Thermally stimulated current and electrical conduction in metal (1)-ethyl cellulose-metal (1)/(2) systems

Depolarization current characteristics of solution grown pure ethyl cellulose (EC) films of about 20μm thickness have been studied as a function of electrode materials at constant poling field (5 × 10⁴ V/cm) and poling temperature 40°C. Thermally stimulated current (TSC) thermograms of EC consists of two well resolved peaks (located at 60°C and 140°C) for Al-Al system, which are attributed to the deorientation of strongly attached ethoxy groups of glycosidal units and diffusion of space charges either at electrodes or due to their thermal release at higher temperatures from the defect levels. For dissimilar electrode combinations (Al-Ag/Cu/Au/Sn/Pb), an indication of peak of lower magnitude at around (50–70°C) alongwith a higher temperature peak (140–155°C), have been observed. TSC parameters are found to change with the choice of electrode material. The dependence of dark current at 40°C in metal-ethyl cellulose-metal systems on applied voltage in the range (2·0–5·0) × 10⁴V/cm has also been studied. The results of current-voltage measurement on EC have been interpreted to show that the Schottky-Richardson mechanism is the controlling transport mechanism. Zero field current density extrapolated fromI-E ^1/2 plots are found to vary with metal work function.     

Influence of Interfacial LSMO Nanoparticles/Layer on the Vortex Pinning Properties of YBCO Thin Film

YBa₂Cu₃O_7?δ (YBCO) thin films have been deposited on bare and La_0.67Sr_0.33MnO₃ (LSMO) modified single crystal SrTiO₃ (STO) substrates. The effect of randomly distributed ferromagnetic LSMO nanoparticles and a complete LSMO layer, present at STO/YBCO interface, on the superconducting properties of YBCO thin films has been investigated by temperature dependent magnetization studies. The YBCO thin film on LSMO nanoparticles decorated STO substrate shows significant improvement in the critical current density and pinning force density as compared to the YBCO thin film deposited on bare STO substrate and this improvement is more significant at higher applied magnetic field. However, the LSMO/YBCO bilayer showed the improved flux pinning properties only up to a magnetic field of 1.5 T above which it deteriorates. In the case of LSMO/YBCO bilayer, the underlying LSMO layer gives rise to magnetic inhomogeneities due to domain structure, which leads to improved flux pinning properties limited to lower field. However, in the case of LSMO nanoparticles decorated substrate, the presence of LSMO nanoparticles at YBCO/STO interface seems to introduce magnetic inhomogeneities as well as structural defects, which might be acting as correlated pinning sites leading to improved flux pinning properties of the YBCO thin film over a wide range of applied magnetic field.     

Intel 870: a building block for cost-effective, scalable servers

Architects based the Intel 870 system architecture on the scalability port, a coherent system interconnect. The system's building-block approach lets a single chip set support a wide range of server segments.     

Yield-oriented computer-aided defect diagnosis

Any good yield-oriented defect strategy must have two main components-(a) the ability to perform rapid defect diagnosis for yield learning, and (b) the ability to efficiently extract defect parameters from the manufacturing line. In this work, an inductive fault analysis (IFA)-based defect methodology is investigated to see if it meets the above requirements. Using an SRAM test vehicle as an example, the research analyzes whether computer-generated mappings between defect types and tester fail data can provide sufficient resolution for both, defect diagnosis and defect parameter characterization     

Photoelectrochemical solar cells using electrodeposited GaAs and AlSb semiconductor films

Electrodeposited GaAs and AlSb thin film semiconductors were prepared under various deposition conditions. Reasonable stoichiometry could be attained as revealed by EDAX studies. The best stoichiometry was obtained are Ga_1·04As_0·96 and Al_1·12Sb_0·88. The band gap of the GaAs and AlSb films was ∼1·5 eV and 1·6 eV respectively. The electrochemical and photoelectrochemical studies on these films are reported with different redox-couples in aqueous and non-aqueous medium.     

Heat transfer through electrolytic solutions under the action of electrolytic currents

Heat transfer rates from an electrically heated thin platinum wire in dilute NaOH and Na₂CO₃ solutions of different concentrations have been measured under the influence of electrolytic currents, using a sensitive Kelvin double bridge. In the low concentration region, the rate of heat transfer is initially found to increase with concentration and then to decrease with further increase in concentration. An explanation of these results on the basis of the behaviour of the thermal boundary layer surrounding the hot wire electrode is suggested. It has been indicated that these results can be employed to improve the performance of boiler systems and electro chemical machining processes.     

CD73 expression and fyn-dependent signaling on murine lymphocytes

CD73 is a glycosyl phosphatidylinositol-anchored protein with both ecto-enzyme activity (ecto-5'-nucleotidase) and signal transducing capabilities for human T lymphocytes. We now report an analysis of the distribution and function of CD73 in murine lymphoid tissues made possible by the development of the first monoclonal antibodies (mAb) specific for murine CD73. Subsets of T and B lymphocytes are CD73+ and the level of expression increases with lymphocyte maturation in both species. Among B cells, CD73 is largely restricted to cells which have undergone isotype switching. The signal transmitting function of CD73 is also conserved, as splenic T cells treated with anti-CD73 mAb plus phorbol 12-myristate 13-acetate proliferate and secrete IL-2. Fyn-/- mice are unresponsive to CD73 ligation, however, demonstrating the requirement for this tyrosine kinase in CD73-mediated signal transduction. CD73 is down-regulated after mAb plus cross-linking, suggesting that expression may be controlled by interaction with a ligand. Only small numbers of thymocytes are CD73+, so CD73 receptor functions are unlikely to be important for developing T cells. However, immunohistochemical analysis reveals that reticular and vascular cells throughout the thymus and other lymphoid tissues are markedly CD73+. Therefore, CD73 might mediate lymphocyte-stromal cell interactions or condition the local microenvironment to facilitate lymphocyte development and/or function.