2,508 research outputs found

    Azimuthal anisotropy (v2v_{2}) of high-pT_{T} π0\pi^{0} and direct γ\gamma in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV

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    Preliminary results from the STAR collaboration of the azimuthal anisotropy (v2)(v_{2}) of π0\pi^{0} and direct photon (γdir\gamma_{dir}) at high transverse momentum (pT_{T}) from Au+Au collisions at center-of-mass energy sNN=200\sqrt{s_{_{NN}}}=200~GeV are presented. A shower-shape analysis is used to select a sample free of direct photons (π0\pi^0) and a sample rich in direct photons γrich\gamma_{rich}. The relative contribution of background in the γrich\gamma_{rich} sample is determined assuming no associated charged particles nearby γdir\gamma_{dir}. The v2v_{2} of direct photons (v2γdirv_{2}^{\gamma_{dir}}) at mid-rapidity (ηγdir<1|\eta^{\gamma_{dir}}|<1) and high pT_{T} (8<pTγdir<168< p_{T}^{\gamma_{dir}}<16~GeV/cc) is extracted from those of π0\pi^{0} and neutral particles measured in the same kinematic range. In mid-central Au+Au collisions (10-40%\%), the v2v_{2} of π0\pi^0 (v2π0(pT)v_{2}^{\pi^{0}}(p_{T})) and charged particles (v2ch(pT)v_{2}^{ch}(p_{T})) are found to be \sim 0.12 and nearly independent of pT_{T}. The measured v2γdir(pT)v_{2}^{\gamma_{dir}}(p_{T}) is positive finite and systematically smaller than that of π0\pi^{0} and charged particles by a factor of \sim 3. Although the large v2π0v_{2}^{\pi^{0}} at such high pT_{T} might be partially due to the path-length dependence of energy loss, the non-zero value of v2γdirv_{2}^{\gamma_{dir}} indicates a bias of the reaction plane determination due to the presence of jets in the events. Systematic studies are currently in progress.Comment: 4 pages, 2 figures, Hot Quarks 2010, LaLonde Franc

    STR-941: NUMERICAL INVESTIGATION OF REINFORCED CONCRETE BARRIERS SUBJECTED TO BLAST LOADING

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    People’s lives are threatened by explosions; the tragic terrorist attacks have forced the governments to consider the importance of dealing with these attacks. With the rising threat of terrorism, protecting critical civil infrastructure such as embassies, governmental buildings, and airports against bomb attacks has become a critical issue. In the current research, reinforced concrete barriers subjected to blast loading are numerically investigated using Applied Element Method “AEM”. The blast loads adopts the ASCE guidance for design of blast-resistant buildings in petrochemical facilities. Fully nonlinear dynamic analysis was considered where the barriers thickness and reinforcement, end connections were parametrically investigated. It was found that the thickness and reinforcement of the barriers affect the barriers’ response, where the most significant parameter was the wall thickness

    Evaluation of Allelopathic Potential of Rumex dentatus Root Extract and Allelochemicals on Cicer arietinum

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    The present study aimed to evaluate the allelopathic potential of root extract of Rumex dentatus L. and various allelochemicals on some physiological parameters in roots of Cicer arietinum L. The tested allelochemicals were benzoic, caffeic, cinnamic, ferulic, gallic, sinapic and vanillic acids. Seed germination of Cicer was inhibited by Rumex extract. Lipid peroxidation and hydrogen peroxide production increased gradually in response to extract concentration as well as allelochemicals treatment. The total soluble protein decreased whereas the total phenol increased under the various treatments. The activities of superoxide dismutase (SOD: 1.15.1.1) and catalase (CAT: 1.11.1.6) increased continuously with increasing extract concentration. However, peroxidase (POD: 1.11.1.7) increased sharply at 2% (w/v) followed by reduction at the higher concentrations and reached 1.1 U g-1 fresh weight at 10% (w/v) which was still higher than that of the control value. Ferulic acid was the most effective inducer for SOD activity followed by cinnamic acid. The POD activity increased remarkably particularly with cinnamic, benzoic and gallic acids. Sinapic, ferulic and coumaric acids enhanced CAT activity by 150.4%, 139.5% and 124.4%, respectively. The results reveal the possible use of R. dentatus as bioherbicide

    The Extended Burr XII Distribution with Variable Shapes for the Hazard Rate

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    <p>We define and study a new continuous distribution called the exponentiated Weibull Burr XII. Its density function can be expressed as a linear mixture of Burr XII. Its hazard rate is very flexibile in accomodating various shapes including constant, decreasing, increasing, J-shape, unimodal or bathtub shapes. Various of its structural properties are investigated including explicit expressions for the ordinary and incomplete moments, generating function, mean residual life, mean inactivity time and order statistics. We adopted the maximum likelihood method for estimating the model parameters. The flexibility of the new family is illustrated by means of a real data application.</p

    The Use of Talc Powder in Bleaching Cotton Fibers

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    It is known that the use of sodium silicate (Na2 Si2 O3) in bleaching has some disadvantages such as its high cost, harsh handle of the bleached fabric, and the reduction of the tensile strength of the fabric.Talc Powder is used in the bleaching of woven cotton fabrics as a stabilizer for hydrogen peroxide (H2O2) instead of using sodium silicate. Many experiments were carried out using talc powder at variable condi-tions such as temperature and pH. The same experiments were carried out using sodium silicate stabilizer. Several experiments were carried out on fabrics without a stabilizer.The bleached samples were tested for whiteness, absorbence, and tensile strength. The untreated samples were tested for comparison. The results of the tested samples were recorded and analysed using statistical methods.The study proved that very good whiteness and higher absorbence were obtained when using talc powder, besides that the loss in tensile strength is relatively low. Also it was observed that the softness and handle of fabrics were improved

    Task Scheduling Optimization in Cloud Computing by Jaya Algorithm

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    Cloud computing provides resources to its consumers as a service. The cloud computing paradigm offers dynamic services by providing virtualized resources via the internet for enabling applications, and these services are provided by large-scale data centers known as clouds. Cloud computing is entirely reliant on the internet to provide its services to consumers. Cloud computing offers several advantages, including the fact that users only pay for what they use weekly, monthly, or yearly, that anybody with an internet connection may use the cloud, and that there is no need to purchase resources, hardware, or software on their own. This paper proposes an efficient task scheduling algorithm based on the Jaya algorithm for the cloud computing environment. We evaluate the performance of our method by applying it to three instances. The recommended technique produced the optimal solution in makespan, speedup, efficiency, and throughput, according to the findings

    Video Genre Classification Using Weighted Kernel Logistic Regression

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    Due to the widening semantic gap of videos, computational tools to classify these videos into different genre are highly needed to narrow it. Classifying videos accurately demands good representation of video data and an efficient and effective model to carry out the classification task. Kernel Logistic Regression (KLR), kernel version of logistic regression (LR), proves its efficiency as a classifier, which can naturally provide probabilities and extend to multiclass classification problems. In this paper, Weighted Kernel Logistic Regression (WKLR) algorithm is implemented for video genre classification to obtain significant accuracy, and it shows accurate and faster good results
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