An improved dual threaded fastener for composite materials having a head and a shaft. The head is affixed to one end of the shaft and the shaft includes a point at its other end. The shaft includes an upper threaded portion and an upper threaded portion. The diameter of the shaft within the lower threaded portion is greater than the diameter of the shaft within the upper threaded portion. In this manner, as the fastener is rotated within the workpiece, producing remnants may be stored in the area surrounding the upper threaded portion.

When conventional screws are inserted into materials, remnants or shavings can be produced that are displaced toward the top of the screw insertion point. The remnants can remain on the surface of the material at or near the screw insertion point, requiring removal by sanding or other methods. Remnants and otherwise displaced composite material may also result in "mushrooming," where a mound or bump of raised material surrounds the perimeter of the screw head. The mushroom then must be hammered or forced back down to maintain a flush surface.
Although pre-drilling holes for the screw may reduce remnants on the surface and/or mushrooming, this technique is laborious and time-consuming.
Several patents disclose dual threaded screws for securing a workpiece. For instance, U.S. Pat. No. 6,666,638, issued to Craven, discloses a deck screw having multiple threaded sections. The upper threaded portion has a thread pitch that is lesser than the lower threaded portion and the upper threaded portion has an outer thread diameter that is greater than the outer diameter of the lower threaded portion.
U.S. Pat. No. 6,966,737, issued to McGovern, discloses a deck screw suitable for use with composite lumber having an upper threaded portion and a lower threaded portion. The shaft in the upper threaded portion has a larger diameter than the shaft in the lower threaded portion, and the upper threaded portion has more threads per unit length than the lower threaded portion.
U.S. Pat. No. 6,000,892, issued to Takasaki, discloses a wood screw having an upper threaded portion and a lower threaded portion. The upper threaded portion has a thread angle greater than that of the lower threaded portion, and the upper threaded portion has a lead angle smaller than the lower threaded portion.
U.S. patent application Ser. No. 2004/0141827 discloses a self-tapping screw for composite materials having an upper threaded portion and a lower threaded portion separated by a thread-free section. The threads of the upper threaded portion have an opposite pitch from the lower threaded portion.
U.S. Pat. No. 6,074,149, issued to Habermehl et al., discloses a threaded fastener with an upper threaded portion and a lower threaded portion. The lower threaded portion has threads of a larger size and greater cross-sectional area than the threads of the upper threaded portion.
While these configurations have their benefits, the need exists for an improved dual threaded screw or fastener having enhanced performance yet providing maximum opportunity for retaining remnant material below the surface of the workpiece.

Dual threaded screw for composite materials


The present invention is a unitary piece block formed of polymers (such as polystyrene or other high strength polymer) by a single injection molding step which are assembled into a recreational vehicle leveler. The invention ramp provides four sets of four connectors at a top of a floor plate, which are adapted to interlock in cavity structures formed within a cavity on the underside of the block. Two adjacent blocks are secured together by applying to their top surfaces the securing cavity structure of an underside of a third such block. Such blocks can be stacked in an interlocking manner to reduce storage space.

The prior art describes several forms of interlocking pieces connected so that trucks and recreational vehicles can drive on to them and be leveled at an uneven site.
US Patent D426,933 shows one of a set of at least three interlocking blocks that are set up with two side by side and the third placed on top of halves of the bottom two to lock the three together. It has been found that this form of interlocking block suffers from substantial (over 20%) breakage in actual use with loaded trucks and recreational vehicles. The breakage is due to the particular strains placed on the blocks. A tire must be able to drive up a stepped ramp formed by the blocks and then come to rest preferably at the top of the third or top block or at any place on the stepped ramp. The strain that this makes on plastic pieces has been found to be unique in engineering of plastic parts.
U.S. Pat. No. 5,458,315 attempts to solve this breakage problem by using a heavily reinforced skeleton of brace plates. While in some ways preferable over the device of US Patent D426,933, the polygonal form of the raised part to interlock with a cavity in another block allows substantial lateral twisting that is not allowed with the square raised part shown in US Patent D426,933.
U.S. Pat. No. 7,040,603 shows that, for an interlocking type of ramp piece, from a floor plane level four square upward extensions are formed with four "key recesses" cavities formed therein. The underside of the each piece is formed to receive and interlock with the upward extensions.
There is a need for a device that would combine the non-rotation form of a leveling block with an improved non-breakable form.


A disk drive uses the integration of the instantaneous velocities of the heads to estimate the distance the heads travel while latched. The disk drive can then determine if the heads are properly parked based solely on the distance traveled, thus avoiding the use of costly sensors. In the event that the heads cannot be properly parked due to some malfunction, the disk drive may store a special code in a nonvolatile memory. The special code directs the controller not to spin up or attempt to load the heads on any disk, preventing the disk from being damaged by the heads.

A disk drive is a data storage device that stores data in concentric tracks on a disk. Data is written to or read from the disk by spinning the disk about a central axis while positioning a transducer contained on read/write heads near a target track of the disk. During a read operation, data is transferred from the target track to an attached host through the transducer. During a write operation, data is transferred in the opposite direction.
For a number of years, it has been a common practice to build hard disk drives with a head parking arrangement, where the magnetic head is moved to a parked position when it is not in use. In the parked position, the head is aligned with a radially inner or radially outer edge portion of the hard disk, beyond the region of the disk where information is stored. The parked position keeps the heads safe from mechanical shock and vibration. The heads cannot be on the media unless it is spinning, or else they may become stuck there, and damage to the heads or media may occur.
In the case of a removable disk drive, the heads must also be kept in a safe place during disk insertion and removal, or else they may be damaged by moving parts, such as shutters and doors. Currently, additional sensors may added to a disk drive to determine if the heads are properly parked. However, adding sensors or other parts to a disk drive is undesirable as additional parts increase the overall cost and complexity of the drive.
What is needed is a disk drive that can determine if the heads of the drive are properly parked without adding costly sensors or parts to the drive. Preferably the drive would use a system that takes advantage of parts already needed on the drive for other functions.

Preventing damage to the heads and media in a removable cartridge and disk drive


A control system for a fuel delivery system provides enhanced functionality and diagnostic capabilities relative to known systems. In accordance with one aspect of the invention, enhanced functionality and diagnostic capability is provided by integrating the pump controller and the tank gauge by way of a control or integration unit. The control unit includes a microprocessor and communication hardware for communicating with the tank gauge and the pump controllers. In accordance with alternate embodiments of the invention, a control unit is included which provides additional functionality, such as automatic logging of controller faults.

1. Field of the Invention
The present invention relates to a fuel delivery system and more particularly to a control system for a fuel delivery system for use in gasoline service stations which provides enhanced functionality and diagnostic capabilities heretofore unknown.
2. Description of the Prior Art
Retail fuel delivery systems, for example, for dispensing gasoline, are known to include: one or more underground storage tanks for carrying various grades of fuel; a submersible pump disposed within each of said storage tanks for pumping fuel from the storage tank to a dispenser on demand; a level probe and a tank gauge for monitoring fuel level within the tank; and a dispenser which acts as a point of sale (POS) device for dispensing fuel to consumers. A pump controller is provided to run the submersible pump in response to certain signals being present. For example, many known dispensers include credit card readers for enabling a consumer to charge the purchase at the dispenser and enable the pump. In addition, the pump controller can be enabled from a service station attendant for an unspecified amount of purchase or a specified purchase. When one or more enabling signals are present, the pump controllers are under the control of a trigger mechanism disposed at the dispenser. Examples of such fuel delivery systems are disclosed in: U.S. Pat. Nos. 5,361,216; 5,363,093; 5,376,927; 5,384,714; 5,423,457; 5,757,664 and 6,302,165. Fuel delivery systems are also disclosed in published Patent Application No. U.S. 2001/0037839 A1, as well as commonly-owned U.S. Pat. No. 5,577,895, all hereby incorporated by reference.
Due to regulations promulgated by the Environmental Protection Agency over ten years ago, retail fuel delivery systems are now required to include leak detection systems for detecting leaks in the underground storage tanks. As such, a number of leak detection systems for such underground storage tanks are known. Examples of such leak detection systems are disclosed in U.S. Pat. Nos. 5,363,093; 5,376,927; 5,384,714; 5,423,457; 5,526;679; 5,757,664; and 5,779,097, all hereby incorporated by reference.
Other than the leak detection capabilities, the functional as well as the diagnostic capabilities of such fuel delivery systems are relatively limited. In particular, various common operating conditions exist which either go undiagnosed or are relatively difficult to diagnose. For example, conditions are known in which the submersible pump is installed incorrectly in that it is located too far from the bottom of the tank. This condition is often undiagnosed causing the pump controller to indicate that the tank is empty long before the tank gauge indicates a low level alarm resulting in fuel in the bottom of the tank never being used.
Various conditions are also known to exist which result in false alarms. For example, situations are known in which the pump controller is faulted during a leak detection test. During such a condition, a leak is indicated. False leak detection alarms can also be indicated in fuel delivery systems in which the underground tanks are connected together by piping or are "manifolded" and a check or relief valve is stuck in an open position.
In addition to limited and faulty diagnostics, fuel delivery systems are also known to have relatively limited functionality. For example, when a pump controller is faulted, such faults are indicated on the pump controller itself. As such, service station attendants are known to reset the pump controllers without logging the pump controller fault, thus, losing the fault history. Moreover, the pump controllers are normally contained in locked rooms. Thus, the attendants must be given access to the locked rooms to enable the pump controllers to be manually reset. Thus, there is a need for a control system with enhanced functionality and diagnostic capability for fuel delivery systems.

Fuel delivery system with enhanced functionality and diagnostic capability


A retro-reflective sensor for sensing mechanical, chemical or temperature related information, is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation, said optical waveguide having a glass transition temperature substantially higher than that of silica. Preferably the sensor is written into a length of sapphire fiber or within a zirconium waveguide. Preferably the pulse duration of the short pulsed electromagnetic radiation is less than 500 picoseconds.

Fiber Bragg grating sensors (FBG sensors) have attracted considerable attention in sensing temperature and strain on an optical fiber due to the variation in the spectral response of the grating as a result of strain and temperature on the grating structure. These FBG sensors offer important advantages such as electrically passive operation, EMI immunity, high sensitivity and multiplexing capabilities. Fiber gratings are simple, intrinsic sensing elements which traditionally have been UV photo-inscribed into photosensitive Ge-doped silica fiber. Each FBG sensor has a characteristic retro-reflective Bragg resonance or Bragg wavelength, which is dependent upon the periodicity of the grating within the fiber and the effective refractive index of the fiber. The FBG sensors can then easily be multiplexed in a serial fashion along a length of single fiber. When embedded into composite materials, fibers with an array of FBG sensors allow for distributed measurements of load, strain, temperature and vibration of the material creating what has is commonly referred to as "smart structures" where the health and integrity of the structure is monitored on a real-time basis.
Typically fiber Bragg gratings are generated by exposing the UV-photosensitive core of a germanium doped silica core optical fiber to a spatially modulated UV laser beam in order to create permanent refractive index changes in the fiber core. Such a spatially modulated UV beam can be created by using a two-beam interference technique as disclosed in U.S. Pat. No. 4,807,950 by Glenn et al. or by using a phase mask as disclosed in U.S. Pat. No. 5,367,588 by Hill et al.
A limitation of the prior-art UV-induced fiber Bragg gratings, especially for high temperature sensor applications is that operation of the sensor at elevated temperatures results in the erasure or annealing of the UV-induced color centers which are responsible for the induced index change of the grating. In fact, at temperatures approaching the glass transition temperature of the fiber, which for silica is approximately 1000° C., total erasure of the induced index modulation results. The fiber also is modified at such high temperatures making it brittle with diffusion of the core material into the cladding. The fiber can easily be deformed by its own weight.
Another method for creating permanent photoretractive index changes in glasses employs the use of intense UV beams with fluences or energy/unit-area per laser pulse densities that approach those required to produce macroscopic damage of the glass. Askins et al. in U.S. Pat. No. 5,400,422 teach a method for producing permanent photoretractive index changes in the photosensitive cores of Ge-doped optical fibers with single high intensity UV laser pulses. The high intensity portions of the interference fringes created by two crossed UV beams split from a single UV beam create localized damage at the core-cladding interface within the fiber. Because the process for inducing index change is one of structural change due to localized physical damage to the glass, rather than due to UV photoinduced color center formation, the induced index change is more robust and does not decrease with elevated temperature. In fact Askins et al. disclose that gratings produced in this way cannot be removed by annealing until the fiber or waveguide approaches the material's glass transition temperature. The drawback of this approach for induction of index change is that the Bragg gratings produced in this fashion have relatively low refractive index modulations (Δn=10−4) and are mechanically weak since the effective refractive index change results from periodic localized damage at the core-cladding interface. When the pulse duration is long (>a few tens of picoseconds) laser-excited electrons can transfer energy to the surrounding lattice faster than the thermal diffusion of the material can remove the energy resulting in damage. If the laser pulse continues to feed energy into the damage site, the damage can propagate beyond the irradiated zone. For damage grating structures written with long laser pulse durations greater a few tens of picoseconds, the spectral quality of the resulting Bragg grating is often poor.
The prior art FBG sensors suffer from serious limitations when measurement of displacement, temperature, strain and pressure are required at high temperatures. The materials used to fabricate the FBG sensing element deform or melt. The softening or glass transition temperature of silica optical fibers is typically 1000° C. At temperatures equal to or above this, silica optical fibers are not useful, even if they are coated with materials which melt at higher temperatures.
One approach to fiber-based measurements at high temperatures is to use sensor elements fabricated in fibers made of sapphire. Because sapphire has a very high glass transition temperature (˜2030° C.), a sensor fabricated in this fiber can be operated in high temperature environments. Currently, sapphire fibers are only made in the form of rods with diameters as low as 50 μm. These rods lack a cladding or a coating material similar to conventional silica fibers. The large diameter of the sapphire fiber does not support single mode propagation at typical wavelengths used for FBG sensors in silica fiber thus does not allow the implementation of the FBG sensor as described previously. A technique for the fabrication of a sapphire based optical fiber interferometer based on the fabrication of a Fabry-Perot etalon on the tip of the sapphire fiber has been taught by Murphy et al. in U.S. Pat. No. 5,381,229. Although this device is effective as a point sensor, is relies on the monitoring of the broadband interference fringe pattern generated by the Fabry-Perot etalon and therefore is extremely difficult to address in a wavelength-division or time-division multiplexing fashion. This makes the Fabry-Perot based fiber sensor inappropriate for distributed sensor arrays.
Mihailov et al. in U.S. Patent Application 20040184731 published Sep. 23, 2004, incorporated herein by reference discloses a technique for fabrication of Bragg grating structures in optical media such as optical fibers and waveguides with an ultrafast (<500 ps) laser source and a phase mask using a direct writing technique. The resultant grating structures have high induced-index modulations (>1×10−3). Since the refractive index change need not be dependent on the dopant in the core or cladding of the optical fiber or waveguide, refractive index changes can be induced in both regions of the waveguide. Processes that employ high-intensity laser pulses in the femtosecond pulse duration regime for creating permanent changes in the refractive indices of glasses have been explored by several groups of researchers. K. M. Davis et al. disclose a technique for inducing index change in bulk glasses with ultra-high peak power femtosecond infra-red radiation in Opt. Lett 21, 1729 (1996). The creation of waveguides in bulk glasses using this technique is taught by Miura et al. in U.S. Pat. No. 5,978,538 while the modification or trimming of existing waveguide structures is taught by Dugan et al. in U.S. Pat. No. 6,628,877. The physical process that causes the refractive index change in the materials is due to the creation of free electrons through non-linear absorption and multi-photon ionization of bound charges, followed by avalanche ionization and localized dielectric breakdown as these free electrons are accelerated by the intense but short time duration laser field. Also, this leads to a localized melting and restructuring of the material and a concurrent increase in the index of refraction. Recently Sudrie et al. in Opt. Comm., vol. 191, no. 3-6, pp. 333-339, 2001 disclosed a technique for inducing index changes in bulk silica using a femtosecond IR laser source with a power threshold below that needed for multi-photon ionization. The resultant index change induced by multiphoton absorption produced microscopic defects or color centers in the lattice. Unlike the index change created through localized dielectric breakdown of the material, the color center induced index change can be removed or annealed out at temperatures below the glass transition temperature of the material.
For a fiber grating sensor application it is desirable to obtain a single mode response in the reflection spectrum because the bandwidth of the response is narrower and there is improved signal to noise ratio as there is only one mode being inspected rather than a superposition of hundreds if not thousands of modes that can be supported in a multimode fiber. For step index fibers the normalized frequency or V number is given by:
                    V        =                                            2                            π                                                                                r                        λ                                                        (                                                n                  co                  2                                -                                  n                  cl                  2                                            )                                                          (        1        )
where r is the core radius, l is the wavelength and nco and ncl are the refractive indices of the core and cladding respectively. For single mode operation, V≦2.405. When a fiber is tapered, by using the hydrogen flame brushing technique for example (see Bilodeau et al U.S. Pat. No. 4,895,423 enclosed herein as reference) the ratio of cladding/core radii remains constant however V decreases. As disclosed in J. D. Love et al IEE Proceedings Journal vol. 138, no. 5, p.343-354 (1991), herein enclosed as reference, when single mode optical fiber is tapered down such that the normalized frequency or V number of the taper is V<0.84, the fundamental LP01 mode is no longer confined to the core but instead is guided by the cladding-air interface resulting in a mode field with the same diameter as the tapered fiber. By launching this expanded fundamental LP01 mode that has the same mode field diameter as the cladding of the multimode fiber, only the fundamental mode of the multimode fiber will be excited, in the absence of perturbations such as twisting and bending of the multimode fiber. The retro-reflection from the grating would still consist of a small number of modes however the fundamental from the grating would be reciprocally collected by the taper and converted to a core guided LP01 as it exited the tapered region of the coupling fiber.
As the technology for fabrication of long lengths of single crystal fiber is in its infancy, it is difficult and costly to have long lengths (>4 m) of sapphire fiber for a multiplexed sensor web. An alternative to single strands of fiber may be to couple short lengths of sapphire fiber, with gratings present, to single mode fiber which has been appropriately tapered to excite the fundamental mode of the sapphire fiber segment. If an identical taper to the input taper is placed at the output of the multimode sapphire fiber, then a single mode transmission response can be obtained. The device is a one way device in that at the Bragg resonance wavelength a single mode response is retro-reflected. Light propagating in the sapphire fiber that is not at Bragg resonance is transmitted through. If another sapphire grating is coupled into the fiber further along the line with another Bragg resonance, then its light is reflected from the second grating but is retro-reflected through the first. Therefore in one length of fiber comprising tapered and sapphire links two different locations can be monitored. In this fashion, sapphire fiber grating elements can be multiplexed together into a sensor web.
In another embodiment of this invention, for lower temperature applications that are near the glass transition temperature of silica, the sapphire multimode fiber rod could be replaced with a pure silica rod. The grating that could be written could be in silica rather than sapphire if the temperatures at which the device would operate would be below the glass transition temperature of silica. In such an instance, gratings written in the silica rod would not be distorted by out diffusion of the core dopant as the fiber approaches the glass transitions temperature. If the fiber is a silica rod without dopant (ie a core) then there is no core distortion as the fiber approaches the glass transition temperature. In another embodiment of this invention, the expanded mode field propagating through the multimode fiber is guided by air-material interface with the cross-section of the fiber acting as the guiding core. The single mode reflection obtained with the taper as described above would be dependent on the effective index seen by this mode. Since the mode as it propagates through the multimode fiber has a mode field the same as the fiber diameter, its effective index is influenced by the refractive index of the medium surrounding the multimode fiber. It is therefore possible to measure the refractive index of the medium in which the multimode fiber is embedded thus fabricating a chemical sensor. This defines a new chemical sensor, for measurement of refractive index external to the sapphire rod.
It is an object of this invention to overcome the aforementioned limitations within the prior art systems for fabrication of high temperature FBG sensors by inducing refractive index modulations in optical fibers with high melting temperatures such as sapphire fiber.
It is a further object of this invention to provide a method for probing a Bragg grating structure inscribed in a multimode fiber that results in a single mode response by using tapered fiber which launches a fundamental LP01 with an expanded mode field diameter that is the same as the fiber diameter.
It is a further object of this invention to provide a method for fabrication of a single mode core in the sapphire fiber rod into which a FBG sensor can be inscribed.
It is an object of this invention to overcome the aforementioned limitations within the prior art systems for fabrication of high temperature FBG sensors by inducing refractive index modulations in optical fibers with high melting temperatures such as sapphire fiber.
It is a further object of this invention to provide a method for fabrication of a single mode core in the sapphire fiber rod into which a FBG sensor can be inscribed.
It is a further object of this invention to provide a method for fabrication of a single mode core in the sapphire rod by the inscription of a localized FBG structure along the length of the sapphire rod.

Optical fiber sensor based on retro-reflective fiber Bragg gratings

Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, through the Communications Research Centre Canada


All purpose cleaning or microemulsion compositions more environmentally friendly, which is especially effective in the removal of a mixture of oil and kaolin soil, contains a negatively charged complex, a Lewis base, neutral polymer, and water.

This invention relates to an improved all-purpose liquid cleaner which can be in the form of a microemulsion designed in particular for cleaning hard surfaces and which is effective in removing grease soil and/or bath soil and in leaving unrinsed surfaces with a shiny appearance.
In recent years all-purpose liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, etc.. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered all-purpose cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art all-purpose liquids. For example, such early phosphate-containing compositions are described in U.S. Pat. Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No. 1,223,739.
In view of the environmentalist's efforts to reduce phosphate levels in ground water, improved all-purpose liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self pacified liquid of the latter type is described in U.S. Pat. No. 4,244,840.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the foregoing disadvantage of the prior art all-purpose liquid, U.S. Pat. No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free all-purpose liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today's consumers.
Another approach to formulating hard surfaced or all-purpose liquid detergent composition where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a "cosurfactant" compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of "oil" phase particles having a particle size in the range of 25 to 800 .ANG. in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616--Herbots et al; European Patent Application EP 0160762 - Johnston et al; and U.S. Pat. No. 4,561,991--Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published Mar. 13,1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
The following representative prior art patents also relate to liquid detergent cleaning compositions in the form of o/w microemulsions: U.S. Pat. Nos. 4,472,291--Rosario; 4,540,448--Gauteer et al; 3,723,330--Sheflin; etc.
Liquid detergent compositions which include terpenes, such as d-limonene, or other grease-removal solvent, although not disclosed to be in the form of o/w microemulsions, are the subject matter of the following representative patent documents: European Patent Application 0080749; British Patent Specification 1,603,047; 4,414,128; and 4,540,505. For example, U.S. Pat. No. 4,414,128 broadly discloses an aqueous liquid detergent composition characterized by, by weight:
(a) from 1% to 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant or mixture thereof; PA1 (b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio of (a):(b) being in the range of 5:1 to 1:3; and PA1 (c) from 0.5% 10% of a polar solvent having a solubility in water at 15.degree. C. in the range of from 0.2% to 10%. Other ingredients present in the formulations disclosed in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium or alkanolammonium soap of a C.sub.13 -C.sub.24 fatty acid; a calcium sequestrant from 0.5% to 13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to 10% by weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl sulfonates, up to 10% by weight. All of the formulations shown in the Examples of this patent include relatively large amounts of detergent builder salts which are detrimental to surface shine. PA1 about 3 to about 40 wt. %, more preferably about 5 to about 20 wt. % of an analephotropic negatively charged complex comprising at least one an alkali metal salt or an alkaline earth metal salt of a sulfate or sulfonate anionic surfactant and mixtures thereof being complexed with an amphoteric (zwitterionic) surfactant or a high dipole moment surfactant selected from the group consisting of amine oxides or alkylene carbonates. PA1 0.5% to 10%, more preferably 1% to 7%, of a Lewis base, neutral polymer; PA1 0 to about 15% of magnesium sulfate heptahydrate; PA1 the balance being water, said proportions being based upon the total weight of the composition. PA1 (a) at least one anionic surfactant which is an alkali metal salt or an alkaline earth metal salt of a sulfonate or sulfate surfactant; and PA1 (b) an amine oxide, zwitterionic surfactant or an alkylene carbonate, wherein the ratio of the anionic surfactant to the zwitterionic surfactant or amine oxide is 4:1 to 0.2:1, more preferably 2.5:1 to 0.4:1 and the ratio of the anionic surfactant to the alkylene carbonate is 7:1 to 1.2:1. The instant composition contains about 3 to about 40 wt. %, more preferably about 5 to about 20 wt. % of the analephotropic negatively charged complex.
A pH neutral microemulsion composition based on paraffin sulfonate and ethoxylated nonionic surfactant is able to deliver improved grease cleaning versus built, alkaline compositions. Besides the improved grease cleaning, this approach is much safer to surfaces as well as less aggressive on consumer's hands (Loth et al--U.S. Pat. No. 5,075,026).
The microemulsion technology provides outstanding oil uptake capacity because of the adjustment of the curvature of the surfactant micelles by the molecules of the cosurfactant. Rod-like micelles are preferred as they can "swallow" oil to become globular without increasing the surface of contact between the hydrophobic core of the micelle and the hydrophilic continuous phase.
In diluted usage however, the microemulsion state is usually lost and the cleaning performance relies on the adsorption efficacy and leaving character of the surfactant system. Nonionic surfactants perform very well on grease, as they are excellent grease "solubilizers". Actually, they spontaneously form swollen micelles. In moderate climate countries such as the northern states of the United States and the northern countries of Europe, the soil on the hard surfaces contains a major proportion of greasy materials. It is accordingly not surprising that the anionic-nonionic surfactant based microemulsion is so efficient in those countries. In hot weather countries however, the amount of particulate soils is more important (as doors and windows remain open) and the classical microemulsion (U.S. Pat. No. 5,075,026) shows weaknesses on this type of soil which is a mixed grease-particulate soil in nature.
The instant invention solves this problem by delivering on the solid surface to be cleaned the proper surfactant mixture that best adsorbs on the surface while keeping a good "leaving" character.
The instant invention teaches that all purpose cleaning or microemulsion compositions containing a negatively charged complex of an anionic surfactant with an amphoteric or high dipole moment surfactant deliver this desired property. The analephotropic complex adsorbs much better on grease than on silica surface than individual anionic surfactants alone. This results in enhanced capabilities to disperse complex mixtures of grease with embedded particles of soil which are essential for particulate soil removal.
As illustrated in the examples, it is essential that the complex mixture is negatively charged. Pseudo-nonionic surfactants resulting from anionic-cationic complexes which are not negatively charged show very low particulate soil removal.

Liquid cleaning composition consisting essentially of a negatively charged complex of an anionic surfactant and an amine oxide or alkylene carbonate


Light emitting polymers can include a plurality of arylene monomeric units and a plurality of soft segment units independently selected from soft segment end caps; soft segment side chains coupled to a portion, but not all, of the arylene monomeric units; internal soft segment monomeric units; and combinations thereof. These light emitting polymers can be used in forming electroluminescent devices or other articles.

Electroluminescent materials can be used to make organic electroluminescent (OEL) devices such as organic light emitting diodes (OLEDs). There is continuing research and development of materials suitable for such devices and methods for making the devices. In some instances, materials can be selected or developed which facilitate one or more of these methods.
Patternwise thermal transfer of materials from donor sheets to receptor substrates has been proposed as one method for forming OEL devices. Selective thermal transfer of organic light emitters for formation of organic electroluminescent devices has been shown to be particularly useful.

This patent is subject to a terminal disclaimer.

Electroluminescent materials and methods of manufacture and use


An annular vent assembly is provided for securement over one side of a panel having a vent opening therethrough. The vent assembly is equipped with a readily removable and rotatably supported incident wind scoop as well as alternately usable perforated and imperforate closures capable of enjoying weather tight connections with the vent assembly. Also, the vent assembly includes a semipermanently mounted annular base assembly from which all other components of the vent assembly may be readily removed.

1. Field of the Invention
This invention relates to an improvement on my prior cover equipped flexible panel vent disclosed in U.S. Pat. No. 3,892,169 and incorporates a rigid surface mount therefore, an alternate solid closure and retaining tabs for the rotatable scoop to prevent accidental dislodgement thereof.
2. Description of Related Art
The ventilator of the instant invention comprises an improvement over the vent disclosed in my prior U.S. Pat. No. 3,892,169 and incorporates additional structure whereby the vent may be mounted from a rigid panel by conventional fasteners, wherein an alternate solid closure is provided therefore and whereby the wind scoop or hood is equipped with retaining tabs preventing unintentional dislodgement thereof.
The main object of this invention is to provide a readily installed vent for a solid panel having a vent opening therein.
Another object of this invention is to provide a vent construction incorporating an alternate solid closure for the vent passage extending therethrough.
Yet another important object of this invention is to provide the vent with a rotatably adjustable wind scoop equipped with retaining tabs preventing accidental dislodgement thereof.
Still another very important object of this invention is to provide a ventilator or vent construction in accordance with the preceding objects and which may be rendered substantially weatherproof.
A final object of this invention to be specifically enumerated herein is to provide a vent construction in accordance with the preceding objects and which will conform to conventional forms of manufacturer, be of simple construction and easy to use so as to provide a device that is economical feasible, long lasting and relatively trouble free in operation.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numeral refer to like parts throughout.


A method for controlling the switching of an inverter, a bridge of which is adapted to chop a voltage from a direct voltage source for feeding a chopped voltage to a primary of a transformer; the inverter comprises a diode rectifier circuit receiving the input voltage from the secondary of the transformer in order to achieve a voltage fed to a chopper which feeds a load. The method comprises: a step in which the switches of the bridge are driven so that the power source is disconnected from the primary, the terminals of which are connected to each other by at least two of the electronic switches and recirculation diodes of the bridge itself, so that the voltage present on the secondary of said transformer is null; a step in which the switching of at least one electronic switch of a chopper branch is achieved when the voltage on the secondary is substantially null in order to minimize switching losses due to the opening/closing of the electronic switch of the chopper.

Inverters are known in which a bridge (e.g. an H bridge) is adapted to chop a voltage from a direct voltage source for feeding an alternating voltage to a primary of a transformer; the inverter further comprises a diode rectifier-leveler circuit receiving the input alternating voltage from the secondary of the transformer in order to achieve a leveled voltage fed to a chopper which in turn feeds a load. The chopper generally includes a plurality of parallel branches (different chopper structures with two, three or more stages are possible), each of which consists of a pair of electronic semiconductor switches arranged in series and interposed between a positive power supply line and a negative power supply line from the rectifier-leveler circuit. The common terminals of the electronic switches of the chopper communicate with load power supply lines; each electronic switch of the chopper is also provided with a recirculation diode arranged in parallel.
The switching of the electronic switches of the chopper is controlled by an electronic unit which operates a certain load feeding program (for example, if such a load is an electric motor, the rotation speed of the motor and the power delivered by the motor itself can be set and adjusted).
Known electronic units control the switching of the chopper switches, under many operating conditions, in the presence of voltage at the ends of the switches themselves; such an operation—as known from the physics Of semiconductors—results in a power dissipation that contributes to a considerable part of switching losses.

Method for driving inverters, and inverter adapted to reduce switching losses


Disclosed is a gas detection system and method using a smart phone. The gas detection system includes a sensor module detachably mounted to the smart phone and configured to detect and measure a combustible gas or a toxic gas; and a gas detection APP installed inside the smart phone and configured to acquire measurement data by detecting the combustible gas or the toxic gas and measuring the detected combustible gas or toxic gas through the drive of the sensor module, after automatically recognizing user information and location information by reading a radio frequency identification (RFID) tag indicating a user or a location of gas detection, using a contact unit having built therein an RFID reader inside the smart phone, wherein the smart phone transmits the user information, the location information and the measurement data acquired from the gas detection APP to an operation server through a communication network.

1. Field of the Invention
The present invention relates to a gas detection system and method using a smart phone, and more specifically, to a gas detection system and method using a smart phone, which can secure reliability of data on the inspection location and inspection result when gas is measured for a user, by minimizing artificial manipulation and input error of an inspector.
2. Description of Related Art
A conventional gas detection method entails a problem in that since an inspector visits each home and inspects gas using a detector, and inputs and confirms data through a PDA based on the inspected content, efficiency is lowered due to the two kinds of works, including both inspection of gas and input of data according to the gas inspection.
In addition, when the inspector visits a building such as each home and inputs an address of an inspection target (hereinafter, referred to as "a user"), i.e., a target of inspection, and confirms the user using a PDA, an input error may occur or a decision error may be made in the input process, thereby deteriorating accuracy of data.
Furthermore, since reliability of the gas inspection is doubted due to the problems of artificial manipulation of an inspector and a mistake of the inspector in making a decision, there occurs a problem in that complaints are endlessly raised.
Specifically, first, with regard to management of the inspector, i.e., a worker, since details regarding a work performance of the inspector are reported based on the conscience of the inspector and the signature of a householder in the current working environment, there is a problem in the reliability of gas inspection.
Furthermore, with regard to reliability of the gas inspection result, the reason why doubts are constantly raised over the reliability of the gas inspection result in the current working environment is that manipulation on the handwriting record book and the PDA input is suspected.
Furthermore, with regard to work efficiency and convenience of customers, in the current working environment, an inspector should get a signature of an inspection target living in the house at the inspection location in an attempt to confirm the inspection result after performing the inspection. However, in this process, although the inspector revisits the inspection location to get a signature, the householder may refuse signing the inspection result or leave the house, inefficiency of work and inconvenience of customers may be invited due to disputes with customers.
Furthermore, with regard to safety of inspection behaviors, in the current inspection procedure, although inspection is periodically performed on a monthly basis and a result of the inspection is recorded through handwriting or a PDA and kept and managed in an office, there is a limitation in that the inspection is merely simple management of confirmation on whether or not abnormality is present and cannot analyze data and take previous measures against an expected danger such as a progressive gas leakage or the like.
Furthermore, with regard to utilization of inspection data, since most of existing inspection data are recorded through handwriting, they are just stored in a document storage room as long as leakage of gas is not detected. Although some of the data are computerized using a PDA, they are just stored but are not utilized.
Furthermore, with regard to efficiency of the detector, in the current working process, an inspector should carry a gas leakage detector, a handwriting record book, a PDA or all of these as basic equipment.
Finally, with regard to reliability of the detector, since an existing detector secures reliability of the detector only by a correction (test) record on an annual basis, reliability of a situation at the time moment where detection was performed is lowered.
Therefore, there is a need for the development of a technique for securing reliability of measurement of gas for a user by an inspector and reliability of a measured data.

Gas detection system and method using smart phone


Epitaxial silicon carbide layers are fabricated by forming features in a surface of a silicon carbide substrate having an off-axis orientation toward a crystallographic direction. The features include at least one sidewall that is orientated nonparallel (i.e., oblique or perpendicular) to the crystallographic direction. The epitaxial silicon carbide layer is then grown on the surface of the silicon carbide substrate that includes features therein.

The present invention relates to methods of fabricating semiconductor materials used in electronic devices, such as power electronic devices. In particular, some embodiments of the invention relate to processes that can reduce crystal defects in silicon carbide, and the resulting structures and devices. The present invention is related to the subject matter disclosed and claimed in commonly assigned U.S. Pat. No. 6,849,874, issued Feb. 1, 2005, as well as commonly assigned U.S. Pat. No. 7,018,554, issued Mar. 28, 2006, the contents of both of which are incorporated entirely herein by reference in their entirety, as set forth fully herein.
Silicon Carbide
Silicon carbide (SiC) has emerged over the last two decades as an appropriate candidate semiconductor material that can offer a number of advantages over both silicon and gallium arsenide. In particular, silicon carbide has a wide bandgap, a high breakdown electric field, a high thermal conductivity, a high saturated electron drift velocity, and is physically extremely robust. Silicon carbide has an extremely high melting point and is one of the hardest known materials in the world.
Because of its physical properties, however, silicon carbide also may be relatively difficult to produce. Because silicon carbide can grow in many polytypes, it may be difficult to grow into large single crystals. The high temperatures used to grow silicon carbide also may make control of impurity levels (including doping) relatively difficult, and likewise may raise difficulties in the production of thin films (e.g. epitaxial layers). Because of its hardness, the traditional steps of slicing and polishing semiconductor wafers also may be more difficult with silicon carbide. Similarly, its resistance to chemical attack may make it difficult to etch in a conventional fashion.
In addition, silicon carbide can form over 150 polytypes, many of which are separated by relatively small thermodynamic differences. As a result, growing single crystal substrates and high quality epitaxial layers ("epilayers") in silicon carbide has been, and may remain, a difficult task.
Nevertheless, based on a great deal of research and discovery in this particular field, including that carried out by the assignee of the present invention, a number of advances have been made in the growth of silicon carbide and its fabrication into useful devices. Accordingly, commercial devices are now available that incorporate silicon carbide as a substrate for other useful semiconductors such as the Group III nitrides, to produce blue and green light emitting diodes. Also, commercial silicon carbide-based devices are available for microwave and radio frequency (RF) high-power, high-voltage applications, and/or for other applications.
As the success of silicon-carbide technology has increased the availability of certain SiC-based devices, particular aspects of those devices have become more apparent. In particular, it has been observed that the forward voltage (Vf) of some silicon carbide-based bipolar devices such as bipolar power devices may increase noticeably during operation of some devices. This increase is generally referred to as "Vf drift." For a number of reasons, such functional problems in semiconductor devices can often result from defects in the crystal structure of the material from which the devices are formed. Examples of these defects are discussed below.
Deposition systems and methods are commonly used to form layers of semiconductor materials, such as thin epitaxial films, on substrates. For example, a chemical vapor deposition (CVD) reactor system and process may be used to form a layer of semiconductor material such as silicon carbide (SiC) on a substrate. CVD processes may be particularly effective for forming layers with controlled properties, thicknesses, and/or arrangements such as epitaxial layers. Typically, in a deposition system, such as a CVD system, the substrate is placed in a reaction chamber within a susceptor and one or more process gases including reagents or reactants to be deposited on the substrate are introduced into the chamber adjacent the substrate. The process gases may be flowed through the reaction chamber in order to provide a uniform or controlled concentration of the reagents or reactants to the substrate.
Silicon Carbide Crystal Structure
A deposition system, such as a CVD reactor, may be used to form epitaxial layers of silicon carbide on a single crystal silicon carbide substrate having a predetermined polytype such as 2H, 4H, 6H, 15R, 3C and the like. The term "polytype" refers to the ordering and arrangement of layers of atoms within a crystal structure. Thus, although the different polytypes of silicon carbide are stoichiometrically identical, they possess different crystal structures and consequently may have different material properties such as bandgap, carrier mobility and breakdown field strength. The letters H, R and C refer to the general crystal structure of the polytype, namely, hexagonal, rhombohedral and cubic, respectively. The numbers in the polytype designations refer to the repetition period of layer arrangements. Thus, a 4H crystal has a hexagonal crystal structure in which the arrangement of atoms in a crystal repeats every four bi-layers.
FIG. 1 illustrates a hexagonal unit cell of a hypothetical crystal. The unit cell 60 includes a pair of opposing hexagonal faces 61A, 61B. The hexagonal faces are normal to the c-axis, which runs along the <0001> direction as defined by the Miller-Bravais indexing system for designating directions in a hexagonal crystal. Accordingly the hexagonal faces are sometimes called the c-faces, which define the c-planes or basal planes of the crystal. Planes perpendicular to the c-plane are referred to as prismatic planes.
Silicon carbide possesses a number of potentially advantageous physical and electronic characteristics for semiconductor performance and devices. These may include a wide bandgap, high thermal conductivity, high saturated electron drift velocity, high electron mobility, superior mechanical strength, and radiation hardness. However, the presence of crystalline defects in silicon carbide films may limit the performance of electronic devices fabricated in the films, depending on the type, location, and density of the defects. Accordingly, significant research has focused on reducing defects in silicon carbide films. Certain defects, such as micropipes, are known to severely limit and even prevent device performance. Other defects, such as threading dislocations, are not considered to be individually catastrophic to device operation, and therefore they may not significantly impact device performance at densities normally found in epitaxial films.
For applications where a high voltage blocking capability is desired (for example power switching applications), silicon carbide films are usually grown "off-axis." That is, the substrate crystal is sliced at an angle that is slightly oblique to the normal crystal axis (the c-axis). Taking for example a hexagonal polytype such as 4H or 6H, the oblique angle of the cut may be made in one of the standard crystallographic directions illustrated in FIG. 2, namely the <11 20> direction (towards a point of the hexagonal unit cell) or the <10 10> direction (towards the center of a flat side of the hexagonal unit cell), or along a different direction. As a result of the off-axis slicing, the face of a prepared substrate may be characterized by a periodic arrangement of plateaus and steps. See, for example, U.S. Pat. No. 4,912,064 to Kong et al, entitled Homoepitaxial Growth of Alpha-SiC Thin Films and Semiconductor Devices Fabricated Thereon, assigned to North Carolina State University, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein.
Thus when an epitaxial layer is grown on the substrate, the deposited atoms bond to atoms at the exposed edges of the crystal layer steps, which causes the steps to grow laterally in so-called step-flow fashion. Step-flow growth is illustrated in FIG. 3. Each layer or step grows in the direction in which the crystal was originally cut off-axis (the <11 20> direction in the case illustrated in FIG. 3).
Crystallographic Defects
At the most basic level, structural crystallographic defects may fall into four categories: point defects, line defects, planar defects and three dimensional defects. Point defects include vacancies, line defects include dislocations, planar defects include stacking faults and three-dimensional defects include polytype inclusions.
A dislocation is a kind of structural imperfection that extends for many unit cell lengths throughout a crystal. A more definite description of dislocation may classify them as screw and edge dislocations. As recognized by those persons skilled in this art, a symmetrical path followed from atom to atom (or from ion to ion) in a real crystal that returns upon itself, is referred to as a Burgers circuit. If the same path in the lattice that typifies the structure does not return upon itself, so that the beginning and end do not lie on the same atom, then the Burgers circuit encloses one or more dislocations. The vector that completes the closed circuit in the lattice is referred to as the Burgers vector and measures the magnitude and direction of the dislocation.
If the Burgers vector is parallel to the line that locates the dislocation, the defect is referred to as a screw dislocation. Alternatively, if the Burgers vector is perpendicular to the dislocation, it is referred to as an edge dislocation. The simplest version of an edge dislocation is an incomplete plane of atoms or ions interleaved between two normal planes in a manner somewhat analogous to an extra card inserted halfway into a deck.
Screw dislocations are not necessarily disadvantageous and, in fact, can be advantageous for the growth of a crystal. For example, a 1C threading screw dislocation at the nominally (0001) oriented growth surface of a silicon carbide crystal presents a regenerating edge that is one or a few atoms high. At this edge, continued growth of the crystal is relatively easy. Dislocations, however, allow plastic flow to occur in a crystal relatively easily. Dislocations may move preferentially along slip planes. The dislocation moves relatively easily through the crystal because motion in the slipped plane involves only a slight displacement of the structural elements. Stated differently, the slipped planes provide a low-energy intermediate state by which a crystal can be reorganized.
Defects in Silicon Carbide
In silicon carbide power devices, the availability of such a relatively low-energy intermediate state may encourage faults to continue to grow, since the operation of the device can provide the relatively small amount of energy that may be required to drive dislocation motion.
Commercial quality SiC wafers and epilayers typically include both screw and edge dislocations. These dislocations can be further grouped by their alignment within the crystal. Those dislocations that propagate along the c-axis are called threading dislocations, while dislocations that lie within the c-plane are termed basal plane dislocations. In general, in SiC, it is energetically favorable that basal plane dislocations may preferentially decompose into partial dislocations via the mechanism described below:⅓<11 20>→⅓<10 10>+⅓<01 10>  Equation 1
The above decomposition reaction describes the decomposition of a basal plane dislocation into two Shockley partial dislocations. The line defects generated during the above decomposition will bound a stacking fault defect. In fact, partial dislocations will generally bind the entire perimeter of the stacking fault unless the stacking fault reaches a free surface. This stacking fault will generally be electrically active in bipolar devices, and, during forward operation, the density of the electron-hole plasma may be reduced in the vicinity of the stacking fault. The reduced plasma density may increase the forward voltage of the device. A further potential complication is that through recombination enhanced dislocation glide, the stacking fault may continue to expand during forward operation of the device. This behavior can raise a substantial barrier to device exploitation because it can result in devices with functional properties that can change unpredictably during operation.
Stated differently, the application of electric current through a silicon carbide bipolar device may tend to initiate or propagate (or both) changes in the crystal structure due to preexisting defects in the crystal. As noted above, many SiC polytypes are in close thermodynamic proximity, and solid phase transformations are quite possible. When the stacking faults impact a significant portion of the active area of a device, they tend to cause the forward voltage to increase in an undesirable manner that can prevent the device from operating as precisely and/or efficiently as required or desired in many applications.
In some conventions, dislocation density is described by centimeters of dislocation length per cubic centimeter of material, and thus report dislocation density units of per square centimeter (cm−2). In another convention (and as used herein) the off-axis orientation of 4H—SiC substrates for SiC epilayer growth and the common etch technique used to detect dislocations make it more convenient to use etch pit density (also in the units of cm−2), to describe dislocation densities in SiC. Those of skill in this art will thus recognize that for a given dislocation density expressed as cm/cm3, one could get a very different dislocation pit density when expressed as pits/cm2 depending on the typical dislocation configuration and the off-axis angle of the substrate. Therefore, although the two numbers will have the same net units (cm−2), they do not necessarily indicate the same actual dislocation density. For the sake of clarity and consistency, in the present application, dislocation density will be described as the density of specific pits delineated on an etched epi-surface of a silicon face prepared, 8° off-axis (0001) oriented substrate.
Present commercially available 4H—SiC substrates may have approximately 1E3 to 1E5 (about 103-105) dislocations per cm2 by the convention used herein. This includes threading screw and edge dislocations and basal plane dislocations. Presumably, all types of dislocations can impact device performance, but the basal plane dislocation has been particularly implicated as the prevalent nucleation site of the stacking faults that may cause Vf drift.
In turn, defects in the substrate are often replicated in epitaxial layers grown on such substrates, thus making substrate crystal quality a profoundly important factor with respect to the quality and performance of resulting devices.
Conventional substrate preparation and epilayer growth practices can fairly effectively reduce the density of basal plane dislocations from 1E3-1E4 cm−2 in the substrate to about 400 cm−2 in the epilayer. This reduction in dislocation density may be accomplished via changes in both the substrate preparation and the epilayer growth operations.
Accordingly, for continued improvement in the structure and operation of SiC-based bipolar and other devices it may be desirable to provide continued improvement in the underlying substrates and their crystal structures.

Featuring forming methods to reduce stacking fault nucleation sites


Liquid fabric softener compositions containing a combination of certain block copolymers and water soluble polymers to provide excellent storage stability and viscosity characteristics, especially at elevated temperatures.

Fabric softener compositions, especially concentrated and/or superconcentrated, are dispersions of positively charged vesicles containing the softener active. These vesicles are believed to be comprised of alternating concentric layers of water and lamellar cationic bilayers, so-called lamellar droplets. The presence of lamellar droplets in a fabric-softening composition can be detected by methods known to persons skilled in the art like optical techniques, rheometrical measurements, X-ray diffraction and electron microscopy. The droplets consist of an onion-like configuration of, as pointed out above, concentric bilayers of molecules of fabric-softening material with entrapped water or electrolyte solution, the so-called aqueous phase.
A well-appreciated fabric softener product exists of physical stability and desirable flow properties combined in one system.
However, upon storage the dispersions above-mentioned are thickening and eventually gelling. The reason for this phenomenon is not yet clear. There are, at least, two theoretical possibilities: the lamellar vesicles are increasingly interconnecting with time and eventually (1) form an infinitely inter-connected vesicle network or gel, or (2) change from a lamellar vesicle to a two-phase lamellar phase in which gelation may occur.
Regardless of the mechanism, gelation probably will be avoided as long as the vesicles are kept separated from each other.
It is well-known that two factors mainly determine the viscosity and stability of the fabric softening composition. First of all, it is the volume (fraction) of the dispersed lamellar phase in the composition and secondly it depends on the state of aggregation of these droplets. In general, the higher the volume (fraction) of the droplets (dispersed lamellar phase), the higher the viscosity which, if too high, results in an unpourable product. One way to solve this problem is using electrolytes whereby apparently the size of the lamellar vesicles is reduced and, as such, increases the inter-vesicle distances preventing aggregation/gelation.
However, the stability of other components in the fabric-softener composition is affected using higher electrolyte levels.
So there are limits to the amount of fabric softening material and electrolyte to be used whilst still having an acceptable product. There is a continued need for more concentrated, sometimes superconcentrated, fabric softening compositions for convenience and cost reduction purposes. The problem to be solved is that these high concentrations of softener active in the compositions must have an acceptable stability and at the same time pourability upon use.

Block copolymers for improved viscosity stability in concentrated fabric softeners


Systems and methods of controlling signal polarization for an antenna system are provided herein. The antenna system includes an ultra wide band or greater array of dual linear polarization elements. The antenna system also includes polarization synthesis networks. Each of the polarization synthesis networks is coupled to the first differential interface of the first element of a respective dual linear polarization element of the dual linear polarization elements and the second differential interface of the second element of the respective the dual linear polarization element of the dual orthogonal linear polarization elements. Each of the polarization synthesis networks has a flat response for phase shift and amplitude over the ultra wide bandwidth.

Embodiments of inventive concepts disclosed herein relate generally to communication systems including but not limited to antenna systems for and methods of communicating signals having polarization characteristics.
Modern sensing and communication systems may utilize various types of antennas to provide a variety of functions, such as communication, radar, and sensing functions. For example, ultra-high frequency (UHF) and very high frequency (VHF) radio systems use directional and omnidirectional antenna arrays for data and voice communication. In another example, radar systems use antenna arrays to perform functions including but not limited to: sensing, intelligence gathering (e.g., signals intelligence, or SIGINT), direction finding (DF), electronic countermeasure (ECM) or electronic self-protection (ESP), electronic support (ES), electronic attack (EA) and the like. Various active electronically scanned array (AESA) applications utilize a particular polarization state, such as linear, circular, or elliptically polarizations for communicated or sensed radio frequency (RF) signals. Some applications operate across a large band (ultra-wide band (UWB) or ultra-ultra-wide band (UUWB)).

Element level polarization synthesis network for electronically scanned arrays


An imaging apparatus 10 according to one implementation of the present invention includes: a plurality of photodetectors 5a and 5b; a transparent layer 2 provided at the side of a light-receiving surface 15a, 15b of the photodetectors 5a and 5b; a plurality of spectroscopic portions 3 provided between a light-entering surface 2a of the transparent layer 2 and the photodetectors 5a and 5b; and a plurality of high refractive index transparent members 6 provided closer to the photodetectors 5a and 5b than are the spectroscopic portions 3. The high refractive index transparent members 6 have a higher refractive index than does the transparent layer 2.

In recent years, the increased numbers of pixels in digital cameras and digital movie cameras have necessitated miniaturization of cell sizes in CCD structures, CMOS structures, and the like. However, miniaturized cell sizes introduce a physical decrease in the geometric area in which light is received, thus lowering the amount of received light. Therefore, what is needed in the future is imaging structures for introducing an increase, even if only a little, in the efficiency of light utilization.
Patent Document 1 proposes an imaging apparatus without color filters which is meant to provide an improved efficiency of light utilization. Light entering the imaging apparatus passes through a plate-like transparent spectroscopic portion which has a higher refractive index than do the surroundings, whereby 0th order light and ±1st order light of respectively different wavelengths occur. It is designed so that the resultant 0th order light and ±1st order light enter respectively different photodetectors. The proposal is to, by using such a transparent spectroscopic portion, enhance the efficiency of light utilization over that of conventional imaging apparatuses in which color filters are employed.
Patent Document 2 discloses an inner-layer lens as a converging device in an imaging apparatus, where light convergence is enhanced through a lens effect. Patent Document 3 discloses an optical waveguide, as a converging device in an imaging apparatus.

Panasonic Intellectual Property Management Co., Ltd.


A manually operable luggage cart includes a central and unitary storage chamber with planar top and bottom surfaces. The assembly further includes a handle that is pivotal between rectilinear oblong displaced positions extending parallel and diagonal to a longitudinal length of the storage chamber, a plurality of casters rotatably connected to the storage chamber, and a mechanism for automatically biasing the casters between exposed and retracted positions from the bottom surface of the storage chamber when the handle is pivoted between the parallel and diagonal positions and about a curvilinear path defined adjacent to the proximal end of the storage chamber. The adaptable luggage cart further includes a plurality of straps.

1. Technical Field
This invention relates to luggage carts and, more particularly, to an adaptable luggage cart for transporting goods between remote locations.
2. Prior Art
Everyday, countless consumers climb into automobiles, buses and airplanes and embark on business trips and family vacations. Whether traveling across state lines in order to visit a favorite relative, trekking across country for a relaxing stay at a beach front resort, or climbing aboard a 747 for an important business meeting, spending time away from home is a fact of life for millions of people. Regardless if one travels for business or pleasure, most consumers do not leave home without first packing personal belongings necessary for the trip. Changes of clothing, shoes, toiletries, hair dryers and personal mementos are but a few of the many items most people pack into a suitcase and take with them on the road.
While packing a suitcase for travel is necessary, actually transporting packed luggage can be a difficult task. For those who utilize traditional, handled suitcases and travel bags, transporting these goods involves the burden of balancing the entire weight of the bag on one arm or shoulder. Straining the muscles of the neck and back, carrying a packed suitcase can be an exhausting endeavor, particularly for elderly persons and those who are not in the best physical shape. Although luggage manufactures have recently begun adding two wheels to the design of many suitcases in order to facilitate transport, transporting several bags at once can be problematic.
Simply stated, most consumers find that they must carry more than one suitcase or travel bag with them when they travel, simply in order to make room for such necessities as toiletries, extra shoes, hairdryers, curling irons and similar goods. In addition, for those traveling with small children, items such as car seats, portable cribs and similar infant accessories are absolute necessities which must be manually carried when transporting items through an airport, train station, or even from one's vehicle to a hotel room. Obviously, it would be advantageous to provide a more practical means of transporting the many items needed during travel.
U.S. Pat. No. 7,219,904 to Boom discloses a luggage cart assembly including a base that has a top side, a bottom side, a first end edge, a second end edge, a first lateral edge and a second lateral edge. A plurality of wheels is rotatably coupled to the bottom side. The top side has a plurality of wells extending therein. Each of the first and second side edges have two wells positioned adjacent thereto. A plurality of posts each has a first end and a second end and a bend positioned between the first and second ends. Each of the first ends is positionable into one of the wells such that second ends of adjacent posts extend toward each other. A pair of fastening members removably secures adjacent ones of the second ends together. A rod has a pair of opposite ends. Each of the opposite ends is removably attached to one of the fastening members. Unfortunately, this prior art example does not incorporate a storage chamber.
U.S. Pat. No. 7,140,635 to Johnson discloses a frame assembly, two wheel holding carriers which are arcuately pivotably mounted to the frame assembly, and a support platform which is also pivotally mounted to the frame assembly and controls the movement of the wheel holding carrier. A small, compact, two wheeled, luggage cart/carrier is achieved which is capable of quickly and easily arcuately pivoting wheel support brackets between two alternate positions, with ease and convenience. In addition, the arcuate pivoting movement of the wheel supporting brackets is automatically achieved simultaneously with movement of the luggage support platform from a stowed position to a deployed, usable position. The support platform is pivotally mounted to the terminating end of the frame assembly for being arcuately pivoted between a first, stowed position and a second, deployed position wherein the support platform is substantially perpendicular to the plane established by the frame assembly. Unfortunately, this prior art example does not incorporate a storage chamber.
U.S. Pat. No. 6,367,602 to Chang discloses a retractable wheel for a built-in luggage cart with a pair of telescopic pull rods, a handle mounted on the upper ends of the pull rods and retractable wheels provided at opposite sides of the lower edge of the luggage near the lower ends of the pull rods. The retractable wheel has a frame attached to the luggage and defined with a wheel well, a retractable wheel mount having an upper end pivotally connected to the frame, and a wheel rotatably attached to the lower end of the wheel mount, a strut vertically movable in the frame, a pair of arms having one end thereof pivotally connected to the strut and the other end thereof pivotally connected to the wheel mount, thereby the retractable wheel is extendable and retractable when the pull rods of the built-in luggage cart are extended and retracted. Unfortunately, this prior art example does not include straps for securing additional luggage to the cart.
Accordingly, the present invention is disclosed in order to overcome the above noted shortcomings. The present invention satisfies such a need by providing an assembly that is convenient and easy to use, lightweight yet durable in design, and designed for transporting goods between remote locations. The adaptable luggage cart is simple to use, inexpensive, and designed for many years of repeated use.

Adaptable luggage cart for transporting items between remote locations


A probe assembly for a process vessel for viewing the inside of the vessel, the probe assembly includes an elongated bracket, an elongated frame, an ICPC unit, and a camera unit. The elongated bracket has a front face and a rear face, the elongated bracket having an upper portion and a lower portion, the lower portion has a first aperture. The elongated frame has a proximal end and a distal end, the distal end of the elongated frame is coupled to the upper portion of the front face of the bracket. The ICPC unit includes a housing that has a front wall, a rear wall, and side wall extended between the front wall and the rear wall, the front wall has a second aperture, the rear wall has a third aperture. The ICPC unit further includes an actuator enclosed in the housing and an elongated tube operably coupled to the actuator, the tube extends through the second aperture and the first aperture away from the rear face of the bracket, the actuator configured to reciprocate the tube between an extended position and a retracted position. The camera unit includes a camera enclosure housing a camera, wherein the actuation member is configured to reciprocate the camera unit between the engage mode and stand-by mode, in the engage mode, the lens' hood is within the tube of the ICPC unit, and in the stand-by mode, the camera unit is away from the ICPC unit towards the proximal end of the elongated frame.

For many years, operators of process vessels such as melting furnaces, degassers, smelters, and such equipment had no visibility of the condition of the vessel before, between, and after a process cycle other than by the human eye when a roof is removed or through portholes or other openings in the vessels such as slag holes, etc. In these cases, operators would have to get into possibly dangerous positions and quickly observe the condition in the vessel after a process stop and if possible after loading of the vessel.
Over the years, camera systems with protective cooled jackets were developed to allow operators to observe certain conditions within the vessels. In some cases, cameras were developed with retraction mechanisms that allow the cameras to be moved into position for a short time and removed using timers or after temperatures reached the maximum allowable for the camera.
Known are roof-mounted camera systems for process vessels having the cameras mounted on the roof of the vessels to view the vessel from above. These cameras by the nature of the violence of the reactions during processing could be inserted into the roof when feasible and retracted. The views from the camera while helpful do not show a view of the sidewalls of the vessel or the vertical view of the charge or heel. Also known are the camera systems having the cameras mounted above the vessel and to the side: This application is relatively new and allows the operator to look into the vessel between process cycles when the roof is removed for charging. These cameras are limited to the view from above but do provide a valuable and safe evaluation of the conditions within the vessel including if possible, the activity at the surface of the process liquids.
Also are known other methods for observing the interior of the process vessel. For example, cameras positioned outside of the slag hole can observe the flow of slag or waste and once the vessel is emptied (tapped) there is a momentary and restricted view of the inside of the furnace. Also, known are cameras mounted on robots that have as their primary purpose to perform minor repairs to the vessel refractory and taking temperature and chemical samples of the liquid process material.
However, the known camera systems for looking into the process vessels have several limitations. In specific, the known camera systems do not allow for in-situ observation and measurement of high temperature and molten material processes. A need is therefore appreciated for a camera system for process vessels that can provide a better inside view of the vessel when needed. A need is there for a system that improves the process efficiencies. A need is there for a system that can improve the overall safety of the process. Moreover, a need is there for a system that may allow equipment condition evaluations without opening the vessel. A need is there for a system that may allow looking inside molten material vessels before, after, and between melts without opening the vessel.


An image recording apparatus comprises a beam generating unit for generating a light beam modulated in accordance with input image signal, a beam deflecting unit for scanning a recording medium using the light beam generated by the beam generating unit, the beam deflecting unit comprising a rotating polygon mirror having a plurality of reflecting surfaces. The apparatus can be operated in a mode for forming an image using all the reflecting surfaces of the rotating polygon mirror and in a mode for forming an image using predetermined reflecting surfaces of a plurality of reflecting surfaces of the rotating polygon mirror. The apparatus thus permits the dot density to be changed to a plurality of values with a simple structure so that image information can be recorded with high definition on the surface of a recording medium.

1. Field of the Invention
The present invention relates to an image recording apparatus, and particularly to an image recording apparatus in which a laser beam modulated by an image signal is emitted from a light source such as a semiconductor laser or the like and is used for optically scanning the surface of a recording medium through a deflecting unit such as a rotating polygon mirror or the like to record an image thereon, and which is preferably applied to laser beam printers, facsimile and the like. The image recording apparatus has a variable pixel density in the subscanning direction.
2. Related Background Art
Various image recording apparatuses have previously been proposed in which an image is recorded by optically scanning the surface of a recording medium using the laser beam emitted from a laser source and modulated on the basis of image information through a deflecting unit such as a rotating polygon mirror or the like and a lens system having f.theta. characteristics.
A laser beam printer of such image recording apparatuses has the characteristics that the noise produced during the operation is low due to its non-impact operation and that high-definition (high-resolution) printing can be relatively easily performed.
In such a laser beam printer, the surface of a recording medium generally has a constant dot density. An example of methods of making the dot density on the surface of the recording medium variable is a method of making the rotation number of a rotating polygon mirror or the speed (rotational speed) of the recording medium in the subscanning direction variable in view of the structure of the laser scanning optical system.
The method of making the rotational number of the rotating polygon mirror variable for making the dot density of image information variable causes deterioration in the basic driving state of a motor used as a driving means. Particularly, the method has the problems that it is difficult to precisely control the changing amount of the rotation number and attempt to stabilize the motor without producing jitters or vibrations when the rotation number is changed.
There is also the problem that the current cannot be set to a minimum value because the rotation number of the motor strictly varies.
In addition, since the rotation number of the motor is within a range optimum for setting, the variable range of the rotation number is within about 50% of the basic rotation number.
Namely, the method of making the rotation number of the polygon mirror variable has difficulty in changing the dot density over a wide range and causes deterioration in quality of the image printed due to the instability of the motor even when the dot density is changed within a narrow range.
Further, for example, when the dot density is doubled both in the main scanning and subscanning directions, the sending speed of the image signal generated from an image signal generating section must be quadrupled. Even when the dot density is changed only in the subscanning direction, the sending speed of the image signal generated from the image signal generating section must be changed. The load on the image signal generating section is thus increased.
On the other hand, the method of making the speed of the recording medium variable causes the need for changing the process conditions of an apparatus which employs an electrophotographic process according to the speed of the recording medium. Since the electrophotographic process includes many units, it is difficult to variably control all the units according to the speed of the recording medium, and this method is thus impossible to attempt to improve image quality.
None of the above methods is thus capable of partially changing the dot density of an image on one page when the electrophotographic process is employed. In addition, although the power of the laser beam emitted from a semiconductor laser must be variably controlled over a wide range according to at least the dot density, this variable control is difficult from the viewpoint of variations in the emission angles of semiconductor laser solids, and the dot density cannot be changed over a wide range.
On the other hand, there has recently been a demand for recording various types of image information by a single laser beam printer. For example, when a half tone is recorded with a high gradation, or when a line image is recorded with higher definition (higher resolution), it is indispensable to change the dot density over a wide range.


An image super-resolution method includes preprocessing the low-resolution image to obtain a vertical gradient map, a horizontal gradient map, and a luminance map, which are used as three different dimensions of information to constitute a to-be-input feature map, performing size conversion on the to-be-input feature map to obtain an input feature map, performing nonlinear transformation on the input feature map to obtain an input feature map obtained after the nonlinear transformation, and performing weighted processing on the input feature map and the input feature map obtained after the nonlinear transformation, to obtain an output feature map, performing size conversion on the output feature map to obtain a residual map, and combining the low-resolution image and the residual map to obtain a high-resolution image.

Image super-resolution reconstruction is referred to as an image super-resolution for short, and is also referred to as image super-resolution (SR), which is a processing technology for reconstructing a low-resolution (LR) image into a high-resolution (HR) image using an image processing method, can effectively improve image definition, and is of great significance to various fields such as video surveillance, satellite images, camera photography, high-definition television, and medical imaging. For example, in the video surveillance field, a high-definition video better supports road traffic supervision, and effectively improves social security. However, many applications actually cannot directly obtain a high-resolution image or video for various reasons. The image super-resolution technology can effectively resolve the problem.
Currently, many image super-resolution methods have been proposed. Earlier image super-resolution methods are based on interpolation such as bicubic interpolation and Lanczos resampling. Because there are many solutions to mapping of each pixel from an LR image to an HR image, and only information about the LR image is used in such methods, the HR image cannot be reconstructed well. In recent years, with application of a convolutional neural networks (CNN) in the computer vision field, many CNN-based super-resolution methods appear, for example, very deep convolutional networks super resolution (VDSR). A neural network structure used in the VDSR has a plurality of direct network branches. In an embodiment, an output of a specific layer of neural network directly skips several layers of neural networks and then is directly connected to a processed signal. The direct network branch does not need to undergo an operation such as intermediate convolution such that when computing a loss function and returning a gradient, an output layer can directly deliver the gradient to the previous several layers using the direct branch, thereby avoiding a gradient disappearance problem occurring in a training process of a deep neural network (DNN), and improving convergence of the deep neural network.
To achieve a better super-resolution effect, the VDSR achieves better super-resolution performance by increasing a network depth. Consequently, a quantity of parameters is excessively large, and super-resolution is more time-consuming. In addition, although the VDSR can resolve a convergence problem to some extent based on the neural network structure having the plurality of direct network branches, a convergence problem still exists when a quantity of convolutional layers in the network reaches a specific value. Consequently, a super-resolution effect is affected, and image super-resolution quality is deteriorated.

Image super-resolution method and apparatus


Decoding power is enhanced by (1) flagging only those codewords where the ECC capability has been exceeded; (2) permitting codewords to be of any byte length (n) and codeword depth (.lambda.) subject only to the requirement that n and .lambda. be relatively prime; and (3) interleaving encoded bytes of successive codewords diagonally in a single continuous sequence to form an array with a toroidal topology so that all burst errors will be continuous from codeword to codeword, irrespective of where they occur in the array. These attributes assure that there will never be a problem with burst errors affecting.ltoreq..lambda. rows because there is no "last row" and "first row".

The most common technique for correcting a mixture of burst errors and random errors in data is by interleaving the codewords of an error correcting code (ECC). The conventional interleaving approach is to encode bytes 0 of each successive codeword columnwise, then bytes 1 of each codeword, etc., until all bytes of all codewords in each of a series of successive rectangular blocks have been written; whereas all codewords in each particular block are decoded successively row by row. As a result of this interleaving, an m-burst error will be spread serially over m successive codewords instead of all or most of all of these m errors being in a single codeword. This interleaving hopefully will assure that the error correction capability of each individual codeword will not be exceeded.
Various interleaving techniques are described by Clark et al. in "Error-correction Coding for Digital Communications", published by Plenum Press, 1981.
A widely used ECC is a so-called Reed-Solomon (RS) code. RS codes are byte-correcting codes over the finite Galois field denoted as GF(q), where q is a power of a prime number. A common value for q is 2.sup.8. An [n,k] RS code is one where the length n of a codeword in bytes is .ltoreq.q-1; the number of information bytes is k; the number of redundant bytes r is n--k; and the minimum distance d of the code is (n-k)+1. An [n,k] RS code can correct s errors and t erasures if 2s+t.ltoreq.(n-k). "Erasures" are errors where the location is known. Since one error is thus roughly equivalent to two erasures, the power of a decoder can be enhanced without increasing redundancy by treating certain errors as erasures.
U.S. Pat. No. 4,559,625 is the only prior art known to applicants which describes a forecasting technique to treat errors as erasures and thereby attempts to enhance decoding power. This patented technique has the following characteristics:
(1) If the codewords have a length (n) of 128 bytes, which is common, this technique requires that 127 (n-1) codewords (an undesirably high number) must be interleaved to complete helical symmetry; otherwise, additional complexities will be introduced in the burst forecasting technique.
(2) Whenever a codeword has a correctable error, the locations in the next codeword adjacent to each such error are flagged, and errors are automatically forecasted as erasures at these adjacent locations.
(3) Codewords are encoded in staggered blocks; i.e., row by row but with corresponding bytes of successive codewords laterally offset from codeword to codeword.
These characteristics and their consequences will be discussed more fully in the following description.
There is a need for a technique for decoding ECC codewords that enhances the decoding power over that described in the prior art.

Enhanced decoding of interleaved error correcting codes

International Business Machines Corporation