The whiteness and stability of a polyolefin have been found to be improved upon addition of a first phosphite, an arylalkyl diphosphite, and a second phosphite selected from a second arylalkyl disphosphite or a triarylphosphite. In addition, the addition of a triarylphosphite with an arylalkyl disphoshite has been found to improve the hygroscopic nature and the hydrolytic stability of the arylalkyl disphosphite.

Polymers are used in a variety of diverse applications. For example, such applications include food packaging, electronic components, automobile parts, fibers and fabrics, and medical equipment. Polymers could not perform such diverse functions without the assistance of a very broad range of polymer additives. Without additives, polymers can degrade during processing and over time can lose impact strength, discolor, and become statically charged. Additives not only overcome these and other limitations, but also can impart improved performance properties to the final product.
One type of additive is antioxidants which usually are used to retard the oxidative degradation of polymers. Degradation can be initiated when free radicals, highly reactive species with an unpaired electron, are created in polymers by heat, ultraviolet radiation, mechanical shear, and/or metallic impurities. It is believed when a free radical is formed, a chain reaction can begin that initiates polymeric oxidation. Subsequent reaction of the radical with an oxygen molecule can yield a peroxy radical, which then can react with an available hydrogen atom to form an unstable hydroperoxide and another free radical. In the absence of an antioxidant, these reactions can become self-propagating and can lead to polymer degradation.
There are two basic types of antioxidants, primary and secondary antioxidants. It is believed that primary antioxidants can intercept and stabilize free radicals by donating active hydrogen atoms. It also is believed that secondary antioxidants can prevent formation of additional free radicals by decomposing unstable hydroperoxides into a stable product. When primary antioxidants, such as hindered phenols, are utilized, polymers can have a more yellow color than unstabilized polymers, therefore decreasing the commercial value of polymers. Secondary antioxidants, such as phosphite compounds, often are utilized to increase the stability and whiteness of polymers.
Unfortunately, phosphite additives also can create difficulties in polymer production and applications. First, some phosphite additives are hygroscopic and upon absorption of water, phosphites can clump and can be difficult to feed into the polymer production process. Some phosphites are hydrolytically unstable and can react with water resulting in a lower active phosphite concentration for stabilizing polymers. Furthermore, this hydrolysis reaction can leave moisture and acidic residues in polymers. There is a need in the polyolefin industry for a hydrolytically stable phosphite additive product that increases polymer stability and improves the whiteness of polymers.


The present invention relates to an improved synthesis method for the making of citraconimides wherein a citraconic anhydride is reacted with 0.5 to 2.0 equivalents of at least one amine salt. This process may be carried out in a solvent and generally leads to excellent yields of the citraconimides with high selectivity and easy purification. The present inventional so relates to a process for the production of citraconic anhydride from itaconic anhydride with an amine or phosphine catalyst and in a cosolvent.

Two methods for the production of aliphatic or aromatic bridged biscitraconimides are known. The first method is described in Hartford, S. L., et al., J. Polym. Sci. Polym. Chem. Ed., 16 (1982) 137.
This method begins with itaconic anhydride and an aromatic bis-amine. In a two step reaction the bis-amic acid is ring-closed with sodium acetate and acetic anhydride. The biscitraconimides were formed in low yield of less than 50%, as by-products and were purified by column chromotography.
The second synthesis, found in Galanti, A. V., et al., J. Polym. Sci., Polym. Chem. Ed., 19 (1981) 451 and Galanti, A. V. and Scola, D. A., J. Polym. Sci, Polym. Chem. Ed., 20 (1982) 233, is a one-step reaction from itaconic anhydride to aliphatic bridged biscitraconimides. The itaconic anhydride is reacted with an aliphatic bisamine in toluene to form bis-amic acid, which, under reflux and with azeotropic distillation, forms the imide. The compounds are purified by column chromotography followed by recrystallization. The reaction time is 10-16 hours and the yields are between 17 and 70%.
Both of these known synthesis methods suffer from the problems of poor yields and the requirement of a difficult purification process to isolate the biscitraconimide from the reaction products. Further, the first method is performed under difficult reaction conditions, and the second method takes too long. Thus, there is a need in the art for a better synthesis method for making citraconimides.
In maleimide synthesis, the most frequently employed method is a base-catalyzed synthesis employing either sodium acetate or triethylamine as the base catalyst. These methods are described in U.S. Pat. No. 2,444,536 and U.S. Pat. No. 4,130,564, respectively. One synthesis employing sulfuric acid and an onium salt is disclosed in Japanese patent application J6 2072-663.
However, the maleimide synthesis processes cannot be readily adapted to citraconimide synthesis because, during citraconimide synthesis one is always faced with the problem of isomerization of citraconic molecules to itaconic molecules, a problem which does not exist in maleimide synthesis. This isomerization can lead to low selectivity and poor yields.
Finally, citraconic anhydride is a necessary reactant in the present process. The citraconic anhydride may be obtained commercially, or it may be made by the process described in U.S. Pat. No. 2,966,498, or in Galanti, M. C., Galanti, A. N., J. Org. Chem., 47, 1575 (1982).
However, the foregoing process for making citraconic anhydride suffers from the serious disadvantage that water must be completely removed during the synthesis, by distillation. Thus, the time required to melt the itaconic acid starting material and to completely remove the water is too long for the process to be useful on a commercial scale since, citraconimide polymers begin to form during the distillation. Further, the separated water also gave rise to the formation of citraconic acid, an undesirable by-product.
Thus, there is also a need in the art for a better process for the synthesis of citraconic anhydride, which process provides high yields of the citraconic anhydride without significant polymer formation and allows for simple and economically efficient purification of the citraconic anhydride.
These and other objects of the invention will be apparent to one of ordinary skill in the art from the Summary and Detailed Description which follow.

Process for the synthesis of citraconimides


A method of producing a semiconductor device includes the steps of: preparing a base member; laminating sequentially a barrier film formed of titanium nitride, a wiring portion film formed of tungsten, and a mask film formed of titanium nitride on the base member to form a multi-layer film; forming a resist mask on the mask film so that the resist mask covers a wiring portion forming area and exposes a wiring portion non-forming area; etching the mask film using a first gas in which titanium nitride has a large etching ratio with respect to tungsten; and etching the wiring portion film using a second gas in which tungsten has a large etching ratio with respect to titanium nitride so that a portion of the wiring portion film in the wiring portion non-forming area is removed and a portion of the wiring portion film in the wiring portion forming area remains.

The present invention relates to a method of producing a semiconductor device. In particular, the present invention relates to a method of forming a wiring portion containing a high melting temperature metal.
When a wiring portion is formed of a high melting temperature metal, as compared with a wiring portion containing an aluminum alloy, it is possible to prevent a life of the wiring portion from being shortened due to electro-migration and reduce a cost thereof. Accordingly, it is preferred to use a wiring portion formed of a high melting temperature metal in a semiconductor device.
A conventional method of producing a semiconductor device will be explained with reference to FIGS. 11(A)-11(C) to 13(A)-13(B) (refer to Patent Reference).
Patent Reference Japanese Patent Publication No. 06-275625
FIGS. 11(A) to 11(C) are schematic sectional views showing the conventional method of producing the semiconductor device. FIGS. 12(A) to 12(C) are schematic sectional views showing the conventional method of producing the semiconductor device. FIGS. 13(A) and 13(B) are schematic sectional views showing the conventional method of producing the semiconductor device.
First, a base member 100 is prepared. The base member 100 is formed of a semiconductor substrate having an element such as a transistor formed thereon and an interlayer insulation film formed on the semiconductor substrate. A conductive plug is formed in the interlayer insulation film for electrically connecting the element formed in the semiconductor substrate to a wiring portion formed in a later step.
In the next step, a titanium nitride film is formed on the base member 100 with a sputter method. The titanium nitride film is referred to as a barrier film 120. Then, tungsten is deposited on the barrier film 120 with a CVD method to form a wiring portion film 130. Afterward, as shown in FIG. 11(A), a silicon nitride film 145 is formed on the wiring portion film 130 with a CVD method.
In the next step, as shown in FIG. 11(B), a resist is coated on the silicon nitride film 145 to form a resist film. The resist film is patterned through photolithography to form resist masks 160. The resist masks 160 cover wiring portion forming areas 105 such that wiring portion non-forming areas 107 are exposed.
In the next step, as shown in FIG. 11(C), the silicon nitride film 145 and the wiring portion film 130 are patterned using the resist masks 160 through RIE (Reactive Ion Etching). A SF6 gas is used as an etching gas.
An etching ratio of tungsten with respect to the resist is about 2.0. Accordingly, when the wiring portion film 130 is formed of a tungsten film, the resist masks 160 are etched in a vertical direction upon etching tungsten. As described later, the resist masks 160 have poor plasma resistance, so that the resist masks 160 are etched in a horizontal direction as well. In FIG. 11(C), there are shown etching remaining portions 162 of the resist masks 160 and etching remaining portions 147 of the silicon nitride film 145.
Further, when the SF6 gas is used as an etching gas, tungsten has a large etching ratio with respect to titanium nitride. Accordingly, as shown in FIG. 12(A), when the wiring portion film 130 is etched, the wiring portion film 130 in the wiring portion non-forming areas 107 is removed, and the wiring portion film 130 stops being etched when the barrier film 120 is exposed. That is, the barrier film 120 functions as an etching stopper.
Remaining portions of the wiring portion film 130 after the RIE are referred to as tungsten wiring portions 136 or wiring portions 136. Further, in FIG. 12(A), there are shown etching remaining portions 164 of the resist mask 160 and etching remaining portions 148 of the silicon nitride film 145.
In the next step, the RIE is performed using a Cl2 gas as an etching gas, so that portions of the barrier film 120 in the wiring portion non-forming areas 107 are removed, and etching remaining portions 122 of the barrier film 120 remain in the wiring portion forming areas 105. In the RIE using the Cl2 gas as an etching gas, tungsten has a large etching ratio with respect to titanium nitride. Accordingly, as shown in FIG. 12(B), when the barrier film 120 is etched, the tungsten wiring portions 136 are not etched to a large extent.
In the next step, as shown in FIG. 12(C), an NSG (Non-doped Silicate Glass) is deposited on the base member 100 with a CVD method to form an interlayer insulation film 170 embedding the wiring portions 136.
In the next step, as shown in FIG. 13(A), through holes 171 are formed in the interlayer insulation film 170 on the wiring portions 136 through photolithography and dry etching.
In the next step, as shown in FIG. 13(B), a titanium nitride film 182 and a metal film 184 are sequentially formed with a CVD method and a puttering method, so that the through holes 171 are filled with the titanium nitride film 182 and the metal film 184. The titanium nitride film 182 and the metal film 184 filling the through holes 171 are referred to as an upper layer metal wiring portion 180. The upper layer metal wiring portion 180 is electrically connected to the tungsten wiring portions 136 or lower layer wiring portions.
In the conventional method of producing the semiconductor device described above, the tungsten wiring portions 136 or lower layer wiring portions have a section with a forward tapered shape, in which a width of a bottom portion 136a on a base member side (lower side) becomes larger than a width of a top portion 136b on a resist mask side (upper side). The forward tapered shape is formed for the following reason.
When a fine wiring portion such as the wiring portions 136 having a width less than 150 nm is formed, a KrF excimer laser or an ArF excimer laser is used as a stepper. A KrF type resist or an ArF type resist used in this process has poor plasma resistance. Accordingly, during the RIE, a resist mask is etched not only in a vertical direction (an arrow direction G in FIG. 11(C)) but also a horizontal direction (an arrow direction H in FIG. 11(C)).
Accordingly, when the wiring film 136 formed of tungsten is etched, a width of the resist mask 160 decreases in the horizontal direction. When the wiring film 136 formed of tungsten is further etched, the width of the resist mask 160 gradually decreases. As a result, as shown in FIG. 12(B), the tungsten wiring portions 136 have the section with the forward tapered shape, in which a side surface 138 of the tungsten wiring portion 136 is inclined by an angle β of 80 degrees with respect to an upper surface 102 of the base member 100.
When the tungsten wiring portions 136 have the section with the forward tapered shape, a sectional area of the tungsten wiring portions 136 decreases by an amount proportional to the decrease in the width of the top portions 136b of the tungsten wiring portions 136 on the resist mask side. Due to the decrease in the sectional area, a wiring resistance of the tungsten wiring portions 136 increases, thereby deteriorating a performance of the semiconductor device.
Further, when the tungsten wiring portions 136 have the section with the forward tapered shape, the etching proceeds along the side surfaces 138 of the tungsten wiring portions 136 upon forming the through holes 171. As a result, a space X is formed next to the side surfaces 138 of the tungsten wiring portions 136 as shown in FIG. 13(A). When the titanium nitride film 182 is formed, the space X may not be filled with the titanium nitride film 182, thereby remaining as a space Y as shown in FIG. 13(B). Accordingly, a gas or chemical remaining in the space Y may deteriorate the tungsten wiring portions 136.
Further, when the tungsten wiring portions 136 have the section with the forward tapered shape, a contact area of the tungsten wiring portions 136 with respect to the titanium nitride film 18 thereabove decreases. As a result, a resistivity of the tungsten wiring portions 136 in the through holes 171 increases, thereby deteriorating a performance of the semiconductor device.
In view of the problems described above, an object of the present invention is to provide and a method of producing a semiconductor device capable of solving the problems of the conventional method of producing the semiconductor device. In the method of producing a semiconductor device, it is possible to obtain a tungsten wiring portion with a preferable sectional shape. Accordingly, it is possible to prevent a resistance of the tungsten wiring portion from increasing, and to prevent reliability of the wiring portion from decreasing.
Further objects and advantages of the invention will be apparent from the following description of the invention.

Method of producing semiconductor device


This invention relates to polyolefin compositions. In particular, the invention pertains to elastic polymer compositions that can be more easily processed on cast film lines, extrusion lamination or coating lines. The compositions of the present invention preferably comprise an elastomeric polyolefin resin and a high pressure low density type resin.

Styrenic block copolymers, such as SEBS (polystyrene-saturated polybutadiene-polystyrene), SBS (polystyrene-polybutadiene-polystyrene), SEPS (polystyrene-saturated polyisoprene-polystyrene), SIS (polystyrene-polyisoprene-polystyrene), and SEPSEP are known in the art. They exhibit excellent physical properties, such as elasticity and flexibility. However, they often cannot be readily processed on typical polyolefin processing equipment, without the need for flow enhancers and other processing aids. Upon formulation with such materials, end-use properties such as tensile strength and heat resistance can suffer. Furthermore, they can suffer from thermal instability such as cross-linking (i.e. SBS) and scission (i.e. SIS).
Ethylene/α-olefin multi-block interpolymer compositions are readily processible using typical polyolefin processing equipment. They exhibit desirable end-use properties such as high heat resistance and high tensile strength. However, ethylene/α-olefin multi-block interpolymer compositions are typically are not as flexible and elastic as the most elastic styrenic block copolymers when used at high strains (i.e. >100%).
It would be desirable to have a thermoplastic elastomer composition which exhibits excellent physical properties, such as elasticity and flexibility, while at the same time being readily processible using typical polyolefin processing equipment.
Elastomeric compositions have found particular use in elastic films and fibers. They can be used by themselves, but are more commonly used in laminated structure wherein the substrate is a nonwoven fabric. The elastic film or fiber imparts elasticity to the nonwoven laminates. Such elastic nonwoven laminate materials have found use in the hygiene and medical market particularly in such applications as elastic diaper tabs, side panels of training pants, leg gathers, feminine hygiene articles, swim pants, incontinent wear, veterinary products, protective clothing, bandages, items of health care such as surgeon's gowns, surgical drapes, sterilization wrap, wipes, and the like. These materials may also find use in other nonwoven applications including but are not limited to filters (gas and liquid), automotive and marine protective covers, home furnishing such as bedding, carpet underpaddings, wall coverings, floor coverings, window shades, scrims etc.
Elastomeric films can be made in a number of ways known to those of ordinary skill in the art. Single or multi-layer elastic films are possible. Such processes can include bubble extrusion and biaxial orientation processes, as well as tenter frame techniques. In order to facilitate elasticity, the elastic film is usually employed singly or as a layer, in the case of multi-layer films. As many elastic compositions tend to be sticky and hence difficult to process or poor in hand feel, at least one non-sticky/non-tacky material may be used to comprise at least a portion of the film surface to mitigate this effect. Alternatively, various additives and modifiers such (i.e. slip agents, anti-block etc.) may also be employed.
Elastomeric fibers or filaments can be made in a number of ways known to those of ordinary skill in the art. Monofilament, bicomponent, multicomponent, islands-in-the-sea, crescent, side-by-side and other configurations known to those of ordinary skill in the art are suitable for use with the inventive composition. Like films, elastic fibers also tend to be sticky and hence difficult to process or poor in hand feel. At least one non-sticky/non-tacky material may be used to comprise at least a portion of the film or fiber surface to mitigate this effect. Alternatively, various additives and modifiers such (i.e. slip agents, anti-block etc.) mentioned above may also be employed.
Elastomeric compositions are often used for their retractive force. They are commonly used in various forms including fibers, film, laminates and fabric. When used in an article, the retractive force of the elastomer provides the "holding force" of the structure. For example, in health and hygiene articles such as infant diapers, training pants, and adult incontinence articles, the elastomers are commonly used in laminate structures. These laminate structures help to maintain fit of the article to the body. Body heat can result in the decrease of the holding force of the elastomer over time (measured as stress-relaxation) which can translate to loosening and eventual sagging of the article resulting in a decrease in fit. Styrenic block copolymers and their formulations used in these structures can suffer from excessive stress-relaxation and consequently articles fabricated using these materials can sag unacceptably in end-use. Accordingly, it is a goal to reduce the amount of stress-relaxation (increase in heat resistance) of the elastomer. This phenomenon is a known problem and has been described previously in the art. Such art includes but is not limited to WO9829248A1, WO0058541A1, US20020052585A1, US20040127128A1, U.S. Pat. No. 6,916,750B2, U.S. Pat. No. 6,547,915B2, U.S. Pat. No. 6,323,389B1, U.S. Pat. No. 6,207,237B1, U.S. Pat. No. 6,187,425B1, U.S. Pat. No. 5,332,613A, U.S. Pat. No. 5,288,791A, U.S. Pat. No. 5,260,126A, U.S. Pat. No. 5,169,706A, GB2335427A, and WO2004037141A1.
The compositions suitable for use in elastic films and laminates comprise a polymer blend comprising at least one ethylene/α-olefin interpolymer, wherein the ethylene/α-olefin interpolymer:
(a) has a Mw/Mn (Mw denotes weight averaged molecular weight; Mn denotes number averaged molecular weight) from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:Tm>−2002.9+4538.5(d)−2422.2(d)2; or
(b) has a Mw/Mn from about 1.7 to about 3.5, and is characterized by a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships:ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,ΔT≧48° C. for ΔH greater than 130 J/g,wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.; or
(c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α-olefin interpolymer is substantially free of a cross-linked phase:Re>1481-1629(d); or
(d) has a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer; or
(e) has a storage modulus at 25° C., G′(25° C.), and a storage modulus at 100° C., G′(100° C.), wherein the ratio of G′(25° C.) to G′(100° C.) is in the range of about 1:1 to about 9:1.
and, at least one styrenic block copolymer;
wherein the ethylene/α-olefin interpolymer has a density of from about 0.855 to about 0.878 g/cc and a melt index (I2) of from about 0.5 g/10 min. to about 20 g/10 min.

This patent is subject to a terminal disclaimer.

Compositions of ethylene/α-olefin multi-block interpolymer for elastic films and laminates


A charge coupled device (CCD) camera includes a CCD imager circuit, a compression engine, and a control circuit coupled to both the CCD imager circuit and the compression engine. The CCD imager circuit is characterized by an integration time defined by clock pulses from the control circuit. The compression engine generates successive frame requests. The control circuit generates the clock pulses to define the integration time based on a time between the sucessive frame requests. The camera further includes a histogram accumulator and an automatic gain controlled (AGC) amplifier coupled between the CCD imager circuit and the histogram accumulator. The CCD imager circuit is characterized by a predetermined maximum imager dynamic range and generates successive frames of imager data values, each successive frame of imager data values being characterized by an imager data value dynamic range and each frame of imager data values being generated based on a corresponding integration time. The AGC amplifier is characterized by an AGC gain defined by a gain control signal and characterized by a maximum output dynamic range. The AGC amplifier processes the successive frames of imager data values into corresponding successive frames of gain controlled data values, each successive frame of gain controlled data values being characterized by a gain controlled data value dynamic range. The histogram accumulator processes a first frame of gain controlled data values to determine a first frame result. The control circuit generates the clock pulses based on the first frame results to define the integration time that corresponds to a second frame of imager data values so that the integration time is maximized while the imager data value dynamic range is less than the maximum imager dynamic range, and the control circuit further generates the gain control signal based on the first frame results and the maximum imager dynamic range to minimize the AGC gain required so that the gain controlled data value dynamic range is equal to a predetermined range within the maximum output dynamic range.

1. Field of the Invention
The present invention relates to video telephone systems. In particular, the invention relates to adaptive control of a CCD camera to simplify and speed computations needed in a compression engine such as discrete cosine transforms of video conference standard H.263 or an MPEG compression engine.
2. Description of Related Art
CCD cameras are known. A CCD camera includes a CCD imager IC (a large CCD integrated circuit) and control circuits typically mounted on a printed wiring assembly. The CCD imager IC includes a two dimensional array of photosites. In a CCD imager IC, the photosites are exposed to an imaging fight for a short integration period. At the end of the integration time, the charge accumulated in the photo sites are typically parallel transferred rapidly to a plurality of vertical shift registers (protected from further exposure to light) and then serially shifted down to a horizontal shift register. The end element of each vertical shift register forms a plurality of parallel signals. This plurality of parallel signals are rapidly parallel transferred into the horizontal shift register. From there, the horizontal shift register is clocked serially to transfer the charge to an output circuit for the CCD imager IC. When all elements of the horizontal shift register are transferred out of the CCD imager IC, the plurality of vertical shift registers are again clocked once to make a new vertical shift register element available from each vertical shift register for parallel transfer into the horizontal shift register. By this process, the CCD imager IC produces a serial signal that corresponds to a raster scan such as for an NTSC compatible signal.
When such a CCD camera is used with an H.263 or MPEG compression engine, compressed video results. Since CCD imager ICs are typically designed for compatibility with NTSC (or PAL for Europe) signal generation, the H.263 or MPEG compression engine is designed to use the input of the NTSC signal. The CCD imager IC has a variety of control parameters that must be specified and are usually controlled by a signal from outside of the CCD imager IC. For example, the integration time, and the clock rates of the vertical and horizontal shift registers. A number of anti-blooming and charge reset features are usually provided, and these too are controlled by signals from outside of the CCD imager IC. In color cameras, even more control is effected from outside the imager IC. Sometimes the imager IC architecture provides even more flexibility, such as the selective control to average a 2 by 2 array of pixels to reduce resolution and reduce output bandpass requirements. Known CCD cameras uses these control signals to selectively switch between, for example, an NTSC signal and a PAL signal, or between black and white and color.

CCD camera with adaptive compression control mechanism


A pixel defining layer is disclosed including a display area and a non-display area located at a periphery of the display area, wherein the display area includes pixel units, and the non-display area includes dummy pixel units arranged outside one or more corners of the display area. A display panel, a display device, a method of fabricating a pixel defining layer, and a method of fabricating the display panel are also disclosed.

An organic electroluminescent display device (OLED) has the advantages of self-luminescence, fast response, wide viewing angle, high brightness, lurid colors, light weight and thin thickness, etc., and is considered to be the development trend of the next generation display technology. Films in the electroluminescent display device are usually prepared by a vacuum evaporation process and a solution process. The solution process comprises spinning, inkjet printing, nozzle applying, etc. Inkjet printing is widely used in the fabrication of electroluminescent display devices due to the advantage of its high material utilization, etc. However, the thickness uniformity of organic functional layers formed by inkjet printing still needs to be improved.

Pixel defining layer, display panel, fabricating method thereof, and display device


Copper(I) complexes for the emission of light with a structure according to formula A:

In principle, OLEDs are outstandingly suitable for the production of large-area illumination and display applications but can be found only in devices of small format at the moment due to extensive production methods. OLEDs are generally implemented in layer structures. For better understanding, FIG. 1 shows a basic structure of an OLED. Owing to the application of external voltage to a transparent indium tin oxide (ITO) anode and a thin metal cathode, the anode injects positive holes, and the cathode negative electrons. These differently charged charge carriers pass through intermediate layers, to which also hole or electron blocking layers not shown here may belong, into the emission layer. The oppositely charged charge carriers meet therein at or close to doped emitter molecules, and recombine. The emitter molecules are generally incorporated into matrices molecules or polymer matrices (in, for example, 2 to 10% by weight), the matrix materials being selected so as also to enable hole and electron transport. The recombination gives rise to excitons (=excited states), which transfer their excess energy to the respective electroluminescent compound. This electroluminescent compound can then pass into a particular electronic excited state, which is then converted very substantially and with substantial avoidance of radiationless deactivation processes to the corresponding ground state by emission of light.
With a few exceptions, the electronic excited state, which can also be formed by energy transfer from a suitable precursor exciton, is either a singlet or triplet state, consisting of three sub-states. Since the two states are generally occupied in a ratio of 1:3 on the basis of spin statistics, the result is that the emission from the singlet state, which is referred to as fluorescence, leads to maximum emission of only 25% of the excitons produced. In contrast, triplet emission, which is referred to as phosphorescence, exploits and converts all excitons and emits them as light (triplet harvesting) such that the internal quantum yield in this case can reach the value of 100%, provided that the also excited singlet state, which is above the triplet state in terms of energy, relaxes fully to the triplet state (intersystem crossing, ISC), and radiationless competing processes remain insignificant. Thus, triplet emitters, according to the current state of the art, are more efficient electroluminophores and are better suitable for ensuring a high light yield in an organic light emitting diode.
The triplet emitters suitable for triplet harvesting used are generally transition metal complexes in which the metal is selected from the third period of the transition metals. This predominantly involves very expensive noble metals such as iridium, platinum or else gold (see also H. Yersin, Top. Curr. Chem. 2004, 241, 1 and M. A. Baldo, D. F. O'Brien, M. E. Thompson, S. R. Forrest, Phys. Rev. B 1999, 60, 14422). The prime reason for this is the high spin-orbit-coupling (SOC) of noble metal central ions (SOC constants Ir(III): ≈4000 cm−1; Pt(II): ≈4500 cm−1; Au(I): ≈5100 cm-1; Ref.: S. L. Murov, J. Carmicheal, G. L. Hug, Handbook of Photochemistry, 2nd Edition, Marcel Dekker, New York 1993, p. 338 ff). Due to this quantum mechanical characteristic, the triplet-singlet transition, which is without SOC strictly forbidden for optical transitions, is allowed and an emission lifetime of a few μs, needed for OLED applications is achieved.
Economically, it would be highly advantageous if these expensive noble metals could be replaced with less expensive metals. Moreover, a large number of OLED emitter materials known to date are ecologically problematic, so that the use of less toxic materials would be desirable.

Copper(I) complexes for optoelectronic devices

Abstract: wherein:                M is Cu(I);        L-B-L: a neutral, bidentate ligand,        Z4-Z7: includes N or the fragment CR, with R=organic group, selected from the group consisting of: hydrogen, halogen or deuterium or groups which are bound via oxygen (—OR′″), nitrogen (—NR′″2), or phosphorous atoms (PR′″2) as well as alkyl, aryl, heteroaryl, alkenyl, alkinyl, trialkylsilyl and triarylsilyl groups or substituted alkyl, aryl, heteroaryl and alkenyl groups with substituents such as halogens or deuterium or lower alkyl groups;        X is either CR′″2 or NR′″;        Y is either O, S or NR′″;        Z8 includes the fragment CR′, with R′=O*R′″, N*R′″2 or P*R′″2, wherein the bond to the Cu atom is carried out via these groups;        R″ is a sterically demanding substituent, which inhibits a change in geometry in direction to planarization of the complex in excited state,        R′″=organic group which is selected from the group consisting of: hydrogen, halogen or deuterium, as well as alkyl, aryl, heteroaryl, alkenyl, alkinyl groups or substituted alkyl, aryl, heteroaryl and alkenyl groups with substituents such as halogens or deuterium, alkyl groups, and further generally known donor and acceptor groups        * indicates the atom which receives the complex bond; and        # indicates the atom which mediates the bond with the second chemical unit.


In one embodiment, the invention may comprise a computer-implemented system for managing access to a controlled space in a simulator environment, comprising: means for requiring initialization of a simulated hardware control object by a user code application operable to run on a simulated target platform in the simulator environment, wherein the simulated hardware control object is associated with at least a partition of the controlled space that is simulated by an architectural simulator in the simulator environment; and means for verifying if the simulated hardware control object associated with the partition has been initialized by the user code application when the user code application issues a transaction that attempts to access the partition.

Architecting reliable software for high performance computing platforms has become a daunting task. In today's multiprocessor (MP) systems having a large number of processors in various architectural arrangements, the task is even more challenging. Because the teachings of the present invention will be exemplified in particular reference to MP platforms, a brief introduction thereto is set forth below.
In the most general sense, multiprocessing may be defined as the use of multiple processors to perform computing tasks. The term could apply to a set of networked computers in different locations, or to a single system containing several processors. As is well known, however, the term is most often used to describe an architecture where two or more linked processors are contained in a single or partitioned enclosure. Further, multiprocessing does not occur just because multiple processors are present. For example, having a stack of personal computers in a rack is not multiprocessing. Similarly, a server with one or more "standby" processors is not multiprocessing, either. The term "multiprocessing" is typically applied, therefore, only to architectures where two or more processors are designed to work in a cooperative fashion on a task or set of tasks.
There exist numerous variations on the basic theme of multiprocessing. In general, these variations relate to how independently the processors operate and how the workload among these processors is distributed. In loosely-coupled multiprocessing architectures, the processors perform related tasks but they do so as if they were standalone processors. Each processor is typically provided with its own private memory and may have its own mass storage and input/output (I/O). Further, each loosely-coupled processor runs its own copy of an operating system (OS), and communicates with the other processor or processors through a message-passing scheme, much like devices communicating over a local area network. Loosely-coupled multiprocessing has been widely used in mainframes and minicomputers, but the software to do so is closely tied to the hardware design. For this reason, among others, it has not gained the support of software vendors and is not widely used in today's high performance server systems.
In tightly-coupled multiprocessing, on the other hand, operation of the processors is more closely integrated. They typically share main memory, and may even have a shared cache. The processors need not be identical to one another, and may or may not perform similar tasks. However, they typically share other system resources such as mass storage and I/O. Additionally, instead of a separate copy of the OS for each processor, they run a single copy, with the OS handling the coordination of tasks between the processors. The sharing of system resources makes tightly-coupled multiprocessing platforms somewhat less expensive, and it is the dominant multiprocessor architecture in the business-class servers currently deployed.
Hardware architectures for tightly-coupled MP platforms can be further divided into two broad categories. In symmetrical MP (SMP) systems, system resources such as memory, disk storage and I/O are shared by all the microprocessors in the system. The workload is distributed evenly to available processors so that one does not sit idle while another is heavily loaded with a specific task. Further, the SMP architecture is highly scalable, i.e., the performance of SMP systems increases, at least theoretically, as more processor units are added.
In asymmetrical MP systems, tasks and resources are managed by different processor units. For example, one processor unit may handle I/O and another may handle network OS (NOS)-related tasks. Thus, it should be apparent that an asymmetrical MP system may not balance the workload and, accordingly, it is possible that a processor unit handling one task can be overworked while another unit sits idle.
SMP systems are further subdivided into two types, depending on the way cache memory is implemented. "Shared-cache" platforms, where off-chip (i.e., Level 2, or L2) cache is shared among the processors, offer lower performance in general. In "dedicated-cache" systems, every processor unit is provided with a dedicated L2 cache, in addition to its on-chip (Level 1, or L1) cache memory. The dedicated L2 cache arrangement accelerates processor-memory interactions in the multiprocessing environment and, moreover, facilitates higher scalability.
As alluded to at the beginning, designing software intended for reliable cross-platform execution on numerous MP systems available nowadays has become an arduous undertaking. Further, with ever-shrinking design/debug cycle times, software developers are continuously looking for ways to streamline the debug operations necessary to architect well-tested code, be it application software, OS software, or firmware (collectively, "applications").
One of the difficulties that can arise in situations where access to a computer system's controlled space is managed by means of hardware control objects such as control status registers, is when the contents of such control objects remain in an indeterminate or undefined state upon returning from a reset. Thus, when a software application attempts to access a controlled space partition in a computer system that is managed by a control object having indeterminate values, a machine fault may result. Since such anomalies are dependent upon the state of the control objects, the condition that some of the software code responsible for issuing transactions that access indeterminate control objects may give rise to potential instabilities in a hardware platform can remain latent until something serious happens. In addition, the problem can be compounded by the fact that oftentimes the hardware development of a particular platform may not have advanced far enough to allow complete testing of the software code targeted for that platform.

System and method for managing access to a controlled space in a simulator environment

Hewlett-Packard Development Company, L.P.


The present invention provides the cloning and expression of purified and isolated DNA molecules, obtainable from fungi, which encode enzymes having arabinan-degrading activity. The present invention also provides DNA constructs containing these DNA molecules and methods for their enhanced expression in selected microbial host cells. The present invention further provides methods for the use of the thus-produced arabinan-degrading enzymes.

The composition of the plant cell wall is complex and variable. Polysaccharides are mainly found in the form of long chains of cellulose (the main structural component of the plant cell wall), hemicellulose (comprising various .beta.-xylan chains) and pectic substances (consisting of galacturonans and rhamnogalacturonans; arabinans; and galactans and arabinogalactans). From the standpoint of the food industry, the pectic substances, arabinans in particular, have become one of the most important constituents of plant cell walls (Whitaker, J. R. (1984) Enzyme Microb. Technol., 6, 341).
Arabinans consist of a main chain of .alpha.-L-arabinose subunits linked .alpha.-(1.fwdarw.5) to one another. Side chains are linked .alpha.-(1.fwdarw.3) or sometimes .alpha.-(1.fwdarw.2) to the main .alpha.-(1.fwdarw.5)-L-arabinan backbone. In apple, for example, one third of the total arabinose is present in the side chains. The molecular weight of arabinan is normally about 15 kDa.
Enzymes capable of degrading arabinans are becoming increasingly important to the food industry. In juice production, for example, the demand to increase yields in order to reduce production costs has necessitated the modification of traditional processes. The utilization of enzymatic pre-treatments of the fruit pulp before pressing with specific enzymatic products drastically improves the juice yield by solubilizing the cell wall polysaccharides.
However, a persistent turbidity commonly referred to as "arabinan haze" has been a source of problems in the production of concentrated juices. The arabinan haze is more often present in concentrated juice than in non-concentrated juice. This may indicate that water activity has an influence on the solubility of arabinan. Furthermore, it has been found that this haze is soluble between 60 and 80.degree. C.
It has also been found that while branched arabinan is soluble in concentrated chilled apple and pear juices, the linear, debranched .alpha.-(1.fwdarw.5)-L-arabinan is much less soluble. This debranched .alpha.-(1.fwdarw.5)-L-arabinan is formed from the L-arabinan by the action of an arabinan-degrading enzyme present in the commercial pectic enzyme preparations from Aspergillus niger, commonly used to increase juice yield after pulp treatment but before pressing.
On the other hand, debranched araninans are considered desirable for certain other applications. WO 90/06343 discloses the debranching of sugar beet araban by the action of an .alpha.-L-arabinofuranosidase, free of endo arabinanase activity, which is isolated from a culture filtrate of Aspergillus niger or from a commercial pectinase mixture using ion-exchange and gel filtration chromatography procedures. The debranched araban may be used as a fat substitute in foods.
Arabinan-degrading enzymes are known to be produced by a variety of plants and microorganisms, among these, fungi such as those of the genera Aspergillus, Corticium, Rhodotorula (Kaji, A. (1984) Adv. Carbohydr. Chem. Biochem., 42, 383), Dichotomitus (Brillouet et al. (1985) Carbohydrate Research, 144, 113), Ascomycetes and Basidomycetes (Sydow, G. (1977) DDR patent application Ser. No. 124,812).
In particular, the filamentous fungus Aspergillus niger is known to produce three different arabinan-degrading enzymes: an .alpha.-L-arabinanase having a molecular weight of approximately 35 kDa and two .alpha.-L-arabinofuranosidases having molecular weights of approximately 118 and 60 kDa, respectively, (Rombouts et al. (1988) Carbohydrate Polymers, 9, 25). [N. B. van der Veen et al. ((1991) Arch. Microbial., 157, 23) reports molecular weights of 43, 83 and 67 kDa for these same three enzymes, respectively.]
The 35 kDa arabinanase (also known as ABN A) has endo activity and exclusively cleaves 1-5 linkages. The activity of this enzyme decreases as the 1,5-.alpha.-L-arabinan sequences become shorter and the concentration of arabinose dimers and trimers increased (Rombouts et al., supra). [N. B. van der Veen et al. (1991) reported a molecular weight of 43 kDa.]
The 118 kDa .alpha.-L-arabinofuranosidase (also known as arabinofuranosidase A, ABF A or EXO A) exclusively cleaves 1.fwdarw.5 linkages with exo-type activity as shown by the accumulation of arabinose monomers. This enzyme displays the highest activity on low molecular weight substrates (Rombouts et al., supra). [N. B. van der Veen et al. (1991) reported a molecular weight of 83 kDa.]
The 60 kDa .alpha.-L-arabinofuranosidase (also known as arabinofuranosidase B, ABF B or EXO B), also having exo-type activity, predominantly cleaves 1.fwdarw.3 and 1.fwdarw.2 .alpha.-L-arabinans, yet also demonstrates the ability to cleave 1.fwdarw.5 .alpha.-L-arabinans. Again, only arabinose monomers are detected after degradation of an .alpha.-L-arabinan-containing substrate (Rombouts et al., supra). [N. B. van der Veen et al. (1991) reported a molecular weight of 67 kDa.]
The A. niger ABF B enzyme has also demonstrated the ability to cleave the 1.fwdarw.6 linkage between a terminal arabinofuranosyl unit and the intermediate glucose of monoterpenyl .alpha.-L-arabinofuranosylglucosides (Gunata et al. (1989) European Patent Application No. 332.281; Gunata et al. (1990) J. Agric. Food Chem., 38, 772).
Enzymes having an activity similar to that of the A. niger ABF B enzyme have been identified in other fungi such as Dichotomitus scualens (Brillouet et al., supra), Corticium rolfsii and Rhodotorula flava (Kaji, A., supra).
A possible solution to the problem of haze formation in juices may be to use an enzyme formulation having an improved balance between the endo arabinanase (ABN A) and the ABF A and ABF B enzymes, or alternatively, enzymes having similar activities, i.e. one or more arabinofuranosidases obtained from another microorganism which is capable of cleaving 1.fwdarw.3 and 1.fwdarw.2 .alpha.-L-arabinans, as well as 1.fwdarw.5 .alpha.-L-arabinans. However, normal fermentation of A. niger fails to yield sufficient levels of the desired arabinofuranosidases. Moreover, it would be advantageous to be able to attenuate the amount of ABF A, ABF B and ABN A activities for optimal results in specific applications.
The ability of the ABF B enzyme to cleave the terminal 1.fwdarw.6 linkage of monoterpenyl .alpha.-L-arabinofuranosylglucosides may be used to assist in the release of aroma components from various fruit juices and thus, the enhancement of their flavors (Gunata, Z. et al. (1989 and 1990), supra). However, it would be preferable to use a purified ABF B or ABF B-like enzyme for this purpose since the presence of other enzymatic activity may degrade other important components of the juice and, in so doing, have a detrimental effect on the ultimate quality of the juice.
In nature, microbial arabinan-degrading enzymes are always produced together with other enzymes having polysaccharide-degrading activities, such as pectinases, xylanases, acetyl xylan esterases, acetyl esterases, galactanases and cellulases. As mentioned above, for some applications, these enzyme activities are not needed or are unwanted. Moreover, due to relatively low expression levels in the wild-type strains, the arabinan-degrading enzymes have proven to be somewhat difficult to isolate both from each other and from other enzymes produced by A. niger.
It is known that fermentation conditions may be varied to favor the production of an enzyme of interest. It is also known that the cloning of the gene encoding the desired enzyme and overexpressing it in its natural host, or in another compatible expression host will specifically enhance the production of the enzyme of interest. This latter method is particularly useful if the enzyme of interest is to be obtained in increased amounts, or in a form which is free of other, undesired enzymatic activity.
Clearly, it would be useful to increase arabinan-degrading activity via recombinant DNA techniques. However, until now, the genes encoding the A. niger arabinan-degrading enzymes have not been available. Accordingly, it would be of great importance to obtain genes encoding arabinan-degrading enzymes of fungal origin which may be brought to expression in its native host or, alternatively, in other microbial hosts wherein high expression levels of one or more arabinan-degrading enzymes may be achieved.
The expression of recombinant bacterial .alpha.-L-arabinofuranosidase has been previously described by Schwarz et al. ((1990) Biochem. Biophys. Res. Commun., 170, 368). The gene encoding a bacterial arabinofuranosidase was isolated from Clostridium stercorarium and brought to expression in an E. coli host.
A gene encoding an arabinosidase was cloned from the anaerobic bacterium Bacteriodes ovatus and brought to expression in E. coli, as disclosed by Whitehead & Hespell ((1990) J. Bacteriol., 172, 2408).
However, E. coli expression hosts are, in some instances, considered to be unsafe for the production of proteins by recombinant DNA methods due to their production of unacceptable by-products such as toxins. Furthermore, in E. coli expression, large amounts of heterologous protein tend to accumulate inside the cell. Subsequent purification of the desired protein from the bulk of E. coli intracellular proteins can sometimes be difficult.
Moreover, since bacterial genes contain no introns, one is confronted with few problems in cloning and expressing such genes in prokaryotic hosts. On the other hand, the expression of eukaryotic genes is not always so straightforward. It is well known that genes isolated from eukaryotic strains may contain introns. This inherently introduces complications in the cloning and expression of these genes, should a prokaryotic host be preferred.
Furthermore, certain differences exist between the physical characteristics of arabinan-degrading enzymes of fungal origin and those from bacteria. In general, fungal enzymes have a pH optimum in the range from .ltoreq.3.0-6.0. A few fungal species produce arabinan-degrading enzymes having pH optima as low as pH 2.0. These pH optima are generally significantly lower as compared to similar enzymes from bacterial strains which have a pH optimum in the range of pH 5.0-7.0 (Karimi and Ward (1989) J. Indust. Microbiol., 4, 173; Lee and Forsberg (1987) Can. J. Microbiol., 33, 1011). Thus, it is clear that bacterial arabinan-degrading enzymes are less suitable for use in, for example, processes requiring lower pH conditions.

Cloning and expression of DNA molecules incoding arabinan-degrading enzymes of fungal origin


A method for producing spunlace non-woven cloth includes the following steps: clearing cotton—carding—spreading the web—water jetting—bleaching—drying—rolling the finished products. This method improves the good ratio of the finished products of the whole procedure, reduces the producing cost, economizes raw materials and save the power as well as reduces the impurity content of products and ensures the hygiene of finished products and greatly reduces the bacteria content. Moreover, the direct products of the present invention have the advantages of being soft, having good skin tolerance, no toxic, no stimulation, no sensibility, having good absorbency, convenient and comfortable to use.

At present, medical non-woven cloth is made of synthetic fiber. The components of synthetic fiber are commonly 70% Rayon and 30% Polyester (these are coming from petroleum). The raw material resources are non-renewable, the production cost is high, after using, the destroying cost is high, and it damages the environment. At the same time, some patients are sensitive to this material. Therefore the prospect of synthetic fiber non-woven medical dressing is not optimistic. However, the nature spunlace non-woven cloth medical dressing will be widely used, because the raw material of this non-woven cloth is naturally planted cotton; the raw materials are abundant and recycled. It is simply dealt with, as well as being soft, protecting environment, having good absorbency, no toxic, no stimulation, no sensibility, being convenient and comfortable to use. At present, the method for producing spunlace non-woven cloth is, clearing cotton—degreasing—bleaching—drying—carding cotton—spreading the web—water jetting—drying—rolling the finished products. The disadvantages of this producing method are with more procedures, high cost and bigger waste of power. As this producing method is degreasing and bleaching the cotton fiber first, therefore the cotton fiber is not smooth, and it is difficult to spread fiber into the web. With this method, the impurity content of finished products is high, so the quality cannot be guaranteed. In a word, it is much more wasteful by this process, the good ratio of finished products is low, and the production cost is high, therefore the price is terribly high. In this case, till today, this type of spunlace non-woven cloth is not used widely.
In the medical trade gradually uses more and more non-woven cloth. The non-woven cloth is folded in multi layered dressing to use in hemostasia, examining blood, sucking blood or body fluid in operation. In operations, the dressings are dropped in human body because of subjective or objective reasons. And the dressings which are soaked with blood or body fluid have the similar color with the body tissue in human body or in the wound, which is hard to discover. Therefore they are difficult to discover so that they are left over in the human body. Moreover, they are difficult to be checked out after the wound is sewn up, unless cutting the seam again. Leaving the dressings in the human body is a very dangerous accident. If it cannot be checked out in time and be cleared, it will cause worse of patient's condition and even death. The disadvantage of present non-woven is that when they are left over in the human body, they are difficult to be checked out.

Method for producing spunlace non-woven cloth, method for producing spunlace non-woven cloth with X-ray detectable element, spunlace non-woven cloth with X-ray detectable element produced thereby


A composition and method for treating some symptoms associated with cognitive and emotional conditions wherein the composition comprises at least one butyrate alkali metal or alkaline earth metal salt of n-butyric acid, preferably, a mixture of calcium and magnesium butyrate.

This invention relates to a composition and method for treating the symptoms associated cognitive and emotional conditions such as those found in attention deficit disorder (ADD), attention deficit/hyper activity disorder (AD/HD), Tourette""s Syndrome, some forms of autism, and other physiological conditions which manifest cognitive or emotional abnormalities.
It has been recognized that a significant number of children are persistently hyperactive and have an attention span so short that they have difficulty in school and in social interactions. For example, such children have difficulty in situations that require sustained attention such as listening to teacher instructions, working on class assignment alone or in groups, and in completing assignments that require concentration. This condition carries over into adulthood, and manifests itself in many ways. For example, various physiological and/or psychological conditions cause symptoms that manifest in low frustration tolerance with temper outbursts, bossiness, stubbornness, insistence that requests be met, mood lability and poor self esteem, among others.
There are no established diagnostic laboratory tests in the clinical assessment of ADHD, as it is not yet clear as to the cognitive deficit responsible for the abnormal mental processing exhibited in ADHD.
For many years, methylphenidate hydrochloride (RITALIN) has been used to treat ADD and/or ADHD. Ritalin is a mild stimulant that has undesirable side effects such as nervousness, insomnia, hypersensitivity, anorexia, nausea, among others. Ritalin and other stimulants also do not relieve the often encountered excessive emotional response as they do not generate the emotional buffering or filtering necessary to delay and attenuate an excessive emotional response.
There are other physiological and/or psychological conditions that cause similar symptoms of uneasiness, restlessness, edginess, difficulty in concentration, recognition and memory deficiency, etc, requiring the use of prescription drugs such as WELLBUTRIN (1-(3-chlorophenyl)-2-[(1,1-dimethylethyl)amino]-1-propanone), which tend to cause side effects. Imipramine, desipramine, nortriptyline, amitriptyalin and cloripramine may also be used to treat symptoms such as associated with ADD/ADHD, excessive emotional response, etc. but these tricyclic drugs follow diverse mechanisms and tend to cause side effects. As these are normally chronic conditions, long term tolerance of the treatment is essential to successfully managing these symptoms. It is difficult for an individual to tolerate daily doses of a drug with even moderate side effects for life, yet that is what is presently required for theses individuals to function in society.
The search continues for a safe, effective and convenient treatment for the symptoms associated with diverse cognitive and emotional symptoms caused by conditions such as ADD and AHDH, for both adults and children, without the disadvantages and side effects found in the existing treatments.
It is an object of the present invention to provide a composition for the treatment and relief of the symptoms associated with conditions such as encountered with ADD or ADHD, and anxiety syndromes/conditions.
It is a further object to provide a method for treating the symptoms associated with various cognitive and/or emotional disorders such as ADD or ADHD.
It is yet another object to provide a method of treating the symptoms described above caused by diverse conditions, that is safe, effective and free of the side effects associated with prior treatments.
These and other objects of the present invention are achieved by a composition comprising at least one butyrate formulated preferably for oral administration, in a pharmaceutically acceptable carrier. Preferably, the butyrate is an alkali or alkaline earth metal salt of nbutyric acid, hereafter collectively termed the xe2x80x9cbutyratexe2x80x9d. An example of the alkali metal salt may be the lithium, sodium or potassium butyrate, the alkaline earth salt may be calcium, magnesium or barium butyrate, or combinations thereof. Certain other butyrates may also be effective such as the ammonium or zinc butyrate, and thus the invention is not limited to those listed above.
The method comprises treating the symptoms of cognitive or emotional disorders, such as those described above relative to ADD/ ADHD, though caused by any of a number of psychological and/or physiological conditions, by administrating an effective amount of a butyrate to a person in need of such treatment.
The invention utilizes one or more alkali metal or alkaline earth metal salts of n-butyric acid in a pharmaceutically acceptable carrier. Preferably, one or more of the lithium, sodium, potassium, calcium, magnesium, zinc and barium butyrate is used.
In a preferred embodiment magnesium butyrate is used, though in another embodiment, a mixture of calcium and magnesium butyrate is used.
In a more preferred embodiment, the composition is formulated with one ore more optional ingredients such as antioxidants, antidepressants, memory promoters/enhancers, various vitamins, nutritional and herbal supplement that can be co-factors or otherwise enhance or synergize with the inventive compound and/or in the inventive treatment method.
The method of the invention comprises the administration of an effective amount of at least one butyrate, whether an alkali metal or alkaline earth metal, ammonium or zinc salt of 4-butyric acid. The salt may be selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, zinc, magnesium, calcium, strontium or barium, more preferably, sodium, potassium, magnesium and the calcium salts, most preferably the calcium and magnesium salts.
While any one salt may be used, it may be preferred to use a combination of salts such as a mixture of calcium and magnesium salts of 4-butyric acid, in a ratio of from 10:90 to 90:10 parts calcium to magnesium. More magnesium to calcium is preferred.
Butyric acid is a short claim fatty acid synthesized in the mammary glands. It is an oily liquid that has an unpleasant, rancid odor. It is produced by bacterial fermentation of unabsorbed carbohydrate in the colon and reaches concentrations of up to 20 mM in the colon and feces of animals and man. The other source of butyric acid is in the diet where it is present in low levels in many fruits and vegetables, but the best source is from milk fat, such as in butter, which contains 3-4% butyrate in a complex of glycerides or esters of glycerol butter fat. The calcium and magnesium butyrates apparently have no side effects when taken as a nutritional supplement and are classified as food by the Department of Agriculture. They are known for use as digestive aids and for desensitizing the gastrointestinal tract.
While alkali metal butyrates have been proposed for use in reducing food sensitivity, their use as agents for treating cognitive and emotional problems have not been recognized.
It is believed that the effectiveness of the proposed compounds relies on an increase in gamma amino butyric acid (GABA) in the brain, a well known inhibiting neurotransmitter. Thus, absorption of these compounds is believed to promote transfiguration into GABA, to raise the level of GABA in the brain. It is believed that these butyrates, or derivatives thereof formed in the blood stream, cross the blood brain barrier for conversion into GABA.
Preferably, one or more butyrates are formulated with promoters to enhance transformation to GABA. These may include, but are not limited to pyridoxine 5-phosphate, cyanocobalamin, folic acid, niacin and magnesium, which may be released from magnesium butyrate during the formation of GABA. L-glutamine, 1-phenylalanine, 1-tyrosine and 1-taurine may also be included to promote dopamine, epinephrine, and norepinephrine formation, and to provide a calming effect.
Herbal supplements such as adaptogen including a medicinal mushroom cordyceps sinensis, could be used as it is a known moderator that enhances brain functions that are under active and calms down brain functions that are over active.
Phosphatidyl serine is an agent shown to have positive effects on short term memory and to treat symptoms associated with ADD/ADHD, and is complementary to the inventive composition. Pregnenolone is also a possible choice as a complementary compound, as is ginkgo biloba and/or the flavenols or oligomeric proanthocyanodins, known antioxidants, as well as the plant extract from huperzia serrata, a promoter for developing serotonin receptors on neurons.
Of course, many other compounds and ingredients can be formulated with the inventive compounds to enhance effectiveness or provide complementary beneficial effects in the treatment of cognitive and emotional disorders as discussed above.
The beneficial effects of the butyrate may be obtained by a dose level of about 200 to 3000 mg butyrate per day, preferably by oral supply of tablets containing from 200-1500 mg butyrate per capsule, the dose split into, for example, 2 tablets 3 times per day or 3 tablets, two times per day (500 mg per tablet). Smaller doses at multiple times per day may be preferred.

Alkali or alkaline earth metal of n-butyric acid for treatment of cognitive and emotional conditions


Devices, systems, and methods for a manually controlled operating system for permitting a handicapped person to brake and accelerate an automobile with hand operated controls. The system comprises a brake handle operably coupled to a foot brake pedal with a first cable and an accelerator handle operably coupled to a foot accelerator pedal with a second cable, wherein the brake handle and accelerator handle are positioned within hand reach of the handicapped person while positioned within the automobile.

The prior art has put forth several designs for hand control mechanisms for driving an automobile. Among these are:
U.S. Pat. No. 4,078,628 to Anton J. Reichenberger describes an automotive control system for use by handicapped drivers who have lost the functional mobility of their lower extremities. A second wheel concentric with the steering wheel is added such that it is reachable by either the thumb or fingertips when hands are on a steering wheel in normal driving fashion. Movement of this second control wheel in a direction away from the driver actuates the automotive braking system through an electro hydraulic servo system. Pulling the second wheel towards the driver actuates the throttle of the automobile through a similar servo system. The brake and throttle interfaces with existing automotive control systems so that very few additional add on mechanisms are necessary.
U.S. Pat. No. 4,143,734 to Bishnu P. Bhattacharya describes a pair of hand grips claimed to the steering wheel. The grips are connected by a pair of cables extending through flexible tubes to opposite ends of a pivotable bar mounted on the steering column of the steering wheel. The opposite ends of the pivotable bar are respectfully affixed to the accelerator pedal and the brake pedal of the vehicle. Pressure applied by an operator's hands on the hand grips selectively depresses the accelerator pedal and the brake pedal. Springs mounted in the hand grips and at the distal ends of the tube maintain the cables in the open position yieldable to pressure on the hand grips.
U.S. Pat. No. 5,103,946 to John V. Masters and Norris R. Harod describes a hand operated automobile brake and accelerator operation assembly for the handicapped that is readily transferred from car to car without tool and is adaptable to various models of cars. The assembly is installed by clamping manually operable wing nuts on the brake pedal shaft as the sole fixed connecting bracket on the car. The brake pedal and accelerator pedal are respectively operated by pushing and pulling by hand an operating rod to move an operating lever fulcrumed on a pivot axis fixed relative to the brake pedal shaft. This operating lever moves an accelerator operating shaft into contact with the accelerator pedal to depress it as the hand operated rod is pulled. Conversely when pushed, the hand operated rod depresses the brake pedal and releases the accelerator. To accommodate different car models, an accelerator operating shaft has a manually operated lock to fix its length and the accelerator assembly distance from the brake is adjustable.
None of these prior art references describe the present invention.


A slow speed high torque shear technology is disclosed having optional configurations and attachments for its construction and methods for reconfiguring existing shears to improve performance, and maintenance economics. A method is provided for the readily replacement of individual cutters and tooth modules, reconfiguration of cutter and tooth assemblies in a mix and match manner, in combination with matching anvils having replacement cutting elements with multiple cutting faces. Alternative embodiments are provided illustrating methods of configuration of various types of cutting elements and material feed systems. Methods for converting a shear a rough cut shear to a fine particle shear and then to a granulator is provides. A method for rejecting unprocessable material is also disclosed.

1. Field Of The Invention
The present invention relates to rotary shredders in general and more particular to high volume shredders used to shred waste material and being of a type having high torque, slow speed, and capable of producing small particle size materials in a single pass.
2. General Background
Typically, modular or slow speed shear shredders utilize a series of intermeshing cutting faces which shear material as it is captured by the cutters and pulled through the machine. Examples of such machines are taught by U.S. Pat. Nos. 5,402,950, 3,931,935, 5,145,120, 4,119,277, 4,690,337, 4,925,116, 5,062,576, 5,094,392, 5,248,100, and 5,402,948. Cutters, generally are of two types (1) teeth attached and arrayed around a rotatable cylindrical core or (2) comprised of heavy steel plates stacked on a mandrel. In either case the teeth shear material by shearing such material between an anvil and the tooth or between counter-rotating, intermeshing disk. It is this arrangement of teeth and the associated anvil and/or the configuration of intermeshing disk which determines the efficiency and particle size of the materials passing through the machines. During operation, the cutter's teeth are subjected to abrasion and wear from their shearing of material. The shear's teeth or hooks as they are sometimes called tend to round off along the cutting edges due to abrasion and wear. When this happens, the gap between intermeshing disks and/or anvils begins to open wider until the hooks or teeth are no longer capable of grabbing the infeed material effectively. The cutters begin to rip and tear instead of shearing and it often becomes necessary to replace the entire set of cutters in order to restore the performance of the shear machine. Excessive wear and damage to the cutters is a constant problem. Therefore, various apparatus have been employed to help alleviate such problems as can be seen in the ,337 and ,100 patents which employ movable anvils, while other such as the U.S. Pat. Nos. 4,946,109, 5,507,441, or ,277, ,950, and ,948 patents utilize replaceable cutter face blade or element. The ,948 patent provides a cutter bar having a plurality of carbide cutter elements along its length. In such cases where insertable cutting teeth are used, the arrangement and configuration of the teeth are restricted to a particular type and size due to their contact with a fixed anvil. In cases where replaceable inserts are used they are generally restricted to the face or edges of the cutter and are held in position with bolts or brazed to the cutter tooth. Such arrangements bring the bolt heads in direct contact with the material being sheared, resulting in lost inserts and/or making it difficult to remove the bolts for replacement.
Disk type, slow speed, shredders often require spacer disk between the cutter disk and a series of cleaning fingers to dislodge material build-up between the cutter disk. Other problems associated with this type shredder include shaft fracture due to large objects being pulled between a pair of counter rotating disk. To overcome such problems hydraulic drives and load sensors have been developed such as that disclosed in the ,100, and ,948 patents. However, in such cases the systems fail to address the need.
As mentioned above, In most cases slow speed, shredders pull material into the machine with the shredder teeth or the material is feed by a rotary feeder units such as that taught by the ,948 patent or to conveying systems line that disclose by the ,277 patent. However, such feeders are usually limited to small particles or simply serve to feed the material to the cutters. No attempt has been made to force feed materials to the cutters or to presize the material.
It is known within the shredder art that a center anvil, such as is taught by the ,392 patent, may be employed to assist in shredding which may also prevent material jams between the cutters and thus prevent rotating shaft fracture. However, the ,392 patent relies on a one piece unitized construction for its rotating cutters. There is also no provision made for replacement of the cutter teeth or wear surfaces of the cutter teeth or anvil.
Replacing cutters in shear shredders having cutters permanently attached to its rotating members requires complete disassembly of the shredder. Typically, replacement cutter assemblies plus the labor to install them is a very expensive procedure even for a small machine and much more costly for a large one. Therefore, one of the major drawbacks associated with shear shredder operation is the high cost of maintaining the equipment. Further, shear shredders tend to cut material into long strips. In cases where particle size is important, it becomes necessary to classify the shredded material and route all oversized material back through the shredder repeatedly until it is properly sized to exit the classification system. This repeated passing of material through a single shredder lowers the shredder's processing capacity and decreases the life of the cutters. The only alternative would be to simply stack shear shredders so that material can cascade through a number of shredders having increasingly narrower cutters. Usually, the capital cost of multiple shredders prohibits this approach. Therefore there is a need for a more efficient shredder system in which; the particle size can be controlled, the cutter teeth can be replaced readily, tooth configuration can be changed rapidly, and older machines can be rebuilt, incorporating new and improved efficient concepts at an economical cost.


A system (1) for producing thermoplastic material bottles (5),

In the field of packaging, the sterility of the containers, e.g. bottles for sensitive products packaged in an aseptic environment, is a crucial aspect. Examples of such products are foods, pharmaceuticals and cosmetics.
The containers made of thermoplastic material, e.g. polyethylene terephthalate (PET), are typically sterilized by means of solutions of hydrogen peroxide (H2O2) or peroxyacetic acid (PAA).
Although they are commonly used, such sterilization methods have a series of disadvantages, including: presence of chemical compound residues, relatively lengthy processing times, difficulty in controlling the sterilization apparatus, and use of consumables, in particular H2O2 and PAA, with relatively high costs.
Moreover, certain systems include using particular systems which are used to keep the sterility of the system itself. However, such systems are expensive, difficult to be produced and require an expensive maintenance.
The need is therefore felt to improve the method of industrially sterilizing thermoplastic material containers for food use.

System and process for producing thermoplastic material containers

Abstract: the system (1) comprising in sequence:

Abstract: an extruder (10);        a molding apparatus (20) for producing preforms;        a thermal conditioning apparatus (30) for thermally conditioning the preforms;        a blowing apparatus (40) for producing bottles (5) from the preforms;        a pulsed light irradiation apparatus (50, 55, 60, 70);        an aseptic filling and capping apparatus (80).

S.I.P.A. SOCIETA' INDUSTRIALIZZAZIONE PROGETTAZIONE E AUTOMAZIONE S.P.A.


A floppy disk drive controller has a control part which performs a plurality of kinds of controls by means of outputting control information appropriate to each kind of control, and a memory part in which information which selects a predetermined kind of control from among the plurality of kinds of controls is pre-stored, the control part outputting the control information corresponding to the predetermined kind of control which is selected based on the information from the memory part.

The present invention relates generally to Floppy Disk Drive Control Units, and more particularly to a control information unit which performs a plurality of kinds of controls by means of outputting control information appropriate to each kind of control of the floppy disk drive.
In a floppy disk drive (called FDD for short), the following functions which the FDD is to be equipped are occasionally changed depending upon the needs of customers, such as the presence of a READY signal which indicates a predetermined part thereof is in a ready state for the operation of the floppy disk drive, the data output level, the presence of a calibration signal which is an initial movement of a head to a predetermined track on a disk, the lighting state of the front light emitting diode (called LED for short).
As shown in FIG. 1, the principal part of the conventional control information output unit is a large scale integrated circuit (called LSI for short) so that the LSI is equipped with various control functions. LSI 9 has selecting terminals 10 which are to be connected to jumper lines (or strap pins) 11. And predetermined kinds of controls are selected by means of switching the connection between each of the selecting terminals 10 and each of the jumper line 11. However, since there are numerous kinds of controls to be selected, if the number of selecting terminals are increased, a printed circuit board (called PCB for short) on which the LSI is mounted has to become larger. Additionally, the number of the selecting terminals cannot be increased beyond a certain limit. Accordingly, all the controls are divided so as to be distributed to several LSIs. However, the conventional control information output unit has the following disadvantages:
1. It is troublesome to connect each jumper line (or strap pin) to each selecting terminal;
2. If the number of selecting terminals are increased, the PCB has to become larger, and then, in turn, the FDD has also to become larger;
3. If the required functions are distributed to the several LSIs, the number of different kinds of LSIs and PCBs are increased so that the number of manufacturing processes are increased accordingly and thus the cost of the FDD becomes higher.

Floppy disk control unit and apparatus having a floppy disk control unit


A method for refining an easily polymerizable matter while preventing an easily polymerizable matter-containing substance from being polymerized and an apparatus for use in the method are disclosed. The method and apparatus for refining and separating the easily polymerizable matter-containing substance by the use of a distillation column provided with a heat exchanger set the linear velocity of a vapor in a connecting line intervening between the distillation column and the heat exchanger at a level of not less than 5 m per second and the retention time of the vapor at a level of not more than 3 seconds.

1. Field of the Invention
This invention relates to a method for refining an easily polymerizable matter-containing substance and an apparatus therefor. More particularly, it relates to a method for refining (meth) acrylic acid and/or a (meth) acrylic ester while preventing the acid and/or the ester from being polymerized particularly in the vapor phase and an apparatus to be used therefore.
2. Description of the Related Art
Such an easily polymerizable matter as impurities-containing (meth)acrylic acid has been heretofore refined as follows.
In a distillation column with a condenser and a re-boiler, the condenser is connected to the top of the distillation column via a (inter) connecting line and the re-boiler is positioned near the lower part of the distillation column via a (inter)connecting line. Here, the feed material such as the impurities-containing (meth)acrylic acid is supplied to the distillation column and distilled therein. The vapor distilled from (meth)acrylic acid which has entered the condenser via the connecting line is condensed and apart thereof is returned to the distillation column and the rest thereof is recovered as distillate D or subjected further to a subsequent treatment. Meanwhile, the liquid containing (meth)acrylic acid through the bottom of the distillation column is supplied to the re-boiler and reboiled therein, with the result that the vapor containing (meth) acrylic acid will be returned via the connecting line to the distillation column.
It is well known that (meth)acrylic acid and/or a (meth)acrylic ester is so easily polymerized very often during the process of production such as refinement and that the apparatus of production compellingly stopped. As a measure, the practice of adding a polymerization inhibitor such as hydroquinone or phenothiazine during the production of (meth)acrylic acid and/or (meth)acrylic ester thereby preventing polymerization in the liquid phase of the purification process has found popular recognition.
U.S. Pat. No. 3,988,213 discloses a method for preventing the vapor of a vinyl compound from condensing or polymerizing by providing a distillation column with a jacket.
Further, U.S. Pat. No. 3,717,553 discloses a distillation column which, by having an opening formed near the wall of a tray tower and consequently allowed to have the wall of its own wetted, is enabled to prevent a vinyl monomer from polymerizing.
Perfect prevention of the polymerization that occurs during the distillation of an easily polymerizable matter or during the condensation of a vapor or the re-condensation of the vapor in a vapor phase has not yet been accomplished.

Method for refining easily polymerizable matter-containing substance and apparatus therefor


A well treatment fluid containing borated galactomannan may be used to isolate a pre-determined productive zone in an oil or gas well. The fluid is pumped into the well in a substantially non-hydrated form and forms a temporary seal. The fluid may be used as a chemical packer in place of a mechanical packer. After the pre-determined productive zone is isolated, a well intervention operation may be performed within the isolated pre-determined zone.

Typically, a subterranean formation penetrated by a well has a plurality of distinct zones or formations of interest. During production of fluids from the well, it usually is desirable to establish communication with only the zone or formations of interest such that intervention treatments do not inadvertently flow into a non-productive zone or a zone of diminished interest.
Zonal isolation can be paramount to successfully complete a well intervention operation. Well intervention operations alter, manage and/or diagnose the health of the well. Well intervention, which can be used at any stage in the productive life of the well to maintain optimal operation conditions, is typically confined to one or more particular zones within the well.
There are various types of well intervention operations. Each type addresses a specific concern of the well. For instance, when an oil or gas is young, it may be useful to manage pressure and flow by the addition of equipment or by otherwise altering the existing well. Well intervention might be necessary in such a case to safely and effectively apply the desired changes and manage or increase well production. Older oil or gas wells may further require periodic cleaning or other maintenance. Well intervention is often used for this type of management strategy. An example of well intervention is known as pumping, in which chemicals are pumped into the well to encourage resource production or clean up extraction by-products.
More recently, the use of isolation assemblies have been reported to provide zonal isolation and which allow for selected treatment of productive (or previously producing intervals) in multiple interval wellbores. For instance, U.S. Pat. No. 6,386,288 discloses a mechanical zonal isolation system which may be provided on the outside of the casing string (cemented to the wellbore) to permit an interval of the formation to be completed and stimulated and/or treated independent of the others. In this manner, selected intervals of the subterranean formation may be stimulated and/or treated. Such assemblies may include the use of flapper valve assemblies positioned between perforating gum assemblies.
See further, U.S. Pat. No. 7.575,062 which discloses an isolation assembly containing screen-wrapped sleeves and a plurality of swellable packers disposed in a liner and a tool within the liner for shifting openings for the control of fluids from the wellbore.
Zonal isolation assemblies are expensive. When held in place by a cementitious slurry, such assemblies may only be removed from the wellbore by damaging or destroying the assembly. Alternative methods are further needed which will hold the casing in place in the wellbore.
In addition, alternatives have been sought for securing casing to the wellbore. Traditionally, cementitious slurries are used to cement the well pipe and casing to the wellbore. Typically, the slurry is pumped down the inside of the pipe or casing and back up the outside of the pipe or casing through the annular space between the exterior of the casing and the wellbore. The cement slurry is then allowed to set and harden to hold the casing in place. The use of conventional cementitious slurries is undesirable for use with zonal isolation assemblies since, in order to be removed from the well, damage to or destruction of the zonal isolation assembly becomes necessary.
Further, alternatives have been sought for materials capable of forming a seal within the well prior to subjecting the well to intervention. While mechanical barriers and packers are typically used, they often are not capable of providing effective seals under certain conditions.

Well intervention method using a chemical barrier


Servo tracks for magnetic tape storage are written using two opposite polarities, rather than the one polarity normally used in servo tracks. Timing continues to be performed using only pattern members of like polarity, due to physical restraints, but the use of two polarities allows additional information to be encoded in the pattern more efficiently.

1. Field of the Invention
This invention relates generally to recording and reading data from magnetic storage media and, more particularly, to servo control systems that maintain the position of a magnetic head relative to tracks in magnetic tapes.
2. Background of the Invention
As the magnetic storage of information becomes more sophisticated, greater amounts of data are packed into smaller volumes of space. In storing large amounts of data on a magnetic tape, multiple "tracks" of data are stored paralleling the length of the tape. The number of tracks that can be stored on a particular width of tape depends on the sensitivity of the technology used, but it is currently possible to have hundreds of tracks on a ½ inch wide magnetic tape.
A major hurdle in recording and reading data from these hundreds of tracks is the lateral movement of the tape media as it traverses the read/write head. This is overcome by manufacturing the tape with recorded tracks of servo information at various lateral locations across the tape. These servo tracks provide information that allow the servo mechanisms in a tape transport to correctly position the head with respect to the data tracks.
FIG. 1 shows a diagram of a tape and read/write head. Tape 100 has a number of servo tracks 101–105. Data is stored in bands 106–109 between servo tracks 101–105, with each data band containing a given number of tracks, depending on the technology. In these examples, read/write head 112 contains three servo read elements 114, 116, 118 and a number of data read/write elements that are not specifically shown; read/write head 112 can be positioned over an upper portion 124 or a lower portion 126 of tape 100. Read/write head 112 is made wider than the tape so that no matter what its position, the head 112 supports tape 100. Servo read elements 114, 116, 118 read the information from the servo tracks; from this, the servo mechanism can calculate any movements necessary to maintain the proper position of read/write head 112 with regard to tape 100.
The servo tracks, in addition to providing positioning information for the servo mechanisms, can be encoded to carry additional useful information, such as identifying the individual servo tracks and the current longitudinal position along the tape. As a tape stretches over its lifetime, the servo tracks can also be used to adjust for the distortion.
There are a number of different methods of coding information in the patterns written in the servo tracks. One very useful method is timing-based coding, as it provides a method of position sensing that is insensitive to reading speed. This method is discussed in U.S. Pat. No. 6,021,013, which is hereby incorporated by reference. In this patent, each servo track is written with a repeating cyclic sequence of two patterned lines whose separation from each other varies in a consistent manner across the width of the servo track, with periodic gaps in the pattern to serve as a starting point for the pattern. Two exemplary patterns 200 and 300 from this patent are reproduced in FIG. 2 and FIG. 3. The time A between the detection of two dissimilar lines is compared to the time B between the detection of two similar lines. The value of A:B reveals how far off center the servo read head is at the time of reading, and thus the amount of correction necessary to properly locate the read head. Using this ratio rather than distances allows for the fact that the tape can be moving at different speeds or may have stretched slightly. Thus, it is possible to maintain a position over a given band of data.
While the two patterns 200, 300 demonstrate the principles of timing-based servo patterns, it has been found that single comparisons of A and B are not enough for accurate measurements. Therefore, nested patterns, such as pattern 400 shown in FIG. 4, are more commonly used. Using a nested pattern of four chevrons, four measurements can be taken across a given length of tape; their averaged value of A:B is much more accurate. The detection of an expected sequence of stripes (generally, two sets of five followed by two sets of four) also provides an efficient means of error detection, as the software can immediately detect when an expected input is not found.
To provide the high accuracy necessary, the tape is recorded on a special servo-track machine. The first portion of the recording head contains an erase head, which erases the entire width of the tape, followed by a single-coil, multi-gap write element, capable of writing all servo tracks on a tape in one pass. Unlike normal data write elements, which are continuously powered and switch from one polarity to the opposite polarity repeatedly, the servo write element is switched on and off and normally writes in only one polarity. Additionally, the write element is patterned, so that a each time it is powered, it produces an image on the tape of the patterned write element. By controlling the switching of the write element as the tape moves across the head, the pattern is repetitively written on each of the servo tracks. For a nested pattern, images of both the left and right component of a pattern are written simultaneously to maintain the accuracy.
Creation of the pattern shown in FIG. 4 is demonstrated in FIGS. 4A–J. In this example, the figures show the same section of the tape as it moves from right to left across the write head. The portion of the tape that appears white has already been erased. FIG. 4J is a timing pattern that shows when the write element is pulsed, while FIGS. 4A–I show the tape sequentially after each pulse. Looking at FIG. 4A, the first pulse P1 of the write element has produced an image of the pattern that is on the write element, creating the two-chevron pattern 410-1. FIG. 4B shows the tape after pulse P2 has written pattern 410-2, FIG. 4C shows it after pulse P3 has written pattern 410-3, FIG. 4D shows it after pulse P4 has written pattern 410-4, FIG. 4E shows it after pulse P5 has written pattern 410-5. After the initial five pulses, the write element is not pulsed again until the initial five nested chevrons 410-1 through 410-5 have all passed the write element, then four further pulses P6–P9 write the pattern of four nested chevrons 410-6 through 410-7. The process will continue until all servo patterns are written along the entire length of a tape.
In order for the timing based servo patterns to work properly, several factors that can adversely affect the outcome must be taken into account. First, the servo read elements must be much narrower than the servo track, so that each servo read element detects only a narrow width of the pattern created. This serves to minimize tracking errors due to false position signals. Secondly, all of the pattern lines are written using a uni-polar write current and the timing is measured only between magnetic flux transitions having the same polarity (e.g., always timing the transition at the beginning of a line). Variations in the write head or the writing process, as well as other difficulties can cause apparent shifts in the timing of transitions having opposite polarities, so opposite transitions are never compared.
In order to position the read head 112 of FIG. 1 over the correct band of data 106, 107, 108, 109, different patterns are used for different servo tracks. For example, if pattern 200 is used on three servo tracks 101, 102, 105 of FIG. 1, and pattern 300 is used on servo tracks 103 and 104, then by reading two adjacent servo tracks and recognizing their patterns, it is possible to determine which data band is between the two servo tracks, using the following Table 1:
Upper servo patternLower servo patternData band200200106200300107300300108300200109
Within the servo tracks, additional information, such as the longitudinal location, can be encoded by varying specific portions of the pattern, such as the distance between successive groupings of the pattern. Because servo tracks are typically recorded at a much lower density than the data tracks, they can be read at high speeds. This ability to read longitudinal data at high speeds makes searches much more efficient.
While the beauty of a timing-based servo system lies in the fact that it utilizes comparisons rather than individual symbols, this very concept also confines it. Since meaning is only carried in comparative relationships, the density of information is necessarily low. It would be desirable to carry additional information in the timing pattern without destroying the timing pattern itself.
One solution that has been disclosed is U.S. Pat. No. 6,169,640. This patent discloses using, for example, four servo tracks on which the timing patterns are identical, but not synchronized with each other. Rather, as seen in FIG. 8 in U.S. Pat. No. 6,169,640, the two inner tracks 102 and 103 are offset a given amount from the two outer tracks 101 and 104. The result is that each adjacent pair of servo tracks exhibits a different timing relationship as compared to the other pairs of servo tracks, providing identification of the servo tracks by this offset. However, this scheme comes with its own drawback. Since the servo tracks are not synchronized with each other, the software must be concerned with phase differences between the servo tracks when creating a position error signal. It would be beneficial to identify the tracks without losing synchronicity.

Polarity encoded pattern for timing based servo