199 research outputs found
TGA-FTIR study of the vapors released by triethylamine-acetic acid mixtures
Proprietary mixtures of amines and carboxylic acids are used as volatile corrosion inhibitors (VCIs) for
the protection of iron and steel components against atmospheric corrosion. This study was focused on
the nature of the vapors they release. VCI model compounds comprising mixtures of triethylamine and
acetic acid were studied using thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy
(TGAâFTIR) at 50 âŠC. As vaporization progressed, the composition of the remaining liquid and
the emitted vapor converged to a fixed amine content of ca. 27 mol%. This was just above the composition
expected for the 1:3 amine to carboxylic acid complex. Mixtures close to this composition also featured
the lowest volatility.The National Metrology
Institute of South Africa (NMISA), the Institutional Research Development
Programme (IRDP) of the National Research Foundation of
South Africa, and Xyris Technology CC.http://www.elsevier.com/locate/tcaai201
Thermal analysis and FTIR studies of volatile corrosion inhibitor model systems
Model compounds simulating amineâcarboxylic acid-based volatile corrosion inhibitors were characterized
by thermogravimetric analysis and Fourier transform infrared spectroscopy. These systems are usually
employed as equimolar mixtures to protect ferrous metals against atmospheric corrosion. The key
finding of this study was that the vapors released by such equimolar mixtures initially contain almost
free amine only. After prolonged vaporization a steady-state azeotrope-like composition is approached.
It contains excess carboxylic acid and features impaired corrosion inhibition efficiency according to the
Skinner test. In part, this behavior can be attributed to the mismatch in the volatilities of the amine
and carboxylic acid constituents.http://www.elsevier.com/locate/corscihb2013ai201
Transcriptional implications of intragenic DNA methylation in the oestrogen receptor alpha gene in breast cancer cells and tissues
Background DNA methylation variability regions (MVRs) across the oestrogen receptor alpha (ESR1) gene have been identified in peripheral blood cells from breast cancer patients and healthy individuals. In contrast to promoter methylation, gene body methylation may be important in maintaining active transcription. This study aimed to assess MVRs in ESR1 in breast cancer cell lines, tumour biopsies and exfoliated epithelial cells from expressed breast milk (EBM), to determine their significance for ESR1 transcription. Methods DNA methylation levels in eight MVRs across ESR1 were assessed by pyrosequencing bisulphite-converted DNA from three oestrogen receptor (ER)-positive and three ER-negative breast cancer cell lines. DNA methylation and expression were assessed following treatment with DAC (1 ÎŒM), or DMSO (controls). ESR1 methylation levels were also assayed in DNA from 155 invasive ductal carcinoma biopsies provided by the Breast Cancer Campaign Tissue Bank, and validated with DNA methylation profiles from the TCGA breast tumours (nâ=â356 ER-pos, nâ=â109 ER-neg). DNA methylation was profiled in exfoliated breast epithelial cells from EBM using the Illumina 450 K (nâ=â36) and pyrosequencing in a further 53 donor samples. ESR1 mRNA levels were measured by qRT-PCR. Results We show that ER-positive cell lines had unmethylated ESR1 promoter regions and highly methylated intragenic regions (median, 80.45%) while ER-negative cells had methylated promoters and lower intragenic methylation levels (median, 38.62%). DAC treatment increased ESR1 expression in ER-negative cells, but significantly reduced methylation and expression of ESR1 in ER-positive cells. The ESR1 promoter was unmethylated in breast tumour biopsies with high levels of intragenic methylation, independent of ER status. However, ESR1 methylation in the strongly ER-positive EBM DNA samples were very similar to ER-positive tumour cell lines. Conclusion DAC treatment inhibited ESR1 transcription in cells with an unmethylated ESR1 promoter and reduced intragenic DNA methylation. Intragenic methylation levels correlated with ESR1 expression in homogenous cell populations (cell lines and exfoliated primary breast epithelial cells), but not in heterogeneous tumour biopsies, highlighting the significant differences between the in vivo tumour microenvironment and individual homogenous cell types. These findings emphasise the need for care when choosing material for epigenetic research and highlights the presence of aberrant intragenic methylation levels in tumour tissue
Deuteron frozen spin polarized target for nd experiements at the VdG accelerator of Charles University
A frozen spin polarized deuteron target cooled by the 3He/4He dilution
refrigerator is described. Fully deuterated 1,2-propanediol was used as a
target material. Deuteron vector polarization about 40% was obtained for the
target in the shape of a cylinder of 2 cm diameter and 6 cm length. The target
is intended for a study of 3N interactions at the polarized neutron beam
generated by the Van de Graaff accelerator at the Charles University in Prague
Tune in to your emotions: a robust personalized affective music player
The emotional power of music is exploited in a personalized affective music player (AMP) that selects music for mood enhancement. A biosignal approach is used to measure listenersâ personal emotional reactions to their own music as input for affective user models. Regression and kernel density estimation are applied to model the physiological changes the music elicits. Using these models, personalized music selections based on an affective goal state can be made. The AMP was validated in real-world trials over the course of several weeks. Results show that our models can cope with noisy situations and handle large inter-individual differences in the music domain. The AMP augments music listening where its techniques enable automated affect guidance. Our approach provides valuable insights for affective computing and user modeling, for which the AMP is a suitable carrier application
Degradation of insecticides used for indoor spraying in malaria control and possible solutions
BACKGROUND: The insecticide dichloro-diphenyl-trichloroethane (DDT) is widely used in indoor residual spraying
(IRS) for malaria control owing to its longer residual efficacy in the field compared to other World Health
Organization (WHO) alternatives. Suitable stabilization to render these alternative insecticides longer lasting could
provide a less controversial and more acceptable and effective alternative insecticide formulations than DDT.
METHODS: This study sought to investigate the reasons behind the often reported longer lasting behaviour of DDT
by exposing all the WHO approved insecticides to high temperature, high humidity and ultra-violet light.
Interactions between the insecticides and some mineral powders in the presence of an aqueous medium were
also tested. Simple insecticidal paints were made using slurries of these mineral powders whilst some insecticides
were dispersed into a conventional acrylic paint binder. These formulations were then spray painted on neat and
manure coated mud plaques, representative of the material typically used in rural mud houses, at twice the upper
limit of the WHO recommended dosage range. DDT was applied directly onto mud plaques at four times the
WHO recommended concentration and on manure plaques at twice WHO recommended concentration. All
plaques were subjected to accelerated ageing conditions of 40°C and a relative humidity of 90%.
RESULTS: The pyrethroids insecticides outperformed the carbamates and DDT in the accelerated ageing tests. Thus
UV exposure, high temperature oxidation and high humidity per se were ruled out as the main causes of failure of
the alternative insecticides. Gas chromatography (GC) spectrograms showed that phosphogypsum stabilised the
insecticides the most against alkaline degradation (i.e., hydrolysis). Bioassay testing showed that the period of
efficacy of some of these formulations was comparable to that of DDT when sprayed on mud surfaces or cattle
manure coated surfaces.
CONCLUSIONS: Bioassay experiments indicated that incorporating insecticides into a conventional paint binder or
adsorbing them onto phosphogypsum can provide for extended effective life spans that compare favourably with
DDTâs performance under accelerated ageing conditions. Best results were obtained with propoxur in standard
acrylic emulsion paint. Similarly, insecticides adsorbed on phosphogypsum and sprayed on cattle manure coated
surfaces provided superior lifespans compared with DDT sprayed directly on a similar surface.The Bill & Melinda Gates Foundation through the Grand Challenges Exploration Initiative.http://www.malariajournal.com
Degradation of insecticides used for indoor spraying in malaria control and possible solutions
BACKGROUND: The insecticide dichloro-diphenyl-trichloroethane (DDT) is widely used in indoor residual spraying
(IRS) for malaria control owing to its longer residual efficacy in the field compared to other World Health
Organization (WHO) alternatives. Suitable stabilization to render these alternative insecticides longer lasting could
provide a less controversial and more acceptable and effective alternative insecticide formulations than DDT.
METHODS: This study sought to investigate the reasons behind the often reported longer lasting behaviour of DDT
by exposing all the WHO approved insecticides to high temperature, high humidity and ultra-violet light.
Interactions between the insecticides and some mineral powders in the presence of an aqueous medium were
also tested. Simple insecticidal paints were made using slurries of these mineral powders whilst some insecticides
were dispersed into a conventional acrylic paint binder. These formulations were then spray painted on neat and
manure coated mud plaques, representative of the material typically used in rural mud houses, at twice the upper
limit of the WHO recommended dosage range. DDT was applied directly onto mud plaques at four times the
WHO recommended concentration and on manure plaques at twice WHO recommended concentration. All
plaques were subjected to accelerated ageing conditions of 40°C and a relative humidity of 90%.
RESULTS: The pyrethroids insecticides outperformed the carbamates and DDT in the accelerated ageing tests. Thus
UV exposure, high temperature oxidation and high humidity per se were ruled out as the main causes of failure of
the alternative insecticides. Gas chromatography (GC) spectrograms showed that phosphogypsum stabilised the
insecticides the most against alkaline degradation (i.e., hydrolysis). Bioassay testing showed that the period of
efficacy of some of these formulations was comparable to that of DDT when sprayed on mud surfaces or cattle
manure coated surfaces.
CONCLUSIONS: Bioassay experiments indicated that incorporating insecticides into a conventional paint binder or
adsorbing them onto phosphogypsum can provide for extended effective life spans that compare favourably with
DDTâs performance under accelerated ageing conditions. Best results were obtained with propoxur in standard
acrylic emulsion paint. Similarly, insecticides adsorbed on phosphogypsum and sprayed on cattle manure coated
surfaces provided superior lifespans compared with DDT sprayed directly on a similar surface.The Bill & Melinda Gates Foundation through the Grand Challenges Exploration Initiative.http://www.malariajournal.com
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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