An apparatus prevents developer wraparound in a wet electrophotographic printer using wraparound preventing units. Each of the wraparound preventing units has varied diameter parts formed at both ends of a developing roller, and matching parts formed at both ends of a metering roller to correspond to the varied diameter parts of the developing roller. Since the varied diameter parts and the matching parts are respectively installed at both ends of the developing roller and the metering roller, developer wraparound is not generated in the developing roller and a photosensitive roller during development.

1. Field of the Invention
The present invention relates to a wet electrophotographic printer using a high density liquid developer, and in particular, to an apparatus for preventing wraparound in a wet electrophotographic printer which can prevent developer wraparound in a developing roller and a photosensitive body during development.
2. Description of the Related Art
In general, an electrophotographic printer obtains a desired image by forming an electrostatic latent image on a photosensitive medium or body such as a photosensitive belt or drum, developing the electrostatic latent image by using developers having predetermined colors, and transferring the developed image to paper. The electrophotographic printer is divided into a wet type and a dry type according to a kind of developer. The wet electrophotographic printer employs a liquid developer obtained by mixing a volatile liquid carrier with a powder type toner.
Since the wet electrophotographic printer using the liquid developer utilizes a toner having a grain size below about 0.5 to 5 μm, the wet electrophotographic printer obtains higher quality image than an image formed by the dry electrophotographic printer using the powder type toner in development of the electrostatic latent image, and prevents damage due to harmful toner dusts. Therefore, the wet electrophotographic printer has gradually become popular.
However, the wet electrophotographic printer obtains an appropriate image density by using a low density liquid developer, the density generally being below 3% solid. Accordingly, a complicated developer delivery system to supply sufficient liquid developer to a developing region of a developing apparatus and collecting the developer is required to obtain the appropriate image density, thus increasing a bulk of the developing apparatus and complicating the system.
In addition, an apparatus to control a density of the liquid developer is necessary to obtain the appropriate image density when replenishing the developer due to variations of toner grains after the development.
Therefore, the developer delivery system needs to be removed or simplified to prevent the wet electrophotographic printer from being oversized or excessively complicated. Accordingly, the wet electrophotographic printer that uses a high density liquid developer over 3% solid, rather than a low density liquid developer below 3% solid, has been more polular.
FIG. 1 is a schematic view illustrating a general electrophotographic printer using a high density liquid developer.
The wet electrophotographic printer includes a photosensitive body 9 such as an organic photoconductive (OPC) drum, a laser scanning unit 11, a charged roller 12, a developing apparatus 13, a transfer belt 10 moving on a caterpillar-like photosensitive belt, primary and secondary rollers 21 and 22 for rotating the transfer belt 10 on the photosensitive belt, a first transfer roller 8 for transferring an image to the transfer belt 10, a second transfer roller 23 for transferring the image to paper P, a fixing roller 25 for fixing the image, and a cleaning blade 51 for removing a residual image from the transfer belt 10. The constitutional elements of the printer sequentially perform an image formation process including charging, exposure, development, transfer and fixation by mutual operations, to form a wanted image on the paper P.
In general, a color printer includes four laser scanning units 11 for color printing, and four developing apparatuses 13 for individually containing high density liquid developers 48 of 3 to 40% solid, which have four colors, namely black, yellow, cyan and magenta.
As illustrated in FIG. 2, each of the developing apparatuses 13 includes a storing unit 6 for storing the high density liquid developer 48, a developing roller 7 positioned below the photosensitive body 9, a deposit roller 14 installed below the developing roller 7 for transmitting an electric force to the liquid developer 48 to form a charged developer layer on the developing roller 7, a metering roller 15 for transmitting a predetermined voltage to the charged developer layer formed on the developing roller 7 by the deposit roller 14 to adhere a large volume of toner to the developing roller 7, and restricting the charged developer layer to a predetermined toner amount or density (% solid) to be supplied into a nip between the developing roller 7 and the photosensitive body 9, and a cleaning roller 16 for cleaning the developing roller 7.
The deposit roller 14 and the metering roller 15 serve to supply a predetermined toner amount or density of developer layer into the nip between the developing roller 7 and the photosensitive body 9, regardless of a density of the high density liquid developer 48 having 3 to 40% solid, or the liquid developer 48 having a density that varies during use.
The operation of the wet electrophotographic printer is explained below.
According to a print command, an electric charge layer, namely an electrostatic latent image corresponding to an image to be printed is formed on the photosensitive body 9 by the charged roller 12 and the laser scanning unit 11. A predetermined amount of toner of the developer layer formed on the developer roller 7 is adhered to the electrostatic latent image region from the liquid developer 48 of the storing unit 6 by the deposit roller 14 and the metering roller 15, thus forming a toner image.
Here, the liquid developer 48 is formed as a charged developer layer on the developing roller 7 due to an electric force from the deposit roller 14, and formed as a predetermined toner amount of a developer layer on the developing roller 7 due to a predetermined voltage from the metering roller 15.
The image formed on the photosensitive body 9 by the developing apparatus 13 is first transferred from the photosensitive body 9 to the transfer belt 10 due to a voltage and pressure of the first transfer roller 8 positioned inside the transfer belt 10. Since the transfer belt 10 is rotated by the primary and secondary rollers 21 and 22, the image transferred to the transfer belt 10 is moved to the second transfer roller 23 and then is transferred to the paper P due to a voltage and pressure of the second transfer roller 23.
The image transferred to the paper P is fixed to the paper P by the fixing roller 25 and a fixing backup roller 26, thus forming a desired image.
After the image transferred to the transfer belt 10 is transferred to the paper P, the transfer belt 10 is continuously rotated by the primary and secondary rollers 21 and 22 and moved to the cleaning blade 51 installed to contact the image formation side of the transfer belt 10 at the side of the primary roller 21. Here, residual developer sediments (generally 90 to 98% of developer is transferred to the paper) are removed from the surface of the transfer belt 10 by the cleaning blade 51 for succeeding image printing, and collected in a used developer storing unit 52.
The transfer belt 10 from which the residual developer sediments are removed repeats the aforementioned procedure to perform the succeeding electrostatic latent image formation and development through the photosensitive body 9, the laser scanning unit 11 and the developing apparatus 13.
However, as shown in FIGS. 3A to 3C, the conventional printer has a structure wherein the outer surfaces of the metering rollers 15, 15′ and 15″ for varying the charged developer layers formed on the developing rollers 7, 7′ and 7″ by the deposit roller 14 into the predetermined toner amount or density of developer layer and the outer surfaces of the developing rollers 7, 7′ and 7″ touch each other.
Accordingly, as shown in FIG. 4, in a state wherein the charged developer layer is formed on the developing roller 7 by the deposit roller 14, when the metering roller 15 forms the nip with the developing roller 7 and restricts the charged developer layer to have a predetermined toner density by rotation, the liquid developer 48 pushed toward both side surfaces of the metering roller 15 is collected in the space between the metering roller 15 and the developing roller 7 where the developer layer 17 restricted to have a predetermined density by the nip between the developing roller 7 and the metering roller 15 is positioned. At the worst, the liquid developer 48 is transferred to the photosensitive body 9 through the developing roller 7 to form wraparound 18, thus partially or wholly supplying the toner over a predetermined amount or density into the nip between the developing roller 7 and the photosensitive body 9.
As described above, the toner over a predetermined amount or density supplied into the nip between the developing roller 7 and the photosensitive body 9 reduces a quality of the image. In addition, after the image is transferred to the paper P, the toner is left on the surface of the photosensitive body 9, increasing the developer segments collected in the used developer storing unit 52 by the cleaning blade 51. Therefore, consumption of the developer is unnecessarily increased.
Referring to FIG. 5A through FIG. 5C, a developing apparatus of another conventional wet electrophotographic printer is illustrated using a squeezing unit squeezing a developer transferred on a latent image region of a photosensitive body to change a toner contained in the developer into an image film and to remove a carrier except for the toner contained in the developer when excess developer is supplied on the photosensitive body. The developing apparatus is disclosed at Korean patent laid-open No. 2000-56601 of Lee youn Keun et al., filed on Feb. 24, 1999 and laid open on Sep. 15, 2000 in the title of "A Squeezing Unit of Wet Electrophotographic Printer".
In the developing apparatus, the squeezing unit 27 comprises a squeeze roller 28 disposed to come in contact with a photosensitive body 9′ such as a photosensitive belt and away from a developing roller 7′″ to be driven by the photosensitive body 9′ during development, and a blade 30 disposed to be separable from squeeze roller 28 to remove a drip line 33 (FIG. 5C) forming on the photosensitive body 9′ when the squeeze roller 28 is rotated in a direction opposite to a rotation direction of the photosensitive body 9′ to remove the developer remaining on the photosensitive body 9′ after development.
The squeeze roller 28 has taper portions 29 formed at both ends thereof to prevent a wraparound generating between the blade 30 and the squeeze roller 28 when the drip line 33 is removed by the blade 30, from being transferred to the photosensitive body 9′.
However, in the developing apparatus of the conventional printer, the squeezing unit 27 needs a separate blade 30 and is disposed away from the developing roller 7′″. Also, the photosensitive body 9′ is formed of a photosensitive belt. Accordingly, the printer is oversized or excessively complicated.

Apparatus for preventing developer wraparound in wet electrophotographic printer


A plug flow reactor having an inner shell 27 surrounded by outer shell 21 and having at least one annular flow passage 35 therebetween can be used to prepare compositions, including polymers. The plug flow reactor also includes inlet port 36, an outlet port 37 and a plurality of exchanger tubes 26 wherein the exchanger tubes are in fluid communication to the at least one annular flow passage. Polystyrene and high impact polystyrene can be prepared using the reactor.

1. Technical Field
The invention relates to a plug flow reactor. The invention particularly relates to a plug flow reactor for use in preparing polystyrene and impact polystyrene.
2. Background of the Art
Exothermic processes for the production of compositions such as, for example, polystyrene are known. In these processes, the reactants are first heated to initiate the reaction, but then the reactants are cooled during the reaction. The capacity to cool the reactants is often a limiting process parameter.
Such highly exothermic processes, unless carefully controlled, can cause the operation of reactors both to be hazardous and to lead to undesirable side reactions. For example, in the production of synthetic natural gas, run-away reactor conditions can lead to the depositing of coke and eventually plugging the equipment. Control of such reactors can be further complicated as a commercial reactors generally must handle reactant feeds that may vary widely in composition over a given period of time.
One solution to this problem is to use a back-mixed reactor. In such a reactor there ideally is no temperature gradient as the material within the reactor is of uniform composition and temperature. There are several means of achieving a back-mixed reactor which means are well known to those versed in the art. These include the use of a fluidized bed of solid material as well as back-mixing by purely hydrodynamic means. While the back-mixed reactor is a satisfactory manner of solving the problem of temperature control, it has several disadvantages when compared to a plug-flow reactor. Many applications require reaction conditions having minimal back-mixing such as that found in a plugflow reactor. Also, use of a back-mixed reactor may lead to problems in the formation of unwanted by-products.
Thus, it would be desirable in the art to prepare certain products using a plug flow reactor that has good temperature control and is economical to employ.

Plug flow reactor and polymers prepared therewith


The present invention discloses a process for the on-demand production of small quantities of lead azide. First, a metered quantity of sodium azide solution and a metered quantity of a solution of a lead salt sufficient to react with the sodium azide are introduced into a T-mixer or Y-mixer. Then, the sodium azide and lead salt solutions are conveyed into a static mixer and the azide and lead compounds are permitted to react together, forming insoluble crystals of lead azide as a slurry in an aqueous medium. The lead azide crystals are then separated from the aqueous medium. The process is carried out within an explosion-proof chamber.

1. Field of the Invention
The present invention relates to a process for the on-demand production of small quantities of lead azide. In particular, the present invention relates to a process for the on-demand production of small quantities of lead azide, said process comprising the steps of:
in a reactor assembly,
introducing a metered quantity of an azide component comprising sodium azide solution and a metered quantity of a lead component comprising a solution of a lead salt sufficient to react with said azide component into a primary mixing chamber that may be in the form of a T-mixer or Y-mixer;
conveying said azide component and said lead component into a static mixer;
permitting said azide component and said lead component to react together, forming insoluble crystals of lead azide as a slurry in an aqueous medium; and,
separating said lead azide crystals from said aqueous medium,
wherein the process is carried out within at least one explosion-proof chamber.
2. Description of Related Art
Lead azide remains a required component in the detonation, and the detonators, of nearly every type of munitions. Unfortunately, however, lead azide is no longer produced in the United States. The Department of the Army's existing stockpile of lead azide is stored at Lone Star AAP. A recent study showed that the material could recrystallize under long-term storage conditions, causing potentially dangerous changes in sensitivity and performance. Recent analyses of samples of stockpiled lead azide have identified batches with such modified crystals.
Traditional commercial production of lead azide has required stainless steel mixing kettles, air-driven agitation, and safety barricades in a dedicated facility, with all the capital costs, which are attendant to such requirements. Commercial production is typically carried out in a batch process, with a typical production being three and a half kilograms (3.5 kg) in a sixty-liter (60L) stainless steel kettle. Production is based upon simple chemistry in which an aqueous solution of a lead salt, typically lead (II) acetate or nitrate, is mixed with an aqueous solution of sodium azide. The reaction is essentially instantaneous, and the lead azide product precipitates out.
Because lead azide is so unstable, however, and because other metal azides can result that are even more unstable, the manufacturing process is dangerous. Further, the presence of lead, a heavy metal, creates environmental risks and regulatory issues.

The United States of America as represented by the Secretary of the Army


Embodiments of a user station (STA) and methods for synchronizing with devices in a wireless communication network are generally described herein. In some embodiments, a STA receives a first beacon from a device in the first social network. The STA may synchronize to the first social network based on time synchronization information in the first beacon. The STA may transmit the time synchronization information of the first beacon to a second social network. A portion of a coverage area of the second social network may be outside a coverage area of the first social network.

Recently, there has been an upsurge in the use of residential Institute of Electrical and Electronics Engineers (IEEE) 802.11 wireless networks to provide a distribution medium between homes in a neighborhood. This wireless connectivity may be provided over so-called social channels, defined by Wi-Fi Direct. User devices may use time synchronization information of a wireless access point (AP) to receive services or discover other user devices in a social network served by the AP and communicating over the social channels. If no APs are nearby, or if no APs can provide services at a threshold level, a user device may join or form a social network comprised of other user devices, and this social network may have its own synchronization information.
A user device may wish to communicate with a device in a neighboring social network, and these communications may require the user device to have knowledge of synchronization information for the neighboring social network. Accordingly, there is a general need for methods for providing time synchronization and discovery-related information of a social network to neighboring AP-based and non-AP-based social networks so that user devices in neighboring social networks may discover each other and communicate over social channels.

Methods, wireless communication stations, and system for time synchronization and discovery


A transmission cable includes a conductor or a bundle of conductors extending along a longitudinal axis, which is circumferentially covered by an insulation layer having an extruded insulation material, whereby the transmission cable passes the electrical type test as specified in Cigré TB496, whereby the rated voltage U0 is 450 kV or more. The type test includes subjecting the power cable to a DC voltage of 1.85*U0 during 10 to 15 cycles at negative polarity, followed by a polarity reversal with another 10 to 15 cycles at positive polarity at a DC voltage of 1.85*U0, followed by additional 2 to 5 cycles during at least 4 to 10 days at positive polarity, and wherein U0 is 450 kV, or 525 kV, or more.

Electrical power transmission systems, such as cables, that are used for the transmission of power generally comprise a metallic conductor surrounded by an insulating coating. Insulation for such transmission cables is important for the reliability of the transmission cable. The reliability depends on the material used for covering the conductor or conductor layers. Extruded insulation materials for direct current (DC), alternating current (AC) or transient current (impulse) power cables may be exposed to high stresses. This is especially true for extruded insulation materials used in high voltage and extra/ultra high voltage (hereinafter collectively referred to as HV) systems. Such extruded insulation materials require a good combination of electrical, thermal and mechanical properties to provide for a system having an optimal power transmission capacity. The extruded insulation material is suitably flexible, strong and nonconductive.
A typical transmission cable comprises a conductor or a bundle of conductors extending along a longitudinal axis, which is circumferentially covered by an insulation layer comprising the extruded insulation material. The insulation layer may be covered by a sheath.
As illustrated in FIGS. 2 and 3, for some transmission cables, such as HVDC cables, the conductor 7 may be circumferentially covered by an inner or first semiconductive layer 8, which layer is then covered by the extruded insulation layer 9. The extruded insulation layer 9 may be circumferentially covered by an outer or second semiconductive layer 10. The second semiconductive layer 10 may be covered by a screen and/or sheath 11, which may be lead or another metal. This sheath may be further covered by a protection layer 12 that may also have insulation and mechanical properties such as a plastic or rubber material. The transmission cables may also be a concentric cable with a metallic return.
At voltages over hundreds of kV, the extruded insulation material must be strong enough to withstand the voltage, since the conductor of the cable is on high voltage potential and the periphery of the cable has to be on earth potential. Losses of energy are reduced by increasing the voltage.
As shown in FIG. 1, for illustrative purposes only, a plant for transmitting electrical power has a direct voltage network 1 for HVDC having two cables 2, 3 for interconnecting two stations 4, 5, which are configured to transmit electrical power between the direct network 1 and an alternating voltage network 6, 7, which may have three phases and connected to the respective station. One of the cables 2 is intended to be on positive potential, while the other cable 3 is on negative potential. Accordingly, the plant has a bipolar direct voltage network. A monopolar network with a return current flowing through earth electrodes is also conceivable.
There is a need for transmitting more power in HV transmission cables. This can be done by increasing the size of the transmissions cables, or by increasing the current by using conductors with a higher conductivity. This conductivity is however limited by the conductor material, such as copper or aluminium. Another way of increasing the capacity of transmission cables is by improving the extruded insulation material.
The types of HVDC cables commonly used today are mass impregnated cables, oil-filled cables, and extruded cables. The electrical field acceptable for these cables is for the mass impregnated cables around 30 kV per millimetre and for extruded cables around 20 kV per millimetre.
The preference of extruded cables also for applications in HVDC has been obvious, because of the relative light weight and flexibility. Several reports have been published in the past, where crosslinked low density polyethylene (XLPE) has been tested for HVDC applications. The cables are operated in bipolar mode, one cable with positive polarity and one cable with negative polarity. The cables are installed close in bipolar pairs with anti-parallel currents and thus eliminating the magnetic fields.
Extrusion is a technique to deposit a uniform layer of an olefin polymer around a conductor, between two layers of semiconductive layers. The extruded insulation layer is obtained through a single extrusion process of the entire insulation thickness plus the inner and outer semiconductive layers, followed by a crosslinking phase of the insulation to the appropriate thermomechanical properties. In a so-called triple extrusion line, the bare conductor enters the triple extrusion head, where insulation and semiconductive layers are applied in sequence. Then, the insulated conductor enters a vulcanization pipe at high pressure and high temperature for the thermochemical crosslinking treatment. Degassing may be applied to remove the by-products from the crosslinking process.
An extruded resin composition typically comprises an olefin polymer as the base component. Olefin polymers, such as polyethylene polymers, e.g. low density polyethylene, have been used as extruded insulation materials for low, medium and high voltage cables. Olefin polymers may be cross-linked by using a cross-linking agent. These polymers have advantageous processability and electrical properties.
However, this material may not always be suitable for use in transmission cables for HV, such as voltages over 320 kV. One reason may be the existence of space charges in the insulation leading to uncontrolled local high electric fields causing dielectric breakdowns. Another reason may be uneven stress distribution due to temperature dependent resistivity causing overstress in the outer part of the insulation layer.
The space charges distort the stress distribution and persist for a long period, because of the high resistivity of the polymers. When subjected to the forces of an electric DC-field, space charges accumulate in an insulation body. As a result, a polarized pattern similar to a capacitor is formed. This results in a local increase of 5 or even 10 times in electrical field in relation to the contemplated field for the cable.
Space charges build up slowly in the insulation layer. This process is accentuated when the polarity of the cable is reversed. As a result of the space charge accumulation, a capacity field is superimposed on the field when the polarity is reversed, especially when the reversal is done after a long period of using one polarity. As a consequence, the point of maximum field stress is moved from the interface and into the insulation layer.
To improve the physical properties of the extruded insulation and its capacity to withstand degradation and decomposition under the influence of conditions prevailing under production, shipment, laying and use, the olefin polymer based insulation material may comprise additives such as stabilizers, ion scavengers, anti-oxidants, lubricants, scorch retarding agents, fillers, and the like. When selecting additive, the aim is to improve certain properties, while other properties are maintained or also improved. However, in practice it has shown to be difficult to choose and forecast the effect of additives. For example, certain additives do not bind with the olefin polymer and start migrating.
When selecting materials for HVDC insulation intended for high electric fields, the conductivity has to be sufficiently low in order to avoid significant temperature rise due to the leakage current. What is sufficiently low depends on the heat transfer conditions of the cable as well as on the intended electrical field. Since the heat generation is proportional to the square of the electrical field it is easy to understand that the conductivity has to be lower, the higher the electrical field, in order to keep the temperature rise fixed. The better the cooling of the cable, the higher heat generation can be allowed for fixed temperature rise. The cooling conditions can be characterized by the heat transfer coefficient of the cable surface and the cable diameter. In addition, the thickness of the insulation layer in which the heat is generated influences the temperature rise for two reasons. One is that the thicker the insulation at fixed electrical field the more power is dissipated that has to be cooled by the cable surface. The other is that the electrical insulation also will act as thermal insulation and therefore a thicker insulation layer will cause a larger temperature difference between the inner and outer part of the insulation layer. For the development of extruded high performance insulation materials for HVDC that would allow higher voltage of cable systems, the conductivity of the extruded insulation material needs to be considered. The maximum allowed conductivity is selected based on the intended electrical field and the insulation thickness. For cost reasons the insulation thickness is minimized. Therefore, a high electrical field is desired.
Many attempts have been made to improve different qualities of insulation materials. For example, US2012/0171404 describes a method to decrease conductivity in insulation material by decreasing the amount of peroxide in insulation material. However, if the concentration of peroxide is too low the polyethylene will not be cross-linked properly.
However, sulphur containing antioxidants, like 4,4″-thiobis (2-tertbutyl-5-methylphenol) (TTM), contain phenols groups. Peroxides, such as dicumyl peroxide, react with these phenols. As a consequence, through the addition of TTM, not enough peroxide may be available for crosslinking the olefin polymer.
The conductivity of insulation material is important because the conductivity for electrical transmission cable determines the leakage current and the heat generated by such a leakage. The conductivity is as low as possible. At the same time, the insulation material must be strong, flexible and have good low temperature impact strength.


A radiant heating unit for treating patients suffering from hypothermia is adapted to be used with a standard stretcher so that the patient may be moved into and removed from the device without moving the patient from one support surface to another. The unit includes an enclosure for defining a chamber into which the patient may be inserted. A guard is placed between the patient and the heated surfaces of the enclosure to protect the patient against direct contact with the heated surface of the enclosure.

1. Field of the Invention
The subject invention is directed to elevating the core body temperature of a human being and is specifically directed to a radiant heating surface for elevating the temperature of a patient suffering from hypothermia.
2. Description of the Prior Art
Thermal recovery devices of the type used for elevating the temperature of human beings are well known. For example, U.S. Pat. No. 2,579,964 issued to J. L. Reynolds on Dec. 25, 1991 discloses a heating unit which is adapted to be mounted directly on the frame of a bed and defines a hood for enveloping the patient. Heat is applied to the surface of the hood. By design, the hood is in close proximity to the extremities of the patient, particularly the arms and legs. If the patient moves or extends his extremities during treatment, there is a risk of thermal injury caused by direct contact with the heated surface of the recovery unit.
U.S. Pat. No. 2,184,418 issued to A. A. Faigle on Dec. 26, 1939 discloses a heating unit which includes a sectioned hood permanently attached to a massage table, where in both the hood and the table contain heating elements for warming the patient. The surface temperature is limited since the patient is in direct contact with a heated surface on the table. In addition, the Faigle design requires that the patient be moved from one surface to another since the table is a permanent part of the device and is not possible. Further, the table is not readily suited for any use other than heat treatment. U.S. Pat. No. 2,960,986 issued to B. F. Gibbons on Nov. 22, 1960 is an improved therapeutic heat and massage table, similar to that disclosed in Faigle. As in Faigle, a specifically designed table is required for use of the unit. Gibbons utilizes light bulbs as the heating element.
U.S. Pat. No. 3,741,218 issued to K. Novak on Jun. 26, 1973 also discloses a heat therapy apparatus using light bulbs as the heating elements for a hood. The Novak device also requires a specially designed table for supporting the hood, requiring that the patient be moved from another surface onto the table for treatment. As with Reynolds, the Novak device does not provide any means for protecting the patient from direct contact with the hood during treatment.
U.S. Pat. No. 1,643,399 issued to M. W. Wentworth on Sep. 27, 1927, and U.S. Pat. No. 959,743 issued to J. C. Hoyt on May 31, 1910, discloses hooded units which include a drape for closing the open end of the unit for enveloping the body of the patient during treatment.
U.S. Pat. No. 1,968,015 issued to W. H. Cooke et al on Jul. 31, 1934, and U.S. Pat. No. 2,437,016 issued to H. E. Christensen on Mar. 2, 1948 discloses therapeutic heating devices which may be placed either on the patient's bed or a standard table for heating extremities or a portion of the patient's body. Neither of these devices provide for protection of the patient from direct contact with the heating elements or heated surfaces during treatment.
U.S. Pat. No. 4,501,275 issued to J. D. Maahs on Feb. 26, 1985 discloses a closed heating unit for elevating the core body temperature of mammals to a hyperthermic condition for treatment of cancer of the like. The Maahs device is self-contained and requires movement of the patient from another device in order to place the patient in the unit for treatment.
All of the devices of the prior art have shortcomings in that they either are not self-contained or, where they are self-contained, require that the patient be moved from a separate apparatus onto the unit for treatment. As with all medical procedures, during the critical stages of treatment, it is desired to move the patient as little as necessary. Further, the units of the prior art do not provide means for elevating the body temperature by a radiant heating technique while protecting the patient from accidental contact with the heated surfaces of the patient chamber, increasing the risk of thermal injury to the patient during treatment.


A double-sided wear insert, for a knife assembly that includes a knife, a clamp, and a holder. In one embodiment, the wear insert can be turned end-for-end, and in another embodiment the wear insert can be flipped up-side down, to double the service life of the part.

Disc, drum, and conical head chippers are basic equipment in sawmills, used for processing logs into useable lumber. They employ revolving chipper heads in either disc, drum, or conical configurations to which, typically, a number of knives are attached. In a disc chipper (or chipper disc) the knives may be attached to the periphery of the disc or the sides of the disc. In drum and conical head chippers, the knives are attached to the periphery of the drum. Any of these chippers will be referred to hereinafter simply as a "chipper," and either a disc, drum, or conical head will be referred to simply as a "cutting head" or "head."
The knives are typically clamped to the head between a pair of clamping members, an "outer" or "upper" clamping member, and an "inner" or "lower" clamping member that is attached to the base of the chipper. The knife has front and back sides, the former facing the direction of rotation of the head. The upper clamping member contacts the back side and the lower clamping member contacts the front side, clamping the knife therebetween.
The wood article to be chipped by the chipper is fed into the chipper at a given feed speed, the cutting head revolves at a given rotational speed, and the knives have a given knife density, i.e., they are angularly spaced apart from one another on the head a given amount. These three parameters determine the size, particularly the length, of the chips. While the wood article is chipped fundamentally to shape it into useable lumber, the chips themselves have economic value as components of engineered or manufactured wood products, such as pulp and paper, fiberboard, and oriented strand board.
The knife is typically removed from the chipper head by removing the upper clamping member. In some more advanced prior art systems, the knife can be removed by a threaded adjustment that pivots the lower clamping member, such as described in Swartwood et al., U.S. Pat. No. 5,979,522.
FIG. 1 shows, in cross-section, a generic knife assembly 2 for clamping a chipper knife. The knife assembly 2 is mounted to a chipper head 4. The assembly has four main components, a knife 5, an upper clamping member (or "clamp") 6, a lower clamping member (or "holder") 7, and a replaceable wear insert 8. The clamp 6 and holder 7 clamp the knife, and a bolt 11 passes through the clamp and into, or through, the holder.
The assembly rotates in the direction "R." The knife has a front side 3 and a back side 4, the front side facing the direction of rotation R. Chips cut by the knife follow the path "P" and contact a wear surface 9 of the wear insert 8. The wear surface becomes worn as a result of this contact. The wear surface, since it is closest to the knife, experiences more wear than the holder 7.
The wear insert 8 is substantially smaller (less massive) than the holder 7. For this reason, and because the greatest amount of wear occurs in the localized area of the wear insert, it is economically advantageous to provide, in addition to the holder 7, the wear insert as a disposable part. The wear insert is also, typically, substantially smaller than the clamp. The wear insert may or not be bolted to the holder; however, it is not bolted to the clamp.
The wear insert is typically provided with a "wear coating," that is applied to and hardens the wear surface 9. One example is referred to more particularly as a "hardsurface," which results from hardsurfacing, i.e., the application to the wear surface 9 of a diamond carbide powder coating. With a wear coating, the wear surface is harder or more wear resistant than the tool steel of which it, and particularly the holder, is formed. Alternatively, the entire wear insert may be formed of a harder or more wear resistant material.
The term "counterknife" is sometimes used to refer to a wear insert. However, a counterknife is defined more generally as a part used for breaking and deflecting chips cut by the knife, and the term has consequently been applied to holders in assemblies that do not contain a separate wear insert. Herein, the term wear insert is used to refer to a specific, relatively small component of an assembly like the assembly 2.
FIG. 2 shows two important parameters relating the knife 5 and wear insert 8. The impact angle θ determines the "impact" of the cutting head on the chips. In a "high impact" configuration, θ=90 degrees and the wear surface 9 is a blunt obstacle to chip flow. To provide lower impact configurations, θ is increased resulting in a more gentle path for chip flow. It is desired to break the chips with only as much force as is necessary, to minimize wear and damage to the chips, so the impact angle is adjusted for various factors, including the strength of the wood being chipped.
The other important parameter shown in FIG. 2 is the depth "D" of the wear insert relative to the cutting edge CE of the knife. This parameter is adjusted to be appropriate for the chip length mentioned above.
Referring back to FIG. 1, the wear insert 8 is indexed to the holder 7 by a side of the wear insert 10a abutting the holder at a seat 10b of the holder. As the insert wears and the wear surface 9 erodes, the surface retreats in the direction of the seat 10b and the depth D is undesirably increased. When the wear has become unacceptable, the wear insert is removed and either the wear surface renewed or the part replaced.
It may be noted that the above discussion is based on a simplifying assumption that the knife does not wear appreciably relative to the wear insert. This is generally not true, so the actual relationship between wear of the wear insert and the depth parameter "D" is of course more complex than indicated.
Providing the wear insert, especially as a disposable part in a knife assembly like the assembly 2, is economical, however, it remains that the part must be replaced or reworked at intervals, and it would be desirable to increase the service life of the wear insert.


The present invention disclosed a light module, which comprises a plurality of LED package units and a plurality of connecting units. Opposite sides of each of the LED package units has one connector respectively, and opposite sides of each of the connecting units has one connector respectively. The LED package unit and the connecting unit connect each other through the connectors. To vary the arrangement and the amount of the connecting units and the LED package units is to suit different dimensions of side light modules of liquid crystal displays with different luminosities.

(1) Field of the Invention
The invention relates to a light module, more particularly to a side light module applied to a liquid crystal display (LCD).
(2) Description of the Prior Art
Liquid crystal display (LCD) is well known to be applied to portable electronic products, such as notebook PCs, cell phones, digital cameras, digital video machines, and personal digital assistants (PDAs). But the liquid crystal display does not generate light by itself, hence, a light source is needed to LCD.
Normally, a backlight module has a light source, which is divided into two kinds of cold cathode fluorescent lamp (CCFL) and light emitting diode (LED). The light effect of CCFL is higher in order to meet the needs of colorization, high illumination, and larger products, but it is with a larger volume. The light effect of LED is lower than CCFL, and LED has the merits of light weight and volume, focused light path, longer life, low contamination, etc. Therefore, LED is more suitable to be a backlight module of the electronic products with power-saving and light weight and volume.
The backlight module is further divided into two types of a direct illumination backlight module generating light lower to the display and a side illumination backlight module generating light lateral to the display.
Please refer to FIG. 1, which illustrates a schematic exploded view of a backlight module of a LCD in prior arts. A LCD 1 includes a liquid crystal panel 11 and a backlight module 12. The backlight module 12 includes a LED module 13, a light guide 14, a frame 15, and a PCB 16. The LED module 13 includes two sets of LEDs 131 welded on a flexible printed circuit board 132. The circuit layout of the flexible printed circuit board 132 is to electrically connect the LEDs to a plurality of light-source driving elements (not shown in the figure) of the PCB 16.
The LCD 1 described above is applied to different types of electronic products. Different electronic products may need different dimensions of liquid crystal panels and different luminosities. Logically, there are different sorts of flexible printed circuit boards to cooperate with the LEDs during production flows. Hence, such accommodations for the production flows shall waste time and materials. As a conclusion, to develop a side light module for easy installment to be adjusted in the dimensions of the module may be put more effort continuously.


An imaging apparatus is provided with an imaging element for outputting both a color signal of high-power image data and a color signal of low-power image data; gamma correcting means for gamma-correcting the high-power image data and for gamma-correcting the low-power image data; image synthesizing means for adding the high-power image data which has been gamma-corrected by the gamma correcting means to the low-power image data which has been gamma-corrected by the gamma correcting means, and also for multiplying the added image data by a total gain value in response to a scene so as to perform an image synthesizing operation; converting means for converting the synthesized image data synthesized by the image synthesizing means into both a luminance signal and a color difference signal; and saturation correcting means for performing a saturation correcting process operation with respect to the color difference signal in response to the luminance signal obtained by the converting means and a dynamic range of the synthesized image data.

The present invention is related to an image synthesizing method and an imaging apparatus. More specifically, the present invention is directed to an image synthesizing method and an imaging apparatus, capable of obtaining an image signal whose dynamic range has been widened, while both a white balance and a color balance are properly adjusted.
In the case that, for example, an indoor scene is imaged by such an imaging apparatus as a digital still camera, even if good pictures of photographic objects located in an indoor space can be acquired, the blue sky viewed from a window is skipped from an entire image in a white color, so that this entire image may sometimes become unnatural. This is because a dynamic range of the image is narrow. In order to solve this problem, dynamic ranges of images have been conventionally widened by photographing two sets of images and by synthesizing these two images with each other.
For instance, a first short-exposing-time image (low-sensitivity image) is photographed by actuating a shutter in a high speed, and continuously, a second long-exposing-time image (high-sensitivity image) is photographed by actuating the shutter in a low speed, and then, since these two images are synthesized with each other, a scene outside a window, which has been photographed in the low-sensitivity image, may be overlapped with the high-sensitivity image in which an indoor scene has been photographed under better condition.
When such an image synthesizing operation is carried out, since the red (R) signal of the high-sensitivity image can be hardly saturated, as compared with the green (G) signal and the blue (B) signal, the entire high-sensitivity image mainly owns a cyan color. As a result, since the synthesized image is also influenced by the color signal mainly having the cyan color of the high-sensitivity image, there is a problem that the color balance of the entire synthesized image is no longer maintained.
To solve the color balance problem, in the conventional techniques described in, for example, Japanese Patent Publication No. Hei-7-131796, the color signal of one image to be synthesized is multiplied by "k", and then this k-multiplied image is synthesized with the other image so as to adjust the saturation of the synthesized image.
In the above-explained art, when the color signals of the two photograph images are synthesized with each other, the gray color balance is controlled. However, this conventional technique does not consider shifts contained in white balances of these two images. As a result, the white balance of the high-sensitivity image is different from the white balance of the low-sensitivity image, which are contained in the synthesized image. Thus, there is such a problem that a synthesized image having a sense of incongruity may be formed, depending upon a photographic scene.
Recently, such an imaging apparatus as a digital still camera has been proposed. For instance, while both high-sensitivity pixels and low-sensitivity pixels are mounted on a solid-state imaging element of this digital still camera, a high-sensitivity image (will also be referred to as "high-power image" hereinafter) imaged by the high-sensitivity pixels is synthesized with a low-sensitivity image (will also be referred to as "low-power image" hereinafter) imaged by the low-sensitivity pixels so as to output the synthesized high-sensitive/low-sensitive images as a single image data. When this proposed imaging apparatus performs the image synthesizing operation, executions of not only a color balance, but also a white balance are required.

Apparatus and method for synthesizing image signals into a wide dynamic range image that has been processed with saturation correction


A light controlling apparatus includes a substrate in which an optical aperture is formed, a first light controlling means and a second light controlling means, each having an optical aperture regulating portion, and a drive source which operates the first light controlling means and the second light controlling means. The first light controlling means and the second light controlling means move mutually to a first stationary position retracted from a position of the optical aperture and a second stationary position which overlaps with the position of the optical aperture. A rotating shaft member is formed integrally with the first light controlling means. A coupling portion is formed on at least one of the first light controlling means and the second light controlling means, and the first light controlling means is rotated by rotating the rotating shaft member by the drive source, and the second light controlling means is also rotated in conjunction by the coupling portion. The first light controlling means and the second light controlling means rotate with the same axis of rotation as a center of rotation.

1. Field of the Invention
The present invention relates to a light controlling apparatus.
2. Description of the Related Art
In recent years, with improved high-quality performance of a portable equipment having an image pickup function and a small-size optical apparatus such as micro video scope, there has been increasing demand for an application of a focusing lens and a variable aperture instead of a conventional fixed focusing lens and a fixed aperture.
Further small-sizing has been sought in the optical elements as well. In Japanese Patent Application Laid-open Publication No. 2002-296637, a structure in which, a diaphragm blade is divided into two, and the two diaphragm blades are accommodated at a position upon being retracted from an optical aperture formed in a substrate, making it suitable for small-sizing has been proposed.
However, in the abovementioned conventional technology, the two diaphragm blades are driven simultaneously by one drive source. Each of the two diaphragm blades has a coupling section for coupling with a separate rotating shaft and a drive source, thereby making the structure complicated. Therefore, the assembling is extremely difficult.


A cable tray support assembly for a raised floor system which has a plurality of support pedestals and a platform section. Each support pedestal has an elongated stringer member, a first upright channel member, and an opposing second upright channel member. The stringer member has an opposing pair of flanges depending from the proximal and distal ends of the stringer member. In use, the flanges of the stringer member may be releasably connected to the channel members so that the elongated stringer member is supported above the respective bottom ends of the channel members. At least one of the channel members of each support pedestal may be positioned adjacent to at least a portion of one column to aid in maintaining spatial orientation of the channel member with respect to an upright column. One platform section is suspended from the stringer members of a pair of opposing support pedestals.

Cable trays in general have been used in power stations and large industrial plants for a number of years to support and route various cables through the plants rather than placing these cables inside a conduit. These cable trays are normally supported from a wall or a ceiling at levels which are above a person's head in order to avoid obstructing normal floor space. An alternative to the elevated cable tray has been elevated distribution ducts which are also normally mounted from a wall or a ceiling at elevations so as not to interfere with a person standing on the floor and thus, again, conserve floor space.
In many multi-floor buildings, a current practice is to utilize poured concrete floors. Electrical conductor distribution ducts are normally provided within the poured concrete of these floors in order to provide electrical power distribution to various locations within the building. These electrical power distribution ducts are permanently located within the poured concrete making it impossible to accommodate the rearrangement of equipment as both the use of the floor space changes as well as to accommodate the changes in the equipment due to changes in technology. This has lead to the development of raised floors for certain uses of floor space.
Computer rooms, data processing rooms and electronic equipment rooms, in general, are examples of room uses wherein the overhead wiring distribution approach and/or the power distribution ducts have been partially or totally replaced by the distribution of wires and cables on top of the concrete subfloor and below a removable panel raised floor on which the electrical equipment is placed. These raised floors are normally supported on column assemblies and the area below the raised floor is designed to be utilized as access for the distribution of the various electrical cables.
With the increased complexity of electronic equipment and the increasing number of pieces of equipment being placed in a single room due to the equipment continuously becoming smaller, the interconnection of these pieces of electronic equipment by communication cables and power cables has become more complex. The space between the subfloor and the raised panel floor is somewhat restricted and there may be times when there is moisture on the concrete subfloor such as due to condensation. Cables lying on the concrete subfloor have to remain unaffected by the moisture on the subfloor and these cables also need to avoid the problems associated with entanglement. Cables simply lying on a concrete subfloor can become so entangled that it is difficult to remove one particular cable from the mass of cables on the subfloor should the individual cable need to be changed or rerouted for any reason.
Prior art cable trays have been developed to eliminate some of the problems associated with the routing of cables beneath the raised panel floor. Most prior art cable trays are simply placed on the concrete subfloor. Other cable tray designs are suspended from the structure which supports the removable panels of the raised panel floor. These prior art designs are normally suspended between the raised panel floor and the concrete subfloor and provide an organized route for the various cables to travel in order to interconnect the numerous pieces of electronic equipment placed on the raised panel floor.
While the introduction of these prior art cable trays has significantly reduced the entanglement and moisture problems associated with the concrete subfloors, they are not without their problems. As the number of pieces of electronic equipment being placed in a single room increases so does the number of electrical cables. Consequently the number of electrical cables which are being placed within the prior art cable trays is also increasing. This increasing number of cables in the prior art cable trays can now lead to an entanglement problem within the tray. In addition, when it is desired to have specific cables kept separate from each other, the prior art cable trays are used to route one, or one set of cables, while the second or other set of cables, which need to be kept separate, are routed across the concrete subfloor encountering the problems explained above.
Accordingly, there is a need for a cable management system which can accommodate the larger number of cables being routed beneath the raised panel floor as well as providing for the separate routing of specific cables without relying on the subfloor beneath the raised panel floor for routing of cables. Further, there is a continuing need for improved cable management systems which require fewer number of components. A need also exists for raised floor and cable management systems which are easier to install than existing systems and which provide increased storage capacity and accessibility. Finally, a need exists for cable management systems that do not apply stress onto the raised floor systems.


Methods and apparatuses for optimizing switching delay in integrated circuits are described. Combinational logic gates are modified with precharge circuitry and instantiated in order to reduce switching transitions of circuit elements in a signal path.

Integrated circuits contain a plurality of signal paths which essentially carry information (data and control signals) across the circuit. Each signal path is made up of a plurality of circuit elements connected together serially (i.e., in series). Each of these signal paths experiences a delay as signals travel across the circuit. These signal path delays occur due to the time required for signals to propagate through each of the plurality of circuit elements from the input to the output of the signal path. Each circuit element has its own switching delay known as the switching delay of a circuit element. This circuit element switching delay is the time required for a circuit element to switch logic states from either a high-to-low logic state (logic 1→0) or from a low-to-high logic state (logic 0→1). The path switching delay is determined by the accumulation of time it takes for a signal to pass through each of the circuit elements in a particular path. This time, in turn, is based on the total switching delay of each circuit element in the path. Paths with the highest number of combined switching delays of circuit elements are known as speed paths or critical paths. These critical paths dictate how fast an integrated circuit can operate. The maximum frequency an integrated circuit can operate at depends directly on how fast signals can propagate across the worst-case critical paths.
FIG. 1A illustrates the switching of static logic states for a series of inverters according to the prior art. Circuit 100 includes a series of connected inverting logic gates 110-1, 110-2, 110-3, 110-4, through 110-n. These inverting logic gates are referred to simply as "inverters" or INV gates. The switching delay experienced by each of these inverters in the path will determine how much time it takes for a signal to propagate from the input IN of inverter 110-1 through to the output (OUT) of inverter 110-n. In the illustrated example, the input to inverter 110-1 switches from a logic state 0 (low) to a logic state 1 (high). This results in the output of inverter 110-1 switching from logic 1 to 0. When the output of logic gate 110-1 transitions from logic 1 to 0, the signal propagates into the input of the next circuit element, inverter 110-2, causing the output of inverter 110-2 to transition from logic 0 to 1. Similarly, logic gate inverter 110-3 causes an inversion on the output that propagates into the input of inverter 110-4 causing an inversion on the output of inverter 110-4, and so on and so forth until the output (OUT) of inverter 110-n is reached. The output of each of the inverters are said to be in an inverting relationship since the output of one inverter causes a corresponding inversion on the output of the next downstream inverter, and so on. Each of these transitions occurs sequentially, one being essentially complete before the other begins. The accumulation of time it takes for each of inverters 110-1 through 110-n to switch (invert) logic states from logic 0 to logic 1, or from logic 1 to logic 0 is the total switching delay of the circuit path shown in FIG. 1A. Hence, FIG. 1A demonstrates the switching of static logic states in the case of a series of inverters, which requires a long switching time before valid data appears at the end of the series of inverters 110-1 through 110-n. The path switching delay is the accumulation of all switching delays of each of the inverters 110-1 through 110-n. This path switching delay occurs not only for inverters, but for any inverting logic functions such as NAND gates, NOR gates, AOI (and-or-invert), OAI (or-and-invert), and etcetera.
Switching delays may be optimized in order to facilitate a signal propagating along a critical path from input to output with reduced switching delays. Conventionally, circuit path delays are optimized in two ways. The first way is to reduce the number of logic stages by combining multiple stages into a single stage. The second way is to reduce the amount of switching delay that a particular stage requires. Such reduction in delay can be accomplished using several techniques known in the art such as transistor resizing, reducing output load, improving input transition time, breaking the complex cells into simpler cells, and etcetera.
Other methods to reduce the switching delays of the logic gates in a path include precharging logic gates (i.e., dynamic logic) and skewing logic gates through transistor resizing. In the case of using dynamic logic, a method for optimizing switching delays of a path in an integrated circuit using dynamic logic gates includes using output prediction logic (OPL) circuits. In OPT circuits every logic gate includes dynamic logic with a precharge circuit. FIG. 1B illustrates a method for optimizing switching delay of logic gates in a circuit path using output prediction logic (OPL) according to the prior art. Circuit 140 includes inverters 150-1, 150-2, 150-3, 150-4, through 150-n. Each inverter includes clock inputs CK 160-1, CK 160-2, CK 160-3, CK 160-4, through CK 160-n respectively that are supplied to precharge circuits in each inverter (not shown) to precharge the output of all the logic gates to a certain value (usually logic=1) during a precharge phase of the clock inputs. In order to facilitate the OPL method, delayed clocks with a small difference in delay are provided to enable each stage in succession so that a reduced number of outputs potentially switch states. It is noted that, because the logic gates are precharged to logic 1, switching of the logic states is avoided on the output of logic gates 150-2 and 150-4. As a result, OPL is faster than the regular static logic gates shown in FIG. 1A.
U.S. Pat. No. 6,549,038 entitled, "Method of High Performance CMOS Design," discloses optimizing signal path delays using the OPL method. However, in OPL circuits there is a somewhat cumbersome requirement of clock signal generation with a very small delay difference between two consecutive logic stages that results in the need to design each clock path with some precision. The generation of clocks with such small delay difference is not straight forward and requires complicated techniques like Delay Locked Loops (DLLs) and carefully designed clock networks. Secondly, the need to supply every stage with a separate clock signal adds to a substantial clocking overhead in the design that requires extra metal resources and careful routing. Also, there are serious concerns about sensitivity to process variation and noise since any significant glitching variation could trigger a regenerative cascading effect across the path. These issues and possibly others may give rise to adoption challenges among the IC design community for this technique. U.S. Pat. No. 6,980,033 entitled, "Pseudo CMOS Dynamic Logic With Delayed Clocks," discloses circuitry similar to the OPL, technique, but using pseudo-CMOS logic gates instead of CMOS.

Clock guided logic with reduced switching


A phase change memory device includes a semiconductor substrate which includes a plurality of phase change memory cells, a plurality of local bit lines extending over the semiconductor substrate, each of the plurality of local bit lines being coupled to the plurality of phase change memory cells, and a plurality of global bit lines extending over the plurality of local bit lines, each of the plurality of global bit lines being selectively coupled to the plurality of local bit lines. The plurality of global bit lines are located at two or more different wiring line levels over the semiconductor substrate.

1. Field of the Invention
The present disclosure relates generally to memory devices and, more particularly, the present invention relates to phase change memory devices.
A claim of priority is made to Korean Patent Application No. 10-2006-003272, filed on Jan. 11, 2006, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
2. Description of the Related Art
Phase change random access memory devices (PRAM) store data using a phase change material, such as, for example, a chalcogenide alloy, that transforms into a crystalline state or an amorphous state during cooling after heat treatment. Each state of the phase change material has different resistance characteristics. Specifically, the phase change material in the crystalline state has low resistance and the phase change material in the amorphous state has high resistance. The crystalline state is typically referred to as a "set state" having a logic level "0", and the amorphous state is typically referred to as a "reset state" having a logic level "1".
In the phase change memory devices, data is written using Joule heat. This Joule heat is generated when a write current is supplied to the phase change material having a predetermined resistance. Specifically, the phase change material is heated to at least a melting temperature of the material and then rapidly cooled, so that the phase change material transforms into the amorphous state. Alternatively, the phase change material is heated to temperature that is higher than a crystallization temperature but less than the melting temperature, kept at the temperature for a predetermined time, and then cooled. By this process, the phase change material transforms into the crystalline state.
Furthermore, in order to provide high capacity and high integration in the phase change memory devices, the phase change memory devices can be implemented by a hierarchical bit line structure using global bit lines and local bit lines. In this case, there may be a difference in length between phase change memory cells that are coupled to local bit lines distant from a wiring circuit and/or a reading circuit and phase change memory cells coupled to local bit lines close to the writing circuit and/or the reading circuit. This difference in length may affect the operation of the phase change memory device. That is, because resistance exists on the individual global bit lines, resistance from the writing circuit and/or the reading circuit to the selected phase change memory cell may not be uniform. Instead, the resistance may vary according to the position of the selected phase change memory cell with respect to the writing circuit and/or the reading circuit. Thus, a difference in resistance depends on a physical distance between the cell and the writing/reading circuit.
These differences in resistance between phase change memory cells and reading/writing circuits may lead to undesirable consequences. In particular, as described above, the phase change memory devices write data using the write current. This write current may be sensitive to the difference in resistance. Accordingly, a write current to be applied to the phase change memory cells that are coupled to the local bit lines distant from the writing circuit and/or the reading circuit may be smaller than a write current to be applied to the phase change memory cells that are coupled to the local bit lines close to the writing circuit and/or the reading circuit. This difference in write current may lead to errors in the programming operations of phase change memory devices.


The development of subunits and subunit analogs of the cholera exotoxin by recombinant DNA techniques provides vaccine products that can retain their biological activity and immunogenicity, and can confer protection against disease challenge. Genetically-engineered modifications of the subunits result in products that retain immunogenicity, yet are reduced in, or are essentially free of, enzymatic activity associated with toxin reactogenicity.

1. Field Of The Invention
The present invention relates to the recombinant expression of analog subunits of cholera exotoxin, and to vaccines based on such analogs. More particularly, genetically engineered modifications of the exotoxin provide analogs of cholera toxin having the capability to elicit a protective response with reduced or essentially no catalytic activity which can contribute to the reactogenicity of cholera vaccines.
2. Description Of The Art
The term "cholera" refers to the disease caused by infection with the etiologic agent Vibrio cholerae, most commonly occurring in geographical areas where poor hygienic conditions prevail. Cholera remains a major cause of morbidity and mortality in many parts of the world(1,2). Experience has shown that contraction of the disease usually confers long-lasting protection against subsequent exposure to the etiologic agent(3). Consequently, considerable effort has been devoted to the development of a vaccine that would be similarly protective. A parenteral whole cell cholera vaccine has been produced, but some no longer regard it as useful, particularly for young children who are at greatest risk from the disease(1).
As for many other infectious diseases, a biological exotoxin (in this case, "cholera toxin" or "CTX") encoded by the genome of the infectious agent and secreted by it, contributes significantly to the ability of the microorganism to colonize the infected host(4). Moreover, exposure to the toxin causes severe diarrhea and vomiting which result in dehydration, a life-threatening condition of the disease(3,5). These experiences suggest that a vaccine which elicits an immunologic response (e.g., antibodies) sufficient to neutralize the toxin would thus significantly help to prevent or reduce bacterial colonization and attendant symptoms such as diarrhea and vomiting. Thus, substantial effort has been applied toward developing a vaccine containing a non-toxic analog of the toxin, i.e., a "toxoid" (1,3-13). It is known that cholera toxin is a multi-subunit macromolecule consisting of a subunit termed "A", containing a catalytic region called "A1" which ADP-ribosylates G-proteins in target cells, and a "B" oligomer which binds the holotoxin to the target cells(6). Non-toxic analogs of cholera toxin have been produced for purposes of vaccine development by various means. These methods include chemical treatment of the holotoxin or toxin subunits, deletion of the A subunit and use of the remaining B oligomer, and synthesis or isolation of peptide fragments of toxin subunits(1,3-13).
In recent years, efforts have turned toward the development of oral vaccines, with two approaches apparently having received the most attention. One of these approaches is based on the use of killed V. cholerae (i.e., chemically- or heat-inactivated), alone, or supplemented with the B oligomer of cholera toxin(1,11,12). This approach has been found to produce incomplete protection, particularly in young children(12). The other approach involves the use of living, but attenuated, strains of V. cholerae which fail to produce the A1 subunit of the toxin(13). Vaccines of this kind have provided greater levels of protection, but until recently have also been associated with unacceptable intestinal side-effects. A recently-developed vaccine based on V. cholerae strain CVD 103-HgR, in which the gene encoding the A subunit is omitted, appears to be better tolerated, at least in adults(13). However, to our knowledge, this vaccine has not been tested in children or in large-scale clinical trials.
Recent studies on the nature of cholera toxin have provided insights concerning its structure that may have application in vaccine development based on a recombinant approach. It is known that naturally-ocurring subunit A is synthesized in V. cholerae as a preprotein(14), which is subsequently cleaved to proteolytically remove a signal peptide sequence of approximately 2,160 kDa. Further post-translational processing yields an amino-terminal polypeptide of approximately 21,817 kDa (subunit A1) and a carboxyl-terminal polypeptide of approximately 5,398 kDa (subunit A2), which are linked by a disulfide bridge(6,15,16); reduction of the disulfide bond is believed necessary for catalysis of the ADP-ribosyltransferase reaction (6,15,16). Likewise, the B subunit is synthesized as a preprotein which is subsequently cleaved by protease to remove a signal peptide. The genes, or cistronic elements, for the A1, A2 and B subunits of cholera toxin have all been fully sequenced and described in the literature(16).

Mutagenized DNA molecules encoding modified subunit a of Cholera-toxin


A system and method for managing a hybrid firewall solution, employing both hardware and software firewall components, for a cloud computing data center is provided. A virtual application is hosted by a first plurality of application virtual machines and a second plurality of firewall virtual machines provides firewalling services for traffic associated with the virtual application. A cloud management entity determines that the virtual application requires an increased number of application virtual machines. A security profile for the virtual application is verified to determine if an increased number of firewall virtual machines is required by the increased number of application virtual machines. The cloud management entity can instantiate additional application virtual machines and firewall virtual machines as required.

With the rapid evolution of Cloud Computing it has become increasingly common to run computer programs on virtual machines operating on servers. A virtual machine (VM) is a software implementation of a machine (i.e. a computer) that executes programs like a physical machine. The physical hardware on which virtual machines run is referred to as the host or host computer(s) and can reside in data center facilities.
Data centers are facilities used to house computer systems and associated components, typically including routers and switches to transport traffic between the computer systems and external networks. Data centers generally include redundant power supplies and redundant data communications connections to provide a reliable infrastructure for operations and to minimize any chance of disruption. Information security is also a concern, and for this reason a data center must offer a secure environment to minimize any chance of a security breach.
Virtualization has several advantages over conventional computing environments. The operating system and applications running on a virtual machine often require only a fraction of the full resources available on the underlying physical hardware on which the virtual machine is running. A host system can employ multiple physical computers, each of which runs multiple virtual machines. Virtual machines can be created and shut down as required, thus only using the resources of the physical computer(s) as needed. A virtualized application can run on one or a number of virtual machines that can be scaled up or down as required by the application.
Another advantage of virtualization is the flexibility provided by the ability to manipulate and move a virtual machine from one physical site to another, or to move a virtual machine between hosts within the same data center. Virtual machines can be moved in order to better utilize the host machines and to provide the elasticity to scale up or down in size.
Many data centers use appliances, employing dedicated hardware and software, to provide various services in the data center. Such services can include firewall services, load balancing services, Unified Threat Management (UTM) services, intrusion detection and prevention systems (IDS/IPS), data loss prevention (DLP) systems, Proxy/Gateway services, and other security services.
FIG. 1 illustrates a data center 100 with a hardware appliance 102 deployed in front of the data center 100 providing firewall and security services. Data center 100 has 7 blades 104, 106, 108, 110, 112, 114, 116. Blades 1-5, 104-112, run virtual machines VM1-VM10 managed by virtualization layer 118. Blades 6 and 7, 114 and 116, run virtual storage components VS1-VS4 managed by virtualization layer 120. The hardware firewall 102 inspects and filters traffic from the network 122 to the data center 100. The capacity of this firewall 102 is determined based on the maximum throughput for the data center 100. In practice, this often leads to the over-dimensioning of the firewall 102.
If in the future, the data center 100 hardware is upgraded and the overall capacity of the data center 100 is increased, the firewall appliance 102 will also need to be upgraded to meet the increasing traffic demand. This type of operation may require service interruption, an investment in hardware/software upgrades, and a high operational cost.
Virtualization of the services provided by hardware appliances is also gaining momentum. For example, a virtual firewall (VF) is a network firewall service running entirely within a virtualized environment which can provide the same packet filtering and monitoring as is conventionally provided by a physical network firewall or firewall service appliance.
FIG. 2 illustrates a data center 200 employing a purely virtual firewall. Data center 200 has 7 blades 204, 206, 208, 210, 212, 214, and 216. Blades 1-5, 204-212, run virtual machines VM1-VM10 managed by virtualization layer 218. Blades 6 and 7, 214 and 216, run virtual storage components VS1-VS4 managed by virtualization layer 220. Blades 4 and 5, 210 and 212, can be provisioned to virtual machines VM7-VM10 running firewalling applications, or more simply called "virtual firewalls". Blade 4, 210, can be dedicated for virtual firewalls at all times, while blade 5, 212, can be assigned to the firewall when traffic increases. These virtual machines, VM9 and VM10, can be released when the traffic decreases. The virtual firewall can inspect and filter traffic from the network 222 to the data center 200 similar to the hardware firewall 102 of FIG. 1. A virtualized firewall service allows the resources to scale with the traffic requirements.
Therefore, it would be desirable to provide a system and method to integrate hardware and virtual firewall components and to mitigate the associated scalability problems.

Hybrid firewall for data center security


This invention exploits the synchronization properties of coupled, nonlinear oscillators arrays to perform power combining, beam steering, and beam shaping. This architecture utilizes interactions between nonlinear active elements to generate beam patterns. A nonlinear array integrates the signal processing concurrently with the transduction of the signal. This architecture differs fundamentally from passive transducer arrays in three ways: 1) the unit cells are nonlinear, 2) the array purposely couples the unit cells together, and 3) the signal processing (beam steering and shaping) is done via dynamic interactions between unit cells. The architecture extends to both 1- and 2-dimensional arrays.

This invention relates to phased array systems. With greater specificity, but without limitation thereto, the invention relates to phased array systems that employ the intrinsic synchronization properties of nonlinear oscillators. With further specificity, but without limitation thereto, the invention relates to using the intrinsic synchronization properties of nonlinear oscillators in phased array systems to provide simultaneous beam forming and beam shaping to such systems.
Traditionally, passive sensor or radiative arrays have employed linear, independently controlled transducers (also known as "radiators") as the constituent elements of the array. The geometry of these elements controls the radiation of the beam pattern and signal processing gain. Classic phased array aperture (antenna) operation in a receiving mode can be broken into four steps: 1) transduce the received energy; 2) synchronously demodulate the transduced signal; 3) apply weights to phase shift the inputs from each of the transducer elements; and 4) sum the weighted signals together to produce an output signal. The maximum gain possible is proportional to the number of antenna elements. Reciprocity permits the process to be reversed for the transmission of signals.
Implicit in the traditional phased array aperture (antenna) design is that each transducer is either assumed or engineered to be linear and to operate independently of (without an input from) the other transducers in the array. Due to these assumptions, interactions (i.e., "mutual coupling") between array elements are viewed negatively, as such interactions frustrate the formation of a desired antenna pattern. Mitigation of these mutual radiative coupling effects typically requires that transducer spacing be limited to a minimum of half a wavelength of the lowest frequency the array is designed to receive or transmit.
In such arrays, electronic beam steering (or beam scanning) is commonly realized through use of a phase-shifter at each transducer element. A computer typically controls each phase shifter, with control lines to each element being used to program the phase of each individual element. Unfortunately, the phase-shifters add to the weight, power losses, operating power, size, complexity and, significantly, to the cost of the phased array. For certain applications, one or more of these factors will eliminate the viability of using phase-shifters for beam steering an array.
To this end, solutions to phase-shifterless beam steering have been investigated. Several alternatives exist, such as frequency-scanning and multiple beam-forming networks (e.g. Rotman lenses and Butler matrices).
One of the earliest attempts to exploit synchronization for phase-shifterless beam steering was made by Stephan and Morgan (see K. D. Stephan and W. A. Morgan, "Analysis of Inter-Injection-Locked Oscillators for Integrated Phased Arrays", IEEE Transactions of Antennas and Propagation, vol. AP-35, pp. 771–781, July 1987). By injecting a sinusoidal signal into the two elements at each end of a 1-dimensional array of intentionally coupled oscillators, Stephan et al showed that the phase distribution across the array will evolve toward a uniform phase gradient. Although experimentally successful, the scan angles are inversely dependent on the number of elements in this interinjection-locking technique. Consequently, the scanning ability of large arrays is very limited.
Professor Robert York of the University of California, Santa Barbara, has suggested an alternative approach. Professor York and his co-workers also utilized an array of nonlinear oscillators. These oscillators were interactively coupled by what is known in the art as "nearest neighbor" coupling. This alternative method does not rely on signal injection (see P. Liao and R. A. York, "A new phase-shifterless beam-scanning technique using arrays of coupled oscillators", IEEE Transactions of Microwave Theory and Techniques, vol. 41, pp. 1810–1815, October 1993). Instead, York and company demonstrated both experimentally and analytically that oscillator phase distribution could be manipulated through control of the oscillator natural frequencies. Unlike Stephan's method, York's approach yields phase gradient values between ±90 regardless of the number of oscillators used.
While advances have been made in phase-shifterless beam steering approaches, there is a continued desire to expand the capabilities of such approaches. Besides providing a phase shifterless array system having enhanced scanning capabilities, there is also a desire to provide beam shaping to the attendant beam that is steered, so that simultaneous beam steering and beam shaping (i.e. sidelobe reduction) is possible.

Nonlinear beam forming and beam shaping aperture system

The United States of America as represented by the Secretary of the Navy


A moisture crosslinkable thermoplastic composition is produced by a process of grafting an unsaturated silane of the formula:G1R1SiZwhere G1 is vinyl, R1 is methyl and Z is a divalent hydrolyzable group under reactive mechanical working conditions and in the presence of at least two peroxides and subsequently is converted into a crosslinked thermoplastic composition by exposure to moisture in the presence of a crosslinking catalyst.

(1) Field of the Invention
This disclosure relates to a composition comprising a silane, and a system of peroxides and a process of crosslinking thermoplastic polymers with said composition. The disclosure further relates to the moisture crosslinked thermoplastic polymers resulting from the process and articles made therefrom.
(2) Description of Related Art
For many applications, e.g., wire and cable insulation, weatherstripping, fibers, seals, gaskets, foams, footware, flexible tubing, pipes, bellows, tapes, etc., certain selected properties (e.g. tensile strength, compression set, thermal and chemical resistance) of articles manufactured from one or more thermoplastic polymers can be enhanced by introducing chemical linkages between the polymeric molecular chains which constitute the polymer, during or specifically following, the shaping or molding process. These chemical linkages between different polymeric molecular chains are commonly referred to as "crosslinks". Crosslinks can be introduced between different molecular chains of a thermoplastic polymer by a number of mechanisms, one of which is to graft to the individual polymer backbones or chains that constitute the bulk polymer with a chemically reactive compound in such a manner that the grafted compound on one backbone may subsequently react with a similar grafted compound on another backbone to form the crosslink. Exemplary of this process is the "silane crosslinking" process.
The silane crosslinking process employs a silane-containing thermoplastic polymer that crosslinks when exposed to moisture. Silanes can be grafted onto a suitable thermoplastic polymer by the use of a suitable quantity of free radical initiator, either before or during a shaping or molding operation. Additional ingredients such as stabilizers, pigments, fillers, catalysts, processing aids etc., may also be included in the mixture.
When using practicing silane cross-linking for thermoplastic polymer, a compromise must be made between grafting efficiency and processing efficiency, such as extrusion rate and run times. The formation of a crosslinkable material by this means is, however, difficult to carry out since it requires critical control of the process. If the free radical initiator, for example, reacts too quickly with the thermoplastic polymer, then the thermoplastic polymer may partially crosslink and solidify in the processing apparatus, for example an extruder, with consequent difficulties in achieving consistent and good quality products and in avoiding delays involved in removing the partially crosslinked product from the processing equipment.
It has been observed that gel formation, screw-build up and scorching may result when using highly reactive silane cross-linking blends. This gel formation is particularly significant for processes using conditions and processing equipment that impose severe melting and mixing conditions leading to high shearing stresses in the thermoplastic polymer. These problems generally arise due to early and eventually complete activation of the free radical initiator during the initial melting and homogenization process. The prior art has dealt with these problems by using less reactive silane cross-linking blends but this approach can diminish the grafting efficiency of the crosslinkable thermoplastic polymers.
The silane compositions of the prior art can also generate volatile organic compounds in amounts that are a potential fire or explosion hazard and may be deleterious to the environment.
Thus, there remains a need for a means of crosslinking polyolefins and other silane crosslinkable thermoplastic polymers under reactive mechanical-working conditions using silane crosslinkers and free radical initiators while minimizing such aforenoted problems as gel formation, screw-buildup and/or scorching, fire or explosion hazards while maintaining a high level of grafting efficiency.

Process for crosslinking thermoplastic polymers with silanes employing peroxide blends, the resulting crosslinked thermoplastic polymer composition and articles made therefrom


An ergonomically configured computer mouse comprising a hand held housing body having one or more features to provide comfort in the operation of said mouse. For example, it may include a covering of a pliable memory material designed to yield to the impression of the user's palm and resile to its initial shape after use. As another example, the mouse may be provided with finger detents to facilitate handling of the mouse. Furthermore, the mouse can have a pair of aligned buttons for inputting information into the computer, or a scrolling mechanism, preferably in the form of a rocker switch, in proximity to the aligned buttons for activation with the user's index finger.

The computer mouse has been used for many years as an input device with desktop and laptop computers. The computer mouse is used to position a cursor at a selected location on a computer screen. If a button on the computer mouse is activated at the selected location, then the software running on the computer responds in a predetermined manner.
While efforts have been made to improve the ergonomic nature of computer mice, the fact remains that no two people have the same size and shape hands, and there is no computer mouse that allows the individual to operate the device with one finger, and no computer mouse that allows the individual to rest their finger on the mouse button without activating the software, or moving the cursor.
Recent studies claim that one of the most significant increases in the number of people who are being afflicted with carpal tunnel syndrome and repetitive strain injuries is due to the continuous rise in the use of computers. The number of computer users has increased from 5 million to 50 million in just the past 10-years, and the young age at which children begin using computers is going to create an even larger epidemic of carpal tunnel syndrome and repetitive strain injuries in the near future. Children are especially affected by the difficulty in operating an ordinary mouse.


This invention is to provide a process for producing a composite material that contains a thermoplastic resin as a matrix and is reinforced with electrically conductive fibers. This invention is to provide a process for producing a composite material that has a small percentage of voids and is excellent in mechanical properties such as flexural strength, flexural modulus.

A fiber-reinforced composite material containing a thermoplastic resin as a matrix (to be sometimes referred to as "FRTP" hereinafter) is widely known. Generally, FRTP is a prepreg obtained by impregnating reinforcement fibers in the form of dispersed pellets, unidirectional pellets, a single strand, a unidirectional sheet (UD sheet), a woven fabric or a non-woven fabric with a resin. A prepreg is processed into a structural member, various parts, etc., by injection molding, press molding, in-mold forming, filament winding molding, etc.
When FRTP is produced, however, the following points are to be noted. That is, since a thermoplastic resin generally has a high viscosity, its adhering amount to fibers is large and it tends to adhere non-uniformly, so that it is difficult to impregnate each one of fibers with a thermoplastic resin. Further, a gas generated by heating a thermoplastic resin is difficult to dissipate to an outside, and the adherence of fibers and a resin is liable to be insufficient.
FIG. 5 shows one example of an apparatus for impregnating a continuous fiber by a melting method using external heating (parenthesized numerals indicate reference numerals in FIG. 5). This apparatus has a vessel (11) containing a molten thermoplastic resin (12), and is constituted to ensure that a continuous fiber bundle (1) is immersed in the vessel (11) to impregnate the continuous fiber bundle (1) with the molten resin (12). In this case, it is arranged that the viscosity of the thermoplastic resin is decreased by heating (external heating) with pinch rollers (14) so that the fiber bundle may be easily impregnated with the thermoplastic resin.
In this method, it is required to increase the temperature of the resin in the vicinity of the fiber for decreasing the viscosity of the resin in the vicinity of the fiber and improving the adherence to the fiber. Since, however, heat in this method is transmitted in the order of the resin→an interface between resin and the fiber→the fiber, it is required to increase the temperature of the entire resin for increasing the temperature of the interface, and as a result, the entire resin comes to be exposed to a high temperature and is thermally deteriorated.
Further, various proposals have been made with regard to a method of improving the adherence of a resin and a fiber and improving the mechanical properties of FRTP. For example, the following proposals are examples.
Patent Document 1 proposes a process for continuously producing a prepreg sheet, which comprises the steps of continuously taking up a fiber bundle while a tension is exerted along a curved surface press-widening the above fiber bundle, drying the thus-press-widened fiber bundle and impregnating the dry fiber bundle with a molten resin. The above process not only overcomes the problem of a residual solvent but also overcomes the insufficiency of press-widening of the fiber bundle in a dry method. In this method, however, it is difficult to control the amount ratio of the resin and the fiber, and it cannot be said that sufficient adherence can be accomplished.
Patent Document 2 discloses a process for producing a prepreg, which comprises impregnating a sheet-shaped continuous carbon fiber widened/opened unidirectionally in parallel with a solution of a resin different from a matrix resin and compatible with the matrix resin and bonding the impregnated carbon fiber without drying to a sheet-shaped resin that is the matrix resin. Since this method uses, as glue, a resin solution compatible with the matrix resin, it has a defect that a residual solvent degrades the performance of a composite material.
Patent Document 3 proposes a method for producing a prepreg, in which a sheet-shaped continuous carbon fiber widened/opened unidirectionally in parallel is pressed to a thermoplastic resin film in a molten state to impregnate the carbon fiber with the thermoplastic resin. This method cannot yet be said to give sufficient adherence.
Patent Document 4 proposes a method for continuously producing a fiber-reinforced plastic, in which a fluid plastic is separated into many flows and the many flows are caused to collide with a fiber material by ejecting them perpendicular to the fiber material. When this method is applied to a thermoplastic resin, the viscosity of a molten thermoplastic resin is too high, so that it is required to prepare a solution or dispersion thereof. It cannot be said, either, that the above method fully overcomes the problem of a residual solvent.
Patent Document 5 discloses a method for producing a prepreg, which comprises removing a sizing agent of a fabric with a solvent in a prepreg containing the fabric as a reinforcing material and the thermoplastic resin as a matrix, then drying the prepreg, stacking a thermoplastic resin film and pressing the resultant set under heat. Even in this method, however, it cannot be said, either, that the adherence of the resin and the fabric to each other is sufficient.
Patent Document 6 discloses a laminate molding method in the stamping forming of a fiber-reinforced prepreg containing polypropylene as a matrix resin, in which an additive for improving a dielectric loss coefficient is incorporated into the matrix resin and the prepreg is heat-melted by means of microwave. In this method, however, the additive in the matrix resin is heated by the microwave, and the fiber and the resin in the vicinity thereof cannot be selectively heated. It is therefore required to heat the entire matrix resin to a high temperature for decreasing the melt-viscosity of the resin close to the fiber to a desired melt-viscosity, so that the entire matrix resin may be thermally deteriorated.
(Patent Document 1) JP-A 57-56220
(Patent Document 2) JP-A 58-162317
(Patent Document 3) JP-A 59-14924
(Patent Document 4) JP-A 61-286107
(Patent Document 5) JP-A 63-54441
(Patent Document 6) JP-A 64-34733

Composite material and process for the production thereof

Abstract: This invention is a process for producing a composite material, which comprises (1) the step (A) of causing the thermoplastic resin to adhere to the electrically conductive fibers and (2) the step (B) of applying microwave to said fibers to cause them to generate heat and impregnating said fibers with said resin, the composite material comprising a thermoplastic resin and the electrically conductive fibers being impregnated with the thermoplastic resin.