A viscous fluid is shown which is useful in treating subterranean formations. The fluid is formulated from an aqueous base, an alkyl sarcosinate surfactant and a buffer suitable for adjusting the pH of the blended fluid to a range in which the fluid is suitably viscosified. The fluid can also include an additional source of anions, such as chloride or fluoride ions, in order to increase the temperature stability of the fluid. The fluids have application for conventional well fracturing, coiled tubing fracturing, gravel packing and frac packing, as well as for use as selective water control additives and other applications.

1. Field of the Invention
This invention relates to the art of treatment fluids used in the recovery of hydrocarbon fluids from subterranean formations, and more particularly, to a fracturing fluid and method of fracturing a hydrocarbon-bearing formation.
2. Description of Related Art
Where hydrocarbons are being recovered from subterranean formations, it is common, particularly in formations of low permeability, to hydraulically fracture the hydrocarbon-bearing formation to provide flow channels to facilitate production of the hydrocarbons to the wellbore. Fracturing fluids typically comprise a thickened base fluid which primarily permits the suspension of particulate proppant materials in the fluid. Typical proppant materials include sand, sintered bauxite and the like. These materials will remain in place within the fracture when fracturing pressure is released thereby holding the fracture open. Such thickened fluids also aid in the transfer of hydraulic fracturing pressure to the rock surfaces and help to control leak-off of the fracturing fluid into the formation.
For many years, the most commonly used fracturing fluids comprised polymer thickened base fluids. The thickening polymers utilized were typically galactomannan gums, cellulosic polymers or synthetic polymers. It was generally necessary to cross-link the hydrated polymers in order to increase the viscosity and, thus, the proppant carrying capacity as well as to increase high temperature stability of the fracturing fluids. Typical cross-linking agents were borates or soluble organo metallic salts. Cross-linking or tying together of the polymer chains increases the viscosity and improves the rheology of the fracturing fluid.
In order to reduce the pumping friction pressure in such fluids, various methods of delaying cross-linking of the polymers have been developed. Delayed cross-linking allows the pumping of a relatively less viscous fracturing fluid having relatively low friction pressures within the well tubing. Cross-linking is then effected at or near the subterranean formation so that the previously mentioned advantages of the thickened cross-linked fluids are available downhole.
One disadvantage of the polymer thickened fluids was the necessity to hydrate the polymer at the well surface in a batch mix operation for several hours in a mixing tank or other container. It was often necessary to cross-link the polymer over a period of time to viscosify the fluid so that it is capable of carrying the proppant into the fracture. Natural polymers including polysaccharides, such as guar, have been used in this way in the past.
The hydration and cross-linking steps were time consuming and required expensive and bulky equipment at the wellsite. Such equipment, and the associated personnel to operate it, significantly increase the cost of the fracturing operation. Further once the polysaccharide is hydrated and crosslinked, it is generally not feasible to add additional polysaccharide to the solution, or to regulate the concentration of polysaccharide in the fracturing fluid during the pumping of the job.
The polymer based fluids of the type described also typically required a large number of additives in addition to the polymer, for example: bactericides, antifoam agents, surfactants to aid dispersion, pH control agents, chemical breakers, enzymatic breakers, iron control agents, fluid stabilizers, antioxidants, salts and the like. These materials must be formulated correctly, transported to the jobsite, and then pumped and metered accurately during the execution of the fracturing treatment.
Another difficulty with polymer-thickened fluids is the deposit and retention of polymer residues at the rock face and within the proppant pack. These characteristics can reduce the effectiveness of the fracturing operation. While there have been significant advancements in the use of oxidative or other breaker systems to reduce the effects of a polymer filter cake and other polymer residue within the fracture, such methods are always less than completely effective.
For example, during the course of a treatment, water from the fracturing fluid may leak into the formation leaving the polymer thickener behind. Concentrations of polysaccharide thickeners, such as guar, show dramatic increases as a factor of twenty as compared to the concentration of guar in the actual fracturing fluid. Many fracturing fluid materials, therefore, when used in large concentrations, have relatively poor xe2x80x9cclean-upxe2x80x9d properties, meaning that such fluids undesirably reduce the permeability of the formation and proppant pack after fracturing the formation. Well productivity after fracturing increases dramatically as the amount of polysaccharide returned to the surface increases.
One means of overcoming the effects of polymer residues remaining within a fracture would be to use a fracturing fluid that has components that allow themselves to associate, forming structures that are responsible for dramatically increasing the viscosity of the fluid. After the pumping into the fracture is completed, conditions within the fracture and fluid change, resulting in the loss of structure and consequently, viscosity. Example components capable of forming associating structures are certain surfactants. Thus, various emulsions of water and oil have been proposed. These surfactants, under specific conditions, can associate with one another to produce viscosified fluids having properties similar to polymer based fluids. Changes in pH or hydrocarbon content can then dramatically reduce viscosity without the need of traditional breakers and clean-up can occur unhindered due to the lack of proppant pack residue.
While structured surfactant based fluids offer certain advantages over traditional polymer based fluids, there remains room for improvement. These surfactant based fluids have tended to utilize expensive surfactants which were cost prohibitive in some instances. Cost limitations have resulted in the design of these structured fluids that can be characterized as marginal fracturing fluids. There have also been limitations on the temperature stability of such fluids, limiting treatment sizes to rather small fracturing treatments.
U.S. Pat. No. 5,964,295, issued Oct. 12, 1999, to Brown, et al., teaches a method and composition for treating subterranean formations utilizing a xe2x80x9cviscoelastic fluidxe2x80x9d which purports to overcome certain of the above-noted deficiencies of the prior art polymer containing fluids. However, the Brown fluid continues to be subject to temperature and stability limitations and forms emulsions which are oil wetting to the formation.
An object of the present invention is to develop a surfactant based fluid with the ability to suspend proppants that is economical, having superior properties compared to existing product available on the market, as well as being more temperature tolerant.
The viscous fluids of the invention can be used for transporting particulate through a conduit to a subterranean location. In one form, the fluids comprise an aqueous base, a surfactant comprising an alkyl sarcosinate having from 12 to 24 carbon atoms and a buffer for adjusting the pH of the combined aqueous base and surfactant at or for the formation pH. The alkyl sarcosinate is preferably present in the range from about 0.5 to 10% by weight, based upon the weight of the total fluid. The pH of the viscous fluid is preferably adjusted with the buffer to be in the range from about 6.5 to 10.0 for most formations.
The viscous fluids of the invention can also include an additional source of anions in addition to those furnished by the surfactant. The additional source of anions can comprise a carboxylic acid salt present in the range from about 0.1 to 2% by weight, based upon the weight of the total fluid. The carboxylic acid salt, if present, is preferably selected from the group consisting of monovalent acetates, divalent fumerates, trivalent citrates and tetravalent EDTA. Alternatively, the additional source of anions comprises a source of chloride or fluoride ions. The preferred source of chloride ions are inorganic salts such as ammonium chloride and potassium chloride. The preferred sources of fluoride ions can comprise a fluoride salt or acid compound present in the range from about 0.5 to 10% by weight, based upon the weight of the total fluid. The most preferred sources of fluoride ions are inorganic fluoride salts selected from the group consisting of ammonium bifluoride and sodium or potassium fluoride or a fluoride acid such as fluosilicic acid. Where the additional source of anions comprises a source of fluoride ions, the viscous fluid contains a buffer to adjust the pH of the resulting viscous fluid within the range from about 6.5 to 10.
In the method of fracturing a subterranean formation of the invention, an aqueous base fluid is combined with a surfactant comprising an alkyl sarcosinate having from 12 to 24 carbon atoms. The combined fluid is buffered to thereby adjust the pH of the combined aqueous base and surfactant at or for the formation pH, thereby creating a viscous fluid capable of supporting proppant. The viscous fluid is pumped through a wellbore and into a surrounding formation at a pressure sufficient to fracture the formation.
The viscous fluids of the invention can also be used in a method for reducing the amount of water produced from a subterranean oil producing formation. An aqueous base fluid is combined with a surfactant comprising an alkyl sarcosinate having from 12 to 24 carbon atoms as before. The combined fluid is buffered to thereby adjust the pH of the combined aqueous base and surfactant sufficiently to produce a viscous fluid. The viscous fluid is pumped through a wellbore and into a surrounding formation having an aqueous zone and a hydrocarbon zone, the aqueous zone comprising water. The viscous fluid is then allowed to contact the aqueous zone and the hydrocarbon zone. Contact with the hydrocarbon zone serves to thin the viscous fluid while contact with the aqueous zone serves to preferentially block the flow of water from that portion of the formation.
Additional objects, features and advantages will be apparent in the written description which follows.
The present invention is a new viscous fluid which is particularly useful in transporting particulate through a conduit. The viscous fluid of the invention has application for conventional well fracturing, coiled tubing fracturing, gravel packing and frac packing, as well as for use as a selective water control additive.
The viscous fluids of the invention, unlike conventional polymer based viscous fluids, are based upon surfactant compositions. In a preferred form, the viscous fluids of the invention comprise at least an aqueous base, a surfactant comprising an alkyl sarcosinate having from about 12 to 24 carbon atoms in the alkyl group and a buffer for adjusting the pH of the combined aqueous base and surfactant at or for the formation pH. In other words, the optimum pH for the system is the formation pH. As will be explained in detail, the fluids of the invention are optimized for viscosity and for the formation pH in order to reduce ion exchange at the formation, thereby avoiding clay dispersion and swelling. The water used in formulating the fluids can be fresh water or light brines from any convenient source. The particularly preferred alkyl sarcosinates used as the surfactant have an alkyl group ranging from 14 to 18 carbon atoms.
Sarcosine is a naturally occurring amino acid. It can be produced by thermal decomposition of caffine in the presence of barium carbonate. Sodium sarcosinate is manufactured commercially from formaldehyde, sodium cyanide and methyl amine. The preferred sarcosinates are the condensation products of sodium sarcosinate and a fatty acid chloride. The fatty acid chloride is reacted with sodium sarcosinate under alkaline conditions to produce the fatty sarcosinate sodium salt, which is water soluble. Upon acidification, the fatty sarcosine acid, which is water insoluble, is formed and may be isolated from the reaction medium. The acyl sarcosines may be neutralized with bases such as sodium, potassium, ammonia, or triethanolamine to produce aqueous solutions. The preferred sarcosinates of the invention can be represented structurally as:
wherein R1 is a fatty acid hydrocarbon chain having from 12 to 24 carbon atoms, R2 is selected from the group consisting of hydrogen, methyl, propyl, butyl and ethyl and X is selected from the group consisting of carboxyl and sulfonyl.
The particular surfactant selected for use in the method of the invention is an anionic sarcosinate surfactant available commercially from BJ Services Company of Tomball, Tex., as xe2x80x9cMA-1.xe2x80x9d The MA-1 sarcosinate is a viscous liquid surfactant with at least 94% oleoyl sarcosine. For hydraulic fracturing, a sufficient quantity of the sarcosinate is present in aqueous solution to provide sufficient viscosity to suspend proppant during placement. The surfactant is preferably present in the range from about 0.5 to 10% by weight, most preferably from about 0.5 to 6% by weight, based upon the weight of the total fluid. Laboratory procedures are employed to determine the optimum concentrations for any particular job.
As will be explained in the laboratory evaluations, to prepare the aqueous hydraulic fracturing fluids of the invention, the surfactant is added to an aqueous solution in which there is typically dissolved a quantity of at least one water soluble salt to effect formation stability. Typical water soluble salts include potassium chloride, sodium chloride and the like. Formation stability is typically achieved with only small concentrations of salt. The water soluble salts may be considered part of the xe2x80x9cbufferxe2x80x9d for adjusting the pH of the combined aqueous base and surfactant in the method of the present invention. Other salts/buffer combinations can also be used, for example, ammonium or potassium persulfates can be used at pH between about 6.0 to 8.0 on gravel pack jobs or in filter cake removal jobs where a polymer based drill fluid was utilized. For sand or proppant clean out treatments, NaCl/NaOH combinations can be utilized at pH ranges from about 6.0 to 8.0. For treatments requiring a pH lower than about 7.0, potassium citrate has been successfully employed.
The viscosity of the fluids of the invention are improved significantly by the addition of certain additional anions to the surfactant-laden solution. These anions can be carboxylic salts such as monovalent acetate, divalent fumerate, trivalent citrate or tetravalent ethylenediaminetetraamine (EDTA). Typically the concentration of these salts ranges from about 0.1 to 2% by weight, based upon the weight of the total fluid and the pH of the solution is adjusted above about 6.5. The pH can be adjusted, for example, by the addition of alkali metal or ammonium ions of hydroxide, carbonate, phosphate or borate, or organic amines, especially alkanol amines such as mono, di or tri ethanolamine.
High temperature stability of the fluids in question is achieved if the source of additional anions is a source of chloride or fluoride ions preferably provided in the form of an inorganic chloride or fluoride salt or a fluoride acid such as fluosilicic acid. When the preferred fluoride salts are substituted for the carboxylic acid salts or supplemented with the carboxylic salts, significant improvements in temperature stability were observed. The fluoride salt concentration can range from about 0.5 to 10%, with the most preferred range being from about 3 to 6% by weight, based upon the total weight of the fluid. Typical fluoride salts include ammonium bifluoride and sodium and potassium fluoride and the pH of the surfactant-fluoride salt solution is adjusted to range from about 6.5 to 10. The pH can be adjusted with the same bases as discussed above.
Each salt will produce a peak viscosity at a different pH. The fluids of the invention are optimized for viscosity and formation pH as will be discussed with respect to the laboratory analyses which follow.
In addition to the surfactant, water soluble salts and additional sources of anions discussed above, the formulations of the invention can also contain other conventional additives which perform specific functions such as, e.g., corrosion inhibitors, fluid-loss additives, scale inhibitors and others. The proppant can then be suspended in the fluid. Conventional proppants will be familiar to those skilled in the art and include sand, resin coated sand sintered bauxite and similar materials.
The fluids of the invention are easily degraded by contamination with hydrocarbon based fluids naturally present in the reservoir or by a decline in the pH of the fluid so that an additional breaker compound is generally not necessary in the fluid being pumped. The pH decline is often observed in sandstone formations or by aqueous formation fluids, for example.
In the method of fracturing a formation using the formulations of the invention, an aqueous base fluid is combined with a surfactant comprising an alkyl sarcosinate having from 12 to 24 carbon atoms. Standard mixing procedures known in the art can be employed since heating of the solution or special agitation procedures are not normally required. The aqueous base has been buffered with a buffer to thereby adjust the pH of the combined aqueous base and surfactant above about 6.5, thereby creating a viscous fluid capable of supporting proppant. The proppant can be added and the viscous fluid can then be pumped through a wellbore and into a surrounding formation at a pressure sufficient to fracture the formation. Typically, the viscous fluid can be allowed to contact the formation for a period of time sufficient to break the fluid viscosity without the use of additional breaker materials.
The fluid of the invention can also be used as selective water control additives. The viscous fluids can be pumped into a water rich sector of a producing interval. Once placed, the gel viscosity will prevent formation water flow through that portion of the reservoir. On the other hand, gel pumped into the oil rich sector of the formation reservoir will immediately thin on contact with the oil contained within the reservoir. Consequently, oil production will be uninhibited while water flow will be preferentially stopped.
For fracturing applications, the fluids of the invention are typically pumped downhole at or slightly above the formation pH. Preferably, when the fluids of the invention are used for water control purposes, the fluids are pumped downhole at about {fraction (3/10)} of a pH unit less than the formation material pH. The fluid is thus pumped in a thinned state, reducing the friction pressure of the pumping job. Upon contacting the formation material, the pH of the fluid moves up, resulting in gellation of the fluid at the formation location rather than at the well surface.
In order to more fully describe the fracturing fluids of the invention, the following examples are set forth. However, it is to be understood that the examples are not intended to limit the scope of the present invention as defined in the appended claims.
Each of the components of the viscous fluids of the invention is readily soluble in water or light brines at pH higher than 4.5. The fluid is easily prepared in mixing equipment that allows circulation or agitation, i.e. blenders, tanks equipped with augers or tanks that are connected to a circulating pump, such as an acid transport trailer or in displacement tanks of cementing units.
A preferred mixing procedure is as follows:
1. Load the fresh water necessary to prepare the desired volume of viscous fluid into a clean tank.
2. While agitating or circulating, slowly add and dissolve the required amount of the salt, for example, KCl, KF, NH4Cl and or ABF.
The salt concentration will depend on the type of salt used and the final pH, as part of the xe2x80x9cadditional anionsxe2x80x9d requirement for optimum viscosity as discussed above. The following table can be used as a guideline. Unless otherwise stated, the percentages are by weight of total fluid solution.
3. Add the required volume of pH adjuster/buffer solution.
4. Add the MA-1 and mix slowly mix (to avoid foam) for 5-10 minutes or until it disperses well to produce a uniform linear gel.
5. Add the remainder of the buffer for completed activation and full viscosity development.
In the case of KF, the anionic surfactant is supplied in the acid form is not soluble in field water. The pH of the water in the mixing tank must be alkaline enough before the addition of MA-1, so that when the MA-1 is added, the pH is at least above 4.5 and preferentially above 7.0. This buffering of the mixing water will prevent waxing out of the surfactant and speeds the mixing process. Usually with field water, the addition of 40% solution of base such as KOH at one-half of the concentration of MA-1 will neutralize the pH of the mixing water when the MA-1 is added.
In the case of systems utilizing ABF as the additional source of anions, for every 1% of ABF, an additional 0.5% of the buffer is generally required. In any case, the optimum pH for the system is the formation pH. As increases in temperature reduce the pH it is recommended that the final pH be one pH unit higher for KOH systems or xc2xd unit higher when most other buffer systems are used. This can be done in the mixing tank or on the fly at the blender.
The tables below are examples of the viscosity optimization process using 4% MA-1 (sarcosinate surfactant) for a target formation pH of 8.0 using KCl and KF with field water. The BF-7L is a commercially available buffer commonly used in the formulation of fracturing fluids. It can be obtained commercially from BJ Services Company of Tomball, Tex.
Example Using KCl
Formation pH: 8.0 @ 180xc2x0 F.; design for a pH of 8.5 to 9.0 at the well surface.
Fluid viscosity requirements=200 cps @ 180xc2x0 F. and 40 secxe2x88x921
For KCl Determination
The 12% KCl system produced 285 cps @ 40 sec-1 and a pH of 8.2 when tested @180xc2x0 F., therefore a system with 3.5% MA-1 may be sufficient for this treatment.
Example Using KF
Formation pH: 8.0 @ 180xc2x0 F.; design for 8.5 to 9.0 at the well surface.
Fluid viscosity requirements=200 cps @ 40 secxe2x88x921
For KF Determination
The 8% KF system produced 452 cps @40 sec-1 and a pH of 8.6 when tested @ 180xc2x0 F., therefore a system with 3% MA-1 may be sufficient for this treatment.
As indicated in the above examples, the formulations utilizing KF produce about twice the viscosity of similar formulations that contain KCl. However, KF is not available in all geographic locations. The following formulations utilize ABF and KOH in order to produce KF in solution. Because the formulations are mixing cations (potassium and ammonium) it is more difficult to optimize the viscosity and pH. The following examples illustrate systems for four different concentrations of MA-1 and for a fixed pH of 9.0 to 9.5 depending on the pH of local water. When the solutions are heated as they are pumped downhole, the pH will drop to around 8.5 to 9 depending on bottom hole injecting temperature.

Viscous fluid applicable for treating subterranean formations


A light emitted diode circuit includes: a plurality of driving circuits, wherein the plurality of driving circuit are connected in series, and each driving circuit includes a plurality of diodes; and a plurality of loading circuits connected with the driving circuits, respectively; wherein the plurality of driving circuits are arranged for generating a plurality of driving voltages to drive the plurality of loading circuits, respectively.

1. Field of the Invention
The present invention relates to a diode circuit, and more particularly, to a light emitted diode (LED) circuit that can reduce power consumption effectively and generate less heat.
2. Description of the Prior Art
Generally, a LED circuit has higher temperature in operation which causes a bad effect to whole circuit, therefore, how to utilize a simple circuit architecture to reduce the generated heat when the LED circuit is operating is an important issue.


The invention relates to a brake system for braking aircraft wheels, the brake system being of the type which, for each wheel, comprises a stator central portion coaxially surrounding a wheel axle on which a rotor annular portion is mounted to rotate, and a succession of brake disks disposed between the stator central portion and the rotor annular portion with alternate disks being constrained to rotate with one and the other of said portions, said stator central portion being provided with a brake collar equipped with a plurality of sets of pistons and, rigidly secured to said collar, a torsion tube internally provided with a transverse annular web, a centering bearing being interposed between the annular web and the axle. According to the invention the centering bearing has structural characteristics that vary circumferentially in a distribution configuration suitable for generating different bearing stiffnesses along two orthogonal axes contained in a plane that is perpendicular to the axis of the axle.

Such brake systems having stacks of disks (generally made of carbon) are in widespread use on aircraft of recent design. Generally, the stator central portion is provided with a brake collar equipped with a plurality of sets of pistons and, rigidly secured to said collar, a torsion tube. The stator portion is supported on the axle in question firstly at the brake collar, and secondly at a transverse annular web present inside the torsion tube. A centering bearing is then interposed between the annular web and the axle. Reference may be made, for example, to Documents U.S. Pat. No. 6,003,641 and EP-A-0 990 813.
In conventional landing gear, a landing gear leg is provided together with a telescopic rod to the end of which a wheel lever carrying a pair of wheels is hinged. The wheel lever is thus hinge mounted on a yoke secured to the bottom end of the telescopic rod, and a bar is interposed between the brake collar and one of the branches of the above-mentioned yoke for the purpose of taking up the torsion forces generated during braking.
When the brake system is actuated by the pilot, the axles are subjected to simple flexing in two perpendicular directions, which corresponds to two coupled characteristic modes. In addition, the structure which surrounds the axle is also subjected to flexing forces of the same type, generating dynamic deformations of the same type, which deformations take place with a small amount of phase delay relative to the deformations of the axle. The two coupled modes combine to generate an unstable mode, and specialists know that if the two modes have frequencies that are close to each other, the probability of the two modes combining into an unstable mode is high. Thus, an approach has emerged aiming to move the characteristic modes apart to so as to prevent the resulting unstable mode from appearing.
Proposals have been made to act hydraulically on the brake collar by throttling hydraulic fluid to generate damping. However, in addition to being complex, such a solution is unsatisfactory in terms of reliability, in particular in the event of hydraulic failure.
Attempts have also been made to act on the stiffness of the torsion tube by using a sandwich of different materials. That theoretically makes it possible to adapt the axial stiffness of the torsion tube or of the surrounding structure. However, in that approach, it is extremely difficult to control the stiffnesses reliably in different directions.
A more advantageous solution has recently been proposed, aiming to make use of the presence of the transverse annular web by constraining said web to have a particular and non-uniform behavior. Unlike the other conventional designs in which the transverse annular web is uniformly perforated with circular holes, that solution has focused on providing slots which are circumferentially elongate, which slots generate asymmetry. The axle is then retained on a portion of circumference with rigidity that is larger in one zone than in the residual zone associated with the presence of circumferential slots. By appropriately selecting the angular extent of the circumferential slots and their positions relative to the main axes, that solution appears to make it possible to lower the low-frequency mode. However, such an approach suffers from the drawback of weakening the transverse annular web. In addition, modifying radial stiffnesses also induces a modification in axial stiffness, which is also unfavorable structurally.

Brake system for braking aircraft wheels


An intramedullary nail for treating fractures of a bone includes a body having a head, an intermediate portion and a distal tip. At least one transverse opening for receiving a screw is provided in the body. The opening comprises an insert adapted to receive the screw.

A variety of devices are conventionally used to treat bone fractures. Intramedullary nail systems (also known as intramedullary rod systems) are employed in orthopedic surgery for repairing fractures of long bones, such as the femur and humerus. Use of intramedullary nail systems reduces healing time, permits less immobilization of the affected limb, and simplifies treatment of complex fractures.
An example of a conventional intramedullary nail used for humeral repair generally takes the form of an elongated cannulated body. At various locations along its length, the nail is provided with one or more transverse openings for receiving screws. Typically, at least one transverse opening is located near an end of the nail. The openings are commonly adapted to receive the screws at various angles in order to repair a wide range of fractures in a variety of patients using the same nail design. The nail is normally provided with a securing arrangement on at least one end. The securing arrangement is for securing a tool or device for inserting and extracting the nail, as well as maintaining the nail's desired position during insertion. In order to facilitate correct insertion of the nail into a medullary canal, various guiding devices and arrangements are used. Examples of such arrangement are guiding wires, sleeves, or pins.
To repair a bone fracture using an intramedullary nail system, a medullary canal of the bone is reamed using an appropriate tool or device. An intramedullary nail is inserted into the medullary canal and advanced axially through the canal so that the nail traverses the fracture site. Then, one or more screws or pins are applied to the nail through the transverse openings in the nail. The screws extend through the bone on one or both sides of the fracture site so that the nail is attached to portions of the bone on each side of the fracture, thereby securing the bone segments and allowing healing along the fracture site.
One of the problems commonly associated with the intramedullary nail systems is insufficient retention of the screws or pins in the nail, which causes undesirable movement in the system. Detrimental to healing consequences of such undesirable movement include but are not limited to, the fracture becoming unreduced, collapse of parts of the bone onto each other, or damage to bones or soft tissues by bone parts or parts of the system.
Intramedullary nail systems are commonly designed to allow insertion of the screws or pins in the nail at various angles. In one aspect, this feature ensures an ability to use the same nail to repair various fractures in bones in a range of sizes and shapes. This eliminates the necessity to have available different types of intramedullary nail systems, each allowing insertion of screws at specific angles. In another aspect, the ability to vary the angle of insertion of a screw into an opening in the nail allows to compensate for misalignments that occur during surgery.
There are, however, problems associated with the openings capable of receiving screws at a range of angles. Particularly, this feature leads to wobbling of the end of the screw inserted in the nail. For stabilization, the screw relies on purchase of its other end to the bone tissue. The undesirable movement occurs if the purchase to the bone tissue is inadequate, or is lost after the reduction of the fracture. Moreover, wobbling of the end of the screw inserted in the nail increases the tension applied by the other end of the nail to the bone tissue and may facilitate the destruction of the bone tissue.
Long bones such as femur and humerus can be fractured in the lower portion, the mid portion or the upper portion, where the bone connects to the joint. The third scenario is typically referred to as a proximal fracture. Proximal fractures of long bones, such as femur or humerus, frequently occur in women with osteoporosis, a condition of brittle, fragile bones. Osteoporosis is highly prevalent in women, especially in those post menopause, thus making repair of the proximal fractures of femur and humerus an important public health issue.
The repair of proximal humeral fractures using intramedullary nails is especially difficult. In proximal humerus, the bone is mostly cancellous and of relatively low density. Due to poor bone quality, adequate stabilization of the humeral head or tuberosities during bone fracture repair is challenging and is not provided by currently available intramedullary nail systems and techniques.
Traditional humeral nails use one or two proximal screws for fixation. To reduce a fracture, these constructs rely on purchase of screw threads to the bone in order to hold the fragments of the bone together. When the thread purchase in the bone is lost, the fracture becomes unreduced. Additionally, the loose screws cause damage to the surrounding bone and the soft tissues.
Other currently available nails for repair of proximal humeral fractures use multiple non-coplanar screws for proximal fixation. These designs are less dependent upon thread purchase due to the use of diverging or converging fixation pattern. By having two non-coplanar screws attached to a single bone fragment, the pullout forces are directed away from axes of each the screws. These constructs rely on fixation of the screws to bone tissue, which can lead to the deterioration of the bone tissue.
Both types of constructs described above require sufficient amount and quality of bone tissue for fixation of the fracture. When the bone tissue is lost due to disease or a pathological condition or for other reasons, the constructs become unstable. Persons with thin or fragile bones, such as osteoporosis patients, avascular necrosis patients and patients with metastatic bones, are particularly prone to fractures. Therefore, currently available intramedullary nail systems do not satisfy the requirements of the patients who are in particular need of such constructs.
In view of the foregoing, there is a need for intramedullary nail systems which provide increased stabilization of screws in an intramedullary nail, while simultaneously allowing insertion of the screws into the nail at a range of angles. There is also a need for intramedullary nail systems which reduce undesirable movement in a bone fracture stabilized with the system, and reduce undesirable movement of the components of the system with respect to each other. Ability of an intramedullary nail system to reduce the fractures of bones of poor quality, such as those occurring during osteoporosis, cancer or other pathological conditions, is also desirable. In general, there is a need for intramedullary nail systems which are versatile, allow for faster healing with fewer complications, require less immobilization, are easy to use and manufacture, and are less costly to produce and operate.


There is provided a receptor layer transfer sheet which is capable of providing images of high quality on a transfer receiving material having an unsmooth surface, even when it is used in combination with a conventional thermal transfer material.. There is also provided a thermal transfer sheet which is capable of providing images of high quality on a transfer receiving material having an unsmooth surface.. There is further provided a thermal transfer method and a thermal transfer apparatus which are capable of providing images of high quality and do not require a special detection mark provided in (or on) a thermal transfer sheet to be used in combination therewith.

The present invention relates to a receptor layer transfer sheet and a thermal transfer sheet, and more specifically to a thermal transfer sheet and a receptor layer transfer sheet capable of providing images of high quality and high image density even on a transfer receiving material having an unsmooth surface.
The present invention also relates to a thermal transfer method and a thermal transfer apparatus, and more specifically to a thermal transfer method and an apparatus to be used therefor which are capable of providing images of high quality by using a thermal transfer system.
According to the present invention, it is possible to form gradation images such as photo-graphic images together with words and marks on ready made transfer receiving materials such as name cards, post cards, leaflets, curriculum vitaes, resumes, identification cards, licenses, commuter passes, membership cards, passports, notebooks, and coupon tickets.
Heretofore, various thermal transfer methods are known. Among these, there has been proposed a method wherein a sublimable dye (or subliming dye) is used as a recording agent, and is carried on a substrate sheet such as paper and plastic film to obtain a thermal transfer sheet, and various full color images are formed on a transfer receiving material such as paper and plastic film having thereon a dye receptor layer by using the resultant thermal transfer sheet. In such a case, a thermal head of a printer is used as heating means so that a large number of color dots of three or four colors are transferred to the transfer receiving material under heating in a very short period of time. As a result, a full color image of an original is reproduced by using the multi-color color dots.
The thus formed images are very clear and are excellent in transparency since the dyes are used therein as a colorant. Accordingly, these images are excellent in half tone reproducibility and gradation characteristic and are substantially the same as the images formed by the conventional offset printing and gravure printing. Further, when the above image forming method is used, there can be formed images of high quality which are comparable to full color photographic images.
In the above image forming method, however, the transfer receiving material on which the above mentioned images can be formed is restricted to a plastic sheet having a dyeing property (or dyeability) which is dyeable by a dye, paper on which a dye receptor layer has been formed in advance, etc. Accordingly, the above mentioned method cannot provide an image directly on ordinary plain paper, etc. As a matter of course, when a receptor layer is formed on the surface of ordinary plain paper, the resultant paper can be subjected to such image formation. However, such a method generally requires a high cost, and it is difficult to apply this method to generally ready made transfer receiving materials such as post cards, memo papers, letter papers, and writing pads.
As a measure for solving such a problem, there is known a receptor layer transfer sheet which is capable of easily providing a dye receptor layer on an essential part (i.e., a part on which an image is to be formed) of the ready made transfer receiving material such as paper when an image is intended to be formed on the ready made transfer receiving material. As such a receptor layer transfer sheet, there has been proposed one comprising a substrate sheet having a releasability and a resin layer disposed thereon for forming a receptor layer, e.g., as disclosed in Japanese Laid Open Patent Application (JP-A, KOKAI) No. 264994/1987.
In a case where the receptor transfer sheet as described above is used so as to transfer the receptor layer to the transfer receiving material, substantially no problem is posed when the transfer receiving material comprises a coated paper having a smooth surface. However, when the transfer receiving material comprises plain paper, a post card, and other paper having a rough texture, the surface of such paper is composed of exposed fibers and is poor in surface smoothness. Accordingly, the receptor layer cannot uniformly be transferred to the surface of such paper and therefore white dropout or transfer failure occurs in the image formed on the resultant receptor layer, whereby high quality images cannot be obtained.
Further, when the receptor layer is partially transferred to the transfer receiving material so as to provide a small pattern or a pattern having a complicated configuration by means of a thermal head, etc., the film of the receptor layer is not necessarily cut properly so that the transfer thereof is not necessarily effected accurately.
In order to solve these problems, it is conceivable that the receptor layer is caused to have a large thickness (e.g., about 20 to 30 .mu.m) so that the surface unevenness of the paper is filled with the receptor layer. In practice, however, when the thickness of the receptor layer is increased, there occur various problems such that the thermal efficiency at the time of the transfer is lowered, cutting of the film becomes poor, and the film thickness becomes uneven. As a result, it is practically difficult to transfer the receptor layer per se, and the above problems cannot be solved.
As a measure for further simplifying the above operation, there has been proposed a thermal transfer sheet such that dye layers of yellow, magenta, and cyan (and optionally black, as desired) are sequentially formed on the surface of a continuous substrate film, and then a transfer receptor layer is formed on the same surface of the substrate film (Japanese Laid Open Patent Application Nos. 84281/1986 and 297184/1987). When such a thermal transfer sheet is used, the receptor layer is first transferred to a transfer receiving material, and then the dye layer of the respective colors are transferred to the receptor layer to form a full color image.
However, when the above thermal transfer sheet is used, it is required that the dye layer is firmly bonded to the substrate film, because the dye layer is liable to be transferred when the bonding therebetween is low. On the other hand, it is required that the receptor layer is bonded to the substrate film so as to provide an appropriate bonding strength. When the bonding strength is low, the peeling thereof is easy but the film cutting becomes poor. On the other hand, the bonding strength is too high, transfer failure occurs. As a result, the above requirements or performances for the dye layer and the receptor layer are antagonistic to each other.
There has also been proposed a method wherein a polyester film having a surface with an improved bonding property is used as a substrate film. However, the above antagonistic performances have not been satisfied even when such an improved polyester film is used.

Receptor layer transfer sheet, thermal transfer sheet, thermal transfer method and apparatus therefor


A pattern matching method includes: detecting an edge of a pattern in a pattern image obtained by imaging the pattern; segmenting the detected pattern edge to generate a first segment set consisting of first segments; segmenting a pattern edge on reference data which serves as a reference for evaluating the pattern to generate a second segment set consisting of second segments; combining any of the segments in the first segment set with any of the segments in the second segment set to define a segment pair consisting of first and second segments; calculating the compatibility coefficient between every two segment pairs in the defined segment pairs; defining new segment pairs by narrowing down the defined segment pairs by calculating local consistencies of the defined segment pairs on the basis of the calculated compatibility coefficients and by excluding segment pairs having lower local consistencies; determining an optimum segment pair by repeating the calculating the compatibility coefficient and the defining new segment pairs by narrowing down the segment pairs; calculating a feature quantity of a shift vector that links the first and second segments making up the optimum segment pair; and performing position matching between the pattern image and the reference data on the basis of the calculated feature quantity of the shift vector.

1. Field of the Invention
The present invention relates to a pattern matching method, program and a semiconductor device manufacturing method and, is directed to position matching between an image of a semiconductor pattern and CAD data, for example.
2. Related Art
The accuracy of patterns in semiconductor lithography processes has been managed conventionally by measuring the dimensions of line patterns and the internal diameters of hole patterns in an image obtained with an SEM (Scanning Electron Microscope).
However, with the recent advances in miniaturization of LSIs (Large Scale Integrated Circuits), there is an increasing need of measuring a particular portion of patterns having complex geometries on the basis of tolerance data provided while LSIs are designed in addition to measuring the average dimensions of simple patterns. Accurate position matching between design data and an SEM image is a prerequisite for performing such measurement.
There has been one method for matching an SEM image to design data, in which an edge image is generated from CAD data, for example, and the SEM image, the edge image is smoothed with a smoothing filter, and then matching is performed based on the correlation between the images (Japanese Patent Laid-Open No. 2002-328015, for example).
However, the method disclosed in Japanese Patent Laid-Open No. 2002-328015 has a problem that when a high-magnification SEM image is obtained in order to evaluate changes in geometry, the difference between a geometry in the SEM image and a geometry in CAD data is large, which degrades the accuracy of matching.

Pattern matching method, program and semiconductor device manufacturing method


A single sheet of flexible fabric is folded and creased to form a compact pouch or pocket that can be attached to and detached from a golf bag. The pocket connects to the bag by hooks carded at the opposite ends of the pocket. The pocket has a long central zippered opening in the front, and a pleated back, but is constructed so that, when empty, the pocket lies flat against the golf bag.

The following patents illustrate prior devices for providing supplemental storage for a golf bag or a golf cart:
U.S. Pat. No. 715,759 (Crane) PA1 U.S. Pat. No. 1,718,952 (Fischer) PA1 U.S. Pat. No. 1,739,780 (Buhrke) PA1 U.S. Pat. No. 3,373,911 (Kebelbeck) PA1 U.S. Pat. No. 4,032,054 (Duncan) PA1 U.S. Pat. No. 4,350,194 (Brown) PA1 U.S. Pat. No. 4,459,827 (Rhodes) PA1 U.S. Pat. No. 4,869,365 (Perdue et al.) PA1 Canadian Patent No. 613,456 (Amess)
The patents issued to Crane and Fischer disclose special holders for golf balls.
The patent issued to Buhrke discloses a special holder for golf tees.
The Kebelbeck patent discloses a "shoe pack" attachable to a golf cart.
The patent issued to Duncan discloses a holder or caddy for miscellaneous golfing paraphernalia.
The patent issued to Brown discloses a golf bag having detachable pockets that can be secured to the golf bag in desired positions by snaps or hook-and-pile fasteners.
The patent issued to Rhodes discloses a holder for beverage cans.
The patent issued to Perdue et al. discloses a plurality of pockets carried on a backing panel which, in turn, is attachable to a golf bag.
The Canadian patent discloses an umbrella holder.
Of the above patents, only Perdue et al. and Brown disclose general purpose compartments attachable to a golf bag, but the compartments protrude from the bag and the attaching mechanism is of complicated construction.


A method of producing an adeno-associated virus (AAV) in an insect cell comprising (i) providing at least one insect cell-compatible vector comprising a first nucleotide sequence comprising at least one AAV ITR nucleotide sequence, a second nucleotide sequence containing an open reading frame encoding AAV VP1, VP2, and VP3 capsid proteins, a third nucleotide sequence comprising a Rep52 or a Rep40 coding sequence, and a fourth nucleotide sequence comprising a Rep78 or a Rep68 coding sequence, (ii) introducing the at least one insect cell-compatible vector into an insect cell, and (iii) maintaining the insect cell under conditions such that AAV is produced. Also provided are recombinant AAV made in accordance with the method, insect cell-compatible vectors, and insect cells comprising nucleotide sequences for production of AAV in an insect cell.

Viruses of the Parvoviridae family are small DNA animal viruses characterized by their ability to infect particular hosts, among other factors. Specifically, the family Parvoviridae is divided between two subfamilies: the Parvovirinae, which infect vertebrates, and the Densovirinae, which infect insects. The subfamily Parvovirinae (members of which herein are referred to as the parvoviruses) includes the genus Dependovirus, the members of which genus are unique in that, under most conditions, these viruses require coinfection with a helper virus such as adenovirus or herpes virus for productive infection in cell culture. The genus Dependovirus includes adeno-associated virus (AAV), which normally infects humans (e.g., serotypes 2, 3A, 3B, 5, and 6) or primates (e.g., serotypes 1 and 4), and related viruses that infect other warm-blooded animals (e.g., bovine, canine, equine, and ovine adeno-associated viruses). The parvoviruses and other members of the Parvoviridae family are generally described in Kenneth I. Berns, "Parvoviridae: The Viruses and Their Replication," Chapter 69 in FIELDS VIROLOGY (3d Ed. 1996).
In recent years, AAV has emerged as a preferred viral vector for gene therapy due to its ability to efficiently infect both nondividing and dividing cells, integrate into a single chromosomal site in the human genome, and pose relatively low pathogenic risk to humans. In view of these advantages, recombinant adeno-associated virus (rAAV) presently is being used in gene therapy clinical trials for hemophilia B, malignant melanoma, cystic fibrosis, and other diseases.
AAV is able to infect a number of mammalian cells. See, e.g., Tratschin et al., Mol. Cell Biol., 5(11):3251-3260 (1985) and Grimm et al., Hum. Gene Ther., 10(15):2445-2450 (1999). However, AAV transduction of human synovial fibroblasts is significantly more efficient than in similar murine cells, Jennings et al., Arthritis Res, 3:1 (2001), and the cellular tropicity of AAV significantly differs between serotypes. See, e.g., Davidson et al., Proc. Natl. Acad. Sci. USA, 97(7):3428-3432 (2000) (discussing differences among AAV2, AAV4, and AAV5 with respect to mammalian CNS cell tropism and transduction efficiency). Most commonly, rAAV is produced in 293 cells, COS cells, HeLa cells, KB cells, and other mammalian cell lines. See, e.g., U.S. Pat. Nos. 6,156,303, 5,387,484, 5,741,683, 5,691,176, and 5,688,676; U.S. Patent Application 2002/0081721, and International Patent Applications WO 00/47757, WO 00/24916, and WO 96/17947. Although virus-like particles (VLPs) of parvoviruses have been produced in insect cells (see, e.g., Ruffing et al., J. Virol., 66(12):6922-6930 (1992), Brown et al., J. Virol., 65(5):2702-2706 (1991), and Yuan et al., Virology, 279(2):546-547 (2001)), the production of infectious AAV in nonmammalian, invertebrate cells currently is not known. The replication of parvoviral viral genomes, including, particularly, Dependovirus genomes, in nonmammalian, invertebrate cells, is similarly heretofore unknown.
The difficulties involved in scaling-up rAAV production for clinical trials and commercialization using current mammalian cell production systems can be significant, if not entirely prohibitive. For example, for certain clinical studies more than 1015 particles of rAAV may be required. To produce this number of rAAV particles, transfection and culture with approximately 1011 cultured human 293 cells, the equivalent of 5,000 175-cm2 flasks of cells, would be required. Related difficulties associated with the production of AAV using known mammalian cell lines are recognized in the art. See, e.g., Grimm et al, supra. There also is the possibility that a vector destined for clinical use produced in a mammalian cell culture will be contaminated with undesirable, perhaps pathogenic, material present in a mammalian cell.
In view of these and other issues there remains a need for alternative and improved methods of efficiently, safely, and economically producing a large amount of infectious rAAV particles. The invention provides such methods. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.

This patent is subject to a terminal disclaimer.

Production of adeno-associated virus in insect cells

United States of America, represented by the Secretary, Department of Health and Human Services


An outer peripheral surface of a tip end portion of the core body has a tapered surface which is thinner toward the tip end and is edged at the tip end. Recesses 2B are formed at an opening peripheral edge of the tip end portion to attach cutting chips 3. A portion of the core body 2 which is adjacent to a forward portion of each of the recesses in the rotational direction is bent radially inward. Each of the cutting chips 3 has a stepped portion such that a radially inner portion 3a of a forward end portion protrudes forward and a radially outer portion of the forward end portion recedes rearward. A radially inner portion of a rearward end portion of the stepped portion is located forward and a radially outer portion of the rearward end portion is located rearward.

Conventionally, a core drill is used to drill a hole with a relatively large diameter in materials in which the hole is to be drilled. The core drill includes a cylindrical core body, a shank member which is provided above the cylindrical core body and attached to a chuck disposed at a drive shaft, and cutting chips provided at the peripheral portion of the tip end portion of the core body such that the cutting chips are arranged to be spaced apart from each other. In addition, gullets are formed at portions of the core body, in locations forward relative to the cutting chips in a rotational direction of the core drill, to discharge cutting waste toward a base end of the core drill. At a portion of the core body which is located at a base end side of each gullet, a discharge groove having a spiral shape (tilting shape) is provided to feed the cutting waste toward the base end. In addition to the above constituents, in some core drills, a center drill having a tip end protruding farther than the tip end of the core body is provided at the center of the core body to easily determine a drilling position.
The core drill having the above structure is configured to drill an annular groove which is the same as a rotational trajectory of the cutting chips, deeper, in a material in which a hole is to be drilled, such as wood, resin, metal or a composite material of these, for example, an upper plate of a kitchen unit, thus efficiently drilling a hole with a large diameter substantially equal to the outer diameter of the core drill (see patent literature 1).
After drilling the hole as described above, cylindrical waste is left inside the core body of the core drill.


A vehicle brake force generation device is provided with an electric motor for applying drive force and regenerative brake force to the wheels of an electric vehicle, a brake hydraulic pressure generation device for generating the brake hydraulic pressure to be applied to the calipers of the electric vehicle, a slip information computation unit for computing the slip information of the wheels, a VSA device for controlling the friction braking of at least the brake hydraulic pressure generation device such that the slipping of the wheels is inhibited, a first diagnosis unit for diagnosing the VSA device, and a brake control unit for controlling the cooperative braking which includes controlling the regenerative braking of the electric motor and/or controlling the friction braking of the brake hydraulic pressure generation device.

For a hybrid vehicle, for example, in addition to an existing brake system for generating a brake force through a hydraulic circuit, a by-wire brake system for generating a brake force through an electric circuit is adopted. In such a by-wire brake system, the operation amount of a brake pedal by a driver is converted into an electrical signal to be provided to an electric motor for driving a piston of a slave cylinder (hereinafter, referred to as an "electric servo brake system"). Then, a hydraulic brake pressure is generated by compressive driving of the piston by the electric motor to be applied to the electric servo brake system. Thus generated hydraulic brake pressure operates wheel cylinders to generate brake forces caused by friction.
In addition to the control of the friction braking caused by an electric servo brake system, the control of the regenerative braking caused by a wheel driving electric motor is performed in such a by-wire brake system. A wheel driving electric motor is used as an electric power generator in the control of the regenerative braking caused by a wheel driving electric motor, wherein a brake force is generated by a regenerative torque generated by the wheel driving electric motor.
Further, conventionally, in order to obtain a brake force corresponding to the operation amount of a brake pedal by a driver, a technology is known that performs control integrating the control of regenerative braking caused by a wheel driving electric motor and the control of friction braking caused by an electric servo brake system. The recovery efficiency of kinetic energy can be increased by this integrated brake control technology.
Among by-wire brake systems to which the above-described integrated brake control technology is applied, known is one provided with an ABS (Antilock Brake System) having a function to avoid a locked state of wheels in braking a vehicle (see Patent Literature 1). In the brake force control technology according to Patent Literature 1, the behavior of the vehicle is estimated, based on a signal from a wheel speed sensor, an acceleration sensor, and the like, and based on a result of this estimation, brake forces applied to the wheels are controlled so as to stabilize the behavior of the vehicle.
In detail, in the brake force control technology according to Patent Literature 1, if the result of a diagnosis of the ABS is normal, it is determined whether or not ABS control is to be executed based on the slip ratios of the wheels, and torque control of a wheel driving electric motor is performed, based on the operational state of the ABS according to this result of determination. Concretely, an electric motor for driving wheels is controlled to be in a power running state when ABS control is performed, and is controlled to be in a regenerative state when ABS control is not performed.
On the other hand, if the diagnosis result of the ABS is abnormal, the wheel driving electric motor is immediately prohibited from being controlled in the regenerative brake control state and is controlled to be in the power running state.
In brief, in the brake force control technology according to Patent Literature 1, if a diagnosis result of the ABS is abnormal, the wheel driving electric motor is subjected to drive control so as to avoid locking of the wheels caused by erroneous regenerative braking.
Thus, in the brake force control technology according to Patent Literature 1, the wheel driving electric motor can be appropriately controlled to stabilize the behavior of the vehicle.


A ballistic laminate includes a layer including first fibers of a first material oriented at both a first direction and a second direction and second fibers of a second material oriented at both the first direction and the second direction. The first fibers are flammable, and the second fibers are flame retardant. A periodic distance greater than about 9 mm is between the second fibers of the second material oriented at the first direction. A periodic distance greater than about 9 mm is between the second fibers of the second material oriented at the second direction.

The present invention relates to a ballistic laminate. It finds particular application in conjunction with a ballistic laminate that offers both ballistic and flame retardant properties and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other applications.
Ballistic resistant body armor and vehicle armor are made from either woven fabrics or unidirectional fabrics comprising high performance fibers such as ultra-high-molecular-weight-polyethylene (UHMWPE) fibers, aramid fibers, and glass fibers, etc. Unidirectional fiber reinforced composite where fibers are encapsulated in a polymeric matrix materials generally has better ballistic resistance than traditional woven fabrics.
Various unidirectional composite constructions are currently used for formation of soft and hard armors in ballistic protection applications. Some composite constructions use high performance fibers such as UHMWPE fibers in matrix materials. However, some high performance fibers such as UHMWPE fibers are flammable when exposed to fire and heat. There is a growing demand for fire resistance armors.
One conventional composite construction use a layer-by-layer hybrid composite construction (i.e., one or more layers comprising flame resistant fibers and one or more layers comprising flammable fiber to improve the flame resistance of the composite). One multilayer composite design includes one or more first layers of flammable fibers in a matrix and at least one second layer adjacent to the first layer. The second matrix includes a fire retardant material. The second matrix is different than the first matrix.
Another conventional composite construction includes at least one layer of UHMWPE fibers or aramid fibers in a matrix and at least one fire retardant layer. The fire retardant layer includes a fire retardant agent that absorbs heat when exposed to fire and heat in a matrix. The matrix includes one or more relatively high chart yield resins that results in better flame resistant performance.
Another conventional composite construction includes a molded ballistic panel for use in aircraft and land vehicles for structural, ballistic, and fire resistant performance. The molded panel is formed by inserting a honeycomb between panels including non-woven high performance fiber layers and one or more fire resistant fiber layers.
U.S. Pat. No. 7,288,307 to Bhatnagar, et al. discloses hybrid laminated unidirectional fiber sheets produced from continuous roll of unidirectional prepregs, having application for impact absorption, ballistic resistance, and penetration resistance. The laminated unidirectional fiber sheets include two or more types of unidirectional fibers with different composition in a matrix. The two or more types of fibers are arranged in a side by side position. The periodic distance between fibers that have the same composition is not greater than 9 mm. However, neither distinguishes flame resistant fibers compared with flammable fibers nor gives any description on hybrid fiber-by-fiber composite constructions and/or fiber arrangements that improve the flame resistance performance of a composite.
The present invention provides a new and improved apparatus and method which addresses the above-referenced problems.


Am improved shaded pole A.C. motor with dynamic brake that includes a secondary high resistance winding that is selectively connected to a D.C. source when the A.C. voltage is removed. To stop a motor the A.C. voltage applied to the motor is removed with tandem switches that apply the D.C. voltage immediately upon removal of the A.C. voltage or the D.C. voltage can be selectively applied subsequently. The brake winding produces a magnetic flux in the same core where the main stator winding produces the magnetic flux responsible for causing the rotor to move. The brake winding can be connected in parallel during the time the A.C. voltage is applied to increase of the combined windings' inductance (resulting in an overall higher torque) and/or in series when during the braking operation when the D.C. voltage is applied to increase the combined winding's resistance (limiting further the peak D.C. current or reducing the secondary winding size). Relays are used in the preferred embodiment to implement the switching functions, which require arc-suppressing circuitry. More expensive active solid-state switches can be used obviating the need for the arc suppressing circuitry. The improved shaded pole A.C. motor is capable of running and stopping, like other motor types, with a relatively simple dynamic brake circuit compatible with these inexpensive motors.

1. Field of the Invention
The present invention relates to a shaded-pole A.C. motor, and more particularly, to such a motor that includes a dynamic brake.
2. Description of the Related Art
Shaded-pole A.C. motors are widely used for low cost applications where high torque is not required. To stop these motors, a dynamic brake such as the ones used in other types (split capacitor, etc.) of A.C. motors is not feasible. The dynamic brakes typically involve the application of a D.C. current through to stator's winding to stop the rotor's rotation. However, the low resistance of the stator's winding would cause a high D.C. current to go through deteriorating, or even possibly destroying, the stator's winding. The inventor herein found a solution by including a secondary or brake coil with a relatively higher resistance to permit the safe application of the braking D.C. voltage.

Shaded-pole A.C. motor with dynamic brake


The present invention provides a system for the electronic management and redemption of coupons. The system includes an integrated coupon card comprising a microprocessor, a random access memory means, a scanner, and a communications port. The coupon card is capable of scanning coupon bar codes from paper coupons and receiving redemption requirement data from a periphery device. The coupon card will allow bar codes and redemption requirement data to be transferred to a periphery device and will store what bar codes were redeemed because they corresponded to purchase data received from a cash register memory. The system further includes one or more periphery devices having a microprocessor, a first communications port for communicating with said coupon card, and a second communications port for communicating with a cash register. The periphery devices receive purchase data from a cash register memory and compare said purchase data to coupon bar codes received from a coupon card in order to determine which coupons are redeemable. The system also includes a server computer which will be connected to the periphery devices. The server computer will collect redeemed coupon information from the periphery devices and also provide the periphery devices with information such redemption requirement data or coupons which may be loaded onto a coupon card. A clearing house will collect coupon redemption information from all servers in the system to create redemption reports. The clearing house allows redemption requirement data and other information to be transferred through the servers to individual periphery devices and/or coupon cards.

Currently a large marketing tool for both manufacturers and supermarket chains is the production, distribution and redemption of the retail, paper, product coupon. Manufacturers use coupons to stimulate consumers to purchase products by creating product awareness, prompting product trials or rewarding repeat product purchases. This results in manufacturers printing and distributing hundreds of billions of paper coupons a year. This practice of paper coupon distribution is widely considered to be inefficient, as well as a producer of large quantities of redemption fraud.
The first step in the coupon redemption process is the retrieval of paper coupons by the consumer from the newspaper Free Standing Inserts (FSIs) in which the coupons are published. Currently, the vast majority of the coupons that are included in FSIs each week in the United States go unredeemed. 1995's redemption rate stood at approximately 1.9 percent of all coupons distributed. The primary reason for low coupon redemption is that couponing is time-consuming for people. The use of the paper coupon requires the consumer to sit down each week, examine coupon FSIs, and cut out the coupons they want to use. This is not the only disincentive for consumers to use coupons. It is also estimated that coupons received at the time of checkout in the supermarket (which are related to purchases and do not need to be chosen or removed from an FSI) are only redeemed at approximately an 8 percent rate. This suggests that even when not required to cut coupons out of FSI's, consumers consider coupons too much trouble to constantly organize and carry about. The redeeming of paper coupons requires even more effort since the consumer must determine which coupons he has that match items on his shopping list or that match items which he has purchased. While many companies sell coupon organizers, coupon categorizers and coupon alphabetizers, these methods still require coupon clipping, constant coupon organization and maintenance (removing expired coupons). The ineffectiveness of these methods is evidenced by the consistently low redemption rates. Still another reason why coupons go unredeemed is because the consumer simply forgets and leaves the coupons at home when he goes shopping. This is even more likely to occur as shopping trips are increasingly incorporated into the drive home from work or the like rather than a specially planned trip to the supermarket. Thus the consumer loses any possible benefit of coupon discounts. As a result of these difficulties, the majority of consumers do not investigate FSIs for coupons and consequently, advertising dollars manufacturers spend on FSIs provide comparatively little promotional benefit. Therefore, while per page FSI costs are low, the inefficiency of paper couponing makes it a very expensive form of advertising.
Even after the consumer reaches the supermarket with his coupons, there are further problems with the present paper-based system. The most common system of redeeming coupons requires a paper coupon to be presented to a cashier when the consumer is checking out. The cashier scans the coupon bar code with a scanner associated with the cash register and the cash register software identifies whether the coupon corresponds to an item just purchased. When the consumer has numerous coupons, the individual scanning of each coupon can be very time consuming, delaying all other consumers waiting in line. This delay is greatly exacerbated when the cash register indicates that no corresponding product has been purchased for one or more of the coupons, stopping the transaction. To discover why a coupon is not appropriate, the cashier must examine the coupon and then review the cash register receipt to determine what aspect of the purchased product does not meet the coupon redemption requirements. In the case where the cashier desires to accept the inappropriate coupon as a customer service gesture, the cashier must "override" the cash register's rejection of the coupon. Typically this requires the pressing of several additional keys on the cash register. When this entire process must be repeated for multiple coupons not accepted by the cash register, which is common in the majority of transactions in which coupons are used, the delay disrupts the entire checkout process delaying consumer checkout and negatively affecting transaction speed, customer service and front-end productivity.
Further problems and inefficiencies in the coupon redemption process arise after the retailer has accepted the coupons from consumers. The retailer must determine the total value of each manufacturer's coupons the retailer has redeemed in order for the retailer to be reimbursed by the manufacturer. The method of doing this varies widely among retailers. Some retailers may have employees hand sort the coupons at the retailer's location. Other retailers may make no effort themselves to organize the coupons and keep records of what coupons have been redeemed. In either case, retailers periodically, such as on a weekly basis, collect all redeemed paper coupons and deliver the coupons to a third-party clearinghouse. At the clearinghouse, coupons are generally sorted either by hand, or perhaps by scanning, in order to determine what coupons belong to which manufacturer and the amount the manufacturer owes the retailer for redeeming the coupons. After the coupons are returned to the manufacturer, the manufacturer may again sort the coupons (using its own employees or another clearinghouse) to insure all the coupons are the manufacturer's. The manufacturer then recalculates the total value of the coupons in order to verify the amount the retailer claims is owed on the redeemed coupons. This process is completed for every one of the billions of coupons redeemed annually. By the time the coupons have been collected by the retailer, passed through one and possibly two clearinghouses, and the manufacture reimburses the retailer, several weeks or months may have passed. This results in a considerable disadvantage to the retailer since the time between when the retailer gives the consumer the coupon discount and when the manufacturer reimburses the retailer is, in effect, an interest-free loan to the manufacturer. The manufacturer also suffers from the slow redemption process since the manufacturer cannot determine the effect of the coupon promotion until the manufacturer receives information on the number of coupons redeemed. Therefore, it is impossible for a manufacturer to quickly react to product performance, coupon redemption rates, or market changes.
In addition to the legitimate redeeming process being cumbersome, there exists wide spread problems with fraudulent misredemption and malredemption. Misredemption occurs where a retailer accepts a coupon for a product that has not been purchased. When done on a selective basis as a customer service gesture, such misredemption may serve the retailer and manufacturer sufficiently to justify the fraud. For example, a coupon may be accepted where the customer has attempted to comply with the coupon but has mistakenly selected a size or quantity of the product which does not match what is called for by the coupon. However, the situation may arise where retailer personnel may accept large numbers of coupons that are not closely related to the products bought by the consumer. In such a case, the manufacturer eventually (whether initially or through an invoice reduction by the retailer following a manufacturer's refusal to pay) reimburses the retailer while receiving no corresponding benefit in sales. Some misredemption occurs internally by retail employees, and is fought by the retailer. In other cases, the retailer is intentionally involved in misredemption to increase profits. When retailers can not provide the appropriate invoices to support such coupon submissions, they are placed on suspend lists by the affected manufacturers and their coupons are no longer accepted for reimbursement. Such fraud prevention by manufacturers requires large financial resources for the staffing of coupon fraud reduction departments. Misredemption can run into the double digits for retailers, and manufacturers are plagued with the costs of paying for and preventing it. Malredemption is another type of coupon fraud often practiced on an even larger scale. Malredemption is the large scale collection of coupons which are then directly submitted to the manufacturer for reimbursement with the coupons never actually passing through consumers. Typically malredemption is carried out by illegitimate retailers acting as a "front" for persons who have set up mass coupon clipping systems. Together misredemption and malredemption cost manufacturers hundreds of millions of dollars annually.
Another disadvantage of the present paper coupon redemption system is that if consumer response to the coupon offer is not what the manufacturer had anticipated and the manufacturer wishes to restimulate consumers with a higher coupon discount, the manufacture must publish a whole new coupon "drop." The previously printed coupons, therefore, become a largely wasted marketing effort. Additionally, it is difficult to track the buying habits of consumers on a national level because those who purchase with cash are not recorded by conventional marketing database collection. On a local level, frequent shopper cards allow demographic and buying history profiles to be compiled on cash purchases, but this has not worked well on the national level.

Method and apparatus for coupon management and redemption


The cooking hob (1) comprises a continuous glass or glass ceramic support plate (2) having a treatment area (4) capable of supporting a cooking vessel (50). A drive motor (6) is operatively connected for rotating a lower magnetic coupling member (5) located below the support plate (2) at the treatment area (4). The cooking vessel (50) is provided with rotary blades (53) connected to an upper magnetic coupling member (54) magnetically coupleable to the lower magnetic coupling member (5) through the support plate (2). The cooking hob (1) and the cooking vessel (50) comprise respective components of detection means for detecting an angular position change of the cooking vessel (50) in relation to the treatment area (4) and electronic control means (30) are configured for modifying or stopping the operation of the electric drive motor (6) when the angular position change is detected.

Patent U.S. Pat. No. 5,549,382 describes a cooking hob provided with a support plate having several cooking areas, in each of which a cooking vessel can be supported. The hob includes heating means associated with each cooking area and driving means aligned with one of the cooking areas. The driving means comprise a lower magnetic coupling member driven by a motor for rotating below the support plate in a position close enough to it to magnetically transmit torque to an upper magnetic coupling member attached to a stirrer located inside a cooking vessel placed in the corresponding cooking area.
Document DE-A-1131372 discloses a cooking hob comprising a magnetic coupling between a driving device and rotary blades installed inside a vessel. The magnetic coupling is established through a support plate on which the vessel rests.
Patent application DE-A-102006052475 discloses a cooking hob provided with a glass or glass ceramic support plate having several cooking areas associated with heating means and a magnetic coupling driven to rotate a stirrer inside a vessel placed on one of the cooking areas through the support plate.
A drawback of these cooking hobs equipped with a substantially smooth support plate driving means and magnetic coupling through the support plate for rotating rotary blades inside a cooking vessel supported on the support plate is that if for any reason the rotary blades increase resistance to rotation or are locked inside the vessel, then the entire vessel tends to rotate on the support plate driven by the driving means with the risk of ruining the culinary preparation inside the vessel and scratching the support plate.
Documents DE-A-3000593, DE-A-3836099, EP-A-0725556, WO-A-9631739, U.S. Pat. No. 4,587,406 describe different wireless communication systems for communicating between a cooking vessel placed on a cooking area with electric heating means of a cooking hob and the cooking hob for the purpose of transmitting data relating to the cooking conditions, especially the temperature in the vessel, and controlling the electric heating means according to the data received from the vessel by means of a control device. However, the transmitted data, for example the temperature, are scalar magnitudes which do not depend on the angular position of the vessel with respect to the treatment area of the cooking hob, and accordingly are not useful for detecting a change in said angular position, which would be indicative of a rotation of the vessel.
An advantage of the cooking hobs provided with a continuous glass or glass ceramic support plate is that the support plate has a very easy to clean smooth and completely cleared upper surface. Nevertheless, this smooth and cleared surface offers very little resistance to rotation of the vessel, for example, in the event that an increase in the resistance to rotation or a locking of the rotary blades occurs inside the vessel caused by the conditions of the food being processed.

Cooking system including a cooking hob and a cooking vessel


An expandable electrical enclosure system is presented where expansion collars can be serially added to an existing base box to increase the dimension of the enclosure in only the Z direction. A removable cover can be disconnected and connected as each expansion collar is added.

1. Field of the Invention
The field of the present invention relates generally to housings and enclosures for containing electrical and other equipment and more particularly to methods and apparatus for a system of such housings that permits the storage or capacity to be expanded as required without interruption of existing service or having to replace the existing enclosure.
2. Background
Housings for enclosing and protecting electrical equipment are well known in the art. Many different types of electrical equipment must be retained in appropriate housings to protect the equipment from hostile environments from rain, snow, insect damage, animal damage, human tampering, and so forth. For example, in the power industry sensitive electrical equipment, such as surge protectors, must be stored in housings to protect the equipment from the elements, and from tampering.
Enclosures, boxes, and housings commonly used to house electrical equipment are typically mounted on walls that have limited space for multiple boxes. Enclosures are sized based on industry Standards and Safety Codes such as NEC and NFPA. Once equipment is mounted to a wall and wired to a service or branch circuit, it is difficult and expensive to upgrade to modern equipment. Initially, a customer of particular electrical equipment may require only a very limited system. However, as the business of the customer grows, the need for more electrical equipment also grows and therefore a new enclosure must be added or the existing one somehow expanded. When this occurs it may be difficult for the customer to expand their present enclosure in that the existing enclosure is limited in the additional equipment that can be stored in the housing.
As a result, to be prudent the customer must attempt at the time of initially purchasing the electrical equipment or associated system to predict future expanded service requirements at the time of installation. In this manner, the user typically has a larger than required housing installed in order to accommodate the anticipated future requirements. This places an additional burden on the customer in that capital must be allocated at the time of initial installation of the system to cover requirements that are not yet necessary. Also, as technology changes, it may occur that existing housings specifically designed for a particular technology or system, must be replaced with new housings specifically designed to house the new technology.
As such there is a need in the field of the present technology for an electrical equipment housing design that is universal and easily expanded. Also, it is recognized that such expandable housings should maintained the dimension of the originally installed enclosure in the X and Y directions and should only increase the capacity or volume to hold additional or add-on equipment in the Z direction. The housing must be expandable without the loss or interruption of existing service. This invention solves the problems associated with adding electrical components by allowing the expansion of the enclosure in the Z direction without removal of the enclosure and removal of and subsequent rewiring.
These as well as other advantages of various aspects of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description, with appropriate reference to the accompanying drawings.

Electrical enclosure expandable in the Z direction


Embodiments of a system and method for tracking objects are described herein. Aspects of this disclosure efficiently update object “belief” data by creating a bitmap representation of object locations and velocities. The bitmap provides a three-dimensional representation of the object as viewed by one or more sensors. The bitmap representations are blended with sensor data over time to determine a current object belief state which can accurately account for asynchronous sensor data. Peaks in the belief data, which may be represented by pixels with an intensity value above a threshold value, are identified as likely objects. Additional sensor data is used to detect longitudinal velocities located at one or more of the peaks.

During common daily activities, human beings rely on input from a multitude of senses. The brain is very efficient at combining sight, sound, and other senses to provide a current environmental state that are used to perform daily tasks such as walking, driving, and the like. Data is aggregated and evaluated unconsciously, efficiently, and accurately.
Computer systems and software exist that attempt to provide an electronic analog to the data aggregation and analysis functions provided by the brain. These systems are capable of determining an object location, a type of object, and other features based on sensor data to assist with the operation of various devices. However, such systems tend to require significant processing power, and thus may not be suitable for use in activities that necessitate real-time performance.


A method of inhibiting corrosion of metals such as low carbon steel in contact with calcium chloride brine comprising adding to the brine or to the salt prior to dissolution 2-hydroxyphosphono-acetic acid.

Calcium chloride is a widely used industrial chemical. Significant volumes are used as a curing accelerator in concrete, as an additive in drilling muds to control density and clay flocculation, as a drainage aid in paper mills, as a dessicant in refrigeration plants, and as a heat transfer fluid in closed recirculating cooling systems operating at temperatures below zero degrees C.
Calcium chloride brines in applications such as for concrete accelerators or as additives to drilling muds create serious corrosion problems. Most construction concrete is reinforced with steel bars which are embedded in the concrete and the presence of calcium chloride in the concrete accelerates corrosive attack of the reinforcing steel. The calcium chloride in drilling muds causes an accelerated corrosion of well tubing and equipment used in oil drilling applications. The use of calcium chloride as a drainage aid in the paper industry has been limited by the corrosive nature of its solutions.
In closed recirculating cooling systems where calcium chloride brine is employed as a heat transfer medium, corrosion control is necessary. Historically, chromates have been used to inhibit corrosion in calcium chloride brine systems. Chromates are soluble in these concentrated solutions and are extremely efficacious in these aggressive environments. However, the environmental and health concerns that the use of chromates presents have resulted in their being phased out as corrosion inhibitors. Nitrites are also soluble and compatible in calcium chloride brines and have been employed as a replacement for chromates. However, high levels of nitrite, that is up to 0.5%, are necessary for corrosion protection in calcium chloride brine systems.

Corrosion inhibition of calcium chloride brine


A subscriber associated with a private branch exchange (PBX) terminal without a Direct-Inward-Dialing (DID) line establishes a first call connection with a particular service node via a mobile station. The subscriber then instructs the service node to originate a second call connection from the service node towards the PBX serving said subscriber. The first and second call connections are interfaced to enable the subscriber to communicate with a PBX operator answering the second call connection. The subscriber then instructs the operator to forward the received call to the subscriber's PBX terminal. Thereafter, the subscriber instructs the service node to originate a third call connection towards a particular called party terminal. The established third call connection is interfaced with the second call connection to enable the subscriber to communicate with the called party subscriber terminal via the PBX terminal. The first call connection with the mobile station is terminated. Since no outgoing call connection has been originated by the PBX, no additional PBX associated charges are incurred by the subscriber for the communication.

1. Technical Field of the Invention
The present invention relates to a telecommunications network and, in particular, to the effectuation of a call connection through a manual switchboard within such a network.
2. Description of Related Art
With the advent of long distance calling cards, toll-free "800" numbers, and associated subscriber features, traveling subscribers are able to utilize their existing subscriber data, such as speed dialing lists, subscriber features, subscription record for billing purposes, etc., while utilizing a remote terminal associated with a visited telecommunications exchange. As an illustration, a subscriber located remotely from the subscriber's terminal is able to dial an access number, such as a toll-free number, identify the subscriber's account number via dual tone multi-frequency (DTMF) transmission, and originate a long distance call connection towards a called party subscriber and still have the incurred long distance charges be billed to the subscriber's existing subscription. Such a capability is especially convenient for traveling salespersons or business persons who need to be in constant contact with their offices and associates.
However, even with the above described capabilities, there still remains a disadvantage for subscribers utilizing private branch exchanges (PBXs). Most PBXs associated with hotels, for example, charge their hotel guests for making outgoing call connections regardless of whether the guests are using their own long distance service or not. Furthermore, some hotels charge not only on a per call basis but also for the duration of the outgoing call connection made by hotel guests. Furthermore, with a wide proliferation of personal computers and fax machines, hotel guests are then forced to incur unreasonable charges for effectuating long lasting data communications or connections via hotel PBXs.
Even with the wide usage of mobile stations, the above described inefficiency is not completely solved. Due to expensive air-time charges and unreliable battery-life time, most subscribers prefer to use a wireline terminal if such a terminal is readily available. Furthermore, for data communications, such as a modem connection, a more desirable bandwidth and connection quality can be achieved via a wireline connection.
As a result, there is a need for a mechanism to enable a traveling subscriber to effectuate a speech or data call connection without incurring additional charges associated with a serving PBX.

User controlled call setup through manual switchboard


A braking device for a vehicle is provided which includes a braking simulator, thus resulting in improved mountability of the braking device in the vehicle. The braking device is designed to permit component parts of the hydraulic booster to slide on one another in response to a braking effort on a brake pedal, thereby absorbing an undesirable load on the braking device and also ensuring the stability in operating the brake pedal. This results in improved durability and maneuvering feeling of the braking device.

1 Technical Field
This disclosure relates generally to a brake system for vehicles which works to control braking force applied to, for example, an automobile.
2 Background Art
EP2212170 A2 teaches an automotive brake system designed to control braking force applied to a vehicle. The brake system is equipped with a pedal simulator serving to simulate characteristics of a conventional boost system felt by a vehicle operator at a brake pedal and a hydraulic booster serving to boost pressure in an accumulator to produce pressure in a master cylinder which is to be applied to a friction brake as a function of an operation of the brake pedal.
The hydraulic booster and the pedal simulator are separate from each other, thus resulting in an increase in overall size of the brake system and a deterioration in mountability thereof in the vehicle. The brake system also encounters a drawback in that a transmission mechanism, such as an operating rod, through which an effort on a brake operating member is transmitted to an input piston of the master cylinder is subjected to a mechanical load upon movement of the brake operating member, which impinges on the durability and maneuvering feeling of the transmission mechanism.

Brake system for vehicle designed to improve durability and maneuvering feeling


The present invention relates to methods and compositions to detect analytes in a sample using antibody molecules that are transformed into nanoscale “self-signaling” biosensors. It relates in particular to those methods and compositions that provide for single-step detection of target analytes without the need for labor-intensive steps necessary in conventional assays.

1. Field of the Invention
Embodiments of the present invention relate to methods and compositions to detect analytes in a sample using antibody molecules that are transformed into nanoscale "self-signaling" biosensors, in particular those methods and compositions that provide for single-step detection of target analytes without the need for labor-intensive steps necessary in conventional assays.
2. Description of the Related Art
Immunoassays are based on specific interactions between antibodies and antigens. They are indispensable in modern clinical diagnostics, drug screening practices, and medical research in general. Among the immunoassay formats, enzyme-linked immunosorbent assay (ELISA), lateral-flow immunoassays, and Western-blot assays are most widely used. ELISA and Western-blot techniques require multiple cycles of incubation/washing steps and are hence laborious and prone to operator error. Lateral-flow immunoassays, such as dip-stick type assays, generally provide faster detection but are not as sensitive or accurate as conventional ELISAs. All of these assays are conducted using the heterogeneous format, i.e. they all require immobilization of antibodies or antigens onto a solid surface. In comparison, homogeneous assays, in which no antibody/antigen immobilization is necessary, provide many important advantages over the heterogeneous assays. First and foremost, homogeneous immunoassays enable direct detection in solution, in a "mix and detect" manner, without needing multiple incubation steps or additional signal-generating elements, and hence greatly accelerate assay throughputs while preserving assay sensitivity and specificity. Furthermore, it is preferred to conduct the homogeneous assays in the non-competitive format as opposed to competitive format since the former is in general more sensitive by orders of magnitude [Ohiro et al. 2002, herein incorporated by reference in its entirety]. Having an effective and universal assay platform that allows homogeneous solution-phase non-competitive immunoassays is particularly valuable when interrogating a large number of samples since such format is more amenable to automation using robotic liquid-handling systems prevalent in modern high-throughput screening applications. However, a key technical challenge has been the development of a simple and effective reporting mechanism to signal the antigen-antibody interaction in solution.

Cooperative reporter systems, components, and methods for analyte detection