Disclosed are aromatic condensation compounds useful as building blocks for construction of various types of optically active substances and reagent, wherein the aromatic condensation compounds are represented by general formula (1) below and capable of forming enantiomeric isomers. In the formula, two Rs are the same or different functional groups and selected from among linear, branched and cyclic hydrocarbon groups of 1-16 carbon atoms, either of which R may be hydrogen. A portion of the aromatic nucleus may be reduced, or at least one of the two nitrogen atoms may be quaternary. The aromatic condensation compounds can be produced by heating and reacting N,N'-diphenyl-p-phenylenediamine with a carboxylic acid represented by the general formula --RCOOH in an amount of at least 2 molar equivalents with respect to the diamine, at 180-210.degree. C. in the presence of a Lewis acid such as zinc chloride. ##STR1##

1. Field of the Art
The present invention relates to aromatic condensation compounds which form enantiomeric isomers, and more specifically it relates to novel aromatic condensation compounds useful as optically active building blocks for construction of various types of optically active substances, and to a process for their production.
2. Prior Art
Optically active substances which give enantiomeric isomers (hereunder, "enantiomers") which have a relationship often likened to that of the right and left hands, are very important in the development of medicines, foods, agricultural chemicals and aromatics. This is because the physiological activity and chemical reactivity of optically active substances is usually completely different depending on the enantiomer. For example, in the case of glutamic acid, one of the enantiomers (L-form) has flavor while the other enantiomer (D-form) has no flavor. Also, as in the well known thalidomide case, unfortunate drug toxicity was caused by the use of an enantiomer mixture (racemic mixture) including the enantiomer with teratogenicity.
Consequently, in research and development of optically active substances, it is essential to selectively obtain only one enantiomer with the desired physiological activity and chemical reactivity, and optically active substances are used exclusively for this purpose as well. For example, there are known methods wherein a separate optically active substance is added to an enantiomer mixture (racemic mixture) to form a diastereomer, and methods of separating optically active substances (optical separation) using chromatography with the optically active substance supported on a solid phase. Also, research is being ardently pursued using various optically active asymmetric reagents for the purpose of asymmetric synthesis of one optically active enantiomer and asymmetric reduction or oxidation to obtain the desired optically active substance.
A large number of optically active substances (asymmetric molecules or asymmetric compounds) have been discovered toward achieving these purposes, and attempts have also been made at their synthesis by artificial molecular design, but most of these are expected to be asymmetric based on the presence of symmetry elements, with point symmetry or face symmetry. Furthermore, most conventional optically active substances are suited entirely for specific uses, and few can provide useful units as building blocks for constructing various optically active substances. For example, no optically active substances have been found which can be expected to provide materials which function as asymmetric reduction reagents or asymmetric oxidation reagents while also being useful as pharmaceuticals and research reagents by interaction with complicated biological substances such as DNA.

Aromatic condensation compounds useful as optically active building blocks

Japan Science and Technology Corporation


An electrical connector includes a connector body and an array of posts extending out at least one side of the connector body. Each of the posts defines a tip and two opposed pairs of post faces that intersect at edges extending along the post. The tip defines four tip faces which converge toward a tip nose, and each tip face is aligned with a respective one of the post faces. Each of the tip faces is convex outwardly, and the edges between the post faces adjacent the tip are curved with a radius of curvature greater than about 0.005 inches. The electrical connector is assembled by press fitting the posts through pre-formed through holes, and the tip geometry reduces skiving of material out of the through hole as well as assembly forces.

This invention relates to electrical connectors of the type having a connector body and a plurality of posts extending out of at least one side of the connector body. In particular, this invention relates to an improved tip geometry for such posts.
In the past, posts have been press fit into connector bodies such as pin headers. Pin headers often include either shrouded or shroudless plastic bodies which define preformed through holes into which the posts are press fit for retention in order to form a header assembly. The dimensions of the through holes and the posts are selected such that the corners of the posts interfere with the through holes, thereby retaining the posts in the connector body by a force fit.
In the past, problems have arisen during assembly of posts into such connector bodies. The assembly force required to push a post through a through hole may be undesirably high, and longer posts have experienced buckling due to excessively high assembly forces. Cracking of the plastic body of the connector has also occurred due to large interference forces, which may result in broken shrouds or loose posts. Additionally, plastic material may be skived or driven out of the through hole, accumulating on the tip of the post as it is pushed through the through hole. Such plastic material tends to accumulate on the post tip proper, and can lead to undesirable side effects when soldering the header assembly to a printed circuit board. Poor solder joints have been experienced.

Electrical connector with posts having improved tip geometry


An electronic control system and a device is disclosed proving improved control and diagnostics of glow plugs as are typically energized in diesel engines prior to and during cold start and also during engine warmup, especially for motor vehicles under human operator control. These improved control functions result in: Increased life of the glow plugs, longer service life, greater reliability, a simplified maintainence diagnostic interface, greater diagnostic capability, reduced emission of undesirable hydrocarbons, reduced unburned fuel as white smoke, more complete fuel combusion, reduced lubricating oil contamination, quiter and smoother operation, increased engine power, reduced fuel consumption, and quicker engine warmup all by controlling power applied to the glow plugs based upon electronically controlled fixed and/or adaptive functional algorithms based upon input variables such as battery voltage, glow plug voltages, glow plug currents, engine temperature based upon algorithms which can correct for sensing system hysteresis and time lag, ambient air termperature ambient air density, ambient air humidity, fuel injector duration and timing, intake mass air flow, exhaust gas composition, exhaust gas temperature, alternator output, engine speed, engine torque, engine power, engine compression, engine age, fuel type, and the like for affecting an on and off cycling using open loop control and/or closed loop feedback control of glow plug power so as to maintine glow plugs more closely within an optimal temperature range specific to engine system operational conditions and consistent with improved glow plug life.

Diesel engines are substantially different from the standard 4 or 2 cycle, sparked ignition internal combusion engines. The diesel engine does not have a sparking device such as a standard spark plug. Fuel is ignited when fuel and hot compressed air are mixed in the engine cylinder(s). For this ignition to occur efficiently, the engine must be brought to a temperature at or above a given minimum operating temperature, i.e. a cold diesel engine will not achieve ignition and run efficiently.
A preferred method for heating a diesel engine prior to initial startup is to use electric "glow plug" heaters. These heaters serve to bring the diesel engine up to an efficient operating temperature before the engine is started. Ideally glow plug heaters will rapidly bring a diesel engine up to a desired starting temperature in a "pre-glow" period. After the engine has started, the glow plugs will go into an "after glow" period where they will operate sufficiently long to maintain desired engine temperature until engine self-heating reaches an efficient sustain point. The glowplugs also enable the engine to run smoothly during an initial idle and minimize emission of white smoke due to incompletely burned fuel. Once an engine can sustain its operating temperature, the glow plug is turned off.
U.S. Pat. No. 4,882,370 to Arnold et al shows a solid state microprocessor controlled device for regulating certain aspects of glow plug performance. The Arnold circuitry adjusts the duty cycle of glow plugs as a function of temperature, regulates preglow function, and detects undesirable short circuits and open circuits for implementing a disable function. U.S. Pat. No. 4,300,491, to Hara et al., achieves a variable time control of the preglow period by means of a plurality of transistors and diodes. Van Ostrom, U.S. Pat. No. 4,137,885 describes means for cyclicly interrupting a glow plug energizing circuit when a maximum temperature is reached. Cooper, U.S. Pat. No. 4,312,307 describes circuitry for control of the duty cycle of glow plugs by means of heat-sensitive switches.


A composition and method for the rapid elimination of fat from the human body, prior to digestion, is provided. A quantity of the chemical composition is intended to be ingested by humans, preferably with a glass of water prior to each meal, to aid in absorbing and binding fat, prior to its being digested, so that it may be rapidly eliminated from the human body, instead of stored as fat within the body. In a preferred embodiment the composition comprises at least one fibrous agent, and ideally, psyllium, in an amount of generally about 50% by weight of the composition, and an amount of glucosamine, preferably glucosamine HCL, at generally about 40% by weight of the composition, and amounts of glucomannan, apple pectin, and stearic acid forming the other generally about 10% by weight of the composition.

1. Field of the Invention
The present invention relates to a chemical composition and a method of treatment for accomplishing weight loss by a human ingesting the chemical composition in recommended dosages prior to eating a meal, thereby facilitating the absorption and binding of undigested fat to a fibrous agent for rapid elimination from the human body.
2. Description of the Related Art
In this day and age, many people's lifestyles have become less physically active. A natural result of a sedentary lifestyle is the tendency to gain weight, which is further compounded by the modern day tendency of many people to consume food which has a high fat content. Indeed, it is commonly thought that many people are now over-weight or at least moderately obese, and such individuals typically suffer from certain health problems associated with such conditions, at least at some later point in life, if not sooner than expected. Due to this trend, countless efforts have been made to help people control their weight. As a few examples, many have proclaimed to have won the "battle of the bulge" with a specific diet program or a particular exercise program. Others in the scientific arena formulated sugar substitutes and are pursuing fat substitutes as methods to reduce the caloric intake of an individual hopefully without, sacrificing the taste of otherwise highly fattening foods. While these efforts are generally capable of aiding many in their fight to lose weight and establish a healthier life style, many such attempts are generally ineffective or simply not practical. For example, some good meaning souls have tried in earnest to follow a particular diet plan but eventually, deviate from the plan because of lack of will-power in continue a given program for weeks or months at a time. Finally, some view sugar substitutes as being tasteless or carrying an intolerable health risk, given that some studies have linked them to carcinogens and/or the formation of brain tumors.
It has been appreciated in recent years that the fat content of foods which people eat are a major culprit behind human weight gain. For example, regardless of the type of fat present in a food product, fat has the highest caloric value per gram--about 9 calories per gram--of any food group. It is understood that the body tends to store fat for future use, rather than to utilize it immediately, and this factor helps lead to weight-gain. Unfortunately, fat also makes many food items more tasty--whether butter on bread, dressings on salads, sour cream on potatoes, or frosting on cake--and are therefore, difficult to eliminate entirely from one's diet. Thus, fat usually finds its way into the body. Once it does so, a healthy body automatically proceeds with the digestion process by the secretion of lipase, an enzyme that accelerates synthesis of fats, i.e., breaking down the fat molecule. The majority of all fats in foods are present in "triglyceride form", which the body seeks to break down by removing the glycerol molecule from the triglyceride and thereby, release the free fatty acids. Once this occurs, the body is well on its way to absorbing and storing the fat instead of utilizing it for energy.
From the foregoing, it will be understood that there remains an appreciable need in the art for a product and attendant safe and easy method of treatment which facilitates a person's efforts to lose weight. Any such product and method should be capable of aiding a person in accomplishing this goal without relying exclusively on a person's having sufficient will-power to maintain a strict diet and/or a rigorous exercise program. In addition, any such product and method should not interfere with the taste of foods. Ideally, any such product or method would permit a person to eat the foods that they most like, while not being as mindful about the amount of fats contained therein, and further, would prevent the body from absorbing the fat in such foods once they have been eaten. Any such product and method would ideally also aid the body in rapid elimination of the ingested fats in a safe, comfortable and natural manner. The present invention is designed to satisfy these and other needs which remain in the art and is believed to represent a significant advance in improving a person's health while facilitating weight loss by means of the rapid elimination of fat from the human body.

Chemical composition and method for more rapidly aiding the absorption, binding an elimination of undigested fat in the human body


An IPS LCD (100) includes a first and a second substrates (110, 120) opposite to each other, and a liquid crystal layer (130) sandwiched therebetween. A first polarizer (111) is disposed at an outer surface of the first substrate, and a second polarizer (121) is disposed at an outer surface of the second substrate. Polarizing axes of the first and second polarizers are parallel to each other. A plurality of pixel electrodes (160) and common electrodes (170) are disposed at the second substrate. A first alignment layer (114) is disposed at an inner surface of the first substrate, and a second alignment layer (124) is disposed at an inner surface of the second substrate. The first alignment layer maintains a rubbing direction of approximately 90° relative to the second alignment layer, and the second alignment layer has an anchoring strength greater than that of the first alignment layer.

Liquid crystal displays (LCDs) are typically used as the information display in various devices such as computers and vehicle and airplane instrumentation. One type of LCD called the twisted nematic liquid crystal display (TN-LCD) often has the drawback of a narrow range of viewing angles. Thus an improved design called the in-plane switching liquid crystal display (IPS LCD) has been developed in order to provide a broad range of viewing angles. The IPS LCD typically has a plurality of common electrodes and a plurality of pixel electrodes all disposed on one of two opposite substrates, for driving liquid crystal molecules contained in a liquid crystal layer between the two substrates. The resulting electric field is substantially planar and parallel to surfaces of both substrates. The IPS LCD typically has a broad range of viewing angles.
According to the particular electrode array of its pixel electrodes and common electrodes, an IPS LCD can be classified as a single-domain type or a two-domain type. FIG. 6 is a schematic, exploded isometric view of a typical IPS LCD 10. The IPS LCD 10 includes a first substrate 11, a second substrate 12 opposite to the first substrate 11, and a liquid crystal layer 13 sandwiched between the substrates 11, 12. The liquid crystal layer 13 includes a multiplicity of liquid crystal molecules 18. A first and a second polarizers 14, 15 are formed at outer sides of the substrates 11, 12 respectively. A plurality of pixel electrodes 16 and common electrodes 17 are disposed parallel to each other at an inner surface of the second substrate 12. A first alignment layer (not shown) is disposed at an inner surface of the first substrate 11. A second alignment layer (not shown) is disposed at the inner surface of the second substrate 12, the second alignment layer covering the pixel and the common electrodes 16, 17. Original rubbing directions of the first alignment layer and the second alignment layer are parallel to each other. Long axes of the liquid crystal molecules 18 adjacent to the alignment layers are approximately parallel to the first and the second substrates 11, 12. Polarizing axes of the first and second polarizers 14, 15 are perpendicular to each other.
When no voltage is applied to the pixel and common electrodes 16, 17, the long axes of the liquid crystal molecules 18 maintain an angle relative to the pixel and common electrodes 16, 17. Light beams are emitted from a back light module (not shown) below the second substrate 12. When the light beams pass through the liquid crystal layer 15, their polarizing directions do not change, and the light beams are absorbed by the first polarizer 14. Thus the IPS LCD 10 is in an "off" state, and cannot display images.
As shown in FIG. 7, when a voltage is applied to the pixel and common electrodes 16, 17, an electric field E1 is generated between the pixel and common electrodes 16, 17. A direction of the electric field E1 is parallel to the second substrate 12, and perpendicular to the pixel and common electrodes 16, 17. The long axes of the liquid crystal molecules 18 twist to align in the direction of the electric field E1. When light beams pass through the liquid crystal layer 13, the polarization state of the light beams is converted to match the polarizing axis of the first polarizer 14. Thus the light beams pass through the first polarizer 14 to display images, and the IPS LCD 10 is in an "on" state.
When the voltage is applied, all the liquid crystal molecules 18 are aligned in the same new direction according to the electric field E1. When the voltage is switched off and the IPS LCD 10 returns to the "off" state, the liquid crystal molecules 18 twist to align in the original direction according to the first and second alignment layers. The amount of time needed for all the liquid crystal molecules 18 to realign is relatively long. This means that the response time of the IPS LCD 10 is unduly long.
What is needed, therefore, is an IPS LCD which overcomes the above-described problems.

In-plane switching liquid crystal display having fast response time


There is disclosed 103 novel methylation-altered DNA sequences (“marker sequences”) that have distinct methylation patterns in cancer, compared to normal tissue. In many instances, these marker sequences represent novel sequences not found in the GenBank data base, and none of these marker sequences have previously been characterized with respect to their methylation pattern in human cancers including, but not limited to those of bladder and prostate. These 103 sequences have utility as diagnostic, prognostic and therapeutic markers in the treatment of human cancer, and as reagents in kits for detecting methylated CpG-containing nucleic acids.

The identification of early genetic changes in tumorigenesis is a primary focus in molecular cancer research. Characterization of the nature and pattern of cancer-associated genetic alterations will allow for early detection, diagnosis and treatment of cancer. Such genetic alterations in vertebrates fall generally into one of three categories: gain or loss of genetic material; mutation of genetic material; or methylation at cytosine residues in CpG dinucleotides within "CpG islands." Among these, DNA methylation is uniquely reversible, and changes in methylation state are known to affect gene expression (e.g., transcriptional initiation of genes where CpG islands located at or near the promoter region) or genomic stability.
Methylation of CpG dinucleotides within CpG islands. DNA, in higher order eukaryotic organisms, is methylated only at cytosine residues located 5′ to guanosine residues in CpG dinucleotides. This covalent modification of the C-5 position of the cytosine base by the enzyme DNA (cytosine-5)-methyltransferase results in the formation of 5-methylcytosine (5-mCyt), and gives this base unique properties (e.g., susceptibility to undergo spontaneous deamination). This enzymatic conversion is the only epigenetic modification of DNA known to exist in vertebrates, and is essential for normal embryonic development (Bird, A. P., Cell 70:5-8, 1992; Laird & Jaenisch, Human Molecular Genetics 3:1487-1495, 1994; Li et al., Cell 69:915-926, 1992).
The presence of 5-mCyt at CpG dinucleotides has resulted in the 5-fold depletion of this sequence in the genome during the course of vertebrate evolution (Schroderet & Gartler, Proc. Nat. Acad. Sci. USA 89:957-961, 1992), presumably due to spontaneous deamination of 5-mCyt to Thymidine. Certain areas of the genome, however, do not show such depletion, and are referred to as "CpG islands" (Bird, A. P., Nature 321:209-213, 1986; Gardiner-Garden & Frommer, J. Mol. Biol. 196:261-282, 1987). These CpG islands comprise only approximately 1% of the vertebrate genome, yet account for about 15% of the total number of genomic CpG dinucleotides (Antequera & Bird, Proc. Nat. Acad. Sci. USA 90:11995-11999, 1993). CpG islands contain the expected (i.e., the non-evolutionarily depleted) frequency of CpGs (with an Observed/Expected Ratio1>0.6), are GC-rich (with a GC Content2>0.5) and are typically between about 0.2 to about 1 kb in length. 1Calculated as: [number of CpG sites/(number of C bases×number of G bases)]×band length for each fragment.2 Calculated as: (number of C bases+number of G bases)/band length for each fragment.
Methylation within CpG islands affects gene expression. CpG islands are located upstream of many housekeeping and tissue-specific genes, but may also extend into gene coding regions (Cross & Bird, Current Opinions in Genetics and Development 5:309-314, 1995; Larsen et al., Genomics 13:1095-1107, 1992). The methylation of cytosines within CpG islands in somatic tissues is believed to affect gene expression. Methylation has been inversely correlated with gene activity and may lead to decreased gene expression by a variety of mechanisms including inhibition of transcription initiation (Bird, A. P., Nature 321:209-213, 1986; Delgado et al., EMBO Journal 17:2426-2435, 1998), disruption of local chromatin structure (Counts & Goodman, Molecular Carcinogenesis 11:185-188, 1994; Antequera et al., Cell 62:503-514, 1990), and recruitment of proteins that interact specifically with methylated sequences and thereby directly or indirectly prevent transcription factor binding (Bird, A. P., Cell 70:5-8, 1992; Counts & Goodman, Molecular Carcinogenesis 11:185-188, 1994; Cedar, H., Cell 53:3-4, 1988). Many studies have demonstrated the effect of methylation of CpG islands on gene expression (e.g., the CDKN2A/p16 gene; Gonzalez-Zulueta et al., Cancer Research 55:4531-4535, 1995), but most CpG islands on autosomal genes remain unmethylated in the germline, and methylation of these islands is usually independent of gene expression. Tissue-specific genes are typically unmethylated in the respective target organs but are methylated in the germline and in non-expressing adult tissues, while CpG islands of constitutively expressed housekeeping genes are normally unmethylated in the germline and in somatic tissues.
Methylation within CpG islands affects the expression of genes involved in cancer. Data from a group of studies show the presence of altered methylation in cancer cells relative to non-cancerous cells. These studies show not only alteration of the overall genomic levels of DNA methylation, but also changes in the distribution of methyl groups. For example, abnormal methylation of CpG islands that are associated with tumor suppressor genes or oncogenes within a cell may cause altered gene expression. Such altered gene expression may provide a population of cells with a selective growth advantage and thereby result in selection of these cells to the detriment of the organism (i.e., cancer).
Insufficient correlative data. Unfortunately, the mere knowledge of the basic existence of altered methylation of CpG dinucleotides within CpG islands of cancer cells relative to normal cells, or of the fact that in particular instances such methylation changes result in altered gene expression (or chromatin structure or stability), is inadequate to allow for effective diagnostic, prognostic and therapeutic application of this knowledge. This is because only a limited number of CpG islands have been characterized, and thus there is insufficient knowledge, as to which particular CpG islands, among many, are actually involved in, or show significant correlation with cancer or the etiology thereof. Moreover, complex methylation patterns, involving a plurality of methylation-altered DNA sequences, including those that may have the sequence composition to qualify as CpG islands, may exist in particular cancers.
Therefore there is a need in the art to identify and characterize specific methylation altered DNA sequences, and to correlate them with cancer to allow for their diagnostic, prognostic and therapeutic application.

Methylation altered DNA sequences as markers associated with human cancer


A system securing a plurality of tape pancakes includes a compressible baffled core support on which the pancakes can be mounted. An interior rod having a head fits and is received within the baffled core support. A nub on the inside surface of the core support engages a groove on the outside surface of the interior rod to provide a threaded engagement between the interior rod and the core support. Rotation of the interior rod within the core support after the head contacts the end of the core support provides an axial compression load onto the core support to hold together the pancakes. This axial compression also expands the baffles which contact and tighten against the inside of the tape pancake cores and provide a radial force to secure the pancakes in place.

In producing magnetic recording media, there is a recurring need to transport large quantities of recording tape from the point of tape manufacture to other locations for final loading into cassettes, cartridges, or other carriers. It is common to transport the tape in the form of relatively large rolls, called "pancakes." A pancake of 1.27 cm (0.5 in) wide tape is typically wound on a hollow annular core having an outer diameter of 11.4 cm (4.5 in), and a width of 1.8 cm (0.7 in), slightly larger than the width of the tape. The outer diameter of the pancakes is typically about 35.6-40.7 cm (14-16 in). Shipping these tape pancakes over long distances under conditions of mechanical shock and vibration requires that they be well supported.
One primary form of damage to pancakes is axial shifting of the layers of tape relative to the pancake such that the pancake is no longer flat. This shifting, called core drop, hub drop, popped strands, or tape shift, can be caused by a stack of pancakes being dropped on a hard floor or being transported over rough or bumpy surfaces. Other problems and damage caused with known pancake containers include the offsetting of a portion of the pancake, called "upset," rotation of the core relative to the pancake, and transfer of cushion adhesive to the tape.
While effective protection of the tape in the pancake stacks is essential, the magnetic tape market is very price-competitive. Thus, protective packaging must be low cost, both in the packaging material itself, and in the labor required to apply and remove the packaging. It is also desirable to minimize the amount of packaging waste material which is discarded.
Known methods of protecting pancakes during shipping generally involve sliding several pancakes over a shaft or hollow tube, placing resilient spacers between each pancake, and placing a solid end plate on the top and bottom of the stack. The stack can be held together by shrink wrap film, as disclosed in U.S. Pat. No. 4,955,471.
U.S. Pat. No. 4,883,178 eliminates shrink wrap and discloses holding a pancake stack together with a threaded member running coaxially along the center of the stack, and a nut which tightens on an end plate. The compression is created by the threaded member being disposed within the pancake cores.
U.S. Pat. No. 4,708,246 discloses spacers and other packaging features which improve compression control. However, sometimes spacers move during shipping and can generate debris. Also, some spacer materials can create static which attracts debris to the pancakes.
Radially expanding mandrels are also known. U.S. Pat. No. 4,124,173 discloses an inflatable tube inside of an expandable mandrel. Cam mechanisms which press cylinder segments outwardly when a central shaft rotates relative to the outer segments are also known. U.S. Pat. No. 4,516,786 discloses a rotatable core chuck and U.S. Pat. No. 4,730,779 disclose an expanding assembly for a web-coiling core.
U.S. Pat. No. 5,094,346 assigned to Minnesota Mining and Manufacturing Company stacks pancakes on a mandrel within a container. The mandrel could radially expand to secure the pancakes and/or the pancakes could be secured by axial pressure.


In an approach to attesting control over network devices, responsive to receiving a first signal from a client, wherein the first signal initiates a network connection between the client and a server, a first certificate is sent to the client that contains a common name that is an internet protocol (IP) address. A second certificate is sent to the client that contains a common name that is a uniform resource locator (URL) of the server. Responsive to receiving a second signal from the client that the first certificate and the second certificate are trusted, the client is connected with the server.

The present invention relates generally to the field of cryptographic mechanisms for secure communication, and more particularly to attesting control over network devices.
Transport Layer Security (TLS), and its now-deprecated predecessor, Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communications security over computer networks, including the Internet. A primary use case of TLS is encrypting the communication between web applications and web servers, such as a web browser connecting to a website. TLS is also used to encrypt other communications such as email, messaging, and Voice over Internet Protocol (VoIP).
TLS can be used on top of a transport-layer protocol like Transmission Control Protocol (TCP). There are three main components to TLS, namely encryption, authentication, and integrity. Encryption encodes the data being transferred to and from third parties. Authentication ensures that the parties exchanging information are who they claim to be. Integrity verifies that the data has not been forged or tampered with.
The TLS protocol aims primarily to provide privacy (security) and data integrity between two or more communicating computer applications. The connection is private (or secure) because symmetric cryptography is used to encrypt the data transmitted, where the keys for this symmetric encryption are based on a shared secret that was negotiated at the start of the session during the TLS handshake. The TLS handshake establishes a cypher suite for each communication session. The cypher suite is a set of algorithms that specifies details such as which shared encryption keys, or session keys, will be used for that particular session.

International Business Machines Corporation


Methods and systems for managing energy sources and energy consumers in an integrated system are provided. Certain subject matter presented herein relates to automatically scheduling jobs and their sub-tasks to maximize profit by comparing power source configurations and determining the best job schedule for the power source configurations. This system broadly involves two sub-problems: determining the best power source configuration and determining the best job schedule for the given power source configuration.

The subject matter described herein generally relates to managing energy sources and energy consumers in an integrated system, such as a microgrid energy system. Certain subject matter presented herein relates to automatically scheduling jobs and their sub-tasks to maximize profit by comparing power source configurations and determining the best job schedule for the power source configurations.
A microgrid is an integrated energy system consisting of interconnected loads and distributed energy resources which can operate in parallel with the main power grid or as an independent, separate energy grid. Microgrids can be independent from the main power grid because they are able to generate their own energy using local alternate energy sources, such as photovoltaic, wind turbines, and diesel power generators to power the loads in the system.
The recent increase in popularity of microgrids is due to the strong interest in reliable and clean energy sources. In particular, microgrids offer the following benefits: (1) reduced cost, since many utility companies are introducing time of use pricing, microgrids reduce the cost of energy by using local energy sources when cost of grid energy is high, (2) increased reliability, because having local energy sources improves reliability and reduces the dependence on the main power grid, (3) reduction of environmental impact through use of cleaner energy sources, and (4) increased energy security through the geographical dispersal of power resources.
As such, existing microgrids are able to provide users with more reliable energy sources that are not as susceptible to problems occurring in the main power grid. In addition, microgrids are able to provide cost savings to users because microgrid energy sources can be used instead of the main power system when it is more cost effective to be off of the main grid, such as during times of peak energy consumption.
In addition, existing microgrid technology has been used to perform some basic management of energy consuming devices based upon historical data, weather forecasts, and consumer demands on the main power grid. However, such existing microgrid technology has been focused on scheduling upper level energy consumers and jobs based upon straightforward cost calculations which do not take account of profit or job sub-tasks.

Management of power sources and jobs in an integrated power system

INTERNATIONAL BUSINESS MACHINES CORPORATION


A semiconductor device comprising a substrate, a conductor and an insulating film provided on the surface of the substrate, part of the surface of the substrate being electrically connected with the conductor through a contact hole made in the insulating film, wherein a barrier layer present between part of the surface of the substrate and the conductor is provided only on the bottom of the contact hole, and the barrier layer provided on the bottom comprises amorphous titanium silicon nitride.

1. Field of the Invention
This invention relates to a semiconductor integrated-circuit device used in microprocessors, DRAMs (dynamic random access memories), theoretical circuits and so forth, and more particularly to a semiconductor device characteristic of structure at its contact holes. It also relates to a process for forming amorphous titanium silicon nitride on a substrate.
2. Related Background Art
FIG. 11 is a schematic cross-sectional view at the part of a contact hole of a conventional semiconductor integrated-circuit device.
On the surface of a substrate 1 such as a silicon wafer, an insulating film 2 is formed where the contact hole has been formed. A barrier layer 4 is formed on the surface of the insulating film 2 inclusive of that on the sidewall of the contact hole and on the substrate surface to which the bottom of the contact hole is laid bare. A conductive layer 8 such as an Alxe2x80x94Cu or Alxe2x80x94Sixe2x80x94Cu layer is formed on the barrier layer 4.
The aluminum (Al) which is an element constituting the conductive layer 8 that functions as an electrode or wiring tends to react with the silicon (Si) which is an element constituting the substrate. Hence, in order to prevent such reaction, the barrier layer 4 is provided between the substrate and the conductive layer. Titanium nitride (TiN) is used in the barrier layer.
FIG. 12 shows an example of a contact hole disclosed in Japanese Patent Application Laid-Open No. 8-274173.
In this example, two layers, a titanium (Ti) layer 3 and a TiN barrier layer 4, are formed on the insulating film 2 and the sidewall and bottom of the contact hole, and a W (tungsten) wiring 9 is formed in the contact hole. A TiN layer 5, a Ti layer 6 and TiN layer 7 are further provided as a triple diffusion barrier for preventing the wiring 8 formed of Alxe2x80x94Cu or the like from reacting with the tungsten wiring 9.
FIG. 13 shows a structure disclosed in Japanese Patent Application Laid-Open No. 8-316233. This structure is basically the same as the prior art shown in FIG. 11, except that an insulating film 10 of silicon nitride (SiN) is formed on the surface of the substrate 1 and an insulating film 2 having contact holes is formed thereon.
In all the prior art described above, the barrier layer 4 is so provided as to cover the whole substrate surface, i.e., the surface of insulating film 2 and the sidewall and bottom of each contact hole.
Then the barrier layer has a thickness of from 30 nm to 50 nm. Hence, if the contact hole has a side length smaller than 0.25 xcexcm, the inside of the contact hole may come to be substantially filled up with the barrier layer 4, resulting in a high contact resistance. For example, a barrier layer of 50 nm thickness is formed in a contact hole of 0.18 xcexcm in side length, the inside of the contact hole is half or more held by the barrier layer.
Accordingly, it is desired to form the barrier layer comprised of TiN, only on the bottom of the contact hole, i.e., only on the surface of the substrate 1 which is laid bare at the contact hole. However, any growth process for such selective formation is unknown.
Under such circumstances, a method is available in which, using titanium silicon nitride (TiSiN) in place of TiN, a barrier layer comprised of TiSiN is formed only on the bottom of the contact hole.
FIG. 14 shows how it stands.
A titanium silicide (TiSi2) film 11 is formed on the surface of a substrate 1, and an insulating film 2 having a contact hole is formed on the titanium silicide film 11. Then a titanium silicon nitride (TiSiN) 12 is formed only on the bottom of the contact hole. No titanium silicon nitride is present on the sidewall of the contact hole.
This structure can be set up by forming the TiSi2 film on the substrate comprised of silicon (Si), forming the insulating film thereon, making the contact hole, and then nitriding the Ti uncovered surface, laid bare to the bottom of the contact hole (H. Shinriki et al., Extended Abstracts on SSDM (1994), p.946).
However, this method has a possibility of causing impurities to be sucked up into TiSi2 as a result of high-temperature heat treatment.
Meanwhile, as a method different from the above selective film formation on the contact hole bottom surface, Extended Abstracts of The 43rd Spring Meeting (1996), The Japan Society of Applied Physics and Related Societies, page 673, 26p-Q-4, discloses a method in which a TiSiN film is formed over the whole substrate surface at a low temperature. In this method, the TiSi2 film is formed on the silicon substrate in a thickness of 70 nm, and the back thereof is exposed to nitrogen (N2) plasma. It is done at an N2 pressure of 80 mTorr and an applied power of 300 W.
However, the TiSiN film thus obtained by N2 plasma processing at a pressure of 80 mTorr and a temperature of 50xc2x0 C. is, as will be detailed later, a coarse crystalline film in which titania (TiO2) is much produced, and can not be made into a uniform continuous film if it is formed in a thin film of about 10 nm. Moreover, it has been found that this coarse crystalline TiSiN film may cause a low film quality for the conductor film to be deposited thereon. Hence, the TiSiN film formed by this method is not suitable for its working according to the design criterion of a minimum working size of less than 0.25 xcexcm.
An object of the present invention is to provide a structure having a barrier layer with a low contact resistance.
Another object of the present invention is to provide a structure that can attain a good electrical conduction even at fine contact holes of smaller than 0.25 xcexcm in side length.
Still another object of the present invention is to provide a structure having a barrier layer that enables formation of a conductor film of good quality on the barrier layer.
A further object of the present invention is to provide a process for forming by CVD (chemical vapor deposition) a titanium silicon nitride film that can form a good barrier layer.
The semiconductor device according to the present invention is a semiconductor device comprising a substrate, a conductor and an insulating film provided on the surface of the substrate, part of the surface of the substrate being electrically connected with the conductor through a contact hole made in the insulating film, wherein;
a barrier layer present between part of the surface of the substrate and the conductor is provided only on the bottom of the contact hole; and
the barrier layer provided on the bottom comprises amorphous titanium silicon nitride.
The process for forming amorphous titanium silicon nitride according to the present invention is a process for forming amorphous titanium silicon nitride on the surface of a substrate, comprising the steps of:
a) forming titanium silicide on the surface of the substrate; and
b) exposing the titanium silicide formed on the surface of the substrate, to nitrogen plasma while maintaining the temperature of the substrate within the range of from 200xc2x0 C. to 450xc2x0 C. and keeping the inside of a reaction chamber at a pressure of 13.3 Pa or above, to form the amorphous titanium silicon nitride.
The process for forming amorphous titanium silicon nitride according to the present invention is also a process for forming amorphous titanium silicon nitride on the surface of a substrate provided in a reaction chamber, comprising the step of introducing a tetradiethylaminotitanium gas and an Si2H6 gas into the reaction chamber while maintaining the substrate temperature within the range of from 200xc2x0 C. to 450xc2x0 C. and keeping the inside of the reaction chamber at a pressure of from 13.3 Pa to 267 Pa, to form the amorphous titanium silicon nitride on the substrate.

Process for forming amorphous titanium silicon nitride on substrate

Abstract: This can provide a structure that has a barrier layer with a low contact resistance, enables formation of a conductor film of good quality on the barrier layer, and can attain a good electrical conduction even at fine contact holes.


The present disclosure relates to a hydraulic system of a construction machine. The hydraulic system of the construction machine includes: an electronic proportional pressure reducing valve configured to control a flow rate, to which a maximum pressure is input as a control current value, and which is set to a minimum flow rate; a gear pump configured to provide pilot operation oil to the EPPRV; a shuttle valve configured to compare a pressure of first pilot operation oil passing through the EPPRV and a pressure of a flow rate control signal, and output second pilot operation oil having the greater pressure; a hydraulic pump of which a swash plate angle is controlled by the second pilot operation oil; and a pump control device configured to control a pressure of the EPPRV to be decreased from a maximum pressure by a predetermined inclination when the flow rate control signal is generated.

In general, a hydraulic system discharges operation oil from a hydraulic pump, and the operation oil stands by at an inlet of a main control valve. A plurality of spools is provided inside the main control valve, and a plurality of actuators is connected to the outside of the main control valve. Further, pilot pressure, which is a flow rate control signal, is generated in a flow rate demanding unit, such as a joystick and a pedal, and the pilot pressure is provided to the main control valve. In the main control valve, a specific spool is opened/closed by the pilot pressure, and the operation oil is provided to an actuator connected to the corresponding spool by an opening/closing operation of the corresponding spool.
That is, the operation oil discharged from the hydraulic pump is provided to the actuator via the main control valve according to an operation of the joystick, and thus the actuator is operated.
In the meantime, the hydraulic pump receives power from an engine, and the engine combusts fuel to generate power.
Hereinafter, a hydraulic system of a construction machine adopting a mechanical hydraulic pump will be described with reference to accompanying FIG. 1.
FIG. 1 is a diagram for describing a hydraulic system for a construction machine.
A mechanical hydraulic pump 10 includes a swash plate r, and a discharged flow rate is controlled to be increased and decreased according to an inclination angle of the swash plate. The inclination angle of the swash plate is adjusted by a pump regulator 40.
Operation oil discharged from the hydraulic pump 10 is provided to a main control valve 20, and when a specific spool is operated in the main control valve 20, the aforementioned operation oil is provided to an actuator 30 connected to the corresponding spool. The actuator 30 receiving the operation oil is operated to perform a desired operation.
In the meantime, a worker generates a flow rate control signal by operating a joystick, a pedal, and the like. The flow control signal moves a specific spool in the main control valve 20 according to a flow rate control signal line pi.
That is, when the worker operates the joystick, the flow rate control signal operates the spool of the main control valve 20 to open/close the spool, and when the corresponding spool is opened, the operation oil is provided to the actuator 30, so that the actuator 30 performs a desired operation.
In the meantime, the hydraulic pump 10 receives power from an engine 100. The engine 100 is controlled under control of an engine control device 104.
Further, revolutions per minute (rpm) of the engine 100 may be set by an engine rpm controller 102 in advance, and the rpm may be changed by a command of a pump control device 50.
When the command of the rpm is input to the engine control device 104, the engine control device 104 operates an engine governor 106 to make fuel be provided to the engine 100. For example, when the command for increasing the rpm is given, the amount of injection fuel is increased, when the command for decreasing the rpm is given, the amount of injection fuel is decreased, and when a specific rpm is desired to be maintained, the amount of injection fuel is constantly maintained.
In the meantime, a gear pump 70, which is an auxiliary pump, is further provided in the hydraulic pump 10. The gear pump 70 provides pilot operation oil to the joystick, the pedal, and the like, and generates a flow rate control signal when the worker operates the joystick and the pedal to transmit a pressure of the flow rate control signal.
In the meantime, a first hydraulic line L1 is connected so that the pilot operation oil discharged from the gear pump 70 passes through an electronic proportional pressure reducing valve 60 to be connected to a shuttle valve 80. One side of the shuttle valve 80 receives a flow rate control signal pi. The shuttle valve 80 selects a larger pressure between a pressure of the first hydraulic line L1 and the pressure of the flow rate control signal line, and provides the selected pressure to a pump regulator 40 through a second hydraulic line L2.
The aforementioned electronic proportional pressure reducing valve 60 receives a control signal from the aforementioned pump control device 50 through a first signal line s1. Particularly, when an optional operation (ex. a breaker/shear) is performed in the construction machine, a higher pressure is output by comparing the pilot pressure of the flow rate control signal line pi with a pressure corresponding to a flow rate set for the optional operation by using the electronic proportional pressure reducing valve 60 to control the flow rate.
Hereinafter, the pump regulator 40 for controlling the hydraulic pump 10 will be described with reference to FIGS. 1 and 2.
FIG. 2 is a diagram for describing a control of the mechanical hydraulic pump in the hydraulic system of the construction machine.
The control of the mechanical hydraulic pump 10 includes a flow control, a constant horse power control, and a power shift control, and will be described in detail based on each control.
[Flow Control]
The flow control generates a demanded flow rate by operating the joystick, and the flow rate control signal pi corresponding to displacement of an operation of the joystick is generated by the flow control. For example, when the flow rate control signal pi is increased from p1 to p2 as illustrated in FIG. 2A, the pump regulator 40 controls a flow rate Qp to be increased from q1 to q2 by adjusting the swash plate r. Accordingly, a discharged flow rate of the hydraulic pump 10 is increased.
[Constant Horse Power Control]
The constant Horse power control controls a constant pump horse power, which is set by receiving a load pressure Pd, to be maintained.
In the constant horse power control, a correlation between the pressure and the flow rate is set as a P-Q map, and the discharged flow rate is changed according to the P-Q map set by receiving the pressure load Pd applied to a hydraulic line between the hydraulic pump 10 and the main control valve 20.
For example, when the load pressure Pd is increased from p1 to p2 as illustrated in FIG. 2B, the pump regulator 40 controls the flow rate Qp to be decreased from q1 to q2 by adjusting the swash plate r. Accordingly, the discharged flow rate of the hydraulic pump 10 is controlled to be decreased, but the pump horse power is constantly maintained.
[Power Shift Control]
The power shift control is a control of adjusting a pump horse power according to a load state of the engine. That is, a plurality of P-Q maps is set in the constant horse power control, and a P-Q map is selected from the plurality of P-Q maps according to a load to control the hydraulic pump. The plurality of P-Q maps receives a command from the pump control device 50 through a second signal line s2.
For example, as illustrated in FIG. 2C, the plurality of P-Q maps may be provided as a heavy load map, a standard load map, and a light load map, and the hydraulic pump is controlled by selecting a specific P-Q map according to a load.
Accordingly, even though the same load pressure Pd is applied, when the heavy load map is selected, a large flow rate corresponding to q1 is discharged. However, when the standard load map is selected, a flow rate corresponding to q2, which is smaller than q1, is discharged. Further, when the light load map is selected, a flow rate corresponding to q3, which is smaller than q2, is discharged.
That is, according to the power shift control, when it is determined that a load of an operation target is large, the P-Q map close to a heavy load is selected, when it is determined that the load of the operation target is general, the standard load map is selected, and when it is determined that the load of the operation target is small, the P-Q map close to a light load is selected, thereby controlling the hydraulic pump 10.
The hydraulic system in the related art, which is configured and operated as described above has problems below.
When the joystick is suddenly operated, so that a large flow rate is suddenly and instantaneously demanded, the hydraulic system becomes temporarily unstable, which will be described with reference to FIGS. 3 and 4.
FIG. 3 is a diagram for describing a change in a flow rate in the constant horse power control in the hydraulic system of the construction machine in the related art. FIG. 4 is a diagram for describing a change in a pump discharged flow rate, a change in an rpm of an engine, and a change in an output of the engine by an operation of the joystick in the hydraulic system of the construction machine in the related art.
As illustrated in FIG. 3, when the pump load pressure Pd is suddenly increased, the flow rate is suddenly increased so as to respond to the sudden increase of the load pressure Pd. However, a capacity of the hydraulic pump 10 is physically limited, so that there is a case where when an excessive flow rate is demanded, the demanded flow rate exceeds a range handled by the hydraulic pump 10, and in this case, the flow rate is controlled to be gradually decreased by the constant horse power control.
That is, the pump load pressure is maintained at the low pressure p1 at an initial stage and the small flow rate q1 is discharged, and when the demanded flow rate is suddenly increased, the flow rate Qp is suddenly increased in comparison with a change in the pump load pressure Pd, so that the flow rate Qp is increased to a maximum flow rate q2, and then, the flow rate is controlled to be decreased by the constant horse power control and thus the decreased flow rate Qp is discharged. Then, the flow rate is stabilized from a stabilization time point t2 while maintaining the high pump load pressure Pd.
As described above, when the joystick is suddenly operated, as illustrated in FIG. 4A, as can be seen from the change in the pump discharged flow rate, a delta flow rate delta Qp is discharged until just before a maximum flow rate immediately after a joystick operation time point t1, and the flow rate is stabilized by the constant horse power control after a predetermined time elapses.
As described above, the excessive operation oil flow rate, which is discharged from a peak portion indicated by the delta flow rate Qp to the stabilization of the hydraulic pump due to the sudden increase in the flow rate generates a hydraulic impact, thereby making the hydraulic system be unstable.
Further, as illustrated in FIG. 4B, investigating a change in the rpm of the engine, large power is instantaneously demanded, but the rpm of the engine is not immediately reflected due to a mechanical dynamic property, and the rpm of the engine is sharply decreased, so that a delta rpm is also decreased. Then, after a speed of a turbo charger is increased and fuel is appropriately injected, the rpm of the engine reaches a target rpm.
That is, in the hydraulic system using the mechanical hydraulic pump 10 in the related art, there is a problem in that when the demanded flow rate is sharply increased, the rpm of the engine is sharply decreased or the engine is stalled.
Further, even when the engine is stalled or the rpm of the engine is sharply decreased as described above, fuel is continuously supplied, thereby degrading fuel efficiency.
The decrease phenomenon of the rpm of the engine will be additionally described with reference to FIG. 4C.
When the demanded flow rate is increased, the hydraulic pump 10 requires larger power, so that the rpm of the engine 100 is increased. However, it is impossible to immediately implement a desired rpm due to the mechanical dynamic property. The reason is that an engine governing section is required until the rpm of the engine is increased. Particularly, a turbo charger time lack section is present in the engine governing section because a predetermined time is inevitably consumed until the turbo charger is rotated from a low speed to a high speed. Accordingly, when the demanded flow rate is suddenly increased, the rpm of the engine is increased within an allowed range of the output of the engine, and is delayed until the turbo charger is normally operated, and the rpm of the engine is increased when the turbo charger normally performs the function.
In the meantime, in a construction machine including the mechanical hydraulic pump in the related art, a rotation speed of the engine is decreased by a hydraulic load when an initial operation is performed, and a controller detects the decrease in the rotation speed of the engine to decrease a pump load through a power shift control (pump power shift control) so as to prevent the rotation speed of the engine from being decreased.
However, the power shift control does not have a method of decreasing a flow rate control of determining a flow rate discharged by a joystick lever or a driving lever, so that there is a problem in that when an initial operation or a sudden operation is performed, the rpm of the engine is decreased.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.

Hydraulic system of construction machine


A static random access memory (SRAM) structure is provided. The structure includes a plurality of SRAM bit cells on a substrate. Each SRAM bit cell includes at least six transistors including at least two NMOS transistors and at least two PMOS transistors. Each of the six transistors is being lateral gate-all-around transistors in that gates wraps all around a cross section of channels of the at least six transistors. The at least six transistors positioned in three decks in which a third deck is positioned vertically above a second deck, and the second deck is positioned vertically above a first deck relative to a working surface of the substrate. A first inverter is formed using a first transistor positioned in the first deck and a second transistor positioned in the second deck. A second inverter is formed using a third transistor positioned in the first deck and a fourth transistor positioned in the second deck. A pass gate is located in the third deck.

In the manufacture of a semiconductor device (especially on the microscopic scale), various fabrication processes are executed such as film-forming depositions, etch mask creation, patterning, material etching and removal, and doping treatments. These processes are performed repeatedly to form desired semiconductor device elements on a substrate. Historically, with microfabrication, transistors have been created in one plane, with wiring/metallization formed above the active device plane, and have thus been characterized as two-dimensional (2D) circuits or 2D fabrication. Scaling efforts have greatly increased the number of transistors per unit area in 2D circuits, yet scaling efforts are running into greater challenges as scaling enters single digit nanometer semiconductor device fabrication nodes. Semiconductor device fabricators have expressed a desire for three-dimensional (3D) semiconductor circuits in which transistors are stacked on top of each other.
As the semiconductor industry transitions to a new device architecture, from finFET to lateral gate-all-around nano-sheet (LGAA NS), there is a significant research focus on the complementary FET device architecture, or CFET. CFET comprises stacking an NMOS device on top of a PMOS device (or vice versa). This physical arrangement takes advantage of the vertical dimension to provide better power, performance and area (PPA) scaling. The CFET architecture considered herein is based on the LGAA NS device architecture, which is nano-sheet stacked on nano-sheet instead of finFET stacked on finFET. In conventional technology, that is, planar bulk and finFET, NMOS and PMOS are built and arranged side-by-side on the same plane of the Si wafer. CFET takes advantage of the vertical dimension to stack the NMOS on top of the PMOS (or vice versa). A vertical common gate between NMOS and PMOS replaces the horizontal gate running from N to P side to make the complementary functions of CMOS.

CFET SRAM bit cell with three stacked device decks


A method for making a blade includes stacking a plurality of modular segments having formed conduits, threading and tensioning cables through the conduits of the stacked segments, and clamping the cables to hold the modular segments together.

This invention relates generally to aerodynamic blades and their uses, as well as methods for making such blades. The blades are particularly useful for wind turbine energy generators, but are not limited to such use.
Blade stiffness and structural strength are critical to wind turbine performance. The size of a continuous blade is not conducive to high quality composite material processing and, therefore, structural performance. At least one known contemporary blade is made from fiberglass/epoxy composite material using full blade-length female tooling. The sheer size of the blade makes it difficult to eliminate all trapped air during the lamination process and to achieve uniform processing conditions (and thus, uniform mechanical and physical properties) along the entire blade length. The likelihood of re-work during manufacturing is high because the cost of scrapping is high. Blade quality may suffer as a result, and the cost of manufacturing is high.

Modular blades and methods for making same


The present invention provides a process for preparing an enzyme catalyst having nitrilase activity for hydrolysis of glycolonitrile to glycolic acid with improved retention of recovered catalyst activity in consecutive batch reactions with catalyst recycle, said process comprising pretreating the enzyme catalyst with glutaraldehyde. The glutaraldehyde-pretreated enzyme catalyst has improved specific activity when compared to non-glutaraldehyde-pretreated enzyme catalysts, and thereby, has improved overall catalyst activity and productivity.

Glycolic acid (HOCH2COOH; CAS Registry Number is 79-14-1) is the simplest member of the α-hydroxy acid family of carboxylic acids. Its properties make it ideal for a broad spectrum of consumer and industrial applications, including use in water well rehabilitation, the leather industry, the oil and gas industry, the laundry and textile industry, as a monomer in the preparation of polyglycolic acid (PGA), and as a component in personal care products. Glycolic acid also is a principle ingredient for cleaners in a variety of industries (dairy and food processing equipment cleaners, household and institutional cleaners, industrial cleaners [for transportation equipment, masonry, printed circuit boards, stainless steel boiler and process equipment, cooling tower/heat exchangers], and metals processing [for metal pickling, copper brightening, etching, electroplating, electropolishing]). It has also been reported that polyglycolic acid is useful as a gas barrier material (i.e., exhibits high oxygen barrier characteristics) for packing foods and carbonated drinks (WO 2005/106005 A1). However, traditional chemical synthesis of glycolic acid produces a significant amount of impurities that must be removed prior to use. New technology to commercially produce glycolic acid, especially one that produces glycolic acid in high purity and at low cost, would be eagerly received by industry.
Microbial enzyme catalysts can hydrolyze a nitrile (e.g., glycolonitrile) directly to the corresponding carboxylic acids (e.g., glycolic acid) using a nitrilase (EC 22.214.171.124), where there is no intermediate production of the corresponding amide (Equation 1), or by a combination of nitrile hydratase (EC 188.8.131.52) and amidase (EC 184.108.40.206) enzymes, where a nitrile hydratase (NHase) initially converts a nitrile to an amide, and then the amide is subsequently converted by the amidase to the corresponding carboxylic acid (Equation 2):

It has been demonstrated that the enzyme catalyst specific activity measured as micromoles glycolic acid produced per minute per g dry cell weight of catalyst, decreases by from 35% to 50% of initial activity after a single use in consecutive batch reactions with biocatalyst recycle. This represents a significant loss in specific activity of the enzyme catalyst in batch reactions, and, in turn, overall enzyme activity and productivity. For a commercially feasible enzymatic process for producing glycolic acid, this loss in enzyme activity needs to be addressed.
One aspect of the loss of enzyme activity may be attributable to impurities and other components present when reacting the enzyme catalyst with glycolonitrile for glycolic acid production. Methods to synthesize glycolonitrile by reacting aqueous solutions of formaldehyde and hydrogen cyanide have previously been reported (U.S. Pat. No. 2,175,805; U.S. Pat. No. 2,890,238; and U.S. Pat. No. 5,187,301; Equation 3).

However, these methods typically result in an aqueous glycolonitrile reaction product that requires significant purification (e.g., distillative purification) as many of the impurities and/or byproducts of the reaction (including excess reactive formaldehyde) may interfere with the enzymatic conversion of glycolonitrile to glycolic acid, including suppression of catalyst activity (i.e., decreased specific activity). In particular, it is well known that formaldehyde can create undesirable modifications in proteins by reacting with amino groups from N-terminal amino acid residues and the side chains of arginine, cysteine, histidine, and lysine residues (Metz et al., J. Biol. Chem., 279 (8): 6235-6243 (2004)). Suppression of catalyst activity decreases the overall productivity of the catalyst (i.e., total grams of glycolic acid formed per gram of catalyst), adding a significant cost to the overall process that may make enzymatic production economically non-viable when compared to chemical synthesis. As such, reaction conditions are needed that can help to protect the enzymatic activity against undesirable impurities that decrease the activity of the catalyst.
A method of producing high purity glycolonitrile has been reported by subjecting the formaldehyde to a heat treatment prior to the glycolonitrile synthesis reaction (U.S. application Ser. No. 11/3143865 and U.S. application Ser. No. 11/314905; Equation 3). However, glycolonitrile can reversibly disassociate into formaldehyde and hydrogen cyanide. As such, there remains a need to protect nitrilase activity against the undesirable effects of both formaldehyde and hydrogen cyanide produced by dissociation of glycolonitrile.
U.S. Pat. No. 5,508,181 also describes similar difficulties related to rapid enzyme catalyst inactivation when converting nitrile compounds to α-hydroxy acids. Specifically, U.S. Pat. No. 5,508,181 provides that α-hydroxy nitrile compounds partially disassociate into the corresponding aldehydes, according to the disassociation equilibrium. These aldehydes were reported to inactivate the enzyme within a short period of time by binding to the protein, thus making it difficult to obtain α-hydroxy acid or α-hydroxy amide in a high concentration with high productivity from α-hydroxy nitriles (col. 2, lines 16-29). As a solution to prevent enzyme inactivation due to accumulation of aldehydes, phosphate or hypophosphite ions were added to the reaction mixture. Similarly, U.S. Pat. No. 5,326,702 describes the use of sulfite, disulfite, or dithionite ions to sequester aldehyde and prevent enzyme inactivation, but concludes that the concentration of α-hydroxy acid produced and accumulated even by using such additives is not sufficient for most commercial purposes.
Moreover, U.S. Pat. No. 6,037,155 teaches that low accumulation of α-hydroxy acid product is related to enzyme inactivation within a short time due to the disassociated-aldehyde accumulation. These inventors suggest that enzymatic activity is inhibited in the presence of hydrogen cyanide (Asano et al., Agricultural Biological Chemistry, Vol. 46, pages 1165-1174 (1982)) generated in the partial disassociation of the α-hydroxy nitrile in water together with the corresponding aldehyde or ketone (Mowry, David T., Chemical Reviews, Vol. 42, pages 189-283 (1948)). The inventors address the problem of aldehyde-induced enzyme inactivation by using microorganisms whose enzyme activity could be improved by adding a cyanide substance to the reaction mixture. The addition of a cyanide substance limited the disassociation of α-hydroxy nitrile to aldehyde and hydrogen cyanide. While this tactic provides a benefit to the system, it only addresses one aspect associated with enzyme inactivation in conversion of glycolonitrile to glycolic acid, in that, as stated above, glycolonitrile is known to reversibly disassociate to hydrogen cyanide and formaldehyde, and both are known to negatively effect enzyme catalyst activity.
A separate process has been developed to protect the specific activity of an enzyme catalyst having nitrilase activity when converting glycolonitrile to glycolic acid in the presence of formaldehyde (see copending U.S. application Ser. No. 11/931,069 incorporated herein by reference), where significant improvements in catalyst activity and stability were achieved by adding an amine protectant to the reaction mixture, or by immobilization of the nitrilase catalyst in or on a matrix that is comprised of an amine protectant, e.g. PEI, polyallylamine, PVOH/polyvinylamine, etc. In that system, the specific activity of the catalyst in the presence of formaldehyde is improved, but does not address, altogether, issues related to the loss in specific activity of recovered catalyst activity in consecutive batch reactions with catalyst recycle.
U.S. Pat. No. 4,288,552 discloses (column 1, lines 46-49, and column 2, lines 50-55) that glutaraldehyde-sensitive enzymes (such as thiol-enzymes (e.g, nitrilase) and others with an SH group in or very near the active site of the enzyme molecule) are inactivated by thiol-reactive agents such as glutaraldehyde. Therefore, use of glutaraldehyde to improve the retention of initial catalyst activity during hydrolysis of glycolonitrile to glycolic acid was heretofore unpredictable. Said unpredictable benefit is demonstrated herein.
Therefore there is a need for a process that provides improved retention of initial nitrilase activity during hydrolysis of glycolonitrile to glycolic acid, thereby improving overall catalyst activity, catalyst productivity, and volumetric productivity for the conversion of glycolonitrile to glycolic acid.

Immobilized microbial nitrilase for production of glycolic acid


The present invention relates to a circuit for eliminating radiated electric field noise in a video appliance which can completely offset radiated electric field noise generated on the front face of the CRT by variably adjusting and applying the waveform signal, the amplitude and phase of which are opposite to those of the radiated electric field noise formed on the front face of the CRT. The circuit for eliminating radiated electric field noise according to the present invention includes a high voltage ripple offset section including a cylindrical core, wherein a high voltage lead wire of the FBT passes through the cylindrical core, for eliminating a ripple component of the high voltage applied to the anode of the CRT according to the negative polarity pulse signal from the FBT induction coil, and an electric field noise offset section operable to offset the radiated electric field noise generated from the front face of the CRT by applying the negative polarity pulse signal to the periphery of the CRT.

1. Field of the Invention
The present invention relates to a circuit for eliminating radiated electric field noise in a video appliance, and more particularly to a circuit for eliminating radiated electric field noise in a video appliance which can eliminate noise of the radiated electric field generated from the front face of a cathode ray tube (CRT).
2. Description of the Prior Art
In general, a video appliance employing a CRT emits electron beams through an electron gun in order to display images on the CRT screen. Magnetic field of a deflection yoke mounted on the neck of the CRT (not illustrated in the drawings) is utilized to control emitting direction of the electron beams for an appropriate positioning on the screen. If electric current is to be flown through a deflection yoke to generate such magnetic field, however, electric field is also generated. Accordingly, a great amount of electronic wave is always generated around the periphery of the monitor. As a consequence, a video appliance normally requires an apparatus for eliminating the electronic wave in a video appliance.
FIG. 1 shows a circuit for eliminating electronic wave in a video appliance.
Referring to FIG. 1, the circuit for eliminating electronic wave comprises: a horizontal driving pulse generation section 70 for generating a horizontal driving pulse signal according to the horizontal synchronous signal inputted from the PC (not illustrated in the drawing); a flyback transformer 72 for generating a high voltage according to a horizontal driving pulse signal of the horizontal driving pulse generation section 70, and supplying the high voltage to an anode of a CRT 71; an electro-magnetic wave offset section 74 for correcting waveform of the negative polarity pulse signal applied from the induction coil 73 integrally wound at a predetermined number with the flyback transformer 72; and a lead wire 75 for offsetting an electro-magnetic wave generated from the front face of the CRT 71 according to the negative polarity pulse signal of the offset section 74.
The lead wire 75 is wound at least once along the external periphery of the CRT, at which a bezzle section is positioned, with no closing loop being formed.
The horizontal driving pulse generation section 70 comprises a transistor Q switched according to the horizontal synchronous signal inputted from the PC, and a deflection coil DY generated from the neck of the CRT 71 for deflecting the electrons on the screen of the CRT 71.
A capacitor C1 and a diode D1 are connected in parallel between the collector terminal of the transistor Q and the deflection coil. A capacitor C2 is connected to the other end of the deflection coil DY. An anode of the CRT 71 is connected to the secondary primary winding of the flyback transformer 72 via a diode D2.
The electro-magnetic wave offset section 74 includes a resistor R1 and a resistor R2 connected to one end of the induction coil 73 for dividing the voltage to level-adjust the negative polarity pulse signal applied by the induction coil 73. A capacitor C3 for correcting the waveform of the negative polarity pulse signal and a resistor R3 are connected in parallel to the other end of the resistor R1. A capacitor C4 and a resistor R4 are connected between the resistor R3 and the lead wire 75 for eliminating spike-like noise of the negative polarity pulse signal.
The reference C.sub.HV denotes a capacitor.
The conventional circuit for eliminating electronic wave in a video appliance operates as follows.
If a power supply is applied to a primary winding of the flyback transformer 72, and a horizontal synchronous signal is inputted to the base terminal of the transistor Q of the horizontal driving pulse generation section 70 from the PC, the transistor Q1 drives the flyback transformer 72. In other words, if the transistor Q is switched on/off, the flyback transformer 72 induces and applies the high voltage to the anode of the CRT 71.
The voltage at the primary winding of the flyback transformer 72 is inputted to the deflection coil DY as the transistor Q is switched on. Accordingly, deflected electric current flows through the deflection coil DY to deflect the electron beams emitted through the electron gun.
The negative polarity pulse voltage Va induced at the secondary winding of the flyback transformer 72, as expressed in the following equation 1, is divided by a predetermined voltage B.sup.+ and the resistors R1, R2 to be level-adjusted. ##EQU1##
The amplitude and level of the DC of the negative polarity pulse voltage Va can be adjusted according to the values of the resistors R1, R2. The waveform of the negative polarity pulse voltage Va divided by the resistors R1, R2 is corrected by the resistor R3 and the capacitor C4 of the electro-magnetic wave offset section 74. The negative polarity pulse voltage Va, the waveform of which has been corrected by the resistor R3 and the capacitor C4, is inputted to the lead wire 75 after the spike-like noise is eliminated by the resistor R4 and the capacitor C4.
The lead wire 75 induces only a predetermined voltage on the front face of the CRT 71 without inducing the electric current component of the inputted negative polarity pulse signal Va on the front face of the CRT 71. Accordingly, the radiated electric field wave emitted through the front face of the CRT 71 is offset by the negative polarity pulse voltage Va of the lead wire 75, the amplitude of which is the same thereas but the phase of which is opposite thereto.
However, such a conventional circuit for eliminating electronic wave in a video appliance has a disadvantage that it fails to completely eliminate the radiated electric field noise generated from the front face of the CRT 71. Also, whereas the scale and waveform of the noise of the radiated electric field generated from the front face of the CRT 71 are variable, no amplitude control means has yet been available to generate the negative polarity pulse voltage in conformity with the scale of the noise of the radiated electric field emitted from the front face of the CRT 71. Thus, the noise of the radiated electric field induced to the CRT 71 cannot be completely offset, thereby failing to satisfy the standard required by the Swedish Confederation of Professional Employees (TCO).

Electric field noise eliminating circuit in a video display appliance


The present invention relates to novel processes for producing ethanol from citrus waste using suitable solvent extractions to reduce the presence of fermentation inhibiting compounds, such as limonene, from citrus waste. The extraction can be performed before or after the polysaccharides present in aqueous mixtures comprising citrus waste are converted into fermentable sugars.

Florida produces approximately 5 million tons of orange peel waste each year. Most of this peel waste is dried, pelletized, and sold as beef or milk cattle feed filler commonly referred to as citrus pulp pellets.
High gasoline prices, overdependence on foreign oil, and a continuing demand for renewable energy sources have led to increased research interest in the general field of citrus peel waste conversion, and in particular, to the transformation of peel waste to ethanol. Current processes generally involve hydrolyzing citrus peel comprising a complex mixture of polysaccharides to provide fermentable sugars, fermenting the sugars to produce ethanol, and isolating the ethanol and other by-products.
Unfortunately, some compounds found in citrus peel or produced during the steps converting citrus peel into fermentable sugars act as fermentation inhibitors in the conversion of these sugars to ethanol. Among these compounds, limonene, a terpene-based component in citrus peel, is known to impede fermentation processes (See Grohmann, et al., Production of Ethanol from Enzymatically Hydrolyzed Orange Peel by the Yeast Saccharomyces Cerevisiae, Applied Biochemistry and Biotechnology, Vol. 45 (1994)). Limonene is generally understood to provide a natural defense for citrus against bacteria, viruses, molds, and other organisms and to inhibit fermentation by typical processes that would yield ethanol. It has been estimated that, for efficient fermentation, limonene in the citrus peel waste should be below 3000 parts per million and perhaps even below 1500 ppm.
Stewart et al. (U.S. Patent Application No. 2006/0177916) describes a process of producing ethanol from citrus waste where limonene is removed prior to fermentation. The disclosed process includes limonene removal via evaporation and steam stripping from citrus peel, hydrolysis of the limonene-stripped citrus peel waste, and fermentation of the resulting hydrolysis mixture to produce ethanol (or simultaneous hydrolysis and fermentation). The steam-stripped limonene may be recovered by condensation. Stewart does not address the possibility of employing extraction as a means of reducing the level of fermentation-inhibiting compounds found in citrus waste or the complex polysaccharide or sugars derived therefrom.
Among the problems associated with steam-stripping and similar processes is the substantial usage of energy (e.g., electricity, fuel consumption, etc.) that is necessary to carry out the processes. Such energy expenditures and particularly problematic where the overall goal is to produce alternative fuel sources, such as fossil fuel replacements, because ideally the energy input will be minimized to yield an overall energy-efficient process. Although Stewart discloses the use of centrifuging as an alternative method for removing limonene, Stewart does not address any issues associated with energy usage or otherwise suggest extraction as a means for reducing the level of fermentation-inhibiting compounds.
Previous attempts to use extraction to remove fermentation-inhibiting compounds prior to fermentation have proved unsuccessful. For example, Grohmann (Grohmann, et al., Production of Ethanol from Enzymatically Hydrolyzed Orange Peel by the Yeast Saccharomyces Cerevisiae, Applied Biochemistry and Biotechnology, Vol. 45, 1994) attempted to remove limonene from an aqueous citrus waste mixture using solvent extraction but abandoned the approach because of the formation of inseparable emulsions with a series of organic solvents. Ultimately, Grohmann used filtration to remove the limonene based on the inability to successfully carry out the extraction. Such solutions do not address the problems presented by the extraction and would be problematic on scale-up.
Although extraction has recently been used under certain conditions to remove volatiles from the peel of citrus fruits (Bhupesh, et al., Supercritical Carbon Dioxide Extraction of the Volatiles from the Peel of Japanese Citrus Fruits, J. Essent. Oil Res., 19, 78-84 (2007)), the disclosed procedures did not involve a pre-fermentation extraction step designed to lower the level of fermentation-inhibiting compounds in a feedstock for the production of ethanol. Furthermore, Bhupesh does not teach or suggest converting one or more polysaccharides contained in the citrus waste into fermentable sugars either before or after the extraction, or in turn, fermenting these sugars into ethanol in the absence of the fermentation-inhibiting compounds.
Inasmuch as there is a continuing demand for alternative and/or renewable energy resources, a need to reduce dependence on foreign oil supplies, and a need to reduce or stabilize gasoline prices for example, there is still an unfulfilled need for a specific and effective solution to address one or more of these issues. In view of the above, it is highly desirable to find new methods of eliminating limonene, other similar terpene components, or other fermentation-inhibiting compounds from citrus waste in order to enhance the production of ethanol therefrom. The present invention is directed to these, as well as other important ends.

Removal of fermentation inhibiting compounds from citrus waste using solvent extraction and production of ethanol from citrus waste


A method for graphene functionalization that preserves electronic properties and enables nanoparticles deposition comprising providing graphene, functionalizing the graphene via non-covalent or covalent functionalization, rinsing the graphene, drying the graphene, and forming functionalized graphene wherein the functionalized graphene preserves electronic properties and enables nanoparticles deposition. A functionalized graphene wherein the graphene functionalization preserves electronic properties and enables nanoparticles deposition.

This disclosure teaches a method to functionalize graphene to allow for modulation of graphene's electrical properties as well as for deposition of nanoparticles, such as oxides, metals, and quantum dots.
Graphene is a single layer of sp2 bonded carbon, and has emerged as a unique conductor due to its zero-band gap, the ability to easily manipulate the carrier concentration and carrier type (electron or hole) through electrical gating, extremely high electron mobilities of 10 000-70 000 cm2V−1 s−1 and low absorption (2.3%) in the visible spectrum.
In addition, graphene is one of the strongest materials with a Young's modulus of 1 TPa and high thermal conductivity of 5000 WmK−1. Furthermore, the quantum Hall effect was observed at room temperature.
However, graphene has an inert chemical nature so chemical functionalization is needed for integrating graphene with other materials, for the attachment of biomolecules and catalysts, and to allow the deposition of metals and dielectrics onto it. Both covalent and non-covalent approaches have been extensively explored.
It should be noted however that since graphene is all surface, any modification of its chemistry and structure leads to changes of its electrical properties as well so careful selection of the functionalization approach is needed.
The main covalent functionalization routes of graphene include free radical addition reactions, polymerization, cycloaddition, and introduction of single atoms (hydrogenation, fluorination, chlorination, oxygenation). Free radical reactions are based on the reduction of diazonium salts to form aryl radicals that attach to graphene forming C(sp3)-aryl bonds and which can be achieved through thermal or electrochemical decomposition. This functionalization is very effective (12.7-20% coverage of nitrophenyl group was reported) but difficult to control and may also result in the formation of insulating layers on the graphene surface, thus hindering electronic device performance. Changes in the structure of graphene can be assessed using Raman spectroscopy—single layer graphene is characterized by two peaks at 1586 cm−1 and 2686 cm−1. If defects are present, then a D peak appears at 1350 cm−1. The intensity ratio of D and G peaks is usually used as a measure of the degree of functionalization as well as an indication of the deterioration of the electrical properties. Reported values of ID/IG in the case of aryl radical reactions varied—in one case 0.2-0.8, in another 2.6 for SiC/EG-NO2-Ph. Cycloaddition reactions change the hybridization of pairs of neighboring atoms. Examples include the formation of cyclopropane or aziridine adducts, the formation of aryne or benzene intermediate via an elimination-addition mechanism, functionalization towards a five membered ring via six electrons cycloaddition between 1, 3 dipole and dipolarophile (graphene). The cycloaddition reactions latter provide a high level of control of the degree of functionalization and defect density, however it is reversible. Introduction of fluorine, chlorine and hydrogen atoms into the graphene lattice have been reported as well. However, that type of modification induced high levels of disorder—ID/IG=1.3-2.5 for Cl; ID/IG=1.0-1.5 for F; ID/IG=3.2 for H.
Non-covalent functionalization of graphene by graphene-ligand interactions is another approach.
An extensive literature review reveals that most of the work follows in two categories—attachment of molecules to graphene oxide (GO) followed by the reduction of the GO to graphene or using dispersed graphene nanopalets and functionalizing them in solution. There are only a few reports of functionalization of a complete graphene monolayer with ligands. Wang et. al. reported functionalization with pyrene butanoic acid sucidymidyel ester (PBSA) to change the power conversion of a solar cell from 0.21 to 1.71%. An et al. showed graphene functionalized with 1-pyrenecarboxylic acid (PCA) that was laminated onto PDMS membranes. The hybrid had unique optical properties—it blocked 70-95% of UV light and allowed more than 65% of the visible light. Pyrene functionalization of graphene was used for biosensing applications as well. Plasma-based functionalization of graphene is also possible; however, it greatly degrades the electronic properties of graphene (by increasing the resistivity).
The effect of the non-covalent pyrene- and pyridine based functionalization on graphene's electromagnetic properties has not been explored in the prior art and is one of the purposes of this invention.
The covalent azide based functionalization was realized in a way that does not damage graphene (no D peak) and is thus unique to this work. As a result, we observed the quantum Hall effect in functionalized graphene that is typical only for pristine graphene systems. This discovery will help in the development of quantum Hall resistance standards based on graphene technology and provides a platform for other graphene devices such as sensors with superior electronic properties compared to other functionalization methods.

Method for graphene functionalization that preserves characteristic electronic properties such as the quantum hall effect and enables nanoparticles deposition

The Government of the United States of America, as represented by the Secretary of the Navy


In one aspect, a method of storing data includes setting a first data node in a first storage area and setting a second data node in a second storage area. The second data node is an element of a plurality of elements forming a first flat table of at least one flat table in the second storage area. The step of setting a first data node includes storing in the first data node a two-tuple linker which comprises a first identifier indicating the first flat table and a second identifier indicating the row of the element in the first flat table. In another aspect a corresponding data storage structure is further provided.

A special-purpose processor, like a mathematical processor which serves as a coprocessor of a universal processor and performs mathematical operations, and a network processor which is used for processing network services (switches, routers etc) or the like, is a high-performance processor that is specifically designed for some specific applications.
However, as special applications demand, a special-purpose processor may have to trade some of its flexibility for realization of its specific functions. In general, a special-purpose processor employs a collection of high-performance hardware engines, and each of them is crafted to support specific functions, such as queue management, table lookup, and access to memory or the like. In order to achieve higher performance, a special-purpose processor often adopts a memory structure which departs from the conventional memory hierarchy (e.g., main memory, cache memory or the like). In a special-purpose processor, memory are often partitioned into control memory which houses host information for data processing and data memory which houses data accompanying requests for processing.
In a special-purpose processor which employs at least a search engine, an index table can be implemented for fast lookup. Therefore, there are at least two types of tables supported in such special-purpose processor: index table and flat table. An index table can be implemented as an index tree which is a limited set formed by n (n≧0) nodes and includes a root node, leaf nodes (end nodes) and non-end nodes. Usually, relevant information is stored in leaf nodes. The path from the root node of the index tree to a leaf node is identified by a key in the index table. A user can access an index table by providing a tree ID and a key and then invoking a table lookup (index tree search) command. Latency of a lookup depends on the length of the key and the structure of the tree.
A flat table can be implemented as a memory array. Each row or column of a memory array may store a row (element) of a flat table.
In data processing, data chaining allows data to be well-linked logically, thereby reducing spatial requirements on storage unit while keeping data integrity at the same time. The flexibility of software design of data processing heavily depends on the single pointer as a single and simple mechanism of data chaining.
Due to use for special applications, a special-purpose processor often does not support memory access via a pointer (address of a memory location) and consequently, loses the capability of data chaining via a single pointer. The lack of such a single pointer prevents data chaining from being implemented easily and results in worse flexibility of software design.
Because of upper limit on the size of a leaf node, the capacity of information that can be stored in a leaf node is also restricted. As a result, demands of some complex applications (e.g., tunneling application involved in network communication, or the like) cannot be met. Therefore, there is a need to expand the information capacity of a leaf node, for example.
However, since a special-purpose processor lacks the capability of data chaining via a single pointer, the efficiency of data chaining is rather low, which gives rise to a conflict between large data and small capacity of data storage unit.

Data storage method and data storage structure