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91.
92.
R. Thangaraj S. B. Gadgil B. K. Gupta J. Vaidhyanathan Iyer O. P. A. Agnihotri 《国际能源研究杂志》1982,6(2):169-173
High absorptance and low thermal emittance selective surfaces have been formed by evaporating lead sulphide onto Al evaporated Al substrates. The dependence of selectivity, α/?, on thickness has been studied. The maximum selectivity was obtained for PbS thickness of 400 Å. The emissivity is found to increase with temperature. The coatings are stable up to a temperature of 240°C in air. Long term ultraviolet irradiation causes the photo-oxidation of PbS to PbSO4 which results in the increase of emittance and a decrease in absorptance. When cycled between 0°C and 200°C, the coatings do not show any signs of degradation. 相似文献
93.
Memory module manufacturers face an ongoing challenge to incorporate more functionality and superior performance with each new generation of product offering. The growth in demand for memory capacity is surpassing the pace at which memory component manufacturers are able to cost-effectively produce the next generation of monolithic memory devices. This drives the need for utilizing stacked components for memory module assemblies. The complex nature of stacked chip-scale package (CSP) components coupled with a lead-free process presents unique rework challenges that needed to be studied and addressed. Reworking a CSP is complicated as the solder joints are hidden underneath the component. The process window available for the lead-free rework process is very narrow. There are number of other critical factors, which complicate and affect the repeatability of the rework process. The complications only increase with the use of stacked CSP devices. The rework of package stacked CSP components, which are complex in nature, is a daunting task. The key issues and observations with regard to the issues and challenges associated with the lead-free rework of mirror-imaged package stacked CSP components has been presented in this paper. In addition, the paper also provides a recipe for reliably reworking these packages. 相似文献
94.
Tyrone L. R. Humphries Kunyu Shen Abishek Iyer David W. Johnson Glenda C. Gobe David Nikolic-Paterson David P. Fairlie David A. Vesey 《International journal of molecular sciences》2021,22(14)
Coagulopathies common to patients with diabetes and chronic kidney disease (CKD) are not fully understood. Fibrin deposits in the kidney suggest the local presence of clotting factors including tissue factor (TF). In this study, we investigated the effect of glucose availability on the synthesis of TF by cultured human kidney tubular epithelial cells (HTECs) in response to activation of protease-activated receptor 2 (PAR2). PAR2 activation by peptide 2f-LIGRLO-NH2 (2F, 2 µM) enhanced the synthesis and secretion of active TF (~45 kDa) which was blocked by a PAR2 antagonist (I-191). Treatment with 2F also significantly increased the consumption of glucose from the cell medium and lactate secretion. Culturing HTECs in 25 mM glucose enhanced TF synthesis and secretion over 5 mM glucose, while addition of 5 mM 2-deoxyglucose (2DOG) significantly decreased TF synthesis and reduced its molecular weight (~40 kDa). Blocking glycosylation with tunicamycin also reduced 2F-induced TF synthesis while reducing its molecular weight (~36 kDa). In conclusion, PAR2-induced TF synthesis in HTECs is enhanced by culture in high concentrations of glucose and suppressed by inhibiting either PAR2 activation (I-191), glycolysis (2DOG) or glycosylation (tunicamycin). These results may help explain how elevated concentrations of glucose promote clotting abnormities in diabetic kidney disease. The application of PAR2 antagonists to treat CKD should be investigated further. 相似文献
95.
96.
The usefulness of the ferritic nitrocarburizing treatment for improving the tribological properties of ferrous components is well established. However, the thin compound layer of beneficial epsilon carbonitride that develops at the surface lacks the ability to bear high Hertzian stresses. Nitrocarburizing in the austenite phase field of the Fe---N---C system overcomes this disadvantage since the formation of a hard zone of martensite-bainite below the compound layer provides the back-up to withstand point loads. Results of the Falex scuffing test indicate that the failure load increases on account of the thicker compound layer at the surface. The results indicate further that the frictional heat generated during the test coupled with working by the jaws convert the retained austenite present in the sub-compound layer to harder microconstituents. The study suggests that the austenitic treatment could be useful for applications involving simultaneous heat and work such as hot working dies. 相似文献
97.
Venkatesh A. Iyer 《Mechanism and Machine Theory》1996,31(8):1185-1194
Linkage-type dwell mechanisms are less expensive to manufacture and maintain, and can be superior to cams at high speed. They are also easily adjustable for satisfying variable output motion requirements. In spite of these advantages they have not found wide application. Part of the reason for this lack of popularity is the absence of proper design tools. The inspiration for this work stems from the need to bridge this technological gap. RECDWELL helps to design both circular-arc and straight-line dwell mechanisms using a technique which is simple, efficient and accurate. 相似文献
98.
Iyer R Liu YS Boisset GC Goodwill DJ Ayliffe MH Robertson B Robertson WM Kabal D Lacroix F Plant DV 《Applied optics》1997,36(35):9230-9242
The design and implementation of a robust, scalable, and modular optical power supply spot-array generator for a modulator-based free-space optical backplane demonstrator is presented. Four arrays of 8 x 4 spots with 6.47-mum radii (at 1/e(2) points) pitched at 125 mum in the vertical direction and 250 mum in the horizontal were required to provide the light for the optical interconnect. Tight system tolerances demanded careful optical design, robust optomechanics, and effective alignment techniques. Issues such as spot-array generation, polarization, power efficiency, and power uniformity are discussed. Characterization results are presented. 相似文献
99.
Rajib Ahmed Mehmet Ozgun Ozen Merve Goksin Karaaslan Cecilia A. Prator Cassandra Thanh Shreya Kumar Leonel Torres Nikita Iyer Sadie Munter Sarka Southern Timothy J. Henrich Fatih Inci Utkan Demirci 《Advanced materials (Deerfield Beach, Fla.)》2020,32(19):1907160
Metasurfaces are engineered nanostructured interfaces that extend the photonic behavior of natural materials, and they spur many breakthroughs in multiple fields, including quantum optics, optoelectronics, and biosensing. Recent advances in metasurface nanofabrication enable precise manipulation of light–matter interactions at subwavelength scales. However, current fabrication methods are costly and time-consuming and have a small active area with low reproducibility due to limitations in lithography, where sensing nanosized rare biotargets requires a wide active surface area for efficient binding and detection. Here, a plastic-templated tunable metasurface with a large active area and periodic metal–dielectric layers to excite plasmonic Fano resonance transitions providing multimodal and multiplex sensing of small biotargets, such as proteins and viruses, is introduced. The tunable Fano resonance feature of the metasurface is enabled via chemical etching steps to manage nanoperiodicity of the plastic template decorated with plasmonic layers and surrounding dielectric medium. This metasurface integrated with microfluidics further enhances the light–matter interactions over a wide sensing area, extending data collection from 3D to 4D by tracking real-time biomolecular binding events. Overall, this work resolves cost- and complexity-related large-scale fabrication challenges and improves multilayer sensitivity of detection in biosensing applications. 相似文献
100.