A fuel cell stack in which at least one of a plurality of fuel cell units constituting a fuel cell stack includes a water absorbing member with a surface exposed to the atmosphere in a portion where an oxidizer flow path forming member and a separator are in contact with each other, and an area of a surface exposed to the atmosphere of the water absorbing member of the fuel cell unit the temperature of which becomes relatively lower is larger than an area of a surface exposed to the atmosphere of the water absorbing member of the fuel cell unit the temperature of which becomes relatively higher.

1. Field of the Invention
The present invention relates to a fuel cell stack, and more particularly, to a fuel cell stack in which water discharge ability and water holding property of an oxidizer flow path of a fuel cell unit in the stack are designed depending on the temperature distribution during electrical power generation.
2. Description of the Related Art
The polymer electrolyte fuel cell basically includes a polymer electrolyte membrane having proton conductivity and a pair of catalyst layers and electrodes provided on both surfaces of the polymer electrolyte membrane.
The catalyst layer generally includes a catalyst layer made of platinum or a platinum group metal catalyst. A gas diffusion layer is provided on the outside of the catalyst layer, for supplying a gas and collecting current.
An assembly in which the polymer electrolyte membrane and the catalyst layers are integrated into one is referred to as a membrane electrode assembly (MEA), and a fuel (hydrogen) is supplied to one of the electrodes and an oxidizer (oxygen) is supplied to another electrode to perform power generation in the process of generating water.
The electrode that is supplied with the fuel is called a fuel electrode, and the electrode that is supplied with an oxidizer is called an oxidizer electrode. Electrical power is drawn from the electrodes located on both sides.
Although the theoretical voltage of a fuel cell unit having one membrane electrode assembly is about 1.23 V, there are many cases where a fuel cell unit is driven at about 0.7 V in a normal operation state, and a part of the reaction energy is converted into heat.
Accordingly, in a case where a higher activation voltage is required, a plurality of fuel cell units are stacked, and the respective fuel cell units are electrically connected in series and used.
This type of stack structure is called a fuel cell stack. In the stack, normally, an oxidizer flow path and a fuel path are isolated by a member called as a separator. Each of the plate-shaped separators is provided with a recessed portion and a protruding portion. A recessed portion facing the membrane electrode assembly is used as a gas flow path, and a protruding portion is used as a current collecting portion.
In such a fuel cell stack, a plurality of fuel cell units generate electrical power simultaneously, and the ratio of heat radiation varies depending upon respective portions of the stack because of the stack structure. The heat generated accompanying the electrical power generation is more likely to stay in the fuel cell unit located at the center of the stack, and is more likely to be released from fuel cell units located at either end. Therefore, a temperature distribution is generated in the stack direction such that the temperature is the highest at the center and is relatively lower at both ends. Due to such a temperature distribution, the respective fuel cell units of the fuel cell stack generate electrical power under different temperature conditions.
Therefore, the following inconveniences are likely to occur.
First, flooding is more likely to occur in fuel cell units located at both ends in the stack direction. Flooding is a phenomenon in which water generated at the oxidizer electrode condenses to decrease the gas diffusion of the oxidizer electrode, which degrades fuel cell characteristics. When a temperature distribution is generated in the stack, since water is more likely to condense in fuel cell units having lower temperatures, flooding is more likely to occur in fuel cell units located at the ends.
Furthermore, a dry-out is more likely to occur at the cell units located at the central part in the stacking direction. The dry-out is a phenomenon in which the water content in the polymer electrolyte decreases with the temperature increase, resulting in the internal resistance in the cell unit, which causes a degradation of the fuel cell characteristics.
The dry-out phenomenon is likely to occur at a position where the temperature is sufficiently high so that water generated at the oxidizer electrode does not condense, but is transpired.
In order to eliminate the instability of the characteristics due to such temperature distribution, Japanese Patent Application Laid-Open No. 2005-340173 proposes a fuel cell stack in which there is a distribution in the amount of air provided to each cell unit of a fuel cell stack.
Specifically, the sectional area of an oxidizer flow path formed in a separator of each cell unit, which has a low temperature and is located at an end, is set to be the largest.
By virtue of this structure, the amount of air supplied at both ends becomes large. Therefore, even when the temperature is lower, water hardly condenses, so that the variation in the degree of flooding in the stacking direction is reduced.
Furthermore, Japanese Patent Application Laid-open No. 2004-311279 proposes the following fuel cell. The fuel cell is configured such that the pressure loss of the gas in fuel cell units at both ends of a fuel cell stack is set to be smaller than in the other fuel cell units, whereby a decrease in the ability to discharge generated of water in the fuel cell units at both ends of the stack having lower temperatures and the inconvenience, such as blocking a gas flow path involved therein, can be suppressed.
However, the above-mentioned conventional examples disclosed in Japanese Patent Application Laid-open Nos. 2005-340173 and 2004-311279 have the following problems.
In the fuel cell stacks with configurations disclosed in Japanese Patent Application Laid-open Nos. 2005-340173 and 2004-311279, in order to discharge generated water and to reduce the variation in temperature, it is necessary to generate the flow of an oxidizer with a blower or the like.
More specifically, it is necessary to set auxiliary devices, such as an air circulation mechanism and a blower, and to supply electrical power for driving the auxiliary devices.
Thus, for example, in mobile applications and the like, where the size of the fuel cell system needs to be reduced as much as possible, this creates problems in terms of the size and weight.


A method is disclosed for enforcing the sequential playback of a multimedia file. In one aspect of the method, a sending server stores a multimedia file which is then partitioned into a plurality of sequential data blocks. The server generates a plurality of enabling tokens each corresponding to one of the plurality of sequential data blocks. The server then encodes each respective one of the pluralities of sequential data blocks with a corresponding one of the plurality of enabling tokens, producing a plurality of encoded sequential data blocks. The server then transfers the encoded sequential data blocks to a receiving client. The server also transfers the plurality of enabling tokens to the receiving client. In this manner, the server retains control over the client receiver's playback of the multimedia file.

Media delivery today is done either by preloading a media file to local cache and then giving the user access to the contents of the file or, alternately, using streaming technology. In streaming technology, a media file is delivered in real time. Advantages of preloading include that there is no real time requirement as is needed for streaming and one can avoid unpredictable playback defects due to unpredictable congestion on the network. Disadvantages of preloading include the likely probability that a stored media file may not be secure and the possibility of unauthorized playback or copying of the stored media file may occur. In addition, the content of the media file delivered has only coarse control when accessed or played back. For example, the deliverer or copyright owner of the media file may impose a time limit for authorized access or playback of the stored media file. Additionally, the deliverer or copyright owner would not normally know exactly how much time was actually spent by the user accessing or playing back the media file. Furthermore, the deliverer or copyright owner would not normally know precisely when access or playback of the media would have occurred and at what time such access or playback actually occurred. Playback information would typically be available only in broadcast mode in the prior art, since the deliverer or copyright owner would know exactly when each segment of the media file was broadcast, to whom it was broadcast, and to whom it would have been received by or delivered to.
Advantages with prior art broadcast mode streaming techniques are similar to the advantages with on-demand or multicasting on the internet. The deliverer or copyright owner will know exactly when every portion of the media is delivered. Disadvantages of broadcast mode streaming, on-demand or multicasting, are that the bandwidth requirements are typically significant, many users with differing receiving equipment are typically participating, and many of the receiving users may request diverse media file contents. Streaming does have the advantage, however, that one receives media only as desired.
What is needed is the ability to deliver a media file to a cache which is local to a user, but which is not accessible by the user until the media file deliverer or copyright owner authorizes access to or playback of the media file.

Digital media delivery with local cache and streaming tokens

International Business Machines Corporation


Provided are a carbon nanotube in which a difference between a thermal decomposition initiation temperature and a thermal decomposition termination temperature is less than or equal to approximately 250° C., an electron emission source including the carbon nanotube, and an electron emission device including the electron emission source.

1. Field of the Invention
The present invention relates to a carbon nanotube, an electron emission source including the carbon nanotube, and an electron emission device including the electron emission source. In particular, the present invention relates to a carbon nanotube in which a difference between a thermal decomposition initiation temperature and a thermal decomposition termination temperature is less than or equal to 250° C., an electron emission source including the carbon nanotube, and an electron emission device including the electron emission source.
2. Description of the Related Art
Electron emission devices are displays that create images by emitting light by having phosphors in a phosphor layer of an anode plate collide with electrons emitted from electron emission sources of a cathode under an electric field generated when a voltage is applied to the anode and the cathode.
Carbon-based materials, including carbon nanotubes having good electron conductivity, have properties such as a good field enhancement effect, low work function, good field emission property, low driving voltage, and an ability to be fabricated over a large area. Therefore, carbon-based materials are good electron emission sources for electron emission devices.
Korean Patent Laid-Open Publication No. 2002-0040133 discloses a method of growing carbon nanotubes for field emitters of a field emission display, e.g., a method of growing carbon nanotubes for field emitters of a field emission display, including forming a Fe—Ni or Ni—Fe alloy layer on a support substrate, forming a catalytic metal layer on the alloy layer, and growing the carbon nanotubes on the catalytic metal layer.
Japanese Patent Laid-Open Publication No. 2003-059436 discloses a cathode substrate and an anode substrate for a carbon nanotube field emission display and a method of forming a cathode substrate. According to this patent publication, the cathode substrate includes a glass substrate, a cathode layer patterned into a plurality of electron emission areas on the glass substrate, and a plurality of carbon nanotube structures grown on the electron emission areas.
Carbon nanotubes having the above-described carbon nanotube structures and other common carbon nanotube structures decompose at a temperature of approximately 400° C. or greater. The thermal decomposition of carbon nanotubes causes a loss of carbon nanotubes when the upper and lower plates are sealed during fabrication or when a carbon nanotube paste is fired, thereby reducing an amount of electron emission and a lifetime of the cathode.

Carbon nanotube, electron emission source including the carbon nanotube, electron emission device including the electron emission source, and method of manufacturing the electron emission device


A foldable articulation for a playpen includes a mounting seat, two pivot rods pivotally mounted on two opposite ends of the mounting seat, and a folding device mounted on the mounting seat and releasably rested on each of the two pivot rods. Thus, the articulation is operated to fold the playpen when not in use, thereby saving the space of storage. In addition, a user only needs to press the press member of the folding device to fold the articulation, so that the user's one hand will not be inserted into the inside of the mounting seat, thereby preventing the user's one hand from being clamped so as to protect the user's safety.

1. Field of the Invention
The present invention relates to a foldable articulation, and more particularly to a foldable articulation for a playpen.
2. Description of the Related Art
A conventional foldable articulation for a playpen comprises a base, a press block and two support seats. The foldable articulation is pivotally mounted between any two support rods of the playpen, so that the playpen can be expanded and folded by operation of the foldable articulation. However, the folding angle of the support rods is not limited, so that when the user exerts a force on the support rods to fold the support rods, the user's fingers are easily clamped and hurt.
Another conventional foldable articulation for a playpen was disclosed in the Taiwanese Patent Application No. 00261742 and comprises an inner mounting block, an outer mounting block, a slide and a plurality springs. The foldable articulation is mounted between any two support rods of the playpen, so that the playpen can be expanded and folded by operation of the foldable articulation. However, such a conventional foldable articulation has a complicated construction, thereby increasing costs of fabrication, and thereby causing inconvenience to a user when assembling the playpen.


Disclosed is a very light-weight, Mg and Be-based material which has the ability to reversibly store hydrogen with very good kinetics. This material is of the formula (M.sub.1-x A.sub.x) D.sub.y wherein M is Mg, Be or a combination of them; A is an element selected from the group consisting of Li, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Y, Zr, Nb, Mo, In, Sn, O, Si, B, C and F; D is a metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt (preferably Pd); x is a number ranging from 0 to 0.3; and y is a number ranging from 0 to 0.15. This material is in the form of a powder of particles of the formula M.sub.1-x A.sub.x as defined hereinabove, having an average size ranging from 0.1 to 100 .mu.m, each particle consisting of nanocrystalline grains having an average size of 3 to 100 nm or having a nano-layered structure with a layer spacing of 3 to 100 nm. Some of these particles have clusters of metal D attached thereto, with an average size ranging from 2 to 200 nm. Also disclosed are a process for preparing this material which has a very high hydrogen absorption capacity, and a method of use of the same for the transportation and/or storage of hydrogen and/or the storage of thermal energy.

a) Field of the Invention
The present invention relates to light-weight, Mg and Be-based materials of specific composition and structure, which have the ability to reversibly store hydrogen with very good kinetics.
The invention also relates to a process for preparing these materials and to their use for the transportation and/or storage of hydrogen and also for the storage of thermal energy.
b) Brief description of the prior art
It is known that some metallic alloys are able to absorb hydrogen in the reversible manner. Examples of alloys that can form hydrides reversibly, are FeTi, LaNi.sub.5 and Mg.sub.2 Ni.
Thanks to their ability to absorb hydrogen, these alloys are particularly useful for storing hydrogen, since they have the following advantages:
(1) a large hydrogen storage capacity, which is even higher than that of liquid hydrogen, because of the higher volume density of hydrogen in hydrides due to the formation of hydrogen-metal bonds that allows hydrogen-to-hydrogen distance to be smaller than in liquid hydrogen; PA1 (2) a reversibility of the hydride formation; PA1 (3) an endothermal release of the hydrogen from the alloys, which reduces the safety problems; and PA1 (4) no need for an advanced technology to obtain hydrogen transfer to or from the alloys. PA1 (1) First of all, some alloys like Mg.sub.2 Ni are not easy to prepare inasmuch as their phase diagram does not allow direct preparation of the alloy by mere cooling of a molten mixture of their constituting metals; PA1 (2) Secondly, because of oxides that are formed on their surface when they are in contact with air, the known alloys must be activated in order to absorb hydrogen. The activation treatment consists in annealing the alloys for, several times at high temperature under vacuum and/or a high pressure of hydrogen. This treatment must be repeated every time the alloy is exposed to air. PA1 (3) Moreover, during the absorption/desorption cycle, the known crystalline alloys usually fragment into small particles and loose their structural integrity. This results in a deterioration of the hydrogen absorption kinetic and in a heat transfer problem. PA1 they are capable of absorbing hydrogen at temperatures lower than 200.degree. C. without any activation (by way of comparison, the conventional crystalline magnesium-nickel alloys react with hydrogen only at temperature higher than 250.degree. C. and after several activation cycles): PA1 their activation is much easier to carry out (with the conventional Mg.sub.2 Ni alloys, it is necessary to initiate hydrogen absorption at temperatures higher than 300.degree. C., usually after several cycles at high temperatures under high pressure); PA1 their are less subject to decrepitation (viz. they have a better structural integrity). PA1 M is Mg, Be or a combination thereof; PA1 A is at least one element selected from the group consisting of Li, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Al, Y, Zr, Nb, Mo, In, Sn, 0, Si, B, C and F (preferably Zr, Ti and Ni); PA1 D is at least one metal selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Ir and Pt (preferably Pd); PA1 x is a number (atomic fraction) ranging from 0 to 0.3; and PA1 y is a number (atomic fraction) ranging from 0 to 0.15 (preferably from 0 to 0.02). PA1 as a solid solution in Mg, Be or a combination of them (equilibrium solid solution or supersaturated solid solution, or amorphized solid solution, or spinodally decomposed solid solution), PA1 as a compound with Mg or Be, appearing as precipitates or grain-boundary phases (equilibrium or metastable), PA1 as clusters, particles or layers of a separate phase. PA1 low energy ball milling PA1 aerosol processes PA1 gas phase condensation PA1 sputtering or the combination of two or more of the above techniques.
In spite of these advantages, the known alloys that are capable of absorbing hydrogen in a reversible manner have never been used on an industrial scale, because of the following difficulties.
It is also known that, amongst the above mentioned alloys having the ability to reversibly store hydrogen, magnesium-based alloys are prime candidates for hydrogen storage and applications related to energy storage. As a matter of fact, pure magnesium can theoretically store a large amount of hydrogen (7.6 wt.%) in the form of hydride MgH.sub.2. Such an amount is very attractive for hydrogen storage and much higher than the amounts of hydrogen that can be stored in the other alloys mentioned hereinabove, because magnesium is very light as compared to the other alloys mentioned hereinabove. Moreover, the formation of magnesium hydride has a large heat of reaction (75 kg/mol.). Because of the reversibility of the reaction, Mg-hydrogen systems can be effectively used for energy storage and related application, like hydrid heat pumps.
However, under normal conditions, magnesium does not react with hydrogen, because it oxidizes easily and MgO coating on the surface blocks the hydrogen uptake. Therefore magnesium is extremely difficult to activate and hydrogenate. By way of example, it has been found that to form magnesium hydride, a treatment under a hydrogen pressure of 150 atm at 300.degree. C. for 150 h is required.
Because of the large nominal value of hydrogen uptake (7.6 wt.%) and the low cost of magnesium, continuous efforts have been made to overcome the above drawbacks, and more particularly to improve the hydrogenation kinetics. In the recent years, there have been two main trends in research to improve hydrogenation characteristics of magnesium.
The first one of these trends has been to alloy Mg with other elements like rare earth elements, to add In, Ni, Y or La to Mg-Al alloys, or to add transition metals to Mg-Ni alloys. Although there has been a considerable improvement in the hydrogenation kinetics observed for the alloys that were so prepared, the enhancement in kinetics has always been obtained at the price of a reduction in the maximum hydrogen capacity (reduced to a maximum 3-5 wt.%) and vice versa. Moreover, for many Mg-based alloys, the hydrogenation/dehydrogenation temperature is still about 350-400.degree. C. to obtain reasonable kinetics.
The other trend in research has been to enhance the activity of magnesium by modification of it with organic compounds. For example, hydrogenation was performed in organic solvents, typically tetrahydrofurane (THF) using soluble organo-transition metal catalysts, or by co-condensation of Mg atoms with organic compounds (tetrahydrofurane, perylene). Although magnesium powders modified by chemical methods usually exhibit improved activity with no significant reduction of hydrogen capacity, the methods that have been devised to prepare them suffer from disadvantages. They are costly (for example, one of them calls for a high-vacuum system for powder condensation operating at 77K), and they are complicated. They are also unsafe and environmentally unfriendly if extended to a larger scale, because of the use of volatile and toxic organometallic catalysts. Moreover, the powders that are so-prepared are usually pyrophoric, thereby making it compulsory to provide protective atmosphere during handling.
In Canadian patent application No. 2,117,158 filed on Mar. 7, 1994 in the name of the same Applicants, Ni-based alloys have been disclosed, which are particularly efficient for use to reversibly store hydrogen.
These alloys are made of Ni and of another metal selected amongst Mg, La, Be and Li. They preferably consist of Mg.sub.2-x Ni.sub.1+x wherein x is a number ranging from -0.3 to -0.3, or of LaNi.sub.5.
In accordance with the invention disclosed in this Canadian application, it is compulsory that such alloys be in the form of a powder of crystallites having a grain size lower than 100 nm and preferably lower than 30 nm. Indeed, it has been found that if the selected alloy consists of crystallites having such a very low grain size, hydrogen absorption is much faster than with a similar polycrystalline alloy, even when this polycrystalline alloy is activated to eliminate the external layer of oxides which reduce its absorption kinetics.
In other words, it has been found that if use is made of a nanocrystalline powder of an alloy capable of absorbing hydrogen, such as Mg.sub.2 Ni (which has the additional advantage of being also very light as compared to FeTi), it is not necessary to activate the powder to make it able to absorb hydrogen. At worst, a single activation treatment at low temperature is sufficient. Moreover, it has been discovered that the kinetics of absorption (diffusion of hydrogen throught the surface and within the alloy) are much faster since the nanocrystalline alloy has a very large number of grain boundaries and surface defects. It has further been discovered that the nanocrystalline alloys keep their structural integrity when they are subjected to absorption-desorption cycles, since the size of the crystallites is already lower than the typical size of grains after hydrogen decrepitation.
Therefore, the nanocrystalline alloys disclosed in this patent application have been found particularly useful and efficient for storing and/or transporting hydrogen. As a matter of fact, these alloys have the following advantages as compared to the corresponding polycrystalline alloys:
In Canadian patent application No. 2,117,158, there is also disclosed a very simple yet efficient process for preparing the above described nanocrystalline alloys directly from powders of the metals that form the alloy. This direct preparation is carried out in a very simple manner, by merely grinding at ambient temperature under an inert atmosphere, a mixture of a powder of Ni with a powder of the other metal of the alloy, in amounts selected to obtain the requested composition. To be efficient, this grinding must be intense and carried out under inert atmosphere. It allows the preparation by mechanical alloying of the alloy from powders of Ni and of the other metal and at the same time reduces the crystal size to the requested value.
From a practical standpoint, grinding can be carried out with a high energy ball milling machine. By way of examples of such ball milling machines, reference can be made to those sold under the trademarks SPEC 8000 or FRITCH.
In order to further improve the quality and efficiency of the nanocrystalline alloys disclosed herein above, Canadian application No. 2,117,158 further suggests to apply a material capable of catalysing the dissociation of the hydrogen molecule, such as, for example, palladium, directly onto the surface of the crystalline particles. This material can be applied in a very simple manner, by grinding for a much shorter period of time the pre-synthesized nanocrystalline particles with a powder of the catalyst material. Thus, one can grind the nanocrystalline alloy particles with a powder of Pd for a given time onto the surface of the nanocrystalline alloy particles.
If the nanocrystalline alloys disclosed in this Canadian patent application are very efficient as absorbent medium for storing hydrogen, they still have the drawback of being too heavy for many potential applications. For example, Mg.sub.2 Ni with a volume density of 3.46 g/cm.sup.3, which is much higher than that of gaseous or liquid hydrogen, has a capacity of absorption of hydrogen per mass unit (expressed in weight of absorbed hydrogen per weight of absorbent medium) equal to 3.8. However, such as capacity is still low, especially if the alloys is intended to be used as a "storage means" onto a transportation vehicle. As a matter of fact, for such application, an absorption capacity equal to 6 or more would be extremely attractive.

Nanocrystalline Mg or Be-based materials and use thereof for the transportation and storage of hydrogen


The present invention provides a method of stimulating an excitable tissue (e.g., in vitro, in vivo) with a primary electrical stimulus through a primary electrode at a primary stimulation frequency, to produce a propagating action potential in the excitable tissue. The invention is carried out by concurrently stimulating the excitable tissue with a secondary electrical stimulus through at least one secondary electrode at a secondary stimulation frequency. The primary and secondary stimulation frequencies are preferably different from one another. The secondary electrical stimulus preferably has an amplitude not more than one third that of the primary electrical stimulus. Preferably, propagation of the action potential in the excitable tissue is enhanced (e.g., when propagation of action potentials in the tissue is otherwise unstable, partially blocked, or fully blocked). Apparatus for carrying out the method is also described.

Post-traumatic adjustment of pulse propagation in nerves with reduced excitability is a challenging biomedical and technological problem. In many cases such adjustments can be achieved with surgical interventions. However, surgery does not necessarily restore nerve conductivity to its pre-trauma levels, therefore still impaired conduction may cause partial or complete muscular paralysis. In this case propagation of excitation waves can be enforced only by applying external functional electrical stimulation (FES) using implantable [1] or surface stimulation electrodes [2-4]. This method has been confirmed as an effective tool for restoration of movement of paralyzed muscles in individuals with variety of neurological impairments [5].
Computerized systems for control of FES can deliver sequences of electrical stimuli with different frequency, amplitude and duration [6]. Commonly, these systems include variety of control units and electrical leads with multiple array or patch type stimulation electrodes. These electrodes deliver programmable stimuli, which are designed to maximize the effect of stimulation based on configuration of a particular stimulation field [7-10].
Successful FES process of functional restoration of muscle contraction depends on ability of nerve tissue to adequately conduct action potential. It also depends on excitation-contraction coupling in neuromuscular junctions, which transmit nervous impulses to muscular fibers. If any of these steps is impaired muscle does not contract normally. Usually, after severe neuromuscular injuries nerve conductivity is significantly reduced which, in turn, prevents the passage of excitation waves through neuromuscular transmitters. Under these circumstances propagation of excitation pulses is marginally stable and implementation of FES necessitates a significant increase of frequencies and amplitudes of functional electrical stimuli. The latest, instead of stabilization of propagation, can facilitate conduction blocks and may completely disrupt the process of training paralyzed muscles.
Accordingly, there is a need for new methods, systems and apparatus for stimulating excitable tissues which treat the problem of conduction instability and blockage therein.

This patent is subject to a terminal disclaimer.

Method and system of stimulation of nerve tissue with a sequence of spatially distributed resonant sub-threshold electrical stimuli

The University of North Carolina Greensboro


An auxiliary tailboard assembly for attachment to a drop-down tailgate that allows a user to bring the tailboard into vertical position, confining a load to the tailgate, after the goods have been loaded on the tailgate. The tailboard assembly includes a case for attachment to an inside face of the tailgate and a panel which can be extended and retracted in the case. A slot is provided into which the panel is seated when the panel is extended and rotated into vertical position and a stop for preventing removal of the panel from either the case or slot.

1. Field of the Invention
The present invention relates to an auxiliary tailboard assembly for a drop-down tailgate that can be brought into vertical position to confine a load on the tailgate after the goods have been loaded.
2. Brief Description of the Prior Art
Pickup trucks and other vehicles such as station wagons and some sport utility vehicles have a bed for carrying a load and a drop-down tailgate for retaining the load on the bed. Such vehicles are used to carry a wide variety of objects, such as furniture, appliances, lumber, tools and other bulky items. There are often times when the length of the load is greater than the length of the vehicle bed. In such a case, the tailgate may be left in a lowered or horizontal position to accommodate the longer load. When the tailgate is in the lowered position, however, the load is no longer confined by the tailgate and there is a possibility that the load may roll out and become lost, in addition to creating a hazard for other vehicles that follow behind.
There are many attachments proposed for extending the length of a vehicle bed. Some of them have panels that slide or fold out from the tailgate or from the truck bed for extending the effective length of the tailgate. Others provide panels that do not extend the length of the tailgate but are hinged along the top edge of the tailgate, providing an auxiliary tailboard. The attachments described in U.S. Pat. Nos. 5,501,500, 5,468,038, 5,456,511, 5,478,130, 4,932,703, 4,889,378, 4,778,213, 4,531,773, 4,472,639, 4,023,850, 2,729,499, 2,712,470 and 1,953,084 are representative of the prior art. The patents describe attachments that require the user to fold out the attachment before the goods are loaded as the load otherwise gets in the way of using the attachment. Some of the attachments extend the vehicle bed but do not confine the goods at the rear. Those that are pivoted to the top edge of the tailgate with a piano hinge or a pair of pivot pins may shear under load if the vehicle accelerates quickly or if the goods roll.
What is needed is an attachment for a tailgate, with excellent strength and rigidity, that allows a user to bring an auxiliary tailboard into vertical position after the goods are loaded, as an afterthought, if required.

Auxiliary tailboard assembly for drop-down tailgate


An enhanced space allocation mechanism (ESAM) for dynamically allocating space for a fixed length part of variable length fields, such as VARCHAR fields, in database tables. Each record in such a variable length field has a fixed length part, a variable length part, and a pointer to the variable length part. The ESAM determines how much space to allocate based on the data that was historically put into these tables. In one embodiment, a database management system (DBMS) maintains a historical record that includes fields identifying the table, column and application ID, as well as fields that track a count and a total length. For each variable length field in a Structured Query Language (SQL) statement such as CREATE table or ALTER table, the DBMS finds a matching historical record, determines an estimated optimal fixed portion length based on the matching historical record, and sets a space allocation length for the fixed length part of the variable length field based on the estimated optimal fixed portion length. This dynamic space allocation approach is especially advantageous in situations where an empty table will be loaded with a massive amount of data.

1. Field of Invention
The present invention relates in general to the digital data processing field and, in particular, to database management systems. More particularly, the present invention relates to a mechanism for dynamically allocating space for a fixed length part of a variable length field (e.g., a VARCHAR field) in a database table.
2. Background Art
In the latter half of the twentieth century, there began a phenomenon known as the information revolution. While the information revolution is a historical development broader in scope than any one event or machine, no single device has come to represent the information revolution more than the digital electronic computer. The development of computer systems has surely been a revolution. Each year, computer systems grow faster, store more data, and provide more applications to their users.
A modern computer system typically comprises at least one central processing unit (CPU) and supporting hardware, such as communications buses and memory, necessary to store, retrieve and transfer information. It also includes hardware necessary to communicate with the outside world, such as input/output controllers or storage controllers, and devices attached thereto such as keyboards, monitors, tape drives, disk drives, communication lines coupled to a network, etc. The CPU or CPUs are the heart of the system. They execute the instructions which comprise a computer program and direct the operation of the other system components.
The overall speed of a computer system is typically improved by increasing parallelism, and specifically, by employing multiple CPUs (also referred to as processors). The modest cost of individual processors packaged on integrated circuit chips has made multiprocessor systems practical, although such multiple processors add more layers of complexity to a system.
From the standpoint of the computer's hardware, most systems operate in fundamentally the same manner. Processors are capable of performing very simple operations, such as arithmetic, logical comparisons, and movement of data from one location to another. But each operation is performed very quickly. Sophisticated software at multiple levels directs a computer to perform massive numbers of these simple operations, enabling the computer to perform complex tasks. What is perceived by the user as a new or improved capability of a computer system is made possible by performing essentially the same set of very simple operations, using software having enhanced function, along with faster hardware.
The overall value or worth of a computer system depends largely upon how well the computer system stores, manipulates, and analyzes data. One mechanism for managing data is called a database management system (DBMS), which is a computer program that is used to access the information stored in a database. Databases are used to store information for an innumerable number of applications, including various commercial, industrial, technical, scientific and educational applications.
At a most basic level, a database stores data as a series of logical tables. Each table is made up of rows and columns. Each table has a unique name within the database and each column has a unique name within the particular table.
As the reliance on information increases, both the volume of information stored in most databases, as well as the number of users wishing to access that information, likewise increases. Moreover, as the volume of information stored in a database and the number of users wishing to access the database increases, the amount of computing resources required to manage such a database increases as well.
Database management systems therefore often require tremendous resources to handle the heavy workloads placed on such systems. As such, significant resources have been devoted to increasing the performance of database management systems with respect to processing searches, or queries, of databases for information. Different statements called queries allow the user or an application program to obtain data from the database. As one might imagine, queries range from being very simple to very complex.
Improvements to both computer hardware and software have improved the capacities of conventional database management systems. For example, in the hardware realm, increases in microprocessor performance, coupled with improved memory management systems, have improved the number of queries that a particular microprocessor can perform in a given amount of time. Furthermore, the use of multiple processors and/or multiple networked computers has further increased the capacities of many database management systems.
From a software standpoint, the use of relational databases, which organize information into formally-defined tables consisting of rows and columns, and which are typically accessed using a standardized language such as SQL (Structured Query Language), has substantially improved processing efficiency, as well as substantially simplified the creation, organization, and extension of information within a database. Furthermore, significant development efforts have been directed toward query "optimization", whereby the execution of particular searches, or queries, is optimized in a manner to minimize the amount of resources required to execute each query.
Through the incorporation of various hardware and software improvements, many high performance database management systems are able to handle hundreds or even thousands of queries each second, even on databases containing millions or billions of records. However, further increases in information volume and workload are inevitable, so continued advancements in database management systems are still required.
A table is a logical structure maintained by the database management system. Tables are made up of columns and rows. There is no inherent order of the rows within a table. At the intersection of every column and row is a specific data item called a value. A column, or a field, is a set of values of the same data type. A row is a sequence of values such that the nth value is a value of the nth column of the table. An index is a set of pointers to a table that has an entry for each record of the table. This entry is dependent on the value of that record in one or more columns of the table.
Variable character data types (often referred to as a "VARCHAR" fields) allow, in many instances, up to 32K characters of a character string to be stored. One common activity which database users frequently perform on such character strings is to search the text in the string for a particular matching sub-string using the LIKE predicate. An example SQL statement might resemble:
SELECT LastName FROM Customers
WHERE Lastname LIKE 'Mar %'
This query would return all the last names of all the records in the table that start with the letters "Mar".
When a database receives a query, the database interprets the query and determines what internal steps are necessary to satisfy the query. These internal steps may include identification of the table or tables specified in the query, the row or rows selected in the query, and other information such as whether to use an existing index, whether to build a temporary index, whether to use a temporary file to execute a sort, and/or the order in which the tables are to be joined together to satisfy the query. When taken together, these internal steps are typically referred to as an access plan (AP), although they are sometimes referred to as an execution plan. The access plan is typically created by a software component that is often called a query optimizer.
Allocating the appropriate amount of space for VARCHAR fields in a database table is a tricky task. Typically, a static/variable space allocation approach is used for VARCHAR fields. In such a static/variable space allocation approach, the system allocates for each record in a VARCHAR field a fixed, or static, amount of space (i.e., a "fixed length part"), plus a pointer for the rest (i.e., a "variable length part"). Thus, each record in a VARCHAR field has two parts—the first being the fixed length part and the second being the remaining variable length part. In addition, each record in a VARCHAR field has a pointer that allows the DBMS to put the two parts together. So, in a table with a single VARCHAR column with five records, each record has the fixed length part, a pointer to a variable length part, and a variable length part (which could be a different length for each of the records). The amount of space allocated for the fixed length part is fixed by a system setting. The static nature of the fixed length part often makes the static/variable space allocation approach inefficient. The static amount of space allocated by the system for the fixed length part is typically made relatively small to avoid wasting database storage space. However, by making the static amount of space allocated by the system for the fixed length part relatively small, for a given VARCHAR field the system is more likely to be burdened with the process of following pointers, which slows the speed at which the data may be accessed.
Therefore, a need exists for an enhanced mechanism for dynamically allocating space for a fixed length part of a variable length field in a database table.

Dynamically allocating space for a fixed length part of a variable length field in a database table


A compact, low profile golf putting practice apparatus includes a two-part flipper including a longitudinal flipping member and a coaxially mounted base section supporting the flipper member. A torsion spring pivots the flipper from its retracted position into an extended position whereby it propels a ball forwardly from a pocket area, and a powered retractor reversely pivots the flipper from its extended orientation into its retracted orientation. For safety, the two sections of the flipper are normally coupled together for movement as a unit by a resilient coupler which is capable of expanding temporarily when the flipper encounters an obstruction to its movement from the extended orientation to the retracted orientation.

This invention relates to golf putting practice devices and, more particularly, to golf putting practice devices of the type embodying a mechanism for kicking a ball back to the person making a putt thereinto.
Golf putting practice devices employing various ball return mechanisms mounted therein have been heretofore known in the art. One improvement over the prior art embodies a spring powered flipper device to return the ball, as demonstrated in U.S. Pat. No. 6,508,720. In operation, a motorized mechanism retracts a flipper device against the tension force of an elongated spring member and then releases it to rotate freely forwardly through the contracting force of the spring and, thereby, contact the ball forcefully and send it back to the person. The flipper is again retracted, through the power of the motorized mechanism, into the operational position for returning the next putt.
Although the embodiment of the aforementioned patent results in a putt return device significantly smaller than that of prior art, the profile of the housing and the attached ball tray provide a limited target for putting practice. Also, the amount of torque generated by the motorized mechanism to retract the flipper is sufficient to cause injury if the user's finger is accidentally placed between the flipper and the housing during retraction. It is a primary object of the present invention to afford novel improvements over the golf putting practice devices heretofore known in the art.
One of the primary objects of the present invention is to afford a novel putting practice device that incorporates a two-part flipper device resiliently connected between a flipper section and supporting base section by a resilient means in a manner that allows the flipper portion to stop if obstructed by an object while retracting, thus preventing injury to the user or damage to the device.
A further object of the present invention is to afford a novel golf putting practice device with a lower profile and larger ball receiving tray to provide an improved, more realistic putting target.
Another object of the present invention is to afford a novel golf putting practice device, which embodies a flipper device of a substantially reduced size and a coaxially mounted torsion spring, constituted and arranged in a novel manner inside the device for returning a ball putted therein.
Yet another object of the present invention is to afford a novel golf putting practice device with a flipper apparatus that consistently returns a ball in a path perpendicular to the front of the device in a more efficient manner.
Another object of the present invention is to afford a novel golf putting practice device that can use either DC or AC power for operation.
Yet another object of the present invention is to afford a novel golf putting practice device with a means for monitoring battery power to the device and for indicating when battery replacement is necessary.
Another object of the present invention is to afford a novel golf putting practice device with a means to automatically shutoff power to the device after a set period of time of inactivity to conserve battery power.
A further object of the present invention is to afford a novel golf putting practice device which is practical and efficient in construction and operation, and which may be more readily and economically produced commercially.
Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings, which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what is to be considered the best mode in which to apply these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.


Disclosed are piperazine derivatives having the general formula: (I) Also disclosed are methods of treating a subject having cancer with this compound or a pharmaceutical composition comprising the compound.

Temozolomide is an oral alkylating agent that has been in use since the turn of the century for the treatment of aggressive brain tumors.
Temozolomide is thought to alkylate/methylate deoxyribonucleic acid (DNA) at the N-7 and O-6 positions of guanine (Newlands E S et al., Cancer Treatment Reviews 23:35-61, 1997). This methylation is believed to act as a trigger for apoptosis, which ultimately results in lesions in the DNA and death of the cancer cells. In some tumor cells, the effectiveness of temozolomide is limited by the presence of O-6-methylguanine-DNA methyltransferase (MGMT) or O-6-alkylguanine-DNA alkyltransferase (AGT or AGAT) in the cells. These enzymes are part of the cell-repair machinery of a cell and can reverse the methylation caused by temozolomide.
Since tumor cells that synthesize the MGMT/AGT enzyme are more resistant to killing by temozolomide, various researchers have investigated whether the inclusion of O-6-benylguanine (O6-BG), an inhibitor of MGMT, would be able to overcome this resistance and improve the drug's therapeutic effectiveness. In the laboratory, this combination indeed showed increased activity in tumor cell culture in vitro and in animal models in vivo (Ueno et al., Mol. Cancer Ther. 5(3):732-8, 2006). However, a recently completed phase II clinical trial with brain tumor patients yielded mixed outcomes; while there was some improved therapeutic activity when 06-BG and temozolomide were given to patients with temozolomide-resistant anaplastic glioma, there seemed to be no significant restoration of temozolomide sensitivity in patients with temozolomide-resistant glioblastoma multiforme (Quinn et al., J. Clin. Oncol., 27(8):1262-1267, 2009). As such, the effectiveness of temozolomide in the treatment of cancers could be improved.


An LED lamp includes a heat sink, a plurality of vapor chambers mounted on the heat sink and an LED module mounted on the vapor chambers. The heat sink includes a base, a plurality of fins extending from a first surface of the base and a triangular ridge formed on a second surface opposite to the first surface of the base. The vapor chambers are mounted on the ridge of the base. The LEDs over two slopes of the ridge are oriented slantwise outwardly, thereby increasing an irradiation angle and area of the LED lamp.

1. Field of the Invention
The present invention relates to a light emitting diode (LED) lamp, and more particularly to an LED lamp incorporating vapor chambers for improving heat dissipation of the LED lamp.
2. Description of Related Art
An LED lamp is a type of solid-state lighting that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction comprising two different semiconductors, electrons and cavities are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
LED modules for use in an LED lamp require many LEDs, and most of the LEDs are driven at the same time, which results in a quick rise in temperature of the LED modules. Therefore, a heat dissipation device is needed to dissipate heat generated by the LED modules of the LED lamp. A related heat dissipation device attached to the LED modules usually comprises a heat sink having a base and a plurality of fins mounted on the base. The fins are located parallel to each other and each fin is perpendicular to the base. A plurality of channels are defined between the fins of the heat sink and arranged parallel to each other. A cooling airflow passes through the channels defined by the fins of the heat sink, whereby heat of the fins from the base by absorbing the heat generated by the LED modules can be dissipated to atmosphere. Accordingly, the LED lamp can be cooled to some degree.
However, as a power of the LED modules for use in the LED lamp continues to increase, an amount of heat generated by the LED modules becomes more and more huge. Operation of the conventional LED modules has a problem of instability because of insufficient heat dissipating efficiency of the heat dissipation device. Consequently, the light from the LED lamp often flickers, which degrades the quality of the illumination.
Besides, since the LED modules are generally arranged on a flat surface of a heat dissipation device, an illumination angle and area of the LED lamp is limited.
What is needed, therefore, is an LED lamp with a heat dissipation device, which has a great heat dissipating capability. Furthermore, the heat dissipation device has a unique design, whereby the LED lamp can have a larger illumination angle and area.

Fu Zhun Precision Industry (Shen Zhen) Co., Ltd.


A method for smoothing input current to a power delivery system having regeneration capability. The method comprises evaluating input current to an input converter of the power delivery system for a first fundamental cycle, and shifting a window relative to a waveform of an input voltage after the first fundamental cycle. The method also comprises evaluating input current to the input converter for a second fundamental cycle, and determining whether the input current of the second fundamental cycle is smoother than the input current of the first fundamental cycle. The method further comprises shifting the window in the same direction the window was shifted after the first fundamental cycle if the input current of the second fundamental cycle is smoother than the input current of the first fundamental cycle, and shifting the window in the opposite direction the window was shifted after the first fundamental cycle if the input current of the second fundamental cycle is not smoother than the input current of the first fundamental cycle.

This application discloses an invention that is related, generally and in various embodiments, to a method for smoothing input current to a power delivery system having regeneration capability.
Power delivery systems such as AC motor drives are generally available as either a fully regenerative system or as a non-regenerative system. For non-regenerative systems, input power flows from an input power source to the load, and power produced by the load is blocked from flowing back to the input power source. In fully regenerative systems, input power flows from an input power source to the load, and the power produced by the load may flow back to the input power source.
It is known in the art for such fully regenerative systems to comprise an active front end to control regenerative current. However, active front ends may tend to cause some level of distortion of the incoming AC power. To reduce the distortion and smooth the input current on each leg of the AC input, it is also known to utilize line reactors on each leg of the AC input. However, the line reactors tend to be a relatively bulky and expensive solution to the distortion problem.
For many applications, only a portion of the power produced by the load is required for purposes of braking, etc. For such applications, a regenerative system generally provides much more regeneration capability than is required. Accordingly, most regenerative systems are not very cost-effective for applications which require limited regeneration capability.
To realize a drive with limited regeneration capability, it is known to configure a drive with a combination of regenerative and non-regenerative cells. For example, U.S. patent application Ser. No. 11/419,064 (the '064 application) discloses such a drive. The drive disclosed by the '064 application may be configured to have varying levels of regeneration capability by varying the number of regenerative versus non-regenerative cells in the drive, and each regenerative power cell may comprise an active front end that comprises switching devices controlled by pulse width modulation. Although the drive disclosed in the '064 application provides a cost-effective solution for applications requiring limited regeneration capability, any use of line reactors therewith to reduce any distortions caused by the active front end unnecessary adds to the size and cost of the system.

Method for smoothing input current to a power delivery system having regeneration capability


An electrical disconnect apparatus includes a housing having an interior and an exterior, first and second conductors extending from the exterior into the interior, a movable conductor, and an actuator assembly coupled to the housing. The movable conductor has a connected position in which the movable conductor electrically connects the first conductor and the second conductor, and a disconnected position in which the first conductor is electrically disconnected from the second conductor. The actuator assembly is adapted to move the movable conductor between the connected position and the disconnected position, and can be actuated manually or automatically.

1. Field
The disclosed concept pertains generally to power distribution equipment and, more particularly, to electrical disconnect apparatus.
2. Background Information
Two primary objectives of the electric utility industry in the delivery of electrical power are safety and reliability.
Secondary network systems, for example, are used in certain locations such as downtown business districts and commercial areas in order to provide a high degree of service continuity. In such secondary network systems, a failure of any one distribution line will not result in an interruption of service to the customers since electrical power will be supplied to the customers over the remaining distribution lines. A network protector is employed in the event of a failure or fault to prevent power from the secondary network from being fed back through the network transformers to the fault. When a network protector is approached for, for example, maintenance, testing, or repair, the network protector must be electrically and physically disconnected from the power distribution equipment on both the network transformer side and the secondary network side. By way of example, arc flash, which is a dangerous condition associated with the explosive release of energy caused by an electrical arc due to either a phase-to-ground or phase-to-phase fault, is a serious safety concern.
FIGS. 1 and 2 show an example electrical disconnect apparatus 1, which includes a housing 100 and a connection device 200 having a handle 210. The housing 100 includes a first conductor 110 having a first conductive surface 111 configured to electrically connect to a first external circuit (not shown), and a second conductor 120 (FIG. 2) having a second conductive surface 121 (FIG. 2) configured to electrically connect to a second external circuit (not shown). As shown in FIG. 2, the first conductor 110 further includes a first receptacle 112 and a first flexible conductor 113, and the second conductor 120 further includes a second receptacle 122 and a second flexible conductor 123. The handle 210 is attached to a fuse 230, which includes opposing first and second conductive end portions 231,232 mechanically coupled by a tube 233 and electrically connected by a fusible element 234.
When the fuse 230 is inserted into the housing 100, it is received by the first receptacle 112 and the second receptacle 122 such that the first conductive end portion 231 contacts the first flexible conductor 113 and the second conductive end portion 232 contacts the second flexible conductor 123 to electrically connect the first and second conductors 110,120, which in turn creates a conductive circuit with the first and second flexible conductors 113,123 and the first and second conductive surfaces 111,121. Operating (e.g., turning and pulling) the handle 210 to partially remove the fuse 230 from the housing 100 moves the fuse 230 out of electrical contact with at least one of the flexible conductors 113,123, thereby electrically disconnecting the first conductor 110 from the second conductor 120. Thus, when the electrical disconnect apparatus 1 is employed, for example, between a network protector and an electrical network, a technician can relatively easily determine whether the network protector is isolated from the electrical network based on the presence or absence of the connection device 200 in the housing 100. The technician can also relatively easily electrically connect or disconnect the network protector from the electrical network by operating the handle 210 to insert or remove the connection device 200. However, this requires direct physical contact and manual operation of the connection device 200 on the part of the technician.
There is, therefore, room for improvement in electrical disconnect apparatus.

Remotely operable electrical disconnect apparatus


An image forming apparatus has: an image bearing member that bears a toner image and moves; a transfer means that transfers the toner image on the image bearing member to a transfer medium; a first eliminating member that comes in contact with the image bearing member and collects and eliminates the toner on the image bearing member by applying a bias in a first eliminating area where toner is eliminated from the image bearing member; a second eliminating member that comes in contact with the image bearing member so as to eliminate the toner on the image bearing member in a second eliminating area where the toner remaining on the image bearing member from which the toner is eliminated in the first eliminating area is eliminated; a controller that variably controls a bias condition of the bias to be applied to the first eliminating means based on a relationship between voltage and electric current when a test bias is applied to the first eliminating means in contact with the image bearing member; and a separating member that separates the second eliminating means from the image bearing member when a part of the image bearing member which passes through the first eliminating area during application of the test bias to the first eliminating means is in the second eliminating area.

1. Field of the Invention
The present invention relates to an eliminating member that eliminates toner on an image bearing member, and particularly relates to an image forming apparatus that has a first eliminating member to which bias is applied and which comes in contact with the image bearing member so as to eliminate toner and a second eliminating member which comes in contact with the image bearing member so as to eliminate the toner.
2. Description of the Related Art
In recent years, from the viewpoint of reduce in printing cost, a toner eliminating means of an image bearing member has desirably long life.
A first eliminating member comes in contact with the image bearing member so as to apply a bias to the member and collects and eliminates toner. Since deterioration of an eliminating ability due to abrasion of the first eliminating member hardly occurs, this member is suitably used for a long time. A charging amount of some toner on the image bearing member, however, is small, and it is difficult that such toner is sufficiently eliminated by the first eliminating member that collects toner electrostatically.
In order to compensate the eliminating ability of the first eliminating member, therefore, a second eliminating member that comes in contact with the image bearing member so as to eliminate toner is provided. In the first eliminating member that collects toner by application of bias, a resistance value changes due to adhesion of toner. In order to apply suitable bias according to the change in the resistance value, a condition of the bias to be applied to the first eliminating member is controlled based on a relationship between a voltage and an electric current at the time of applying test bias to the first eliminating member.
When, however, the test bias is applied, the toner borne by the first eliminating member occasionally transfers to the image bearing member. That is to say, in the case where the test bias is lower than an adequate bias, electrostatic binding force of the toner is weakened, and thus the toner transfers. On the contrary, in the case where the test bias is higher than the adequate bias, discharge occurs between the first eliminating member and the image bearing member so that the toner is charged, and thus the toner transfers.
The transferred toner moves together with the image bearing member, and is accumulated on a contact portion between the second eliminating member and the image bearing member. The accumulated toner is pushed against the image bearing member by the second eliminating member, so that the toner adheres to the image bearing member.


An IGBT includes a plurality of n+ doped regions (11) selectively formed in a main surface (103) of a p+ semiconductor layer (12) opposite from an n type semiconductor layer (80) without being connected to the n type semiconductor layer (80). The n+ doped regions (11) are formed in corresponding relation to and only under channel regions (CH1a-CH1d) of structures (200a-200d), respectively. This lowers the effective concentration of the p+ semiconductor layer (12) on the n+ doped regions (11) to reduce the number of holes injected from a collector layer (9) in an off state, reducing a leakage current.

1. Field of the Invention
The present invention relates to an insulated gate bipolar transistor (referred to hereinafter as an "IGBT") for use in an inverter and the like.
2. Description of the Background Art
FIG. 7 is a schematic sectional view showing a structure of a first background art IGBT. As shown in FIG. 7, p doped regions 2 and 20 spaced a predetermined distance apart from each other are selectively formed in one main surface 100 of an n semiconductor layer 1 serving as an n type semiconductor substrate. N+ doped regions 3a and 3b spaced a predetermined distance apart from each other are selectively formed in a surface of the p doped region 2. Similarly, n+ doped regions 30a and 30b spaced a predetermined distance apart from each other are selectively formed in a surface of the p doped region 20.
An insulation film 40 is formed on part of the main surface 100 of the n semiconductor layer 1 which lies between the n+ doped regions 3b and 30a, and a gate electrode 50 is formed on the insulation film 40. An interlayer insulation film 70 is formed to cover the gate electrode 50. Similarly, an insulation film 41 is formed on part of the main surface 100 of the n semiconductor layer 1 which lies between the n+ doped region 3a and an n+ doped region not shown in FIG. 7, and a gate electrode 51 is formed on the insulation film 41. An interlayer insulation film 71 is formed to cover the gate electrode 51. An insulation film 42 is formed on part of the main surface 100 of the n semiconductor layer 1 which lies between the n+ doped region 30b and an n+ doped region not shown in FIG. 7, and a gate electrode 52 is formed on the insulation film 42. An interlayer insulation film 72 is formed to cover the gate electrode 52.
An emitter electrode 6 is formed on the main surface 100 of the n semiconductor layer 1 and on the interlayer insulation films 70 to 72. The emitter electrode 6 is connected to the n+ doped regions 3a, 3b, 30a, 30b and the p doped regions 2, 20.
An n+ buffer layer 8 having an impurity concentration higher than that of the n semiconductor layer 1 is formed on a main surface 101 of the n semiconductor layer 1 opposite from the main surface 100. A collector layer 90 which is a p+ semiconductor layer having a substantially uniform impurity concentration is formed on a main surface of the n+ buffer layer 8 opposite from the n semiconductor layer 1. A collector electrode 10 is formed on a main surface of the collector layer 90 opposite from the n+ buffer layer 8.
The first background art IGBT having the above-mentioned structure is disadvantageous in that a large number of holes injected from the collector layer 90 which is the p+ semiconductor layer in an off state make an off-state leakage current (referred to simply as a "leakage current" hereinafter) high at elevated temperatures. In general, the reduction in thickness of the n semiconductor layer 1 is very effective to improve characteristics, such as an on-state voltage and a turn-off power dissipation, of a high-breakdown-voltage IGBT. However, in reaction to the reduction in thickness of the n semiconductor layer 1, the current gain hFE of an internal pnp transistor increases in the off state to increase the leakage current. In particular, the first background art IGBT in which a large number of holes are injected from the collector layer 90 in the off state as discussed above presents a problem such that the reduction in thickness of the n semiconductor layer 1 significantly increases the leakage current. The "internal pnp transistor" in the first background art IGBT means a pnp bipolar transistor comprising the n semiconductor layer 1 and the n+ buffer layer 8 regarded as a base region, the p doped region 2 or the p doped region 20 regarded as a collector region, and the collector layer 90 regarded as an emitter region. The "off state" is a state in which, for example, the emitter electrode 6 and the gate electrodes 50 to 52 are placed at the same potential whereas a higher potential is applied to the collector electrode 10 than to the emitter electrode 6 and the gate electrodes 50 to 52, and in which the IGBT is off. The "leakage current" means a current flowing between the collector electrode 10 and the emitter electrode 6 in the off state.
To solve the above-mentioned problem, there has been proposed a second background art IGBT. FIG. 8 is a schematic sectional view showing a structure of the second background art IGBT. Although the collector layer 90 in the first background art IGBT is the p+ semiconductor layer having a substantially uniform impurity concentration, the second background art IGBT comprises a collector layer 91 in which collector short regions 120 which are n+ doped regions and p+ doped regions 92 alternate with each other.
More specifically, as shown in FIG. 8, the collector layer 91 has the collector short regions 120 and the p+ doped regions 92 which are formed alternately on the main surface of the n+ buffer layer 8 opposite from the n semiconductor layer 1. The collector electrode 10 is formed on a main surface of the collector layer 91 opposite from the n+ buffer layer 8. In other words, the collector electrode 10 is formed to cover the collector short regions 120 and the p+ doped regions 92. Such a structure is referred to as a "collector short structure."
In the second background art IGBT having the above-mentioned structure, most electron currents leaked from the emitter electrode 6 side flow through the collector short regions 120 into the collector electrode 10 in the off state. This reduces the number of holes injected from the p+ doped regions 92. Therefore, the second background art IGBT can reduce the leakage current below that of the first background art IGBT, and alleviate the increase in leakage current resulting from the reduction in thickness of the n semiconductor layer 1.
There has been proposed a third background art IGBT different in structure from the second background art IGBT for reducing the leakage current below that of the first background art IGBT.
FIG. 9 is a schematic sectional view showing a structure of the third background art IGBT. Although the collector layer 90 in the first background art IGBT is the p+ semiconductor layer having a substantially uniform impurity concentration, the third background art IGBT comprises a collector layer 93 in which p+ doped regions 94 and p− doped regions 95 having an impurity concentration lower than that of the p+ doped regions 94 alternate with each other.
More specifically, as shown in FIG. 9, the collector layer 93 has the p+ doped regions 94 and the p− doped regions 95 which are formed alternately on the main surface of the n+ buffer layer 8 opposite from the n semiconductor layer 1. The collector electrode 10 is formed on a main surface of the collector layer 93 opposite from the n+ buffer layer 8. In other words, the collector electrode 10 is formed to cover the p+ doped regions 94 and the p− doped regions 95.
In the third background art IGBT having the above-mentioned structure, the total amount of impurity in the collector layer 93 is less than that in the collector layer 90 of the first background art IGBT. In the off state, the electron currents leaked from the emitter electrode 6 side are more easily flow through the p− doped regions 95 having a lower impurity concentration into the collector electrode 10. This reduces the number of holes injected from the collector layer 93. Therefore, the third background art IGBT can reduce the leakage current below that of the first background art IGBT, and alleviate the increase in leakage current resulting from the reduction in thickness of the n semiconductor layer 1, as compared with the first background art IGBT.
Unfortunately, the second background art IGBT configured to have the collector short structure includes a parasitic diode comprised of, for example, the p doped region 2, the n semiconductor layer 1, the n+ buffer layer 8 and the collector short regions 120. When used in an inverter and the like, the second background art IGBT is broken down in a freewheeling mode.
In the third background art IGBT, the electron currents flowing from the emitter electrode 6 side at turn-off flow rapidly through the p− doped regions 95 having a lower impurity concentration into the collector electrode 10. This rapidly decays the tail current in the collector current of the IGBT to reduce the turn-off power dissipation, but a collector-emitter voltage oscillates in some cases in timed relationship with the abrupt decay of the tail current. Thus, the third background art IGBT might malfunction or be broken down in the worst case.
There has been another problem such that the electron currents flowing from the emitter electrode 6 side while the IGBT is on are crowded in the IGBT to degrade the characteristics of the IGBT, depending on the position and number of regions easily conducting the electron currents in the collector layer, e.g. the collector short regions 120 in the second background art IGBT and the p− doped regions 95 in the third background art IGBT. FIG. 10 shows electron currents flowing in the second background art IGBT, and FIG. 11 shows electron currents flowing in the third background art IGBT.
As illustrated in FIG. 10, electron currents 300 from the emitter electrode 6 side while the IGBT is on flow toward the collector layer 91. Since the collector layer 91 has the collector short regions 120 which are the n+ doped regions, most of the electron currents 300 flow into the collector short regions 120. This gives rise to the crowding of the electron currents 300 in the second background art IGBT, depending on the position and number of collector short regions 120, as shown in FIG. 10. Hole currents 301 flowing in the IGBT are also shown in FIG. 10.
As illustrated in FIG. 11, the electron currents 300 from the emitter electrode 6 side while the IGBT is on flow toward the collector layer 93. Since the collector layer 93 has the partially formed p− doped regions 95 having a lower impurity concentration, most of the electron currents 300 flow into the p− doped regions 95. This gives rise to the crowding of the electron currents 300 in the third background art IGBT, depending on the position and number of p− doped regions 95, as shown in FIG. 11.


A noise muffler is configured to substantially surround a sound generating object, disposed in or to be disposed in, a structure including a wall or ceiling to be sound limited by, and attenuate sound emitted from the sound generating object, the wall or ceiling including a board having an exposed surface and an opposite surface. The noise muffler has front, rear, left and right sides and a bottom. The sound generating object is positioned in the muffler cavity. The front, rear, left and right sides, and the bottom of the muffler are formed with an outer barrier layer. At least one of the front, rear, left, right sides and bottom of the muffler are formed with a noise absorbing layer positioned adjacent the outer barrier layer to absorb a predetermined amount of sound emitted from the object. At least one of the front, rear, left and right sides includes a first opening into the inner volume of the muffler cavity, the size of which first opening is adjustable.

The present invention relates to a system for attenuating noise. In particular, the present invention relates to a system for attenuating noise that may be emitted from a room through a hole or opening. Additionally, the invention can attenuate noise when the opening houses any low STC object that cannot be completely enclosed, such as a recessed light fixture. The present invention further relates to a methodology for attenuating noise from a room that contains at least one hole or opening for receiving a low STC object that cannot be completely enclosed, such as a recessed light fixture or other mechanism.
Hearing noises such as for example, footsteps, speech, music or environmental sounds from adjacent rooms, upper floors, pipes, outside the dwelling or adjacent dwellings is something that many people experience on a daily basis. At a minimum, it can be distracting. Many spend large sums of money to reduce the overall transmission of sound into and/or through their dwellings in order to create quieter surroundings. Various sound insulating techniques exist to significantly reduce and/or limit the transmission of sound through the walls, ceilings and other objects contained in today's commercial and residential buildings. A great deal of attention is paid to the configuration of the walls, floors and ceilings and the materials forming the same to provide for high transmission loss, which minimizes the transmission of noise from one room or space to another.
The configuration and the materials are rated by its STC. STC stands for "sound transmission class" and is a single number rating derived from measured values of sound transmission loss in accordance with the American Society for Testing and Materials (ASTM) E90 standards. The transmission loss through an object is a measure of its effectiveness in preventing the sound power incident on one side of the object from being transmitted through it and radiated on the other side. The STC provides a single number estimate of an object's performance for certain common sound reduction applications.
Typically, ceilings and walls have openings and/or holes formed therein to receive various devices including electrical outlets, air ducts, lighting, speakers, etc. While the walls, floors and ceilings can be adequately insulated to limit noise transmission, these openings have an adverse impact on the transmission loss. As such, noise can enter the room or space through the opening and the device mounted therein.

Perforation acoustic muffler assembly and method of reducing noise transmission through objects


A method includes applying a first dielectric material onto a semiconductor substrate to form a first dielectric layer on the semiconductor substrate, creating a plurality of openings in the dielectric layer, depositing a sacrificial material within the openings of the dielectric layer, removing the sacrificial material from at least a first segment of a first trench of the openings, depositing a second dielectric fill material into the first segment of the first trench opening where the sacrificial material was removed, removing the sacrificial material from at least some of the remaining openings and depositing a metallic material within the first trench opening to define at least first and second lines in the first trench and form a metallic interconnect structure.

The present disclosure relates to semiconductor fabrication techniques and, in particular, relates to a back-end-of-line (BEOL) methodology and structure to create self-aligned metal cuts before metal fill.
A semiconductor integrated circuit chip is typically fabricated with a BEOL interconnect structure, which comprises multiple levels of metal lines and inter-level metal vias, to connect various integrated circuit components and devices that are fabricated as part of a front-end-of-line (FEOL)/middle-of-line (MOL) layer(s) of the semiconductor integrated circuit chip. Metal gaps are formed in some of the metal lines to avoid "shorts" in the circuit components. However, the gaps must be properly aligned and of appropriate size to maintain a well-defined "tip-to-tip spacing," between the ends of the metal lines otherwise significant degradation in yield, performance, and reliability may be observed.


A hand truck includes handles; a ledge comprising a cavity; a fastening device comprising a quick release and a clamp; and a locking device comprising a hollow first section including an opening on either side, a hollow second section releasably put on the first section, the second section including an opening on either side, the openings being in registration to each other, a block member in the first section and including a transverse channel aligned with the openings and the cavity, a sliding lock pin in the cavity, the openings, and the channel to lock the first and second sections, the lock pin having a projection in the channel, a depressible shuttle member in the first section and including a hook partially disposed in the block member, and an inclined slot in the hook with the projection disposed therein, and an actuation rod releasably secured to the shuttle member.

1. Field of Invention
The invention relates to hand trucks and more particularly to such a hand truck having an arrangement for mounting on a carrier of a bicycle after retracting its handles.
2. Description of Related Art
A conventional hand truck comprises a small ledge adapted to set objects thereon, the ledge being flat against the floor when the hand truck is upright, two wheels at the base, and two handles extending upward from wheel mounts. The handles can be fixed, telescopic, or telescopic and pivotal one. A hand truck is designed to easily move a relatively heavy load.
Taiwanese Utility Model Patent Nos. 419,974, 492,441, 413,189, 335,783, and 299,733 each discloses a hand truck having two telescopic handles.
However, portability of the conventional hand trucks even after retracting is still not convenient. Thus, continuing improvements in the exploitation of hand truck are constantly being sought.

Hand truck having arrangement for mounting on a carrier of bicycle after handles retracting


The present invention relates to a device and method for controlling the braking system of a vehicle equipped with a wheel slip control system. In this context, the wheel slip control system is in a position, when certain conditions are met, to initiate the buildup of first braking torques at least one wheel brake. Furthermore, the wheel slip control system initiates preparatory measures for the buildup of second braking moments in the wheel brakes of the remaining wheels, the preparatory measures leading to no, or no significant, braking action in the wheel brakes of the remaining wheels. The present invention provides the preparatory measures for the buildup of second braking moments in reaction to the buildup of the first braking moments.

German published patent document DE 196 15 294 discloses a device and a method for controlling the braking power at least one wheel of a vehicle, which device includes the following means: Means for ascertaining a criterion that describes and/or influences the vehicle's motion, means for ascertaining the size and the means describing the wheel dynamics of the respective wheel, using which, as a function of the ascertained criterion describing and/or influencing the vehicle motion, it is determined whether a braking operation independent of the driver at one wheel is foreseeable. Furthermore, the device includes means using which, upon the presence of the requirement of a foreseeable driver-independent braking operation, a slight actuation of variable duration of the actuators allocated to the wheel is able to be carried out, ahead in time of this foreseeable, driver-independent braking operation. In this context, the duration of the slight actuation of the actuators is ascertained at least as a function of the quantity describing the wheel dynamics of the appertaining wheel.
German published patent document DE 195 47 111 discloses a method and a device for controlling the braking system of a vehicle, in which, even before the beginning of a wheel slip control system, pressure is applied to the wheel brakes if predefined conditions exist, with no significant braking effect being applied to the drive wheels.
Driving Safety Systems, pp. 206-207 (2nd ed., 1998) (ISBN no. 3-528-03875-6), discusses a change among braking interventions at various wheels.
Kraftfahrtechnisches Taschenbuch (Motor Vehicle Technical Pocket Book), pp. 654-655 (23rd ed.) (ISBN no. 3-528-03876-4), discusses a braking system that has two brake circuits: one that extends over the front wheels, and another that extends over the rear wheels.

Method and device for improving pressure build-up dynamics


A stick lever unit is provided that is capable of eliminating uncomfortable feeling during manipulation of the stick, as well as, minimizing breaking of a wiring conductor of the variable resistor. The stick lever unit includes a fixing member, a first variable resistor attached to the fixing member, a first rotational member rotatably journalled to the fixing member for rotationally controlling the first variable resistor, a second variable resistor attached to the first rotational member, and a second rotational member having a stick lever and being rotationally journalled to the first rotational member to rotationally control the second variable resistor. The wiring conductors of the second variable resistor are derived out from the lead-out hole in the rotational shaft of the first rotational member, which is attached to the second variable resistor.

The present invention relates to stick lever units, which are capable of creating control signals for maneuvering of models, control of industrial machines, manipulation of game consoles, and the like.
Generally, stick lever units for creating control signals are attached to radio controlled transmitters for maneuvering models, respectively. The basic structure of a conventional stick lever unit will be explained below by referring to the schematic diagram of FIG. 12. A first variable resistor 101 is attached to the outer side of a frame fixing member 100, which is attached on the housing of a radio-controlled transmitter. A first rotational member 104 having a frame shape is rotatably journalled inside of the fixing member 100 by means of the shaft 102 of the first variable resistor 101 and by means of one rotational shaft 103 coaxial to the shaft 102. A second variable resistor 105 is attached outside the first rotational member 104. A second rotational member 107 with a stick 106 is rotationally journalled inside the first rotational member 104 through the shaft 108 of the second variable resistor 105. Wiring conductors 109 of the first variable resistor 101 are connected to the control substrate (not shown). Wiring conductors 110 of the second variable resistor 105 are externally derived beyond the frame wall of the fixing member 100 and are connected to the control substrate.
The rotational shaft 103 of the first rotational member 104 (or the shaft 102 of the first variable resistor 101) is perpendicular to the rotational shaft of the second rotational member 107 (or the shaft 108 of the second variable resistor 105). Accordingly, when an operator manipulates the stick lever 106 attached to the second rotational member 107 in given directions with his fingers, the two variable resistors 101 and 105 are controlled suitably and rotatably, so that control signals of two kinds are created.
A radio-controlled transmitter for a model airplane, for example, respectively manipulates the rudder and the elevator, each which controls the attitude of the model airplane, by means of two servomotors mounted on the fuselage. With one stick lever unit mounted on the radio-controlled transmitter, allocated for control of the rudder and the elevator, control signals for two servomotors respectively driving the rudder and the elevator are obtained by controlling one stick to control the attitude of the airplane. Japanese Utility Model Laid-open Publication No. 57-169393 and Japanese Utility Model Laid-open Publication No. 62-87697 disclose a further specific structure of the above stick lever unit.
In the conventional stick lever unit, the first rotational member 104 is attached to the second variable resistor 105 by rotating the stick 106. As a result, the whole of the wiring conductors 110 derived out from the second variable resistor 105 through the fixing member 100 moves largely. This works as a resistance when the stick 106 is operated which causes an uncomfortable feeling to the operator.
Since the wiring conductors 110 from the second variable resistor 105 always moves together with the first rotational member 104, the wiring conductors 110 undergo repeatedly deformation such as expansion, contraction, twisting, and the like. This repeated deformation over a long period of time may cause the wiring conductors 110 to break.


A computerized method for encoding video comprising: dividing a video frame into macroblocks; for each macroblock finding a minimal movement or minimal error motion estimation compensation algorithm pair that encodes and decodes said macroblock with a smallest amount of motion or error; and encoding said frame by encoding each macroblock with a motion estimation algorithm of said respective minimal error motion estimation compensation pair.

The present invention relates to a device and method for motion estimation and compensation in video encoding.
Motion estimation is the process of determining motion vectors that describe the transformation from one 2D image to another; usually from adjacent frames in a video sequence. Motion estimation is an ill-posed problem as the motion is often in three dimensions but the images are a projection of the 3D scene onto a 2D plane. The motion vectors may relate to the whole image (global motion estimation) or specific parts, such as rectangular blocks, arbitrary shaped patches or even per pixel. The motion vectors may be represented by a translational model or many other models that can approximate the motion of a real video camera, such as rotation and translation in all three dimensions and zoom.
Closely related to motion estimation is optical flow, where the vectors correspond to the perceived movement of pixels. In motion estimation an exact 1:1 correspondence of pixel positions is not a requirement.
Applying the motion vectors to an image to synthesize the transformation to the next image is called Motion compensation. The combination of motion estimation and motion compensation is a key part of video compression as used by MPEG 1, 2 and 4 as well as many other video codecs. The present application relates to combinations of motion estimation and motion compensation algorithms.
For any given codec a particular motion estimation algorithm is used. More advanced codecs are able to vary parameters of the motion estimation algorithm dynamically during processing, say to compensate for different circumstances appearing in the video.
International Patent Application WO 2009/066284A2 teaches a codec that switches dynamically between several motion estimation algorithms. However it always uses a standard motion compensation algorithm so that it can work with a standard decoder.


Disclosed is a method and system for multi-character multi-pattern pattern matching. In the multi-character multi-pattern pattern matching method, patterns in an input stream are detected by transitioning between states of a “compressed deterministic finite state automaton (DFA)”, with each transition based on multiple characters of the input stream. The compressed DFA is created by compressing an original DFA, such as an Aho-Corasick DFA, such that each state of the compressed DFA represents multiple consecutive states of the original DFA and each transition between the states of the compressed DFA is a combination of all of the transitions between the multiple consecutive states of the original DFA. This method can be implemented using a Ternary Content-Addressable Memory (TCAM) to store the transitions of the compressed DFA and compares the transitions with multiple characters of an input stream at a time to detect patterns in the input stream.

The present invention is generally directed to pattern matching. More specifically, the present invention is directed to a method and system for multi-character multi-pattern pattern matching.
Pattern matching is used to detect the occurrence of a pattern or keyword in a search target. For example, given two strings, a simple pattern matching algorithm can detect the occurrence of one of the strings in the other. Pattern matching algorithms are widely used in information retrieval applications, such as data mining, bibliographic searching, search and replace text editing, word processing, etc., and content inspection applications, such as Network Intrusion Detection Systems (NIDS), virus/worm detection using signature matching, IP address lookup in network routers, DNA sequence matching, etc.
For many applications, it is necessary to detect multiple patterns in a particular search target. A conventional multi-pattern pattern matching algorithm is the Aho-Corasick (AC) algorithm. The AC algorithm locates all occurrences of any of a finite number of keywords in a string by constructing a finite state pattern matching machine to process the string in a single pass. For example, this algorithm can be used to detect virus/worm signatures in a data packet stream by running the data packet stream through the finite state machine byte by byte.
The AC algorithm constructs the finite state machine in three pre-processing stages, namely the goto stage, the failure stage, and the next stage. In the goto stage, a deterministic finite state automaton (DFA) or keyword trie is constructed for a given pattern set. The DFA constructed in the goto stage includes various states for an input string, and transitions between the states based on characters of the input string. Each transition between states in the DFA is based on a single character of the input string. The failure and next stages add additional transitions between the states of the DFA to ensure that a string of length n can be searched in exactly n cycles. Essentially, these additional transitions help the algorithm to slide from the currently matched pattern (not a match anymore) to another pattern which is the next best (longest prefix) match in the DFA. Once the pre-processing has been performed, the DFA can then be used to search any target for all of the patterns in the pattern set.
During the search stage, the AC DFA processes one character (or byte) per transition in the DFA, and each transition is stored in a memory. Accordingly, the AC DFA transitions to a different state based on each character of the input string. Hence, for each character in an input string, a memory lookup operation must be performed to access the transitions from the current state of the AC DFA and compare the transitions to the character.
Virus/worm detection applications must detect the presence of multiple virus/worm signatures in a stream of packets in a single pass as the packets are transmitted in a data network. As network speeds have increased, conventional pattern matching algorithms, such as the AC algorithm, cannot perform at high enough speeds to keep up the network speeds. One reason that conventional pattern matching algorithms cannot perform at high speeds is because a memory lookup operation must be performed for each byte of the stream of packets.
What is needed is a multi-pattern matching method that can be used for high speed applications.

Method and system for multi-character multi-pattern pattern matching