A plasma processing apparatus includes a plasma-generation high-frequency power supply which generates plasma in a processing chamber, a biasing high-frequency power supply which applies high-frequency bias electric power to an electrode on which a sample is placed, a monitor which monitors a peak-to-peak value of the high-frequency bias electric power applied to the electrode, an electrostatic chuck power supply which makes the electrode electrostatically attract the sample, a self-bias voltage calculating unit which calculates self-bias voltage of the sample by monitoring the peak-to-peak value of the high-frequency bias electric power applied to the electrode, and an output voltage control unit which controls output voltage of the electrostatic chuck power supply based on the calculated self-bias voltage.

The present invention relates to a plasma processing method and a plasma processing apparatus (e.g. plasma etching apparatus) having a mechanism for holding a sample or wafer (semiconductor wafer, liquid crystal substrate, etc.) on an electrode (sample stage) by means of the so-called electrostatic chuck (electrostatic attraction), and in particular, to a plasma processing method and a plasma processing apparatus suitable for reducing damage to the inner wall of the processing chamber of the plasma processing apparatus caused by a rise in plasma potential.
In a plasma processing apparatus such as a plasma etching apparatus, a method called "electrostatic chuck" or "electrostatic attraction" is widely used for holding a wafer in the processing chamber. The electrostatic chuck (electrostatic attraction) is a method of holding a wafer on an electrode (sample stage) by electrostatic force which is caused by the potential difference between the wafer and the electrode. The electrostatic chuck has advantages over mechanical holding methods (using a holding member such as a clamp) in that wafer contamination due to contact can be avoided and wafer temperature control is easy (since the whole of the back of the wafer is attracted). Methods for the electrostatic chuck generally include a monopole method (applying electrostatic chuck voltage to one electrode) and a dipole method (using two or more electrodes and generally applying electrostatic chuck voltages of different polarities to the electrodes, respectively).
FIG. 2 is a schematic diagram showing the general composition of a plasma processing apparatus.
An electrostatic chuck power supply 111 is capable of applying DC voltage to an electrode 108 which is embedded in a sample stage 109. The value of the DC voltage will hereinafter be referred to as "ESC voltage (output voltage) of the electrostatic chuck power supply 111". Average electric potential of the wafer 113 caused by application of output of a biasing high-frequency power supply 110 to the electrode 108 via a capacitor will hereinafter be referred to as "self-bias voltage" (Vdc). The self-bias voltage Vdc is a negative DC voltage. In this case, the potential difference between the electrode 108 and the wafer 113 (i.e. the difference between the ESC voltage and the self-bias voltage Vdc) is the electrostatic chuck voltage (Vchuck). The self-bias voltage Vdc is dependent on the peak-to-peak value (Vpp) of the high-frequency bias power applied to the wafer 113 in the following relationship:α=|Vdc/Vpp|≦0.5where α is a constant which can vary depending on the plasma processing apparatus (0.3-0.45 in a standard plasma processing apparatus).
The peak-to-peak value Vpp can be monitored with a Vpp monitor 112.
FIG. 3 is a graph showing an example of the relationship among the ESC voltage, the self-bias voltage Vdc, the peak-to-peak value Vpp and the electrostatic chuck voltage Vchuck.
The self-bias voltage Vdc appears in the negative region of the graph with an absolute value α×Vpp (positive). As shown in FIG. 3, there exist two ESC voltages that cause the same Vchuck with respect to the value of Vdc. The ESC voltages on the positive side and on the negative side of Vdc will hereinafter be expressed as VESC+ and VESC−, respectively.
In this case, the relationship among the ESC voltages (VESC+, VESC−), the electrostatic chuck voltage Vchuck and the self-bias voltage Vdc can be expressed by the following equations:VESC+=Vdc+Vchuck VESC−=Vdc−Vchuck where Vdc is negative and Vchuck is positive.

Plasma processing apparatus and plasma processing method


Embodiments of a register file test circuit are disclosed that may allow for determining write performance at low power supply voltages. The register file test circuit may include a decoder, a multiplexer, a frequency divider, and a control circuit. The decoder may be operable to select a register cell within a register file, and the control circuit may be operable to controllably activate the read and write paths through the selected register cell, allowing data read to be inverted and re-written back into the selected register cell.

1. Technical Field
This invention is related to the field of processor implementation, and more particularly to the implementation and testing of register files.
2. Description of the Related Art
Computing systems may include one or more systems on a chip (SoC), which may integrate a number of different functions, such as, graphics processing, and memories onto a single integrated circuit. With numerous functions included in a single integrated circuit, chip count may be kept low in mobile computing systems, such as tablets, for example, which may result in a smaller form factor for such mobile computing systems.
SoCs typically include a number of data storage blocks of various storage capacities. Typically, large data storage blocks may be implemented as static random access memories (SRAMs) or dynamic random access memories (DRAMs). In some cases, smaller data storage blocks may be implemented as register files, whose data storage cells may be implemented according to one of various design styles.
During the semiconductor manufacturing process, variations in lithography, transistor dopant levels, etc., may result in different electrical characteristics between data storage cells that are intended to have identical characteristics. Additional variation in electrical characteristics may occur due to aging effects within the transistors as the device is repeatedly operated. These differences in electrical characteristics between transistors can result in data storage cells, such as those used in implementing register files, requiring different amounts to time to store data into the cells.
In some cases, the variation within data storage cells, as well as changes in power supply voltage, may result in a processor or SoC not being able to store data into a data storage cell within a pre-determined clock cycle period. Such data storage cells may be identified as failures during testing and may require re-design in order to achieve manufacturing yield goals.


A device (10) for transferring ultrasonic energy into a liquid or pasty medium, the device consisting of the following functional elements: a) an AC generator (35) designed for frequencies between 1 kHz and 100 kHz, b) a magnetostrictive or piezoelectric transducer (20) controlled by the output voltage of the AC generator to execute high-frequency (longitudinal) mechanical oscillations, c) a cylindrical waveguide (23) which is excited by the transducer to execute longitudinal resonant oscillations and d) a tubular cavity resonator (24) which is acoustically coupled to the waveguide and which converts the longitudinal resonant oscillations into oscillations transverse to its longitudinal axis (26'), the oscillation energy of the resonator being transferred into the medium (11) which is to be exposed to the ultrasonic energy. The cavity resonator (24) is designed so that the resonance condition is fulfilled for both longitudinal and transverse natural oscillations of its case (36).

1. Field of the Invention
The invention concerns a device for transferring or transmitting ultrasonic energy into a fluid or pasty medium, and with the further, characteristics particular to this species of invention. A device of this type is known from U.S. Pat. No. 4,016,436.
2. Description of the Related Art
In this known device a wave guide is provided on one side of a tubular shaped cavity resonator which, by means of a piezo-electric transducer, which for its part converts electrical alternating current output signals of an alternating current generator into longitudinal mechanical oscillations, is capable of being brought or excited to resonant longitudinal oscillations. On a flange shaped area on this transducer the cavity resonator is mechanically rigidly connected and acoustically coupled.
In a further device of the above described type (U.S. Pat. No. 5,200,666), which is substantially a functional analog of the first described, respective transducers transmit ultrasound energy at both ends of a tubular resonator, which is designed for conversion of longitudinal oscillations into transverse oscillations.
It is also known (U.S. Pat. No. 4,537,511), to use a tubular cavity resonator, which is closed on both ends and from one side is impinged by ultrasound from a coupled transducer.
In all these devices the length of the tubular cavity resonator is almost always selected to be in a first approximation described according to the equation, EQU L=nc.sub.0 /2f.sub.r (1)
in which n represents a whole number, with c.sub.0 being the oscillation frequency in a steel type resonator and with f.sub.r being the mechanical resonance frequency of the wave guide utilized for introduction of ultrasound in the resonator and which is acoustically coupled with the transducer. The oscillation frequency c.sub.0, is here described by the relationship, ##EQU1## in with E being the modulus of elasticity (Youngs modulus) and with .rho. being the specific weight of the resonator material.
In order, in such ultrasound devices, to convert the greatest possible proportion of electrical energy into utilizatable sound energy, it is also known (FR-A-2 354 827 and EP-A-0 044 800), to so attempt to arrange or design the cavity resonator, so that the longitudinal as well also the transverse natural oscillating frequency of its jacket satisfies the resonance conditions.
In such devices the oscillating effective element is constructed as a three dimensional tubular cavity resonator, in which the propagation velocity V.sub.x and v.sub.r, and therewith also the wave lengths .lambda..sub.x and .lambda..sub.r of the oscillations, which are associated with deflection in the direction of the longitudinal axis (x-direction) and radial thereto, are necessarily different. Those respective ultrasound waves, of which the deflection is in the direction of the longitudinal axis (x-direction) of a resonator, of which the axial length is selected to correspond to a whole number multiple of the half wave length (.lambda..sub.x /2), do not contribute to the outward radiation of ultrasound energy, however prevent a buildup of ultrasound energy and facilitate a good even form or shape of the distribution of the ultrasound energy over the total-axial-resonator length, while those ultrasound waves, of which the oscillation form of the resonator corresponds with deflection radial to the resonator-length axis and to its outer surface, mediate an effective radiating out of ultrasound energy in the environment.
Such an arrangement or design, given that the characteristics of the resonator wall material are pre-determined, requires a very precise coordination of the geometric dimensions of the resonator, namely its length L, its outer diameter D.sub.0 and its wall thickness .delta.. This relationship can in the case of pre-determined values of the outer diameter D.sub.0 and the wall thickness .delta. of course be achieved by adaptation or adjustment of the resonator length L, which however as a rule requires time consuming experiments or testing and only then is justifiable, when a subsequently larger number of such devices can be built following this experimentation to determine optimal length. Special devices which are only constructed in small quantities are thus very expensive.
From DE-33 16 353 A1 it is known, in connection with a cleaning device, in which the material to be cleaned, for example a length of textile material, is exposed to an ultrasound field, to use a so-called broad horn for transmission our application of ultrasound into a fluid bath through which the length of textile material is transported, which by means of an ultrasound transmitter corresponds is excited to resonate both in the longitudinal direction--the excitation direction--as well also in the thereto right angled transverse direction, in which the expansion or spreading of the broad horn corresponds at least approximately to the breadth of the textile material to be cleaned corresponds. This broad horn is designed as a flat rod-shaped, massive transmission body ("Sonotrode"), which corresponds in the excitation direction measured length to the half ultrasound-wave shape (.lambda./2) and in transverse direction measured breadth corresponds to a whole number multiple of this value; the thickness of the plate shaped broad horn measured between the broad longitudinal surface is significantly smaller than the half ultrasound wave length, which in longitudinal-and transverse direction has the same value. Through this dimensioning of the broad horn there should, which in principle is also possible, over the total breadth (n.multidot..lambda./2) an even shaped broadcasting characteristic of the broad horn and therewith also be achieved the even good cleaning of the length of material; however, the Q-factor (usable ultrasound-energy/electrical excitation energy), in comparison with ultrasound devices, which work with hollow space resonator-excitation, is comparatively small, so that very high output and correspondingly expensive ultrasound transmitters must be utilized, which makes the operation of this known type of cleaning device, which works with block-shaped massive broadcast elements, significantly more expensive.
It is the object of the invention, beginning with a device of the type known in the art, to provide a design of a device which produces a desirable high transmission operating effectiveness, and, after it has once been designed, does not, or at least not to any significant degree, have a post-working or reworking requirement, in order to be configured for a operation with optimal working effectiveness, and in particular to provide a device, which with a predetermined construction and type of coupling or transmission provided for excitation to oscillation, for its part by a transducer driven wave guide on a hollow tubular cavity resonator functions with a operating effectiveness which is a close to the optimal operating effectiveness.
This task is solved for devices in which the tubular cavity resonator is "strongly", that is mechanically substantially rigidly, coupled with the wave guide, according to the characterizing portion of Patent claim 1, thereby that the resonator length L is selected according to the relationship the formula ##EQU2## wherein with v the Poisson transverse contraction co-efficient of the tubular cavity resonator-material, with .delta. the wall thickness of the tubular cavity resonator and with D.sub.0 the outer diameter of the tubular cavity resonator are indicated.
The hereafter provided deviations from the relationship or equation (1) can be very small, so that the equation or relationship (2) with respect to the relationship for equation (1) produces only a minimal improvement, but can however in practical cases also deviate by about approximately 40% from the result obtainable through the relationship (1), so that, in comparison with such a case, the construction according to the relationship (2) produces a substantially better result.
In a preferred embodiment of a device according to the invention there is a "weak" coupling of the tubular shaped cavity resonator and the wave guide provided, wherein weak coupling means that between the resonant oscillations of the cavity resonator, on the one hand, and the resonating-longitudinal-oscillations of the wave guide, on the other hand, a significant phase difference exists. Such a weak coupling can for example be realized thereby, that the wave guide is swingingly or flexible coupled with the cavity resonator via a yieldable spring element, which may have the form of a disc spring, is pivotably coupled with the cavity resonator. For this case, in which the wave guide must have in advance carried out a multiplicity of longitudinal oscillations, before the hollow cavity resonator is brought into resonance, that is, oscillates with maximal amplitude, the length L.sub.w thereof is provided according to the relationship ##EQU3## when at the same time or simultaneously the ultrasound is coupled into the resonator only from one side.
For a likewise given case of weak acoustic coupling between the cavity resonator and the wave guide, wherein the cavity resonator is acted upon from both its ends equiphasally with oscillation energies produced by two transducers, its length L.sub.w is determined by the relationship ##EQU4##
By the characteristics of claims 4 through 6 conditions are given, in which satisfaction of the oscillation form of the cavity resonator is completely radially symmetrical (symmetry group C.sub..sub..infin.), that is, the radial deflections in the plane extending at right angle to the central longitudinal is always equiphasic, or as the case may be the resonator in each transverse section plane is circular shaped, the cross-section of this circle however along the length of the resonator is spatially periodically varied, and in each cross-sectional plane of the resonator diameter time-wise varies periodically.

Device for transferring ultrasonic energy into a liquid or pasty medium

Tech Sonic Gesellschaft Fur Ultraschall-Technologie m.b.H.


Disclosed herein are test control circuit, semiconductor memory device, and testing method embodiments for suppressing variations in test time while reducing the influence of a failed cell. An embodiment operates by performing a first verify of a cell selected in a predetermined order; storing an address of the cell when the first verify is a fail until the number of addresses is a predetermined number; applying a predetermined voltage to a plurality of cells of an erase unit when a next fail is determined in the first verify after the predetermined number of addresses have been stored; and performing a second verify to one or more cells indicated by the predetermined number of addresses, wherein the first verify is performed from a cell at the next fail according to the predetermined order after the second verify has finished.

An erase test is generally performed in an erase unit, e.g., a sector unit in an erase test for a semiconductor memory device. For example, an erase pulse may be impressed to a memory cell group divided into a plurality of groups until a group determined to have been subjected to the completion of erasure appears in performing a first erase test. Next, a second erase test may be performed on the memory cell group on the basis of the number of erase pulses at the detection of each group determined as having been subjected to the completion of erasure (as in, for example, Japanese Unexamined Patent Application Publication No. 2013-1378445).
However, when performing the erase test with division into the plurality of groups, the address of a firstly failed cell is stored, and a predetermined voltage for erasure is applied only when a fail has been determined as to each cell in the plural groups. In an address sequencer, the erase test is performed again in an overlapping form after having returned to the stored address. That is, the erase test is continued without application of the predetermined voltage, even if the fail has been determined with respect to the cell in one group is failed, and it is possible to reduce the influence of the failed cell. In the address sequencer, however, the erase test is performed again after having returned to the stored address, and therefore a loop of addresses has occurred and dispersion has arisen at testing time.

Test control circuit, semiconductor memory device and method for testing the same


This invention relates to a method for identifying non-essential genes of the human cytomegalovirus (HCMV) genome through the insertion of a .beta.-glucuronidase marker gene into a specified HCMV gene, such that, if the product of the HCMV gene is not expressed, the gene is identified as non-essential for replication of HCMV. This invention also relates to a method of screening for compounds which inhibit HCMV by the insertion of the .beta.-glucuronidase marker gene into a HCMV gene, such that the enzyme marker is expressed and cleaves a conjugate chemical substrate in an assay system to yield a detectable fluorescing product or to result in a color change. This invention further provides the gene responsible in HCMV early cytopathic effect.

Human cytomegalovirus (HCMV) is a beta-herpesvirus and is an important opportunistic pathogen of immunocompromised adults and can cause neurological abnormalities in some infants infected in utero (1). Such infected individuals are prone to suffer from a variety of diseases, including retinitis and systemic sequelae. The 230 kilobase (kb) genome of HCMV is similar in structure to that of herpes simplex virus (HSV), another human herpesvirus (2). HCMV has long and short unique regions, UL and US, respectively, each bounded by inverted repetitions. The UL region is bounded by the TRL (terminal repeat of the long) region and the IRL (inverted repeat of the long) region. The US region is bounded by the TRS (terminal repeat of the short) region and the IRS (inverted repeat of the short) region. Sequencing of the entire HCMV genome was completed recently (3). Sequencing indicates that the cytomegalovirus genome contains over 200 significant open reading frames. To date, relatively few of these open reading frames have been studied as to the function of the proteins which they may encode.
In the HSV system, the analysis of viral mutants has proven to be invaluable in the study of the function of many viral genes. Several temperature-sensitive mutants of HSV have been described. Other studies of HSV mutants have exploited the viral thymidine kinase gene as a selectable marker for site-directed mutagenesis (4-7). Random mutagenesis of HSV through the use of mini-Mu phage and transposon Tn5 has also been reported (8,9).
More recently, the prokaryotic .beta.-galactosidase gene has been used for site-directed insertion into the HSV genome, allowing for the easy identification of viral mutants as blue plaques after overlay with a chromogenic substrate, X-gal (10,11). In contrast to conditionally lethal mutants in which mutations lie in essential genes, these latter methodologies offer the advantage that mutants in non-essential genes can be created and identified. These successful strategies for the creation of HSV mutants have not been employed to any great extent in the HCMV system.
Probably due to the long replication cycle of this virus, there have only been a few reports concerning the creation or analysis of HCMV temperature-sensitive mutants. Due to the limited host range of HCMV in tissue culture (human diploid fibroblasts), mutagenesis by exploitation of a thymidine kinase gene would be exceedingly difficult.
To date, the only successful site-directed insertion of a marker gene into the genome of HCMV has been the insertion of .beta.-galactosidase within a repeat sequence region bounding UL (12).
However, genomic DNA analyses (12) of this recombinant indicated that an unexpected deletion of 5.5-kb of viral DNA sequences adjacent to the site of the insertion had occurred. One hypothesis given for this deletion was that the size of wild-type DNA is very close to the maximal size of packageable viral DNA, so that large insertions into the wild-type genome are not tolerated without a compensatory deletion elsewhere.
At present, there are few therapeutic agents approved for use against HCMV-infected patients. Ganciclovir, a nucleoside analog sold by Syntex Laboratories, Inc., under the tradename "CYTOVENE", is approved for use against HCMV-induced retinitis. However, ganciclovir is associated with side effects such as neutropenia and azoospermia. In addition, it has low oral bioavailability and thus must be administered intravenously.
Accordingly, there is a need for additional therapeutic agents against HCMV having decreased side effects and improved modes of administration.

Human cytomegalovirus containing a .beta.-glucuronidase marker gene


A method and system for machine translation of text is disclosed. The method includes processing an image comprising a text to generate a pattern associated with the text based on a trained Convolution Neural Network (CNN). The method further includes mapping the pattern to a word in a mapping table and at least one text attribute, based on a classifier network. The method further includes initiating an Optical Character Recognition (OCR) conversion for the pattern, when at least one of the mapping between at least one of the pattern and at least one word in the mapping table and the mapping between the pattern and the at least one text attribute is below a predefined threshold. The method further includes performing incremental learning for the trained CNN and the classifier network based on the OCR conversion.

Digitization or translation of a scanned document or an image, which includes text or hand-written papers, into machine readable text is increasingly being used in several applications. For translation of the scanned document that includes characters, conventional algorithms for optical character recognition (OCR) perform efficiently. However, efficiency in performance for the conventional algorithms is limited to character recognition, as in order to process and translate large and text rich documents, the conventional algorithms take a lot of time. Moreover, the OCR often fails to accurately identify punctuations and digits, without requiring manual intervention or supervision. Additionally, the capabilities of the OCR mechanism may be restricted to a specific font, thereby further limiting robustness of a system implementing the OCR mechanism.
Some conventional methods convert word images to words that are specific to a document. In such methods, image of a word is stored, and when same word image appears, the image is decoded in same way. Moreover, other conventional methods use word spotting in bitmap images based on word bounding boxes.
However, the conventional methods have the following drawbacks. The digitization of documents happens at character level, as a result, recognition happens one by one in a word leading to issues including requirement of significant time, lack of a method to support translation of hand written words in one language to hand written words in other languages, absence of a method to check if the system can support a specific font text or not.

System and method for machine translation of text


A data transfer method and system are provided that prevent the length of a time required for writing to a flash memory from appearing on the surface as a system operation when the flash memory is used in place of an SRAM. The method of transferring data includes the steps of writing data from a controller to a volatile memory, placing the volatile memory in a transfer state, transferring the data from the volatile memory in the transfer state to a nonvolatile memory, and releasing the volatile memory from the transfer state in response to confirming completion of the transfer of the data.

1. Field of the Invention
The present invention generally relates to data transfer methods and systems for use in information processing systems, and particularly relates to a data transfer method and system for use in an information processing system which employs a plurality of different types of memory devices.
2. Description of the Related Art
Together with a recent increase in the sophistication of service functions provided in the field of mobile communications such as cellular phones, the size of data being handled increases, resulting in a need for a larger memory volume. In mobile phones, for example, service functions are provided for moving picture data (movie functions), still images (camera functions), game functions, WEB access functions, etc. The required size of memory has significantly increased compared to the time when voice communication was the main mode of communication.
In mobile telephone equipment, SRAMs (Static Random Access Memory) were used as work memory in the days when voice communication was predominant. An SRAM is comprised of 6 transistors per memory cell, and, thus, the number of devices for storing 1-bit data is relatively large compared to a DRAM (Dynamic Random Access Memory), for example, resulting in difficulties in achieving a large memory capacity. Accordingly, it is extremely difficult to attain such highly sophisticated services as described above by use of a system employing only SRAMs.
Against this background, pseudo SRAMs (PSRAMs) have been developed that use a DRAM as a memory core but provide an SRAM-type interface. The pseudo SRAM can replace the SRAM while taking advantage of the accumulation of past technologies and assets, thereby making it possible to achieve highly sophisticated services by providing a memory system having a large storage capacity.
Many of the memory systems for mobile phones use three types of memories, i.e., an SRAM, a pseudo SRAM, and a flash memory. The flash memory is used to store programs and data. The SRAM is used to store data of relatively small size such as cache data while the power is on. The pseudo SRAM is used as work memory that is used at the time of moving picture processing or the like. Each of these memories is optimized according to its usage, and its replacement is regarded as a difficult challenge. The SRAM is characterized by its low standby current consumption and high-speed read/write access, but is not suitable for achieving a large memory capacity. The SRAM is also volatile. Accordingly, the SRAM is suited to store cache data of small size, but is not suited to store programs and data, which are required to be maintained after the power is off. The flash memory has low read/write access speed, but is characterized by its nonvolatile nature and large capacity as well as low standby current consumption. Accordingly, the flash memory is indispensable for use as storage for storing programs and data which need to be sustained after the power is off. The pseudo SRAM needs refresh operations, and its standby current consumption is large. The pseudo SRAM is also volatile. However, the pseudo SRAM has a large memory capacity and high read/write access speed. Accordingly, the pseudo SRAM is suitable for use as a work memory.
The use of a plurality of memory devices in a single system gives rise to a problem of a cost increase, which results from an increase in the number of memory components inside the mobile telephone equipment. Further, the technology for grinding chips for the purpose of sealing these memories in a single package needs to be developed, and the technology for achieving an MCP (multi-chip package) needs to be developed. These are the issues that need to be addressed.
In order to obviate the problems described above, the number of types of memories used in a system needs to be reduced. In the following, problems that arise when one of the three types of memory devices is replaced with one of the remaining two memory devices will be examined.                1) Flash Memory->SRAM: insufficient capacity, data loss upon power-off        2) Flash Memory->pseudo SRAM: data loss upon power-off, large current consumption        3) SRAM->Flash Memory: lengthy write time        4) SRAM->pseudo SRAM: large current consumption        5) pseudo SRAM->Flash Memory: lengthy write time        6) pseudo SRAM->SRAM: insufficient capacity
It is difficult to overcome the problem of insufficient capacity with respect to 1) and 6). The option 2) is not viable since data is lost upon power-off. These three options are thus not possible in consideration of the mobile phone specifications and systems of the present day. It thus turns out that the flash memory is indispensable. In consideration of the issue of a write time with respect to 5), it can be said that the pseudo SRAM is also an indispensable memory device. Accordingly, the issue at hand is whether the SRAM can be replaced with another memory.
With respect to 4), the pseudo SRAM has a problem of large current consumption although some pseudo SRAMs have been developed that achieve a standby current compatible to that of the SRAM by use of such functions as a power-down mode and a partial refresh mode. Accordingly, it is preferable to replace the SRAM with the flash memory as in 3) than replacing the SRAM with the pseudo SRAM as in 4). In this case, however, there is a need to solve the problem of a lengthy write time.
Accordingly, there is a need for a data transfer method and system that prevents the length of a time required for writing to the flash memory from appearing on the surface as a system operation when the flash memory is used in place of the SRAM.


A method of designing an exhaust assembly that includes the steps: developing an initial exhaust assembly design; evaluating the initial design based on a design guide; developing an interim exhaust assembly design, or a plurality of interim exhaust assembly designs, based on the initial design and a parametric model; evaluating the interim design or designs using a computational fluid dynamics model; and developing a final exhaust assembly design based on the parametric and the fluid dynamics models.

Many vehicles currently employ exhaust systems with decorative features in close proximity to the tailpipe and related components. Often these decorative features are curved and in close proximity to exhaust soot and condensate emanating from the tailpipe of vehicles during operation. The exhaust soot and/or condensate often deposits, discolors and otherwise adversely impacts these decorative features. Customer dissatisfaction is one adverse impact associated with these effects.
Vehicles with gasoline turbocharged direct injection (GTDI) engines are particularly prone to this problem. These engines produce high levels of carbon soot due to the level of enrichment required to maintain an acceptable throttle response under wide open throttle conditions. This soot exits the tailpipe as gas-borne and condensate-borne particulate. Both mechanisms of soot contribute to high rates of soot accumulation on the vehicle surfaces in close proximity to the tailpipe, particularly decorative exhaust tips and/or rear fascia. These soot accumulation rates are higher in vehicles with GDTI engines as compared to vehicles with non-GDTI engines.
Often the design of exhaust assemblies for a vehicle is driven in significant part by aesthetic considerations with various engineering constraints governed by the power systems and other aspects of the drive system selected for a given vehicle. Conventional methods of designing exhaust assemblies are iterative and rely on numerous computer aided design (CAD)-models that are tested using computational fluid dynamics (CFD) simulation models. Typically, these CAD models are developed on a time consuming element-by-element basis and then repeatedly tested through computer simulations. Considerations related to soot accumulation and discoloration are not understood through these conventional computer simulations. Often, only expensive prototype testing uncovers these problems late in the design cycle.
Accordingly, there is a need for exhaust assemblies that eliminate and/or mitigate the adverse effects associated with soot accumulation, discoloration and the like on the surfaces of a vehicle in proximity to the tailpipe. There is also a need for a more efficient model and approach to designing exhaust assemblies for vehicles in view of these adverse effects and other engineering considerations.

This patent is subject to a terminal disclaimer.

Methods for designing an exhaust assembly for a vehicle


A method and system in a telecommunications network for visually alerting a user of an incoming call are disclosed herein. A call can be transmitted to a mobile device associated with a user of the telecommunications network. An alert can also be transmitted to one or more visual alerting devices associated with the user and/or the mobile device, in response to transmitting a call to the mobile device. A visual alerting signal can then be transmitted via the visual alerting device, in response to transmitting the alert to the at least one visual alerting device associated with the user. Each visual alerting device can provide a visually alerting signal when there is an incoming message for its user. The visual alerting device can receive its signal directly from a base station within said telecommunications network.

Wireless telephones, which include both cellular telephones and the higher frequency personal communication devices (PCDs), are growing in numbers and also shrinking in size and weight. The growth in numbers is influenced by the convenience and the per call cost of wireless telephones with respect to pagers and wire line telephones or coin telephones for completing calls, especially when the user is away from home or office. The shrinking size is influenced by two related technologies: more efficient receive/transmit processing circuits and higher power density batteries.
Wireless handsets are more frequently being carried in purses, briefcases, coat pockets where they are away from close contact with the user. As the wireless handset is carried further from the user, the ringing sound and more so the vibrator alerting become less effective. The vibrator-alerting mode is typically used in places where audible alerting would be disruptive, such as meetings or meal times. However, if the vibration is not effective because the handset is in a purse, briefcase or coat, then a call can be missed. So, there is a need in the art for another type of alerting signal for wireless telephones that is non-audible and thus not disruptive.
Some attempts at a non-disruptive alerting use a flashing handset holder or a flashing antenna. These devices by design are located in the immediate proximity of a wireless handset. So, if a wireless handset using a flashing cover or a flashing antenna is located in a purse, briefcase or loosely worn coat pocket, the visual alerting will be just as ineffective as vibrator alerting. Furthermore, these devices do not work for some wireless service providers.
Another attempt at a non-disruptive alerting signal is known from a pen that is worn clipped in a pocket or such and visually alerts the user to an incoming telephone call. This type of pen has usage limited to cellular telephones since it senses the response signal of the wireless handset to trigger its visual alerting. Further, a visual alerting signal may be triggered by someone else's cell telephone handset ringing within a 5 to 7 foot radius. This pen also flashes as it scans for signal. The flashing sequences will vary depending on service and geographic area. The pen will not flash if for all service providers.
Wireless telephones also are growing in functionality. Many wireless telephone handsets have voice-mail and there is an alerting for indicating the receipt of voice mail. Many wireless telephones have short messaging service capabilities. Other wireless telephones can connect to the Internet. And still others can take digital photographs and send the digital photographs to the other party of the telephone call. The present inventors have thus concluded that a need exists for an improved method and system, including devices thereof, which efficiently permit a user to be alerted of an incoming telephone call or receipt of other telecommunications data, such as text messages and/or e-mail. The present inventors believe that the method and system described herein meets this challenge.

Wireless visual alerting method and system


A hand-operated cutting tool in the form of shears having handle portions and cutting portions pivoted so that the cutting portions may be rotatably moved toward and away from each other. The cutting portions each include a pair of cutting edges angularly disposed with respect to each, providing an included angle there between which is obtuse. As the cutting edges are rotated toward each other, a first portion thereof are brought into sliding, overlapping contact for shearing a flexible material such as flexible ducting and a second portion thereof are brought in sliding, overlapping contact for cutting wire.

In the heating and air conditioning industry, it is common to run ducting from the source of the conditioned air to registers disposed at various positions within a structure. This allows the delivery of the conditioned air to particularly desired spaces defined within the structure. Until recently, such ducting has been constructed utilizing prefabricated or on-site fabricated sheet metal, and still is in some instances. However, it has now become more common to utilize a flexible ducting which varies in diameter from 4 inches to 22 inches and traditionally is manufactured in lengths of 25 feet. This flexible ducting is constructed of inner and outer layers of a plastic material, such as mylar, with an insulating foam or similar material sandwiched therebetween. A wire constructed of spring steel in a helical form is positioned between the layers of mylar and usually is encapsulated within the inner layer of mylar to maintain the flexible ducting in the desired cylindrical form.
During installation, the installer measures the length of flexible ducting of the desired diameter which is needed in any particular run. The available flexible ducting is then cut to the desired length and installed in place between the source of the conditioned air and the register by appropriate clamps or the like. In most cases, the distance between a source of air and a register is not exactly 25 feet or a multiple thereof. Therefore, the flexible ducting must usually be cut during installation. In the prior art, such cutting has been accomplished by utilizing a double-edged knife to sever the mylar-insulating-foam sandwich and when the spring steel wire is encountered, the knife is put aside and a pair of side-cutter pliers is utilized to cut the spring steel wire. Obviously, the utilization of two separate tools to cut the flexible ducting into the desired lengths requires more time, and often results in the cut being somewhat ragged.
Applicant is aware that there exists cutting tools of many types and in many forms. Such cutting tools take the form of shears for cutting relatively soft material and side-cutter type tools designed to cut wire or cable. Applicant is unaware if any cutting tool which includes a combination of cutting edges formed on the same blade designed specifically to cut soft material on one section thereof and a hard metal wire strand on another section thereof.


A new and distinct cultivar of crapemyrtle, Lagerstroemia indicia×L. fauriei, which is characterized by very compact, mounded growth habit; reddish-purple foliage all growing season, which holds up well in heat and humidity; high leaf powdery mildew and Cercospora leaf spot resistance; pink flowers, not as profusely borne as other Gamad varieties.

The present invention relates to a new and distinct cultivar of the ornamental flowering shrub Lagerstroemia indicia×Lagerstroemia fauriei, commonly known as crapemyrtle, and hereafter referred to by the varietal denomination 'Gamad IV'.
The new crapemyrtle originated from open-pollinated seed of 'Pocomoke' (unpatented) a compact, rose-pink flowered introduction in 1999.
1,017 seedlings were evaluated from 1999 for compact habit and year long reddish-purple foliage. 'Gamad IV' was selected as a single plant by the inventor in the summer of 1999 at Dearing, Ga.

University of Georgia Research Foundation, Inc.


The present invention relates to a composition of citric acid based emulsifiers comprising polyamides for oilfield drilling applications that exhibit very low fluorescence, and to a process for their preparation.

The present invention generally relates to a composition of citric acid based emulsifiers for oilfield drilling applications exhibiting low fluorescence. The compositions of the present invention are particularly useful in oilfield drilling applications.
Drilling generally occurs in two phases: exploration and development. Exploration activities are those operations involving the drilling of wells to locate hydrocarbon bearing formations and to determine the size and production potential of hydrocarbon reserves. Development activities involve the drilling of production wells once a hydrocarbon reserve has been discovered and evaluated.
Drilling for oil and gas is generally performed by rotary drilling methods that use a circularly rotating drill bit that grinds through the earth's crust as it descends. Drilling fluids are pumped down through the drill bit via a pipe that is connected to the bit, and serve to cool and lubricate the bit during drilling. The rock chips that are generated as the bit drills through the earth are termed drill cuttings. The drilling fluid also serves to transport the drill cuttings back up to the surface through the space between the drill pipe and the well wall, termed the annulus). The drilling fluid also controls downhole pressure and stabilizes the well bore.
As drilling progresses, large casing pipes called are inserted into the well to line the well wall. Drilling continues until the hydrocarbon bearing formations are encountered. In areas where drilling fluids and drill cuttings are allowed to be discharged under the current regulations, well depths range from approximately 1219 to 3658 meters deep, and it takes approximately 20 to 60 days to complete drilling.
On the surface, the drilling fluid and drill cuttings undergo an extensive separation process to remove as much fluid from the cuttings as possible. The fluid is then recycled into the system, and the cuttings become a waste product. The drill cuttings retain a certain amount of the drilling fluid that is discharged or disposed with the cuttings. Drill cuttings are discharged by the shale shakers and other solids separation equipment. Drill cuttings are also cleaned out of the mud pits and from the solid separation equipment during displacement of the drilling fluid system. Intermittently during drilling, and at the end of the drilling process, drilling fluids may become wastes if they can no longer be reused or recycled.
In the relatively new area of deepwater drilling, generally greater than 914 meters water depth, new drilling methods are evolving which can significantly improve drilling efficiencies and thereby reduce the volume of drilling fluid discharges as well as reduce non-water quality effects of fuel and steel consumption and air emissions. Subsea drilling fluid boosting, referred to as subsea pumping is one such technology. Rotary drilling methods are generally performed as described with the exception that the drilling fluid is energized or boosted by use of a pump at or near the seafloor. By boosting the drilling fluid, the adverse effect on the wellbore caused by the drilling fluid pressure from the seafloor to the surface is eliminated, thereby allowing wells to be drilled with as much as a 50% reduction in the number of casing strings generally required to line the well wall. Wells are drilled in less time, including less trouble time. To enable the pumping of drilling fluids and cuttings to the surface, some drill cuttings, larger than approximately one-fourth of an inch, are separated from the drilling fluid at the seafloor since these cuttings cannot reliably be pumped to the surface. The drill cuttings that are separated at the seafloor are discharged through an eductor hose at the seafloor within a 91 meter radius of the well site. For purposes of monitoring, representative samples of drill cuttings discharged at the seafloor can be transported to the surface and separated from the drilling fluid in a manner similar to that employed at the seafloor. The drilling fluid, which is boosted at the seafloor and transports most of the drill cuttings back to the surface, is processed as described in the general rotary drilling methods described above in this section.
Once the target formations have been reached, and a determination made as to which have commercial potential, the well is made ready for production by a process termed "completion". Completion involves cleaning the well to remove drilling fluids and debris, perforating the casing that lines the producing formation, inserting production tubing to transport the hydrocarbon fluids to the surface, and installing the surface wellhead. The well is then ready for production, or actual extraction of hydrocarbons.
Drilling fluids and drill cuttings are the most significant wastestreams from exploratory and development well drilling operations. Recently proposed regulations establish discharge limitations for drilling fluids in areas where drilling fluids and drill cuttings are allowed for discharge. These discharge areas are the offshore waters beyond 4.8 kilometers from shore except the offshore waters of Alaska which has no 4.8 kilometer discharge restriction, and the coastal waters of Cook Inlet, Ak. Drilling is currently active in three regions in these discharge areas: (i) the offshore waters beyond three miles from shore in the Gulf of Mexico (GOM), (ii) offshore waters beyond three miles from shore in California, and (iii) the coastal waters of Cook Inlet, Ak. Offshore Alaska is the only other area where drilling is active and effluent guidelines allows discharge. However, drilling wastes are not currently discharged in the Alaska offshore waters. Increased activity in the deepwater increases the usefulness of synthetic based drilling fluids. Operators drilling in the deepwater cite the potential for riser disconnect in floating drill ships, which favors synthetic fluids; higher daily drilling cost which more easily justifies use of more expensive synthetic based fluids; and greater distance to barge drilling wastes that may not be discharged.
As a result of recently proposed regulations, it is desirable to provide drilling fluids having low fluorescence. Fluorescence is a relative brightness test and discharged drilling fluids having low fluorescence are less likely to impart a sheen to the ocean's surface. Accordingly, it is the primary object of the present invention to provide citric acid based emulsifiers for oilfield drilling applications exhibiting low fluorescence.

Citric acid based emulsifiers for oilfield applications exhibiting low fluorescence


A bobbin includes a first winding frame to wrap primary winding coils thereon, a first winding chassis defining a first opening to receiving the first winding frame therein, a pair of second winding chassis positioned at two opposite ends of the bobbin and each defining a second opening, a pair of second winding frames received in the second openings of the second winding chassis to wrap secondary winding coils thereon, and a receiving hole extending through the second winding chassis and the first winding frame. The first winding frame is positioned between the second winding chassis. Each of the second winding frames defines a through hole communicating with the receiving hole. The first opening of the first winding chassis faces to a first direction, and each of the second openings of the second winding chassis faces to a second direction different from the first direction.

1. Technical Field
The present disclosure generally relates to transformers, and more particularly to a transformer with separated bobbin.
2. Description of Related Art
A transformer has become an essential electronic component for various kinds of electronic devices. FIG. 4 illustrates a schematic diagram of a commonly used transformer 10. The transformer 10 includes a U-U shaped core assembly 13, a pair of primary winding coils 11 positioned on a side of the core assembly 13, and a pair of secondary winding coils 12 positioned on another side of the core assembly 13. A beeline distance D1 between the pair of primary winding coils 11 and the pair of secondary winding coils 12 is great to avoid arcing therebetween, resulting in a large transformer 10, whose design resists attempts to minimize the electronic device.
Therefore, a need exists in the industry to overcome the described limitations.


An arrangement (apparatus and method) for detecting jitter caused during transport of digitally-coded information, such as MPEG-encoded data packets, and for correcting time stamp reference values in accordance with the detected jitter. The disclosed arrangement detects program clock reference (PCR) values from an MPEG-encoded transport stream, where each PCR value represents an expected arrival time of a corresponding stream segment. An actual arrival time for the corresponding stream segment is determined in response to detection of the corresponding PCR value and an independent clock signal. The expected arrival time of the stream segment and the actual arrival time are correlated with an accumulation of expected and actual arrival times of previously-received data packet stream segments in order to determine the jitter and the desired expected arrival time of the corresponding stream segment. The jitter is corrected by a combination of adaptive buffering techniques and restamping the PCR value with corrected values coinciding with the actual arrival time of the stream segments. The disclosed arrangement may be implemented in a receiver system, or as part of the network node that minimizes the effects of cell delay variation in an ATM network.

There is a trend in the communications industries to develop digital systems that provide more efficient transmission of information. This development is found in digital cellular telephone systems, facsimile transmission systems, data networking systems, and video distribution systems. A number of systems have recently been proposed for distributing information in digital data form using Asynchronous Transfer Mode (ATM) technology.
ATM technology has been designed with the intention of providing service for a wide variety of applications such as voice, video, and data. Each of these applications has different service requirements in terms of cell loss, time delay, and cell delay variation. For example, voice traffic can withstand a small amount of cell loss, but it is rather intolerant to time delay and cell delay variation. Due to the asynchronous statistical nature of ATM, voice traffic must be smoothed at the receiver end in order to eliminate any accumulated cell delay variation incurred in the network. The requirements for video traffic are somewhat dependent upon coding and compression schemes. These coding schemes can produce either constant bit-rate or variable bit-rate traffic. Data services can withstand a considerable amount of time delay and cell delay variation, but cannot lose any information, or else retransmission is required. Video traffic can typically tolerate a small amount of cell loss, however, it is sensitive to time delay and cell delay variation, and asynchronous transport of video creates a number of problems as discussed more fully below.
Various wideband digital distribution networks have been proposed for offering subscribers an array of video services, including true Video On Demand Service. For example, U.S. Pat. No. 5,247,347 to Litteral et al., assigned in common with the present invention and incorporated herein in its entirety by reference, integrates a public switched telephone network with video-on-demand service. A Digital Cross-connect System (DCS) receives compressed video data from a video provider and supplies the video data to selected central office (CO) interfaces. Electronic devices associated with the subscriber loops modify the transmission characteristics of the subscriber loops to permit delivery of full motion video information over existing loop plant facilities.
Such wideband distribution networks transport digitized, compressed video program information supplied from a video headend in order to improve transport efficiency. For example, MPEG (moving picture experts group) is a broad generic standard for digital video program compression. A number of specific compression algorithms satisfy MPEG requirements. MPEG-2 is a second generation compression standard capable of encoding video program material into a 6 Mbits/sec bit stream and packetizing a number of 6 Mbits/sec channel streams into a single higher rate signal transport stream.
At the subscriber premises, the digital compressed program stream transported by the wideband digital distribution networks must be recovered in order to provide the video information to video display systems for displaying the video information to the subscribers. Unlike a computer data file composed of data downloaded from a remote server for use in a local computer, certain applications such as voice reproduction and presentation of animated video requires synchronous presentation in order to provide intelligible information to the user. Video data, by definition, consists of "real-time" information, requiring synchronization of the encoding and decoding processes to insure accurate real-time reproduction for viewing. Various MPEG receiver systems have been developed to synchronize MPEG decoders to a received MPEG-encoded stream. Basic MPEG receiver systems synchronize internal clocks to received time stamp values, known as Program Clock Reference (PCR) values, by sampling the PCR values, calculating the difference between the sampled PCR values and counted internal clock values (C) between PCR samples to obtain an error signal, and outputting an error signal to the internal clock to synchronize the internal clock according to the calculated difference.
U.S. Pat. No, 5,396,497 to Veltman discloses an MPEG I demultiplexer/decoder including a clock producing a time reference, and a demultiplexing switch separating a composite data stream into audio sample batches, audio time stamps, video frames, and video time stamps. The disclosed demultiplexer/decoder also includes an audio phase locked loop that produces an audio timing signal in response to the audio time stamps and time reference, and a video phase-locked loop that produces a video timing signal in response to the video time stamps and the timing signal. The audio timing signal and the video timing signal are supplied to audio and video decoders, respectively. Data packets in the MPEG I stream, referred to as a system clock reference (SCR), are used to control the transfer data rate in the decoder. The SCR is used during initialization of the device in order to synchronize the phase-locked loops with the respective data streams.
U.S. Pat. No. 5,381,181 to Deiss discloses a clock recovery apparatus for an MPEG I decoded signal. According to Deiss, the receiver comprises a counter, responsive to a controlled receiver clock signal, that is sampled at the arrival of a count value embedded in the MPEG transport layer. The differences of successive sampled count values from the receiver counter are compared with the differences of corresponding successive values of the MPEG count value in the MPEG transport layer to provide a signal to control the receiver clock signal.
FIG. 1 is a simplified block diagram of the clock recovery apparatus disclosed in Deiss. The clock recovery apparatus comprises a PCR detector 10 that receives a MPEG I-encoded data stream. The MPEG stream comprises count values, denoted program clock references (PCR), embedded as auxiliary data within the transport packets. As disclosed in Deiss, these PCRs are supplied during encoding of the video signal as presentation time stamps in order to provide lip synchronization of associated audio and video information at the receiver.
The PCR detector 10 produces a control pulse 10a to a counter 12 upon the detection of a PCR value in the data stream. The counter 12 is driven by a voltage controlled oscillator (VCXO) 14. Upon receiving the control pulse 10a, the counter 12 outputs the count value to a subtraction circuit 16, and resets itself to restart counting modulo 230 in response to the count pulses from the VCXO 14. The subtractor 16 calculates an error signal (E) in response to the differences between the detected PCR values from the MPEG stream and the counted values (L) latched from the counter 12. Thus, according to Deiss, the error signal E is calculated by the subtractor 16 according to the following equation: EQU E=.vertline.PCR.sub.n -PCR.sub.n-1 .vertline.-.vertline.L.sub.n L.sub.n-1.vertline.
The calculated error signal E is passed through a low pass filter 18 and then applied to the VCXO 14, designed to operate substantially at 27 MHz. The error signal E is utilized to condition the voltage controlled oscillator 14 to a frequency tending to equalize the differences between the counted values output by the counter 12 and the detected PCR values from the MPEG stream to enable the MPEG stream to be decoded by the MPEG decoder 20. Thus, Deiss contemplates adjusting the system clock to synchronize with the detected PCR stream.
As disclosed in Deiss, the digital video signal transmission arrangement generates presentation time stamps (PTRs) in response to a fixed frequency 27 MHz clock in the encoder. In addition, the receiver system of Deiss is intended to perform the inverse function of the encoder and transmitting modem at the transmitting headend. As such, Deiss assumes that there is no differential delay in the transport of the MPEG encoded stream, such that the detected PCR values at the receiver end represent an interarrival time corresponding to the interdeparture time defined by the system clock at the encoder.
However, attempts to improve the core switching, multiplexing and transmission technologies in integrated digital networks for transport of voice, data and video services to multiple users may cause differential delays in the transport of the digital data. ATM provides broad-bandwidth, low delay, packet switching and multiplexing at speeds of 1.544 Mbit/s to 1.2 gigabits per second (Gbit/s), whereby usable capacity can be assigned dynamically (on demand) by allocating bandwidth capacity to fixed-sized information-bearing units called "cells". Each cell contains header and information fields. The ATM standard, CCITT.121/2 specifies a 53 byte cell which includes a 5 byte header and a 48 byte payload.
The conversion of MPEG-2 data into ATM cell format, however, may impose differential timing delays due to the transport of the ATM cells throughout the network. The "asynchronous" nature of ATM causes timing problems in reception and reproduction of certain types of broadband information.
Further, certain transmission protocols may require a stream of continuous data. Thus, an ATM data stream carrying MPEG video data may need to be padded with ATM idle cells, or "dummy cells", in order to ensure proper synchronization with the physical layer. Adding such idle cells may create delays between the ATM cells carrying the respective PCR values of the MPEG stream. Moreover, delays in the ATM cell stream are introduced each time an ATM cell stream passes through an ATM switch. Finally, different ATM cell streams may be multiplexed together to improve transport efficiency in the broadband network. For example, commonly-assigned, copending application Ser. No. 08/380,744, filed Jan. 31, 1995, entitled "Full Service Network Using Asynchronous Transfer Mode Multiplexing" (attorney ref: 680-109), the disclosure which is incorporated in its entirety by reference, discloses an ATM edge device which is used to multiplex a plurality of ATM cells from different input sources onto a reduced number of output paths by combining the cell streams from the different sources.
The delay imposed by each of these different ATM processes varies over time, for example as a function of the data rates of input cells and resultant loading on each ATM processing device. For such reasons, the delay imposed on one cell in a particular stream may vary with respect to the next cell in the same stream.
Thus, an ATM cell stream passing through different ATM network components undergoes cell delay variation, whereby the cell transport rate at a receiving end is different than the cell transport rate at the transmitting end. In other words, ATM transport of MPEG-encoded information causes a variation in the interarrival time between the MPEG packets carried by the ATM cells. The cell delay variation may create a delay on the order of one millisecond, causing the synchronous payload data within the received ATM cell stream to lose the data rate originally output at the transmitting end before conversion to an ATM cell stream. Thus, the reconstructed MPEG stream may have PCR values that do not accurately reflect the interarrival time for the MPEG stream segment due to the differential delay caused by the cell delay variation. Thus, transport through an ATM network creates jitter in the MPEG stream caused by cell delay variation ATM cells carrying the MPEG stream.
As discussed above, the prior art receiver systems assume no differential delay in the PCR values stored in the MPEG stream and assure a uniform, constant delay between data packets. Thus, these prior art systems would be unable to compensate for jitter in the received MPEG stream. Moreover, the jitter in the received MPEG stream in FIG. 1 may cause a miscalculation in the error signal (E) supplied to the VCXO 14, resulting in a loss of synchronization. Thus, any jitter in a received MPEG stream would result in a degradation in receiver performance.
Moreover, a data stream passing through an ATM network receives additional cell delay variation each time the data stream passes through another network component (also referred to as network element or network node), such as an ATM switch. As networks become more complex, data streams may have a greater tendency to reach an unacceptable level of cell delay variation unless the cell delay variation at each node is carefully monitored. Further, the amount of cell delay variation may increase as the performance of a network node deteriorates over time due to hardware or software failures, or traffic overload.

Apparatus and method for correcting jitter in data packets


Bone matrix compositions having nanoscale textured surfaces and methods for their production are provided. In some embodiments, bone matrix is prepared for implantation and retains nanoscale textured surfaces. In other embodiments, nanostructures are imparted to bone matrix wherein collagen fibrils on the surface of the bone matrix have been compromised, thus imparting a nanoscale textured surface to the bone matrix. Generally, these methods may be applied to mineralized or demineralized bone including partially or surface demineralized bone.

Overview of Bone Grafts
The rapid and effective repair of bone defects caused by injury, disease, wounds, or surgery is a goal of orthopedic surgery. Toward this end, a number of compositions and materials have been used or proposed for use in the repair of bone defects. The biological, physical, and mechanical properties of the compositions and materials are among the major factors influencing their suitability and performance in various orthopedic applications.
Autologous cancellous bone ("ACB"), also known as autograft or autogenous bone, is considered the gold standard for bone grafts. ACB is osteoinductive and nonimmunogenic, and, by definition, has all of the appropriate structural and functional characteristics appropriate for the particular recipient. Unfortunately, ACB is only available in a limited number of circumstances. Some individuals lack ACB of appropriate dimensions and quality for transplantation, and donor site pain and morbidity can pose serious problems for patients and their physicians.
Much effort has been invested in the identification and development of alternative bone graft materials. Urist published seminal articles on the theory of bone induction and a method for decalcifying bone, i.e., making demineralized bone matrix (DBM). Urist M. R., Bone Formation by Autoinduction, Science 1965; 150(698):893-9; Urist M. R. et al., The Bone Induction Principle, Clin. Orthop. Rel. Res. 53:243-283, 1967. DBM is an osteoinductive material in that it induces bone growth when implanted in an ectopic site of a rodent, at least partially because of the osteoinductive factors contained within the DBM. Honsawek et al. (2000). It is now known that there are numerous osteoinductive factors, e.g., BMP2, BMP4, BMP6, BMP7, which are part of the transforming growth factor-beta (TGF-beta) superfamily. BMP-2 has become the most important and widely studied of the BMP family of proteins. There are also other proteins present in DBM that are not osteoinductive alone but still contribute to bone growth, including fibroblast growth factor-2 (FGF-2), insulin-like growth factor-I and -II (IGF-I and IGF-II), platelet derived growth factor (PDGF), and transforming growth factor-beta 1 (TGF-beta.1).
Accordingly, a known technique for promoting the process of incorporation of osteoimplants is demineralization over outer surfaces, inner surfaces, or the entire volume of the implant. Various methods for demineralizing bone have been discussed. In this regard see, Lewandrowski et al., J. Biomed Materials Res, 31, pp. 365 372 (1996); Lewandrowski et al., Calcified Tiss. Int., 61, pp. 294 297 (1997); Lewandrowski et al., J. Ortho. Res., 15, pp. 748 756 (1997), the contents of each of which is incorporated herein by reference.
DBM implants have been reported to be particularly useful (see, for example, U.S. Pat. Nos. 4,394,370, 4,440,750, 4,485,097, 4,678,470, and 4,743,259; Mulliken et al., Calcif Tissue Int. 33:71, 1981; Neigel et al., Opthal. Plast. Reconstr. Surg. 12:108, 1996; Whiteman et al., J. Hand. Surg. 18B:487, 1993; Xiaobo et al., Clin. Orthop. 293:360, 1993, each of which is incorporated herein by reference). DBM typically is derived from cadavers. The bone is removed aseptically and treated to kill any infectious agents. The bone is particulated by milling or grinding, and then the mineral component is extracted by various methods, such as by soaking the bone in an acidic solution. The remaining matrix is malleable and can be further processed and/or formed and shaped for implantation into a particular site in the recipient. The demineralized bone particles or fibers can be formulated with biocompatible excipients to enhance surgical handling properties and conformability to the defect or surgery site. Demineralized bone prepared in this manner contains a variety of components including proteins, glycoproteins, growth factors, and proteoglycans. Following implantation, the presence of DBM induces cellular recruitment to the site of injury. The recruited cells may eventually differentiate into bone forming cells. Such recruitment of cells leads to an increase in the rate of wound healing and, therefore, to faster recovery for the patient.


The present invention provides a method for the effective dispersion of carbon nanotubes into a polymer matrix. Through a combination of dispersion through sonication, in situ polymerization, dissolution, and film casting, transparent polymer carbon nanotube composites are produced.

Carbon nanotubes were discovered in 1991 by Iijima on the negative electrode during the direct current arching of graphite for the preparation of fullerenes. Nanotubes are concentric graphitic cylinders closed at either end due to the presence of five membered rings. Carbon nanotubes can either be multi walled or single walled. Multi-walled nanotubes (MWNT) have a central tubule surrounding graphitic layers whereas single walled nanotubes (SWNT) have only one tubule and no graphitic layers.
Single-walled carbon nanotubes (SWNT) have moved to the forefront of present and future nanoscale discoveries that will serve as a portal into the enhancement of modern technology. Many different applications of carbon nanotubes have recently been developed, including the use of nanoscale transistors and chemical sensors. Carbon nanotubes exhibit a high aspect ratio, mechanical strength, and high moduli. These properties have spurred an interest in fabricating polymer-nanotube composites.
Composites are developed to achieve desired properties that cannot be obtained from the individual components. By fabricating materials with properties of the individual components and creating a material with novel properties that are specific to the composite and not to the individual components, a stronger and more useful material exists. As a result, polymer-nanotube composites have several useful applications such as structural supports for building, spacecrafts, and military aircrafts, non-linear optics, nano-wires, battery cathodes and ionics.
Various methods are known in the art to disperse carbon nanotubes in a polymer matrix. These known methods include: (1) solution mixing of polymer and carbon nanotubes; (2) a combination of sonication and melt processing; (3) melt blending and; (4) in-situ polymerization in the presence of nanotubes.
Advancements are known in the art providing methods of carbon nanotube dispersion in a polymer matrix, however the resulting nanocomposites produced to date exhibited limited transparency in the visible range.
There remains a need, therefore, for a method of preparation for nanocomposites that overcomes the shortcoming previously experienced with the dispersion of CNTs in polymer matrices. The resulting novel nanocomposites exhibit increased transparency and improved dielectric properties.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified need could be fulfilled.

Transparent polymer carbon nanotube composites and process for preparation


Methods, devices, and systems for a) revascularization and/or b) performing other medical procedures at vascular or non-vascular intracorporeal locations within a mammalian body. The methods generally comprise the formation of at least one extravascular passageway from a blood vessel to a vascular or non-vascular target location. In the revascularization methods the extravascular passageway is utilized for blood flow. In the medical procedure methods the extravascular passageway is utilized as a conduit for accessing or performing procedures at the vascular or non-vascular target location. Also disclosed are catheter devices and systems which are useable to form the extravascular passageways of the invention, as well as apparatus for modifying, maintaining and/or closing such extravascular passageways.

A. Background Relating to Revascularization Procedures
In modern medical practice, it is often desirable to bypass segments of artery which have become obstructed, diseased or injured. The typical surgical procedures used for bypassing of obstructed, diseased or injured segments of blood vessel require open surgical exposure of the artery, and the attachment (e.g., suturing) of a tubular graft (e.g., homograft, xenograft, allograft, prosthetic or bioprosthetic graft) to the affected artery such that one end of the graft is connected upstream of the obstructed, diseased or injured segment, and the other end of the graft is connected to the artery downstream thereof. In this manner, arterial blood is channeled through the bypass graft, thereby restoring blood flow distal to the obstructed, diseased or injured segment of artery, and preventing tissue ischemia, infarction, and other sequelae which may result from impaired blood flow through the affected artery.
Although surgical bypass grafting of arteries has been performed at various locations within the body, it is most typical for such arterial bypass procedures to be performed for the treatment of either i) coronary artery disease or ii) peripheral vascular disease affecting the lower extremities.
i. Coronary Artery Disease
Coronary artery disease continues to be one of the leading causes of morbidity and mortality, throughout the world. The typical etiology of coronary artery disease is characterized by the build-up of atherosclerotic plaque within the coronary arteries. Such deposits of atherosclerotic plaque tend to fully or partially block the flow of blood through the affected coronary arteries, and if untreated can result in myocardial ischemia, infarction and death.
For many years, the traditional surgical treatment of coronary artery disease has been coronary artery bypass surgery wherein the patient is generally anesthetized, placed on cardiopulmonary bypass and the patient's heart is temporarily stopped. A thoracotomy (e.g., a median sternotomy) is performed and the obstructed coronary blood vessels are exposed by surgical dissection. One or more segments of the patient's saphenous vein or internal mammary artery is/are harvested for use as bypass graft(s). The harvested segment(s) of vein or artery is/are then anastomosed to the obstructed coronary artery(ies) to form bypass conduit(s) around the arterial obstruction(s). Such traditional coronary artery bypass surgery is expensive, extremely invasive, and is associated with significant operative and preoperative complications.
One alternative to traditional coronary artery bypass surgery is balloon angioplasty. In balloon angioplasty, a flexible guide catheter is percutaneously inserted into a peripheral artery (e.g., the femoral artery) and is transluminally advanced through the vasculature until the distal tip of the catheter is within the ostium of an obstructed coronary artery. Thereafter, a balloon catheter is passed through the guide catheter and into the obstructive lesion. The balloon of the balloon catheter is inflated one or more times to dilate coronary artery in the region of the obstructive lesion. These balloon angioplasty procedures tend to be less expensive and less traumatic than traditional coronary artery bypass surgery. However, balloon angioplasty procedures of this type may be associated with a significant incidence of restenosis at the angioplasty site. The cause and mechanism of such restenosis continues to be the subject of ongoing study. However, such restenosis has generally been attributed to either a) an increase in the mass of the artery wall (e.g., neointima formation), b) a thickening of the artery wall without substantial change in it's mass (e.g., vascular remodeling) and/or c) radial contraction of the balloon-dilated artery wall upon healing of cracks and fissures that have been created by the balloon dilation process.
Another alternative to traditional coronary artery bypass surgery is intraluminal removal (e.g., atherectomy) or ablation (e.g., ultrasound, laser) of the obstructive matter within the coronary artery. These intraluminal removal or ablation procedures are performed by passing a catheter-mounted removal or ablation apparatus through the vasculature to the site of the coronary obstruction. The catheter-mounted removal or ablation apparatus is then utilized to cut, shave, sonicate, pulverize, or vaporize or otherwise ablate the obstructive matter from the lumen of the coronary artery. These procedures must be performed with caution to avoid perforation or damage to the artery wall, as such perforation or damage can result in hemorrhage or excessive scaring and subsequent reocclusion of the artery lumen. Furthermore, these ablative procedures may, in some cases at least, be confounded by the need to meticulously contain and remove dislodged or severed fragments of the obstructive matter, in order to prevent such fragments of obstructive matter from escaping into the patient's circulatory system. Examples of atherectomy catheters and other catheter-mounted ablative apparatus are described in U.S. Pat. No. 3,433,226 (Boyd), U.S. Pat. No. 3,823,717 (Pohlman, et al.), U.S. Pat. No. 4,808,153 (Parisi), U.S. Pat. No. 4,936,281 (Stasz), U.S. Pat. No. 3,565,062 (Kuris), U.S. Pat. No. 4,924,863 (Sterzer), 4B70,953 (Don Michael, et al.), U.S. Pat. No. 5,069,664 (Suess, et al.), U.S. Pat. No. 4,920,954 (Alliger, et al.) and U.S. Pat. No. 5,100,423 (Fearnot), as well as foreign patents/patent publications EP0347098A2 (Shiber), WO87-05739 (Cooper), WO89-06515 (Bernstein, et al.), WO90-0130 (Sonic Needle Corp.), EP316789 (Don Michael, et al.), DE 3,821,836 (Schubert), DE2438648 (Pohlman), and EP 0443256A1 (Baruch).
Other alternatives to traditional coronary artery bypass surgery have included minimally invasive endoscopic procedures which may, ostensibly at least, be performed through small (e.g., 1-3 cm) incisions formed in the patient's chest wall, by insertion of a thoracoscope and associated operative instruments through such incisions. One such minimally invasive coronary bypass procedure is described in U.S. Pat. No. 5,452,733 (Sterman et al.). If perfected, these minimally invasive coronary artery bypass procedures may lessen the discomfort and length of recovery time experienced by patients who undergo such minimally invasive procedures vis a vis those who undergo traditional coronary artery bypass surgery. However, endoscopic surgical procedures of this type typically require a great deal of operator skill and training. Furthermore, as with traditional coronary artery bypass surgery, these thoracoscopic procedures are typically performed under general anesthesia, and typically require that one or more chest tubes be left in place during the postoperative period to drain any blood which leaks from the graft anastomoses and to reduce the pneumothorax which has been orated by the formation of full-thickness incision(s) in the chest wall. Moreover, some of these thoracoscopic coronary artery bypass procedures require that the patient be placed on cardiopulmonary bypass, and that the patient's heart be temporarily stopped. Others of these thoracoscopic procedures purport to be useable without placing the patient on cardiopulmonary bypass, and without stopping the heart. However, those thoracoscopic procedures which purport to be useable without cardiopulmonary bypass and heart stoppage are relatively complex to perform and typically require temporary clamping or ligating of the coronary artery which is to be bypassed. Accordingly, even those thoracoscopic procedures which may be useable without cardiopulmonary bypass/heart stoppage are prone to unique and significant risks and difficulties due to the complexities of the procedure and the need for temporary clamping or closing off the coronary artery(s) being bypassed. Thus, many of the drawbacks associated with traditional coronary artery bypass surgery, as well as additional potential drawbacks, may be associated with these minimally invasive thoracoscopic procedures.
Another previously described procedure which does not actually bypass coronary artery obstructions but which nonetheless may be useable to improve blood flow to ischemic regions of the myocardium, is a procedure known as transmyocardial revascularization (TMR). In the TMR procedure a tissue-penetrable probe, such as a laser probe, is utilized to form numerous full-thickness penetrations through the ischemic myocardial wall, and into the chamber of the left ventricle. Oxygenated blood from the left ventricle then flows outwardly through such penetration tracts, so as to perfuse the ischemic myocardium. Examples of such transmyocardial revascularization procedures are described in U.S. Pat. No. 5,554,152 (Aita et al.), U.S. Pat. No. 5,380,316 (Aita et al.), and U.S. Pat. No. 5,125,926 (Linhares et al.)
One modification of the TMR procedure requires the formation of a valved and/or internally stented transmyocardial passageway (e.g., an interstitial tunnel formed in the muscular wall of the heart) from the left ventricle of the heart to an obstructed coronary artery, downstream of the obstruction. Such modified TMR procedure, is described in U.S. Pat. No. 5,287,861 (Wilk), U.S. Pat. No. 5,409,019 (Wilk), and U.S. Pat. No. 5,429,114 (Wilk).
ii. Peripheral Vascular Disease
Peripheral vascular disease commonly results from the build up of atherosclerotic plaque and/or thrombotic matter within peripheral arteries. In many cases, when arteries of the lower extremities have become obstructed by peripheral vascular disease, a phenomenon known as intermittent claudication results. Intermittent claudication is characterized by the occurrence of pain and progressive weakness in the legs during exertion (i.e., walking or running).
The typical surgical approach to the treatment of peripheral vascular disease, especially in patients who exhibit symptoms of intermittent claudication, is to surgically expose the affected artery and to anastomose a tubular bypass graft (e.g., a tube of woven polyester or expanded polytetrafluoroethylene (ePTFE)) to the affected artery such that one end of the graft is attached upstream of the obstruction, and the other end of the graft is attached downstream of the obstruction. In this manner, arterial blood will flow through the tubular bypass graft and around the arterial obstruction, thereby restoring blood flow to the portion of the artery downstream of the obstruction.
One alternative to traditional arterial bypass graft surgery for the treatment of peripheral vascular disease of the lower extremities, is a procedure known as in situ vein bypass. These in situ vein bypass procedures are typically carried out by forming at least two (2) open incisions in the leg, to expose the affected artery at sites upstream and downstream of the obstruction. A peripheral vein, which extends through the leg generally parallel to the affected artery, is then prepared by inserting an instrument into the vein to lyse or disrupt the venous valves located within the vein. Thereafter, any side branches which extend from the vein are cut, ligated or blocked by embolization. The prepared vein is then transected at locations above and below the arterial obstruction, and the transected ends of the vein are placed in contact with, and sutured directly to, the artery at sites upstream and downstream of the obstruction. In this manner, arterial blood flow becomes channeled through the prepared segment of vein, such that the prepared segment of vein will act as bypass conduit around the arterial obstruction. Examples of current in situ vein bypass procedures are described in White, R. A. and Fogarty, T. J., Peripheral Endovascular Interventions, Pgs., 166-169, Mosby & Co. (1996).
iii. Trauma and Other Diseases Which May Impair Flow Through Arteries
Various arteries of the body may become damaged by trauma (e.g., lacerations, crushing injury, blunt abdominal trauma) or may become invaded or compressed by extra-vascular disease processes (e.g., to proliferation and ingrowth of an adjacent tumor). The typical surgical approach to treatment of arteries affected by such trauma or disease is to surgically expose and direct the affected segment of artery, and to thereafter a) resect and reconnect or b) bypass the affected segment of artery, to restore arterial blood flow through or around the affected segment of the artery. In many such cases, the segment of artery affected by the injury or disease may be so large as to preclude simple resection, removal of the affected segment, and end-to-end anastomosis of the adjacent cut ends of the artery. Accordingly, in such instances where resection and end-to-end anastomosis is not an available option, it may be desirable to attach a tubular bypass graft (e.g., a tubular graft formed of woven polyester, or ePTFE) to the affected artery, to bypass the affected segment of the artery.
Although a number of the above-described surgical procedures represent relatively recent advancements whereby the invasiveness and risk associated with traditional surgical approaches have been mitigated, there remains a need in the art for the development of new, safe, and reliable minimally invasive and/or transluminal procedures for bypassing segments of arteries which have become obstructed, injured or affected by disease.
B. Background Relating to Other Extravascular Surgical/Interventional Procedures
Many types of surgical and interventional procedures have previously been formed in organs, tissues or body cavities of the body. Traditionally, access to such organs, tissues or body cavities is attained through the formation of one or more open surgical incisions in the body, whereby the affected organs, tissues or body cavities are surgically exposed.
In recent years, substantial efforts have been undertaken to develop "minimally invasive" surgical techniques whereby one or more endoscopes are utilized to view the affected organ, tissue or body cavity, operative instruments or other devices are inserted into the body to accomplish the desired surgical or interventional procedure through relatively small, "minimal access" (e.g., less than 3 cm) incisions.
Although the advent of these endoscopic "minimal access" surgical procedures may have advantageous over traditional open surgical techniques insofar as they may minimize the size of the surgical incision, and accordingly, may lead to less post-operative discomfort, such endoscopic procedures are often limited to procedures within accessible body lumens or cavities which may be filled with clear liquid or insufflated with a gas to provide an open area within which to place the operative endoscope(s) and instrument(s).
In view of the limitations associated with the even the most modern "minimal access" surgical and interventional procedures, there remains a need in the art for the development of new methods and apparatus for accessing tumors, organs, tissues and other extravascular locations within the body, to permit the performance of surgical and/or interventional procedures without the need for forming any open surgical incisions in the body.

Methods and apparatus for bypassing arterial obstructions and/or performing other transvascular procedures