A method of evaluating the immunosuppressive activity of a compound including contacting the compound with calcineurin and determining the ability of the compound to bind to the calcineurin. The ability to bind to the calcineurin is positively correlated to the immunosuppressive activity of the compound.

This invention relates to agents which decrease the immune response, i.e., immunosuppressive agents.
Cyclosporin A (CsA), a cyclic undecapeptide of fungal origin, and FK506, a neutral macrolide of fungal origin, are potent immunosuppressants. Despite their lack of structural similarities, CsA and FK506 have similar biological properties (Johansson et al., 1990, Transplant. 50:1001; Lin et al., 1991, Cellular Immunol. 133:269). Both molecules interfere with a T-cell receptor-mediated signaling pathway that results in the transcription of early T cell activation genes, although FK506 is able to do so at 100-fold lower concentrations (Tocci et al., 1989, J. Immunol. 143:718).

President and Fellows of Harvard College

Board of Trustees of the Leland Stanford Junior University


Methods, non-transitory computer readable media, and computing devices that receive data from a primary storage node. The data is stored in a primary volume within a primary composite aggregate hosted by the primary storage node. A determination is made when the data is tagged to indicate that the data is stored in the primary volume on a remote data storage device of the primary composite aggregate. The data is stored on another remote data storage device without storing the data in a local data storage device, when the determining indicates that the data is tagged to indicate that the data is stored in the primary volume on a remote data storage device of the primary composite aggregate. Accordingly, this technology allows data placement to remain consistent across primary and secondary volumes and facilitates efficient operation of secondary storage nodes by eliminating two-phase writes for data stored on cloud storage devices.

Storage nodes or servers in storage networks generally store data across multiple data storage devices that together comprise a data container, which is also referred to herein as an aggregate. Storage nodes may employ various forms of local data storage devices, such as hard disk drives, solid state drives, flash drives, or tape devices, as well as remote data storage devices, such as cloud storage devices or repositories for example.
Typically, the data storage devices host one or more data stores or volumes within the aggregates, which are associated with file systems that define an overall logical arrangement of storage space in a storage network. Volumes can be established to have tiering policies in order to store data in multiple performance tiers. For example, composite aggregates can include volumes that span relatively high performance flash data storage devices and relatively low performance cloud storage devices for warmer and colder data, respectively.
To facilitate load sharing, disaster recovery, or archival functionality, for example, data is often replicated from primary volumes to secondary volumes. When the replicated data is received at a secondary storage node, the data is stored in a secondary volume of a composite aggregate in a relatively high performance tier associated with a local storage device (e.g., a flash storage device). Subsequently, the data may be moved to a remote or cloud storage device associated with the secondary volume of the composite aggregate as it becomes colder based on a stored policy.
Accordingly, replication currently requires a two-phased write and post-processing irrespective of the type of storage or tier from which the replicated data originated. The additional processing is computationally expensive. Moreover, storage administrators have difficulty providing appropriately-sized performance tier storage at a secondary storage node, and often allocate enough flash memory, for example, to store most or all of a primary volume, which is costly and inefficient.

Methods for improved data replication across hybrid cloud volumes using data tagging and devices thereof


A high voltage avalanche diode formed in an integrated circuit includes vertical power components. The integrated circuit is formed in an N-type semiconductor substrate. The rear surface of the substrate corresponds to a first main electrode of the power components, whose second main electrodes correspond to regions formed in P-type wells which are formed in the front surface of the substrate. The diode includes a P-type region wound substantially as a spiral that is formed in the front surface of the substrate; non-overlapping N-type regions formed in equal number in each turn of the spiral and forming with the spiral elemental avalanche diodes; metallizations connecting in series the elemental diodes; and a connection between an end of the spiral and the first electrode.

1. Field of the Invention
The present invention relates to high voltage vertical power transistors that are devices vertically formed on a silicon wafer (usually comprising an N-type epitaxial layer on an N.sup.+ substrate), the rear surface of which is connected to a high voltage. The invention relates to vertical power transistors of the MOS, bipolar or insulated-gate type, and more particularly relates to smart power switches that are circuits including, on a single silicon chip, vertical power components and logic circuits for controlling the power components.
2. Discussion of the Related Art
Power transistors are designed to withstand a definite forward voltage (for example 400 volts). If the external circuit applies a higher voltage, a damaging breakdown mode may occur. For example, the switching of an inductive load causes an overvoltage having a predetermined amount of energy that needs be dissipated. This overvoltage is applied onto the power switch which is off. One of the solutions to protect the device is to briefly set it in the conductive state for the time required to allow the excessive energy to flow through the device.
Therefore, it has been suggested to provide a device such as an avalanche diode that is set to a conductive state for a value slightly lower than the breakdown voltage of one or several power transistors, for example, to trigger the conductive state of such transistors before they reach their breakdown threshold, thus avoiding any damage.
FIG. 1, useful for understanding the problem that the invention aims to solve, is a cross-sectional view of a cell of an exemplary conventional dual structure including a vertical diffused power MOS (VDMOS) transistor TP. The VDMOS transistor is connected to logic circuits, an N-channel MOS transistor TL of which is schematically illustrated.
The structure is formed in a substrate 11 of a first conductivity type, for example of the N-type. A cell of the power MOS transistor TP includes a region 9-1, 9-2, formed by dopants of a second conductivity type, for example of the P-type. In each region 9-1, 9-2, are formed two N.sup.+ -type regions 14 which form the source of the power transistor. The two regions 14 are interconnected by a conductive layer 15 which is, for example, made of aluminum. The lateral edges of regions 9-1, 9-2 form a power transistor channel region 20.
Each cell of the power MOS transistor TP includes a gate 12 formed by a polysilicon layer. Gate 12 is separated from substrate 11 by an oxide layer 13.
The rear surface 17 of substrate 11 includes an overdoped layer 19 coated with a drain metallization 18.
The MOS transistor TL of the logic portion is formed in a P-type well 24. Well 24 includes two N.sup.+ -type diffusions. The first diffusion forms the source 22 and the second diffusion forms the drain 23 of transistor TL. Transistor TL includes a gate 21 formed by a polysilicon layer. Gate 21 is separated from well 24 by an oxide layer 25. Source 22 and drain 23 are respectively connected to a conductive line referenced 26, 27. Conductive lines 26, 27 are, for example, made of aluminum.
Conventionally, a P.sup.+ -type area 28 connected to a conductive layer 29 is provided in well 24. Area 28 and the conductive layer 29 connect well 24 to ground.
In normal operation mode, the rear surface metallization 18 is connected to a positive voltage and the front surface metallizations 15 of the power transistor are connected to voltages negative with respect to this positive voltage, for example voltages close to the ground voltage.
The problem to be solved is to prevent the power transistor from becoming conductive due to break down of the junction between substrate 11 and the P-type wells 9-1 and 9-2, i.e. when the drain voltage increases while the transistor is in the off state. Also, it should be noted, in the exemplary integrated circuit including a logic portion, that there is a risk that the junction, between the substrate and the wells in which are disposed the logic components, will break down.
To fabricate a diode capable of breaking down before the junction breaks down between substrate 11 and the wells, the diode can be vertically formed by providing in the N-type substrate a P-type region having a doping level selected so as to have a break down voltage lower than the junction between the substrate and the wells of the power transistors or of the logic portion. However, this would require an additional technological step in order to form this specifically doped P-type region. Despite the complexity of the process, the prior art approaches are directed to this method. However, the implementation of a diode on the front surface of the substrate makes it necessary to convey the high voltage available on the rear surface metallization to the front surface. Such method impairs the distribution of the field lines in the component while this distribution is carefully adjusted to provide the desired maximal breakdown (for example 400 volts, as indicated above).
U.S. Pat. Nos. 4,792,840 and 5,053,743 teach how to form, on the front surface of the substrate a resistor, a terminal of which is connected to the rear surface, the resistor being shaped like a spiral. However, none of these patents suggests that this technology can be extended to provide diodes.

Protection diode for a vertical semiconductor component


Provided is a light source device including a laser light source group including at least one multi-emitter laser light source and at least one non-multi-emitter laser light source that emits a colored light different from that of the multi-emitter laser light source, a collimator lens having at least one cylindrical surface that adjusts a laser light emitted from the at least one multi-emitter laser light source, and a light guide unit that performs color synthesis of a laser light emitted from the at least one multi-emitter laser light source and having passed through the cylindrical surface and a laser light emitted from the at least one non-multi-emitter laser light source.

An optical module, which is one of main components of a projection type display device, is generally constituted of an illumination optical system including a light source and a projection optical system including a light modulation element. As the light source, a light emitting diode (LED) light source or a semiconductor laser (LD) light source can be used. Since LEDs and LDs are small, for example, they are used as light sources for small projection type display devices such as pico projectors and portable projectors that are easy to carry.
Techniques for improving the illumination optical system of the projection type display device have been proposed hitherto. For example, Patent Document 1 below discloses a lighting device including a light source and a uniform illumination optical system that has a first fly-eye lens including a plurality of two-dimensionally arranged lenses and passing light based on emitted light from the light source, in which incident light on the first fly-eye lens has directivity, a first reference direction in a surface shape of an illumination target area extends along a direction substantially parallel to a major axis direction or a minor axis direction of an intensity distribution shape of the incident light on the first fly-eye lens, and a periodic direction of an arrangement of the lens in the first fly-eye lens is inclined with respect to the major axis direction or the minor axis direction (claim 1). By having the above configuration, the lighting device can reduce uneven brightness of the illumination light (paragraph 0012).

Light source device and projection type display device


The present invention provides a musical sound control device wherein, based on the movements of the fingers or other body parts of the performer, control of pitch bender and vibrato effects can easily achieved, and wherein the mobility and dexterity of each of the five digits of a human hand have been taken into careful consideration, whereby touch intensity musical control can be achieved.. The present invention provides detectors which can be applied to various portions of a performer's body, whereby movement of each body portion to which the detectors have been applied can be detected. Additionally, the present invention provides a control signal generator, whereby based on the output of the above mentioned detectors a musical control signal is generated. The above mentioned control signal generator includes a predetermined region wherein a musical control signal is not generated to impart a desirable effect on a musical tone, and in the other region, the control signal therefor carries out touch intensity conversion for the movement of each of the operators digits.

1. Field of the Invention
The present invention relates to musical sound control devices, and in particular, to musical sound control devices for which control is effected based on the movements of the fingers or other body parts of the performer.
2. Prior Art
With conventional musical instruments, for example, with a piano, a guitar, wind instruments, etc. , depending on the type of instrument and the desired sound, the individual playing the instrument plucks a string or rubs a bow against a string, depresses a key on a keyboard with a finger or thumb, blows into a mouth piece, or performs some other appropriate action, whereby control of the generation of musical sound is effected. In the majority of conventional electronic musical instruments as well, control is generally effected by depressing keys on a keyboard using a finger or thumb. When it is possible to effect musical sound control using a modality other than the conventional methods, that is, when it is possible to effect musical sound control by means other than playing on a keyboard, plucking a string, blowing into a mouthpiece, etc., it be comes possible to significantly alter the experience perceived by the operator of the musical instrument during a performance.
In consideration of the above, the present applicants have in the past proposed a musical sound control device in Japanese Patent Application Laid-Open No. Hei 1-250997 wherein a device for detecting motion of a portion of a performer's body is applied to one or more suitable portions of the body of the individual operating the musical instrument, whereby when the operator moves particular portions of his/her body, one or more signals are generated on which basis musical control is carried out. With such a device, control of pitch, volume, timbre, and various other parameters can be effected based on movements of the operators body. Such devices are applicable to dancers, performers simultaneously playing some kind of rhythm instrument, and the like.
As examples of detection means and their use with the above described type of musical sound control device, finger sensors can be applied to one or more of the performer's fingers and thumbs whereby control signals are generated based on the movement of the performer's digits . Similarly, elbow sensors can be applied to one or both of the performer's elbows, whereby control signals can be generated based on the movement of the performer's elbows. With this type of musical sound control device, the output signal of each sensor, for example of each finger sensor and/or elbow sensor in use, is supplied to a conversion unit wherein the output signal of the respective sensor is converted to a musical control signal. The musical control signals thus generated can then be supplied to a tone generation apparatus and/or various other auxiliary circuits. In this way, based on movements of the operators fingers, elbows, and/or possibly other body parts, musical control signals are generated whereby the pitch, timing, volume, timbre, and various other parameters of corresponding musical output generated in the tone generation apparatus can be controlled. As an example, such a musical sound control device could be set up so that when the performer's right thumb is flexed, a pitch corresponding to "do" is generated, when the performer's right index finger is flexed, a pitch corresponding to "re" is generated, etc.. Similarly, such a device could be set up so that to the extent the performer flexes his/her right elbow, control for a pitch bender effect of corresponding magnitude is carried out.
With this type of musical sound control device, however, in which pitch bender and vibrato effects are controlled on the basis of elbow movements, if the operator inadvertently flexes one of his elbows, an undesired pitch deviation or vibrato effect may result in the musical output. Similarly, when pitch control signals are generated on the basis of finger movements, finger motion that is imperceptible to the operator may result in the generation of unwanted musical tones. Additionally, with this kind of conventional musical sound control device, it is not possible to control the volume of generated tones based on the speed or force with which the operator flexes his/her fingers or thumbs.

Musical sound control device responsive to the motion of body portions of a performer


Methods, apparatus, systems and articles of manufacture to combine frames of overlapping scanning systems are disclosed. An example apparatus includes a time delay controller to determine a first time value and a second time value, the first time value different from the second time value; a capture synchronizer to, in response to the first time value corresponding to a first time, capture a first frame from a first scanning system and, in response to the second time value corresponding to a second time, capture a second frame from a second scanning system; and a capture combiner to combine the first frame and the second frame into a third frame, the third frame including data from the first frame and data from the second frame.

Scanning technologies such as Light Detection and Ranging (LIDAR) and Radio Detection and Ranging (RADAR) enable the measurement of the range, angle, and/or velocity of objects. Scanning systems may cast electromagnetic waves (e.g., radio waves, ultraviolet waves) into an environment and measure the time over which a wave reflects off an object and returns. Such scanning enables other systems such as autonomous vehicles to determine the presence and characteristics of nearby objects in real time. Multiple scanning technologies may be combined to detect nearby objects in a large field of view.
The figures are not to scale. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. Although the figures show layers and regions with clean lines and boundaries, some or all of these lines and/or boundaries may be idealized. In reality, the boundaries and/or lines may be unobservable, blended, and/or irregular.
Descriptors "first," "second," "third," etc. are used herein when identifying multiple elements or components which may be referred to separately. Unless otherwise specified or understood based on their context of use, such descriptors are not intended to impute any meaning of priority, physical order or arrangement in a list, or ordering in time but are merely used as labels for referring to multiple elements or components separately for ease of understanding the disclosed examples. In some examples, the descriptor "first" may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as "second" or "third." In such instances, it should be understood that such descriptors are used merely for ease of referencing multiple elements or components.

Methods and apparatus to combine frames of overlapping scanning systems


Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats. The mechanical seal can further include a closed loop cooling channel in its outer cylinder that is connected to a circulating source of cooling fluid.

Stirred tank polymerization reactors for producing, for example, ethylene-propylene-diene (EPDM) elastomers are generally known. Such reactors generally comprise a reactor tank, and a stirring assembly including a motor-driven shaft that drives an array of paddles in the interior of the tank. The shaft of the stirring assembly is typically rotatably and sealingly mounted in the reactor tank by means of a mechanical seal. Such seals usually include an outer cylindrical shell that is fixedly mounted in the top wall of the tank, and an inner cylindrical shell that is rotatable within the outer shell and affixed to the motor-driven shaft of the stirring assembly. The inner cylindrical shell generally includes a pair of sealing rings which are spaced apart along its axis of rotation. Each of the sealing rings is typically spring-biased against an annular sealing seat fixedly mounted in the outer sealing ring. A pressurized source of barrier fluid, which may be mineral oil, is connected to an annular space defined between the inner diameter of the outer ring and the outer diameter of the inner ring.
In operation, a flow of monomer is introduced into the interior of the tank along with a catalyst. At the same time, the shaft of the stirring assembly is rotatably driven by a motor so that the paddle array continuously agitates the monomer and catalyst, thereby promoting the reaction of the monomer into polymers such as EPDM elastomers. During this process, the fluid contents of the tank is typically subjected to both elevated pressures, e.g., on the order of 120 bars, which adiabatically generates elevated temperatures, e.g., around 400° F.-500° F. (204° C.-260° C.). In order to prevent the fluid contents of the tank from contaminating the barrier fluid used in the mechanical seal, the barrier fluid is usually pressurized to a level slightly above that of the reaction tank. Moreover, in order to protect the lowermost sealing ring and sealing seat from elevated temperatures generated within the reaction tank, a "seal flush" flow of externally-supplied monomer of about two to three gallons per minute is typically provided at the vicinity of the lowermost sealing ring and sealing seat.
While the aforementioned mechanical seal prevents leakage of the reactor contents during polymer production, the applicants have observed that such seals can effectively function only for a limited period, e.g., about eight or nine months, which often makes the seals the limiting component of reactor overhauls. Consequently, the applicants' experience has been that the reactor would need to be completely shut down every eight or nine months solely for the purpose of replacing the seal. The resulting downtime and disruptions in production significantly increase the costs of the final products.
Close inspection of worn seals by the applicants have revealed the presence of spalling on the interfacing surfaces between the sealing rings and sealing seats. The applicants believe such spalling is caused by the combination of mechanical and thermal stresses that the sealing rings and seats are subjected to during operation. In particular, the applicants have determined that lowermost sealing ring and sealing seat are subjected to high temperatures due to their constant exposure to the fluid contents of the reactor tank (despite the continuous use of the aforementioned seal flush to lower these temperatures), while the uppermost sealing ring and sealing seat are constantly subjected to a high differential pressure (i.e., the difference between the pressure of the barrier fluid and the ambient atmospheric pressure to which the barrier fluid ultimately flows).

Polymerization reactor and related process


Herein disclosed is an apparatus that includes a porous rotor positioned about an axis of rotation and surrounding an interior space wherein the porous rotor comprises sintered metal or ceramic; an outer casing, wherein the outer casing and the porous rotor are separated by an annular space; and a motor configured for rotating the porous rotor about the axis of rotation.

1. Technical Field
The present invention generally relates to the separation of gases. More specifically, the present invention relates to separation of light and heavy components of a feed gas via centrifugation. Even more specifically, in embodiments, the present invention relates to gas separation via centrifugation utilizing a porous rotor.
2. Background of the Invention
Separation of gases, especially gases having similar molecular weights, is a challenging task. Isotope separation is a particularly difficult and energy intensive activity. For example, separating uranium into naturally-occurring uranium-238 from uranium-235. Around 99.284% of naturally-occurring uranium is uranium-238, while about 0.711% is uranium-235, and about 0.0058% is uranium-234. Enriching uranium is difficult because the two isotopes have very nearly identical chemical properties, and are very similar in weight: uranium-235 is only 1.26% lighter than uranium-238. Separation methods, including diffusion techniques and centrifugation, that exploit the slight differences in atomic weights of isotopes have been employed to separate isotopes of uranium and produce depleted uranium consisting mainly of the 238 isotope, and enriched uranium having a higher-than-natural quantity of the uranium-235 isotope.
Diffusion techniques are used to separate similar-molecular weight gases. Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride through semi-permeable membranes, typically silver-zinc membranes, and separating the different isotopes by difference in diffusion rates. This produces a slight separation between the molecules containing uranium-235 and uranium-238, as uranium-238 is heavier and thus diffuses a bit more slowly than uranium-235. Thermal diffusion applies the transfer of heat across a thin liquid or gas to accomplish isotope separation. The process exploits the fact that the lighter uranium-235 gas molecules will diffuse toward a hot surface, and heavier uranium-238 gas molecules will diffuse toward a cold surface.
Centrifugation is also known for the separation of gases of similar molecular weight. A gas centrifuge is a separating machine specifically developed to separate uranium-235 from uranium-238 by applying forces to the gas mixture by placing material inside a mechanism that rotates the material at high speed. The gas centrifugation process uses a large number of rotating cylinders in series and parallel formations. The rotation of each cylinder creates a strong reactive centrifugal force accelerating molecules based upon mass and causing heavier gas molecules containing uranium-238 to move toward the outside of the cylinder and the lighter gas molecules rich in uranium-235 to collect closer to the center. Gas centrifugation requires much less energy to achieve similar separation to older gaseous diffusion processes, and thus gas centrifugation has largely replaced gaseous diffusion as an enrichment method. The Zippe centrifuge is an enhancement on the standard gas centrifuge, the primary difference being the use of heat. The bottom of the rotating cylinder is heated, producing convection currents that move the uranium-235 up the cylinder, where it can be collected.
A feature common to all large-scale enrichment schemes is that they employ a number of identical stages to produce successively higher concentrations of uranium-235. Each stage concentrates the product of the previous step further before being sent to the next stage. Similarly, the tailings from each stage are returned to the previous stage for further processing. This sequential enriching system is called a cascade. For example, gas centrifugation is performed with multiple centrifugal runs using cascades of centrifuges.
Another expensive gas separation, for example, is separation of undesired components from methane obtained downhole. Removal of carbon dioxide and other components from the methane to provide a pipeline-grade methane generally involves the use of very low temperatures and/or amine units. Such units can be costly and their operation time-consuming.
Accordingly, in view of the art, there is a need for efficient and economical apparatus and methods of separating gases. Desirably, the separation is performed in the absence of a large cascade of separation stages and/or in the absence of cooling.


A nonlinear optical chromophore having the formula D-xcfx80-A, wherein xcfx80 is a xcfx80 bridge including a thiophene ring having oxygen atoms bonded directly to the 3 and 4 positions of the thiophene ring, D is a donor, and A is an acceptor.

All patents, patent applications, and publications cited within this application are incorporated herein by reference to the same extent as if each individual patent, patent application or publication was specifically and individually incorporated by reference.
The invention relates generally to the organic chromophores for second order nonlinear optical (NLO) applications, compositions including such chromophores, and applications including such chromophores and compositions.
The development and uses of NLO chromophores, including polymer matrix development, waveguide fabrication, and optical device fabrication are well documented. An NLO chromophore (also known as a xe2x80x9cpush-pullxe2x80x9d chromophore) comprises three fundamental building blocks represented by the general formula D-xcfx80-A, where D is a donor, xcfx80 is a xcfx80-bridge, and A is an acceptor. In the art, a xe2x80x9cxcfx80-bridgexe2x80x9d is sometimes referred to as a xe2x80x9cxcfx80-conjugated bridge,xe2x80x9d xe2x80x9cxcfx80-electron bridge,xe2x80x9d xe2x80x9cconjugated xcfx80-electron bridge,xe2x80x9d and the like. Examples of such bridges are described, for example, in U.S. Pat. Nos. 5,670,091, 5,679,763, 6,067,186, and 6,090,332. A xe2x80x9cxcfx80-bridgexe2x80x9d allows charge transfer from a donor to an acceptor in a chromophore. Exemplary acceptors are shown in FIG. 1, where, independently at each occurrence, R1 is hydrogen, a halogen except when bonded to a carbon alpha to or directly to a nitrogen, oxygen, or sulfur atom, or an alkyl, aryl, heteroalkyl, or heteroaryl group; Y is O, S or Se; and q is 0 or 1. Exemplary donors are shown in FIG. 2, where, independently at each occurrence, R1 is hydrogen, a halogen except when bonded to a carbon alpha to or directly to a nitrogen, oxygen, or sulfur atom, or an alkyl, aryl, heteroalkyl, or heteroaryl group; R2 is hydrogen or an alkyl, aryl, heteroalkyl, or heteroaryl group; Y is O, S or Se; m is 2, 3 or 4; p is 0, 1 or 2; and q is 0 or 1. Herein, a heteroalkyl group includes, but is not limited to, functional groups, halogen substituted alkyl groups, perhalogenated alkyl groups, and dendrons. What is meant by a functional group in generally understood in the art of organic chemistry, for example see Appendix B in Jerry March, xe2x80x9cAdvanced Organic Chemistryxe2x80x9d 4th Edition, John Wiley and Sons, New York, pp 1269-1300. A xe2x80x9cdendronxe2x80x9d is a substituent that has regularly repeating subunits. A dendron may be further comprised of one or more heteroaryl group. A xe2x80x9cdendrimerxe2x80x9d is a macromolecular structure that contains a xe2x80x9ccorexe2x80x9d surrounded by one or more dendrons. Often in the art, the terms dendron and dendrimer are used interchangeably. Dendrons and dendrimers are illustrated and discussed in Bosman et al., Chem. Rev. 1999, 99, 1665 and U.S. Pat. No. 5,041,516.
The particular D-xcfx80-A arrangement affects the ability of the molecule to achieve large second order NLO effects. Thus, the first molecular electronic hyperpolarizability (xcex2, sometimes given as xcexcxcex2, where xcexc is the dipole moment of the chromophore), which is a measure of this ability, can be tuned and optimized by changing the electronic properties of any one of D, xcfx80, or A, see Gorman and Marder Proc. Natl. Acad. Sci, USA 1993, 90, 11297. Molecular NLO effects, in turn, can be translated into bulk EO activity in a material by aligning molecules in one direction by applying an electric field.
In one aspect, a nonlinear optical chromophore has the formula D-xcfx80-A where xcfx80 is a xcfx80 bridge including a thiophene ring having oxygen atoms bonded directly to the 3 and 4 positions of the thiophene ring, D is a donor, and A is an acceptor. The oxygens bonded directly to the 3 and 4 ring positions of the of the thiophene ring may be further independently substituted with an alkyl group comprising 1 to about 20 carbons, a heteroalkyl group comprising 1 to about 20 carbons, an aryl group comprising 1 to about 20 carbons, or a heteroaryl group comprising 1 to about 20 carbons.
In a second aspect, a nonlinear optical chromophore has the formula:
wherein, independently at each occurrence: xcfx801 is absent or a xcfx80-bridge; xcfx802 is absent or a xcfx80-bridge; D is an donor; A is an acceptor; X is O or S; and R is an alkyl group comprising 1 to about 20 carbons, a heteroalkyl group comprising 1 to about 20 carbons, an aryl group comprising 1 to about 20 carbons, or a heteroaryl group comprising 1 to about 20 carbons. These chromophores may be combined with a polymer matrix to form second order nonlinear optical compositions useful in a variety of applications, including electro-optic devices such as optical modulators, optical switches, and optical directional couplers. For example, the chromophore and polymer matrix may contain crosslinkable functional groups, and may be combined to form a guest-host composite, in which the chromophore is the guest and the polymer matrix is the host. An electric field is then applied to the composite to induce electro-optic activity, after or during which the composite is crosslinked to covalently bond the chromophore to the polymer matrix. Other features and advantages of the invention will be apparent from the following description of preferred embodiments thereof, and from the claims.

Second order nonlinear optical chromophores and electro-optic devices therefrom


An improved method of interconnecting electronic devices is described. In the method a blended material for forming a conducting layer and an insulating layer are deposited between a contact of a first electronic device and a second electronic device. The blended material leads to formation of a conductor overlayed by an insulator such that after formation, the conductor is capable of carrying current from the first electronic device to the second electronic device and the insulator forms a protective layer over the conductor.

Oxygen, humidity, light and heat amongst other environmental parameters, can damage polymeric materials. To minimize material degradation, polymer based electronic devices are often fabricated and tested under tightly controlled environmental conditions, typically in a "glove box" filled with an inert gas, or under vacuum conditions. Large scale fabrication under tightly controlled environments increases the cost of fabrication reducing commercialization opportunities.
Encapsulation of semiconducting and conducting polymers in fabricated devices minimizes environmental exposure and thus device degradation after fabrication. However, encapsulating polymeric layers is difficult because of polymeric layer incompatibility with the processes used in encapsulation. Many materials available for encapsulation utilize process steps that involve high temperatures or solvents that may damage the polymeric semiconductor. Light used when depositing solid encapsulating layers can also damage the polymeric layers.
Thus an improved non-destructive method for forming and encapsulating polymeric layers in electronic devices is needed.

Method for interconnecting electronic components using a blend solution to form a conducting layer and an insulating layer


The invention relates to a heat-exchanger element for connection to tubes of a heat exchanger, the heat-exchanger element (1, 29, 32) consisting of a plurality of components (13, 14) welded to each other, and said components (13, 14) being interconnected by electron beam welding and being part of a heat exchanger head.

The invention relates to a heat exchanger element for connecting to tubes of a heat exchanger.
Heat exchangers for exchanging thermal energy between flowable media, in particular between liquids and gases, have, for media separation, ducts, in particular in the form of tubes, through which a heat exchange medium flows. The tubes are connected to what is known as a tube sheet, which is a constituent part of a heat exchanger head. Heat exchanger heads and the tubes of heat exchangers usually consist of metal on account of its high thermal conductivity. Accordingly, the heat exchanger heads are often in the form of welded structures. The welding of media-carrying components places high demands on the welding method, since fluid-tightness, even under sometimes high pressures and under high thermal cycling, must not result in fatigue phenomena during operation. For this reason, sometimes complicated weld preparations have to be carried out for fillet welds and butt welds. Particular welding methods, such as submerged arc welding, plasma arc welding, TIG welding or electrode welding are used in order to ensure a high welding quality.
An example is intended to illustrate how much work is required to weld thick-walled components (>10 mm) for heat exchangers: in the case of components of greater thickness that are to be connected using submerged arc welding, after the two-sided seam preparation for a double V-seam, first submerged arc welding is carried out from one side (root side) as a counter weld/cap. The counter weld is necessary because it is not permissible to use components in heat exchangers in which very high pressures prevail, which are not fully welded at their connection points or have notches. The counter weld is located on the inside of the heat exchanger. The seam preparation on the outside must reach so deep that only a narrow contact surface remains between the components, which is completely melted during welding.
For materials that are difficult to process, especially from the group of highly corrosion-resistant nickel-molybdenum alloys, relatively large, i.e. wide seam preparations are made. In any case, it must be avoided that microcracks occur in the structure during welding, which can be identified by subsequent X-rays or ultrasound of the welded connection. The relatively large seam preparations mean that, depending on the thickness of the workpiece, 10 or more welding layers have to be applied in succession. The first welding layers are usually made by hand. In this way, the heat input can be better controlled and specifically kept low. The other layers can then be machined. With a component thickness of 20 mm, for example, 9 layers can already be produced on one outer side plus the counter weld on the inner side. With a component thickness of 30 mm, 15 layers are required on the outside for a professional welding and with a component thickness of 35 mm, even 20 welding layers. For components over 100 mm thick, the manufacturing effort is immense. The processing times are very long. The cost of the welding consumables is considerable.
The prior art also includes electron beam welding processes, which are described, for example, for the production of multi-part assemblies in AT 500 655 A1. DE 102 58 503 A1 describes a tunnel tube sheet for prior art heat exchangers, in which sheet steel plates of the tube sheet are welded to webs of a supporting sheet by means of laser beam welding or electron beam welding. This is intended to achieve higher quality in execution and thus in the technical parameters of the heat exchanger, and to reduce manufacturing costs. The components are prepared in such a way that in the case of a butt connection on a first component, a shoulder is made on which the second component is placed. An L-shaped cross-section is created, into which the electron beam is directed, so that the electron beam is directed directly at the shoulder that is melted by the electron beam. In the case of thin-walled components, the shorter leg of the joint can also be melted completely. In the case of thick-walled components, the tolerance fields may be larger. In addition, the shoulder as a support is then wider and in particular significantly wider than an electron beam. In this case, the electron beam cannot completely weld the L-shaped joint. The longer the shoulder, the more problematic is the requirement to completely melt the weld joint.
The invention is based on the object of demonstrating a heat exchanger element for connecting to tubes of a heat exchanger, which can be produced more cost-effectively, is of particularly high welding quality and ensures high operational reliability. A method for producing such a heat exchanger head is also to be demonstrated.

Heat-exchanger element and method for producing a heat-exchanger element


According to one embodiment, an information processing apparatus includes a state change controller and a display processor. When a first key of a keyboard is pressed, the state change controller changes a state of a first operational environment. The display processor displays a first message indicative of a current state of the first operational environment in an informing area of a display screen for a first duration of time. When a second message indicative of a past state of the first operational environment is displayed by the display processor for the first duration of time in the informing area, the display processor display the first message in the informing area together with the second message.

In recent years, various portable personal computers of notebook type or laptop type have been developed. Such a computer uses a function of using a function key to change its operational environment. The user can readily change the operational environment by only pressing a specific key in combination with a function key.
There is also known a technique of presenting to the user the current state of the operational environment which has been changed using a function key.
It may be difficult for the user to identify whether the operation environment has been actually changed or state transition which has been performed for the operational environment.

Information processing apparatus and operation control method


An oral tobacco product (1) has a pouch (2) made of a nonwoven fabric, a tobacco mixture containing tobacco particles made from tobacco materials as a major ingredient, enclosed in the pouch (2), and a water-repellent area (30) formed on an inner surface of the pouch (2) to account for 50% of the entire inner surface of the pouch, the water-repellent area preventing permeation of water.

Cigarettes have long been enjoyed as recreational goods. In recent years, however, smokeless tobacco, usable anywhere, has been attracting attention. Use of such smokeless tobacco is permitted even in places where smoking is prohibited, including airplane cabins and train compartments.
Snus is known as an oral tobacco product belonging to the class of smokeless tobacco. Snus contains, as a major ingredient, shreds obtained by finely shredding tobacco materials, and those tobacco shreds have a high moisture content.
Specifically, snus is classified into a loose type, which is non-packaged tobacco shreds, and a portion type called also a pouch type, which is tobacco shreds packaged with nonwoven fabric or other material.
The pouch-type snus is designed such that the user puts it directly in the mouth and holds it between the upper lip and gum to be able to enjoy the aroma of tobacco shreds and take tobacco active constituents, extracted from tobacco shreds into saliva, into the body through the gum.
Pouch-type snus with a water-soluble film covering the inner surface of the pouch is also known. Snus of this type is designed such that after the user puts it in the mouth, the film dissolves in saliva to allow tobacco active constituents to be extracted from tobacco shreds into saliva (patent document 1).


An antenna system is disclosed. A wireless device includes two antennas. The first antenna is optimized at a first frequency band. The second antenna is optimized at a second frequency band. The signals received from respective optimized frequency bands are used as primary received signals. The signals having frequencies beyond respective optimized frequency bands are used as diversity signals. Likewise, the signals transmitted from a transceiver to base stations are sent to respective antennas based upon their frequency bands. By employing this optimized antenna configuration, the wireless device can provide high quality wireless signals for both frequency bands.

Wireless communication systems are widely used to provide voice and data services for multiple users using a variety of access terminals such as cellular telephones, laptop computers and various multimedia devices. Such communications systems can encompass local area networks, such as IEEE 801.11 networks, cellular telephone and/or mobile broadband networks. The communication system can use one or more multiple access techniques, such as Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA) and others. Mobile broadband networks can conform to a number of standards such as the main 2nd-Generation (2G) technology Global System for Mobile Communications (GSM), the main 3rd-Generation (3G) technology Universal Mobile Telecommunications System (UMTS) and the main 4th-Generation (4G) technology Long Term Evolution (LTE).
As technologies evolve, different generation standards may co-exist in a wireless network for a period. For example, when a wireless device user moves from one region covered by GSM to another region covered by UMTS, the user demands a seamless handover between two standards. Such a seamless handover requires a multi-mode wireless device. On the other hand, in specific regions of the world, each standard may operate within different frequency bands. In order to accommodate different frequency bands in a wireless system, the wireless device must have a multi-band communication capability. In short, a modern wireless device such as a mobile phone must be a multi-band and multi-mode device.
Each wireless standard may have different frequency bands. For example, GSM may operate on frequency bands in a range around 850 Megahertz (MHz), 900 MHz, 1800 MHz and 1900 MHz. Similarly, UMTS may operate on even diversified frequency bands in a range from low 800 MHz up to 2200 MHz. CDMA may operate on frequency bands in a range around 850 MHz and 1900 MHz. LTE may support both future and existing frequency bands used by current 3G systems. In consideration of the antenna design of a wireless device, frequency bands around 850 MHz and 900 MHz are defined as a low-band frequency. Likewise, frequency bands above 1700 MHz are defined as a high-band frequency.
A wireless device capable of operating in multi-band frequencies may have at least two antennas so that both high-band frequency signal and low-band frequency signal reception/transmission can be optimized. For example, when a mobile phone is operating in a wireless system having both GSM bands and UMTS bands, it has one primary antenna and one secondary antenna. The primary antenna usually has a higher efficiency than the secondary antenna. Traditionally, some important signals such as transmitted signals and primary received signals are connected to the primary antenna to achieve best performance. However, as more and more access techniques are deployed, the existing primary-secondary antenna architecture may not deliver the highest performance for all frequency bands. Therefore, there is an ever increasing pressure to improve the performance of these two antennas.

Multi-band and multi-mode antenna system and method


In an embodiment of the disclosure, there is provided an apparatus for calibrating a laser projection system. The apparatus has a structural frame assembly extending along three mutually orthogonal axes. The apparatus further has a plurality of non-movable reflective targets disposed on the structural frame assembly. The apparatus further has at least three positioning stages coupled to the structural frame assembly respectively about each of the three mutually orthogonal axes. At least one movable reflective target is disposed on each positioning stage. The non-movable reflective targets and the at least one movable reflective target are each configured to reflect a laser beam from a laser projection system.

1) Field of the Disclosure
The disclosure relates generally to calibrating laser projection systems, and more specifically, to devices, systems and methods having three-dimensional measurement capability for calibrating laser projection systems.
2) Description of Related Art
Laser projection systems are used to record visible images directly onto components during an assembly process. In some applications, laser projection systems may be used to provide guidance during manufacturing and assembly of components, such as carbon fiber reinforced plastic (CFRP) components. In other applications, laser projection systems may be used to create markings and images on production parts. The laser marking of such parts may facilitate the subsequent processing and assembly of the parts into a cohesive superstructure. Typically, a laser projection system includes a plurality of laser projectors capable of generating laser beams. Accordingly, the use of laser projection systems for guidance and marking applications generally demands that the orientations of the projected laser beams be properly calibrated with respect to one another. Current calibration mechanisms typically rely on visual estimation of the offsets between the orientations of the various lasers of a laser projection system to create a best fit value for calibration. The use of visual estimation by a human operator to calibrate a laser projection system that is critical to manufacturing may be a time consuming trial and error process that reduces overall component production and assembly efficiency.
Known two-dimensional calibration walls for laser projection systems, such as disclosed in U.S. Pat. No. 7,965,396 B2 ("Enhanced Laser Projector Calibration Wall"), have been used to perform two-dimensional calibration of laser projectors of known laser projection systems and have improved efficiency over visual estimation calibration methods in determining the proper two-dimensional calibration of such known laser projection systems. However, such known two-dimensional calibration walls, alone, are not capable of three-dimensional measurement and cannot enable measurement of defined features in three-dimensional space. Thus, for known laser projection systems with laser projectors that use three-dimensional laser projections in manufacturing applications and that require standards to enable additional types of feature based measurements, there is a need for an apparatus, system and method having three-dimensional measurement capability and enabling three-dimensional laser projection system calibrations.

Apparatus and method for calibrating laser projection system


An electronic apparatus having a storage device received in a bracket, a printed circuit board on which the bracket is mounted, and a blower for cooling the storage device. The bracket forms a casing surrounding the blower and the casing extends through an opening of the printed circuit board. In this way, the blower is received in correspondence with the opening.

In an electronic apparatus, a storage device is generally provided to store data of any kind. In the field of information technology, this data can define the way the apparatus operates (software) or information to be used by the various programs. In the field of consumer electronics, the data are generally a coded representation of a video signal and/or an audio signal.
The storage device can be either removable, such as an optical disc, or non-removable, such as a hard disc drive or a solid-state memory. In any case, in an effort to reduce the size of the electronic apparatus, designers must integrate electronic circuits linked to the storage device in a limited space, which generates too much heat to be evacuated by natural convection.
It has thus been proposed to provide the electronic apparatus with a blower to generate artificial convection, as described for instance in patent application US 2002/0051 338 and patents U.S. Pat. No. 6,480,380 and U.S. Pat. No. 6,538,886. U.S. Pat. No. 5,511,055 discloses an optical disk drive that is equipped with an air-cooling fan. The air-cooling fan is attached on a PCB, and the fan and the PCB are mounted to a bracket which takes up the optical disk drive. U.S. Pat. No. 5,191,230 discloses a fan module which can be mounted in a housing together with electronic circuit modules. The fan module comprises a PCB with an opening that is larger than the fan that is mounted. The fan can be moved to any position over the opening along two mounting rails.
Previous designs are however complicated. Notably, they cannot be easily integrated in an electronic apparatus having a printed circuit board implementing further functions, such as video processing, for instance in a personal video recorder.

Electronic apparatus with a storage device


A cold cathode device wherein a cold cathode and an anode face each other with an electron transit path intermediated therebetween, and one or more control electrodes structurally insulated from the said cathode and the anode, are provided exposing to the electron transit path. A cold cathode vacuum tube has an electron emission element having a p-type semiconductor region on an electron emission side and a work function lowering region with junctional relation to the p-type semiconductor region; and a plate electrode structurally insulated from the electron emission element by using an insulation layer which is formed with an electron transmit path corresponding in position to an electron emission area of the electron emission element.

1. Field of the Invention
The present invention relates to a cold cathode device which can perform various functions such as amplification by controlling the flow of electrons emitted from a cold cathode.
2. Related Background Art
Semiconductor devices such as diodes and transistors constructed of p-type and n-type semiconductor regions are widely used as circuit elements performing rectification or amplification.
Semiconductor devices have many advantages: small size, light weight, feasibility of integration, large cost reduction, long life, high reliability and so on. Semiconductor devices are used accordingly in various applications such as information machines including computers, electronic household appliances including television, radio and the like.
Semiconductor devices such as diodes and transistors have some problems, including that malfunctioning may occur due to radiation of alpha-rays or the like. Semiconductor devices cannot be used in the range of GHz due to a limit of response speed which is in the order of up to 100 MHz in case of Si transistors.
A vacuum tube may be used to realize a high speed response. However, a hot cathode is generally used in a tube to emit electrons from the surface of a metal by heating it to high temperature in vacuum. One of the disadvantages of tubes is therefore a warm-up time required for such heating. Further, A tube of this kind includes therein a cathode, grid, plate and other electrodes so that it is difficult to make it compact. Because of heat radiation, a tube cannot be integrated with semiconductor devices.


A vehicle seat mounting assembly is provided in which the seat mounts are attached to body cross-members that are, in turn, mechanically coupled to battery pack cross-members contained within a battery pack enclosure mounted under the vehicle.

Modern vehicles use a variety of structures to protect the vehicle's occupants during a crash. Some of these structures are used to control the transmission of the crash energy into the passenger compartment while other structures, such as seat belts, head restraints, and air bags, are intended to restrain passenger movement during a crash, thereby preventing the passengers from hurting themselves as their bodies react to the crash forces. At the heart of most, if not all, vehicle passenger safety features is a rigid and strong seat mounting assembly.
Conventional vehicle seats are attached to the vehicle floor panel. Examples of such seat mounting assemblies are shown in U.S. Pat. Nos. 4,262,963, 4,526,424, 4,784,434, 4,818,022, 5,322,348 5,653,506, 6,811,186, 7,066,521, 7,780,230 and 7,887,094. While this approach to mounting a vehicle seat has proven to be adequate, an improved seat mounting assembly is desired in order to achieve improved structural characteristics. The present invention provides such an improved seat mounting assembly.


The present invention provides methods and compositions for regulation of gene expression in plants. In particular, the invention provides nucleic acids that can confer tissue specific and constitutive expression to operably linked polynucleotides of interest.

A promoter is a specific DNA sequence that is involved in regulating the expression of operably linked downstream coding or other noncoding nucleic acids. In order to efficiently express a foreign gene in genetic modified organism (GMO), promoters exhibiting strong activity under various conditions and in different species have been identified.
Cauliflower mosaic virus (CaMV) 35S promoter is one of the most frequently used constitutive promoters in plant research (Odell et al. Nature 313(6005):810-812 (1985); Benfey, P. N. and N. H. Chua, Science 250(4983):959-966 (1990)). The CaMV 35S promoter, with a length of 343 base pairs, was isolated from a double-stranded cauliflower mosaic virus, in which the TATA box "tatataa" is localized between −32 bp to −26 bp. Another strong constitutive promoter was isolated from the maize Ubi-1 gene. The maize ubiquitin promoter exhibits very strong activity in most monocot tissues and so it is frequently utilized to drive foreign genes and expression cassettes in monocot plants (Cornejo et al. Plant Mol Biol. 23(3):567-81 (1993): Rooke et al. Annals of Applied Biology 136(2): 167-172 (2000): Castillo et al. Bio-Technology 12(13):1366-1371 (1994); Miki et al. Plant Physiology 138(4):1903-13 (2005)). Besides the CaMV 35S and maize ubiquitin promoters, other constitutive promoters used in transgenic plants include NOS and OCS, which were isolated from Ti plasmid of Agrobacterium tumefaciens. Both of these promoters have strong activity in dicots (Ebert et al. Proc Natl Acad Sci USA 84(16):5745-9 (1987); Velten et al. EMBO J. 3(12):2723-30 (1984); De Block et al. The EMBO Journal, 3(8):1681 (1984).). A further monocot promoter is that cloned from the rice actin 1 gene (McElroy et al. The Plant Cell Online 2(2):163-171 (1990)).
However, strong constitutive promoters such as those discussed above can have drawbacks. In some instances, accumulation of heterologous proteins or final metabolites may interrupt the metabolic homeostasis of a transgenic plant, which may result in repressed growth and development, or may even cause death. Furthermore, excess transcripts can result in repression of expression, or 'transgene silencing' or 'co-suppression' of the transgene (Dietz-Pfeilstetter, A., Plant Science, 179(3): 164-167 (2010); Kooter et al. Trends Plant Sci. 4(9):340-347(1999): Kumpatla et al. Trends Plant Sci. 3(3):97-104 (1998)). To avoid the adverse consequences brought by constitutive promoters in transgenic plants, inducible promoters and tissue specific promoters may be used, such as the light inducible rice original promoter rbcS, which is expressed in leaf and stem, the heat-inducible promoter Gmhsp17 cloned from soybean, the light inducible and green-tissue specific rice promoter Cab1R, the root and seedling specific Pyk10 promoter cloned from Arabidopsis, the fruit specific promoter E-8 cloned from tomato (Lycopersicon esculentum), and the seed specific promoter from the napin gene cloned from Brassica napus (Nomura, M., et al. Plant Mol Biol. 44(1):99-106 (2000); Schoffl, F., et al., Mol Gen Genet. 217(2-3):246-53(1989); Luan, S. and L. Bogorad Plant Cell 4(8): p. 971-81 (1992); Ellerstrom, M., et al. Plant Mol Biol. 32(6): 1019-27 (1996); Krasnyanski, S. F., et al. In Vitro Cellular & Developmental Biology—Plant 37(4):427-433 (2001); Nitz, I., et al. Plant Science, 161(2):337-346 (2001)). However, a disadvantage of most inducible and tissue specific promoters is that their activities are generally weaker than that of constitutive promoters.
The present invention overcomes previous shortcomings in the art by providing tissue specific promoters useful for modulating gene expression in plants.

Methods and compositions for modulating gene expression in plants


A novel process is disclosed for preparing a 3-substituted methyl-3-cephem-4-carboxylic acid or pharmaceutically acceptable salt thereof. The process comprises reacting a 3-acetoxymethyl-3-cephem-4-carboxylic acid or pharmaceutically acceptable salt thereof with a specific compound, such as a boric acid ester, an orthoester or an acetal, in the presence of at least one specific catalyst selected from the group consisting of Lewis acids or complexes thereof, proton acids and mixtures thereof. In the process, formation of impurities, such as a lactone, is sufficiently suppressed without protection of the carboxylic acid, so that the high purity desired product, i.e., a 3-substituted-methyl-3-cephem-4-carboxylic acid or pharmaceutically acceptable salt thereof, which is useful as an intermediate for various cephalosporin antibiotics having excellent antimicrobial activity, can be prepared in one step in high yield.

1. Field Of The Invention
The present invention relates to a process for preparing 3-substituted methyl-3-cephem-4-carboxylic acids which are useful as intermediates for various cephalosporin antibiotics having a high antimicrobial activity across a broad antimicrobial spectrum. More particularly, the present invention is concerned with a process for preparing a 3-substituted methyl-3-cephem-4-carboxylic acid represented by formula (I) or a pharmaceutically acceptable salt thereof, ##STR1## wherein R.sup.1 represents a hydrogen atom or a lower alkoxy group and R.sup.2 represents an unsubstituted or substituted lower alkyl group or an unsubstituted or substituted aryl group, which can be carried out in one step and which can provide the desired product with high purity in high yield.
2. Discussion Of Related Art
As a process for preparing a 3-substituted methyl-3-cephem-4-carboxylic acid represented by formula (I) from a starting 3-acetoxymethyl-3-cephem-4-carboxylic acid represented by formula (II), ##STR2## wherein R.sup.1 represents a hydrogen atom or a lower alkoxy group, there have heretofore been proposed, for example, a method (1) in which the compound of formula (II) is reacted with a lower alcohol in the presence of a halide of an alkali metal, a halide of an alkaline earth metal or a halide of a quaternary ammonium (see U.S. Pat. No. 4,482,710), a method (2) in which the compound of formula (II) is reacted with a lower alcohol in the presence of boron trifluoride or a boron trifluoride complex (see European Patent Application Publication No. 204,657), a method (3) in which the compound of formula (II) is reacted a lower alcohol in the presence of an alkylsulfonic acid and a complex of boron trifluoride (see Japanese Patent Application Laid-Open Specification No. 63-115887), and a method (4) in which the compound of formula (II) is reacted with a lower alcohol in the presence of a halide of antimony, tin, iron, zinc or bismuth, or a complex thereof (see European Patent Application Publication No. 262,744).
However, none of the above-mentioned conventional methods, (1), (2), (3) and (4) can be satisfactorily practiced on a commercial scale.
According to method (1), the yield of the desired product is as low as, for example, 16 to 43%. In method (2), a lactone represented by the following formula, ##STR3## wherein R.sup.1 has the same meaning as defined above, is formed as a by-product in a large amount so that there is a cumbersome problem in isolation of the desired product. That is, for isolation of the desired product from the reaction mixture containing a large amount of a lactone, (i) a large amount of a solvent for extraction-separating the lactone and/or a plurality of steps for extraction-separating the lactone are required, (ii) an extremely large amount of a resin for the separation and purification of the desired product must be used, or (iii) treatment for the precipitation-separation of the desired product at its isoelectric point must be repeated many times. Therefore, method (2) is unsatisfactory as a practical matter. Particularly, when the amount of boron trifluoride or a boron trifluoride complex is increased to improve the yield of the desired product of formula (I), formation of the undesired lactone is increased. As a result, the purity of the desired product is lowered, and isolation of the desired product becomes very cumbersome, so that loss of the desired product during the isolation is likely to be large. In methods (3) and (4), formation of the undesired lactone is not sufficiently suppressed. Accordingly, these methods are not satisfactory in yield and purity of the desired product.
Further, in other conventional processes for preparing a 3-substituted methyl-3-cephem-4-carboxylic acid, for avoiding the side reactions at the carboxyl group of the starting material, it has inevitably been necesssary to protect the carboxyl group of the starting material by, for example, esterifying the carboxyl group of the starting material prior to the reaction with the reactant. The resultant ester can be easily deesterified and, after the reaction, the esterified carboxy group is deesterified to reinstate the carboxyl group, thereby obtaining the desired product.
Therefore, there has still been a strong demand in the art for an improved practical process for preparing a 3-substituted methyl-3-cephem-4-carboxylic acid represented by formula (I), which can be carried out in one step and can provide the desired product with high purity in high yield.

Process for preparing 3-substituted methyl-3-cephem-4-carboxylic acid


A Raman spectroscopy based system and method for examination and interrogation provides a method for rapid and cost effective screening of various protein-based compounds such as bacteria, virus, drugs, and tissue abnormalities. A hand-held spectroscope includes a laser and optical train for generating a Raman-shifting sample signal, signal processing and identification algorithms for signal conditioning and target detection with combinations of ultra-high resolution micro-filters and an imaging detector array to provide specific analysis of target spectral peaks within discrete spectral bands associated with a target pathogen.

This section provides background information related to the present disclosure which is not necessarily prior art.
Methicillin resistance of Staphylococcus aureus (MRSA) is determined by the mecA gene which is carried by a mobile genetic element, designated staphylococcal cassette chromosome mec (SCCmec). MecA encodes a beta-lactam-resistant penicillin-binding protein called PBP2a (or PBP2′). Beta-lactam antibiotics normally bind to PBPs in the cell wall disrupting the synthesis of the peptidoglycan layer which results in bacterium death. However, since the beta-lactam antibiotics cannot bind to PBP2a, synthesis of the peptidoglycan layer and the cell wall continues. While the mechanism responsible for mecA transfer is still obscure, evidence supports horizontal transfer of the mecA gene between different staphylococcal species. Typically MRSA is diagnosed using culture based methods.
The Clinical and Laboratory Standards Institute (CLSI) recommends the cefoxitin disk diffusion test supplemented with the latex agglutination test for PBP2a. Phenotypic expression of resistance can vary depending on the growth conditions, as well as on the presence of subpopulations of staphylococci that may coexist (susceptible and resistant) within a culture making susceptibility testing by standard microbiological methods potentially problematic. In addition, culture takes time, usually 1 to 5 days. Faster techniques of MRSA screening by molecular methods, such as Polymerase Chain Reaction (PCR), have been developed to test for the mecA gene that confers resistance to methicillin, oxacillin, nafcillin, and dicloxacillin and other similar antibiotics. Such techniques, while faster, still take hours and are sent out to labs. In addition, commercially available molecular approaches (used for screening) are unable to detect mecA-variants of MRSA.
Raman spectroscopy is a reagentless, non-destructive, technique that can provide the unique spectral fingerprint of a chemical and/or molecule allowing for target identification without sample preparation. With this technique, a sample is irradiated with a specific wavelength of light whereby a small component, approximately 1 in 107 photons, is in-elastically scattered (at wavelengths shifted from the incident radiation). The inelastic scattering of photons, due to molecular vibrations that change the molecule's polarizability, provide chemical and structural information uniquely characteristic of the targeted substance. Raman Spectroscopy can be extremely useful in fully characterizing a material's composition, and allows for relatively fast identification of unknown materials with the use of a Raman spectral database. In addition, since Raman Spectroscopy is a non-contact and non-destructive technique, it is well suited for in-situ, in-vitro and in-vivo analysis.
Raman Spectroscopy has high potential for screening of bacteria, virus, drugs, as well as tissue abnormalities since it: 1) is practical for a large number of molecular species; 2) can provide rapid identification; and 3) can be used for both qualitative and quantitative analysis. A portable or handheld micro Raman based detection instruments would be useful to reliably and rapidly assess Staphylococcus aureus strains in wounds or nasal passages. Rapid assessment and typing would enable tracking the spread of such pathogens and could significantly decrease the number of hospital-acquired infections and the associated costs in treatment thereof.

Raman based detection instrument and method of detection


The tube (60) includes first and second portions (66, 58) that each have mating spherical sections (82, 84) at adjacent ends (72, 74) of each portion (66, 68). The second portion (68) includes a spring sleeve (92) configured to surround an outlet end (72) of the first portion (66). A spring (102) is captured inside the spring sleeve (92) and secured between a retaining clip (100) and a shoulder (88) protruding from the exterior surface of an outlet end (72) of the first portion (66) to maintain fluid seals between the spherical sections (82, 84). The spherical sections (82, 84) permit slidable motion relative to each other thereby facilitating rotational and angular motion between the tube portions (66, 68). One of the two portions (66, 68) may include a telescope mount (110) to permit limited axial motion of the tube (60).

In the field of aircraft engine technology, it is well known that extremely hot fluids and combusting fuel mixtures are directed to flow through varying types of conduits ranging from tubes to augmentors, or after-burner sections of gas turbine engines. As disclosed in U.S. Pat. No. 5,385,015 that issued on Jan. 31, 1995 to Clements et al., which Patent is owned by the owner of all rights in the present disclosure, a pilot assembly is utilized to direct flow of flames through flame passages into an augmentor of a gas turbine engine. The flame passages dispense flames into a combustion section of the augmentor through openings that define a circumferential disposition around a tail cone within the augmentor. A pilot combustor is located within the tail cone, and flames are directed from within the cone to the openings around the tail cone.
The hot gases or flames from the flame passages of the pilot are utilized to efficiently ignite fuel within a combustion chamber of the augmentor when the fuel is injected into the combustion chamber through struts or vanes passing between the tail cone and an outer wall of the augmentor. The openings of the flame passages are defined immediately downstream from the fuel dispensing struts and the flames thereby serve to propagate an efficient combustion of the fuel within the augmentor.
The flame passages of the pilot assembly may be formed by metallic tubes that direct flow of hot gases or flames from the pilot combustor to outlets defined around the tail cone within the augmentor. It has been found that such flame tubes are subject to extraordinary mechanical and thermal stresses as the augmentor is used to substantially enhance the thrust of the gas turbine engine, frequently propelling combustion products at supersonic speeds.
Many efforts have been undertaken to produce fluid conduits that provide for limited movement within the conduit to compensate for axial, rotational and angular stresses. For example, published European Patent Application No. EP 0919774 A3 published on Jun. 2, 1999 shows a "flame tube interconnector" that discloses a joint providing limited movement. The joint includes a first transfer tube having a seat that mates with a spherical or conical seat of a second transfer tube. A spring is included within one of the tubes to draw the two tubes into contact with each other, and exterior flanges include complex throughbores for flexibly bolting the tubes together. While providing for limited axial, radial and rotational motion at the joint, this disclosure exposes the spring to rapid wear by being within the tubes, and the bolting mechanism requires complicated manufacture and installation complexities.
More recently, U.S. Pat. No. 6,709,023 that issued on Mar. 23, 2004, to French discloses a "flexible slide joint" that provides for limited motion in a fluid conduit. French shows first and second tube members secured together by a sliding sealing sleeve member that houses an axially compressible element. One of the two members defines a spherical end portion that abuts an interior slide surface of the sealing sleeve member to provide the limited motion. Like Clements et al., the French disclosure requires complex manufacture, assembly and installation of many separate parts that utilize intricate components to secure the many parts as a single tube.
Therefore, there is a need for a tube having a joint that provides for limited angular, rotational and axial movement between portions of the tube while tolerating flow through the tube of extremely hot fluids and experiencing severe mechanical duress associated with supersonic gas turbine engines.

Tube having an integral, spring-loaded, spherical joint


Processing Internet Group Management Protocol (IGMP) messages in which a response-mode determination process is facilitated after receiving an IGMP Membership Report designating a requested multipoint leaf connection, where in a proactive expedited leave process is performed in response to determining that implementation of the requested multipoint leaf connection is required and that required network resources are unavailable. A multicast leaf connection implementation process for implementing the requested multipoint leaf connection is performed in response to determining that required network resources are available.

The Internet Group Management Protocol (IGMP) is described in Request For Comments document No. 1112 (hereinafter referred to as RFC-1112 and as IGMP version 1) and in Request For Comments document No. 2236 (hereinafter referred to as RFC-2236 and as IGMP version 2). Through the use of various IGMP messages, a requesting system (i.e. an end user download device) is able to facilitate joining and leaving one or more multicast groups. Thus, the requesting system device may selectively receive one or more streams of multicast information.
Conventional operation of the IGMP RFC-2236 (IGMP Version 2) makes provisions for a multicast routing device to automatically determine when multicast streams are no longer required. Specifically, IGMP Version 2 allows multicast routers to determine when no hosts on a particular interface need to receive one or more multicast streams any more. When a multicast router has reached such a determination, the multicast router may take steps to turn the multicast stream off.
To this end, multicast routers query each of their attached networks periodically to determine which multicast streams are still required by one or more hosts on that network. If the multicast router does not receive a response for a particular multicast stream, it retransmits the query one or more times before assuming that no hosts require that particular multicast stream any more. These retransmissions are to account for loss or error in one of the query messages or its responses. The multicast router will only turn off a multicast stream on a particular network when it is sure that there are no longer any hosts on that network wanting to continue receiving it. The interval between the last host no longer requiring a stream and the time at which the multicast router recognizes this is called "the leave latency".
As a partial improvement to the leave latency, hosts may issue a special "IGMP Leave" message. The IGMP Leave message is intended to cue the multicast router into commencing the check for remaining hosts. The IGMP Leave message reduces the average leave latency for a particular multicast stream somewhat (by prompting the router to immediately commence the query cycle for that group). However, the IGMP Leave message does not substantially reduce the leave latency.
This conventional IGMP Version 2 Leave message mechanism is relatively slow compared with the speed that a subscriber (e.g. a video service subscriber) would "zap" from channel to channel (i.e. change channels). This conventional IGMP Version 2 Leave message mechanism typically takes as much as tens of seconds to confirm that a stream is no longer required. A channel zap should be as fast as practical and certainly is no longer than about one second.
A limitation of IGMP Version 2 is that when any terminal issues an IGMP Leave message, the multicast router is typically not sure whether there are any other subscribers receiving the same multicast stream. Accordingly, the multicast router cannot immediately stop transmitting the multicast stream. Instead, IGMP Version 2 facilitates broadcast of a group specific membership query and then waits to see if any other hosts respond. If no other terminals respond within a prescribed timeout and retransmit period, the multicast router may then stop transmission of the multicast stream.
For some Digital Subscriber Line (DSL) applications, this conventional IGMP Version 2 behaviour is not completely acceptable due to the capacity of a DSL line (or a subtending DSLAM link) being finite. There are several problems caused by such finite capacity. For example, when a subscriber download device starts quickly zapping through channels, several zaps could be received at an IP Gateway in the time it takes for a conventional IGMP version 2 implementation to query a particular multicast router for other group members and then remove the unnecessary groups. If the IP Gateway cannot facilitate deletion of a group that is no longer required quickly enough, the capacity of the DSL line will quickly be exhausted with the channels that the subscriber has zapped past, but that are still active. A point will be reached where the subscriber cannot zap to another channel because their DSL line is completely full of traffic from the channels that the subscriber has already zapped past.
Another limitation of IGMP Version 2 is that IGMP Version 2 requires that all hosts and routers revert to IGMP Version 1 mode whenever an IGMP Version 1 format message is seen on the network interface. IGMP Version 1 does not include the Leave message. Accordingly, leave latencies are therefore longer (on average) than for IGMP Version 2.
Therefore, facilitating processing of IGMP messages in a manner that overcomes time and resource limitations associated with conventional implementations of IGMP is useful.

Facilitating accelerated processing of internet group management protocol messages


Methods are provided for manufacturing an integrated circuit device in which a metal layer is formed on an integrated circuit substrate. A capping layer is formed on the metal layer opposite the integrated circuit substrate. The metal layer covered with the capping layer is heat-treated. The capping layer is removed and the metal layer, which is exposed by removal of the capping layer, is plasma-treated.

This application claims priority from Korean Application No. 2001-18960, filed Apr. 10, 2001, the disclosure of which is hereby incorporated herein by reference.
Various integrated circuit devices include an insulating layer and a conductive layer arranged on an integrated circuit substrate according to a fabrication pattern. Devices such as transistors, capacitors, interconnection layers, and plugs for connecting to interconnection layers, may be formed in this manner. For certain structures, an additional device may be formed on an upper surface of a first, already-formed, integrated circuit device. In such a case, the electrical characteristics of the first formed device may be changed and/or degraded by the later formed device.
An example of a device subject to this problem is a capacitor, such as a metal-insulator-metal (MIM) capacitor. MIM capacitors are widely used in integrated circuit devices. As is well known to those having skill in the art, a MIM capacitor comprises spaced apart first (lower) and second (upper) metal layers (electrodes) and a dielectric layer therebetween. As the integration density of integrated circuit devices continues to increase, the area occupied by an individual device may continue to decrease. Thus, in MIM capacitors, it may be desirable to increase the capacitance by increasing the effective area of the capacitor, by forming a thin dielectric layer and/or by forming the dielectric layer of a material having high dielectric constant. Furthermore, in order to increase the effective area of a capacitor, the capacitor may be formed to have a three-dimensional structure, such as a fin structure, a cylinder structure and/or a trench structure. Unfortunately, a thin film dielectric may produce decreased reliability and high dielectric constant dielectrics may require new manufacturing processes.
The lower electrodes of a MIM capacitor may be formed of noble metals, such as platinum (Pt), ruthenium (Ru), iridium (Ir), and their oxides which generally do not react with the dielectric layer and have a high work function value. As Ru, in particular, can be easily etched by plasma containing oxygen and can form conductive oxides, Ru often may be used in forming the lower electrode of a MIM capacitor. The lower electrode of a MIM capacitor may be formed to have a three-dimensional structure, such as a cylinder structure, a pin structure and/or a trench structure.
In order to obtain a high dielectric constant from the MIM capacitor, the dielectric layer may be crystallized, for example, by annealing at a temperature above the crystallization temperature, after forming the dielectric layer, and/or the MIM capacitor may be cured by heat-treating the MIM capacitor after forming the upper electrode. In order to reduce defects occurring during processes for forming a capacitor, after forming the capacitor, curing may be performed at a temperature lower than a crystallization temperature, that is, at about 400xc2x0 C., in an oxygen atmosphere. However, the dielectric layer may crack due to heat treatment. Thus, there may be limitations in the heat treatment, and the characteristics of a capacitor may be degraded due to the heat treatment.
Various problems associated with MIM capacitors will now be described further with reference to FIGS. 1A and 1B, FIGS. 2A and 2B, and FIGS. 3 and 4. FIGS. 1A and 1B illustrate a capacitor in which ruthenium (Ru) is used as the metal for the lower and upper electrode, and tantalum oxide (TaOx) is used as a dielectric layer. FIGS. 2A and 2B illustrate the capacitor of FIGS. 1A and 1B after the dielectric layer has crystallized by annealing the lower electrode in a nitrogen (Nx) atmosphere at 700xc2x0 C. for about 30 minutes. As shown in the figures, the lower electrode, which is formed of metals, and the dielectric layer are sequentially formed. An annealing process for crystallizing the dielectric layer is subsequently carried out. As a result, surface roughness of the metal used as the lower electrode may be increased, variations in morphology may occur, and fine cracks may be caused in the dielectric layer during cooling after annealing due to a difference in the thermal expansion coefficient of the dielectric layer and the metal used for the lower electrode. The morphology of the upper electrode and/or the lower electrode of the MIM capacitor may be changed after annealing and/or other heating processes, such as curing in a subsequent thermal treatment, because the grains of the metal for the lower electrode and/or the upper electrode may grow larger in the subsequent thermal treatment.
Further processing of the capacitor may include high-temperature heating during an intermetal dielectric (IMD) deposition or an interconnection process following formation of the upper electrode. A curing step may also be used, which may cause further variations in the upper electrode surface roughness and/or morphology. Thermal expansion coefficient differences between the upper electrode IMD, and/or interconnection materials may then cause similar problems to those discussed relative to the lower electrode. By way of example, a capacitor may be formed using Ru as the metal for a lower and upper electrode and TaOx as a dielectric layer. The capacitor may be annealed in a nitrogen atmosphere at a temperature of about 600-700xc2x0 C. for about 30 minutes before subsequent processing. Such a capacitor is shown in FIG. 3, where the morphology of the upper electrode, as well as that of the lower electrode, has been changed by subsequent high-temperature heating.
As shown in FIG. 4, the leakage current in the capacitor shown in FIG. 3 may be increased by fine cracks in the dielectric layer caused by variations in the surface morphology of the upper electrode and/or the lower electrode. In addition, the adhesive strength of an insulating layer contacting an electrode may be reduced by variations in the surface morphology of the electrode. This could cause the electrode to be stripped from the insulating layer. Such a stripping or flaking problem may be found with contact plugs or interconnection layers as well as capacitors.
Embodiments of the present invention include methods for manufacturing an integrated circuit device. A metal layer is formed on an integrated circuit substrate. A capping layer is formed on the metal layer opposite the integrated circuit substrate. The metal layer covered with the capping layer is heat-treated. The capping layer is removed and the metal layer, which is exposed by removal of the capping layer, is plasma-treated.
In other embodiments of the present invention, a dielectric layer is formed on the plasma treated metal layer opposite the integrated circuit substrate. The formed dielectric layer is heat-treated, for example, to crystallize the dielectric layer. Heat-treating of the metal layer and heat-treating of the formed dielectric layer may be performed in a nitrogen atmosphere at between about 500xc2x0 C. and about 800xc2x0 C. or at about 700xc2x0 C. As a result of the pre-heating and plasma-treating the metal layer may substantially retain its surface morphology during heat-treating of the formed dielectric layer.
In further embodiments of the present invention, the capping layer is an oxide layer. The plasma-treating of the metal layer may include exposing the metal layer to a plasma containing argon (Ar) and/or nitrogen (N2). The integrated circuit device may be an integrated circuit capacitor and the metal layer may be an electrode of the capacitor and the dielectric layer may be a dielectric layer of the capacitor.
In other embodiments of the present invention, the metal layer is formed from at least one of ruthenium (Ru), iridium (Ir), platinum (Pt), rhodium (Rh), palladium (Pd), and metal oxides of Ru, Ir, Pt, Rh, and Pd. The dielectric layer may be an oxide layer formed of tantalum (Ta), titanium (Ti), and/or aluminum (Al). In yet other embodiments, the dielectric layer may be formed of at least one of SrTiO3 (STO), (Ba, Sr)TiO3 (BST), PbTiO3, Pb(Zr, Ti)O3 (PZT), SrBi2Ta2O5 (SPT), (Pb, La)(Zr, Ti)O3, Bi4Ti3O12, and BaTiO3 (BTO).
In further embodiments of the present invention, methods are provided for manufacturing an integrated circuit device including forming a metal layer on an integrated circuit substrate. A capping layer is formed on the metal layer opposite the integrated circuit substrate. The metal layer, covered with the capping layer, is heat-treated. The capping layer is removed and a dielectric layer is formed on the heat-treated metal layer opposite the integrated circuit substrate. The formed dielectric layer is heat-treated, for example, to crystallize the dielectric layer.

Methods for manufacturing semiconductor devices having a metal layer


An optimization method to be carried out within a digital computer under programmed control for eliminating or removing from a loop body alternate exit tests substantially of the form .alpha.i+.beta.cond.phi., where .alpha., .beta. and .phi. are loop invariant expressions, i is the innermost loop index variable, and cond is one of the relational operators (=,.noteq.,>,.gtoreq.,<,.ltoreq.). Each alternate exit test is compared to a list of elimination conditions. If an alternate exit test matches one of the elimination conditions, it is eliminated entirely from the loop body. If the alternate exit test cannot be eliminated, it is then compared to a list of restriction conditions. If the alternate exit test matches one of the restriction conditions, the loop index upper bound is modified if necessary and the alternate exit test is moved from inside to outside of the loop body. The resulting altered loop body is near optimum in terms of both the storage area utilized and the program execution time.

Supercomputers are high performance computing platforms that employ a pipelined vector processing approach to solving numerical problems. Vectors are ordered sets of data. Problems that can be structured as a sequence of operations on vectors can experience one to two orders of magnitude increased throughput when executed on a vector machine (compared to execution on a scalar machine of the same cost). Pipelining further increases throughput by hiding memory latency through the prefetching of instructions and data.
A pipelined vector machine is disclosed in U.S. Pat. No. 4,128,880, issued Dec. 5, 1978, to Cray, the disclosure of which is hereby incorporated herein by reference. In the Cray machine, vectors are processed by loading them into operand vector registers, streaming them through a data processing pipeline having a functional unit, and receiving the output in a result vector register. A vector machine according to U.S. Pat. No. 4,128,880 supports fully parallel operation by allowing multiple pipelines to execute concurrently on independent streams of data.
For vectorizable problems, vector processing is faster and more efficient than scalar processing. Overhead associated with maintenance of the loop-control variable (for example, incrementing and checking the count) is reduced. In addition, central memory conflicts are reduced (fewer but bigger requests) and data processing units are used more efficiently (through data streaming).
Vector processing supercomputers are used for a variety of large-scale numerical problems. Applications typically are highly structured computations that model physical processes. They exhibit a heavy dependence on floating-point arithmetic due to the potentially large dynamic range of values within these computations. Problems requiring modeling of heat or fluid flow, or of the behavior of a plasma, are examples of such applications.
Program code for execution on vector processing supercomputers must be vectorized to exploit the performance advantages of vector processing. Vectorization typically breaks up a loop of the form: ##EQU1## into a nested loop of the form: ##EQU2## where VL is the length of the vector registers of the system. This process is known as "strip mining the loop". In strip mining, the number of iterations in the internal loop is defined by the length of a vector register. The number of iterations of the external loop is defined as an integer number of vector lengths. The remaining iterations are performed as a separate loop placed before the nested loop. Vector length arrays of data from the original data arrays are loaded into the vector registers for each iteration of the internal loop. Data from these vector registers can then be processed at the one or more elements per clock period rate of a vector operation.
Compilers exist that will automatically apply strip mining techniques to scalar loops within program code to create vectorized loops. This capability greatly simplifies programming efficient vector processing. The programmer simply enters code of the form: ##EQU3## and it is vectorized.
There are, however, certain types of operations that inhibit the effectiveness of vectorization. One such operation is the automatic addition of alternate loop exits traditionally associated with array bounds checking. If array bounds checking is enabled, even relatively simple program source statements may generate a large number of alternate exit tests within a loop body because the upper and lower bounds must be checked for each array subscript contained in each program source statement. The presence of a large number of alternate exit tests greatly reduces the efficiency of the loop, and may cause a further loss of performance by preventing a compiler from vectorizing the loop. An equivalent loss of efficiency may also occur with scalar computers.
Therefore, there is a need for a method to remove or eliminate alternate exit tests from a loop body without changing the functionality of the loop.