There is provided a method of fabricating a semiconductor device having a multi-layered structure and including an interlayer insulating film composed of carbon family material, the method including the steps of (a) depositing an insulating film on a lower wiring layer, the insulating film being composed of carbon family material, (b) annealing the insulating film in hydrogen atmosphere at a first temperature equal to or greater than a temperature at which the insulating film has been deposited, and (c) forming an upper wiring layer on the insulating film. The method suppresses gas from being discharged out of an insulating film without an increase in dielectric constant, and prevents deposited films on the insulating film from being peeled off.

1. Field of the Invention
The invention relates to a method of fabricating a semiconductor device including an insulating film composed of carbon family material, and more particularly to a method of fabricating a semiconductor device having a multi-layered wiring structure including an interlayer insulating film composed of carbon family material.
2. Description of the Related Art
With an increase in integration of a semiconductor integrated circuit such as LSI, it becomes more and more important to fabricate a multi-layered wiring structure with high reliability in fabrication of a semiconductor integrated circuit.
Reliability of a multi-layered wiring structure is dependent in particular on a characteristic of an interlayer insulating film. A material of which an interlayer insulating film is composed and a method by which an interlayer insulating film is formed have been determined from the standpoint of heat-resistance, electrical insulation, and coverage ability. For instance, an interlayer insulating film has been usually composed of silicon dioxide (SiO.sub.2), silicon nitride (SiN) or phospho silicate glass (PSG), and has been usually formed by chemical vapor deposition (CVD).
However, with a design rule for LSI getting smaller, wiring delay caused by parasitic capacity between wirings has recently become more serious than signal delay caused by individual elements such as a transistor constituting LSI. As a result, due to writing delay, LSI could not be improved, even if individual elements were fabricated in a size as small as possible.
Under such circumstance, there is presently developed an interlayer insulating film having a smaller dielectric constant .di-elect cons.r than a dielectric constant of a silicon nitride film and a dielectric constant of a silicon dioxide film both of which have been widely used as an interlayer insulating film in fabrication of a semiconductor integrated circuit. Herein, both a silicon nitride film and a silicon dioxide film have a dielectric constant .di-elect cons. r smaller than seven (7).
An insulating film composed of carbon family material attracts attention as a material having a small dielectric constant to be used in place of an insulating film composed of silicon family material, because an insulating film composed of carbon family material is expected to have a smaller dielectric constant. Herein, carbon family material of which an insulating film is composed includes organic polymer family material such as polyimide, poly-p-xylylene, and benzocyclobuten, and inorganic carbon family material such as amorphous carbon.
An insulating film composed of such carbon family material has a smaller dielectric constant than that of a conventional insulating film composed of silicon family material, and could have a further smaller dielectric constant by additionally containing fluorine thereinto. For instance, if an amorphous carbon film contains fluorine therein, it would be possible to decrease a dielectric constant of the amorphous carbon down to approximately 2. Composing a semiconductor device of such an amorphous carbon film has recently been reported.
The inventors had reported a method of fabricating a multi-layered wiring structure including an interlayer insulating film composed of fluorinated amorphous carbon in IEDM Technical Digest, 1996, pp. 369-372. In this report, combination of a film composed of carbon family material and a silicon dioxide film was suggested in order to make it possible to employ conventional interlayer technology.
The suggested method has the following steps.
First, a lower wiring layer composed of aluminum is covered with an amorphous carbon film containing fluorine therein and having a dielectric constant of 2.3. Then, a silicon dioxide (SiO.sub.2) film is deposited on the amorphous carbon film by a thickness of about 2 microns by plasma-enhanced chemical vapor deposition. The silicon dioxide film is deposited for the purpose of ensuring processability in planarization to be carried out later by chemical mechanical polishing (CMP), and enhancing accuracy in planarization.
When the silicon dioxide film is deposited on the amorphous carbon film, the silicon film is made silicon-richer at least at an interface between the silicon dioxide film and the amorphous carbon film in order to enhance adhesion between the films.
After the deposition of the silicon dioxide film, the silicon dioxide film is planarized by CMP. Then, the amorphous carbon film is formed with via-holes with the silicon dioxide film being used as a hard mask. Then, the thus formed via-holes are filled with aluminum plug. Thus, there is completed a multi-layered wiring structure.
The multi-layered wiring structure formed in the above-mentioned manner can have a parasitic capacity which is reduced by about 50% relative to that of a conventional multi-layered wiring structure including an interlayer insulating film composed of silicon dioxide.
As having been explained so far, in order to form a multi-layered wiring structure including an insulating film composed of carbon family material, with high processability being maintained, it is necessary to deposit an insulating film which is to be planarized later and which is composed of a conventional material such as silicon dioxide, on an interlayer insulating film composed of carbon family material with high adhesion being maintained therebetween.
In addition, a thin film composed of refractory metal such as titanium nitride, titanium, tantalum nitride, and tantalum may be sandwiched between the interlayer insulating film and the silicon dioxide film in order to prevent mutual diffusion between the interlayer insulating film and metal of which a wiring layer is composed, such as aluminum and copper.
As explained above, it is necessary to carry out various steps including steps of depositing films after deposition of an interlayer insulating film composed of carbon family material, in order to fabricate a multi-layered wiring structure. These steps are inevitably accompanied with an annealing step. Hence, it is necessary to prevent various defects such as peeling-off and mutual diffusion from being caused by an annealing step to be carried out after formation of an insulating film composed of carbon family material, between the insulating film and other films to be deposited on the insulating film such as the above-mentioned film to be planarized and refractory metal film. If defects such as peeling-off and mutual diffusion are caused, a semiconductor device could not work properly, resulting in reduction in reliability and fabrication yield.
However, if an insulating film composed of carbon family material is heated up to about 400 degrees centigrade, gas is discharged out of the insulating film. The gas breaks adhesion between the insulating film and a silicon dioxide film or other films deposited on the insulating film, resulting in film peeling-off in a multi-layered wiring structure. Hence, it is necessary to reduce an amount of gas discharged out of the insulating film to thereby prevent peeling-off of films caused in an annealing step to be carried out after formation of the insulating film.
In order to prevent films from peeling off in an annealing step, it is necessary to reduce an amount of gas desorped out of an insulating film by annealing. If an insulating film composed of carbon family material is annealed after deposition of the insulating film, but prior to deposition of films on the insulating film, gas desorped out of the insulating film is discharged out of a multi-layered wiring structure. Accordingly, it would be possible to prevent films deposited on the insulating film from being peeled off, even if those films are subject to annealing.
In a conventional method, an insulating film composed of carbon family material are subject to an annealing step in a vacuum atmosphere or in an inert gas atmosphere such as nitrogen and argon. The conventional method makes it possible to reduce an amount of gas to be discharged in later steps, but is accompanied with a problem that a dielectric constant of the insulating film is increased in comparison with the dielectric constant before carrying out an annealing step. In other words, a small dielectric constant by which an insulating film composed of carbon family material is characterized is incompatible with processability.
For instance, Japanese Unexamined Patent Publication No. 8-195565has suggested a method of fabricating a multi-layered wiring structure, comprising the steps of forming a wiring layer on a substrate, applying photosensitive polymer on the wiring layer, drying the photosensitive polymer, exposing the photosensitive polymer to a light in a pattern, developing the photosensitive polymer to thereby form via-holes in the photosensitive polymer, curing the photosensitive polymer to thereby form an interlayer insulating film, and forming an upper wiring layer on the insulating film.
Japanese Unexamined Patent Publication No. 8-264648 has suggested a semiconductor device including an interlayer insulating film composed of fluorine-containing amorphous carbon, an electrode, a wiring layer, and a buffer layer sandwiched between the interlayer insulating film and the wiring layer. The buffer layer prevents gas from being discharged out of the interlayer insulating film in an annealing step.
Japanese Unexamined Patent Publication No. 9-237837 has suggested a method of fabricating a multi-layered wiring structure, comprising the steps of forming a first wiring layer on a substrate, patterning the first wiring layer, forming a photosensitive polymer layer on the thus patterned first wiring layer, exposing the photosensitive polymer layer to a light, developing the photosensitive polymer layer to thereby form an interlayer insulating film, and forming a second wiring layer on the insulating film.
However, none of the above-mentioned Publications can overcome the problem mentioned earlier that a dielectric constant of the insulating film becomes greater than before carrying out an annealing step.

Method of fabricating semiconductor device


The invention relates to a method for operating an internal combustion engine which is operated in at least one engine operation range in a substantially homogeneous self-ignited manner and in at least a second engine operation range in a substantially homogeneous spark-ignited manner, with a changeover occurring during engine operation between homogeneous self-ignited operation and homogeneous spark-ignited operation depending on the load and vice-versa.

The invention relates to a method for operating an internal combustion engine which is operated in at least one engine operation range in a substantially homogeneous self-ignited manner and in at least a second engine operation range in a substantially homogeneous spark-ignited manner, with a changeover occurring during engine operation between homogeneous self-ignited operation and homogeneous spark-ignited operation depending on the load and vice-versa, as well as an internal combustion engine for performing the method.
The combustion of a lean fuel/air mixture which is ignited by self-ignition leads to the advantage that due to the homogeneous concentration and temperature distribution extremely low emission values are achieved for NOx and exhaust particulates. This method is known in the English-speaking countries as xe2x80x9cHCCIxe2x80x9d method (Homogeneous Charge Compression Ignition). The low content of NOx exhaust gas in the HCCI method is obtained by the fact that the combustion commences at a plurality of ignition locations, as a result of which the combustion occurs with a relatively low combustion temperature. Gasoline shows considerable advantages over diesel fuel for the HCCI method due to its very low willingness for auto-ignition and the lower boiling range of between approx. 30xc2x0 and 190xc2x0. The compression ratio can be increased in this case, as in a diesel engine, to values of approx. 15 to 17. Since the precise time of the ignition can fixed only at low effective medium pressure in the desired manner shortly before the upper dead center, the achievable effective mean pressure is limited in the HCCI method in a disadvantageous manner to the partial-load range, as is explained in the publication xe2x80x9cAn Experimental Study on Premixed-Charge Compression Ignition Gasoline Enginexe2x80x9d, Taro Aoyama et al., SAE 960081.
DE 199 27 479 A1 describes a method for operating an internal combustion engine operated with gasoline which provides that the internal combustion engine is self-ignited in a homogeneous way below a predetermined limit value of the effective medium pressure and is operated in a spark-ignited manner above the limit value. In this way the advantages of the HCCI method can be used without its disadvantages.
The HCCI operating mode is provided primarily to cover the low- and partial-load fields, whereas the spark-ignited engine operation is used for the higher partial load and the full load. In the dynamic operation of an internal combustion engine it is unavoidable to change between the two operating modes during the operation of the engine without producing serious losses in the torque delivery in the transition phases.
From EP 1 085 192 A2 an internal combustion engine is known which is operated in the medium partial-load range in a homogeneous self-ignited manner and in the upper partial-load range, in the full-load range as well as the lowermost partial-load range in a homogeneous spark-ignited fashion. In the range of the changeover from spark-ignited to self-ignited operation the quantity of recirculated exhaust gas is increased in order to ensure a secure self-ignition. Conversely, during the changeover from self-ignited to spark-ignited operation the quantity of recirculated exhaust gas is reduced on time in order to prevent knocking phenomena. During the change from one operating mode to another a transitional operation is performed while fuel is injected directly into the combustion chamber and a stratified charge is produced. A stable and even combustion during the change of the operating times is to be thus achieved. The transitional operation has a disadvantageous effect on the response characteristic and the emissions.
In homogeneous spark-ignition operation, the filling is usually realized by throttling the supply of fresh air by means of a throttling member in the fresh-air line or by throttling the fresh-air supply by means of a variable valve drive mechanism. If one examines a constant speed/load load in both operating modes it will be seen that at the same torque delivery in the homogeneous spark-ignited operation substantially more energy is bound in the exhaust gas than in HCCI operation. This fact is of decisive importance when the operating mode is to be changed. In addition, the homogeneous spark-ignition mode is operated with a substantially lower exhaust gas recirculation than the homogeneous spark-ignition operation.
During HCCI operation, the filling of the cylinder is not throttled. Instead, the engine is driven in this operating mode in an unthrottled manner. On changing the operating point, the filling composition changes which is composed of the mass of fresh-air, the recirculated mass of exhaust gas of the last combustion and the injected fuel mass. In this operating mode the cylinder charge is conditioned with the help of the recirculated exhaust gases in such a way that a self-ignition process can occur. The compression ignition occurs via the temperature increase of the fuel-air mixture during the compression phase in which the cylinder charge is compressed to a minimum residual volume.
When the internal combustion engine is operated in both operating modes in a stationary manner, the required mass of fresh air and the mass of recirculated exhaust gas is read out from engine characteristics map records which were determined under stationary conditions and set via adjusting the phase adjuster, the variable valve drive and/or the electric throttle member. Since the temperature conditions, and in particular the exhaust gas temperatures, deviate to an extremely high extent from the stationary values in the transitional phases, it is necessary to correct the mass of fresh air and the recirculated or compressed residual gas mass in these transitions in such a way that no excessive strain occurs in the internal combustion engine in the transient phase.
The choice as to which internal combustion engine is most suitable for which operating point is determined by a superset operating mode coordinator. The critical aspect in the change of the operating mode is the transition from the homogeneous spark-ignited operation to the homogeneous self-ignited operation because already in the first cycle after the changeover the cylinder charge needs to be composed in such a way that a combustion with self-ignition occurs at the right crank position. A very decisive variable which influences the position of the combustion in homogeneous self-ignition operation is the mixing temperature of the cylinder charge. If the mixing temperature of the cylinder charge is too high, the combustion occurs too early and the occurrence of very high pressure increases must be expected. This is accompanied by an enormous strain on the engine and a loud combustion noise. If on the other hand the mixing temperature of the cylinder charge is too low, the combustion occurs either too late or the conditions for the self-ignition are not achieved and a combustion misfire occurs. This constellation is to be avoided in order to avoid any noticeable torque drop at the clutch and on the other hand to keep the emissions of the internal combustion engine low.
It is the object of the present invention to improve a method of the kind mentioned above in such a way that an engine-protecting, low-emission and delay-free transition is possible between the engine operation ranges with homogeneous spark ignition and homogeneous self-ignition.
This is achieved in accordance with the invention in such a way that the homogeneous self-ignition operation is changed into the homogeneous spark-ignition operation and/or the homogeneous spark-ignition operation into the homogeneous self-ignition operation in a transitionless way from one cycle to the next cycle. An exhaust gas mass which is reduced with respect to the requirements for a stationary homogeneous self-ignition operation is recirculated or left in the cylinder during the changeover process from the homogeneous spark-ignition operation to the homogeneous self-ignition operation. By reducing the recirculated exhaust gas mass during the changeover phase it is possible to reduce the mixing temperature of the cylinder filling and subsequently the combustion state can be kept constant.
Due to the high exhaust gas temperatures in homogeneous spark-ignition operation, the recirculated exhaust gas mass is reduced for the first cycles of the homogeneous self-ignition operation because otherwise a combustion at a too early time would occur otherwise in which very high pressure gradients would have to expected in the combustion chamber. The adjustment of the recirculated exhaust gas mass can occur in such a way that for the purpose of reducing the recirculated exhaust gas mass the opening of at least one exhaust valve, which opening is performed for the purpose of internal exhaust gas recirculation during the inlet phase, is reduced during the intake phase and thus the mixing temperature of the filling is reduced. The adjustment of the recirculated exhaust gas mass can also occur as an alternative thereto via a combination of intake and exhaust control time by extending the intake control time and reducing the exhaust control time in order to compensate a filling loss. A further possibility is that for reducing the remaining exhaust gas mass the exhaust control time is increased during the exhaust phase. As a result, a lower exhaust gas mass remains in the cylinder at the end of the exhaust phase.
In order to enable a smooth transition from the spark-ignition operation to self-ignition operation it is advantageous when after the changeover-induced reduction the recirculated exhaust gas mass is increased continuously or discontinuously according to the requirements for homogeneous self-ignition operation depending on the combustion cycles that have occurred since the changeover. In an especially advantageous embodiment it is provided that at the time of the changeover a cycle counter is started which adds up the combustion cycles since the last homogeneous spark-ignited combustion and that the recirculated exhaust gas mass is determined as a function of the cycle count.
During the transition from homogeneous self-ignition operation to homogeneous spark-ignition operation, the valve control times can be changed abruptly from one cycle to the next cycle. In order to enable the performance of a compensation of the torque during the changeover phase, the ignition point can be adjusted during the changeover in the direction towards the upper dead center of the ignition.
The first engine operation range is allocated to homogeneous self-ignition and the second engine operation range to homogeneous spark-ignition.
The method is preferably employed with an internal combustion engine operated with gasoline in which it is provided that the internal combustion engine comprises a fully variable valve actuation device and a device for the controlled recirculation of exhaust gas, so that it is possible to change in a transitionless manner between homogeneous self-ignition operation and homogeneous spark-ignition operation and/or between homogeneous spark-ignition operation and homogeneous self-ignition operation.

Method for operating an internal combustion engine

Abstract: In order to enable the changeover process between the engine operation ranges in an engine-protecting and delay-free manner and with low fuel consumption and low emissions it is provided that the homogeneous self-ignition operation is changed into the homogeneous spark-ignition operation and/or the homogeneous spark-ignition operation into the homogeneous self-ignition operation in a transitionless way from one cycle to the next cycle, with an exhaust gas mass which is reduced with respect to the requirements for a stationary homogeneous self-ignition operation being recirculated or left in the cylinder during the changeover process from the homogeneous spark-ignition operation to the homogeneous self-ignition operation.


A developing device includes: a developer carrying body which supplies developer to a predetermined image carrying body; a layer thickness regulating member which is made of a magnetic material, which has a layer thickness regulating face opposing the developer carrying body so as to form a predetermined gap between the layer thickness regulating face and the developer carrying body and regulating the layer thickness of the developer on the developer carrying body, and which forms a magnetic path between the layer thickness regulating face and the developer carrying body; an installation member on which the layer thickness regulating member is installed; and an elastic sheet member arranged in the gap in a state of contact with a surface of the developer carrying body.

1. Field of the Invention
The present invention relates to a developing device which forms a toner image on a predetermined image carrying body, and to an image forming apparatus including the same.
2. Description of the Related Art
An image forming apparatus, such as a copying machine, a printer, a facsimile device, or a composite of these, which employs an electrophotographic method includes a developing device that forms a toner image on an image carrying body (for example, a photosensitive drums or transfer belt) by supplying toner to the image carrying body.
The developing device includes, as basic constituent elements, a developer storing portion which stores developer composed of a non-magnetic toner and a magnetic carrier, a developing roller which receives developer from the developer storing portion and forms a toner image on the image carrying body by supplying the developer to the image carrying body, and a regulating blade, disposed so as to oppose the circumferential surface of the developing roller, and regulating the layer thickness of the developer on the circumferential surface of the developing roller.
In order to form a good toner image on the image carrying body, it is important to form a developer layer having a uniform thickness on the circumferential surface of the developing roller, by means of a regulating blade. A first prior art technology is known as technology for achieving a uniform thickness of the developer layer.
The developing apparatus according to the first prior art technology includes a regulating blade constituted by a magnetic plate which is disposed opposite the circumferential surface of the developing roller, and a non-magnetic elastic plate which is attached to the downstream surface of the magnetic blade as viewed in terms of the direction of rotation of the developing roller. When the developer adhering to the circumferential surface of the developing roller passes a gap formed between the regulating blade and the circumferential surface of the developing roller, firstly, the thickness of the layer of the developer is regulated magnetically by the magnetic plate and then the layer thickness is regulated physically by the elastic plate. In this way, it is possible to achieve uniform thickness of the developer layer using the magnetic plate and the elastic plate.
However, in the developing device according to the first prior art technology, the gap between one end of the magnetic plate and the circumferential surface of the developing roller is liable to vary with the dimensional accuracy of the magnetic plate, and the installation accuracy of the magnetic plate in the developing vessel. Therefore, although one end of the elastic plate projects further toward the developing roller than one end of the magnetic plate, if the dimensional accuracy of the magnetic plate or the installation accuracy of the magnetic plate in the developing vessel, or the like, is poor, then there will consequently be variation in the gap between one end of the magnetic plate and the circumferential surface of the developing roller. In this way, in the developing device according to the first prior art technology, variation is liable to occur in the gap through which the developer layer passes, and therefore the layer thickness cannot be made uniform. As a result of this, it is difficult to form a good toner image on the image carrying body.

Developing device with a thickness regulating member for regulating a thickness of a developer on a developer carrying body and image forming apparatus comprising same


This application discloses a method for separating banana clusters into individual fruits. In this method, the banana cluster is hung on a carrier (such as a cable) in such a way that the hanging point is the place where the banana fruit stalks converge (at the crown). The cluster and/or the cutter are moved toward each other and the cutter is positioned such that the cutter cuts the fruit stalks at a point lower than the cluster hanging point.

As everyone knows, bananas grow in bunches and they are generally marketed to the public in clusters (i.e., a portion of a bunch consisting of several bananas attached together at their crowns). Sometimes it is desired to sell individual bananas to the consumer. The separation of these individual bananas from the clusters in a cost-effective way, without damaging them, is not an easy problem. The inventors herein are not aware of any existing methods or means for mechanically separating banana clusters into individual bananas on a large scale automated basis. In the areas of banana harvesting and processing, the following patent may be relevant—GB 1077435. This patent describes a semi-cylindrical cutting tool for manually cutting banana clusters off the tree trunk. The cutter is not designed for an automated process or for separating those clusters into individual bananas.
Nevertheless, there have been engineering solutions related to the separation of clusters into individual fruits, as applied to other types of fruit (other than bananas).
A device has been disclosed for separation of cherry clusters into individual cherries ("Cherry Splitter," U.S. Pat. No. 5,050,492, Watton, et al., issued Sep. 24, 1991). The device separates a cluster of cherries while retaining the maximum length of the cherry stems. The cherries are arranged horizontally on belt conveyors that are positioned close to one another. The conveyors are strung along several pairs of cutters and separating guides, installed one behind another along one line.
A cluster moves on the belts into the operating zone of the separator. The separator is a revolving disk that ensures: a) the divergence of cherry stems to different sides, and b) that the cluster is oriented in such a way that when it goes under the disk cutter, the stems are on different sides of the disk. This allows cutting the cluster into two parts while preserving stems.
The patent "Tandem Drum Cluster Separator," U.S. Pat. No. 4,784,057, Mietzal, et al., issued Nov. 15, 1988, describes a device for separation of pod vegetable clusters. It includes two horizontally arranged drums with a cylindrical surface. Each drum is equipped with rods that are secured on its cylindrical surface and directed radially outward. The free ends of the rods are equipped with upward-facing hooks. During operation of the device, pod clusters fall into the space between the drums. As they fall, they get hooked on the rods. The drums, rotating in opposite directions, bring the rods with hanging clusters out of the confined area between the drums; the rods transfer the clusters toward sickle-shaped knives located under the rods in such a way that the knives cut the pods off clusters at the base of the stem.
A device also exists for separation of petals from the edible chrysanthemum flower cup ("Separation of petals of edible chrysanthemum and separator for petal," Japanese Patent 8116944, published May 14, 1996). The device includes a support on which the flower is located—a vertical, hollow, truncated cone, its smaller (upper) end having an opening that corresponds to the size of the flower cup. The flower is positioned on the support in such a way that the cup is located above the upper hole, and the petals fall long the sides of the cone. To separate the cup from the petals, the device uses a lever and a stamping punch.
The structure of banana clusters and the shape of bananas differ significantly from cherry clusters, pod vegetables, and chrysanthemum flowers. Therefore, none of the above-described inventions can be used to separate banana clusters into individual fruits.

Method for separating banana clusters into separate bananas


The present disclosure is directed to the introduction of an additive to a contaminated gas stream using an additive introduction system including one or more of a compressor, a cooled lance, and an educator nozzle on the lance to inhibit scaling from the additive or a derivative thereof.

Injection of hydrated lime and other alkaline materials is a promising technology for control of acid, such as NOx (NO and NO2), HCl, and SOX (SO2 and SO3) from coal—and biomass-fired sources. Acid gas control is becoming obligatory due to the problems arising from increased corrosion, acid mist emissions and associated impacts to plant opacity, and the propensity of certain acid gases, such as SO3, to interfere with powdered activated carbon ("PAC") used for mercury capture from these sources. Concerns with SO3 emissions have increased due to selective catalytic reduction reactors ("SCRs") oxidizing sulfur dioxide to sulfur trioxide. SCRs are being installed on an increasing number of coal-fired sources for control of nitrogen oxides. SOx species are also present in flue gas at elevated levels when burning high sulfur coals. The presence of sulfur species and the ammonia reactants used for nitrogen oxide control can combine to form condensable compounds that foul or degrade air heater performance over time.
Injection of dry alkaline sorbents to control acid gas emissions continue to be used successfully at many coal-fired sources to chemically control emissions. When dry alkaline materials are injected into a gas stream for the purpose of controlling acid gases, the desired chemical reactions occur in the flue gas stream.
A major goal of any injection system is to maximize the desired reactions and minimize undesired reactions and/or interactions with the walls and mechanical systems downstream. As an example, one of the desired acid gas reactions between hydrated lime and SO3 is shown below:Ca(OH)2+SO3→CaSO4+H2Ohydrated lime+sulfur trioxide=calcium sulfate+waterOne of the major undesired reactions that occurs within the alkaline sorbent injection system is that of hydrated lime with carbon dioxide:Ca(OH)2+CO2→CaCO3+H2Ohydrated lime+carbon dioxide=calcium carbonate+waterThe rate of carbonate formation is believed to be a temperature-dependent process; that is, the higher the gas temperature the greater the rate of conversion of hydrate to carbonate. Calcium carbonate has been shown to be inversely soluble, therefore increasing temperature leads to greater carbonate deposition within the injection system. Managing the temperature of the injection system and lime carrier gas reduces the rate of formation and subsequently minimizes the deposition of calcium carbonate. Due to the presence of air in the injection system, CO2 is always available for reaction in either the carrier gas or in the flue gas that contaminates the carrier gas through leakage or recirculation into the injection system. Therefore, thermal management of the injection system is employed to successfully moderate carbonate formation, reduce lime consumption, and increase system reliability.
A carrier gas treatment system 200 according to the prior art includes an optional dehumidifier 204, a regenerative or positive displacement blower 208 (air having a pressure in the range of 3 to 25 psi), and a refrigerated air dryer 212 and/or after cooler 216. Other configurations and arrangements of the illustrated equipment are possible. This system 200 generally reduces the dew point of the conveying air to a temperature just above 32° F. Although the reaction of calcium hydroxide and carbon dioxide to air is slowed by the gas dehumidification and cooling, the degree of dehumidification and cooling is limited. Accordingly, conventional systems 200 generally experience debilitating issues with scaling, abrasion, plugging in the lines, lances, and other conveying surfaces in the system 200.
These problems increase the necessity for time-consuming and expensive manual cleaning and maintenance of the introduction system.

Process for dilute phase injection of dry alkaline materials


An IC device (100) includes an IC body (106) having a base layer (108) and first and second upper layers (114, 116) on the base layer. The IC body includes a cavity region (104) extending through said base and first upper layers and at least a portion of said second upper layer. In the IC device, a portion of said second upper layer in the cavity region comprises a planar inductive element (102) having first and second contacting ends (140, 142). In the IC device, at least one support member (128, 130, 132) extends at least partially into said cavity region from said IC body in at least a first direction parallel to said base layer and intersects at least a portion of said planar inductive element.

1. Statement of the Technical Field
The invention is directed to integrated circuit (IC) devices, and more particularly IC devices including inductor structures formed therein.
2. Description of the Related Art
Reactive components, such as capacitors and inductor, are important components for implementing various types of signal processing devices, including low-noise amplifiers (LNAs), voltage controlled oscillators (VCOs), filters, and impedance matching networks, to name a few. As a result, a significant number of components are typically needed to implement such devices. However, the number of components for such devices can be reduced by using an IC including inductors and capacitors formed therein. As a result, signal processing devices can be formed in a compact package, reducing overall device size.
The performance of inductors, including inductors formed within an IC (monolithic inductor), is typically evaluated based on the quality (Q) factor. An ideal inductor will generally be lossless irrespective of the amount of current through the winding. However, inductors, including monolithic inductors, typically have winding resistance from the electrically conductive materials used for forming the coils. Since the winding resistance appears as a resistance in series with the inductor, it is often called the series resistance. The inductor's series resistance converts electrical current through the coils into heat, thus causing a loss of inductive quality. The Q factor measures this loss (i.e., the inductor's efficiency), as Q factor for an inductor is the ratio of its inductive reactance to its resistance at a given frequency. In general, the higher the Q factor of the inductor, the closer it approaches the behavior of an ideal, lossless, inductor. In general, the Q factor of an inductor can be computed from Q=(ωL)/R, where R is its internal electrical resistance of the inductor and ωL is capacitive or inductive reactance at resonance.
In the case of monolithic inductors, the Q factor is primarily limited by conductor losses arising from conductor resistances, the conductive silicon substrate, and parasitic substrate capacitances (which lower the inductor self-resonant frequency). Additionally, time-varying magnetic fields can penetrate the silicon substrate and cause eddy currents as per Lenz's law, thus resulting in power loss. Furthermore, eddy currents create their own magnetic fields that oppose those of the monolithic inductor and effectively decrease the inductance of the inductor.

Inductor structures for integrated circuit devices


The present document discloses a semiconductor device structure (1) comprising a SiC substrate (11), an Inx1Aly1Ga1-x1-y1N buffer layer (13), wherein x1=0-1, y1=0-1 and x1+y1=1, and an Inx2Aly2Ga1-x2-y2N nucleation layer (12), wherein x2=0-1, y2=0-1 and x2+y2=1, sandwiched between the SiC substrate (11) and the buffer layer (13). The buffer layer (13) presents a rocking curve with a (102) peak having a FWHM below 250 arcsec, and the nucleation layer (12) presents a rocking curve with a (105) peak having a FWHM below 200 arcsec, as determined by X-ray Diffraction (XRD).

Materials based on indium aluminum gallium nitride (InxAlyGa1-x-yN, x=0-1, y=0-1 and x+y=1), for example gallium nitride (GaN), are of great interest for use in semiconductor devices such as, but not limited to, high electron mobility transistors (HEMTs) due to excellent high frequency and power handling capabilities.
High thermal conductivity substrates, typically silicon carbide (SiC), are used in such devices in order to efficiently extract the heat and to minimize temperature rise of the device. In order to achieve high-quality heteroepitaxial growth of InxAlyGa1-x-yN on SiC, interfacial layers of the InxAlyGa1-x-yN type, x=0-1, y=0-1 and x+y=1, may be introduced between the InxAlyGa1-x-yN layer and the SiC substrate, and typically an aluminum nitride (AlN) nucleation layer is used to wet SiC substrate surface for two-dimensional nucleation process and to compensate for the lattice mismatch.
In order to use these materials in such applications, a high crystallinity of the InxAlyGa1-x-yN and AlN layers is of high importance.
Efforts to improve the crystal quality of an AlN nucleation layer sandwiched between a GaN buffer layer and a SiC substrate has been done and are discussed, e.g. by S. Qu and S. Li et al. in journal of Alloys and compounds 502 (2010) 417-422.
It is highly desirable to develop a semiconductor device structure with even further improved crystallinity of the constituting layers. Further, it is desirable to produce a semiconductor device structure with a reduced number of leakage current paths via structural defects like threading dislocations. Moreover, it is desirable to produce a semiconductor device structure with a reduced thermal boundary resistance (TBR).

Semiconductor device structure and methods of its production

Abstract: Methods of making such a semiconductor device structure are disclosed.


An electrical power system includes an electric power source providing AC power to a load. A wideband voltage controller provides a wideband control signal vector to the electric power source. A fundamental component removal module interfaces to the AC power, receiving a fundamental component Park vector of the AC voltage, and providing a resonant frequency content in Park vector format of the AC current. A narrow band voltage regulator uses a resonant component Park vector of the AC current and the resonant frequency content in Park vector format to provide a narrow band output vector signal. A dead band compensating circuit rotates narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector to the electric power source. The wideband control signal vector and compensated control signal vector are used to regulate the AC power so that the resonant frequency content is attenuated.

The present invention generally relates to power generation systems, and, more particularly, to power generation systems that utilize digitally or processor controlled inverters to generate AC power.
Inherent within the design of power generation systems that utilize digitally or processor controlled inverters to generate AC power are time intervals that must pass between the sampling of the system state, and the action required as a result of computation in the processor. These time intervals, commonly referred to as the update rate, can be represented as a transport time delay, or transport lag.
Transport lag, i.e. the time delay required to propagate a signal through a physical system, is an inherent property of many physical systems. The transport lag time delay can cause deterioration of performance, or limit performance, of control systems used to operate the physical system. Transport lags can be continuous or discrete in form. For example, a continuous transport lag is exemplified by thickness measurement and control in the process of rolling sheets in steel mills. If the rollers and the measurement sensors have to be separated by a significant distance, due, for example, to the environment near the rollers being too hostile for the measurement sensors, a considerable delay, relative to the amount of steel processed through the rollers, results between the thickness measurement of the rolled sheets and the control of the rollers.
A discrete transport lag may be exemplified by the discrete nature in which a microprocessor samples the state of a system at time zero, and then computes over a period of time (the update rate) what must be done to make the output equal to the commanded reference. Clearly, as the computational time becomes longer (the lower the update rate), the transport lag becomes longer, which in turn limits the response of the control system. A second example of a discrete transport lag is illustrated by the discrete updates of a microprocessor-based control system. The update rate, or the time between updates, is, in essence, a transport lag time delay which is a function of the speed of the microprocessor and the amount of computation demanded by the control system.
Transport lags impact control systems differently than first order lags. While both produce a phase shift between their respective inputs and outputs, the major difference is the attenuation associated with them. For example, in the case of a first order lag at a frequency with a 60 degree delay, there is an approximately 6 decibel (dB) attenuation, while there is no attenuation associated with a corresponding transport lag.
An important feature of a control system is its capability to minimize the effects of external disturbances. The time delay associated with the transport lag deteriorates the performance of the control system by limiting its transient response. Conventional frequency domain based compensation techniques, such as pole-zero cancellations, for example, can provide only first-order approximation in the case of transport lags.
An electrical power distribution system representative of the type used on aircraft may supply electricity in the form of 3-phase power at 400 Hertz (Hz) and 115 Volts alternating current (VAC). Power for such an aircraft electrical power distribution system may be supplied from a 270 Volt direct current (VDC) power source, for example, the alternating current (AC) power output of a generator may be rectified, i.e. converted to DC, and passed through a solid state power converter, also commonly referred to as an inverter, to provide 3-phase alternating current at 400 Hertz and 115 VAC. The electrical power distribution system may be used to power various subsystems and components, for example, electric motors, which can inject noise or power fluctuations into the electrical power distribution system. The power quality of the AC voltage at the interface of the inverter with the electrical power distribution system may be subject to certain requirements and constraints. For military aircraft, for example, the power quality of the AC voltage at the interface of the inverter with the electrical power distribution system is typically specified by a military standard such as Mil-Std 704.
Electrical distribution systems on aircraft are also subject to requirements limiting the amount of electromagnetic energy conducted to the distribution system, which may interfere with other electronics systems on the aircraft, and is referred to as electromagnetic interference (EMI). To meet EMI requirements, which are stringent for military aircraft in particular, electrical distribution systems contain LC-type filters, comprised of inductances and capacitances, such as coils and capacitors, to filter out fluctuations, such as harmonics, in the current and voltage. For example, the electrical power distribution system described above may require an EMI filter at the output of the inverter or may at least contain a 3-phase capacitor bank at the output of the inverter. The LC filter circuits are prone, however, to harmonic resonance, i.e., such circuits may resonate at certain frequencies.
For example, an electric motor powered by the electric power distribution system may inject some amount of current harmonics into the distribution system, despite interfacing with its feeder through appropriate EMI filters. The frequency of the harmonics may vary with the speed of the electric motor. At some intermediate speeds, the current harmonics injected by the electric motor resonate with some of the LC filter components situated at or near the electric motor. The amplitude of the resonant currents circulating throughout the electrical power distribution system may become so large as to create unacceptable voltage fluctuation, or ripple, at the output of the inverter. Such large voltage ripples are unacceptable because they interfere with voltage control of the electric power distribution system, and may even interfere with voltage control to the extent of creating limit-cycle conditions, and because they exceed allowable power quality limits.
The conventional, wideband voltage controller used to regulate voltage in an electric power distribution system, such as described above, has insufficient selectivity to minimize the effects of external disturbances, such as voltage and current fluctuations due to EMI and resonance, in electric power distribution systems with significant transport lag. By merely increasing the selectivity of the voltage controller in a system with significant transport lag, voltage control to minimize the effects of external disturbances can be achieved over a narrow range of frequencies of a disturbance, but by merely increasing the selectivity of the voltage controller, the necessary voltage control for disturbances over the broad range of frequencies outside the narrow range is lost.
As can be seen, there is a need, in electrical power distribution systems, for a voltage controller with sufficient selectivity to control voltage fluctuations over a narrow range of frequencies of a disturbance, which can operate independently of, but in conjunction with, a wide band voltage controller. There is also a need, in electrical power distribution systems with significant transport lag, for a transport lag compensation technique which can eliminate performance deterioration of the voltage control system due to transport lags.
The present invention provides, in electrical power distribution systems, a transport lag compensator for voltage regulation, with sufficient selectivity to minimize the effects of external disturbances, and which can operate independently of, but in conjunction with, a wide band voltage controller. The present invention also provides, in electrical power distribution systems with significant transport lag, a transport lag compensation technique which can eliminate performance deterioration of the voltage control system due to transport lags.
In one aspect of the present invention, an electrical power system includes an electric power source capable of providing AC power to a load; a wideband voltage controller, which provides a wideband control signal vector to the electric power source; a fundamental component removal module having an interface to the AC power, receiving a fundamental component Park vector of the AC voltage, and providing a resonant frequency content in Park vector format of a resonant frequency content of the AC power from the interface; a narrow band voltage regulator receiving a resonant component Park vector of the AC voltage and current, receiving the resonant frequency content in Park vector format from the fundamental component removal module, and using the resonant component Park vector of the AC voltage and the resonant frequency content in Park vector format to provide a narrow band output vector signal; and a dead band, or transport lag, compensating circuit, which rotates the narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector to the electric power source, where the wideband control signal vector and the compensated control signal vector are used to regulate the AC power and the resonant frequency content is attenuated in regulating the AC power.
In another aspect of the present invention, an electrical power system includes an electric power source adapted for providing AC power to a load; a wideband voltage controller, which provides a wideband control signal vector to the electric power source; a fundamental component removal module having an interface to the AC power, receiving a fundamental component Park vector of the AC power, and providing a resonant frequency content in Park vector format of a resonant frequency content of the AC power from the interface; a narrow band voltage regulator receiving a resonant component Park vector of the AC voltage, receiving the resonant frequency content in Park vector format from the fundamental component removal module, and using the resonant component Park vector of the AC voltage and the resonant frequency content in Park vector format to provide a narrow band output vector signal; a dead band, or transport lag, compensating circuit configured to rotate the narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector; a decoupling module for assuring that the resonant frequency content is not included in the wideband control signal vector provided by the voltage controller; a summer for combining the compensated control signal with the wideband control signal vector to form a control signal vector, and a gating logic module, which uses the control signal vector to control the electric power source to regulate the AC voltage so that the resonant frequency content is attenuated in regulating the AC power.
In yet another aspect of the present invention, an electrical power system includes an electric power source adapted for providing AC power to a load; a wideband voltage controller for providing a wideband control signal vector to the electric power source; a fundamental component removal module having an interface to the AC voltage, receiving a fundamental component Park vector of the AC power, and providing a resonant frequency content in Park vector format of a resonant frequency content of the AC power from the interface, a narrow band voltage regulator receiving a resonant component Park vector of the AC power, receiving the resonant frequency content in Park vector format from the fundamental component removal module, and using the resonant component Park vector of the AC power and the resonant frequency content in Park vector format to provide a narrow band output vector signal, a dead band, or transport lag, compensating circuit, which rotates the narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector, a decoupling module for assuring that the resonant frequency content is not included in the wideband control signal vector provided by the voltage controller; a summer for combining the compensated control signal vector with the wideband control signal vector to form a control signal vector; and a gating logic module, which uses the control signal vector to control the electric power source to regulate the AC power so that the resonant frequency content is attenuated in regulating the AC power.
The fundamental component removal module includes a first rotator, which rotates a Park vector of the AC voltage by the fundamental component Park vector of the AC voltage to provide a signal referenced to a fundamental synchronous frame; a high pass filter which passes the resonant frequency content in the signal referenced to the fundamental synchronous frame and blocks a fundamental component of the AC voltage; and a second rotator, which rotates the signal referenced to the fundamental synchronous frame by the negative of the fundamental component Park vector of the AC voltage to provide the resonant frequency content in Park vector format referenced to a stationary frame.
The narrow band voltage regulator includes a first rotator, which rotates the resonant frequency content in Park vector format referenced to the stationary frame by the resonant component Park vector of the AC power to provide a resonance signal referenced to a resonant synchronous frame; a PI-regulator, which regulates the resonance signal referenced to the resonant synchronous frame against a zero-valued command signal; and a second rotator, which rotates an output signal of the PI-regulator by the negative of the resonant component Park vector of the AC power to provide the narrow band output vector signal in Park vector format referenced to the stationary frame.
The dead band, or transport lag, compensating circuit includes a transport lag angle module, which adjusts the transport lag compensation angle to be commensurate with the resonant frequency content; and a transport lag rotator, which rotates the narrow band output vector signal by the transport lag compensation angle to provide the compensated control signal vector.
In a further aspect of the present invention, a method for electrical power distribution includes the steps of: supplying electric power from an electric power source adapted for providing AC power to a load; providing a wideband control signal vector for controlling the electric power source; removing a fundamental frequency component from the AC power and providing a resonant frequency content in Park vector format of a resonant frequency content of the AC power using a fundamental component Park vector of the AC voltage; providing a narrow band output vector signal using the resonant frequency content in Park vector format and a resonant component Park vector of the AC power; rotating the narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector; decoupling the resonant frequency content from the wideband control signal vector using the resonant frequency content in Park vector format; combining the compensated control signal vector with the wideband control signal vector to form a control signal vector; logically processing the control signal vector to control the electric power source to regulate the AC power so that the resonant frequency content is attenuated in regulating the AC power.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.


A footprints device includes an input module and an output module. The input module receives a request for footprint data. The footprint data relates to names of users. The output module sends the footprint data to an address book. The footprint data is marked to indicate when at least one of the names of the users is a contact of the address book.

A user may have access to a Yellow Pages in which information regarding business entities may be found. The user may also have an electronic address book which has access to the Yellow Pages. The user may perform a search of the business entities to find one that meets the requirements of the user. However, the user may also want a recommendation. For example, the recommendation relate to a reliability of the product, a reliability of the company, a general cost analysis of the product among companies, etc. The user may be limited to reading comments from unknown people, hearing from word of mouth, merely making a decision oneself, etc.

This patent is subject to a terminal disclaimer.


An IC includes both “volatile” CMOS transistors (FETs) and embedded non-volatile memory (NVM) cells, both including polysilicon gate structures, sidewall oxide layers, sidewall spacer structures, and source/drain regions. The sidewall spacers of both the NVM cells and the FETs are made up of a spacer material with local charge storage nodes that is capable of storing electrical charge (e.g., silicon-nitride with traps or oxide with silicon nanocrystals). The source/drain regions of the NVM cells omit lightly-doped drains (which are used in the CMOS FETs), and the NVM cells are formed with thinner sidewall oxide layers than the CMOS FETs to facilitate programming/erasing operations. A production method includes a modified CMOS process flow where the CMOS FET gate structures receive different source/drain diffusions and oxides than the NVM gate structures, but both receive substantially identical sidewall spacers, which are used as charge storage structures in the NVM cells.

Several non-volatile memory (NVM) devices have been introduced that reduce memory size by facilitating the storage of multiple bits per NVM cell. For example, a 2-bit non-volatile semiconductor memory transistor including oxide-nitride-oxide storage structure has been described in U.S. Pat. No. 5,768,192, to Eitan. A problem with these types of 2-bit NVM devices is that they require a special photolithographic fabrication procedure (process flow), and therefore are not conducive to use as embedded NVM memory in larger circuits (e.g., system-on-a-chip devices). Further, the operating voltages (i.e., to perform program/erase operations) is typically much higher than the operating voltage of a modern CMOS integrated circuit (IC).
Another type of 2-bit NVM device disclosed, for example, in U.S. Pat. Application No. 2003/222,303, to Fukuda et al. utilizes special (e.g., silicon nitride) storage structures formed inside silicon-oxide sidewall spacers to store data. This type of 2-bit NVM may be utilized to provide an embedded NVM array in a larger integrated circuit (IC), but requires substantial modification to an existing (e.g., CMOS) process flow in order to form both the storage structures and the sidewall spacers. Further, such NVM cells can be relatively unreliable due to misalignment between the relatively small storage structures and associated source/drain regions, which can lead to process related variations that inevitably lead to strong Vt (threshold voltage) and programmability spread.
What is needed is a low-cost embedded NVM cell array that can be implemented using a minimum of additional masks to an existing CMOS process flow, that would not require high operating voltages (i.e., less than 6V), and that would exhibit a reliability that is equal to or greater than existing embedded NVM solutions.

Embedded non-volatile memory cell with charge-trapping sidewall spacers


Fiber aggregate comprising organic polymeric fibers, wherein the organic polymeric fibers have an average length in a range from 2 to 20 millimeters, an average diameter up to 100 micrometer, and comprise at least 75 percent by solid volume of the fiber aggregate, wherein the fiber aggregate has an unrestrained bulk density of at least 0.05 g/cm3, and wherein at least 85% by volume of the fiber aggregate disassociates to provide dispersed fibers. The fiber aggregates are useful, for example, for flowback control in wellbores and reservoirs.

Various fiber aggregates are known, including those for use in applications such as concrete composites, filtration, and absorption.
In another aspect, various multi-component fibers are known. Useful properties of some of these fibers include fiber bonding, wherein for example, a low melting or softening sheath covers a higher melting core. The sheath, when melted or softened serves as a bonding agent for the core.
In another aspect, oil and gas field operators have a need for controlling proppant flowback. Several different approaches have been used to solve this problem, including the use of resin coated (e.g., the coating may be thermosetting resins, such as epoxies and phenolics, and thermoplastic elastomers, such as acrylic resins) proppants. The coated proppants are expected to adhere to each other at the down hole to form an integrated proppant block in down hole. A disadvantage of resin coated proppants for proppant flowback control is the potential premature curing of the proppants, as well as compatibility with the components of hydraulic fracture fluid, such as breakers.
Relatively short fibers (see, e.g., U.S. Pat. No. 5,330,005 (Card et al.), U.S. Pat. No. 5,501,275 (Card et al.), and U.S. Pat. No. 6,172,011 (Card et al.)) have been applied to flowback control. A disadvantage of this approach is its efficiency in controlling flowback. Other approaches have been proposed, such as inclusion of short fibers in the resin coated layers on the proppant, and the modification of proppant geometry including the aspect ratio and particle size distribution.
There is a need for additional flowback control options.


Various embodiments of the present invention include assemblies and methods for utilizing antennas with high gain in small satellites. In one embodiment, a satellite comprising a payload configured for transmitting data is provided. The payload may include various components of the satellite, such as the attitude control system, electrical power system, and/or communication system. The satellite may be configured to communicate with one or more ground stations. The satellite includes a support structure comprising at least one deployable panel, wherein the support structure houses the payload. The satellite also includes at least one antenna coupled to the support structure, wherein the deployable panel is configured to cover the antenna in a non-deployed state and to expose the antenna in a deployed state.

Some satellites, such as nano- and pico-satellites in low earth orbits, unlike their larger counterparts, have more stringent limitations on antenna design due to power constraints that govern the operational frequency and size that defines the space constraints. For high bandwidth applications, higher frequencies with higher transmission power may be used with wide band high gain antenna. Transmission power for a satellite can be reduced by utilizing high gain antennas, but at the cost of additional space. However, due to space and power limitations in small satellites, such options to increase gain on antennas is less desirable. Thus, there is a need for an improved system that provides for higher gain in antennas for small satellites without the increase in power or space requirements.

University of Florida Research Foundation, Inc.


Thermoplastic heteropolysaccharide derivatives, articles employing such thermoplastic heteropolysaccharide derivatives and methods for making such thermoplastic heteropolysaccharide derivatives are provided.

With the ever increasing price of existing raw materials, such as petroleum-based materials, used in making polymeric articles, such as nonwovens, films including packaging films, foams and molded articles, the search for alternative raw materials continues. In the past, formulators have identified various types of possible alternatives for use in making polymeric articles, especially nonwovens, such as cellulose acetate and polyhydroxyalkanoate materials. Formulators have also attempted to reduce the level of petroleum-based materials by replacing some of the petroleum-based materials with thermoplastic hemicellulose and/or hemicellulose derivatives to form a blend, for example, a blend of polyethylene and a hemicellulose derivative. However, such alternative raw materials and/or blends have always presented some negatives either in the cost and/or complexity of processing such raw materials or in the existence of certain properties, such as water-solubility, that are not desired within certain polymeric articles, especially certain nonwovens, such as sanitary tissue products.
Accordingly, there is a need for novel raw materials suitable for use in making polymeric articles, especially nonwovens, which overcome the negatives associated with existing raw materials.

Thermoplastic heteropolysaccharide derivatives and methods for making same


Paper products can be made from cellulose derived from corn husks. A method of making paper products may include obtaining corn husks, extracting cellulose fiber pulp from the corn husks, forming a paper sheet from the extracted cellulose fiber pulp, adding a chitosan acetic acid solution having a concentration of at least 5 wt. % chitosan to the paper sheet, forming the paper product from the paper sheet, and coating the paper product with a paraffin wax.

Pollution caused by accumulating non-biodegradable plastic waste is an enormous environmental issue that plagues bodies of water. More than 8 million metric tons of plastic wash into the oceans each year, including 7.5 million straws. Traditional polymer straws are made with non-biodegradable materials. These materials do not break down completely and can form micro plastic that can cause substantial harm to ocean animals and ecosystems. Biodegradable straws made from paper have been developed. While paper straws are more environmentally friendly than their plastic counterparts, millions of trees must be cut down to make the paper.

Biodegradable straws and methods of making biodegradable straws


A control method for a laser diode is conducted such that optical output and OMA (optical modulation amplitude) or extinction ratio of the laser diode are controlled while modulating the optical output of the laser diode by applying a bias current and a modulation current to the laser diode. The method has: a first step of measuring the optical output of the laser diode; a second step of measuring a slope efficiency or a corresponding value of the slope efficiency while conducting APC (automatic power control) to adjust the bias current such that the optical output coincides with a predetermined value; and a third step of adjusting the modulation current by AAC (automatic amplitude control) according to the slope efficiency or the corresponding value of the slope efficiency such that the OMA or extinction ratio coincides with a predetermined value.

1. Field of the Invention
This invention relates to a control method and a control circuit for a laser diode (LD) and, particularly, to a control method and a control circuit that can cope with a change in optical output intensity of LD due to a temperature change and an elapsed-time change, and further relates to an optical transmitter using the same.
2. Description of the Related Art
An optical transmitter used for optical communications is equipped with a light source to output light with an intensity according to a bias current and a modulation current, and a modulation circuit to generate the modulation current according to a transmission signal. A transmission signal (herein, a digital signal with a voltage corresponding to logical "1" or "0") sent from an external device is differentially amplified and buffer-amplified, and one or both of its differentially amplified signals are applied to a laser diode, and, thereby, an optical transmission signal can be obtained that its optical output intensity changes between "1" level and "0" level according to "1" and "0" of the transmission signal.
In optical transmitters, LD control is required such that OMA (optical modulation amplitude) and extinction ratio are increased as much as possible so as to obtain good identification sensitivity. The OMA and extinction ratio are values relating to the identification sensitivity of optical signal. The OMA is a difference between the "1" level and the "0" level of optical output, and the extinction ratio is a ratio of between the "1" level and the "0" level of optical output.
However, as the transmission rate of optical signal is increased, if the extinction ratio is too big, the oscillation of LD cannot follow, causing deterioration in waveform and an increase in jitter of the optical transmission signal. Further, in case of high-speed and long-distance transmission using an existing single mode fiber, if the extinction ratio is too big, a transitional change (chirp) is generated in the oscillation wavelength of LD. This causes deterioration in waveform after the long-distance transmission depending on a dispersion characteristic of optical fiber, and the identification sensitivity deteriorates by contrast. Therefore, in optical transmitters for high-speed or long-distance transmission, accurate control of extinction ratio is required.
On the other hand, LD has a property that its oscillation threshold current and slope efficiency change depending on temperature change and elapsed time change. Since the change of oscillation threshold current causes a change in optical output intensity and the change of slope efficiency causes a change in OMA and extinction ratio, control of bias current and modulation current is needed.
FIG. 1 shows a relationship between applied current and optical output intensity of LD. As shown in FIG. 1, when DC current (applied current I) exceeds an oscillation threshold Ith, the LD emits light. As the applied current I increases, the optical output intensity P increases linearly to the applied current I. The slope η (η=optical output intensity P/applied current I) of the linear section is called slope efficiency of LD. As shown in FIG. 1, when a bias current Ib and a modulation current Im are applied to LD, a modulated optical output can be obtained. The values of Ib and Im are set to obtain a predetermined optical output and OMA or extinction ratio.
FIG. 2 shows a temperature change and an elapsed-time change (relationship between the applied current and the optical output intensity) in LD. As shown in FIG. 2, the oscillation threshold Ith and slope efficiency η change depending on the temperature change and elapsed time change. In view of FIG. 2, it is understood that, when Ith is increased to Ith′ and η is reduced to η′ due to the temperature change or elapsed-time change, the predetermined optical output and OMA or extinction ratio cannot be obtained unless, according to such a change, the bias current Ibis increased to Ib′ and the modulation current Im is increased to Im′.
In order to prevent the change of optical output intensity in LD, APC (automatic power control) is used that the bias current is subjected to a feedback while monitoring the optical output. Methods for preventing the change of OMA or extinction ratio are as follows.
(1) Surrounding temperature of LD is measured using a temperature sensor and its modulation current is controlled depending on the surrounding temperature (for example, Japanese patent application laid-open No.2002-111120, paragraphs [0030] to [0050]).
(2) OMA or extinction ratio is measured using a peak hold circuit etc. based on optical current of PD (photodiode) to monitor the optical output, and its modulation current is subjected to a feedback (for example, Japanese patent application laid-open No.2001-352125, paragraphs [0025] to [0038]).
(3) OMA or extinction ratio etc. is measured such that a RF signal with low frequency is superposed on bias current or modulation current and only the RF signal component is extracted from optical current of PD to monitor the optical output. Based upon this, its modulation current is subjected to a feedback (for example, Japanese patent application laid-open No.2003-169022, paragraphs [0018] to [0020]).
(4) Based on the variation of bias current and modulation current, a bias current or a modulation current is estimated that the OMA or extinction ratio can be kept constant. Based upon this, its modulation current is subjected to a feedforward. This method is based on a statistical prediction that the change of bias current and modulation current with the change of LD characteristic is generated in like manner whichever of temperature change or elapsed-time change causes that change. For example, the ratio of a variation in bias current and a variation in modulation current is controlled to be constant, and the ratio is set in manufacturing. Alternatively, data of bias current and modulation current are taken that the OMA or extinction ratio can be kept constant while changing the surrounding temperature in manufacturing, and it is controlled based on the data.
Method (1) can be most simply implemented and is in wide use. Method (2) can surely control the extinction ratio since it measures directly the extinction ratio. Method (3) allows the collection of a peak value of optical output since it uses the low frequency RF signal applicable to the response speed of PD.
However, the conventional LD control methods (1) to (4) each have problems as follows.
Method (1) cannot cope with an elapsed-time change of LD characteristic. Further, in method (1), since individual difference in temperature characteristic of LD is big, it is difficult to conduct the adjustment in manufacturing.
In method (2), when the transmission speed of signal increases such that it exceeds the response speed of PD to monitor the optical output, it becomes impossible to detect the peak value. Further, in method (2), it becomes difficult to downsize an optical transmitter equipped with such a LD control circuit since the external circuits are needed.
In method (3), since the test signal is additionally superposed on the transmission signal, there is a risk such as deterioration in optical waveform and an increase, oscillation etc. in jitter. Further, since the external circuits are needed, it is not suitable for a high-density package.
In method (4), the guarantee for elapsed-time change is obtain only within the statistical data. Further, due to dispersion in LD characteristic, adjustment in manufacturing needs a large load.

Control method and control circuit for laser diode, and optical transmitter using the same


A liquid crystal display according to an exemplary embodiment of the present invention includes a first substrate and a second substrate facing each other, an alignment layer disposed on at least one of the first substrate or the second substrate, the alignment layer including at least one vertical alignment monomer and a photo-alignment layer separated from the at least one vertical alignment monomer, and a liquid crystal layer disposed between the first substrate and the second substrate. The photo-alignment layer includes a main chain and at least one side chain connected to the main chain, and the at least one side chain includes at least one vertical photo-alignment material.

1. Field of the Invention
Exemplary embodiments of the present invention relate to a liquid crystal display.
2. Discussion of the Background
Among display panels, a liquid crystal display (LCD) is one type of flat panel display that is currently being widely used, and may include two display panels in which field generating electrodes such as a pixel electrode and a common electrode are formed, with a liquid crystal (LC) layer disposed therebetween. The LCD may display images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer that determines the orientation of LC molecules therein to adjust polarization of incident light.
An alignment layer may be formed on the inner surfaces of the two display panels to align LC molecules of the LC layer. If no voltage is applied to the field generating electrodes, the LC molecules may be aligned in a predetermined direction by way of the alignment layer. With the application of a voltage to the field generating electrodes, the LC molecules may be rotated in the direction of the electric field.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form any part of the prior art.


An optical fiber coupler includes a main body and a cover detachably coupled with the main body. The main body includes a coupling member, at least two lenses, at least two optical fibers and a connecting post. The lenses and the optical fibers are mounted on the coupling member. The optical fibers couples with corresponding lenses. The lenses protrudes from the coupling member. The connecting post protrudes from the main body adjacent to the lenses. The cover defines a fixing hole and a covering groove corresponding to the lenses. The fixing hole engages with the connecting post, for positioning the coupling member to the cover. The cover covering the lenses via allowing the at least two lenses to be received in the covering groove.

1. Technical Field
The present disclosure relates to an optical fiber connector, particularly to an optical fiber coupler employed in the optical fiber connector.
2. Description of Related Art
An optical fiber coupler is configured to abut joint at least two optical fibers. The optical fiber coupler may include a main body. The main body may include a coupling member, a plurality of transmission lenses, and a plurality of optical fibers. The transmission lenses are mounted on the coupling member, and partially protrude from the coupling member. The optical fibers are mounted on the coupling member, and are coupled with the transmission lenses. Because the transmission lenses protrude and are exposed from the coupling member, which results in the transmission lenses may become polluted, and thus causes a low optical signal transmission precision and efficiency.
Therefore, there is room for improvement in the art.


A ribbon cartridge for an endless ribbon used in high speed printers, with increased reliability due to fewer parts, is constructed from a molded casing which is rectangular in shape into which are formed a post on which a cylindrical porous ink reservoir is mounted, a ribbon protector which isolates the ink reservoir from the ribbon in the stuffer box portion of the cartridge, and a forked bracket for mounting a shaft on which gears are mounted. A combination gear for driving a ribbon into the stuffer box and for re-inking the ribbon is mounted on a post and then rotatably mounted on the bracket formed into the housing and is inked by contact with the ink reservoir. An idler gear is rotatably mounted on a bracket which is pivoted from a socket molded into the socket wall and is spring biased into contact with the drive and transfer gear, which is turned by its extended shaft advance and ink the ribbon. As a result a simplified re-inking arrangement is achieved with the minimum of components. Also, by re-inking a central drive and transfer gear, only the print track of a ribbon is reinked thereby extending the re-inking life by conserving ink.

With the advent of high speed printing, ribbon life became a problem. A solution is to continuously reuse ribbons by re-inking them, resulting in extended life. Re-inking is achieved by various techniques including using wicks supplied by an ink reservoir to apply ink to a ribbon surface. Another method of re-inking is to pass a ribbon against a porous ink reservoir and yet another method is to ink a roller from an ink reservoir and transfer the ink to the ribbon.
In U.S. Pat. No. 4,616,942, Nagasawa et al. a ribbon cassette, with re-inking mechanism, is shown in which a removable ink supply is mounted within the cassette and a first roller is inked by contact with the ink supply and a second roller is pivotally mounted to engage a ribbon between it and the first roller to advance a ribbon into the cavity of the cassette and re-ink it. The second roller is mounted on a pivot arm and has a drive gear for rotating it and thereby advancing the ribbon. The pivot arm is biased to affect the cooperative engagement of the first and second rollers.
In U.S. Pat. No. 4,636,097, Goubeaux, there is shown in a cartridge for an endless ribbon, an ink reservoir in the form of a transfer roller pivotally mounted and spring biased into engagement with a transfer roller for re-inking the transfer roller which is pivotally mounted on a fixed post affixed to the housing of the cartridge. A second roller is spring biased to pinch a ribbon between it and the transfer roller. An external drive mechanism engages the transfer roller to drive it and advance the ribbon.
In U.S. Pat. No. 4,653,947, Echols, a re-inking device for an endless ribbon is taught in which a cartridge has a rotatable ink reservoir mounted within a case and a transfer roller likewise mounted within this case which is in contact for re-inking and the transfer roller is exposed through an opening in the case to contact a ribbon driven between it and a second roller on a fixed posted which is driven by an external means to advance the pair of rollers and the ribbon. The contact between the rollers to grasp and advance the ribbon is achieved by pivotally mounting the case within the cartridge and spring biasing it toward the stationary roller.
Applicants having pending an application for Patent, filed May 30, 1989 in the U.S. Patent and Trademark Office which disclose and claims a ribbon re-inking device which incorporates a combination drive-transfer gear which cooperates with a rotatable porous ink reservoir body to transfer ink to the print track of a reusable ribbon. The mechanism has a toothed gear biased into engagement with the drive-transfer gear to grasp a ribbon therebetween and by rotation of the drive-transfer gear advance the ribbon and re-ink the print track of a ribbon.

Ribbon cartridge with endless ribbon reinking mechanism

International Business Machines Corporation


An information provision exchange service system that can securely prevent the transmission of information that can be used to identify a user to another party and enable users to provide and exchange information between themselves free from confidentiality concerns. A server checks registered personal information to determine whether or not information that can be used to identify any of the users using a plurality of communication terminals is included in information exchanged between the communication terminals via a communication network, and replaces the information that can be used to identify a user with other information if the information that can be used to identify the user is detected in the information exchanged between the communication terminals via the communication network.

1. Field of the Invention
The present invention relates to an information provision exchange service system and method, a program for implementing the method, and a storage medium storing the program, and more particularly, to an information provision exchange service system and method that provides, via a communications network, an information provision exchange service to all communication terminal subscribers by mediating the exchange of information between a plurality of communication terminals each one of which is allocated to a particular subscriber, and a program for implementing the method, and a storage medium storing the program.
2. Description of the Related Art
Generally, as services that provide information using a communication network, a wide array of information provision services exist, including interactive television services, telephone fax information provision services, and internet information provision services. The interactive television service is a service that provides information indiscriminately to a large number of unspecified individuals without specifying the recipient of information. For this reason, among the individuals to which the information is provided there exist those for whom the provided information is useful and appropriate and those for whom it is not.
With information provision services by using telephone faxes and the like, when the recipient is in a position to receive the information, information is provided to the recipient unilaterally. For example, even if this telephone fax information provision service provides only voice data, a recipient is designated by an information provider who is unknown to the recipient and information is provided from the information provider to the recipient. The designation of the recipient means designation of the telephone number of the recipient. Accordingly, it is possible for the recipient or the information provider (the sender), or both, to identify a particular individual from the telephone number. This state of affairs, although ordinarily beneficial to the information provider, when the recipient denies or refuses the information, or when the recipient is slandered, in many cases puts the recipient in an uncomfortable or disadvantageous position, particularly uncomfortable psychologically.
As an information provision service type that has partially solved these disadvantages and defects, there is an internet-based bulletin board-like information provision exchange service. According to this method, normally called a chat room, individuals who subscribe to an internet connection service provided by an internet services provider have individual fictitious names under which they provide information to an information provision area (site) called an internet bulletin board and are provided with information from such site. This type of technology is introduced, for example, in Japanese Laid-Open Patent Publication (Kokai) No. 10-257189, Japanese Laid-Open Patent Publication (Kokai) No. 11-184786, Japanese Laid-Open Patent Publication (Kokai) No. 2000-115153 and Japanese Laid-Open Patent Publication (Kokai) No. 2000-57374. In Japanese Laid-Open Patent Publication (Kokai) No. 2000-57374, a fictitious other self called avatar is allowed to participate, carrying out conversations and exchanging information.
Moreover, as places to provide information and to receive information there are also ordinary cellular telephone e-mail sites and I-mode (registered trademark) sites.
However, with the technology described in Japanese Laid-Open Patent Publication (Kokai) No. 2000-57374, even though an individual might be using a fictitious name, if information in the form of criticism or slander is directed toward the individual behind the fictitious name, that fictitiously named person might be put in an extremely disadvantageous position, and might even be forced to withdraw from the site or to change his or her fictitious name to a new fictitious name.
Moreover, with a site like that described above, if information that can identify an individual, such as the individual's name or telephone number, is mistakenly leaked by a sender, the sender runs the risk of being heavily disadvantaged. Further, in Japanese Laid-Open Patent Publication (Kokai) No. 2000-57374, although a technology is described of chat room participants getting together to form a group and to meet and for preventing information on those within the group from being leaked to others who connected to the network and are not members of the group (others who have entered the group), there is no mention of any technology for shielding or preventing leakage of information that can be used to identify individuals within that group (that is, two or more chat room participants).
Further, in a chat service, participants enter the chat room under fictitious names that do not identify individuals, and therefore an environment is created in which it is easy for participants to make slanderous statements. Accordingly, if the name of an individual who has made slanderous statements becomes known to the other participants, then that individual runs the risk of being exposed to many and great disadvantages.
Further, a major problem arises whenever someone uses an actual personage's name and that personage then virtually slanders that actual person, causing that the actual person to suffer damage or injury.
Moreover, with the widespread diffusion of Internet connection terminals (that is, personal computers and the like) and cellular telephones, etc., minors such as grade-school children are included among the users of these terminals. There is a risk that, among users such as these, the very young (such as the grade-schoolers noted above) will give away information that should be kept confidential, such as actual names, addresses, by sending and receiving e-mail messages or by accessing internet sites via cellular telephones or the like. Moreover, crimes committed by minors through accessing sites that contravene public morals have become a serious social problem.
Thus, as described above, although the use of the Internet and of convenient information communications devices such as cellular telephones makes it possible to enjoy easy and convenient conversation, talking with a large number of unidentified parties creates many risks of leaking of confidential personal information, which chills the enjoyment of such easy conversation. Moreover, although limiting the exchange of information only to acquaintances eliminates the need for vigilance against the loss of confidential personal information, such a limitation cannot be said to afford maximum advantage of the opportunities offered by the Internet and cellular telephone e-mail messaging for exchanging information with an unlimited number of people.

Information provision exchange service system and method, program for implementing the method, and storage medium storing the program


A dispenser for use with a pressurizable fluid container. The dispenser comprises a head removably connectable with the container. The head includes an inlet, an outlet, a valve seat, a cavity and a chamber for fluid communication between the inlet and outlet. The valve seat is located between the inlet and the chamber. The cavity is located between the inlet and the valve seat. A valve body has a portion locatable in the chamber. The valve body is actuatable for movement between an open position allowing fluid flow through the chamber and a closed position blocking fluid flow through the chamber. The valve body includes a seal seat surface adapted to face in a direction towards the inlet when the valve body is within the chamber. A seal is receivable on the valve body for engagement with the seal seat surface. The seal is engageable with the valve seat to define the closed position. A cap member is engageable with a surfaced defining the cavity in the head to fixedly attach the cap member within the cavity. A bias mechanism is engageable with the cap member for normally biasing the seal towards the valve seat.

1. Technical Field
The present invention relates generally to a liquid dispensing apparatus which is connectable with a container. In particular, the present invention relates to a beverage dispensing apparatus sealingly connectable with a bottle, such as is used for storing a carbonated soft drink, and relates to a seal structure used in the dispensing apparatus.
2. Description of the Prior Art
Dispensing a liquid, such as a carbonated beverage drink, from a container is typically accomplished by manipulating the uncapped container so a dispensing neck is lower than the liquid level. The liquid is then free to exit through an opening in the neck of the container. The container needs to be recapped properly to store the liquid so that carbonation of the beverage is not lost If the container is not properly recapped, or remains uncapped for even a relatively short time, the carbonation could be lost by escaping to the atmosphere and the drink becomes "flat".
The containers are becoming larger and at times difficult to handle because of their relatively large size and weight when filled. The containers are especially difficult to handle if the container has relatively smooth exterior surface. Dispensers, which permit a carbonated beverage bottle to remain upright during dispensing, have been developed in order to overcome the disadvantages associated with manipulating and dispensing a liquid drink from a container, such as the one described above.
A household, business or the like may typically have more than one bottle of a carbonated beverage opened at any one time. The household, business or the like will, therefore, require more than one dispensing apparatus in order to accommodate all of the opened bottles. Thus, a relatively inexpensive and easy to assemble dispenser is needed. However, it is also equally important that the dispenser be effective to seal the beverage container for a relatively long period of time, for example, a week or month, in which the carbonation of the beverage drink is not diminished to any significant degree.