Polymeric encapsulation of 1-2-3 ceramic superconductors

YBa₂Cu₃O_7−x pellets have been found to degrade and lose superconducting properties when exposed to the normal atmosphere for long durations. Hence, coating the superconducting pellets with a polymer to protect it from moisture and CO₂ of the ambient atmosphere is highly desirable. In this paper the criteria of selection of a polymer and some preliminary studies on polymeric encapsulation of 1-2-3 pellets are reported. Fevitite epoxy and stycast have been found to show encouraging results.     

Oxide glass filaments and their superconducting phase by annealing

Bi₄Ca₃Sr₃Cu _x O _y (4334) oxide glasses with different concentrations of the transition metal copper have been prepared by rapid quenching technique from respective melts. These glasses have been characterized from electrical, magnetic, dielectric and other properties. The semiconducting glasses are not superconducting even down to 4·2 K. However, by properly annealing the glasses in air or in oxygen atmosphere they can be converted into the corresponding superconducting phases with superconducting transition temperatures between 70 and 110 K depending on the Cu ion concentrations. The dc conductivity of the glasses could be explained with small polaron adiabatic hopping mechanism. Analysis shows that the correlated barrier hopping (CBH) mechanism is the most appropriate model for explaining the a.c. conductivities of these glasses. Addition of a small amount (about 2 wt%) of B₂O₃ makes it possible to draw glass filaments which could also be converted into the superconducting phase withT _c values lower than those obtained from the respective pure glasses.     

A novel technique for isolation of pure sperm heads from disintegrated mammalian spermatozoa

The phenomenon of differential charge distribution on sperm surface membrane has been utilised here in a low e.m.f. (electro motive force) capillary electrophoresis system to effect separation of sperm heads from disintegrated mixed spermatozoal subfractions. Washed caudal sperm of goat (Black Bengal variety) and ejaculated washed human sperm were fractionated by sonication into head, mid-piece and tail portions. Routine techniques of density gradient centrifugation on Percoll and/or sucrose were performed with sonicated spermatozoa for separation into their respective subfractions. The products obtained were not free of contamination in either case. Mixed sperm fractions when subjected to the afore mentioned modified capillary electrophoresis technique only the head pieces exhibited high affinity for migration towards the cathode terminal. With this method around 50% of the total sperm heads were separated and collected in absolutely pure form at the cathode side within 2 hrs. at 150 volts (V) and 1.5 milliampere (mA) current at 37.5 degrees C. A 4 cm. long capillary tube with a bore size 1.2 mm. was used for this purpose.     

SQL Server Integration Services 2005中的模糊查找和模糊分组

简介 由于拼写错误、意外的缩略语和其他不规则问题，实际的数据是“有问题”的。因此，在数据仓储项目中，很大一部分的时间和金钱都花费在了数据提取、数据转换和数据加载（ETL，Extraction、Transformation、Loading）阶段。在ETL阶段，新数据被清理、标准化，并使其与现有数据一致。在Microsoft SQL Server 2005中可用的模糊查找和模糊分组转换，有助于使ETL过程在遇到若干种在交际数据中观测到的常见错误时更易复原。它们解决一般的匹配和分组问题，而无需特定于域的规则和脚本的专家集合。通过为您的域自定义模糊查找和模糊分组，您可以利用Business Intelligence Development Studio内的通用数据清理算法，并避免创建复杂的自定义规则和代码。     

Mixed-sensitivity approach to H/sub /spl infin// control of power system oscillations employing multiple FACTS devices

This paper demonstrates the enhancement of inter-area mode damping by multiple flexible AC transmission systems (FACTS) devices. Power system damping control design is formulated as an output disturbance rejection problem. A decentralized H/sub /spl infin// damping control design based on the mixed-sensitivity formulation in the linear matrix inequality (LMI) framework is carried out. A systematic procedure for selecting the weights for shaping the open loop plant for control design is suggested. A 16-machine, five-area study system reinforced with a controllable series capacitor (CSC), a static VAr compensator (SVC), and a controllable phase shifter (CPS) at different locations is considered. The controllers designed for these devices are found to effectively damp out inter-area oscillations. The damping performance of the controllers is examined in the frequency and time domains for various operating scenarios. The controllers are found to be robust in the face of varying power-flow patterns, nature of loads, tie-line strengths, and system nonlinearities, including device saturations.     

Unilateral abdominal muscle herniation with pain: a distinctive variant of diabetic radiculopathy

Thoracic diabetic radiculopathy causing truncal pain and abdominal muscle bulging is a recognized though extremely rare complication of diabetes. We report here six cases, describing their clinical features and natural history in detail: the condition affects predominantly middle-aged men, usually on the right side of the abdominal wall, involving three to five adjacent nerve roots between T6 and T12. It may be accompanied by profound weight loss which is not normally due to poorly controlled diabetes. Complete resolution of this syndrome occurs after 3 to 12 months.     

Enhancement of over expression and chaperone assisted yield of folded recombinant aconitase in Escherichia coli in bioreactor cultures

A major portion of the over expressed yeast mitochondrial aconitase, a large 82 kDa monomeric TCA cycle enzyme, in Escherichia coli led to the formation of inclusion bodies. Bacterial chaperonin GroEL mediated the correct folding of aconitase with the assistance of its co-chaperonin GroES in an ATP dependent manner. Till date the chaperonin assisted folding of aconitase was limited to the shake flask studies with relatively low yields of folded aconitase. No attempt had yet been made to enhance the yield of chaperone mediated folding of aconitase using a bioreactor. The current report deals with the effect of co-expression of GroEL/GroES in the production of soluble, biologically active recombinant aconitase in E. coli by cultivation in a bioreactor at different temperatures under optimized conditions. It revealed that the yield of functional aconitase was enhanced, either in presence of co-expressed GroEL/ES or at low temperature cultivation. However, the outcome from the chaperone assisted folding of aconitase was more pronounced at lower temperature. A 3-fold enhancement in the yield of functional aconitase from the bioreactor based chaperone assisted folding was obtained as compared to the shake flask study. Hence, the present study provides optimized conditions for increasing the yield of functional aconitase by batch cultivation in a bioreactor.     

Space-Variant Approaches to Recovery of Depth from Defocused Images

The recovery of depth from defocused images involves calculating the depth of various points in a scene by modeling the effect that the focal parameters of the camera have on images acquired with a small depth of field. In the approach to depth from defocus (DFD), previous methods assume the depth to be constant over fairly large local regions and estimate the depth through inverse filtering by considering the system to be shift-invariant over those local regions. But a subimage when analyzed in isolation introduces errors in the estimate of the depth. In this paper, we propose two new approaches for estimating the depth from defocused images. The first approach proposed here models the DFD system as a block shift-variant one and incorporates the interaction of blur among neighboring subimages in an attempt to improve the estimate of the depth. The second approach looks at the depth from defocus problem in the space-frequency representation framework. In particular, the complex spectrogram and the Wigner distribution are shown to be likely candidates for recovering the depth from defocused images. The performances of the proposed methods are tested on both synthetic and real images. The proposed methods yield good results and the quality of the estimates obtained using these methods is compared with the existing method.