Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.

In the conventional Von Neumann computer architecture, memory is structured as a linear array of fixed-size cells, indexed by sequential addresses. FIG. 1 shows an example of this conventional architecture. Execution of instructions 102 results in contents of memory 104 being as shown. Although this approach is simple to implement, and is relatively easy to use for fixed-sized application data units, software structures and techniques are required to handle variable-sized and structured data.
With variable-sized data, software typically implements a dynamic memory allocator that locates a contiguous region of the memory that is at least as large as that requested. However, over the course of extended execution, the memory space can become fragmented into smaller regions so that a memory allocation request fails even though the total amount of memory available is ample. Mechanisms such as generational garbage collectors can re-compact memory periodically by copying regions to make them contiguous but such garbage collection can interfere with the on-going execution of the application when invoked, an aspect not acceptable in real-time systems in particular or ones requiring predictable response in general. Moreover, if a variable-size data item grows in length, software must allocate a new contiguous region of the required size and copy the data to the new location and change all references pointing to the old location to now point to the new location. To facilitate this latter action, some software introduces an extra level of indirection through a fixed size location that provides the actual pointer to the variable-sized data, so there is a single location to update, but at the cost of an extra indirection on each access.
An alternative approach to variable-sized data is to construct the variable-sized data types from non-contiguous memory units using pointers (i.e., use structured data). Structured data is challenging to handle because it is difficult to determine when a memory region can be freed in the presence of the complicated pointer references characteristic of structured data. Access to data in a structured data representation also incurs the overhead of indirecting through pointers to fix the next entry in a variable-size data item.
For applications running in multiple separate processes, structured data introduces further overhead because it is generally necessary to serialize structured data and copy the result to a separate address space and then de-serialize it in order to share the structured data. This arises because the addresses used to structure the data are unique to each address space as a result of the virtual address translation used to provide isolation between processes. Sharing is further impeded by the large granularity of memory pages (e.g., 8 kilobyte or larger) used for address translation in comparison to typical application data units (e.g. 32-128 bytes). As a consequence, applications are either organized as multiple threads within one process, forgoing the protection of separate addresses or else pay a significant penalty in serializing, copying and de-serializing structured data between address spaces.
Recent and anticipated technology developments make the disadvantages of this standard Von Neumann model much more problematic. First of all, memory system performance has not kept pace with increased processor performance, making memory performance an increasingly limiting factor for computer performance. Thus, memory-intensive operations such as copying and garbage collection are becoming proportionally more expensive. Caching has been the primary means to deal with the processor/memory speed mismatch. However, with increasing sizes of memory, larger and more complex application objects and more data-intensive applications, caches are becoming significantly less effective using this conventional memory model.
As a second direction, computer hardware is increasingly relying on parallel execution to achieve performance benefits. In particular, it is feasible to implement multiple "cores" on a single microchip, improving cost-efficiency while allowing sharing of memory controller and cache. However, the extra copying induced by structured data leads to inefficient use of caches because of duplicated data. Moreover, extraneous updates such as reference count updates and false sharing in cache lines with updates leads to further memory and cache inefficiencies.
As a final trend, applications are becoming larger and more complex, enabled by increased memory sizes and processor performance, but increasing the difficulty of maintaining software correctness, especially with demands for on-going improvements and features. At the same time, applications are taking on increasingly time-, mission- and even life-critical functions, making their reliability that much more important.
For these and other reasons, alternative memory architectures have been considered. For example, in U.S. Pat. No. 4,989,137, a user processor accesses memory exclusively by way of a binding register unit which is part of a memory management system. In this manner, the memory management system can hide low level details of physical memory organization from the user processor, and instead presents a logical memory abstraction to the user processor. In U.S. Pat. No. 4,695,949, a block oriented memory is described, where a reference count is maintained for each block, thereby alleviating the need for frequent garbage collection.
In U.S. Pat. No. 5,784,699, a block-oriented memory system having several standard block sizes is considered. Memory allocation requests are rounded up to the nearest standard block size. In U.S. Pat. No. 5,950,231, a block-oriented memory management system controlled with a stack of pointers is considered. In U.S. Pat. Nos. 5,247,634 and 5,864,867, memory management based on the use of trees is considered.
However, these preceding approaches, and the standard Von Neumann cache approach, both tend to have difficulties, particularly for structured data. Accordingly, it would be an advance in the art to provide improved memory management, especially for variable-sized and structured data.

Hierarchical immutable content-addressable memory processor


Provided are a photosensitive silane coupling agent for forming a low-defect microparticle pattern, dot array pattern, or hole array pattern through fewer steps, and a method of forming a pattern using such photosensitive silane coupling agent. Used is a photosensitive silane coupling agent comprising a 1,2-naphthoquinone-2-diazido-5-sulfonyl group or a 1,2-naphthoquinone-2-diazido-4-sulfonyl group.

1. Field of the Invention
The present invention relates to a photosensitive silane-coupling agent, a method of modifying a surface and a method of forming a pattern using such photosensitive silane coupling agent, and a method of fabricating a device.
2. Description of the Related Art
Recently, in the fields of various electronic devices which require microfabrication, such as semiconductor devices, there has been ever increasing demands for increased density and integration of the devices. In the step of fabricating a semiconductor device, it is the photolithography process that plays an important part in forming the fine circuit pattern.
Most current photolithography processes are carried out by reduced projection exposure. However, the resolution of reduced projection exposure is limited by the light diffraction limit, which is about one-third the wavelength of the light source. Thus, attempts have been made to achieve shorter wavelengths using techniques such as employing an excimer laser as the exposure light source, whereby microfabrication at about the 100 nm level is now possible.
Thus, although photolithography continues to have improving fineness, many problems needing to be resolved have arisen, such as the increased size of the equipment resulting from shortening the wavelength of the light source, as well as development of lenses for such wavelength region, equipment costs and costs of the corresponding lenses.
Further, devices have recently been proposed which require a high-density dot array pattern. Examples thereof include a single-electron device (Japanese Patent Application Laid-Open No. 2001-168317), patterned media (Japanese Patent Application Laid-Open No. 2005-190624), a chemical sensor (Japanese Patent Application Laid-Open No. 2003-268592), a quantum dot laser element (Japanese Patent Application Laid-Open No. H10-012968), and a photonic crystal optical device (Japanese Patent Application Laid-Open No. H11-218627). However, because these devices require even greater high-precision microfabrication techniques than those for semiconductor devices, mass production has been difficult with conventional photolithography techniques.
On the other hand, as a low-cost and simple method for forming a micropattern taking the place of lithography techniques, methods have been reported which cause the microparticles to arrange in a self-organizing manner.
Further, in recent years methods have also been proposed for forming a micropattern by forming a chemically reactive group in a pattern on a substrate surface using an energy beam, and then utilizing the interaction between the chemically reactive group and the microparticles. Specific examples are disclosed in Polymer Preprints, Japan, Japanese Ed., Vol. 53, 4196 (2004) and Japanese Patent Application Laid-Open No. 2003-168606. These examples are techniques which fuse lithography and self-organization. In the present invention such techniques will be referred to as "build-up lithography".
In Polymer Preprints, Japan, Japanese Ed., Vol. 53, 4196 (2004), it is disclosed to expose a monomolecular film of a photosensitive silane coupling agent to a light, and then adhere microparticles to the exposed portion.
Specifically, it is disclosed to irradiate UV rays onto a photosensitive silane coupling agent having a carboxyl group which is protected by a nitrobenzyl group to thereby generate a carboxyl group on the irradiated portion, and to dip the resultant object in an aqueous solution of fluorescent microparticles for selectively adhering fluorescent microparticles to the exposed portion.
Polymer Preprints, Japan, Japanese Ed., Vol. 53, 4196 (2004) also discloses the results of examples in which a monomolecular film of a photosensitive silane coupling agent having an unsaturated alkyl group was irradiated with X-rays in a pattern to excite the unsaturated bonds of the exposed portion, whereby bonds were formed with the organic film of the surface of the metal microparticles.
The photosensitive silane coupling agent used in Polymer Preprints, Japan, Japanese Ed., Vol. 53, 4196 (2004), which has a carboxyl group protected by a nitrobenzyl group, generates a nitrosobenzaldehyde as a byproduct upon exposure. To remove this byproduct, a rinsing step is necessary. However, in mass production of a device, a smaller number of steps is preferable from the perspective of costs.
Further, in Japanese Patent Application Laid-Open No. 2003-168606, there is the problem of a high rate of defects due to the microparticles not properly adhering to the energy beam irradiation portion. This is because the excited state of the unsaturated bond group is easily deactivated to the ground state.

Photosensitive silane coupling agent, method of modifying surface, method of forming pattern, and method of fabricating device


At least one exemplary embodiment is directed to an image pickup apparatus which includes an optical member that is vibrated in a direction substantially perpendicular to an optical axis to facilitate removal of particles (e.g., dust), where the vibration of the optical member is substantially isolated from an image pickup element.

1. Field of the Invention
The present invention relates to an image pickup apparatus and, in particular though not exclusively, to a technique of removing a foreign object from an optical member.
2. Description of the Related Art
An image pickup apparatus that performs imaging by converting an image signal into an electrical signal, such as a digital camera, receives light with an image pickup element (e.g., a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS) device), converts a photoelectric conversion signal output from the image pickup element into image data, and records the image data on a recording medium (e.g., a memory card). In such an image pickup apparatus, an optical low-pass filter or an infrared cut filter is arranged adjacent to a subject with respect to the image pickup element, and when a foreign object (e.g., dust), adheres to a surface of the filter or a cover glass of the image pickup element, the adhering portion is present in a taken image as a black spot. This results in a degraded appearance of the image.
In particular, for a digital single-lens reflex camera with an interchangeable lens, since mechanical operational units, including a shutter, and a quick return mirror, are arranged adjacent to an image pickup element, a foreign object (e.g., dust), produced from the operational units can adhere to the image pickup element or a low-pass filter. Additionally, while the lens is interchanged, dust or other objects can enter a camera body from an opening of a lens mount and adhere to the camera components.
One approach to address this problem that has been suggested is to remove a foreign object (e.g., dust), on a surface of a dustproof curtain that allows a light beam for image taking to pass therethrough arranged adjacent to a subject with respect to the image pickup element by vibrating the dustproof curtain with a piezoelectric element, as discussed in Japanese Patent Laid-Open No. 2003-319222.
According to the technique discussed in this patent document, in order to remove a foreign object on the surface of the dustproof curtain, the dustproof curtain is vibrated by being displaced along the optical axis by the application of a drive voltage to a piezoelectric element connected to the dustproof curtain. However, in order to remove the foreign object from the dustproof curtain, it is necessary to shake the foreign object off the dustproof curtain by application of a force larger than adhesion of the foreign object in the optical axis, and as a result, a large amount of energy is required.
Additionally, according to the above technique, since the dustproof curtain is vibrated by being displaced along the optical axis, if the shape of the dustproof curtain is not circular, it is known that the vibration mode is complicated and vibration efficiency is decreased.
However, an effective imaging area of an image pickup apparatus generally has a rectangular shape with an aspect ratio of 4:3 or 3:2, and therefore, the shape of an effective light beam is rectangular in cross section. In order to allow the effective light beam having a rectangular shape to appropriately pass therethrough, the circular dustproof curtain is large with respect to the effective light beam. Therefore, arranging the circular dustproof curtain within the image pickup apparatus is unfavorable in terms of layout. This produces problems, such as an increase in the size of the image pickup apparatus, an inefficient layout therein.
At the same time, since the above technique requires a special component (namely the dustproof curtain) arranged in the optical axis for image taking, transmittance of the light beam for image taking is reduced, and as a result, the technique is unfavorable in terms of optical function or optical performance, in addition to inefficiency in layout.
Furthermore, a large amount of electric power is necessary for vibration of the dustproof curtain, which has a large size with respect to the effective light beams.

Image pickup apparatus with foreign object removal capabilities


An electrode arrangement for a discharge lamp is provided, including an electrode unit including an electrode and an electrode plate, and a conductive connection unit for coupling to an energy source. The connection unit includes a connection unit plate. The arrangement includes a cylinder composed of a nonconductive material, said cylinder arranged between the electrode plate and the connection unit plate, and at least one conduction film which is arranged on an outer side of the cylinder and extends from the connection unit plate as far as the electrode plate and connects the connection unit plate and the electrode plate to one another. The arrangement includes a cap-shaped and integrally embodied protective film arranged on the electrode plate or connection unit plate, such that the film covers a plate side facing away from the cylinder and an outer lateral surface of the electrode plate or of the connection unit plate.

Various embodiments generally belong to the field of electrode arrangements or electrode systems for discharge lamps, specifically to the field of discharge lamps having all-round film sealing systems, and can find application here e.g. both for DC discharge lamps and for AC discharge lamps. Such discharge lamps usually include two above-described electrode arrangements arranged in a quartz glass bulb in a manner lying coaxially with respect to one another. In particular, said electrode arrangements are arranged here within such a bulb in such a way that the electrode tips facing one another and in particular also a large part of the abovementioned electrode arrangement are situated within said bulb, while at least part of the connection unit for coupling to the energy source, in particular for providing the power supply, is situated outside said bulb.
The bulb has to be closed in an air-tight fashion, which is normally achieved by this outer glass bulb being fused to the electrode arrangement or electrode arrangements at high temperatures. It is problematic in this case if metal components are fused to glass in this case since mechanical stresses can occur on account of temperature changes during fusion or else during later operation, which mechanical stresses arise as a result of the different coefficients of thermal expansion of the materials and can in turn lead to cracks in the quartz glass. Therefore, by way of example, the cylinder composed of the material that is not electrically conductive, said cylinder being arranged between the electrode plate and the connection unit plate, is usually likewise formed from quartz glass, such that it can be fused to the glass bulb, without any stresses on account of differences in thermal expansion having to be feared during operation. Therefore, the contacting between the connection unit plate and the electrode plate is also realized by at least one electrically conductive conduction film arranged on the outer side of the cylinder. Such a film, which is correspondingly also usually composed of metallic material, can then be made correspondingly thin, such that during the process of sealing in said film or fusing said film to the surrounding glass bulb, appreciable mechanical stresses on account of the different coefficients of thermal expansion likewise do not occur. What is problematic, however, is primarily the contact—arising during fusion—between the molten quartz glass of the glass bulb and the electrode plate, and in particular also the connection unit plate. Here, the different coefficients of expansion can lead to cracks in the quartz glass which, in the case of an unfavorable position and direction of propagation, result in a defect in the vacuum-tight seal.
In order to prevent this, it is conventionally provided to cover the plates, that is to say for example the electrode plate and/or the connection unit plate, with a metal film as protective film. This protective film is intended to prevent quartz glass from adhering to the electrode plate through the outer glass bulb and the film can absorb material stresses between quartz and metal plate perpendicular to the film surface. In this case, said film, for example for covering the electrode plate, is embodied in two parts, first as a disk having a hole for the electrode. The disk is then correspondingly arranged on that side of the electrode plate on which the electrode is also arranged centrally, such that this ring-shaped disk surrounds the electrode attachment point, as far as the edge of the electrode plate. Furthermore, a separate protective film strip is provided for the outer radius of the electrode plate. This film strip is secured on the circumference with the aid of resistance welds.
However, the abovementioned electrically conductive conduction film lies below said strip at least regionally, said conduction film electrically conductively connecting the two plates, that is to say the connection unit plate and the electrode plate, to one another. Said conduction film is also welded on. As a result of the overlying film strip of the protective film, this film strip likewise being welded on, this second weld can, however, damage the underlying first weld. This can impair both the conductivity and the stability of the electrode arrangement.

Electrode arrangement for a discharge lamp, gas discharge lamp, protective film and method for providing a protective film on an electrode arrangement


A novel route has been developed for substituted 2-[-6-benzyl-5-oxo-3-phenyl-(3s,7s,7aR)-perhydroimidazol[1,5-c][1,3]thiazol] compounds; crucial intermediates for D(+)-biotin of formula (7) which involves simple, efficient, practical and cost effective protocol. These are crucial intermediates for commercially important D(+)-biotin preparation. These compounds are more stable and are produced by non-hazardous methods.

The invention relates to novel substituted 2-[-6-benzyl-5-oxo-3-phenyl-(3s,7s,7aR)-perhydroimidazol[1,5-c][1,3]thiazol] compounds having general formula (7)
Wherein R=benzyl, R1=alkyl group exemplified by 1-phenyl-1-ethanone, 1-(4-chlorophenyl)-1-ethanone, 1-(4-methoxypheny)-1-ethanone,2-oxocyclohexyl, 1-trimethylsilyloxy-2-oxocyclohexyl, allyl,1-hexanyl,4-dimethylaminophenyl, or 2-methylpropanoate. Still more particularly it relates to methyl 6-[benzyl-5-oxo-3-phenyl-(3S,7aR)-perhydroimidazo[1,5-c][1,3]thiazol-7yl]-6-oxohexanoic acid of formula (1) which is very useful intermediate for D(+)-Biotin
Biotin (Vitamin H) is one of the B-complex group of vitamins and has immense commercial importance in the area of animal health and nutrition. It is one of the biocatalysts of the reversible metabolic reactions of carbon dioxide transport in micro and macro organisms. It is used in poultry feeds of rapid growth of chicks and healthy hatching of eggs. Biotin avidin complex finds a vital role in the area of biochemistry. D(+)-Biotin prepared by the process of the present invention is represented by formula 2
D(+) Biotin is prepared in the prior art from amino acids viz., cysteine, cyctine and serine. These processes involving L-cystine as the precursor, incorporate intramolecular radical cyclization (E. J. Corey, M. M. Mehrotra, Tet.Lett., 29, 57 1988) as the key step is construct the tetrahydrothiophene moiety of biotin.
Another prior art process involves intramolecular cycloaddition (3+2) of derivatives of L-cystine (E. G. Baggiolini, H. L. Lee, G. Pizzolato and M. R. Uskokovic, J.Am.Chem.Soc., 104, 6460, 1982), and L-cysteine (, H. L. Lee, E. G. Baggiolini and M. R. Uskokovic, Tetrahedron 43, 4887, 1987).
In another process starting from L-cysteine, a bicyclic imidazolidine is the key intermediate leading to D(+)-biotin (E. Poetsch and M. Casutt, EP 242,686 1986 CA:108:1612077k 1988; Chimia 41, 148 1987). In an totally different and novel approach. L-cysteine was converted to its thiazolidine derivative which on treatment with bromine is converted stetreospecifically to a bicyclic intermediate as a single stereoisomer and eventually transformed to D(+)-biotin (P. N. Confalone, E. G. Baggiolini, D. Lollar, and M. R. Uskokovic, J. Am. Chem. Soc., 99, 7020 1977). Process for stereospecific synthesis of D(+)-Biotin from sugars of suitable configuration are known. [From Mannose Tet. Lett., 32, 2765 1975].
The use of L-cysteine in known from U.S. Pat. Nos. 4,000,972, 4,130,713, 4,337,345 and J. Am. Chem. Soc., 99, 7020, 1977 avoids the handling of labile intermediate steps but involves 18 steps, in all with the separation of undesired isomer leading to unsatisfactory yields of optically active D(+)-Biotin.
In another process J. Am. Chem. Soc., 105, 5946, 1983 and EP 0094776, substituted 3H, 5H-Imidazo[1,5-C]tetra hydro thiazole are described from which after racemate resolution, synthesis of optically active biotin is described.
In another process by Moolenaer, M. J.; Speckamp, W. N.; Hiemstra, H.; Poetsch, E.; Casutt, M. Angew. Chem., Int. Ed. Engl. 1995, 34,2391 and DE 3,926,690 involves the intramolecular version of the condensation of a silyl enol ether with N-acyliminium intermediates to effect the ring closure of thio ether to the thiophane nucleus.
In yet another process by Poetsch, E.; Casutt, M., EP 242,686 1986; CA: 108: 112077K 1988; Chimia 41, 141-150, 1987 describes the formation of keto acid and further elaboration of acid to D(+)-Biotin. The main draw back of this method is use of hazardous 2 eq of diisobutylaluminium hydride (DIBAL-H). Potassium cyanide (KCN), Carbonyldiimidazole and involves reactions to be performed under anhydrous conditions.
In yet another prior art of biotin syntheses by Chavan, S. P.; Chittiboyina, A. G.; Kamat, S. K., Indian Patents NF135/98, 136/98 and Ravindranathan, T.; Chavan, S. P.; Tejwani, R. B. U.S. Pat. No. 5,274,107 (1993) describes the formation of substituted imidazolidines from L-cysteine and further elaboration of hydantoin to D(+)-biotin. This process also involves the use of expensive and hazardous chemicals viz., DIBAL-H, tertiary butyl dimethyl silyl chloride (TBDMSCI), trifluoromethane sulphonic acid (Triflic acid) etc.,
Hitherto known processes involve highly toxic and hazardous chemicals e.g., phosgene for the formation of imidazolidine. Moreover the intramolecular radical cyclization leads to both desired five membered as well as undesired six membered ring along with tin inclusion compounds as the undesired byproducts.
In another prior art process involving the intramolecular (3+2) cylcoaddition reaction of nitrone, the precursor olefin is obtained as a mixture (9:1) of which the desired olefin has to be purified and separated by chromatography. Moreover, the chiral intermediates obtained during the above mentioned sequence of reactions were prone to racemization.
In another prior art process involving the intramolecular cyclization of thiazolidine required Collins oxidation as one of the steps. Use of heavy metals on an industrial scale would lead to problems during waste disposal. Moreover Wittig reaction on the aldehyde leads to a mixture of isomers, which should be separated and the desired isomer subjected to further reactions leading to biotin.
All these processes are however characterized by large number of synthetic steps resulting in low overall yields. The non crystallizable intermediate stages mostly due to sugar nature are often obtained in impure form and require tedious purification on account of their polyfunctionality and chemical liability connected with it maintenance of comparatively very narrow range of reaction parameters. Additionally these sugars are not easily available in nature which leads to high prices.
Hitherto known processes involve highly toxic, expensive and hazardous chemicals for example carbonyldiimidazole, Methyl Iodide, potassium cyanide DIBAL-H etc., for the formation of keto acid (1). More over these reactions required anhydrous conditions.
An object of the present invention is to provide substituted [6-benzyl-5-oxo-3-phenyl-(3S,7S,7aR)-perhydroimidazo[1,5-c][1,3]thiazol]-7yl compounds of formula (7) especially as given table-1 which can be used for synthesis of D(+)-biotin of formula (2).
Another object of the present invention is to provide selective Baeyer Villiger oxidation and new methodology for nucleophilic addition to imidazolodine of the formula (6) at C-7 position for the synthesis of compound having formula (7).
Accordingly the present invention provides substituted [6-benzyl-5-oxo-3-phenyl-(3S, 7S, 7aR)-perhydroimidazo[1.5-c][1,3]thiazol]-7yl compounds having general formula (7)
Wherein R=benzyl, R1=alkyl exemplified by 1-phenyl-1-ethanone, 1-(4-chlorophenyl)-1-ethanone, 1-(4methoxypheny)-1-ethanone, 2-oxocyclohexyl, 1-trimethylsilyloxy-2-oxocyclohexyl, allyl, 1-hexynyl, 4-dimethylaminophenyl, or 2-methylpropanoate
The present invention also provides a process for the preparation of compounds having formula (7) which comprises reacting the compound of formula (6) with Lewis acid and a nucleophile at a temperature ranging between 0xc2x0 to 30xc2x0 C. in an organic solvent for 10-30 minutes quenching the reaction mixture with either water or saturated aqueous solution of quenching agent, separating and concentrating the organic layer, purifying by conventional methods such as chromatography to obtain compounds of formula (7a) to (7g) as mentioned in the following table.
In one of the embodiment of the present invention the compound the alkyl group may be 1-phenyl-1-ethanone, 1-(4-chlorophenyl)-1-ethanone, 1-(4-methoxypheny)-1-ethanone,2-oxocyclohexyl, 1-trimethylsilyloxy-2-oxocyclohexyl, allyl, 1-hexanyl,4-dimethylaminophenyl, or 2-methylpropanoate.
In another embodiment the organic solvent used is selected from the group consisting of dichloromethane, dichloroethane, chloroform, tetrahydrofuran, benzene or toluene.
In still another embodiment the quenching agent is selected from the ammonium chloride, potassium chloride, sodium chloride.
The compound having formula (6) can be prepared by known procedures as per the scheme given herein below:
The present invention also provides a process for the preparation of D(+) biotin of formula (2) as per the scheme given hereinbelow
which comprises reacting compound having formula [7(e)/7(exe2x80x2)] with an oxidising agent in presence of alkaline alcohol at temperature ranging between 15-40xc2x0 C. for the period of 30 mints to 90 min, removing the alcohol by conventional methods and extracting with an organic solvent, separating the aqueous layer and acidifying to pH 4.0 to 5.0 further extracting the mixture with an organic solvent, separating and concentrating the solvent layer, removing the solvent by conventional methods like evaporation to obtain compound of formula (1), converting the compound of formula (1) to obtain D(+) biotin by known methods.
In another embodiments of the present invention the organic solvent used for the reaction may be methanol, ethanol water.
In another embodiment of the present invention the alkali used for the reaction may be KOH, NaOH, NaHCO3, Na2CO3, KHCO3, K2CO3.
In still another embodiment the oxidising agent used may be conventional peroxides exemplified by hydrogen peroxide, tertiary butyl hydrogen peroxide and cumene hydroperoxide etc.,
In a feature of the present invention the electrophile of formula (6) is prepared by known procedure as given in (Poetsch, E.; Casutt, M., EP 242,686 1986; CA: 108: 112077K 1988; Chimia 41, 141-150, 1987).
In another feature the present invention synthesis of D(+)-biotin can be done by obtaining methyl ether of compound having formula (6). The methyl ether can be prepared by conventional methods.
The merits of invented processes are use of easily accessible. cheap chemicals, selective Baeyer-Villiger oxidation and new methodology for the preparation of C-7 substituted imidazolidines, which provides an economically feasible method for the D(+)-biotin synthesis, as the synthesis of biotin of formula (2) from compound of formula (1) is well reported in literature, and avoids the use of costlier and hazardous chemicals such as DIBAL-H, KCN, etc.

Substituted 2-[-6-benzyl-5-oxo-3-phenyl-(3s,7s, 7aR)-perhydroimidazol[1,5-c][1,3]thiazol-7yl] compounds

Council of Scientific and Industrial Research


A support arm includes a generally elongated support arm housing having first and second ends; an arm mounting member pivotally carried by the first end of the support arm housing, the arm mounting member pivotal throughout a first range of rotation; a device mounting member pivotally carried by the second end of the support arm housing, the device mounting member pivotal throughout a second range of rotation; a position equalizing assembly engaging the arm mounting member and the device mounting member, the position equalizing assembly pivoting the arm mounting member and the device mounting member in opposite directions throughout the first range of rotation and the second range of rotation; anda counterbalance adjusting assembly carried by the arm mounting member and engaging the device mounting member, the counterbalance adjusting assembly applying counterbalance force to the device mounting member.

Medical and dental offices may utilize devices such as computers, monitors, keyboards, laptop computers and the like to store medical or dental records and treatment protocols for patients. It may be desirable that these devices be adjustable in position for the benefit of a physician, dentist, assistant or other personnel as he or she attends to the patient. However, these devices are frequently mounted in a fixed position on a desk, countertop or other surface. Access to the device may require that the personnel either remain sitting and assume an uncomfortable position or move from the patient to the device to retrieve the necessary information and then return to the patient.
Therefore, a support arm which can be used to support a device relative to a fixed surface and allows controlled freedom of movement of the device may be desirable for medical, dental or other applications.


Methods, devices, systems, and apparatus including computer-readable mediums for managing error correction coding in memory systems are provided. In one aspect, a memory system includes a system controller configured to communicate with a host device, and a memory device coupled to the system controller. The memory device includes at least one memory and a memory controller coupled to the at least one memory. The memory controller includes an error correction code (ECC) circuit configured to perform error correction coding for data received from at least one of the system controller or the at least one memory.

Some memory systems include system controllers and memory devices that communicate with each other through electrical circuit boards. In some cases, the system controllers perform error correction coding for data to or from the memory devices, which causes large data transfer through the electrical circuit boards. This may cause high power consumption and high operation temperature.

Managing error correction coding in memory systems


A two way messaging terminal includes a transmitter and a receiver. A voice message is encoded using a CODEC after which the resulting data is compressed in non-real time prior to transmission. On receipt the compressed message is first decompressed in non-real time prior to decoding and playing back.

1. Field of the Invention
This invention relates generally to the field of two way messaging systems. More particularly, this invention relates to a non-real time two way messaging system which utilizes data compression to minimize transmission time and thus conserve battery life and optimize bandwidth utilization.
2. Background of the Invention
Two way radio systems have been in use for a number of years to facilitate two way communication between parties. However, use of these systems has largely been limited to specialized business applications (e.g. security), police, government and military use due to the cost and bulk of the devices. Consumers have found pagers and cellular telephone devices to provide a more convenient mechanism for everyday communication needs both for business and private use. Unfortunately, the cost of use of cellular telephones remains high for some users and paging devices generally permit only one way communication, thus requiring access to a telephone to enable the user to provide a response.
Recently, personal two way messaging systems (such as Motorola's Tango and Tenor pagers) which provide limited two way messaging capability have become available. Like pagers, such two way messaging systems are designed to be personal devices which are compact and easy to carry. Unfortunately, the convenience of small size and weight limits the size of the battery used to power such devices. As a result, substantial efforts have been devoted to the problem of optimizing battery drain in such devices in order to maximize the battery life for these devices. Moreover, the availability of bandwidth is problematic and thus use of the available bandwidth should be optimized.

Two way messaging system with non-real time voice compression and decompression


A fiber optic cable includes a tape comprising a substrate of an extrudable thermoplastic, core items of the fiber optic cable, and a jacket around the tape and core items. The tape includes water-swellable material integrated therewith and the core items include one or more optical fibers. The tape is incorporated with core items such that the water-swellable material of the tape is configured to limit water from flowing lengthwise along the cable through gaps among the core item.

Aspects of the present disclosure relate generally to fiber optic cables, and more specifically to fiber optic cables that include water-blocking tapes.
Fiber optic cables, especially those designed for outdoor environments, typically include water-blocking components to limit the flow of water through the cables. Some cables use "dry" water-blocking components, such as water-swellable tapes and yarns that carry super-absorbent polymers (SAP). When exposed to water, the SAP expand and fills gaps in the cable to block the flow of water through the cable. Water-swellable tapes typically include layers of nonwoven material, such as polyester fiber, that are laminated together, with the SAP between the layers or coated on or adhered thereto. Similarly water-swellable yarns are typically coated with super-absorbent material.
Water-swellable tapes and yarns are typically supplied on reels or spools, and the tapes and yarns are drawn into the core of a cable during manufacturing, such as when other components are joined together in stranding, when a tube is extruded around the components, and/or when the cable is jacketed. As the tapes and yarns are pulled from the reels and spools, water-swellable materials may break loose and fall from the tapes and yarns, such as on to the floor of the corresponding manufacturing facility. Also, when cable components, such as unjacketed cable cores are moved within a manufacturing facility or into inventory, the water-swellable materials may also break loose and fall from the tapes and yarns.
In environments that have humidity, the loose water-swellable materials may absorb water from the air and expand. As such, the loose powders may become quite messy in the manufacturing facility. Other components of cables, such as fire-retardant tapes that carry fire-retardant powder particles may behave similarly. A need exists for cleaner way to make fiber optic cable, and fiber optic cable components such as cable cores, that do not drop or drop fewer powder particles, such as water-swellable powder, in a manufacturing facility or elsewhere.


The present invention relates to imaging agent compositions comprising radiolabelled c-Met binding peptides suitable for positron emission tomography (PET) imaging in vivo. The c-Met binding peptides are labelled with the radioisotope 18F. Also disclosed are pharmaceutical compositions, methods of preparation of the agents and compositions, plus methods of in vivo imaging using the compositions, especially for use in the management of cancer.

Hepatocyte growth factor (HGF), also known as scatter factor (SF), is a growth factor which is involved in various physiological processes, such as wound healing and angiogenesis. The high affinity interaction of HGF interaction with its receptor (c-Met) is implicated in tumour growth, invasion and metastasis.
Knudsen et al have reviewed the role of HGF and c-Met in prostate cancer, with possible implications for imaging and therapy [Adv. Cancer Res., 91, 31-67 (2004)]. Labelled anti-met antibodies for diagnosis and therapy are described in WO 03/057155.
c-Met has been shown to be involved in tumour growth, invasion and metastasis in many human cancers of epithelial origin. c-Met is expressed by most carcinomas and its elevated expression relative to normal tissue has been detected in cancers of: lung, breast, colorectal, pancreatic, head and neck, gastric, hepatocellular, ovarian, renal, glioma, melanoma and a number of sarcomas. In colorectal carcinoma (CRC), over-expression of c-Met has been detected in dysplastic aberrant crypt foci, the earliest pre-neoplastic lesions of the disease. In head and neck squamous cell cancer, c-Met is reportedly expressed or overexpressed in roughly 80% of primary tumours. In prostate cancer metastasis to bone, c-Met was reported overexpressed in over 80% of bone metastasis.
Under normal conditions, c-Met is expressed on epithelial cells and activated in a paracrine fashion, by mesenchymally derived HGF. The activation of c-Met in normal cells is a transient event and is tightly regulated. In tumour cells, however, c-Met can be constitutively active. In cancer, aberrant c-Met stimulation can be achieved through c-Met amplification/over-expression, activating c-Met mutations (e.g. structural alterations) and acquisition of autonomous growth control through creation of autocrine signalling loops. In addition, a defective down-regulation of the c-Met receptor will also contribute to aberrant c-Met expression in the cell membrane. While the over-expression of c-Met is HGF dependent (autocrine/paracrine), structural alterations caused by mutations are HGF independent (e.g. loss of extracellular domain).
WO 2004/078778 discloses polypeptides or multimeric peptide constructs which bind c-Met or a complex comprising c-Met and HGF. Approximately 10 different structural classes of peptide are described. WO 2004/078778 discloses that the peptides can be labelled with a detectable label for in vitro and in vivo applications, or with a drug for therapeutic applications. The detectable label can be: an enzyme, a fluorescent compound, an optical dye, a paramagnetic metal ion, an ultrasound contrast agent or a radionuclide. Preferred labels of WO 2004/078778 are stated to be radioactive or paramagnetic, and most preferably comprise a metal which is chelated by a metal chelator. WO 2004/078778 states that the radionuclides therein can be selected from: 18F, 124I, 125I, 131I, 123I, 77Br, 76Br, 99mTc, 51Cr, 67Ga, 47Sc, 167Tm, 141Ce, 111In, 168Yb, 175Yb, 140La, 90Y, 88Y, 153Sm, 166Ho, 165Dy, 166Dy, 62Cu, 64Cu, 67Cu, 97Ru, 103Ru, 186Re, 203Pb, 211Bi, 212Bi, 213Bi, 214Bi, 105Rb, 109Pd, 117mSu, 149Pm, 161Tb, 177Lu, 198Au and 199Au. WO 2004/078778 states (page 62) that the preferred radionuclides for diagnostic purposes are: 64Cu, 67Ga, 68Ga, 99mTc and 111In, with 99mTc being particularly preferred.
WO 2008/139207 discloses c-Met binding cyclic peptides of 17 to 30 amino acids which are labelled with an optical reporter imaging moiety suitable for imaging the mammalian body in vivo using light of green to near-infrared wavelength 600-1200 nm. The c-Met binding peptides comprise the amino acid sequence SEQ ID NO: 1:
Cysa-X1-Cysc-X2-Gly-Pro-Pro-X3-Phe-Glu-Cysd-Trp-Cysb-Tyr-X4-X5-X6;                wherein X1 is Asn, H is or Tyr;                    X2 is Gly, Ser, Thr or Asn;            X3 is Thr or Arg;            X4 is Ala, Asp, Glu, Gly or Ser;            X5 is Ser or Thr;            X6 is Asp or Glu;and Cysa-d are each cysteine residues such that residues a and b as well as c and d are cyclised to form two separate disulfide bonds. The optical reporter of WO 2008/139207 is preferably a cyanine dye.
WO 2009/016180 discloses c-Met binding cyclic peptides analogous to those of WO 2008/139207, wherein the optical reporter is a benzopyrylium dye. The agents of WO 2008/139207 and WO 2009/016180 are stated to be useful for in vitro and in vivo optical applications, especially optical imaging in vivo of the human body. Optical imaging of colorectal cancer is a preferred application.


A power supply for a travelling-wave tube (TWT) includes a beam power supply (14) connected to the cathode and collector of the TWT, and a further power supply (20) connected to ground and to the collector for establishing the cathode-to-body voltage. A feedback cathode voltage regulator includes a transresistance arrangement (31) connected between ground and a terminal of the further power supply which, in one version, includes a cascade of a control transresistance device (32) with a plurality of further transresistance devices (234s) for reducing the voltage to which the control device is subjected. In another version, a plurality of such transresistance arrangements (A,B) are paralleled for reducing the power which any one device must handle. In a preferred embodiment, a current equalizer (240) equalizes the load carried by each of the transresistance arrangements (A,B).

This invention relates to power supplies, and more particularly to power supplies for high-voltage pulse applications, such as in a radar system using a travelling-wave tube transmitter.
Radar systems have been used for more than fifty years, and during that time many varieties have emerged, including continuous-wave varieties. Many radar systems continue to use relatively short, high-power pulses of radio-frequency electromagnetic radiation to detect, locate and track targets. Modern radars provide very sophisticated features and capabilities at long range on small targets. In order to provide such features and capabilities, the recurrently transmitted electromagnetic pulses are often required to meet stringent frequency, power, and stability criteria while executing a recurrent program involving changing frequency and power.
In general, high performance in a radar system depends upon having a large bandwidth, so that at some times very short-duration pulses can be transmitted for making fine determinations of distance and dimensions, and at other times much longer-duration pulses can be transmitted for long-range detection. At one time, radar systems used simple vacuum tubes in their transmitters, but the power and frequency limitations of such tubes made them somewhat unsatisfactory. The development of the klystron and magnetron provided increased power at high frequencies, but with limited bandwidth. Modern radar systems use broadband sources of transmitted electromagnetic radiation, which are often in the form of one or more travelling-wave tubes (TWTs), and sometimes of arrays of solid-state transistors. At the current state of technology, the highest power with wide bandwidth is available with travelling-wave tubes.
FIG. 1 is a simplified diagram in block and schematic form, illustrating a prior-art travelling-wave tube power supply 10. In general, stability of the transmitted pulse from a travelling-wave tube, such as 12 of FIG. 1, can be achieved by maintaining constant the various TWT electrode voltages. In the simplest type of high-power TWT transmitter, a travelling wave tube, such as 12, is energized by a voltage supply, such as 14 of FIG. 1, connected to its cathode 12ca and collector 12co. Such an arrangement sets the power dissipation of the TWT to equal the product of the tube current and the voltage of source 14. The actual tube voltage and power are often determined by considerations including the best linearity or least distortion introduced by the tube. In an actual system, the voltage of power supply 14 may be about 35 kilovolts (kv). This type of supply can be effective, but the unavoidable internal impedance of the power supply 14 undesirably results in a decrease of the applied voltage each time an energy pulse is produced by the TWT 12.
In order to reduce the voltage drop attributable to the internal impedance of the power supply 14 of FIG. 1, the prior art parallels the power supply with an energy storage capacitor, illustrated as 16 in FIG. 1. The energy storage capacitor tends to reduce the instantaneous voltage drop at the inception of the pulse, but a voltage decrease or xe2x80x9cdroopxe2x80x9d still occurs over the duration of the transmitted pulse. A sufficiently large energy storage capacitor 16 can, however, keep the voltage droop within acceptable limits. The presence of the energy storage capacitor 14, in turn, results in the possibility of a large current discharge in the event of a short-circuit or flashover within the TWT. A current-limiting resistor 18 is introduced in a serial connection between the TWT cathode and the combination of the power supply 14 and the capacitor 16, to prevent damage to the TWT and power supply.
It should be noted at this point that the terms xe2x80x9cbetweenxe2x80x9d and xe2x80x9cacross,xe2x80x9d and certain other terms, have meanings in electrical usage which are different from those commonly used. More particularly, the terms have meanings which are not related to physical placement, but rather relate to the terminals to which electrical coupling is made. Thus, signal flow xe2x80x9cbetweenxe2x80x9d A and B takes place if the signal leaves one of A and B and arrives at the other, regardless of whether the path taken happens to lie on, or pass through, a straight line extending from A to B. Those skilled in the art know this so thoroughly that little though is given to the use of the terms, and they are automatically understood.
It has been found that greatest modulation sensitivity (somewhat corresponding to xe2x80x9cgainxe2x80x9d) of a travelling-wave tube occurs at specific values of voltage between the cathode 12ca and the body 12b of the tube 12. The body 12b of the TWT 12 should be grounded, for reasons of safety and to reduce the possibility of flashover. In general, the maximum-modulation-sensitivity cathode-to-body voltage does not correspond with the optimum cathode-to-collector voltage of the TWT. In order to obtain maximum modulation sensitivity of TWT 12 of FIG. 1, a second voltage or power supply 20 is provided, with its negative (xe2x88x92) terminal coupled to the collector 12co of TWT 12 by way of a current-limiting resistor 22, and with its positive (+) terminal coupled essentially to ground, by way of a control or regulator arrangement designated generally as 30. The voltage produced by power supply 20 introduces an offset voltage which drives all the voltages associated with the TWT in a negative direction, except for the ground voltage at 12g applied to the TWT body connection 12b. The voltage of power supply 20 is selected to a value which sets the cathode-to-ground voltage to about the maximum-modulation-sensitivity voltage, which is to say that the floating voltages of power supply 14 are driven negative until the cathode 12ca of TWT 12 is at the desired negative voltage relative to the ground voltage at body terminal 12b. In one application, the voltage of power supply 20 is about 8 kilovolts, which sets the cathode-to-ground voltage at about xe2x88x9243 kv. The voltage offset introduced by power supply 20 does not change the power dissipation of the TWT, because power supply 14 continues to establish the voltage (about 35 kv in the example) between cathode 12ca and collector 12co. Thus, the arrangement of FIG. 1 as so far described maintains the cathode-to-body voltage of the TWT near the optimum for modulation sensitivity, and the cathode-to-collector voltage at some value optimized for a combination of signal distortion and TWT dissipation.
In the arrangement of FIG. 1, power supply 20 is also associated with a collector energy storage capacitor 24, which serves the same purpose for power supply 20 as energy storage capacitor 16 serves for power supply 14. It will be appreciated that the internal impedances of power supplies 14 and 20 necessarily result in reduction of TWT voltage when current is drawn, whether or not the power supplies are paralleled by energy storage capacitors. For very short pulses, such energy storage capacitors can be very helpful in ameliorating voltage drop. However, as the desired transmitted pulses become longer (of longer duration or of increased duty cycle), the size of the requisite energy storage capacitance can itself become a problem. In a large, high-power radar system using an energy storage capacitor across the cathode-to-collector path of a TWT, the weight of energy storage capacitors can be hundreds of pounds, which may be undesirable for some applications.
To the extent that transmitted frequency and power do not conform to the desired pattern or program because of variation in the power supply voltages of the TWT of a radar transmitter, signal processing can in some instances be used to compensate for the resulting deficiencies. In general, reduction in the amount of signal processing is desirable, both for reducing the amount of processing power required, and therefore the costs of the system, and for increasing the processing speed, thereby allowing improved performance. The need for additional processing in order to compensate for deficiencies in the radar transmitter characteristics, then, suggests that it is desirable to further stabilize the power supplies associated with a TWT transmitter. As mentioned, one way to do this is to increase the sizes of the energy storage capacitors, but this may not be desirable or possible, and the desired level of stability of the cathode 12ca voltage relative to ground at the body terminal 12b may not be achievable without very large energy storage capacitors. The magnitude of the problem may be understood by considering that the allowable variation of the cathode-to-ground voltage may be one or two volts out of 40 or more thousands of volts. An additional aspect of the problem associated with the use of ever-larger energy storage capacitors is that the arrays of capacitors, by virtue of their large size, introduce irreducible inductance into the power-supply circuits, which adversely affects their effectiveness in reducing droop in the presence of very short-duration pulses.
In the power supply of FIG. 1, the control circuit 30 provides a measure of feedback voltage control which tends to reduce the effective or dynamic internal impedance of the combined power supplies 14 and 20. In general, control circuit 30 includes a controllable resistance element 31 consisting of a control FET 32 having its source connected to ground by way of a sensing resistor 33 and its drain connected to the positive (+) terminal of power supply 20 by way of a tetrode 34. The gate 32g of FET 32 is connected to the output port 36o of a cathode voltage control circuit illustrated as a box 36. A cathode voltage sensing input port 30c of block 36 is connected, by a sense conductor or xe2x80x9clinexe2x80x9d 36s, to sense the xe2x80x9ccathodexe2x80x9d voltage at the negative (xe2x88x92) terminal of power supply 14. Block 36 internally compares the cathode voltage with a reference voltage to produce an error voltage at its output port 36o, and provides the error voltage to the gate 32g of FET 32, all in known fashion. Tetrode 34 is connected between the drain of FET 32 and the positive terminal of power supply 20 to keep the FET drain voltage within a range which the solid-state FET 32 can handle. When the beam voltage regulator 30 of FIG. 1 is in operation, the dynamic impedance of the combined power supplies 14, 20 supplying the cathode 12ca of the TWT 12 relative to ground is much reduced from that which it would have in an open-loop or unregulated condition. The reduction in effective internal impedance of the combined power supplies may be used directly to improve the voltage stability at the cathode 12ca of TWT 12, or may be used to reduce the sizes of the energy storage capacitors, or both.
It should be noted that each of the power supply or voltage source blocks 14 and 20 of FIG. 1 may have their own internal negative-feedback controls for setting their output voltages and for reducing their effective internal impedances.
As performance requirements of radar systems increase, with increasing requirements for both short- and long-pulse operation, it has been found that the power supply 10 of FIG. 1 can no longer be used, because the shorter transmitter pulses are outside the useful bandwidth of the controller. In some cases, operation with short pulses may even cause regeneration, which may require that the feedback control circuit be deactivated during the transmitted pulse.
A power supply for a travelling-wave tube (TWT) according to an aspect of the invention provides voltage for the cathode-to-collector beam of a travelling-wave tube. The travelling-wave tube includes a cathode, a collector, and a body connected to ground or other reference voltage source. The power supply includes a first voltage source including a negative (xe2x88x92) terminal and a positive (+) terminals coupled to the collector of the travelling-wave tube. An electrical coupling arrangement, such as a conductor or a current-limiting resistor, is coupled to the negative terminal of the first voltage source and to the cathode of the travelling-wave tube, for thereby establishing a cathode-to-collector voltage of the travelling-wave tube at a value near the first voltage. The power supply also includes a controllable impedance including a first terminal coupled to the ground (or other reference) and also including a second terminal. The controllable impedance further includes a control terminal responsive to a control signal for controlling the impedance between the first and second terminals of the controllable impedance. In a particular embodiment, the controllable impedance comprises (a) a sensing resistor having one end coupled to the ground (or other reference); (b) a first controllable solid-state device including first and second electrodes, and a control electrode to which a control signal can be applied for controlling the impedance between the first and second electrodes. The first controllable solid-state device has its first electrode coupled to the ground (or other) reference by way of the sensing resistor, and also has its control electrode coupled to (or in common with) the control terminal of the controllable impedance. The controllable impedance also includes (b) at least two additional controllable solid-state devices, each of the additional controllable solid state device including first and second electrodes and a control electrode to which a control signal can be applied for controlling the impedance between the first and second electrodes. The additional controllable solid-state devices are in a cascade in which each such cascaded additional solid-state device, except those at the ends of the cascade, has its second electrode coupled to the first electrode of the next adjacent one of the additional controllable solid-state devices in the cascade, and in which the first electrode of that one of the additional controllable solid-state devices at a first end of the cascade is connected to the second electrode of the first controllable solid-state device, and in which the second electrode of that one of the additional controllable solid-state devices at a second end of the cascade is connected to, or common with, the second terminal of the controllable impedance. Additionally, the controllable impedance includes (c) means for equalizing the voltages applied between the first and second terminals of the additional controllable solid-state devices. The power supply further includes a second voltage source including a negative (xe2x88x92) terminal coupled to the collector of the travelling-wave tube and a positive (+) terminal connected to the second terminal of the controllable impedance, and a cathode-to-ground voltage controller coupled to the cathode of the travelling-wave tube, to the ground, and to the control terminal of the controllable impedance, for controlling the control signal in a manner which tends to maintain the voltage between the ground and the cathode of the travelling-wave tube constant. In an embodiment of the invention, the voltage controller is of the feedback type.
In a preferred embodiment, the power supply further comprises a capacitance arrangement coupled across the first voltage source. In another embodiment, the means for equalizing the voltages includes a resistive voltage divider defining plural taps, with the taps of the resistive voltage divider being connected to the control electrodes of the additional controllable solid-state devices. In yet another embodiment of the invention, a second controllable impedance includes a first terminal coupled to the ground (or other reference) and also includes a second terminal coupled to the negative terminal of the second voltage source, the second controllable impedance further including a control terminal responsive to a control signal for controlling the impedance between the first and second terminals of the controllable impedance, and means are provided for coupling the cathode-to-ground voltage controller to the control electrodes of the first-mentioned and second controllable impedances, for parallel control of the first-mentioned and second controllable impedances. In one manifestation of this last embodiment, means are provided for tending to equalize the current through each of the first-mentioned and second controllable impedances, and in one version, this means includes a first sensing resistor coupled between the ground and the first electrode of the first controllable solid-state device for developing a signal representing the current through the first controllable solid-state device, and a second sensing resistor connected between the first terminal of the second controllable impedance and the ground for developing a signal representing the current through the second controllable impedance, together with first and second amplifiers, each including an inverting input port and a noninverting input port, the inverting input ports of the first and second amplifiers being connected to the first and second sensing resistors, respectively, and the noninverting input ports of the first and second amplifiers being connected in common to the cathode-to-ground voltage controller for receiving the control signal therefrom.
Another avatar of the invention lies in a power supply for the cathode-to-collector beam of a travelling-wave tube including a cathode, a body connected to ground (or other reference potential), and a collector. In this avatar, the power supply comprises a first direct voltage source including a negative terminal, and also includes a positive terminal coupled to the collector of the travelling-wave tube. An electrical coupling means is coupled to the negative terminal of the first voltage source and to the cathode of the travelling-wave tube, for thereby establishing a cathode-to-collector voltage of the travelling-wave tube at a value near, or ideally at, the first voltage. A first controllable impedance includes a first terminal coupled to the ground (or other reference) and also includes a second terminal. The first controllable impedance further includes a control terminal responsive to a control signal for controlling the impedance between the first and second terminals of the first controllable impedance. A second controllable impedance includes a first terminal coupled to the ground (or other reference) and also includes a second terminal. The second controllable impedance further includes a control terminal responsive to a control signal for controlling the impedance between the first and second terminals of the second controllable impedance. A second voltage source includes a negative terminal coupled to the collector of the travelling-wave tube and a positive terminal connected to the second terminal of the first and second controllable impedances, and a cathode-to-ground voltage controller coupled to the cathode of the travelling-wave tube, to the ground (or other reference), and to the control terminals of the first and second controllable impedances, for controlling the control signal in a manner which tends to maintain constant the voltage between the ground (or other reference) and the cathode of the travelling-wave tube.
In a particular manifestation of this avatar, a capacitance means is coupled across the first voltage source. In another particular manifestation, the coupling means comprises a resistance. In one version of this avatar, each of the controllable impedances comprises (a) a resistor having one end coupled to the ground or other reference, (b) a first controllable solid-state device including first and second electrodes, and a control electrode to which a control signal can be applied for controlling the impedance between the first and second electrodes. This first controllable solid-state device has the first electrode coupled to the ground (or other reference) by way of the resistor, and also has the control electrode coupled to the control terminal of the controllable impedance. This version of the avatar also includes (b) at least two additional controllable solid-state devices, where each the additional controllable solid state device includes first and second electrodes and a control electrode to which a control signal can be applied for controlling the impedance between the first and second electrodes. The additional controllable solid-state devices are coupled in a cascade in which each such cascaded solid-state device, except those at the ends of the cascade, has its second electrode coupled to the first electrode of the next adjacent one of the additional controllable solid-state devices in the cascade, and in which the first electrode of that one of the additional controllable solid-state devices at a first end of the cascade is connected to the second electrode of the first controllable solid-state device, and in which the second electrode of that one of the additional controllable solid-state devices at a second end of the cascade is connected to the second terminal of the controllable impedance; and (c) means for equalizing the voltages applied between the first and second terminals of the additional controllable solid-state devices.

TWT power supply with improved dynamic range


There is provided a method of crystallizing amorphous silicones, which includes: forming a stacked structure of a second amorphous silicon film followed by a first amorphous silicon film on an underlay film, the second amorphous silicon film having a faster crystal growth rate than the first amorphous silicon film; and performing a crystallization treatment on the stacked structure to crystallize silicones contained in at least the second amorphous silicon film.

A crystallized silicon film obtained by crystallizing amorphous silicones is used as a channel of a thin film transistor (TFT) for driving pixels of a flat panel display (FPD), a channel of a memory cell transistor of a non-volatile semiconductor memory, or the like.
The reason why the amorphous silicones are crystallized is to improve carrier mobility. The carrier mobility increases in order of amorphous silicon→polycrystalline silicon→single crystalline silicon. As such, in a film forming process, silicones of a silicon film being in an amorphous state is first crystallized to use as the channel of the transistor, for example. There are known various methods of crystallizing the amorphous silicones.
A first conventional method includes depositing amorphous silicones on an insulating film in two stages. At this time, a deposition temperature in the first stage is set to be higher than that in the second stage. Further, a hydrogen doping process is performed in the first stage. This suppresses an increase in density of crystal seeds so that an SOI (silicon-on-insulator) substrate having large grain size is manufactured.
A second conventional method includes forming a stacked structure of a non-doped amorphous silicon film followed by a phosphorus (P)-doped amorphous silicon film on a substrate, and heating the stacked structure at 600 degrees C. This method is based on the fact that a grain size increases with increases in the doping amount of the phosphorus. Initially, amorphous silicones of the phosphorus-doped amorphous silicon film are crystallized and subsequently, amorphous silicones of the non-doped amorphous silicon film are crystallized using the crystallized amorphous silicones as crystal seeds. Thus, a polycrystalline silicon film having large grain size is obtained.
However, the first conventional method requires switching the deposition temperature in the deposition of the amorphous silicones. To do this, a period of time is required to increase or decrease the temperature, which results in a degradation of productivity.
Further, in the second conventional method, a phosphorus (P) doping process is performed. Phosphorus is a chemical element of V group and serves to change a chemical element of IV group into an N-type semiconductor. When the doping amount of phosphorus is increased to increase a grain size, an N-type polycrystalline silicon film is obtained. If the N-type polycrystalline silicon film is used as the channel of the transistor, only a P-channel transistor is formed. To obtain an N-channel transistor requires changing the N-type polycrystalline silicon film into a P-type polycrystalline silicon film. In order to change the N-type polycrystalline silicon film, in which a large amount of phosphorus is diffused, into the P-type polycrystalline silicon film, it is necessary to introduce a large amount of a chemical element of III group. However, such an introduction is not practical in terms of productivity. In addition, the introduction may cause a crystal defect.

Amorphous silicon crystallizing method, crystallized silicon film forming method, semiconductor device manufacturing method and film forming apparatus


An apparatus for displaying a basic input output system (BIOS) power-on self-test (POST) code and a method thereof are provided. The apparatus includes a BIOS, a conversion module, and an output module. The BIOS is used for generating a POST code. The POST code is transmitted via a low pin count (LPC) interface. The conversion module receives the POST code and converts the POST code into a system management bus (SMBus) format. The output module is used for receiving and outputting the POST code transmitted by the conversion module. The output module is an SMBus interface.

1. Field of Invention
The present invention relates to an apparatus for displaying a power-on self-test (POST) code and a method thereof, and more particularly to an apparatus for displaying a basic input output system (BIOS) POST code and a method thereof.
2. Related Art
When an apparatus such as a computer system is started or reset, a basic input output system (BIOS) performs a power-on self-test (POST) on the hardware. The POST is a test performed by the computer system for the purpose of normal operation. It first tests whether elements of each portion are in order or whether a particular apparatus failed to be properly installed before an operating system is loaded. After the POST is performed, a POST code is generated if an abnormal situation occurs in the computer system. The POST code identifies non-functional hardware, so the problem can be overcome.
In older systems, the POST code is transmitted to a PCI bus by a system main chip, and then decoded and displayed by a device connected to the PCI bus. Nowadays, the POST code is generally transmitted to a low pin count (LPC) interface bus by the system main chip, and then received and displayed by an external inspection device.
When the POST code is transmitted via an LPC interface, a connection port needs to be reserved on the motherboard of the computer system, so as to connect the inspection device and receive the POST code. As an LPC interface has seven signal lines, a space consisting of seven pins must be occupied. However, with the increasing progress of notebook technology, requirements of low weight and small width make the space in the notebooks fairly valuable. Therefore, the connection port to be reserved for the LPC interface occupies too much space on the motherboard.
Moreover, in the prior art, in order to connect the inspection device to the connection port of the LPC interface on the motherboard to receive and display the POST code, the computer's case must be disassembled. This is very inconvenient, and the procedure becomes more difficult.
Therefore, a method of transmitting the POST code through a USB port is proposed in the prior art. However, an USB interface has to be initialized by the computer system in order to operate normally, and as a result the USB interface cannot work normally before a USB device is initialized by the computer system. If an abnormal situation occurs in the computer system at this point, the POST code cannot be transmitted.
Further, a method for displaying the POST code through LEDs on a notebook computer system is also proposed in the prior art. Built-in LEDs such as keyboard lights, power lights, and hard disk lights of a notebook are used to represent corresponding POST codes using an LED combination display. However, such a method requires that users know in advance the POST codes indicated by various combinations of the LED lights. Therefore, the users need to be trained first, or must look up corresponding tables, which takes time.
Therefore, the problem to be solved is how to display the BIOS POST code in the computer system.

Apparatus for displaying BIOS POST code and method thereof


Methods for forming anisotropic features for high aspect ratio application in etch process are provided in the present invention. The methods described herein advantageously facilitates profile and dimension control of features with high aspect ratios through a sidewall passivation management scheme. In one embodiment, sidewall passivations are managed by selectively forming an oxidation passivation layer on the sidewall and/or bottom of etched layers. In another embodiment, sidewall passivation is managed by periodically clearing the overburden redeposition layer to preserve an even and uniform passivation layer thereon. The even and uniform passivation allows the features with high aspect ratios to be incrementally etched in a manner that pertains a desired depth and vertical profile of critical dimension in both high and low feature density regions on the substrate without generating defects and/or overetching the underneath layers.

1. Field of the Invention
The present invention generally relates to methods for forming anisotropic features for high aspect ratio applications. More specifically, the present invention generally relates to methods of forming anisotropic features for high aspect ratio applications by an etch process in semiconductor manufacture.
2. Description of the Related Art
Reliably producing sub-half micron and smaller features is one of the key technologies for the next generation of very large scale integration (VLSI) and ultra large-scale integration (ULSI) of semiconductor devices. However, as the limits of circuit technology are pushed, the shrinking dimensions of interconnects in VLSI and ULSI technology have placed additional demands on processing capabilities. Reliable formation of gate pattern is important to VLSI and ULSI success and to the continued effort to increase circuit density and quality of individual substrates and die.
As the feature sizes have become smaller, the aspect ratio, or the ratio between the depth of the feature and the width of the feature has steadily increased, such that manufacturing processes are being required to etch materials into features having aspect ratios of from about 50:1 to about 100:1 or even greater. Traditionally, features having aspect ratios of about 10:1 or so were produced by anisotropic etching the dielectric layers to a predetermined depth and width. However, when forming higher aspect ratio features, anisotropic etching using conventional sidewall passivation techniques, has become increasingly harder to obtain, thereby resulting in the features having uniform spacing and/or having double or multiple sloped profiles, thus losing the critical dimensions of the features.
Moreover, redeposition or build-up of passivation layers generated during the etching process on the top or sidewall of the features may block the opening defined in a mask. As the mask opening and/or opening of the etching features are narrowed or sealed by the accumulated redeposition layer, the reactive etchants are blocked from penetrating into the opening, thereby limiting the aspect ratio that may be obtained. As such, failure to sufficiently etch the features results in inability to obtain the desired aspect ratio of the features.
Another problem in etching features with high aspect ratio is the occurrence of a microloading effect, which is a measure of the variation in etch dimensions between regions of high and low feature density. The low feature density regions (e.g., isolated regions) receive more reactive etchants per surface area compared to the high feature density regions (e.g., dense regions) due to larger total openings of the surface areas, thereby resulting in a higher etching rate. The sidewall passivation generated from the etch by-products exhibited the similar pattern density dependence where more passivation is formed for the isolated features due to more by-products being generated in the region. The difference in reactants and the passivation per surface area between these two regions increase as feature density difference increase. As shown in FIG. 8A, due to different etch rates and by-products formation in high and low feature density regions, it is often observed that while the low feature density regions 802 have been etched and defined in a certain desired and controlled vertical dimension, the high feature density regions 804 are bowed and/or undercut 806 by the lateral attacking due to the insufficient sidewall passivation. In other processes, the low feature density regions 808 are described being etched at a faster rate with more passivation than the high feature density regions 810, as shown in FIG. 8B, resulting in a tapered top portion 812 on the sidewall of the etched layer 814. Therefore, insufficient sidewall protection associated with the different etch rates in high and low feature density regions with high aspect ratios often results in inability to hold critical dimension of the etch features and poor patterned transfer.
Yet another challenge associated with etching features with high aspect ratios is controlling the etch rate in feature formed through multiple layers and having different feature density. Here, each layer may etch at a different rate depending on feature density. As shown in FIG. 9, faster etch rates in the low feature density regions 902 often results in selectively overetching a layer 904 disposed below the upper etched layer 906, while slower etch rates in the dense feature regions 908 prevents a portion of the layer 910 from being completely etched. As the features move toward even higher aspect ratios, maintaining efficient etching rate over the low and high feature density regions without either underetching the upper layers or overetching into the lower layers has become increasingly difficult to control. The failure to form the features or patterns on the substrate as designed may result in unwanted defects, and further adversely affect subsequent process steps, ultimately degrading or disabling the performance of the final integrated circuit structure.
Therefore, there is a need in the art for improved methods to etch features with high aspect ratios.

Etch methods to form anisotropic features for high aspect ratio applications


A forum monitoring device allows an agent to monitor the traffic in a computer-mediated discussion. When the agent determines that there is a significant degree of traffic on a particular topic, or other predetermined rules are satisfied, the agent proposes to the contributors of messages on that topic that a new discussion forum, for example, a new discussion list, be created. If any of the contributors agrees to this suggestion, a new discussion forum, or child forum, is created by the agent. The agent and the contributors are then automatically subscribed to the child forum, and an invitation to join the new forum is sent optionally to the full membership of the parent forum plus any other recipients of postings on the topic.

1. Field of the Invention
This invention relates to discussion fora. In particular, this invention relates to systems and methods for managing electronic messages within a discussion forum.
2. Description of Related Art
Fora provide environments for discussion by a community. In general, forum members supply information, such as, by posting or uploading of electronic messages, to a predetermined location. This information is then available to the remaining forum members for reading, comments, copying, transmission, or the like. Furthermore, a forum allows for subscribers to subscribe to the forum. For example, a subscriber can join a forum and be updated as new information is provided or posted to the forum.

System and method for managing a computer-mediated discussion forum


A method to store point-in-time data, comprising establishing a block size, providing source data storage comprising (S) blocks, and target data storage comprising (T) blocks. The method configures (B) source storage segments and (B) target storage segments, and receives updated point-in-time data for original point-in-time data written to an (i)th source storage segment. The method then determines if a (j)th target storage segment comprises available storage capacity to store the original point-in-time data. If a (j)th target storage segment comprises available storage capacity to store the original point-in-time data, the method writes the original point-in-time data to that (j)th target storage segment.

Data storage systems are used to store information provided by one or more host computer systems. Such data storage systems receive requests to write information to a plurality of data storage devices and requests to retrieve information from that plurality of data storage devices.
Point-in-time ("PIT") data comprises data generated at a specified time. When portions of such point-in-time data are updated later, the original point-in-time data is first copied to target data storage before that original PIT data is updated. This procedure preserves the original PIT data. If the original PIT data is updated in a random order, then using prior art methods the original PIT data to be updated is written to the target storage in a similar random order.

Apparatus and method to store original point-in-time data

International Business Machines Corporation


A poppet valve is provided to open and close a valve seat in an internal combustion engine. At the end of a valve stem of the valve, a cylindrical support is fixed, and on the outer circumferential surface of the support, a moving coil is wound. There is formed an annular cavity in a yoke fixed to a bracket fixed on a cylinder head, and a permanent magnet is fixed in the annular cavity of the yoke. Between the permanent magnet and the yoke in the annular cavity, the support which has the moving coil is inserted. By a control system having CPU, an electric current is applied to the moving coil, thereby providing optimum valve timing and lift to decrease seating noise and improving engine performance.

The present invention relates to an electric valve drive device which opens and closes an intake or exhaust poppet valve electrically.
A valve drive system in an ordinary engine mainly comprises a cam shaft, a rocker arm (or a tappet), a valve spring and a valve spring retainer. Rotational force of a cam of the cam shaft driven by a crank shaft is transferred to a poppet valve via the rocker arm to make opening/closing movement.
Output performance and fuel efficiency of an engine generally depend on intake and exhaust efficiency, and the higher they are, the higher engine performance is obtained owing to smooth gas exchange in a cylinder.
However, an automobile engine has broad rotation range so that it is difficult to increase engine performance over the whole operation range. If high speed performance is increased, low speed performance is decreased, and if low speed performance is increased, high speed performance is decreased.
To solve the problem, there is high-speed valve timing wherein lifts of intake and exhaust valves become larger with a larger overlapping range to increase intake/exhaust efficiency. There is also a small overlapping range valve timing wherein lifts become smaller to form a strong swirl at low speed where combustion is likely to be unstable.
Recently, to meet such requirements, an engine which has a valve operating mechanism of both low and high speed performance, or a variable valve timing lift mechanism which has two valve timing and lifts for low and high speeds is utilized.
However, the variable valve timing lift mechanism is basically similar to the mechanical valve operating mechanism which has the above cam shaft as the drive source. It is thus impossible to remove the inherent performance decrease factor of the valve operating mechanism or performance decrease factor caused by mechanical loss and followability of a valve to a cam.
Valve timing and lift are determined by phase and profile of a cam. It is impossible to vary them over the whole working range of the engine. There is no choice but to set two valve timings and lifts for low and high speed as above.
To solve the problem, as disclosed in Japanese Patent Laid-Open Pub. Nos. 10-37726 and 10-141928, it has been suggested to provide an electromagnetic valve drive device in which a valve is opened and closed by magnetic force instead of mechanical valve drive system having a cam shaft. But, in such an electromagnetic valve drive device, the valve is merely opened and closed by the attractive force of an electromagnet, thereby increasing seating noise and providing low responsiveness during valve operation.
Furthermore, because the control range for valve timing and lift is small, it is difficult to obtain optimum valve timing and lift corresponding to any working condition of an engine, and it would be impossible to improve engine performance over the whole working range.
There is a moving iron core or piece in the valve, so that inertial mass is increased during opening and closing of the valve to decrease responsiveness and reliability at control.
To overcome the disadvantages in the foregoing electromagnetic valve drive device, the applicant suggested an electric valve drive device in which a valve is driven by an electromagnetic actuator called a voice coil motor. A moving coil in the electric valve drive device is repeatedly moved at high speed in an axial direction to drive a valve directly, so it is necessary to increase mounting strength to improve durability and reliability. Also, it is necessary to connect the ends of the moving coil to an input terminal and to keep durability of a lead for connecting a fixed terminal to a terminal of the moving coil which always moves. In the electric valve drive device, electric current intensity in the moving coil is controlled to obtain optimum valve timing and lift corresponding to the working condition of the engine, and thus, it is necessary to cool the moving coil to increase durability.

Electric valve drive device in an internal combustion engine


In a particular embodiment, a method of managing a cache memory includes, responsive to a cache size change command, changing a mode of operation of the cache memory to a write through/no allocate mode. The method also includes processing instructions associated with the cache memory while executing a cache clean operation when the mode of operation of the cache memory is the write through/no allocate mode. The method further includes after completion of the cache clean operation, changing a size of the cache memory and changing the mode of operation of the cache to a mode other than the write through/no allocate mode.

Advances in technology have resulted in smaller and more powerful computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs), and paging devices that are small, lightweight, and easily carried by users. More specifically, portable wireless telephones, such as cellular telephones and Internet Protocol (IP) telephones, can communicate voice and data packets over wireless networks. Further, many such wireless telephones include other types of devices that are incorporated therein. For example, wireless telephones can also include a digital still camera, a digital video camera, a digital recorder, and an audio file player. Also, such wireless telephones can process executable instructions, including software applications, such as a web browser application, that can be used to access the Internet. As such, these wireless telephones can include significant computing capabilities.
Digital signal processors (DSPs), image processors, and other processing devices are frequently used in portable personal computing devices and operate in conjunction with one or more caches. A cache is memory that may store a copy of data that exists somewhere in a memory hierarchy. In some cases, the cache may have the only "up to date" copy of the data in the system. One component of a cache is a data memory that may be divided into multiple cache lines. Another component of a cache is a mechanism (e.g., a tag) to associate a system memory address with a particular cache line. An additional component of a cache is a state indicator to indicate whether a cache line is valid, modified, owned, and the like.
When a cache memory is re-sized, re-configured, and/or a line of the cache memory is locked, access to the cache memory may be restricted. For example, to change a size of the cache memory, a clean operation copies data stored in the cache memory to a backing memory. Generally, during the clean operation, only a single thread (or only a single processor) may access the cache memory (i.e., to perform the clean operation) while other threads (or other processors) are blocked from accessing the cache. After the clean operation is completed and the size of the cache memory is changed, the other threads (or other processors) may then perform operations on the cache memory. Blocking the other threads (or other processors) from accessing the cache memory during execution of the clean operation causes a performance loss that can extend for several clock cycles. As another example, to lock or unlock a line of the cache memory, a block of addresses (including the line of the cache memory to be locked) is only accessible to a single thread (or a single processor) that operates on the block of addresses (e.g., to lock or unlock the line of the cache memory).

Cache memory with write through, no allocate mode


A computer-implemented method for effective agriculture and environment monitoring. The method may comprise measuring a desired variable over an area of interest using a remote inspection platform according to an inspection plan, predicting an occlusion of the remote inspection platform, and in response to the predicted occlusion, determining whether to invoke a local inspection platform to complete the inspection plan. The occlusion in some embodiments interrupts the inspection plan for the remote inspection platform.

The present invention relates to agriculture, and more specifically, to an agricultural method and system using a high resolution sensor platform for analyzing and servicing crops.
Agricultural crops are an important source of food. When the crop yield of a given tract of land increases, more of the crop is available for consumption and/or seeding. In addition, when the crop yield increases, the unit cost of the crop may decrease.
Crops may be planted in remote areas and/or in large tracts of land, making inspection of the growth progress of the crops located away from the edge of the tract difficult or costly. Crops may be susceptible to harm by parasites, drought, etc. The cause of potential crop loss may be discovered too late to save the plants in some cases.

Effective agriculture and environment monitoring