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61.
A melt-mixing LPE growth technique to obtain a graded composition AlxGa1−xAs layer is described. The graded bandgap AlGaAs/GaAs solar cell requires the Al fraction (x) in the AlxGa1−xAs surface layer to increase from the junction towards the surface. The graded composition AlxGa1−xAs layer creates a built-in electric field for minority carriers which improves the carrier collection process. This graded
bandgap solar cell should enable one to realize the full potential of GaAs as a material for solar energy conversion. Quantitative
evaluation of the composition profile for these graded layers is needed to develop the proper growth technique and to understand
the resulting solar cell characteristics. Rutherford backscattering analysis technique is described which has been successfully
used to profile such layers. 相似文献
62.
A general purpose computer model for describing the transport phenomena and resulting rate of deposition has been described. Partial differential equations describing the conservation of mass, momentum, energy, and chemical species are solved by a computer program employing the finite difference method. The system considered in this paper is deposition of silicon in a vertical stagnation flow reactor by the reaction of silicon tetrachloride and hydrogen. The program allows for multiple chemical species and natural convection effects. Predicted silicon deposition rates along the substrate are in reasonable agreement with experimental values available in the literature. The effect of gas inlet configuration on the uniformity of deposition has been studied. The model can be used as a tool for design optimization of such reactors. 相似文献
63.
Dangi Manik Saxena Raghvendra Sahai Niranjan Vandana 《Microsystem Technologies》2022,28(12):2755-2764
Microsystem Technologies - A new readout circuit for HgCdTe based Infrared photodiodes has been proposed. In this work, the conventional source follower per detector (SFD) architecture of the... 相似文献
64.
Paper deals with implementation of variable bit rate steganographic data transmission over ETSI GSM 06.10 FR coder at five different bitrates. Then, few modifications are suggested in Regular Pulse Excitation section of ETSI GSM FR coder which ultimately claims to produce state of the art proposed GSM FR coder. In contrast with ETSI GSM FR coder, proposed coder also exhibits same bit rate steganographic data transmission. Here, in order to facilitate the same, few RPE pulses are identified and being utilized for embedding and hiding the information bits into them. Key element of this research is to allow for joint speech coding and data hiding and that is accomplished with two different approaches like Fixed and Joint Approach. These both approaches are implemented on both Standard and Proposed coders for their overall analytical evaluation of performance using Subjective (Mean opinion Score and Degraded MOS) and Objective (Perceptual Evaluation of Speech Quality) analysis. Small data information is represented as stego signal which can be embedded over different encoded wave files (chosen from NOIZEUS corpus) that serve as carrier signal. Simulation results for both coders reveal the trade off between data embedding rate and recovered speech quality (for both approaches). It is quite evident from both Subjective and Objective analysis that proposed coder offers comparable performance at the same time with lesser simulation delay because of its inherent constructional difference. It remains the fact that for both the coders, Joint approach performs better but at the cost of more simulation delay. 相似文献
65.
Yogeshwar Chauhan Sanjiv Puri 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2008,266(1):30-36
The Lk (k = l, α, β1,4, β3,6, β2,15,9,10,7, γ1,5 and γ2,3,4) X-ray production (XRP) cross sections have been measured for six elements with 56 ? Z ? 68 at 22.6 keV incident photon energy using the EDXRF spectrometer. The incident photon intensity, detector efficiency and geometrical factors have been determined from the K X-ray yields emitted from elemental targets with 22 ? Z ? 42 in the same geometrical setup and from knowledge of the K XRP cross sections. The L1 and L2 subshell fluorescence yields have been deduced from the present measured Lk XRP cross sections using the relativistic Hartree-Fock-Slater (HFS) model based photoionization cross sections. The present deduced ω1 (exp) values have been found to be, on an average, higher by 15% and 20% than those based on the Dirac-Hartree-Slater (DHS) model and the semi-empirical values compiled by Krause, respectively, for elements with 60 ? Z ? 68. 相似文献
66.
Optimization of xylanase production by Melanocarpus albomyces IIS68 in solid state fermentation using response surface methodology 总被引:2,自引:0,他引:2
Xylanase production by the thermophilic fungus, Melanocarpus albomyces IIS68, during solid state fermentation of wheat straw was studied and the effects of various variables were observed. Using the response surface methodology and the multivariant statistical approach, the optimum levels of the variables affecting xylanase production were determined. The optimum levels of the variables were 600-850 microm particle size, 43 h inoculum age, 1.37% Tween 80, 86% initial moisture content, 5.1% urea, 0.74% yeast extract and a harvest time of 96 h. Under these optimized conditions, xylanase activity of 7760 U/g initial dry substrate was obtained which was in very good agreement with the value predicted by the quadratic model (7890 U/g initial dry substrate). 相似文献
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69.
Brittany Rupp Sarah Owen Harrison Ball Kaylee Judith Smith Valerie Gunchick Evan T. Keller Vaibhav Sahai Sunitha Nagrath 《International journal of molecular sciences》2022,23(14)
As pancreatic cancer is the third deadliest cancer in the U.S., the ability to study genetic alterations is necessary to provide further insight into potentially targetable regions for cancer treatment. Circulating tumor cells (CTCs) represent an especially aggressive subset of cancer cells, capable of causing metastasis and progressing the disease. Here, we present the Labyrinth–DEPArray pipeline for the isolation and analysis of single CTCs. Established cell lines, patient-derived CTC cell lines and freshly isolated CTCs were recovered and sequenced to reveal single-cell copy number variations (CNVs). The resulting CNV profiles of established cell lines showed concordance with previously reported data and highlight several gains and losses of cancer-related genes such as FGFR3 and GNAS. The novel sequencing of patient-derived CTC cell lines showed gains in chromosome 8q, 10q and 17q across both CTC cell lines. The pipeline was used to process and isolate single cells from a metastatic pancreatic cancer patient revealing a gain of chromosome 1q and a loss of chromosome 5q. Overall, the Labyrinth-DEPArray pipeline offers a validated workflow combining the benefits of antigen-free CTC isolation with single cell genomic analysis. 相似文献
70.