Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

In a wide range of well and formation treatment methods it is desirable to use various materials such as solids for downhole operations or procedures, and then later to remove or destroy the materials, after they have fulfilled their function, to restore properties to the wellbore and/or subterranean formations such as permeability for oil and gas production, or to activate the materials to fulfill a function such as a viscosity breaker or breaker aid.
Fluid loss control agents provide one example. When placing fluids in oilfield applications, fluid loss into the formation is a major concern. Fluid loss reduces the efficiency of the fluid placement with respect to time, fluid volume, and equipment. Thus, controlling fluid loss is highly desired. There are many oilfield applications in which filter cakes are needed in the wellbore, in the near-wellbore region or in one or more strata of the formation. Such applications are those in which, without a filter cake, fluid would leak off into porous rock at an undesirable rate during a well treatment. Such treatments include drilling, drill-in, completion, stimulation (for example, hydraulic fracturing or matrix dissolution), sand control (for example gravel packing, frac-packing, and sand consolidation), diversion, scale control, water control, and others. When the filter cake is within the formation it is typically called an "internal" filter cake; otherwise it is called an "external" filter cake. Typically, after these treatments have been completed the continued presence of the filter cake is undesirable or unacceptable.
Conventional water-based drilling and completion fluids, for example, often rely on polymers to provide viscosity and fluid loss control. This approach requires acid, oxidizer or enzyme to remove polymer residue and filter cake buildup, to reduce the extent of formation damage. It is, for example, a common practice for drilling fluid to use sized calcium carbonate as a bridging agent, in which case acid plus a corrosion inhibitor package is subsequently required for filter cake removal. The overall drilling/completion strategy based on polymer fluids is often operationally cumbersome, can lack long-term stability, can employ corrosive chemicals, and/or can be prone to cause formation damage.
Hydraulic fracturing, gravel packing, or fracturing and gravel packing in one operation (called, for example frac and pack or frac-n-pack, or frac-pack treatments), are used extensively to stimulate the production of hydrocarbons, water and other fluids from subterranean formations. These operations involve pumping a slurry of "proppant" (natural or synthetic materials that prop open a fracture after it is created) in hydraulic fracturing or "gravel" in gravel packing. In low permeability formations, the goal of hydraulic fracturing is generally to form long, high surface area fractures that greatly increase the magnitude of the pathway of fluid flow from the formation to the wellbore. In high permeability formations, the goal of a hydraulic fracturing treatment is typically to create a short, wide, highly conductive fracture, in order to bypass near-wellbore damage done in drilling and/or completion, to ensure good fluid communication between the rock and the wellbore and also to increase the surface area available for fluids to flow into the wellbore. Gravel is also a natural or synthetic material, which may be identical to, or different from, proppant. Gravel packing is used for "sand" control. Sand is the name given to any particulate material, such as clays, from the formation that could be carried into production equipment. Gravel packing is a sand-control method used to prevent production of formation sand, in which, for example a steel screen is placed in the wellbore and the surrounding annulus is packed with prepared gravel of a specific size designed to prevent the passage of formation sand that could foul subterranean or surface equipment and reduce flows. The primary objective of gravel packing is to stabilize the formation while causing minimal impairment to well productivity. Sometimes gravel packing is done without a screen. High permeability formations are frequently poorly consolidated, so that sand control is needed. Therefore, hydraulic fracturing treatments in which short, wide fractures are wanted are often combined in a single continuous ("frac and pack") operation with gravel packing. For simplicity, reference may be made below to any one of hydraulic fracturing, fracturing and gravel packing in one operation (frac and pack), or gravel packing, and include them all; the term "proppant" may likewise refer to and include gravel and the term "gravel" proppant.
Solid, substantially insoluble, or sparingly or slowly soluble materials (that may be called fluid loss additives and/or filter cake components) are typically added to the fluids used in these treatments to form filter cakes, although sometimes soluble (or at least highly dispersed) components of the fluids (such as polymers or crosslinked polymers) may form some or all of the filter cakes. Removal of the filter cake is typically accomplished either by a mechanical means (scraping, jetting, or the like), by subsequent addition of a fluid containing an agent (such as an acid, a base, an oxidizer, or an enzyme) that dissolves at least a portion of the filter cake, or by manipulation of the physical state of the filter cake (by emulsion inversion, for example). These removal methods usually require a tool or addition of another fluid (for example to change the pH or to add a chemical). This can sometimes be accomplished in the wellbore but normally cannot be done in a proppant or gravel pack. Sometimes the operator may rely on the flow of produced fluids (which will be in the opposite direction from the flow of the fluid when the filter cake was laid down) to loosen the filter cake or to dissolve at least a part of the filter cake (for example if it is a soluble salt). However, these methods require fluid flow and often result in slow or incomplete filter cake removal. Sometimes a breaker can be incorporated in the filter cake but these must normally be delayed (for example by esterification or encapsulation) and they are often expensive and/or difficult to place and/or difficult to trigger.
In hydraulic fracturing, a first, viscous fluid called a "pad" is typically injected into the formation to initiate and propagate the fracture and often to contribute to fluid loss control. The choice of the pad fluid depends upon the nature of the subsequently injected fluid, the nature of the formation, and the desired results and attributes of the stimulation job. This is typically followed by a second fluid designed primarily to carry the proppant that keeps the fracture open after the pumping pressure is released. Occasionally, hydraulic fracturing is done with a second fluid that is not highly viscosified; this choice is made primarily to save chemical costs and/or as a way to reduce the deleterious effect of polymers described below. This technique, sometimes called a "water-frac" involves using extremely low polymer concentrations, so low that they cannot be effectively crosslinked, throughout the job. This alternative has a major drawback: since there is inadequate viscosity to carry much proppant, high pump rates must be used and only very small concentrations of proppant (pounds mass proppant added per gallon of fluid ("PPA")) can be used. Very little proppant will be placed in the fracture to keep it open after the pumping is stopped.
Pads and fracturing or gravel packing fluids are usually viscosified in one of three ways. If the injected fluid is an oil, it is gelled with certain additives designed for the purpose, such as certain aluminum and phosphate compounds. If the fluid is water or brine, for hydraulic or acid fracturing, it is gelled with a polymer (usually a polysaccharide like guar, usually crosslinked with a boron, zirconium or titanium compound), or with a viscoelastic surfactant fluid system ("VES") that can be formed using certain surfactants that form appropriately sized and shaped micelles. VES's are popular because they leave very clean proppant or gravel packs, but they do not form a filter cake by themselves. Polymers, especially crosslinked polymers, often tend to form a "filter cake" on the fracture face, that is, they coat out on the fracture face as some fluid leaks off, provided that the rock pores are too small to permit entry of the polymer or crosslinked polymer. Some filter cake is generally desirable for fluid loss control. This process of filter cake formation is also called wallbuilding. VES fluids without fluid loss additives do not form filter cakes as a result of leak-off. VES leak-off control, in the absence of fluid loss additives, is viscosity controlled, i.e., the resistance due to the flow of the viscous VES fluid through the formation porosity limits the leak-off rate. The viscosity controlled leak-off rate can be high in certain formation permeabilities because the highly shear-thinning fluid has a low apparent viscosity in high flow velocity areas. Reducing the flow velocity (by correspondingly reducing the pressure gradient or simply as a result of the same injected volumetric flow rate leaking off into the formation through a greater surface area as the fracture grows in length and height) will allow micelle structure to reassemble and will result in regeneration of viscosity and fluid loss control. Fluid loss control may not always be optimal with VES systems, especially in higher permeability formations. On the other hand, polymers have two major deficiencies: a) the filter cake, if left in place, can impede subsequent flow of hydrocarbons into the fracture and then into the wellbore, and b) polymer or crosslinked polymer will be left in the fracture itself, impeding or cutting off flow, either by physically blocking the flow path through the proppant pack or by leaving a high viscosity fluid in the fracture. VES fluids do not form a filter cake or leave solids in the fracture. VES fluids, therefore, leave a cleaner, more conductive and, therefore, more productive fracture than polymer-based fluids. They are easier to use because they require fewer components and less surface equipment, but they may be less efficient (in terms of fluid loss) than polymers, depending upon the formation permeability and the specific VES system. It would be desirable to make use of VES fluid systems more efficient in terms of fluid loss.
To overcome high fluid loss in polymeric and VES-based fluids (in particular in hydraulic fracturing fluids, gravel carrier fluids, and fluid loss control pills), various fluid loss control additives have been proposed. Silica, mica, and calcite, alone, in combination, or in combination with starch, are known to reduce fluid loss in polymer-based fracturing fluids, by forming a relatively water-impermeable filter cake on the formation face, as described in U.S. Pat. No. 5,948,733. Use of these fluid loss control additives alone in a VES-based fluid, however, has been observed to give only modest decreases in fluid loss, as described in U.S. Pat. No. 5,929,002. The poor performance of these conventional fluid loss additives is typically attributed to the period of high leak-off (spurt) before a filter cake is formed and to the formation of a filter cake permeable to the VES-based fluid.
Instead of conventional fluid loss additives and filter cake formation, it is known to treat a subterranean formation by pumping a colloidal suspension of small particles in a viscoelastic surfactant fluid system; see for example U.S. Patent Application Publication No. 2005-0107265 assigned to the assignee of the present application. The colloidal suspension and the viscoelastic surfactant interact to form structures that effectively bridge and block pore throats. Colloidal suspensions are typically dispersions of discrete very small particles, spherical or elongated in shape, charged so that the repulsion between similarly charged particles stabilizes the dispersion. Disturbance of the charge balance, due for instance to removing water, changing the pH or adding salt or water-miscible organic solvent, causes the colloidal particles to aggregate, resulting in the formation of a gel. These particles are typically less than 1 micron in size, and typically in the range of from about 10 to about 100 nanometers. The dispersion is prepackaged as a liquid, transparent in the case of relatively low concentrations of particles, becoming opalescent or milky at higher concentrations. In any case, the dispersion may be handled as a liquid, which greatly simplifies the dosage.
The use of a hydrolysable polyester material for use as a fluid loss additive for fluid loss control has previously been proposed for polymer-viscosified fracturing fluids. After the treatment, the fluid loss additive degrades and so contributes little damage. Further, degradation products of such materials have been shown to cause delayed breaking of polymer-viscosified fracturing fluids. U.S. Pat. No. 4,715,967 discloses the use of polyglycolic acid (PGA) as a fluid loss additive to temporarily reduce the permeability of a formation. SPE paper 18211 discloses the use of PGA as a fluid loss additive and gel breaker for crosslinked hydroxypropyl guar fluids. U.S. Pat. No. 6,509,301 describes the use of acid forming compounds such as PGA as delayed breakers of surfactant-based vesicle fluids, such as those formed from the zwitterionic material lecithin. The preferred pH of these materials is above 6.5, more preferably between 7.5 and 9.5.
Since VES fluid systems cause negligible damage, it would be desirable to use a fluid loss additive that is compatible with the VES system and also causes negligible damage. The use of polyglycolic acid and similar materials as a fluid loss additive for VES fluid systems is described in U.S. patent application Ser. No. 11/159,023, filed Jun. 22, 2005, hereby incorporated herein by reference in its entirety. Briefly, polyglycolic acid and similar materials most often degrade by a mechanism of hydrolysis, catalyzed by acid or base. However, these fluid loss additive materials, as commercially obtained, often contain small amounts of acid or they start to hydrolyze to form acids when the fluids are first mixed or injected. To prevent the deleterious effects of these factors, a base or buffer was included in the fluid.
In some cases viscous fluids are used in treatments in which some or all of the fluid may be allowed to invade the formation, in which case a component is needed that is a breaker but not necessarily a fluid loss additive.
In the placement of tip screen out (TSO) fracturing treatments, it is desirable to include a fluid loss agent (FLA) to place a temporary filter cake on the faces of the fracture in the early part of the treatment, e.g., during the pad stage. Ideally, this filter cake would then be destroyed in the later stages of the treatment so that increased fluid loss during the proppant stages will allow a tip screen out to occur. The end result is a short but wide fracture with a high proppant concentration. The FLA is usually injected into the fracture with the initial pad volume used to initiate hydraulic fracturing. After the pad is injected, proppant slurry, that may also contain an FLA, is pumped into the fracture in various stages depending on job design. The proppant is designed to hold the fracture open and allow reservoir fluid to flow through the proppant pack. The proppant slurry generally includes a viscous carrier fluid to keep the proppant from prematurely dropping out of the slurry. After the proppant has been placed in the fracture, the pressure is released and the fracture closes on the proppant. However, it is necessary to remove or break both the viscosifier in the carrier fluid and the filter cake (that may contain concentrated polymer) so that reservoir fluids can thereafter flow into the fracture and through the proppant pack to the wellbore and the production string.
Conventional fracture design is well known in the art. See, e.g., U.S. Pat. No. 5,103,905, Method of Optimizing the Conductivity of a Propped Fractured Formation, assigned to Schlumberger.
Fracture clean-up issues are well recognized in the literature. Although other systems such as viscoelastic surfactants, gelled oil, slick water, etc. are used, the majority of fluids used to create the fracture and carry the proppants are polymer-based. In most reservoirs with lower permeability, the polymer concentrates as carrier fluid leaks off during the fracturing process. The concentrated polymer hinders fluid flow in the fracture and often results in underperforming fractures. Typical remedies include use of breakers, including encapsulated breakers that allow a significant increase of the breaker loading. The breaker is added to the fluid/slurry and is intended to reduce the viscosity of the polymer-based carrier fluid and facilitate fracture clean-up. Despite high breaker loading, the retained permeability of the proppant pack is still only a fraction of the initial permeability and this has been the accepted situation in the industry.
U.S. Pat. Nos. 4,848,467 and 4,961,466 discuss the use of hydroxyacetic acid and similar condensation products which naturally degrade at reservoir temperature to release acid that may be a breaker for some polymers under some conditions and which offer fluid loss control. U.S. Pat. No. 3,960,736 (Oree) discusses the use of esters to provide a delayed acid, which will break the fluid by attacking both the polymer and the borate crosslinks. Similarly, acid generation mechanisms are employed in U.S. Pat. Nos. 4,387,769 and 4,526,695 (Erbstoesser), which suggest using an ester polymer. U.S. Pat. No. 3,868,998 (Lybarger) also mentions acid generation. These references rely on acid, which generally has a relatively low activity as the breaker, but oxidative breakers are much more effective and have become the industry standard for removing polymer damage. In addition, while low pH may break borate crosslinks, it is less effective for breaking the commonly used zirconium and titanium crosslinked gels. In fact, some gel systems employing zirconium or titanium are designed to be effective viscosifiers at low pH.
As used herein, the term "breaker" refers to a chemical moiety or suite of moieties whose primary function is to "break" or reduce the viscosity of the proppant-carrying fluid. Typically in the prior art, though not always, this occurs by oxidation.
In addition, "breaker aids" are often used in conjunction with breakers to promote breaker activity. Breaker aids are disclosed in, e.g., U.S. Pat. No. 4,969,526, Non-Interfering Breaker System for Delayed Crosslinked Fracturing Fluids at Low Temperature, assigned to Schlumberger (disclosing and claiming triethanolamine); and, U.S. Pat. No. 4,250,044. Similarly, "retarding agents" (or materials designed to inhibit cross-linking) are operable in conjunction with the present invention. See, e.g., U.S. Pat. No. 4,702,848, Control of Crosslinking Reaction Rate Using Organozirconate Chelate Crosslinking Agent and Aldehyde Retarding Agent, assigned to Schlumberger (disclosing and claiming aldehydes). Copper ion, silver ion, or the like are also known to function as catalysts in conjunction with a chemical breaker, dissolved oxygen, or other oxidant source, accelerating the breaker activity. In addition, different proppant-carrying matrices can be used with different breaker types—e.g., injecting in a first stage a less viscous and/or less dense fluid followed by fluids of lesser mobility. See, e.g., U.S. Pat. No. 5,036,919, Fracturing with Multiple Fluids to Improve Fracture Conductivity, assigned to Schlumberger. U.S. Pat. No. 5,036,919 discloses, for instance, pumping a zirconate cross-linked fluid followed by a borate cross-linked fluid. Hence, it is known to use different fluids in different stages of the treatment.
SPE 68854 and SPE 91434 disclose that fibers included in the slurry of proppant in carrier fluid may serve to aid in the transport of proppant at lower viscosities and/or lower slurry flow rates, provided that fibers of the appropriate length, diameter, and stiffness are chosen and used in the right concentration.
For years fibers have been used for different purposes in oilfield treatment operations. Most recently, fiber assisted transport technology has been used to improve particle transport in fracturing and wellbore cleanout operations while reducing the amount of other fluid viscosifiers required. Recent efforts to improve this technique have looked at better ways to more completely remove fiber that can be left in the wellbore or fracture.
In commonly assigned U.S. patent application Ser. No. 11/156,966, filed Jun. 20, 2005, and Ser. No. 11/059,123, priority date Jul. 2, 2004, polyester materials such as fibers and particles are disclosed for fiber assisted transport of proppant in a fracturing method, and for fluid loss control, respectively. The polyesters can be selected from substituted and unsubstituted lactide, glycolide, polylactic acid, polyglycolic acid, copolymers of polylactic acid and polyglycolic acid, copolymers of glycolic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and copolymers of lactic acid with other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid-containing moieties, and mixtures of those materials. The polyester materials are naturally degraded typically 4 hours to 100 days after treatment to facilitate the restoration of permeability.
Other references that may be pertinent to the present invention include US2004/0216876; US2005/0034865; and U.S. Pat. No. 6,394,185.
Each of the references mentioned herein are hereby incorporated herein by reference in their entirety for the purpose of US patent practice and other jurisdictions where permitted.
There is a need for improved methods of placing a fluid loss control agent and removing the fluid loss control agent to restore permeability to the producing formation, especially where removal of the fluid loss control agent does not require a pH change or rely on a chemical reaction to initiate removal. Similarly, there is a need for improved methods of breaking viscosified well treatment fluids, especially employing a breaker or breaker aid that does not require changing pH or chemical reaction to activate the breaker and/or breaker aid. There is also a need for improved methods employing a fluid loss control agent or breaker that can be placed downhole in insoluble form and solubilized by salinity changes and/or by exposing the fluid loss agent or breaker to a temperature above a dissolution trigger temperature. Furthermore, there is a need for improved methods wherein a well treatment fluid additive can be used in insoluble form as a fluid loss control agent, fiber assisted proppant transfer fiber, or the like, and can then be solubilized by changing salinity conditions or exceeding a trigger temperature for removal to restore permeability, for breaking a viscosified well treatment fluid, or the like.


The present invention provides methods and apparatus for transmitting a data-bearing signal and a non-data-bearing signal. One embodiment comprises communicatively coupling a data-bearing signal during a first time period and communicatively coupling a non-data-bearing signal during a second time period. The data-bearing signal has a first PSD. The non-data-bearing signal has a second PSD substantially the same as the first over a range of frequencies. The non-data-bearing signal has characteristics facilitating echo cancellation. Another embodiment comprises a line interface and a transmitter coupled to the line interface, comprising a data encoder and a periodic signal generator. The encoder is configured to produce a data-bearing signal with a first PSD. The periodic signal generator is configured to produce a non-data-bearing signal with a second PSD. The second PSD is substantially the same as the first PSD over a first range of frequencies. The non-data-bearing signal has characteristics facilitating echo cancellation.

Crosstalk is a well-known phenomenon in which an electrical signal transmitted on one wire pair in a cable bundle causes interference on other pairs in the same cable. This interference by a "crosstalk disturber" can result in data errors for communications equipment using the affected pair ("crosstalk victims"), such as analog modems, ISDN adapters, and DSL modems. Various techniques are used to reduce errors resulting from crosstalk. For example, some DSL modems test the wire pair when initializing a connection, and only utilize those parts of the spectrum that have low crosstalk impairment.
This technique is of limited value when the disturber uses time domain duplexing (TDD), as explained by FIG. 1. Remote device 101 and local device 102 are modems at two ends of a DSL connection. Remote device 101 and local device 102 take turns transmitting, with only one of the transmitters active at any one time. In this example, remote device 101 transmits during period 103 and period 104, while local device 102 transmits during period 105 and period 106. Victim device 107 is another communications device using a wire pair colocated with the pair used by local device 102, and therefore a victim subject to possible crosstalk from local device 102. Local device 102 is the disturber.
In order to minimize the effect of crosstalk, victim device 107 measures impairments at the start of a connection, and adjusts spectrum usage to avoid any frequency ranges that are strongly affected by crosstalk. The effectiveness of this strategy depends on whether or not the disturber (local device 102) is actually transmitting at the same time that victim device 107 measures the line impairments. If the victim device 107 measures at time 108, this is an accurate measurement, because the measurement time 108 coincides with the period 105 when the disturber is transmitting. However, if the crosstalk victim device 107 measures at time 109, this is inaccurate because the disturber is not transmitting at this time. Since crosstalk victim device 107 has no information about when the disturber (local device 102) transmits, the effectiveness of the crosstalk avoidance strategy when used with TDD disturbers is unpredictable. A need therefore exists to address these and other shortcomings in the prior art.

This patent is subject to a terminal disclaimer.

System and method for subliminal time domain duplexing


An electric wire connector is disclosed. The electric wire connector includes an insulative lower connector formed in a shape extending in a first direction, the lower connector being open at a top thereof, the lower connector being provided at sides thereof with a plurality of fixing protrusions and shaft openings, an insulative upper connector formed in a shape extending in the first direction, the upper connector being open at a bottom thereof, the upper connector being provided at sides thereof with fixing holes into which the fixing protrusions of the lower connector are inserted and a fixing shaft inserted through the shaft openings of the lower connector, and a conductive member disposed in the lower connector, the conductive member having a plurality of cutting blades for peeling off sheaths of electric wires, the cutting blades being electrically connected to cores of the electric wires.

1. Field of the Invention
The present invention relates to an electric wire connector, and, more particularly, to an electric wire connector that is capable of connecting electric wires to each other without peeling off sheaths of the respective electric wires.
2. Description of the Related Art
Connection between two or more separate electric wires may be achieved using a method of peeling sheaths of the electric wires, connecting exposed cores of the electric wires, and wrapping the connected cores with an insulating tape.
In the method using insulating tape, however, a tool for twisting the cores of the electric wires is needed. Furthermore, the connection operation is complicated and troublesome. In addition, safety against electric shock is not guaranteed.

Electric wire connector for press connecting electric wires


A surface mountable multi-chip device is provided which includes first and second lead frames portions and at least two chips. The lead frame portions each include a header region and a lead region. Beneficially, the header regions of the first and second lead frame portions lie in a common plane, with at least one semiconductor chip being placed on each of the header regions. A conductive member link is placed on top of the two chips to electrically and mechanically interconnect the chips.

FIG. 1 is a schematic, cross sectional view of a known surface-mount structure, which contains a diode chip 10. Diode chip 10 is disposed within a package 40, the outline of which is illustrated. The structure contains an upper lead frame 20, a lower lead frame 21. Lead frames, conductive frames containing leads and headers to which an unpackaged die (or "chip") can be attached, are well known in the semiconductor industry. The lead frames 20, 21 have header regions 20A, 21A (also known as "chip pads" or "die pads"), which are in electrical contact with diode 10 and which are commonly provided with dimples (not shown) to enhance electrical contact. The lead frames 20, 21 also have lead regions 20B, 21 B that extend beyond the packaging 40. By wrapping the lead regions 20B, 21B around the underside of the packaging 40 (into a so-called "J-bend" configuration) or by bending lead regions lead regions 20B, 21B downward and outward (into a so-called "gull wing" configuration.), the structure can be readily surface mounted on another structure such as a circuit board.
Surface-mount devices having thin packaging are desirable in a number of applications, for example, in circuit boards for laptop computers, where vertical space is at a premium. The present invention addresses these and other needs by providing a multichip surface-mount device, while at the same time avoiding the need stack chips upon one another within the device.


There is provided a control arm comprising a shell-like shell of a first material and a reinforcement of a plastic material, wherein the reinforcement has a flex-element which protrudes therefrom and which can be supported or guided by means of a vehicle structure in order in the event of jounce and/or rebound of the suspension to produce a resilient action equivalent to a conventional spring.

Vehicles generally have suspension or damping devices serving to absorb unevenness of the roadway over which the vehicle wheels are rolling and thereby isolate the un-sprung portion of the vehicle from unwanted bumps and roughness that may occur during jounce and/or rebound of the wheels and related suspension components. To this end, modern passenger vehicles and light utility vehicles often employ helical spring suspensions or compressed air suspensions which, in combination with a hydraulic damper, control the movement of the vehicle and consequently influence the travel behavior in a positive manner. In this instance, the springs and the dampers are often oriented in a vertical position, and therefore a specific space must be provided for these components at the expense of utility space for passengers or loads space. The objective is therefore to provide alternatives to conventional vehicle suspensions.

Suspension control arm with integrated resilient element


An electrochromic device comprising a pair of glass, plastic plates or plastic films At least one plate or film, is provided with an electrically conductive coating. At least one plate or film and its conductive coating are transparent and the other may be mirrored. The plates or films are joined together and form a volume filled with an electrochromic medium which comprises at least one reducible electrochromic substance OX2 and at least one oxidizable electrochromic substance RED1. The OX2 corresponds to the formula

(1) Field of the Invention
The present invention relates to an electrochromic device, and to electrochromic substances.
Electrochromic devices are already known, for example from D. Theis in Ullmann's Encyclopaedia of Industrial Chemistry, vol. A 8, p. 622, Verlag Chemie 1987 and WO-A 94/23333. A distinction is made between two basic types:
(2) Description of Related Art
Type 1: full-area electrochromic devices;
Type 2: electrochromic display devices having structured electrodes.
Type 1 is used, for example, in electrically darkenable window panes or electrically dimmable automobile mirrors. Such devices are disclosed, for example, in U.S. Pat. No. 4,902,108.
Type 2 is used in segment and matrix displays. Such display devices are proposed, for example, in DE-A 196 31 728. Devices of this type can be observed transmissively or, in the case of reflection, reflectively.
WO-A 94/23333 compares electrochromic materials having different constructions, but these are not used as display devices:                Construction a: the electrochromic substances are in the form of a fixed film or layer on the electrodes (Ullmann, see above).        Construction b: the electrochromic substances are deposited on the electrodes as a layer by the redox process (Ullmann, see above).        Construction c: the electrochromic substances remain permanently in solution.
For construction a), the best-known electrochromic material is the tungsten oxide/palladium hydride pair.
For construction b), viologens have been described as electrochromic substances. These devices are not self-erasing, i.e. the image produced remains after the current has been switched off and can only be erased again by reversing the voltage. Such devices are not particularly stable and do not allow a large number of switching cycles.
In addition, such cells constructed using tungsten oxide/palladium hydride in particular cannot be operated in transmitted light, but only reflectively, owing to light scattering at these electrochromic layers.
Elektrokhimiya 13, 32–37 (1977), U.S. Pat. Nos. 4,902,108 and 5,140,455 disclose an electrochromic system of the latter construction c). An electrochromic cell which is constructed from glass plates with a conductive coating comprises a solution of a pair of electrochromic substances in an inert solvent.
The pair of electrochromic substances used is one electrochemically reversibly reducible substance and one reversibly oxidizable substance. Both substances are colourless or only weakly coloured in the ground state. Under the action of an electric voltage, one substance is reduced and the other oxidized, both becoming coloured. When the voltage is switched off, the ground state re-forms in the case of both substances, resulting in disappearance or fading of the colour.

U.S. Pat. No. 4,902,108 discloses that suitable pairs of redox substances are those in which the reducible substance has at least two chemically reversible reduction waves in the cyclic voltammogram and the oxidizable substance correspondingly has at least two chemically reversible oxidation waves.
Various applications have been described for electrochromic cells of construction c). For example, they can be formed as automobile rear-view mirrors which can be darkened during night driving by application of a voltage and thus prevent dazzling by the headlamps of following vehicles (U.S. Pat. Nos. 3,280,701, 4,902,108 and EP-A 0 435 689). Furthermore, such cells can also be employed in window panes or automobile sunroofs, where they darken the sunlight after application of a voltage. Likewise described is the use of such devices as electrochromic display devices, for example in segment or matrix displays having structured electrodes (DE-A 196 31 728).
The electrochromic cells normally consist of a pair of glass plates, of which, in the case of the automobile mirror, one is mirrored. One side of these plates is coated over its surface with a light-transparent, electroconductive layer, for example indium-tin oxide (ITO), and in the case of display devices this conductive coating is divided into electrically separated segments provided with individual contacts. These plates are used to construct a cell by joining them by means of a sealing ring with their electroconductively coated sides facing one another to form a cell. This cell is filled with an electrochromic liquid via an opening, and the cell is tightly sealed. The two plates are connected to a voltage source via the ITO layers.
For many applications it is important to be able to adapt the colour of the electrochromic device in the energized state to the particular requirements. A colour which is as neutral as possible is often desired, for example a grey colour. Although dipyridinium salts (viologens) and dihydrophenazines are proven electrochromic compounds, mixing them results in a greenish blue colour (e.g. U.S. Pat. No. 4,902,108, WO 97/30134). WO 98/44384 discloses derivatives of dipyridinium salts and dihydrophenazines whose colours are different from the parent compounds. By appropriate mixing of up to 5 electrochromic compounds of this type, a preselected colour can be achieved, including, for example, a grey colour. However, complex mixtures of this type are difficult to balance, especially when the electrochromic device is to be operated at different voltages and the colour is to be independent from the voltage. Furthermore, the dipyridinium salt and dihydrophenazine derivatives disclosed in WO 98/44384 are not always readily obtainable.
Accordingly, there was a need for an electrochromic compound which harmonizes well with dipyridinium salts and dihydrophenazines in terms of redox behaviour, provides the missing red component in admixture with dipyridinium salts and dihydrophenazines in the solvents customary for electrochromic cells, and is readily obtainable synthetically.

Abstract: in which R201 and R202, each are alkyl, cycloalkyl, alkenyl, aralkyl, aryl, −[C(PQ)]− or a bivalent bridge B, Z201 is a bivalent radical of the formulae CR210R211, O, C═O or o-phenylene, R210 and R211, each are hydrogen, methyl or ethyl, or CR210R211 is C3- to C7-cycloalkane-1,1-diyl. The rings C, D, E and F, each may be substituted by up to 4 alkyl and/or alkoxy radicals, or respectively, may be linked via a —(CH2)4— or —CH═CH—CH═CH— bridge. P and Q, each are —CN or —COO-alkyl. X— is an anion.


Benign prostatic hypertrophy specific polynucleotides and polypeptides are provided. Methods of diagnosing benign prostatic hypertrophy using these polynucleotides and polypeptides are also provided. Human BPH1 polypeptides and DNA (RNA) encoding such BPH1 and a procedure for producing such polypeptides by recombinant techniques is disclosed. Also disclosed are methods for utilizing such BPH1 for the treatment of prostate disease. Antagonists against such BPH1 and their use as a therapeutic to treat prostate disease are also disclosed. Also disclosed are diagnostic assays for detecting diseases related to mutations in the nucleic acid sequences and altered concentrations of the polypeptides. Also disclosed are diagnostic assays for detecting mutations in the polynucleotides encoding the BPH1 and for detecting altered levels of the polypeptide in a host.

Benign prostatic hypertrophy (BPH) is one of the most common diseases in adult males. Histological evidence of BPH has been found in more than 40% of men in their fifties and almost 90% of men in their eighties. The disease results from the accumulation of non-malignant nodules arising in a small region around the proximal segment of the prostatic urethra which leads to an increase in prostate volume. If left untreated, BPH can result in acute and chronic retention of urine, renal failure secondary to obstructive uropathy, serious urinary tract infection and irreversible bladder decompensation.
The majority of men over fifty years of age are considered to have some urinary symptoms attributable to BPH. Treatment of BPH accounts for about 1.7 million physician office visits and more than 300,000 prostatectomies annually in the Unites States alone, resulting in total annual estimated charges of more than five billion dollars (Guess, Epidem. Rev. 1992 14:131-136; Holtgrewe, Urology 1995 46(Suppl3A):23-25).
There are two main courses of treatment for patients diagnosed with BPH. For over 50 years, transurethral resection of the prostate has been the standard treatment for men with an enlarged prostate and obstructive symptoms (Lepor, J. Urol. 1990 143:533-537). However, this has not been entirely satisfactory. Morbidity associated with the surgical approach includes clot retention, excessive bleeding, bladder neck contracture, impotence, retrograde ejaculation and infection and an increase in long term mortality (Roos et al. N. Engl J. Med. 1989 320:1120-1124). The other approach is pharmacological. Alpha-adrenergic antagonists have been shown to block the adrenergic receptors in the prostatic capsule and bladder neck (Lepor, Urology 1993 42:483-501). This results in a loss of smooth muscle tone and a concomitant decrease in the resistance to urine flow. This leads to an improvement in symptoms but does not affect the prostate volume. Another compound, finasteride is a potent competitive inhibitor of the enzyme 5a-reductase (involved in the conversion of testosterone to DHT). Clinical studies have demonstrated that patients treated with this drug exhibited significant reductions in prostate volume, measured by transrectal ultrasound. Continuous therapy with finasteride maintained a 25% reduction in prostate volume during three years of administration in over 50% of patients with no loss of efficacy suggesting that the progress of the disease had been halted (Rittmaster, N. Eng. J. Med. 1994 330:120-125, Gormley et al. N. Eng. J. Med. 1992 327:1184-1191).
However, information concerning the factors which initiate and promote the development of BPH, the mechanisms by which BPH alters voiding mechanisms, and definitive diagnostic criteria to establish the role of BPH in clinical changes is lacking. Despite the high prevalence of BPH, the clinical diagnostic criteria are not very specific and no single BPH case definition has gained wide acceptance for use in epidemiological studies. A three-fold definition of BPH is provided by Roylance et al. Biomed. and Pharmacol. 1995 49:332-338. First, BPH is characterized by microscopic evidence of hyperplasia. Second, a clinical definition of BPH is based on a medical history which includes information on symptoms and a digital rectal examination. However, this information actually defines prostatism rather than urologically confirmed disease. Third, not all patients with BPH diagnosed clinically have urologically confirmed disease; other conditions such as urethral stricture, dysfunction of the bladder neck and prostate also give rise to symptoms of prostatism. A diagnosis of BPH on prostate size alone can be misleading because only a weak correlation exists between prostate size and symptoms of outflow. Thus, while the pathologic diagnostic criteria for BPH are relatively specific, clinical diagnostic criteria are much less specific.
The only marker currently available for BPH is PSA (prostate specific antigen) (Wang et al. Prostate 1996 28:10-16, Lee and Oesterling Sem. in Surg. Oncol. 1995 11:23-25). PSA levels are elevated in many patients with BPH. However, elevated levels of PSA also are found in diseases such as prostate cancer and thus can not be used to distinguish among the various types of pathology. Accordingly, there is a need for a specific marker and method for the unambiguous diagnosis of BPH.
Clearly, there is a need for factors that are specific markers for prostate disease, particularly BPH and their roles in dysfunction and disease. There is a need, therefore, for identification and characterization of such factors that specific markers for prostate disease, particularly BPH, and which can play a role in preventing, ameliorating or correcting dysfunctions or diseases.

Polynucleotides and polypeptides associated with benign prostatic hypertrophy


Modified crystalline zeolite materials have a zeolite framework with both tetra-coordinate Lewis aluminum single sites and Brønsted aluminum sites. The tetra-coordinate Lewis aluminum single sites include aluminum atoms covalently bonded to a variable group and to two oxygen atoms and further coordinated to a third oxygen atom. The variable group may be alkyl, hydride, or hydroxyl. Methods for incorporating tetra-coordinate Lewis aluminum single sites into a crystalline zeolite material include contacting the crystalline zeolite material with a dialkylaluminum hydride R2AlH, where each R is alkyl, to react the dialkylaluminum hydride with the zeolite framework and form tetra-coordinate alkyl aluminum single sites. Heating the alkyl-aluminum zeolite induces β-hydride elimination of the alkyl groups, whereby tetra-coordinate aluminum hydride single sites are formed. By oxidizing the hydride-aluminum zeolite, at least a portion of the tetra-coordinate aluminum hydride single sites are converted to tetra-coordinate aluminum hydroxide single sites.

Zeolites have widespread uses in many diverse industries. In the petroleum industry, for example, zeolite catalysts may be included in processes such as fluid catalytic cracking (FCC) and hydrocracking to catalyze reactions such as hydrogenation, dehydrogenation, isomerization, alkylation, and cracking, for example. These processes each share constant needs for developing zeolites having single sites with goals such as increased activity and increased shape selectivity with control and predictability. A greater understanding of the active sites in a zeolite can benefit searches for catalyst materials that are highly selective to catalyzing individual chemical reactions over other chemical reactions, thereby giving preference to desirable products of the selected reactions. There remain ongoing needs for zeolites having structures with active sites that are highly defined in terms of number, structure, and properties.

Zeolites with tetra-coordinated Lewis aluminum sites and methods for their preparation

King Abdullah University of Science and Technology


Compounds that modulate natural .beta. amyloid peptide aggregation are provided. The modulators of the invention comprise a peptide, preferably based on a .beta. amyloid peptide, that is comprised entirely of D-amino acids. Preferably, the peptide comprises 3-5 D-amino acid residues and includes at least two D-amino acid residues independently selected from the group consisting of D-leucine, D-phenylalanine and D-valine. In a particularly preferred embodiment, the peptide is a retro-inverso isomer of a .beta. amyloid peptide, preferably a retro-inverso isomer of A.beta..sub.17-21. In certain embodiments, the peptide is modified at the amino-terminus, the carboxy-terminus, or both. Preferred amino-terminal modifying groups include cyclic, heterocyclic, polycyclic and branched alkyl groups. Preferred carboxy-terminal modifying groups include an amide group, an alkyl amide group, an aryl amide group or a hydroxy group. Pharmaceutical compositions comprising the compounds of the invention, and diagnostic and treatment methods for amyloidogenic diseases using the compounds of the invention, are also disclosed.

Alzheimer's disease (AD), first described by the Bavarian psychiatrist Alois Alzheimer in 1907, is a progressive neurological disorder that begins with short term memory loss and proceeds to disorientation, impairment of judgment and reasoning and, ultimately, dementia. The course of the disease usually leads to death in a severely debilitated, immobile state between four and 12 years after onset. AD has been estimated to afflict 5 to 11 percent of the population over age 65 and as much as 47 percent of the population over age 85. The societal cost for managing AD is upwards of 80 billion dollars annually, primarily due to the extensive custodial care required for AD patients. Moreover, as adults born during the population boom of the 1940's and 1950's approach the age when AD becomes more prevalent, the control and treatment of AD will become an even more significant health care problem. Currently, there is no treatment that significantly retards the progression of the disease. For reviews on AD, see Selkoe, D. J. Sci. Amer., November 1991, pp. 68-78; and Yankner, B. A. et al. (1991) N. Eng. J. Med. 325:1849-1857.
It has recently been reported (Games et al. (1995) Nature 373:523-527) that an Alzheimer-type neuropathology has been created in transgenic mice. The transgenic mice express high levels of human mutant amyloid precursor protein and progressively develop many of the pathological conditions associated with AD.
Pathologically, AD is characterized by the presence of distinctive lesions in the victim's brain. These brain lesions include abnormal intracellular filaments called neurofibrillary tangles (NTFs) and extracellular deposits of amyloidogenic proteins in senile, or amyloid, plaques. Amyloid deposits are also present in the walls of cerebral blood vessels of AD patients. The major protein constituent of amyloid plaques has been identified as a 4 kilodalton peptide called .beta.-amyloid peptide (.beta.-AP)(Glenner, G. G. and Wong, C. W. (1984) Biochem. Biophys. Res. Commun. 120:885-890; Masters, C. et al. (1985) Proc. Natl. Acad Sci. USA 82:4245-4249). Diffuse deposits of .beta.-AP are frequently observed in normal adult brains, whereas AD brain tissue is characterized by more compacted, dense-core .beta.-amyloid plaques. (See e.g., Davies, L. et al. (1988) Neurology 38:1688-1693). These observations suggest that .beta.-AP deposition precedes, and contributes to, the destruction of neurons that occurs in AD. In further support of a direct pathogenic role for .beta.-AP, .beta.-amyloid has been shown to be toxic to mature neurons, both in culture and in vivo. Yankner, B. A. et al. (1989) Science 245:417-420; Yankner, B. A. et al. (1990) Proc. Natl. Acad. Sci. USA 87:9020-9023; Roher, A. E. et al. (1991) Biochem. Biophys. Res. Commun. 174:572-579; Kowall, N. W. et al. (1991) Proc. Natl. Acad. Sci. USA 88:7247-7251. Furthermore, patients with hereditary cerebral hemorrhage with amyloidosis-Dutch-type (HCHWA-D), which is characterized by diffuse .beta.-amyloid deposits within the cerebral cortex and cerebrovasculature, have been shown to have a point mutation that leads to an amino acid substitution within .beta.-AP. Levy, E. et al. (1990) Science 248:1124-1126. This observation demonstrates that a specific alteration of the .beta.-AP sequence can cause .beta.-amyloid to be deposited.
Natural .beta.-AP is derived by proteolysis from a much larger protein called the amyloid precursor protein (APP). Kang, J. et al. (1987) Nature 325:733; Goldgaber, D. et al. (1987) Science 235:877; Robakis, N. K. et al. (1987) Proc. Natl. Acad. Sci. USA 84:4190; Tanzi, R. E. et al. (1987) Science 235:880. The APP gene maps to chromosome 21, thereby providing an explanation for the .beta.-amyloid deposition seen at an early age in individuals with Down's syndrome, which is caused by trisomy of chromosome 21. Mann, D. M. et al. (1989) Neuropathol. Appl. Neurobiol. 15:317; Rumble, B. et al. (1989) N. Eng. J. Med. 320:1446. APP contains a single membrane spanning domain, with a long amino terminal region (about two-thirds of the protein) extending into the extracellular environment and a shorter carboxy-terminal region projecting into the cytoplasm. Differential splicing of the APP messenger RNA leads to at least five forms of APP, composed of either 563 amino acids (APP-563), 695 amino acids (APP-695), 714 amino acids (APP-714), 751 amino acids (APP-751) or 770 amino acids (APP-770).
Within APP, naturally-occurring .beta. amyloid peptide begins at an aspartic acid residue at amino acid position 672 of APP-770. Naturally-occurring .beta.-AP derived from proteolysis of APP is 39 to 43 amino acid residues in length, depending on the carboxy-terminal end point, which exhibits heterogeneity. The predominant circulating form of .beta.-AP in the blood and cerebrospinal fluid of both AD patients and normal adults is .beta.1-40 ("short .beta."). Seubert, P. et al. (1992) Nature 359:325; Shoji, M. et al. (1992) Science 258:126. However, .beta.1-42 and .beta.1-43 ("long .beta.") also are forms in .beta.-amyloid plaques. Masters, C. et al. (1985) Proc. Natl. Acad. Sci. USA 82:4245; Miller, D. et al. (1993) Arch. Biochem. Biophys. 301:41; Mori, H. et al. (1992) J. Biol. Chem. 267:17082. Although the precise molecular mechanism leading to .beta.-APP aggregation and deposition is unknown, the process has been likened to that of nucleation-dependent polymerizations, such as protein crystallization, microtubule formation and actin polymerization. See e.g., Jarrett, J. T. and Lansbury, P. T. (1993) Cell 73:1055-1058. In such processes, polymerization of monomer components does not occur until nucleus formation. Thus, these processes are characterized by a lag time before aggregation occurs, followed by rapid polymerization after nucleation. Nucleation can be accelerated by the addition of a "seed" or preformed nucleus, which results in rapid polymerization. The long .beta. forms of .beta.-AP have been shown to act as seeds, thereby accelerating polymerization of both long and short .beta.-AP forms. Jarrett, J. T. et al. (1993) Biochemistry 32:4693.
In one study, in which amino acid substitutions were made in .beta.-AP, two mutant .beta. peptides were reported to interfere with polymerization of non-mutated .beta.-AP when the mutant and non-mutant forms of peptide were mixed. Hilbich, C. et al. (1992) J. Mol. Biol. 228:460-473. Equimolar amounts of the mutant and non-mutant (i.e., natural) .beta. amyloid peptides were used to see this effect and the mutant peptides were reported to be unsuitable for use in vivo. Hilbich, C. et al. (1992), supra.

Modulators of .beta.-amyloid peptide aggregation comprising D-amino acids


Seat belt tension is determined by measuring the resistance of a flexible potentiometer which is deformed to produce a controlled change in resistance with increased belt tension. A seat belt mounting has a spring which allows limited extension of the seat belt in response to belt tension. A flexible potentiometer is mounted to the spring so that spring deformation produces a change in resistance which can be directly correlated to belt tension. Belt tension is input to an airbag deployment logic which may incorporate a seat position sensor, a weight-on-seat sensor and various other sensors which detect the existence, size and direction of any crash. The logic draws conclusions from the tension sensor in the seat belt and other sensors to determine if deployment of the front passenger airbag is likely to be advantageous to an occupant of the front passenger seat.

Airbags were developed to protect occupants of cars during vehicle crashes. Originally airbags were viewed as an alternative to seat belts, because they are passive devices which do not require the cooperation of the car's occupants to be effective. However, experience has shown that airbags should be considered an adjunct to seat belts. When used properly, airbags can in certain crash situations reduce injuries to occupant. An airbag is a gas-filled bag which is rapidly deployed in the event of a vehicle crash. When appropriate crash sensors determine that a crash has occurred, the airbag is rapidly inflated to create an impact cushion between the occupant(s) of a vehicle and the structure of the vehicle. Consideration is also being given to the design of airbags which better position the vehicle occupant(s) to withstand crash-induced accelerations.
An airbag system is made up of two basic functional components: the airbag module, including the means for deploying the airbag; and the sensors and circuitry which determine whether the airbag should be deployed.
Recently sensors have been developed to determine the weight imposed on the front seat, and the value of the determined weight may then be used as an input into the system logic which determines whether or not an airbag should be deployed or whether the mode of deployment should be modified in airbag systems which are capable of varying the deployment sequence to accommodate varying circumstances. In some cases, however, these weight sensors can be confused by loads imposed by the compression of the seat resulting from installing a child's car seat and tensioning the seat belt to hold the child seat into place.
One proposed solution is to place a device on each child seat which can be detected by a sensor and thus used to determine the presence of a child seat. However, this approach relies on gaining cooperation of all manufacturers of child car seats and it would take many years before all old child car seats would be replaced with child car seats containing the needed sensor. What is needed is a sensor which can provide data for determining whether a child's car seat is positioned in the front passenger seat of an automobile.

Seat belt tension sensor employing flexible potentiometer


In a dynamic flip-flop circuit with a data selection function, for example, when data having an H value is selected using a selection signal, a first node N1 is L, a second node N2 of a second dynamic circuit is H, so that an output signal has an H level. In this case, when none of a plurality of pieces of data is selected using a selection signal, the first node N1 is H, so that the electric charge of the second node N2 is discharged and the output signal erroneously has an L level. However, in this case, an output node N3 is H and a fourth node N4 is L, so that an n-type transistor of the second dynamic circuit is turned OFF, thereby preventing the second node N2 from being discharged. Therefore, a normal operation is performed while securing a satisfactorily high-speed operation even when none of the pieces of data is selected.

The present invention relates to a semiconductor integrated circuit, and more particularly, to a high-speed semiconductor integrated circuit.
Conventionally, the speed of a semiconductor integrated circuit, particularly a flip-flop circuit, is increased by incorporating a dynamic circuit into its internal structure as described in, for example, JP No. 2003-060497 A. The dynamic flip-flop circuit described in this publication receives a plurality of pieces of data, selects any one of them, and holds and outputs the selected data.
Hereinafter, the structure of the flip-flop circuit having the data selection function will be described with reference to FIG. 3A. In FIG. 3A, a data selection circuit 91 is provided at the previous stage of a holding circuit 90. In the data selection circuit 91, when a clock CLK is at a Low level (Low period), a node N1 is precharged to a power source potential Vdd by a p-type transistor Tr1, while a node N2 is precharged to the power source potential Vdd by a p-type transistor Tr50. Near the end of this period, one of selection signals S0 to S2 which is used to select a corresponding one of a plurality of pieces of data D0 to D2 is turned High. Subsequently, when the clock CLK goes to High and the selected data (e.g., D0) is at a High level, the electric charge of the node N1 is discharged via an n-type transistor Tr2, so that the potential of the node N1 becomes equal to that of the ground. Therefore, an n-type transistor Tr51 is turned OFF, so that the precharge potential of the node N2 is held. In this case, this potential is held as an H value by the holding circuit 90, which in turn outputs an output signal Q indicating the H value.
On the other hand, when the selected data D0 is at a Low level, the electric charge of the node N1 is not discharged, so that the potential of the node N1 is held as it is the precharge potential and the n-type transistor Tr51 is turned ON. As a result, the electric charge of the node N2 is discharged via the n-type transistor Tr51 and the n-type transistor Tr2, so that the potential of the node N2 becomes an L value. The L value is held by the holding circuit 90, which in turn outputs an output signal Q indicating the L value.
Note that, in FIG. 3A, SI indicates a data input when scanning is performed, SE indicates a scan shift control signal, and SEB indicates an inverted signal of the scan shift control signal.
However, it was found that the conventional dynamic flip-flop circuit having the data selection function malfunctions when none of the plurality of pieces of data is selected. Hereinafter, the malfunction will be described.
In an ordinary operation, for example, the node N2 is at the precharge potential (H value) and the holding circuit 90 outputs the output signal Q indicating the H value. In this case, when none of the plurality of pieces of data D0 to D2 is selected during the next High period of the clock CLK (i.e., all the selection signals S0 to S2 have the Low value), the n-type transistor Tr2 is turned ON. However, the precharge potential of the node N1 is held, so that the n-type transistor Tr51 is turned ON. Therefore, the electric charge of the node N2 is discharged via the n-type transistors Tr51 and Tr2 to the L value. As a result, the holding circuit 90 erroneously outputs an output signal Q indicating the L value.
To solve the above-described problems, for example, the following circuit is considered which inputs a signal to the gate of the n-type transistor Tr2 as shown in FIG. 3B. Specifically, a static circuit comprising a circuit 92 including an OR circuit which receives all the selection signals S0 to S2 and a latch circuit which latches an output of the OR circuit during a High period of the clock CLK, and an AND circuit 93 which receives an output of the latch circuit and the clock CLK, is additionally provided, and an output of the AND circuit 93 is input to the gate of the n-type transistor Tr2.
In this case, however, all the selection signals S0 to S2 need to be passed through the OR circuit and the latch circuit by a rising time of the clock CLK. Therefore, an extra setup time (a time required for the static circuit to establish its output by a rising time of the clock CLK) is required, resulting in impairment of the speed of operation.

Matsushita Electric Industrial Co., Ltd.


A device and method for delivering a high viscosity composition is described. The composition includes a bioactive agent for delivery to a subject in need thereof. The method delivers the bioactive agent at a high bioavailability and with little loss of agent to the natural defense mechanisms of the body. The device includes one or more microneedles with structures fabricated on a surface of the microneedles to form a nanotopography. A random or non-random pattern of structures may be fabricated such as a complex pattern including structures of differing sizes and/or shapes.

Targeted drug delivery in which a bioactive agent (e.g., a drug or a therapeutic) is provided in an active state to a subject's system at effective concentrations is a long sought goal. Many difficulties must be overcome to reach this goal. For instance, a bioactive agent must first be successfully delivered internally, and the human body has developed many barriers to prevent the influx of foreign substances. In addition, the nature of the bioactive agent itself or the concentration of a bioactive agent necessary to obtain the desired effect often leads to formation of a high viscosity composition, which further amplifies the difficulties in successfully passing the body's natural barriers.
Delivery methods presently utilized for high viscosity compositions include oral delivery, injections, and infusions. Unfortunately, these methods all include aspects that are problematic not only with regard to successful delivery of the high viscosity composition, but also for the subject receiving the composition. For instance, injections often utilize small gauge needles that require extremely high pressure over a long period of time for delivery of high viscosity compositions, if they are capable of use for the high viscosity compositions at all. For example, 0.5 milliliter of a 20 centipoise (cP) proteinaceous solution can take up to about 600 seconds for delivery through a 34 gauge needle. In addition, injections are painful particularly when considering the time required for a single dose delivery and, when considering long term use of an agent, can lead to development of scar tissue. Oral delivery requires successful absorption through the epithelial lining of the digestive tract as well as avoidance of break down of the bioactive agent by digestive materials, and both of these hurdles can be extremely difficult to cross. In addition, oral delivery often leads to gastrointestinal distress for the subject. Moreover, both injection and oral delivery tend to provide bursts of agents and wide swings in system concentration rather than a preferred steady-state delivery. Infusion therapy can be used to deliver bioactive agents directly to blood vessels, muscles, or subcutaneous connective tissue. While delivery via infusion therapy now can be carried out on an out-patient basis, or even with long term, relatively steady-state delivery by use of infusion pumps, infusion therapy is invasive, increasing chances for infection at the infusion site, and necessitates the utilization of associated equipment such as pumps, transdermal tubing, etc.
Transdermal delivery devices have been developed in an attempt to provide a painless route for successful delivery of bioactive agents over a sustained period. For instance, transdermal delivery patches have been found useful for providing bioactive agents such as nicotine, scopolamine, estrogen, nitroglycerine, and the like to a subject's system. In order to be successful, a transdermal scheme must deliver an agent across the epidermis, which has evolved with a primary function of keeping foreign substances out. The outermost layer of the epidermis, the stratum corneum, has structural stability provided by overlapping corneocytes and crosslinked keratin fibers held together by coreodesmosomes and embedded within a lipid matrix, all of which provides an excellent barrier function. Beneath the stratum corneum is the stratum granulosum, within which tight junctions are formed between keratinocytes. Tight junctions are barrier structures that include a network of transmembrane proteins embedded in adjacent plasma membranes (e.g., claudins, occludin, and junctional adhesion molecules) as well as multiple plaque proteins (e.g., ZO-1, ZO-2, ZO-3, cingulin, symplekin). Tight junctions are found in internal epithelium and endothelium (e.g., the intestinal epithelium, the blood-brain barrier, blood vessel walls) as well as in the stratum granulosum of the skin. Beneath both the stratum corneum and the stratum granulosum lays the stratum spinosum. The stratum spinosum includes Langerhans cells, which are dendritic cells that may become fully functioning antigen-presenting cells and may institute an immune response and/or a foreign body response to an invading agent.
The addition of microneedles on transdermal delivery devices such as patches has helped to breach initial barriers in the dermis. Unfortunately, even with such improvements, transdermal delivery devices are presently limited to delivery of low viscosity compositions, and in particular low molecular weight agents that have a moderate lipophilicity and no charge. Moreover, even upon successful crossing of the natural boundary, problems still exist with regard to maintaining the activity level of delivered agents and avoidance of foreign body and immune response.
What are needed in the art are devices and methods for delivery of bioactive agents. More specifically, what are needed are devices and methods that can successfully deliver a high viscosity composition that includes a bioactive agent and can also prevent targeting of the bioactive agent by the body's own defensive mechanisms.

Transdermal delivery of high viscosity bioactive agents


The disclosed embodiments include a method, apparatus, and computer program product for generating a cross-sensor standardization model. For example, one disclosed embodiment includes a system that includes at least one processor; at least one memory coupled to the at least one processor and storing instructions that when executed by the at least one processor performs operations comprising selecting a representative sensor from a group of sensors comprising at least one of same primary optical elements and similar synthetic optical responses and calibrating a cross-sensor standardization model based on a matched data pair for each sensor in the group of sensors and for the representative sensor. In one embodiment, the at least one memory coupled to the at least one processor and storing instructions that when executed by the at least one processor performs operations further comprises generating the matched data pair, wherein the matched data pair comprises calibration input data and calibration output data.

Various multivariate models are used to predict chemical compositions and other properties of unknown reservoir fluid samples during formation fluid analysis that are based on the measurements of downhole optical tools. The application of pre-calibrated fluid prediction models is tool dependent, often requiring data standardization or transformation to convert measured sensor responses from the tool data space to the calibration data space. The costs associated with fluid prediction model development and management affects how instrument standardization is performed.


A method for securing at least one message transferred in a communication system from a first computing device to a second computing device in a peer-to-peer manner. At the first computing device, an identity based authenticated key exchange session is established with a third computing device operating as a peer authenticator. The identity based authenticated key exchange session has an identity based authenticated session key associated therewith. The first computing device obtains from the third computing device a random key component of the second computing device, wherein the random key component of the second computing device is encrypted by the third computing device using the identity based authenticated session key prior to sending the random key component of the second computing device to the first computing device. A peer-to-peer messaging key is computed at the first computing device using the random key component of the second computing device.

Messaging services, as are known today, had their origins in Instant Messaging (IM), which started prior to the advent of the World Wide Web. Since then, the concept of messaging has undergone a healthy and continued evolution while maintaining its status as a very popular application program across many communication systems. More recent extensions include chat rooms and micro blogging with a social network aspect (e.g., Twitter). Extensions of these messaging services are being adopted inside enterprise environments as well. Over mobile networks, conventional messaging services include short message service (SMS) and multimedia message service (MMS). Simultaneously, messaging services have also served as a platform to offer various value added services such as ringtones and wallpaper downloads. Given the unprecedented growth and adoption of smart phones, mobile messaging services are also undergoing a rapid evolution, which includes mobile versions of micro blogging, enterprise mobile messaging services, and group messaging services.
In all the above examples, there are participants and a messaging provider (who could be different from the provider of the communication network infrastructure, i.e., network provider, within which the messaging service is hosted). Moreover, all messages traverse the network with little or no support for security even though messages are stored in various servers before delivery. In particular, messages are seldom encrypted or authenticated. The only form of security that may be available is encryption and/or integrity protection over an access link (such as mobile wireless). Even in these limited settings, access network providers often "turn off" security features to conserve computing power.


In a method of coating a photo resist over a wafer, dispensing the photo resist from a nozzle over the wafer is started while rotating the wafer, and dispensing the photo resist is stopped while rotating the wafer. After starting and before stopping the dispensing the photo resist, a wafer rotation speed is changed at least 4 times. During dispensing, an arm holding the nozzle may move horizontally. A tip end of the nozzle may be located at a height of 2.5 mm to 3.5 mm from the wafer.

A photolithography operation is one of the key operations in the semiconductor manufacturing process. Photolithography techniques include ultraviolet lithography, deep ultraviolet lithography, and extreme ultraviolet lithography (EUVL). A photolithography operation is generally a high cost process, and reduction of the cost is one of the problems to be solved. In particular, in EUV lithography, the cost of the photo resist is much higher than the cost of a deep UV resist.

Method and apparatus for coating photo resist over a substrate

TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.


A heat-resistant, light-shielding film having high light shielding capacity, high heat resistance, high sliding characteristics, low surface gloss and high electroconductivity, and useful for optical device parts, e.g., shutter or aperture blades for digital cameras and digital video cameras, and aperture blades for adjusting light intensity for projectors; method for producing the film; and aperture and light intensity adjusting device using the film.

1. Field of the Invention
The present invention relates to a heat-resistant, light-shielding film, method for producing the film, and aperture and light intensity adjusting device using the film, more specifically a heat-resistant, light-shielding film having high light shielding capacity, high heat resistance, high sliding characteristics, low surface gloss and high electroconductivity, and useful for optical device parts, e.g., shutter or aperture blades for aperture or lens shutter for digital cameras and digital video cameras, and aperture blades for adjusting light intensity for projectors; method for producing the film; and aperture and light intensity adjusting device using the film.
2. Description of the Prior Art
Reentry, shutter blades or aperture blades for cameras have been required to be lighter and have higher sliding characteristics as shutter speed increases, because they are subjected to starting/stopping cycles in a very short time. At the same time, they are basically required to have light shielding capacity, because they cover photosensitive materials, e.g., films, or front surfaces of imaging devices, e.g., CCDs, to shield light. Moreover, they are required to have sufficient lubricity for smooth motion of blades for which they are used, because a plurality of blades work while overlapping each other in optical devices. Still more, they are required to have a low surface reflectivity to prevent leakage of light between blades. Still more, they are required to be resistant to heat, because cameras for which they are used may evolve high temperature inside depending on service environments.
On the other hand, light-shielding films for light intensity adjusting aperture blades for liquid-crystal projectors as projectors for presentation or image viewing devices for home theaters or the like are required to have characteristics similar to those for digital cameras and digital video cameras, or in particular higher heat resistance.
The commercial light-shielding films described above are generally supported by a base of plastic film, e.g., polyethylene terephthalate (PET) film, or thin metallic plate of stainless steel (SUS), SK, Al or the like. When a light-shielding film supported by a metallic base is used as a shutter or aperture blade in a camera, the metallic plates will graze with each other as the blades are opened and closed to create large noise. The blade in a liquid-crystal projector is required to move at a high speed to reduce brightness changes when images are changed, with the result that the blades will graze with each other to repeatedly create noise. To operate the blades at a lower speed to reduce noise will produce unstable images, because light intensity adjustment may not sufficiently follow changed images.
Recently, light-shielding films have been mainly supported by a plastic film, in order to solve the above problems and to reduce the weight. Moreover, they are required to be electroconductive to reduce evolution of dust. Therefore, it is accepted that they are required to satisfy the characteristics of high light shielding capacity, high heat resistance, low surface gloss, high sliding characteristics, high electroconductivity and low soot evolution. Various film materials and structures have been proposed to satisfy the characteristics which light-shielding films are required to have.
For example, Patent Document 1 discloses a light-shielding film with a resin film, e.g., polyethylene terephthalate (PET) film, impregnated with fine, black, electroconductive particles of carbon black, titanium black or the like to provide the film with light-shielding capacity and electroconductivity, and is matting treated at least on one side to decrease surface gloss, wherein the fine black particles work to absorb light emitted from a light source, e.g., lamp, for high light-shielding capacity, low surface gloss and high electroconductivity.
Patent Document 2 discloses a light-shielding film with a resin film coated with a thermosetting resin layer containing a black pigment, e.g., carbon black, having light-shielding capacity and electroconductivity, lubricant and delustering agent to have light-shielding capacity, electroconductivity, lubricity and low surface gloss.
Patent Document 3 discloses a light-shielding material comprising a metallic blade material of aluminum alloy or the like, coated with a hard carbon film.
Patent Document 4 discloses a light-shielding blade structure with a plastic base coated and reinforced with a prepreg sheet of thermosetting resin containing carbon fibers on each side, to improve blade rigidity.
Light-shielding films have been widely used as light-shielding blade materials for optical devices, e.g., digital cameras, digital video cameras and liquid-crystal projectors. Recently, liquid-crystal projectors have been required to produce high-quality, bright images of high contrast in bright atmospheres, e.g., those in living rooms. As a result, a lamp as a light source produces high output for brighter images, which tends to increase temperature in an aperture device for light intensity adjustment. Light-shielding films for light intensity adjustment, when irradiated with light of high output, are placed in atmospheres in which they tend to thermally deform.
Light-shielding films with a base of polyethylene terephthalate or the like have been widely used because of their low specific gravity. However, polyethylene terephthalate has a low thermal deformation temperature and low mechanical strength, e.g., modulus of elongation, with the result that light-shielding blades of polyethylene terephthalate may be deformed by vibrations and shocks evolving in the service or braking period as output of light sources.
Moreover, light-shielding films are matting-treated by sand blasting to have low surface gloss and high sliding characteristics. This treatment brings another effect of improving image visibility by scattering incident light to decrease surface gloss. This treatment is considered to prevent deterioration of sliding characteristics, because of controlled growth of contacting area between the light-shielding films even when they come into contact with each other.
Digital cameras, digital video cameras and liquid-crystal projectors inevitably include a plurality of light-shielding films as shutter or aperture blades which work while overlapping each other. Light-shielding films which include an organic light-shielding material, lubricant and delustering agent have been subjected to severer service conditions, e.g., temperature or humidity, in digital cameras, digital video cameras and liquid-crystal projectors. In liquid-crystal projectors, in particular, temperature inside of their devices (light-intensity adjusting devices, aperture devices and so forth) is increasing to near 200° C., as output of light sources, e.g., lamps to produce images of higher brightness, increases, as discussed above. In these severe environments, the conventional light-shielding films described above show unfavorable conditions, e.g., deformation or discoloration, and cause practical problems.
Light-shielding films, when used at high temperature of 200° C. or higher, will be greatly deformed by heat, even when they have a fine irregular structure on the surface, with the result that they can no longer work at a high speed when they come into contact with each other, and have deteriorated sliding characteristics and surface gloss because they are grazing with each other more frequently irregularly. As a result, the devices in which they are used, e.g., digital cameras, digital video cameras or liquid-crystal projectors, may no longer exhibit their intended functions.
Matting treatment of a plastic film as a base forms fine irregularities on the surface to bring effects of improving adhesion between the base and coating film with which the base is coated and reducing surface gloss. Sand blasting, however, provides film surface roughness which depends on material and particle size of a shot material and pressure at which it is ejected, among others. A shot material of large particle size may be removed from the surface by an adequate method, e.g., washing or flushing with water. A shot material of fine particles smaller than 1 μm, on the other hand, cannot be completely removed, and the particles remain on the surface in no small quantity, even it is washed. The remaining shot material may cause separation of the film, e.g., light-shielding film of metal alloy formed on the base film, and also separation of the residual shot material from the film at high temperature to which the light-shielding film is exposed, because of a thermal stress created by differential thermal expansion coefficient between the shot material and film. These troubles can have adverse effects on the surrounding parts, and a device in which the film is used may no longer exhibit its intended functions.
Patent Documents
[Patent Document 1]: JP-A-1-120503
[Patent Document 2]: JP-A-4-9802
[Patent Document 3]: JP-A-2-116837
[Patent Document 4]: JP-A-2000-75353

Heat-resistant, light-shielding film, production thereof, and aperture and light intensity adjusting device using the same

Abstract: The heat-resistant, light-shielding film comprising a heat-resistant resin film base (A) resistant to 200° C. or higher, coated, on one or both sides, with an Ni-base metallic film (B) having a thickness of 50 nm or more by sputtering and then with a low-reflectivity film (C) of Ni-base oxide also by sputtering, and having a surface roughness (arithmetic average height Ra) of 0.1 to 0.7 μm.


A remote-controlled system and method for transporting trash comprises a carrier with wheels, a remote box having a remote transmitter and a motor, a conveyor bar attached to at least one stand, and a pair of rails. The carrier sits on the rails and moves along the rails based on its communication with the remote box. The box has a remote transmitter and a motor component that commands the carrier to move vertically down the rails at the discretion of a user. The rails are parallel to the conveyor bar and are attached to the remote box on the conveyor bar.

Generally, refuse produced or discharged by residents of a building, such as a multiple dwelling house, an apartment, or the like, has been treated in such a way that the refuse is filled into plastic bags, plastic buckets, or the like by each resident in the building, and the bags or the buckets are brought by each resident from each room to an established refuse accumulation area or site on the lowest floor. For example, a resident brings one or more plastic bags that are filled with refuse, gets on an elevator box or goes down the stairs on foot to the established refuse accumulation area, and dumps them out on a predetermined refuse gathering day.
Furthermore, an installation called "trash transporting system" has also been employed, which is provided in a building for conveying refuse. The trash chute system is of a vertically extended hole structure in which a trash chute that is defined by surrounding side walls extends vertically through a building, and has openings in one of the side walls at respective floors through which residents can throw refuse.
When using the trash chute, residents put home refuse in a container, such as a plastic bag or plastic or metal bucket, bring the bag or the like container containing the refuse to the nearest opening, and throw away the refuse into the trash chute. The refuse falls down to the bottom of the chute, at the lowest floor, and is accumulated there. The accumulated refuse is taken out from the bottom portion of the chute at predetermined intervals, e.g., once a day or twice a week.
Various other conventional systems are available that are related to trash chutes. For example: U.S. Pat. No. 5,000,641 to Shimizu Construction Co., Ltd., U.S. Pat. No. 5,762,083 to Skyscraper Cleaning Services Inc., U.S. Pat. No. 8,196,735 to Masami Sakita, U.S. Pat. No. 6,196,240 to Howard Liao, Hen Liao, Gun Je Liao, Han-Pin Liu, Chih Hsiung Kuo, and U.S. Pat. No. 4,285,624 to Herman Miller, Inc.
The conventional trash transporting methods described above have various problems. For example, carrying the refuse to the accumulation site on foot is a time-consuming job for residents, and a bad smell is discharged from the refuse and hangs in the air when carrying the refuse from each home to the accumulation site. Also, in the former case, the comfortable or hygienic environment in the home is disrupted by the bad smell or similar discharge by the refuse which the residents are compelled to keep in the room in order to avoid dumping it in a public space, such as the accumulation site on the day or days other than the specified gathering days. In the case of the trash chute, the refuse also adheres to the inner walls of the trash chute, and the adhering refuse gives off a bad smell in the air.
The present invention provides a remote-controlled trash transporter system for household purposes or the like that transports the trash from one place to another by means of using a remote controlled trash bin. This system allows for the transportation of garbage without contaminating the building. It also transports garbage without manpower and it is simple and inexpensive to manufacture. Furthermore, the system is simple to use.

Remote-controlled system and method for transporting trash


A syringe includes a threaded plunger disposed for axial movement within a housing. When it is designed to aspirate a fluid into the syringe barrel, a cam member mounted on the barrel is moved to a free flow position in which it is disengaged from the plunger to allow the plunger to be freely axially movable along the barrel. When it is desired to inject the fluid, such as into an angioplasty balloon, the locking cam is moved to an engaged or locking position, in which it threadably engages the plunger, such that the plunger can only be moved along the barrel in small, controlled increments by rotating the plunger, thereby to enable the operator to achieve the desired accurate control over the fluid pressure in the syringe.

Syringes have been commonly used for many years in medical applications to inject a fluid into a patient. In recent years, syringes have been used to inject a fluid into a patient's blood vessel in the performance of an angioplasty procedure, a relatively common procedure used to remove, or at least reduce, the amount of blockage typically caused by an accumulation of plaque that may have occurred in a blood vessel, commonly an artery.
In an angioplasty procedure, a balloon-tipped catheter or balloon is inserted into the artery involved in the procedure. Thereafter, a fluid is injected at an accurately controlled, relatively high pressure, in the order of 25-30 atmospheres, into the balloon or catheter to inflate the balloon. As the fluid fills the balloon, the latter inflates to fill the artery, thereby to compress the plaque in the artery. The physician then withdraws the fluid from the balloon causing the balloon to deflate, after which the catheter is removed from the patient.
A syringe is the preferred device used by physicians to introduce fluid into the balloon catheter. It has been found, as described in U.S. Pat No. 5,047,015, that in order to provide sufficient fluid pressure as well to achieve precise control over the fluid pressure, it is advantageous to employ a threaded plunger which can be freely, rapidly, axially reciprocated in a barrel, particularly when the balloon is being deflated. When greater control of fluid pressure, as well as a mechanical advantage to provide increased pressure, is desired, the threaded plunger engages mating threads on the interior surface of the barrel. When the plunger and barrel are thus threadably engaged, the syringe is locked, such that free, sliding, reciprocating movement of the plunger in the barrel is prevented. The plunger, however, in this condition or mode of operation can be screwed into, and thereby moved axially along the barrel in precisely controlled increments.
In the syringe described in the aforesaid U.S. Patent, transition of the syringe between the locked, threaded mode and the freely reciprocating mode of operation is achieved by the manual operation of an actuating trigger mechanism. Although this syringe is generally effective to achieve the desired high pressure and accurate control over the fluid pressure, the actuating trigger mechanism is relatively complex and is made up of a relatively large number of components, which adds to the overall cost of the syringe. There is thus a need for a syringe for use in angioplasty and related procedures that provides the precise control over the high fluid pressure required in such a procedure with a syringe that is less complex and less costly than those presently available.


Disclosed herein is a method for making and screening a combinatorial library comprising disposing in a substrate comprising boron, boron nitride, or boron carbide at least one reactant, wherein the reactants are lithium, magnesium, sodium, potassium, calcium, aluminum or a combination comprising at least one of the foregoing reactants; heat treating the substrate to create a diffusion multiple having at least two phases; contacting the diffusion multiple with hydrogen; detecting any absorption of hydrogen; and/or detecting any desorption of hydrogen.

This disclosure is related to hydrogen storage compositions and methods of manufacture thereof.
Hydrogen is a "clean fuel" because it can be reacted with oxygen in hydrogen-consuming devices, such as a fuel cell or a combustion engine, to produce energy and water. Virtually no other reaction byproducts are produced in the exhaust. As a result, the use of hydrogen as a fuel effectively solves many environmental problems associated with the use of petroleum based fuels. Safe and efficient storage of hydrogen gas is, therefore, essential for many applications that can use hydrogen. In particular, minimizing volume and weight of the hydrogen storage systems are important factors in mobile applications.
Several methods of storing hydrogen are currently used but these are either inadequate or impractical for wide-spread mobile consumer applications. For example, hydrogen can be stored in liquid form at very low temperatures. However, the energy consumed in liquefying hydrogen gas is about 40% of the energy available from the resulting hydrogen. In addition, a standard tank filled with liquid hydrogen will become empty in about a week through evaporation; thus dormancy is also a problem. These factors make liquid hydrogen impractical for most consumer applications.
An alternative is to store hydrogen under high pressure in cylinders. However, a 100 pound steel cylinder can only store about one pound of hydrogen at about 2200 psi, which translates into 1% by weight of hydrogen storage. More expensive composite cylinders with special compressors can store hydrogen at higher pressures of about 4,500 psi to achieve a more favorable storage ratio of about 4% by weight. Although even higher pressures are possible, safety factors and the high amount of energy consumed in achieving such high pressures have compelled a search for alternative hydrogen storage technologies that are both safe and efficient.
In view of the above, there is a need for safer, more effective methods of storing and recovering hydrogen. In addition, there is a desire to minimize the overall system volume and weight.

Hydrogen storage compositions and methods of manufacture thereof


A disinfecting solution includes hydrogen peroxide at a concentration of from about 1.5% w/w to 8% w/w; at least one readily biodegradable anionic surfactant in a concentration of from about 10% w/w to about 25% w/w; at least one of salicylic acid and salts thereof, in a concentration of from about 1% w/w to about 8% w/w; at least one chelating agent in a concentration of from about 0.005% w/w to about 10% w/w; and at least one low-corrosive non-surfactant sulfonic acid selected from benzenesulfonic acid, benzene disulfonic acid, xylene sulfonic acid, toluene sulfonic acid, cumene sulfonic acid, sulfosalicylic acid, naphthalene mono- or di-sulfonic acid, methane sulfonic acid, and isethionic acid in a concentration of from about 1% w/w to about 15% w/w. The solution is free of acetic acid, furoic acid, phenylacetic acid, cationic surfactants, amphoteric surfactants, aromatic alcohols, halogen acids, phenols, peracid activators, bleaches, and (optionally) benzoic acid.

A wide range of disinfectants is known, as discussed for example in Disinfection, Sterilization, and Preservation, edited and partially written by Professor Seymour S. Block, Fifth Edition, published 2001 by Lippincott Williams & Wilkins, Philadelphia. Certain peroxygen compounds, chlorine compounds, phenolics, quaternary ammonium compounds and surface active agents are known for their germicidal properties. The rate of disinfection is relatively slow in many cases, and some compounds emit volatile organic compounds or leave a persistent and/or toxic residue in the environment.
Peroxide compounds, including hydrogen peroxide, are finding favour in many applications because their breakdown products, water and oxygen, are innocuous. Furthermore, they tend to have a broad spectrum of antimicrobial activity which is important in situations where harmful organisms are present but their identity is not known. However, even "broad spectrum" disinfectants may not be effective to kill all organisms or may harm the environment or user.
Formulating commercially viable hydrogen peroxide solutions is quite challenging. Desirable properties are often at odds with each other. For example, it is desirable to provide concentrated solutions that can be diluted by the end user prior to use, to save costs in terms of storage and transport. However, solutions containing 8% w/w or higher of hydrogen peroxide can be corrosive and hazardous to handle. On the other hand, solutions with lower hydrogen peroxide concentrations may be ineffective at high dilution ratios, e.g. at ratios of 1:40 or 1:64. Likewise, it is desirable to make solutions, that are antimicrobially-effective, low in toxicity, low in corrosiveness, biodegradable, and low in volatility. However, doing so can lead to instability of the peroxide in solution.
Therefore, a need still exists for a shelf-stable, commercially viable, hydrogen peroxide solution that is (at least) effective at high dilution ratios and environmentally-friendly.

Shelf-stable hydrogen peroxide antimicrobial compositions