648 research outputs found

    Pyrolysis of brominated feedstock plastic in a fluidised bed reactor

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    Fire retarded high impact polystyrene has been pyrolysed using a fluidised bed reactor with a sand bed. The yield and composition of the products have been investigated in relation to fluidised bed temperature. The bromine distribution between the products and a detailed analysis of the oils using GC-FID/ECD, GC-MS, FT-ir, and size exclusion chromatography has been carried out. It was found that the majority of the bromine transfers to the pyrolysis oil and the antimony was detected in both the oil and the char. Oil made up over 89.9% of the pyrolysis products. Over 30% of the oil consisted of benzene, toluene, ethylbenzene, styrene and cumene. The pyrolysis gases were mainly hydrocarbons in the C1-C4 range but some HBr and Br2 was detected

    Cosmology and Dark Matter at the LHC

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    We examine the question of whether neutralinos produced at the LHC can be shown to be the particles making up the astronomically observed dark matter. If the WIMP alllowed region lies in the SUGRA coannihilation region, then a strong signal for this would be the unexpected near degeneracy of the stau and neutralino i.e., a mass difference \Delta M\simeq (5-15) GeV. For the mSUGRA model we show such a small mass difference can be measured at the LHC using the signal 3\tau+jet+E_T^{\rm miss}. Two observables, opposite sign minus like sign pairs and the peak of the \tau\tau mass distribution allows the simultaneous determination of \Delta M to 15% and the gluino mass M_{\tilde g} to be 6% at the benchmark point of M_{\tilde g}=850 GeV, A_0=0, \mu>0 with 30 fb^{-1}. With 10 fb^{-1}, \Delta M can be determined to 22% and one can probe the parameter space up to m_{1/2}=700 GeV with 100 fb^{-1}.Comment: 11 pages, 7 figures, Talk at IDM 2006, 11th September to 16th September, Greec

    Probing Compressed Top Squarks at the LHC at 14 TeV

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    A feasibility study is presented for the search of the lightest top squark in a compressed scenario, where its mass is approximately equal to the sum of the masses of the top quark and the lightest neutralino. The study is performed in the final state of two b-jets, one lepton, large missing energy, and two high-ETE_{\rm T} jets with large separation in pseudo-rapidity, in opposite hemispheres, and with large dijet mass. The LHC could discover compressed top squarks with mass up to approximately 340 GeV (390 GeV) with an integrated luminosity of 1000 ifb (3000 ifb).Comment: Version updated with major changes: (a) 3-body stop decay (to b+W+n1) analyzed for first time (b) systematics calculation and discussion significantly upgraded (c) new kinematic and mass reach plots for the 3-body decay scenario added (d) discussions clarified throughou

    Probing Compressed Bottom Squarks with Boosted Jets and Shape Analysis

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    A feasibility study is presented for the search of the lightest bottom squark (sbottom) in a compressed scenario, where its mass difference from the lightest neutralino is 5 GeV. Two separate studies are performed: (1)(1) final state containing two VBF-like tagging jets, missing transverse energy, and zero or one bb-tagged jet; and (2)(2) final state consisting of initial state radiation (ISR) jet, missing transverse energy, and at least one bb-tagged jet. An analysis of the shape of the missing transverse energy distribution for signal and background is performed in each case, leading to significant improvement over a cut and count analysis, especially after incorporating the consideration of systematics and pileup. The shape analysis in the VBF-like tagging jet study leads to a 3σ3\sigma exclusion potential of sbottoms with mass up to 530 (462)530 \, (462) GeV for an integrated luminosity of 300300 fb−1^{-1} at 14 TeV, with 5%5\% systematics and PU =0 (50)= 0 \, (50).Comment: 5 pages, 4 figures. Discussions and references updated, reach for PU=50 case give

    Large language models can accurately predict searcher preferences

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    Relevance labels, which indicate whether a search result is valuable to a searcher, are key to evaluating and optimising search systems. The best way to capture the true preferences of users is to ask them for their careful feedback on which results would be useful, but this approach does not scale to produce a large number of labels. Getting relevance labels at scale is usually done with third-party labellers, who judge on behalf of the user, but there is a risk of low-quality data if the labeller doesn't understand user needs. To improve quality, one standard approach is to study real users through interviews, user studies and direct feedback, find areas where labels are systematically disagreeing with users, then educate labellers about user needs through judging guidelines, training and monitoring. This paper introduces an alternate approach for improving label quality. It takes careful feedback from real users, which by definition is the highest-quality first-party gold data that can be derived, and develops an large language model prompt that agrees with that data. We present ideas and observations from deploying language models for large-scale relevance labelling at Bing, and illustrate with data from TREC. We have found large language models can be effective, with accuracy as good as human labellers and similar capability to pick the hardest queries, best runs, and best groups. Systematic changes to the prompts make a difference in accuracy, but so too do simple paraphrases. To measure agreement with real searchers needs high-quality ``gold'' labels, but with these we find that models produce better labels than third-party workers, for a fraction of the cost, and these labels let us train notably better rankers

    Probing Compressed Sleptons at the LHC using Vector Boson Fusion Processes

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    The vector boson fusion (VBF) topology at the Large Hadron Collider at 14 TeV provides an opportunity to search for new physics. A feasibility study for the search of sleptons in a compressed mass spectra scenario is presented in the final state of two jets, one or two low pTp_{T} non-resonant leptons, and missing energy. The presence of the VBF tagged jets and missing energy are effective in reducing Standard Model backgrounds. Using smuon production with a mass difference between l~L\tilde{l}_{L} and χ~10\tilde{\chi}_{1}^0 of 5-15 GeV, the significance of observing the signal events is found to be ∼\sim 3-6σ\sigma for ml~m_{\tilde{l}}=115-135 GeV, considering an integrated luminosity of 3000 fb−1^{-1}.Comment: 6 pages, 1 figure, 3 tables; v3: Journal matched versio

    Prevalence of gestational diabetes mellitus and its feto-maternal outcome in Kamla Nehru state hospital for mother and child, IGMC, Shimla, India

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    Background: Gestational Diabetes Mellitus (GDM) is defined as carbohydrate intolerance of variable severity with the onset or first recognition during pregnancy. It is a disease entity that adversely affects maternal as well as fetal outcome. DIPSI guideline having suggested one-time plasma glucose level has emerged as a simple, practical and cheap method to detect GDM. This study was done to evaluate the prevalence of gestational diabetes using Diabetes in Pregnancy Study Group India (DIPSI) criteria and further assess its feto maternal outcome in Kamla Nehru State Hospital for Mother and Child, IGMC, Shimla.Methods: This study was conducted in 500 patients between 24 and 28 weeks of gestation, attending the antenatal OPD. These patients were given 75g oral glucose irrespective of last meal and their plasma glucose was estimated at 2h. Patients with plasma glucose ≥140mg/dl were diagnosed as GDM and the rest as control or the non GDM group. The GDM patients were followed up and treated with medical nutrition therapy (MNT) and/or insulin therapy till delivery and maternal and fetal outcomes were then noted.Results: The prevalence of GDM in this study was 6%. Maternal and fetal complications were more in the GDM patients. Vaginal candidiasis and PROM were the common maternal complications, while hypoglycemia and hyperbilirubinemia were common in the fetuses.Conclusions: GDM adversely affects the mother as well as fetus. DIPSI guideline having suggested a single plasma glucose level test has emerged as a practical and economical method to detect GDM
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