The illumination intensity and applied bias voltage on dielectric properties of au/polyvinyl alcohol (Co,Zn‐doped)/n‐Si Schottky barrier diodes

The Au/polyvinyl alcohol (PVA) (Co, Zn‐doped)/n‐Si Schottky barrier diodes (SBDs) were exposed to various illumination intensities. Illumination effect on the dielectric properties has been investigated by using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) characteristics at 1 MHz and room temperature. The values of dielectric constant (ε′), dielectric loss (ε″), loss tangent (tanδ), electric modulus (M′ and M″), and AC electrical conductivity (σ_AC) were found strongly intensity dependent on both the illumination levels and applied bias voltage especially in depletion and accumulation regions. Such bias and illumination dependency of these parameters can be explained on the basis of Maxwell–Wagner interfacial polarization and restructuring and reordering of charges at interface states. In addition, the ε′–V plots also show an intersection feature at ～ 2.8 V and such behavior of the ε′–V plots appears as an abnormality compared with the conventional behavior of an ideal SBD. The obtained results revealed that illumination intensity enhances the conductivity of Au/PVA(Co, Zn‐doped)/n‐Si SBD. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Radiation from a Current Filament Located inside a Cylindrical Frequency Selective Surface

We consider electromagnetic field radiation properties of a current filament placed at the origin of a cylindrical frequency selective surface (CFSS). The CFSS consists of free standing metal strips with two‐dimensional periodicity. The analysis is based on a cylindrical Floquet mode wave expansion technique. We observed that near the half wavelength resonance frequencies, there exist some specific frequencies at which the surface becomes totally transparent.     

Design of CMIP-SNMPv2 Proxy Gateway for Network Management Interoperability

This paper describes the essential specificationand design of a CMIP-SNMPv2 application gateway fornetwork management integration and interoperability.Such a intermediate proxy software device allows management of Internet MIB-II objects throughISO/CCITT manager supporting CMIP protocol and CMISmanagement services. All the gateway functionality areexplained using dataflow diagrams. CMIP indication PDUs are transformed into functionallycorresponding SNMPv2 PDUs. Detailed service-mapping andname-mapping aspects consistent with the protocols,Internet MIB-II and the GDMO MIB are fully explored.SNMPv2 to CMIP inverse mapping is also explained indetail, followed by conclusions capturing the salientaspects of this design.     

Minimization of warpage and sink index in injection-molded thermoplastic parts using Taguchi optimization method

The objective of this paper consist of minimization of the warpage and sink index in terms of process parameters of the plastic parts have different rib cross-section types, and rib layout angle using Taguchi optimization method. Considering the process parameters such as mold temperature, melt temperature, packing pressure, in addition to rib cross-section types, and rib layout angle, a series of mold analyses are performed to exploite the warpage and sink index data. The polymeric materials were selected PC/ABS, POM, and PA66. Taguchi optimization method was used by exploiting mold analyses based on three level factorial design. Orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, the analysis of variance (ANOVA) are utilized to find the optimal levels and the effect of process parameters on warpage and sink index. Confirmation analysis test with the optimal levels of process parameters are carried out in order to demonstrate the goodness of Taguchi method. From this, it can be concluded that Taguchi method is very suitable to solve the quality problem occurring the injection-molded thermoplastic parts.     

The effect of Dy3+ doping on the thermoluminescence properties of Ba2SiO4

The thermoluminescence (TL) properties of barium silicate phosphor, Ba₂SiO₄:%3Dy³⁺ synthesized by using hydrothermal method were investigated and presented in detail. The crystallographic structure of Ba₂SiO₄:%3Dy³⁺ was determined by conventional x-ray diffraction technique and the results showed that the sample was grown in orthorhombic phase with Pmcn (62) space group (PDF: 01-077-0150). The excitation spectra of Ba₂SiO₄:Dy³⁺ were measured in the wavelength range of 220-400 nm and the spectra showed that there were several excitation bands in the sample. The CIE chromaticity coordinates were also calculated from emission spectra for Dy³⁺-doped Ba₂SiO₄. In order to calculate the kinetic parameters of the sample the additive dose, peak shape and computerized glow curve deconvolution methods were used. It was found that Ba₂SiO₄:Dy³⁺ was composed of five general order TL glow peaks. The fading characteristics of the sample were also studied over a period time. At the end of the planned storage times, the normalized TL peak area of Ba₂SiO₄:Dy³⁺ reduced 60% of its original value.     

Energy recovery from hydrogen combustion at elevated pressures

Hydrogen is assumed as one of the most environmentally benign fuels. By the combustion of hydrogen enormous amount of H₂O; and therefore, latent heat is produced. Because, there is not so much need to heat at low temperatures, methods are needed to recover latent heat at higher temperatures. One of the methods to upgrade the latent heat at higher temperatures is the method of combustion at elevated pressures. Increasing the pressure of the exhaust gas makes it possible to recover latent heat and higher extra exergy output from the system. In this work, both latent and sensible heat recoveries at elevated pressures are investigated using environmentally friendly fuel hydrogen. It is shown that coefficient of performance (COP) and exergy efficiency (${\eta }_{ex}$) is very satisfactory even at high pressures.     

Ionising Radiation Promotes Invasive Potential of Breast Cancer Cells: The Role of Exosomes in the Process

Along with the cells that are exposed to radiation, non-irradiated cells can unveil radiation effects as a result of intercellular communication, which are collectively defined as radiation induced bystander effects (RIBE). Exosome-mediated signalling is one of the core mechanisms responsible for multidirectional communication of tumor cells and their associated microenvironment, which may result in enhancement of malignant tumor phenotypes. Recent studies show that exosomes and exosome-mediated signalling also play a dynamic role in RIBE in cancer cell lines, many of which focused on altered exosome cargo or their effects on DNA damage. However, there is a lack of knowledge regarding how these changes in exosome cargo are reflected in other functional characteristics of cancer cells from the aspects of invasiveness and metastasis. Therefore, in the current study, we aimed to investigate exosome-mediated bystander effects of 2 Gy X-ray therapeutic dose of ionizing radiation on the invasive potential of MCF-7 breast cancer cells in vitro via assessing Matrigel invasion potential, epithelial mesenchymal transition (EMT) characteristics and the extent of glycosylation, as well as underlying plausible molecular mechanisms. The findings show that exosomes derived from irradiated MCF-7 cells enhance invasiveness of bystander MCF-7 cells, possibly through altered miRNA and protein content carried in exosomes.     

高性能汽车中的电源设计

引言 高可靠性、低成本、极短的研发周期等等相互冲突的设计要求迫使电源设计人员采用新的具有突破性的技术方案,而这些技术是传统的汽车电源设计中不曾涉足的。     

Evaluation of antioxidant and antimicrobial potential of strawberry tree (<Emphasis Type="Italic">Arbutus Unedo</Emphasis> L.) leaf

In present study, antioxidant and antimicrobial activities of strawberry tree (Arbutus unedo L.) leaves were investigated. Antioxidant activity was determined by methods of DPPH scavenging, β-carotene bleaching, reducing power, metal chelating, superoxide anion scavenging, and hydrogen peroxide scavenging activity. Total phenolic content were determined to be 197.16±1.43 mg GAE/g extract in aqueous extract. The EC₅₀ value of methanolic extracts was found to be 0.423 mg/mL. The extracts of leaves showed nearly 1/4 metal chelating capacity of standard EDTA, high reducing power, superoxide anion scavenging, and hydrogen peroxide scavenging activities. While the strawberry tree leaves exhibited antibacterial activity against Staphylococcus aureus, there was no inhibitory effect against Escherichia coli and Salmonella enteritidis. The strawberry tree leaves exhibited antifungal effect against 2 aflatoxigenic molds namely Aspergillus parasiticus NRRL 2999 and NRRL 465. These results suggest that the strawberry tree leaves may be used as an antioxidant source for pharmaceutical application, nutraceutical and functional food industries.