A method for the extraction, separation, fractionation and purification of biopolymers from plant materials using supercritical and/or subcritical solvent extractions is disclosed. Specifically, the process can be used for the separation of resins and rubber from guayule shrub (Parthenium argentatum), and other rubber and/or resin containing plant materials, using supercritical solvent extraction, for example supercritical carbon dioxide extraction. Additionally, polar and/or non-polar co-solvents can be used with supercritical carbon dioxide to enhance the selective extraction of resins and rubbers from the shrub.

Guayule is a desert shrub native to the southwestern United States and northern Mexico and which produces polymeric isoprene essentially identical to that made by Hevea rubber trees (e.g., Hevea brasiliensis) in Southeast Asia. As recently as 1910 it was the source of half of the natural rubber used in the U.S. Since 1946, however, its use as a source of rubber has been all but abandoned in favor of cheaper Hevea rubber and synthetic rubbers. However, demand for natural rubber is expected to produce shortages of that material in the future and rubber prices are expected to rise significantly. Natural rubber having lower heat hysteresis is required for many kinds of tires and amounts to about 35% of U.S. rubber use.
As an alternative to synthetic rubber sources, attention is being directed to the production of hydrocarbons in plants such as guayule (Parthenium argentatum). Guayule normally yields one half ton to one ton of rubber per acre in cultivation when, after two years, the entire plant is harvested and processed. Guayule plants store latex in tiny inclusions in the bark, making harvest of the outer fibrous layers, or bagasse, of the plant, desirable.
Using traditional techniques, as much as 95% of the available natural rubber may be recovered from plant materials, using parboiling, which coagulates the latex in the cells, followed by a milling step in a caustic solution to release the rubber. This traditional process then causes the milled bagasse to sink to the bottom of the processing vessel and allows resin to float to the surface for collection. More specifically, in traditional processes, resins from plant materials are obtained by solvent extraction with polar solvents such as alcohols, ketones, and esters. A commonly used solvent for extracting the guayule resin is acetone. The resin is recovered from the solution by evaporating the solvent. The rubber from the shrub is generally extracted using hydrocarbon solvents such as hexane, cyclohexane or toluene. Such processes are normally very expensive and not environmentally friendly. A water floatation method has also been used for the extraction of rubber.
Further, using traditional methods of guayule processing, plant material is prepared by initially grinding it into small particles. Generally, the entire plant is fed whole, that is, with the leaves thereon as well as dirt or foreign debris, into a grinding apparatus, for example, a hammermill. The ground material can be flaked, that is crushed, by adding to a two-roll mill or other conventional equipment, which ruptures the rubber-containing cells. The communited plants are subjected to a resin-rubber solvent system. The solvent system contains one or more solvents which extract the resin as well as the rubber from the guayule-type shrub. Examples of single-solvent systems include halogenated hydrocarbons having from 1 to 6 carbon atoms, such as chloroform, perchloroethylene, chlorobenzene, and the like; and aromatic hydrocarbons and alkyl-substituted aromatic hydrocarbons having from 6 to 12 carbon atoms, such as benzene, toluene, xylene, and the like.
This solvent system typically contains one or more polar resin solvents as well as one or more hydrocarbon rubber solvents. Typical polar resin solvents include alcohols having from 1 to 8 carbon atoms, such as methanol, ethanol, isopropanol and the like; esters having from 3 to 8 carbon atoms such as the various formates, the various acetates and the like; ketones having from 3 to 8 carbon atoms, such as acetone, methyl ethyl ketone, and the like. Typical non-polar hydrocarbon rubber solvents include alkanes having from 4 to 10 carbon atoms, such as pentane, hexane, and the like; and cycloalkanes having from 5 to 15 carbon atoms, such as cyclohexane, decalin, the various monoterpenes, and the like. Although the two types of solvents can form a two-phase system, they often form a single phase when utilized in proper proportions. One manner of adding different type solvents to the shrub is separately, but simultaneously. However, they are generally prepared as a mixture and added as such.
Accordingly, numerous combinations of a polar resin solvent and a hydrocarbon rubber solvent can exist. A specific solvent system is an azeotropic composition of approximately 80% by weight of pentane, more specifically 78.1% by weight, and 20% by weight of acetone, more specifically 21.9% by weight. The ratio by weight of solvent to the amount of shredded shrub can be any amount sufficient to generally extract most of the rubber and resin, as for example from about 1 part by weight of solvent up to about 20 parts by weight of solvent for each 1 part by weight of shrub, and preferably about 3 parts by weight of solvent to 1 part by weight of shrub. The rubber-resin miscella so obtained typically contains about 1 to 25% by weight of total solids, that is resin plus rubber, and preferably about 9 to 18% by weight of total solids with the amount of resin by weight being from about 1 to about 3 parts for every 1 part by weight of rubber.
Furthermore, traditional methods of plant processing have been hampered by the use of these highly toxic compounds and cumbersome processes. For example, in prior industrial operations, hexane and heptane solvents have been used in the solvent extraction of oil-containing vegetable matter. The extraction apparatus typically includes vertical extraction towers, screw extractors and bucket extractors. With current equipment, several extraction stages are necessary in order to circulate the miscella and attain sufficient wetting of the material to be extracted, thereby requiring the use of a higher proportion of solvent.
In addition, overall energy consumption inherent in previous slurry separations has been excessive, if not prohibitive. Processing of this type of plant material traditionally requires wetting to form a liquid slurry, a high amount of heat, and a difficult separation of the solvent from the extracted oil and defatted meal. Complete removal of solvents, such as hexane, from the spent botanical residue is practically impossible by conventional steam stripping techniques.
The method of using gaseous solvents at both supercritical and subcritical conditions, such as carbon dioxide and propane, is also problematic. In these systems, the operating pressure must exceed 125 psi to remain in liquid state and even higher if temperatures are elevated. Because of the difficulties in working at high pressure, multiple extraction vessels are required, which limits the speed and efficiency of these extractions. Further, it is difficult to maintain pressures consistently, resulting in freezing, gumming, or poor separation of the extracted materials, which may clog the system. Also hydrolysis of lipids or inadequate processing may decrease the yield.
In an effort to overcome some of these difficulties, in recent years cellulose degradation methods using enzymes such as pectin hydrolases, cellulose, alkalis, or acids have been taught. In addition, the prior art teaches a number of processes for production of glucose from cellulose in the presence of lignin. Crushing and extraction processes for hydrocarbon-containing plants have also been taught. However, prior art processes have not dealt with the problem of obtaining hydrocarbons from hydrocarbon-containing plants wherein the hydrocarbon content is low and is contained in laticifer cells.
Additionally, traditional extraction methods make it difficult and inefficient to extract resins from plant materials, particularly from the bagasse. Bagasse is difficult to extract with hydrocarbon solvents for several reasons. First, the compounds of interest are adhered in the botanical matrix, so the material needs to be ground finely for accessibility of the solvent to these compounds. Second, the compounds of interest are significantly different in polarity, namely, resins are polar and rubber is non-polar. This makes it difficult to utilize a single solvent system, and therefore, most extraction processes utilize a two-solvent extraction system, e.g., acetone for resin extraction followed by cyclohexane for rubber extraction. Third, ground bagasse has physical properties that translate into very slow percolation rate for liquid solvents. Fourth, contact with oxygen can oxidize the rubber extract in other processes.
Thus, it has been difficult to design a commercially viable process for the extraction of bagasse with liquid solvents. Additionally, due to the problems with slow percolation rate through the bagasse, traditional processing methods have resulted in a low commercial output, and much of the unused bagasse contains residual solvents. The residual solvents in the remaining bagasse pose environmental safety hazards and make the excess bagasse mostly unusable for other applications. Finally, the low output makes these prior art extraction processes not commercially viable methods of extraction.
Therefore, a need exists for a cost-effective, efficient, and environmentally friendly method of extracting and fractionating rubber and resins from plant materials, such as guayule.

Extraction and fractionation of biopolymers and resins from plant materials


The present invention describes methods and apparatus for electromagnetic band gap structure synthesis. An exemplary embodiment of the present invention provides a method of electromagnetic band gap structure synthesis, which includes the step of providing a set of desired characteristics for an electromagnetic band gap structure. Furthermore, the method includes generating populations of patch shape members with a genetic algorithm routine and solving one or more of patch shape members of the populations with an electrodynamics modeling technique. Thereafter, the method includes the step of converting the output of the electrodynamics modeling technique into a set of response data for one or more of the patch shape members and calculating a fitness level for one or more of the sets of response data in comparison to the set of desired characteristics for the electromagnetic band gap structure. Next, the method includes the step of determining whether the fitness level of one of the patch shape members is within a predetermined tolerance. Subsequently, if none of the patch shape members provides a fitness level within the predetermined tolerance, then the steps of generating, solving, converting, calculating, and determining are repeated.

Explosive developments in microelectronic processing speeds, chip densities, and transmission bandwidths have enabled many new advanced electronic devices. While these high-speed and highly compact devices have created new applications, the design and implementation of these devices have been significantly hindered by increased problems from noise and interference. Problems due to noise are especially limiting in devices having both analog circuits and digital circuits, otherwise known as mixed signal systems.
Mixed signal systems are used in numerous electronic devices, including wireless devices and other transceivers. For example, an ultra wide band (UWB) transceiver can be used with a mixed signal system, which transmits and receives data over a relatively high frequency band. FIG. 1 provides an illustration of a UWB transceiver 105 configured on the same board as digital circuits. As shown in FIG. 1, the modulator 110 and demodulator 115 are configured to either receive input from, or output data to, the digital circuitry resident on the same board as the UWB transceiver 105. The low-noise amplifier (LNA) 120 of the UWB transceiver 105 is extremely sensitive to noise as it is located at the front-end of the demodulator and used to detect low power signals. More particularly, the LNA 120 is sensitive to noise spikes generated by the digital circuits in or close to the operating frequency of the UWB transceiver 105. Therefore, noise spikes from the digital circuits have the capability of de-sensitizing the UWB transceiver 105 and compromising the functionality of the UWB transceiver 105.
The need for noise suppression to preserve the precision and functionality of the mixed signal system containing the UWB transceiver 105 shown in FIG. 1 is just one example of the desire for noise suppression in many electronic applications. An additional example can be found in systems using both analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), components contained in the majority of wireless transmission devices. DACs convert complex digital signals for analog transmission and ADCs process complex analog signals for digital processing. To meet the needs of present and future-generation wireless systems, ADCs and DACs must perform at RF rates and with outstanding linearity. Therefore, the current trend for ADCs is towards obtaining high-speed and high resolution. This trend makes ADCs more sensitive to noise.
FIG. 2 provides a block diagram of the layout of a mixed signal wireless system 205 containing both analog and digital circuitry, including a series of ADCs 210 and 215 and DACs 220 and 225. As shown in FIG. 2, the analog components exist within the same layout as the digital components. As high-speed and high-resolution ADCs are highly sensitive, a noise spike from digital circuits can affect ADC performance. This high sensitivity has resulted in a significant reduction in the acceptable noise margins for the mixed signal wireless system 205. Therefore, many prior art devices implement measures that attempt to isolate the sensitive RF/analog circuits, such as those in wireless system 205, from the power and ground noise generated by the digital circuits.
One noise suppression technique used in the prior art is to split the power/ground plane by inserting a slot between the planes. The slot in the power/ground plane can partially block the propagation of power/ground noise. This prior art technique is ineffective for many applications, however, because a portion of the electromagnetic energy can still couple through the slot at high frequencies. Due to the electromagnetic coupling, this method only provides a marginal isolation (i.e., −20 dB to −60 dB) at high frequencies (i.e., above 1 GHz) and becomes ineffective as the sensitivity of the RF circuit increases and the operating frequency of the system increases. At low frequencies (i.e., below 1 GHz), the split plane can provide an isolation of −70 dB to −80 dB.
In addition to the failure to be effective at high frequencies, prior art systems with split power/ground planes are ineffective for systems requiring the same DC power supply. As systems become more complex, multiple power supplies become a luxury a designer cannot afford. An alternative technique used in the prior art for systems requiring the same DC power supply is to use ferrite beads to attempt to suppress the power/ground noise. Ferrite beads are non-conductive ferrimagnetic ceramic compounds, which essentially act as a high impedance to high frequency EMI/RFI electronic noise. The absorbed energy is converted to heat and dissipated by the ferrite. Thus, ferrite beads can be included in the layout of the mixed signal systems using the same DC power supply for both the analog circuits and the digital circuits. Similar to the prior art technique of splitting the power/ground plane, however, the prior art technique of using ferrite beads for power/ground noise isolation is not effective at high frequencies. Therefore, as the operation frequencies of mixed signal systems increase, the need for a technique to adequately and efficiently suppress noise at these high frequencies also increases.
An alternative noise suppression technique involves the use of band gap structures. For example, photonic band gap structures are used for electromagnetic (EM) wave applications. Photonic band gap structures can have a two- or three-dimensional periodic array structure in which the propagation of EM waves is governed by band-structure types of dispersion relationships. These photonic band gap structures provide electromagnetic analogs to electron-wave behavior in crystals. Photonic band gap structures can also be formed with local disturbances in the periodic array structure, thereby generating defect or cavity modes with frequencies within a forbidden band gap, for use in forming high-Q resonators or filters.
Electromagnetic band gap structures are another type of band gap structure that have been implemented in many prior art devices in an attempt to combat error due to noise. Electromagnetic band gap structures are the microwave counterpart of the photonic band gap structure. Electromagnetic band gap structures have become very popular due to their advantageous applications for suppression of unwanted electromagnetic transmission and radiation in the area of microwave and millimeter waves. Electromagnetic band gap structures are periodic structures in which the propagation of electromagnetic waves is restricted in a specified frequency band.
Electromagnetic band gap structures can be used in a variety of applications. For example, electromagnetic band gap structures can enhance the performance of planar antennas by placing an electromagnetic band gap shield structure proximate to a microstrip patch. The inclusion of the electromagnetic band gap structure proximate a microstrip patch can improve the front to backward radiation ratio of the antenna. Additionally, an electromagnetic band gap structure can be incorporated as the ground plane for a rectangular microstrip antenna for enhanced performance. In filter applications, electromagnetic band gap substrates can be incorporated to achieve greater isolation. Furthermore, electromagnetic band gap structures have proven effective in isolating the power/ground noise in mixed signal systems. In fact, electromagnetic band gap structures have proven effective in isolating the power/ground noise even in systems that use the same DC power supply.
Despite the potential benefits of electromagnetic band gap structures, conventional implementation of these structures is costly and prohibitive. More particularly, the most popular method of electromagnetic band gap structure design in the prior art involves a manual process that is time consuming, computationally expensive, and unreliable. FIG. 3 provides a block diagram of the conventional manual process of electromagnetic band gap structure synthesis 305. The manual process involves devising a set of input specifications 310 for the electromagnetic band gap structure. A prototype electromagnetic band gap structure is then created in step 315 based on estimations in view of these input specifications. The prototype electromagnetic band gap structure is then solved 320, with either a circuit simulator or electromagnetic simulator. The solved results of the prototype electromagnetic band gap structure are then compared in step 325 with the input specifications to determine the sufficiency of the estimated prototype electromagnetic band gap structure. Should the prototype electromagnetic band gap structure be insufficient, the prototype electromagnetic band gap structure is modified 330 in accordance with the insufficiencies shown in the test. Thereafter the modified prototype electromagnetic band gap structure is solved 320 and the results are compared 325 with the input specifications. The process of modifying 330, solving 320, and comparing 325 are repeated until the electromagnetic band gap structure sufficiently complies with the input specifications 310 or no acceptable result is obtained.
The conventional manual method of electromagnetic band gap structure synthesis 305, shown in FIG. 3, suffers from many drawbacks. Significantly, the number of iterations required for the manual method of electromagnetic band gap structure synthesis 305 is often relatively large. Therefore, one must perform numerous iterations of the manual process to achieve a workable electromagnetic band gap structure. Additionally, there is no upper bound on the number of iterations required by the manual method. Furthermore, many input specification sets have no solution. Therefore, a designer implementing the manual method of electromagnetic band gap structure synthesis 305 may go through hundreds of iterations of the method without ever achieving a satisfactory electromagnetic band gap structure. The manual method of electromagnetic band gap structure synthesis 305 is computationally expensive and time consuming. Thus, while electromagnetic band gap structures have the potential to present many advantages in noise suppression applications, there is no method in the prior art that enables reliable and efficient synthesis of these electromagnetic band gap structures.
Therefore, it would be advantageous to provide an apparatus and method for efficiently and effectively synthesizing electromagnetic band gap structures.
Additionally, it would be advantageous to provide an apparatus and method to automatically synthesize an electromagnetic band gap structure.
Additionally, it would be advantageous to provide an apparatus and method to automatically determine when the synthesis of an electromagnetic band gap structure with a particular set of band gap parameters is not possible.

Systems and methods for electromagnetic band gap structure synthesis


A photo mask includes an asymmetrical diffraction grating pattern in which diffraction efficiencies of plus primary diffracted light and minus primary diffracted light are different, the asymmetrical diffraction grating pattern including a shielding portion which shields light, a first transmitting portion which transmits light, and a second transmitting portion which transmits light, a ratio of widths of the shielding portion, the first transmitting portion, and the second transmitting portion being n11 where n is a positive real number except 2, the asymmetrical diffraction grating pattern approximately satisfying 163°≦360°/(n+2)+θ≦197° where θ (≠90°) indicates an absolute value of a difference between a phase of the light transmitted through the first transmitting portion and that of the light transmitted through the second transmitting portion, and a reference pattern for obtaining an image as a reference for measuring a shift of an image of the asymmetrical diffraction grating pattern.

1. Field of the Invention
The present invention relates to a photo mask for use in a semiconductor field, a focus measuring method using the mask, and a method of manufacturing a semiconductor device.
2. Description of the Related Art
A tolerance of focus permitted in lithography has been narrowed as a design rule of a semiconductor device to be manufactured is miniaturized. When the tolerance of the focus is narrowed, flatness of a wafer and specifications with respect to curvature of field of an exposure apparatus has been strict. Moreover, a high-precision measuring method of the focus, curvature of field and the like using a resist pattern transferred onto the wafer has become important.
A focus test mask comprising an asymmetrical diffraction grating pattern and a reference pattern, and a focus measuring method using the focus test mask and utilizing a phenomenon in which an image of the asymmetrical diffraction grating pattern shifts in proportion to a focus value have been known (Jpn. Pat. No. 3297423). Since the focus measuring method has a high measurement precision having a measurement error of 5 nm or less, and the measuring is simple, the method can be said to be one of most promising techniques at present.
The asymmetrical diffraction grating pattern comprises a shielding portion, a transmitting portion, and 90° phase grooved portion. A line width ratio of the shielding portion, transmitting portion, and 90° phase grooved portion is ideally 2:1:1. On the other hand, an alternating type phase shift exposure mask including a pattern (device pattern) for manufacturing an actual semiconductor product comprises a 180° phase grooved portion.
A method of manufacturing an exposure mask comprising the asymmetrical diffraction grating pattern and the device pattern includes a step of forming the 90° phase grooved portion, and a step of forming the 180° phase grooved portion. When these two steps are performed, a manufacturing process is complicated, and manufacturing costs remarkably rise. This respect will be further described hereinafter.
The step of forming the 180° phase grooved portion includes a step of forming a trench vertically in the surface of a quartz glass substrate by a dry process (e.g., a vertical etching process such as an RIE process); and a step of expanding the trench by predetermined amounts in a lateral direction and a vertical direction by a wet process (isotropic etching process). A sum of grooved amounts by the dry and wet processes is a grooved amount by which a phase of transmitted light delays by 180° as compared with a case where there is not any grooved portion.
To obtain a high-precision alternating type phase shift exposure mask, the groove has to be made vertically, and further expanded in the lateral direction. However, an etching process to expand the groove only in the lateral direction does not exist. Therefore, as described above, combined use of the dry and wet processes is required. Since an amount to be expanded in the lateral direction needs to be controlled with a high precision, the grooved amount in the dry process is a depth obtained by subtracting the amount to be expanded in the lateral direction from the amount corresponding to 180°. On the other hand, to obtain a high-precision focus test mask, a grooved portion corresponding to 90° has to be formed only by the dry process.
Therefore, in a conventional technique, the above-described etching processes have to be separately performed in order to realize the high-precision alternating type phase shift exposure mask and the high-precision focus test mask in one exposure mask, and a mask manufacturing cost rises by at least 30% or more as compared with the conventional alternating type phase shift exposure mask.

Photo mask, focus measuring method using the mask, and method of manufacturing semiconductor device


A wheel hub for a utility vehicle includes a brake element abutment surface against which a brake element bears in an installed state, and a positive-locking arrangement which interacts in positively locking fashion, as viewed in a direction of rotation, with the brake element in the installed state, and/or a receiving region for a positive-locking arrangement which interacts in positively locking fashion, as viewed in a direction of rotation, with the brake element in the installed state.

The present invention relates to a wheel hub and to a system composed of a brake element and of a wheel hub.
Wheel hubs are well known from the prior art. They serve for the attachment of a wheel to an axle element, for example to an axle of a utility vehicle. Here, it is commonly the case that brake element, such as for example brake disks or brake drums, are attached rotationally conjointly to the wheel hub. Brake disks are typically fixed axially by means of screws engaging into the wheel hub. This axial fixing by means of the screw leads here to a non-positively locking connection at an interface between the wheel hub and the brake disk bearing against the wheel hub. In order to withstand the loads that arise during operation, in the prior art, relatively high demands are placed on a fastening means by which the brake disk is fixed axially to the wheel hub.
It is an object of the present invention to provide a wheel hub which has, in relation to the prior art, an improved interface for the attachment of a brake element, in particular with regard to a load-bearing capacity of the interface.

Wheel hub and a system formed of wheel hub and brake element


A method and apparatus for detecting previous packet loss in non-packetized speech by applying one or more filters to a segment of said non-packetized speech, each of said one or more filters determining an energy parameter value for a given frequency band of said segment of said non-packetized speech; comparing one or more of said determined energy parameter values to one or more corresponding thresholds; and detecting previous packet loss based on said comparison of said one or more of said determined energy parameter values to said one or more of said corresponding thresholds.

When different telecommunications network carriers exchange voice-over-IP traffic—for example, when a Voice-over-IP telephone call is made from a subscriber of a first carrier to a subscriber of a second carrier—the exchange of data is, in accordance with current practice, invariably performed with use of traditional Time Division Multiplexed (TDM) links. Meanwhile, the transmission of Internet Protocol (IP) traffic (i.e., network packets) within a given carrier is commonly performed with use of a packet loss concealment technique which recognizes, and compensates for, the loss of packets (i.e., the failure to receive one or more of the transmitted packets). However, such packet loss concealment techniques are far from perfect, and often introduce audible distortions in the resultant speech.
In addition, it is often necessary for network carriers to guarantee (or at least to be able to measure) a Quality-of-Service (QoS) level to (or for) its customers. In order to be able to do so when VoIP calls have been received from another carrier, it would be highly advantageous for the receiving carrier to be able to identify (e.g., count) the presence of packet losses which occurred in the other carrier's IP network, particularly those that have introduced such audible distortions. However, while Real-time Protocol (RTP) header information is used within an IP packet network to detect lost packets on IP networks, there are currently no methods for detecting whether such packet losses have occurred on speech that is no longer packetized.
Therefore, it would be highly desirable to be able to estimate a packet loss rate and pattern from a speech signal that has been encoded, transmitted through an IP network, decoded with the use of concealed packet loss techniques, and subsequently converted to a non-packetized form (e.g., TDM). In other words, it would be desirable to be able to determine packet loss that has occurred once the speech has been reconstructed and, therefore, lost packet information is no longer available.

Method and apparatus for the detection of previous packet loss in non-packetized speech


An improved aqueous soluble surfactant which has particular utility for incorporating in etchants for semiconductor devices is provided. The surfactant comprises a combination of a linear perfluorocarboxylic acid, a cyclic amine and an aliphatic alcohol.

As integrated circuit component dimensions become smaller, physical wetting by etchant solutions on a substrate becomes more difficult. This is especially important for those buffered etchant solutions used in silicon dioxide etching, which in the absence of surfactants exhibit unacceptably high surface tension.
Due to the increasingly stringent requirements suitable silicon dioxide etchants must possess lower surface tension wherein the surfactant incorporated maintains an acceptable level of surface activity in hydrofluoric acid and ammonium fluoride etch systems.
Prior attempts have been made to produce stable aqueous solutions of surfactant containing ammonium fluoride and hydrofluoric acid etchants. For example, in U.S. Pat. No. 4,517,106 a fluoroalkylsulfonate is used to improve the wetting properties of the acid solutions. In U.S. Pat. No. 4,761,245 a nonionic alkylphenol polyglycidol is used for the same purpose.
In U.S. Pat. No. 4,795,582, it is disclosed that surfactants selected from the group consisting of aliphatic carboxylic acids and salts thereof, aliphatic amines and aliphatic alcohols are added to aqueous mixtures of ammonium fluoride and hydrofluoric acid to improve surface wetting. Among the various surfactant compounds, octylamine is disclosed in this patent as being suitable.
In U.S. Pat. No. 5,496,485 the patentee discloses the utilization of branched aliphatic amine surfactants. The addition of relatively substantial quantities of the surfactant, i.e., amounts in excess of 100 ppm based on the weight of etchants, are functionally required according to that patent.
The present invention provides the means to produce significantly improved surfactants which are superior from a practical standpoint of filterability, effectiveness and reduction of the surfactant quantity required.
In accordance with the invention, filtration of the surfactant must be conducted so as to reduce to a minimum the presence of particulates which may adversely affect the end use of semi-conductor components processed with compositions containing the surfactant.
In general, in pilot plant runs, integration of the surfactant into the etchant solution is effected by using a rotating mixer with a mixing period of the order of about 3 to 5 minutes. Also, in pilot plant runs, to assure a reasonable period for maximum removal of undesirable particulates from the surfactant containing etchant solution (water being the solvent unless otherwise indicated), a recirculating filtration process for a period of the order of at least about 12 hours is employed. The normal flow rate through the centrifugal pump associated with the recirculating filtration system is approximately one gallon per minute.
In commercial runs, i.e., in 100 lbs. to 3,000 lbs. batches, for example, a rotating mixer of a kind employed in the art is used to blend the surfactant into the etchant solution using a minimum blending period of approximately 3 to 5 minutes. The blend is then subjected to suitable multipass filtration operation that is continued until the desired minimum level or elimination of undesirable particulates is attained while still retaining a minimum but sufficient quantity of surfactant to provide the desired surface tension reduction in the etchant composition.
It is apparent that the quantity of surfactant retained in the etchant, for practical reasons, is the minimum amount that provides the suitable surface tension reduction. Generally, it is desired that a surfactant amount impart a functional level to the solution after the surfactant containing solution is filtered. For example, for etchants, an effective amount of surfactant retained in the filtered etchant may vary from about 10 ppm to about 100 ppm with about 35 to about 65 ppm (based on the weight of the etchant) being the more optimal quantities.

General Chemical Performance Products, LLC


A bunker comprising an exterior pyramid or cone structure made from an energy-absorbing material and an interior hollow spherical structure. The bunker may further comprise a sloped enclosing structure disposed around the exterior pyramid or cone structure. The energy absorbing material may be a solid, liquid or gel, and may be a compressible material. The combination of an outer pyramid or cone structure and an inner spherical structure is very stable. Persons or materials are housed in the inner hollow structure, and are protected from the impact of projectiles such as bombs or shells, or from other dynamic loads, by this combination of two strong geometric shapes with an energy-absorbing material in between.

In some environments it is important to have a protective and resistant structure to enclose materials (i.e., munitions; chemicals; nuclear waste storage), persons or buildings (control centres; hospitals), the structure able to mitigate or withstand the impact of projectiles such as bombs or shells, or that can otherwise withstand very high dynamic loads, such as cyclic, impactive or impulsive loads.
Such protective structures, known as bunkers, can be portable or fixed. They are often partially or completely buried underground under compacted layers of soil, especially in military settings. In a military setting, portable protective bunkers which are easy to set up at a selected site to enhance the safety of military personnel are very desirable.
As well, larger more permanent bunker structures that can protect ammunition or other explosive or dangerous materials, or that can house entire rooms or buildings to protect them from outside attack are also very desirable.
A portable combat bunker is described in U.S. Pat. No. 6,067,889. This bunker is stated to be portable and reusable, formed of molded hollow plastic modules temporarily joinable by wooden beams and metal brackets. The modules are assembled on site and filled with water or sand, which is drained when the bunker is moved to a new location.
U.S. Pat. No. 6,205,717 describes a bunker construction that is formed of precast concrete arch elements which form a semicircular roof of the bunker, and front and back plates on the ends of the bunker. This bunker is covered with protective earth, thereby allegedly forming a bunker construction with enhanced structural integrity due to the mechanically stabilized earth in combination with the precast arch elements and the front and back plates.
Canadian patent application no. 2,000,436 describes a device for improving the resistance of structures, in particular made of concrete, such as shelters, sheds, building, walls, paved surfaces, to the impact of conventional projectiles such as bombs and shells. The device comprises a surface formed by a succession of ribs and grooves with a substantially V-shaped profile and smooth, inclined lateral faces. These surfaces deflect a projectile after impact, to weaken the impact of the projectile on the structure.
Canadian patent no. 2,438,802 describes a structural system that absorbs impactive and impulsive loads and that comprises a main structure, a crushable filling layer around the main structure and an outer shield around the crushable filling layer. If an impactive load exceeds a certain level, the outer shield slides, crushing the filling layer and absorbing a substantial amount of energy.
What is needed is a better bunker system that can withstand forces that are applied to it to protect persons or property inside the bunker, and one that is easy to set up when being used as a portable bunker system.


Drilling apparatus for receiving, moving and aligning pipe sections as they are added to a string of pipe on a drilling rig when using an iron roughneck. After the iron roughneck is moved to well centerline and engaged with the box connection of the pipe suspended in the well bore, a hydraulically controlled pipe engagement mechanism is extended radially away from the iron roughneck and in the general direction of the pipe rack. The pipe engaging mechanism receives the lower end of the next stand of pipe to be added and is hydraulically retracted to lock around the pipe stand and bring the pipe stand into alignment with the pipe string suspended in the well bore.

Rotary drilling operations for oil and gas wells generally employs a drill string consisting of many joints of drill pipe at the top of the string and several joints of drill collars at the bottom of the string nears the bit.
Periodically during the drilling of a well the drill string, partially or entirely, must be removed from the hole. Such cases include the need for changing bits, running casing or for other reasons. Also, as the drilling progresses and the borehole becomes deeper, additional joints or stands of pipe must be added for drilling to continue.
To add or remove drill pipe or drill collar segments to or from the drill string, the existing connections between the drill pipe or drill collar segments must be broken loose and then rotated multiple times to disengage the threaded connection and separate the segments so the segments may be removed from the drill string. The pipe sections, known as "stands" of pipe may be comprised of one or more individual pipe joints depending on the particular configuration of the drilling rig. When the pipe string is reassembled into the well bore, the opposite procedure is followed. The pipe sections must be reinserted, rotated clockwise and retightened before drilling can recommence. For these operations, current art often utilizes large machines known as "iron roughneck" machines, to hydraulically make these connections. When recombining the pipe segments into a continuous string inside the well bore, it is necessary to guide the next stand to be added into alignment with the drill string suspended in the well bore. This portion of the operation is known as "stabbing the pipe". On large or specialized rigs, expensive and complex pipe handling machines are sometimes used to move pipe between the setback area or pipe rack and the well center in preparation for reattaching the next pipe segment in the string. On most rigs, however, the pipe is lifted with elevators attached to the rig's hoisting equipment and the male threaded segment of the tool joint, or "pin", is manually guided into alignment with the female threaded segment of the tool joint, or "box", of the drill string suspended in the well bore. Due to the movement of the pipe being added, this process is somewhat inexact and "mis-stabs" are common, resulting in scarring of the sealing face of the tool joint. Due to the proximity of the rig personnel to the well center, it is also somewhat dangerous.
When using an "Iron Roughneck" type machine, much of the danger for the rig personnel is reduced during tripping operations but the risks inherent in manually stabbing pipe remain.
Additionally, when tripping with manual tongs, in order to speed operations, it is common to clamp the lower tong onto the box portion of the tool joint of the top segment of the drill string the suspended in the well bore before stabbing the pin portion of the next stand of pipe to be added into it. When using an iron roughneck, this practice is seldom used because of the increased risk of injury from accidental pinching of the hands of the rig personnel between the moving pipe and the stationary iron roughneck. Current practice when using an iron roughneck is to wait until the pipe is manually stabbed before engaging the iron roughneck with the drill string. This delay results in lost rig time.

Apparatus for stabbing pipe when using an iron roughneck


A screen for attachment to an front forked portion of a motorcycle has improved aerodynamic characteristics. An upper garnish is located on the forward side of the screen. The upper garnish extends substantially horizontally across the screen. An expanded portion protrudes forwardly and extends substantially across the entire length of the upper garnish. The expanded portion redirects any horizontal air current impacting thereagainst. The redirected air current influences the horizontal air currents impacting the screen by causing a turbulence area slightly in front of the screen. This turbulence acts to lessen the impact of the horizontal air currents against the screen, resulting in a decrease in an overall running resistance of the motorcycle.

1. Field of the Invention
The present invention relates to a windshield device to be mounted to a front wheel suspension of a motorcycle, or similar vehicle.
2. Description of Background Art
It is known to mount a screen to an upper, front portion of a motorcycle to shield a rider from wind and other elements. For example, a screen may be mounted to a front cowling or a front wheel suspension of a motorcycle.
When the screen is subjected to air currents during movement of the motorcycle, forces such as drag and lift are exerted on the screen and are transmitted from the screen to the motorcycle. These drag and lift forces intensify as the screen size increases. If the screen is mounted to the front wheel suspension, the forces are exerted directly to the front wheel suspension, thus changing the performance and characteristics of the suspension.


A wheel puller for handling a heavy wheel assembly. The puller comprises a beam having one end for securing a heavy wheel assembly thereto, and an opposite end having a weight member connected thereto. The weight member has a mass comparable to the wheel assembly. At a location intermediate the beam ends, the hook of a lifting device is received.

The present invention relates generally to overhead cranes used in present-day industries, and more particularly to means for removing worn or broken wheel assemblies from such cranes and reinstalling spare wheel assemblies.
Industrial overhead cranes comprise an "end truck" having four or more wheels that ride on overhead parallel rails located near the ceilings of industrial plants and factories. End trucks support the ends of a bridge of an overhead crane that spans the distance between the parallel overhead rails. Such cranes and trucks are, of course, used to transport heavy objects that can be lifted and lowered by an electrical winch or winches that are an integral part of such cranes.
The wheels of most domestic crane trucks have double flanges, as depicted in FIG. 4 of the subject drawings, that maintain the wheels on the parallel rails, but some wheels have only one flange, and some have none. In addition, each wheel is an assembly of components that includes bearings, spindles, bearing races and housings (that house the bearings), shafts, flanges and other components. The wheels per se are forged steel structures that can be brittle such that the wheel flanges break or running surfaces become worn, which then requires replacement of the wheel assembly. In addition, bearings, bearing races and wheel spindles and shafts become worn, which, again, requires removal of the worn assembly and reinstallation of a spare wheel assembly.
The precision at which crane wheel components are required to operate may not be apparent, but it can be appreciated that the overhead rails upon which the crane travels must be as near perfectly parallel as possible. Otherwise, the wheels and wheel assemblies will not "track" the rails properly, and will be subject to lateral forces imposed upon wheel flanges and other wheel components while traveling on the rails. Precise alignment of the end truck, wheel assembly and crane wheels is critical due to the following: Wheel flanges that ride on the rails cause a high amount of friction resulting in: (1) wheel wear ($15,000 each), (2) rail wear, which are, of course, difficult to change, (3) increased motor loads on crane drive system, resulting in blown fuses and motor damage. This can result in inability to move the crane in a desired direction.
Heretofore, the industry accepted practice of removing worn or damaged crane wheel assemblies, with each assembly weighing as much as 2000 pounds or more, is unbolting the wheel assembly from the crane truck, manually rolling the wheel assembly unsupported out from under the end of the truck longitudinally along the rail beneath the truck and wheel, and then placing a "choker" cable around the wheel so that the wheel could be lowered to the floor by a separate, floor operated, mobile crane. Personnel handling, actually manhandling, such assemblies worked from catwalks provided at the level of the rails.
Such a procedure places the mechanics working on the overhead crane at substantial risk due to the heavy wheel assembly being unsupported for the period of time it is removed from the crane truck to the occasion the floor crane is connected to the choker cable. In the case of overhead cranes used in potrooms that electrolytically smelt aluminum metal, strong magnetic fields are present that pull and jerk the wheel assembly about, as the magnetic fields acting on the assembly and on other iron and steel structures in and of the building housing the potrooms repel and attract the assembly such that it can be wrenched free of the personnel handling the wheel and either fall to ground level or fall back upon the catwalk and on personnel working on the catwalk. The strong magnetic fields are caused by electrical current flowing in large buses supplying current to the electrolytic cells of the potline.


A brush is made up of: a handle an aluminum tubular body which is coated with an artificial plastic material, vinyl fluoride polymer, and holes with polygonal shape, arranged in a herringbone pattern, which end in bevelling and are arranged forming oblique lines in respect of the longitudinal axis of the brush. Nylon fibers are ionized by radiation, and are fixed helicoidally to a supporting center rod, located inside the tubular body. The fibers emerge through the holes of the tubular body, and a front top closes the fore end of the tubular body.

Nowadays the use of hair brushes is common for hair brushing and soft perms either at home or in hairdressing and beauty salons. An example of commonly used brushes in hairdressing salons are the ones which comprise a hollow and holed tubular body which has a handle for it to be held on one end and a top to close it on its other end. Inside this tubular body are a bunch of fibers arranged helicoidally which come out through the holes of the tubular body. This kind of brush allows making a soft perm and a hairdo while applying heat.
In these brushes the tubular body is made in aluminum coated or not with ceramic which allows the accumulation and transmission of calories provided by an external heat source, generally a hairdryer.
When the tubular body is coated with ceramic it accumulates calories for more time than just aluminum but transmits heat with less speed and effectiveness. Another known inconvenience of this kind of brush is that the hair products applied adhere on the tubular body little by little thus avoiding a smooth and uniform sliding of hair on the tubular body.
Furthermore, another inconvenience of this kind of brush lies in the fibers when emerging through the holes of the tubular body because they do not come out perpendicularly to it due to the fact that normally the holes are circular which cause most of the fibers to lean slightly avoiding the hair sliding smoothly over the brush and making effective contact with the surface of the tubular body, reducing thus the effectiveness of the brush notably, especially during the straightening and soft perm works. In this kind of brush the holes of the tubular body are generally made by means of a die cut on an aluminum plate and during this process little imperfections remain all around the edges of the holes on one of the sides of the aluminum plate.
The presence of these imperfections becomes an important problem during the assembly of the different pieces that compound the brush or during the use of it, because in the case of these imperfections remaining at the internal side of the tube they become a means of retention for the fibers to come out through the tubular body, whereas in the case that the imperfections are on the external side of the tubular body they are so jagged that can damage the hair cuticle.
If it is preferred that the little imperfections are left on one concrete side of the tubular body, the aluminum plates from which the tubular bodies of the brushes will be shaped must be placed in a given position, then the imperfections can be all on the same side, but it slows down the manufacturing process.


An apparatus for removing a sterilant from a sterilant containing atmosphere of a room includes an enclosure having an inlet to receive sterilant containing air from the room following sterilization of the room, outlet nozzles to return air from which sterilant has been removed to atmosphere, and a catalyst within the enclosure for removing sterilant from the air. A fan draws sterilant containing air from the inlet through the catalyst and thence to atmosphere. An additional fan is provided to circulate air containing sterilant from the room during a room sterilization process through that part of the enclosure which is downstream of the catalyst to ensure sterility of that part of the enclosure for the sterilant removal phase.

1. Field of the Invention
This invention relates to an apparatus for removing a sterilant from a sterilant containing atmosphere in a room or other enclosure. A method of removing hydrogen peroxide gas from a room following gaseous surface sterilisation.
2. Relevant Technology and Summary of the Invention
It is frequently necessary to sterilise the surfaces inside clean rooms in which pharmaceutical manufacturing processes are operated. Similar sterilising is also required in the biotechnology, biomedical and health care industries.
The traditional technique used for the sterilisation process has been to generate formalin vapour and allow this to remain in the room for a period of time and then using an air extraction system to remove the formalin by dilution until it is safe to re-enter the room. This technique although effective in reducing the bio-burden has the disadvantage that it leaves a residue of para-formaldehyde which is persistent and causes an unpleasant smell.
More recently it has been possible to use gaseous hydrogen peroxide as the sterilising agent. This has the advantage of breaking down to water and oxygen, and therefore does not leave a residue. When properly applied it is also a much faster process than fumigation with formalin but there is still the problem of removing the residual gas once sterilisation has been achieved.
With hydrogen peroxide it is generally true that the largest phase of a sterilisation cycle will be the time for aeration to remove the residual gas to a safe level. Frequently it is possible to use the room ventilation system to extract the air and residual hydrogen peroxide gas, but in some buildings this may not be possible. If for example there is a common extract system, with some percentage of re-circulation then the extracted air containing the hydrogen peroxide may be circulated back to other areas and under such circumstances it is desirable to have an alternative aeration technique.
As a good general rule it may be assumed that by doubling the air extraction rate after hydrogen peroxide sterilisation it is possible to halve the time required to remove the active gas.
Most of the commercially available hydrogen peroxide gas generators circulate the gas through the room to be sterilised and then back to the generator. The air that is returned to the generator is then processed and further amounts of hydrogen peroxide gas are added. At the end of a gassing phase of a sterilisation cycle the air continues to circulate through the gas generator but the returning hydrogen peroxide is decomposed in the generator to water and oxygen. This circulating process breaking down the hydrogen peroxide would eventually remove all of the active gas from the room, but as this circulating flow is small the time taken to reduce the gas concentration would be very long.
JP-A-11221443 discloses a method of reducing the release of hydrogen peroxide from a sterilisation chamber in which hydrogen peroxide is used as the active sterilant. The chamber has a vacuum pump for withdrawing gases from the chamber and discharging them to atmosphere. Catalytic converters are located in the conduit between the chamber and inlet to the pump and between the outlet to the pump and the outlet to atmosphere to convert hydrogen peroxide flowing in the conduit into oxygen and hydrogen to reduce the concentration of hydrogen peroxide released at the outlet.
DE-A-199 45 500 discloses a method and apparatus as described and illustrated for sterilising containers in a filling machine, which are intended for the filling in particular of liquid or pasty foodstuffs, wherein the containers are flushed with hydrogen peroxide (H2O2) immediately before the filling operation and the filling operation is carried out in a sterile environment, wherein the H2O2 contained in the exhaust air is decomposed to H2O2 and O2 in a catalyst, and wherein the resultant sterile air serves to remove the hydrogen peroxide from the containers. For optimisation in respect of efficiency, environmental compatibility and process safety there is provision for the sterile air to form a laminar flow in the interior of the filling machine and for it to be used to seal the filling chamber by the surplus air volume being released into the environment.
DE-A-36 42 674 A1 discloses the sterilisation of filling installations and packing installations used for packing foodstuff and in the pharmaceutical industries. Hydrogen peroxide is often used in such applications. The hydrogen peroxide can be broken down after use with the aid of a platinum or palladium catalyst. However such catalysts decline in effectiveness in a relative short period of use. This difficulty can be overcome by the provision of a catalyst support in which a support body consists of carbon particles bonded together without binder, the common particles comprising a first carbon fraction which forms the support skeleton and a second carbon fraction of highly porous activated carbon with an inorganic catalytically active substance, in particular noble metals and their compounds, applied to the support body and/or the activated carbon particles to break down hydrogen peroxide flowing through the body.
It is an object of this invention to provide an apparatus for removing the sterilant such as hydrogen peroxide from an atmosphere in a room containing the sterilant without causing the circulation used to remove the sterilant from the atmosphere to contaminate the room.
This invention provides an apparatus for removing a sterilant from a sterilant containing atmosphere of a room comprising an enclosure having an inlet to receive sterilant containing air from the room following sterilization of the room, an outlet to return air from which sterilant has been removed to atmosphere, a catalyst within the enclosure for removing sterilant from the air, means for drawing sterilant containing air from the inlet through the catalyst and thence to atmosphere and means to circulate air containing sterilant from the room during a room sterilization process through that part of the enclosure which is downstream of the catalyst to ensure sterility of that part of the enclosure for the sterilant removal phase.
Preferably a filter is located in the enclosure between the inlet and outlet to filter air passing therethrough.
More specifically the filter may be located downstream of the catalyst and to be sterilized by supplemental means for drawing sterilant through the enclosure downstream of the catalyst during the room sterilization process.
In any of the above arrangements the catalyst may be a carbon filter.
Also in any of the above arrangements the outlet may comprise a nozzle or nozzles for directing the stream of air from which sterilant has been removed into the atmosphere around the enclosure to create turbulence in the air.
The supplemental means to draw sterilant through the part of the enclosure downstream of the catalyst during the room sterilization process may comprise further fan means of relatively low throughput compared with the first mentioned fan means, the further fan means having a further inlet disposed in said enclosure on said downstream side of the catalyst to draw air containing sterilant from the atmosphere into the enclosure during the room sterilization process and to circulate air through the downstream side of the enclosure to sterilize that part of the enclosure, the air containing sterilant being released from the enclosure by said outlet from the enclosure.
The apparatus may be mounted on, wheels to be readily mobile.
The present invention provides a rapid method of removing the active gas from the room without the necessity of providing an additional extract system.

Apparatus for removing sterilant from a sterilant containing atmosphere


Apparatus (10) for controlling supply of electricity through an electrical distribution network to a customer. An electrical meter (12) is plugged into an electrical socket (14) at a customer's premises. Electricity flows from a power line through the socket into the premises, the amount of electricity used being measured by the meter. The apparatus is interposed between the meter and the socket and includes a switch (18) to interrupt flow of electricity into the premises. The switch is controlled by the utility, preferably through programming of the apparatus or through a TWACS® communication system. This enables the utility to selectively control supply of electricity to the premises apart from the flow of electricity to any other premises connected to the same power line (L).

This invention relates to the supply of electricity by a utility to its customers; and more particularly, to a disconnect switch interbase, or DSI, which is either used as a stand alone unit or often integrated with an electricity meter such as a meter which can be automatically read by the utility, and which enables the utility to remotely control power usage by the consumer through the disconnect switch.
It is well-known in the art that electricity supplied to a house or commercial establishment is routed into the premises through a meter. The meter measures the amount of electricity supplied to the user at the facility and the user pays the utility for the electricity used. This payment is based upon periodic measurements of electrical consumption taken from the meter and a utility bill generated from the meter reading. Recently, electrical utilities have begun using automated or automatic meters which are remotely "read" by the utility, instead of having a utility worker periodically come onto the premises and read the meter as has traditionally happened. A number of automatically read meters, or AMRs, are available, and many are capable of being interrogated (polled) from a remote location. The response provided by the meter identifies the location of the meter and the current electricity consumption at the premises where it is installed. The customer is then billed by the utility based upon the electrical usage output transmitted from the meter.
Sometimes people don't pay their electricity bills. When they don't, the utility, absent special circumstances such as extreme heat in the summer or extreme cold in the winter, is entitled to turn-off electricity to the premises. In the past, when someone's electricity needed to be turned-off, the utility had to send out someone to affect the disconnection. This took time, and sometimes there was a risk involved to the worker. If the overdue bill was subsequently paid, then the crew had to go back out and reconnect the service.
Besides shutting off service for non-payment of a bill, there are other times when a utility needs to control the flow of electricity to a building. A common occurrence is in the summer when it gets very hot at the same time there is high humidity. During such times, there is a peak demand for electricity, and occasionally the demand reaches or exceeds the generating capacity of the utility. When this occurs, the utility can try to buy additional electricity from other utilities to cover its shortage, but this is usually expensive, and adjoining utilities typically are experiencing their own shortages. The utility can also request its customers to cut back on their electrical usage during peak periods of consumption. Usually the peak extends from late afternoon when people start coming home and fixing dinner to sometime in the evening when they go to bed. If consumers do not sufficiently reduce their electricity usage during this time, then the utility often has to resort to floating "brown-outs" in which service is reduced for periods of time, first to one segment of the distribution network, and then to another segment, so the overall load on the system does not take the system down.
Other circumstances in which a utility's ability to effectively and efficiently control service to a home or business include providing back-up overcurrent protection in the event a circuit breaker malfunctions, and arc fault circuit back-up protection.


The present invention discloses a safety devices adapted to prevent workers from going into hazardous environment, such as underground using the faulty safety device. As a safety device, typically embodied as a cap lamp, must be charged prior to each use, the device is adapted to detect when the device is removed from the charger. The device starts to blink continuously when disconnected from the charger. An automated test procedure is completed on the device. The user may also complete a manual portion of the test procedure to make the device usable. When the test procedure is completed successfully, the lamp stops blinking. If the test procedure is not successful, the lamp continues blinking to effectively prevent user from using a faulty device.

Numerous underground mines are in operation throughout the world. In these harsh, remote and confined environments there are significant risks of injuries or fatalities caused by workplace hazards such as fires, rock falls, gas intoxications, heat strokes, and collisions with machines etc.—and these risks are compounded by delays for rescue and treatment, if an accident happens.
To mitigate these risks, safety devices are increasingly given to workers to provide them with a variety of safety features such as notification of evacuation, tracking of location, proximity warning, man down detection, etc. These systems come in various configurations and use various technologies, all with their inherent advantages and drawbacks.
However, even if these types of safety devices and systems can provide valuable warnings to enhance safety at mine sites, it remains that these systems rely on workers going underground with a functional device. For example, if a worker goes underground with a safety device that has a broken antenna, the proximity warning signal the safety device normally transmits won't work properly, therefore this worker will be invisible in the blind spots of machinery operators.
Despite well-documented test procedures to confirm the personal safety device is functional, a small percentage of workers still don't seem to care if the device works or not—and knowingly or unknowingly go underground with a faulty device. One reason for this can be that some workers don't like their whereabouts to be tracked.
Hence, in view of the foregoing, there is a need for an improved safety device and methods to detect faulty devices and preferably force a user to select a working one.

Safety device and method to prevent use of the same device if faulty


Embodiments in accordance with the present invention provide for the use of polycycloolefins in electronic devices and more specifically to the use of such polycycloolefins as gate insulator layers used in the fabrication of electronic devices, the electronic devices that encompass such polycycloolefin gate insulator and processes for preparing such polycycloolefin gate insulator layers and electronic devices encompassing such layers.

Electronic devices, for example field effect transistors (FETs) are used in display devices and logic capable circuits. A conventional FET typically includes source, drain and gate electrodes, a semiconducting layer made of a semiconductor (SC) material, and an insulator layer (also referred to as "dielectric" or "gate dielectric"), made of a dielectric material and positioned between the SC layer and the gate electrode. Also known are organic electronic devices, for example organic field effect transistors (OFETs) that are useful in display devices and logic capable circuits. A conventional OFET also includes source, drain and gate electrodes but rather than an inorganic semiconductor layer, an OFET includes a semiconducting layer made of an organic semiconductor (OSC) material and generally an insulator layer made of an organic dielectric material positioned between the OSC layer and the gate electrode.
U.S. Pat. No. 7,029,945 B2 discloses embodiments of an organic field effect transistor (OFET) wherein the gate insulator layer is made of a dielectric material having a permittivity (∈) (also known as relative permittivity or dielectric constant (k)) of less than 3.0. Such materials, generally referred as "low k materials", are reported to provide good mobility regardless of whether or not the organic semiconductor layer is disordered or semi-ordered. US '945 further reports that commercially available fluoropolymers such as Cytop™ (from Asahi Glass) or Teflon AF™ (from DuPont) are exemplary low k materials.
In EP1687830B1 the use of Cytop as a gate insulator material is disclosed as being advantageous for solution processed OFET devices where the OSC material is selected from soluble, substituted oligoacenes, such as pentacene, tetracene, anthracene, or heterocyclic derivatives thereof. These OSC materials are soluble in most common organic solvents. Therefore, when preparing a top gate OFET, the solvents for the gate dielectric formulation have to be carefully chosen to avoid dissolution of the OSC material by the solvent of the gate dielectric formulation when deposited in adjacent layers. Such a solvent is generally referred to as being orthogonal to the material of the OSC layer. Similarly, when preparing a bottom gate device, the solvent for carrying the OSC material onto a previously formed gate dielectric layer is selected to be orthogonal to the gate dielectric material.
It has been reported that the above-mentioned fluoropolymers are problematic with regard to limited structural integrity and integration into processing in the mass production of OFET devices. Regarding proccessability, fluoropolymers often do not adhere well to other layers, for example the substrate and OSC layer, among others, generally exhibiting poor wetting of such layers. Also, many fluoropolymers, such as those of the aforementioned Cytop™ series, have low glass transition temperatures, Tg (˜100-130° C.) that make it difficult to use standard physical or chemical deposition methods for applying a metallized gate electrode layer over such a fluoropolymer dielectric layer. With regard to structural integrity, if a fluoropolymer having a low Tg is heated to, or above the Tg temperature during a metallization process, polymer cracking due to built-in stress can occur. Even where such cracking can be avoided, differential expansion between the fluoropolymer and any adjacent layer due to heating can result in polymer wrinkling. Where fluoropolymers with a higher Tg, like those of the Teflon AF™ series (e.g., Teflon AF 2400 with Tg=240° C.), have been used to overcome the aforementioned wrinkling or cracking problems, such materials often exhibit wetting and adhesion problems that are more severe than those exhibited by the low Tg materials. Thus there is a need for a polymer with good wettability and high Tg capable of forming a low k gate dielectric layer.
In FIGS. 3 to 22, the X-axis depicts the gate voltage, left Y-axis depicts the drain current, and the right Y-axis depicts the mobility. The upper two curves, which are exemplarily labeled "c" in FIG. 3, depict the current-voltage characteristic for forward and reverse scans, illustrating the current hysteresis of the device. The lower two curves, which are labeled "a" and "b" as exemplarily shown in FIG. 3, depict the mobility-voltage characteristic, wherein curve (a) shows the mobility obtained in the linear regime, and curve (b) shows the mobility obtained in the saturation mode.

Gate insulator layer for organic electronic devices


It is an object of this invention to make it possible to accurately simulate a manner in which carriers are transferred in a semiconductor device. A Fermi level setting means sets a Fermi level in a sink region of carriers, such as a vertical CCD portion of a CCD, and Boltzmann distribution equation solving means solve a Boltzmann distribution equation to obtain a carrier density in this Fermi level set region. In a CCD, the manner in which carriers are transferred from a photodiode portion to a vertical CCD portion in a CCD can be simulated accurately.

The present invention relates to a device simulator for analyzing an operation of a semiconductor device and, more particularly, to a device simulator for two-dimensionally analyzing a three dimensional device structure.
FIGS. 5 and 6 are block diagrams showing first and second examples of a conventional device simulator, in which FIG. 5 shows a decouple method, and FIG. 6 shows a couple method. (Ryo Dan ed., "Process Device Simulation Technique," pp. 4 to 9, Sangyo Tosho).
The first conventional example of FIG. 5 comprises a data input means 10, a simulating means 20c, a data output means 40, and an auxiliary storage unit 50. The simulating means 20c includes a potential setting means 21, a Poisson's equation solving means 23, an electron current continuity solving means 24, a hole current continuity solving means 25, and a result confirming means 28. For semiconductor fundamental equation data supplied by the data input means 10, the simulating means 20c applies a potential to electrodes by using the potential setting means 21 and sequentially solves a Poisson's equation, an electron current continuity, and a hole current continuity for an entire region except for the electrodes by using the respective solving means 23 to 25 while checking the convergences. After the result confirming means 28 confirms the result, the data output means 40 outputs the result.
The second conventional example of FIG. 6 comprises, in place of the solving means 23, 24, and 25 shown in FIG. 5, a Poisson's equation current continuity solving means 29 as a simulating means 20d. This second conventional example solves a Poisson's equation, an electron current continuity, and a hole current continuity in a batch manner and checks the convergence.
Note that as the solution of a semiconductor fundamental equation data described above, a solution using a numerical analysis such as calculus of finite differences has been established in the case of a two dimensional model.
A conventional analysis scheme for analyzing a charge coupled, device (referred to as a CCD hereinafter) as a three dimensional structure by using a tow dimensional device simulator will be described below. In a CCD 60 as shown in FIG. 7, carriers produced by light incident on a photodiode portion 61 are transferred to a vertical CCD portion 63 by a potential applied to a transfer gate portion 62. The carriers transferred to the vertical CCD portion 63 are transferred to the direction of depth (the direction perpendicular to the drawing surface of FIG. 7) of the CCD 60 by a potential difference applied in the direction of depth of the CCD 60. In the conventional analysis scheme, in order to analyze a potential distribution below the transfer gate, dummy electrodes are provided in the vertical CCD portion 63. A voltage is applied to the dummy electrodes until a region including the dummy electrodes is depleted sufficiently, thereby performing a simulation. Thereafter, another simulation is performed again after the dummy electrodes are removed, thus checking the physical quantity distribution inside the semiconductor. (Kawazoe et al., Application of 2D Device Simulator to Development of CCD Image Sensor, 1990, spring, the 37th Applied Physics Association Joint Lecture Meeting Manuscripts, the 0th Separate Volume, page 1,208; and Kitamura et al., Sensitivity Simulation of a Frame Transfer CCD Image Sensor, 1990, spring, the 37th Applied Physics Association Joint Lecture Meeting Manuscripts, the 2nd Separate Volume, page 629.)
In the conventional 2D device simulation system of Kawazoe or Kitamura, in order to check the physical quantity inside a device, dummy electrodes which provide as a carrier transfer portion to the vertical CCD portion are detached in order to perform the simulation. Therefore, since no place is present to absorb carriers transferred from the photodiode portion to the vertical CCD portion, no current can flow. As a result, it is impossible to analyze the manner in which carriers produced in the photodiode portion are transferred to the vertical CCD portion.

Device simulator for semiconductor device


Methods of packaging microelectronic imagers and packaged microelectronic imagers. An embodiment of such a method can include providing an imager workpiece having a plurality of imager dies arranged in a die pattern and providing a cover substrate through which a desired radiation can propagate. The imager dies include image sensors and integrated circuitry coupled to the image sensors. The method further includes providing a spacer having a web that includes an adhesive and has openings arranged to be aligned with the image sensors. For example, the web can be a film having an adhesive coating, or the web itself can be a layer of adhesive. The method continues by assembling the imager workpiece with the cover substrate such that (a) the spacer is between the imager workpiece and the cover substrate, and (b) the openings are aligned with the image sensors. The attached web is not cured after the imager workpiece and the cover substrate have both been adhered to the web. As such, the web does not outgas contaminants into the compartments in which the image sensors are housed.

Microelectronic imagers are used in digital cameras, wireless devices with picture capabilities, and many other applications. Cell phones and Personal Digital Assistants (PDAs), for example, are incorporating microelectronic imagers for capturing and sending pictures. The growth rate of microelectronic imagers has been steadily increasing as they become smaller and produce better images with higher pixel counts.
Microelectronic imagers include image sensors that use Charged Coupled Device (CCD) systems, Complementary Metal-Oxide Semiconductor (CMOS) systems, or other solid state systems. CCD image sensors have been widely used in digital cameras and other applications. CMOS image sensors are also quickly becoming very popular because they are expected to have low production costs, high yields and small sizes. CMOS image sensors can provide these advantages because they are manufactured using technology and equipment developed for fabricating semiconductor devices. CMOS image sensors, as well as CCD image sensors, are accordingly "packaged" to protect the delicate components and to provide external electrical contacts.
FIG. 1 is a schematic view of a conventional microelectronic imager 1 with a conventional package. The imager 1 includes a die 10, an interposer substrate 20 attached to the die 10, and a spacer 30 attached to the interposer substrate 20. The spacer 30 surrounds the periphery of the die 10 and has an opening 32. The imager 1 also includes a transparent cover 40 over the die 10.
The die 10 includes an image sensor 12 and a plurality of bond-pads 14 electrically coupled to the image sensor 12. The interposer substrate 20 is typically a dielectric fixture having a plurality of bond-pads 22, a plurality of ball-pads 24, and traces 26 electrically coupling bond-pads 22 to corresponding ball-pads 24. The ball-pads 24 are arranged in an array for surface mounting the imager 1 to a board or module of another device. The bond-pads 14 on the die 10 are electrically coupled to the bond-pads 22 on the interposer substrate 20 by wire-bonds 28 to provide electrical pathways between the bond-pads 14 and the ball-pads 24.
The imager 1 shown in FIG. 1 also has an optics unit including a support 50 attached to the transparent cover 40 and a barrel 60 adjustably attached to the support 50. The support 50 can include internal threads 52, and the barrel 60 can include external threads 62 engaged with the threads 52. The optics unit also includes a lens 70 carried by the barrel 60.
One aspect of fabricating the imager 1 is forming the spacer 30 and attaching the cover 40 to the spacer 30. The spacer 30 can be formed by placing an uncured, flowable epoxy onto the interposer substrate 20. In a typical application, the interposer substrate 20 has a plurality of separate dies 10, and the spacer 30 is formed as a grid of uncured epoxy on the interposer substrate 20 in the areas between adjacent dies 10. After depositing the epoxy, the cover 40 is attached to the spacer 30. The epoxy is then cured to harden the spacer 30 such that it becomes dimensionally stable after enclosing the die 10 between the cover 40 and the interposer substrate 20.
One problem of forming the spacer 30 by stenciling an uncured epoxy on the interposer substrate is that the stenciling process produces a textured surface on the top surface of the spacer 30. This can lead to leaks between the spacer 30 and the cover 40 through which moisture or other contaminants can enter into the cavity where the image sensor 12 is located. Another problem of forming the spacer 30 by stenciling an uncured epoxy onto the substrate is that the height of the spacer 30 is limited because the epoxy tends to slump after the stencil is removed. This causes the epoxy to flow laterally and occupy a significant percentage of the real estate on the substrate 20. Additionally, a significant problem of using an uncured epoxy is that the uncured epoxy outgases during the curing cycle after the cover is mounted to the epoxy. Such outgasing can contaminate the compartment and impair or ruin the performance of the die 10.
Another process for forming the spacer 30 is to dispense a small flow of uncured epoxy via a needle-like tube or nozzle between adjacent dies. This process is undesirable because it is difficult to control the flow of the uncured epoxy at the intersections of the grid. The intersections typically have rounded corners that occupy additional real estate on the interposer substrate. Additionally, as with the stencil printing process, the epoxy is cured after the cover 40 is mounted to the spacer 30 such that it outgases into the image sensor compartment. Therefore, processes that dispense an epoxy using needle-like tubes are also undesirable.
U.S. Pat. No. 6,285,064 discloses another process in which a preformed adhesive matrix is fabricated in the shape of a wafer. The adhesive matrix has openings in the pattern of the image sensors, and it is formed separately from the wafer. In operation, the adhesive matrix is attached to the wafer such that the openings are aligned with the microlenses, and a cover glass is then attached to the top of the adhesive matrix. The adhesive matrix is subsequently activated by application of light, pressure and/or heat.

Spacers for packaged microelectronic imagers and methods of making and using spacers for wafer-level packaging of imagers


An information-processing apparatus shown in FIG. 4 is a wireless communication apparatus for communicating prescribed data in wireless with a back-scattering communication scheme, in which a tag (10) for receiving a carrier wave signal Sf having a frequency of 2.45 GHz and transmitting response signal Sf (D) obtained by modulating the carrier wave signal Sf based on the data and a tag reader (20) for transmitting a carrier wave signal to the tag (10) and receiving and signal-processing a response composite signal that is returned from the tag (10) are provided. This tag reader (20) has a carrier-wave-compensating circuit (30) that compares a phase of the carrier wave signal in transmitting the carrier wave signal and a phase of the carrier wave signal in receiving the carrier wave signal and eliminates a carrier wave composite signal that is not synchronized with the carrier wave signal in transmitting the carrier wave signal based on a comparison result thereof.

Recently, wireless communication technology has been often applied to a communication-processing art such as a cellular phone and an information-processing art such as a wireless mouse and an access point, accompanying with development of technology on a semiconductor integrated circuit. As an applied example of such the wireless communication technology, a tag and reader system has been invented. This tag and reader system performs the wireless communication of prescribed data according to the back-scattering scheme and is applied to a system for reading an electronic price tag attached to a dish or a plate in an eatery, for example.
The tag and reader system 1 shown in FIG. 1 has a tag 10 and a tag reader 20′, in which the tag reader 20′ transmits a carrier wave signal having a prescribed frequency to the tag 10 in succession and receives an amplitude modulation signal scattered and returned from the tag 10 to acquire data that is unique to the corresponding tag.
In FIG. 1, the tag 10 receives a carrier wave signal (an interrogation signal) having a frequency of 2.45 GHz and performs, for example, amplitude modulation on the corresponding carrier wave signal based on such the unique data, to transmit a tag amplitude modulation signal thus modulated (hereinafter referred to as "response signal Sf (D)"). This tag 10 is attached to, for example, an object to be specified such as a dish or a plate in an eatery. The tag 10 has a receiving antenna body 1A, a transmitting antenna body 1B, an amplitude modulation unit 2, a memory unit 3, a clock oscillator 4 and a power-supplying unit 5. Although the antenna bodies 1A and 1B are separately described on their operations in two parts, they actually constitute one antenna.
The antenna body 1A receives a carrier wave signal Sf that is the interrogation signal in the tag and reader system 1. As the antenna bodies 1A and 1B, a loop antenna in which conductor is coiled is used. The antenna bodies 1A and 1B are connected to the power-supplying unit 5 that operates so as to supply to the amplitude modulation unit 2, the memory unit 3, and the clock oscillator 4 induced power according to the carrier wave signal Sf received by the antenna body 1A.
The memory unit 3 stores data, which is unique to the object to be specified, such as a price of cooked food on the dish or the plate, and this data is read out thereof based on the clock signal (CLK) to transmit the data to the amplitude modulation unit 2. As the memory unit 3, a read only memory (ROM) is used. The memory unit 3 is connected to the clock oscillator 4 that operates so as to oscillate a clock signal having a prescribed frequency and transmit the clock signal to the memory unit 3. The amplitude modulation unit 2 performs amplitude modulation on the carrier wave signal Sf based on the data read out of the memory unit 3. The amplitude modulation unit 2 is connected to the antenna body 1B from which the response signal Sf (D) thus amplitude-modified is transmitted.
The tag and reader system 1 is also provided with the tag reader 20′ in addition to the above tag 10. The tag reader 20′ operates to transmit the carrier wave signal Sf to the tag 10 and to receive the response signal Sf (D) returned from the tag 10 and process the signal. Actually, the antenna 13B may receive a non-modulated carrier wave composite signal Sf′ that is reflected by and returned from surrounding matters, in addition to the response signal Sf (D). In other word, it may receive a response composite signal Sin including the response signal Sf (D) and the carrier wave composite signal Sf′.
In the tag reader 20′, its main portion includes an oscillator 11, a signal-transmitting unit 12, a transmitting antenna body 13A, a receiving antenna body 13B, a signal-receiving unit 14′ and the like. Although the antenna bodies 13A and 13B are separately described on their operations in two parts, they actually constitute one antenna. The oscillator 11 oscillates a carrier wave signal Sf having a frequency of 2.45 GHz. The oscillator 11 is connected to the signal-transmitting unit 12 that amplifies the carrier wave signal Sf based on an output permission signal S1 received via a control terminal 72 and transmits a carrier wave signal Sf (namely, Sout) thus amplified to the transmitting antenna body 13A. The transmitting antenna body 13A radiates the carrier wave signal Sf thus amplified.
The signal-receiving unit 14′ operates to receive the response signal Sin in receiving it and to perform data de-modulation on it. The signal-receiving unit 14′ has a de-modulation circuit 40 and a data-reading unit 50. The de-modulation circuit 40 is connected to the antenna body 13B and de-modulates the response signal Sf (D) based on the carrier wave signal Sf to transmit data (DATA) that is unique to the tag. The data-reading unit 50 is connected to the de-modulation circuit 40 and operates to read the data (DATA) that is unique to the tag and to transmit it to an output terminal 60. To the output terminal 60, a monitor 16 shown in FIG. 2 is connected through a control device, not shown. The monitor 16 displays the data, which has been read in the data-reading unit 50 and is unique to the tag.
Next, the following will describe some disadvantages in the tag and reader system 1. In the tag and reader system 1 shown in FIG. 2, a tag reader body 101 is provided with the monitor 16, read operation buttons 171, and the like.
In the tag and reader system 1, if an operator pushes any of the read operation buttons 171 of the tag reader body 101 down, the antenna body 13A shown in FIG. 1 radiates the amplified carrier wave signal Sout (namely Sf) so that the carrier wave signal Sf can be transmitted to the tag 10 via a channel I. If an object 90 stays in anywhere around, the carrier wave signal Sf transmitted to the tag 10 is reflected by the object 90 via a channel II and the tag reader 20′ then receives a carrier wave composite signal Sf′ thus reflected. It is to be noted that based on the data, the tag 10 performs amplitude modulation on the carrier wave signal Sf transmitted via the channel I.
On the other hand, the tag reader body 101 receives the response composite signal Sin returned from the tag 10 and performs signal-processing on it. Actually, the response composite signal Sin includes the response signal Sf (D), which is returned from the tag 10 via the channel III, based on the carrier wave signal Sf and the non-modulated carrier wave composite signal Sf′, which is reflected by and returned from the object 90, and the antenna body 13B shown in FIG. 1 then receives the response composite signal Sf′. Thus, if the object 90 stays in anywhere around, the carrier wave composite signal Sf′ returned from the object 90 causes any noise to be generated.
Regarding the tag and reader system, a Japanese patent Application Publication 1 (Japanese patent Application Publication No. H11-239078) discloses a wireless communication system of a modulation-back-scattering scheme. The wireless communication system has an interrogator and remote tags and the interrogator transmits an interrogate signal having a prescribed frequency to any of the remote tags. In this moment, as the interrogate signal, a narrow band downlink signal is used. Further, the remote tag performs an amplitude modulation on it to generate a response signal that has become a wide band uplink signal after the amplitude modulation and the interrogator receives the response signal to process it. Thus, use of the narrow band downlink signal and the wide band uplink signal allows a modulation-back-scattering (MBS) wireless communication system having a processed gain concerning an MBS background noise to be provided.
Regarding a background noise reduction method in such the system, a Japanese Patent Application Publication 2 (Japanese Patent Application Publication No. H07-193519) discloses a background noise reduction apparatus. This background noise reduction apparatus has a de-modulation unit, a frame power measurement circuit, a linear prediction analysis circuit, an inverse filtering circuit, and a subtraction unit. The frame power measurement circuit receives a de-modulated audio signal (hereinafter referred to as "de-modulation signal") from the de-modulation unit and obtains a power level thereof for every frame to compare it with a previously set threshold value. Based on a comparison result thereof, if the power level indicates the one on or below the threshold value, the linear prediction analysis circuit receives the de-modulation signal and performs linear prediction analysis on it to generate a linear prediction coefficient. The inverse filtering circuit performs an inverse filtering process on the de-modulated signal based on the linear prediction coefficient to obtain a prediction value thereof. The subtraction unit subtracts the prediction value from the received de-modulation signal. This allows only the background noise level to be decreased below the previously set value so that a receiver side can realize comfortable communication with the background noise being used as a part of the information.
The tag and reader system to which the MBS wireless communication system is applied relative to the conventional example has some disadvantages as follows:
(i) As shown in FIG. 2, if the object 90 stays in anywhere around the tag reader body 101, the carrier wave composite signal Sf′ reflected by and returned from the object 90 causes any noise. This may result in a deterioration of S/N ratio of the response signal from the tag 10; and
(ii) In order to restrain the deterioration of S/N ratio of the response signal received from the tag 10, such method is conceivable that the wireless communication system disclosed in the Patent Application Publication 1 and the background noise reduction apparatus disclosed in the Patent Application Publication 2 are combined. If, however, such the two technology concepts are merely combined, it is difficult to teach a configuration for eliminate the carrier wave composite signal Sf′ reflected by and returned from the object 90. Therefore, a merely combined system accompanies a difficulty to compensate a data modulation component in the proper response signal transmitted from the tag 10.

Information-processing apparatus, wireless communication system and wireless communication method


Some methods for detecting and avoiding radio interference in a wireless sensor network can include an access point device periodically transmitting a beacon message to a plurality of IoT enabled devices via a radio channel, upon receipt of the beacon message, an IoT enabled device attempting to decode the beacon message, the IoT enabled device measuring and storing a signal strength of a successfully decoded beacon message as signal strength data in a memory of the IoT enabled device, the IoT enabled device increasing a missed beacon counter stored in the memory of the IoT enabled device responsive to a beacon message that cannot be decoded, each of the plurality of IoT enabled devices periodically transmitting stored data to the access point device, and the access point device using the received data to identify an interference source, or an interference issue or a fading issue on the radio channel.

Many consumer electronic devices, such as household items, are Internet of Things (IoT) enabled devices such that these devices have the ability to connect to the Internet so that data can be collected and exchanged via the Internet. Furthermore, many IoT enabled devices are wirelessly connected to the Internet so that each device does not need a cable tethered to a router.
Known IoT enabled devices communicate using one or more communication protocols, including, for example, WiFi, 6LowPan, Zigbee PRO, Zigbee iControl, and Thread. Although there are different protocol standards for IoT device communication, all known IoT enabled devices use the 2.4 GHz radio band to communicate, thereby potentially causing harmful interference to each other. Furthermore, because communication between IoT enabled devices is primarily burst mode communication, inter-device interference resulting from such communication is difficult to detect with traditional RF jamming detection algorithms. For these and other reasons, the co-existence of devices communicating on the 2.4 GHz radio band is an issue that can cause poor RF performance for all such devices present in a region.
In view of the above, there is a continuing, ongoing need for improved systems and methods.

Systems and methods for detecting and avoiding radio interference in a wireless sensor network