648 research outputs found
Pyrolysis of brominated feedstock plastic in a fluidised bed reactor
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
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
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- 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
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: final state
containing two VBF-like tagging jets, missing transverse energy, and zero or
one -tagged jet; and final state consisting of initial state radiation
(ISR) jet, missing transverse energy, and at least one -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 exclusion potential of sbottoms with mass up to GeV for an integrated luminosity of fb at 14 TeV, with
systematics and PU .Comment: 5 pages, 4 figures. Discussions and references updated, reach for
PU=50 case give
Large language models can accurately predict searcher preferences
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
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 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 and of 5-15 GeV,
the significance of observing the signal events is found to be
3-6 for =115-135 GeV, considering an integrated
luminosity of 3000 fb.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
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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