A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

1. Field of the Invention
This invention relates to the process of recovering titanium values from waste generated in the process of machining titanium metal. In particular this invention relates to a process for recycling titanium grinding waste into an environmentally safe form for subsequent use in industrial processes requiring high titanium feed stock.
2. Description of the Related Art
The process of grinding titanium metal creates a residue of partially oxidized titanium metal fibers or slivers, commonly known in the industry as "swarf". In addition to swarf, the residue of the titanium grinding process contains, coarse trash, and grinding wheel fragments. As a waste by-product, grinding swarf is stockpiled for later disposal. Because titanium is a highly reactive material, it has been known for these swarf piles to spontaneously ignite. The resultant titanium oxide is extremely brittle and of little titanium value. Currently, there is no processing method to render the grinding swarf chemically stable to the environment. Accumulation of titanium grinding swarf is estimated to reach one million pounds per year. Recovery of titanium values from accumulating titanium grinding swarf would conserve a valuable resource and reduce problems associated with the accumulation of hazardous process waste material.
The titanium value may be recovered from grinding swarf by rechlorinating it, introducing it with titanium tetrachloride and reducing the mixture to titanium chloride. However, titanium chloride, has a lower market value compared to scraps of titanium metal mixed with the grinding swarf.
Processes and methods for recovery of iron units from flue dust are similar to the method described herein and are generally well known in the art. One such method is described in U.S. Pat. No. 4,407,672, issued Oct. 4, 1983, to Ruger A. Deuschle and Charles P. Mueller, entitled "Method for the Recovery of Iron Units from Flue Dust Generated in a Steel Making Process." Recovery of iron units from flue dust does relate to the problems of handling fine particle material but does not address the problems associated with highly reactive titanium and the need to keep materials out of the recovery process which could contaminate the final ferrotitanium and/or titanium slag produced. Also, Megy, U.S. Pat. No. 5,171,359 discloses a composition that reuses high purity titanium slivers, commonly known as swarf, produced by a wet grinding process. The titanium swarf, for use with the invention of Megy, is low in impurities such as oxides and nitrides. Megy does not disclose a process for treating a low grade milling waste that may contain grinding residue, titanium oxide, or coarse impurities.
The present invention overcomes the deficiencies in the prior art methods for recovering titanium values from what would otherwise be considered a waste by-product of the titanium and steel industries. It provides a method of handling and smelting titanium grinding swarf without contaminating on going ferrotitanium and titanium slag production processes. In addition to recovering titanium values from the grinding swarf, the problem of disposing the metallic waste is solved and the recovered titanium will increase concentrations of titanium in high titanium slag and ferrotitanium for the steel industry.

Recovery of titanium values from titanium grinding swarf by electric furnace smelting

The United States of America as represented by the United States Department of Energy


Information can be provided in a convenient manner to help a user decide what events to attend. The information can include information regarding a popularity of the events. The popularity of the events can be based upon the number of people expected to attend, the number of the user's friends expected to attend, and/or the number of people fitting user-defined criteria who are expected to attend. The events for a user-specified time period can be shown on a map along with information representing the popularity of the events. Thus, the user can choose to attend those events in the user's area which are more popular. The map can be displayed on a user device, such as a cellular telephone. In this manner, the user can more readily attend those particular events which the user is more likely to enjoy.

1. Technical Field
The present disclosure generally relates to electronic commerce and, more particularly, relates to a method and system for providing a user with a map of events wherein the events can be coded, for example, according popularity as determine by user-specified criteria.
2. Related Art
Event calendars are well known. Event calendars show when events such as concerts and sporting event will Occur. For example, event calendars can commonly be found in newspapers, magazines, and online. Such event calendars typically specify what the event is (such as the name of a band for a concert event or the names of the opposing teams for a sporting event), the time and date of the event, and the venue for the event. Such information can be helpful to a person who is searching for an event to attend. However, such information does not let the person know how popular the event is or how many of the person's friends may be attending the event.
Social networks may provide information regarding what events the person's friends are planning to attend. However, this information is not presented in a convenient and sufficiently useful manner. The person may have to search through many of their friend's social network pages and/or messages to determine which of the user's friends are going to which events. Often, such information regarding what events the person's friends are planning to attend is not available via social networks.


MW of an FCMDB sequentially registers device configuration information of MDRs 1 and 2 in the FCMDB. The MW registers the device configuration information of the MDR 2 in the FCMDB, including a process policy indicating that “at a class lower than or equal to a Server class, an unknown component is added to last of device configuration integration information”, which is provided by the MDR 2 as a process policy in a case where the device configuration information of the MDR 2 is read. An MW 2 reconstructs the device configuration information of the MDR 2, according to order information of metadata of the device configuration information of the MDR 2 and a predetermined process policy indicating that “at a class not higher than a Server class, an unknown component is added to last of device configuration integration information”, as a process policy to reconstruct the device configuration information.

In recent years, in a field of system operation and management, a document where the know-how about success cases is accumulated, which is called ITIL (Information Technology Infrastructure Library; registered trademark), has been widely used. The ITIL is published by CCTA (Central Computer and Telecommunications Agency), which is a British government agency, in 1989 and becomes a de facto international standard in the field of system operation and management at the present time.
For example, as disclosed in Non-Patent Document 1, CMDB (Configuration Management Database) is proposed as a standard to manage pieces of device configuration information in a system. The CMDB is a device configuration information database that is defined in the ITIL.
According to the CMDB, in order to manage the pieces of device configuration information in the system, a device configuration information database is constructed as a database to manage the pieces of device configuration information in the system and a relationship between the pieces of device configuration information. In the device configuration of the system, various components such as a variety of hardware, a software, and a variety of data are included. In this case, how to efficiently and easily configure the device configuration information database has to be considered.
Accordingly, in Patent Document 1, a software configuration managing mechanism that provides a unit for automatically customizing a unit for providing metadata of device configuration information databases to people who register various devices so as to enable easy construction of the device configuration information database and easy change of a device configuration management target is disclosed.
Specifically, a configuration schema registering unit generates a schema of a device configuration information database and metadata for access. A resource configuration information access unit allows a person accessing to the pieces of device configuration information to read, add, update, and delete data of a customized schema type. A configuration information display/maintenance unit collects data from the device configuration information database and integrates metadata as logical resources with the device configuration information database at a higher hierarchy than the metadata.
The device configuration information database at the higher hierarchy, which is called an FCMDB (Federated CMDB), is a database for integrated management of a plurality of pieces of device configuration information. Implementation of a database for each piece of the device configuration information is called an MDR (Management Data Repository).
However, the related art such as "CMDB Federation (CMDBf)", Committee Draft Version 1.0, [online], Oct. 22, 2007, CMDB Federation Working Group, [searched on Jan. 23, 2008], Internet <URL: http://cmdbf.org/schema/1-0-0/CMDBf%20v1.0.pdf> and Japanese Laid-open Patent Publication No. 09-91122 has the following problems. In integrated management, by the FCMDB, of pieces of device configuration information of respective MDRs in a system, the FCMDB uses a common data model, but the data formats of respective MDRs are not unified. For example, schema may be different, data order may be different even when a common schema is used, or although data that is read from the MDR has a hierarchical structure and a parent-child relationship, the hierarchical structure and the parent-child relationship are not stored in the common data model.
For this reason, the pieces of device configuration information that are read from the MDR may be in different order and the parent-child relationship is not stored in the common data model, and a device that reads the device configuration information from the FCMDB in the format of the MDR cannot express a portion of the pieces of device configuration information included in a schema of the common data model. Therefore, there has been a disadvantage that the pieces of device configuration information that are integrated in the common data model are discrepant with the pieces of device configuration information of respective components before integration.

Device configuration integration information managing device and device configuration information managing device


The present invention relates to an organo-ceramic composite material useful for the extraction of metal ions from solution. The organo-ceramic composite material is formed according to a sol gel synthesis scheme by reacting a functional precursor silane and its homopolymers with either (i) a mixture of a cross-linking silane and its homopolymers or (ii) the cross-linking silane, under conditions effective to yield the composite material of the present invention. Further aspects of the present invention relate to methods of removing a metal ion from a water stream and recovering a metal ion from a water stream, both of which include contacting a water stream containing a metal ion with an organo-ceramic composite material of the present invention under conditions effective to remove the metal ion from the water stream.

Many industries utilize heavy metals and/or rare earth metals in their manufacturing processes. Such use typically results in liquid (generally aqueous) waste streams that contain residues of the rare earth or heavy metals utilized in the given manufacturing process. For example, the waste streams resulting from electronics, hydrometallurgical, electrochemical metal refining, electroplating, and photographic processes typically contain metal ions such as copper, nickel, zinc, chromium (III), chromium (VI), cadmium, aluminum, lead, antimony, silver, and gold, amongst others in various aqueous solutions such as sulfates, chlorides, fluoroborates and cyanides. Because of the potential adverse effect of such substances on health and the environment, the removal of rare earth metals and heavy metal ions from aqueous waste streams is a problem of continuing significance.
Mining industries are also responsible for contributing significantly to pollution of waterways and ground water, including wells, as a result of contaminated waste streams (i.e., acid mine drainage solutions) flowing into such water sources. For example, the Berkeley Pit is a vast open-pit mine located in an ore-rich section of southwestern Montana which has been closed since the 1980's. The Berkeley Pit is filled with some 17 billion gallons of water which contains high concentrations of various metal ion contaminants, including aluminum (approximately 2.6 mg/L), cadmium (approximately 2.1 mg/L), calcium (approximately 450 mg/L), copper (approximately 170 mg/L), iron (approximately 1070 mg/L), lead (approximately 0.03 mg/L), magnesium (approximately 400 mg/L), manganese (approximately 185 mg/L), sodium (approximately 75 mg/L), zinc (approximately 550 mg/L), nitrate (less than 1 mg/L), and sulfate (approximately 7600 mg/L). Not only is the clean up of such waste sites important from an environmental aspect, but the recovery of such useful metals is important from an economical perspective as well.
A variety of polymeric systems have been developed and applied for metal separations from aqueous solutions. Organo-polymeric synthesis techniques are well established and polymeric metal extractants can be tailored and adapted for specific applications, such as noble metal separations, nuclear waste treatments, and electroplating waste clean-up. Polymeric extractants can be classified as either water-soluble polymer systems or solid-resin systems.
In the case of noble metal and platinum group metal separations, improved methods to more efficiently separate these precious commodities from ore body leach solutions are a continual need, particularly as the quality of ores decline. Because gold, platinum, silver, etc. are in significant demand for use in various commercial products and processes, the recovery of such precious metals from ore solutions will, over time, accommodate this increased demand.
Water-soluble polymer systems for metal extraction utilize water-soluble polymers which are separated from solution (i.e., following extraction) using ultrafiltration techniques. An attractive feature of this system includes the elimination of diffusive mass transfer resistance which exists in solid supports, thereby yielding faster extraction rates than most solid resin systems (Smith et al., ACS Symposium Series 716: 294-330 (1999), and Jarvinen et al., Proceedings of A Symposium Sponsored by Engineering Foundation Conference and National Science Foundation, The Mineral, Metals & Materials Society, Hawaii, pp. 131-138 (1999)).
Solid-resin systems have been studied widely and applied for many applications over the latter half of the past century (Al-Bazi et al., Talanta 31:815-836 (1984); Kantipuly et al., Talanta 37:491-517 (1990); and Alexandratos et al., Macromolecules 29:1021 (1996)). Of particular interest are inorganic network systems, which have received much attention due to their mechanical strength, thermal stability, wide range of particle size, and well-defined pore structure. The well-defined pore structure is important for creating an environment in which the metal ions can diffuse in the solid matrix.
The inorganic network systems have typically been created using either solvent deposition or covalent bonding techniques to immobilize a functional extractant or chelating agent to the solid support. Surface attached hydroxy groups such as Si—OH, Ti—OH, Zr—OH, and Al—OH, which are common to most inorganic supports, provide the reactive sites for surface modification. The density of the hydroxyl groups for silica gel support is constant for a fully hydroxylated surface (8 μmol OH/m2).
In order to prepare inorganic chemically active adsorbents with high stability, capacity, and kinetic rates equal or greater than pore diffusion rates, the chelating agent(s) should possess the following properties: very low solubility in water; hydrocarbon chains away from the complexing moiety to retain hydrophilicity at the complexing end and to prevent steric hindrance to the formation of chelate rings; sufficient thermal stability so that the extract moiety is not destroyed or altered during immobilization (i.e., while heating to remove excess solvent); sterically compact geometry that is compatible (as well as comparable) to the pore size and pore volume of the functional support, which enables the extractant to penetrate into the pores and interact with the bonded functional groups; and sufficient chemical stability to retain activity during operation and regeneration. Two approaches can be used to make these materials: solvent deposition and covalent attachment.
Solvent deposition techniques are performed by immobilizing functional groups on the silica gel via silanization reactions. Various silylating agents can be used. For example, to immobilize alkyl groups, a dialkyl-dichloro-silane can be used. The chain length of the functional alkyl group is selected on the basis of desired pore size and pore volume of the silica gel. In addition, titanium coatings can be added to the surface through the silanol group in order to prevent dissolution of the surface in highly caustic solutions. After the functional groups have been deposited onto the silica gel, extractant or chelating agent(s) are deposited by dissolving the agent(s) in a solvent, immersing the silica gel in the solvent solution, and subsequently evaporating the solvent.
Covalent attachment of extracting or chelating agent(s) to an inorganic support is a very elegant approach. This approach typically can produce inorganic chemically active adsorbents with greater stability, selectivity, and adsorption rates. Covalent bonds between an organic moiety (i.e., an extracting or chelating agent) and a substrate are formed through an intermediary coupling agent. Selection of the functional group to be immobilized depends on the intended application. The groups taking part in the formation of chelate rings usually include nitrogen, oxygen, and sulfur atoms. The attachment of specific complexing groups into organic matrices makes them capable of reacting with metal ions, owing to the coordinate covalent or ionic bond. The interaction between metal ion and functional group depends on properties of the metal (e.g., charge, size, coordinate number), adsorption conditions (e.g., solution pH, ionic strength), functional group, and physical nature of the matrix (i.e., steric factors). Chelate rings can be formed with the participation of donor atoms situated in one unit of matrix or at the matrix chain. Accordingly, highly selective inorganic chemically active adsorbents can be prepared by careful planning and execution of synthesis schemes to introduce desired donor atoms in a preferred geometry.
In performing covalent attachment, selected extracting or chelating agent(s) or derivatives of functional groups capable of complexing the desired metal ions are attached to the silica surface of the inorganic support. The functional groups can be attached to the support using commercially available silane coupling agents. This attachment is performed according to one of two methods. According to one approach, the coupling agent is first attached to the silica surface, then a functional group precursor is attached to the lattice, and the precursor modified to yield the desired functional group. According to another approach, the silane coupling agent and functional group are bonded together, then the resulting functional silane coupling agent is covalently attached to the silica support. Details of these synthesis procedures are disclosed, for example, in U.S. Pat. Nos. 5,612,175, 5,616,533, 5,624,881 and 5,668,079 to Tavlarides et al.
Similar approaches have been employed using specially designed meso-porous silica material (Feng et al., Science 276:923-926 (1997), and Mercier et al., Environ. Sci. Technol 32:2749-2754 (1998)) Meso-porous silica material are attractive supports because they have high surface area (i.e., up to about 1500 m2/gm) and well-defined uniform pore size. In the synthesis of these extractant materials, a series of silanizations with a silane containing a functional moiety has been performed to increase ligand density on the meso-porous silica. With this technique, up to about 3.2 mmol/gm of mercury uptake capacity has been reported (Mattigod et al., Proceedings of A Symposium Sponsored by Engineering Foundation Conference and National Science Foundation, The Mineral, Metals & Materials Society, Hawaii, pp. 71-79 (1999)).
Certain organo-ceramic composite materials prepared via a direct sol gel reaction have also been described. In such direct sol gel reactions, a cross-linking silane and a functional precursor silane are co-polymerized and co-condensed to yield an organo-ceramic composite material that contains functional moieties dispersed randomly throughout the composite material. For example, Zhmud et al., "Acid-Base Properties and Electrokinetic Behavior of Amine-Containing Organopolysiloxane Matrices," J. Colloid Interface Sci. 173:71-78 (1995), describes the formation of such composite materials by directly reacting (i.e., in a co-condensation reaction) a tetraalkoxysilane and a trialkoxysilane containing a functional amino or imidizole moiety. The specific reaction parameters and the properties of the resulting composite materials are described in Zhmud et al., "Aminopolysiloxane gels: Production and Properties," J. Non-crystall. Solids 195:16-27 (1996). While such organo-ceramic composite materials can be used as metal adsorbents, they are not as desirable as the organo-ceramic composite materials of the present invention, because the dispersion and density of the functional moiety in the resulting gel is random and cannot easily be controlled during the direct co-condensation reaction.
While the above-described compositions are capable of effecting metal ion adsorption, vast improvements would be desirable for various characteristics of such compositions. For instance, it would be desirable to obtain compositions which are characterized by higher ligand densities, controlled clustering of ligands throughout the matrix, and better controlled pore characteristics. By improving these characteristics, it should be possible to achieve higher capacity extraction rates. Accordingly, there still exists a need for more cost efficient processes for the separation and removal of metal ions from waste streams by producing compositions having a variety of chelating agents which are specific and selective toward desired metal ions.
The present invention overcomes the various deficiencies in the art.

Method of removing a metal ion from a water stream using organo-ceramic composite materials


A liquid thermosetting epoxy resin composition contains a base resin in combination with a curing agent and a curing accelerator or with a curing catalyst. The base resin includes a cycloaliphatic epoxy compound having at least one alicyclic skeleton and two or more epoxy groups per molecule, and a polyol oligomer having two or more terminal hydroxyl groups. An optical semiconductor device includes an optical semiconductor element sealed by using the liquid thermosetting epoxy resin composition. The composition yields a cured resinous product which is free from curing failure, is optically homogenous, has a low elastic modulus in bending, a high bending strength, a high glass transition temperature, a high optical transparency and is useful for optical semiconductors.

Liquid epoxy compounds containing an alicyclic skeleton and having satisfactory optical transparency and high heat resistance are frequently used in epoxy resin compositions for sealing optical semiconductor elements. Examples of these epoxy compounds are CELLOXIDE 2021 (3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate), CELLOXIDE 2081 (an adduct between 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate and ε-caprolactone dimer), and CELLOXIDE 3000 (1,2,8,9-diepoxylimonene), each available from Daicel Chemical Industries, Ltd.
Epoxy compounds having a 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate structure typified by CELLXIDE 2021 yield cured products excellent in heat resistance and optical transparency and are used in resins for sealing optical semiconductors such as LED. These cycloaliphatic epoxy compounds such as CELLOXIDE 2021, however, are insufficient in heat-cycle resistance and invite cracking to thereby decrease the reliability of product electronic parts.
Conventional proposals for improving physical properties of epoxy resins, such as for increasing impact resistance and preventing cracking, are as follows. Japanese Unexamined Patent Application Publication (JP-A) No. 09-255764, for example, discloses an epoxy resin composition for sealing optical semiconductors, containing a diglycidyl ether of hydrogenated bisphenol-A. JP-A No. 10-156952 discloses a stereolithographic resin composition using a cycloaliphatic epoxy compound as in the present invention. JP-A No. 2000-63485 discloses a curable composition for buildup, containing a specific cycloaliphatic epoxy compound and a polyepoxy compound having a polyphenol skeleton. JP-A No. 09-71636 discloses an active energy ray-curable composition using a cycloaliphatic epoxy compound as in the present invention.    Patent Document 1: Japanese Unexamined Patent Application Publication (JP-A) No. 09-255764    Patent Document 2: Japanese Unexamined Patent Application Publication (JP-A) No. 10-156952    Patent Document 3: Japanese Unexamined Patent Application Publication (JP-A) No. 2000-63485    Patent Document 4: Japanese Unexamined Patent Application Publication (JP-A) No. 09-71636

Composition containing cycloaliphatic epoxide, polyol oligomer, and curing catalyst


An integrated multiprocessor architecture simplifies synchronization of multiple processing units. The multiple processing units constitute a general-purpose or control processor and a vector processor which has a single-instruction-multiple-data (SIMD) architecture so that multiple parallel processing units in the vector processor all complete an instruction simultaneously and do not require software synchronization. The control control processor controls the vector processor and creates a fork in a program flow by starting the vector processor. An instruction set for the control processor includes special instructions that enable the control processor to access registers of the vector processor, start or halt execution by the vector processor, and test flags written by the vector processor to indicate completion of tasks. The two processors then execute separate program threads in parallel until the control processor stops the vector processor, an exception is encountered, or the vector processor completes its program thread and enters an idle state. An instruction set for the vector processor includes special instructions that interrupt the first processor to indicate a task is complete. A register coupled to and accessible by both processors stores a state bit indicating whether the vector processor is running or idle. The control processor can synchronize the separate program threads by executing a loop which polls the state bit. When the state bit indicates the vector processor is idle, the general-purpose processor can process results from the vector processor and restart the vector processor.

1. Field of the Invention
This invention relates to multiprocessors and particularly to systems and methods for coordinating or synchronizing parallel execution of separate program threads.
2. Description of Related Art
Multiprocessors are known to include multiple processors that cooperate to accomplish a task. A relatively simple multiprocessor system includes a co-processor (such as a 80386 processor) and a floating point processor (such as a 80387 math co-processor). In such systems, when the processor encounters an instruction which requires a floating point operation, the processor activates the co-processor which executes the instruction. Math co-processors such as the 80387 are limited to executing a single instruction when directed and are idle between floating point instructions. The increase in processing power provided by such co-processors is correspondingly limited.
Another multiprocessor architecture contains two or more identical processors which execute separate but coordinated program threads. Keeping program threads coordinated or synchronized, for example, to pass results between program threads can be difficult because the time required to complete a section of a program thread varies. For example, cache hits and misses and instruction dependencies can delay execution pipelines and change the number of cycles required to complete instructions. Accordingly, instruction sequences in different program threads often get out of synchronization with each other.
To maintain proper synchronization, hardware connected between the processors can delay or idle processors as required to synchronize one program thread with another. In some systems having multiple identical processors, each program thread is responsible for delaying itself or other program threads. Such systems often have complex synchronization hardware and required complicated software to maintain synchronization and coordination of program threads. The complex synchronization hardware increases chip size in an integrated system, and the complicated synchronization makes software longer and more difficult to develop.
Multiprocessor systems are sought which provide the high processing power, the flexibility of multiple separate program threads, and a simple method for synchronizing or coordinating the program threads.

Coordination and synchronization of an asymmetric, single-chip, dual multiprocessor


A gas supply system that supplies a gas after making confluence of the gas flows from gas containers includes: a supply pressure detector that detects supply pressure of the gas following the confluence; and a controller that permits a gas supply-destination apparatus to be activated if the supply pressure detected after an elapse of a determination time from a start of the gas supply is greater than or equal to a threshold pressure, and that prohibits the apparatus from being activated if the supply pressure is less than the threshold pressure. The controller uses a first determination time as the determination time if it is determined that internal pressures that are the gas pressures in the containers are not imbalanced between the containers, and uses a second determination time that is longer than the first as the determination time if it is determined that the internal pressures are imbalanced.

1. Field of the Invention
The invention relates to a gas supply system. More particularly, the invention relates to a gas supply system that includes a plurality of gas containers and that is capable of avoiding an incorrect control resulting from a delay of the time of the rising of supply pressure of gas which results from a difference in pressure between gas containers.
2. Description of Related Art
In response to growing awareness about energy saving and global environment protection in these days, electric vehicles equipped with electric motors as a motive power source, for example, are coming into widespread use. Along with this trend, research and development are being vigorously Pursued on electric power sources for electric motors used as motive power sources of such electric vehicles, for example, a fuel cell that generates electricity through an electrochemical reaction of hydrogen with oxygen from the air. The hydrogen for use in the fuel cell is often in the gas state since hydrogen is easier to handle in the gas state than in the liquid state. Therefore, means often used to store hydrogen gas is, for example, a high-pressure container such as a tank or the like. Furthermore, hydrogen gas motor vehicles equipped with an internal combustion engine that burns hydrogen gas instead of a fossil fuel, for example, gasoline or the like, are drawing attention in view of environmental issues. The hydrogen gas motor vehicles are also generally equipped with a high-pressure container for storing hydrogen for substantially the same reason as mentioned above.
A material used for the aforementioned high-pressure container can be a metal, for example, iron or the like, from the viewpoint of strength and air tightness. However, from the viewpoint of weight reduction, a material obtained by reinforcing a base material of a plastic, for example, polyethylene or the like, with a reinforcing material, for example, carbon fiber or the like, for improved pressure resistance is also used. Furthermore, when the hydrogen gas stored in, for example, a high-pressure container decreases in amount as it is consumed, the high-pressure container can be re-charged from a hydrogen gas supply source that is installed at a hydrogen gas station or the like. Incidentally, the storage means for hydrogen gas can also be constructed of a plurality of high-pressure containers.
In a gas supply system which supplies a gas from a high-reassure container to a mechanism that functions by using the gas (hereinafter, sometimes referred to as "gas usage mechanism"), for example, a fuel cell, an internal combustion engine, etc., and which is equipped with a plurality of high-pressure containers, if the pressures of the gas stored in the high-pressure containers (internal pressures of the high-pressure containers) vary between a high-pressure containers, the gas flows from the high-pressure container that has relatively high internal pressure to a high-pressure container that has relatively low internal pressure, giving rise to possibility of occurrence of a phenomenon, such as a change in temperature resulting from adiabatic irreversible expansion of the gas in the high-pressure container that has relatively low internal pressure (e.g., the Joule-Thomson effect in hydrogen gas, or the like), or a delay of the rising of the pressure of the gas in the supply channel when the gas starts to be supplied to the gas usage mechanism, etc.
Therefore, in this technical field, with, regard to the aforementioned phenomenon of a change in temperature, there is a technology, for example, in which a gas supply system equipped with a plurality of high-pressure containers is provided with reverse flow prevention means, such as a check valve or the like, for preventing a gas from flowing from a gas supply channel side to the high-pressure containers, in order to prevent an event in which the gas flows from a high-pressure container that has relatively high internal pressure to a high-pressure container that has relatively low internal pressure, and heat production due to adiabatic compression of the gas (and, in the case of hydrogen gas or the like, heat production due to the Joule-Thomson effect associated with adiabatic irreversible expansion of the gas) occurs resulting in rapid rise of the temperature in the high-pressure container that has relatively low internal pressure (e.g., see Japanese Patent Application Publication No. 2002-206696 (JP 2002-206696 A)). There also exists a technology related to a gas supply system equipped with a plurality of high-pressure containers in which, in order to prevent an event in which if the high-pressure containers are charged with a gas when the remaining amounts of the gas in the high-pressure containers are not uniform (i.e., vary), heat production due to adiabatic compression of the gas associated with the charging with the gas occurs concentratedly in a high-pressure container whose remaining amount of the gas is small (whose internal pressure is low), the gas is allowed to flow between the high-pressure containers prior to the charging of the containers with the gas so as to reduce the differences between the internal pressures of the high-pressure containers (e.g., see Japanese Patent Application Publication No. 2005-226716 (JP 2005-226716 A)).
With regard to the phenomenon of delay of the rising of the pressure, however, the fact of the matter is that the latter one of the aforementioned phenomena has not drawn much attention in this technical field. That is, this technical field has not found an effective solution to the delay of the rising of the pressure in the gas supply channel which occurs when the gas starts to be supplied to a gas usage mechanism.
In the meantime, in this technical field there exists, for example, a gas supply system that is equipped with a plurality of high-pressure containers and that determines whether to continue supplying a gas to a gas usage mechanism on the basis of the pressure of the gas in a gas supply channel to the gas usage mechanism. In such a gas supply system, if the pressures of the gas stored in the high-pressure containers (internal pressure) vary among the high-pressure containers, the gas flows from a high-pressure container that has relatively high internal pressure to a high-pressure container that has relatively low internal pressure, so that the rising of the pressure in the gas supply channel when the gas starts to be supplied to the gas usage mechanism delays, as mentioned above. As a result, in the gas supply system, there arises possibility, for example, that the delay of the rising of the pressure in the gas supply channel when the gas starts to be supplied may be incorrectly recognized as resulting from insufficient amount of the gas remaining and the supply of the gas may be incorrectly stopped (and the function of the gas usage mechanism that requires supply of the gas may be incorrectly stopped).
Therefore, in this technical field there is demand for a technology in a gas supply system that supplies a gas from a plurality of gas containers to a gas usage mechanism (e.g., a fuel cell, an internal combustion engine, etc.) which makes it possible to reduce the event in which if the rising of the pressure in the gas supply channel at the time of start of supply of the gas delays due to imbalance in the internal pressure between the plurality of gas containers, it is incorrectly recognized that the remaining amount of the gas is insufficient.


A mobile station comprises a substrate having circuitry adapted to perform communication functions. The mobile station also comprises a keypad adapted to receive input from a user to control the mobile station, wherein at least one key of the keypad is operably coupled to the substrate. The mobile station also comprises an antenna at least partially housed in the at least one key to receive wireless communications. The wireless communications may comprise satellite communications, such as digital multimedia communications. The keypad may comprise input keys adapted to receive input of numbers and characters, and the a multi-key having a plurality of radially arranged buttons. The keypad may also comprise function keys arranged around the multi-key, and a padbase adapted to fix the input keys, the multi-key, and the function keys on the surface of the keypad. The antenna may be positioned in a lower portion of the multi-key.

Mobile stations enable wireless communications between parties. A mobile station may include a satellite antenna to provide digital multimedia services via digital multimedia broadcasting (DMB).
FIG. 1 is a diagram illustrating a disassembled perspective view of a mobile station 100 having a satellite antenna, according to a related art.
Referring to FIG. 1, the mobile station with a satellite antenna includes a body 10 having a connector 17 embedded in one side thereof, and a satellite antenna 30 removably coupled to the connector 17. The body 10 includes a first body portion 11 having a printing circuit substrate mounted therein, and a second body portion 21 slidably coupled to the first body portion 11. The first body portion 11 has a plurality of keys on a front surface thereof to enable users to input data. The first body portion 11 also has a battery 15 removably coupled to a rear surface thereof to supply power. An antenna 13 is coupled to one side of an upper surface of the first body portion 11. Functions of the antenna 13 differ according to communication system type, e.g. cellular system or PCS system. The connector 17 is formed at the other side of the upper surface to allow the satellite antenna 30 to be removably coupled thereto. The second body portion 21 has a display 23 on the front surface thereof for outputting visual information. Keys 25 for inputting data are arranged at one side of the display 23. The satellite antenna 30 includes an (outer) housing 32, a helical antenna installed in the housing 32, and an antenna cable 33 that protrudes downward to the housing 32.
Because the size of the satellite antenna 30 is greater than that of the (cellular/PCS) antenna 13, the satellite antenna 30 is separated from the first body portion 11 when not in use, as shown in FIG. 1. The satellite antenna 30 is used after inserting the antenna cable 33 into the connector 17 for coupling therewith.
Thus, the conventional mobile station with satellite antenna has several problems. As discussed above, using the satellite antenna requires that it be coupled to the connector by inserting the antenna cable thereinto. Furthermore, because the satellite antenna has greater size and is more protruded than the cellular/PCS antenna, the satellite antenna is normally separated from the mobile station when not in use, which may lead to the misplacement of the satellite antenna.


A badge for displaying indicia. The badge includes a base plate that defines a landing area that has a recessed portion. The badge also includes a top panel coupled to the base plate. The top panel defines an at least partially transparent portion. A strip is disposed between the base plate and the top panel and at least partially disposed underneath the at least partially transparent portion such that a portion of the strip is viewable through the at least partially transparent portion. The strip is removable from between the base plate and the top panel without removing the top panel from the base plate.

For convenience of expression, the term "badge" is used hereinafter to identify generically all similar devices, such as badges, business cards, ID cards, luggage tags, signs, key ring tags, and the like. The terms "graphics" or "graphic material," as used herein, includes text, artwork or both.
A large number of badges exist in today's marketplace for displaying identification or other indicia thereon. These typical badges include a display area with indicia thereon. Such indicia can include a wearer's name, an identification number, other words, names, symbols, graphics, illustrations or pictures. Badges are used in a variety of environments, such as service, retail, employment, military, educational, and meeting environments. They are most commonly attached to a wearer's clothing through a variety of means such as pins or adhesives.


A disk brake including a mount member having a pin insertion portion integrally connected to a connection portion so as to outwardly protrude from an outer surface of the connection portion in a radial direction of a disk rotor. A tip of a pin insertion hole of the pin insertion portion is positioned at an inner side of a vehicle relative to an outer portion. Thus, it is possible to prevent a braking torque from affecting the pin insertion portion of the mount member. As a result, it is possible to prevent a slide pin from interfering with an inner wall surface of the pin insertion hole, thereby preventing a brake judder phenomenon from occurring during a braking operation.

The present invention relates to a disk brake for use in braking of a vehicle.
Conventional disk brakes include a mount member attached to a non-rotatable portion of a vehicle, and a caliper, as disclosed in Japanese Patent Public Disclosure No. 2006-207722. The mount member includes a pair of arm portions, and the pair of arm portions are spaced apart from each other along a circumferential direction of a disk and are disposed so as to axially extend over the disk. The caliper is slidably attached to the arm portions of the mount member with use of, for example, slide pins. An inner-side frictional pad and an outer-side friction pad are pressed against the respective surfaces of the disk by the caliper. The slide pins are attached to the caliper, and are slidably fitted in pin insertion holes formed at the respective arm portions of the mount member.
However, according to the disk brake disclosed in Japanese Patent Public Disclosure No. 2006-207722, when the mount member receives a braking torque from the pair of frictional pads, especially due to elastic deformation of an outer-side leg portion of the mount member, the slide pins may interfere with the inner wall surfaces of the pin insertion holes of the respective arm portions. More specifically, the slide pins scrape interiors of the pin insertion holes, thereby increasing sliding resistance between the slide pins and the inner walls of the pin insertion holes during a braking operation, leading to a high possibility of occurrence of a brake judder phenomenon.


A method for producing a dental adaptive element for alleviating recession of gingiva around an alveolar socket of a patient includes: obtaining images of a tooth; creating a 3D model having a crown part and a root part based on the images; obtaining a boundary curve on the 3D model between the crown part and the root part; on the root part of the 3D virtual model, obtaining an imaginary surface that protrudes in a direction from the crown part toward the root part; extracting a sub-model from the 3D model by removing a portion of the root part that extends between the imaginary surface and an end of the root part; and producing a dental adaptive element according to the sub-model.

After extraction of a tooth of a patient, an alveolar socket, in which the tooth was originally embedded, is exposed. In general, tooth extraction results in the loss of 30%-60% of the volume of gingiva and alveolar bone around the alveolar socket in the first six months because of a natural reaction of the human body to absorb the gingiva and the alveolar bone, thereby causing recession of the gingiva. The recession of the gingiva and bone may compromise the placement of a dental implant, function, and aesthetics.
To alleviate the recession of the gingiva and bone, one known procedure is to place a temporary dental crown at an opening of the alveolar socket, thereby blocking the opening of the alveolar socket. However, conventional temporary dental crowns are designed to have standardized sizes and shapes. A dentist can only select one that matches the opening of the alveolar socket in question and most suitably fits the patient's gingiva. However, the fit may not be perfect so the selected conventional temporary dental crown may be too tight or too loose for the opening of the alveolar socket.

Method for producing dental adaptive element for alleviating recession of gingiva


A non-volatile semiconductor memory device is provided which includes a data memory block having a plurality of non-volatile memory cells, in which data in the plurality of non-volatile memory cells of the data memory block is erased before writing data into the non-volatile memory cells of the data memory block. The non-volatile semiconductor memory device further includes: an erase complete data memory region having a plurality of non-volatile memory cells which are subjected to erasure simultaneously with the plurality of non-volatile memory cells of the data memory block; a writing element for writing erase complete data including a plurality of bits into the erase complete data memory region, after erasing data in the non-volatile memory cells of the data memory block and data in the non-volatile memory cells of the erase complete data memory region; and a reading element for reading the erase complete data in the erase complete data memory region.

1. Field of the Invention
The present invention relates to a rewritable non-volatile semiconductor memory device.
2. Description of the Related Art
As are well known in the art, EPROMs (Erasable Programmable Read-Only Memory), EEPROMs (Electrically Erasable Programmable Read-Only Memory), and the like, represent non-volatile semiconductor memory devices into which a user can rewrite data.
In the case of an EPROM, data is written using a writing element called a programmer (or a writer). In an EPROM, UV light is used to collectively erase data stored in the entire array of memory cells.
Each memory cell of an EPROM may be made from a transistor, which reduces the area of the memory cells. This is advantageous in that integration of a mass storage device becomes easy and a bit unit price may be reduced.
However, since data in an EPROM is erased by radiating UV light onto the chip, a ceramic package using expensive quartz glass is required. This limits possible reduction in the chip unit price. Moreover, since data is written by a dedicated writing device (e.g., a programmer, or a writer), an EPROM needs to be installed on a board via a chip-detachable socket. This enables the chip (i.e., EPROM) to be detached in order for the data to be written thereto and thereafter re-attached to the socket. This is not only troublesome but also undesirable in view of cost required for chip installation.
An EEPROM, on the other hand, is desirable in that data can be written and erased while the EEPROM is installed on a board. However, in order to enable writing and erasing, for example, at a bit level, a select transistor is required for each memory cell to enable the memory cell to be selected. Thus, the area required for each memory cell of an EEPROM is about 1.5 to 2 times larger than that of a memory cell in an EPROM. Accordingly, a bit unit price of an EEPROM is increased as compared to an EPROM. An EEPROM is therefore less desirable for application as a mass storage device.
A flash memory has been proposed as a non-volatile semiconductor memory device having advantages of both an EPROM and an EEPROM. A memory cell of a flash memory is disclosed, for example, in U.S. Pat. No. 4,949,158. FIG. 9 is a schematic diagram showing the structure of a memory cell within the flash memory. As shown in FIG. 9, the memory cell according to U.S. Pat. No. 4,949,158 is a floating-gate-type FET (Field Effect Transistor) which is a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) in which a control gate CG is provided on a gate oxide film, with a floating gate FG being provided in the gate oxide film.
In the above-described flash memory, each memory cell is made from one transistor without any select transistor, and a plurality of memory cells are collectively erased at a chip level or at a block level. Accordingly, a bit unit price of the flash memory can be reduced as low as that of an EPROM and the flash memory is applicable as a mass storage device. Furthermore, in the same manner as an EEPROM, data can be written to and erased from the flash memory without detaching the chip from the board. In addition, since no UV light irradiation is required, an inexpensive plastic package can be used.
Generally, a NOR type flash memory and a NAND type flash memory are used. In the NOR type flash memory, transistors of memory cells (hereinafter, simply referred to as "cell transistors") are individually connected to a bit line. In a NAND type flash memory, a plurality of serially connected cell transistors are collectively connected to a bit line. Accordingly, the NAND type flash memory requires small connection areas between the bit line and the cell transistors, and thus the areas of the memory cells can be reduced. However, the access speed for reading data by random access is decreased. Other than the NOR and the NAND flash memories, there are, for example, an AND type and a DINOR type flash memory. In these AND type and DINOR type flash memories, processes of injecting electrons into and removing electrons from the floating gate FG during erase and write operations are opposite to those processes in the NOR and NAND type flash memories. For this reason, hereinafter, only NOR and NAND type flash memories will be described as examples.
In the above-described flash memories, the presence or absence of electrons within the floating gate represents data of "0" or "1".
In order to read data from each cell transistor of the flash memory, a power-supply voltage Vcc (usually about 5 V) is applied to the control gate CG while the source S is grounded (0 V) and a low voltage of about 1 V is applied to the drain D. In the case where no electrons are stored in the floating gate FG, a threshold value of the cell transistor is low such that a drain current (a channel current) flows between the drain D and the source S. In the case where electrons are stored in the floating gate FG, a threshold value of the cell transistor is high such that no drain current flows between the drain D and the source S. Accordingly, data stored in the cell transistor can be read out by detecting the magnitude of the drain current.
Hereinafter, data "0" refers to a state where the threshold value is high because electrons are stored in the floating gate FG, and data "1" refers to a state where the threshold value is low because no electrons are stored in the floating gate FG.
In reading data from the cell transistors, as described above, the voltage applied to the drain D is as low as about 1 V. Otherwise, an application of a high voltage induces undesirable parasitic weak write (soft write).
In order to erase data stored in each cell transistor of the flash memory, a high voltage of about 12 V is applied to the source S while the control gate CG is grounded. By doing so, a high electric field is generated between the floating gate FG and the source S, whereby electrons stored in the floating gate FG are removed as a tunnel current through the thin gate oxide film. Accordingly, a threshold voltage of the cell transistor is reduced, whereby the cell transistor is initialized to a state where data "1" is stored, i.e., data is erased. Such erasing of data is collectively performed on the cell transistors at a chip level or at a block level.
In order to erase data by applying a high voltage to the source S as described above, a withstand level of the source junction with respect to an applied voltage must be increased. This causes some disadvantages. For example, forming fine voltage supply lines that extend to source electrodes becomes difficult, or hot holes generated in the vicinity of the source junctions may be partially trapped in the gate oxide films, thereby deteriorating the reliability of the cell transistors.
In a method for erasing data which has overcome the above-described problem, a power-supply voltage Vcc (usually about 5 V) is applied to the source S while applying a negative voltage of about -10 V to the control gate CG so as to remove the electrons stored in the floating gate FG as a tunnel current (hereinafter, the method is referred to as "a negative gate erase method"). According to the negative gate erase method, a voltage applied to the source S is sufficiently low for the withstand level of the source junction with respect to an applied voltage to be low, and thus gate lengths of the cell transistors may be reduced.
Furthermore, according to a method where a high voltage is applied to the source S, a tunnel current that flows through the cell transistor at the time of erasing data may reach a total of several milliamps (mA) for the entire chip. Since a step-up circuit integrated in the chip has a very small current supply ability, a sufficiently high voltage cannot be supplied. Therefore, not only the power-supply voltage Vcc but also the high voltage used for erasing data needs to be supplied from an external power source. On the other hand, according to the negative gate erase method, a power-supply voltage Vcc is sufficient as a voltage applied to the source S, and thus, a high voltage is not necessary.
After erasing data stored in the cell transistors as described above, data is written into the cell transistors. In writing data into each cell transistor, a high voltage of about 12 V is applied to the control gate CG while the source S is grounded and a voltage of about 7 V is applied to the drain D. Accordingly, a large current flows between the drain D and the source S, and hot electrons with high energy generated in the vicinity of the drain junction are injected in the floating gate FG, whereby electrons are stored, i.e., data "0" is stored.
According to the above-described write operation, only the initialized data "1" is rewritten as data "0" and data "0" cannot be rewritten as data "1". Therefore, in a flash memory, an erase operation is performed to the cell transistors prior to a rewrite operation. In other words, all of the cell transistors in the chip or the block are initialized once, after which cell transistors are selected and data "0" is stored in the selected cell transistors.
In order to inject electrons into the floating gates FG by utilizing hot electrons as described above, a large current of about 1 mA needs to be supplied to each cell transistor at the time of writing. Regarding this fact, a flash memory has been developed which operates in the same manner as an EEPROM, where electrons are injected by utilizing a Fowler-Nordheim (FN) tunnel current, thereby reducing a current required at the time of writing. Accordingly, the power source is simplified in this flash memory.
In each cell transistor of a flash memory, a write operation is performed on a drain junction side and erase operation is performed on a source junction side. Accordingly, in designing the device, it is preferable that each of the junction profiles be individually optimized in accordance with their respective operations. Specifically, a field-concentration-type junction profile is applied to the drain junction so that write efficiency is enhanced, whereas a field-relaxed-type junction profile is applied to the source junction so that a high voltage is applicable at the time of erasing, whereby the drain junction profile and the source junction profile being asymmetrical.
In view of recent portable electronic apparatuses designed to operate using battery power source, or in view of the desirability of producing reduced-size semiconductors, there has been a need for a semiconductor device which can operate with a lower voltage. In order to meet such a demand, semiconductor devices in which a power-supply voltage Vcc is reduced from 5 V to 3.3 V have been vigorously developed. Accordingly, flash memories which are operable with a power source of 3.3 V have also been developed. At present, however, even in a flash memory employing a power source of 3.3 V, a voltage applied to the control gates CG of the cell transistors is supplied by stepping up a power-supply voltage Vcc from 3.3 V to 5 V by a word line step-up circuit integrated on the chip, in order to ensure high speed operation and sufficient operation margin.
The flash memory differs from RAM (Random Access Memory) in that it is capable of selectively setting various operation states such as writing and reading data, collectively erasing a plurality of memory cells at a chip level or at a block level, and reading out from a status register. In the case where these operation states are to be specified by a combination of external control signals such as a chip enable signal /CE, a write enable signal /WE, an output enable signal /OE, or the like, the number of types of control signals need to be increased compared with available EPROMs or EEPROMs. In this case, since additional input terminals are required for the corresponding control signals, the input terminals of the flash memory are no longer compatible with those of the EPROM, EEPROM or the like, thereby rendering the device less usable. Thus, according to a major command system of an actual flash memory, instead of inputting the combinations of control signals, combinations of data or addresses are input as various commands for specifying various operation states. In this case, the flash memory is provided with a command state machine (CSM) for determining each of the various externally input commands, and a write state machine (WSM) for executing the determined command.
Furthermore, the above-described flash memory in which an erase operation is performed at a block level may include blocks of various sizes or blocks of equal sizes (U.S. Pat. No. 4,945,570).
In addition, there is a flash memory in which each block is provided with a BP (Block Protect) data memory region. BP data which inhibits erase and write operations of data in the block is stored so as to protect data in the block. In this particular flash memory, /WP (Write Protect) input terminals are provided to which /WP signals are externally input. When the /WP signal is active (low), BP data in each block is validated. When the /WP signal is inactive (high), BP data in each block is invalidated. Thus, in the case where an active (low) /WP signal is input into the /WP input terminal, when BP data is stored in the BP data memory region, erase and write operations to the block are inhibited, and when BP data is not stored in the BP data memory region, erase and write operations to the block are allowed. In the case where an inactive (high) /WP signal is input into the /WP input terminal, erase and write operations to the block are allowed regardless of the presence of BP data in the BP data memory region of the block.
Instead of providing /WP input terminals, a WP setting command and a WP releasing command may be used, in which case there is no need for increasing the number of the input terminals. Specifically, when a WP setting command is input to a flash memory employing the above-described command system, a /WP signal stored in the flash memory is activated (low). When a WP releasing command is input to the flash memory employing the above-described command system, a /WP signal is inactivated (high). In this manner, the BP data in the BP data memory region is either validated or invalidated. Since /WP input terminals are not necessary in this case, compatibility between input terminals of the flash memory and input terminals of an EPROM, EEPROM or the like is maintained.
However, cell transistors of a flash memory may be in an excessive erase state where electrons are excessively removed from floating gates FG during the course of an erase operation, whereby a threshold value of the cell transistor becomes a negative voltage. Since select transistors are omitted in the cell transistors, when the threshold value of the cell transistor becomes a negative voltage during the course of the erase operation, a leakage current is generated in non-selected cell transistors which share the same bit line as the selected cell transistors during the course of a read operation. As a result, data stored in the selected cell transistors is not accurately read out, which results in a critical defect.
In order to prevent such an excessive erase in such a flash memory, a pre-write operation (Program Before Erase) is performed which provides electrons, i.e., which writes data "0", beforehand in a floating gate FG of each cell transistor which is to be subjected to an erase operation, thereby standardizing the amount of electrons in the floating gates FG of all of the cell transistors. Accordingly, in an erase operation following the above-described pre-write operation, electrons stored in the floating gates FG of all of the cell transistors are equally removed, thereby preventing electrons from being excessively removed from floating gates FG of only some of the cell transistors.
In an erase operation, after a short period of erase process, whether or not the erase process has completed is confirmed by an erase verification. The short period of erase process and erase verification are repeated until data in all of the cell transistors are completely erased. According to the above-described method, unnecessary removal of electrons from the floating gates FG of the cell transistors is prevented.
In the above-described flash memory, however, a significantly long period of time (e.g., several hundreds of milliseconds) is required for erasing data in every cell transistor. Thus, a probability of a power source being cut-off or a reset signal being received during an erase operation is increased during this long erase operation. The erase operation may be forcibly terminated as a result, and the probability of this occurring is not negligible.
When an erase operation of a cell transistor is terminated for some abnormal reason, not all of the data in the cell transistor is initialized as data "1" (where a threshold value of the cell transistor is small) and a part of data in the cell transistors will remain as data "0" (where a threshold value of the cell transistor is large). Since a write operation is only capable of rewriting initialized data "1" as data "0" as is described above, data "1" is written by remaining the initialized data "1" unchanged. Thus, when data of the cell transistors partially remain as data "0" after the erase operation, data "1" cannot be written into such cell transistors.
For this reason, the flash memory is troublesome in that a possibility of data not being completely erased for all cell transistors is a concern. This complicates programming of a system incorporating the flash memory.
Alternatively, there is a flash memory which is provided with a status register for storing a bit representing whether or not the erase operation has succeeded.
However, when the erase operation is forcibly terminated due to the cut-off of the power source or a reset of the device, the status register is reset as well. Thus, whether or not the erase operation has been successful is no longer confirmed by the register in such situation.
A counter measure against the above-described forcible termination of the erase operation is disclosed in Japanese Laid-Open Publication No. 5-325577. FIG. 10 is a block diagram showing a flash memory device according to this conventional method. Referring to FIG. 10, a flash memory card 101 includes an I/O port 102, a power control section 103, a terminal control section 104, an address latch section 105, an address control section 106, first to eighth flash memory ICs 107a to 107h, a data bus 108 connected between the I/O port 102 and each of the flash memory ICs 107a to 107h, and an address bus 109 connected between the address control section 106 and each of the flash memory ICs 107a to 107h.
In the flash memory card 101, when data stored in the first flash memory IC 107a is erased, data "0" as a flash memory IC erase complete information is written into a flash memory card final address (i.e., an erase area recording region). Furthermore, when data stored in the second flash memory IC 107b is erased, data "0" as a flash memory IC erase complete information is written into an address preceding the flash memory card final address (i.e., the erase area recording region). This process is repeated for every erase operation of the flash memory ICs 107a to 107h.
According to the above-described method, the erase complete information is 1 bit. When the erase operation is forcibly terminated due to cut-off of the power source or a reset of the device (in other words, when sequential processes of pre-writing data as "0" and initializing the pre-written data as "1" are forcibly terminated), the erase complete information cannot be specified as data "0" or "1". In this case, whether or not the erase operation has been successful cannot be confirmed.
Therefore, when the erase operation is forcibly terminated due to the cut-off of the power source or reset of the device, for example, the only way to confirm whether or not data has been successfully erased is to read out data from every cell transistor one-by-one. Since data "0" is no longer writable, the write operation should not be continued and thus additional error operation is required, thereby complicating programming of a system incorporating the flash memory.

Non-volatile semiconductor memory device


A substrate processing apparatus comprises a reaction chamber which is to accommodate stacked substrates, a gas introducing portion, and a buffer chamber, wherein the gas introducing portion is provided along a stacking direction of the substrates, and introduces substrate processing gas into the buffer chamber, the buffer chamber includes a plurality of gas-supply openings provided along the stacking direction of the substrates, and the processing gas introduced from the gas introducing portion is supplied from the gas-supply openings to the reaction chamber.

1. Field of the Invention
The present invention relates to a substrate processing apparatus and a reaction container, more particularly, to a substrate processing apparatus and a reaction container used in one step of producing process of a semiconductor device for processing a substrate in a reaction chamber, and more particularly, to an improvement of a gas introducing portion which supplies gas to a substrate.
2. Description of the Related Art
A conventional technique for processing a substrate in a reaction chamber by a CVD (Chemical Vapor Deposition) method or an ALD (Atomic Layer Deposition) method will be briefly explained with reference to FIG. 14 while taking a vertical type substrate processing apparatus as an example.
FIG. 14 is a schematic sectional view of the inside of a reaction tube which is a reaction chamber in the conventional vertical type substrate processing apparatus.
A plurality of wafers 107 are stacked on a boat 108 as substrates to be processed. The boat 108 is inserted into a reaction tube 106. A gas nozzle 101 as a gas introducing portion for processing the wafers 107 in the reaction tube 106 is provided in the reaction tube 106.
The gas nozzle 101 is provided with a plurality of gas nozzle holes 103 (five in the example shown in FIG. 14). With this arrangement, processing gas flows into the gas nozzle 101 from a gas introducing opening 105, and is supplied to the wafers 107 from the gas nozzle holes 103.
The gas supplied to each wafer 107 passes through a process for forming a desired film on the wafer 107 and then, is discharged out from the reaction tube 106 through an exhaust opening 118.
However, when all of the gas nozzle holes 103 provided in the gas nozzle 101 have the same opening areas, there is a problem that a flow rate and flow velocity of gas supplied from the gas nozzle holes 103 to the wafers 107 are reduced from an upstream side closer to the gas introducing opening 105 toward a downstream side further from the opening 105.
That is, if the apparatus for collectively processing the plurality of wafers 107 shown in FIG. 14 is considered from a viewpoint of gas supply with respect to each of the wafers, it seems that the gas nozzle 101 supplies gas uniformly to the wafers 107, but in reality, a difference in the gas flow rate or flow velocity is generated, and the gas is not supplied to all of the wafers 107 under the same conditions.
For example, if the five gas nozzle holes 103 provided in the gas nozzle 101 are defines as a first hole, a second hole, . . . and a fifth hole from the upstream side closer to the gas introducing opening 105 of the gas nozzle 101 toward the downstream further from the opening 105, and if the flow rates of gas supplied from the respective gas nozzle holes 103 are defined as q1, q2 . . . q5, a relation of q1>q2> . . . >q5 is established.
Concerning the flow velocities of gas also, a velocity of gas from the first gas nozzle holes 103 is the fastest, and velocities of gas from the second, third, . . . are gradually reduced.
As a result, the flow rates and flow velocities of gas supplied to the wafers 107 become nonuniform.
Therefore, in the process of wafers which largely depends of a supply amount of gas, the film forming states of the stacked wafers 107 become nonuniform.
Referring back to FIG. 14, a cause of the nonuniformity of the supply amount of gas will be considered.
In the gas nozzle 101 in a state in which gas is supplied to the wafers 107, a gas flow rate between the introducing opening 105 and the first gas nozzle hole 103 is defined as q00 and a gas pressure therebetween is defined as p0. Next, a gas flow rate between the first and second gas nozzle holes 103 is defined as q01 and a gas pressure therebetween is defined as p1. Similarly, a gas flow rate between the n−1-th and n-th gas nozzle holes 103 is defined as q0(n−1) and a gas pressure therebetween is defined as pn−1.
A flow rate of gas injecting from the n-th gas nozzle hole 103 is defined as qn.
At that time, gas flow rates qn (n=1, 2, . . . ) injecting from the plurality of gas nozzle holes 103 provided from the upstream side to the downstream side and having the same opening areas are reduced from the upstream gas nozzle hole toward the downstream gas nozzle hole as shown in the following expression (1):q1>q2> . . . >qn−1>qn  (1).
This is because, in the case of gas flowing from the upstream side toward the downstream side through the gas nozzle 101, its gas flow rate q0(n−1) is reduced by a gas flow rate qn injecting from the gas nozzle hole 103 when the gas passes through the gas nozzle hole 103, and the gas flows toward a next gas nozzle hole. A flow rate of gas after the gas passed through the gas nozzle hole 103 is reduced from the upstream side toward the downstream side as shown in the following expression (2):q0n=q0(n−1)−qn  (2)
At that time, a gas concentration of fluid in the gas nozzle 101 is reduced by a flow rate of gas injecting from the gas holes from the upstream side toward the downstream side. Since there is a correlation between the gas concentration and gas pressure, a gas pressure pn at a location in the gas nozzle 101 corresponding to the gas nozzle hole 103 is reduced from the upstream side toward the downstream side as shown in the following expression (3):p1>p2> . . . >pn−1>pn  (3)
Therefore, flow rates of gas injecting from the respective gas nozzle holes 103 do not become equal to each other. If an opening area of the gas nozzle hole 103 is defined as S, a flow velocity V of gas injecting from the gas nozzle hole is expressed as shown in the following expression (4):V=qn/S  (4)
Since the flow rates of gas injected from the respective gas nozzle holes 103 are not equal to each other, if the opening areas of the nozzle holes are the same, flow velocities of gas injected from the respective gas nozzle holes 103 become different. In the above-described conventional gas nozzle 101, since the flow rates and flow velocities of gas injected from the respective gas nozzle holes 103 are different, it is considered that gas can not be supplied to the wafers uniformly.
To solve the above problem, two conventional solutions have been proposed.
According to a first solution, opening areas of the gas nozzle hole 103 are increased from the upstream side toward the downstream side, and a gas flow rate which is reduced toward the downstream side is supplemented by increasing the opening area. However, if the gas flow rates are equalized by adjusting the opening areas, the gas flow velocities are adversely varied depending upon the size of the opening area. Therefore, gas injecting from the gas nozzle holes 103 is nonuniform in the flow velocity.
According to a second solution, a capacity of the gas nozzle itself is increased to such a degree that such a large amount of gas that the injecting amount can be ignored is stored so that even if gas is injected from the gas nozzle holes 103 from the upstream side toward the downstream side, gas pressures in the gas nozzle 101 at locations corresponding to the respective gas nozzle holes 103 are not changed, thereby equalizing the flow rates of gas injecting from the gas nozzle holes 103. However, if the capacity of the gas nozzle itself is increased to such a size that the gas pressure in the gas nozzle 101 is not affected by the gas injecting amount, since there is limitation in space of the reaction chamber which accommodates the gas nozzle, this is not practical.
The above problem is not limited to a wafer, and a substrate in general also has the same problem.

Substrate processing apparatus and reaction container


A sauna apparatus includes an air blower, a blow channel and a humidifier. The air blower suctions and blows air. The blow channel conveys the suctioned air and humidified air. The humidifier has a sprayer that sprays humidifying water into the air passing through the blow channel for humidification, and a spray-water droplet splitter installed in a direction to which the sprayer sprays the water for humidification. By letting the sprayed water droplets collide with the splitter, the water droplets are split into much finer water droplets.

FIG. 10 is a schematic diagram showing a constitution of a conventional sauna apparatus. This type of sauna apparatus is disclosed in Unexamined Japanese Patent Publication No. H2-264659, for instance. A conventional sauna apparatus is described hereinafter.
The sauna apparatus has discharge port 102 and suction port 103 both opening into bathroom 101. Suction port 103 is communicated to discharge port 102 through blow channel 104. In blow channel 104, spray nozzle 105 (hereinafter, referred as 'nozzle') is installed. Nozzle 105 is connected to warm water supply 106. Cross flow fan 107 is installed at suction port 103.
Hot air generator 108 installed in a middle of blow channel 104 has case 109. Case 109 is provided with suctioned-air communication port 110, blow-air communication port 111, and drain port 112. Suctioned-air communication port 110 is communicated with the suction side of blow channel 104 and blow-air communication port 111 is communicated with the discharge side of blow channel 104. Inside case 109, a plurality of air flow directing plates 113 are disposed. Air flow directing plates 113 constitute meandering mixing room 114. Suctioned-air communication port 110 and blow-air communication port 111 are communicated to each other through meandering mixing room 114. Nozzle 105 is installed near the suctioned-air communication port 110 side rather than the meandering mixing mouth 114 side. In the sauna apparatus thus constituted, warm water spray sprayed by nozzle 105 is mixed with air in meandering mixing room 114. The air is thus humidified and heated and then sent into bathroom 101 through discharge port 102.
With this conventional sauna apparatus, when hot water is sprayed in blow channel 104, water droplets having a relatively large diameter are produced. Accordingly, the suctioned air is not efficiently humidified and an effective humidification amount is not obtained. For this reason, producing finer water droplets and sending out a much larger amount of the water droplets are required.
When water droplets of a large diameter are blown out from discharge port 102, a person in the bathroom feels unpleasant with the droplets. For this reason, it is desired to control generation of the large diameter droplets or collecting such droplets efficiently. In order to solve this task, a conventional constitution needs a countermeasure such as installing a plurality of air flow directing plates 113 of a large scale. However, such constitution increases air flow resistance, or makes the constitution complicated.


A method is provided for removing organic impurities in the recycling of phosphors from fluorescent lamps. Particles created from the lamps are washed with a bleaching agent to decompose the organic materials. The organic materials are thereby solubilized and can be removed. The phosphors can then be recovered and reused to manufacture fluorescent lamps.

Fluorescent lamps are typically constructed from a sealed glass tube that contains a small amount of mercury and an inert gas such as argon, xenon, neon, or krypton. Electrodes made of e.g., coiled tungsten are placed at different ends of the tube and are connected with an electrical circuit. When the mercury is properly vaporized within the lamp tube, applying a sufficient voltage difference across the electrodes will cause a current to flow through the gas in the tube thereby exciting the gas molecules and causing a release of photons—albeit in the form of short wave, ultraviolet light—a wavelength that does not provide the visible light that is desired.
The inside of the gas tube generally comprises a layer which includes phosphors—i.e. substances that can luminesce or give off light. More particularly, these phosphors are commonly applied as a paint-like coating to the inside of the tube. Organic solvents in the applied coating are allowed to evaporate leaving behind the phosphors. The tube may also be heated to remove residual solvent and fuse the coating to the lamp tube.
Photons released from the excited gas are absorbed by this coating of phosphors. In turn, the phosphors also emit photons but at a longer wave length than the photons released from the excited gas and, more importantly, at a wavelength that provides visible light. Variables such as the length of the glass tube determine how much visible light is provided by a particular lamp.
Advantageously, the fluorescent lamp converts the electrical energy supplied to its electrodes into a useful light more efficiently than a traditional incandescent lamp. In fact, much of the energy supplied to an incandescent lamp is lost in the form of heat. As a result, the fluorescent lamp is relatively less expensive to operate than an incandescent. Although the initial cost of a fluorescent is somewhat higher due to a ballast that is required in order to regulate the current, this cost is typically recovered in saved energy costs. Thus, the use of fluorescent lamps has become ubiquitous particularly in commercial applications.
For various reasons, after a period of use, fluorescent lamps eventually require replacement. By way of example, the electrodes may eventually fail, the small amount of mercury in the tube may absorb into the glass, the efficiency of the phosphors in absorbing and emitting photons may decrease, and other reasons may require replacement as well. As a result, a significant amount of fluorescent lamps must be disposed of each year.
The phosphors used in fluorescent lamps are typically rare earth compounds of various types. For example, europium-doped yttrium oxide (YEO) is widely used in fluorescent lamps as a red-emitting phosphor. Yttrium oxide that has been doped with other lanthanide series rare earth metals can also be used. A blend of phosphors, sometimes referred to as a triphosphor blend, is commonly used to provide white light from e.g., a red-emitting phosphor, a green-emitting phosphor, and a blue-emitting phosphor.
While the amount of phosphors used in producing an individual fluorescent lamp is relatively small, these phosphors are valuable materials. As such, recycling phosphors from discarded fluorescent lamps is desirable. Unfortunately, certain challenges are presented in attempting to reclaim these phosphor materials.
For example, the phosphors must be separated from multiple other materials that are used in the construction of the fluorescent lamps. These other materials can include glass used in constructing the tube, metals for the electrodes and other components, and plastics for parts such as a lamp base. In addition, certain organic materials may be present. These impurities may be introduced, for example, at some point between disposal of a spent lamp and recovery of the lamp from a waste disposal facility. The organic impurities can also result from the pyrolysis of a variety of materials during a mercury retorting heat treatment. Regardless, the organic impurities can discolor the phosphors causing them to exhibit e.g., a grey appearance and can also reduce the desired excitation by photons from the energized gas as discussed above.
One method for removing such organic impurities involves heating the recovered fluorescent lamp materials to a high temperature in the presence of a special atmosphere. Unfortunately, this process can be detrimental to some phosphors. Additionally, many of these organic materials may not be water soluble and, therefore, cannot be sufficiently removed by washing with water. Oxidizing acids or bases can be used but such can also result in phosphor damage and/or dissolution especially to yttrium europium oxide.
Accordingly, a process for the recycling of phosphors from fluorescent lamps would be useful. More particularly, a process for separating organic materials from the phosphors used in fluorescent lamps would be beneficial. Such a process that can be used with a variety of different phosphors and organic materials would also be particularly useful.

Chemical bleaching for improved performance of recycled lamp phosphors


A method for the additive manufacturing of a closed-cell porous matrix is described herein. A powder-bed, additive manufacturing process is used to create a piece with partially-closed cavities filled with unfused powder. Vacuum, negative pressure, positive pressure, or solvent is used to evacuate the powder from the cavities. Finally, a fresh layer of powder is used to cover the opening of the cavity and the powder is fused on top to close the opening.

Cellular solids are space-filling assemblies of prismatic or polyhedral cells with solid edges or faces. Solid cellular materials can be classified into lattices (with solid edges and open faces), honeycomb structures (two-dimensional arrays of cells with solid faces), as well as sponges (solids filled with inter-connected cavities) and foams (structures where cavities are not connected). Examples of these cellular materials are presented in FIGS. 5A-5F. These structures can be further classified into periodic and stochastic assemblies as well as into open-cell or closed-cell topologies as represented on the chart in FIG. 6A.
Cellular solids have low relative density ρ (defined as the ratio of the volume of lattice material to the volume of the unit cell)—usually below 0.3 and can have a number of advantages over solid (non-cellular) counterparts such as lower weight for structural applications, superior thermal and sound insulation, better energy absorption, and higher surface area, making the cellular materials a great fit for many engineering applications. Due to these advantages, cellular structural topologies appear ubiquitously in nature—from bees' honeycombs to internal bones' structure and plants' morphology. Non-limiting examples of applications for the various classes of cellular materials are presented in FIG. 6B.
Depending on topologies of unit cells, the cellular materials can be broadly separated into bending-dominated and stretching-dominated structures where stiffness and mechanical strength of stretching-dominated structures are typically superior to that of bending dominated structures. It has been demonstrated that stretching-dominated behavior is mainly associated with closed-cell morphology.
There are a wide variety of fabrication approaches to manufacture open-cell lattices with metal alloys (for example, via weaving wires, additive manufacturing with e-beam and selective laser melting, stereolithography with subsequent metal plating, deformation forming, or investment casting. Similarly, additive manufacturing techniques such as selective laser sintering (SLS) and microstereolithography can be used to produce polymer lattices. Meanwhile, majority of sponges and foams are produced by air bubbling or gas generation during matrix solidification, resulting in distribution of pore sizes. One approach to produce a regular foam employs consolidation of hollow metal spheres that fuse together (for example, via isostatic pressure), but this approach results in several types of porosities—those of inner voids inside the spheres and the interstitial voids between the spheres, additionally, only low relative density is possible to achieve with this approach. Modification of hollow sphere consolidation technique employs several types of metal powder where smaller powder fills the interstitial sites between the hollow spheres. Presently, no fabrication approach exists that would produce regular polymeric foam.
Additive manufacturing systems are used to print or otherwise build 3D substrates from digital representations of the 3D substrates using one or more additive manufacturing techniques. Examples of commercially available additive manufacturing techniques include jetting, selective laser sintering, powder/binder jetting, electron-beam melting, and stereolithographic processes. For each of these techniques, the digital representation of the 3D substrates is initially sliced into multiple horizontal layers. For each sliced layer, a tool path is then generated, which provides instructions for the particular additive manufacturing system to print the given layer.
A subset of additive manufacturing methods is the powder-bed methods. Using current powder-bed methods, it is 'impossible' to fabricate a hollow but fully enclosed element. This is because the un-sintered powder within the element cannot be drained. While other additive manufacturing methods such as filament based methods can be used to manufacture hollow substrates, there are certain limitations to these methods which are solved by powder-bed methods. For example, powder-bed methods can be used with a much wider range of materials, unlike filament based methods.
It would be beneficial to be able to fabricate substrates that could have enclosed cavities since it could provide lighter substrates without significant sacrifice in the substrate's strength and enhance properties of the substrate (for example, lowered heat conduction while retaining high electrical conduction). It is also possible to create a functionally graded substrate where a property (such as density, heat conduction, etc.) of the substrate in specific area of the substrate would depend on size and spacing of the enclosed cavities. This present invention, for the first time, demonstrates additive manufacturing approach for production of regular polymeric foams.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.

Powder bed additive manufacturing method of fabricating a porous matrix

THE REGENTS OF THE UNIVERSITY OF CALIFORNIA


A device and method are provided to allow the flowpaths in a fuel cell stack to be reconfigured dependent on reactant gas throughput in order to maintain appropriate pressure drop, sufficient velocities, and reactant concentrations of each cell of a fuel cell stack.

Fuel cells have been used as a power source in many applications, for example, fuel cells have been proposed for use in electrical vehicular power plants to replace internal combustion engines. In proton exchange membrane (PEM) type fuel cells, hydrogen is supplied to the anode of the fuel cell, and oxygen is supplied as the oxidant to the cathode. A typical PEM fuel cell and its membrane electrode assembly (MEA) are described in U.S. Pat. Nos. 5,272,017 and 5,316,871, issued Dec. 21, 1993 and May 31, 1994, respectively, and commonly assigned to General Motors Corporation. MEAs include a thin, proton transmissive, non-electrically conductive solid polymer electrolyte membrane having the anode catalyst on one of its faces and a cathode catalyst on the opposite face.
The term "fuel cell" is typically used to refer to either a single cell or a plurality of cells (stack) depending on the context. A plurality of individual cells are commonly bundled together to form a fuel cell stack. Each cell within the stack comprises a membrane electrode assembly which provides its increment of voltage. Typical arrangements of multiple cells in a stack are described in U.S. Pat. No. 5,763,113 assigned to General Motors Corporation.
The electrically conductive elements sandwiching the MEAs may contain an array of channels or grooves in the faces thereof for distributing the fuel cells gaseous reactants over the surfaces of the respective cathode and anode. In the fuel cell stack, a plurality of cells are stacked together in electrical series while being separated one from the next by a gas impermeable, electrically conductive bipolar plate. The bipolar plate of a fuel cell stack has a practical volumetric flow turndown capability of about 10:1. This limitation can be partially addressed by reducing inlet pressure and/or increasing the stoichiometric ratio as stack throughput decreases. With a pressure turndown of about 3 and a low-flow anode stoichiometry of 4, one can realize a stack turndown ratio of about 120:1. Unfortunately, higher inlet pressure (at high throughputs) and/or higher reactant stoichiometries (at low throughputs) require more parasitic losses to be incurred, reducing system efficiency. Distribution of the reactants to each and every cell in the stack is accomplished by providing some pressure drop between the inlet and outlet manifolds. This pressure drop causes the flow to distribute more uniformly across all of the cells.
Therefore, it is desirable to provide a system that maintains a reasonable pressure drop while providing sufficient velocities and reactant concentrations at each cell for varying throughputs.

Device and method to expand operating range of a fuel cell stack