660 research outputs found

    Design of a Broadband Amplifier for High Speed Applications

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    This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal

    Drag Reduction by Polymers in Wall Bounded Turbulence

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    We address the mechanism of drag reduction by polymers in turbulent wall bounded flows. On the basis of the equations of fluid mechanics we present a quantitative derivation of the "maximum drag reduction (MDR) asymptote" which is the maximum drag reduction attained by polymers. Based on Newtonian information only we prove the existence of drag reduction, and with one experimental parameter we reach a quantitative agreement with the experimental measurements.Comment: 4 pages, 1 fig., included, PRL, submitte

    Tumor metastasis to bone

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    Establishment of skeletal metastasis involves bidirectional interactions between the tumor cell and the cellular elements in the bone microenvironment. A better understanding of the pathophysiology of bone metastasis will be critical in developing the means to prevent bone metastasis or inhibit its progression. The receptor activator of nuclear factor-κB (RANK)/RANK ligand pathway has emerged as the key pathway regulating osteolysis in skeletal metastasis. A number of candidate factors, including the Wnt (wingless int) proteins, endothelin-1, and bone morphogenetic proteins, have been implicated in the establishment of osteoblastic metastasis. The complex nature of tumor-bone microenvironment interactions and the presence of multiple pathways that lead to bone metastasis suggests that simultaneous targeting of these pathways in the metastatic cascade are required for effective treatment. This review discusses current understanding of the pathophysiologic mechanisms that underlie the establishment of bone metastasis and potential molecular therapeutic strategies for prevention and treatment of bone metastasis

    Antibiofilm Potential of Metal Based Nanoparticles: Synthesis and Mode of Action

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    oai:ojs.pkp.sfu.ca:article/2Biofilm refers to a group of microbes colonizing together and often adhered to a surface. The adherence is attributed to secretion of polymeric substances comprising of extracellular DNA, proteins, and polysaccharides thereby limiting the access and inhibitory activity of existing antimicrobial agents. Biofilm are a major cause of acute infections and pose immense clinical threat especially in conditions employing the use of invasive devices thus being a major source of mortality and morbidity. Hence there is a dire need to develop alternative treatment against biofilm-related infections. Advances in nanotechnology has opened new horizons. Nanoparticles derived from various metal present promising candidates to ameliorate biofilms owing to their antioxidant potential

    A 43-Gbps Lithium Niobate Modulator Driver Module

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    This paper describes the realization of a 43-Gbps Lithium Niobate modulator driver module. The NRZ driver module utilizes four stages of GaAs p-HEMT MMIC amplifiers integrated with an output level detector and feedback loop to provide thermal stability and external control of the output swing. The bias and loop control circuitry are contained in the housing on a PC board external to the sealed MIC section. The integrated module (50.8 x 73.4 x 9.5 mm 3) provides 6.0 Vp-p controllable single-ended output voltage while dissipating only 4 watt

    Are nonwoven synthetic pollination bags a better choice for sorghum breeding?

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    This work investigated the effects of seven pollination bag treatments on three varieties of sorghum for: grain loss to birds; total weight of five panicles (g); total grain weight of five panicles (g); average grain weight per panicle (g); germination per cent; and occurrence of grain mold during 2016. Varieties were: 1167048 hybrid (brown seeded); BR007B (red seeded); and P9401 (white seeded). The bag treatments were: 1. No bagging; 2. Kraft paper; 3. Kraft paper + plastic bag screen; 4 Used duraweb® SG1; 5. Used duraweb® SG2; 6. New duraweb® SG1; 7. New duraweld® SG2. High bird pressure resulted in 100% seed loss on uncovered panicles and 75% under Kraft paper pollination bags. Birds preferred white seeded P9401, which led to no seed recovery under Kraft paper bags. There was virtually no bird damage with all other pollination bags. For panicle and grain yields the varieties performed in the order 1167048>BR007B>P9401. Unprotected panicles and paper bag treatments had the lowest yields. Panicles covered with the new synthetic bags exhibited 195 to 652% higher yields compared to Kraft paper bags. Varieties x bag type interactions were not important as they contributed 4 to 6% to the total sum of squares for yield traits. Germination test under normal and stress conditions showed no significant adverse effect of bag treatments on seed health. Reused bags performed as well as new bags for all of these traits. Varieties differed significantly for the occurrence of five grain mold pathogens, with highest occurrence of Alternaria, up to 40%, on 1167048 hybrid. Of the five pathogens, bag types differed significantly for Phoma with the highest occurrence of 9% on re-used duraweb®SG2 bags. Thus bags require disinfecting and cleaning before re-use. It is concluded that nonwoven synthetic bags are a better choice than the Kraft paper pollination bags for increasing the grain yield and virtually eliminating the bird damage in sorghum
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