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The magnetic and conductive properties of polycrystalline La0.5Pb0.5MnO3containing ~13at.% of a second phase PB3Mn6O13. were investigated. The studies reported include measurements of magnetization, electrical resistivity and magnetoresistance, in a temperature range 10 ÷ 400 K and at applied magnetic fields up to 5 Tesla. It was found that the sample exhibits a ferromagnetic ordering with relatively low coercive field at room temperature. Measurements of field-cooled and reversed-field-cooled magnetization support models of coexisting magnetic phases in ferromagnetic La-based manganites. The resistivity measured eshibits a maximum at ~ 230 K and a broad shallow minimum at ~ 20+25 K. These features are also attnbuted to the temperature dependence of the magnctic inhomogeneities. Measurcments of magnetoresistance show a characteristic giant effect at low temperatures.

We fabricated an anthracene thin‐film transistor (TFT) with an ultrathin layer (∼450 nm) of poly‐vinylidene fluoride (PVDF)/graphite oxide nanoplatelets (GOnP) nanocomposite as a gate insulator. We obtained a TFT device with excellent electrical characteristics at low operating voltages (<1 V). The dielectric is a high‐εgate insulator with a static dielectric constant of εr= 15.6. This device was found to have a field effect mobility of 1.1 cm2V−1s, a threshold voltage of 0.34 V, an exceptionally low subthreshold slope (SS) of 380 mV decade−1and an on/off ratio of 105. The combination of favorable properties opens up the possibility to utilize such TFTs effectively at voltages as low as below 1 V. Such high‐εPVDF/GOnP gate dielectric appears to be highly promising candidates for organic nonvolatile memories and sensor field effect transistors (FETs).

A substantial proportion of the streptococcal species found in dental plaque biofilms are able to interact with the abundant salivary enzyme -amylase. These streptococci produce proteins that specifically bind amylase. An important plaque species, Streptococcus mitis, secretes a 36-kDa amylase-binding protein into the extracellular milieu. Proteins precipitated from S. mitisNS51 cell culture supernatant by the addition of purified salivary amylase were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to a membrane, and a prominent 36-kDa band was cut from the membrane and sequenced to yield the N-terminal amino acid sequence DSQAQYSNGV. Searching the S. mitisgenome sequence database revealed a single open reading frame containing this sequence, and the gene was amplified by the S. mitisgenomic DNA polymerase chain reaction. The coding region of this open reading frame, designated amylase-binding protein C (AbpC), was cloned into an Escherichia coliexpression vector and the recombinant AbpC (rAbpC) was purified from the soluble fraction of the E. colicell lysate. Purified AbpC was found to interact with immobilized amylase, confirming AbpC as a new streptococcal amylase-binding protein.

A combination of histogram and heuristic rule based approaches are used for detection of different patterns of ECG waves and extraction of few important time -plane features, which are used for ECG interpretation and classification. At first, an efficient, simple and new approach for detection of base line and QRS complexes from the horizontal and vertical histogram of ECG images plotted on computer screen is described. The vertical and horizontal histograms are generated from the computation of number of ordinates for a particular abscissa at the vertical and horizontal direction respectively. The base line is determined at the maximum of the horizontal histogram whereas QRS or R peaks are determined from the local maximas of the maximum area zone of vertical histograms. A high accuracy is achieved for both the cases ( 99.5% for QRS and 92% for base line). This method is advantageous for onscreen pictorial analysis because both QRS and base lines can be determined directly from computer screen ECG data without use of complex mathematical models, even when ECGs are tilted due to respiration and disturbed in the presence of power line oscillation. After detection of R points and base points, an efficient algorithm is developed using priory knowledge of different patterns of ECG wave for detection of P, Q, R, S and T waves and their different attributes which are useful for ECG interpretation.

Monovalent ion (MOI) doping effect on the grain size and giant dielectric constant (ε ′ ∼ 104) of lead free environment friendly NiO-based KxTi0.02Ni0.98–xO (KTNO, x = 0.04, 0.25, and 0.30) type ceramics have been investigated. Increasing K concentration (MOI) enhances the grain size along with the increase of ε ′ values. The dielectric constant of KTNO also increases with increase of the sintering time and temperature (within the range of our measurement) due to enhancement of crystalline size. The giant ε ′ value and the leakage current in KTNO show weak field dependent behavior. Estimated temperature coefficient of permittivity (TCP) of KTNO is very low (less than 6%). All these properties meet the requirements of the ceramics used in X7R EIA specification. High ε ′ in KTNO is attributed to the boundary layer mechanism. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

This paper deals with a complete recognition system for unconstrained off-line Bangla (Bengali) handwritten numerals. To take care of variability involved in the writing style of different individuals, a robust scheme is presented here. The scheme is mainly based on new features obtained from the concept of water overflow from reservoir as well as topological and structural features of the numerals. The proposed scheme is tested on data collected from different individuals of various background and we obtained an overall recognition accuracy of about 92.8% from 12000 data.

AbstractThe paper extends the concept of simultaneous stabilization in the multi-vaziable framework. The concept is applied for multiple swing mode damping through a single FACTS device. An optimization problem is solved to determine controller parameters that would guarantee closed-loop poles in certain target locations with preferential treatment to those corresponding to the inter-area modes. Plant models under different operating conditions are incorporated in the design formulation to achieve performance robustness. Amin-max approach is adopted to optimize the worst case scenario. The control design methodology is illustrated for a prototype power system. The performance is verified through time-domain simulations.

This paper is concerned with research on OCR (optical character recognition) of printed mathematical expressions. Construction of a representative corpus of technical and scientific documents containing expressions is discussed. A statistical investigation of the corpus is presented, and usefulness of this analysis is demonstrated in the related research problems, namely, (i) identification and segmentation of expression zones from the rest of the document, (ii) recognition of expression symbols, (iii) interpretation of expression structures, and (iv) performance evaluation of a mathematical expression recognition system. Moreover, a groundtruthing format has been proposed to facilitate automatic evaluation of expression recognition techniques.

AbstractStudy of the possible involvement of environmental and genetic factors in determining the evolution of phenotypic varieties in the pulse beetle, Callosobruchus maculatus(F.) fed on chickpea (Cicer arietinumL.) seeds was made. Callosobruchus maculatus(F.) appears in two distinct forms, referred to, herein, as short-winged and long-winged forms. Short-winged individuals were smaller than those with long wings, differing in several basic traits, such as, width of head and thorax, length of elytron and hind wing, degeneration of flight muscles and strength and formation of trachéal tissue in the thorax and dorso-longitudinal indirect flight muscles. As compared to the long-winged females, the short-winged females began egg laying earlier, producing more eggs with deposition of 1 – 6 eggs (comparatively smaller) singly on one chickpea seed, and had faster larval development and earlier death. The evolutionary significance of phenotypic polymorphism in C. maculatusmay be an ecological response developing some basic characteristics for making utmost use of the environment and preferred food source availability.

Abstract: Using the photoacoustic spectroscopic (PAS) technique for the first time, the composition-dependent optical absorption coefficient and band gap of Zn1-xBexSe semiconductors (with x = 0.0–0.25) have been measured at room temperature. The band gap 0estimated from the PAS spectra varies nonlinearly with Be concentration. The exchange interaction of electrons in conduction and valence bands, effects of polytypes, microstructures, and the mixed crystallization (zinc-blend and wurtzite structures) effect are considered for the analysis of the data. The observed exponential edge (Urbachrsquos edge) can be considered as an internal Franz–Keldish effect arising from the charged impurity generated and ldquofrozen-inrdquo optical phonon-generated fields. The phonon-assisted indirect transition at the band tail regions for some samples is also observed in the present studies.

The effect of atmosphere on the sintering of nano-crystalline α-silicon carbide, doped with boron carbide and carbon, and prepared by attrition milling, has been studied under vacuum, argon and nitrogen atmospheres between 2000° and 2100°C. It has been found that the sintering atmosphere has a very critical influence on the sintering of silicon carbide. Sintering in vacuum provides maximum theoretical density, whereas the nitrogen atmosphere has a retarding effect and does not yield full densification. Argon atmosphere takes an intermediate role in the sintering process. The results have been explained in terms of a diffusion model.

Three new sesquiterpene quinols (1, 2, and 5) and two known ones (3 and 4) were isolated along with halistanol sulfate (6) from a marine sponge of the genus Aka collected from Yap Island, Federated States of Micronesia. Their structures were determined from spectral data, and the structure of siphonodictyal C (3) was revised. Sulfates 3 and 6 inhibit CDK4/cyclin D1 complexation, whereas 1 and 4 do not.

In a multi-lingual country like India, a document page may contain more than one script form. Under the three-language formula, the document may be printed in English, Devnagari and one of the other Indian official languages. For Optical Character Recognition (OCR) of such a document page, it is necessary to separate these three script forms before feeding them to the OCRs of individual scripts. In this paper an automatic technique of separating the text lines is presented for almost all triplet of script forms. To do so, the triplets are grouped into five classes according to their characteristics, and shape based features have been employed to separate them without any expensive OCR-like algorithms. The proposed approaches are tested on many documents and the experimental results are presented. At present, the system has an overall accuracy of about 98.5%.

Abstract: Sinterable nano silicon carbide powders of mean particle size (37 nm) were prepared by attrition milling and chemical processing of an acheson type alpha silicon carbide having mean particle size of 0.39 μm (390 nm). Pressureless sintering of these powders was achieved by addition of boron carbide of 0.5 wt% together with carbon of 1 wt% at 2050° C at vacuum (3 mbar) for 15 min. Nearly 99% sintered density was obtained. The mechanism of sintering was studied by scanning electron microscopy and transmission electron microscopy. This study shows that the mechanism is a solid-state sintering process. Polytype transformation from 6H to 4H was observed.

Abstract: Sinterable silicon carbide powders were prepared by attrition milling and chemical processing of an acheson type α-SiC. Pressureless sintering of these powders was achieved by addition of aluminium nitride together with carbon. Nearly 99% sintered density was obtained. The mechanism of sintering was studied by scanning electron microscopy and transmission electron microscopy. This study shows that the mechanism is a solid state sintering process.

Novel 2-benzylidene-benzofuran-3-ones were designed and synthesized to mimic flavopiridol, a well-established inhibitor of cyclin-dependent kinases (CDKs) which is currently undergoing clinical evaluation. The underlying design concepts as well as the synthesis and structure−activity relationships (CDKs 1, 2, and 4 enzyme assays) of these mimics are described. Inhibitors of CDKs 1 and 2 that are more potent and selective than flavopiridol were obtained.

Abstract: This paper deals with an Optical Character Recognition (OCR) system for printedOriya script. The development of OCR for this script is difficult because a large number of character shapes in the script have to be recognized. In the proposed system, the document image is first captured using a flat-bed scanner and then passed through different preprocessing modules like skew correction, line segmentation, zone detection, word and character segmentation etc. These modules have been developed by combining some conventional techniques with some newly proposed ones. Next, individual characters are recognized using a combination of stroke and run-number based features, along with features obtained from the concept of water overflow from a reservoir. The feature detection methods are simple and robust, and do not require preprocessing steps like thinning and pruning. A prototype of the system has been tested on a variety of printed Oriya material, and currently achieves 96.3% character level accuracy on average.

Flexural Strength, fracture toughness and microstructure of sintered silicon carbide doped with boron carbide prepared by pressureless sintering route from nano-crystalline silicon carbide particles (prepared by attrition grinding from an Acheson type α-SiC) were studied. The strength of the materials was characterized in terms of baseline strength, strength distribution and microstructure. The average flexural strength was found to be 390 MPa and average fracture toughness was 3.95 MPa.m½.

Abstract: The cost effectiveness of the deep X-ray lithography and electrodeposition process, LIGA, depends directly on the throughput of the process. The use of high energy photons allows the exposure of stacked photoresist and results in high throughput. High energy X-ray exposures require a different mask than low energy X-ray exposures. The high energy mask allows a large area exposure but requires a thicker X-ray absorber. The cost of generating high energy X-ray masks can be drastically reduced by using a thick optical photoresist process rather than an X-ray exposure process. The cost can be further reduced by using alternatives to the typical X-ray absorber, gold. High atomic weight (high Z) materials are ideal absorbers. Lead has been demonstrated as being a useable alternative as an X-ray absorber.

Monophasic and polycrystalline double perovskite Eu2CoMnO6has been synthesized, and its structural characterization, frequency and temperature-dependent dielectric relaxation have been studied. Observed thermally activated dielectric relaxation was explained using the empirical Havriliak–Negami (HN) dielectric relaxation function with an estimated activation energy E∼0.22 eV and attempt frequency f0∼2.46 × 109Hz. The frequency-dependent AC conductivity data, over a wide range of temperature (100–325 K), followed the empirical universal power law behavior (∼fn, nis the constant exponent) showing two different frequency exponents, respectively, in the high- and low-temperature regions. The high-temperature (>275 K) conductivity data followed the continuous time random walk (CTRW) approximation model proposed by Dyre. However, this model failed to reproduce the observed conductivity spectra in the low-temperature side (<200 K). Interestingly, both the high- and low-temperatures’ conductivity data can be scaled to the master curve with suitably chosen scaling parameters.

Discusses a study which proposed modified metric which contains a single term representing geometric distance only, which reduces to the classical Hausdorff distance when the fuzzy sets are crisp, and which is relatively insensitive to noise. Distances between fuzzy sets; Proposed modified Hausdorff distance; Examples and alternatives.

A liquid−liquid process for the dimerization of α-methylstyrene (AMS) in order to produce selectively the commercially useful 2,4-diphenyl-4-methyl-1-pentene has been developed. The aqueous phase contained sulfuric acid as a catalyst and methanol as an additive, and the organic phase was 97% α-methylstyrene (AMS). An AMS conversion of 55% was achieved in 7 h when the dimerization was conducted at 80 °C. The product dimer contained 93% 2,4-diphenyl-4-methyl-1-pentene and only 0.06% 1,1,3-trimethyl-3-phenylindan, the saturated dimer. The liquid−liquid process can be used commercially to produce selectively 2,4-diphenyl-4-methyl-1-pentene at locations where cation-exchange resins are not readily available.

Characterization of the binary V2O5-Bi2O3 glasses prepared by rapidly quenching the melt has been made from the studies of X-ray diffraction, scanning electron microscopy, infrared absorption, differential thermal analysis, electron paramagnetic resonance, chemical analysis, density and electrical properties. Stable glasses are obtained for 95 to 75 mol % V2O5 by quenching on a stainless steel substrate, while quenching on a copper substrate extends the glass formation range from 95 to 70 mol % V2O5. The V-O bond vibration in the glasses occurs at 1020 cm-1 and the V5% ion exists in six-fold coordination as in crystalline V2O5. All the glasses appear to be in single phase. The spin concentration in the glasses is found to be independent of temperature. A second heat-treatment at 255° C develops crystalline phase in the glasses. Unlike infrared absorption, electron paramagnetic resonance, density and chemical compositions, the electrical and thermal (DTA) properties are found to be slightly sensitive to the thermal history of preparation of the glasses. The high-temperature (300 to 500 K) conduction in the glasses seems to be due to adiabatic hopping of polarons. The thermopower is observed to be independent of temperature and provides evidence for small polaron formation in the glasses.

A heterogeneous mixed culture, originally collected from two different sources, namely cow-drug and sludge from the city waste-water treatment plant, was grown in mineral medium containing 1% glucose and then adapted on benzene as the carbon and energy source. Under anaerobic conditions benzene was degraded via benzoic acid as a major intermediate in the benzene degradation pathway. The degradation rate of benzene was improved stepwise by the number of enrichments and optimization of the culture medium. The effects of microaerobic conditions and/or physicochemical treatment with H 2O 2 prior to anaerobic degradation were studied with respect to variations in benzene degradation rate, growth of biomass and gas composition. It was noticed that the amount of gas produced is less than the theoretical value expected and the percentage of methane in the product gas was very small (3%–3.5%). The reason for this is not well understood but it is presumed that the major group of benzene-degrading bacteria present in the culture medium are sulphate reducers and the mixed consortium is unable to degrade certain complex aromatic intermediates in the benzene degradation pathway under the experimental conditions. For an actual explanation of the situation arising in this study, further investigations must be carried out. However, the mixed culture is capable of oxidizing benzene more rapidly to intermediate compounds and also partly into gas under the culture conditions, compared to the published data for the anaerobic degradation of benzene.

Using radioactive iodine, the effect of 1 month's yogic exercises has been investigated on the thyroid function of subjects resident at sea level (SL) specially after their exposure to high altitude (HA). The results have been compared with a group of SL subjects who underwent physical training (PT) exercises for the same duration. Ten healthy male volunteers in the age range of 20–30 years were used as test subjects in this study with each serving as his own control. The subjects were randomly divided into two groups of 5 each. One group practised hatha yogic exercises, while the other group performed the regular PT exercises. The thyroidal accumulation and release of radioactive iodine have been measured in each of the subjects of both groups before and after 1 month of their respective exercises at SL. One month of yogic exercises at SL has been observed to cause a significant reduction in the trans-thy-roidal availability of radioiodine. The thyroid radioactivity in this group of subjects was always below normal levels with the exception of two peaks of radioactive iodine uptake, when the levels of radioactivity in the thyroid were similar to the control values of pre-yogic exercises. The release of radiolabel at 24–48 h was significantly increased after yogic exercises. In contrast, the subjects performing PT exercises for the same duration at SL showed significant thyroid uptake of radioactive iodine at 24 h. Subsequently their131I uptake continued to rise slowly until 72 h without any demonstrable thyroidal release of radiolabel. This indicated that increased thyroid activity was induced by conventional PT exercise. Exposure of SL residents to HA irrespective of their exercise regime altered the thyroidal handling of radioiodine. Thyroidal concentrations of freshly administered radioiodine at early and late sampling intervals were very high in both of the groups, especially the yogics, after their return to SL from HA. Possible mechanisms of the observed changes have been discussed.