A composition of matter for the self-pressurized (aerosol) spraying of dusters and similar products. The composition includes a fluorinated propene-based propellant and fluorinated butene-based volatile solvent. The composition is totally non-flammable under all reasonably foreseeable conditions of use. The fluorinated propene-based propellant may include trans-1,3,3,3-tetrafluoroprop-1-ene, as typified by Honeywell Fluorine Products Division's SOLSTICE® HFO-1234ze(E) product. The fluorinated butene-based volatile solvent may include cis. (or cis./trans.) 1,1,1,4,4,4-hexafluoro-2-butene, as typified by the DuPont Fluorochemicals Division's FORMACEL® 1100 (HFO-1336mzz) product. The fluorinated propene-based propellant component may be present at about 60 to 95%. The fluorinated butene-based volatile solvent component may be present at about 5% to 40%, but preferably between about 20% to 25% and ideally at about the azeotropic concentration of about 22%. Some or all of the fluorinated butene based component may be replaced with up to about 25% of a totally non-flammable component, such as iodotrifluoromethane (CIF.sub.3).

Self-pressurized (aerosol) dispensers for dust removal have been marketed since at least about 1960. They were originally formulated using 100% CFC-12 (dichlorodifluoro-methane), or sometimes 100% CFC-114 (sym. dichlorotetrafluoroethane), which are totally non-flammable. The non-flammability of these products permitted them to be safely used, even near open flames, or where electrical or electronic equipment might generate sparks with sufficient energy to ignite potentially flammable sprays. When the CFC propellants were almost entirely banned by the U.S. government, as of 1 Apr. 1978, the industry reformulated the aerosol duster products to utilize a totally non-flammable blend of 40% HCFC-22 (monochlorodifluoromethane) and 60% HCFC-142b (1-chloro-1,1-difluoroethane). Marketers then faced two problems. The HCFC-22 was discovered to be a very weak mutagen, and the method of operation—by emitting gas from the vapor space above the liquid—resulted in the depletion of the more volatile, totally non-flammable HCFC-22 during use, so that the sprayed vapors gradually become so enriched with HCFC-142b that they became slightly flammable. More HCFC-22 could not be added to the formulation because the internal pressure would then exceed the 180 psi-gauge limit at 130 F. (degrees Fahrenheit) under U.S. DOT (Department of Transportation) regulations. With no other course of action the aerosol duster industry tolerated these problematic circumstances until about 1993, when the U.S. EPA (Environmental Protection Agency) banned the two propellants after determining that they, like the CFCs, were capable of stratospheric ozone deletion. The duster industry went into a brief decline until 1994, when DuPont (E.I. DuPont de Nemours and Company, Inc.) introduced HFC-134a (1,1,1,2-tetrafluoroethane) as a totally non-flammable propellant. Although it was primarily designed to be used in such pharmaceuticals as MDIs (Metered Dose Inhalants), the propellant proved useful for aerosol dusters and certain other products. Unfortunately, it had a vapor pressure of about 202 psi-gauge at 130 F. and thus it exceeded the DOT regulations for interstate transportation. The issue was quickly resolved by the use of so-called "pressure relief" aerosol cans, where three-piece tinplate cans were produced with approximately 12 tiny, work-hardening notches upon the top of the top double seam. When a can might be accidentally heated, causing an exorbitant rise in internal pressure, the dome (or top section) would rise, permanently deforming and eradicating the countersink and causing the notched locations to open, lense-like, and release the propellant safely, well below the pressure range at which the dispenser might burst. A two-piece aerosol can was also developed, where the base section was precisely indented so that, when it inverted due to excess pressure, the crescent-shaped indented area would crack and open, allowing the rapid and safe discharge of propellant. All these aerosol cans, with their heavy pressure resistant construction and specialized pressure relief fitments, are known as "DOT Specification 2Q—exempt" dispensers and are unusually high in cost.
From 1995 to about 2010 virtually all aerosol dusters used 99.9 to 100.0% HFC-134a. (The 99.9% formulas contain a very small amount of a repugnant additive, designed to counteract a life threatening incident where a person deliberately concentrates propellant vapors and inhales them deeply, hoping to get a brief psychedelic "high".) Since about the year 1998 concerns about the environmental compatibility of HFC-134a have greatly increased. It is a well-recognized global warming agent, with a potential 1320 times as great as carbon dioxide. For over a decade DuPont and other HFC-134a suppliers have utilized multi-disciplinary committees to either approve or disapprove the sale of HFC-134a to prospective buyers. They consider the product type, the requirement in tons per year, if an alternative propellant could be used and other factors; but the most important is the intended use. If the HFC-134a would contribute to life safety and health the committee might approve the request. But for ordinary, and certainly for frivolous products, the application would be denied. The aerosol duster products, while approved to use HFC-134a, have long been considered borderline. The situation became more critical in 2008, when the California Senate passed their SA-32 Bill into law. It directed CARB (California Air Resources Board) to undertake immediate actions to reduce, to the greatest extent possible, the manufacture and use of HFCs and other global warming chemicals. The CARB regulators quickly selected aerosol dusters as their first targeted product. After a number of studies they concluded that the HFC-134a could be safely replaced with HFC-152a (1,1-difluoroethane), a much less potent global warming agent, with a potential of only about 134 times that of carbon dioxide. Unfortunately, HFC-152a is somewhat flammable, eliminating its safe use in certain areas where ignition sources might be present. The final result was that HFC-152a has now replaced HFC-134a in about 80 to 85% of the aerosol dusters sold in California. At least one NGO (Non-Governmental Organization) has pointed out that the combustion or pyrolysis of HFC-152a produces HF (hydrogen fluoride) an extremely poisonous and corrosive gas, with a mammalian toxicity somewhat greater than that of HCN (hydrogen cyanide). More recently, about 2009, the U.S. Congress directed the U.S. EPA to develop regulations that would act to phase out the HFCs and certain other global warming agents within about a decade. The assignment is very complicated and slow, but the agency has announced that the first reduction, to 83% of the benchmark year of 2005, will be finalized soon. The program is a slow one because it will affect not only aerosols, but air-conditioners, food freezants, foaming agents and other uses, unless they are exempted.
Until rather recently the mix of private and government restrictions on HFC-134a—the only available totally non-flammable propellant—were very unsettling to duster product marketers. The enforced use of somewhat flammable HFC-152a evoked concerns about fires, toxicity and possible lawsuits. Other totally non-flammable propellants, such as HFC-227ea (1,1,1,3,3,3-heptafluoropropane) and HFC-245fa (1,1,1,3,3-pentafluoropropane) were more intense global warming agents than HFC-134a, and often too low in pressure to produce good atomization. But during about 2010 both DuPont and Honeywell (Honeywell Fluorine Products Division) announced that they were developing new products called HFOs (hydrofluoroolefins). DuPont's primary focus was on HFO-1234yf (1,1,1,2-tetrafluoroprop-1-ene) which is only slightly flammable and considered suitable for automobile air-conditioning systems as a replacement for HFC-134a. Pilot plant quantities were available, while a major production facility was being constructed in the People's Republic of China. The isomeric product created by Honeywell was of greater interest. It is known as HFO-1234ze(E) (trans-1,3,3,3-tetrafluoroprop-1-ene) which is even less flammable, and actually totally non-flammable at temperatures below about 26 C. (degrees Celsius) (79 F.). Pilot line quantities were available from Buffalo, N.Y., while a major production facility was being constructed in the company's plant at Baton Rouge, La. Both products, being olefins, were found to be destroyed by atmospheric OH′ (hydroxyl free radicals) at rates about 320 times as fast as the corresponding HFC compounds. As a result they have very brief half-lives in the atmosphere and very low GWPs (Global Warming Potentials). The physical and toxicological properties of HFO-1234ze(E) are presented in FIG. 1.
While a few U.S. and European marketers have marketed aerosol dusters with either pure HFO-1234ze(E) or mixtures of HFO-1234zer(E) and HFC-134a—sometimes with the 0.1% or so addition of deliberate inhalation repellent, as described above, the current high price of HFO-1234ze(E), produced on a pilot line to date, has been a marketing deterrent. The price should decrease significantly when full-scale production begins. The very slight flammability would be a secondary deterrent. This is less easily correctable and forms the basis of this Patent Application.
As is well known to physicists, most chemists and chemical engineers, when two liquids of different volatility are mixed and form a solution, the gas phase above the solution will usually contain more of the volatile ingredient than the solution. This is the basic principle of fractional distillation, used to separate liquids of different volatility. An example would be the separation of propane and iso-butane. Propane has a pressure of 122 psi-absolute at 21 C. (70 F.), while iso-butane has a pressure of 45 psi-absolute at 21 C. (70 F.)—or about 37% that of propane. Thus, the vapor above a solution of 50% propane and 50% iso-butane will be about 82% propane and 18% iso-butane by weight. (A more accurate calculation must be on a molar basis.) The calculation will be valid for binary mixtures where the molecules of the two components are neutral to each other. In these ideal situations the molecules neither attract nor repel each other.
Much less commonly and less well known are situations where molecules repel each other. In binary mixtures of polar and apolar liquids, for example, the molecules will usually repel each other and this will lead to pressures that are higher than those that can be calculated on the basis of ideal liquids. In some cases, especially where the two liquids have similar individual pressures, the pressure developed by certain mixtures may be higher than that of the pure, more volatile liquid. When graphed, often on a mol-percent basis, the solution pressure can be seen as a humped up or upward arching curve. The composition at the highest point of this curve is called the azeotropic blend, and the pressure at that point is called the azeotropic pressure. At the azeotropic condition the compositions of both liquid and vapor are the same. More specifically, this is known as the positive azeotrope. Even more rarely, there are certain liquid solutions where the different molecules have an affinity or attraction for each other. In such cases the pressures are suppressed to levels below the theoretical values. When graphed the pressure trace will be seen to droop downward forming a catenary curve. If the lowest point is below the pressure of the less volatile component it is called the negative azeotropic pressure or composition.
Since aerosol propellant blends at the positive azeotropic composition have the same composition in both the liquid and vapor phases, it follows that any release of the vapor through an aerosol valve will not change the composition of the liquid phase. If this condition could be established for a totally non-flammable propellant blend, the result would be of great interest for such products as dusters, portable boat horns, freezants for the testing of electronic circuit boards and other specialized applications. Conversely, if a mixture behaved in the most commonly seen ideal fashion, or even with molecular attractions but not capable of producing a positive azeotrope, then as the vapor phase of the duster type aerosol is dispensed, the composition of the liquid would progressively change, leading to a much higher concentration of the less volatile component and the development of a lower delivery rate and a less effective spray, sometimes with a streaming center portion. Such products would be unacceptable in the market.
The Honeywell HFO-1234ze(E) propellant, introduced to the aerosol industry in a trade journal article (Spray Technology & Marketing, May 2011), disclosed that mixtures of between 7.7 and 8.7 volume-percent HFO-1234ze(E) gas in air, at 30 C. (86 F.) were flammable, according to an official ASTM E 681 test method. Upon request, other documents were obtained from Honeywell, showing that the flammable range rapidly increased with rising temperatures. This is a very common occurrence. Using the additional Honeywell LFL (Lower Flammability Limit) and UFL (Upper Flammability Limit) data a graph was constructed showing the flammable range as a function of gas concentrations and temperature. Based upon a very modest graphic extrapolation it was then established that a mixture of about 8.2 volume-percent HFO-1234ze(E) gas in air would become potentially flammable at temperatures equal to or greater than 26 C. (79 F.). When an aerosol of the duster type is actuated the gas-air mixture will range from very concentrated gas near the spray head to ultimately very dilute gas compositions as the gas becomes progressively more and more admixed with the large mass of surrounding air. During this transition, if the ambient temperature is 26 C. (79 F.) or higher, compositions in the flammable range will be produced.
At a temperature of 40 C. (104 F.) the flammable range became considerably enlarged, extending from 6.6 to 10.0 volume-percent of the gas, and at a test temperature of 60 C. (140 F.) the flammable range became quite significant: from 5.8 to 11.3 volume-percent of HFO-1234ze(E). The State of California has determined that about 15% of all aerosol dusters are used in areas where free flames are present. They are usually in industrial settings. In other situations high-energy electrical sparks may be encountered where warm air or equipment can cause the large MIR (minimum ignition energy) of HFO-1234ze(E) to be exceeded and produce an ignition. In Japan, where their equivalent of the ASTM E 681 test is conducted at 30 C. (86 F.), HFO-1234ze(E) is classified as flammable.
Reducing the admittedly slight flammability of HFO-1234ze(E), and thus contributing to life safety and health, was the primary focus of the research program. This had to be done by the addition of the smallest possible amount of totally non-flammable liquids or gases. Ideally, the additives would have to be environmentally compatible, commercially available and be toxicologically innocuous. They had to be colorless, essentially odorless, and soluble in the HFO-1234ze(E) primary ingredient. Carbon dioxide was considered, for instance, but only about 1.5% could be added before the pressure in the aerosol dispenser reached the U.S. DOT imposed limit of 180 psi-gauge at 54.4 C. (130 F.). Water might have been useful, except that it was almost totally insoluble in HFO-1234ze(E). HFC-134a could have been a candidate but for its high global warming potential and concomitant regulatory problems. Other totally non-flammable HFC propellants had similar problems. A rather exotic compound: iodotrifluoromethane (CIF3), was considered, but it was determined to be a non-commercial gas-liquid. Finally, we came across a volatile liquid, developed by DuPont and known as HFO-1336mzz (1,1,1,4,4,4-hexafluorobut-2-ene). It was designed to function as a totally non-flammable foaming agent for plastics, used in mattresses and upholstered furnishings. It was not yet TSCA (Toxic Substance Control Act) approved for marketing purposes, but had all the desired attributes except one: it was a liquid boiling at 33.4 C. (92.1 F.). Additional physical and toxicological properties are described in FIG. 2.
Initially, the HFO-1336mzz was of minor interest, since it was so low in pressure that it was thought to accumulate in the liquid phase of the aerosol dispenser as the vapor phase was dispensed. This would create low delivery rate and very coarse spray problems, as described above. The possibility of azeotropy was dismissed because HFO-1234ze(E) and HFO-1336mzz, being hydropolyfluorinated olefins, were so similar in electronic molecular composition and configuration that this highly desirable effect was deemed impossible. Nevertheless, a sample was obtained from DuPont and several aerosol formulations were produced for testing purposes. The spray patterns were excellent, and when pressures were taken at the aerosol reference temperatures it was discovered that the 21 C. (70 F.) pressures clearly demonstrated an azeotropic condition. Surprisingly, there was no azeotropy at 54.4 C (130 F.), although pressures were higher than those calculated for an ideal system. The lack of azeotropy at the higher temperature is academic, since aerosols are never sprayed with the dispensers heated to 54.4 C. (130 F.). Pressures at this temperature are only taken to assure compliance with U.S. DOT regulations. Additional studies showed that azeotropy remained present to at least 36 C. (97 F.). This would show that the very beneficial azeotropic condition would be in existence for all reasonably foreseeable temperatures at which the aerosol duster dispensers would be used.
U.S. regulators have a long history of applying certain test procedures and pass/fail criteria to aerosols, primarily used for warning labels and the marking of outer shipping cartons. Safety aspects, such as pressure limits and filling limits (as a percent of dispenser capacity) are also regulated. In the complex area of aerosol flammability we have the Flame Propagation Test, used by the U.S. CPSC (Consumer Product Safety Commission), the U.S. EPA (Environmental Protection Agency), and formally by the U.S. DOT (Department of Transportation). It requires that the aerosol, first equilibrated to 21 C. (70 F.), be sprayed through the top third of a candle flame from a distance of 152 mm. (6 inches). If the spray ignites, producing a fire plume longer than 457 mm. (18 inches) from the candle the dispenser of that product must be labeled with the signal word "Flammable" followed by standard precautions—provided the dispenser capacity is 118.2 ml (4 fluid ounces) or greater. This does not mean that products passing this test may be labeled as "Non-Flammable", unless they also pass the ASTM E 681 Test. Quite often they may just have a somewhat lesser degree of intrinsic flammability, such as the ability to produce a flame only 406 mm (15 inches) long.
A second test is the Closed Drum Test (in Europe, the Enclosed Space Test). While currently obsolete in the U.S. it is currently used in Europe, Japan, by other nations, and by certain international transportation organizations, such as IMO (International Maritime Organization) and IATA (International Air Transport Agency). In the interest of global harmonization of aerosol labeling and shipping both the FEA (Federation of European Aerosol Associations—representing 17 countries) and the UN (United Nations) are seeking to re-establish this test in the U.S. The test consists of spraying a fixed amount of aerosol product into a 205 liter (55 U.S. Gallon) metal drum or similar vessel, which is laid on its side and contains a lit candle or gas burner. The open end of the drum is covered with a thin film of polyethylene, in which a 200 mm. (8 inch) slit has been made. If the LFL is reached within the time or weight limit a large volume of flame will be produced, normally accompanied by a "whooshing" sound, and with heat and pressure sufficient to rupture the plastic film. Here again there will be aerosol products that will pass the test but would fail it if more product entered the drum. Aerosols that pass this test must not be labeled as "Non-Flammable", unless they also pass the ASTM E 681 Test. In a few cases they have been legally labeled as "Non-Flammable by the Closed Drum Test", or the equivalent. Even these modified warnings can lead to consumer confusion and possible misuse of the product.
A listing of the official aerosol flammability tests, including the two described above, is presented as follows:                a. The Flame Propagation Test.        b. The Flashback Test.        c. The Closed Drum Test. Japan, IMO, IATA, et al.)        d. The Ignition Distance Test (Europe and the U.N.)        e. The Enclosed Space Test (Europe and the U.N.)        f. The Foam Flammability Test (Europe and the U.N.)        g. The U.S. CPSC Open Cup Flash Point Test        h. The U.S. EPA Open Cup Flash Point Test.        i. Other tests have been published, such as the Closed Cup Flammability Test and the 200 C. (392 F.) Preheated Hot Plate Test, but they have no official sanction.
All of these tests are used to differentiate aerosols according to their relative flammability. None of them, either individually or in concert, can be used to qualify an aerosol product as "Totally Non-Flammable", "Almost Completely Non Flammable" or "Non-Flammable". However, in the USA and Canada there are no laws or regulations that would prevent an over-jealous marketer from marking his aerosol product as being "Non-Flammable" or the equivalent, provided it passes that country's applicable official flammability tests. The primary deterrent for companies considering such labeling is being accused of "failure to warn" or "misleading labeling" in the event of an accident involving fire. A secondary deterrent is that the U.S. FTC (Federal Trade Commission) may respond to complaints from competitors and determine that such products are labeled with false advertising statements.
In the USA the only test for establishing "Non-Flammability" is the ASTM E-681 (American Society for Testing Materials Method E-681) assay. The test equipment utilizes a five liter (c.a. 1.2 U.S. Gallon) pressure resistant glass flask with an enclosed sparking device. A precisely measured amount of the aerosol product is introduced, the atmospheric pressure in the flask is restored to the ambient air pressure, and the sparking device is actuated. The test is typically conducted at 68 F. If no flame propagation occurs, that particular gas-air mixture is deemed to be non-flammable. The testing is continued, using a multiplicity of gas-air mixtures. Flammability is said to occur if a flame is produced that reaches the wall of the container. The effect must occur at an angle greater than 90 degrees from the spark source. For a gas to be considered flammable, a positive result must occur at a gas concentration of less than 12 volume percent. The term "gas", as used in the test, means a fluid (including mixtures) with a boiling point of 20 C. (68 F.) or lower, under the atmospheric condition of 760 mm. of mercury absolute pressure.
The lowest concentration of gas in air that produces the above flame propagation is known as the LFL (Lower Flammability Limit). The highest concentration of gas in air that still produces the above flame propagation is designated as the UFL (Upper Flammability Limit.). The terms LEL and UEL are used interchangeably with LFL and UFL, resp. The "E" stands for "Explosive". The "window of flammability" between the LFL and UFL is described as the "vapor flame limits" or "flammable range". Gases that exhibit a flammable range at 20 C. (68 F.) are considered to be "Flammable" by this test. Conversely, gases that fail to produce an LFL or UFL at 20 C. (68 F.) are considered to be "Non Flammable". During the last decade the test has been expanded by those seeking to demonstrate that a gas or gas mixture remains non-flammable at such elevated temperatures as 40 C. (104 F.), 60 C. (140 F. and even 100 C. (212 F.). This is because some gases that are marginally non-flammable at 20 C. (68 F.) may become flammable as the temperature is increased. This is the case with HFO-1234ze(E), which becomes flammable at about 26 C. (79 F.), and with the flammable range widening significantly as the temperature is further increased. This is demonstrated by the graph in FIG. 3. In contrast, DuPont has shown that HFO-1336mzz (a key factor in this Patent Application) remains non-flammable, even when tested at 100 C. (212 F.).
The European counterpart to the ASTM E-681 test is the EU A11 test. The apparatus consists of a 56 mm. (2 inch) inside diameter by 304 mm. (12 inch) long glass tube with an internal ignition source composed of an electric sparking device that lights a match. The procedure and assessment criteria are similar to those applied in the ASTM E-681 method.
To positively define the flammability or non-flammability of their HFO-1234ze(E) product Honeywell tested it using both the ASTM E-618 and EU A11 test methods. Their results are summarized as:
Method ASTM E-618:                a. At 68 F. No flammability. (No LFL or UFL.)        b. At 86 F. LFL=7.8 volume-% and UFL=8.7 volume-%. (Flammable.)        c. At 140 F. LFL=5.8 volume-% and UFL=11.3 volume-%. (Flammable.)        d. At 212 F. LFL=5.8 volume-% and UFL=11.8 volume-%. (Flammable.)
Method EU A11:                a. At 73 F. No flammability. (No LFL or UFL.)        b. At 212 F. LFL=7 volume-% and UFL=12 volume-%. (Flammable.)
One may conclude from this rather intensive testing that Honeywell's HFO-1234ze(E) begins to develop a flammable range at about 26 CF. (79 F.). The range rapidly increases with rising temperature.
Whenever an aerosol is sprayed the gaseous content of the spray becomes increasingly diluted with ambient air. The gaseous concentration then runs from essentially 100% at or very close to the spray actuator terminal orifice, moving ultimately down to essentially 0% when fully diluted with air. During the spraying episode some parts may be ephemerally diluted into the critical area, such as 7.7% to 8.7% if the temperature is at 30 C. (86 F.). If the temperature is 26 C. (79 F.) or higher, and a free flame or intense spark is present as an ignition source, then an ignition may become possible, perhaps with serious consequences. In another scenario, spraying onto a warmed or heated surface may raise the temperature of the spray to the point where combustion may occur if a suitable ignition source is also present. The potential for a fire hazard increases with increasing temperature, since the flammable range broadens.
In considering the addition of totally non-flammable fluids (gases or volatile liquids) to HFO-1234ze(E) to decrease its slight flammability profile we have invoked the approximation that HFC and HFO compounds become non-flammable when their fluorine content is about 67% or higher. This percentage can be determined by dividing the formula weight of the fluorine content (atoms) by the molecular weight of the gas-liquid. The following list illustrates these data for a group of compounds:                a. 63.3% for HFC-152a (1,1-Difluoroethane) Flammable.        b. 66.6% for HFO-1234yf (1,1,1,2-Tetrafluoroprop-1-ene) Slightly flammable.        c. 66.6% for HFO-1234ze(E) (1,3,3,3-tetrafluoroprop-1-ene) Very slightly flammable.        d. 67.3% for a mixture of 78% HFO-12234ze(E) & 22% HFO-1336mzz. Non-flammable.        e. 69.5% for HFO-1336mzz (1,1,1,4,4,4-hexafluoro-2-butene) Non-flammable.        f. 70.8% for HFC-245fa (1,1,1,3,3-Pentafluoropropane) Non-flammable.        g. 74.6% for HFC-134a (1,1,1,2-Tetrafluoroethane) Non-flammable.        h. 76.0% for FC-318 (Perfluorocyclobutane) Non-flammable        i. 82.6% for FC-116 (Perfluoroethane) Non-flammable.
Listed products identified by a, f, g, h, and i have environmental detractions associated with global warming. As can be seen from b. and c. the positions of the fluorine atoms on these isomeric molecules can affect the degree of potential flammability.
Further limitations and disadvantages of traditional aerosol systems will become apparent to one of ordinary skill in the art through a comparison of such systems with the present invention described herein.

Compositions for totally non-flammable aerosol dusters


An adjustable wheelchair foot bracket that is releasably attachable to the footplate of a wheelchair between an attached position and an unattached position. The foot bracket includes an attachment member having a first plate and a second plate disposed in parallel to superimpose upon either side of a wheelchair footplate and frictionally engage the footplate therebetween. A rubberlike foot guard is disposed arcuately normal the attachment member, and curves to shield the foot of a user riding in the wheelchair, around said user's toes to terminate in a position proximal the tarsus of said user's foot. Impacts of the foot guard with objects externally situated relative the wheelchair act to compress the foot bracket directionally toward the attached position, whereby the attached position in maintained during use.

Various types of wheel chair foot accessories are known in the prior art. However, what is needed is an adjustable wheelchair foot bracket that includes at least one attachment member and at least one foot guard, said attachment member readily attachable to an extant wheelchair footplate, whereby a foot, resting upon said footplate, is protectable from impact with external objects.


A prism sheet includes: a first portion including a prism elongated in a first direction; and a second portion including a prism elongated in a second direction different from the first direction. The second direction is vertical to a light incident surface of a light guide plate of a backlight unit, a light source of the backlight unit faces the light incident surface of the light guide plate, and the prism sheet overlaps a light emitting surface of the light guide plate.

(a) Field
The invention relates to a prism sheet, a backlight unit including the same, and a method of manufacturing the same.
(b) Description of the Related Art
In accordance with size and weight reductions of display devices based on a rapidly developed semiconductor technology, a demand for flat panel displays having improved performance is explosively increasing.
Among the flat panel displays, a liquid crystal display ("LCD") which has come into the limelight has advantages such as reduced size and weight, and low power consumption. Thus, the LCD has received attention as an alternative display device which overcomes drawbacks of a display device including a cathode ray tube ("CRT"), such that the LCD is mounted and used in almost all information processing devices requiring a display device.
The LCD generally includes a LCD display panel which includes a liquid crystal material between an upper substrate in which a common electrode, a color filter and the like are disposed, and a lower substrate in which a thin film transistor, a pixel electrode and the like are disposed. The LCD displays an image by applying different potentials to the pixel electrode and the common electrode to form an electric field in the liquid crystal material, thus changing the arrangement of liquid crystal molecules of the liquid crystal material to adjust transmittance of light passing through a liquid crystal layer including the liquid crystal material.
In the LCD, since the LCD panel is a non-emissive element and uses light from a separate light source, the LCD includes a backlight unit providing light to the LCD panel at a lower portion of the LCD panel. The backlight unit includes a light source, a light guide plate, a reflection sheet, optical sheets and the like.
In the backlight unit, the light source may be a fluorescent light source such as cold cathode fluorescent lamp ("CCFL"), or may adopt a light emitting diode ("LED"). Further, in the backlight unit, the light source may be positioned under the light guide plate or may be positioned adjacent to a lateral surface of the light guide plate.

Prism sheet, backlight unit including the same, and method of manufacturing the same


The disclosed technology relates to a mobile terminal adapted to receive a memory card comprising a processing unit, an input interface and a card locking actuator configured to lock the memory card into the mobile terminal. The card locking actuator is controlled by the processing unit. In one aspect, the card locking actuator is configured to be locked when the mobile terminal is switched on. In another aspect, the processing unit is configured to lock the screen until a screen unlocking authentication procedure is performed by a user at the input interface and is configured to command unlocking of the card locking actuator after detecting that a predetermined authentication procedure is performed by a user at the input interface.

Mobile terminals such as smartphones generally receive small memory cards such as subscriber identification module (SIM) cards (for securely storing the international mobile subscriber identity (IMSI) number and its related key, to identify and authenticate a subscriber on mobile networks), or Secure Digital (SD) cards (for external storage of data).
These memory cards are either directly inserted into a slot of the mobile terminal, or placed into a dedicated tray within the mobile terminal.
In both cases, the memory card can be easily mechanically pulled out (by grasping its extremity with the nails, by pushing it so as to trigger a spring, or by inserting a thin stick into a specific hole, etc.).
This can become a problem if the terminal is lost or stolen.
Indeed, even if most of mobile phones have a screen lock set by the user preventing third party to use them, the ability to locate and get contact with the lost or stolen terminal (for instance to erase the data or even to make the terminal unusable) can be disabled by a thief, simply by turning off the mobile phone, or extracting the SIM card in order to cut off the connection to network. What's worse, the thief can eliminate the original lock by reinstalling the terminal system through a computer.
The thief may also easily pull any other memory card out from the terminal and get the user's personal information or data.
There is consequently a need for a solution to prevent pulling a SIM or another memory card out from the terminal without the consent of the user, and generally for improving the safety of mobile terminals in case of theft.
To this end, solutions have been proposed wherein a SIM card cannot be easily mechanically extracted.
In particular, document CN101330681 relates to old mobile phones wherein the SIM is located under a removable battery in the phone. In this document, when activating a "safety mode", the user ability to turn off the terminal is disabled and the battery is physically locked. Thus, a theft cannot turn off the terminal normally, or by just detaching the battery, so that the mobile phone is kept in power on state all along during the period of time before the battery is exhausted. Such a solution can allow the owner more time to locate, trace and find a stolen terminal, or at least clear up the important data in the lost phone by sending instructions to it, before it is "powered off".
However, such a solution is not adapted to recent mobile terminals, such as smartphones, wherein the battery is embedded and not removable. Besides, this solution presents a serious drawback, as the user has to deactivate the safety mode when he wants to turn the terminal off, so there is a risk for the user to forget turning on this safety mode back later.
There is consequently a need for an improved anti-theft solution for mobile terminals, more adapted to recent mobile terminals.

Anti-theft mobile terminal and method for controlling the extraction of a memory card out from a mobile terminal


A variable lift valve operating system for an internal combustion engine, including a variable lift mechanism capable of changing a lift amount of an engine valve in accordance with rotation of a control shaft rotatably supported in a cylinder head, and an actuator which has an electric motor and power transmission means interposed between the electric motor and the control shaft, and which is connected to the control shaft. The actuator is constructed to have an oilless structure without oil supply, thereby always stably and rotationally driving the control shaft.

1. Field of the Invention
The present invention relates to a variable lift valve operating system for an internal combustion engine, including: a variable lift mechanism which has a control shaft rotatably supported in a cylinder head, and which is capable of changing a lift amount of an engine valve in accordance with rotation of the control shaft; and an actuator which has an electric motor and power transmission means that is interposed between the electric motor and the control shaft, and which is connected to the control shaft.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 2005-42642 discloses a valve operating system in which one end portion of a lever is fixed to a control shaft, and the control shaft is rotated by sliding a nut connected to the other end portion of the lever by the rotating operation of a screw shaft on which the nut is screwed, whereby the lift amount of an intake valve is changed.
In such a variable lift valve operating system, when an actuator has a structure which lubricates, with oil, power transmission means interposed between the electric motor and the control shaft, friction in the power transmission means changes due to change in oil viscosity depending on the ambient temperature, and therefore, it is difficult to rotationally drive the control shaft stably at all times.

Variable lift valve operating system for internal combustion engine


A mobile heating system is disclosed. In one embodiment, the system includes an enclosure defining a plenum that houses a fan and an internal combustion engine. The heating system also includes a hydraulic circuit including a hydraulic pump operably coupled to the internal combustion engine and a first heat exchanger located in the plenum and in fluid communication with the hydraulic pump. The hydraulic circuit also includes a hydraulic motor operably coupled to the fan wherein the hydraulic motor is in fluid communication with and driven by the hydraulic pump. A first valve is disposed between the hydraulic pump and the heat exchanger and is configured to restrict fluid flow and to increase a fluid pumping pressure of the hydraulic pump. A second valve is located upstream of the first valve and is configured to selectively direct hydraulic fluid between the first valve and the hydraulic motor.

Industrial heaters are used in a wide variety of situations, including outdoor construction, oil drilling, airports, unheated buildings, etc. Most industrial heaters utilize an internal combustion engine along with a combustion-type generator or burner which uses a flame to produce heat. However, in some instances, such as oil wells, a flame cannot be used to produce the heat due to safety concerns. In such instances, flameless heaters have been developed. However, improvements in flameless heater technology are desired, particularly with regard to efficiency.


The present invention relates to novel hydroxyethylamine compounds having Asp2 (β-secretase, BACE1 or Memapsin) inhibitory activity, processes for their preparation, to compositions containing them and to their use in the treatment of diseases characterised by elevated β-amyloid levels or β-amyloid deposits, particularly Alzheimer's disease.

Alzheimer's disease is a degenerative brain disorder in which extracellular deposition of Aβ in the form of senile plaques represents a key pathological hallmark of the disease (Selkoe, D. J. (2001) Physiological Reviews 81: 741-766). The presence of senile plaques is accompanied by a prominent inflammatory response and neuronal loss. β-amyloid (Aβ) exists in soluble and insoluble, fibrillar forms and a specific fibrillar form has been identified as the predominant neurotoxic species (Vassar, R. and Citron, M. (2000) Neuron 27: 419422). In addition it has been reported that dementia correlates more closely with the levels of soluble amyloid rather than plaque burden (Naslund, J. et al., (2000) J. Am. Med. Assoc. 12: 1571-1577; Younkin, S. (2001) Nat. Med. 1: 8-19). AP is known to be produced through the cleavage of the beta amyloid precursor protein (also known as APP) by an aspartyl protease enzyme known as Asp2 (also known as 13-secretase, BACE1 or Memapsin) (De Strooper, B. and Konig, G. (1999) Nature 402: 471-472).
Therefore, it has been proposed that inhibition of the Asp2 enzyme would reduce the level of APP processing and consequently reduce the levels of Aβ peptides found within the brain. Therefore, it is also thought that inhibition of the Asp2 enzyme would be an effective therapeutic target in the treatment of Alzheimer's disease.
APP is cleaved by a variety of proteolytic enzymes (De Strooper, B. and Konig, G. (1999) Nature 402: 471-472). The key enzymes in the amyloidogenic pathway are Asp2 (β-secretase) and γ-secretase both of which are aspartic proteinases and cleavage of APP by these enzymes generates Aβ. The non-amyloidogenic, α-secretase pathway, which precludes Aβ formation, has been shown to be catalysed by a number of proteinases, the best candidate being ADAM10, a disintegrin and metalloproteinase. Asp1 has been claimed to show both α- and β-secretase activity in vitro. The pattern of expression of Asp1 and Asp2 are quite different, Asp2 is most highly expressed in the pancreas and brain while Asp1 expression occurs in many other peripheral tissues. The Asp2 knockout mouse indicates that lack of Asp2 abolished Aβ production and also shows that in this animal model endogenous Asp1 cannot substitute for the Asp2 deficiency (Luo, Y. et al. (2001) Nat Neurosci. 4: 231-232; Cai, H. et. al. (2001) Nat Neurosci. 4: 233-234; Roberds, S. L. et al. (2001) Hum. Mol. Genet. 10: 1317-1324).
For an agent to be therapeutically useful in the treatment of Alzheimer's disease it is preferable that said agent is a potent inhibitor of the Asp2 enzyme, but should ideally also be selective for Asp2 over other enzymes of the aspartyl proteinase family, e.g Cathepsin D (Connor, G. E. (1998) Cathepsin D in Handbook of Proteolytic Enzymes, Barrett, A. J., Rawlings, N. D., & Woesner, J. F. (Eds) Academic Press London. pp 828-836).
WO 01/70672, WO 02/02512, WO 02/02505, WO 02/02506 and WO 03/040096 (Elan Pharmaceuticals Inc.) describe a series of hydroxyethylamine compounds having β-secretase activity which are implicated to be useful in the treatment of Alzheimer's disease.

Hydroxyethylamine derivatives for the treatment of Alzheimer's disease


An annular positioning projection integrally has a body portion extending in a circular arc, one end portion projecting from one circumferential end of the body portion toward one raised portion and connected to a radial outer surface of the one raised portion, and the other end portion projecting from the other circumferential end of the body portion toward the other raised portion and connected to a radial outer surface of the other raised portion. An outer surface of one end portion thereof extends in a tangential direction with respect to one circumferential end of an outer surface of the body portion, and an outer surface of the other end portion extends in a tangential direction with respect to the other circumferential end of an outer surface of the body portion.

1. Field of the Invention
The present invention relates to a hose clamp holding structure for positioning and holding a hose clamp on an outer periphery of an end portion of a hose. The hose clamp is used, for example, for connection of a fuel hose and a pipe in a motor vehicle.
2. Description of the Related Art
In a fuel piping of a motor vehicle, for example, for fluid communication between pipes, used is a rubber or elastomer fuel hose including a gasoline fuel impermeable layer. A gasoline fuel path is constructed between the pipes by fitting each end portion of the fuel hose to an outer periphery of each of the pipes.
In order to prevent leakage of gasoline fuel at a joint between the fuel hose and the pipe, a seal ring is disposed in an inner periphery of the fuel hose for providing a seal therebetween. And, in order to prevent dislodgment of the fuel hose from the pipe, the fuel hose is tightly fitted to the outer periphery of the pipe. Unlike a resin tube, however, sufficient securing strength with respect to the pipe cannot be expected for the rubber or elastomer fuel hose by itself. So, in a connecting structure typically employed, a hose clamp is fitted on an outer periphery of an end portion of the fuel hose, and the fuel hose is tightened and secured to the pipe by the hose clamp (for example, refer to Patent Document 1).
A hose clamp for firmly securing the fuel hose to the pipe comprises an annular clamp body, and an operating portion for diametrically contracting and expanding the clamp body. The operating portion is, for example, in a form of an operation screw. When this hose clamp is used, the clamp body in diametrically expanded state is preliminarily fitted on a clamp mounting portion of an end portion of the hose while being positioned in a longitudinal direction of the hose, and then, the fuel hose with the hose clamp is fitted to the pipe. After that, the clamp body is diametrically contracted, for example, by rotating the operation screw with an electric driver or air driver, to tighten the fuel hose to the pipe. In this manner, connecting work may be carried out relatively easily.
Meanwhile, for example, in the hose clamp with an operation screw, it is necessary to turn the hose clamp on the outer periphery of the end portion of the hose so as to locate the operation screw in a predetermined circumferential position when the operation screw is rotated, and to hold the hose clamp non-rotationally or non-turnably while the clamp body is diametrically contracted by rotating the operation screw. Thus, basically, connecting work requires both hands. However, in many cases, connecting work of the fuel hose and the pipe is done in a narrow engine compartment where parts are closely arranged and an operator has difficulty to do connecting work by using his/her both hands freely. So, it bothers considerably the operator to tighten the hose clamp.
A technique for eliminating such inconvenience is disclosed. For example, Patent Document 2 discloses a hose clamp holding structure where an anti-rotation engaging portion protruding in a longitudinal direction of a hose is formed on a clamp body of a hose clamp, an engaging recessed portion is formed in an outer periphery of an end portion of the hose for receiving the anti-rotation engaging portion, and thereby the hose clamp can be positioned circumferentially with respect to the hose.
[Patent Document 1] JP-A-2003-314759
[Patent Document 2] JP-A-4-194486
By the way, for ensuring anti-rotation function with respect to the anti-rotation engaging portion of the clamp body, it is effective to provide a pair of raised portions on an outer periphery of the end portion of the hose in circumferentially spaced relation to define an engaging recessed portion between the pair of the raised portions. And, the pair of the raised portions may be formed on an outer end or an outer end portion of the end portion of the hose to fit the hose clamp on a portion of the hose longitudinally inward from the pair of the raised portions. In this arrangement, the raised portions prevent the hose clamp from falling off or slipping off from the end portion of the hose. And, for preventing the hose clamp from escaping via other region of the hose than the raised portions it is favorable that, an annular positioning projection is formed on outer periphery of the outer end portion of the end portion of the hose. The annular positioning projection could be designed in low height in order to increase a space around the outer periphery of the end portion of the hose as much as possible. However, in this case, there is a concern that the hose clamp obliquely passes through the end portion of the hose, from a diametrically opposite side of the raised portions toward the raised portions, then, completely passes through the raised portions and falls off entirely of the end portion of the hose.
Under the circumstances described above, it is an object of the present invention to provide a hose clamp holding structure for holding a hose clamp consistently on an end portion of a hose.


Providing an optical system having a large aperture ratio, a long back focal length, high optical performance with excellently correcting various aberrations, and an optical apparatus equipped with the optical system. The system includes, in order from an object along an optical axis of the optical system, a first lens group having positive refractive power, and a second lens group having positive refractive power. The second lens group includes a negative lens, a first positive lens, and a second positive lens, and the optical system includes a compound type aspherical lens constructed by a glass material and a resin material.

1. Field of the Invention
The present invention relates to an optical system used as an interchangeable lens for a single-lens reflex camera and a photocopy lens, an optical apparatus using the optical system.
2. Related Background Art
There have been proposed a lot of cases that a so-called Double-Gauss type lens system is used as a lens system for a single-lens reflex camera or a photocopy lens system such as Japanese Examined Patent Application Publication No. 58-057725.
However, in the optical system disclosed in Japanese Examined Patent Application Publication No. 58-057725, spherical aberration, curvature of field, and distortion have been excellently corrected, but sagittal coma, which is specially generated in a Double-Gauss type lens system upon fully opening the aperture stop, considerably remains, so that it has been hardly to say that the optical system has sufficiently high optical performance.


A system includes a laser generator, and a signal distortion generator circuit inline with the laser generator modulation signal and configured to generate distortion vectors in any of four distortion vector quadrants.

One technique for sending more signals down an existing fiber optic infrastructure involves the use of multi-wavelength systems. Such systems are subject to various distortions and other negative effects that degrade the optical signal passing through the system. One class of such negative effects involves chromatic dispersion, both positive and negative. Other negative effects in multi-wavelength systems result from fiber nonlinearities, including stimulated Raman scattering (SRS) cross-talk, stimulated Brillioun scattering (SBS), cross-phase modulation (XPM), and self-phase modulation (SPM).
SRS and chromatic dispersion are generally the dominant limiting effects in multi-wavelength systems. There is typically little or no interaction between SRS and chromatic dispersion. SRS is a phenomenon depending upon power output and wavelength, total power in the fiber, a number of wavelengths used in the fiber, spacing of the optical wavelengths, fiber distance, fiber dispersion, RF frequency, and state of polarization. The interplay between these various parameters may be complex.
Fiber optic transmission systems signals are affected by two types of distortions: device distortions and fiber distortions. These distortions are due to the non-linearity of the devices (such as lasers) and of the fiber used in the optical fiber transmission system. Both the fiber and the laser may introduce distortions as a function of frequency. The magnitude and phase of the laser generator distortions may depend on frequency, temperature, and current value. The magnitude and phase of the fiber distortions may depend on frequency and on the dispersion characteristics of the fiber.
Typical distortion compensators attempt to cancel these distortions by sending signals of opposite polarity so they will cancel out the non-linear effects of the system. However, conventional systems do not accommodate distortions in a four quadrants of the real and imaginary signal axis.
Conventional device distortion compensating circuits compensate for device distortions with an inline pre-distorter (FIG. 4) or auxiliary line pre-distorter (FIG. 5). Examples include those described in U.S. Pat. Nos. 5,115,440, 4,992,754, 5,132,639, 5,252,930, and 5,798,854, the entire contents of each are incorporated by reference. Prior art inline pre-distorterers may be compact circuits that are lossy and do not cover all quadrants without greater complexity or an increase in signal loss. The devices may have a high impedance (unless lossy impedance transformers are used) such that component parasitics are more difficult to handle in a 1 GHz design. The devices may exhibit good phase control due to compact design but poor phase control due to component parasitics. Prior art auxiliary path predistorterers are large expensive circuits that offer lower loss and an ability to adjust distortion phase and amplitude. However, these devices are overly complex to handle distortion phase errors at high (1 GHz) frequencies.
More advanced devices include chromatic dispersion compensator circuits which compensate for positive chromatic dispersion, such as when a standard (e.g., single mode fiber (SMF) 28) fiber has analog or quasi analog signals at 1550 nm (e.g., U.S. Pat. Nos. 6,687,432 and 6,574,389, the entire contents of each are incorporated by reference). These devices work by varying an input signal delay as a function of frequency to handle positive chromatic dispersion effects. Chromatic dispersion compensators which compensate for composite second order (CSO) and composite triple beat (CTB) or both are described in U.S. Pat. Nos. 6,574,389 and 6,687,432, the entire contents of each are incorporated by reference. These devices operate by varying an input signal delay to overcome chromatic dispersion. These devices cannot change distortion phase to handle negative chromatic dispersion distortion. These devices also cannot handle certain types of laser distortion.
In another conventional approach, a non-linear feedback loop is used to cancel out distortions in the input signal (see e.g., U.S. Pat. No. 6,593,811, the entire contents of which are incorporated herein by reference). This is a relatively non-lossy circuit which can cover multiple quadrants due to presence of both signal polarities. This device does support 1 GHz amplifier operations and provides an ability to swap predistortion phase to compensate varying laser distortion as temperature or output power is varied. This device also enables use of uncooled coaxial lasers due to ability to adjust distortion phase in multiple quadrants. However, feedback delay limits the useful bandwidth of linearization and limits the phase control of a linearizer output. This device also does not operate over 4 quadrants (simultaneously/sequentially).
In addition to distortions in the fiber optic communication system there is also crosstalk from other wavelengths in the case that more than one wavelength is carried in a single glass fiber. This crosstalk is caused by sources such as XPM and SRS [Ref. A: Journal of Lightwave Technology, Vol. 18, p. 512, 2000] and also polarization state modulation through XPM and WDM filter crosstalk. Ref A teaches a method to reduce the effects of XPM crosstalk in an externally modulated system by using 3 wavelengths in a dual output/dual receiver system. This is an undesirably complicated system that also requires dispersion compensation to achieve XPM reduction.


Provided is a battery module including a flexible member including: a housing; at least one separation wall partitioning an inside of the housing into a predetermined number of separated spaces; at least two unit battery cells including a case, a battery cell included in the case, and negative and positive electrodes tabs connected to the battery cell; and a flexible member inserted between the unit battery cells, wherein the unit battery cells and the flexible member are included in a space partitioned by the separation wall.

Generally, a secondary battery may be rechargeable and have increased capacity. A representative example of the secondary battery includes a nickel cadmium battery, a nickel hydrogen battery, a lithium ion battery, and the like. Among them, the lithium ion battery has been spotlighted as the next generation power source due to excellent characteristics such as a long lifespan, high capacity, and the like. Among them, a lithium secondary battery, which has operating voltage of 3.6 V or more, is used as a power supply of a portable electronic device or several lithium secondary batteries are connected in series with each other to thereby be used for a high output hybrid vehicle. Since this lithium secondary battery has operating voltage three times higher than that of the nickel-cadmium battery or the nickel-metal hydride battery and is more excellent in view of energy density characteristics per unit weight than the nickel-cadmium battery or the nickel-metal hydride battery, the use of the lithium secondary battery has rapidly increased.
The lithium secondary battery may be manufactured in various types. A representative type of the lithium secondary battery may include a cylindrical type and a prismatic type that are mainly used for the lithium ion battery. A lithium polymer battery that has been recently spotlighted is manufactured in a pouch type having flexibility, such that it has a relatively free shape. In addition, the lithium polymer battery has excellent stability and light weight, such that it is advantageous for slimness and lightness of the portable electronic device.
Meanwhile, in a case of a power supply for driving a motor of an electric automobile, or the like requiring a large amount of power, several tens of secondary battery cells are connected in series or parallel with each other to thereby configure a battery module.
When a plurality of battery modules are charged or discharged, heat is generated from the cell and charging or discharging performance of the battery cell may be varied depending on a temperature of the cell.
Therefore, it is important to maintain an internal temperature of the battery at appropriate temperature.
A secondary battery module disclosed in Korean Patent Laid-Open Publication No. 2007-0014631 according to the related art includes a plurality of unit cells which are stacked and arranged to efficiently cool heat generated from the unit cell, and a plurality of partitions installed between the unit cells and having a cooling passage formed therein and protrusions formed on both surfaces thereof.
Therefore, the related art relates to a method of cooling the plurality of cells while a heat transferring medium is circulated in the plurality of partitions.
However, since the related art has a configuration of cooling only regions in which the protrusions formed on the both surfaces of the partition and the plurality of unit cells are in contact with each other, there is a problem that regions in which the protrusions and the plurality of unit cells are not in contact with each other are not cooled.

Battery module including a flexible member


The image processing method according to the present invention comprises the steps of: performing morphology processing for removing a catch light in a pupil in an original image including a face image, calculating a difference between the original image and an image subjected to the morphology processing extracting a catch light region which includes the catch light based on the calculated difference, specifying a catch light region in the original image based on the extracted catch light region, and emphasizing the specified catch light region against the original image.

1. Field of the Invention
The present invention relates to an image processing method, an image processing apparatus and an image processing program, more specifically to a technique of emphasizing catch lights in pupils.
2. Description of the Related Art
An amusement seal printing machine which combines and prints a face photograph and a template image is desired to print the face photograph by making the eyes bright and make the face impressive. Specifically, it is important to emphasize catch lights in pupils.
If sharpness is strengthened for the photographed image to "make eyes bright" and "make catch lights clear", however, the person's skin roughness is emphasized or a noise caught at taking the picture is emphasized. This may lead a problem in emphasizing roughness of the surface.
An image processing method (Japanese Patent Application Laid-Open No. 10-75374) has been proposed for solving the problem. This conventional method has an operator specify a region of an eye and strengthen a contrast in the region in order to emphasize catch lights in pupils.
Japanese Patent Application Laid-Open No. 2000-40154 discloses a technique for performing morphology filter process to prevent granulation of a film which appears on an image read from a photo film.

Image processing method, image processing apparatus and program for the same


In one embodiment, a device for generating ultra-high precision rectilinear movement based on aerostatic suspension and magnetic traction, the device including a nut, a leadscrew, a thrust bearing, a contactless motor, and feedback drive electronics. The contactless motor provides the actuation by turning the leadscrew which is made of magnetically soft materials and has a pitched helical groove machined on its surface. The leadscrew passes through the core of the nut which is free to move in a rectilinear motion on a aerostatically suspended guide. The nut, also made with magnetic material, has a matching helical groove in its core so that a closed magnetic circuit is formed between the grooves of the leadscrew and the nut. The closed circuit in turn provides the necessary magnetic traction to move the nut in a rectilinear fashion. A primary aerostatic suspension is utilized to stabilize and center the leadscrew and nut transversally. A secondary transversal stabilization is provided by the thrust bearing to center the leadscrew in the axial direction. The nut is vibrationally isolated and can be rectilinearly moved with precision. Thus, all surface friction is eliminated, thereby reducing friction to that generated by air.

It is well recognized that ultra-high precision assembly or manufacturing, typically requiring up to 10 nanometers linear resolution, is of strategic importance to industrial processes such as optoelectronics assembly, precision machining, and semiconductor manufacturing. In such processes, both the machine dynamics and operating environment are critical to the quality of the end product. "Hard" nonlinearities such as surface friction, backlash, and hysteresis are generally difficult to predict and to compensate for, resulting in significant degradation of the process performance.
To eliminate thread friction and wear and provide damping on the axis of motion, hydrostatic and aerostatic leadscrews have been used to replace conventional ball or roller leadscrews in manufacturing machines. For example, at least one known device utilizes a hydrostatic leadscrew for behind-the-wheel dressing system with a claimed resolution of 10 nanometers. Satomi studied the use of aerostatic leadscrew as a positioning and guiding system for machine tools. See "Studies on aerostatic lead screws," T. Satomi, World Congress of IFToMM, 1987, pp. 1545-1548. These approaches use pressurized fluids to separate enmeshed, i.e., mechanically coupled, threads.
On the other hand, magnetic coupling has also been investigated for achieving contactless drives. For example, Kikuchi and Tsurumoto experimented with a permanent magnet worm gear. See "Design and characteristics of a new magnetic worm gear using permanent magnet," IEEE Trans. on Magnetics, Vol. 29, No. 6, 1993, pp. 2923-2925. Various other linear actuators are described in the following patents, all of which are incorporated herein in their entirety: U.S. Pat. No. 3,777,587 issued to Hoshina et al.; U.S. Pat. No. 3,824,420 issued to Stegeman et al.; U.S. Pat. No. 4,123,691 issued to Seilly; U.S. Pat. No. 4,145,625 issued to Seilly; U.S. Pat. No. 4,214,180 issued to Kuwako et al.; U.S. Pat. No. 4,439,702 issued to Belikov et al.; U.S. Pat. No. 4,712,027 issued to Karidis; U.S. Pat. No. 4,734,605 issued to Hayashi; U.S. Pat. No. 4,920,292 issued to Albrecht et al.; and U.S. Pat. No. 5,099,161 issued to Wolfbauer, III.
Therefore, it is a principal object of the present invention to provide a means of generating high or ultra-high precision movement
It is another object of the present invention to provide a means of generating high or ultra-high precision movement based on the principle of magnetic traction and aerostatic suspension.
Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures.


An non-contact article rotating device is disclosed that rotates articles without impacting or contacting the article other than the bottom of the article. The device is designed to accept a stream of articles with minimum gaps between them, and rotate only those that are programmed to be rotated. The device accepts any combination of rotated and non-rotated articles and can rotate them through angles up to and through 360 degrees. One embodiment of the disclosed device uses only one single-speed drive motor and pneumatic components to operate two conveyor roller sections. While one conveyor roller section maintains a constant speed, the conveyor rollers of the second conveyor roller section are sequentially braked and unbraked to rotate an article that is positioned partially on the first conveyor roller section and partially on the second conveyor roller section. The difference in speeds between the two conveyor sections rotates the article.

1. Technical Field
The invention relates to an article rotating assembly for rotating conveyed articles. More particularly, the invention relates to an apparatus and method for the in-line rotating of selected articles without contacting or bumping the articles.
2. Background Art
Article turner assemblies are well known for rotating conveyed articles, i.e., for rotating the articles a designated amount, usually 90°, as they are conveyed along a path. Article turner assembles have many applications in a variety of article handling applications. For instance, an article turner assembly often is used as part of a pattern former of a palletizer.
Known article rotating devices have operating and structural characteristics which make them undesirable for use with many products and packages. Present day high speed conveying operations make any slow down in movement along the line or any shut-down of the line caused by package or product deterioration unacceptable.
Some article turner assemblies require contact between the operative element of the article turner assembly and a front and/or side surface of the article to turn the article. Article turner assemblies of this type are called "bump" or "turnpost" turners. In this type of article turner assembly, the article is conveyed so that the front surface of the article contacts a vertically-extending stationary turnpost and spins about the turnpost to effect the desired 90° of article rotation. The article impacts the turnpost with substantial force when the article is conveyed at high speeds. In the usual case in which the article comprises a package containing goods, this impact may result in substantial abrasion or other marring of the package and may damage goods contained in the package.
U.S. Pat. No. 6,126,383 uses a diverting mechanism which shoves turned cases to the side at a very high rate of speed. This diverter causes impact and friction to the sides of each turned article, while requiring the bottom of the article to slide across the infeed conveyor. Damage to the contents of the package (e.g., loose glass bottles in a case) is possible, while some soft-sided loose packages (e.g. bundles of paper towels, or stacks of newspapers) may be damaged on the sides or bottoms. Loosely packaged articles may shingle and not shift over at the bottom, causing a faulty turn or no turn at all. This device also relies on guides at the discharge end of the rotating mechanism for squaring centering turned articles, which is another point of potential impact, frictional product damage, or product jams.
Many turners require a significant number of precise adjustments when changing over from one article size to another. Adjustment in conveyor angle, diverter position, horizontal and vertical conveyor position, and speed differential must all be made when products change. Since most users run a variety of different products (sometimes hourly changes) this tedious adjustment and fine-tuning process is not desirable. While settings can be written down and repeated to some extent each time a product is to be run, it is a very difficult trial and error process to initially get the settings correct. Automatic linear actuation devices can be utilized to reduce the manual input into article changeover, but this adds significant cost and complexity to the device.
Brewpack Ltd. of Surrey, England makes a twin mattop belt inline turner which utilizes two side-by-side modular plastic conveyor belts, commonly referred to as mattop belts. The device typically consists of a wide belt with a low friction material, and a higher friction narrow belt that runs parallel to the wide belt. Both belts run at constant, but different speeds, so that when an article is in contact with both belts, the article tends to rotate (however, not about its center of gravity or geometrical center.) Articles are fed onto the turner largely in contact with the wide low friction belt. The narrow high friction belt stays slightly below the level of the wide belt, if the article is to remain unturned. If the article is to be turned, then one or more actuators raise one or more sections of the narrow belt to provide the speed differential required for article rotation. Since most of the article must rest on the wide belt so it is transported in a stable manner when not turned, only one edge is in contact with the narrow high friction belt when the article is to be turned. This style of turner basically references both turned and non-turned articles to one side of the device (the side with the narrow belt.)
A large gap is required between turned/non-turned articles since the sections of narrow belt that raise and lower are relatively long (a turned article cannot be in this section at the same time a non-turned article is.) Articles do not turn about their geometrical centers or their centers of gravity. Articles are referenced to one side of the device upon their exit. This can have a negative impact on the operation of downstream equipment such as slat dividers or pattern forming conveyors. It is desirable to have product exit the turner on the centerline in many applications.
There are several designs for devices that employ the "lift and turn" method of selectively rotating articles. However this is a very slow process, and is not suitable for high-speed inline applications.
U.S. Pat. No. 3,580,379 describes an inline article rotating device that utilizes a "slat divider" method for rotating packages. This type of device is very difficult to accurately control and fine tune. Different article sizes may require different size platens and lane locations that make this an impractical device for use with multiple products.
There are several designs for article turners that consist of multiple parallel conveyors with fixed speed differentials where all articles that pass through the device are rotated.


A digital to analog converter including a current source for providing a master current, a first sub digital to analog converter coupled to the current source which generates a plurality of currents, and a second sub digital to analog converter coupled to at least one of the plurality of currents from the first sub digital to analog converter which generates a second plurality of currents. The digital to analog converter also includes an overlap adjustment circuit coupled with the second sub digital to analog converter which adds current. The digital to analog converter is configured to operate in a first mode for generating a sine wave with a first bit level accuracy and, when in the first mode, the overlap adjustment circuit adds no current. to the second sub digital to analog converter The digital to analog converter is configured to operate in a second mode for generating a ramp wave with a second bit level accuracy and, when in the second mode, the overlap adjustment circuit adds current to the second sub digital to analog converter. When in the second mode, the total current of the second sub digital to analog converter and the overlap converter is greater than one of the plurality of currents generated by the first sub digital to analog converter.

A digital-to-analog converter (DAC) is an electronic circuit that converts an input digital signal to an output analog signal. A numerical value represented by the digital signal input to the DAC corresponds with a magnitude of the analog signal output by the DAC. Various factors determine the performance of a DAC, including speed, resolution, and noise. Resolution refers to the smallest incremental signal that is generated by the DAC and corresponds with the Least Significant Bit (LSB) of the input digital signal. Noise refers to deviations of the output analog signal relative to an expected or desired level, particularly during switching from one digital value to another.
High performance DACs are useful for converting data with high resolution at high frequency and low noise. High performance DACs are used to generate a variety of signal outputs, including ascending and descending ramps and sinewaves. Typically, separate DACs are implemented to generate the various signal outputs. Various methods have been used in an attempt to improve behavior and performance, but many such conventional techniques introduce increased costs or increased size allocation.
Many prior art current-steering DACs are implemented using a segmented architecture. This architecture of the DAC is divided into two sub-DACs: the LSBs are implemented using a binary architecture while the most significant bits (MSBs) are implemented in a unary way. The major differential nonlinearity (DNL) errors occur during the transition of all LSBs to each MSB. DNL is the deviation between two analog values corresponding to adjacent input digital values. In many systems, the MSB current source needs to be matched to the sum of all the current sources of LSBs to within a small error range, for example 0.5 LSB. Because of statistical spread, such matching is difficult to achieve.
A frequency-modulated continuous-wave ("FMCW") radar system often uses a highly linear frequency ramp to provide accurate range and velocity information. The resolution of the ranging information is directly dependent on the linearity of the transmit signal as the transmit signal is also used to detect the signal received from the target. The output of the voltage-controlled oscillator ("VCO") that is used to generate the radar signal is typically non-linear. Therefore, digital-to-analog controller architecture for controlling the chirp linearity of the radar system is desired.
The figures are not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be understood that the invention can be practiced with modification and alteration, and that the invention be limited only by the claims and the equivalents thereof.

This patent is subject to a terminal disclaimer.


An apparatus and method are provided for scheduling transmit network events in a multiprocessing environment. Each processing node handles its own linked list of transmit object queues and linked list of transport queues. Therefore efficient handling of the transmit network events is enabled. Queues may be added, made inactive, or removed depending on the status of a specific transmit event the queue handles. By maintaining queues in memory, the apparatus is easily scalable, in linear relationship with the size of the memory made available.

1. Field of the Invention
The present invention relates to the management of network transmission events handled by a multiprocessing system. More specifically, the invention relates to a highly scalable apparatus for managing termination of transmission transport via a plurality of transmit transport queues (TTQs).
2. Background of the Related Art
In the related art, operation in multiprocessing environments can handle tasks requiring a significant amount of computing power, which is best achieved by a plurality of processors operating in parallel. Over time, it has become easier in the related art to integrate more than one processing node on a single chip and thus create a more powerful related art parallel processing unit. While the foregoing related art parallel processing unit is highly effective in general processing applications, there exist other areas where it would be advantageous to employ multiprocessing, such as network processing.
In network processing, many events occur in parallel over short periods of time, and are generally independent of one another. For example, a file transfer protocol (FTP) session initiated by one user may be handled in parallel to another FTP session initiated by that same user or by another user. Also, other types of protocols may be handled in parallel.
In the above related art example, each FTP session generates its own events that follow FTP requirements, but are independent of each other. To achieve higher throughput for FTP in the related art system, these FTP sessions should be handled in parallel.
Network traffic is transported over the related art network using transmission control protocol (TCP) or user datagram protocol (UDP). TCP is used when a reliable transport medium is required, and is applied in the related art as described below.
TCP is a connection-oriented transport protocol that sends data as unstructured streams of bytes by sending a sequence of segments (i.e., a collection of data bytes sent as a single message) individually through the network. By using a sequence number and acknowledgment messages, TCP provides the source node with status of the bytes transmitted to the destination node. When data is lost during transmission, TCP can resend lost data, thereby ensuring reliable connectivity.
The related art TCP data transport process is as follows. First, the data (i.e., a file or a message) is broken into segments. To properly break up the data, the TCP must be notified of the size of the segments that the network is capable of handling, which may vary over time depending on network conditions.
Next, a header is affixed to the beginning of each segment. The header includes information related to the transmission of the segment, such as the source address, the destination address, the source port and destination port numbers, checksum information, segment length and a byte sequence number. In the header information, the checksum field contains a digest of the header and the payload, and confirms correct reception of data. The segment length field of the header specifies the number of payload bytes contained in the segment, and the sequence number of the header indicates the position of the last byte of the segment in the continuous byte stream.
After affixing the header, TCP sends the datagram to the destination and waits for an acknowledgement indicating successful transmission. The acknowledgment message may be piggybacked on an incoming segment directed to the source. If the sender (i.e., the source node) does not receive the acknowledgement message within a defined amount of time, the source node resends the unacknowledged bytes.
At the destination node, TCP receives the segment and performs a checksum test. If checksum test passes and no data bytes were lost, the destination TCP acknowledges the source TCP, as described above. Thus, the transmission process is complete.
In the related art, scaling software-based solutions for higher performance is considered a significant challenge, because the related art system usually correlates the number of bits per second to be transferred with the number of instructions per second to be processed. Accordingly, at the TCP level, it would be necessary for processors to be capable of providing performance of 10 giga instructions per second for a 10 Gbps network, resulting in a very high related art system cost.
With the advent of related art high speed network systems capable of transmission at speeds of over one gigabit per second (e.g., related art 1 Gbps and 10 Gbps systems) it would be advantageous to move the related art software based activities for TCP to a hardware environment. However, the related art does not include such a solution for TCP.
Therefore, the related art system has various problems and disadvantages. For example, but not by way of limitation, the related art system cannot produce the aforementioned desired high performance, because of the above-noted deficiencies of the related art software TCP system. As noted above, attempting such a high performance software solution would have a tremendously high cost due to its complexity.
Further, the challenges that require addressing in a multiprocessing environment for termination of transmit transport in a computer network are substantially different from the challenges of general application multiprocessing. For example, but not by way of limitation, traffic flowing over the network must be handled efficiently without impacting overall system performance.

Apparatus and method for transmit transport protocol termination


Disclosed are an antioxidant for a fuel cell having a high degree of dispersion and/or distribution and excellent antioxidant capability and a membrane-electrode assembly including the same. The antioxidant includes a metal oxide and a sulfur-containing organic compound, for example, an organic compound including a sulfinic acid anion group (R—SO2−), adsorbed on the metal oxide.

A proton exchange membrane fuel cell (PEMFC or polymer electrolyte membrane fuel cell) is an electricity generation device using hydrogen fuel, which has high energy efficiency, simple system configuration and environmentally friendly advantages. A proton exchange membrane fuel cell is recently receiving attention as an energy conversion device for environmentally friendly vehicles.
The reaction for generating electricity in fuel cells occurs in a membrane-electrode assembly (MEA) composed of a perfluorinated-sulfonic-acid-(PFSA)-ionomer-based electrolyte membrane and an anode and a cathode. After hydrogen supplied to the anode, which is the oxidation electrode of the fuel cell, is separated into protons and electrons, the protons move to the cathode, which is the reduction electrode, via the membrane, and the electrons move to the cathode via the external circuit. At the cathode, oxygen molecules, protons and electrons react together to generate electricity and heat, and at the same time, water (H2O) is generated as a reaction byproduct.
As the reaction gases of the fuel cell, hydrogen and oxygen cross over through the electrolyte membrane, thus promoting the production of hydrogen peroxide (HOOH). Hydrogen peroxide produces highly reactive oxygen-containing radicals such as hydroxyl radicals (.OH) and hydroperoxyl radicals (.OOH). These radicals attack the ionomer binder in the electrode and the perfluorinated-sulfonic-acid-based electrolyte membrane, causing chemical degradation of the membrane-electrode assembly, ultimately reducing the durability of the fuel cell.
As techniques for reducing chemical degradation, methods of adding various types of antioxidants have been proposed. The antioxidants are classified into primary antioxidants having a radical scavenger (or quencher) function and secondary antioxidants having a hydrogen peroxide decomposer function. These may be used alone or in combination.
Typical examples of the primary antioxidant may include cerium-based antioxidants, such as cerium oxide (or ceria) and cerium(III) nitrate hexahydrate, and manganese-based antioxidants, and typical examples of the secondary antioxidant may include manganese-based antioxidants such as manganese oxide, etc., and transition metal catalysts such as platinum (Pt), etc.
The cerium-oxide-based antioxidant that is used as the primary antioxidant is introduced in the form of nanoparticle or powder having a crystallite size of ones of nanometers or tens of nanometers. Since the cerium-oxide-based antioxidant is generally manufactured and then stored in the form of an agglomerate, it has to be dispersed before addition to the electrolyte membrane. Thus, in order to increase the degree of dispersion and/or distribution, an interfacial surfactant may be used to stabilize the surface of the antioxidant, but may decrease the active surface area of the antioxidant, which deteriorates the durability of the fuel cell. Therefore, it is necessary to develop antioxidants having distributional stability and antioxidant capability through a large active site.

Antioxidant having high antioxidant capability for fuel cell, and electrolyte membrane and membrane-electrode assembly comprising same


An embodiment of the present invention relates to a repair circuit of a semiconductor memory device. The repair circuit includes an address counter that sequentially generates a first column address signal and a second column address signal in response to a write enable signal or a read enable signal, a repair controller that generates a repair column address signal earlier than the second column address signal in response to the first column address signal, an address latch enable signal, a command enable signal, and a write enable signal, and a repair scramble unit that selects a repair cell in response to a repair I/O control signal and the repair column address signal. If an address on which a repair operation must be performed occurs, the repair controller directly receives the write enable signal or the read enable signal and activates the repair controller earlier than a general cell using a previous address, thereby offsetting an operating time consumed in the repair controller. Therefore, the operating speed of the repair cell can become faster than that of the general cell and the operating speed of the device can be improved accordingly.

1. Field of the Invention
The present invention generally relates to a repair circuit of a semiconductor memory device, and more particularly, to a repair circuit of a semiconductor memory device, in which it can prevent a repair cell from operating slower than a normal memory cell.
2. Discussion of Related Art
A semiconductor memory device does not function as a memory device if even one of many delicate cells fails. To discard the whole device as a failed product despite the fact that only several cells within the memory have failed, however, is inefficient in terms of the yield.
Currently, the memory device is restored by replacing a failed normal unit cell with a reservation unit cell that is previously provided in the memory device in order to improve the yield.
FIG. 1 is a block diagram illustrating the process of performing the repair operation in the related art. FIG. 2 is a timing diagram of signals illustrating the address generating operation in the related art. The address generating process and the repair operation principle of the NAND flash memory device in the related art will be described below with reference to FIGS. 1 and 2.
(1) Address Generating Process of NAND Flash Memory Device
The NAND flash memory device does not include address pins since the I/O of data is performed serially. Furthermore, addresses are generated by a write enable signal WE# or a read enable signal RE#.
An address start signal is first input through an ALE (Address Latch Enable) pin and the I/O. The ALE pin is a pin for address input. The write enable signal WE# is input to an address counter. The address counter increases the address whenever the write enable signal WE# is toggled. The address counter also increases the internal address by detecting the rising edge of the write enable signal WE# within the chip. When it is sought to output data, the address is increased in the same manner as above using the read enable signal RE#.
If the write enable signal WE# or the read enable signal RE# is input to the input terminal, the address counter increases the address.
The increased address COLADD or ROWADD must be transferred to a cell operation block (a repair controller,) within the chip. Eventually, a column address signal COLADDC[j] is generated by an address counter when a write enable signal WE# or a read enable signal being inputted through an input terminal is inputted to the address counter. It takes a time Tadd for the column address signal to reach the cell operation block (a repair controller). As a result, the time taken for a repair address signal RADD to reach the repair scramble unit is longer than is the time taken for a column address signal COLADD[j] to reach the address scramble by the time taken for the repair address signal RADD generated in the repair controller to reach the repair scramble. This causes the operating speed of the repair cell to be later than that of the normal memory cell.
(2) Repair Operation
In the normal memory cell or the repair cell, input or output of the data is performed according to the address change. However, to perform the repair operation, addresses to be repaired must be compared and I/O to be repaired must be set. This operation is performed by the repair controller.
If a new address is input when data are output, the data I/O operation is performed by the page buffer in the case of a general cell. In the case of a repair cell, however, the I/O operation is performed according to control signals (a signal RIO to indicate I/O to be repaired, an address RADD to indicate a repair column), which are generated by the repair controller.
Therefore, the operation of the repair cell becomes later than the operation of the general cell by a time during which the repair controller is activated and is transmitted to the repair scramble. As a result, the operating speed of the repair cell defines the operating speed of the chip.
There is a limit to a reduction of a time which is taken for the repair controller to operate. If the spec defining the data I/O time is reduced, the desirable spec of the device cannot be obtained due to the operating time of the repair controller.
For example, in the case of a 512 Mb NAND flash memory, the time taken to input and output one byte is 50 ns. In the case of a 2 Gb NAND flash memory, the time taken to input and output one byte is 30 ns, and in the case of 4 Gb, 25 ns. However, in the 512 Mb, 2 Gb, and 4 Gb, the operating time of the repair controller is the same or longer. Therefore, they do not satisfy the spec of the device for the I/O time.

Repair circuit of semiconductor memory device


A chemical vapor deposition apparatus is provided. The chemical vapor deposition apparatus includes a susceptor support base and a susceptor, and configured to rotate the susceptor with a rotary shaft, a gap as wide as about 1 mm or more is provided along the boundary between the support base and the perimeter of the susceptor to prevent Ga from forming bridges between the support base and the susceptor during growth of III-V compound semiconductors such as GaN, thereby preventing disturbance of rotation.

This invention relates to a chemical vapor deposition apparatus, especially suitable for application to a metal organic chemical vapor deposition (MOCVD) apparatus.
Devices manufactured by using III-V compound semiconductors, such as light emitting devices including LEDs and semiconductor lasers, and other devices like communication-purpose high-frequency transistors, are important devices constituting hardware infrastructures of the modern communication society, together with silicon (Si)-based devices.
III-V compound semiconductor devices, having structures ingeniously making use of hetero junctions of III-V compound semiconductors, take a complementary part with Si-based devices in regions impossible to realize with Si.
For manufacturing compound semiconductor devices including III-V compound semiconductors, excluding simple-structured devices such as MESFET, hetero epitaxial techniques are important techniques. It is no exaggeration to say that hetero epitaxial techniques basically support the manufacture of such devices. Molecular beam epitaxy and chemical vapor deposition, in particular MOCVD, are currently major hetero epitaxial techniques, which have been studied in laboratories since 1960s.
MOCVD was bought into practice as an epitaxial growth technique for manufacturing GaAs semiconductor lasers. Currently, an MOCVD apparatus enabling epitaxial growth on a number of substrates simultaneously is commercially available. In terms of componential techniques of the multi-substrate MOCVD apparatus, there are various types. Regarding the susceptor configuration, there are a barrel type and a pancake type. In terms of the gas flow mode, there are a high-flow-rate horizontal type, high-revolution type, vertical down-flow type, and so on. In terms of the substrate-supporting mode, there are schemes of putting substrates above the gas flow (face-down) or putting substrates under the gas flow (face-up). Regarding heating there are a RF induction heating type, electrical resistance heating type, lamp heating type, and so on. These componential techniques are combined variously to make up various types of MOCVD apparatuses.
Conventional MOCVD apparatuses for epitaxial growth of III-V compound semiconductors uses gallium (Ga), aluminum (Al) or indium (In) as a group III element and arsenic (As) or phosphorus (P) as a group V element, and the growth temperature was 800° C. at most. On the other hand, there is a recent demand for an MOCVD apparatus capable of epitaxially growing GaN compound semiconductors using ammonia (NH3) as a source material.
A MOCVD apparatus for GaN semiconductors is configured to invite reaction of a group III organic metal compound and ammonia (NH3) at a temperature around 1100° C. to grow a single-crystal thin film on a sapphire or SiC substrate. Concerning the single-crystal thin film, gas composition and growth conditions for growing high quality crystals were academically reported and known. However, MOCVD apparatuses for realizing optimized gas composition and growth conditions for obtaining high quality crystals have been modified after individual technical researches, and almost none of their actual improvements are known. Among some known MOCVD apparatuses, there are some proposals directed to the structure of the reaction tube (for example, Japanese Patent Laid-open Publications Nos. JP-H02-288665A, JP-H04-94719 A and JP-H11-12085). Even with these techniques, it has been difficult to manufacture semiconductors of long-lasting good crystal qualities under acceptable reproducibility because of various entangled factors.


A vehicle is capable of maintaining a cooling capacity of a heat exchanger constant. The vehicle includes ahead pipe, a main frame connected to the head pipe so as to extend rearwardly and downwardly, an engine arranged below the main frame and including a cylinder having a cylinder shaft, which is inclined forwardly and obliquely upward at a predetermined angle, leg shields that cover the front of legs of a driver of the vehicle, a radiator arranged within the leg shields to cool the engine, and a reservoir tank arranged below a lower surface of the cylinder of the engine within the leg shields and connected to the radiator.

1. Field of the Invention
The present invention relates to a vehicle, and more particularly, the present invention relates to a vehicle provided with a heat exchanger that cools an engine.
2. Description of the Related Art
Conventionally, motorcycles (vehicles) provided with a heat exchanger that cools an engine are known among underbone type motorcycles in which a frame (main frame) between a seat and a handle is decreased in height to make it easy for a driver to straddle (for example, see JP-A-2002-37165 and JP-A-2002-37166).
These patents disclose motorcycles in which a radiator (heat exchanger) for cooling an engine is provided in leg shields that cover the front of a driver's legs.
Since the underbone type motorcycles in these patents are not constructed so that a quantity of cooling water in the radiator is maintained constant at all times, there is a disadvantage in that a quantity of cooling water in the radiator is varied. Specifically, the quantity of the cooling water in the radiator is increased in the case where water temperature in the radiator rises causing the cooling water to expand in volume, and a quantity of the cooling water in the radiator is decreased in the case where water temperature in the radiator drops to cause the cooling water to contract in volume. In this manner, when a quantity of the cooling water in the radiator is varied according to water temperature, the radiator (heat exchanger) is also varied in cooling capacity so that it becomes difficult to maintain the cooling capacity of the radiator constant.