The Gelfand-Kirillov conjecture and Gelfand-Tsetlin modules for finite W-algebras

We address two problems with the structure and representation theory of finite W-algebras associated with general linear Lie algebras. Finite W-algebras can be defined using either Kostant`s Whittaker modules or a quantum Hamiltonian reduction. Our first main result is a proof of the Gelfand-Kirillov conjecture for the skew fields of fractions of finite W-algebras. The second main result is a parameterization of finite families of irreducible Gelfand-Tsetlin modules using Gelfand-Tsetlin subalgebra. As a corollary, we obtain a complete classification of generic irreducible Gelfand-Tsetlin modules for finite W-algebras. (C) 2009 Elsevier Inc. All rights reserved.

First study of the radiation-amplitude zero in W gamma production and limits on anomalous WW gamma couplings at root s=1.96 TeV

We present results from a study of p (p) over bar -> W gamma+X events utilizing data corresponding to 0.7 fb(-1) of integrated luminosity at root s = 1.96 TeV collected by the D0 detector at the Fermilab Tevatron Collider. We set limits on anomalous WW gamma couplings at the 95% C.L. The one-dimensional 95% C.L. limits are 0.49 51 and -0.12 We make the first study of the charge-signed rapidity difference between the lepton and the photon and find it to be indicative of the standard model radiation-amplitude zero in the W gamma system.

Doxorubicin biocompatible O/W microemulsion stabilized by mixed surfactant containing soya phosphatidylcholine

Microemulsions (ME) containing soya phosphatidylcholine (SPC/polyoxyethylenglycerol trihydroxystearate 40 (EU)/sodium oleate (SO) as surfactant cholesterol (CHO) as oil phase and aqueous buffer were studied. Pseudo-ternary phase diagrams of the investigated systems were obtained at constant SPC/EU/SO weight ratio 3.5:3.5:3.0 by titration, in order to characterize the proportions between the components to form clear systems. The dynamic light scattering results showed that the size of the oil droplets decreases significantly with the ratio of surfactant/oil phase added to system. Depending on the composition ME system could exhibit a thixotropic behavior. The apparent viscosity increased 25- and 13-folds with cholesterol concentration for drug-free and drug-load ME, respectively. It was also verified that the octanol/aqueous buffer partition coefficient (K-O/B) of doxorubicin (DOX) was pH dependent increasing abruptly above pH 6.0. It was possible to incorporate 2.24 mg/ml of DOX into ME. The incorporation of DOX in the ME systems increased the droplets size for all surfactant concentrations used in the system. The results suggest that DOX interacts with the microstructure of the ME at the studied pH increasing significantly the drug solubility. It was possible to conclude that the investigated ME can be a very promising vehicle as drug-carrier for administration of doxorubicin. (c) 2006 Elsevier B.V. All rights reserved.

Evaluation of Ir, Ru, and W as permanent modifiers for the simultaneous determination of As, Bi, Pb, Sb, and Se in natural water by electrothermal atomic absorption spectrometry

Iridium-, Ru-, and W-coated platforms were prepared by thermal treatment of the transversely heated graphite atomizer and investigated for the simultaneous determination of As, Bi, Pb, Sb, and Se in tap water by electrothermal atomic absorption spectrometry. The maximum pyrolysis temperature for As and Bi increased in a modifier sequence W < Ru < Ir. For Pb, Sb, and Se, this sequence was W < Ru, It. Calculated characteristic masses in the presence of It, Ru, and W were 35, 33, and 35 pg for As; 63, 51, and 52 pg for Bi; 50, 32, and 34 pg for Pb; 40, 35, and 31 pg for Sb; and 39, 39, and 93 pg for Se, respectively. Ruthenium was elected as the optimum modifier.Repeatability of the measurements was typically < 6%. Recoveries of As, Bi, Pb, Sb, and Se added to tap water samples varied from 79 to 109%. Accuracy was also checked by analysis of five certified reference materials (CRMs) from the National Institute of Standards and Technology (NIST1640 - Trace Elements in Natural Water; NIST 1643d Trace Elements in Water) and High Purity Standards (Trace Metals in Drinking Water Standards, lots #812708, #591107, and #710710). A paired t-test showed that the results for the CRMs were in agreement at the 95% confidence level with the certified values. The graphite tube lifetime was about 650 firings. multi-element determination is particularly challenging due to the necessity of carefully optimizing compromise conditions.Based on the considerations listed above, the aim of this paper was to evaluate the behavior of Ir, Ru, and W as permanent modifiers for the simultaneous determination of As, Bi, Pb, Sb, and Se. The performance of the proposed procedure was also verified after the ETAAS analysis of tap waters and reference materials.

Efeito da densidade de plantas de Panicum maximum Jacq. sobre o crescimento inicial de Eucalyptus grandis W.Hill ex Maiden

In order to verify the effect of Panicum maximum plant density on the initial growth of Eucalyptus grandis plants, one assay was conducted under semi-controlled conditions of soil fertility and humidity. Dark red Latossol, collected from the arable layer, was used as substrate in 50 liters amianthus cement boxes. One seedling of Eucalyptus was planted in each box. Fifteen days later, seedlings of P. maximum were transplanted on the same box. The treatments consisted of 0, 4, 8, 12, 16 and 20 plants of P. maximum per m 2. The experimental design was the complete randomized design, with six treatments and eight replicates for P. maximum. One hundred and ten and 190 days after transplanting, Eucalyptus plants grown among P. maximum showed an average reduction of 30.80 and 46.55% stem diameter, 25.10 and 22.50 plant high, 40.18 and 31.29% stem dry weight, 61.32 and 54.06% branch dry weight, 53.72 and 51.82% root dry weight, 44.62 and 38.50% leaf dry weight, 22.51 and 23.16 branch number, 20.72 and 19.97% leaf number, and 33.88 and 17.05% leaf area, respectively.

First study of the radiation-amplitude zero in W gamma production and limits on anomalous WW gamma couplings at root s=1.96 TeV

We present results from a study of pp̄→Wγ+X events utilizing data corresponding to 0.7fb-1 of integrated luminosity at s=1.96TeV collected by the D0 detector at the Fermilab Tevatron Collider. We set limits on anomalous WWγ couplings at the 95% C.L. The one-dimensional 95% C.L. limits are 0.49<κγ<1.51 and -0.12<λγ<0.13. We make the first study of the charge-signed rapidity difference between the lepton and the photon and find it to be indicative of the standard model radiation-amplitude zero in the Wγ system. © 2008 The American Physical Society.

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at s=7TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0fb-1 of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at s=7TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W'→tb, leading to a final state signature with a single electron or muon, missing transverse energy, and jets, at least one of which is identified as a b-jet. A W' boson that couples to the right-handed (left-handed) chiral projections of the fermions with the same coupling constants as the W is excluded for masses below 1.85 (1.51) TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge couplings for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits. © 2012 CERN.

Preparação, caracterização e aplicação de eletrodos bicomponentes de 'W' / 'WO IND. 3' / 'TIO IND 2' na oxidação fotoeletrocatalítica e fotocatalítica de corantes de cabelos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desinfecção fotoeletrocatalítica de águas contaminadas com Candida Parapsilosis utilizando eletrodos de W/WO3 em tratamento fotoeletrocatalítico

Pós-graduação em Química - IQ

Estudo da resistência à corrosão de ligas Ni-Cr-Mo-Ta E Ni-Cr-Mo-W em solução NaF 0,08 mol/L, pH 4,7 para aplicações odontológicas

A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

Estudo da resistência à corrosão de ligas Ni-Cr-Mo-Ta E Ni-Cr-Mo-W em solução NaF 0,08 mol/L, pH 4,7 para aplicações odontológicas

A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

TUNGSTEN ISOTOPIC COMPOSITIONS IN STARDUST SiC GRAINS FROM THE MURCHISON METEORITE: CONSTRAINTS ON THE s-PROCESS IN THE Hf-Ta-W-Re-Os REGION

We report the first tungsten isotopic measurements in stardust silicon carbide (SiC) grains recovered from the Murchison carbonaceous chondrite. The isotopes (182,183,184,186)Wand (179,180)Hf were measured on both an aggregate (KJB fraction) and single stardust SiC grains (LS+ LU fraction) believed to have condensed in the outflows of low-mass carbon-rich asymptotic giant branch (AGB) stars with close-to-solar metallicity. The SiC aggregate shows small deviations from terrestrial (= solar) composition in the (182)W/(184)Wand (183)W/(184)Wratios, with deficits in (182)W and (183)W with respect to (184)W. The (186)W/(184)W ratio, however, shows no apparent deviation from the solar value. Tungsten isotopic measurements in single mainstream stardust SiC grains revealed lower than solar (182)W/(184)W, (183)W/(184)W, and (186)W/(184)W ratios. We have compared the SiC data with theoretical predictions of the evolution of W isotopic ratios in the envelopes of AGB stars. These ratios are affected by the slow neutron-capture process and match the SiC data regarding their (182)W/(184)W, (183)W/(184)W, and (179)Hf/(180)Hf isotopic compositions, although a small adjustment in the s-process production of (183)W is needed in order to have a better agreement between the SiC data and model predictions. The models cannot explain the (186)W/(184)W ratios observed in the SiC grains, even when the current (185)W neutron-capture cross section is increased by a factor of two. Further study is required to better assess how model uncertainties (e. g., the formation of the (13)C neutron source, the mass-loss law, the modeling of the third dredge-up, and the efficiency of the (22)Ne neutron source) may affect current s-process predictions.

Measurement of W+W- production in pp collisions at √s=7 TeV with the ATLAS detector and limits on anomalous WWZ and WWγ couplings

This paper presents a measurement of the W+W- production cross section in pp collisions at root s = 7 TeV. The leptonic decay channels are analyzed using data corresponding to an integrated luminosity of 4: 6 fb(-1) collected with the ATLAS detector at the Large Hadron Collider. The W+W- production cross section sigma(pp -> W+W- + X) is measured to be 51.9 +/- 2.0(stat) +/- 3.9(syst) +/- 2.0(lumi) pb, compatible with the Standard Model prediction of 44.7(-1.9)(+2.1) pb. A measurement of the normalized fiducial cross section as a function of the leading lepton transverse momentum is also presented. The reconstructed transverse momentum distribution of the leading lepton is used to extract limits on anomalous WWZ and WW gamma couplings.