe2x80x83 PN j [ m · SF + l ] Equation 4
The term CrossCorr1,2[m]xc2x7a2[m] in Equation 3 denotes the interference caused to user 1 by user 2. This, simple example reveals a well known weakness of the SU receiver, namely, its performance are governed by the noise level induced by the cross-talk from all other channel users (see for example, A. J. Viterbi, xe2x80x9cCDMA Principals of Spread Spectrum Communicationxe2x80x9d, Addison-Wesley Publishing Company, 1995). A more advanced SU receiver includes some means of interference cancellation, which are aimed at reducing these cross-talks, and improving the receiver""s performance. For example, see the following references:
Yoshida, xe2x80x9cCDMA-AIC highly spectrum Efficient CDMA cellular system based on adaptive interference cancellationxe2x80x9d, IEICE transactions on communication v e79-b n 3 March 1996, p. 353-360,
A. Yoon, xe2x80x9cA Spread spectrum multi-access system with co-channel interference cancellationxe2x80x9d, IEEE journal of selected areas in communications, September 1993,
U.S. Pat. No. 5,105,435 to Stilwell, entitled xe2x80x9cMethod And Apparatus For Canceling Spread Spectrum Noisexe2x80x9d, and
Y. Li, xe2x80x9cSerial interference cancellation method for CDMAxe2x80x9d electronics letters, September 1994.
Multi-user (MU) receivers, jointly demodulate several or all of the received signals associated with the currently active users. The structure of MU receivers is much more complicated than that of SU receivers, but their performance are significantly better since these receivers are less sensitive to cross-talks between the users. (see for example, S. Verdu xe2x80x9cMulti-user Detectionxe2x80x9d Cambridge University Press, 1998, and the references therein).
In practice, the communication link, between the transmitter and the receiver, is often time varying. Therefore, the CDMA receiver, which can be an SU, MU or IC receiver, is required to be adaptive, thereby being capable of tracking the time variations of the communication channel. See for example U.S. Pat. No. 5,572,552 to Dent et. al, entitled xe2x80x9cMethod and system for demodulation of down-link CDMA signalsxe2x80x9d. See also, G. Woodward and B. S. Vucetic, xe2x80x9cAdaptive Detection for DS-CDMA,xe2x80x9d Proceedings of the IEEE, Vol 86, No. 7, July 1998.
Adaptive algorithms, like those available for DS-CDMA applications, are designed to minimize the expectation of a predetermined cost function (preferably a convex one) with respect to the receiver""s parameters. For example, S. Verdu, xe2x80x9cAdaptive Multi-User Detectionxe2x80x9d, Proc. IEEE Int. Symp. On Spread Spectrum Theory and Applications, (Oulu Finland, July 1994), is directed to an adaptive least-mean-squares (LMS) MU algorithm which minimizes the mean squared error between the transmitted and reconstructed symbols, i.e.
MSEixe2x89xa1E{(xc3xa2i[n]xe2x88x92ai[n])2}xe2x80x83xe2x80x83Equation 5
where xc3xa2i[n] are the MU receiver output samples at the i-th terminal, and ai[n] are the transmitted symbols of the i-th user. The cost function in Equation 5 requires training sequences. In other words, the receiver must know the exact value of at least some of the transmitted symbols (the ai[n]""s) in order to minimize this cost.
Other methods, which are known in the art, do not require training data. S. Verdu, xe2x80x9cAdaptive Multi-User Detectionxe2x80x9d, Proc. IEEE Int. Symp. On Spread Spectrum Theory Applications, (Oulu Finland, July 1994), is also directed to such a method. This method encompasses a decision directed approach, which replaces the unknown ai[n]""s by estimation values thereof.
In the binary case, for example, ai[n] accepts only two levels: xe2x80x9c1xe2x80x9d and xe2x80x9cxe2x88x921xe2x80x9d. Thus, an estimate of which can be obtained from the sign of the corresponding receiver outputs. In this case, the cost in Equation 5 reduces to
E{(xc3xa2i[n]xe2x88x92Sign{xc3xa2i[n]})2}xe2x80x83xe2x80x83Equation 6
Another method known in the art, is described in M. Honig, U Madhows and S. Verdu, xe2x80x9cBlind Adaptive Multi-User Detection, IEEE Trans. on Information Theory, July 1995. This reference is directed to a method, which is based on the fact that under certain conditions, the cost in Equation 5 is equivalent to the following cost
OEixe2x89xa1E{xc3xa2i[n]2}xe2x80x83xe2x80x83Equation 7
in the sense that the minimization of these two different cost functions yields the same receiver.
Since the criterion in Equation 7 does not involve the ai[n]""s, then there is no need for a training sequence. The cost in Equation 7 is known as the minimum output energy (MOE) cost, since the receiver is updated so that the energy at its outputs is minimized. The resulting MOE adaptive algorithms are referred to as xe2x80x9cblindxe2x80x9d multi-user algorithms, since they operate xe2x80x9cblindlyxe2x80x9d without knowing the transmitted bits.
It is often convenient to express the cost function in terms of sample averaging instead of stochastic expectations. For example, the MSE cost can be defined, at time instant as follows: MSE i ( n ) ≡ ∑ k = 1 n xe2x80x83 ( a ^ i [ k ] - a [ k ] ) 2 λ ( n - k ) Equation 8
where 0 less than xcexxe2x89xa61 is an exponential forgetting factor giving more weight to recent samples than to previous ones, thus allowing tracking capabilities.
The following references are directed to an adaptive recursive least squares (RLS) type algorithm for the minimization of this criterion:
H. V. Poor and X. Wang, xe2x80x9cCode aided interference suppression for DS/CDMA communications: Interference suppression capabilityxe2x80x9d, IEEE Tran. On Comm, September 1997.
H. V. Poor and X Wang, xe2x80x9cCode aided interference suppression for DS/CDMA communications: Parallel Blind Adaptive Implementationsxe2x80x9d, IEEE Tran. On Comm, September 1997.
Similar algorithms can be derived for the cost function in Equation 7, by re-writing it in the following form OE i ( n ) ≡ ∑ k = 1 n xe2x80x83 a ^ i [ k ] 2 λ ( n - k ) Equation 9
Reference is now made to FIG. 1A, which is a schematic illustration of a system for adaptive detection of a DS-CDMA signal, generally referenced 80, which is known in the art. System 80 is basically a processing unit, which implements any of the above methods. The received samples y[1],y[2], . . . , y[m], are provided as input to the processor. The processor, implementing any of the above methods, calculates the adaptation parameters {circumflex over (xcex8)}[m] for minimizing the cost function which characterizes the receiver 80.
It would be obvious to someone skilled in the art, that the received samples y[1],y[2], . . . , y[m] may also be vector valued, e.g. the outputs from a bank of SU receivers each tuned to a different user.
Reference is now made to FIG. 1B which is a schematic illustration of a bank of rake receivers, known in the art. It is noted that a rake receiver is a single user (SU) receiver.
Section 50 includes an array of rake receivers 52 and a processor 56, connected thereto. The array 56 includes a plurality of rake receivers 54A, 54B, 54C and 54M, which are set to receive the signals of as much as M users.
The input samples to the processor (56) are vector valued in this case, so that each sample Y[i] is given by Y [ i ] = [ Y [ i ] 1 Y [ i ] 2 ⋮ Y [ i ] M ]
where Y[i]k is the i-th sample of the k-th rake receiver.
The embodiment in FIG. 1B is often utilized in adaptive MU receivers where the processor 56 can detect the transmitted information of user 1 by processing the samples provider by rake receiver 54A, while taking into consideration the influence of the respective samples of the second user, as provided by the second rake receiver (54B), the respective samples of the third user, as provided by the third rake receiver (54C) and so forth.
Adaptive algorithms are often conveniently described in terms of their bandwidth. An adaptive algorithm is considered to have an overall response of a low-pass filter due to the inherent averaging operation that is either implicitly or explicitly dominant in any adaptive scheme. The bandwidth of this equivalent low-pass response is considerably lower than that of the data, and it governs the tracking and noise rejection capabilities of the adaptive algorithm. A large bandwidth implies fast tracking but relatively high residual noise (i.e. large error variance of {circumflex over (xcex8)}[m]), whereas low bandwidth implies good noise rejection but poor tracking capabilities.
In many DS-CDMA systems, the spreading code is much longer than the symbol period (the down-link of IS-95 systems, for example). Adaptive algorithms, like the ones reported in the above references, whose bandwidth is lower than the symbol rate, are inappropriate for such systems. This is due to the fact that these algorithms are unable to track the fast varying interference between the users (whose bandwidth is proportional to the symbol rate since a new interference value is produced with each new data symbol). The reason for the fast varying nature of the interference lies in the fact that when the PN sequence spans more than one data symbol, different portions of which are utilized in Equation 4 with different data symbols. Thus, the cross-correlation accepts a different value with each new data symbol.
In some cases, this situation is unavoidable, (e.g. when random spreading codes are utilized). However, in most cases of practical interest, the spreading codes are non-random and finite.
It is an object of the present invention to provide a novel method for receiving a DS-CDMA signal, which overcomes the disadvantages of the prior art.
It is another object of the present invention to provide a novel DS-CDMA receiver, which overcomes the disadvantages of the prior art.
In accordance with the present invention there is provided a method for receiving DS-CDMA signal. The method is for implementing in a receiver receiving a signal, where the signal includes data which is at least modulated by one cyclic sequence. The method includes the steps of:
receiving a portion of the signal, where the portion is modulated by a predetermined section of the cyclic sequence,
receiving an additional portion of the signal, where the additional portion is modulated by the same predetermined section of the cyclic sequence,
jointly processing the portion and the additional portion, and
producing a set of receiver parameters, which minimize a predetermined cost function for the predetermined section of the cyclic sequence.
The method of the invention can also include the step of predetermining sections within the cyclic sequence. It is noted that these sections can include one or more elements of the cyclic sequence.
According to another aspect of the invention, the received signal is demodulated by the cyclic sequence, thereby extracting the data symbols which are contained therein. Then, the above operations are performed for the symbols, with respect to the predetermined sections of the cyclic sequence, where preferably, the length of these sections is in the order of a symbol.
Accordingly, the method of the present invention with respect to this aspect, includes the steps of:
demodulating the signal, by the cyclic sequence, thereby producing a plurality of received samples,
determining a plurality of sections, each the section having a length of at least one sample, each the section being demodulated by a predetermined portion of the cyclic sequence,
detecting portions of the demodulated signal, which are associated with each of the sections,
jointly processing the detected portions, which are associated by a selected one of the sections, and
producing a set of receiver parameters for each the sections, the receiver parameters minimizing a predetermined cost function for the selected section.
It is noted that the received signal can be a signal is a DS-CDMA signal or any other spread signal which is modulated by a cyclic sequence.
The demodulating and extracting of the data symbols can include rake demodulating the DS-CDMA signal, using a rake receiver.
In accordance with another aspect of the invention, there is thus provided a receiver for detecting a signal, where the signal includes data which is at least modulated by a cyclic sequence. The receiver includes a plurality of processing units, each the processing units being associated with a predetermined section of the cyclic sequence, and a distributing unit, connected to each the processing units.
The distributing unit receives the signal, detects portions of the signal, each the portions being associated with one of the predetermined sections. The distributing unit provides selected ones of the portions to a selected one of the processing units, wherein both the selected portions and the selected processing unit are associated with the same predetermined section. Each of the processing units processes the selected portions, thereby producing set of receiver parameters which minimize a predetermined cost function for that specific section.
In accordance with a further aspect of the invention there is thus provided a receiver for detecting a signal. The signal includes data which is at least modulated by a cyclic sequence. The receiver includes a despreading unit, for demodulating the signal by the cyclic sequence, thereby producing a demodulated signal, a plurality of processing units, each the processing units being associated with a predetermined section of the cyclic sequence, and a distributing unit, connected between the despreading unit and each of the processing units.
Accordingly, this receiver demodulates the received signal according to the cyclic sequence and operates on the demodulated symbols, with respect to their location, as they were modulated, within the cyclic sequence. It is noted that the despreading unit can includes a rake receiver.
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1. Technical Field
This invention relates to electrical connector assemblies, and more particularly to an electrical connector assembly for lockably securing a terminal member such that an external force applied to the terminal member will not cause the terminal member to become dislodged or otherwise disengaged from the connector assembly, thereby causing a break in electrical connection between the terminal member and an external terminal element.
2. Discussion
Electrical connector assemblies are used in a wide variety of applications, and particularly in automotive applications, where it is necessary to electrically interconnect a plurality of electrical cables to perform various functions. One drawback with many prior developed electrical connectors, however, is their inability to firmly secure a terminal member therein when the terminal member is subjected to a force, such as a pulling force, from an electrical conductor secured to the terminal member. In such instances, the movement of the terminal member within the connector may cause a temporary break in the electrical contact between the terminal member and another terminal blade inserted within the terminal member. More severe pulling forces on the terminal member may cause the member to be partially or completely dislodged from the connector body. In either event, even a momentary break in the electrical connection between the terminal member within the connector and a terminal blade engaged with the terminal member may result in spurious operation of an electrically driven device or an electrical circuit associated with the connector.
Prior developed connector assemblies have attempted to address the above described problems by incorporating an additional member into an electrical connector assembly which is engaged with the assembly so as to more positively lock the terminal member within the connector body of the connector assembly. These attempts have provided other drawbacks, however, in that the external members have projected into the openings in the terminal body into which the terminal members are inserted, thus making insertion of the terminal members during assembly more difficult.
Still another drawback of prior developed connector assemblies is the inability to consistently determine if the terminal member is fully seated within the connector assembly. Prior attempts to incorporate some form of stuffer member have been met with problems in that a terminal member which is not fully seated within a connector body will not allow the stuffer member to be coupled to the connector body as the stuffer will not be in proper alignment to interengage the terminal member. Thus, even one terminal member which is unseated to a small degree can impede coupling of the stuffer member, thus requiring all of the terminal members to be re-checked and the mis-positioned terminal member to be re-seated.
Accordingly, it is a principal object of the present invention to provide an electrical connector assembly which more securely holds a terminal member therewithin when the terminal member is subjected to external pulling or pushing forces by an electrical conductor electrically secured to the terminal member.
It is yet another object of the present invention to provide an electrical connector assembly having an external member which may be lockably engaged with a connector body of the electrical connector assembly to help maintain a terminal member firmly seated within the connector body.
It is still another object of the present invention to provide an electrical connector assembly having an independent terminal stuffing member which may be lockably engaged with a connector body of the assembly to firmly maintain a terminal member seated within the connector body in spite of external pushing or pulling forces exerted on the terminal member by a conductor secured thereto or an external terminal blade.
It is still another object of the present invention to provide a terminal stuffer for an electrical connector assembly which, when partially inserted into the connector assembly, does not interfere with insertion of a terminal member into a terminal receiving opening in a connector body of the assembly, and consequently does not increase the force required to physically insert the terminal member into the connector body during assembly.
It is yet another object of the present invention to provide an electrical connector assembly having an independent terminal stuffer member which may be lockably engaged to a connector body of the assembly such that the terminal stuffer member is not readily disengageable from the connector body once coupled to the connector body.
It is another object of the present invention to provide an electrical connector assembly having a terminal stuffer member which operates to cause one or more terminal members which are not completely seated within a connector body of the assembly to be properly seated within the connector body as the terminal stuffer member is urged into locking engagement with the connector body.
It is another object of the present invention to provide an electrical connector assembly having an external terminal stuffer member which may be constructed from widely available materials, such as plastic, to form a relatively low cost electrical connector assembly particularly well suited to automotive application.
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The present disclosure relates generally to imaging members, such as layered photoreceptor devices, and processes for making and using the same. The imaging members can be used in electrophotographic, electrostatographic, xerographic and like devices, including printers, copiers, scanners, facsimiles, and including digital, image-on-image, and like devices. More particularly, the embodiments pertain to an imaging member or a photoreceptor that incorporates specific materials, namely organic sulfonic acid, into the anticurl back coating (ACBC) layer.
Electrophotographic imaging members, e.g., photoreceptors, typically include a photoconductive layer formed on an electrically conductive substrate. The photoconductive layer is an insulator in the substantial absence of light so that electric charges are retained on its surface. Upon exposure to light, charge is generated by the photoactive pigment, and under applied field charge moves through the photoreceptor and the charge is dissipated.
In electrophotography, also known as xerography, electrophotographic imaging or electrostatographic imaging, the surface of an electrophotographic plate, drum, belt or the like (imaging member or photoreceptor) containing a photoconductive insulating layer on a conductive layer is first uniformly electrostatically charged. The imaging member is then exposed to a pattern of activating electromagnetic radiation, such as light. Charge generated by the photoactive pigment move under the force of the applied field. The movement of the charge through the photoreceptor selectively. dissipates the charge on the illuminated areas of the photoconductive insulating layer while leaving behind an electrostatic latent image. This electrostatic latent image may then be developed to form a visible image by depositing oppositely charged particles on the surface of the photoconductive insulating layer. The resulting visible image may then be transferred from the imaging member directly or indirectly (such as by a transfer or other member) to a print substrate, such as transparency or paper. The imaging process may be repeated many times with reusable imaging members.
An electrophotographic imaging member may be provided in a number of forms. For example, the imaging member may be a homogeneous layer of a single material such as vitreous selenium or it may be a composite layer containing a photoconductor and another material. In addition, the imaging member may be layered. These layers can be in any order, and sometimes can be combined in a single or mixed layer.
Typical multilayered photoreceptors have at least two layers, and may include a substrate, a conductive layer, an optional charge blocking layer, an optional adhesive layer, a photogenerating layer (sometimes referred to as a “charge generation layer,” “charge generating layer,” or “charge generator layer”), at least one charge transport layer, an optional overcoating layer and, in some belt embodiments, an anticurl backing layer. In the multilayer configuration, the active layers of the photoreceptor are the charge generation layer (CGL) and the charge transport layer (CTL). Enhancement of charge transport across these layers provides better photoreceptor performance.
As more advanced, higher speed electrophotographic copiers, duplicators and printers were developed, however, degradation of image quality was encountered during extended cycling. The complex, highly sophisticated duplicating and printing systems operating at very high speeds have placed stringent requirements, including narrow operating limits, on the imaging members.
In multilayered imaging members, the CTL is usually the last layer to be coated and is applied by solution coating then followed by drying the wet applied coating at elevated temperatures of about 120° C., and finally cooling it down to room ambient temperature of about 25° C. When a production web stock of several thousand feet of coated multilayered photoreceptor material is obtained after finishing application of the CTL coating through drying and cooling processes, exhibition of spontaneous upward curling of the multilayered photoreceptor is observed. This upward curling is a consequence of thermal contraction mismatch between the CTL and the substrate support. Since the CTL in a typical photoreceptor device has a coefficient of thermal contraction approximately 3.7 times greater than that of the flexible substrate support, the CTL does therefore have a larger dimensional shrinkage than that of the substrate support as the imaging member web stock cools down to ambient room temperature. The exhibition of imaging member curling after completion of CTL coating is due to the consequence of the heating/drying/cooling processing.
To offset the curling, an anticurl back coating is then applied to the backside of the flexible substrate support, opposite to the side having the charge transport layer, and render the imaging member web stock with desired flatness. Curling of a photoreceptor web is undesirable because it hinders fabrication of the web into cut sheets and subsequent welding into a belt. An anticurl back coating having a counter curling effect equal to and in the opposite direction to the applied layers is applied to the reverse side of the active imaging member to eliminate the overall curl of the coated device by offsetting the curl effect which is arisen from the mismatch of the thermal contraction coefficient between the substrate and the CTL, resulting in greater CTL dimensional shrinkage than that of the substrate.
Although the anticurl back coating is needed to counteract and balance the curl so as to allow the imaging member web to lay flat, nonetheless, common formulations used for anticurl back coatings have often been found to provide unsatisfying dynamic imaging member belt performance under a normal machine functioning condition; for example, exhibition of excessive anticurl back coating wear and its propensity to cause electrostatic charge buildup are the frequently seen problems that prematurely cut short the service life of the photoreceptor belt and require its frequent costly replacement in the field.
Moreover, high surface contact friction of the anticurl back coating against all these machine subsystems is further been found to cause the development of electrostatic charge buildup problem. In many machines, the electrostatic charge builds up due to high contact friction between the anticurl back coating and the backer bars is seen to significantly increase the frictional force to the point that it requires higher torque from the driving motor to pull the belt for effective cycling motion. In full color electrophotographic machines, using a 10-pitch photoreceptor belt, this electrostatic charge build-up can be extremely high due to large number of backer bars used in the machine.
In an effort to resolve the problems associated with the anticurl back coating, one known wear resistance anticurl back coating formulated for use in the printing apparatuses includes organic particles reinforcement such as the utilization of polytetrafluoroethylene (PTFE) dispersion in the anticurl back coating polymer binder. PTFE particles are commonly incorporated to reduce the friction between the anticurl back coating of the belt and the backer bars. The benefit of using this formulation is, however, outweighed by the instability of the PTFE particle dispersion in the anticurl back coating solution. PTFE, being two times heavier than the coating solution, forms an unstable dispersion in a polymer coating solution, commonly a bisphenol A polycarbonate polymer solution, and tends to settle with particles flocculate themselves into big agglomerates in the mix tanks if not continuously stirred. The difficulty of achieving good PTFE dispersion in the coating solution poses a problem, because it can result in an anticurl back coating with insufficient and variable or inhomogeneous PTFE dispersion along the length of the coated web, and thus, inadequate reduction of friction over the backer bars in the copiers or printers. This causes significant complications in the larger copiers or printers, which often include so many backer bars that the high friction increases the torque needed to drive the belt. Consequently, two driving rollers are included and synchronized to prevent any registration error to occur. The additional components result in high costs for producing and using these larger printing apparatuses. Thus, if the friction could be reduced, the apparatus design in these larger printing apparatuses could be simplified with less components, resulting in significant cost savings.
Some anticurl back coating formulations are disclosed in U.S. Pat. Nos. 5,069,993, 5,021,309, 5,919,590, 4,654,284 and 6,528,226. However, while these formulations serve their intended purposes, further improvement on those formulations are desirable and needed. More particularly, there is a need, which is addressed herein, for a way to create,an anticurl back coating formulation that has intrinsic properties to minimize or eliminate charge accumulation in photoreceptors without sacrificing the other electrical properties.
The term “electrostatographic” is generally used interchangeably with the term “electrophotographic.” In addition, the terms “charge blocking layer” and “blocking layer” are generally used interchangeably with the phrase “undercoat layer.”
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1. Field of the Invention
The present invention relates to the fastening of a row of stirrup-links on the end of a conveyor-belt or the like.
More specifically, the invention is concerned with the attachment of stirrup-links consisting of U-shaped coupling members adapted to be mounted astride each end of a conveyor-belt and secured by means of wire staples having the shape of an inverted U. The fastening operation is performed by inserting the staples through holes provided in the two arms of these coupling members or so-called stirrup-links and then clinching the pointed ends of the staples which project from said stirrup-links.
2. Description of the Prior Art
In order to facilitate their insertion, the above-mentioned coupling members initially have a V-shape, one arm of each coupling member being divergent or directed outwards from its normal position. Under these conditions, when the end of a conveyor-belt or the like has been placed between the coupling members of the row to be fixed in position, it is first necessary to bend-back the arm which had initially been opened-out before proceeding to insert the fastening staples and clinching the ends of the staples.
A certain number of devices designed to carry out these different operations are already in existence at the present time. A typical device has two jaws which are capable of moving in opposite directions or else a driving punch and an anvil which are also mounted so as to be capable of moving in opposite directions. These elements are actuated by a relatively complex drive mechanism which is capable of successively performing the different movements required for carrying out the prescribed operations, namely those which consist in closing the opened-out arms of the coupling members, then inserting the fastening staples and finally clinching their free pointed ends. By reason of the very complexity of their drive mechanism, these devices in fact constitute heavy and cumbersome machines which cannot readily be used at the bottom of driftways or mine galleries. Furthermore, the relative fragility of these devices is also a serious obstacle to their use in mine galleries or on public works and civil engineering construction sites.
Among the different types of fasteners which are in current use, the device described in French patent No. 2,327,451 is worthy of mention. This apparatus comprises an operating head provided with inserting jaws actuated by a lever mechanism. In addition, bending tools are provided for bending-back the free ends of the fastening staples, these tools being displaced transversely with respect to the direction of insertion. However, the operating mechanism provided in this apparatus is particularly complex, thus giving rise to the disadvantages mentioned earlier.
In an apparatus described in French Pat. No. 2,507,728, provision is made for a movable cover which has the same length as the row of coupling members to be fixed in position and which is intended to be applied against the opened-out arms of these latter in order to ensure simultaneous closure of all the coupling members. This cover has a series of openings for receiving the heads of the fastening staples which are mounted in a standby position on the arms of the coupling members. These openings are subsequently intended to receive a punch for inserting the staples one after the other in succession. During this operation, the pointed staple ends are subjected to an initial clinching operation after passing through the coupling members, this being achieved by means of sloping-bottom grooves formed in a stationary anvil located beneath the assembly. However, it is then necessary to place the coupling members on another anvil having a smooth surface in order to permit completion of the operation which consists in clinching the staple ends. This has the effect of complicating the operations to be performed.
For the reasons given in the foregoing, the aim of the present invention is to provide a belt-fastening apparatus so designed as to have an operating mechanism which is as simple as possible while being at the same time very easy to use. Moreover, the design concept of this apparatus is such that this latter can be readily transported and used at the bottom of a mine gallery or at any other location.
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Sigma-delta analog-to-digital modulators, which can be used in a sigma-delta analog-to-digital converter (ADC) or a sigma-delta digital-to-analog converter (DAC), can provide a degree of shaping (filtering) of quantization noise that can be present. The higher the order of the sigma-delta modulator, the further the quantization noise is pushed into the frequency band, away from the signal being converted and the quantization noise. As such, sigma-delta ADCs and DACs (and their attendant modulators) have become popular in high frequency and high precision applications.
However, sigma-delta modulators do not offer noise shaping for noise that is due to a mismatch between the unity elements used in a DAC (referred to as a feedback DAC) that is a part of a feedback loop in the sigma-delta modulator and a quantizer. The mismatch can therefore be a problem in the sigma-delta modulator if it is of significant magnitude. The mismatch can result in an overall reduction in the signal-to-noise ratio (SNR) of the sigma-delta modulator.
One solution that can be used to reduce the mismatch that is present in the feedback DAC is to use a feedback DAC with high linearity. Ideally, the feedback DAC should have a linearity corresponding to the final resolution of the quantizer. A useful technique used to improve the DAC linearity is commonly referred to as dynamic element matching (DEM). Its use can reduce the mismatch in the sigma-delta modulator.
One disadvantage of the prior art is that if the feedback DAC has high resolution, then it can potentially be difficult to achieve an effective DEM. A high resolution feedback DAC may require a large number of elements, and too many elements to average can lead to tones in the signal band for signals with low input levels.
A second disadvantage of the prior art is that even if the mismatch can be transformed into noise, it can remain unshaped and become a component in the signal band, thus having an impact on the SNR of the sigma-delta modulator.
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For example, cryptographic encryption methods are known in which a first entity begins by encrypting a message by means of a public key. Only a second entity, that holds the private key associated with this public key, can then decrypt the message. Among known methods used for this kind of cryptographic task may be cited those based on the RSA (Rivest, Shamir, Adleman) algorithm or on the so-called discrete logarithm problem, involving elliptic curves.
The strength of such algorithms is based on the length of the secret key employed. Currently, for an RSA algorithm, it is usual to use secret keys of up to 2048 bits. This implies that these algorithms are rather slow to apply in practice. Moreover, the complexity curve of such algorithms as a function of the secret key is sub-exponential, which may turn out to be limiting in the future, and allow attackers to break such algorithms with advances in technology and computation speeds.
Finally, constrained environments such as RFID technology for example, offer only a limited implementation area and have energy constraints limiting their storage and execution capability. It is common to have microchips that have a thousand logic gates. However, if only in order to store an RSA number, it is necessary for there to be several tens of thousands of logic gates.
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The present subject matter relates generally to synthetic apertures for visible imaging. More specifically, the present invention relates to synthetic apertures for visible imaging as a promising approach to achieve sub-diffraction resolution in long distance imaging.
Imaging objects from large standoff distances is a requirement in many computer vision and imaging applications such as surveillance and remote sensing. In these scenarios, the imaging device is sufficiently far away from the object that imaging resolution is fundamentally limited not by magnification, but rather by the diffraction of light at the limiting aperture of the imaging system: using a lens with a larger aperture will lead to increased spatial resolution. Physically increasing the aperture of the lens, by building a larger lens, results in expensive, heavy, and bulky optics and mechanics. A number of techniques have been proposed to improve spatial resolution for various imaging systems, including refractive telescopes (1-6), holography (7-11) and incoherent super-resolution (12-16).
The resolution of an imaging system is proportional to both the lens aperture size and the wavelength of the electromagnetic spectrum used. In long wavelength regimes (such as radar), the direct coupling between image resolution and aperture size can be mitigated using synthetic aperture radar (SAR) techniques. SAR improves radio imaging resolution by capturing multiple measurements of a static object using a mobile recording platform, such as an airplane or satellite as shown in the diagram of FIG. 1A. For SAR, the resolution is determined by the synthetic aperture size, which can be many orders of magnitude larger than the physical aperture size. Stitching together multiple radar returns is possible because the full complex field (amplitude and phase) is directly measured by the antenna with picosecond timing resolution.
As noted above, stitching together multiple radar returns from a SAR technique is possible because the amplitude and phase is measured with picosecond timing resolution. To make a comparable measurement using visible light, a detector would have to continuously record information with a time resolution greater than one femtosecond, a requirement well beyond the capabilities of modern devices. As such, current camera sensors record only the intensity of the incoming optical field and all phase information is lost.
Fourier ptychography (FP) has emerged as a powerful tool to improve spatial resolution in microscopy. In FP, multiple low-resolution images under different illumination angles are captured and stitched together (17-27). Redundancy between measurements permits computational recovery of the missing phase information (18,25, 28-31). Fourier ptychography creates a synthetic aperture by sampling a diverse set of regions in Fourier space. Unlike holography, FP does not require the use of a reference beam to encode phase information. The phase of the complex field is recovered computationally in post-processing. FP has found much of its success in microscopy. Early efforts by Kirkland et al. (59, 60) demonstrated that multiple images recorded with different incident beam tilts could be used to effectively double image resolution. Zheng et al. (17) provided a complete framework for FP microscopy and demonstrated wide-field, high-resolution imaging. Subsequent research has improved the quality of FP reconstructions by characterizing the pupil function (18), digitally removing optical aberrations (19), and refocusing the recovered image postcapture (20). FP microscopy (where the illumination direction is varied) inherently assumes that the sample may be modeled as a thin object. Extensions for thick biological samples (21-23) have been proposed at the expense of increased computational complexity.
At the heart of FP is the requirement to recover the phase of the light field at the aperture plane of the lens, which subsequently provides knowledge of the field at the object plane. Phase retrieval is also an important step in standard and many of the techniques used in FP are borrowed from these earlier efforts.
In general, closed form solutions for recovering phase information require prohibitively large datasets to be practical (61-63). Iterative solutions are thus preferred for ptychographic reconstruction. Many FP reconstruction algorithms are based on the iterative update schemes first proposed by Gerchberg and Saxton (28) and Fienup (29). Maiden and Rodenburg (30) introduced the ePIE technique to jointly estimate the field at the detector and the probe used for illumination. Ou et al. (18) adapted ePIE for use in FP whereby the pupil function is jointly estimated with the field at the aperture plane. Experimental robustness of various phase retrieval algorithms were characterized by Yeh et al. (31) who conclude that minimizing the error in amplitude and using second-order gradient descent methods provide the best results. The phase retrieval algorithm used by Tian et al. (25), which incorporates the pupil update step of (18) and uses the second-order Newton's method as the numerical solver, serves as the base of our proposed algorithm. Although the objective function of the reconstruction framework in (25) minimizes intensities and not amplitudes, our experiments have resulted in good reconstruction quality.
Adapting the technique to long-distance imaging requires two important modifications of previous FP microscopy implementations. First, the separation distance between object and camera increases by orders of magnitude. Second, a reflection imaging geometry must be used so that illumination source and camera are placed on the same side of the object. Dong et al. (20) and Holloway et al. (32) succeeded in the first task, scaling up the working distance to 0.7 and 1.5 meters, respectively. Reflective FP microscopy setups have been proposed to fulfill the second task (33-35). However, these systems either require small working distances (34, 35), or exhibit limited reconstruction performance (33).
In FIGS. 1B and 1C, a comparison with existing FP implementations is shown. Previous works have relied on smooth objects and are loosely represented by the transmissive dataset adapted from (32) shown in FIG. 1B. An example dataset of a diffuse object collected in a reflection mode geometry is shown in FIG. 1C. The immediate difference between the two datasets is the random phase associated with diffuse objects effectively spreads out information across the entire Fourier domain. The difference in Fourier patterns is evident in the captured images taken from the same locations in both modalities. As a consequence of the random phase, the spatial information is obfuscated by the resultant speckle.
Tippie et al. (11) proposes a synthetic aperture holographic setup in which the authors experimentally demonstrated synthetic aperture off-axis holographic capture of diffuse objects at a large stand-off distance. Our approach can be interpreted as a reference-free extension of synthetic aperture holography in which computational reconstruction algorithms are used in place of interferometric capture, resulting in more stable implementations and widening the variety of application scenarios that could benefit from the approach. Beck et al. (36) proposes an optical synthetic aperture approach that extends SAR techniques into optical wavelengths in the near-infrared regime of the electromagnetic spectrum. To record phase measurements, the object is raster scanned by moving an aperture. The return signal is then demodulated using a reference signal to reduce the frequency to approximately 100 kHz, which can be sampled with commercially available ADCs.
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Crystallization is an important technique to the biological and chemical arts. Specifically, a high-quality crystal of a target compound can be analyzed by x-ray diffraction techniques to produce an accurate three-dimensional structure of the target. This three-dimensional structure information can then be utilized to predict functionality and behavior of the target.
In theory, the crystallization process is simple. A target compound in pure form is dissolved in solvent. The chemical environment of the dissolved target material is then altered such that the target is less soluble and reverts to the solid phase in crystalline form. This change in chemical environment typically accomplished by introducing a crystallizing agent that makes the target material is less soluble, although changes in temperature and pressure can also influence solubility of the target material.
In practice however, forming a high quality crystal is generally difficult and sometimes impossible, requiring much trial and error and patience on the part of the researcher. Specifically, the highly complex structure of even simple biological compounds means that they are not amenable to forming a highly ordered crystalline structure. Therefore, a researcher must be patient and methodical, experimenting with a large number of conditions for crystallization, altering parameters such as sample concentration, solvent type, countersolvent type, temperature, and duration in order to obtain a high quality crystal, if in fact a crystal can be obtained at all.
Accordingly, there is a need in the art for methods and structures for performing high throughput screening of crystallization of target materials.
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Ozone is an unstable gas with a half-life of less than one hour at room temperature. The methods used to convert oxygen to ozone involve high voltage corona discharge or ultraviolet light. Ozone generators have been available for decades for industrial uses. Indeed, ozone is a powerful oxidizer and has been used for deodorizing air and purifying water. It is a known bactericide and viricide and recently has been used to sterilize medical instruments. Although, the cycle times are so long as to be impractical for many uses.
Ozone generators have been used for therapeutic applications for several years. Such applications include but are not limited to autohemotherapy, rectal insufflations, intradiscal injection, injection into knee and shoulder joints and full body exposure. Ozone has been used to treat diffuse bulging or contained herniation of the spinal disc.
Spinal discs are composed of a fibrous outer ring made of Type I collagen and a softer more flexible nucleus made of Type II collagen, proteoglycans and water. Patients with disc bulging or herniation suffer from pain caused by disc compression of the neurological elements, including the spinal cord, cauda equina and nerve roots. Intradiscal ozone treatment involves direct injection of a gaseous mixture of oxygen and ozone into the nucleus of the disc. Ozone releases water from the proteoglycans, reducing disc size and relieving compression of neurological elements. Some investigators believe that ozone stimulates anti-inflammatory mediators and initiates a healing response.
The mechanism of action and reported success rates of ozone treatment for spinal disc herniation are similar to that of the enzyme chymopapain. Chymopapain was first FDA-approved in 1983 and was widely used with a success rate of 65-85%. A small number of serious complications, including death and paralysis, caused the product to lose favor in the market and the product was eventually discontinued in the United States.
Ozone and chymopapain are two means of performing a chemical discectomy through a needle puncture. This minimally invasive approach may be preferred to surgical discectomy, which requires general anesthesia and direct access to the spinal disc.
Therapeutic ozone must be delivered practically immediately after being produced from oxygen. End-users of ozone such as doctors and health care professionals often procure medical grade oxygen from such sources as bulk tanks or a hopsital's wall supply of oxygen. Both of these sources are usually collect oxygen through cryogenic techniques. Although not previously used for ozone production, oxygen may also be concentrated from the ambient air using adsorption principles and zeolite materials. Existing medical ozone generators pass medical grade oxygen through an electric field or ultraviolet light. This process converts an amount of oxygen into ozone. A syringe is interfaced with the machine whereby ozone is withdrawn for subsequent injection therapy.
The preferred concentration of ozone for intradiscal injection is approximately 6%. The concentration of ozone is important for medical uses. If the concentration is too low the treatment will not be effective; if the concentration is too high detrimental effects may follow. As such, medical ozone generators must include a means for measuring the concentration of ozone. The elements necessary to create and measure ozone are sensitive and require maintenance to ensure precise and accurate operation.
Present ozone generators have basic means for controlling the concentration and delivery of ozone gas. Oxygen is generally passed through a machine containing permanent electrodes; the gas chambers of present generators are often permanent as well. Some generators include components that neutralize excess ozone. Other generators continuously vent ozone. Present ozone generators often include components for gas containment or pass oxygen through reaction chambers that are permanent and reusable, lending to sterility issues. Medical professionals often inject the gas through a bacterial filter to address such sterility issues.
The following patent publications illustrate and describe various background apparatuses, methods and/or systems related to generating ozone. US Patent Publication No. 2005/0074501 (Murphy et al.) teaches an apparatus, in an embodiment, including an ozone generator connected to a scavenger and an ozone administrator via network of tubing and valves. US Patent Publication No 2007/0025890 (Joshi et al.) teaches an apparatus that in various embodiments includes a syringe having a barrel and a plunger and having an ozone generator associated therewith. US Patent Publication No. 2003/0165411 (Engelhard) teaches an ozone generator that is a module having a threaded shaft serving as an electrode and which mechanically secures the various elements with one another. U.S. Pat. No. 6,270,733 (Rodden) teaches a tubular ozone generator comprising concentric inner tubular electrode/dielectric with inner electrode and outer tubular electrode with corona discharge zone between the inner tubular electrode/dielectric and outer tubular electrode. U.S. Pat. No. 6,110,431 (Dunder) teaches an ozone dispensing system comprising an ozone gas generating means, electrical means to control the concentration of ozone produced by said ozone gas generating means, means to control the concentration of ozone in preset dispensed volume, an oxygen supply and venting means disposed between said ozone gas generating means and said dispensing of said ozone, said venting means for continuous venting of said ozone. U.S. Pat. No. 5,052,382 (Wainwright) teaches an apparatus for the controlled generation and administration of ozone, which apparatus comprises a generator for generating ozone, a monitor for monitoring the ozone, a dosage device for providing a correct amount of ozone for administration, and a computer control device for controlling the operation of at least one of the generator, the monitor and the dosage device.
Similarly, the following patent publications illustrate and describe various background apparatuses, methods and/or systems for concentrating oxygen. U.S. Pat. No. 7,121,276 (Jagger et al.) teaches an oxygen separator, for separating oxygen from ambient air utilizing a vacuum swing adsorption process, having a mass of less than 2.3 kg. U.S. Pat. No. 6,949,133 (McCombs et al.) teaches a compact and highly portable combination pressure swing adsorption apparatus and product gas conservation device for medical use, to produce efficiently a gas with a high concentration of oxygen and to deliver the oxygen concentrated gas to a user at selectable times and in selectable doses. U.S. Pat. No. 6,520,176 (Dubois et al.) teaches an oxygen concentrator portable by a patient, permitting producing a flow of gas containing 50% to 95% of oxygen from air, comprising air compression device, elements for gas separation by adsorption with pressure variations, and electrical energy storage unit. U.S. Pat. No. 5,766,310 (Cramer) teaches a single stage secondary oxygen concentrator for receiving a gas mixture from a first stage oxygen concentrator and a method of use therefore.
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Environmental regulations promulgated by government in addition to economic reality have forced mineral producers to recycle water employed in mining and mineral processing operations. Unfortunately, even the most diligent efforts cannot consistently remove all particulates from the liquid flow stream. As a result, mineral aggregate washing systems have been plagued with nozzle clogging problems.
Numerous nozzle designs have been developed in the past to obviate such problems. Nevertheless, individual handling of each nozzle by a human operator has been required to clean a blocked nozzle orifice of unwanted debris. Over time, such designs have proved to be extremely inefficient.
The need has arisen for a nozzle not susceptible to being clogged by particulate matter suspended in the fluid passing through it. Additionally, the nozzle must have the capability of readily allowing the removal of clogging particulates without human intervention. Finally, this nozzle must be capable of being securely mounted to a fluid header system capable of delivering large fluid volumes through a series of like nozzles mounted side-by-side. Such a device would prove to be of benefit to the mineral industry.
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Prescription eyeglass lenses are curved in such a way that light is correctly focused onto the retina of a patient's eye, improving vision. Such lenses are formed from glass or plastic lens “blanks” having certain desired properties to provide the correct prescription for the patient. The blanks are usually circular and of substantially larger dimension compared to the relatively smaller finished lenses assembled into eyeglass frames. Therefore, a lens blank must be edged to fit an eyeglass frame selected by the patient.
Ophthalmic laboratory technicians cut, grind, edge, and polish blanks according to prescriptions provided by dispensing opticians, optometrists, or ophthalmologists. The specifications include the patient's full prescription, including: 1) the total power the finished lens must have; 2) the strength and size of any segments, if needed (i.e. multifocal lenses); 3) the power and orientation of any cylinder curves; and 4) the location of the optical center and any inducted prism that may be needed.
In addition, the large diameter blank is sized and shaped to fit into the frame selected by the patient. The lens blank may be shaped using an edger, such as the edger disclosed in U.S. Pat. No. 6,203,409 to Kennedy et al., the disclosure of which is incorporated herein by reference. The blank is edged so that the periphery of the finished lenses fit into the openings on the frames.
Edging of a lens blank typically requires the application of a block to a surface thereof. The block is releaseably secured to a clamp assembly, so that rotation of the clamp assembly causes corresponding rotation of the lens blank. As the blank is rotated, the periphery of the blank may be cut to a desired size using a router tool. The blank may be either ground or cut. Wet edgers use diamond-impregnated wheels with different abrasive grits to grind the lens material. A coolant is sprayed on the wheels during edging to reduce heat. Dry edgers use carbide steel or diamond blades mounted on the spindle of a motor to shave the lens. The lens periphery may also be polished using a polishing tool. Some edgers are also able to form a bevel about the periphery of the lens.
Information relating to the size and shape of the lens needed for a particular frame (i.e. trace data) may be generated, and subsequently transmitted to the edger. Such trace data may be provided by frame manufacturers, or generated by a tracer machine. Trace data may be downloaded and/or transmitted to a storage medium in a control system, such as a central processing unit, in communication with the edger. The edger processes the edge of the lens blank to create an edge profile according to the trace data. The finished lens may then be assembled with the selected eyeglass frames.
In order to improve efficiency, some edgers use CNC (Computer Numeric Control) technology whereby a computer controls the lens processing equipment by following encoded commands. The commands are based on information from frame tracings or internal lens probes and the user. Information relating to the size and shape of the lens needed for a particular frame (i.e. trace data) may be generated, and subsequently transmitted to the edger. The trace data may be stored in the storage medium and recalled by the control system as needed.
Some lenses require that the lens contain drill features in the surface of the lens. For example, some frame assemblies require that one or more holes be drilled in the lenses, particularly lenses to be used in rimless style frames. Several factors to consider when determining the hole position include the horizontal and vertical coordinates, lens base curve, wrap angle, and the mounting's pantoscopic tilt. Hand drilling is used by some laboratories. Other laboratories use a drill press.
Typically, one drill bit is used to cut holes of varying sizes. In order to provide proper drill hole size, many conventional techniques require a technician to drill holes into a lens blank, and then make an estimation of the hole size correction needed. This is often a tedious and time consuming operation. In addition, accurate drill depth is required for optimal functioning of a lens drilling mechanism. Holes must typically be drilled completely through the lens blank. It is not always obvious to the technician that an adjustment is needed to achieve proper drill depth, particularly when drilling lens blanks having a relatively high wrap, such as frames having a curvature greater than 6 diopters.
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Field
Aspects of the present invention generally relate to an image forming apparatus having a sensor for detecting an object such as a person.
Description of the Related Art
Techniques for returning from a power-saving state when an image forming apparatus detects an object such as a person with a sensor provided in the image forming apparatus are known (see Japanese Patent Application Laid-Open No. 2012-118253). The image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-118253 includes a sensor for detecting a moving object existing within a predetermined range around the image forming apparatus. When the sensor detects the moving object, the image forming apparatus shifts from a power-saving state to a standby state in which the power consumption amount is larger than that in the power-saving state.
The image forming apparatus discussed in Japanese Patent Application Laid-Open No. 2012-118253 includes, in addition to the above-described sensor, a power-saving button for shifting the power state in the image forming apparatus from the power-saving state to the standby state. In response to a pressing operation of the power-saving button by a user, the image forming apparatus shifts from the power-saving state to the standby state.
In some cases, the power-saving button has also a function, in addition to the function for shifting the power state in an image forming apparatus to return from the power-saving state to the standby state, for shifting the power state in the image forming apparatus from the standby state to the power-saving state (see Japanese Patent Application Laid-Open No. 2012-248961). In a state where a value of a power mode register indicating a power state in an image forming apparatus is “001” (indicating that the image forming apparatus is in a power-saving state), if the power-saving button is pressed, the image forming apparatus shifts the power state in the image forming apparatus from the power-saving state to the standby state. In a state where a value of the power mode register indicating a power state in the image forming apparatus is “010” (indicating that the image forming apparatus is in the standby state), if the power-saving button is pressed, the image forming apparatus shifts the power state in the image forming apparatus from the standby state to the power-saving state.
In such an image forming apparatus that shifts from the power-saving state to the standby state in response to the detection of an object such as a person by the sensor, after the detection of the object such as a person by the sensor, the image forming apparatus takes a predetermined period of time to return from the power-saving state to the standby state. This is because the device to which the power supply has started needs a predetermined time for the boot processing. Due to the booting operation, when the user arrives in front of the image forming apparatus, in some cases, the image forming apparatus has not returned to the standby state. In such a case, the user who has arrived in front of the image forming apparatus may mistakenly think that the image forming apparatus has not returned to the standby state, and press the power-saving button to instruct the image forming apparatus to return from the power-saving state to the standby state.
However, if the power-saving button is pressed while the image forming apparatus is shifting from the power-saving state to the standby state in response to the detection of the object by the sensor, the image forming apparatus determines that the pressing operation of the power-saving button is an instruction for shifting from the standby state to the power-saving state. This is because, at the time the object such as a person is detected by the sensor, the value of the power mode register in the image forming apparatus becomes to “010”, and when the value of the register is “010”, the power-saving button is pressed. As a result, after the shift from the power-saving state to the standby state, the image forming apparatus immediately shifts to the power-saving state.
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The present invention relates to electrical connectors, and in particular, to a movable window electrical connector for providing electrical power to an electrical load mounted on the movable window, e.g., a sliding window. More particularly, the present invention relates to a sliding window electrical connector for an automotive sliding window defroster. Even more particularly, the present invention relates to such an electrical connector for the sliding rear window of pick-up trucks or other vehicles having a sliding window with an electrical defroster mounted on or in the sliding window. More particularly, the invention relates to such a connector that employs a magnetically operated connection and disconnection mechanism.
Some vehicles, in particular, pick-up trucks and other trucks, often have a sliding center rear window part so that the rear window can be opened. This allows ventilation and also allows long objects to be extended from the bed into the cab of the truck for transportation of the objects. It is desirable to include a rear window defroster element that is powered electrically in the center movable window part. Such electrical defroster elements are commonly used on automotive vehicles, but they have not been used on slidable windows, particularly in trucks such as pick-up trucks, to the inventors' knowledge.
An aim of the invention is to provide a connector for providing electrical power to the defroster in the center movable window part. Further aims of the invention are to provide a reliable connection and a safe connection that ensures that when the window is in the open position, the exposed connector terminals do not carry electrical current which could come into contact with a person or object.
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Ball joints are often used in the front wheel suspension of automotive vehicles. The ball joints permit steering of the wheels while accommodating changes in angle between the wheel and the suspension members. In conventional ball joints, a pin on which the wheel is mounted carries a ball, which is rigid with the pin, the ball being received in a cup. During both rotation and pivoting of the pin, the surface of the ball slides over a lining of the cup. Thus, since both modes of motion take place between the same sliding surfaces, they are subject to the same level of frictional resistance. However, while relatively high friction is of some advantage for the pivoting movement, in order to give a damping effect to the suspension, low friction rotary movement is often desirable in order to reduce the forces required for steering.
British Patent Specification No. 758805 discloses a ball joint having a ball element which is rotatably mounted on a stud. A thrust bearing comprising balls is provided to withstand axial loads in one direction. The stud is a sliding fit in the ball element, and radial and tilting loads are transmitted by direct contact between the stud and the ball element. This direct contact gives rise to undesirable friction resisting relative rotation between the stud and the ball element.
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When baker's dough is mixed, it is usually blended in a large mixer, and the batch of dough in the mixer must be transferred to a stuffing pump which forms the dough in a continuous stream and moves the dough through subsequent processing equipment such as a metering pump, and through a dough distribution manifold where the single stream of dough is divided into several streams of equal density, and then each stream is moved to a dough divider where each stream of dough is subdivided into dough balls, which after baking, become buns, etc.
The dividing process usually is carefully performed so that each biscuit, bun, etc. divided from the mass of dough is of consistent weight so that when the product is subsequently baked or otherwise cooked, packaged and delivered, each of the products will be of substantially uniform size, weight and density. Examples of equipment used to perform these functions are found in U.S. Pat. Nos. 4,332,538 and 4,449,908.
When dough has been mixed and is waiting to be divided into smaller biscuits, buns, etc., the dough tends to rise so that it becomes less dense and occupies a larger volume per unit of weight. Therefore, while the dough may be at optimum density when still in the mixer, a batch of dough that has been transported to the hopper of a stuffing pump tends to rise, and the batch of dough that is waiting to be handled by the stuffing pump and subsequent processing equipment is likely to be less dense than the first portion of the batch of dough that was processed. Since the equipment used for dividing dough functions to divide the dough into uniform volumes, the dividing equipment continues to form the dough balls with the same volume but with less weight of dough as the dough from the batch rises, causing the subsequent products to be different from those products made from the first dough taken from the batch. As this happens, the dough divider operator usually attempts to compensate for the less dense dough by adjusting the pump pressure, the divider volumetric measuring operation, etc., in an effort to cause the dough balls to be formed in larger volumes but of the same weight.
Attempts have been made to draw the gases from dough as the dough is moved by its stuffing pump toward the dough divider so as to return the dough to its desired mixer density. For example, U.S. Pat. No. 4,449,908 teaches the process of drawing a zone of reduced gas pressure about the dual auger screws of a stuffing pump, which tends to draw the dough into the stuffing pump and to expel gases from the dough which have been released because of the shearing and stretching of the dough. However, the stuffing pump uses interference fit augers with special shaped concave conveying surfaces in order to impart the high pressures to the dough that are necessary to achieve the high pressure and uniform dough product. Further, the shapes of the dual augers and auger housing limits the amount of negative gas pressure that can be applied to the system. If excess negative pressure is used, the dough tends to enter the gas exhaust system. Further, the gas exhaust system usually cannot be started upon start up of the augers, requiring a time delay to start the gas exhaust system.
Thus, it can be seen that it would be desirable to provide a baker's dough stuffing pump which is simple to operate, is of inexpensive construction, and which handles the dough with a minimum of shearing and stretching and disruption of the gluten structure of the dough and which returns the dough substantially to and maintains the dough at mixer density.
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In the past, storages had a one-byte address organization but a two-byte wide data path and the least significant bit of the storage address which is still a part of the byte address selects the high or low byte. Also, two-byte operations, particularly for I/O operations, were facilitated by the byte address but the least significant bit of the byte address must be zero. Additionally, for two-byte operations the address must be incremented by two and for one-byte operations the address had to be incremented by one. The present invention does not require that the least significant bit of the address be zero for two byte or word operations and incrementing is the same for byte addressing as it is for word addressing. Additionally, for a word or two-byte operation only one address is used up as contrasted to effectively using two addresses in the prior art arrangement. Also, when storage is organized on a byte basis, the even byte boundary locations must be observed when doing two-byte operations. That requirement does not exist when storage is organized on a word or two-byte basis. The present invention for direct addressing provides twice as much addressing compared to storages organized on a byte basis rather than a word basis. Hence, in the present invention, a 16-bit address can address 128K bytes of storage whereas in the instance where storage is organized on a byte basis an address of that size can only address 64K bytes of storage.
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The present invention relates to sense amplifiers and, more particularly, relates to sense amplifiers that compensate for variations and mismatches in a memory circuit.
As information technology progresses at an unprecedented pace, the need for information storage increases proportionately. Accordingly, the non volatile information in stationary or portable communication demands higher capability and capacity storage. One approach to increasing the amount of storage is by decreasing physical dimensions of the stored bit (e.g., memory cell) to smaller dimensions such as nanocell technology. Another approach is to increase the storage density per bit. The second approach is known as digital multilevel nonvolatile storage technology. A sense amplifier reads the content of a memory cell by comparison to reference levels. As more bits are stored in a multilevel memory cell, the voltage separation of reference levels decreases. Systematic and random variation and mismatch in a sense amplifier may change data or reference levels to cause erroneous detection of the content of a memory cell.
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The present invention relates generally to the control of temperature of an article. More particularly, the present invention relates to a system and method for the control of reticle temperature in lithography systems, especially in a vacuum environment.
In an electron or ion beam lithography system or a semiconductor exposure apparatus, an electron beam or ion beam projector directs electron or ion beams to a resist layer on a wafer substrate through a reticle which is typically placed on a reticle support or stage. The electron or ion beams are directed toward particular areas of the reticle to expose patterns on the reticle onto the wafer substrate. Thus, because the electron or ion beams of radiation are of relatively high energy, the areas of the reticle being exposed absorb power from the incident electron or ion beams and is heated thereby. Heat strain on the reticle caused by temperature changes impairs accuracy and may cause distortions and errors.
For example, when a 100 kV, 100 xcexcA electron beam is unblanked and directed at a reticle, a 2 xcexcm silicon membrane or stripe of the reticle absorbs approximately 200 mW from the electron beam. Given a coefficient of thermal expansion of 2.6 ppm/K for silicon, a 1xc2x0 K. rise over a 132 mm stripe length will cause approximately 343 nm of expansion. Such expansion may lead to error in the pattern exposed onto the wafer and reduce yield. To avoid such error and distortion, the temperature of the reticle is therefore preferably controlled to within a small fraction of a degree.
However, because the reticle is in a vacuum, controlling the temperature of the reticle silicon membrane presents a difficult challenge. In particular, heat transfer through convection is not available in a vacuum. Without convection, heat must be removed from the silicon by conduction and/or radiation.
In addition, removal of heat from the reticle by conduction is also difficult to achieve in a vacuum. In air, most of the heat transfer between, for example, two metal plates in contact with each other is actually transferred by convection across microscopic gaps between the metal plates with air serving as the fluid. The microscopic gaps generally result from surface roughness. Since the microscopic gaps are relatively small, the thermal conductivity is high and the overall thermal conductivity is usually determined by the material properties of the metal plates.
In a vacuum, heat transfer by conduction requires good thermal contact between two surfaces. To achieve good thermal contact between two surfaces, the clamping forces between the two surfaces must be very high. Alternatively, a compliant material or gasket may be utilized between the two surfaces. A third approach to overcome the contact thermal resistance problem in the case of the reticle heating in a vacuum is to provide a coolant in direct contact with the reticle.
These above-described approaches are undesirable for achieving reticle cooling particularly in view of the operating constraints of the lithography system. For example, reticles must be installed and removed quickly and repeatably on the reticle stage. Applying high clamping forces to the reticle would make the reticle installation and removal from the reticle stage time consuming, difficult and would likely not provide adequate repeatability. In addition, high clamping forces would likely create significant distortion. Installing gaskets would also not provide adequate repeatability and the gaskets are subject to wear and particulate generation. Attaching and disconnecting coolant sources and interconnections would also be very difficult and time consuming.
For the reasons set forth above, radiation has been explored as a method to cool the reticles or masks in a vacuum for both electron and ion lithography systems. For example, U.S. Pat. No. 4,916,322 entitled xe2x80x9cArrangement for Stabilizing an Irradiated Maskxe2x80x9d to Glavish et al., the entirety of which is incorporated herein by reference, discloses providing one or more cooling surfaces disposed adjacent the mask and the mask stage. The cooling surface surrounds an optical path of the beam in the field of view of the mask in the mask exposure station between the mask and the radiation source and/or behind the mask. As energy from the energy beam is transferred to the mask, the cooling surfaces compensate for the thermal energy transfer by transferring thermal energy by thermal radiation from the mask to the cooling surface. Such thermal energy compensation by the cooling surfaces is said to maintain the mask at approximately the chamber temperature during an irradiation. The cooling surface may be provided by a metal cooling tube which has a diameter larger than the mask such that the cooling tube does not block the optical path of the radiation source.
However, the cooling surface or tube disclosed by Glavish et al. is centrally place over the entire reticle, despite that the ion or electron beam is only focused on specific lines or areas of the reticle and does not uniformly heat the entire reticle at one time. Glavish et al. merely attempt to control the temperature of the reticle as a whole by cooling. Glavish et al. do not attempt to compensate for localized temperatures changes which may cause reticle distortion. Thus, an undesirable temperature gradient may nonetheless result.
U.S. Pat. No. 5,390,228 entitled xe2x80x9cMethod of and Apparatus for Stabilizing Shapes of Objects, Such as Optical Elements, as well as Exposure Apparatus Using Same and Method of Manufacturing Semiconductor Devicesxe2x80x9d to Niibe et al., the entirety of which is incorporated herein by reference, discloses determining a temperature distribution of a mask in a thermally stable state and controlling the temperature distribution of the mask being irradiated with radiation energy to be the same as the temperature distribution in the thermally stable state. The temperature distribution is controlled by providing a holder which holds as well as cools the mask and a heating means having resistance wires on a surface of the mask facing the direction of the incident beams to heat the surface of the mask.
The temperature control disclosed by Niibe et al. is of the entire reticle and because Niibe et al. utilize a reflective mask, Niibe et al. are not concerned with the localized heating of the reticle in an ion or electron beam system which can cause physical distortion of the reticle. Thus, Niibe et al. merely attempt to control the temperature of the reticle as a whole by cooling and heating.
It would thus be desirable to provide a method for reticle temperature control to reliably maintain the temperature of the reticle within a small fraction of a degree. It would also be desirable to improve temperature uniformity over the surface of the reticle. It would further be desirable to provide a method for reticle temperature control which is not time consuming, is simple to implement and provides good repeatability characteristics.
The present invention comprises a method for the control of the temperature of an article, particularly an article placed in a vacuum chamber and where the article is subjected to localized energy inputs. The method of the present invention comprises selectively applying irradiation to regions of the article to achieve and maintain temperature uniformity across the article. Since the application of radiation heat with radiation heat sources is non-contacting and obviates the need for physical contact or wires leading to the article, the temperature control apparatus can be relatively simple.
The system and method of the present invention may be utilized to control the temperature of a reticle in both electron and ion lithography systems or other systems. Radiant heat cycles are applied to control the temperature of the reticle geographically, depending upon the areas heated by the beams as a function of time and upon cycles such as wafer load cycle during which the reticle may experience a temperature decrease.
The method generally comprises applying initial heat after the reticle is initially loaded into the lithography system from an external environment, applying exposure heat when other reticles are being exposed and applying heat during the wafer load cycle when a new wafer is loaded and the electron or ion beam is blanked. The initial heat is only applied once when the reticle is initially loaded into the lithography system from the external environment
The present invention uniformly maintains the operating temperature of the reticle at a temperature slightly above the ambient temperature. When an incident electron or ion beam is directed at a region of the reticle, the localized temperature of that region will increase due to the energy of the beam. To equalize the localized temperature increase, radiant heating is applied selectively to certain other regions of the reticle in order to achieve and maintain temperature uniformity across the reticle. Achieving and maintaining temperature uniformity of the reticle is important for fabricating defect-free wafers, resulting in high yields.
The higher operating temperature of the reticle can be easily accounted for and compensated during design to ensure accuracy and result in a high yield. For example, the higher operating temperature of the reticle can be compensated by slightly lowering the ambient temperature, adjusting the design of the reticle and/or adjusting the application of the electron or ion beams in the lithography system.
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Pressurized water nuclear reactors include a core formed of assemblies which are prismatic in shape and which are disposed vertically and rest on a support plate within the chamber of the nuclear reactor.
During operation of the nuclear reactor, it is necessary to carry out periodically measurements of neutron flux within the actual core. For this purpose, use is made of fission detectors which have very small dimensions and which are displaced by remote control by means of flexible remote control cables, within tubes which are closed at one of their ends and which are called glove fingers. The glove fingers are introduced into certain fuel assemblies which are disposed in accordance with a predetermined distribution within the core. By displacing the flux detectors within the glove fingers introduced into the fuel assemblies, it is possible to carry out flux measurements over the entire height of the core. It must be possible for the glove fingers to be extracted from the assemblies of the core, for example in order to facilitate the operations of recharging the core of the reactor; in order to do this, traction is exerted on the end of the glove fingers, from an instrumentation which is disposed laterally relative to the chamber bore of the reactor.
The glove fingers must accordingly be guided from the instrumentation centre as far as the chamber, and then into the interior of the chamber, between the lower domed floor of this chamber and the entry end of the guide tubes of the corresponding assemblies. In order to do this, each one of the glove fingers is introduced into internal cylindrical and rectilinear passage of a guide assembly which includes, in particular, a guide tube passing into a connecting collar of the floor of the chamber, a guide column and an opening traversing the lower core plate in the extension of the guide tube of the assembly.
This cylindrical connecting passage of the glove finger has a diameter which generally decreases from the chamber floor to the fuel assembly, this diameter nevertheless remaining substantially greater than the external diameter of the glove finger, in order to permit facilitated introduction and displacement of this glove finger in the connecting passage.
The terminal part of the guide assembly is generally constituted by a sleeve fixed on the upper face of the core plate in the extension of the opening passing through this plate. A space is nevertheless provided betewen the end of this sleeve and the inlet of the guide tube of the fuel assembly, in order to facilitate the setting-up of this assembly on the occasion of the recharging of the reactor, and to permit the displacements accompanying the differential expansion of the fuel assembly relative to the lower internal equipment of the reactor.
The pressurized cooling water of the reactor, which water circulates at high speed in the chamber, causes the initiation of vibration of the glove fingers and impacts by these glove fingers against the walls of the internal passage of the guide assembly in which the glove finger is mounted with a certain play.
The pressurized water circulating in transverse directions acts on the glove finger, in the zone where the latter is not protected by a guide means, prior to entry thereof into the guide tube of the assembly. The pressurized water likewise passes through the internal cylindrical passage of the guide assembly in its axial direction, and this turbulent flow likewise generates vibrations and impacts by the glove finger against the walls of the connecting passage.
This results in excessive wear and possibly deteriorations of the glove fingers when the reactor is in service.
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When an item moves without any constraints (freely) in a three-dimensional environment with respect to stationary objects, knowledge of the item's distance and inclination to one or more of such stationary objects can be used to derive a variety of the item's parameters of motion, as well as its complete pose. The latter includes the item's three position parameters, usually expressed by three coordinates (x, y, z), and its three orientation parameters, usually expressed by three angles (α, β, γ) in any suitably chosen rotation convention (e.g., Euler angles (ψ, θ, φ) or quaternions). Particularly useful stationary objects for pose recovery purposes include ground planes, fixed points, lines, reference surfaces and other known features.
Many mobile electronics items are now equipped with advanced optical apparatus such as on-board cameras with photo-sensors, including high-resolution CMOS arrays. These devices typically also possess significant on-board processing resources (e.g., CPUs and GPUs) as well as network connectivity (e.g., connection to the Internet, Cloud services and/or a link to a Local Area Network (LAN)). These resources enable many techniques from the fields of robotics and computer vision to be practiced with the optical apparatus on-board such virtually ubiquitous devices. Most importantly, vision algorithms for recovering the camera's extrinsic parameters, namely its position and orientation, also frequently referred to as its pose, can now be applied in many practical situations.
An on-board camera's extrinsic parameters in the three dimensional environment are typically recovered by viewing a sufficient number of non-collinear optical features belonging to the known stationary object or objects. In other words, the on-board camera first records on its photo-sensor (which may be a pixelated device or even a position sensing device (PSD) having one or just a few “pixels”) the images of space points, space lines and space planes belonging to one or more of these known stationary objects. A computer vision algorithm to recover the camera's extrinsic parameters is then applied to the imaged features of the actual stationary object(s). The imaged features usually include points, lines and planes of the actual stationary object(s) that yield a good optical signal. In other words, the features are chosen such that their images exhibit a high degree of contrast and are easy to isolate in the image taken by the photo-sensor. Of course, the imaged features are recorded in a two-dimensional (2D) projective plane associated with the camera's photo-sensor, while the real or space features of the one or more stationary objects are found in the three-dimensional (3D) environment.
Certain 3D information is necessarily lost when projecting an image of actual 3D stationary objects onto the 2D image plane. The mapping between the 3D Euclidean space of the three-dimensional environment and the 2D projective plane of the camera is not one-to-one. Many assumptions of Euclidean geometry are lost during such mapping (sometimes also referred to as projectivity). Notably, lengths, angles and parallelism are not preserved. Euclidean geometry is therefore insufficient to describe the imaging process. Instead, projective geometry, and specifically perspective projection is deployed to recover the camera's pose from images collected by the photo-sensor residing in the camera's 2D image plane.
Fortunately, projective transformations do preserve certain properties. These properties include type (that is, points remain points and lines remain lines), incidence (that is, when a point lies on a line it remains on the line), as well as an invariant measure known as the cross ratio. For a review of projective geometry the reader is referred to H. X. M. Coexter, Projective Geometry, Toronto: University of Toronto, 2nd Edition, 1974; O. Faugeras, Three-Dimensional Computer Vision, Cambridge, Mass.: MIT Press, 1993; L. Guibas, “Lecture Notes for CSS4Sa: Computer Graphics—Mathematical Foundations”, Stanford University, Autumn 1996; Q.-T. Luong and O. D. Faugeras, “Fundamental Matrix: Theory, algorithms and stability analysis”, International Journal of Computer Vision, 17(1): 43-75, 1996; J. L. Mundy and A. Zisserman, Geometric Invariance in Computer Vision, Cambridge, Mass.: MIT Press, 1992 as well as Z. Zhang and G. Xu, Epipolar Geometry in Stereo, Motion and Object Recognition: A Unified Approach. Kluwer Academic Publishers, 1996.
At first, many practitioners deployed concepts from perspective geometry directly to pose recovery. In other words, they would compute vanishing points, horizon lines, cross ratios and apply Desargues theorem directly. Although mathematically simple on their face, in many practical situations such approaches end up in tedious trigonometric computations. Furthermore, experience teaches that such computations are not sufficiently compact and robust in practice. This is due to many real-life factors including, among other, limited computation resources, restricted bandwidth and various sources of noise.
Modern computer vision has thus turned to more computationally efficient and robust approaches to camera pose recovery. An excellent overall review of this subject is found in Kenichi Kanatani, Geometric Computation for Machine Vision, Clarendon Press, Oxford University Press, New York, 1993. A number of important foundational aspects of computational geometry relevant to pose recovery via machine vision are reviewed below to the benefit of those skilled in the art and in order to better contextualize the present invention.
To this end, we will now review several relevant concepts in reference to FIGS. 1-3. FIG. 1 shows a stable three-dimensional environment 10 that is embodied by a room with a wall 12 in this example. A stationary object 14, in this case a television, is mounted on wall 12. Television 14 has certain non-collinear optical features 16A, 16B, 16C and 16D that in this example are the corners of its screen 18. Corners 16A, 16B, 16C and 16D are used by a camera 20 for recovery of extrinsic parameters (up to complete pose recovery when given a sufficient number and type of non-collinear features). Note that the edges of screen 18 or even the entire screen 18 and/or anything displayed on it (i.e., its pixels) are suitable non-collinear optical features for these purposes. Of course, other stationary objects in room 10 besides television 14 can be used as well.
Camera 20 has an imaging lens 22 and a photo-sensor 24 with a number of photosensitive pixels 26 arranged in an array. A common choice for photo-sensor 24 in today's consumer electronics devices are CMOS arrays, although other technologies can also be used depending on application (e.g., CCD, PIN photodiode, position sensing device (PSD) or still other photo-sensing technology). Imaging lens 22 has a viewpoint O and a certain focal length f. Viewpoint O lies on an optical axis OA. Photo-sensor 24 is situated in an image plane at focal length f behind viewpoint O along optical axis OA.
Camera 20 typically works with electromagnetic (EM) radiation 30 that is in the optical or infrared (IR) wavelength range (note that deeper sensor wells are required in cameras working with IR and far-IR wavelengths). Radiation 30 emanates or is reflected (e.g., reflected ambient EM radiation) from non-collinear optical features such as screen corners 16A, 16B, 16C and 16D. Lens 22 images EM radiation 30 on photo-sensor 24. Imaged points or corner images 16A′, 16B′, 16C′, 16D′ thus imaged on photo-sensor 24 by lens 22 are usually inverted when using a simple refractive lens. Meanwhile, certain more compound lens designs, including designs with refractive and reflective elements (catadioptrics) can yield non-inverted images.
A projective plane 28 conventionally used in computational geometry is located at focal length f away from viewpoint O along optical axis OA but in front of viewpoint O rather than behind it. Note that a virtual image of corners 16A, 16B, 16C and 16D is also present in projective plane 28 through which the rays of electromagnetic radiation 30 pass. Because any rays in projective plane 28 have not yet passed through lens 22, the points representing corners 16A, 16B, 16C and 16D are not inverted. The methods of modern machine vision are normally applied to points in projective plane 28, while taking into account the properties of lens 22.
An ideal lens is a pinhole and the most basic approaches of machine vision make that an assumption. Practical lens 22, however, introduces distortions and aberrations (including barrel distortion, pincushion distortion, spherical aberration, coma, astigmatism, chromatic aberration, etc.). Such distortions and aberrations, as well as methods for their correction or removal are understood by those skilled in the art.
In the simple case shown in FIG. 1, image inversion between projective plane 28 and image plane on the surface of photo-sensor 24 is rectified by a corresponding matrix (e.g., a reflection and/or rotation matrix). Furthermore, any offset between a center CC of camera 20 where optical axis OA passes through the image plane on the surface of photo-sensor 24 and the origin of the 2D array of pixels 26, which is usually parameterized by orthogonal sensor axes (Xs, Ys), involves a shift.
Persons skilled in the art are familiar with camera calibration techniques. These include finding offsets, computing the effective focal length feff (or the related parameter k) and ascertaining distortion parameters (usually denoted by α's). Collectively, these parameters are called intrinsic and they can be calibrated in accordance with any suitable method. For teachings on camera calibration the reader is referred to the textbook entitled “Multiple View Geometry in Computer Vision” (Second Edition) by R. Hartley and Andrew Zisserman. Another useful reference is provided by Robert Haralick, “Using Perspective Transformations in Scene Analysis”, Computer Graphics and Image Processing 13, pp. 191-221 (1980). For still further information the reader is referred to Carlo Tomasi and John Zhang, “How to Rotate a Camera”, Computer Science Department Publication, Stanford University and Berthold K. P. Horn, “Tsai's Camera Calibration Method Revisited”, which are herein incorporated by reference.
Additionally, image processing is required to discover corner images 16A′, 16B′, 16C′, 16D′ on sensor 24 of camera 20. Briefly, image processing includes image filtering, smoothing, segmentation and feature extraction (e.g., edge/line or corner detection). Corresponding steps are usually performed by segmentation and the application of mask filters such as Guassian/Laplacian/Laplacian-of-Gaussian (LoG)/Marr and/or other convolutions with suitable kernels to achieve desired effects (averaging, sharpening, blurring, etc.). Most common feature extraction image processing libraries include Canny edge detectors as well as Hough/Radon transforms and many others. Once again, all the relevant techniques are well known to those skilled in the art. A good review of image processing is afforded by “Digital Image Processing”, Rafael C. Gonzalez and Richard E. Woods, Prentice Hall, 3rd Edition, Aug. 31, 2007; “Computer Vision: Algorithms and Applications”, Richard Szeliski, Springer, Edition 2011, Nov. 24, 2010; Tinne Tuytelaars and Krystian Mikolajczyk, “Local Invariant Feature Detectors: A Survey”, Journal of Foundations and Trends in Computer Graphics and Vision, Vol. 3, Issue 3, January 2008, pp. 177-280. Furthermore, a person skilled in the art will find all the required modules in standard image processing libraries such as OpenCV (Open Source Computer Vision), a library of programming functions for real time computer vision. For more information on OpenCV the reader is referred to G. R. Bradski and A. Kaehler, “Learning OpenCV: Computer Vision with the OpenCV Library”, O'Reilly, 2008.
In FIG. 1 camera 20 is shown in a canonical pose. World coordinate axes (Xw,Yw,Zw) define the stable 3D environment with the aid of stationary object 14 (the television) and more precisely its screen 18. World coordinates are right-handed with their origin in the middle of screen 18 and Zw-axis pointing away from camera 20. Meanwhile, projective plane 28 is parameterized by camera coordinates with axes (Xc,Yc,Zc). Camera coordinates are also right-handed with their origin at viewpoint O. In the canonical pose Zc-axis extends along optical axis OA away from the image plane found on the surface of image sensor 24. Note that camera Zc-axis intersects projective plane 28 at a distance equal to focal length f away from viewpoint O at point o′, which is the center (origin) of projective plane 28. In the canonical pose, the axes of camera coordinates and world coordinates are thus aligned. Hence, optical axis OA that always extends along the camera Zc-axis is also along the world Zw-axis and intersects screen 18 of television 14 at its center (which is also the origin of world coordinates). In the application shown in FIG. 1, a marker or pointer 32 is positioned at the intersection of optical axis OA of camera 20 and screen 18.
In the canonical pose, the rectangle defined by space points representing screen corners 16A, 16B, 16C and 16D maps to an inverted rectangle of corner images 16A′, 16B′, 16C′, 16D′ in the image plane on the surface of image sensor 24. Also, space points defined by screen corners 16A, 16B, 16C and 16D map to a non-inverted rectangle in projective plane 28. Therefore, in the canonical pose, the only apparent transformation performed by lens 22 of camera 20 is a scaling (de-magnification) of the image with respect to the actual object. Of course, mostly correctable distortions and aberrations are also present in the case of practical lens 22, as remarked above.
Recovery of poses (positions and orientations) assumed by camera 20 in environment 10 from a sequence of corresponding projections of space points representing screen corners 16A, 16B, 16C and 16D is possible because the absolute geometry of television 14 and in particular of its screen 18 and possibly other 3D structures providing optical features in environment 10 are known and can be used as reference. In other words, after calibrating lens 22 and observing the image of screen corners 16A, 16B, 16C, 16D and any other optical features from the canonical pose, the challenge of recovering parameters of absolute pose of camera 20 in three-dimensional environment 10 is solvable. Still more precisely put, as camera 20 changes its position and orientation and its viewpoint O travels along a trajectory 34 (a.k.a. extrinsic parameters) in world coordinates parameterized by axes (Xw,Yw,Zw), only the knowledge of corner images 16A′, 16B′, 16C′, 16D′ in camera coordinates parameterized by axes (Xc,Yc,Zc) can be used to recover the changes in pose or extrinsic parameters of camera 20. This exciting problem in computer and robotic vision has been explored for decades.
Referring to FIG. 2, we now review a typical prior art approach to camera pose recovery in world coordinates (a.k.a. absolute pose, since world coordinates defined by television 14 sitting in room 10 are presumed stable for the purposes of this task). In this example, camera 20 is mounted on-board item 36, which is a mobile device and more specifically a tablet computer with a display screen 38. The individual parts of camera 20 are not shown explicitly in FIG. 2, but non-inverted image 18′ of screen 18 as found in projective plane 28 is illustrated on display screen 38 of tablet computer 36 to aid in the explanation. The practitioner is cautioned here, that although the same reference numbers refer to image points in the image plane on sensor 24 (see FIG. 1) and in projective plane 28 to limit notational complexity, a coordinate transformation exists between image points in the actual image plane and projective plane 28. As remarked above, this transformation typically involves a reflection/rotation matrix and an offset between camera center CC and the actual center of sensor 24 discovered during the camera calibration procedure (also see FIG. 1).
A prior location of camera viewpoint O along trajectory 34 and an orientation of camera 20 at time t=t−i are indicated by camera coordinates using camera axes (Xc,Yc,Zc) whose origin coincides with viewpoint O. Clearly, at time t=t−i camera 20 on-board tablet 36 is not in the canonical pose. The canonical pose, as shown in FIG. 1, obtains at time t=to. Given unconstrained motion of viewpoint O along trajectory 34 and including rotations in three-dimensional environment 10, all extrinsic parameters of camera 20 and correspondingly the position and orientation (pose) of tablet 36 change between time t=t−i and t=to. Still differently put, all six degrees of freedom (6 DOFs or the three translational and the three rotational degrees of freedom inherently available to rigid bodies in three-dimensional environment 10) change along trajectory 34.
Now, at time t=t1 tablet 36 has moved further along trajectory 34 from its canonical pose at time t=to to an unknown pose where camera 20 records corner images 16A′, 16B′, 16C′, 16D′ at the locations displayed on screen 38 in projective plane 28. Of course, camera 20 actually records corner images 16A′, 16B′, 16C′, 16D′ with pixels 26 of its sensor 24 located in the image plane defined by lens 22 (see FIG. 1). As indicated above, a known transformation exists (based on camera calibration of intrinsic parameters, as mentioned above) between the image plane of sensor 24 and projective plane 28 that is being shown in FIG. 2.
In the unknown camera pose at time t=t1 a television image 14′ and, more precisely screen image 18′ based on corner images 16A′, 16B′, 16C′, 16D′ exhibits a certain perspective distortion. By comparing this perspective distortion of the image at time t=t1 to the image obtained in the canonical pose (at time t=to or during camera calibration procedure) one finds the extrinsic parameters of camera 20 and, by extension, the pose of tablet 36. By performing this operation with a sufficient frequency, the entire rigid body motion of tablet 36 along trajectory 34 of viewpoint O can be digitized.
The corresponding computation is traditionally performed in projective plane 28 by using homogeneous coordinates and the rules of perspective projection as taught in the references cited above. For a representative prior art approach to pose recovery with respect to rectangles, such as presented by screen 18 and its corners 16A, 16B, 16C and 16D the reader is referred to T. N. Tan et al., “Recovery of Intrinsic and Extrinsic Camera Parameters Using Perspective Views of Rectangles”, Dept. of Computer Science, The University of Reading, Berkshire RG6 6AY, UK, 1996, pp. 177-186 and the references cited by that paper. Before proceeding, it should be stressed that although in the example chosen we are looking at rectangular screen 18 that can be analyzed by defining vanishing points and/or angle constraints on corners formed by its edges, pose recovery does not need to be based on corners of rectangles or structures that have parallel and orthogonal edges. In fact, the use of vanishing points is just the elementary way to recover pose. There are more robust and practical prior art methods that can be deployed in the presence of noise and when tracking more than four reference features (sometimes also referred to as fiducials) that do not need to form a rectangle or even a planar shape in real space. Indeed, the general approach applies to any set of fiducials defining an arbitrary 3D shape, as long as that shape is known.
For ease of explanation, however, FIG. 3 highlights the main steps of an elementary prior art approach to the recovery of extrinsic parameters of camera 20 based on the rectangle defined by screen 18 in world coordinates parameterizing room 10 (also see FIG. 2). Recovery is performed with respect to the canonical pose shown in FIG. 1. The solution is a rotation expressed by a rotation matrix R and a translation expressed by a translation vector h, or {R, h}.
In other words, the application of inverse rotation matrix R−1 and subtraction of translation vector h return camera 20 from the unknown recovered pose to its canonical pose. The canonical pose at t=to is marked and the unknown pose at t=t1 is to be recovered from image 18′ found in projective plane 28 (see FIG. 2), as shown on display screen 38. In solving the problem we need to find vectors pA, pB, pC and pD from viewpoint O to space points 16A, 16B, 16C and 16D through corner images 16A′, 16B′, 16C′ and 16D′. Then, information contained in computed conjugate vanishing points 40A, 40B can be used for the recovery. In cases where the projection is almost orthographic (little or no perspective distortion in screen image 18′) and vanishing points 40A, 40B become unreliable, angle constraints demanding that the angles between adjoining edges of candidate recovered screen 18 be 90° can be used, as taught by T. N. Tan et al., op. cit.
FIG. 3 shows that without explicit information about the size of screen 18, the length of one of its edges (or other scale information) only relative lengths of vectors pA, pB, pC and pD can be found. In other words, when vectors pA, pB, pC and pD are expressed by corresponding unit vectors {circumflex over (n)}A, {circumflex over (n)}B, {circumflex over (n)}C, {circumflex over (n)}D times scale constants λA, λB, λC, λD such that pA={circumflex over (n)}AλA, pB={circumflex over (n)}BλB, pC={circumflex over (n)}C, and pD={circumflex over (n)}DλD, then only relative values of scale constants λA, λB, λC, λD can be obtained. This is clear from looking at a small dashed candidate for screen 18* with corner points 16A*, 16B*, 16C*, 16D*. These present the correct shape for screen 18* and lie along vectors pA, pB, pC and pD, but they are not the correctly scaled solution.
Also, if space points 16A, 16B, 16C and 16D are not identified with image points 16A′, 16B′, 16C′ and 16D′ then the in-plane orientation of screen 18 cannot be determined. This labeling or correspondence problem is clear from examining a candidate for recovered screen 18*.
Its recovered corner points 16A*, 16B*, 16C* and 16D* do not correspond to the correct ones of actual screen 18 that we want to find. The correspondence problem can be solved by providing information that uniquely identifies at least some of points 16A, 16B, 16C and 16D. Alternatively, additional space points that provide more optical features at known locations in room 10 can be used to break the symmetry of the problem. Otherwise, the space points can be encoded by any suitable methods and/or means. Of course, space points that present intrinsically asymmetric space patterns could be used as well.
Another problem is illustrated by candidate for recovered screen 18**, where candidate points 16A**, 16B**, 16C**, 16D** do lie along vectors pA, pB, pC and pD but are not coplanar. This structural defect is typically resolved by realizing from algebraic geometry that dot products of vectors that are used to represent the edges of candidate screen 18** not only need to be zero (to ensure orthogonal corners) but also that the triple product of these vectors needs to be zero. That is true, since the triple product of the edge vectors is zero for a rectangle. Still another way to remove the structural defect involves the use of cross ratios.
In addition to the above problems, there is noise. Thus, the practical challenge is not only in finding the right candidate based on structural constraints, but also distinguishing between possible candidates and choosing the best one in the presence of noise. In other words, the real-life problem of pose recovery is a problem of finding the best estimate for the transformation encoded by {R, h} from the available measurements. To tackle this problem, it is customary to work with the homography or collineation matrix A that expresses {R, h}. In this form, the well-known methods of linear algebra can be brought to bear on the problem of estimating A. Once again, the reader should remember that these tools can be applied for any set of optical features (fiducials) and not just rectangles as formed by screen 18 used for explanatory purposes in this case. In fact, any set of fiducials defining any 3D shape in room 10 can be used, as long as that 3D shape is known. Additionally, such 3D shape should have a geometry that produces a sufficiently large image from all vantage points (see definition of convex hull).
FIGS. 4A & 4B illustrate realistic situations in which estimates of collineation matrices A are computed in the presence of noise for our simple example. FIG. 4A shows on the left a full field of view 42 (F.O.V.) of lens 22 centered on camera center CC while camera 20 is in the canonical pose (also see FIG. 1). Field of view 42 is parameterized by sensor coordinates of photo-sensor 24 using sensor axes (Xs,Ys) Note that pixelated sensors like sensor 24 usually take the origin of array of pixels 26 to be in the upper corner. Also note that camera center CC has an offset (xsc,ysc) from the origin. In fact, (xsc,Ysc) is the location of viewpoint O and origin o′ of projective plane 28 in sensor coordinates (previously shown in camera coordinates (Xc,Yc,Zc)—see FIG. 1). Working in sensor coordinates is initially convenient because screen image 18′ is first recorded along with noise by pixels 26 of sensor 24 in the image plane that is parameterized by sensor coordinates. Note the inversion of real screen image 18′ on sensor 24 in comparison to virtual screen image 18′ in projective plane 28 (again see FIG. 1).
On the right, FIG. 4A illustrates screen image 18′ after viewpoint O has moved along trajectory 34 and camera 20 assumed a pose corresponding to an unknown collineation A1 with respect to the canonical pose shown on the left. Collineation A1 consists of an unknown rotation and an unknown translation {R, h}. Due to noise, there are a number of measured image points {circumflex over (p)}i=({circumflex over (x)}i,ŷi), indicated by crosses, for corner images 16A′, 16B′, 16C′ and 16D′. (Here the “hat” denotes measured values not unit vectors.) The best estimate of collineation A1, referred to as Θ (estimation matrix), yields the best estimate of the locations of corner images 16A′, 16B′, 16C′ and 16D′ in the image plane. The value of estimation matrix Θ is usually found by minimizing a performance criterion through mathematical optimization. Suitable methods include the application of least squares, weighted average or other suitable techniques to process measured image points {circumflex over (p)}i({circumflex over (x)}i,ŷi). Note that many prior art methods also include outlier rejection of certain measured image points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) that could “skew” the average. Various voting algorithms including RANSAC can be deployed to solve the outlier problem prior to averaging.
FIG. 4B shows screen image 18′ as recorded in another pose of camera 20. This one corresponds to a different collineation A2 with respect to the canonical pose. Notice that the composition of collineations behaves as follows: collineation A1 followed by collineation A2 is equivalent to composition A1A2. Once again, measured image points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) for the estimate computation are indicated.
The distribution of measured image points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) normally obeys a standard noise statistic dictated by environmental conditions. When using high-quality camera 20, that distribution is thermalized based mostly on the illumination conditions in room 10, the brightness of screen 18 and edge/corner contrast (see FIG. 2). This is indicated in FIG. 4B by a dashed outline indicating a normal error region or typical deviation 44 that contains most possible measured image points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) excluding outliers. An example outlier 46 is indicated well outside typical deviation 44.
In some situations, however, the distribution of points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) does not fall within typical error region 44 accompanied by a few outliers 46. In fact, some cameras introduce persistent or even inherent structural uncertainty into the distribution of points {circumflex over (p)}i=({circumflex over (x)}i,ŷi) found in the image plane on top of typical deviation 44 and outliers 46.
One typical example of such a situation occurs when the optical system of a camera introduces multiple reflections of bright light sources (which are prime candidates for space points to track) onto the sensor. This may be due to the many optical surfaces that are typically used in the imaging lenses of camera systems. In many cases, these multiple reflections can cause a number of ghost images along radial lines extending from the center of the sensor or camera center CC as shown in FIG. 1 to the point where the optical axis OA of the lens intersects with the sensor. This condition results in a large inaccuracy when using the image to measure the radial distance of the primary image of a light source. The prior art teaches no suitable formulation of the homography or collineation to nonetheless recover parameters of camera pose under such conditions.
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This invention relates to indexing information stored in a computer system, and more particularly to indexing data stored in a cache of a directory proxy server.
It is common for computer users (xe2x80x9cclientsxe2x80x9d) interconnected by an institutional intranet or local area network to gain access to various remote (database) server sites via an internetwork of computers, such as the well-known Internet communications network. It is also common in network applications to provide a so-called proxy server that links to the internetwork. A proxy server accesses frequently requested data from the remote servers and stores it locally to effectively speed-up access and reduce the download time of future requests for the data. In response to a request from an application executing on a client, the proxy server attempts to fulfill that request from its local storage; if it cannot, the proxy server forwards the request over the internetwork to a server that can satisfy the request. The server then responds by transferring a stream of data to the proxy server, which stores and forwards the data onto the client.
The term xe2x80x9cclientxe2x80x9d is also used to refer to a computer used by a person, the xe2x80x9cuserxe2x80x9d. Accordingly, the user""s computer is referred to as the xe2x80x9cclient computerxe2x80x9d.
The requests issued from the client and proxy server to the server conform to a conventional protocol, such as the lightweight directory access protocol (LDAP). Specifically, the LDAP protocol provides a client-server communication arrangement to access a directory service over a Transmission Control Protocol/Internet Protocol (TCP/IP) network. Examples of a directory service include the NetWare Directory Services (NDS) from Novell, Inc. and the X.500 directory service. Novell""s Directory Access Protocol (NDAP) is a gateway on NDS that conforms with LDAP. NDS, X.500 and the LDAP protocol are well-known and described in the following documents: Novell Directory Services Internals Overview; Technical Overview of Directory Services Using the X.500 Protocol, RFC 1309; X.500 Lightweight Directory Access Protocol, RFC 1487; Lightweight Directory Access Protocol (v3), RFC 2251.
A directory differs from a database in an essential characteristic, a directory is designed for ease of changing the data stored therein on a dynamic basis. In ordinary data base design, the data is stored in fields of tables, and is accessed and written to and read from using a designated protocol. To change data in a database requires both deleting the data presently there and writing in desired new data. Both the deleting and writing are accomplished by using the command structure of the protocol.
In contrast, a directory is architected so that the access protocol permits easy access to changing data stored in the directory. Protocols for dynamically changing data stored in a directory are designed to make dynamical changes to the data easy and able to be accomplished with a minimum of steps executed by the user, or his/her client computer. An example of directory operation and protocol is given in the Lightweight Directory Access Protocol (LDAP).
The LDAP protocol is described in many books, in particular in the following two books: the first book, by Timothy A. Howes, Mark C. Smith, and Gordon S. Good entitled Understanding and Deploying LDAP Directory Services, published by Macmillan Technical Publishing, Copyright date 1999; and second book, by Timothy A. Howes and Mark C. Smith entitled LDAP, Programming Directory Enabled Applications with Lightweight Directory Access Protocol, published by Macmillan Technical Publishing, Copyright date 1997, and all disclosures of both books are incorporated herein by reference.
A difference between a directory and a database can be expressed by the statement that a directory can include a database, but a database ordinarily cannot include a directory. A reason is that data may be stored in a directory much as it is stored in a database, but the access to a directory for dynamic changes in the stored data is better than access to a database. In the following discussion attention will be primarily directed to directories. However, as is clear from this discussion, a database could also be used in the discussion, with the exception that to use a database would make access for dynamic changes in the data more cumbersome.
In this document, the conventional protocol used to issue requests from a client is a lightweight directory access protocol (LDAP) and the source server used to store data is an LDAP or NDAP/NDS server. The predicate proxy server stores (xe2x80x9ccachesxe2x80x9d) data retrieved from the server and further builds dynamic indexes for searching the cached data stored on the proxy cache. Notably, searching and storage of data on the proxy server is based on the predicate generated by the predicate logic core of the proxy server.
Any database management system may be used in the following description and used in the practice of the following invention. However, because of ease of reference, any database system, and any directory service, will be referred to as an xe2x80x9cLDAPxe2x80x9d directory service, whether or not it uses the LDAP protocol. That is, the present discussion is not limited to any specific protocol utilized by standard LDAP Lightweight Directory Access Protocol, even though the terminology xe2x80x9cLDAP serverxe2x80x9d is used to refer to any electronically stored database.
The variants (types) of data stored in the LDAP (and NDAP and any directories using any other protocol) directories are typically small to make it easier for applications to directly access the data with a fully-qualified distinguished name; a distinguished name is a technique (similar to the Domain Naming System) for accessing data uniquely within a directory store. However, as the amount of data types stored in an LDAP/NDAP directory increases, it becomes increasingly difficult for an application and associated programs to access all the data and know about all their respective types. The directory may, for instance, contain different types (categories) of data such as printer identifiers (IDs), electronic mail (e-mail) addresses and Internet Protocol (IP) addresses.
Companies typically configure their directory servers such that each server stores a subset of data types and, notably, the subsets (data types) do not overlap. For instance, a company may have two LDAP servers (Server A and Server B). All corporate human resource related information (employee IDs, email and residential addresses, emergency contacts, salaries, etc) are stored on LDAP Server A, whereas all corporate research and development work, including the various projects under development along with interactions between development groups (both external and internal to the company), are stored on LDAP Server B. Having a database use a plurality of database servers is referred to as a xe2x80x9cdistributed databasexe2x80x9d, and a system using a distributed database is referred to as a xe2x80x9cdistributed database systemxe2x80x9d.
The subsets of data stored on the LDAP servers are thus reduced and non-overlapping, primarily to avoid overloading each server. LDAP is a database which operates on a schema, i.e., a format of data that the database stores and understands. A directory server (such as LDAP or NDAP) that is configured to increase the amount of data types it stores (e.g., all possible data formats used in an organization) has a complex schema and processing (including searching) of any request is time consuming and inefficient. Attempts by an organization to develop a searching algorithm for such a schema involve use of hash-based, index searching; however, such searching is also quite complex, resulting in overloading of the server and degradation of its performance.
Hash-based indexing is a way of formulating hints that result in faster look-ups; yet indexes generally consume substantial overhead (such as memory and processor cycles) when developing keys for searching the database. Moreover, updates to a hash-based index searching service may adversely affect processing performance of the server because the updates are directed to the indexes as well as to the database itself. Thus, such an approach results in substantial resource commitments that nevertheless degrade performance of the server.
An improved method of indexing directories is needed, including accessing cached information.
The invention relates to a directory proxy caching system that is constructed based on a predicate, i.e., a query from a client. Broadly stated, the predicate is formed by the query (request) issued by the client. The query ordinarily goes to a proxy server. Once the data is found in the directory, or the database, then the data is stored in a cache of the proxy server. The data is indexed in the proxy server by the predicate. The predicate is used to form an index by sorting the predicate into a normal form. Steps in sorting the predicate into the normal form include the following. Each symbol of the predicate is represented by a numerical representation, for example the ASCII value used to represent the symbol in ordinary text files. The predicate is expressed as a plurality of primitive predicates, and individual predicates of the plurality of primitive predicates are joined by logical connectors. The logical connectors, and each term in the primitive predicates are represented by the numbers, and the numbers are chosen so that each different logical connector and each different term in the plurality of predicates is represented by a unique number. The logical connectors and the predicates are sorted in numerical order of the unique numbers to form the normal form of the predicate. The information retrieved by the predicate is stored into a cache using the normal form of the predicate as an index. The next request using a previously used predicate can then be found in the cache by the next request being sorted into normal form and used as an index into the cache.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawings.
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According to a conventionally known technique, example, a flange made of Kovar is brazed to a ceramic, and a pipe member made of a metal is connected to the flange 2 from inside by means of silver solder (Patent Document 1).
According to this technique, the pipe member has a circumferential groove formed at an end portion thereof. The groove obstructs a flow of a molten silver solder so as to prevent flow of the molten silver solder into unnecessary portions, whereby the molten silver solder can be concentrated at a brazing zone for firm brazing.
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The present invention relates generally to moisture analyzers. More specifically, the present invention relates to a continuous flow moisture analyzer for determining the moisture content in a sample material under test.
Various manufacturing processes, chemical reactions, and laws attendant certain industries require that the percentage of certain volatile fluids of interest present within a product be known. Indeed, the determination of moisture (or volatile) content in materials is of such importance in so many fields that a wide variety of devices and analytical methods have been developed to provide such information. One such analytical moisture analysis method is a chemical analysis method known as the Karl Fischer technique. The Karl Fischer moisture analysis technique is a method of titrating a test sample with a reagent to determine trace amounts of water in the test sample. Unfortunately, chemical analysis methods rely on the use of various reagents which may be toxic. Moreover, such chemical analysis methods usually require very skilled operators and are often quite time consuming.
Moisture analysis devices include, for example, vacuum ovens and convection ovens which heat a test sample of the product to a temperature commensurate with the volatile fluid of interest to cause evaporation of such fluid. Devices of this type are often referred to as loss on drying analyzers. Using a loss on drying moisture analyzer, the resulting reduction in weight of the test sample provides data for computing the percent by weight of the volatile fluid of interest in the test sample. Various computational techniques may be employed to forecast the percentage determination based upon the initial weight loss rate. Such computational approximations reduce the time required to complete a test without serious derogation of the accuracy of the determination. Loss on drying techniques are limited to approximately 0.1% minimum moisture loss due to secondary effects such as convective air currents, buoyancy effects, and temperature gradients. In addition, loss on drying techniques can sustain some degree of measurement error relative to the accuracy of the scale used for weighing the test sample.
Other moisture analysis devices employ sensors that measure the quantity of volatile fluid in a gas stream to determine the amount of volatile fluid in a test sample. For example, one such moisture analyzer includes a test sample heater, a dry carrier gas flow system, and a moisture transducer. The moisture analyzer heats a sample of test material contained in a septum bottle. The dry gas is injected into the septum bottle and absorbs the moisture out of the sample material. The dry gas, carrying the moisture from the sample, is ejected from the septum bottle and transported to the moisture transducer where the moisture content of the flowing gas is measured. A processor then integrates the varying moisture signal and converts the integrated signal to total moisture content. Using the sample weight and the total moisture content value, the moisture concentration in the test sample is subsequently calculated.
Unfortunately, problems such as pre-existing moisture levels, transient response times, and contamination render the measurement of moisture content inaccurate. In one such moisture analyzer, uncontrolled moisture can be introduced into the dry carrier gas flow system. This uncontrolled moisture results in a non-consistent baseline, which consequently leads to inaccuracy in the measurement of the moisture content in the sample material.
Accordingly, it is an advantage of the present invention that a continuous flow moisture analyzer is provided.
It is another advantage of the present invention the continuous flow moisture analyzer efficiently and accurately determines the moisture content in a sample of dry material.
It is another advantage of the present invention that the continuous flow moisture analyzer accurately determines the moisture content in a sample material by substantially preventing the introduction of uncontrolled moisture in the gas flow system of the moisture analyzer.
The above and other advantages of the present invention are carried out in one form by a continuous flow moisture analyzer including a first needle portion having a first channel for receiving a carrier gas and having an output orifice from the first channel for expelling the carrier gas and a second needle portion having an input orifice for receiving the carrier gas expelled from the output orifice and having a second channel in communication with the input orifice for transporting the carrier gas. A housing encloses the output orifice and the input orifice when the moisture analyzer is in a standby mode. A bottle retains a sample material when the moisture analyzer is in an active mode. The bottle has a septum configured to face the housing, the first and second needle portions penetrating the septum to position the output and input orifices in the bottle. The carrier gas expelled from the output orifice absorbs moisture from the sample material, and a moisture sensor in fluid communication with the second channel detects moisture in the carrier gas.
The above and other advantages of the present invention are carried out in another form by a continuous flow moisture analyzer. The continuous flow moisture analyzer includes a coaxial needle having a first end and a second end. The coaxial needle includes a first needle portion having a first channel for receiving a carrier gas and having an output orifice from the first channel for expelling the carrier gas. The coaxial needle further includes a second needle portion having an input orifice for receiving the carrier gas expelled from the output orifice and having a second channel in communication with the input orifice for transporting the carrier gas. The output orifice and the input orifice are located proximate the second end. A housing encloses the output orifice and the input orifice when the moisture analyzer is in a standby mode. The housing includes a track in non-moving relation with the coaxial needle, and a sleeve slidably coupled to the track. A bottle retains a sample material and is configured to abut the sleeve when the moisture analyzer is in an active mode. The bottle has a septum facing the sleeve. When the bottle abuts the sleeve, the sleeve retracts along the track to allow the coaxial needle to penetrate the septum to position the output and input orifices in the bottle. The carrier gas expelled from the output orifice absorbs moisture from the sample material, and a moisture sensor in fluid communication with the second channel detects the moisture in the carrier gas.
The above and other advantages of the present invention are carried out in yet another form by a continuous flow moisture analyzer. A continuous flow moisture analyzer a first needle portion having a first channel for receiving a carrier gas and having an output orifice from the first channel for expelling the carrier gas and a second needle portion having an input orifice for receiving the carrier gas expelled from the output orifice and having a second channel in communication with the input orifice for transporting the carrier gas. A housing encloses the output orifice and the input orifice when the moisture analyzer is in a standby mode. The housing includes a track in non-moving relation with the coaxial needle, and a sleeve slidably coupled to the track. A bottle retains a sample material when the moisture analyzer is in an active mode. The bottle has a septum configured to face the housing. The moisture analyzer further includes a transport mechanism for conveying the bottle toward the housing so that the first and second needle portions penetrate a center portion of the septum to position the output and input orifices in the bottle. The carrier gas expelled from the output orifice absorbs moisture from the sample material, and a moisture sensor in fluid communication with the second channel detects the moisture in the carrier gas.
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Solid waste has become a global problem that faces every major industrial nation, including the United States. The municipal and industrial solid waste stream is still largely disposed of in surface landfills that are rapidly diminishing in both volume and number, while the waste stream continues to grow. New incinerators and landfills are equally unpopular whenever they are proposed and ambitious recycling goals, particularly in large metropolitan areas, are not being reached. The crisis, projected for some time to be upon us by the mid-1990's, continues to approach and adequate solutions have yet to materialize.
Various methods are known for the stabilization and storage of solid waste materials. For example, U.S. Pat. No. 4,374,672 discloses a method of producing a stabilized fill material in water which comprises mixing cement (1-6% by weight) fly ash (45-80% by weight) and water (20-50% by weight) and placing said fill material produced directly in water while it is still in a flowable state.
U.S. Pat. No. 4,514,307 discloses a method for disposing of physically unstable, water containing, non-biologic organic waste material. The method comprises combining said waste material with cementitious reactants in the presence of water to form an environmentally acceptable, impermeable, load bearing material.
U.S. Pat. No. 4,576,513 describes a process for the terminal storage of pumpable wastes in salt caverns. The process comprises pumping a water-containing pumpable waste containing a liquid phase into a salt cavern and increasing the specific gravity of said liquid phase with a material selected from soluble salts which crystallize at cavern temperatures, organic materials which solidify at cavern temperature in the liquid phase of the pumpable waste or increase the specific gravity thereof, and adsorbents. The effect is to minimize the convergence of the salt cavern by narrowing the difference between the specific gravity of the salt cavern walls and the specific gravity of the liquid phase of the pumpable waste.
U.S. Pat. No. 4,577,999 discloses a process for storing liquid waste in salt cavities. In the process, the liquid waste with a pH of 7.0 or more is blended with additional materials to produce a pumpable mixture which has a boiling point above 85.degree. C. a flash point above 65.degree. C., vapor pressure at 60.degree. C. of up to 0.5kp/cm.sup.2, a viscosity of less than 300cP, and which forms no toxic or flammable gases. The pumpable mixture is then fed into the mine cavity and, after separation of the heavier and lighter liquid phases, both phases are separately pumped out of the cavern.
U.S. Pat. No. 4,692,061 relates to a process for dumping particulate solid waste materials in an underground salt cavern containing rock salt solution and equipped with pipelines for filling and evacuating said cavern. The process generally comprises pumping out as much of the rock salt solution from the cavity as possible; rendering the particulate solids dust-free with a dust suppressant; introducing the dust-free particulate solids into the cavity until said cavity is two thirds to about three quarters (3/4) full; and, solidifying any water present in the dust suppressant together with any rock salt solution remaining in the cavity, and sealing the cavity.
U.S. Pat. No. 4,917,733 discloses a pozzolanic mixture for stabilizing landfill leachate which comprises fly ash with an excess of lime, kiln dust and optionally bottom ash, which is combined with water to produce a stable cementitious pozzolanic mixture that hardens to a mortar-like materials.
None of the prior art references encountered, however, disclose or suggest an acceptable method for the permanent storage of solid waste in an empty and/or mined salt cavity.
Salt mining activities in bedded salt deposits create a vast underground network of rooms excavated in dry, impervious salt which is encased above and below by virtually impermeable shales. Thus, these empty salt cavities are perhaps the most environmentally isolated places available for the storage of waste materials with permanent isolation from the biosphere.
Salt mines in bedded salt deposits have historically been mined using the room and pillar method wherein pillars of salt are left in place to hold up the mine roof. Alternatively, cribbing or more expensive fill materials are placed in critical mine areas to artificially support the roof. In some areas of weak rock in the roof and/or because of overmining, all mining activities were simply abandoned. Backfilling with a structurally supporting material made from industrial solid waste offers an entirely new area of salt mine stabilization that has not been previously considered. Additionally, this backfilling technique can also provide a partial solution for the todays solid waste disposal problem.
Accordingly, it is an object of the invention to provide a method and pozzolanic mixture which chemically converts to a strong, hard durable mass in a salt environment with favorable leaching and stability characteristics.
A further object is to provide a method of backfilling salt mines with a structurally supporting material said pozzolanic mixture.
Another objective is to provide an environmentally attractive alternative to surface landfills for the permanent reuse/disposal of selected solid waste materials.
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1. Field of the Invention
The present invention relates to an image forming apparatus and, in particular, to an image forming apparatus for preventing color mismatching, by rotating photosensitive bodies for respective colors in a matched state, and a method for preventing a color mismatch in the image forming apparatus.
2. Description of the Related Art
Known is an image forming apparatus for forming a color image by arranging image forming sections for colors such as yellow (Y), magenta (M), cyan (C) and black (K) near a transfer belt along a running direction of the transfer belt and allowing images based on image data for respective colors to be color matched. The respective image forming section of this apparatus comprises a photosensitive drum, a control section configured to allow a light exposure to be applied to the photosensitive body, a developing agent supply section, and so on. In the image forming apparatus thus formed, it is considered necessary to set the portions of respective drums over a transfer belt and, by drawing lines on the transfer belt with an integral multiple of a circumference length of the drum and detecting the lines, a light exposure timing is controlled to prevent any adverse effect exerted by a rotation vibration on a transfer surface during a rotation of the drum about a drum shaft. By doing so, an image of respective color components is transferred to the transfer belt, avoiding color mismatching.
In the case where, however, a rotation vibration is involved in the photosensitive drum itself, an image interval to be formed on the transfer belt varies during a rotation cycle of the photosensitive drum and there occurs a matched image on the transfer belt at some area but there sometimes arises a color mismatch on the transferred image at other areas. As a result, image quality formed in the image forming apparatus is somewhat lowered.
Therefore, there is a need for an image forming apparatus which prevent an image from being transferred from the photosensitive drum for respective colors onto a transfer surface throughout the rotation cycle of the drum in a color-mismatched state.
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The present invention relates to the field of microwave thermal therapy of tissue. In particular, the present invention relates to a catheter for transurethral microwave thermal therapy of benign prostatic hyperplasia (BPH).
The prostate gland is a complex, chestnut-shaped organ which encircles the urethra immediately below the bladder. Nearly one third of the prostate tissue anterior to the urethra consists of fibromuscular tissue that is anatomically and functionally related to the urethra and bladder. The remaining two thirds of the prostate is generally posterior to the urethra and is comprised of glandular tissue.
This relatively small organ, which is the most frequently diseased of all internal organs, is the site of a common affliction among older men: BPH (benign prostatic hyperplasia). BPH is a nonmalignant, bilateral nodular expansion of prostrate tissue in the transition zone, a periurethral region of the prostate between the fibromuscular tissue and the glandular tissue. The degree of nodular expansion within the transition zone tends to be greatest anterior and lateral to the urethra, relative to the posterior-most region of the urethra. Left untreated, BPH causes obstruction of the urethra which usually results in increased urinary frequency, urgency, incontinence, nocturia and slow or interrupted urinary stream. BPH may also result in more severe complications, such as urinary tract infection, acute urinary retention, hydronephrosis and uraemia.
Traditionally, the most frequent treatment for BPH has been surgery (transurethral resection). Surgery, however, is often not an available method of treatment for a variety of reasons. First, due to the advanced age of many patients with BPH, other health problems, such as cardiovascular disease, can warrant against surgical intervention. Second, potential complications associated with transurethral surgery, such as hemorrhage, anesthetic complications, urinary infection, dysuria, incontinence and retrograde ejaculation, can adversely affect a patient's willingness to undergo such a procedure.
A fairly recent alternative treatment method for BPH involves microwave thermal therapy, in which microwave energy is employed to elevate the temperature of tissue surrounding the prostatic urethra above about 45.degree. C., thereby thermally damaging the tumorous tissue. Delivery of microwave energy to tumorous prostatic tissue is generally accomplished by a microwave antenna-containing applicator, which is positioned within a body cavity adjacent the prostate gland. The microwave antenna, when energized, heats adjacent tissue due to molecular excitation and generates a cylindrically symmetrical radiation pattern which encompasses and necroses the tumorous prostatic tissue. The necrosed intraprostatic tissue is subsequently reabsorbed by the body, thereby relieving an individual from the symptoms of BPH.
One method of microwave thermal therapy described in the art includes intrarectal insertion of a microwave antenna-containing applicator. Heat generated by the antenna's electromagnetic field is monitored by a sensor which is positioned near the prostate gland by a urethral catheter. Owing to the distance between the rectum and the tumorous prostatic tissue of the transition zone, however, healthy intervening tissue within the cylindrically symmetrical radiation pattern is also damaged in the course of the intrarectal treatment. Intrarectal microwave thermal therapy applicators are described in the following references: Eshel et al. U.S. Pat. No. 4,813,429; and, A. Yerushalmi et al., Localized Deep Microwave Hyperthermia in the Treatment of Poor Operative Risk patients with Benign Prostatic Hyperplasia, 133 JOURNAL OF UROLOGY 873 (1985).
A safer and more efficacious treatment of BPH is transurethral microwave thermal therapy. This method of treatment minimizes the distance between a microwave antenna-containing applicator and the transition zone of the prostate by positioning a Foley-type catheter-bearing applicator adjacent to the prostate gland within the urethra. Due to the close proximity of the microwave antenna to the prostate, a lesser volume of tissue is exposed to the cylindrically symmetrical radiation pattern generated by the microwave antenna, and the amount of healthy tissue necrosed is reduced. Intraurethral applicators of the type described can be found in Turner et al U.S. Pat. No. 4,967,765 and Hascoet et al. European Patent Application 89403199.6.
While the close proximity of a transurethral microwave thermal therapy applicator to prostatic tissue reduces the amount of damage to healthy tissue, controlling the volume of tissue to be affected by the microwave energy field continues to be problematic. For instance, microwave antennas known in the art have tended to produce electromagnetic fields which affect a volume of tissue, beyond the desired area of treatment, which necroses healthy, normal tissue.
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Web sites, or Internet sites, often provide information, products, services, and the like to their users. Many web sites desire users to “register” before their web servers will grant access to the users. During registration, a user typically supplies personal information such as username, account number, address, telephone number, e-mail address, computer platform, age, gender, and/or hobbies to the registering web site. The registration information may be necessary to complete transactions (e.g., commercial or financial transactions). Typically, the information also permits the web site to contact the user directly (e.g., via electronic mail) to announce, for example, special promotions, new products, or new web site features. Additionally, web sites often collect user information so web site operators can better target future marketing activities or adjust the content provided by the sites.
When registering a user for the first time, a web site may request that the user select a login identifier, or login ID, and an associated password. The login ID allows the web site to identify the user and retrieve information about the user during subsequent user visits to the web site. Generally, the login ID is unique to the web site such that no two users have the same login ID. The combination of the login ID and password associated with the login ID allows the web site to authenticate the user during subsequent visits to the web site. The password also prevents others (who do not know the password) from accessing the web site using the user's login ID. This password protection is particularly important if the web site stores private or confidential information about the user, such as financial information or medical records.
Using a presently available multi-site user authentication system, a web user can maintain a single login ID (and associated password) for accessing multiple, affiliated web servers or services. Such a system permits the user to establish a unique account identified by, for example, an e-mail address.
Large Internet service providers often have many different web sites through which they offer services to consumers. Moreover, a single web service can actually be made up of many different content providers. Other sites may be used to provide content related to children's interests, e-shopping, news, and so forth. Consumers usually perceive these related sites as being essentially the same service. Further, as Internet usage migrates to a subscription-based model that includes content and services from a variety of different sites, the need exists for accurately sharing common information (e.g., billing and subscription information) between related sites.
As described above, a web site often gathers personal information about its users for later use. A typical privacy statement for a web site describes how the site protects and uses personal information. The policy will likely specify first what information the site collects. For example, the site may maintain a profile for the user including information (attributes) such as the user's e-mail address, first and last name, country or region, state or territory, ZIP code or postal code, language preference, time zone, gender, birth date, occupation, telephone number(s), credit card information, billing and shipping addresses, password, PIN, secret question and secret answer, clothing sizes, music preferences, and the like. Inasmuch as this profile information can be quite sensitive, the typical policy also specifies how the information will or will not be used. For example, a web site's privacy policy may forbid the site from selling or renting a user's personal information without prior consent. The same policy, however, may detail a number of permitted uses (e.g., resolving customer support inquiries, performing statistical analyses of the site's services, conforming to legal requirements, protecting the personal safety of users or the public). A typical policy often specifies certain circumstances under which disclosures or uses of information are permitted and those other circumstances under which they are not.
Users typically do not like to provide too much information during a first time sign-up or registration. If asked to provide more information than needed for sign-up or registration, the users may provide inaccurate information in order to speed up the registration process. Such inaccurate user information undermines the purpose of having a profile store.
Furthermore, there has been an increasing movement in local, federal, and international governments to require web sites to provide consumers explicit notice and choice in order for the consumers to grant affirmative consent for the sites to use the obtained consumer information. Prior systems and methods do not effectively address such consent requirements.
Another disadvantage of the prior systems and methods is that there is no mechanism for web sites to collect the same information from users. In other words, web sites get differing amounts of information depending on which users access the web sites. As a result, web sites are forced to collect the missing user information manually or to limit the service features for users who have not provided the necessary information.
Accordingly, a solution is needed that allows accruing consent for an affiliated site or service to use obtained user information while complying with the various consent requirements.
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{
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Vertebrates have a pair of ears, placed symmetrically on opposite sides of the head. The ear serves as both the sense organ that detects sound and the organ that maintains balance and body position. The ear is generally divided into three portions: the outer ear, auris media (or middle ear) and the auris interna (or inner ear).
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{
"pile_set_name": "USPTO Backgrounds"
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The present invention relates to the field of multimedia media content delivery.
For multimedia content delivery, media presentation description (MPD) of dynamic adaptive streaming over hypertext transfer protocol (HTTP) (Dynamic Adaptive Streaming over HTTP or DASH) can be used, specified in 3rd Generation Partnership Project (3GPP) technical specification (TS) 26.247, which appeared earlier as part of the Packet-Switched Streaming (PSS) service, 3GPP TS 26.234.
In order to deliver files over the internet, also the File Delivery over Unidirectional Transport (FLUTE) [Request for Comments (RFC) 3926] can be used. FLUTE is a protocol for unidirectional delivery of files over the Internet. The specification builds on Asynchronous Layered Coding (ALC) [RFC 3450], the base protocol designed for massively scalable multicast distribution.
For serving large groups with the same media content, the Multimedia Broadcast Multicast Service (MBMS) can be employed. The MBMS Download Delivery Method is designed to deliver an arbitrary number of objects via MBMS to a large receiver population. Two delivery methods are defined in MBMS, 3GPP TS 26.346, namely download and streaming.
MBMS download delivery method uses the FLUTE protocol [RFC 3926] when delivering media content over MBMS bearers.
DASH as defined in 3GPP TS 26.247 specifies formats and methods that enable the delivery of streaming service(s) from standard HTTP servers to DASH client(s). It involves the description of a collection of media segments and auxiliary metadata (all referenced by HTTP-uniform resource locators (URLs)) through a MPD.
The download delivery method, i.e. MBMS, allows the delivery of DASH segments and MPDs as defined in 3GPP TS 26.247. Segment URLs are described using FLUTE.
The network may announce the usage of MBMS download delivery method for providing the Media Segments for DASH through the MBMS User Service Description. In such an event, the MBMS User Service Description fragment shall include a MPD element. This element contains a reference to a MPD metadata fragment as defined in 3GPP TS 26.247. Consequently, the User Equipment (UE) can expect that the files provided with the MBMS download delivery method are formatted according to the 3GP file format for DASH as specified in 3GPP TS 26.244. Furthermore, the MPD fragment may contain reference(s) to Initialisation Segment Description fragment(s) as defined in 3GPP TS 26.247.
In order to start consuming a DASH service delivered over MBMS, an MBMS client has to perform the following steps:
Receive the User Service Bundle Description.
Map the MPD to the corresponding Delivery Method.
Set-up the reception of MBMS user service data.
Receive File Delivery Table (FDT) instance from ALC/layered coding transport (LCT) session.
Map the URL of the chosen representation to the Transport Object Identifier (TOI) using received FDT instance.
Store the received object in the UE cache, which can be fetching by DASH client using GET request.
In the process of initializing DASH media content reception transmitted over MBMS a reception of the FDT instance introduces delay which negatively impacts the quality of experience. Before any segment (‘object’) of the chosen representation is received from the MBMS session, an FDT instance must first be received. An FDT instance is transmitted periodically over the ALC/LCT session. The introduced delay depends on the time interval the FDT instance is sent on.
Delivering DASH media content over MBMS for devices that support MBMS reception may be performed by operating a FLUTE client in one of the supported modes. The FLUTE client supports 2 operation modes:
Download-all mode: in this mode the FLUTE client is instructed to download all files (transport objects) in the session, or
Request-based mode: in this mode the FLUTE client is instructed about which files the FLUTE client should download.
However, by the time the DASH client sends the request for a media segment, it might be already being transmitted over the FLUTE session (ALC/LCT session) or the transmission might be already over. This can cause additional delays to enable the FLUTE client to recover the file.
On the other hand, the Download-all mode may not be appropriate in all scenarios as the FLUTE client will download all file sent over the session and this would lead to excessive storage usage, especially when multiple representations are transmitted simultaneously over the same MBMS session.
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{
"pile_set_name": "USPTO Backgrounds"
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Radio communication channels such as HF, VHF and UHF introduce distortion in the form of multipath and fading into the originally transmitted signal. A result of these types of channels is inter-symbol interference (ISI), which occurs if the modulation bandwidth exceeds the coherent bandwidth of the radio channel and causes the modulation pulses to spread in time to adjacent symbols. Intersymbol interference can also be caused by the radio channel exhibiting time and frequency dispersion (e.g., delay spread and Doppler spread) due to the presence of signal reflectors/scatterers in the environment or the relative motion of transmitter and receiver. Intersymbol interference has also been known to cause bit errors at the receiver, which distorts the intended message content. To address such transmission channel distortion, many different types of channel estimation algorithms and adaptive equalizers have been included in the receivers.
Modern communication systems are requiring wider and wider bandwidth signals in order to support the data rates desired by users. The large amount of legacy equipment in the HF/UHF/VHF bands can at times cause unintentional interference to these new wideband systems. In addition, intentional jamming can also occur. Adaptive filters are commonly used in communication systems to reduce the effects of narrowband interferers. An adaptive filter can process the communication signal prior to acquisition, demodulation, equalization and decoding. Adaptive filters do not require knowledge of the channel in advance and incorporate an Infinite Impulse Response (IIR) or Finite Impulse Response (FIR) filter with adaptive filter coefficients that adjust themselves to achieve a desired result, such as minimizing unwanted narrowband interference of the input signal. The adaptive filter typically uses an adaptive Recursive Least Squares (RLS), Least Mean Squares (LMS) or Minimum Mean-Square Error (MMSE) estimation as an algorithm.
Modern communication systems typically transmit a preamble (i.e. a known waveform section) which demodulators can use to achieve waveform synchronization. In addition, the preamble may also contain information transmitted in a very robust fashion used to indicate the waveform parameters used for the data portion of transmission that follows this initial preamble (i.e. modulation type (2-PSK, 4-PSK, 8-PSK, 16-QAM, etc), burst length, type of forward error correction, etc). When a system incorporates waveform information in its preamble it is referred to as an autobaud system. When another mechanism is used to convey this information, such as a control channel or a separate transmission providing this information, the preamble is used only for synchronization. It may be advantageous to a communication system to feedback demodulator state (preamble search state, preamble state, and data state) and demodulator information (modulation type, etc) to adaptive filter to more effectively deal with narrowband interference while reducing the effects of adaptive filter on the data portion of waveform.
There are many design tradeoffs when using adaptive filters in modern wideband UHF/VHF tactical radios such as number of filter taps, speed of adaptation, etc. In addition, many platform (i.e. radio hardware) constraints such as size, weight, power and relatively small Field Programmable Gate Array (FPGA) usage are imposed on the adaptive filter design. The proper tradeoff in the adaptive filter design is necessary so that more than one interferer can be handled by adaptive filter (typically three to four is desired) while still meeting platform constraints. Examples of interferers in the HF/VHF/UHF band are analog frequency modulation (FM) voice, frequency shift keying (FSK) signals (i.e. 16 kbps FSK), tone signals or carriers.
Some adaptive filters incorporate spectral based techniques that use a Fast Fourier Transform (FFT), thus, making them too complex for some radio implementations. Adaptive filters such as Finite Impulse Response (FIR) filters, or Infinite Impulse Response (IIR) filters exist and have been found to work well at lower bit rates and bandwidths. Both types of filters, however, have some drawbacks, but with improvements, should provide important design enhancements for adaptive filters used in complex communications systems.
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{
"pile_set_name": "USPTO Backgrounds"
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The production of rubber for a vehicle tire includes a plurality of successive mixing steps. For example, patent GB423,637 discloses a means for maintaining a predetermined temperature of rubber during mixing on a roller tool. This means operates by expansion and contraction of an element that responds to the change in the rubber temperature and sends water to the open mill. An initial mixture of elastomeric materials with a carbon black filler and/or silica is often carried out inside a mixer, where the temperature of the mixture rises, for example up to values of between 150° C. to 200° C. An automated external mixer (also called “roll mixer” or “roller tool”) in which this mixture is then transferred works the mixture, causing it to flow between two rolls so as to convert it into a continuous sheet. Vulcanization products (including, without limitation, sulfur) may be added to the mixture later in the mixing cycle to obtain the final mixture for commercial use.
During the mixing process, repeated rolling results in plasticization of the mixture and causes the temperature to rise accordingly. The mixture is cooled to prevent premature partial vulcanization and/or degradation of insoluble additives. To perform cooling, some methods include cooling fans or integrated cooling systems (e.g., fluid circulating within the cylinders). Other methods employ spray and aspiration equipment that add water to the mixture being worked.
The properties of the mixture, however, are very sensitive to the proportions of its constituent ingredients. Added water can compromise the quality of the finished tire. Vaporization offers an effective solution to cool the mixture and can be used with temperature control during mixing so that the beneficial properties of the tires are preserved.
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{
"pile_set_name": "USPTO Backgrounds"
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1. Field of the Invention
The invention relates to a blood pump, and more particularly, the invention relates to a centrifugal blood pump system with a turbine drive assembly.
2. Brief Description of the Related Art
Blood pumps used in surgical procedures such as cardiopulmonary bypass (CPB) and coronary artery bypass grafting (CABG) are single-use devices. These blood pumps are generally powered by a reusable electric motor which drives the pump through a magnetic coupling. However, the reusable electric motors are not sterilizable. Thus, the motor and attached pump are positioned outside the sterile surgical field at a location away from the patient. The disposable pump is connected to the patient by long lengths of tubing which transport the patient's blood to and from the blood pump. The long lengths of tubing increase the priming volume of the pump which is the amount of the patient's blood and/or saline which must be drawn into the tubing and the pump to prime the pump before blood begins to be returned to the patient.
Long lengths of tubing connecting the pump to the patient also increase the amount of foreign material which comes into contact with the patient's blood, increasing trauma to the patient. A typical CPB circuit includes several feet of flexible tubing that the patient's blood flows through. In order to prevent blood clots, the patient's blood is generally treated with Heparin. The use of Heparin is preferably minimized because Heparin prevents the blood from clotting.
In either stopped heart or beating heart surgery, it is desirable to minimize the priming volume of the blood pump by placing the pump as close as possible to the surgical site. By placing the pump closer to the surgical field, the amount of saline required to prime the bypass circuit is reduced which reduces the likelihood that a transfusion will be required. Previous attempts to move the blood pump closer to the patient have involved the use of a cable drive for the blood pump which allows the sterile pump to be located within the sterile surgical field while being driven from a remotely located motor. However, the cable used in the cable drive system may break causing pump failure.
Accordingly, it would be desirable to provide a blood pump system which allows the blood pump to be positioned within the surgical field close to the surgical site to minimize the priming volume of the pump. In addition, it would be desirable to drive a blood pump in a manner which does not generate heat as in a system using an electric motor.
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{
"pile_set_name": "USPTO Backgrounds"
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A washing cycle of laundry as performed by a laundry washing appliance generally comprises two phases: a washing phase and a rinse phase.
A wash program o process comprises one or more washing cycles and is possibly terminated by a final spinning phase. Additional spinning steps might be present between consecutive rinsing steps during the rinsing phase.
The washing phase represents the portion of each washing cycle during which water is supplied into the appliance possibly together with the detergent to form a washing liquor (wetting step), the washing liquor is possibly heated (heating step), the laundry to be washed is subjected to tumbling of the drum in order to repeatedly expose it to mechanical action and to the washing liquor, so that dirt is removed from the laundry and stabilized in the washing liquor (tumbling step) and finally the washing liquor in which dirt is stabilized, is drained from the washing chamber (draining step).
The key parameters involved in each washing phase are: temperature, amount of water, mechanical action, detergent type/amount and duration. In order to provide best results in washing performances vs. water and energy consumption, one or more of these parameters are generally optimized.
The rinsing phase aims to remove the residuals of dirt and detergent coming from the washing phase. In many appliances, the rinsing phase is performed stepwise, e.g. generally two or three rinsing steps are performed. Each step is commonly characterized by a defined amount of water, duration, and mechanical action.
In current laundry washing appliances, the duration of each washing phase and the timing between its subsequent phases or steps are preset by the selection of a washing program and other possible parameters without taking into account the effective water and/or laundry conditions. In other words, each next phase or step starts independent of the completion degree of the previous one. By way of an example, each washing phase of a wash program has usually a predefined duration which is fixed and dependent on the specific wash program chosen by the user.
The expression “predefined duration of a washing phase” is used to identify the duration preset by the choice of a specific wash program.
Applicant has realized that the effectiveness of the washing phase depends on the time that the laundry is exposed to the fully dissolved detergent into the washing liquor at the most appropriate temperature.
Furthermore, Applicant has noted that the time required to reach a full dissolution condition varies from detergent type to detergent type.
Many types of detergents to be used in laundry washing appliances are available nowadays.
The detergents can be classified into different kinds, depending on their physical state: there are detergents in powder form and detergents in liquid or gel form. Furthermore, the above detergent kinds can be found on the marked in conventional form or pre-dosed.
Throughout the present description, the expression “detergent in conventional form” is used to refer to a detergent which can be poured or introduced loose into the washing machine drawer in a quantity which can be freely decided by the user. Throughout the present description, the expression “pre-dosed detergent” is used to refer to a detergent which the user introduces directly into the drum in a pre-established quantity. The pre-dosed detergent can be in liquid, gel or powder form (the latter possibly pressed).
Pre-dosed detergents—especially pre-dosed detergents in liquid or gel form, but in some cases, also pre-dosed detergents in powder form—are conventionally encapsulated, namely enveloped in a plastic membrane which dissolves in water. Applicant has noticed that encapsulated detergents require a longer time before a condition of full dissolution into water is reached, compared to the other detergent types since the plastic membrane has to dissolve first, before dissolution of the detergent in water can start.
Moreover, the real dissolution time depends also on the specific loading conditions which could affect the exposure of the plastic membrane to water. By way of an example, the encapsulated detergent should be preferably placed on the bottom of the drum, before the laundry is loaded.
If the user does not follow the above loading sequence, the dissolution of the plastic membrane could take longer than expected so that the detergent would reach its dissolved state only towards the end of the washing phase.
This could lead to a reduced washing effectiveness since less time would be available for the dissolved detergent to act on the laundry during the washing phase.
This problem could arise also if the correct loading sequence is followed by the user. In fact, it could happen that the movement of the laundry inside of the drum pushes the encapsulated detergent towards the top of the laundry or the door gasket. In these positions, the encapsulated detergent does not get in contact with enough water in order to undergo a rapid dissolution.
The above considered, Applicant has realized that, a deeper correlation between the duration of the washing phase and the water and/or laundry conditions could lead to performance improvements and has focused its attention to the lack of coordination between detergent dissolution and the duration of the washing phase in current washing appliances.
Applicant has considered that setting a very long washing phase duration corresponding to the feasible longest detergent dissolution would imply, in most cases, an unnecessary extension of the overall wash program duration which could make the user believe that a deficiency is present in the washing apparatus itself, which is, in his/her opinion, not performing properly.
Applicant has thus understood that a modification in the laundry washing appliance has to be made in order to establish a tuning between detergent dissolution and the washing phase so as to link the duration of the washing phase to the real dissolution level of the detergent, thereby optimizing the washing performances while keeping short the overall washing cycle duration.
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{
"pile_set_name": "USPTO Backgrounds"
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