Synthesis,structural, thermal and optical studies of rare earth coordinated complex: Tb(Sal)3Phen

Complexes of salicylic acid (Sal) and 1,10-phenanthroline (Phen) were synthesized coordinated with terbium ion (Tb³⁺) in crystalline phases. The structural characterizations of the lanthanide complex were made using FT-IR, NMR (¹H and ¹³C) and XRD techniques. These measurements confirm the formation of Tb(Sal)₃Phen complex structure. The thermal aspects of the complex were examined using DTA and TGA techniques. An enhancement in luminescence intensity of Tb³⁺ ion bands were observed in Tb(Sal)₃Phen complex as compared to TbCl₃ crystals on 355 nm laser excitation. Enhancement is reported due to the efficient energy transfer process from Sal to Tb³⁺ ions. This is also confirmed by the time resolved photoluminescence spectroscopy with increase in lifetime of Tb³⁺ ions due to encapsulation in Sal/Phen network. Our system in itself can be a deserving candidate for luminescent solar collector material when coupled with solar cells.     

Lactic acid bacteria isolated from ethnic preserved meat products of the Western Himalayas

We used culture- and molecular-biology-based methods to investigate the diversity of lactic acid bacteria (LAB) in the ethnic chevon (goat) meat products chartayshya, jamma and arjia of the Western Himalayas. In six chartayshya, six jamma and four arjia samples, LAB were the predominant microbial component involved in the fermentation of these samples, and the total LAB population in arjia (7.8 ± 0.1 log cfu g⁻¹; mean ± SD) was significantly higher (P < 0.05) than in chartayshya (6.9 ± 0.1 log cfu g⁻¹) and jamma (7.5 ± 0.1 log cfu g⁻¹). We identified 53 LAB samples by 16S rRNA and phenylalanyl-tRNA synthase (pheS) genes sequencing. The LAB isolates were identified as Enterococcus durans, Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Leuconostoc citreum, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria. These results revealed that there is a high level of diversity of LAB in the Himalayan ethnic preserved meat products.     

A DFT study of BeX (X = S,Se, Te) semiconductor: Modified Becke Johnson (mBJ) potential

The electronic, optical and elastic properties of BeX were performed within full potential liberalized augmented plane wave method based on density functional theory (DFT). Generalized gradient approximation (GGA) and modified Becke Johnson (TB-mBJ) potential were used for exchange correlation. The mBJ gives improved band gap as compare to GGA and in close agreement with the experimental results. The present band gaps of BeS, BeSe and BeTe calculated within mBJ are 4.40, 4.0 and 2.40 eV respectively.     

Magnetic properties of directionally solidified Bi-Mn alloys

Microstructure, composition and magnetic property correlations have been attempted for directionally solidified dilute Bi-Mn alloys. The ingots exhibited predominantly acicular BiMn precipitate particles in a bismuth matrix, and showed magnetic anisotropy along the direction of solidification. The saturation magnetization has been found to increase linearly with the weight percentage of manganese over the entire composition range investigated, starting from the hypoeutectic (0.15% Mn) to the hypereutectic (6.6% Mn) region. The intrinsic coercivity has been observed to be a maximum along the direction of solidification, but it decreased with manganese content in both the as-cast and the directionally solidified alloys. The results are discussed in terms of the crystal anisotropy, shape anisotropy and packing factor of the magnetic particles.     

Evolution of the Water Table in a Finite Aquifer Due to Transient Recharge from Two Parallel Strip Basins

Understanding the dynamic response of phreatic aquifers due to recharge is most important for the proper management of ground-water systems. In this paper an analytical solution is developed to describe the water-table fluctuation in a finite aquifer system due to transient recharge from two parallel strip basins. Application of the solution in the prediction of spatiotemporal variation of the water table and in the sensitivity analysis of the effects of various controlling parameters on the water-table fluctuation is demonstrated with the help of an example problem.     

Estimation of average life for negative exponential distribution

This paper deals with the problem of average life estimation when the life times follow negative exponential distribution. A minimum mean square error estimator belonging to the class of linear combination of complete sufficient statistics has been obtained. The estimator thus obtained requires knowledge of coefficient of variation. The effect of using a guessed value of coefficient of variation on the estimator has also been studied.     

Synthesis of thioesters and thioamides under solvothermal condition using thiourea as thionating agent

A simple, rapid, high-yielding and environmentally benign method for the conversion of esters and amides to the corresponding thio compounds was carried out using thiourea as thionating agent under solvothermal reaction. All the compounds isolated in good yields were characterized both by spectral analysis and comparing them with the authentic samples synthesized using the literature method.     

Metafile-Based Scalable Caching and Dynamic Replacing Algorithms for Multiple Videos Over Quality-of-Service Networks

This paper presents metafile-based scalable caching and dynamic replacing algorithms for multiple videos over quality-of-service networks. A metafile for each video includes the cached-frame sequence, which is made by scalable caching algorithm minimizing client's buffer size and channel bandwidth under the general video traffic condition. Based on the metafiles, we propose a caching algorithm for multiple videos to effectively reduce both the buffer size and the required bandwidth and replacing algorithm to dynamically update the cached frames when user access pattern changes. Finally, experimental results are provided to compare the proposed algorithms with various existing caching and replacing algorithms.     

Internet usage for information provisioning: theoretical construct development and empirical validation in the clinical decision-making context

Despite substantial discussion of the Internet's impact on individual activities, there is an absence of a theoretically grounded measure of Internet usage for the provisioning of information required by decision-makers. Our research addresses this void in the literature. We conceptualize Internet Usage for Information Provisioning (IUIP) as the degree to which the Internet is used to meet information requirements of individual decision-makers engaged in diagnostic decision-making tasks. Drawing on the information processing theoretical framework, three dimensions (usage for breadth of content, usage for depth of content, and usage for interaction dynamism) of IUIP are identified. The construct was validated through a two-phase empirical study conducted in the physician clinical decision-making context. The first phase involved interviewing physicians to establish face validity of the dimensions and to generate multi-item measures for each dimension. The second phase consisted of surveying physicians to evaluate measurement properties and nomological validity. Principal components analysis, confirmatory factor analysis, and partial least squares analysis were the primary statistical techniques used to analyze the data and evaluate construct validity. Our results suggest that decision-makers operating in uncertain and equivocal decision contexts use the Internet to a greater degree for their content needs and selective attention requirements. Our results also suggest that a fit between the user's information processing requirements and technology, and selected social norms, lead to higher levels of IUIP. Implications for practice and future research are discussed.     

Leukemic meningitis in B-cell prolymphocytic leukemia. A clinical, pathologic, and ultrastructural case study and a review of the literature

BACKGROUND: Leukemic meningitis is rare in B-chronic lymphocytic leukemia (CLL) and B-prolymphocytic leukemia (PLL); a MEDLINE search for reports published 1960 and after disclosed only nine prior reports. A patient with stable Rai Stage II CLL/PL developed mental status changes. Lumbar puncture revealed a lymphocytic pleocytosis with prolymphocytes containing intracytoplasmic inclusions. METHODS: The patient's cerebrospinal fluid lymphocyte population was analyzed by immunophenotyping and electron microscopy. RESULTS: The studies revealed a clonal population of B prolymphocytes, with typical immunophenotypic and ultrastructural characteristics. The patient was treated with intrathecal chemotherapy with eventual resolution of the cerebrospinal fluid pleocytosis and return to his normal neurologic status. Prior studies also have revealed the efficacy of intrathecal chemotherapy. CONCLUSION: Leukemic meningitis in CLL or PLL is responsive to treatment with intrathecal chemotherapy.