297 research outputs found

    ENERGY POTENTIAL OF SPECIES FROM FOREST MANAGEMENT PLAN FOR THE RIO GRANDE DO NORTE STATE

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    The objective was to evaluate the energy potential of woods of species under forest management plan from Serid\uf3 region in the Rio Grande do Norte state. It was used the wood species Jurema Preta, Pereiro, Marmeleiro, Catingueira, Moror\uf3, Imburana, Jurema Branca and Mofumbo, at 20 years old, originated from the Dominga's farm in the Caic\uf3/RN municipality. The density, the content of volatiles, the ash and fixed carbon, calorific value, elemental composition and carbon/nitrogen (C/N) and carbon/ hydrogen (C/H) analysis were carried out in the wood. Additionally, the amount of energy produced in kW.h.m-3 and kW.h.ha-1 for all species was estimated. The experiment was conducted in a completely randomized design with eight treatments (species), four replicates (sample trees), adding up to 32 sampling units. There were significant differences, at 5 % significance between treatments for all variables, except for hydrogen percentage and C/H ratio. It was concluded that Moror\uf3's wood shows high energy potential, and along with Jurema Preta, presents higher energy generation per m3, and provides greater economy for the same productivity. The energy potential Jurema Preta wood's stands out among the species. Pereiro's wood stands for energy production per hectare. Marmeleiro and Jurema Branca's woods are indicated as direct burning potential and Imburana's wood is not recommended for power generation.O objetivo do trabalho foi avaliar o potencial energ\ue9tico das madeiras de esp\ue9cies sob plano de manejo florestal provenientes da regi\ue3o do Serid\uf3, no estado do Rio Grande do Norte. Utilizou-se na pesquisa, madeiras das esp\ue9cies Jurema-preta, Pereiro, Marmeleiro, Catingueira, Moror\uf3, Imburana, Jurema-branca e Mofumbo, aos 20 anos de idade, originadas da fazenda Dominga no munic\uedpio de Caic\uf3/RN. Foram realizadas na madeira, as an\ue1lises da densidade b\ue1sica, teores de materiais vol\ue1teis, cinzas e carbono fixo, poder calor\uedfico superior, composi\ue7\ue3o qu\uedmica elementar e rela\ue7\uf5es carbono/nitrog\ueanio (C/N) e carbono/ hidrog\ueanio (C/H). Adicionalmente, estimou-se a quantidade de energia produzida em kW.h.m-3 e em kW.h.ha-1 para todas as esp\ue9cies. O experimento foi realizado segundo um delineamento inteiramente casualizado com oito tratamentos (esp\ue9cies), quatro repeti\ue7\uf5es (\ue1rvores\u2013amostra), totalizando 32 unidades amostrais. Houve diferen\ue7a significativa, a 5 % de signific\ue2ncia, entre os tratamentos para todas as vari\ue1veis analisadas, exceto para a porcentagem de hidrog\ueanio e rela\ue7\ue3o C/H. Conclui-se que a madeira de Moror\uf3 apresenta alto potencial energ\ue9tico, e juntamente com a Jurema-preta, maior gera\ue7\ue3o de energia por m3, al\ue9m de proporcionar maior economia para uma mesma produtividade. O potencial energ\ue9tico da madeira de Jurema-preta se destaca entre as esp\ue9cies estudadas. A madeira de Pereiro se destaca na produ\ue7\ue3o de energia por hectare. As madeiras de Jurema-branca e Marmeleiro s\ue3o indicadas como potenciais para queima direta. A madeira de Imburana n\ue3o \ue9 recomendada para a gera\ue7\ue3o de energia

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

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    The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

    Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    The azimuthal anisotropy of charged particles in PbPb collisions at nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS detector at the LHC over an extended transverse momentum (pt) range up to approximately 60 GeV. The data cover both the low-pt region associated with hydrodynamic flow phenomena and the high-pt region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with pt, reaching a maximum around pt = 3 GeV, and then to gradually decrease to almost zero, with the decline persisting up to at least pt = 40 GeV over the full centrality range measured.Comment: Replaced with published version. Added journal reference and DO

    Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

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    A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter

    Measurement of jet fragmentation into charged particles in pp and PbPb collisions at sqrt(s[NN]) = 2.76 TeV

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    Jet fragmentation in pp and PbPb collisions at a centre-of-mass energy of 2.76 TeV per nucleon pair was studied using data collected with the CMS detector at the LHC. Fragmentation functions are constructed using charged-particle tracks with transverse momenta pt > 4 GeV for dijet events with a leading jet of pt > 100 GeV. The fragmentation functions in PbPb events are compared to those in pp data as a function of collision centrality, as well as dijet-pt imbalance. Special emphasis is placed on the most central PbPb events including dijets with unbalanced momentum, indicative of energy loss of the hard scattered parent partons. The fragmentation patterns for both the leading and subleading jets in PbPb collisions agree with those seen in pp data at 2.76 TeV. The results provide evidence that, despite the large parton energy loss observed in PbPb collisions, the partition of the remaining momentum within the jet cone into high-pt particles is not strongly modified in comparison to that observed for jets in vacuum.Comment: Submitted to the Journal of High Energy Physic

    Lymph vascular invasion in invasive mammary carcinomas identified by the endothelial lymphatic marker D2-40 is associated with other indicators of poor prognosis

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    <p>Abstract</p> <p>Background</p> <p>Immunohistochemical studies of lymphatic vessels have been limited by a lack of specific markers. Recently, the novel D2-40 antibody, which selectively marks endothelium of lymphatic vessels, was released. The aim of our study is to compare lymphatic and blood vessel invasion detected by hematoxylin and eosin (H&E) versus that detected by immunohistochemistry, relating them with morphologic and molecular prognostic factors.</p> <p>Methods</p> <p>We selected 123 cases of invasive mammary carcinomas stratified into three subgroups according to axillary lymph node status: macrometastases, micrometastases, and lymph node negative. Lymphatic (LVI) and blood (BVI) vessel invasion were evaluated by H&E and immunohistochemistry using the D2-40 and CD31 antibodies, and related to histologic tumor type and grade, estrogen and progesterone receptors, E-cadherin, Ki67, p53, and Her2/<it>neu </it>expression.</p> <p>Results</p> <p>LVI was detected in H&E-stained sections in 17/123 cases (13.8%), and in D2-40 sections in 35/123 cases (28.5%) (Kappa = 0.433). BVI was detected in H&E-stained sections in 5/123 cases (4.1%), and in CD31 stained sections in 19/123 cases (15.4%) (Kappa = 0.198). LVI is positively related to higher histologic grade (p = 0.013), higher Ki67 expression (p = 0.00013), and to the presence of macrometastases (p = 0.002), and inversely related to estrogen (p = 0.0016) and progesterone (p = 0.00017) receptors expression.</p> <p>Conclusion</p> <p>D2-40 is a reliable marker of lymphatic vessels and is a useful tool for lymphatic emboli identification in immunostained sections of breast carcinomas with higher identification rates than H&E. Lymphatic vessel invasion was related to other features (high combined histologic grade, high Ki67 score, negative hormone receptors expression) associated with worse prognosis, probable reflecting a potential for lymphatic metastatic spread and aggressive behavior.</p
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