An aluminum or aluminum alloy substrate having a low absorptance high emittance two-layer coating produced by first anodizing the substrate to form an anodic coating, followed by applying a topcoat of an inorganic white paint on the anodic coating, such dual layer coated substrate having spacecraft application, particularly for radiators.

This invention relates to producing a high emittance, low absorptance multilayer coating on aluminum or its alloys, and is particularly concerned with the provision of an inorganic coating on anodized aluminum or its alloys, having a low absorptance with controlled high emissivity and a minimum coating weight, and with procedure for achieving such a multilayer coating.
In space, there is no atmosphere to conduct heat to or from a spacecraft. Therefore, all heat gain or loss must be by radiation. Radiation is accomplished through the use of thermal control surfaces which can absorb solar radiation and emit radiation to space. These surfaces have a range of desirable values for solar absorptivity (.alpha.) and infrared emissivity (.epsilon.). For surfaces such as the radiators, it is important to absorb as little solar radiation as possible (low .alpha.) while radiating as much heat as possible to space (high .epsilon.).
The .alpha. and .epsilon. properties of the thermal control surfaces must be stable to maintain the temperatures of the spacecraft in the range required for effective operation. However, spacecraft which are in orbit near the earth (commonly called the low earth orbit or LEO) experience a hostile space environment consisting of atomic oxygen, ultraviolet radiation, charged particles, and contamination from other spacecraft components. These factors have been known to degrade the optical properties of spacecraft thermal control surfaces.
The development of a suitable long-life thermal control coating particularly on aluminum or its alloys, is therefore essential for the longevity of spacecraft structures. This coating must also be economical and easy to handle and apply to structures. Common radiator coatings include organic and inorganic white paints, silver-coated TEFLON films, and silver-coated quartz tiles and anodic coatings. Although organic coatings can provide the desired optical properties, such as silicone and fluorocarbon base coatings, they are attacked and erode in the LEO environment. Inorganic paints can achieve high emissivity but when applied to aluminum or alloys thereof, the substantial thickness of such paint coating causes it to weigh more than anodic aluminum coatings. In addition, the application of an inorganic paint to a bare aluminum surface provides substantially no corrosion protection and consequently requires strict environmental control from time of manufacture to flight into space. TEFLON is not resistant to the LEO environment. Quartz tiles have been very labor intensive to install particularly for the complex geometry of most spacecraft and are quite fragile. Anodic coatings of aluminum are one of the most attractive thermal coating systems because of the thinness and hence light weight of the anodic coating, it is integral with the aluminum substrate, it does not spall or chip even from micrometeoroid/debris impact, it provides corrosion protection terrestrially, and is completely resistant to erosion from atomic oxygen. In addition, relatively high emissivities can be obtained.
Anodizing is an electrolytic process that produces an oxide film on the surface of a metal. When aluminum is anodized in a sulfuric acid electrolyte, a porous film of aluminum oxide is formed on the surface of the part. Anodized 5657 aluminum represents a promising candidate for the thermal control coating of the radiators. While anodized aluminum surfaces have high emissivities, the drawbacks associated with anodic coatings is the undesirably high solar absorptance obtained with some anodized aluminum alloys and the increase in solar absorptance that occurs with LEO space exposure.
Representative of the prior art is U.S. Pat. No. 4,526,671, directed to the coloration of aluminum and its alloys for use as decorative materials and the like. According to the patent a white or grayish white substance can be formed by dipping, in the first step, aluminum or an aluminum alloy having an anodically oxidized film in a first solution containing a specific salt or electrolyzing with the first solution, thereby causing the product from this salt to enter into the micropore of said film and then, in the subsequent second step, dipping the product from the first step in a second solution containing a substance which reacts with the product from the salt to be converted into a white or grayish white compound or electrolyzing with the second solution.
U.S. Pat. No. 4,111,851 discloses a coating characterized by low thermal absorption, high thermal emittance and high electrical conductivity comprising (a) a fired oxide pigment comprising a minor amount of aluminum oxide and a major amount of zinc oxide; (b) a vehicle-binder comprising an alkali metal silicate; and (c) sufficient water to provide a mixture suitable for application to a substrate. The fired oxide pigment may further include a minor amount of cobalt oxide. The resulting coating is particularly useful for coating the surfaces of spacecraft and similar objects. The patent states that aluminum can be used as a substrate but that anodized aluminum should be avoided.
U.S. Pat. No. 4,397,716 discloses anodizing aluminum surfaces in chromic acid as the anodizing electrolyte to obtain an anodized coating adapted to be exposed to solar radiation and having a thermal emittance in the range of 0.10 to 0.72 and a solar absorptance in the range of 0.2 to 0.4. However a higher thermal emittance is required for more efficient spacecraft thermal surfaces, as noted above.
One object of the invention is to provide a high emittance low absorptance coating on aluminum or its alloys.
Another object is the provision of a multilayer coating on aluminum or its alloys having low absorptance with controlled high emissivity and a minimum coating weight.
A still further object is to provide a coating having the above characteristics on an anodized aluminum substrate surface, and which provides corrosion protection without special environmental controls.
Yet another object is the provision of procedure for achieving the above coatings.


A thin film dc SQUID and its driving electronic circuitry configured with very high symmetry, having a SQUID loop formed with four holes (24, 24, 26, 27) at the respective ends of crossed slits (22, 23). Each of these holes forms a single turn secondary coil for symmetrically arranged pairs of modulation coils and signal coils. The geometrical placement of the modulation coils with respect to the signal coils results in a device which nominally has no mutual inductance between the two groups of coils when the SQUID is biased for normal operation. The external driving circuit (75-85) is configured to preserve the highly balanced nature of the SQUID and forces an equal magnitude of current to flow in all four of the bias leads.

Superconducting quantum interference devices (SQUID) have been commercially available for several years. SQUIDs are the most sensitive magnetic field or small voltage sensors currently available. The operation of SQUID sensors is based on two effects which can be observed only in the presence of superconductivity. These are flux quantization and Josephson effects. SQUID sensors generally use one or two Josephson junctions connected in a closed superconducting loop.
SQUID systems have taken on a number of different forms but what has become an accepted form for thin film implementations is the "washer" design which achieves low inductance in the SQUID loop and tight coupling to multi-turn input coils by making the loop into a slotted groundplane. This design resulted in the first practical thin film SQUID to be realized in a planar geometry. Very sensitive, low-noise devices with usefully large input coil inductance have been fabricated over the years using this design. This widely used washer design is described in Jaycox et al., Planar Coupling Scheme For Ultra Low Noise DC SQUIDs, IEEE Trans. Magn, MAG-17, p. 400-403 (January 1981).
A modulation coil of this traditional design comprises a single turn loop around the outside of the multi-turn signal coil. This results in high mutual inductance between the modulation and input coils, which is undesirable in a practical system because drive currents injected into the modulation coil will appear as an output from the signal coil. This is analogous to the problem created by using an unbalanced mixer in radio receiver circuitry. An example of a modulation coil used in conjunction with a SQUID is shown in EP-A-O 337 123.
For many applications, it is not desired that the SQUID loop itself be sensitive to uniform magnetic fields because magnetic flux should only be coupled into it through the signal coil. It is possible to fabricate double washer designs in which the two washers are configured as a gradiometer to reject the effects of uniform fields. In these designs, however, the bias current which must pass through the Josephson junctions becomes magnetically coupled into the SQUID loop. This results in an undesirable interaction which can introduce noise and drift into the SQUID sensor from the drive electronics.
The non-symmetrical way in which bias currents are introduced into the junctions also makes the SQUID unduly sensitive to common mode noise which may be picked up on the bias leads which run from the electronic drive package at room temperature down to the SQUID sensor in the cryogenic environment. Again, this noise becomes an influence on the output signal.
A reference which suggests constructing parallel SQUID loops is U.S. Pat. No. -A-4 064 029. Elimination of crosstalk between coils of a SQUID is described in Proceedings of the IEEE, vol. 77, No. 8, Aug. 1989, pages 1208-1223. None of the mentioned-references suggest the invention described herein. coil. This makes the device more unilateral which is a desirable feature. Further, currents flowing into the Josephson junctions are not coupled to the SQUID loop. This makes the device more insensitive to fluctuations or noise in the bias current circuitry. Additionally, common mode noise on the bias leads, modulation coils or signal coils does not couple into the junctions.
These improvements are accomplished by employing a balanced thin film dc SQUID system comprising a substrate, a superconductive groundplane layer on said substrate, said superconductive groundplane layer being formed with a slit having an enlarged opening at each end thereof, thin film Josephson junction means located on said substrate, said Josephson junction means being part of a SQUID loop, means for interconnecting said Josephson junction means, a thin film signal coil in coupling relationship with each said enlarged opening at opposite ends of said slit, a modulation coil in coupling relationship with said signal coil, and means for applying bias current to said Josephson junction means, characterized in that: said superconductive groundplane layer is formed with first and second slits forming a mutual intersection intermediate their ends, each said slit having an enlarged opening at each end thereof; said Josephson junction means being located on diagonally opposite corners of said groundplane at said intersection of said slits; said means for interconnecting said Josephson junction means extending across said intersection; and an electrically balanced, physically symmetrical pair of thin film modulation coils, each said modulation coil being in coupling relationship with one of said enlarged openings at opposite ends of the other of said first and second slits; said bias current being applied to said Josephson junction means in a way so as to not disturb the symmetry created by said modulation coil arrangement.
Other aspects of the symmetry of the system of the invention will be described. Four separate electrical leads are provided by which the Josephson junctions are biased. Two of the leads are connected to one side of the parallel Josephson junctions, while the other two leads are connected to the large groundplane structure of the SQUID loop. The external circuit is designed to preserve the highly balanced nature of the chip and force equal magnitudes of current to flow in all four of the bias leads. An additional feature is a superconducting shield layer on top of the SQUID chip which further reduces leakage inductance and RFI sensitivity, and improves coupling in the signal and modulation coils.

Geometrically and electrically balanaced dc SQUID system having a pair of intersecting slits


Sacrificial electrodes with fractal-shaped are formed on a SAW (surface acoustic wave) device. The sacrificial electrodes discharge electro-static charge in the SAW device for protecting the IDT (inter-digital transducer) from electrostatic break. Moreover, the sacrificial electrodes can control the path and the discharging degree of the electro-static discharge to avoid losing the electro-static discharge protection due to the sacrificial electrodes are broken.

Resistors, capacitors and inductances required in conventional filters or sensors may be replaced since the SAW device is capable of processing signals with the design of surface electrodes. The SAW device has the advantages of high performance, small size, low cost, and repetitive manufacturing. Therefore, the SAW device is important both in electronic industry and communication systems, especially in cellular phones which require high performance and small size.
Take SAW filter as an example, as shown in FIG. 1A, the piezoelectric substrate 10, such as quartz, Lithium Niobate or Lithium Tantalate, is coated with designed inter-digital transducers (hereafter referred to IDTs) 4 and 5 having interval D. After receiving high frequency signals 1, the IDT 4 will transform the received signals to surface acoustic waves 2. Then, the surface acoustic waves 2 are passed to IDT 5 through the piezoelectric substrate 10 and outputted after transformed to high frequency signals 3. In the aforementioned IDTs 4 and 5, each interval space between fingers is D, but these intervals may be changed or modified with different dimension according to the various demands or application. Hence, the input high frequency signals having the same resonance frequency with IDT 4 can be transformed to surface acoustic waves 2, and the surface acoustic waves 2 having the same resonance frequency with IDT 5 can be transformed to high frequency signals 3 efficiently. In above transformation, it is imperative to get rid of the unlimited signals and noises but let go signals with certain wavelengths (wavelength selection), to filter signals.
In the process of SAW device manufacturing, such as the procedure of forming IDTs, the SAW device has to bear some temperature rise and fall treatment such as the thermal cycle for curing photo-resistance. For the piezoelectric substrate is made of thermoelectric materials, the change in temperature would produce ionization electrons accumulated on the SAW device so as to generate electrostatic charges. The electrostatic discharge will damage the SAW device as well as alter their characteristics. In view of this, as shown in FIG. 1B, the Japan Patent No. 6-224682 discloses that not only IDTs 14a, 15a and reflection portions 14b, 15b, but also the sacrificial electrodes 16a, 17a for destroying the electrostatic charges are formed on the input electrode 12 and output electrode 13 of the piezoelectric substrate 11. Because of the sacrificial electrodes, the electrostatic discharging would take place on the sacrificial electrodes rather than IDTs 14a and 15a.
Although aforementioned structure makes the electrostatic discharging occur on the sacrificial electrodes, however, it is not easy to control the discharging process, sometimes excessive electrostatic discharge would still destroy the sacrificial electrodes, thereby leading the sacrificial electrodes fail to perform the protection function. Hence, if there are more electrostatic charges, they may discharge on the IDTs 14a, 15a and the characteristics and functions of them would be altered and destroyed. Concerning the excessive electrostatic discharge, the other disadvantage is that the sacrificial electrodes will melt to contact each other to cause short circuit. Accordingly, Japan Patent No. 8-321739 improves forgoing structure. Resistant films 16 and 17 are attached on the sacrificial electrodes 16a and 17a to increase their resistance against electrostatic discharge, as shown in FIG. 1C. The IDTs can be reused to protect the SAW device from electrostatic discharge. However, the structures both require higher specific surface area to attain better resistance against electrostatic discharge. Besides, the path of electrostatic discharge is not controllable, and the sacrificial electrodes are those with smaller digital intervals. The oscillation thereof would influence the characteristics of the SAW device, so the sacrificial electrodes 16a, 17a must be disposed perpendicular to the IDTs 14a, 15a, respectively.
Japan Patent No. 5-121993 discloses another SAW device protection structure, as shown in FIG. 1D. Generally, the horizontal fingers 25, 27 are formed on the front end of the middle between the fingers 24a, 24b and 26a, 26b of the IDT 22 (23) to prevent the ESD break. This structure will increase the capacity of electrostatic charges and then effect the oscillation of the SAW device. Consequently, the horizontal fingers 25, 27 are moved afterward to avoid foregoing problem. Nevertheless, with this structure, it is easy to occur electrostatic discharging to damage SAW device in the position designated P between two digital transducers. Another improved structure is shown in FIG. 1E, the horizontal fingers 25, 27 are extended to form horizontal fingers 28 and adjacent fingers are connected to avoid such a problem. In this way, the properties of frequency response will be altered. Besides, the scope of usage is limited since the energy loss increases during the filtering process.
U.S. Pat. No. 6,034,578 discloses a SAW device with discharge electrodes electrically independent from the IDTs. As shown in FIG. 1F, IDTs 32, input wire bonding pad 33, output wire bonding pad 34, ground wire bonding pads 35, common electrodes 36, and thin film electrodes 37a, 37b, 37c and 37d are provided on the piezoelectric substrate 31. The thin film electrodes 37a, 37b, 37c and 37d are not connected to any aforementioned elements and electrically independent from them. In addition, the spaces S1 between the thin film electrodes 37a and 37b as well as between 37c and 37d are smaller than the spaces S2 and S3 between IDTs 32. The generation of electric charges due to spontaneous polarization is not uniform, and the quantity of charge generation is largest in the dicing margin portion. Since the space S1 is set to be sufficiently narrow, the static electricity is discharged between the thin film electrodes 37a and 37b or between 37c and 37d selectively. Accordingly, there is no fear that the IDTs 2 are subject to ESD breaking. However, this structure requires additional regions to dispose thin film electrodes 37a–37d so that the size thereof increases. Besides, there exist electrostatic charges in the inner region of thin film electrodes 37a–37d, too. These charges would attach to the elements such as IDTs 32. Since IDTs 32 are electrically independent from thin film electrodes 37a–37d, these electrostatic charges cannot be transferred to thin film electrodes 37a–37d. Hence, IDTs may suffer electrostatic breaking.
FIG. 1G shows a SAW device with the protection against electrostatic breaking according to U.S. Pat. No. 6,486,752. The digital transducers 41, 42, and 43 forms first IDTs 61, and the digital transducers 44, 45 and 46 forms second IDTs 62. The IDTs 61 and reflectors 63, 64 and 65 are combined with the series connected resonator, and the IDTs 62 as well as reflectors 67, 68, 69 and 70 are combined with the parallel resonator. The digital transducers 42 and 45 respectively connect to dicing line 55 via connection patterns 91 and 92. Digital transducers 41 and 44, 43, 46 connect to dicing line 55 via connection patterns 81, 84, 86, respectively. Reflectors 65, 66, 67 and 68 connect to dicing line 55 via connection pattern 86, and reflectors 63, 64, 69 and 70 connect to dicing line 55 via connection pattern 86, 82, 83, 85, respectively. Accordingly, all devices connect with dicing line 55 to discharge electrostatic charges thereon to avoid electrostatic break. But, the dicing line will be cut off so that the electrostatic protection vanishes. It is unavoidable to suffer electrostatic break for package process.

Surface acoustic wave device with electro-static discharge protection


A process for the removal of a high percentage of NOx and SOx from the gaseous effluent of a metal pickling operation comprising passing the effluent through an aqueous scrubber, treating the gaseous effluent from the scrubber with ozone, passing the effluent from the ozone treatment through a second aqueous scrubber thereby removing at least 80 vol % of the NOx and SOx present in the original effluent. The scrubbing solutions in both of the scrubbers preferably have a pH of from 7 to 14, more preferably 10 to 14. The scrubbing solutions in both scrubbers are caustic solutions containing sodium hydroxide or calcium hydroxide. The NOx and SOx in the scrubbers are converted into nitrate salts and sulfate salts, which are removed from the scrubbers.

Pickling refers to the treatment of metal during processing such as shaping or size reduction, to remove scale and other metal oxides that have accumulated during storage or earlier processing. The treatment consists of exposing the metal to an aqueous bath of strong inorganic acids, typically nitric acid mixed with one or more of sulfuric acid, hydrofluoric acid or hydrochloric acid. As a result of the chemical reactions taking place in the bath, and at times due to thermal decomposition of the acid fumes therein, the atmosphere over the bath contains a high concentration of NOx and possibly SOx. The atmosphere in the pickling tanks is typically regularly purged using a mixture of dry air and nitrogen. This exhaust gas must be treated to significantly reduce NOx, SOx and acid gases before it can be vented to the atmosphere.
NOx refers to the nitrogen oxides commonly present in waste gas effluents. i.e. NO, N.sub.2 O.sub.3, NO.sub.2 and N.sub.2 O.sub.5. These oxides, which have increasing degrees of oxidation in the order given, likewise have varying degrees of solubility/reactivity with aqueous solutions, preferably caustic solutions having a pH between 7 and 14. In general, the higher the oxidation state, the greater the solubility/reactivity with aqueous caustic solutions. It is important to bear in mind that, unlike combustion wherein large percentage of the NOx formed exists as NO, the effluent gas from a pickling operation commonly contains a much higher percentage of higher nitrogen oxides, particularly NO.sub.2. As a general comparison, combustion typically produces at least about 90 vol. percent NO with the balance being NO.sub.2 whereas the effluent gas from a pickling operation typically contains only from about 60 to 65 vol. percent NO with the balance NO.sub.2. These considerations apply to SOx formation as well.
NOx and SOx are currently removed from pickling lines primary by alkaline scrubbing. The use of multiple scrubbings will remove about 40% to 50% by volume of the NOx and SOx in an effluent gas stream as described above. However, more efficient systems were required to meet ever-tightening NOx emission standards. One such system is a wet oxidation system that utilizes hydrogen peroxide or sodium oxychloride in the first scrubber to convert NO to NO.sub.2. The second scrubber contacts NO.sub.2 with a reducing agent, such as sodium hyposulfide, to convert it to nitrogen that can be vented to the atmosphere. This system suffers from high cost and the possibility of release of dangerous emissions, such ClO.sub.2.
Another technology utilized to address the problem of NOx removal is selective catalytic reduction (SCR) which utilizes catalysts to reduce NOx to nitrogen gas. The problem with the use of such systems to treat pickling line effluents is that the HF and H.sub.2 SO.sub.4 fumes must be initially removed, such as in a scrubber. Failure to effectively remove such acid fumes will result in the catalyst becoming plugged or inactivated by the acids. This will result in the discharge, or "slip", of hazardous substances from the system into the environment. SCR and other non-catalytic reduction technologies may also require heating the gas to an optimum temperature for optimal reduction reaction.
Still another technology for the removal of NOx is referred to as low temperature oxidation. This is, in effect, heat removal followed by an ozone-based oxidation system followed by a wet scrubber. The molar ratios utilized for a system are at minimum 1.5 moles of O.sub.3 for each mole of NOx to be removed. Further, in addition to a fairly high rate of ozone consumption, this system requires a series of process steps, such as the heat exchange, which are not required for treatment of the low temperature, saturated emissions from a pickling of metals processing operation.
It would therefore be a significant advance in the art if a process could be provided that would efficiently remove NOx and SOx from gaseous effluents from metal pickling operations. Such a process is provided in accordance with the present invention.

Removal of NOx and SOx emissions form pickling lines for metal treatment


A process for gas-phase synthesis of titanium dioxide aerosol gels with controlled monomer size and crystalline phase using a diffusion flame aerosol reactor operated in a buoyancy-opposed configuration is disclosed. The process includes introducing a precursor stream into a diffusion flame aerosol reactor, introducing a fuel stream into the reactor, combusting the precursor stream and the fuel stream in a flame to form at least one nanoparticle, and operating the reactor in a down-fired buoyancy-opposed configuration to produce the aerosol gel.

The present disclosure is generally directed to the synthesis of aerosol gels in a buoyancy-opposed flame reactor. The present disclosure is also directed to methods of using the flame reactor to produce nanoparticle aggregates having variable packing densities.
Aerosol gels exhibit unique material properties such as ultralow density and high surface area that give rise to their potential in various environmental applications such as catalysis, water and air purification, and photovoltaic applications. Synthesis of aerosol gels in gas phase has been recently demonstrated as a viable and economical alternative to the conventional wet sol-gel process, which is both time-consuming and expensive. The fundamentals of aerosol gelation theory have been thoroughly investigated in the last two decades. On the experimental front, novel techniques have been demonstrated for lab-scale synthesis of various aerosol gel materials. It is desired to establish gas phase synthesis as a scalable synthesis route for production of aerosol gels with controlled properties. In particular, control of monomer size in aerosol gels is needed because of its importance in governing the specific surface area (SSA), mobility, and optical properties of these materials.
In the present disclosure, the gas-phase synthesis of titanium dioxide (henceforth, TiO2) aerosol gels with controlled monomer size and crystalline phase using a diffusion flame aerosol reactor operated in a buoyancy-opposed configuration is disclosed. The terms negative gravity (−g) and reverse gravity have been used in the recent past to describe this flame configuration. Flame aerosol reactors have been widely adopted by industries for cost-effective, continuous and one-step synthesis of a wide variety of nanomaterials. TiO2, a material with versatility in practical applications ranging from white pigment to photocatalysts, has not yet been synthesized in a gel form via gas phase processes. At the same time, its well-investigated material properties as a function of process parameters make it an ideal reference material to demonstrate the control capabilities of the synthesis process of the present disclosure.

Synthesis of aerosol gels comprising macro-aggregates in a buoyancy-opposed flame reactor by a diffusion-limiting cluster aggregating process


A method of altering a portion of the semiconductive layer of an electric power cable, to increase its resistance so as to render it electrically insulative. The semiconductive layer is loaded with carbon powder which forms chains to provide conductive pathways through the layer. By introducing an intercalant into the semiconductive layer, which causes the layer to swell, the conductive pathways are interrupted and the material is rendered insulative (>10.sup.4 .OMEGA.-cm). The intercalant may be a polymerizable material with a curing agent which is cured in situ, i.e., without removing the semiconductive layer from the cable. By this method, flashover to the semiconductive layer at a cable splice or termination may be prevented without requiring tedious removal of the exposed portion of the semiconductive layer. The method is usable with both strippable and coextruded semiconductive layers.

1. Field of the Invention
The present invention generally relates to fabrication or modification of insulating layers for electrical cables, and more particularly to a method of altering a portion of a cable's semiconductive layer to render it electrically insulative.
2. Description of the Prior Art
A high percentage of high voltage cable installed today is polymeric-based, with a central metal conductor surrounded by a layer of carbon-loaded polymer (a semiconductive layer), further surrounded by a dielectric layer which is also a polymer, and another, outer layer of semiconductive material, for electric field containment. The semiconductive layer is typically made by loading a polymer, such as low density polyethylene, with a large amount of carbon powder (e.g., 30-50% by volume). This high loading of carbon forms chains of overlapping particles to allow conduction through the polymer matrix. There is a dramatic increase in conductivity within a narrow range (usually within about 5 vol. %) in which these conductive chains are established. The volume percent where this increase in conductivity occurs (the percolation threshold) is very dependent on the size and aspect ratio of the conductive particles.
Present technology in cable splicing and terminations for, e.g., 5 kV-25 kV cables typically involves the manual removal of 3 to 6 inches of length of the outer semiconductive layer from the cable end. This step further isolates the center conductor from the grounded semicon so that current does not flashover and destroy the splice or termination. The removal operation requires considerable craft and training to properly accomplish. Scratches or a slightly lifted edge of the semiconductive layer resulting from cable preparation leave air gaps which will breakdown in the high electric field of the energized cable, forming a reactive plasma which degrades the polymer insulation, leading to cable failure, often violent.
There are two major types of electric cables with differing semiconductive layers, strippable or coextruded. The majority of cable in the United States is strippable to allow quicker removal of the layer for splicing or terminating. Although coextruded semicon has better overall electrical characteristics, it is used less because it requires much more extensive work to properly remove the semicon to make a splice or termination. The removal of the semicon has been identified as the largest factor in splice/termination failures. It would, therefore, be desirable to devise a method of preventing flashover to the semiconductive layer at a splice or termination without requiring tedious removal of a portion of the semiconductive layer, and it would be particularly advantageous if the technique were usable with both strippable and coextruded semiconductive layers.

Method for altering cable semiconductive layer


A method of draining and recharging a hermetic compressor with oil using a drainage assembly mounted in the compressor housing. The assembly includes a tube having a valve mounted at one end thereof with the second end of the tube located in the oil sump of the housing. To drain the compressor oil, refrigerant flowing through the discharge and suction lines is shut off. Refrigerant is purged from the housing to create a vacuum therein and the housing is charged with a gas such as dry air or nitrogen. As the compressor housing is charged with gas, the pressure inside the housing increases, forcing the oil through the drainage assembly and out of the compressor. To recharge the compressor with oil, the gases are purged creating a vacuum in the housing. A predetermined amount of oil is drawn into the housing through a service hose. The compressor is purged and recharged with refrigerant.

The present invention relates to hermetic compressors, and more particularly to draining compressor oil from a hermetic compressor and recharging a hermetic compressor with oil.
In general, lubricating fluid such as oil is removed from a hermetic compressor for any number of reasons. One such reason may be that a sample of the oil is needed for testing to analyze its properties such as viscosity, for example. Additionally, it may be desired to determine the amount of oil located in the compressor housing in comparison to the amount of oil the compressor had been initially charged with, thus determining if there had been any oil loss during compressor operation. By determining the amount of oil located in the compressor housing, one can also ensure that a sufficient amount of oil is available to the compressor components during compressor operation. Further, spent oil may be removed from the compressor housing and replaced with fresh, clean, or a different type of oil.
Conventionally, to drain oil from a hermetic compressor, the compressor must be disconnected and removed from its assembly with a refrigeration system. The suction, discharge, and electrical connections are disconnected and the compressor is removed from the refrigeration system. The oil in the compressor housing is poured from the compressor housing through a drain/fill opening in the housing into a suitable container. After being drained, the compressor may be recharged with oil through the drain/fill opening and reassembled to the refrigeration system.
A problem with this method of draining oil from a hermetic compressor is that the removal of the compressor from its assembly in the refrigeration system is time consuming, labor intensive, and expensive. The removal of the compressor requires stopping refrigerant flow through the suction and discharge lines and then disconnecting the suction line, discharge line, and electrical connections. An additional problem is that refrigerant may leak from the suction and discharge lines as well as from the compressor after being disconnected.
It is desired to provide a method and apparatus for draining oil from and recharging oil into a hermetically sealed compressor without having to remove the compressor from its system.

Device for draining and recharging a hermetic compressor with oil


One method for analyzing a bitstream having a plurality of compressed pictures comprises computing an initial arrival time and a final arrival time of a compressed picture, wherein the initial arrival time is equal to an earlier of the final arrival time of the immediately previous compressed picture or equal to a sum of a fixed time plus a sum of removal delays of all of the compressed pictures between the first compressed picture following the buffering period message and the compressed picture, including the compressed picture, and wherein the final arrival time is equal a sum of the initial arrival time and a time calculated based on the number of bits associated with the compressed picture at the bit rate; and verifying that a difference between the final removal time and the initial arrival time does not exceed the time for reaching the buffer size at the bit rate.

1. Field of the Invention
The present invention relates generally to image and video signals. More particularly, the present invention relates to coding or compressing image and video signals.
2. Related Art
In video coding standards, such as MPEG-1, MPEG-2, MPEG-4, H.261, H.263 and the new H.264/MPEG-4 Part 10, a bitstream is determined to be conformant if the bitstream adheres to the syntactical and semantic rules embodied in the standard. One such set of rules takes the form of successful flow of the bitstream through a mathematical or hypothetical model of a decoder, which receives the bitstream from an encoder. Such a model decoder is referred to as the hypothetical reference decoder ("HRD") in some standards or the video buffer verifier ("VBV") in other standards. In other words, the HRD specifies rules that bitstreams generated by a video signal encoder must adhere to for such encoder to be considered conformant under a given standard. Stated differently, a HRD is a normative means according to which encoders must create bitstreams, which bitstreams adhere to certain rules and constraints, and real decoders can assume that such rules have been conformed with and such constraints are met.
The HRD serves to place constraints on the variations in bit rate over time in a compressed bitstream. HRD may also serve as a timing-and-buffering model for a real decoder implementation or for a multiplexor. Associated with the HRD are syntax elements defined in the standard, and algorithms embodied in software or hardware in various products such as encoders, multiplexors, conformance analyzers, and so on.
The HRD represents a means to communicate how the bit rate is controlled in the process of compression. The HRD may be designed for variable or constant bit rate operation, and for low-delay or delay-tolerant behavior. As shown in FIG. 1, HRD 100 includes pre-decoder buffer 110 (or VBV buffer) through which compressed bitstream 105 flows with a precisely specified arrival and removal timing. Compressed bitstream 105 contains a sequence of coded pictures 115 and associated ancillary messages, which flow into pre-decoder buffer 110 according to a specified arrival schedule. All compressed bits associated with a given coded picture 115 are removed from pre-decoder buffer 110 by instantaneous decoder 120 at the specified removal time of the picture. Pre-decoder buffer 110 overflows if the buffer becomes full and more bits are arriving. Pre-decoder buffer 110 underflows if the removal time for a picture occurs before all compressed bits representing the picture have arrived. Typically, HRDs differ in the means to specify the arrival schedule and removal times, and the rules regarding overflow and underflow of pre-decoder buffer 110.
HRDs in accordance with some existing standards such as H.263 and H.261 have been designed for low-delay operation. In short, such HRDs operate by removal of all bits associated with a picture the first time the buffer is examined, rather than at a time transmitted in the bitstream. Such HRDs do not specify when the bitstream arrives in the pre-decoder buffer. Therefore, such HRDs do not allow for precisely timed removal of bits from the pre-decoder buffer and create a difficulty for systems designed to display pictures with precise timing.
Other HRD standards, such as MPEG-2, can operate in variable bit rate or constant bit rate mode and also have a low-delay mode. The MPEG-2 HRD (known as the VBV) has two modes of operation based on whether a picture removal delay is transmitted in the bitstream or not. In the first mode of operation or mode A, when the removal delay is transmitted, the rate of arrival into the VBV buffer of each picture is computed based on picture sizes, the removal delay and additional removal time increments. Mode A can be used by the encoder to create both variable and constant bit rate streams. However, mode A suffers from a shortcoming that the entire bitstream must be scanned in order to make a determination as to whether a given bitstream has a constant bit rate. Mode A further suffers from an ambiguity at the beginning of the sequence that prevents the initial bit rate from being determined. Therefore, technically, mode A does not allow for a determination as to whether the bitstream is a constant bit rate ("CBR") bitstream.
In its second mode of operation or mode B (which is also referred to as a leaky bucket), unlike mode A, the encoder does not transmit the removal delays. In mode B, the arrival rate is constant unless the pre-decoder buffer is full, under which condition no bits arrive. Thus, mode B, having a constant arrival rate, does not introduce an ambiguity regarding the initial arrival rate. However, mode B has an arrival schedule, which may not be constrained to model the real production of bits. This unconstrained aspect of mode B can result in very large delays through a real decoder and limits its use as guidance for real-time multiplexors. In mode B, compressed data arrives in the VBV buffer at the peak rate of the buffer until the buffer is full, at which point the data stops. The initial removal time is the exact point in time when the buffer becomes full. Subsequent removal times are delayed by fixed frame or field periods with respect to the first.
As a hypothetical example of the long delays the Mode B may introduce, consider an encoder that produces a long sequence of very small pictures (i.e. few bits are used to compress each picture) at the start of the sequence. For the purpose providing an example, consider that 1,000 small pictures that can all fit in the VBV buffer are produced. All 1,000 pictures would enter the buffer in a time less than the time-equivalent of the buffer size, which is typically less than one second. The last of such pictures would then remain in the buffer for 999 picture periods longer than the first picture, or roughly 30 seconds. This requires that the encoder create a delay of that same amount of time before transmitting the first picture. However, in real-time broadcast applications, it is not generally possible to insert a thirty-second delay at the encoder. Rather, an encoder can only transmit the bits associated with the small pictures after they have been produced. In terms of a VBV model, this would introduce a series of time intervals during which the VBV buffer is not full, but no bits are entering. Therefore, a real-time encoder cannot imitate the buffer arrival timing of mode B of VBV.
In both modes A and B, the removal times are based on a fixed frame rate. Neither of these MPEG-2 VBV modes can handle variable frame rate, except for the one special case of film content captured as video. In this special case, the removal time of certain pictures is delayed by one field period, based on the value of a bit field in the picture header of that picture or a previous picture.
As opposed to mode A of VBV in which the encoder must prevent both buffer overflow and under flow, in mode B, it is impossible for the buffer to overflow, as data stops entering when the buffer becomes full. However, in mode B, the encoder must still prevent buffer underflow.
The MPEG-2 VBV also includes a separately specified low-delay mode. In the low-delay mode, the pre-decoder buffer may underflow occasionally and there are precise rules, involving skipping pictures, which define how the VBV is to recover. Because of the number of modes of operation, and the arcane method of handling the one special case of variable frame rate, the MPEG-2 VBV is overly complex. It also suffers from the initial rate ambiguity of Mode A and the non-causality of Mode B.
A need exists for an improved hypothetical reference decoder that addresses the problems and deficiencies associated with the existing HRDs.

Hypothetical reference decoder for compressed image and video


The invention is regarding to solid-state imaging device. A solid-state imaging device consistent with the present invention includes, a plurality of unit cells on a semiconductor substrate of a first conductivity type, each unit cell including a photoelectric conversion unit comprising a photodiode having a diffusion layer of a second conductivity type and a signal scanning circuit unit; a trench isolation region for isolating the photoelectric conversion unit from the signal scanning circuit unit, the trench isolation region being formed in the semiconductor substrate;

MOS solid-state imaging elements have advantages such as the ability to be driven by a single low-voltage power source and the ability to reduce design costs. Moreover, the fabrication process of MOS solid-state imaging element is similar to the fabrication process of MOS element. Therefore, it is possible to construct system LSI which includes various signal processing circuits (such as logic circuits) using MOS elements, and MOS solid-state imaging devices simultaneously mounted on one substrate.
Generally, a diffusion layer for a source or a drain of a MOS transistor to be used in a logic circuit tends to become shallower in response to requirements for reduction in film thickness and size along with scaling of a power-source voltage. When MOS transistors are miniaturized in a logic circuit, elements of MOS solid-state imaging device also need to be miniaturized.
Meanwhile, instead of conventional Local Oxidation of Silicon (LOCOS) isolation, trench isolation is used as an element isolation structure for MOS solid-state imaging device for the purpose of downsizing the circuit.
FIG. 1 schematically shows a cross-sectional structure of partial extraction (equivalent to an area including two unit cells adjacent in a horizontal direction) of the CMOS image sensor.
In the CMOS image sensor, a plurality of unit cells are formed on a p-type semiconductor substrate (normally a silicon substrate) 31, for example. Each unit cell includes a photoelectric conversion accumulator unit 32 and a scanning circuit unit, which are mutually isolated by a trench isolation region 36.
In the photoelectric conversion accumulator unit 32, a photodiode is formed from a pn junction of the p-type silicon substrate 31 and an n-type diffusion layer 37 formed on a surface thereof.
The scanning circuit unit includes an amplification transistor 33, a vertical address transistor 34 and a reset transistor 35 each of which is made of an NMOS transistor, a signal readout gate 38, an amplification gate 39, a vertical address gate 40, and a reset gate 41. Reference numeral 42 denotes a drain line; reference numeral 43 denotes a signal line; reference numeral 44 denotes a light-shielding film and a connecting line using aluminum, for example; reference numeral 45 denotes an interlayer film; and reference numeral 46 denotes a condenser lens. Illustration of a gate insulating film, a color filter and the like is omitted herein.
In the CMOS image sensor, incident light is subjected to photoelectric conversion inside the semiconductor substrate 31. Accordingly, if the photoelectric conversion accumulator unit 32 is made shallow to accommodate scaling, then performance is deteriorated in relation to the wavelength of the incident light. Therefore, in the CMOS image sensor including the deep diffusion layer 37 for the photodiode, adoption of a trench isolation structure equivalent to a structure for a logic circuit on the same chip incurs problems in inter-pixel isolation or color mixture.
Moreover, although the trench isolation structure can be downsized in comparison with conventional LOCOS isolation structure, it is well known that the trench isolation structure frequently causes defects and damages the semiconductor substrate in the vicinity of trenches because of large stress attributable to processes thereof. Such defects and damages incur an increase in leakage currents, thus causing white spots or dark noises in the CMOS image sensor.
As described above, in the conventional CMOS image sensor, there has been a problem of increased white spots and dark noise attributes to leakage currents caused by deterioration in performances of inter-pixel isolation and color mixture when the trench isolation structure similar to that for the logic circuit on the same chip is adopted.

Abstract: a first element-isolating diffusion layer of the first conductivity type formed under a bottom face of the trench isolation region down to a position deeper than the diffusion layer of the photodiode from the surface of the semiconductor substrate.


A method and system facilitate telephony over computer based networks. The parties to a telephone call need not have the same telephone application software capabilities before the call is initiated nor does the network have to provide standard signaling. Instead, in accordance with the method and system one of the parties defines to the other party the encoding/decoding technique to be used in the processing of the call. The definition can be either by supplying a copy of the application to the other party or by providing the other party with an indirect reference to where the application can be obtained.

The present invention is directed to a method and apparatus for providing telephony over a computer network. More specifically, the present invention is directed to a method and apparatus by which a party can encode a telephone call and notify the receiver of the call of the encoding or decoding technique appropriate for conducting the call.
For a long time individuals have been able to communicate via telephone. Most commonly, this takes the form of transmissions of communications over a network such as a public switch telephone network (PSTN) which provides connectivity between two or more parties. In the classical telephone communication environment the network has its own predefined signaling requirements and the telephones which are connected to the network interface with those requirements.
As communication techniques have expanded it has become desirable to provide telephony over computer networks. One example of such telephony is referred to as Internet telephony, that is, telephony provided over a network which implements the TCPIP, protocols associated with a communications network commonly referred to as the Internet. In fact there is heightened interest in Internet telephony in that there is little or no marginal cost incurred by telephone connections utilizing the Internet. Despite the apparent benefit of providing Internet telephony, it has not as yet become a popular means of communication. One possible reason is that there is a low quality of continuous media over the Internet. Furthermore, the fact that various Internet telephony applications use separate and distinct proprietary encoding schemes and application signaling provides an obstacle to more universal use of the Internet for telephony. Unfortunately, the possibility that two parties desiring to communicate with one another via Internet telephony will in fact be employing two different proprietary encoding schemes is too high to encourage an explosive growth of this communication technique. The field has not been able to overcome the absence of a communication standard whereby respective parties have software applications that more easily communicate with one another. This problem exists even within the Internet itself where there are gateways that enable software based telephony programs to call regular telephones or gateways that allow telephones to call a computer application. In both of these gateway scenarios the problem still arises that the application software encoding techniques are not uniform or standardized or universal and it is difficult to provide an interface that makes Internet telephony a more common communication experience.
It would be beneficial if a technique could be provided that would facilitate telephony over a computer network without requiring a standardization or uniformity of encoding and signaling requirements.
The present invention provides a method and an apparatus that facilitate telephony over computer networks. In accordance with an embodiment of the present invention a first party initiating a call identifies to a second party, the called party, the encoding technique which will be utilized in connection with the processing of the call. This identification can take the form of either transmitting the application that will decode the call or the identification can be constituted by an indirect reference to another source of the encoding/decoding application. In this circumstance the calling party does not have to concern itself with whether the called party has the capability of encoding/decoding in accordance with the technique that is used by the first party. No negotiation of signaling standards is required. Instead, the called party can easily adapt to the signaling requirements of the calling party.
In an alternative embodiment the calling party can send an invitation to the called party to initiate a telephone call via the computer networks. In that circumstance either the calling party or the called party can determine the coding/decoding technique to be employed. For instance, the calling party can either directly or indirectly identify the standard or signaling techniques that it wishes to employ during the course of the telephone call either directly or indirectly as in the first embodiment, or alternatively the called party can define the encoding/decoding technique to be utilized during the course of the telephone call. In the latter circumstance the second party receiving the invitation would initiate the call and then transmit encoding/decoding identification information to the first party. The second party either explicitly defines the application to be utilized or provides an indirect reference which can be used to retrieve the appropriate application so as to conduct the telephone call.
In yet another embodiment of the invention a method is provided by which a computer based telephone instrument can initiate a telephone call to a regular telephone. In this circumstance a tale end hop off (TEHO) gateway translates the call between the computer network and a standard telephony network such as the PSTN. In this circumstance the computer based telephone party informs the TEHO about the telephone application utilized for encoding and decoding. The TEHO either receives the application from the first party or retrieves it based on an indirect reference provided by the first party. At that time the TEHO then can encode and decode the call portion that is transmitted over the computer network between the calling party and the TEHO. The TEHO then operates as a translator between the two networks so that once it has received information from either network it places it in the appropriate format for transmission to the party connected to the other network.
In yet another embodiment of the present invention a regular telephone can initiate a call to a computer based telephone coupled to a computer network. In this circumstance a front end hop on gateway (FEHO) can either inform the called party about the application program which it intends to utilize in connection with the call initiated from a standard telephone to which the FEHO is connected or, alternatively the FEHO can notify the called party that a call connection is desired and can await receipt of a notifier that identifies the telephone application which the called party intends to use in connection with the portion of the call connection between the FEHO and the called party.
Other advantages and features of the present invention will be described in the detailed description that follows.

Method and apparatus for providing telephony over a computer network


A controlling device for a rotating sprinkler is composed of a sleeve (10), a compressing block (21), a spring (22), a controller (23), a rotator (24), a cushion (25), and a shelter ring (26). The rotator (24) rotates with a rotating sprinkler (50) synchronously and operates with the controller (23) to construct a gap selectively therebetween so that a quantity of water flowing into the rotating sprinkler (50) is changed when the gap is formed or not. Whereby the controlling device arranges a substantially rectangular spraying arrangement of the rotating sprinkler (50).

1. Field of the Invention
The present invention relates to a controlling device for a rotating sprinkler that is connected between a water outlet and a rotating sprinkler, and having a substantially rectangular spraying range achievable by varying the quantity of spraying water therefrom.
2. Description of Related Art
Rotor-type sprinklers are widely used for watering lawns, golf courses, athletics fields, and more particularly for nursery gardening and agricultural farming to irrigate the land. The use of multiple rotor-type sprinklers is well known in the aforementioned situations and therefore, descriptions of the structure and the operation of the rotor-type sprinklers are omitted.
Generally speaking, conventional rotor-type sprinklers are connected to a water source, normally a faucet. Pressure of sprayed water from the water source drives the conventional rotor-type sprinklers to rotate and spray the water in a circular range. Referring to FIG. 6, the conventional rotor-type sprinklers are arranged in two different types that have some restrictions which are listed as following:
1. First type: The margins of the circular spraying ranges of the rotor-type sprinklers (90) are tangential, as shown in the left side portion of FIG. 7, whereby a dry area (91) is caused due to not being within the watering range. Therefore, this arrangement of the conventional rotor-type sprinklers is not usually used.
2. Second type: A high-density arrangement of the rotor-type sprinklers (90) is shown in the right side portion of FIG. 7. Although all areas of the field are irrigated, multiple overlapped areas (92) are too damp because the overlapped areas (92) are watered twice, whereby water is wasted and plants in the field grow unevenly and possibly unhealthily due to the excess water. Besides, the high density arrangement needs more rotor-type sprinklers which results in high costs, and water pipes in accordance with the rotor-type sprinklers are necessarily complex which in turn causes more trouble in construction.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional rotor-type sprinkler.
The main objective of the present invention is to provide a controlling device for a rotating sprinkler that makes the spraying range of the rotating sprinkler defined as a rectangle so as to enable efficient abutment of neighboring irrigation plots.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

Controlling device for rotating sprinkler


Method of evaluating a defect of quality in a data signal, associated device and computer program. The method evaluates the defect of a carrier signal bearing data intended to be restored to a recipient, the signal including a video component and audio component. The method includes the following steps implemented on at least one sample of the signal: detection of a defect in the video component of the sample and calculation of a duration associated with the defect; assigning a class of defect to the defect detected as a function of its associated duration; according to the class of defect assigned, obtaining a result of searching for a defect in the audio component at the instants corresponding to the sample; deciding to confirm the detection of a defect of quality in the sequence as a function of the result of the search for a defect in the audio component.

Today, audiovisual contents are transmitted via video on-demand services, video catch-up, live etc. These services possess well-defined production and broadcasting chains with which errors may appear and accumulate on the various links of these two chains.
Depending on the systems for capture, contribution, encoding, transmission, reception, and the audiovisual terminals employed, the errors may be manifested through the appearance of artifacts in the audio and video components. The appearance of these degradations may occur simultaneously in both these components.
Defects of the video component often arise through image jerk or freeze. Defects in the audio component are manifested for their part as a sound loss. The duration of these two degradations fluctuates from a few milliseconds to a few hours. The frequency of appearance of this type of event can also vary over time. The defects can equally well be of low occurrence as sustained according to a time scale.
These degradations are a source of discomfort to end users, which sometimes leads them to reject the service, if the annoyance caused becomes too significant.
Currently, the appliances deployed which ensure automatic control of audiovisual quality perform measurements on the audio and video components of signals output by the terminal or samples at the level of the decoder without taking account of the reference signal, since these latter are rendered inaccessible technically or by law. They use models classed as "reference-free" and produce scores which fluctuate over a quality scale. The conclusions of appraisals of "reference-free" prediction devices have shown that performance must be greatly improved with respect to human sentiment.
A method for evaluating a degradation in quality of an audiovisual signal based on a model for predicting the impact of the discontinuity of the fluidity of the images on subjective quality is known from document WO2006/103327. A basic scheme of the evaluation method in question is presented in conjunction with FIG. 1. Measurements of discontinuity are conducted in parallel on the video and audio components of the signal to be evaluated. Various audio and video metrics are employed to rate various types of defect (for example image freezes, the presence of blurring or else of blockiness in the images for the video component, sound losses for the audio component). A video decision module takes into account the results of the evaluations carried out with the aid of the various metrics and allots an overall quality score to the video component, with the aid of a video interaction model. An audio decision module does likewise for the audio component and allots an overall quality score to the audio component on the basis of an audio interaction model. An audio/video weighting module takes into account both the video overall quality score and the audio overall quality score so as to assign an overall quality score to the audiovisual signal. This entails a so-called cognitive approach since the model reproduces the mechanism of human judgment through the production of scores on a quality scale.
The prior art calculates the degradation in the perceived quality caused by each break in fluidity, and sound cutoff. The calculations are performed in a disjoint manner on the audio and video components and without a priori or a posteriori interaction of the results obtained. This approach fails when faced with artificially created discontinuities and when they are not considered to be perceivable by human judgment. In these typical cases, interpretation errors appear and generate false alarms.

Method of evaluating at least one defect of quality in a data signal, associated device and computer program


A light emitting diode (LED)-based optically indirect luminaire includes a reflector that receives light generated by an LED light source platform and reflects the light beyond the platform into a space to be illuminated. The LED light source platform can be configured as a pendant that is suspended from the reflector by one or more supports or cables. The LED light source platform can include a heat sink that receives the LEDs and the printed circuit board (PCB) they are disposed upon so that the LEDs are visible to the reflector and hidden from view. An optional lens can be included that covers the LEDs and PCB to protect them from dust and moisture.

Indirect lighting methods are used with a number of different fixtures. In a number of cases, indirect lighting is achieved by using an architectural coffer with a lighting pendant (also called a light source) that hangs underneath and directs light toward the architectural coffer. The light reflects off the coffer toward the space away from the architectural coffer. With the popularity of LEDs, LED-based lighting fixtures may be used for indirect lighting applications.

LED-based optically indirect recessed luminaire


A hollow annular seal for sealing two concentric components in a subsea environment is disclosed. The hollow annular seal is constructed from an elastomeric material with a hollow core. The hollow annular seal also includes a plurality of apertures to allow fluid to flow through the apertures and into the hollow core to prevent collapse of the fluid filled, hollow annular seal.

Flexible seals may be used for a wide range of applications to contain internal pressure, exclude external pressure, or otherwise isolate two environments (e.g., prevent external contaminants from entering a sealed environment). Flexible seals may be defined by a cross sectional shape and a path that the cross section follows, and may commonly include O-rings and other annular seals, and gaskets or weather stripping where the cross section follows a path such as a square or rectangle. Flexible seals are commonly constructed from elastomeric or polymeric materials.
Flexible seals for subsea equipment applications are most commonly used to seal two concentric bodies, where the cross section of the flexible seal follows a circular path thereby defining a ring. For subsea equipment applications, conventional elastomeric O-rings may be used to seal two concentric bodies of a subsea equipment assembly, with the O-ring defining an annular seal with a solid, circular cross section where the cross section follows a continuous circular path. Other types of annular seals used for subsea equipment applications include U-cup seals, lip seals, and modified versions of those types of seals, which have both advantages and disadvantages compared to O-rings.
Unlike conventional applications for annular seals, the subsea environment may present a number of unique requirements, including near-freezing temperatures and very high hydrostatic pressures. The requirements for subsea equipment for the offshore oil industry also present a number of additional challenges unique to this application. Where subsea equipment having annular seals are field-installed (e.g., assembly of subsea connections in the open ocean), the subsea equipment may be exposed to substantial differential pressures or forces, which in some cases may cause the annular seal to be pulled out of its groove due to misalignment with existing subsea equipment, thereby exposing the annular seal to damage or otherwise rendering the seal ineffective.
For example, subsea equipment assemblies may be installed in shallow water depths up to approximately 500 feet with diver support for installation, or alternatively may be installed in deep water conditions up to or exceeding 10,000 feet with support by a remotely operated vehicle (ROV). While the installation vessel will attempt to line up over the true vertical centerline or axis of the subsea equipment interface (e.g., well head, mandrel, hub), it is very common that there will be a substantial error between the alignment of the vessel centerline and the vertical centerline of the subsea equipment interface. Furthermore, any ocean currents present in the open ocean may impose substantial hydrodynamic loads on the subsea equipment assembly during installation, which may further misalign the subsea equipment assembly from the vertical centerline of the subsea equipment interface. Additionally, the subsea equipment interface previously installed directly or indirectly to the seabed will commonly deviate slightly from a true vertical axis, further complicating installation of the subsea equipment assemblies. In these circumstances, a vertical centerline of the subsea equipment assembly (to be installed) may not match the vertical centerline of the existing subsea equipment interface prior to and during installation, thereby complicating installation and increasing the likelihood of damaging the annular seals used on the subsea equipment assemblies.
Furthermore, a great deal of silt and other fine debris may accumulate on the subsea equipment interface over time, a problem that is increased by the directional thrusters of the ROV that will stir up additional silt from the seafloor. During installation of a subsea equipment assembly to an existing subsea equipment interface, the silt stirred up during installation can create a uniformly distributed cloud of silt in the ambient seawater near the seafloor and around the subsea equipment interface. With low visibility, misalignment between the vertical centerlines of the subsea equipment interface and the subsea equipment assembly, and silt accumulating onto the subsea equipment interface and/or the subsea equipment assembly, radial clearances for concentric bodies (e.g., subsea components such as mandrel, pipe, hub, flowlines) used for subsea applications are much larger than would otherwise be required.
Because of the large radial clearances required for coupling subsea equipment assemblies, a conventional approach is to use an oversized annular seal having a substantially large cross-section when compared to conventional annular seals. Use of an oversized annular seal, however, requires a significant compression force (e.g. exceeding 5,000 lbs.) to deflect the seal and may easily exceed the limits of some subsea equipment designs. For example, for a face seal configuration, the compression force required to sealingly engage a subsea equipment component (such as a mandrel of a well head) may require thousands of pounds-force, which may be impractical for some designs. As another example, for a large annular seal used in a piston seal configuration or a rod seal configuration, the compression force required to sealingly engage a subsea equipment component may similarly require thousands of pounds-force. Further, where an oversized annular seal with a large cross-section is installed within a dovetail grove, the amount of force required to compress the annular seal and force the annular seal through the narrow groove opening of the dovetail groove may be very high (e.g. hundreds of pounds or thousands of pounds).
What is needed, therefore, is an annular seal for subsea equipment applications that is capable of sealing large radial clearances between two subsea equipment components regardless of misalignment and debris, requires low compression force to install and adequately seal, is resistant to unintended removal from the seal groove whether wholly or partially, and is resistant to damage during installation and removal.

Hollow annular seal for equipment disposed in a subsea environment


There are provided a viewing angle control device that can provide a black display without coloring and achieve a significantly improved shielding ability during a narrow viewing angle state, and a display using the same. In order to adjust VT (voltage-transmittance) characteristics of a viewing angle control liquid crystal panel (2) that switches a viewing angle between a wide viewing angle state and a narrow viewing angle state by using birefringence of liquid crystal, the viewing angle control liquid crystal panel (2) includes a translucent dielectric film (206g, 206r) for adjusting the voltage-transmittance characteristics of the liquid crystal at a position corresponding to a picture element of at least one color in a display liquid crystal panel (1) on at least one of a pair of translucent substrates (201, 202) that sandwich the liquid crystal therebetween.

Nowadays, a liquid crystal display has been used commonly in personal computers, PDAs (persona digital assistants), mobile phones, and the like. As such devices become widespread, the chances of displaying information on a liquid crystal display screen in public are increasing.
The following is a brief description of a configuration of a conventional liquid crystal display. The liquid crystal display has a liquid crystal layer sandwiched between a pair of translucent substrates. On one of the translucent substrates i.e., an active matrix substrate), data signal lines to which display data is applied and gate signal lines for driving active elements described below are arranged in matrix. At each intersection of the data signal lines and the gate signal lines, the active element such as a thin film transistor (TFT) to which a picture element electrode is connected is connected. The picture element electrodes are arranged on the translucent substrate in matrix. On the other translucent substrate (i.e., a counter substrate), a color filter layer including color filters of red, green, and blue, and a black matrix for preventing light leakage between these color filters is formed. On the color filter layer, a transparent conductive film functioning as a counter electrode for driving liquid crystal is laminated.
Further, on each of the active matrix substrate and the counter substrate, a Liquid crystal alignment film made of polyimide or the like is formed under a predetermined condition, followed by an alignment treatment such as rubbing in accordance with a desired viewing angle. Then, a spacer such as plastic beads for forming a cell gap is arranged on one of the substrates, and an adhesive such as a thermosetting sealant is applied to the periphery of a display area on the other substrate. Thereafter, the active matrix substrate and the counter substrate are adhered to each other with the adhesive, and a liquid crystal material is injected between the substrates by a vacuum injection method or the like, followed by sealing of an injection port. In this manner a liquid crystal display element is obtained.
Meanwhile, a liquid crystal display is required to have display quality such as high brightness, high contrast, high definition, and a wide viewing angle, which is being improved rapidly. In particular, conventional modes such as a TN (twisted nematic) mode and a STS (super twisted nematic) mode are disadvantageous in that they lead to a narrow viewing angle. In order to overcome this disadvantage, liquid crystal modes capable of providing a wide viewing angle, such as MVA (multi-domain vertical alignment), CPA (continuous pinwheel alignment), IPS (in-plane switching), FFS (fringe field switching), OCB (optically compen stated birefringence), are being developed. However, the development of such liquid crystal modes capable of providing a wide viewing angle has led to another problem.
That is, when a user observes a screen of a mobile personal computer, a PDA, a mobile phone, or the like having a wide viewing angle in public, the wide viewing angle of the screen allows others to view the screen from a viewing angle in a direction other than a front direction for the user, such as a horizontal direction, which may result in leakage of private information. Nowadays, combined with enforcement of the Personal Information Protection Law, there has been an increasing demand from users for privacy protection by making a viewing angle narrower contrary to a conventional tendency. To this end, it has been popular to attach a viewing angle adjusting film for making a viewing angle narrower to a screen, which, however, always makes the viewing angle narrower. Thus, it also has been demanded to switch dynamically between a wide viewing angle inherent in a display and a narrow viewing angle in favor of privacy protection according to need. In view of this, a display in which a viewing angle control device capable of switching dynamically between a wide viewing angle and a narrow viewing angle by using birefringence of liquid crystal is provided on a display device for displaying an image has been proposed.
Various systems of viewing angle control devices using liquid crystal have been proposed, such as a light dispersion system using polymer-dispersed liquid crystal (Japanese Patent No. 3481741 and JP 7(1995)-333640 A), a light absorption system using guest host liquid crystal (JP 10(1998)-197844 A), a TN mode (JP 10(1998)-268251 A), an IPS mode (JP 11(1999)-30783 A), a hybrid alignment mode (JP 2005-275342 A), and a homogeneous alignment mode (JP 2005-316407 A).
In particular, the viewing angle control device using homogeneously aligned liquid crystal as disclosed in JP 2005-316407 A has many advantages such as a simple manufacturing process, capability of switching between a wide viewing angle and a narrow viewing angle, and relatively high transmittance in a normal direction. With reference to FIGS. 11A and 11B, a configuration of the viewing angle control device using homogeneously aligned liquid crystal will be described. FIG. 11A is a schematic view showing a state of liquid crystal molecules during a wide viewing angle mode of the viewing angle control device, and FIG. 11B is a schematic view showing a state of the liquid crystal molecules during a narrow viewing angle mode of the viewing angle control device. In FIGS. 11A and 11B, reference numerals 91 and 92 denote a pair of translucent substrates, and reference numeral 93 denotes liquid crystal molecules in a liquid crystal layer sandwiched between the translucent substrates 91 and 92. Arrows denoted by reference numerals 94 and 95 represent polarization-transmission axes of polarizers laminated on the translucent substrates 91 and 92. The polarization-transmission axes 94 and 95 are parallel to each other. Alignment films on the translucent substrates 91 and 92 are subjected to a so-called anti-parallel rubbing treatment in directions substantially parallel to the polarization-transmission axes 94 and 95 and opposite to each other between the translucent substrates 91 and 92.
In this viewing angle control device, in a state where no voltage is applied to the liquid crystal layer, the liquid crystal molecules 93 are arranged such that their long molecular axes are substantially horizontal to the polarization-transmission axes 94 and 95 as shown in FIG. 11A. Thus, even if a view point is inclined horizontally with respect to a panel from a normal direction of the substrates (i.e., in a plane perpendicular to the polarization-transmission axes 94 and 95), no phase difference occurs in the liquid crystal layer, thereby maintaining a wide viewing angle of a display device on which the viewing angle control device is laminated. This state is referred to as a wide viewing angle state.
On the other hand, when a predetermined voltage is applied to the liquid crystal layer; the liquid crystal molecules 93 rise at an inclination angle θ with respect to a substrate surface in accordance with the applied voltage as shown in FIG. 11B. Consequently, if a view point is inclined horizontally with respect to the panel from the normal direction of the substrates, a phase difference occurs in the liquid crystal layer. When the inclination of the view point reaches a certain angle, a black display is caused according to VT (voltage-transmittance) characteristics as shown in FIG. 12. In this manner, a display on the display device is shielded by the black display of the viewing angle control device in a horizontal direction other than the normal direction (front side) of the substrates. This state is referred to as a narrow viewing angle state.

Viewing angle control device and display provided with the same


A vehicle body frame manufactured by welding is configured for weight reduction, and includes first and second frame members. The first frame member has a predetermined thickness including a first flat surface portion wider than the predetermined thickness. The second frame member includes a second flat surface portion touching the first flat surface portion. The first and second frame members are joined by bringing the flat surface portions together and welding the first and second flat surface portions together with laser beams parallel to the first flat surface portion. In this way, the laser welding can be performed with a reduced gap between the two members. Welding using laser beams applied from directions parallel to the flat surfaces allows the weld area to be significantly larger than conventional fillet welding.

1. Field of the Invention
The present invention relates to a vehicle body frame for a saddle-ride vehicle, and to a motorcycle including the vehicle body frame.
2. Description of the Background Art
In many cases, vehicle body frames of saddle-ride vehicles are manufactured by welding together sections of pipe materials and tubular frames.
Two frame members may be joined either by butt welding or by fillet welding (see Patent Document 1 (FIG. 10), for example).
FIG. 10(a) of Patent Document 1 shows a cross section of a vehicle body frame. A stiffener gusset (60) (numbers in parenthesis represent ref. no.s described in the cited document; the same applies below) is joined to a down pipe (40) by welding. Specifically, end portions (65a, 66a) of the stiffener gusset (60) are joined to the down pipe (40) with weld beads illustrated in black.
Each of the weld beads has a substantially triangular cross section, and is therefore a bead formed by "fillet welding." In fillet welding, the distance from the vertex of the right angle side of a right triangle to its hypotenuse is called "throat thickness." The product of this "throat thickness" and the length of the weld (or the circumferential length in the case of circumferential welding) is the "weld area." This weld area determines the "joint strength (or weld strength)."
The throat thickness is determined in proportion to the thickness of the end portion (65a, 66a). The circumferential length is determined by the size of the stiffener gusset (60).
When the required joint strength is large, such a requirement is fulfilled by increasing the thickness (and/or the size) of the stiffener gusset (60). In this way, however, the weight of the stiffener gusset (60) increases. As a result, the vehicle body frame becomes heavy, and therefore the vehicle becomes heavy.
There has been a strong demand for reducing vehicles' weights, driven in part by an effort to reduce fuel consumption. Therefore, welded vehicle body frames are also targeted for weight reduction.    [Patent Document 1] Japanese Patent Application Publication No. 2004-256073

Vehicle body frame for a saddle-ride vehicle, and motorcycle including same