4,080 research outputs found
Determination of Chlorinated organic compounds in aqueous matrices
Thirteen pure volatile, semi-volatile and non-volatile chlorinated organic compounds of molecular weights ranging from trichloroethylene (MW = 131.39 g mole -¹) to hexachlorobenzene (MW = 284.78 g mole-¹) were determined in aqueous matrices by GC-ECD. After 10% salt addition, different extraction tests were performed using fibres whose adsorbing phase was based on microsphere carbon particles characterized by a constant size. Five experimental parameters were optimized: extraction temperature and time, position of the fibre in the GC injector port, desorption temperature and time. The optimized analytical protocol was employed to determine the efficiency of a real activated carbon adsorption plant to remove organic chlorinated pollutants from an industrial wastewater at ng l-¹ levels
HIP AND KNEE LOADING OF KARATE PLAYERS PERFORMING TRAINING AND COMPETITION STYLE VERSIONS OF A ROUNDHOUSE KICK
The main purpose of this study was to examine hip and knee joint loading during the performance of the common roundhouse kicking technique in both a training mode and in a competition mode. 15 black belt karate players performed roundhouse kicks in two different ways, basic kick and competition kick. Motion and force data were collected with a VlCON motion analysis system and two Kistler force plates. 3D joint motions and joint moments about the hip and knee of both the support leg and kicking leg for all kicks were calculated. The maximum moments were more varied between kick types for the kicking leg but the joint angles were similar in most cases. Joint loading comparable to the literature was found for joint previously examined but several high joint moments at extremes of motion were found in the supporting leg
Collider Signatures of the N=3 Lee-Wick Standard Model
Inspired by the Lee-Wick higher-derivative approach to quantum field theory,
Grinstein, O'Connell, and Wise have illustrated the utility of introducing into
the Standard Model negative-norm states that cancel quadratic divergences in
loop diagrams, thus posing a potential resolution of the hierarchy problem.
Subsequent work has shown that consistency with electroweak precision
parameters requires many of the partner states to be too massive to be detected
at the LHC. We consider the phenomenology of a yet-higher derivative theory
that exhibits three poles in its bare propagators (hence N=3), whose states
alternate in norm. We examine the interference effects of W boson partners on
LHC scattering cross sections, and find that the N=3 LWSM already makes
verifiable predictions at 10 fb^(-1) of integrated luminosity.Comment: 15 pages, 4 PDF figures. Version accepted for publication by JHE
A search for heavy Kaluza-Klein electroweak gauge bosons at the LHC
The feasibility for the observation of a certain leptonic Kaluza-Klein (KK)
hard process in {\em pp} interactions at the LHC is presented. Within the
TeV extra dimensional theoretical framework with the focus on
the KK excitations of the Standard Model and gauge bosons, the
hard-process, , has
been used where is the initial state parton, the final state lepton and
is the KK excitation of the
boson. For this study the analytic form for the hard process cross
section has been independently calculated by the authors and has been
implemented using the {\sc Moses} framework. The Moses framework itself, that
has been written by the authors, was used as an external process within the
{\sc Pythia} Monte Carlo generator which provides the phase space generation
for the final state leptons and partons from the initial state hadrons, and the
simulation of initial and final state radiation and hadronization. A brief
discussion of the possibility for observing and identifying the unique
signature of the KK signal given the current LHC program is also presented.Comment: 16 pages 10 figures, MCnet number: MCnet/10/06, Accepted by JHE
Laser-Stimulated Fluorescence in Paleontology
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser’s ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.published_or_final_versio
Racialisation, the EU Referendum result and sentiments of belonging in the UK: a consideration of Roma populations
This article reports on a qualitative study with migrant Roma communities in South Yorkshire, UK. The study was undertaken shortly after the 2016 European Union membership referendum in the UK. It finds that while hostility towards the studied Roma population did increase immediately after the resulting Leave vote, their experiences of racialisation can be situated more clearly in how the result engendered a shift in the expressions and understandings of their own place and position, with their particular histories as EU migrants of Roma heritage. In doing so, it adds to the evidence of how racialisation is manifest for such groups within this period. While acknowledging the specificity of these experiences, the article also argues that Roma share some features with the experiences of other EU migrants, also situated in the Leave period of social, cultural and geopolitical uncertainty
Finite top quark mass effects in NNLO Higgs boson production at LHC
We present next-to-next-to-leading order corrections to the inclusive
production of the Higgs bosons at the CERN Large Hadron Collider (LHC)
including finite top quark mass effects. Expanding our analytic results for the
partonic cross section around the soft limit we find agreement with a very
recent publication by Harlander and Ozeren \cite{Harlander:2009mq}.Comment: 15 page
Volatility forecasting in the Chinese commodity futures market with intraday data
Given the unique institutional regulations in the Chinese commodity futures market as well as the characteristics of the data it generates, we utilize contracts with three months to delivery, the most liquid contract series, to systematically explore volatility forecasting for aluminum, copper, fuel oil, and sugar at the daily and three intraday sampling frequencies. We adopt popular volatility models in the literature and assess the forecasts obtained via these models against alternative proxies for the true volatility. Our results suggest that the long memory property is an essential feature in the commodity futures volatility dynamics and that the ARFIMA model consistently produces the best forecasts or forecasts not inferior to the best in statistical terms
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