A thermoplastic film, and the articles thereof, consisting essentially of vinyl copolymer which exhibits sufficient structural durability and enhanced drapeability suitable for application as a breathable barrier layer in disposable end-use articles such as disposable hygiene and protective medical/industrial products. A preferred form of the vinyl copolymer are those selected from the ethylenic acrylates, with ethylene methyl acrylate being most preferred. Melt additives can be compounded with the ethylene methyl acrylate prior to extrusion include colorants, softening agents, UV stabilizers, and surface energy modifiers such as anti-static, hydrophobic and hydrophilic compounds.

The present invention is directed to a thermoplastic film composition, and more particularly, to a thermoplastic film consisting essentially of a vinyl copolymer, which exhibits structural durability and enhanced drapeability suitable for application as a breathable barrier layer in absorbent disposable hygiene and medical/industrial protective end-use articles.
This invention is directed to breathable barrier films, or films capable of transmitting moderate levels of water vapor but are generally resistant to the passage of water in a liquid form. Breathable films have been known and used for many years in the production of, for example, water-proof clothing, to allow for the escape of water vapor from the surface of the skin of the wearer while improving long-term comfort. Such breathable films can be broadly classified as being of a microporous or monolithic nature.
A microporous film has a large number of pores formed in the film using special processing conditions. One method of obtaining microporsity in films is described in U.S. Pat. No. 3,870,593, wherein a quantity of powdered inert material, such as calcium carbonate, is incorporated as a pore nucleating agent into a thermoplastic matrix prior to extrusion in film form. After extrusion, the loaded film is drawn, thus extending the thermoplastic matrix away from the pore-nucleating agent and inducing the formation of small pores. As described in U.S. Pat. No. 4,308,303 after production of the microporous film, the film may be subsequently coated with fibers to produce a laminate. The lamination of microporous films to fabrics is practicable by a number of well-known and acceptable methods, including adhesive and thermal bonding.
Due to the mode of pore formation in microporous films creating a pathway through the protective film, such films are not suitable for certain applications. The indiscriminate passing of dangerous gases, vapors and biological agents, such as viral pathogens, would be contraindicated in end-uses whereby protection from such dangerous material is desirable, if not critical.
A second class of breathable films is referred to as monolithic films, in which the film offers a generally uniform construction which is free of pores. Monolithic breathable films are capable of allowing the transfer of certain gases and liquid vapors due to chemical absorption into the film matrix and subsequent transfer through the film thickness and release on the opposite film facing. For films, a high rate of moisture transmission is driven by the relatively high concentration and pressure of vapor on one side of the film. This mechanism of transfer is described in U.S. Pat. No. 5,445,874, which discloses thin films of certain polyurethanes that possess inherently water vapor transmission rates higher than the human skin, allowing the film to be used as an outer layer in burn dressings.
As practiced monolithic films require a change in the thickness of the film in order to modify the water vapor transfer rate (WVTR) performance, with thinner films providing higher WVTR""s. As the thickness of a monolithic film is modified in order to adjust the WVTR, and particular when such films are reduced in caliper, the risk increases that a tear or imperfection may occur which will compromise the effectiveness of the barrier properties. Also, these breathable films tend to be harsh and noisy when combined with substrate materials and do not have an attractive visual appearance or a favorable fit to the user.
An unmet need exists for a breathable barrier film, with good WVTR properties, which exhibits sufficient structural durability necessary to maintain barrier performance and improved drapeability for enhanced fit and user comfort.
In accordance with the present invention, a thermoplastic film composition, and more particularly, a monolithic thermoplastic film comprising of a vinyl copolymer which exhibits sufficient structural durability and enhanced drapeability suitable for application as a breathable barrier layer in disposable end-use articles such as disposable hygiene and protective medical/industrial products. The film exhibits a WVTR of at least about 140 and no more than about 450.
The film is composed primarily of an vinyl copolymer, which can optionally be formed into a homogeneous and uniform blend with at least one melt additive. The film exhibits enhanced drapeability and strength for structurally durable breathable barrier performance with the additional benefit of favorable adhesion to a broad number of component polymers and substrate materials when utilized in laminate constructs.
Suitable vinyl copolymers include those families of polymers as well as acetates and acrylates. A preferred form of the vinyl copolymer are those selected from the ethylenic acrylates, with ethylene methyl acrylate being most preferred. Melt additives that can be optionally compounded with the ethylene methyl acrylate prior to extrusion include colorants, softening agents, UV stabilizers, and surface energy modifiers such as anti-static, hydrophobic and hydrophilic compounds and the mixtures thereof.
Advantageously, the film of the present invention can be in cast sheet form that can be used either individually or in conjunction with other separately formed materials, or preferably, can be continuously and directly applied to a substrate material while the film is in a molten or semi-molten state. When the film is applied directly to a substrate material, such as a woven or nonwoven fabric, the film exhibits useful adhesion properties without the necessary addition of other adhesives.
It has also been found that the film of the present invention can be loaded with elevated concentrations of melt additive without undue determent to the performance of the structurally durable, drapeable barrier properties. Of particular benefit, higher concentrations of titanium dioxide can be used to significantly improve the opacity of the resultant breathable barrier film. An improvement in opacity is of particular importance in the fabrication of personal hygiene articles, whereby the increased opacity reduces the printing through of organic exudates expressed into the article during its use.
While the present invention is susceptible of embodiment in various forms, hereinafter is described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
As used herein, the term water vapor transmission rate or WVTR is a value expressed in terms of grams of transmitted moisture per square meter of film over a 24 hour or one day period as determined by the protocol and teachings of U.S. Pat. No. 5,843,056, hereby incorporated by reference.
The present invention contemplates the use of a vinyl copolymer thermoplastic resin, which can optionally be admixed with one or more melt additives and extruded or cast into thin films either as an individual film, or as a film layer applied directly upon a substrate material.
In the preferred embodiment, the vinyl copolymer thermoplastic resin is incorporated into a film in the amount of at least 80% by weight, with the remainder of the film weight comprising one or more aesthetic or performance modifying melt additives. Within the blend parameters set forth above, practical consideration must be made as to the film formation including the structural durability of the film when used alone or as a layer with a fabric, and the minimum thickness at which a film can be formed using conventional equipment. The minimum thickness is on the order of 0.1 to 0.2 thousandths of an inch, and the maximum thickness can extend up to about 2 thousandths of an inch. A thin film having a higher amount of colorant might be used, for example, as an outer barrier for a hygiene product such as diapers. Thicker films might be employed in articles where structural durability and extensive barrier performance is a more important factor, such as in medical or industrial protective products.
The formation of finite thickness films from thermoplastic polymers is a well-known practice. Thermoplastic polymer films can be formed by either dispersion of a quantity of molten polymer into a mold having the dimensions of the desired end product, known as a cast film, or by continuously forcing the molten polymer through a die, known as an extruded film. Extruded thermoplastic polymer films can either be formed such that the film is cooled then wound as a completed product, or dispensed directly onto a substrate material to form a composite material having performance of both the substrate and the film layers. Examples of suitable substrate materials include macroporous or apertured films, polymeric or metallic sheet stock and woven or nonwoven fabrics.
Extruded films utilizing the composition of the present invention can be formed in accordance with the following representative direct extrusion film process. Blending and dosing storage comprising at least two hopper loaders, one for the vinyl copolymer resin chip and one for pelletized melt additive amide in thermoplastic carrier resin, feed into two variable speed augers. The variable speed augers transfer predetermined amounts of polymer chip and additive pellet into a mixing hopper. The mixing hopper contains a mixing propeller to further the homogeneity of the mixture. Basic volumetric systems such as that described are a minimum requirement for accurately blending the fatty acid amide into the thermoplastic polymer. The polymer chip and melt additive pellet blend feeds into a multi-zone extruder. Upon mixing and extrusion from multi-zone extruder, the polymer compound is conveyed via heated polymer piping through a screen changer, wherein breaker plates having different screen meshes are employed to retain solid or semi-molten polymer chips and other macroscopic debris. The mixed polymer is then fed into a melt pump, and then to a combining block. The combining block allows for multiple film layers to be extruded, the film layers being of either the same composition or fed from different systems as described above. The combining block is connected to an extrusion die, which is positioned in an overhead orientation such that molten film extrusion is deposited at a nip between a nip roll and a cast roll.
When a substrate material is to receive a film layer by extrusion, a substrate material source is provided in roll form to a tension-controlled unwinder. The base layer is unwound, optionally treated with a surface modifying process, such as heating or corona discharge, and moves over the nip roll. The molten film extrusion from the extrusion die is deposited onto the substrate material at the nip point between the nip roll and the cast roll. The newly formed base layer and film composite is then removed from the cast roll by a stripper roll and wound onto a new roll.
A number of technologies are capable of forming a substrate materials suitable to receive, by bonding or direct extrusion, at least one layer of film in accordance with the present invention including those substrate materials which are formed as continuous filament nonwoven fabrics, staple fiber nonwoven fabrics, continuous filament or staple fiber woven textiles, and reticulated films. Such substrate materials are typically manufactured from: thermoplastics including polyesters, polyamides and polyolefins, thermoset polymers such as acrylics, natural fibers such as cotton, wood pulp, and viscose rayon, and the blends thereof. Since the film resides as a layer on at least one side of the substrate material, the basis weight of the substrate material is not critical, and depends on the end use of the product. Composite nonwoven fabrics can also be employed, such as multiple-beam spunbonds, meltblowns, and the layering thereof.
In general, continuous filament nonwoven fabric formation involves the practice of the spunbond process. A spunbond process involves supplying a molten polymer, which is then extruded under pressure through a large number of orifices in a plate known as a spinneret or die. The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving foraminous surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs is collected upon the uppermost surface of the previously formed web. The web is then at least temporarily consolidated, usually by means involving heat and pressure, such as by thermal point bonding. Using this means, the web or layers of webs are passed between two hot metal rolls, one of which has an embossed pattern to impart and achieve the desired degree of point bonding, usually on the order of 10 to 40 percent of the overall surface area being so bonded.
A related means to the spunbond process for forming a layer of a nonwoven fabric is the melt blown process. Again, a molten polymer is extruded under pressure through orifices in a spinneret or die. High velocity air impinges upon and entrains the filaments as they exit the die. The energy of this step is such that the formed filaments are greatly reduced in diameter and are fractured so that microfibers of finite length are produced. This differs from the spunbond process whereby the continuity of the filaments is preserved. The process to form either a single layer or a multiple-layer fabric is continuous, that is, the process steps are uninterrupted from extrusion of the filaments to form the first layer until the bonded web is wound into a roll. Methods for producing these types of fabrics are described in U.S. Pat. No. 4,043,203, incorporated herein by reference.
Currently, many nonwoven manufacturing lines include at least two spunbond stations and optionally one or more meltblown stations in between. This enables the continuous production of a composite fabric consisting of discrete spunbond and meltblown layers. These fabrics are commonly called SMS, referring to a spunbond-meltblown-spunbond arrangement of layers. Thermal point bonding, as previously described, is typically used to consolidate such webs.
Staple fibers used to form nonwoven fabrics begin in a bundled form as a bale of compressed fibers. In order to decompress the fibers, and render the fibers suitable for integration into a nonwoven fabric, the bale is bulk-feed into a number of fiber openers, such as a garnet, then into a card. The card further frees the fibers by the use of co-rotational and counter-rotational wire combs, then depositing the fibers into a lofty batt. The lofty batt of staple fibers can then optionally be subjected to fiber reorientation, such as by air-randomization and/or cross-lapping, depending upon the ultimate tensile properties of the resulting nonwoven fabric. The fibrous batt is integrated into a nonwoven fabric by application of suitable bonding means, include, but not limited to, use of adhesive binders, thermobonding by calender or through-air oven, and hydroentanglement.
Production of conventional textile fabrics is known to be a complex, multi-step process. The production of staple fiber yarns involves the carding of the fibers to provide feedstock for a roving machine, which twists the bundled fibers into a roving yarn. Alternately, continuous filaments are formed into bundle known as a tow, the tow then serving as a component of the roving yarn. Spinning machines blend multiple roving yarns into yarns that are suitable for the weaving of cloth. Certain of the weaving yarns are transferred to a warp beam, which, in turn, contains the machine direction yarns, which will then feed into a loom. Other of the weaving yarns supply the weft or fill yarns which are the cross direction threads in a sheet of cloth. Currently, commercial high speed looms operate at a speed of 1000-1500 picks per minute, whereby a pick is a single yarn. The weaving process produces the final fabric at manufacturing speeds of 1260 inches to 1980 inches per minute.
Reticulated films, such as those of U.S. Pat. Nos. 4,381,326 and 4,329,309, are representative of macroporous films. Such macroporous films, which are typically employed in the construction of disposable feminine hygiene products, exhibit apertures within the layer of reticulated film. Application of the breathable barrier film of the present invention across these apertures renders a film laminate that then exhibits controlled breathability with further enhanced barrier performance.
Utilizing the above discussed substrate material forming technologies, combinations of same or different substrate materials with one or more breathable barrier film layers can be practiced to yield composite materials of further improved and specifically tuned performance.
A number of end-use articles can be benefit from the inclusion or substitution of a pre-existing barrier layer with the breathable barrier film of the present invention, including, but not limited to, hygiene absorbent articles, such as diapers and catamenial products, and medical/industrial protective articles.
Disposable waste-containment garments, are generally described in U.S. Pat. Nos. 4,573,986, 5,843,056, and 6,198,018, which are incorporated herein by reference.
An absorbent article incorporating a vinyl copolymer breathable barrier film of the present invention is represented by the unitary disposable absorbent article, diaper 20, shown in FIG. 1. As used herein, the term xe2x80x9cdiaperxe2x80x9d refers to an absorbent article generally worn by infants and incontinent persons that is worn about the lower torso of the wearer. It should be understood, however, that the present invention is also applicable to other absorbent articles such as incontinence briefs, incontinence undergarments, diaper holders and liners, feminine hygiene garments, training pants, pull-on garments, and the like.
FIG. 1 is a plan view of a diaper 20 in an uncontracted state (i.e., with elastic induced contraction pulled out) with portions of the structure being cut-away to more clearly show the construction of the diaper 20. As shown in FIG. 1, the diaper 20 preferably comprises a containment assembly 22 comprising a liquid pervious topsheet 24; a liquid impervious backsheet 26 joined to the topsheet; and an absorbent core 28 positioned between the topsheet 24 and the backsheet 26. The absorbent core 28 has a pair of opposing longitudinal edges, an inner surface and an outer surface. The diaper can further comprise elastic leg features 32; elastic waist features 34; and a fastening system 36 which preferably comprises a pair of securement members 37 and a landing member 38.
Practical application of a vinyl copolymer resin, and preferably an ethylene methyl acrylate resin, as the primary constituent of a breathable monolithic film represented by backsheet 26 results in a diaper that is more flexible and therefore more conforming to deformation of the overall structure as the diaper is worn. Further, as the backsheet is subjected to frictional contact with the user""s environment, the improved adhesion of the film to the substrate materials aid in ensuring that the overall diaper construct does not fail structurally while the diaper is in use. An additional benefit when using an ethylene methyl acrylate loaded with high levels of colorants, such as titanium dioxide, is an increase in opacity. An increase in opacity reduces the ability of urine or other excreta to alter the external coloration of the diaper article.
Catamenial products, such as feminine hygiene pads, are of the same general construction as the aforementioned diaper structure. Again, a topsheet and a backsheet are affixed about a central absorbent core. The overall design of the catamenial product is altered to best conform to the human shape and for absorbing human exudates. Representative prior art to such article fabrication include U.S. Pat. Nos. 4,029,101, 4,184,498, 4,195,634, and 4,886,513, which are incorporated herein by reference.
Medical and industrial protective products, such as CSR, medical gown, surgical drape and oversuits can benefit significantly from the inclusion of the structurally durable and drapeable breathable barrier film of the present invention. Of particular utility in the fabrication of such protective products is the application of the vinyl copolymer film in areas of high abrasion, such a knee, and elbow regions of garments and fixture zones of drapes and wraps, whereby the structural durability of the film improves product performance without determent to the barrier properties. Patents generally describing such protective products include U.S. Pat. Nos. 4,845,779, 4,876,746, 5,655,374, 6,029,274, and 6,103,647, which are incorporated herein by reference.

Structurally durable, drapeable breathable barrier film compositions and articles


An exposure mask comprises a phase shift section including a plurality of opening patterns formed by making openings in part of a shading film provided on a transmissive substrate and digging part of the substrate, and a non-phase shift section including at least one opening pattern. The opening pattern of the non-phase shift section has a dig whose amount of digging has been adjusted according to the amount of digging in the opening patterns of the phase shift section.

1. Field of the Invention
This invention relates to photolithographic techniques used for lithography processes in the manufacture of semiconductor devices, and more particularly to exposure masks using the phase shift effect and a manufacturing method thereof.
2. Description of the Related Art
With the recent advances in semiconductor technology, semiconductor devices have been made faster and more highly integrated, giving rise to the need of making pattern dimensions much finer and more accurate. To meet these requirements, short wavelength light, such as far ultraviolet light, has come to be used as an exposure light source. In recent years, attempts to make pattern dimensions finer without changing an exposure light source have been made. One approach in the attempts is a phase shift method. The approach is such that a phase-inverted layer (phase shifter) is provided partially at a light transmission section to remove an adverse effect of diffraction occurring between adjacent patterns, thereby improving the pattern accuracy.
One phase-shift approach by which resolution is particularly improved is the Levenson-type phase shift method (Jpn. Pat. Appln. KOKAI Publication No. 62-50811). With this approach, phase shifters are provided alternately on the light transmission section in a mask on which a shading pattern is provided. The phase of the light passing through a phase shifter is inverted by 180.degree. with respect to the light passing through a portion where a phase shifter is not provided. Inverting the phase of light at the adjacent transmission sections this way causes negative interference of light between the patterns, thereby improving the resolution.
One known method of manufacturing Levenson-type phase shift masks is the approach of making a mask by digging a substrate (Jpn. Pat. Appln. KOKAI Publication No. 62-189468). Masks using the approach of digging a substrate, however, have a problem: even if the dimensions of the opening are the same, the phase shift section where the substrate is dug differs from the non-phase shift section where the substrate is not dug in the intensity of light. The problem arises from the fact that the dimensions of the opening are optically narrowed by the interference of the pattern edge portion parallel to the optical axis at the phase shift section.
To solve the problem, the adjustment of the desired exposure has been made by adjusting the dimensions of openings in a pattern of a conventional exposure mask. Such adjustment by the dimensions of openings, however, is liable to be restricted by the pattern. For instance, the desired opening width cannot be obtained, depending on the size of adjacent patterns.
As described above, since the Levenson method-applied pattern differs from the Levenson method-unapplied pattern in the desired exposure in a conventional Levenson-type phase shift mask and the adjustment of the desired exposure is made by adjusting the dimensions of openings in a pattern, the pattern has imposed restriction on the adjustment. For instance, the desired opening width cannot be provided, depending on the size of adjacent patterns.
The object of the present invention is to provide an exposure mask capable of adjusting the desired exposure for Levenson method-applied patterns and Levenson method-unapplied patterns without being restricted by the patterns and a manufacturing method thereof.

Exposure mask and manufacturing method thereof


This invention relates to a vacuum drying apparatus for continuously drying treated articles subjected to washing treatment with water such as electronic components. A plurality of vacuum tanks each incorporating therein heaters are disposed concyclically on a rotary table, and a carry-in apparatus for carrying in treated articles washed with water and a carry-out apparatus for carrying out dried treated articles are disposed in a carry-in/out zone of the treated articles. Furthermore, hot air heating devices for blowing hot air to the treated articles subjected to water washing treatment are disposed in the carry-in apparatus.

This invention relates to a vacuum drying apparatus for efficiently drying high-tech components such as components for electronic devices and medical equipment after washing them with water.
Conventionally, high-tech components such as components for electronic devices and medical equipment have generally been washed with solvents such as fluorocarbon, 1.1.1-trichloroethane, or trichloroethylene.
According to the Wien Convention, Montreal Protocol signed in May, 1989, however, it was agreed to totally cancel the use of fluorocarbons by A.D. 2000. Accordingly, the use of the fluorocarbon solvents has been avoided as much as possible and washing with water, which is entirely pollution-free, has been made instead recently. However, washing with water involves the problem that the drying time is longer than washing with the solvents described above.
On the other hand, the high-tech components such as components for electronic devices and medical equipment are produced continuously by automated machine, and come off the line through a washing step generally at a rate of one component per one or two minutes and one component per about 30 seconds in a short case.
Therefore, the greatest future problem will be how efficiently the high-tech components washed with water, the treated articles, can be dried.


Systems and methods for responding to an abnormal event in a region monitored by a security system are provided. Such systems and methods can include a cloud server periodically receiving a heartbeat signal from the security system, the cloud server receiving a notification signal of an occurrence of the abnormal event in the region, and responsive to failing to receive the heartbeat signal after receiving the notification signal of the occurrence of the abnormal event, the cloud server transmitting an alarm to a central monitoring station.

Security systems and methods that communicate alarm events to a central monitoring station are known in the art. However, these known systems and methods suffer from several known issues. First, such known systems and methods utilize expensive proprietary equipment instead of widely available smart home and internet of things devices. Second, such known systems and methods can be slow in responding to an abnormal event in a monitored region. Third, such known systems are susceptible to tampering by savvy burglars who can deactivate local alarm sounders and/or prevent transmission of alarm signals to the central monitoring station. Fourth, such known systems and methods can be overly sensitive, which can result in sending unnecessary alarms to the central monitoring station.
In view of the above, there is a continuing, ongoing need for improved systems and methods.


A logic device that allows the implementation of a fast-switching logic gate is described. One implementation of the logic device includes an output node and a reference node electrically isolated from one another by a transmission gate. During a first period of time, the nodes are charged to complementary logic levels. During a second period of time, the transmission gate is enabled, allowing the charge on the nodes to be redistributed. A pair of complementary input terminals are connected to the reference and output nodes, such that if the input terminal connected to the output node is at the same logic level as the output node during the first period, then the voltage level of the output node is pulled back from its redistributed state to its original state. However, if the input terminal voltage level to the output node is the complement of the original voltage level of the output node, then a charge/discharge circuit is enabled to pull the output node to a voltage level that is a complement to its original voltage level.

1. Field of the Invention
The invention relates in general to logic devices, and more particularly to a fast-switching logic gate.
2. Description of the Related Art
With the growing complexity of modem computer systems, designers are constantly seeking more efficient methods to reduce power and cost, while increasing speed. Generally, the major components in a computer system are formed from the combination of millions of logic gates. Typically, the power, cost, and speed of the components correlate to the operation efficiency of these logic gates. The switching speed of a logic gate is generally defined in the art as the time that it takes for the output terminal to reflect a change at the input terminal. By significantly improving the performance of the logic gate, the overall performance of the computer system can be improved.
FIG. 1 illustrates six MOS (metal oxide semiconductor) transistors 100, 102, 104, 120, 122, 124 connected to form a conventional static CMOS (complementary MOS) logic gate. The transistors essentially function as switches. These switches are normally open, which prevents current from flowing (i.e., charge from redistributing) and corresponds to the transistor being "off." Transistors can be turned "on" by applying a voltage to an enable input terminal. N-type transistors are turned "on" when a high voltage level is applied to the enable input terminal, while P-type transistors are turned "on" when a low voltage level is applied to the enable input terminal. A high voltage level as defined in this application is a voltage level that is approximately equal to a reference voltage, while a low voltage level is approximately equal to a ground voltage. When a node has a high voltage level applied, it is designated as being in a "high" state. A node is designated as being in a "low" state when a low voltage level is applied to the node. The specifics regarding P-type and N-type transistors have not been included because they would be known by one of ordinary skill.
The transistor 100 is a P-type transistor with an enable input terminal 105 referred to as an input terminal A. When a low voltage level is applied to the input terminal A, the transistor 100 "turns on," connecting a reference voltage level V.sub.ref to an output node 110, forcing the output node 110 to a "high" state. At approximately the same time, the low voltage level at the input terminal A is also applied to an enable input terminal 115 of an N-type transistor 120. However, the N-type transistor 120 does not "turn on." One skilled in the art will appreciate that when the input terminals A, B, and C are high, all of the P-type transistors 100, 102, 104 in is FIG. 1 will be "off," while all of the N-type transistors 120, 122, 124 will be "on." When any of the input terminals (i.e., A, B, or C) are low, a high voltage level approximately equal to the reference voltage V.sub.ref is present at the output node 110. Similarly, when all of the input terminals A, B, and C are high, the output node 110 is connected to ground and a low voltage level is present at the output node 110. The circuit shown in FIG. 1 is configured to implement a logical NAND gate.
Disadvantages of the logic gate of FIG. 1 include the use of several N-type and P-type transistors, which generally requires a larger surface area. Typically, an increase in the surface area has a corresponding increase in cost. Connection of both N-type and P-type transistors may also hinder the switching speed. If, for example, the input terminals A, B, and C were designated as being in the low state and then changed to the high state, the P-type transistors 100, 102, 104 would be "turning off" while the N-type transistors 120, 122, 124 are "turning on." Generally, it takes longer for the P-type transistors to "turn off" than it does for the N-type transistors to "turn on." Thus, there is a period when both the P-type and the N-type transistors 100, 102, 104, 120, 122, 124 may be "on," which can delay the output node 110 from achieving the desired state (e.g., a low state). Also, with all of the transistors 100, 102, 104, 120, 122, 124 turned "on," current flows from V.sub.ref to ground, increasing the power consumed by the static CMOS logic gate.
In this example, the N-type transistors 120, 122, 124 operate to apply a low voltage level at the output node 110, while the P-type transistors 100, 102, 104 operate to apply a high voltage level at the output node 110. Thus, there is a type of "fighting" that may occur between the P-type transistors 100, 102, 104 and the N-type transistors 120, 122, 124. In this case, the output node 110 will not fully discharge (i.e., to go to a low voltage level) until after all of the P-type transistors 100, 102, 104 "turn off." This causes a delay between the time the input terminals A, B, and C change and the time the output node 110 reflects the change. This delay results in a decreased switching speed.
FIG. 2A illustrates a conventional, ideal domino logic gate 199, which includes one P-type transistor 200 and several N-type transistors 210, 215, 220, 225 serially connected together. A master common clock signal is applied to the enable input terminal of the P-type transistor 200. When the clock signal is low (i.e., has a low voltage level), the transistor 200 "turns on," applying a high voltage to an output node 205. The same clock signal is applied to the N-type transistor 210, which causes the transistor 210 to remain off during the same period. Enabling the P-type transistor 200 (i.e., turning the P-type transistor "on"), and disabling the N-type transistor 210 causes the output node 205 to be in a high state. Varying the voltage applied to the enable input terminals A, B, and C of the N-type transistors 215, 220, 225 can cause the output node 205 to discharge (i.e., go to a low state). For example, if the input terminals A, B, and C were all at a high voltage level while the clock was at a low voltage level, such that all of the N-type transistors 210, 215, 220, 225 were "turned on," then the output node 205 could begin to discharge. The logic gate 199 shown in FIG. 2A is configured to implement a logical NAND gate.
Problems with the circuit of FIG. 2A include charge-sharing, which can cause an incorrect state at the output node 205. For example, if the input terminal A and input terminal B are high, the transistors 215 and 220 would be "on." Thus, some of the charge present at the output node 205 can be redistributed to the intermediate nodes 216 and 230. The charge shift to the intermediate nodes 216 and 230 can cause the voltage level present at the output node 205 to drop substantially, causing the high voltage level to be seen as a low voltage level. This can cause the logic gate 199 to function improperly.
FIG. 2B illustrates a modified domino logic gate 231, which includes an additional P-type transistor 235 and an inverter 240. The enable input terminal of the P-type transistor 235 is connected to the output terminal of the inverter 240. When the voltage level of the clock is low, the output node 205 is at a high voltage level, which causes the output terminal of the inverter 240 to be at a low voltage level. The low voltage level from the inverter 240 is applied to the enable input terminal of the P-type transistor 235, which causes that transistor to "turn on." When the transistor 235 is "on," it helps to maintain a high voltage level at the output node 205. The logic gate 231 shown in FIG. 2B is configured to implement a logical NAND gate.
If the input terminals A, B, and C have a high voltage level applied, the N-type transistors 215, 220, 225 apply a low voltage to the output node 205, while the P-type transistor 235 applies a high voltage. The output node 205 cannot fully discharge until the P-type transistor 235 "turns off" which causes a delay and limits the switching speed of the logic gate 231. In addition, during this period where both the P-type and N-type transistors are "on" wasted current flows from V.sub.ref to ground. Moreover, the logic gate of FIG. 2B still has a similar potential for charge-sharing as described in conjunction with the logic gate 199 of FIG. 2A.
FIG. 3 shows a conventional Cascode Voltage Switch Logic (CVSL) gate which may function similarly to two domino gates. One side of the circuit charges while the other side of the circuit discharges. CVSL is known in the art as a dual-rail structure. This type of structure employs an inverted input terminal for each input terminal. Thus, in FIG. 3 input terminals A-F have corresponding inverted input terminals A*-F*. Generally, a dual-rail structure employs a larger area and more power. In addition, CVSL may also have "fighting" during the discharge cycle, which can cause the switching speed to be limited. If sense amplifiers are placed on both out and out* nodes to achieve more sensitive detection, noise present at either the out or out* nodes will also be amplified, which can cause the gate to malfunction.
Thus, it would be beneficial to have a fast-switching logic gate for use with computer systems that is capable of overcoming the shortcomings of conventional methods.


A liquid reclamation and recirculation system for a wet saw cutting apparatus comprising: a wet saw having a blade onto which liquid is dispensed by a liquid dispenser adjacent thereto; a first tank for receiving the liquid that has been dispensed onto the blade, the liquid received by the first tank defining a water level of the first tank; a second tank for receiving the liquid at or near the water level of the first tank; wherein the liquid dispensed by the liquid dispenser is drawn from the second tank.

Wet saws are commonly utilized for cutting hard materials, such as concrete, stone, ceramics, tile, etc. In operation, water is applied to the blade to keep the blade and materials cool, and reduce dust and other particulates that may be expelled from the cut during cutting. Because the liquid also lubricates the cut and flushes particulates therefrom, a clean source of water, i.e. one substantially free of particulates, is often essential to making a quality cut without undue breakage. Accordingly, wet saws are often attached to a fresh water source, for example, a faucet. The fresh water source provides a continuous supply of clean water to the saw. However, such wet saws are of limited mobility, as they are required to be near a water source in order to properly operate.
Recirculating wet saws are also known, which filter and recirculate the water expelled during the cutting operation. These wet saws have the advantage that they are not required to be near a water source. One such recirculating wet saw is shown, for example, in U.S. Pat. No. 5,477,844; U.S. Pat. No. 8,347,871; and U.S. Pat. No. 6,557,602, each incorporated herein by reference. However, the water reclamation systems utilized in such wet saws are overly complex, expensive, and inefficient.
It is therefore desirable to provide an improved liquid reclamation and recirculation system for a wet saw cutting apparatus.

Liquid reclamation and recirculation system for a wet saw cutting apparatus


This application relates to a text classification method. The method includes obtaining, by a computer device, a to-be-classified text, and calculating an original text vector corresponding to the text; determining, by the computer device according to the original text vector, an input text vector corresponding to each channel of a trained text classification model; inputting, by the computer device, the input text vector corresponding to each channel into a convolution layer of the corresponding channel of the trained text classification model, the trained text classification model comprising a plurality of channels, each channel being corresponding to a sub-text classification model, and the trained text classification model being used for determining a classification result according to a sub-classification parameter outputted by each sub-text classification model; and obtaining, by the computer device, a classification result outputted by the trained text classification model, and classifying the text according to the classification result.

Text classification refers to classifying a collected text according to a classification intention. Conventional text classification refers to manually classifying a text grabbed by an Internet crawler. This method requires heavy workload and is difficult to ensure accuracy. With the development of machine learning, some topic models, such as Latent Dirichlet Allocation (LDA), are put forward for text classification. However, the classification result is still not accurate.

Text classification method, computer device, and storage medium

TENCENT TECHNOLOGY (SHENZHEN) COMPANY LIMITED


A camshaft adjuster having a first component, a second component rotatable relative to the first component within an angular range, and a locking device for locking the first component relative to the second component. The locking device includes a first locking bolt and a second locking bolt on the first component and a central slotted guide on the second component, and wherein the two locking bolts are movably guided between a locking position and an unlocking position and engage in the central slotted guide in a central angular position relative to one another in their locking position. At least one terminal slotted guide, in which the first locking bolt or the second locking bolt engages in its locking position in a terminal angular position differing from the central angular position of the components, is arranged on the second component.

Camshaft adjusters are industrial modules for adjusting the phase angle between a crankshaft and a camshaft in an internal combustion engine. One of the components, also known as the stator, is rotatably fixedly connected to the crankshaft. The other component, also known as the rotor, is rotatably fixedly connected to the camshaft and rotatably supported relative to the stator. In a hydraulic camshaft adjuster, the stator usually includes a number of separating elements, between which a vane element of the rotor is situated. The vane element divides the space between two adjacent separating elements into an advance chamber and a retard chamber. Both chambers are connected to switchable pressure medium lines. If a pressure medium is applied to the advance chamber via the associated pressure medium line, and if the pressure medium line of the retard chamber is connected to a pressure medium outlet, the rotor is moved in an advance direction with respect to the stator and vice versa. If pressure medium is applied to both chambers, or if the pressure medium lines are blocked, the rotor is hydraulically fixed at the set phase angle with respect to the stator.
The hydraulic camshaft adjuster is usually integrated into the lubricant circuit of the internal combustion engine for the purpose of supplying pressure medium. In a start phase of the internal combustion engine, the pressure of the lubricant (oil pressure) is generally not yet sufficient for flawless operation of the camshaft adjuster. The rotor may oscillate in an uncontrolled manner within the permitted angular range and possibly strike the stator, which results in an undesirable acoustic abnormality. For this reason, hydraulic camshaft adjusters usually have a mechanical locking device which locks the two components which are rotatable relative to each other, i.e., the rotor and stator, in a defined angular position with respect to each other during a standstill or in a start phase of the internal combustion engine. Due to the building pressure of the lubricant, the lock is released, so that the rotor and stator may be adjusted with respect to each other during operation of the internal combustion engine.
The angular position in which the rotor and stator of a hydraulic camshaft adjuster are mechanically locked with respect to each other is usually indicated as an advance or a retard. In other words, in the locked angular position, the rotor strikes a separating element in either in the advance position, i.e., for example in the clockwise direction, or in the retard position, i.e., for example in the counterclockwise direction. A hydraulic camshaft adjuster is also known from EP 0 799 977 A1, in which the two rotatable components are locked to each other in a central angular position between the advance position and the retard position during the standstill. This provides thermodynamic advantages for the correspondingly operated internal combustion engine. In this position, a locking bolt on the one component engages with a correspondingly situated central slotted gate on the other component for the purpose of locking.
A camshaft adjuster of the type mentioned at the outset is known from EP 1 672 187 A1. A central slotted gate is provided herein, with which both locking bolts engage in a central angular position when the two components are locked with respect to each other. Due to this design, a simplified locking of the components in the central position is possible. When the rotating components are locked, one of the locking bolts first enters the central slotted gate, which is widened accordingly in the direction of rotation, and forms a stop therein only upon further rotation. In the defined stop position, the second locking bolt may enter the central slotted gate, so that the two components finally lock in both directions of rotation in a fixed angular position with respect to each other.
A camshaft adjuster of the type mentioned at the outset is also known from DE 10 2005 060 829 A1. Two locking bolts for locking the two components in a central angular position are provided herein, each of which engages with a separate central slotted gate. A third and a fourth locking bolt are additionally provided, which lock the components in an advance position and in a retard position with respect to each other via a first and a second end slotted gate.
Finally, a camshaft of the type mentioned at the outset is also proposed in DE 10 2007 007 073 A1. Herein, the components of the camshaft adjuster may be locked in a total of three different positions with respect to each other, namely in an advance position, in a retard position and in a central adjusting position, with the aid of a total of three locking bolts and three slotted gates.


A method and apparatus for selectively sorting individual particles, such as blood cells of a particular type of interest, from a plurality of particles of different types. Particles of interest are individually differentiated from other particles in a known manner, and a discrete control signal is produced in response to having identified a particle of interest. An impulse generator, acting in response to such control signal, applies a focused impulsive force on the identified particle of interest, such force serving to eject such particle from the plurality of particles of which it is a part. The ejected particles of interested are then collected in a separate container. The apparatus of the invention is preferably embodied in a flow cytometric instrument.

1. Field of the Invention
The present invention relates to improvements in methods and apparatus of the type commonly used to automatically and rapidly sort minute particles, e.g. biological cells, entrained in a moving liquid on the basis of certain predetermined particle characteristics. More particularly, it relates to a particle-sorting method and apparatus in which particles of interest are selectively extracted from their entraining liquid by using a hydraulic impulse to selectively eject such particles of interest from the entraining liquid.
2. The Related Prior Art
Flow cytometry is commonly used to differentiate various types of cells and other "formed bodies" comprising a biological fluid, e.g., whole blood. Conventional flow cytometers commonly comprise an optically-transparent flow cell, usually made of quartz, having a central channel through which a stream of cells to be individually identified is made to flow. Movement of the cell stream through the flow cell channel is hydrodynamically entrained to the central longitudinal axis of the flow cell channel by a cell-free sheath liquid that concentrically surrounds the cell stream and flows along with the cell stream as it passes through the flow cell channel. As each cell passes through a cell-interrogation zone of the flow cell channel, it is irradiated with a focused beam of radiation (as commonly provided by a laser source). Upon impinging upon each cell, the laser beam is scattered in a pattern characteristic of the morphology, density, refractive index and size of the cell. Further, the spectral characteristics of the laser beam may act to excite certain fluorochromes associated with selected cells, as may be the case when a cell's DNA has been previously stained with such fluorochromes, or when a fluorochrome molecule has been previously conjugated with a selected type of cell, either directly or via an intermediate bead or the like. Photodetectors strategically positioned about the optical flow cell serve to convert the light-scattered by each cell and the fluorescence emitted by the excited fluorochromes to electrical signals which, when suitably processed, serve to identify the irradiated cell. In addition to the light scatter and fluorescence measurements made on each cell, some flow cytometers further characterize each cell by measuring certain physical and/or electrical properties of each cell as it passes through the flow cell. Using the well-known Coulter Principle, a DC and/or an RF current is caused to pass through a constricted aperture in the flow cell channel simultaneously with the movement of cells therethrough. The volume of each cell affects the level of DC current through the flow cell aperture, and the cell's electrical conductivity affects the RF current through such aperture. See, for example, the flow cytometer disclosed in the commonly assigned U.S. Pat. No. 6,228,652, issued in the names of Carlos M. Rodriguez et al.
A conventional light scatter and fluorescence-sensing flow cytometer of the type noted above is disclosed in U.S. Pat. No. 3,710,933 issued to Mack J. Fulwyler et al. To this standard flow cytometer, Fulwyler et al. have added a cell-sorting component that operates to selectively remove and collect certain cells of interest (e.g., abnormal cells) from the effluent of cells that have already passed through the optical flow cell and have been identified as to cell type. More specifically, the cell-sorting component comprises a piezoelectric device that acts to vibrate the flow cell so as to effect the production a stream of droplets from the cell-entraining sheath liquid exiting from the flow cell. Ideally, each droplet contains but a single cell that has been characterized as to cell type by the light-scatter and fluorescence measurements just made on such cell. Each droplet in the droplet stream is then electrostatically charged as it passes between a pair of electrically charged plates, and each charged droplet is selectively deflected (or not deflected) towards a collection container as it passes between a pair of electrostatically charged deflection plates, such plates being charged to a droplet-deflecting polarity only at a time to deflect droplets (and cells) of interest. The instantaneous polarity of the deflection plates is determined by a cell-characterization processor that processes the cell-measurement signals from the optical flow cell.
In cell-sorting flow cytometers of the above type, the continuous production of suitably sized droplets can be problematic. Not only is it technically difficult to continuously produce droplets that contain only a single cell, but also the required size of the droplets is so small (aerosol in size) that it is difficult to control their precise movement as they exit from the flow cell. Typically, when it is suspected that a droplet contains more than one cell, the droplet is allowed to proceed to a waste container in order to avoid potential contamination of the collected cells of interest with other cells.

Methods and apparatus for sorting particles hydraulically


A multiple channel transistor provides a transistor with an improved drive current and speed by using tunable hot carrier effects. A thin gate oxide has a carrier confinement layer formed on top thereof. Holes produced by hot carrier effects are retained by the carrier confinement layer directly above the gate oxide layer. The holes switch on the bottom transistor of the multi-channel transistor, thereby increasing the drive current.

A conventional MOSFET operates by driving current through a channel region between the source and drain of a device. The conductivity of the channel region is modulated by the application of a voltage on the conducting gate above the channel surface and insulated from it. Efforts are ongoing within many MOS integrated circuit manufacturing companies as well as at many universities and government laboratories to improve the speed and available drive currents with MOSFETs to reduce their power consumption, and to improve their reliability and radiation hardness for applications in harsher remote environments, including space.
FIG. 1 shows a conventional partially depleted SOI (silicon-on-insulator) MOSFET that has been provided to achieve some of the improvements in speed and drive currents that have been needed. The OSI transistor 10 includes a silicon substrate 12 on which a buried oxide layer 14 is provided. A body layer 16, made of silicon, forms the area in which the semiconductor devices are located. The SOI transistor 10 includes a source region 18, a drain region 20 and a gate 26 that is provided on a gate oxide layer 22. Spacers 24 are formed on the sidewalls of the gate 26 and are employed as masks during the source/drain implantation process.
One of the concerns of a traditional partially depleted SOI MOSFET, such as the SOI transistor 10 of FIG. 1, is the decrease in the threshold voltage Vt of the transistor 10 due to hot carrier effects. As is well known, hot carrier effects in a transistor generate electron/hole pairs. Driven by electric fields, the electrons drift towards the gate 26, while the holes tend to drift toward the buried oxide layer 14. This movement of the holes toward the buried oxide layer undesirably decrease the threshold voltage Vt of the transistor 10.
A plot of Ids vs. Vds is shown in FIG. 2 for a conventional SOI MOSFET transistor 10, such as that depicted in FIG. 1. As can be readily appreciated, the well-known "kink effect" as depicted in FIG. 2, is due to the holes that have drifted near the buried oxide, the uncontrolled kinking increasing the substrate bias and thereby decreasing the threshold voltage Vt.
One of the goals in semiconductor processing is to maximize the use of the available silicon area. This allows increased miniaturization of the electronic circuitry. In particular, it is desirable to maximize the drive current for a given silicon area.

Multi-channel transistor with tunable hot carrier effect


An electronic apparatus includes communication circuitry and processing circuitry. The communication circuitry receives first and second wireless signals from a first terminal when the electronic apparatus reaches first and second measurement points. The communication circuitry receives third and fourth wireless signals from a second terminal when the electronic apparatus reaches third and fourth measurement points. The processing circuitry estimates one or more first candidates of a position of the first terminal and one or more second candidates of a position of the second terminal. The processing circuitry specifies the position of the first terminal and the position of the second terminal.

A method for estimating a position of a terminal by using a Received Signal Strength Indicator (RSSI) between multiple wireless terminals is already known. This type of position estimation system is constructed, for example, by multiple electronic apparatuses (reference terminals) positioned at already-known coordinates, and multiple terminals (target terminals) positioned at unknown coordinates. The positions of target terminals are first estimated coarsely (first estimation processing) via RSSI measurements between the reference terminals and the target terminals, and are further estimated (second estimation processing) via additional use of RSSI information measured between the target terminals. Through this processing, the position estimation accuracy of the target terminals is improved.
This type of position estimation system needs multiple reference terminals positioned at fixed coordinates. Accordingly, only the positions of target terminals within the communication coverage of the reference terminals can be estimated. Thus, if the positioning area is widened, or the number of target terminals increases, a greater number of reference terminals needs to be provided. In addition, for the second estimation processing of the position estimation system, estimation processing needs to be repeated until the results are converged. For this reason, the amount of calculation is significant, and convergence itself is not assured.

Electronic apparatus, system including electronic apparatus, position estimation method


A fluid-filled vibration-damping mount of suspension type, wherein a lower open-end of a second mounting member is fluid-tightly closed by a first mounting member and a tapered elastic body interposed therebetween. An upper open-end portion of the cylindrical portion is closed by a flexible layer for forming a fluid chamber between the elastic body and the flexible layer, which is divided by a partition member into a pressure-receiving chamber defined by the elastic body and an equilibrium chamber defined by the flexible layer, which are mutually communicated through an orifice passage. A pair of elastic restricting projections bonded to the partition member at respective circumferential positions with a circumferential length smaller than a half of a circumference of the partition member, project toward a circumferential region defined between the elastic body and the second mount member, for narrowing the region.

1. Field of the Invention
The present invention relates generally to a fluid-filled vibration damping mount adapted to exhibit a vibration-damping effect on the basis of flow of a fluid sealed therein, and more particularly to such a fluid-filled vibration damping mount that is novel in construction and suitable for use as an engine mount, a body mount or other mounts for use in automotive vehicles.
2. Description of the Related Art
A suspension-type fluid-filled vibration damping mount is known as one type of fluid-filled vibration damping mounts each interposed between two members of a vibration system for flexibly connecting these two members in a vibration-damping or isolating fashion. As disclosed in JP-A-63-167142 and JP-B-2548050, the known suspension-type fluid-filled vibration damping mount elastically supports a vibrative member, e.g., a power unit of an automotive vehicle, with respect to a subject member, e.g., a body of the vehicle, whose vibration is to be damped by suspending the vibrative member from the subject member. FIG. 15 shows an example of the known suspension-type fluid-filled vibration damping mount, by way of example, in which a first mounting member 150 attachable to the power unit and a second mounting member 152 attachable to the body are elastically connected with each other by a tapered rubber elastic body 156 disposed between the first mounting member and a lower open-end portion of a vertically extending cylindrical portion 154 of the second mounting member 152 into which the first mounting member 150 is inserted so as to extend into the cylindrical portion 154 for fluid-tightly closing the lower open-end portion of the cylindrical portion 154 of the second mounting member 152. An axially upper end portion of the cylindrical portion 154 of the second mounting member 152 is fluid-tightly closed by a flexible layer 158, whereby a fluid chamber 160 is formed between and defined by the rubber elastic body 156 and the flexible layer 158. Within the fluid chamber 160, is disposed a partition member 162 extending in a diametric direction perpendicular to an axial direction of the cylindrical portion 154 of the second mounting member 152, while being supported at its peripheral portion by the second mounting member 152. With this arrangement, the fluid chamber 160 is fluid-tightly divided by the partition member 162 into two sections, i.e., a pressure-receiving chamber 164 partially defined by the rubber elastic body 156 and an equilibrium chamber 166 partially defined by the flexible layer 158. The pressure-receiving chamber 164 and the equilibrium chamber 166 are held in fluid communication with each other through an orifice passage 168.
When such a known suspension-type fluid-filled vibration damping mount is installed in position, a static load or weight of the vibrative member, e.g., the power unit, is applied between the first mounting member 150 and the second mounting member 152 in the axial direction, and a vibrational load is primarily applied between the first and second mounting members 150, 152 in the axial direction, as well. Thus, the known suspension-type fluid-filled vibration damping mount is tuned to exhibit a damping effect based on resonance or flow of the fluid through the orifice passage 168 to vibrations applied thereto in the axial direction.
However, the known suspension-type fluid-filled vibration damping mount may be subjected to vibration applied thereto in diametric directions perpendicular to the axial direction (hereinafter referred to as "axis-perpendicular directions, where appropriate), depending upon a state of installation thereof, for example. If the suspension-type fluid-filled vibration damping mount is used as an engine mount for an automotive vehicle, for example, the engine mount may be subjected to vibrational loads applied between the first mounting member 150 and the second mounting member 152 in the axis-perpendicular directions, e.g., in a driving or a longitudinal direction of the vehicle and/or in a lateral direction of the vehicle, when the vehicle is accelerated, runs over steps, goes through corners, or experiences any other possible driving conditions. Actually, the known suspension-type fluid-filled vibration damping mount has not been sufficiently examined in its damping capability in relation to vibrations applied thereto in the axis-perpendicular directions.
In view of the above, the present inventors have conducted extensive studied and researches on damping characteristics of the known suspension-type fluid-filled vibration damping mount upon application of vibrations thereto in the diametric directions, and it has been revealed that the known suspension-type fluid-filled vibration damping mount is incapable of exhibiting a desired damping effect with respect to vibrations applied thereto in the radial directions. In particular, the suspension-type fluid-filled vibration damping mount is susceptible to be considerably deteriorated in its damping capability at around a higher frequency range of input vibrations corresponding to an acceleration noise of 300–500 Hz, e.g., booming noises and chatter noises.


A printed wiring board design method including the steps of designing placement and wiring for circuit components based on circuit information on a mounting surface of the board; excluding a placement region and a wiring region for the circuit components from the mounting surface to thereby calculate a placement and wiring enable region for an EMC component in which the EMC component can be placed and wiring can be laid down; and calculating the placement and wiring range for the EMC component based on an EMC design rule from the calculated placement and wiring enable region for the EMC component. Thus, a printed wiring board design method is provided in which placement of and wiring for a new bypass capacitor or the like can be implemented and a region satisfying restraint items from the design rule can be clearly displayed as a new input enable region on a CAD screen.

1. Technical Field
This invention relates to a CAD system for designing a printed wiring board, a printed wiring board design method, a printed wiring board design device, and a method and device for an EMC design, applicable to the CAD system.
2. Description of Related Art
Electronic equipment in recent years has advanced the progress of downsizing, high functionality and digitalization, which has entailed an increase in unnecessary radiation noise exerting an influence on other electronic equipment of an electromagnetic wave radiated by the electronic equipment of interest, which has increasingly enhanced more and more the necessity for a measure to diminish the unnecessary radiation noise. Whereas, since there is a relationship of a trade-off between the measures to be taken and downsizing, EMC design has become technically more and more difficult to cope with every year.
Various noise reduction designs have been studied such as high frequency isolation of IC power supply wiring using an inductance element and a capacitance element on a digital circuit board, which is a source of generation of unnecessary radiation noise and a strip structure of signal wiring.
Especially, since a bypass capacitor inserted between the power supply terminal and the GND terminal of a digital IC not only stabilizes a high frequency variation in a power supply voltage generated in company with a switching operation of the IC by supplementing the variation with an accumulated charge, but also feeds back a high frequency component to the GND terminal of the IC to thereby play a role in confirming high frequency noise in the neighborhood of the IC, the inserted bypass capacitance has been widely known as the most basic and important means in the unnecessary radiation noise reduction for a circuit board, which leads to proposals offered on a printed wiring board design device using many of the schemes and tools concerning placement of a bypass capacitor and wiring.
For example, a proposal on an automatic placement, wiring devices offered in Patent document 1 (JP 05-205011) in which a board is divided into plural wiring regions and not only are densities of existing components and wires leveled over the regions, being made balanced therebetween, but the shortest wiring length is also achieved, and besides, another proposal on an automatic placement scheme is offered in Patent document 2 (JP 2000-67089) in which a projection area of components and wires is minimized.
The design device, however, is extremely insufficient with respect to the unnecessary radiation noise reduction of a circuit board. The reason why is such that, in the actual board design, a necessity arises for considerations to be given to many of design items such as an operating frequency of an IC, a thickness of a wiring layer or a wire and a capacity characteristic of a capacitor in addition to a distance between the IC and the bypass capacitor and a wiring length for reduction of EMC in order to reduce EMC. Therefore, the work becomes indispensable that design data is deliberately examined based on a design rule obtained by organizing the items to be considered, which is difficult and extremely time consuming, having led to a problem of inability in implementing a sufficient EMC design in a limited design time.
There has been contrived a method as a measure for improvement on such a problem in which placement and wiring data for a bypass capacitor to be inputted to a CAD system used for a printed wiring board design is checked in real time, and if the data falls outside of the allowable range, a warning message is displayed on a screen so that a designer is urged to improve the design to thereby confine the CAD data within the allowable range defined by the design rule. For example, FIG. 11 is a descriptive diagram showing a design flow on CAD according to the conventional method, wherein a designer compares design data with which placement and wiring are temporarily conducted with a design rule DB and component characteristics DB to thereby perform a pass/fail determination and if the determination is fail, a warning message is displayed on a screen.
Patent document 1.JP-A No. 05-205011Patent document 2.JP-A No. 2000-67089Patent document 3.JP-A No. 2001-125943Patent document 4.JP-A No. 2002-16337

Printed wiring board design method, program therefor, recording medium storing the program recorded therein, printed wiring board design device using them and CAD system

Matsushita Electric Industrial Co., Ltd.


A improved activated sludge system and method for treating wastewater containing contaminants is disclosed which offers a broad array of advantages over conventional activated sludge wastewater treatment systems, including smaller size, higher rates of operation, higher oxygen transfer efficiency, lower operating costs, and a substantially decreased level of excess sludge production. The improved activated sludge waste treatment system of the present invention has two processing tanks rather than the several tanks that are commonly found in activated sludge systems for treatment and sludge management equalizations, including anaerobic processes. The first processing tank is a contact tank which hosts a reaction which functions not merely to digest the maximum amount of contaminants, but instead to bind contaminants to the microorganisms through absorption, adsorption, precipitation, or digestion so that they can then be removed from the liquid in a solid/liquid separator. The activated sludge removed by the solid/liquid separator is then supplied to a digester tank containing a high concentration of activated sludge, where virtually complete digestion is achieved to minimize the volume of solids remaining. Activated sludge is provided from the digester tank to the contact tank to facilitate the reaction in the contact tank.

The present invention relates generally to the field of treatment of wastewater, and more particularly to an improved system and method for treating wastewater containing contaminants which system and method offer a broad array of advantages over conventional activated sludge wastewater treatment systems, including smaller size, higher rates of operation, high oxygen transfer efficiency, lower operating costs, and a decreased level of excess sludge production.
With an increased awareness of problems with water quality, particularly those caused by the discharge of wastewater from industrial sources, has come a demand for improved equipment and methods to treat wastewater prior to discharging it into a sewer, as surface water, or to other destination for effluent discharge. While such treatment systems and methods are generally not required to produce potable water, they are increasingly required by law to enhance the quality of wastewater prior to discharging it as effluent. For industrial waste, this treatment process must typically remove certain type of pollutants such as organic contaminants, nitrogen and phosphorus, metals, and suspended solids.
The first wastewater treatment systems were of simple design, with a single container or tank being used for both treatment of the wastewater and the removal of solids from the wastewater, typically by allowing them to settle out. These early wastewater treatment systems were not aerated, and typically generated foul odors as a byproduct of the process utilized by these systems. Over time, these early wastewater treatment systems evolved into systems which use a popular type of wastewater treatment process referred to as the activated sludge wastewater treatment method.
The activated sludge wastewater treatment system and method use an aeration tank which is followed by a solid/liquid separator which acts as a secondary clarifier to remove separated solids from the liquid, which is discharged by the system. As its name suggests, the contents of the aeration tank are aerated and mixed to facilitate an aerobic reaction (a reaction taking place in the presence of oxygen) which is facilitated by the presence of activated sludge. This activated sludge, which is an accumulation of microorganism-rich residue contained in the solids which are separated from the liquid in the solid/liquid separator, is seeded into the incoming wastewater in the aeration tank. In conventional activated sludge wastewater treatment systems, the concentration of activated sludge solids is typically 2,000 to 5,000 milligrams per liter in the aeration tank.
The aerobic reaction which takes place in the aeration tank includes three types of phenomenaxe2x80x94absorption, adsorption, and biological digestion. Absorption takes place when a contaminant is absorbed into the cell wall of the bacteria contained in the activated sludge. Adsorption, on the other hand, is a surface phenomenon which takes place when there is an interaction between a contaminant and the surface of the activated sludge whereby the contaminant adheres to the surface of molecules of the bacteria. Any one of these three phenomena will result in contaminants reacting with the bacteria contained in the activated sludge. Biological digestion takes place when the bacteria contained in the activated sludge consume waste constituents contained in the wastewater. Biological digestion can occur after the material has been absorbed or adsorbed.
As mentioned above, the reaction is an aerobic reaction occurring in the presence of oxygen, which decreases both the amount of time required for the reaction to occur and the level of foul odors produced by the reaction. Typically, the aeration and mixing may be produced by injecting compressed air or oxygen into the mixture, typically through diffuser devices located near the bottom of the aerator tank. As the air bubbles to the surface of the mixture, the diffused air provides both oxygen to the mixture and a vigorous mixing action. The amount of material contained in the wastewater may be characterized by the xe2x80x9cchemical oxygen demandxe2x80x9d or COD of the material. A chemical oxygen demand of one pound indicates that the material contained in the wastewater requires one pound of oxygen to degrade.
Air may also be added by the churning action of mechanical mixers located near the surface of the mixture contained in the aeration tank. In still another variation, mixing of the contents of the aeration tank may be caused by hydraulic pumping in which liquid is pumped out of the tank and back in through nozzles causing highly efficient mixing of the contents of the aeration tank. In a still further variation, air nozzles may be arranged around the liquid nozzles to further stimulate the mixing and simultaneously provide oxygen to the mixture. Still further variations include processes known as extended aeration and contact stabilization, both of which omit the primary settling step, and high-purity oxygen aeration, which can substantially reduce both the aeration time and the size of the aeration tank.
The conditions which are thus provided in the aeration tank promote the growth of the microorganisms introduced in the activated sludge with the resultant reaction removing contaminants from the wastewater. In conventional activated sludge technology, a predetermined period of time related to the strength of the wastewater and treatment objectives is required for the mixture to react in the aeration tank in a batch flow process. This time is required to allow the bacteria in the aeration tank to react with the contaminants contained in the wastewater, with much of the material being oxidized by the microorganisms. Generally, in conventional activated sludge processes, the contaminants are completely digested in the aeration tank.
The mixture is then allowed to flow from the aeration tank into the solid/liquid separator, which can be any of a number of different mechanical devices, all of which are well known in the art. The solid/liquid separator may be as simple as a secondary clarifier, which allows activated sludge to settle out by gravity. The clean liquid then overflows from the clarifier and it is discharged as secondary effluent, while the activated sludge may be separated out in a settling tank. The bacteria will tend to clump together and settle to the bottom of the settling tank, from which the activated sludge may be pumped out.
Some of the activated sludge will be recirculated back into the aeration tank, with this sludge being referred to as xe2x80x9creturn activated sludgexe2x80x9d or RAS. The microorganisms contained in the return activated sludge are thus well acclimated to the environment in the aeration tank. The remaining activated sludge is treated and disposed of in a conventional solids processing technique which is well known to those skilled in the art. This sludge is referred to as xe2x80x9cwaste activated sludgexe2x80x9d or WAS. In conventional activated sludge technology, the waste activated sludge may amount to as much as seventy percent of the sludge recovered in the solid/liquid separator.
The amount of excess activated sludge which is generated by an activated sludge waste treatment system may be controlled by a term referred to as xe2x80x9csolid retention timexe2x80x9d or SRT, which is the amount of time an average particle of solid material remains in the waste processing system. The solid retention time is inversely proportional to the relative volume of excess activated sludge which must be disposed of. Conventional extended activated sludge waste processing systems (designed for surface water discharge of effluent) have a solid retention time of approximately twenty days.
The excess solids produced may be determined by the yield of the activated sludge process multiplied by the mass of the contaminants removed. The yield may be measured in units of pounds of xe2x80x9cchemical oxygen demandxe2x80x9d or COD, which is a term commonly used to measure the amount of contaminants which are removed. Conventional extended activated sludge waste treatment systems produce a yield of approximately 0.25 pounds of xe2x80x9ctotal suspended solidsxe2x80x9d or TSS of excess activated sludge per pound of chemical oxygen demand of yield. Less conservatively operated systems can produce yields of 0.7 pounds of total suspended solids per pound of chemical oxygen demand removed.
The waste activated sludge is typically accumulated, and may be further biologically processed and/or dewatered prior to its ultimate disposal. When stabilized, the waste activated sludge does not have an offensive odor, and can be handled without the requirement for special procedures. While the waste activated sludge thus does not constitute a health hazard, it will be appreciated that its removal does constitute a significant part of the cost of the wastewater treatment process. Similarly, while the waste activated sludge systems and methods currently known in the art present an advantageous way to remove contaminants from wastewater, they do, however, present a number of disadvantages as well.
First, presently known waste activated sludge systems are relatively large in size and therefore present a significant cost to initially purchase and install. In addition, the size of such presently known systems also mandates a relatively large amount of space in which to install them. In addition, another limitation of presently known waste activated sludge systems is that they can only be operated at a relatively low rate in order to achieve treatment objectives, with higher rates of operation resulting in reduced effectiveness of the systems. Also, as noted above, presently known waste activated sludge systems produce a substantial amount of waste activated sludge which must be disposed of. This high disposal burden presents both storage problems and a significant cost to transport the sludge away for disposal.
In addition, a substantial amount of energy is required in order to produce sufficient oxygen to drive the reaction in the aeration tank. These costs result either from electrical energy required to produce compressed air, or from the cost of purchasing oxygen which may be dispensed into the aeration tank. Another problem of conventional waste activated sludge systems is that they have only limited capacity to deal with spills; for example, if a substantial amount of milk is spilled at a dairy, a conventional waste activated sludge system will either have to be radically oversized to deal with the spill, or it will simply not be able to cope with a large volume spill such as this. Finally, operating a waste activated sludge system is a relatively complex process with a number of variables; it would be preferable to have a simpler system if possible.
It is accordingly the primary objective of the present invention that it provide an improved waste processing system which is smaller and therefore less expensive to initially purchase and install than a conventional waste activated sludge system. It is a closely related objective of the waste processing system of the present invention that it be capable of operating at a higher rate than comparable conventional systems to deal with increased loads of contaminants, or to produce higher quality effluent, or both. It is an additional objective of the waste processing system of the present invention that it produce a greatly reduced amount of sludge, thereby substantially reducing the cost of operation of the system.
It is still another objective of the waste processing system of the present invention that it require less energy to provide oxygen to the reaction to further reduce operating costs, and that it do so without adversely affecting either the reaction itself or the amount of time required to react the materials in the waste processing system. It is a further objective of the waste processing system of the present invention that it be capable of handling high-volume spills of highly concentrated biomaterials, thereby being capable of fully and effectively treating such spills without disrupting the normal operation of the waste processing system. It is a still further objective of the waste processing system of the present invention that it present a simplified operating process which is easy to operate and which presents relatively few potential problems in its day-to-day operation.
The waste treatment system of the present invention must also be of construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughtout its operating lifetime. In order to enhance the market appeal of the waste treatment system of the present invention, it should also be of inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives be achieved without incurring any substantial relative disadvantage.
The disadvantages and limitations of the background art discussed above are overcome by the present invention. With this invention, instead of having a single tank in which activated sludge reaction takes place with subsequent solids processing occurring in other tanks, two tanks having very different environments and different purposes are utilized in a waste processing system in order to achieve all of the objectives mentioned above without incurring a single significant disadvantage. These tanks are a contact tank in which an initial reaction directed to removing the contaminants from the solution occurs, and a digester tank having a very high concentration of activated sludge solids in which essentially all of the organic contaminants are digested. Located between the contact tank and the digester tank is a solid/liquid separator, which may be of virtually any conventional design.
The process utilized by the waste processing system of the present invention operates on a novel principle whereby the objective of treatment in the contact tank is not to digest most or all of the organic contaminants in the wastewater, but rather to facilitate the removal of most or all of the contaminants from suspension in the wastewater by using the microorganisms contained in the activated sludge. Thus, by a combination of absorption, adsorption, and digestion, or by precipitation, the activated sludge treatment occurring in the contact tank is focused on the removal of the contaminants from suspension in the wastewater so that they can be separated out in the solid/liquid separator. Thus, wastewater is introduced to the contact tank together with an appropriate amount of waste activated sludge.
The concentration of activated sludge solids in the mixture contained in the contact tank can vary approximately in 200 to 10,000 milligrams per liter, with a level of approximately 2,000 milligrams per liter being typical. For a given level of contaminants in wastewater, the concentration of activated sludge solids in the mixture in the contact tank is substantially lower than the concentration required in a conventional activated sludge aeration tank. Typically, the concentration of activated sludge solids in the contact tank is between approximately ten and fifty percent of the level required in an aeration tank to attain the same level of contaminant removal from similar quality wastewater.
The practical effect of this is that the loading rate of the contact tank is between approximately two and ten times higher than the rates which are achievable in a conventional activated sludge aeration tank. What this means in plain language is that the contact tank of the present invention is capable of removing a substantially higher level of contaminants from wastewater than has previously been possible in conventional activated sludge aeration tank waste treatment systems.
In the preferred embodiment, the contact tank has both mixing and aeration in order to stimulate the rapid removal of contaminants from the wastewater. The mixing and aeration may be achieved by use of air or oxygen pumped into the contact tank, or by mechanical mixing, or both. Alternately, hydraulic mixing may be used instead of mechanical mixing, together with the introduction of air to provide oxygen to facilitate the reaction. The process configuration can also be used in an aerobic mode, an anaerobic mode (a reaction occurring in the absence of oxygen), an anoxic mode (a reaction occurring in the absence of oxygen but with other electron donors such as nitrates, nitrites, or sulfates), or in any combination of these modes occurring consecutively where aeration can be continuous, intermittent, or not used at all. Mixing and aeration conditions can be varied to facilitate desired physical, chemical, and biological reactions.
It should be noted that the contact tank of the present invention is capable of operating in batch mode, continuous mode, or semi-continuous mode, all with equally high quality results. Following the reaction of the wastewater and the waste activated sludge in the contact tank, a high level of the contaminants contained in the wastewater have either been absorbed by, adsorbed to, or digested by the microorganisms contained in the activated sludge, or precipitated into the mixed solution. Thus, when the wastewater is directed into the solid/liquid separator, the microorganisms together with a high percentage of the contaminants are removed from the wastewater, with the cleansed water being discharged from the solid/liquid separator as effluent.
In another significant differentiation from previously noted aeration tank waste treatment technology, all of the particulates which are separated in the solid/liquid separator are directed into the digester tank. As will be appreciated following a brief discussion of the operation of the digester tank, the production of particulates by the waste processing system of the present invention is so much lower than that of previously known aeration tank waste treatment systems that it is not necessary to continuously divert a large portion of the solids produced by the solid/liquid separator.
The concentration of activated sludge solids in the digester tank is quite high, generally being on the order of 5,000 to 100,000 milligrams per liter, with 40,000 milligrams per liter being typical. In fact, the only limitation on the concentration of activated sludge solids in the digester tank is that the mixture must be of sufficient viscosity as to be amenable to being pumped. In the preferred embodiment, whenever the concentration of activated sludge in the digester tank is so high that the mixture may not be easily pumped, it may be watered down somewhat by directing a sufficient quantity of wastewater into the digester tank so as to improve the pumpability of the mixture.
In the preferred embodiment for an aerobic reaction, the digester tank also has both mixing and aeration in order to stimulate the rapid digestion of contaminants contained in the activated waste mixture. The mixing and aeration may be achieved by use of air or oxygen pumped into the digester tank, or by mechanical mixing, or both. Alternately, hydraulic mixing may be used instead of mechanical mixing, together with the introduction of air to provide oxygen to facilitate digestion. The mixing and aeration conditions may be varied to facilitate desired physical, chemical, and biological reactions. Like the contact tank, the digester tank can be operated in an aerobic mode, an anaerobic mode, an anoxic mode, or in any combination of these modes occurring consecutively where aeration can be continuous, intermittent, or not used.
In many embodiments of the present invention, the size of the digester tank will be substantially larger than the size of the contact tank. While this is not necessary per se, it is generally the case due to the fact that the increased efficiency of the reaction process in the contact tank makes it possible to have a contact tank which is substantially smaller than the aeration tanks used by previously known activated waste treatment processes. In addition, since it is an objective of the improved waste processing system of the present invention to create an environment in the digester tank to take the digestion process to the maximum level possible, and to ultimately reduce solid waste to the minimum level possible, having a larger digester tank is advantageous.
The completion of the digestion process in the digester tank thereby tremendously reduces the volume of excess activated sludge solids which must be disposed of. This reduction is produced by the large xe2x80x9csolid retention timexe2x80x9d or SRT, which is the amount of time an average particle of solid material remains in the waste processing system. The solid retention time is inversely proportional to the volume of excess activated sludge solids which must be disposed of. The waste processing system of the present invention has a solid retention time in excess of 200 days, and has produced excess activated sludge yields of less than 0.05 pounds of total suspended solids per pound of chemical oxygen demand removed. In addition, the waste processing system of the present invention also has a higher oxygen transfer efficiency, resulting in additional savings in operating costs.
The processing in the contact tank is maintained by pumping sufficient activated sludge from the digester tank into the contact tank. As mentioned above, the concentration of activated sludge required in the mixture contained in the contact tank is substantially lower than the concentration required by previously known aeration tank waste treatment systems. The activated sludge contained in the digester tank is monitored to periodically check the concentration of bacteria contained therein. Since essentially all of the digestible matter is consumed in the digester tank, the level of indigestible matter will eventually build up to the point where it reduces the concentration of the bacteria in the digester tank to an unsatisfactory level. It is at this point that excess activated sludge will typically be removed from the digester tank.
In alternative embodiments of the waste processing system of the present invention, a number of other features may be utilized. It may be desirable to provide conditioning agents to enhance or optimize the processing in the contact tank, the solid/liquid separator, or the digester tank. For example, it may be desirable to introduce a conditioning agent into the contact tank in order to maintain an optimal level of pH to facilitate the reaction of the bacteria in the contact tank. This may be accomplished by measuring the pH in the contact tank and pumping a sufficient amount of a first conditioning agent into the contact tank in order to optimize the pH in the contact tank.
With some kinds of solid/liquid separators, it may be desirable to introduce a conditioning agent to enhance separation of the solids from the liquid in the separator. For example, if a dissolved air floatation separator or DAF is used, it may be desirable to use a chemical flocculent. Dissolved air floatation separators, which use air bubbles to entrain clumps of solids contained in the liquid, may use a flocculent material which causes the solids to initially aggregate. Such flocculent are typically polymers such as a cationic emulsion polymer, which has large organic molecules which, when dispersed in the wastewater prior to its introduction into the dissolved air floatation separator, facilitates bridging between bacterial solids through an electrical charge phenomenon.
In addition, it may be useful to provide supplements to the contact digester tank, either using nutrients or additional microorganisms to enhance the environment in the digester tank. The addition of a second type of microorganism which will selectively consume primary microorganisms which have died may be useful. Nutrients which may be added to increase the efficiency of digestion include nitrogen, which may comprise fertilizer, urea, or ammonium chloride. Precipitation agents may be added to either tank to remove chemical species, such metals or nutrients.
Finally, it may be desirable to add enzymes or surfactants to the contact tank or the digester tank or both to improve the reaction process to remove contaminants from the wastewater. The addition of surfactants may help the absorption or adsorption processes. The addition of enzymes may enable a modification of the structure of contaminants making them more amenable to the reaction process. For example, the addition of an enzyme may make it easier to remove a food oil from wastewater by solubilizing the oil.
It may therefore be seen that the present invention teaches an improved waste processing system which is smaller and therefore less expensive to initially purchase and install than a conventional waste activated sludge system. The waste processing system of the present invention is also capable of operating at a higher rate than comparable conventional systems to deal with increased loads of contaminants, or of producing higher quality effluent, or both. The waste processing system of the present invention also produces a greatly reduced amount of sludge, thereby substantially reducing the cost of operation of the system.
The waste processing system of the present invention requires less energy to provide oxygen for the reaction, thereby further reducing operating costs, and it does so without adversely affecting either the reaction itself or the amount of time required to react the materials in the waste processing system. The waste processing system of the present invention is also capable of handling high-volume spills of highly concentrated biomaterials, and is thereby capable of fully and effectively treating such spills without disrupting the normal operation of the waste processing system. The waste processing system of the present invention presents a simplified operating process which is easy to operate and which presents virtually no significant problems in its day-to-day operation.
The waste processing system of the present invention is of a construction which is both durable and long lasting, and which will require little or no maintenance to be provided by the user throughout its operating lifetime. The waste processing system of the present invention is also of inexpensive construction to enhance its market appeal and to thereby afford it the broadest possible market. Finally, all of the aforesaid advantages and objectives are achieved by the waste processing system of the present invention without incurring any substantial relative disadvantage.

Activated sludge wastewater treatment system and method