An absorbent structure can include a matrix of fibers, wherein the matrix is reinforced with a reinforcing member, such as scrim. Preferably, the scrim is secured to the fibrous matrix by entanglement of fibers with the scrim and entanglement of fibers in the matrix from opposite sides of the scrim with each other. The scrim layer can be restricted to a longitudinally extending, medial region of the absorbent. In a particular arrangement, the scrim has a cross-directional width dimension which is less than a narrowest width dimension of the fibrous matrix. The scrim can be located between two, opposed, major surfaces of the fibrous matrix.

This invention generally relates to an absorbent article and an absorbent structure for such an article. The absorbent structure may include absorbent fibers and a reinforcing member. The reinforced absorbent structure can be employed in absorbent articles, such as disposable diapers, child's training pants, feminine care articles, incontinence articles, bandages, and the like.
Absorbent articles, such as for disposable absorbent garments, may include absorbent structures or cores conventionally formed by air forming or air laying techniques. For example, the manufacture of the absorbent core may begin by fiberizing a fibrous sheet of cellulosic or other suitable absorbent material in a conventional fiberizer, or other shredding or comminuting device, to form discrete fibers. In addition, particles of superabsorbent material are mixed with the discrete fibers. The fibers and superabsorbent particles are then entrained in an air stream and directed to a foraminous forming surface upon which the fibers and superabsorbent particles are deposited to form an absorbent fibrous web. In addition, bonding agents or other strengthening components may be incorporated to provide a more stabilized web.
Other techniques have also been employed to form webs of stabilized absorbent material. Such techniques have included dry-forming techniques, wet-laying techniques, foam-forming techniques, and various wet-forming techniques. The resulting webs of absorbent material have included absorbent fibers, natural fibers, synthetic fibers, superabsorbent materials, binders, and strengthening components in desired combinations. However formed, the absorbent web may then be stored or immediately directed for further processing (e.g., being cut into individual absorbent cores) and assembly with other components to produce a final absorbent article. Absorbent material webs have been strengthened by adding reinforcing members on at least one side of the absorbent material webs. Such reinforcing members have included reinforcement filaments, tissue layers, fabric layers and netting materials. It is also known to add staple binder fibers to the absorbent materials upon formation of the absorbent material web. The binder fibers are activated by heat to produce adhesion of the absorbent materials.
Integrity of an absorbent core formed from such an absorbent material web is desirable to avoid bunching, clumping, cracking and separating of the absorbent core in either a wet or a dry state. This improves the fit and comfort to the wearer of an absorbent article incorporating the absorbent core even as the article receives insults. Sagging and drooping of the absorbent article can cause gaps between the article and the wearer's body which may lead to leaking. As absorbent cores are made both thinner and narrower (particularly in the crotch region), stresses encountered in manufacture and use can be high, requiring reinforcement. In manufacture, tension on the absorbent core can be particularly high during start up and shut down of processing machinery. In use, the lack of integrity can make the absorbent article fit poorly and impact product performance by breaking up the absorbent core, and thereby inhibiting fluid control, liquid handling and wicking which can contribute to leaking.
Co-assigned European Patent Publication No. 0 467 409 A1 discloses one attempt to reinforce an absorbent pad using a scrim material. In that disclosure, a netting or scrim material is used in which some strands have an inner core of one material and an outer sheath of a second material. The scrim is introduced into a forming chamber in which it is incorporated into a fibrous matrix. The second material of the sheath has a lower melting point than the first material of the core. After incorporation of the scrim into the fibrous matrix, the absorbent web formed is heated to melt the sheath for bonding the scrim to the fibers in the matrix. This requires an extra step in the manufacture of a reinforced absorbent.
European Publication No. 0 467 409 also discloses a method for establishing the position of the scrim within the thickness of fibrous matrix. The method does not necessarily require the use of scrim of strands having inner cores and outer sheaths of different material. However, there is no disclosure or suggestion that securing the scrim to the fibrous matrix can be achieved without the use of adhesive and/or fusion bonding.
Conventional reinforcement materials, such as those described above, have exhibited significant shortcomings when employed to form desired absorbent structures. In order to connect the reinforcing member to the surrounding material adhesives and other forms of bonding have been employed which require additional or more complicated manufacturing techniques. Moreover, the conventional reinforcement materials have been expensive, and have had edges that can excessively irritate a wearer's skin. As a result, it has been difficult to provide an absorbent structure that has a desired combination of low-cost, high strength and low irritation. Accordingly, there has been a continued need for an improved technology for providing the desired, reinforced absorbents.

Absorbent article with reinforced absorbent structure


It is an object of the present invention to control the position in crystal lateral growth of a semiconductor film without making a system cumbersome and complicated.

1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device, and more particularly, relates to a method for manufacturing a semiconductor device that has a thin film transistor (hereinafter, abbreviated as "TFT" in this specification) formed with the use of a semiconductor film, where the semiconductor film is formed due to lateral crystal growth of a semiconductor film formed over an insulating substrate by laser light irradiation.
2. Description of the Related Art
Recently, a technique of crystallizing a semiconductor film (particularly, an amorphous semiconductor film) formed over an insulating substrate such as glass or improving the crystallinity of the semiconductor film by laser annealing has been widely studied. For the semiconductor film, silicon is typically used.
A glass substrate has more workability as compared with a synthesized quartz glass substrate that is often used conventionally, and has the advantage of being able to manufacture a large-area substrate. However, a glass substrate has a lower melting point as compared with a synthesized quartz glass substrate, and thus has the disadvantage that heating is not able to be performed so much in a process of crystallizing a semiconductor film formed over the glass substrate. Consequently, a method using a laser is often used as a method for crystallizing a semiconductor film formed over a glass substrate. This is because high energy can be given to only an amorphous semiconductor film by the laser without increasing the temperature of a substrate so much.
A crystalline semiconductor film formed by laser annealing has a high mobility. Therefore, TFTs formed with the use of this crystalline semiconductor film are extensively used for a monolithic liquid-crystal electro-optical device in which TFTs of a driver circuit and a pixel portion are formed over the same substrate, and the like.
Further, a method is industrially excellent in productivity, and thus is widely used. In the method, a laser beam by pulsed oscillation that is powerful such as an excimer laser is processed by an optical system to be a several-centimeter square spot or a linear shape 10 cm or more in length at a surface to be irradiated, and laser annealing is performed while scanning the laser beam relatively with respect to the surface to be irradiated.
In particular, when a linear beam is used, the productivity is high since the whole of a surface to be irradiated can be irradiated with the laser beam by scanning only in a direction perpendicular to the longitudinal direction of the linear beam unlike a case of using a spot-shaped laser beam and thus requiring scanning from front to back and from side to side. The reason of the scanning in the direction perpendicular to the longitudinal direction is that the direction is the most efficient scanning direction. Due to this high productivity, the use of a linear beam obtained by processing a laser beam of a pulsed-oscillation excimer laser by an appropriate optical system in laser annealing is now becoming mainstream in manufacturing technology of a device such as a liquid crystal display device using a TFT. Further, this technique makes it possible to manufacture a monolithic liquid crystal display device in which TFTs of a driver circuit provided at the periphery of a pixel portion are integrally formed.
However, a crystalline semiconductor film that is manufactured by laser annealing is formed of an aggregate of a plurality of crystal grains, and the crystal grains are random in position and size. A TFT that is manufactured over a glass substrate is formed by separating the crystalline semiconductor film into island-shaped patterns for element separation. However, in this case, it is not possible to specify the positions and sizes of the crystal grains to form the TFT. There are an infinite number of recombination centers and trapping centers derived from amorphous structures and crystal defects at interfaces of the crystal grains (grain boundaries) as compared with within the crystal grains. When a carrier is trapped in this trapping center, the current transporting property of the carrier is known to be decreased since the potential of the grain boundary is increased to become a barrier against the carrier. While the crystallinity of a semiconductor film of a channel forming region has an important effect on electrical characteristics of a TFT, it is almost impossible to form the channel forming region with the use of a single-crystal semiconductor film by eliminating effects of the grain boundaries.
In order to solve these problems, there have been various attempts to form crystal grains that are subjected to position control and are large in grain size in laser annealing. The solidification process of a semiconductor film after irradiating the semiconductor film with a laser beam will be described below.
It takes some time to generate a crystal nucleus in the semiconductor film melted completely by laser beam irradiation, an infinite number of crystal nucleuses are generated uniformly (or non-uniformly) in a completely melted region of the semiconductor film, and crystal growth is terminated to complete the solidification process of the completely melted semiconductor film. The crystal grains obtained in this case are random in position and size.
Alternatively, when the semiconductor film is not completely melted by laser beam irradiation so that a solid-phase semiconductor region partly remains, crystal growth proceeds from the solid-phase semiconductor region after laser beam irradiation. As previously mentioned, it takes some time to generate a crystal nucleus in the completely melted semiconductor film. Therefore, until a crystal nucleus is generated in the completely melted semiconductor film, a solid-liquid interface that is a head of crystal growth (which indicates a boundary between the solid-phase semiconductor region and the completely melted region) moves in a parallel direction (hereinafter, referred to as "a lateral direction") with respect to the surface of semiconductor film so that a crystal grain grows to many times its film thickness. Such growth is completed in such a way that an infinite number of crystal nucleuses are generated uniformly (or non-uniformly) in a completely melted region and crystal growth is terminated. Hereinafter, this phenomenon is referred to as super lateral growth.
In the case of an amorphous semiconductor film or a polycrystalline semiconductor film, there is an energy region of a laser beam for achieving the super lateral growth. However, the energy region is quite narrow, and it is not possible to control positions in which crystal grains that are large in grain size are obtained. Further, a region other than the crystal grains that are large in gain size is a microcrystalline region in which an infinite number of crystal nucleuses are generated or an amorphous region.
As described above, when the temperature gradient in a lateral direction can be controlled (a heat flow in the lateral direction can be generated) in an energy region of a laser beam for completely melting a semiconductor film, the position and direction in growth of a crystal grain can be controlled. In order to accomplish this method, there have been various attempts.
First, as a reflective film, a metal film (a Cr single layer or a lamination layer of a Cr film and an Al film stacked on the Cr film) is formed on an amorphous semiconductor film, and is partially etched to form a region with the metal film on the amorphous semiconductor film and a region without the metal film. At a wavelength of 308 nm, the reflectivity of Cr is approximately 60%, and the reflectivity of Al is approximately 90%. Therefore, when a laser beam with a wavelength of 308 nm is used to irradiate the amorphous semiconductor film, the amorphous semiconductor region below the metal film is less irradiated with the laser beam as compared with the amorphous semiconductor covered with no metal film. Namely, a temperature gradient is generated between the amorphous semiconductor region below the metal film and the amorphous semiconductor covered with no metal film. Therefore, a crystal nucleus generated in the amorphous semiconductor region below the metal film is known to laterally grow to the amorphous semiconductor covered with no metal film, which is kept in a melted state, and to form a crystal grain of 1 to 2 μm.
However, this method has the following problems. In the method of performing crystallization by forming the metal film partially on the amorphous semiconductor film and performing laser beam irradiation, it is difficult to control the position of a crystal grain on a single crystal basis while a position in which a crystal grain is formed can be controlled. In addition, since the metal film is formed directly on the amorphous semiconductor film, the metal element diffuses into the amorphous semiconductor film, and there is a possibility that deterioration in electrical characteristics of a TFT is caused when the TFT is manufactured with the use of a crystalline semiconductor manufactured by crystallizing the amorphous semiconductor film. In addition, there is a possibility that cracks and peeling is generated in the metal film and the amorphous semiconductor film. The metal film is typically formed by sputtering. As compared with CVD, sputtering shows larger in-plane variations in film thickness when the metal film is formed. Therefore, when substrates are larger, it can be said that the use of sputtering is not preferable in the feature.
Further, James S. Im et al. show a Sequential Lateral Solidification method (hereinafter, referred to as "an SLS method") by which super lateral growth can be achieved in any position (for example, refer to Patent Reference 1).                (Patent Reference 1) Japanese Patent No. 3204986
In the SLS method, crystallization is performed while a mask in the shape of a slit is moved on the order of the distance of super lateral growth (approximately 0.75 μm) for every shot.
The use of the SLS method makes lateral growth possible by irradiating an amorphous silicon film formed on a glass substrate with an extra fine beam on the order several microns, where the extra fine beam is obtained by condensing an excimer laser beam passed through a slit. In addition, lateral growth can be proceed continuously by controlling the substrate feed pitch for every shot to be the distance of lateral growth. However, the use of the SLS method has the following problems.
Since an excimer laser is not so good in quality, it is necessary that a mask for condensing light into several μm be used in a laser irradiation system in order to use the SLS method. Further, the mask needs to be replaced periodically, and an automatic focus function for keeping a focal depth constant is indispensable in order to keep a focal point uniformly in the surface of a substrate since a lens that has a short focal length also has a shallow focal depth. As a result, the system becomes complicated and expensive as compared with a typical laser irradiation system.

Method for manufacturing semiconductor device

Abstract: A method for manufacturing a semiconductor device according to the present invention includes the step of forming a semiconductor film over an insulating substrate, forming a reflective film comprising an insulating film on the semiconductor film, exposing a portion of the semiconductor film by patterning of the reflective film, and crystallizing the exposed semiconductor film by irradiating the exposed semiconductor film with laser light while using the patterned reflective film as a mask. In the above-described method according to the present invention, the reflective film has a structure in which an insulating film that has a higher refractive index and an insulating film that has a lower refractive index are stacked alternately.

Semiconductor Energy Laboratory Co., Ltd


A process for catalytically cracking a heavy feed in an FCC unit, with large amounts of shape selective cracking additive is disclosed. The catalyst inventory preferably contains at least 10 wt % additive, of 12-40% ZSM-5 on an amorphous support, equivalent to more than 3.0 wt % ZSM-5 crystal circulating with equilibrium catalyst. Large yields of light olefins are produced, without excessive production of aromatics, or loss of gasoline yield. Operating with large amounts of additives allows yields of butadiene and/or methane to be suppressed, and production of a cracked gasoline fraction with an unusually low olefin content, and high ratio of cyclic unsaturates to normal unsaturates.

1. Field of the Invention
The invention relates to fluidized catalytic cracking.
2. Description of Related Art
In the fluidized catalytic cracking (FCC) process, catalyst, having a particle size and color resembling table salt and pepper, circulates between a cracking reactor and a catalyst regenerator. In the reactor, hydrocarbon feed contacts hot, regenerated catalyst which vaporizes and cracks the feed at 425.degree. C.-600.degree. C., usually 460.degree. C.-560.degree. C. The cracking reaction deposits carbonaceous hydrocarbons or coke on the catalyst, thereby deactivating it. The cracked products are separated from the coked catalyst. The coked catalyst is stripped of volatiles, usually with steam, in a catalyst stripper and then regenerated. The catalyst regenerator burns coke from the catalyst with oxygen containing gas, usually air, to restore catalyst activity and heat catalyst to, e.g., 500.degree. C.-900.degree. C., usually 600.degree. C.-750.degree. C. This heated catalyst recycles to the cracking reactor to crack more fresh feed. Flue gas from the regenerator may be treated to remove particulates or convert CO, and then discharged into the atmosphere.
Catalytic cracking has undergone progressive development since the 40s. The trend of development of the (FCC) process has been to all riser cracking and zeolite catalysts. A good overview of the importance of the FCC process, and its continuous advancement, is the Fluid Catalytic Cracking Report, Amos A. Avidan, Michael Edwards and Hartley Owen, in the Jan. 8, 1990 edition of the Oil & Gas Journal.
The product distribution from modern FCC units is good. The volume and octane number of the gasoline is satisfactory, and the light olefins produced are upgraded via sulfuric or HF alkylation to high quality alkylate.
Unfortunately, refiners are finding it more difficult to make gasoline of sufficient octane and meet new specifications in regard to oxygenates, aromatics and benzene in the fuel. Reduced limits on RVP (Reid Vapor Pressure) and gasoline endpoint limit the amount of butanes that can be added, further exacerbating the problem.
Many refiners will face a shortage of light olefins (needed to make ethers and/or alcohols), with no efficient way of making more.
Most options available to FCC operators have limited potential. Use of shape selective cracking additives, or large cracking catalyst containing such additives, appeared to have only limited potential to increase yields of light olefins.
Pyrolysis units or thermal crackers produce large amounts of olefins, but little gasoline. A high severity, shape selective cracking process is also available, but like its closely related pyrolysis processes it makes large amounts of olefins, but relatively small yields of gasoline, which is highly aromatic and low in octane.
A reasonable way to summarize the state of the art on maximizing yields of light olefins from gas oil and heavier feeds is to focus on three catalytic approaches:
1. FCC Cracking catalyst with ZSM-5 and large pore zeolite sharing matrix, with large amounts of ZSM-5 crystal.
2. FCC units with additive ZSM-5 catalyst, in limited amounts.
3. Production of cracked gas from gas oil over pentasil zeolites at high severity.
These approaches will each be reviewed in more detail hereafter, in the order presented above, which is roughly chronological order.
1. Large Pore+ZSM-5-Shared Matrix
U.S. Pat. No. 3,758,403, Rosinski et al, Catalytic Cracking of Hydrocarbons with Mixture of ZSM-5 and Other Zeolites, taught the benefits of adding ZSM-5 to conventional large pore cracking catalyst formulations.
Example 2 used a catalyst consisting of 5 wt % ZSM-5, 10 wt % REY, and 85% clay. When used to crack a gas oil, it produced 11.42 LV % propylene, and a total yield of alkylate and C5+ gasoline of 89.1 LV %.
Example 3 used a catalyst consisting of 10 wt % ZSM-5, 10 wt % REY, and 80% clay. Although the ZSM-5 content doubled, propylene yields increased from 11.4 LV % to only 13.6 LV %. The total yield of alkylate and gasoline declined slightly, from 89.1 LV % to 88.6 LV %.
U.S. Pat. No. 3,847,793, Schwartz et al, Conversion of Hydrocarbons with a Dual Cracking Component Catalyst Comprising ZSM-5 Type Material, had a slightly different approach. The ZSM-5, which could be in the same particle with the large pore zeolite, or in a separate additive, was used to convert olefins to aromatics. A riser reactor with an enlarged upper portion was used, along with injection of a coking fluid near the top of the riser, to deactivate the large pore catalyst while leaving the ZSM-5 catalyst active. Gasoline boiling range material could be injected into the top of the riser for conversion. Table 2 shows that this approach reduced the mono olefin content of an FCC gasoline from 14.0 wt % to 2.9 wt %. The discussion of Examples 2 reports that ZSM-5 was effective for converting propylene to aromatics over a wide range of catalyst silica-alumina ratios.
Based on '793, large amounts of ZSM-5 should efficiently convert propylene into aromatics. This would reduce light olefin production, and perhaps exacerbate problems of producing gasoline without exceeding aromatics and/or benzene specifications.
Based on '403, use of large pore cracking catalyst with large amounts ZSM-5 additive gives only modest increases in light olefin production. A 100% increase in ZSM-5 content (from 5 wt % ZSM-5 to 10 wt % ZSM-5) increased the propylene yield less than 20%, and decreased slightly the potential gasoline yield (C5+ gasoline plus alkylate).
Neither approach seemed useful for making large amounts of light olefins via the FCC process using cracking catalyst containing large amounts of ZSM-5.
A drawback to an "all in one" catalyst, e.g., REY+H-ZSM-5 in a matrix, is catalyst availability. Mixing zeolite types in the same catalyst makes it impossible to use all the large pore cracking catalysts available today. There are more than 100 types of large pore cracking catalyst, but essentially all of the these are made without any ZSM-5 content. Refiners need to be able to, e.g., shift from a large pore cracking catalyst with bottoms cracking activity and high metals tolerance to an octane catalyst which minimizes hydrogen transfer reactions. FCC operation changes all the time in most refineries, in response to shifting crude supplies and varying product demands, and refiners want to retain the ability to use all of the cracking catalyst available to be able to constantly fine tune their FCC operation. For this reason, the marketplace has decided that use of additive catalysts is the only viable commercial option for the use of ZSM-5 and other shape selective additives. Use of separate additive catalysts will be reviewed next.
2. ZSM-5 Additives
Because refiners must retain the ability to use the myriad types of commercially available large pore cracking catalyst available today, they usually add additive catalysts, with 10-50 wt %, more usually 12 to 25 wt % ZSM-5 in a amorphous support, to their FCC units. Such additives have physical properties which allow them to circulate with the large pore cracking catalyst.
U.S. Pat. No. 4,309,280 taught adding very small amounts of powdered, neat ZSM-5 catalyst, characterized by a particle size below 5 microns. Adding as little as 0.25 wt % ZSM-5 powder to the FCC catalyst inventory increased LPG production 50%. Small amounts of neat powder behaved much like larger amounts of ZSM-5 disposed in larger particles.
A good way to add a modest amount of ZSM-5 to an FCC unit is disclosed in U.S. Pat. No. 4,994,424, incorporated by reference. ZSM-5 additive is added to the equilibrium catalyst in a programmed manner so an immediate boost in octane number, typically 1/2-2 octane number, is achieved.
U.S. Pat. No. 4,927,523, incorporated by reference, taught a good way to add large amounts of ZSM-5 to a unit without exceeding wet gas compressor limits. Large amounts were added, and cracking severity reduced until the ZSM-5 activity tempered from circulating through the FCC unit for several days.
ZSM-5 additive has been used commercially for almost a decade, and is now a well accepted way to increase C3 and C4 olefin yields and gasoline octane, at the cost of some loss in gasoline yield.
Recent work on ZSM-5 additives has been directed at stabilizing it with phosphorus or making the additive more attrition resistant. Phosphorus stabilized ZSM-5 additive is believed to retain activity for a longer time. There may be some change in yield pattern, but none that we have been able to observe in commercial refineries. Phosphorus stabilization thus reduces the makeup rate of ZSM-5 additive required.
One drawback to use of ZSM-5 additive, even with phosphorus stabilization, is that refiners fear dilution of the large pore cracking catalyst by addition of large amounts of ZSM-5, say over 2 or 3 wt % ZSM-5 crystal, or use of more than 5 or 10 wt % additive, will reduce yields of light olefins and seriously impair conversion. Most refiners operate with significantly smaller amounts of ZSM-5 than the upper limits recited above.
Another concern is how well the unit will respond when pushed to make even more olefins. The consensus is that small amounts of ZSM-5 additive make large amounts of olefins in an FCC unit operating at low severity, but the increase in yields of light olefins attributable to ZSM-5 declines as severity increases. "Working at low severity we observe an increase in light olefinic compounds, mostly branched, in the C5-C6 range. At the same time we detect an increase in light branched alkanes and almost no effect on the aromatics and naphthenes contents. When the cracking occurs at higher temperature we observe an increase in the C7-C8 aromatics and naphthenes, but a much smaller increase in the lighter compounds." Effect of Operation Conditions on the Behaviour of ZSM-5 Addition to a RE-USY FCC Catalyst, M. F. Elia et al, Applied Catalysis, 73 (1991) 195-216, 202.
The poor response to unusually large concentrations of ZSM-5 was reported in '403, while Elia et al have shown the unfavorable response of ZSM-5 to high severity FCC operation.
Thus it seemed that ZSM-5 would be of most benefit to refiners when used in small amounts, preferably in FCC units operating at modest severity levels. Attempts to increase yields of light olefins by increasing ZSM-5 content would meet with only modest success, while going to high severity operation (a proven way to increase production of light olefins in FCC) would reduce the effectiveness of the ZSM-5 at increasing yields of light olefins.
It seemed that refiners could not expect to increase yields of light olefins from the FCC units by using conventional amounts of ZSM-5 additive. Higher severity operation would increase olefin yields (due to higher temperatures and conversion) but diminish the olefin yields attributable to ZSM-5.
We wondered what would happen at very severe conditions, at temperatures and conversions beyond those used in FCC.
Any heavy feed can be thermally cracked at extremely high temperatures to produce large yields of ethylene and other light olefins. The high temperatures needed to get high conversions also degrade the C5+ liquid products. Thermal cracking is a good way to make ethylene, but not to make gasoline.
An unusually severe catalytic route to cracked gas over USY and/or pentasil zeolites is reported in U.S. Pat. No. 4,980,053. Although more suited to a petrochemical plant than a cracking refinery, the approach represents an upper limit on conversion over pentasil zeolites, and for that reason is reviewed below.
3. High Severity Pentasil Conversion
U.S. Pat. No. 4,980,053, Zaiting Li et al, Production of Gaseous Olefins by Catalytic Conversion of Hydrocarbons, has examples of conversion of vacuum gas oil to more than 50 wt % cracked gas over zeolites ranging from pentasil, to USY, and mixtures. The process is basically a pyrolysis process, which uses a catalyst to operate at somewhat milder conditions than thermal pyrolysis processes.
Four catalysts were tested. Although precise catalyst formulations, and zeolite concentrations within each catalyst formulation, are not reported, the following information was:
Catalyst Zeolite
A "CHO" Pentasil+REY PA1 B "ZCO" USY PA1 C "CHP" Pentasil PA1 D Mixture of B & C (Mix. of USY & Pentasil)
Thus catalyst A or "CHO", corresponds to the approach of '403, Rosinski, which used ZSM-5 and Y zeolite in the same catalyst particle, while catalyst D represents something closer to the additive approach.
The examples were run at conditions much more severe than those used in catalytic cracking--580 C (1076 F), at a 1 LHSV, a cat:oil ratio of 5, and steam:hydrocarbon ratio of 0.3.
______________________________________ Catalyst A B C D ______________________________________ wt % of: cracked gas 52.0 51.2 54.0 55.6 propylene 11.61 17.39 21.56 21.61 butylene 15.64 14.47 15.64 15.09 C5-205 C 31.0 33.1 27.0 27.5 Conversion 93.3 90.3 87.6 89.1 ______________________________________
It is difficult to say too much about the results because the zeolite content of the catalysts is not specified. The patentees report that "the yields of gaseous olefins over catalyst C and D are higher than the others." As far as gasoline yields, and conversion, the mixture (D=mix of pentasil+USY) gives less conversion and less gasoline yield than a single particle catalyst (A=Pentasil+REY). Use of a mixture also reduced butylene yields slightly, as compared to single particle catalyst A.
Example 2 of '053 reports production of fairly aromatic gasolines, containing more than 50 wt % aromatics. This was to be expected from the high temperatures and severe conditions. The octane number of the gasoline was 84.6 (motor method). The di-olefin content of the gasoline was not reported.
These results show use of separate additives of pentasil zeolite can reduce conversion and butylene and gasoline yield, as compared to use of single particle catalyst with both types of zeolite in a common matrix, during pyrolysis processing.

Catalyst system for maximizing light olefin yields in FCC


A gas production plant has a first separator receiving a feed gas and produces a first offgas stream and a first product stream, and a second separator receives the first offgas stream and produces a second product stream and a second offgas stream. A liquefaction unit receives at least part of the first product stream and at least part of the second offgas stream, and produces a third product stream and a third offgas stream. A first portion of the third offgas stream is combined with the first offgas stream, and a second portion of the third offgas stream is used as a non-waste gas. In a method of removing a first and a second gaseous component from a feed gas, a PSA unit produces a first product stream and a first offgas stream. The first offgas stream is fed into a liquefaction unit that produces a second product stream and a second offgas stream, and at least part of the second offgas stream is recycled into the PSA unit.

The field of the invention is concurrent hydrogen and carbon dioxide production.
Complex mixtures of gases such as refinery gases or offgases from combustion processes are frequently employed as starting materials in the production of purified gases, and various systems have been developed to concurrently isolate at least 2 or more gases at a relatively high purity (i.e., greater than 90% (v/v) from a single gas mixture.
Some systems employ a serial configuration of PSA units, wherein a first PSA unit has a different selectivity from a second PSA unit, and wherein the offgas from the first unit is directed to the feed end of the second PSA unit. An example for this configuration is described by R. Kumar in U.S. Pat. No. 4,913,709. Kumar""s serial configuration of PSA units with beds having non-identical adsorption specificity is favorable in cases where relatively high volumes of offgas are to be purified 1 at a time. However, the complexity and number of coordinated cycle steps generally increases due to the different physico-chemical properties of the adsorbent beds, thereby adversely increasing cost and maintenance requirements.
Other systems utilize configurations with a PSA unit and a non-PSA unit as for example described in U.S. Pat. No. 4,553,981 to Fuderer. In Fuderer""s system, carbon dioxide is removed as a waste gas from a feed gas stream by a CO2 scrubber, and the CO2-depleted stream is subsequently fed into a H2-PSA unit. The H2-PSA offgas is then vented via a waste line into the atmosphere, or recycled to a converter or shift unit. While concurrently separating H2 and CO2 from the feed gas, Fuderer""s configuration advantageously may be employed to reduce undesirable build-up of nitrogen and/or argon in the waste gases from the scrubber and H2-PSA unit by recycling the waste gases to the reformer of shift converter. However, considerable amounts of carbon dioxide and hydrogen remain in the recycling circuit and are typically vented or combusted, rendering them no more amenable to recovery.
Still other systems employ selective membranes to separate a desirable gaseous component from the offgas of a PSA unit. For example, G. Intille describes in U.S. Pat. No. 4,229,188 the use of hydrogen permeable membranes to recover H2 from the offgas of a PSA unit. Intille""s membranes advantageously remove H2 with high selectivity in a single process step, however, the use of such membranes generally requires relatively high pressure, thereby increasing the overall energy demand. To avoid at least some of the problems associated with hydrogen-permeable membranes, Anand et al. teach in U.S. Pat. No. 5,435,836 the use of an adsorbent membrane. Adsorbent membranes typically allow hydrogen recovery at comparably low pressure with relatively high specificity. The advantage of relatively low pressure, however, tends to be offset by the need of membrane exchange, thereby either increasing the complexity of the hydrogen. plant, or necessitating discontinuous operation.
Thus, although various systems for concurrent production of desirable gases from gas mixtures are known in the art, all or almost all of them suffer from one or more than one disadvantage. Therefore, there is a need to provide improved methods and apparatus for concurrent production of desirable gases from gas mixtures.
The present invention is directed to a gas production plant comprising a gas source, a first and second separator, and a liquefying unit. The first separator receives feed gas from the gas source and produces a first offgas stream and a first product stream, whereas the second separator receives the first offgas stream to produce a second offgas stream and a second product stream. The liquefaction unit receives the first product stream and the second offgas stream thereby producing a liquefied third product stream and a third offgas stream, and at least part of the third offgas stream is combined with the first offgas stream.
In one aspect of the inventive subject matter, the gas source provides a feed gas predominantly comprising hydrogen and carbon dioxide, which is produced from natural gas via a steam reformer process. While the first separator preferably comprises a CO2 scrubber, the second separator comprises a hydrogen pressure swing adsorption (PSA) unit, and the liquefaction unit comprises in a particularly preferred aspect an autorefrigeration unit.
In another aspect of the inventive subject matter, a method of removing a first gaseous component and a second gaseous component from a feed gas employs a PSA unit that produces a first product stream predominantly comprising the second gaseous component, and a first offgas stream predominantly comprising the first gaseous component and the second gaseous component. At least part of the offgas stream is fed into a liquefaction unit that produces a second product stream and a second offgas stream, and at least part of the second offgas stream is recycled into the PSA unit.
Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawing. dr
FIG. 1 is a schematic of a gas production plant according to the inventive subject matter.
FIG. 2 is a flow diagram depicting a method of increasing recovery of a gaseous component from a feed gas according to the inventive subject matter.

Hydrogen and carbon dioxide coproduction


A drive train for a vehicle having a pair of mechanically driven wheels, a pair of hydraulically driven wheels, and a mechanically driven accessory is disclosed. The drive train includes a transmission system connected to the pair of mechanically driven wheels and to the accessory. A first drive source including an internal combustion engine is connected to the transmission system. A second drive source, operating through a source of stored mechanical energy, is also connected to the transmission system. At least one of the first and second drive sources is capable of driving the pair of mechanically driven wheels by driving the transmission system. One or both of the first and second drive sources can be disengaged from the transmission system so that the vehicle's kinetic energy is transmitted through the transmission system to drive the accessory. The internal combustion engine of the first drive source has a main piston with an inertia piston slidable received therein to increase the volumetric efficiency of the engine.

Accomplishing an 80 miles per gallon fuel economy in an affordable vehicle by early in the next century will require developmental breakthroughs in a number of areas and a high probability of several significant inventions. Ideally, a vehicle with an 80 mpg fuel economy will be efficient, clean, affordable and will be competitive in deliverable performance with today's models such as a Chevrolet Lumina, Ford Taurus, or Chrysler Concorde.
Current automotive passenger car practice is to size the engine large enough to provide the desired acceleration performance at both low speed (standing start) and high speed (passing performance in level and hilly terrain), and then by the selection of gear ratios, to attempt to tailor this large engine to maximize its fuel economy. This practice generally causes the engine to operate most of the time at load points of 10-30% of maximum power, well off from the engine's maximum efficiency point.
In order to overcome this drive efficiency shortcoming, hybrid drive systems have been devised. A series hybrid system is one in which the total power output of the primary engine power source is directed through an intermediate holding device which combines that energy with energy from secondary sources such as that recovered from regenerative braking. The energy is then distributed as required to meet the demands of the vehicle and driver.
Most serious contenders for high fuel economy drive systems up to this time have expressed a preference for a series hybrid system with an undefined storage capability of at least 0.5 kW which acts as a buffer between the power source and the vehicle propulsion system. The advantages of such a system are that the primary power source can be precisely tailored to a specific single power level to maximize its efficiency, and regenerative braking compatible with a storage device can be easily factored into the energy equation. The disadvantages are that additional losses are introduced with multiple interfaces, as the energy finds its way from the power source to the storage device to the propulsion system through several energy converters and controllers.
The requirements of storing 0.5 kW of energy and also providing high braking and propulsion power on the order of 50-60 kW rule out a number of storage systems such as hydraulic accumulators and batteries as presently known. Accumulators are unsuitable because of their limited energy storage capability relative to their size, and batteries because of the high power discharge requirement. This leaves capacitors and flywheels, both of which require inventions to bring them to fruition. High efficiency power converters and controllers are required at both interfaces: engine to storage and storage to propulsion.
The mainstream of the Partnership For New Generation Vehicles (P.N.G.V.) government/industry cooperative programs for hybrid vehicles is directed toward series hybrid electric vehicles because it has not been heretofore demonstrated that any other (parallel) hybrid arrangement will accomplish the goal of fuel efficiency at three times the current industry average.
A parallel hybrid drive system is one which retains two parallel power paths for at least two power sources. Consideration of a parallel hybrid system which keeps a more conventional mechanical driveline in place opens the door for consideration of current technology hydraulic regenerative energy recovery with hydraulic accumulator storage devices having less than 0.1 kW capacity because of the lessened energy and power requirements. The need for an invention now shifts to the powerplant where a much broader high efficiency power spectrum is needed. As has been pointed out by Ross and Wu (SAE 950958), engine mechanical loss is the largest single source of wasted energy between the fuel tank and the road.

Vehicle drive system featuring split engine and accessory back drive


A liquid cartridge for supplying liquid to an external device connected therewith is provided with a casing, a partition member movably fitted in the casing, which partitions the casing into a first chamber and a second chamber, an outlet port communicating between the first chamber and the external device and a pressure unit housed in the second chamber, which presses the partition member so as to discharge the liquid out of the outlet port.

1. Field of the Invention
The present invention relates to a liquid cartridge for housing and discharging liquid, which can stably discharge the liquid out with substantially no rest, no matter how the cartridge is directed.
2. Description of the Related Art
It is necessary for a device provided with an apparatus employing liquid, such as a fuel cell, to be equipped with a liquid cartridge. The liquid cartridge should be accompanied with feeding means for feeding the liquid, such as a pump. In a case where the pump is employed for feeding the liquid, usually, a strainer connected to the pump is inserted into the liquid housed in the cartridge so that the liquid is extracted through an end of the strainer. Some issues are raised when the liquid cartridge is applied to mobile devices.
Lightweight and compact constitutions are required for the mobile devices due to them carried around. The pump may cause a severe weight gain in mobile devices. Additionally, the mobile devices are carried around so as to be oriented in a variety of directions. Thus, the strainer may be displaced from a proper position in the liquid, therefore it may happen that the end of the strainer can become disposed into a bubble in the liquid. In such cases, the supply of the liquid comes to have a problem and malfunction of the device can be induced.
Japanese Patent Application Laid-Open No. H4-223058 discloses a liquid cartridge which per se includes discharging means for discharging the liquid so as to omit the pump and the strainer.


An exercise device conveniently measures, monitors, and reports electromyograph (EMG) information to the user, for use in effectively strengthening selected muscles. The exercise device includes a sensor circuit responsive to electrical activity in tensioning muscles, and a control circuit responsive to an output signal produced by the sensor circuit. In a preferred embodiment the control circuit regulates an audio device, by attenuating the audio device output signal when the sensor output signal declines to below a preset threshold. Alternatively, the control circuit selectively activates an indication device, such as a vibrator, when the sensor output signal falls too low. The exercise device provides information as to muscle activity to the user in an entertaining fashion, and in a way that the user is not required to pay constant attention and refer to an output meter or other conventional display.

The advantages of biofeedback devices are well known. By monitoring the muscle activity of the user, and providing a sensory indication of that activity, the user can learn to isolate and improve the functioning of the muscles being monitored. As a result, EMG biofeedback devices have been used for many years to help injured persons regain strength and the function of muscle groups that have impaired functionality.
Conventional EMG biofeedback devices consist of sensors applied to the body of the user adjacent the muscle area to be monitored, and a meter or similar device which displays the electrical activity of the sensor. Conventionally, as the sensed muscle activity increases, the connected meter provides an increased reading. By watching the meter the user can tell when the muscle is being contracted properly, and learn to properly control the muscle, on a repetitive basis.
EMG biofeedback devices have been used to treat urinary incontinence caused by loss of muscle tone and function. Some physical therapists utilize a small portable EMG unit with surface electrodes, along with a home exercise program, to improve problems associated with urinary incontinence.
While portable EMG biofeedback devices are currently available on the market, those devices are designed to operate in more of a clinical environment where the output meter readings are observed and correlated with muscle activity on a substantially continuous basis. As a result, it is typically difficult for a user to engage in other activities while the EMG biofeedback device is being used. Moreover, user may have little interest in using a biofeedback device which provides no entertainment value, may require constant attention to effectively utilize, and precludes completion of other tasks while the device is in use. As a result, while existing devices adequately function as EMG biofeedback units, their acceptance is limited.
The present invention addresses these deficiencies by allowing the EMG biofeedback unit to be used in a manner that does not require visual monitoring, may form a portion of an entertainment unit, and does not impede the user's ability to engage in other tasks without sacrificing the ability to monitor muscle activity. The present invention permits the biofeedback to be communicated to the user in a variety of different ways which are more advantageous to the use, enjoyment and effectiveness of the EMG biofeedback device.


A hose stabilizing device for a recreational vehicle sewage hose or the like, which includes a body member having a hose receiving opening and an internal chamber therein. The device is selectively movable between an open condition, wherein the hose may be placed in the hose receiving opening, and a closed condition wherein the hose is clampingly held therein. The body member includes a filling device for enabling the internal chamber thereof to receive and hold a ballast material therein, thereby providing sufficient weight to stabilize the hose. The body member is constructed to enable the device to be securely connected adjacent an end of the hose, and either stood up on its side adjacent a sewage receiving inlet, or placed flat directly on top of the inlet such that the hose receiving opening is in alignment with the inlet, thereby stabilizing the end of the hose in proper communication with the inlet.

The present invention relates to a flexible hose stabilizing device and, more particularly, to a hose stabilizing device for use with a sewage hose of the type found on recreational vehicles or the like for securely maintaining the end of the hose in communication with a sewage receiving inlet.
Recreational vehicles such as motorized homes, trailers and campers are usually equipped with toilets, showers, sinks and the like from which sewage and other waste materials are discharged. Conventionally, such vehicles are equipped with sewage holding tanks which are operable to collect and temporarily store sewage and other waste materials. Due to the fact that such holding tanks have limited storage capabilities, they must be periodically emptied into an appropriate sewage disposal system. Conventionally, emptying of the holding tank is accomplished through the use of a flexible hose which is connected at one end to the tank while the other end is placed in communication with a sewage receiving inlet. Such sewage receiving inlets are commonly found at recreational vehicle parks or the like. The sewage receiving inlets are usually provided in the form of a pipe connected with an underground sewage disposal system, and having an opening which extends adjacent ground level for receiving a sewage hose.
In order to accommodate storage of the sewage hose in the recreational vehicle while not being used, such hoses are typically constructed to be both flexible and collapsible. Conventionally, the sewage hose is constructed with an embedded spring-like member therein which enables the hose to be longitudinally compressed and expanded to a desired length. Such sewage hose construction results in a hose which is quite flexible and unstable, which often makes it difficult to securely maintain the end thereof in communication with the sewage receiving inlet. Due to the "springy" nature of such a sewage hose, the end thereof often either comes out of the inlet, which results in raw sewage being spilled directly on the ground, or extends too far into the inlet, which results in the outer surface of the hose becoming soiled with sewage. Obviously, either one of these occurrences results in an undesirable and unsanitary condition.
Therefore, a need has been created for a simple, economical and effective device which can be used with a flexible hose to securely maintain the end of the hose in communication with a sewage receiving inlet, while also preventing the hose from extending too far into the inlet. The flexible hose stabilizing device of the present invention meets this need.


An automated conveyor sortation and item discharge system for conveying and discharging packages at high speeds. A conveyor assembly includes an elongate crowned conveyor belt which conveys parcels in a longitudinal direction defined across slider beds and across discharge stations. The parcels can take three different routes once they reach the discharge stations. They may be allowed to pass the discharge stations and continue to be conveyed by the crowned conveyor belt, or they can be selectively discharged off of the crowned conveyor belt and into discharge chutes located to either side of the substantially straight path of the crowned conveyor belt. Each of the discharge stations includes a selectively indexable fork member supporting a group of idling rollers. The parcels have sliding contact with the slider beds and "rolling contact" with the idler rollers. When a package is in the desired position, the fork member can be indexed to cause some of the rollers to move upwardly and inwardly. This causes the package to tilt about the top of the crowned conveyor belt until the package contacts a withdrawal roller opposing the conveyor belt from the raised rollers. The withdrawal roller draws the into one of two chutes for sorting purposes.

Modem high volume package delivery systems often include package conveying systems that accept packages from one or more loading stations, and transport the packages to a variety of output destinations such as chutes, bins, and subsequent conveyor systems.
One of the most conventional types of conveyors is a belt conveyor, which includes the use of an endless flexible belt which passes over at least two cylindrical rollers, one of which is a drive roller. Packages are placed atop the upwardly-directed "working" surface of the belt conveyor, and are transported in a generally straight direction from end of the conveyor to the other. Another type of conveyor is a "roller" conveyor which con include powered or idling rollers which contact, support, and in certain instances propel the bottom of the package along its path.
Some conveying systems include diversion features which allow for the discharge of objects from a conveying surface at selected stations located along the path of the conveying surface. Some package diverting systems utilize a pusher element mounted relative to a conveying surface which when actuated ejects an adjacently placed package laterally across the conveyor surface to the desired discharge station. Some package diverting systems include the use of diversion elements which lie along the conveyor and provide the diversion forces against the bottom surfaces of the package.
A modular diverter shoe and slat construction disclosed in U.S. Pat. No. 5,127,510 to Cotter describes a modular diverter shoe for use in a slat conveyor. A diverter shoe is mounted to each slat so that the shoe may glide across the slat. The movement of the diverter shoe is affected by a guide pin and coaxial bearing which engages a network of guide tracks located beneath the conveying surface. When a package is to be diverted, a diverting switch is actuated to switch the guide pins for the diverter shoe adjacent to the package onto a diagonal track, which causes the diverter shoe to move across the slat and eject the package.
Another apparatus for sorting objects is disclosed in U.S. Pat. No. 4,732,260 to Canziani. In that system, a conveyor belt is described in which each conveyor element has a slit. The pusher elements are slidably inserted into the slits and each pusher element is connected to a drive element that extends beneath the conveyor surface. The drive element is attached to rollers and interacts with a series of cams or guide rails located beneath the conveyor. The cams include an electro-pneumatic two-position end portion. In one position, the cam engages the drive element rollers and slides the pusher element. In a second position, the rollers do not engage the guide rails.
U.S. Pat. No. 3,768,624, which issued to Kornylak, discloses a flexible belt conveyor system. Referring to FIG. 3, a flexible endless belt 6 travels between horizontal surfaces 16 and 18. A spring 20 extends downward from an object 14 to engage a notch in the belt 6. As a result, the object 14 travels with the belt 6 and slides across the surfaces 16 and 18. In another embodiment depicted in FIGS. 1 and 2, the traveling belt 6 extends above the edges of a tube 2. A coat hanger hook 12 engages a notch (cleat 10) defined by the belt 6. As a result, the coat hanger hook 12 travels with the belt and slides upon upper portions of the tube 2 that are adjacent to the belt 6.
U.S. Pat. No. 2,895,593, which issued to McKnight et al., discloses another flexible belt conveyor. Referring to FIGS. 10 and 11, anti-friction projections 61 or 63 can be mounted at either side of the driven belt 11.
U.S. Pat. No. 3,857,487, which issued to Meeusen, discloses another flexible belt conveyor. Referring to FIG. 3, the surface of the conveyor belt includes resilient pads 4 with deformable projections 5. Articles 2 being conveyed rest upon the pads 4.
U.S. Pat. No. 1,781,750, which issued to Dodge et al., discloses a conveyor system for conveying lumber 36. As depicted in FIG. 1, the lumber 36 travels upon multiple flexible belts 12.
U.S. Pat. No. 3,138,238, which issued to De Good et al., discloses a conveyor system with a powered diverter. Referring to FIGS. 1 and 3, the De Good et al. device includes a main powered conveyor 10 and a powered side conveyor 22 extending from a side of the main conveyor 10. A traveling continuous belt 20 drives the rollers 16 (FIG. 1) of the main conveyor 10, and a drive belt 24 causes conveyance of objects upon the side conveyor 22. An object traveling in the direction defined from left to right on the main conveyor 10 is diverted to the side conveyor 22 by a powered diverter. The powered diverter includes an assembly of diverting wheels 48 (FIG. 3) that are oriented toward the side conveyor 22. The group of diverting wheels 48 are normally positioned below the tops of the rollers 16 of the main conveyor 10 so that objects traveling on the main conveyor 10 are not contacted by the diverting wheels 48. When it is desirable to divert an object from the main conveyor 10 to the side conveyor 22, the diverting rollers 48 are elevated so that they are slightly above the top surfaces of the rollers 16 of the main conveyor 10. The diverting rollers 48 are pushed upward by a device within the box 32 (FIG. 1) which pushes the belt 20 upward underneath the diverting wheels 48. The belt 20 causes the diverting wheels 48 to rotate and drive an object onto the side conveyor 22. The driven belt 24 of the side conveyor 22 draws the diverted object onto the side conveyor 22 and propels the object along the side conveyor 22.
U.S. Pat. No. 1,462,511, which issued to Lister, discloses another conveyor diverter. Referring to FIG. 1, a side conveyor 37 extends perpendicularly from a main conveyor. Referring to FIG. 8, rollers 36 of the main conveyor are perpendicular to diverting rollers 41 that divert objects from the main conveyor to the side conveyor 37 (FIG. 1). The bed of diverting rollers 41 are in a pivoted configuration in FIG. 8 such that an object (not shown) upon the diverting rollers 41 would roll under the force of gravity across the bed of diverting rollers 41 onto the side conveyor 37 (FIG. 1).
U.S. Pat. No. 5,477,955, which issued to Madden et al., discloses a tilting tray conveyor system. Referring to FIG. 2, pivotably mounted trays 60 carry objects. A leg 67 extends from each tray 60. A particular tray 60 is pivoted to discharge an object when a lever 81 pushes the leg 67 of that tray 60 upward.
Although the prior art includes some advantages, a need always exists in the art for an improved conveyor sorting system which allows for high speed travel of packages while still allowing for effective side discharge, without the need for side impact.

Conveyor having high speed discharge capabilities


A data driver for a display includes a reference current generator that is configured to generate L gray scale reference currents, the L gray scale reference currents being associated with non-zero gray scale levels, a gamma selection module that is configured to select M gamma reference currents from the L gray scale reference currents responsive to a gamma signal, a gamma voltage generator that is configured to generate a zero gray scale level gamma reference voltage, and a data current generator that is configured to generate a data current responsive to a selected one of the M gamma reference currents or the zero gray scale level gamma reference voltage responsive to a color signal.

Organic light emitting diode (OLED) display devices are often characterized as having good linearity between a device current and device luminance. As a result, it is generally easy to adjust the luminance by controlling the device current. In driving an OLED display device, two approaches are typically used: an active matrix approach and a passive matrix approach. In the active matrix approach, the luminance is adjusted by controlling a voltage or a current of the device. In a passive matrix approach, the luminance is adjusted by controlling a duty ratio of the driving signal. The image data is proportional to the light intensity, but the image display device typically has a non-linear relationship between the input image data (gray scale input) and the output luminance. In many displays, the relationship between the gray scale input and the luminance that is output is an exponential relationship where the exponent is called gamma. If the gamma value is not set correctly, then there may be distortion in the displayed image resulting in degradations in the image quality. Different display devices typically have different optimal gamma values such that each device adjusts the gamma to optimize the image quality on the display. In OLED displays, the driving circuit controls the driving current of the driving transistor.
FIG. 1 is a block diagram of a conventional data driver circuit 20 for a display that provides gamma correction. The conventional data driver circuit 20 includes a controller 21, a lookup table 22, and a plurality of digital-to-analog converters (DACs) 23. The lookup table includes corrected gamma values for the red (R), green (G), and blue (B) color intensities for each pixel. The controller 21 receives video or color data 27 and a look-up table setting command 29 from an external controller 25, and receives 8-bit corrected gray scale data 26 from the lookup table 22. The 6-bit color data 27 are assigned to the respective R, G, and B colors to display 260K colors. The controller 21 receives the 6-bit color data and the 8-bit lookup table setting command and provides the 6-bit color data as an input 24 to the lookup table 22. In response, the lookup table 22 provides gamma corrected 8-bit gray scale data 26 to the controller 21. The 8-bit gray scale data 26 are generated by gamma correcting the 6-bit color data 24 and adding two additional dummy bits. The 8-bit gray scale data 26 are provided to the DACs 23, which generate the data current IDATA in response thereto.
Unfortunately, the lookup table 22 and the DACs 23 take up a relatively large amount of chip area and are relative complex due, at least in part, to the two additional dummy bits used in the 8-bit gray scale data 26. Moreover, the mapping data contained in the lookup table 22 may need to be refreshed periodically to account for noise in the system.

Data driver circuits for a display in which a data current is generated responsive to the selection of a subset of a plurality of reference currents based on a gamma signal and methods of operating the same


A method of generating cultured chondrocytes/endochondral bone cells is provided. The method comprising isolating chondrocytes from mandibular condyle tissue, and culturing the isolated chondrocytes. A method of isolating chondrocytes from mandibular condyle tissue is further provided. The method comprises isolating mandibular condyle tissue from a mammal and treating the mandibular condyle tissue so as to selectively remove fibroblast-like cells and/or myocytes therefrom, the modified mandibular condyle tissue including chondrocytes, and selectively collecting the chondrocytes from the modified mandibular condyle tissue.

The present invention relates to methods of isolating chondrocytes, methods of culturing isolated chondrocytes to generate cultured chondrocytes/bone cells, and to uses of such cultured chondrocytes/bone cells. More particularly, the present invention relates to methods of isolating mandibular condyle chondrocytes, methods of culturing same to generate highly differentiated cultured chondrocytes/endochondral bone cells, and to uses of such cultured chondrocytes/endochondral bone cells for treating cartilage/bone diseases.
Cartilage/bone diseases include highly debilitating and/or lethal diseases such as arthritis, articular cartilage injury, meniscal disorders, joint infections, chondrogenesis disorders and cosmetic disorders of cartilaginous structures of the body for which no optimal therapies are currently available. Failure of diarthrodial joints leads to arthritis, the most common form being osteoarthritis. Repair of arthritic joints requires orthopedic surgery to replace the worn-out joints by a prosthesis or by a biological graft. Arthritis alone is an enormous medical and economic problem, with more than thirty million Americans suffering from this highly debilitating disease.
Articular joints, of which various types exist in the body, are a vital component of the musculoskeletal system. Freely moving joints (ankle, elbow, hip, knee, shoulder, and those of the fingers, toes and wrist) are known as diarthrodial or synovial joints and are critical for body movement. The intervertebral joints of the spine, which are not diarthrodial joints as they are fibrous and static, critically provide the flexibility required by the spine. Diarthrodial joints enable local motion and other activities of daily life to take place. They perform their function so well that we are often not even aware of their existence nor the function they provide until injury strikes or arthritis develops. From an engineering point of view, these natural bearings are very uncommon structures. Under healthy and ideal conditions, their function is nearly frictionless and they remain almost entirely wear-resistant throughout life. Diarthrodial joints share common structural features, notably including their being enclosed in a strong fibrous capsule. The inner surfaces of the joint capsule are lined with a metabolically active tissue, the synovium, which secretes the synovial fluid that lubricates the joint and provides the nutrients required by the avascular cartilage. The articulating bone ends in the joint are lined with a thin layer of hydrated soft tissue known as articular cartilage. These linings, the synovium and articular cartilage layers, form the joint cavity which contains the synovial fluid. Thus, in animal joints, the synovial fluid, articular cartilage, and the supporting bone form the bearing system which provides the smooth nearly-frictionless bearing system of the body. While diarthrodial joints are subjected to an enormous range of loading conditions under cyclical conditions, the cartilage surfaces undergo little wear and tear under normal circumstances. Indeed, most human joints must be capable of functioning effectively under very high loads and stresses and at very low operating speeds. These performance characteristics demand efficient lubrication processes to minimize friction and wear of cartilage in the joint. The joint is stabilized by, and in motion is controlled by, ligaments and tendons which may be inside or outside the joint capsule. Breakdown of the joint cartilage as a result of autoimmune, physical, chemical and/or infectious insult leads to arthritis.
Hyaline cartilage, the most abundant form of cartilage, is glass smooth, glistening and bluish white in appearance, although older or diseased tissue tends to lose this appearance. The most common hyaline cartilage, and the most studied, is the articular cartilage. This tissue covers the articulating surfaces of bones within diarthrodial joints. Articular cartilage is characterized by a particular structural organization, consisting of specialized cartilage cells termed "chondrocytes" embedded in an intercellular material, typically referred to as "cartilage matrix", which is rich in proteoglycans, collagen fibrils, other proteins, and water. While cartilage tissue is neither innervated nor penetrated by the vascular or lymphatic systems, in the mature joint of adults, the underlying subchondral bone tissue—which forms a narrow, continuous plate between the bone tissue and the cartilage—is innervated and vascularized. Beneath this bone plate, the bone tissue forms trabeculae, containing the marrow. In immature joints, articular cartilage is underlined by only primary bone trabeculae. A portion of the meniscal tissue in joints (referred to as the "interarticular" cartilage) also consists of cartilage whose make-up is similar to articular cartilage. It is generally believed that because articular cartilage lacks a vasculature, damaged cartilage tissue does not receive sufficient or proper stimuli to elicit a repair response.
The menisci of the knee, and other similar structures such as the disc of the temporomandibular joint and the labrum of the shoulder, are specialized fibrocartilagenous structures which perform functions which are vital for normal joint function. They are known to function in assisting the articular cartilage in distributing loads across the joint, assisting the ligaments and tendons in providing joint stability, playing a major role in shock absorption, and possibly in assisting lubrication of the joint. The menisci, disc and labrum are hydrated fibrocartilage structures composed primarily of collagen (type I) with smaller amounts of other collagens and proteoglycans (including aggrecan and the smaller, non-aggregating proteoglycans). They contain a sparse population of cells which, like the chondrocytes of cartilage, are responsible for the synthesis and maintenance of this extracellular matrix. Damage to these structures can lead to a reduction in joint function and degeneration of the articular cartilage, and surgical removal of such damaged structures, usually the main treatment, can result in early onset of osteoarthritis.
Skeletal ligaments are specialized connective tissues that connect bones. They serve a passive mechanical function in stabilizing joints and in guiding joint motion. Further, they may have a neurosensory role transporting dynamic information to muscles. Ligaments are composed primarily of type I collagen organized in parallel arrays, with small amounts of other collagens, proteoglycans, elastin and other proteins and glycoproteins. The cells are fibroblastic in the midsubstance, and appear more chondroid at and near the insertion sites. Tendons have a similar structure, with a relatively high concentration of collagen, organized primarily as fibers in parallel. Other components are proteoglycans, elastin and other proteins and glycoproteins. The cells are fibroblastic in nature. The cells of the tendon and ligament are metabolically active and are responsible for the synthesis and maintenance of this extracellular matrix.
Proteoglycans comprise the second largest portion of the organic material in articular cartilage. These macromolecules are composed of a protein core to which are attached a number of covalently bound glucosaminoglycan (GAG) chains, such as chondroitin sulfate and keratan sulfate. There are many different types of proteoglycans present in a wide range of tissues throughout the body; presumably, they also have different functions in the various tissues. However, the most extensively studied proteoglycans have been those from articular cartilage because of their role in regulating skeletal growth, joint function and the development of arthritis.
The major proteoglycans present in articular cartilage are the large aggregating type (50-85%) and the large non-aggregating type (10-40%) with distinct small proteoglycans also present. The molecular weights of these proteoglycan monomers range from 1,000-4,000 kDa, and they contribute significantly to the mechanical and physicochemical properties of cartilage. These molecules are highly ordered structures with length scales ranging from 0.01-1 microns. Proteoglycans comprise an extended protein core with several distinct regions, including an N-terminal region with two globular domains (G1 and G2), a keratan sulfate-rich domain, a longer chondroitin sulfate-rich domain which may also contain some interspersed keratan sulfate and neutral oligosaccharide chains, and a C-terminal globular domain (G3) on the proteoglycan monomer. Aggregates are formed when many proteoglycan monomers bind to a long monofilament chain of hyaluronan via their G1 globular domain. Each proteoglycan-hyaluronan bond is stabilized by a separate 41-48 kDa globular link protein. The structure of proteoglycan in cartilage is not uniform. Differences in chain length and amounts of keratan sulfate and chondroitin sulfate, length of the protein core, and degree of aggregation all contribute to the compositional and structural heterogeneities of proteoglycans within cartilage.
The GAG chains of the proteoglycans afford important physicochemical properties to cartilage. First, chondroitin sulfate which has a molecular weight of about 20 kDa is composed of repeating disaccharide units of glucuronic acid and N-acetylgalactosamine with one sulfate (SO4) group and one carboxyl (COOH) group per disaccharide. Evidence exists indicating that these chondroitin sulfate chains are the main determinants of frictional resistance against interstitial fluid flow. Keratan sulfate consists of repeating disaccharide units of galactose and N-acetylglucosamine, again averaging approximately one sulfate group per disaccharide. The keratan sulfate content of proteoglycans progressively increases with age from fetal to senescent cartilage. Both proteoglycan content and size decrease with increasing severity of osteoarthritis.
In articular cartilage, molecular interactions occur through collagen-collagen covalent cross-link interactions, and proteoglycan-proteoglycan and collagen-proteoglycan non-covalent (electrostatic and mechanical) interactions. The best-known interactions are the collagen-collagen covalent cross-links which are important in providing a strong and stiff collagen network. Thus, in the extracellular matrix these two molecular networks (proteoglycan and collagen) must coexist to form a fiber-reinforced composite solid with the collagen network providing the tensile stiffness and strength, and the proteoglycan network providing the compressive stiffness. The physical interactions between collagen and proteoglycan can arise from two sources: electrostatic and mechanical. First, evidence exists indicating that the negative charge groups on the proteoglycans can interact with the positive charge groups along the collagen fibrils, and hyaluronates of the aggregate do interact with type II, IX and X collagen. Second, evidence of strong frictional interaction between the proteoglycans and the fine collagen network also exists. No covalent bonding exists between collagen fibrils and proteoglycans. In normal cartilaginous tissue, proteoglycans are slowly but continuously turned over, the degraded molecules are released from the cartilage and are replaced by newly synthesized components. It is the coordinate control of synthesis and degradation of the matrix components by the chondrocytes that maintain normal cartilage. In experimental models of joint disease, for example, there is evidence of charges in the rate of biosynthesis and turnover of proteoglycans, which may contribute to cartilage degeneration. This chondrocyte-mediated degeneration leads to the whole cascade of degenerative bone and connective tissue events that results in osteoarthritis, limb immobilization, and other effects requiring surgical intervention. Degenerative loss of articular cartilage, for example, at the acetabular/femoral head articulation, results in heavy loading of the soft tissue, and can require radical surgery.
Chondrogenesis is vital to postnatal skeletal growth which occurs mainly by endochondral bone formation, a highly regulated multistep process. The skeletal cellular population follows a cascade of events that includes proliferation of precursor cells, differentiation into chondroblasts, maturation of chondrocytes, hypertrophy, and apoptosis [Chen, Q. et al., 1995. Dev Biol. (N.Y. 1985) 172:293-309]. These processes are accompanied by the synthesis of specific matrix proteins such as cartilage proteoglycans and type II collagen, which are secreted by mature chondrocytes, and type X collagen, which is secreted by hypertrophic chondrocytes (Beier, F. et al., 1999. J Cell Biochem 72:549-557). The sustenance of the differentiated state of the chondrocytes is dependent on close cell-matrix interactions (Svoboda, K. K., 1998. Microsc Res Tech. 43:111-122), such that releasing the cells from their cartilaginous environment results in a rapid loss of their phenotypic morphology and function (von der Mark, K. et al., 1977. Nature 267:531-532). Normal chondrogenesis is a complex process controlled by a combination of systemic and local factors such as growth hormone, thyroid and parathyroid hormones, and, during various developmental stages, also by insulin and sex hormones, the neonatal period and adolescence, respectively (Amizuka, N. et al., 1994. J. Cell Biol. 126:1611-1623; Greenspan, S. L. and Greenspan, F. S., 1999. Ann Intern Med 130:750-758; Maor, G. et al., 1999. Endocrinology 140:1901-1910; Menon, R. K. and Sperling, M. A., 1996. Endocrinol Metab Clin North Am 25(3):633-647; Spagnoli, A. and Rosenfeld, R. G., 1996. Endocrinol Metab Clin North Am 25:615-631). Insulin-like growth factor-I (IGF-I) is the principal local growth factor of chondrogenesis and skeletal growth and acts in an auto/paracrine fashion (Isgaard, J., 1992. Growth Regul 2:16-22).
As described hereinabove, cartilage/bone diseases are of tremendous medical and economic impact, and hence there is an obvious and urgent need for novel and improved methods of treating such diseases.
For example, over one million surgical procedures in the United States each year involve cartilage replacement. Current therapies include transplantation with allografts (removing healthy cartilage from a donor, and reimplanting it into a joint of the recipient), implantation of artificial polymer or metal prostheses, and surgical removal of old or degenerative cartilage and the surgical treatment of underlying bone to stimulate new cartilage formation. This new cartilage is usually a fibrous cartilage significantly inferior to the hyaline cartilage it is replacing. Other surgical procedures of synovial joints involve the replacement of menisci, ligaments and tendons with biological grafts or artificial tissues. Torn or severed menisci, discs of the temporomandibular joint, labrum of the shoulder, tendons and ligaments often undergo surgical repair.
Surgical procedures account for only a fraction of the treatment of individuals who suffer from disabling diseases resulting from connective tissue damage and degeneration in synovial joint. Alternative treatment includes conservative treatment (e.g., rest and physical therapy), and treatment is largely directed at symptomatic relief through the use of analgesics and nonsteroidal anti-inflammatory drugs.
There are significant limitations with all present approaches. Artificial prostheses have a limited lifetime, and can fail prematurely. Recurrent replacements of prostheses is not an advisable treatment, and, therefore, the relatively young and active patient is often consigned to slow joint degeneration until the use of prosthetic implants becomes a reasonable clinical option. Prostheses rarely replicate the performance of the original tissue. A prosthesis cannot adapt in response to environmental stress as does a biological tissue, nor can it repair itself. Biological allograft material is in limited supply, appropriate size shape and tissue type are difficult to obtain, and has the risk of carrying infectious diseases. Use of autograft material compromises the site used for the source tissue (e.g., using patella tendon to replace anterior cruciate ligament), and can only offer this tissue once.
In light of the above described drawbacks of classical treatment methods, an optimal strategy for treating cartilage/bone diseases, would be to utilize cultured cartilage/bone to repair or replace cartilage/bone lost or damaged as a result of disease or injury. Such an approach would be optimal since cultured cartilage/bone could theoretically be produced with essentially any desired characteristics and in essentially any desired quantity. However, culturing cartilage/bone from primary chondrocytes has been found to be highly problematic due to the fact that primary cartilage-derived cell cultures undergo dedifferentiation, acquire fibroblastic features, and lose most of the characteristics of mature chondrocytes. This phenomenon is due mainly to the loss in culture of the close matrix-cell interrelationship typical of cartilage tissue, which, as described above, is a vital element of cartilage formation and homeostasis. This dedifferentiation phenomenon is furthermore a serious obstacle for ex-vivo studies of the endochondral ossification process and its extra- and intracellular regulation, and for in-vitro studies of various articular pathologies such as rheumatoid arthritis or osteoarthritis.
Several prior art approaches have been employed or suggested in order to optimally generate cultured cartilage/bone.
One approach involves culturing limb mesenchyme in micromass cultures in three-dimensional collagen and agarose gels (Miura, T. and Shiota, K., 2000. Anat Rec. 258:100-107).
Another approach involves culturing isolated cells of mouse limb bud mesenchyme (Shakibaei, M. and De Souza, P., 1997. Cell Biol Int 21:75-86), or dedifferentiated human articular chondrocytes (Liu, H. et al., 1998. Biochim Biophys Acta 1425:505-515) in alginate beads.
Yet another approach involves culturing rabbit growth plate chondrocytes in soft agar, or on a substrate coated with type I collagen, type II collagen or fibronectin (Enomoto-Iwamoto, M. et al., 1997. J Bone Miner Res 12:1124-1132).
Still another approach involves culturing primary chondrocytes in the presence of fibroblast growth factor (FGF)-2 in three-dimensional polymer scaffolds (Martin, I. et al., 1999. Exp Cell Res 253:681-688).
A further approach involves culturing dedifferentiated rabbit articular chondrocytes in the presence of transforming growth factor (TGF)-beta 1, with or without the microfilament modifying drug dihydrocytochalasin B (DHCB; Benya, P. D. and Padilla, S. R., 1993. Exp Cell Res 204:268-277).
Yet a further approach involves culturing primary chondrocytes (Borge, L. et al., 1997. In-vitro Cell Dev Biol Anim 33:703-709), mesenchyme of chick embryo wing bud in micromass cultures (Kulyk, W. M. et al., 2000. Exp Cell Res 255:327-332), or fibroblasts under hypoxic conditions (U.S. Pat. No. 6,489,165) in the presence of the protein kinase C (PKC)/actin polymerization antagonist staurosporine.
Still a further approach involves culturing mesenchymal progenitor cells using chemically defined components (U.S. Pat. Application No. 20030026786).
All of the aforementioned approaches, however, suffer from significant disadvantages including: incapacity to generate cultured cartilage/bone displaying optimal cartilage/bone specific differentiation, and/or displaying such differentiation for an optimally long duration in-vitro; and/or their being excessively cumbersome/complex and/or expensive to practice, such as in the case of approaches involving the use of three dimensional supports or biomolecule-coated substrates.
Thus, all prior art approaches have failed to provide an adequate solution for generating cultured cartilage/bone.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method of generating cultured cartilage/bone devoid of the above limitation.

Cultured cartilage/bone cells/tissue, method of generating same and uses thereof

Technion Research & Development Foundation Ltd.


In another embodiment, the above-mentioned design considerations are achieved by a mounting device having a generally vertical mounting post, a base plate, a pair of base brackets, and securing fixtures. The post is securable at one end to a support surface, such as a table or counter top, or even a floor or ceiling. The base plate is, in turn secured to the mounting post and has upper and lower flanges which are engaged by first and second retainers on each of the base brackets. The base brackets include fixtures that secure the appliance to the mounting assembly. Also, the base plate, brackets and appliance are rotatable about the axis of the mounting post.

The present invention relates generally to an apparatus for adjustably mounting an appliance. More particularly, the invention relates to a device used to adjustably and securely mount an appliance such as a flat screen television.
When an appliance such as a flat screen TV is mounted on a support surface such as a wall or other structure, several design considerations should be considered. Positional adjustment may be highly desirable. For example, in a flat screen TV application, the monitor often may need to be oriented toward the viewing audience. In some instances, it may be desirable to angle or tilt the screen to eliminate glare that may otherwise result from an external light source. To take advantage of the flat screen design, it may also be desirable to mount the appliance in close proximity to the mounting surface. The mounting device preferably also has a relatively slim profile, with as much of the device hidden from view as possible for enhanced aesthetic appearance. In other instances it may be desirable to mount a flat screen TV to a table or counter top with a structure having a simplistic and aesthetically attractive design.
The present invention achieves all of these objectives and provides new advantages not previously obtainable with prior appliance mounting devices.


Crystalline forms of Varenicline Tosylate:

Varenicline tartrate salt, 7,8,9,10-tetrahydro-6,10-methano-6H-pyrazino[2,3-h][3]benzazepine, (2R,3R)-2,3-dihydroxybutanedioate (1:1), has a molecular weight of 361.35 Daltons and is described according to the following formula:

Varenicline tartrate is marketed by Pfizer under the trade name of CHANTIX™ as a partial agonist selective for certain subtypes of nicotinic receptors and indicated for smoking cessation.
Varenicline base and a variety of salts thereof are disclosed in U.S. Pat. No. 6,410,550, EP 1044189, and EP 1659114.
Crystalline forms of Varenicline citrate and succinate salts are described in the U.S. Pat. Nos. 6,787,549 and 6,794,388, respectively.
Varenicline L-tartrate and its crystalline forms A, B, and C are described in the U.S. Pat. Nos. 6,890,927 and 7,265,119.

Varenicline tosylate, an intermediate in the preparation process of varenicline L-tartrate

Abstract: are provided, along with processes for preparing those crystalline forms of Varenicline Tosylate, and processes for obtaining high purity Varenicline base using Varenicline Tosylate.


A rapid preparation method of high-quality hot water, includes steps of: a) calculating a temperature difference between an inlet water temperature and an predetermined outlet water temperature, determining an adjacent heating power pair from heating curves of the pipeline heater according to the temperature difference and a predetermined flow rate, wherein the heating power pair is corresponding to one of time points in a slow nonlinear heating area K, then selecting the heating power pair for preparing to heat water in the pipeline heater; and b) inputting the water with the predetermined flow rate into the pipeline heater, heating with one of the heating power pair selected in the step a) in such a manner that the water in the pipeline heater is heated according to the K area of the pipeline heater, obtaining the water with the target water temperature from an outlet.

Field of Invention
The present invention relates to a preparation method of hot water and a preparation device, and more particularly to a rapid preparation method of high-quality hot water and a preparation device thereof.
Description of Related Arts
With the continuous improvement of people's living standards, there is an urgent need to quickly obtain high-quality hot water for improving the quality of life, such as utilizing the high-quality hot water for tea, coffee, etc. The high-quality hot water should be quickly obtained while the original water is not boiled too much, the original molecule structure is not damaged, and the high quality of the original water is maintained.
Patent Application CN 201010207530.5, Pipeline electric heating rapid hot water machine, disclosed a hot water machine which is able to provide 95˜99° C. hot water within 3˜5 s, wherein an amount of the water to be heated can be predetermined and energy is saved as well as time. However, disadvantage of the hot water machine is that due to slow response speed of the NTC (negative temperature coefficient) thermistor utilized by the pipeline heater for feeding back temperature information, information lag and temperature control difficulty will be caused by a response time more than 1 s. Inlet water temperatures also have great differences according to the different seasons and different environments. Because of temperature control lag, outlet water temperature of the rapid hot water machine is instable, and even steam will be sprayed because the water temperature is too high, which not only is likely to scald people, but also reduces the lifetime of the machine. At the meantime, because of the destruction of the micro molecule of over-heated water and decrease of oxygen content, it is difficult to make high-quality and mellow tea with the too hot water.
Patent Application CN 201110009740.8, Tea machine with heating pipe, solves a problem that the water in the heating pipes is easily to be over heated and vaporized due to boiling, in such a manner that the water splashes to scald people and damages the machine. The Patent Application provides a method for obtaining hot water with a target temperature from the outlet and a tea machine utilizing the hot water. However, the predetermined heating temperature is still based on the water temperature of the outlet and the water is heated by each segment of the heating pipe for reaching the predetermined heating temperature. The segmental pipe heater according to the method is difficult to be produced. Each segment of the heater has a constant high temperature. Lag of the NTC thermistor is still not compensated. Therefore, water heating procedure is still not able to be precisely controlled and the quality of the hot water cannot be guaranteed.

Rapid preparation method of high-quality hot water


The invention relates to a spray powder for coating a substrate (2), in particular for coating a bearing part (2) of a bearing apparatus, the spraying powder having at least the following composition: carbon=0.1% to 1.5% by weight, manganese=0.1% to 8% by weight, sulphur=0.1% to 2% by weight, copper=0.1% to 12% by weight and iron=the balance in % by weight to 100%.

The invention relates to a spray powder, an iron-containing surface layer produced using the spray powder, and also a method for applying such a surface layer.
Bearing apparatus of all kinds, for example sliding bearings (plain bearings) and rolling element bearings, account for the majority of bearings used in technical applications. The term "bearing" or bearing apparatus will be understood in the following to mean all bearing parts defining the function of the bearing, for example bearing parts which roll on each other or slide on each other or are supportingly interengaged with each other and which cooperate in bearing contact.
Signs of wear are as a rule associated with the friction arising at the bearing running surfaces cooperating in bearing contact, in particular on the bearing running surfaces. In order to avoid these signs of wear necessitating a complete exchange of the bearing apparatus, bearing shells are used among other things in sliding bearings, which can be exchanged once they have worn out. However, the constructional design of the sliding bearing is made considerably more complicated by this and, moreover, an expensive servicing process is made necessary for the exchanging of the bearing shells.
Sliding bearings are often used for the journaling of shafts. Combined journaling in sliding bearings and rolling element bearings is sometimes also used. As a rule the bearing parts are manufactured from cast iron with spherical graphite or from heat-treatable steel, or are often manufactured from steel-based or iron-based sintering materials or from malleable iron. The bearing shells are mostly realized from so-called two- or three-layered bearings. The manufacture of such bearing shells is relatively expensive however. With long running lifetimes of the engine the bearing shells eventually wear out to such an extent that changing of the bearing shells becomes necessary, with the changing of the bearing shells in such engines being associated with high costs, as has already been mentioned above.
However in other kinds of bearings as well, for example in ball bearings, the premature wear of the bearing parts, for example of the balls of the ball bearing, of an axle to be supported by the ball bearing, of a cage for the balls of the ball bearing, or of other bearing parts of the ball bearing, is a basic problem which involves considerable repair work and servicing and in the end is associated with considerable costs.