9,876 research outputs found

    Fireside corrosion degradation of ferritic alloys at 600°C in oxy-fired conditions

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    This paper reports the results of a study carried out to investigate the effects of simulated coal/biomass combustion conditions on the fireside corrosion. The 1000 h deposit recoat exposure (5 × 200 h cycles) was carried out at 600 °C. In these tests ferritic alloys were used 15Mo3, T22, T23 and T91. Kinetics data were generated for the alloys exposed using both traditional weight change methods and metal loss measurements. The highest rate of corrosion based on EDX results occurred under D1 deposit where provoke mainly by the formation of alkali iron tri-sulphate phase

    Compressive Sensing for Feedback Reduction in MIMO Broadcast Channels

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    We propose a generalized feedback model and compressive sensing based opportunistic feedback schemes for feedback resource reduction in MIMO Broadcast Channels under the assumption that both uplink and downlink channels undergo block Rayleigh fading. Feedback resources are shared and are opportunistically accessed by users who are strong, i.e. users whose channel quality information is above a certain fixed threshold. Strong users send same feedback information on all shared channels. They are identified by the base station via compressive sensing. Both analog and digital feedbacks are considered. The proposed analog & digital opportunistic feedback schemes are shown to achieve the same sum-rate throughput as that achieved by dedicated feedback schemes, but with feedback channels growing only logarithmically with number of users. Moreover, there is also a reduction in the feedback load. In the analog feedback case, we show that the propose scheme reduces the feedback noise which eventually results in better throughput, whereas in the digital feedback case the proposed scheme in a noisy scenario achieves almost the throughput obtained in a noiseless dedicated feedback scenario. We also show that for a fixed given budget of feedback bits, there exist a trade-off between the number of shared channels and thresholds accuracy of the feedback SINR.Comment: Submitted to IEEE Transactions on Wireless Communications, April 200

    The Polymorphism of Model United Nations: Students’ Guide

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    This guide serves as a comprehensive introduction to Model United Nations (MUN), an educational simulation designed to immerse students in the dynamics of international diplomacy and decision-making. MUN conferences allow participants to assume the roles of UN delegates, representing various member states and engaging in debates to address global issues. The guide outlines the foundational aspects of MUN, including the significance of representing assigned countries, the preparation process involving research and position papers, and the practical skills gained such as public speaking and teamwork. It provides a detailed overview of MUN procedures, highlighting the importance of parliamentary rules, points, motions, and the quorum necessary for procedural decisions. The guide also explains the structure of debate, which includes formal and informal phases, moderated and unmoderated caucuses, and the role of the Dais in managing discussions. By offering insights into the operational framework of MUN and the procedural nuances that govern debates, this guide aims to equip students with the knowledge and skills needed to navigate and excel in MUN conferences

    Transnational terrorism as a spillover of domestic disputes in other countries

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    This paper models transnational terrorism as a three-way strategic interaction involving a government that faces armed opposition at home, which may spill over in the form of acts of terrorism by the state’s opponents against the government’s external sponsor. The external sponsor also utilizes deterrence against potential terrorists, which only lowers terrorism if terrorists are not intrinsically motivated by a deep-seated sense of humiliation. A rise in the external power’s preference for deterrence against terrorism may backfire in these circumstances. Increases in the government’s military efficiency against the rebels, who are also terrorists against the government’s sponsor raise overall levels of violence. – conflict ; terrorism ; civil wa

    Non-parabolicity of the conduction band of wurtzite GaN

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    Using cyclotron resonance, we measure the effective mass, mm*, of electrons in AlGaN/GaN heterostructures with densities, n2D16×1012n_{2D}\sim 1-6\times10^{12}cm2^{-2}. From our extensive data, we extrapolate a band edge mass of (0.208±0.002)me(0.208\pm0.002) m_e. By comparing our mm* data with the results of a multi-band \textbf{k.p} calculation we infer that the effect of remote bands is essential in explaining the observed conduction band non-parabolicity (NP). Our calculation of polaron mass corrections -- including finite width and screening - suggests those to be negligible. It implies that the behavior of m(n2D)m*(n_{2D}) can be understood solely in terms of NP. Finally, using our NP and polaron corrections, we are able to reduce the large scatter in the published band edge mass values

    Polo like kinase 2 tumour suppressor and cancer biomarker: new perspectives on drug sensitivity/resistance in ovarian cancer

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    The polo-like kinase PLK2 has recently been identified as a potential theranostic marker in the management of chemotherapy sensitive cancers. The methylation status of the PLK2 CpG island varies with sensitivity to paclitaxel and platinum in ovarian cancer cell lines. Importantly, extrapolation of these in vitro data to the clinical setting confirms that the methylation status of the PLK2 CpG island predicts outcomes in patients treated with carboplatin and paclitaxel chemotherapy. A second cell cycle regulator, p57Kip2, is also subject to epigenetic silencing in carboplatin resistance in vitro and in vivo, emphasising that cell cycle regulators are important determinants of sensitivity to chemotherapeutic agents and providing insights into the phenomenon of collateral drug sensitivity in oncology. Understanding the mechanistic basis and identification of robust biomarkers to predict collateral sensitivity may inform optimal use of chemotherapy in patients receiving multiple lines of treatment

    Reliability growth of open source software using defect analysis

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    We examine two active and popular open source products to observe whether or not open source software has a different defect arrival rate than software developed in-house. The evaluation used two common models of reliability growth models; concave and S-shaped and this analysis shows that open source has a different profile of defect arrival. Further investigation indicated that low level design instability is a possible explanation of the different defect growth profile. © 2008 IEEE

    Fisher profiles and perceptions of sea turtle-fishery interactions: case study of East Coast Peninsular Malaysia

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    The paper focuses on coastal fisheries, particularly examining sea turtle-fishery interactions and determining the socioeconomic profile and perception of local fishers about sea turtle issues along the East Coast of Peninsular Malaysia.Turtle fisheries, Nature conservation, Coastal fisheries, Man-induced effects, ISEW, Malaysia, Malaya, Pahang, Malaysia, Malaya, Kelantan, Malaysia, Malaya, Terengganu,

    The cyclin-dependent kinase inhibitor p57(Kip2) is epigenetically regulated in carboplatin resistance and results in collateral sensitivity to the CDK inhibitor seliciclib in ovarian cancer

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    Carboplatin remains a first-line agent in the management of epithelial ovarian cancer (EOC). Unfortunately, platinum-resistant disease ultimately occurs in most patients. Using a novel EOC cell line with acquired resistance to carboplatin: PEO1CarbR, genome-wide micro-array profiling identified the cyclin-dependent kinase inhibitor p57(Kip2) as specifically downregulated in carboplatin resistance. Presently, we describe confirmation of these preliminary data with a variety of approaches
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