A closed loop selective deposition modeling apparatus having a surface scanning system for actively monitoring the surface height of a layer of a three-dimensional object as it is being built by selectively dispensing a build material. The surface scanning system directs a beam of energy on the surface of the object that establishes an illumination zone which emits scattered light, and has a detector which senses the scattered light and produces a response indicative of the surface condition of the object. The response is processed to establish a plurality of height data signals that are further processed to produce feedback data. The feedback data is then utilized to selectively dispense the build material to desired locations on the surface of the object to therein dimensionally normalize the layer of the object being formed.

1. Field of the Invention
The invention relates in general to solid freeform fabrication and, in particular, to a surface scanning system for generating a plurality of surface height measurements for use in dimensionally normalizing layers of a three-dimensional model being built by a closed loop selective deposition modeling apparatus dispensing a liquid, powder, or paste.
2. Description of the Prior Art
In selective deposition modeling, herein referred to as xe2x80x9cSDMxe2x80x9d, complex parts are produced from a modeling material in an additive fashion as opposed to traditional fabrication techniques, which are generally subtractive in nature. For example, in traditional fabrication techniques material is removed by machining operations or shaped in a die or mold to near net shape and then trimmed. In contrast, additive fabrication techniques such as SDM incrementally add portions of a build material to targeted locations, layer by layer, in order to build a complex part.
In SDM, a solid modeling material is physically deposited in successive fashion to form an object. In one type of SDM technology the solid modeling material is extruded as a continuous filament through a resistively heated nozzle. In yet another type of SDM technology, the solid modeling material is jetted or dropped in discrete droplets in order to build up a part. Often, a thermoplastic material having a low-melting point is used as the solid modeling material, which is delivered through a jetting system such as those used in ink-jet printers. One type of SDM process utilizing ink-jet print heads is described, for example, in U.S. Pat. No. 5,555,176 to Menhennett, et al. Another type of SDM process which extrudes a bead of material to build a part is described, for example, in U.S. Pat. No. 5,303,141 to Batchelder et al. Still others dispense two different solidifiable materials such as the SDM process described in U.S. Pat. No. 5,136,515 to Helinski. In addition, other SDM processes dispense sintered powders as described in U.S. Pat. No. 5,017,753 to Deckard, pastes as described in U.S. Pat. No. 6,110,409 to Allanic et al., and liquids as described in U.S. Pat. No. 5,236,637 to Hull.
Although SDM methods have many advantages compared to conventional fabrication methods, they also have inherent problems rooted in the layer by layer building process. One common problem in the layer by layer building process results from the dimensional variability inherent in the building of each layer. These dimensional inaccuracies result from numerous phenomena, such as the accumulated effects of drop volume variation, thermal distortion, errors in deposition, and the like. In addition, the type of geometrical configurations being formed can also influence these inaccuracies, such as the production of web or branching supports. Also, a weakened dispensing jet will contribute to these inaccuracies. If unchecked, these tolerances can accumulate throughout the part as it is built up in height layer by layer. As the thickness of layers are reduced in order to achieve greater surface resolution, the accumulated effects of these undesirable tolerances can substantially distort the resultant part. Thus, most SDM processes require some method to dimensionally normalize or smooth the top working surface of the part while it is being built. In addition, the maximum build rate of the object is limited by the slowest build rate position of a given layer being formed. Generally, most conventional dimensional normalization methods involve systems which physically adjust the vertical height of the part by smoothing or leveling the build material deposited in the layers, often producing waste material. Such systems are typically open loop systems that are hardwired and utilize no active feedback to compensate the build rate of the layer. For example, in one open loop approach, each layer of build material is dispensed at a greater thickness than desired and then the normalizing device is activated to remove the excess build material to achieve the desired thickness. Although distortions between the layers are eliminated, undesirable waste material is generated.
An example of the excess build material approach is found in U.S. Pat. No. 5,943,235 to Earl et al., wherein a pre-heated rotating planarizer is provided to normalize each layer. Under this approach, after a layer of build material has been to deposited by the SDM apparatus in excess of the necessary amount to achieve a desired thickness, the pre-heated cylindrical roller (planarizer) is precisely passed over the deposited material. The rolling planarizer locally melts a portion of the build material of the layer. Some of the material adheres to the surface of the planarizer as it rolls to thereby dimensionally normalize the deposited layer to conform to the desired thickness of the layer. A wiping or scraping device such as a blade is needed to peel or skive off the excess build material from the planarizer, producing waste material. This approach has drawbacks; for instance, the build time is increased due to the deposition of material that is later removed by the planarizer as waste. In addition, the rolling planarizer must be manufactured to precise tolerances in order to achieve the desired accuracy. It is also difficult to precisely regulate and maintain the temperature of the surface of the planarizer. The planarizer is also thermally inefficient as it consumes a significant amount of energy that is undesirably dissipated into the environment. The planarizer also occupies a significant amount of space within the SDM apparatus and thereby limits the over-travel distance of the dispensing carriage. The planarizer also has moving parts that are subject to wear and degradation. Airborne contaminants are also prone to accumulate on the planarizer. In short, the heated rotating planarizer adds significant cost and complexity to an SDM apparatus, occupies precious space, adds inertia, is subject to wear, requires maintenance and adjustment, and increases build time.
Other approaches to providing a system to dimensionally normalize a part while being built by an SDM apparatus are found in U.S. Pat. No. 5,859,775 to Barlage, III et al. and U.S. Pat. No. 5,572,431 to Brown et al. Under these approaches, a heated body is selectively driven across the dispensed build material in response to a sensed deviation in order to melt and displace the build material. The excess material is then sucked off by a vacuum source connected to the heated body. Thus, dimensional normalization is discretely accomplished by expelling waste material, thereby increasing build time.
Undesirably, all these approaches involve making physical contact with the layer of the object as it is built. Because of this, the types of material that can be dispensed to form the layers are limited to those that can both be locally melted and removed, or can be planed or machined. Furthermore, they must leave a desirable surface finish after being normalized. In addition, removal of waste material generally runs contrary to the advantages of the additive nature of the SDM fabrication process.
Thus, there is a need to provide an SDM process capable of dimensionally normalizing layers of a three-dimensional object without generating waste build material. There is also a need to decrease build time by eliminating the steps of depositing excess build material for each layer. There is also a need to dimensionally normalize the layers without making physical contact with the layers. These and other difficulties of the prior art have been overcome according to the present invention.
The present invention provides its benefits across a broad spectrum of three-dimensional building processes. While the description which follows hereinafter is meant to be representative of a number of such applications, it is not exhaustive. As will be understood, the basic apparatus and methods taught herein can be readily adapted to many uses. It is intended that this specification and the claims appended hereto be accorded a breadth in keeping with the scope and spirit of the invention being disclosed despite what might appear to be limiting language imposed by the requirements of referring to the specific examples disclosed.
It is one aspect of the present invention to form a three-dimensional object with an SDM apparatus at the highest build speeds possible.
It is another aspect of the present invention to dimensionally normalize the layers of a three-dimensional object by an SDM apparatus without generating waste material.
It is yet another aspect of the present invention to dimensionally normalize the layers of a three-dimensional object being formed by an SDM apparatus without making physically contact with the build material already dispensed in the layers with a separate device.
It is still yet another aspect of the present invention to form a three-dimensional object according to a closed loop SDM technique responsive to feedback data.
It is a feature of the present invention to actively monitor the surface height of any portion of a layer of a three-dimensional object while being formed by an SDM apparatus.
It is another feature of the present invention to develop height data signals of the surface of a portion of a layer of a three-dimensional object formed by an SDM apparatus.
It is yet another feature of the present invention to process the height data signals to produce feedback data for selectively dispensing build material in desired locations on the surface of the portion of a layer.
It is yet another feature of the present invention to utilize a surface scanning system consisting of an energy beam directed onto the surface of the object to establish an illumination zone that emits scattered light, and a detector having sensors which monitor the surface height condition of the object by collecting the scattered light.
It is an advantage of the present invention that each layer of an object formed by the SDM apparatus can be dimensionally normalized without generating waste material and thereby eliminate the need for a waste collection tank and waste umbilical.
It is another advantage of the present invention that the build speed of the SDM apparatus is significantly increased by eliminating the time involved in depositing build material in excess for each layer that must be removed as waste.
It is yet another advantage of the present invention that maintenance and service of the SDM apparatus can be significantly decreased as a result of the elimination of mechanical systems previously needed to physically contact and remove excess build material.
It is still yet another advantage of the present invention that a closed loop system is used that can actively adjust the build process in response to monitored imperfections on the surface of the layers during the build process.
And it is still yet another advantage of the present invention that a wider variety of materials can be dispensed from an SDM apparatus to form three-dimensional objects.
These and other aspects, features, and advantages are achieved/attained in the method and apparatus of the present invention that employs a surface scanning system that generates a plurality of surface height data signals of a layer of build material dispensed in response to data descriptive of the layer of a three-dimensional object being built by a SDM technique. The height data signals are processed to establish feedback data that is then utilized to selectively dispense the build material in desired locations on the layer such as in low areas to achieve a desired thickness, and to avoid dispensing material in locations that may have excess material.

Surface scanning system for selective deposition modeling


Aqueous coating slurries useful in depositing a dense coating of a ceramic electrolyte material (e.g., yttrium-stabilized zirconia) onto a porous substrate of a ceramic electrode material (e.g., lanthanum strontium manganite or nickel/zirconia) and processes for preparing an aqueous suspension of a ceramic electrolyte material and an aqueous spray coating slurry including a ceramic electrolyte material. The invention also includes processes for depositing an aqueous spray coating slurry including a ceramic electrolyte material onto pre-sintered, partially sintered, and unsintered ceramic substrates and products made by this process.

Ceramic oxide powders with fine particle sizes have an advantage over conventional ceramic powders in that their high surface area allows them to be densified at relatively low sintering temperatures. Their particulate nature allows them to be formed using inexpensive techniques such as dry pressing and slip casting. However, as particle size is reduced into the nanoscale range (i.e., <100 nm), the fine particle size can be problematic during ceramic processing and fabrication due to agglomeration. Agglomerates create density gradients in green ceramic compacts, resulting in inhomogeneous densification, sintering stresses and exaggerated grain growth during subsequent heat treatment.
Several methods have been demonstrated for the production of nanoscale ceramic powders, using spray pyrolysis and/or vapor condensation processes, which can result in strong aggregation of the product powder. Alternative methods, such as chemical precipitation, sol-gel, and hydrothermal synthesis processes, also result in agglomeration of the powder. Thus, suitable methods are required to achieve dispersion of nanoscale particles.
In suspension, nanoscale particles agglomerate because of short-range attractive (i.e., Van der Waals) forces. These short-range attractive forces between particles overcome the electrostatic repulsion of the electrostatic double layer that surrounds the particles. A cloud of ions and counter-ions surround the particle, creating the repulsive field. Particle-particle interactions can be manipulated by pH control. The magnitude of the particle electrostatic potential, known as the zeta potential, is controlled by the suspension pH. Increasing the zeta potential increases the repulsive force between particles. However, the effectiveness of pH adjustment is limited because adjusting pH also increases the ionic strength of the suspension. As the ionic strength of the suspension increases, the ion cloud surrounding the particle is compressed, allowing closer interparticle approach. Even at extreme values of pH, where the particle surfaces are highly charged, the compression of the ion cloud allows the particles to approach close enough for the short-range attractive forces to overcome the electrostatic repulsion, and agglomeration results.
An alternative method of dispersing ceramic powders is the addition of polymers that attach to the particle surface. The polymer coating prevents particle-particle contact, and agglomeration. Such steric hindrance methods have the disadvantage that they require complete coverage of the particle surfaces. For high surface area powders, the necessary amount of dispersant can be four times the amount of powder.
Well-dispersed nanoscale suspensions can be used in conventional slip and tape casting processes to make parts that sinter at low temperatures. Nanoscale suspensions can also be used in novel approaches, such as aerosol spraying. Functional membranes and corrosion resistant coatings can be sprayed onto substrates or parts and sintered at low temperatures. Depositing such oxide films using conventional powders requires high sintering temperatures to achieve high density. Significant interaction between the coating and the part can occur at high temperatures, in addition to grain growth; as the grains in the film grow, they push one another away, forming pinhole defects. Conventional powder particle sizes are also often near target film thicknesses, making it difficult to achieve films with good cohesion and sinterablility.
The use of suspensions of ceramic powders to produce dense and continuous coatings onto substrates using aerosol spray methods requires methods to circumvent high capillary stresses that can occur during drying. These stresses can become exceptionally high as the particle size of the ceramic particles in the deposited coating is reduced into the nanoscale regime. To avoid these stresses, modifications can be made to the starting suspension and deposited coating. The liquid/vapor interfacial energy of the solvent can be reduced, the packing density of the film can be homogenized and improved, and the strength of the interparticle bonds in the coating can be increased. Drying cracks occur during the falling rate period, where the air/solvent interface has moved into the capillaries of the coating. The adhesion of the solvent to the walls of the capillaries results in tensile forces being exerted on the film. The stress exerted can be expressed by the following formula,pR=2(γlv, cos θ)/awhere: pR=capillary pressure, γlv=liquid-vapor interfacial energy, θ=solid-liquid contact angle, and a=capillary radius of curvature. From this equation and the consideration that capillary radius is directly proportional to grain size, it is evident that a film composed of nanoscale materials will suffer large drying stresses. The drying stresses from capillary pressure can be lowered by decreasing the liquid-vapor interfacial energy, using alternative solvents (e.g., alcohols), or by modifying an aqueous solvent by the addition of surfactants. Examples of surfactants include alcohols such as octanol and butanol and anionic surfactants such as alkali sulfonates, lignosulfonates, carboxolates and phosphates. Sulfonates and phosphates can leave behind inorganic components that are detrimental to sintering and the electrical properties of the fired ceramic, but organic surfactants typically do not, and are favored for ceramic applications.
Development of a successful coating process also requires good particle packing and high green strength of the applied coating. As is well described in the art, bimodal distributions pack better than unimodal distributions in the green state. Green strength of the deposited films can be improved by the addition of binders to impart a degree of plasticity to the film during drying, thus avoiding brittle fracture. Polyvinyl alcohol and methylcellulose are examples of aqueous binder systems for use in ceramics. For nanoscale systems, short chain polymers including low molecular weight starches and proteins are candidate systems.
Solid oxide fuel cells are an excellent example of an application that requires novel coating deposition technologies. Fuel cells generate power by extracting the chemical energy of natural gas and other hydrogen containing fuels without combustion. Advantages include high efficiency and very low release of polluting gases (e.g., NOX) into the atmosphere. Of the various types of fuel cells, the solid oxide fuel cell (SOFC) offers advantages of high efficiency, low materials cost, minimal maintenance, and direct utilization of various hydrocarbon fuels without external reforming. Power is generated in a solid oxide fuel cell by the transport of oxygen ions (from air) through a ceramic electrolyte membrane where hydrogen from natural gas is consumed to form water. Although development of alternative materials continues, the same types of materials are used in most of the SOFC systems currently under development. The electrolyte membrane is a yttrium-stabilized zirconia (YSZ) ceramic, the air electrode (cathode) is a porous lanthanum strontium manganite ((La,Sr)MnO3) (LSM) ceramic, and the fuel electrode (anode) is a porous Ni-YSZ cermet. To obtain high efficiency and/or lower operating temperature, the YSZ ceramic electrolyte membrane must be dense, gas tight, and thin. This requires suitable methods for depositing electrolyte membranes as thin films onto porous electrode substrates (either the cathode or the anode).
Siemens-Westinghouse is developing tubular SOFC systems based on a porous ceramic tube with a deposited YSZ electrolyte coating, and subsequently deposited anode and interconnect coatings. These systems use electrochemical vapor deposition (EVD) to deposit 40 μm thick films of YSZ onto porous LSM cathode tubes (see A. O. Isenberg, U.S. Pat. No. 5,989,634). Gaseous zirconium and yttrium precursors are pumped through a porous LSM tube sealed within a high-temperature, high-pressure enclosure. The gaseous precursors diffuse through the pores in the LSM tube and react with air to form a dense YSZ film on the outer surface of the LSM tube. EVD creates extremely dense and high quality films. However, EVD is a batch process, and difficult to scale up. The EVD process also is capital intensive, requiring a substantial amount of highly specialized equipment and operators.
Several alternative lower cost electrolyte deposition methods, including plasma-spray, sol-gel, and colloidal deposition have been proposed and are at various stages of development. Of these, progress has been made with plasma-spray methods, although cost is still relatively high. Sol-gel methods have not been entirely successful due to difficulties in depositing films onto porous substrates and inherent film thickness limitations. Colloidal deposition methods, involving deposition of ceramic coatings by aerosol spraying or dip coating methods, with subsequent coating densification by sintering, provide inexpensive alternative routes to preparation of dense electrolyte films. The approach previously has been applied to the fabrication of electrolyte films on presintered electrode substrates that do not shrink during sintering of the coating. Prior to the present invention, it has been difficult to achieve dense electrolyte coatings of reasonable thickness (i.e., greater than a few microns) on presintered substrates, because of crack formation during the sintering step. These cracks are caused by excessive shrinkage of the coating during sintering because green densities of the deposited films are relatively low. Multiple coating deposition and sintering cycles (as many as ten coating/annealing cycles) have been applied to achieve leak tight electrolyte coatings (see for example: K. Eguchi, T. Setoguchi, S. Tamura, and H. Arai, Science and Technology of Zirconia V, pages 694-704, 1993).
An alternative to depositing electrolyte films on presintered and non-shrinking substrates is to deposit the films onto electrode substrates that do shrink during sintering of the coating (see for example: G. Blass, D. Mans, G. Bollig, R. Förthmann, and H. P. Buchkremer, U.S. Pat. No. 6,066,364; and J. W. Kim, K. Z. Fung, and A. V. Virkar, U.S. Pat. No. 6,228,521). The fabrication of dense YSZ electrolyte coatings on porous anode (NiO/YSZ) substrates has been demonstrated using colloidal deposition and co-sintering methods. With this process, the green electrolyte coating is applied from a suspension onto a partially sintered and highly porous anode substrate and the bi-layer structure is then sintered at high temperature (typically 1400° C.). Both the substrate and coating shrink during sintering, so that cracking can be avoided and dense and leak tight electrolyte films can be produced. In these previous demonstrations of colloidal deposition processes, coating suspensions typically were produced by extensive milling of YSZ powder in a nonaqueous solvent, followed by sedimentation to remove coarse YSZ particles. The primary disadvantage of these previous approaches is high cost due to the poor yield during production of electrolyte suspensions and use of a nonaqueous solvent. A further disadvantage of these previous processes is that the colloidal YSZ suspensions have particle sizes that are larger than about 300 nm and the particulate YSZ material has relatively low surface areas (less than 20 m2/gram), which results in the need for high sintering temperature (1400° C.) to densify the coatings. With such high sintering temperatures, YSZ would react adversely with the LSM cathode material during co-sintering, and the co-sintered cathode/electrolyte element would exhibit poor electrochemical performance. Thus, for the most part, the previous electrolyte coating processes can only be applied to anode substrates. There are certain advantages of depositing the electrolyte films onto porous LSM cathode substrates prior to co-sintering, which is difficult to do with existing coating methods that require high sintering temperatures. For example, raw materials cost of cathode-supported SOFC plates would be lower than those of anode-supported SOFC plates. Further, one would expect improved reliability of cathode-supported SOFC plates, due to better thermal expansion match between LSM cathode and YSZ electrolyte material, and due to failures of anode-supported plates that are associated with reduction of nickel oxide to nickel metal prior to operation (and due to the undesired re-oxidation of nickel metal to nickel oxide that can occur during shut-down after operation).
There are also advantages of applying interlayer films between the porous support electrode plate (either the LSM cathode or the NiO/YSZ anode) and the deposited electrolyte (YSZ) film. The purpose of such interlayer films could be either to increase performance (e.g., by incorporating catalytic materials that enhance electrochemical reactions or by locally reducing the size of particles and pores so that the density of electrochemical reaction sites is increased), or to prevent adverse chemical reactions between the support electrode and deposited film during sintering or co-sintering. A good example of interlayer materials include lanthanide doped cerium oxide ceramic electrolyte materials, and mixtures of ceria-based electrolytes with other materials (such as catalytic metals for anode interlayer films, and/or praseodymium manganite based perovskite ceramics for cathode interlayer films). Accordingly, there is a need in the art for a lower cost process for colloidal deposition of dense coatings of a ceramic electrolyte material (e.g., YSZ) onto porous substrates of a ceramic electrode material (either the LSM cathode or NiO/YSZ anode) that are either presintered, partially sintered, or unsintered, and particularly a method that utilizes an aqueous coating suspension prepared with high yield, and that provides a deposited coating that can be densified with a low sintering temperature (1400° C. or lower).

This patent is subject to a terminal disclaimer.


A method of making a lightly doped drain transistor includes the steps of forming a gate electrode (52) and a gate oxide (54) over a semiconductor substrate (56) and forming a drain (70) in a drain region (58) and a source (72) in a source region (60) of the substrate (56). The method further includes generating interstitials (62) near a lateral edge of at least one of the drain (70) and the source (72) and thermally treating the substrate (56). The thermal treatment cause the interstitials (62) to enhance a lateral diffusion (84) of the drain (70) under the gate oxide (54) without substantially impacting a vertical diffusion (82) of the drain (70) or the source (72). The enhanced lateral diffusion (84) results in the formation of at least one of a lightly doped drain extension region (75) and a lightly doped source extension region (76) without an increase in a junction depth of the drain (70) or the source (72). The step of generating interstitials (62) may include the step of implanting at least one of the drain region (58) and the source region (60) of the substrate (56) with a large tilt angle implant which creates the interstitials (62) at a location near the gate oxide (54).

Transistor devices make up one of the integral components of today's integrated circuits. Consequently, a reduction in the size of transistors (often called "scaling") is constantly being pursued. Prior art FIG. 1 is a fragmentary cross section diagram illustrating a conventional MOS type transistor 10. The transistor 10 consists of a conductive gate region 12 overlying a thin gate oxide 14 which overlies a substrate 16. The gate 12 and the gate oxide 14 are disposed between a drain region 18 and a source region 20 which are formed in the substrate 16 having a channel region 22 located therebetween which underlies the gate 12 and the gate oxide 14.
As the conventional transistor 10 is scaled into the sub-micron range to reduce its dimensions and thereby improve the transistor packing density on a chip, the transistor 10 begins to experience hot-carrier effects, as illustrated in prior art FIG. 2. These undesirable hot-carrier effects become more evident when the transistor 10 is scaled while maintaining the supply voltage constant or when the supply voltage is not reduced as rapidly as the structural features of the transistor.
The hot-carrier effects are due to an increase in the electrical field within the channel region 22. The increased electric field causes electrons in an inversion layer 26 to be accelerated (or "heated") to an extent that several different undesirable phenomena occur. As illustrated in prior art FIG. 2, the hot-carrier effects can include charge injection, substrate current and electron injection into the gate oxide 14. Perhaps the most crucial hot-carrier effect is the charge injection into the gate oxide 14 which damages the thin oxide and leads to a time-dependent degradation of various transistor characteristics such as the threshold voltage (V.sub.T), the linear transconductance (g.sub.m) and the saturation current (I.sub.DSAT).
One prior art solution which reduces the undesired hot-carrier effects of traditional transistor structures is the lightly doped drain (LDD) transistor 30, which is illustrated in prior art FIG. 3. The LDD transistor 30 includes the gate 12 and the gate oxide 14 formed in a conventional manner, wherein a lightly doped drain extension region 32 is formed adjacent to the drain region 18 between the drain region 18 and the channel 22. The lightly doped drain extension region 32 typically reduces the electric field near the channel region 22 by about 30-40 percent and thus the hot-carrier reliability of the transistor is greatly improved. The extension region 32 reduces the electric field by effectively dropping a portion of the drain voltage across the extension region 32.
As transistor designers continue to scale down the transistor device dimensions, the junction depths of the source and drain regions (as well as the lightly doped drain extension region) also need to be reduced (i.e., make the junctions more shallow). Junction depths must be reduced in conjunction with scaling in order to prevent short channel transistor effects such as punchthrough and threshold voltage shift. One conventional approach to reducing the junction depth is to reduce the implant energy used to form the junctions and reduce the diffusion of the junctions in the vertical direction. The source/drain extension regions, however, require ultra-shallow junctions. The shallow p-type junctions needed for the source/drain extension regions of the LDD structure using B or BF.sub.2 are especially difficult to fabricate. Boron, being a light ion suffers considerable channeling during the implant and boron diffusion is enhanced in the presence of silicon interstitials during the heat treatment step, resulting in deeper than expected junctions. Thus, fabricating shallow p-type junctions for the source/drain extension regions is a big challenge for process engineers.
The current approach to forming the p-type shallow junctions involved reducing the energy of the implant and subsequently aiming to control the ion channeling during the implant and to minimize the enhanced diffusion during the heat treatment step.
Another disadvantage associated with prior art LDD transistors 30 is that they require an additional mask step in the fabrication process. Although the lightly doped drain extension region 32 is self-aligned to the gate 12, a masking step (not shown) must take place to shield portions of the semiconductor wafer where the lightly doped drain implant is not desired.
It is an object of the present invention to overcome the difficulties facing the prior art by providing a new method for fabrication of source/drain extension regions to obtain ultra shallow p-type junctions. It is also an object of the present invention to simplify the semiconductor manufacturing process by not requiring the LDD mask and thus using one less masking step.

Fabrication process employing a single dopant implant for formation of a drain extension region and a drain region of an LDD MOSFET using enhanced lateral diffusion


Stoves fueled by biomass pellets are provided with a grate assembly that supports the pellets for combustion and directs combustion gas into the fire. The grate assembly includes a passive grate of unequally spaced rods. The design of the rods serves to prevent the ash and clinkers from accumulating on the grate in amounts that could reduce the flow of combustion gas into the fire.

Stoves for burning fuel in the form of pellets manufactured from biomass are known to provide acceptable alternative heat sources for conventional heating units such as gas, electric and oil furnaces. Such stoves generally include a sealable firebox into which is fed fuel and air or other gases to support the combustion of the fuel. Stoves for residential heating utilize either a top feed mechanism that delivers the pelletized fuel onto a grate or a bottom feed system that forces the pellets into a burn pot from below. The top feed system is generally considered to be preferable due to its simpler design. In a top feed system, in order to provide sufficient amounts of combustion gases to the fuel, the grate onto which the fuel is deposited includes a perforated plate wherein the combustion gases pass through the perforations into the burning fuel. The major drawback of the top feed system has been the inability to remove the non-combustible ash and clinkers from the grate after combustion of the pellets. The accumulation of the ash and clinkers is troublesome because it eventually blocks the flow of air through the perforations in the grate and into the fire. This results in reduced heat output and burning efficiency.
Accordingly, there is a need for an improved grate and grate assembly which provides the advantages described above with regard to perforated grates, without suffering from the drawbacks associated with the accumulation of non-combustible ash and clinkers. A suitable grate and grate assembly would allow for the effective removal of non-combustible ash and clinkers from the grate to prevent clogging of the perforations in the grate.

Combustion grate with rods for pellet fueled stove


A flow measurement system uses conduits adapted to be coupled to and throughout a liquid or gaseous fluid flow distribution system. Each conduit is instrumented to measure parameters associated with the liquid or gaseous fluid moving therethrough, and wireless transmit a unique code and data indicative of the parameters so-measured. A remotely-located receiver and output device(s) may be used to provide the data and unique code associated with each of the conduits in a human-discernable format. Each conduit may also receive data resulting in adjustment of fluid flow through the conduit.

Firefighters assemble temporary water distribution systems which can deliver water from street-level supply lines to individual firefighters. These systems hook into standpipes supplied with pressurized water by a local infrastructure. The water pressure is increased through the use of pumps (e.g., "pumper trucks") as the water is delivered using lengths of supply lines and valves to take water where needed. The pressure and velocity of the water in these temporary systems is often unknown. This situation can create problems for firefighters in "hot zones" as they wait for a pressurized volume of water to reach their end of a supply line. Further, when one supply source is used to feed a number of lines/nozzle terminations, changes in demand at one nozzle termination can negatively impact the amount of water being delivered to other nozzle terminations coupled to the same supply source.

Parameter measurement/control for fluid distribution systems

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


Methods and systems are provided for cooperating routers in communication networks. The cooperating routers conduct a handshake to exchange information with respect to “cooperation types” which they are capable of performing and/or are configured to perform. In an exemplary “emergency connection” cooperation type, one cooperating router may use the ISP connection of another cooperating router to send and receive packets. In an exemplary “bandwidth sharing” cooperation type, one cooperating router may make excess bandwidth available for use by other cooperating routers. In an exemplary “latency optimization” cooperation type, one cooperating router may use another cooperating router to transmit duplicates of packets or to implement suppression techniques.

Routers are ubiquitous in present day society. In many circumstances, the distance between two routers may be no more than several meters. This relatively close proximity has been known to cause technical problems, particularly wireless interference between different routers. However, such proximity presents new opportunities to improve user connectivity.
The embodiments will be described in detail with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate the same or functionally similar elements.

Systems, apparatuses and methods for cooperating routers

Six Impossible Things Before Breakfast Limited


Disclosed herein are system, method, and computer program product embodiments for incorporating a voice command from a user into a game. An embodiment operates by receiving real-time context data of a game and a voice command from a user of the game. After receipt, the voice command is parsed and a particular module of a plurality of modules containing static context data of the game is identified based on the parsed voice command. Based on the parsed voice command and the static context data of the game, a preliminary outcome is determined. The preliminary outcome and real-time game context data is then provided to determine a preliminary action and a final action different from the preliminary action, wherein the final action is to be incorporated into the game.

Video games provide users with various manners to interact with a virtual environment and virtual characters in that environment. Historically, there have been attempts to have a user's voice be part of video games and permit interaction with the virtual environment and with virtual characters in that environment. However, voice recognition technology and the resulting processing has been unable to accurately interpret the user's voice and precisely provide the appropriate action in the video game based on the user's voice. Similarly, the required computational power for processing the user's voice has been prohibitively high, thus preventing the processing from being done in real time so that users may readily receive feedback.
In the drawings, like reference numbers generally indicate identical or similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.

Voice control for virtual reality platform


A pneumatic tire comprises a bead core formed by helically winding and spirally laminating an organic or inorganic fiber cord obtained by twisting an organic or inorganic fiber reinforcing element in one direction and then twisting at least two twisted fiber reinforcing elements in a direction opposite to the twisting direction of the fiber reinforcing element, in which the cord is formed by successively twisting so that the twisting number in the last twisting is made larger than the twisting number in the initial twisting and the twisting directions from the initial twisting to the last twisting are made different to each other.

1. Field of the Invention
This invention relates to a pneumatic tire, and more particularly to a pneumatic tire in which an organic or inorganic fiber cord usable for reducing a tire weight (weight reduction) is used as a cord constituting a bead core instead of steel cord. Also a critical inner pressure for tire burst apt to be lacking in case of using such a fiber cord is increased to a satisfactory level by appropriating a twisting method of the fiber cord.
2. Description of Related Art
Recently, it is increasingly demanded to attain low fuel consumption and the like in vehicles and hence it is strongly desired to reduce tire weight in accordance with the low fuel consumption of the vehicle.
In general, a bead portion of the tire is required to have a high rigidity because it plays a role of positioning and strongly holding the tire to a rim. For this end, a bead core used in the bead portion is usually made from a high-strength steel cord. From a viewpoint of the reduction of tire weight, there have recently developed so-called weight-reduced tires by using an organic or inorganic fiber cord, which is very light and relatively high in the tenacity, instead of the steel cord forming the bead core.
Up to the present, the tire provided with the bead core made from the above fiber cord cannot be put into practice unless a value of total bead tenacity represented by product of the cord winding number for the formation of the bead core and cord tenacity should be made large as compared with the tire provided with the bead core made from steel cord. This is done in order to render a critical inner pressure for burst as an indication for the judgment of safeness into the same level as the tire provided with the bead core made from steel cord.
It is considered that the difference of tensile properties between the steel cord and the fiber cord, particularly the difference of cord properties over a given period until the occurrence of cord breaking-up largely depends upon the critical inner pressure for burst.
In general, the bead core is formed by helically winding and spirally laminating the cord to form a cord arrangement of plural rows.times.columns. In order to simulate the critical inner pressure for burst in the bead core having such a cord arrangement, when stress distribution in a section of the bead core is investigated by raising an inner pressure of the tire, there is a tendency that stress usually concentrates in the cords located at an innermost row of the bead core in a radial direction of the tire. Hence, the stress distribution in the section of the bead core becomes ununiform.
In case of the bead core made from the steel cord, even if a large stress is applied to steel cords located at the innermost row of the bead core in the radial direction of the tire other than steel cords of the other rows as mentioned above, these steel cords of the innermost row plastically deform while creating a constriction or the like over a constant period until the occurrence of cord breaking-up and are further elongated while causing the plastic deformation without immediately causing the cord breaking-up even at the arrival to their cord tenacity. Thus it is possible to impose stress on steel cords located at the remaining rows of the bead core. As a result, the non-uniform distribution of stress in the section of the bead core is corrected to promote the uniformization of stress and hence stress tends to rise at the breakage of the bead core. Therefore, it is considered that when the bead core is made from the steel cord, the critical inner pressure for burst can be maintained at a high level even if the value of the total bead tenacity is decreased to a certain small level.
On the other hand, when the conventional organic fiber cords not attaining to the appropriation of the cord structure are applied to the bead core, such cords merely indicate even elongation against stress until the occurrence of the cord breaking-up but do not have tensile properties as in the aforementioned steel cord. Therefore, when a large stress is applied to the fiber cords located at the innermost row of the bead core in the radial direction of the tire other than fiber cords of the other rows, it is impossible to sufficiently impose stress to the fiber cords of the other remaining rows over a constant period until the occurrence of cord breaking-up as in the steel cord and hence the non-uniform distribution of stress in the section of the bead core is not corrected and there is not caused the same action of enhancing stress in the breakage of the bead core as in the steel cord. For this end, it is considered that the critical inner pressure for burst can not be maintained at a higher level unless the total bead tenacity in the bead core made from the fiber cords is increased to a certain high level.
In the conventional tire using the bead cord made from the fiber cord, the value of the total bead tenacity should be made large only by increasing the winding number of the fiber cord in order to render the critical inner pressure for burst into the same level as in the tire using the bead core made from the steel cord. However, the increase of the winding number of the fiber cord undesirably brings about the increase of tire weight and the rise of the production cost.

Pneumatic tires with organic or inorganic fiber cord bead core


A gas turbine engine having a longitudinal centerline axis therethrough, including: a fan section at a forward end of the gas turbine engine including at least a first fan blade row connected to a drive shaft; a booster compressor positioned downstream of the fan section including a plurality of stages, where each stage includes a stationary compressor blade row and a rotating compressor blade row connected to the drive shaft and interdigitated with the stationary compressor blade row; and, a combustion system for producing pulses of gas having increased pressure and temperature of a fluid flow provided to an inlet thereof so as to produce a working fluid at an outlet. A first source of compressed air from the booster compressor is provided to the combustion system inlet and a second source of compressed air from the booster compressor is provided to cool the combustion system, where the pressure of the compressed air from the second source has a greater pressure than that of the compressed air from the first source.

The present invention relates generally to an improved gas turbine engine design and, in particular, to an improved core system which replaces the high pressure system of conventional gas turbine engines A booster compressor of the gas turbine engine is utilized in a manner so as to mitigate various effects of such improved core system and thereby retain a conventional low pressure turbine design.
It is well known that typical gas turbine engines are based on the ideal Brayton Cycle, where air is compressed adiabatically, heat is added at constant pressure, the resulting hot gas is expanded in a turbine, and heat is rejected at constant pressure. The energy above that required to drive the compression system is then available for propulsion or other work. Such gas turbine engines generally rely upon deflagrative combustion to burn a fuel/air mixture and produce combustion gas products which travel at relatively slow rates and relatively constant pressure within a combustion chamber. While engines based on the Brayton Cycle have reached a high level of thermodynamic efficiency by steady improvements in component efficiencies and increases in pressure ratio and peak temperature, further improvements are becoming increasingly more difficult to obtain.
Although the combustors utilized in the conventional gas turbine engine are the type where pressure therein is maintained substantially constant, improvements in engine cycle performance and efficiency have been obtained by operating the engine so that the combustion occurs as a detonation in either a continuous or pulsed mode. Several pulse detonation system designs, for example, have been disclosed by the assignee of the present invention in the following patent applications: (1) "Pulse Detonation Device For A Gas Turbine Engine," having Ser. No. 10/383,027; (2) "Pulse Detonation System For A Gas Turbine Engine," having Ser. No. 10/405,561; (3) "Integral Pulse Detonation System For A Gas Turbine Engine" having Ser. No. 10/418,859; (4) "Rotating Pulse Detonation System For A Gas Turbine Engine" having Ser. No. 10/422,314; and, (5) "Rotary Pulse Detonation System With Aerodynamic Detonation Passages For Use In A Gas Turbine Engine" having Ser. No. 10/803,293.
It will be appreciated that a pulse detonation device produces pulses of hot gas that are of approximately the same pressure. Time averaged pressure of such pulses is similar in magnitude to the pressure generated in a typical low pressure turbine engine, but at a higher temperature than normally associated with the low pressure turbine engine. It will be understood that a constant volume combustor similarly produces pulses of high-pressure, high-temperature gas that can also be utilized in the pulse detonation type of arrangement. An example of a stationary constant volume combustor is disclosed in U.S. Pat. No. 3,877,219 to Hagen, while a constant volume combustor including a rotatable element is disclosed in U.S. Pat. No. 5,960,625 to Zdvorak, Sr.
In this way, the core or high pressure system of the conventional gas turbine engine may be replaced with a more efficient and less complicated system involving primarily the combustor. At the same time, the modified gas turbine engine will be able to retain the conventional low pressure turbine, as well as the conventional operability characteristics thereof.
Accordingly, it would be desirable for a practical overall architecture be developed for a gas turbine engine utilizing a pulse detonation device or a constant volume combustor in the core system to further improve overall engine efficiency. Further, it would be desirable for such architecture to incorporate a cooling system and method which mitigates the pulsing nature of the combustion discharge and reduces engine noise.

Gas turbine engine having improved core system


A cutter knife with a blade extendable from and retractable into a cutter knife body by operating a slider. The cutter knife body has a plurality of engagement indentations formed alongside a slit. The slider has a spring member with an engagement head which is engageable with one of the engagement indentations. When an external force is directly applied to the blade in an advancing direction, the blade is inhibited from sliding out, because the distal side of the engagement head comes into contact with the distal end wall of the engagement indentation. When a predetermined external force is directly applied to the blade in a retracting direction, the blade can be withdrawn and held inside the cutter knife body by this external force, because an escapee is provided to the proximal end wall of each engagement indentation, or to the proximal side of the engagement head.

1. Field of the Invention
The present invention relates to a step-sliding type cutter knife which holds a blade slidable in the cutter knife body, and which allows the blade to step-wise slide out or in by operating the slider. More particularly, the invention pertains to an auto-locking and step-sliding type cutter knife, in which the blade is locked so as not to slide when an external force directly acts on the blade, whereas the blade can slide out or in under the operation by the slider.
2. Description of Related Techniques
In the fields of the auto-locking and step-sliding type cutter knife, the applicant of the present invention has already developed a cutter knife, capable of withstanding a large load directly acting on the blade, with a simple structure, to which a patent has been granted (Japanese Patent No. 2,059,272).
FIG. 1 shows a perspective view of the cutter knife, and FIG. 2 shows an exploded perspective view thereof. FIG. 3 shows a plan view of the locking mechanism of this cutter knife, and FIG. 4 shows a longitudinal sectional view of the locking mechanism, taken along a longitudinal axis. The cutter knife has a metallic elongated sleeve member 2, and a blade 1 slidably held in the sleeve member 2. The blade 1 is slid out of or into the cutter knife body by operating the slider 3.
The sleeve member 2 is formed by bending a metal sheet to have a lipped-groove, wherein walls 22 are extended from both sides of a slit 21 into the groove. Each of the walls 22 has a plurality of engagement indentations 23 formed thereon at regular intervals along the advancing or retracting direction of the blade 1. Each of the engagement indentations 23 has a pair of end walls 24, which face to each other in the advancing or retracting direction of the blade 1. A grip 4 of a synthetic resin is fixed to the sleeve member 2 by insert molding or the like.
As seen in the exploded perspective view shown in FIG. 2, the slider 3 comprises a slider body 5, an operating member 6, and a spring member 7 disposed between the slider body 5 and the operating member 6.
The slider body 5 is connected to the blade 1, and slides inside the sleeve member 2. The slider body 5 comprises a base portion 51 and a holder portion 52. The base portion 51 is slidably held between the base wall 25 (see FIG. 4) and the walls 22 of the sleeve member 2, and the holder portion 52 is raised from the base portion 51 to hold the operating member 6. The base portion 51 has a projection 53 at its one end, and the projection 53 is inserted into a connection hole 12 formed at one end of the blade 1 to thereby connect the slider body 5 to the blade 1 within the sleeve member 2.
On the other hand, the operating member 6 is so coupled with the slider body 5 as to be relatively movable to the body 5 in parallel to the sliding direction of the body 5, and is exposed to outside through the slit 21 of the sleeve member 2. The operating member 6 comprises an operating plate 61 having a plurality of anti-slip grooves 62 formed at its upper face, and a locking part 63 which is protruded from the underside of the operating plate 61 and is inserted into the opening 57 of the holder portion of the slider body 5. Claws 64 with widths narrower than the width of the groove 58 of the slider body 5 are formed on both side faces of the locking part 63 and are fitted in the groove 58 and engaged therewith. Thus, the operating member 6 can slide in the advancing or retracting direction of the blade 1, when coupled with the slider body 5.
The spring member 7 has a convex engagement head 72 which is urged into one of the engagement indentations 23 to thereby lock the sliding of the blade 1. The spring member 7 is held between slider body 5 and the operating member 6 in such the blade-locking state. The spring member 7 is formed by bending one metal sheet, so that the flat spring portion 71 with a narrow width which extends along the advancing or retracting direction of the blade 1 is formed integrally with the convex engagement head 72 which has a width wider than that of the spring portion 71 and which is raised from the center of the spring portion 71. The engagement head 72 is composed of a pair of flat faces 73 facing to each other, and a curved face 74 bridging the flat faces.
The base portion 51 of the slider body 5 has a wider central opening 54 (FIG. 4) for receiving the engagement head 72 of the spring member 7, and narrow side openings 55 which are formed at both sides of the central opening 54. The total length of the openings 55 is slightly shorter than the whole length of the spring portion 71 of the spring member 7. Further, a slit 56 communicating with the openings 55 is formed between the holder portion 52 and the base portion 51. The holder portion 52 has an opening 57 at its center, and grooves 58 at its both sides, which communicate with the opening 57.
A V-shaped sloped face 65 is formed on the lower end of the locking part 63 of the operating member 6. This sloped face 65 is in contact with the curved face 74 of the engagement head 72, when the spring member 7 is inserted into the slit 56 of the slider body 5 and coupled with the slider body 5 with its spring portion 71 held substantially flat without any bending.
When the operating member 6 of the slider is operated to slide the blade 1, the operating member 6 is moved relative to the slider body 5 so that the engagement head 72 of the spring member is pushed downward by the sloped face 65 of the operating member 6. As a result, the engagement head 72 is put outside the engagement indentation 23 to unlock the blade. On the other hand, when the engagement head 72 of the spring member is moved to another adjacent engagement indentation, the engagement head 72 is automatically pushed up into this another adjacent engagement indentation by the urging force of the spring member to thereby relock the sliding of the blade (auto-locking).
In the cutter knife constructed as above, the blade can be slid out of or into the cutter knife body by operating the slider. On the other hand, when an external force is directly applied on the blade, the sliding of the blade is inhibited by the action of the locking mechanism. Thus, such a disadvantage can be prevented that the blade is undesirably slid by an external force which acts on the blade from a subject being cut, during the cutting operation.
However, in some situations, the above auto-locking type cutter knife would be rather inconvenience to skilled workers. In many cases, after a cutting operation, the skilled workers push the blades against the hard surfaces of metal plates or the like, to thereby retract the blade inside the cutter knives. However, with the cutter knife constructed as above, even if the blade is pushed against the hard surface, the blade can not be retracted because of the auto-locking mechanism. Therefore, it is needed to operate the slider for retracting the blade inside the cutter knife body. The skilled workers feel this operation troublesome.

Auto-locking and step-sliding type cutter knife


A hemostatic material, a preparation method thereof, and a pharmaceutical composition containing the same are introduced. The hemostatic material includes 200 to 1600 parts by weight of water-insoluble gelatin and 100 to 1000 parts by weight of hydrating material. The preparation method for the hemostatic material includes the steps of (a) providing 200 to 1600 parts by weight of water-insoluble gelatin and 100 to 1000 parts by weight of hydrating material; and (b) combining the water-insoluble gelatin with the hydrating material to form a hemostatic material. The pharmaceutical composition includes an aforementioned hemostatic material and active pharmaceutical ingredients. Through the aforementioned hemostatic material, hemostatic products can increase the blood absorption capacity.

When a doctor performs an operation on a patient, if the patient's body part or trauma wound that undergoes surgery is relatively large, excessive bleeding often occurs. When excessive bleeding happens at the patient's body part or trauma wound that undergoes surgery, it will not only affect the physician's visible size of the surgical site during the operation, but also prolong the operation time, thereby increasing the risk of surgical failure. In order to minimize the excessive bleeding condition at the patient's body part or trauma would happening during the operation. Currently, there are many hemostatic products on the market. These hemostatic products are placed in the surgical site or trauma wound during the operation to absorb a large amount of blood; and can prevent and block bleeding in the patient's body part or trauma wound that undergoes surgery, such as hemostatic cotton, hemostatic gel and other hemostatic products.

Hemostatic material, preparation method thereof and pharmaceutical composition containing the same


Method and apparatus for treating confined material such as buried waste or areas of contaminated earth by injecting a plurality of high velocity jets of treating fluid into the material over a limited depth in multiple directions from each of a plurality of injection holes. The high velocity jets remain stationary, but the arrangement of the jets emanating from an injection hole in multiple directions produces a result similar to a rotating jet but with increased penetrating force. The jets are operated sequentially over the limited depth of each injection hole to treat a layer of the material and are then moved and again operated sequentially over another limited depth of each injection hole to provide treatment of the material by layers. This allows effective treatment of material surrounding each injection hole without substantial interference from treating fluid flowing through the material from a previously treated hole. It is preferred that each injection hole be lined during installation with a material that is easily cut by the high velocity jets so that the jets pass from a source inside the lined injection hole, through the lining, and into the material to be treated surrounding the hole.

The invention is in the field of treating and stabilizing buried waste, areas of contaminated earth or soil, sludge lagoons, or similar types of materials.
In many cases, waste is disposed of by burying the waste. In some cases, particularly in the disposal of radioactive wastes, shallow trenches are dug about three meters wide and between three and five meters deep and waste is deposited in such trenches. When filled with waste to about one meter of the top of the trench, the trench is covered with earth to cover the waste. Such waste presents a huge volume of heterogeneous contamination which is continually percolating into the soil and ground water. The buried waste usually includes various types of containers such as plastic bags, cardboard boxes, steel drums, and glass containers. The useful life of these containers to act as localized containment is usually much less than the time over which the enclosed chemicals or other wastes remain dangerous and can inflict harm to the environment.
It has become desirable for various buried waste sites to stabilize the waste in some way. This may be done by injecting stabilizing fluids into the buried waste. In many cases a grout is injected under relatively low pressure into the waste material with the expectation that the grout will flow through the waste, surround it, and solidify to stabilize such waste. With normal low pressure grouting procedures, however, the grout does not generally penetrate the various containers of waste, but merely surrounds them with grout. It has been found that by merely surrounding the containers with grout, the containers remain unstabilized and can collapse over time, thus creating voids in the mass of grout and waste formed by the low pressure grout treatment. The unstabilized waste, if mobile, can migrate through the open void spaces in the grout and be released and the voids created can lead to subsidence or collapse of the skeletal structure of the solidified grout.
The limitations of conventional low pressure grout injection can be overcome using high velocity jets to cut and mix the waste with stabilizing agents. However, conventional jet injection requires the use of surface drilling equipment to install the injection lances and to pull the lances from the ground during injection. Usually, a single drill hole is injected over its entire length, starting at the bottom of the hole and moving upwardly toward the top. When injection is completed for one hole, the drilling equipment is then moved to the next hole and the process is repeated. When stabilizing contaminated waste in this manner, several problems arise:
a) Because the buried waste includes open void space, grout tends to flow away from the area immediately surrounding the hole being injected. This grout flow is similar to low pressure conventional grouting which cannot form a homogeneous stabilized waste form due to the presence of intact containers. PA1 b) The flow of grout outside the area immediately surrounding the hole being injected, i.e., outside the zone of influence of the cutting jet, increases the depth of grout inside the buried waste and inside adjacent untreated holes. As more drill holes are injected, the grout depth increases inside the buried waste and in remaining untreated drill holes. As injection lances are inserted into these untreated holes, they become submerged in the grout filling these holes. The submergence of the lances and thus the jets of grout emanating therefrom causes a severe loss of cutting energy of the jets. If the grout in an untreated hole has hardened before the lance is inserted, all benefits of the high pressure jet are lost. PA1 c) Conventional jet injection usually requires the use of a surface drill to rotate and extract the injection lances. Rotation of the lances is necessary to direct the jet in various directions around the hole. The rotation, however, does not allow the cutting energy to be projected as far as when the jets are directed in a single direction as they are lifted. The rotating lances do not have enough concentrated cutting energy to cut robust containers, such as steel drums or wooden boxes. PA1 d) Due to the necessary rotation of the jets, the only way to ensure cutting of robust containers is to rupture the containers during the installation of the injection lance. This requires very close spacing between injection holes, typically 50-75 cm. PA1 e) Since a surface drill is used to rotate and extract the injection lances and the injection holes are sequentially injected from bottom to top, there is a very high probability that the surface mounted drill and operators can become exposed to contaminated waste which is ejected from the ground. Alternatively, the stabilizing fluid may break out of the ground and erupt at the surface increasing the likelihood of worker and equipment exposure to contamination.

Method for in situ remediation of waste through multi-point injection


Disclosed is a wireless gauge apparatus and manufacturing method thereof. The wireless gauge apparatus comprises a printed circuit board comprising a wireless transceiver and at least one sensor, a power source electrically coupled with the printed circuit board, an antenna electrically coupled with the wireless transceiver and a casing encasing the printed circuit board, the power source and the antenna. The casing is made of polyurethane having a density of 0.8-1.2 g/cm3. The antenna is surrounded by a protective layer having a thickness of 4-8 mm, a density of at most 50 kg/m3 and a dielectric constant of 1-2.7.

A wireless network consisting of spatially distributed wireless gauge apparatuses to monitor and determine physical or environmental conditions around the wireless gauge apparatuses is well known in the art. One such example includes use of a wireless gauge apparatus in conjunction with a garbage container for determining a fill level or a fill rate of the waste container. Generally, such gauges are subjected to harsh environment, for example, temperature changes, physical shocks, moisture, gases and chemicals. For example, an ambient temperature of a garbage container in areas like middle-east can vary from close to 100° C. in daytime to 0° C. during night. Further, waste or trash collected in such garbage container can be organic material, which decomposes and produces gases, such as methane and carbon dioxide. Also, waste can contain solvents, such as paint and other materials, which can evaporate and cause corrosion. Moreover, a garbage container may be subjected to a physical stress in terms of acceleration/shocks up to tens of G. Additionally, in some instances the gauge may be subjected to fire emergency and in such instances it would be desirable that the gauge should work for at least few minutes when exposed to direct fire or should work for about half an hour when exposed to heat, about 50° C., being thus capable of triggering an alarm and also fulfilling specific regulations.
In order to address the above issues, a gauge typically includes a plastic housing enclosing the electronic elements thereof. For example, the gauge may be casted with a suitable plastic material to substantially enclose the electronic elements and for shielding the gauge from above mentioned harsh environment. Primarily, such gauges are required to operate wirelessly and thus need to have a well-functioning radio unit, which generally operates on cellular network standards. In such instance, an antenna of such gauge needs to work effectively since the gauge is a battery powered device and is expected to have a long battery powered life. However, the robustness requirement (i.e. the plastic housing) for such gauges prevent utilization of an external antenna construction, i.e. the antenna is required to be arranged inside the housing. The plastic housing enclosing the antenna dramatically decreases effectiveness of the antenna. For example, such an antenna leads to increased power need or consumption for a transmitter of the gauge while sending signals. Also, such an antenna reduces sensitivity for a receiver of the gauge while receiving the signals and consequently reduced operation time.
Therefore, in light of the foregoing discussion, there exists a need to overcome the aforementioned drawbacks of a wireless gauge apparatus of having a robust construction and improved wireless communication.

Wireless gauge apparatus and manufacturing method thereof


A motion sickness control system for a vehicle includes a vibrator. The motion sickness control system includes a sensor configured to measure vibration of the vehicle. The motion sickness control system includes a computer having a processor and a memory storing instructions executable by the processor to actuate the vibrator at a target frequency based on the measured vibration of the vehicle. The target frequency attenuates the measured vibration of the vehicle.

Shock absorbers (or dampers) are typically used in conjunction with automotive suspension systems or other suspension systems to absorb vibrations that occur during movement of the suspension system. In order to absorb these vibrations, automotive shock absorbers are generally connected between the sprung (body) and the unsprung (suspension/drivetrain) masses of a vehicle.
The shock absorbers, however, do not damp all of the vertical vibration of the vehicle. Some vertical vibration may cause motion sickness of vehicle occupants. It is desirable to provide a motion sickness control system to improve the riding experience of vehicle occupants.

Systems and methods for minimizing motion sickness in vehicles


According to one embodiment, a semiconductor memory device comprises a memory cell array. The memory cell array has a plurality of magnetic tunnel junction (MTJ) elements. Each of the MTJ elements has a first magnetic layer, a second magnetic layer and a non-magnetic layer therebetween, and a hard mask layer is arranged above the second magnetic layer. The plurality of MTJ elements have a first MTJ element having a first hard mask layer and a second MTJ element having a second hard mask layer, and a dimension of, the first hard mask layer is greater than that of the second hard mask layer.

When a provisional pattern layout of a memory cell array is determined in the process of manufacturing, for example, a semiconductor memory device, the pattern layout is used and an optical proximity correction (OPC), etc., are executed to determine a mask pattern. A hard mask is manufactured based on the mask pattern. An MRAM having a magnetic tunnel junction (MTJ) element is also manufactured by a similar process.
Also, a memory cell array region generally has a plurality of patterns corresponding to memory cells at regular intervals, and a sufficient number of dummy cells to stabilize a critical dimension (CD) of the memory cells are arranged in an end portion of the memory cell array region.

Semiconductor memory device and manufacturing method thereof


A downhole adjustable blade stabilizer is disclosed for varying the position of stabilizer blades to provide an increased ability to control the direction of drilling. The adjustable blade stabilizer includes a plurality of blades mounted in an angled track to permit axial and radial movement of the blades. The blades are driven by a piston in response to a pressure differential created by a sufficient flow of drilling mud through the stabilizer. The stabilizer blades are retracted by a spring when the pressure differential is eliminated. A positioning piston limits blade extension to a desired position. The positioning piston moves in response to a command signal, and remains in place until a new command signal is received. By maintaining the positioning piston in a locked position, the position of the blades can be reset to the prior position after the loss of pressure differential. A measuring device is provided in association with the positioning piston to enable precise measurement of blade position.

1. Field of the Invention
The present invention relates generally to a steerable system for controlling borehole deviation with respect to the vertical axis by varying the angle of such deviation without removing (tripping) the system from the borehole, and more particularly to a directional drilling apparatus that is remotely adjustable or variable during operation for affecting deviation control.
2. Description of the Prior Art
The technology developed with respect to drilling boreholes in the earth has long encompassed the use of various techniques and tools to control the deviation of boreholes during the drilling operation. One such system is shown in U.S. Pat. No. Re. 33,751, and is commonly referred to as a steerable system. By definition, a steerable system is one that controls borehole deviation without being required to be withdrawn from the borehole during the drilling operation.
The typical steerable system today comprises a downhole motor having a bent housing, a fixed diameter near bit stabilizer on the lower end of the motor housing, a second fixed diameter stabilizer above the motor housing and an MWD (measurement-while-drilling) system above that. A lead collar of about three to ten feet is sometimes run between the motor and the second stabilizer. Such a system is typically capable of building, dropping or turning about three to eight degrees per 100 feet when sliding, i.e. just the motor output shaft is rotating the drill bit while the drill string remains rotationally stationary. When rotating, i.e. both the motor and the drill string are rotating to drive the bit, the goal is usually for the system to simply hold angle (zero build rate), but variations in hole conditions, operating parameters, wear on the assembly, etc. usually cause a slight build or drop. This variation from the planned path may be as much as .+-. one degree per 100 feet. When this occurs, two options are available. The first option is to make periodic corrections by sliding the system part of the time. The second option is to trip the assembly and change the lead collar length or, less frequently, the diameter of the second stabilizer to fine tune the rotating mode build rate.
One potential problem with the first option is that when sliding, sharp angle changes referred to as doglegs and ledges may be produced, which increase torque and drag on the drill string, thereby reducing drilling efficiencies and capabilities. Moreover, the rate of penetration for the system is lower during the sliding mode. The problem with the second option is the costly time it takes to trip. In addition, the conditions which prevented the assembly from holding angle may change again, thus requiring additional sliding or another trip.
The drawbacks to the steerable system make it desirable to be able to make less drastic directional changes and to accomplish this while rotating. Such corrections can readily be made by providing a stabilizer in the assembly that is capable of adjusting its diameter or the position of its blades during operation.
One such adjustable stabilizer known as the Andergage, is commercially available and is described in U.S. Pat. No. 4,848,490. This stabilizer adjusts a half-inch diametrically, and when run above a steerable motor, is capable of inclination corrections on the order of .+-. one-half a degree per 100 feet, when rotating. This tool is activated by applying weight to the assembly and is locked into position by the flow of the drilling fluid. This means of communication and actuation essentially limits the number of positions to two, i.e. extended and retracted. This tool has an additional operational disadvantage in that it must be reset each time a connection is made during drilling.
To verify that actuation has occurred, a 200 psi pressure drop is created when the stabilizer is extended. One problem with this is that it robs the bit of hydraulic horsepower. Another problem is that downhole conditions may make it difficult to detect the 200 psi increase. Still another problem is that if a third position were required, an additional pressure drop would necessarily be imposed to monitor the third position. This would either severely starve the bit or add significantly to the surface pressure requirements.
Another limitation of the Andergage is that its one-half inch range of adjustment may be insufficient to compensate for the cumulative variations in drilling conditions mentioned above. As a result, it may be necessary to continue to operate in the sliding mode.
The Andergage is currently being run as a near-bit stabilizer in rotary-only applications, and as a second stabilizer (above the bent motor housing) in a steerable system. However, the operational disadvantages mentioned above have prevented its widespread use.
Another adjustable or variable stabilizer, the Varistab, has seen very limited commercial use. This stabilizer is covered by the following U.S. Pat. Nos. 4,821,817; 4,844,178; 4,848,488; 4,951,760; 5,065,825; and 5,070,950. This stabilizer may have more than two positions, but the construction of the tool dictates that it must index through these positions in order. The gauge of the stabilizer remains in a given position, regardless of flow status, until an actuation cycle drives the blades of the stabilizer to the next position. The blades are driven outwardly by a ramped mandrel, and no external force in any direction can force the blade to retract. This is an operational disadvantage. If the stabilizer were stuck in a tight hole and were in the middle position, it would be difficult to advance it through the largest extended position to return to the smallest. Moreover, no amount of pipe movement would assist in driving the blades back.
To actuate the blade mechanism, flow must be increased beyond a given threshold. This means that in the remainder of the time, the drilling flow rate must be below the threshold. Since bit hydraulic horsepower is a third power function of flow rate, this communication-actuation method severely reduces the hydraulic horsepower available to the bit.
The source of power for indexing the blades is the increased internal pressure drop which occurs when the flow threshold is exceeded. It is this actuation method that dictates that the blades remain in position even after flow is reduced. The use of an internal pressure drop to hold blades in position (as opposed to driving them there and leaving them locked in position) would require a constant pressure restriction, which would even be more undesirable.
A pressure spike, detectable at the surface, is generated when activated, but this is only an indication that activation has occurred. The pressure spike does not uniquely identify the position which has been reached. The driller, therefore, is required to keep track of pressure spikes in order to determine the position of the stabilizer blades. However, complications arise because conditions such as motor stalling, jets plugging, and cuttings building up in the annulus, all can create pressure spikes which may give false indications. To date, the Varistab has had minimal commercial success due to its operational limitations.
With respect to the tool disclosed in U.S. Pat. No. 5,065,825, the construction taught in this patent would allow communication and activation at lower flow rate thresholds. However, there is no procedure to permit the unique identification of the blade position. Also, measurement of threshold flow rates through the use of a differential pressure transducer can be inaccurate due to partial blockage or due to variations in drilling fluid density.
Another adjustable stabilizer recently commercialized is shown in U.S. Pat. No. 4,572,305. It has four straight blades that extend radially three or four positions and is set by weight and locked into position by flow. The amount of weight on bit before flow initiates will dictate blade position. The problem with this configuration is that in directional wells, it can be very difficult to determine true weight-on-bit and it would be hard to get this tool to go to the right position with setting increments of only a few thousand pounds per position.
Other patents pertaining to adjustable stabilizers or downhole tool control systems are listed as follows: U.S. Pat. Nos. 3,051,255; 3,123,162; 3,370,657; 3,974,886; 4,270,619; 4,407,377; 4,491,187; 4,572,305; 4,655,289; 4,683,956; 4,763,258; 4,807,708; 4,848,490; 4,854,403; and 4,947,944.
The failure of adjustable stabilizers to have a greater impact on directional drilling can generally be attributed to either lack of ruggedness, lack of sufficient change in diameter, inability to positively identify actual diameter, or setting procedures which interfere with the normal drilling process.
The above methods accomplish control of the inclination of a well being drilled. Other inventions may control the azimuth (i.e. direction in the horizontal plane) of a well. Examples of patents relating to azimuth control include the following: 3,092,188; 3,593,810; 4,394,881; 4,635,736; and 5,038,872.


The present invention is to provide an optical waveguide capable of allowing a desired incident light to efficiently propagate towards the light emission side and to emit therefrom, and capable of preventing unnecessary incident light from propagating, and in providing a light source module and an optical information processing apparatus using the optical waveguide. The optical waveguide comprises a bonded member of a substrate, a core layer and cladding layers, configured to introduce an incident line coming into the core layer toward a light emission side thereof. A metal layer for preventing the incident light coming into the cladding layer from propagating to the light emission side is formed in a pattern intercepting a sectional plane of light transmission of said cladding layer.

1. Technical Field
The present invention relates to an optical waveguide comprising a bonded member of a core layer and cladding layers, suitable for light source module, optical interconnection, optical communication and so forth, and also to an optical information processing apparatus such as display.
2. Description of Related Art
Heretofore, mainly electric signals have taken part in information transmission over relatively short distances, typically between boards in a single electronic instrument, and between chips on a single board, in which further increase in signal speed and in density of signal wirings will be necessary in order to upgrade performances of integrated circuits. It is, however, difficult for electric signal wirings to increase the signal speed and density of the electric signal wirings, due to problems in occurrence of signal delay or generation of noise ascribable to time constant of the wirings.
Optical interconnection now attracts a public attention as one solution for these problems. The optical interconnection is applicable to various sites such as between electronic instruments, between boards in a single electronic instrument, and between chips on a single board. For the purpose of a short-distance signal transmission such as between chips for example, an optical transmission communication system can be constructed by forming, on a substrate on which the chips are mounted, an optical waveguide which is used as a transmission line for a signal-modulated laser light and so forth.
On the other hand, there is known use of the optical waveguide as a light source module of a display. For example, there is developed a head-mounted display by which a user can enjoy movie software, game, computer screen, and cinema on its own large screen, and this realizes a personal display with which the user can readily enjoy a highly realistic movie anytime anywhere, simply by wearing it like a sunglasses (see U.S. Pat. No. 5,467,104).
The head-mounted display uses red, green and blue light-emitting diodes (LEDs) as the light sources, in which the LED light lacks coherency, has a wide angle of radiation, and is difficult to be multiplexed through condensation of three colors of light. There is known a technique of producing a uniform white light by multiplexing three colors of LED light through an optical waveguide (Nikkei Electronics, Mar. 31, 2003 Issue, p.127).
There is also known an optical waveguide 183 having a structure shown in FIG. 39 (see Patent Document 1, described later).
The optical waveguide 183 is configured, as shown in FIG. 39A and FIG. 39B, so that a cladding layer 102 of 0.5 μm thick, typically composed of InP, is formed on an InP substrate 101 of a predetermined thickness composed of a semiconductor substrate or a dielectric substrate, and a core layer 106 composed of InGaAs, having a width on an incidence surface 127 side of 50 μm and a width on an emission surface 135 side of 2 μm, and also having straight inclined surfaces 155, is formed further thereon.
A cladding layer 105 of 1 μm thick, typically composed of InP, is further formed so as to cover the cladding layer 102 and the core layer 106, to thereby configure the optical waveguide 183.
As shown in FIG. 39C, when a laser 169 (any color allowable) as an exemplary light source is disposed on the incidence side of the optical waveguide 183 on the cladding layer 102, and the light beam emitted from the laser 169 enters the core layer 106 through the incidence surface 127, the light beam narrows its range of spreading and is condensed in accordance with changes in the width of the core layer 106 as indicated by a very thick line, and is then emitted through the emission surface 135 to the external.
As another conventional example, there is also known an optical waveguide 184 having a structure shown in FIG. 40 (see Patent Document 2, described later).
In this example, the optical waveguide 184 has a double-layered structure having a core layer 106 through which the light propagates and a cladding layer 143, in which the core layer 106 in a square form is configured to fill a recess provided to the top surface of the cladding layer 143 having a nearly square form. The cladding layer 143 also serves as a substrate for holding the core layer 106, and contains a light absorbing agent 122 for absorbing the light propagating through the core layer 106 and/or light scattering intercepting agent and so forth.
As a still another conventional example, there is known an optical waveguide 184 having a structure shown in FIG. 41 (see Patent document 3, described later).
This example comprises a substrate 142 mounted in an optical waveguide module package 151, an optical waveguide 185 composed of a cladding layer 143 and a core layer 106, both of which being formed in predetermined geometries on the substrate 142, an LED 141 mounted at a predetermined position on the substrate 142, an optical fiber mounting portion 150 formed on the substrate 142, a wavelength division multiplexing (WDM) filter 148 formed in contact with the substrate 142, and a photodiode mounting carrier 147 disposed behind the WDM filter 148, in which the photodiode mounting carrier 147 has a photodiode element 146, and the WDM filter 148 has a metal film 149 vacuum-evaporated thereon and a pinhole 145 formed nearly at the center of the filter 148.
In thus-configured optical waveguide 185, a part of the light emitted from the LED 141 enters the optical waveguide 185 for the LED, and propagates in the optical waveguide 185. The light propagated in the optical waveguide 185 is totally reflected on the WDM filter 148, and then enters an optical fiber transmission line (not shown) through the optical waveguide 185 for the optical fiber.
The light from the transmission line composed of the optical fiber 140 enters the optical waveguide 185 for the optical fiber from the optical fiber 140, goes through the pinhole 145 of the WDM filter 148, and is received by the photodiode element 146.
[Patent Document 1] Japanese Patent Application Publication (KOKAI) No. HEI 5-173036 (p.2, right column, L.17 to p.3, left column, L.8, FIG. 1d, FIG. 1e)
[Patent Document 2] Japanese Patent Application Publication (KOKAI) No. HEI 2-87102 (p.2, right column, L.29 to p.3, left column, L.40, FIG. 2)
                [Patent Document 3] Japanese Patent Application Publication (KOKAI) No. 2001-305365 (p.3, right column, L.34 to p.4, left column, L.22, FIG. 1).
However, typically in the conventional example shown in FIG. 39, use of an LED (light-emitting diode) as a light source in place of the laser 169 results in entering of the emitted light from the light source not only into the core layer 106 but also into the cladding layers 102, 105, due to a diffusing tendency of the LED light unlike the laser light, and the light then propagates through them, and goes out from the sectional surfaces of the individual cladding layers on the emission surface 135 side of the core layer 106.
The emitted light from the core layer 106 is therefore undesirably mixed with the emitted light from the cladding layers 102, 105, and makes it difficult to recognize the clear emitted light from the core layer 106, and this results in increase in diameter of the beam which should be a point light source, and makes it unacceptable for use in optical communication or display.
In the conventional example shown in FIG. 40 having the light absorbing agent 122 added to the entire portion of the cladding layer 143, the light which enters the core layer 106 and propagates therethrough while being reflected on the interface with the cladding layer 143 may be worsened in terms of light propagation loss.
In addition, mixing of carbon powder or the like into the cladding layer 143 may form regions having different refractive indices at the interface between the core layer 106 and the cladding layer 143, because the light absorbing agent 122 is less likely to uniformly distribute in the cladding layer 143, and this sort of non-uniformity in the mixing may locally modify the propagation loss and so forth of the waveguide 184.
In the conventional example shown in FIG. 41, which is the module package 151 allowing the send and receive operations at the same time by making wavelengths of the sent light and received light differ from each other, any roundabout of the incident light from the LED 141 into the photodiode element 146 is causative of noise for the light in the optical fiber 140, and this degrades the receiving characteristics of the module package.
It is known that efficiency of incidence of the emitted light from the LED 141 into the optical waveguide 185 is as much as 50% in maximum, and the residual emitted light from the LED 141 not entered the optical waveguide 185 propagates as a stray light in the air or in the cladding layer 143 in adjacent to the optical waveguide 185.
The pinhole 145 of the WDM filter 148 is provided in order to prevent the stray light from entering the photodiode element 146, after transmitting through the WDM filter 148, to thereby avoid degradation of the receiving characteristics.
However, even if any effort of eliminating the propagating light (stray light) in the cladding layer 143 should be made by providing the WDM filter 148, having the pinhole 145 formed therein, at the end surface on the light emission side of the optical waveguide 185, difficulty and labor-consuming nature of alignment between the pinhole 145 and the emission surface of the core layer 106 tends to result in misalignment, and this is not only causative of degradation of the receiving characteristics, but also degrade productivity of the module package 151 using the WDM filter 148.
The WDM filter 148 can intercept wavelength region of the emitted light from the LED 141, which is a major component of the stray light, but cannot completely intercept the stray light incident at large angles. Provision of the metal film 149 composed of, for example, CrO or the like, having a light reflectivity and light absorbency, on the light incident side of the WDM filter 148 may be one possible countermeasure, but this will increase the process steps.
Provision of a groove having a predetermined width so as to be laid in a direction crossing the direction of propagation of light, and so as to be extended over the optical waveguide 185, the cladding layer 143 and the substrate 142, and insertion of a metal plate having a pinhole, configured similarly to the WDM filter 148, will be hopeful to give a similar effect with the WDM filter 148, but this discontinues the optical waveguide 185, and consequently results in degradation of light propagation performance of the core layer 106.

Optical waveguide, light source module, and optical information processing apparatus