7,490 research outputs found
top quark properties: prospects at ATLAS
The ATLAS experiment sensitivity, with an expected luminosity of 1 fb^-1, to the study of the top quark properties are presented. The measurements of the top charge, the spin and spin correlations, the SM decay (t -> bW) and rare top decays associated to flavour changing neutral currents (t -> qX, X=gamma,Z,g) are discussed
Further progress in ion back-flow reduction with patterned gaseous hole-multipliers
A new idea on electrostatic deviation and capture of back-drifting
avalanche-ions in cascaded gaseous hole-multipliers is presented. It involves a
flipped reversed-bias Micro-Hole & Strip Plate (F-R-MHSP) element, the strips
of which are facing the drift region of the multiplier. The ions, originating
from successive multiplication stages, are efficiently deviated and captured by
such electrode. Experimental results are provided comparing the ion-blocking
capability of the F-R-MHSP to that of the reversed-bias Micro-Hole & Strip
Plate (R-MHSP) and the Gas Electron Multiplier (GEM). Best ion-blocking results
in cascaded hole-multipliers were reached with a detector having the F-R-MHSP
as the first multiplication element. A three-element F-R-MHSP/GEM/MHSP cascaded
multiplier operated in atmospheric-pressure Ar/CH4 (95/5), at total gain of
~10^{5}, yielded ion back-flow fractions of 3*10^{-4} and 1.5*10^{-4}, at drift
fields of 0.5 and 0.2 kV/cm, respectively. We describe the F-R-MHSP concept and
the relevance of the obtained ion back-flow fractions to various applications;
further ideas are also discussed.Comment: 17 pages, 11 figures, published in JINS
Implantação de um empreendimento agrícola no cerrado no Distrito Federal.
bitstream/item/100433/1/Implantacao-de-um-empreendimento.pd
Sedimentary heterogeneity and petrophysical characterization of Barremian tsunami and barrier island/inlet deposits: The Aliaga outcrop as a reservoir analogue (Galve sub-basin, eastern Spain)
The present study examined two sandstone deposits in the Aliaga outcrop as a reservoir analogue over a distance of 200-m-long and attempted to establish a correlation between sand facies and the petrophysical properties of the sandstones in order to investigate the reservoir heterogeneity. The Aliaga reservoir analogue represents the upper part of Camarillas Fm., deposited during the Barremian synrift phase of the Galve sub-basin (Iberian Basin, Spain). It is characterized by a transitional sedimentary interval from sandy-dominant deposits to carbonate-dominant deposits, which were deposited under the same palaeoenvironmental conditions (in relation to systems of back-barrier sedimentation).
The description of the Aliaga outcrop provided here consists of lithological descriptions of two sandstone deposits: a tsunami and a barrier island/inlet, at both mesoscopic (decimetres to tens of metres) and microscopic scales (millimetres to centimetres). Both deposits recognized at the basin scale were described in terms of sand grain size, sand sorting and cementation; further cores were drilled along outcrop to collect samples for porosity and permeability measurements.
Both sandstone reservoirs are the result of different sedimentary processes that determined facies characteristics, as the different petrophysical properties observed in these deposits. Consequently, the sedimentary process controls the heterogeneity of the sandstones facies and thus, the sand heterogeneity controls the distribution of the petrophysical properties. The classification of sand facies in terms of sand sorting seems to be more appropriate for describing sand heterogeneity; accordingly, petrophysical parameters in both deposits were also influenced by sand sorting.
The sand facies and petrophysics heterogeneity of the described deposits can be hierarchically ordered. First-order heterogeneity is related to the basin scale, second-order heterogeneity is related to genesis and the conditions of sediment deposition, and third-order heterogeneity is related to synsedimentary faults and/or post-sedimentation events.This research is a contribution to the project: Análisis de Cuencas Sedimentarias Continentales, of the Gobierno de Aragón, the Análisis de Cuencas Sedimentarias Group of the UCM-CAM, and the projects CGL2011-23717 (Ministerio de Ciencia e Innovación of the Spanish Government and FEDER) and UZ2015-CIE-10 (University of Zaragoza). Additional financial support was provided by a Cnpq (Conselho Nacional de Pesquisa e Desenvolvimento Tecnologico, Brasil) Research Grant (200147/2011-0) and an IAS Schema 1st session 2014 Postgraduate Grant to F. Veloso.Peer reviewe
Single or Combined Maquet III Osteotomy: Long Term Results
INTRODUCTION: In 1963, based on biomechanics studies, Maquet proposed the advancement of the patellar tendon insertion as a mean of treating patellofemoral pain. The rationale for this procedure was a reduction in the patellofemoral compression force vector by changing the angular relationship between patella tendon and quadriceps tendon. One of the additional procedures, on a malalign knee, was performing a cupuliform osteotomy above the tibial tuberosity (COATT). OBJECTIVES: Evaluating, on a retrospective and comparative trial, the clinical and radiological long-term outcomes of the patients who underwent a single (M) or combined (MC) Maquet III osteotomy, in order to determine if this surgery as or not fulfilled its initially objectives. METHODS: All surgical records of the Service, between 1970 and 1991, were reviewed. We identify 116 cases registered as “M” or “MC” Maquet III osteotomy. A questionnaire as been prepared for collecting data. We evaluated the preoperative complaints, postoperative complications and range of motion recovery time, as well as the postoperative pain absence period. All patients underwent an objective assessment by the Visual Analog Scale (VAS) and the Kujala Patellofemoral Scoring System (KPFSS). A radiological assessment was also made in order to evaluate the arthrosis degree and compartment affected, the Bicondylo-Patellar Angle (BPA) and the Caton-Deschamps Index (CDI). Mann-Whitney, t-Student and Chi-Square tests were applied for statistical evaluation. p <0.05 was considered statistically significant. RESULTS: According to the study criteria, from the 116 selected patients we could review in our clinics 49 Maquet III osteotomies (n= 25 “M” group vs n=24 “MC” group) . On the “M” group, the average age at surgery was 37.6 ±12.0 years and the postoperative follow-up 27.1 ±3.15 years, versus 56,5 ±6,8 years at surgery and a 23,2 ±3,4 postoperative follow up years on the “MC” group. Prior range of motion was accomplished 4.8 ±3.5 months after surgery on the “M” group versus 6,7 ±3,5 months on the “MC” group (p=0,017). About complications, on the “M” group we have 16,0% (n=4) versus 16,6% (n=4) (p=0,763). The “M” group presented40% (n=10) patients who haven’t referred pain until nowadays versus 38,5% (n=5) (p=0,85), and the average period of of pain absence was 20.5 ±5.7 years on the “M” group versus 11,0 ±1,7 (p=0,001). At the COX score, 58,3% (n=14) of the “M” group had good to excellent outcomes versus 53,8% (n=7) (p=0,793). VAS at rest was 1.7 ±0.7, in activity 4.4±3.0 and KPFSS 61.9 ±22.3 points on the “M” group versus 1,1 ±0,3 (p=0,016), 4,3 ±2,0 (p=0,883) and 54,7 ± 16,9 (p=0,364) points on the “MC” group. Radiologically, BPA was 6.3 ±3.9° and CDI 0.9 ±0.1 on the “M” group versus 11,8 ±3,9 (p=0,000) and 0,9 ±0,2 (p=0,99) on the “MC” group. Nowadays, at the“M” group,58,3% (n=14) had a grade I/II of Kellgren&Lawrence at patellofemoral joint and 79,2.% (n=19) at the femorotibial joint versus 53,8% (n=7) (p=0,793) and 46,2% (n=6) (p=0,041). CONCLUSION: With a cut off follow-up period higher than 20 years, the Maquet III group presented58,3% of good to excellent outcomes with patients presenting a majority of low grade osteoarthritic knee. The COATT procedure hasn’t increased the postoperative complications nor worsen the funcional outcomes. On the other side, the femorotibial grade of arthritis was higher on this group
Contribuições da gestão de recursos humanos para a criatividade e inovação organizacional
Inovar é, hoje, um imperativo para as organizações. Desse modo, é importante promover a criatividade dos colaboradores e apoiar o processo que a transforma em inovação. O objetivo desta pesquisa foi compreender como a Gestão de Recursos Humanos (GRH) pode promover um ambiente de trabalho propício à criatividade, na perspectiva dos colaboradores. Para isso, realizou-se um estudo de caso exploratório em uma empresa portuguesa de médio porte da área das Tecnologias de Informação (TI). Recorreu-se a diferentes fontes de análise, como observação participante, documentos organizacionais e entrevistas. Os dados resultantes dessas fontes foram analisados e organizados com ajuda da template analysis. Os resultados revelaram que, para as chefias e colaborador entrevistados, a criatividade na organização pode ser promovida por meio da existência de suporte para as novas ideias, tolerância ao erro, autonomia, liberdade para que os colaboradores exerçam suas funções e debates para a partilha de ideias. A GRH pode criar condições, por meio das suas práticas (p. ex., formação, avaliação de desempenho, recrutamento e seleção), para a promoção da criatividade e inovação organizacional.Innovation is a key factor to organizations’ competitiveness. To achieve that, it is important to promote creativity among employees and support the transformational process from creativity to innovation. The main objective of this research was to understand how Human Resource Management (HRM) can promote a work environment favorable to creativity, from the perspective of the employees. A case study was carried out on a medium-sized Portuguese information technology (IT) enterprise. Various research techniques were used to collect data, including observation, document analysis, and interviews. Data were organized and analyzed using a template analysis. The results revealed that, for the respondents (managers and employee), creativity within the organization can be promoted by the existence of support for new ideas, error tolerance, autonomy, freedom for employees to perform their tasks, and discussions to share ideas. HRM can create conditions, through their practices (e.g., training, performance evaluation, recruitment, and selection), to promote organizational creativity and innovation
Evaluation of the effect of complementary pollination on Actinidia deliciosa 'Hayward' in northwest Portugal
The objective of this research was to study the effect of complementary pollination on kiwifruit production and quality. For 3 years, complementary application of wet or dry pollen have been done at different stages of flower opening on vines in the Portuguese regions of Entre-Douro e Minho and Beira Litoral. Commercial production data were collected and fruit quality attributes were measured at harvest. Complementary pollination did not affect fruit soluble solids content or firmness in any year, and was beneficial for fruit size and commercial production in the third year only, showing that it is important in some conditions, when natural pollination is inadequate
Simulation of VUV electroluminescence in micropattern gaseous detectors: the case of GEM and MHSP
Electroluminescence produced during avalanche development in gaseous
avalanche detectors is an useful information for triggering, calorimetry and
tracking in gaseous detectors. Noble gases present high electroluminescence
yields, emitting mainly in the VUV region. The photons can provide signal
readout if appropriate photosensors are used. Micropattern gaseous detectors
are good candidates for signal amplification in high background and/or low rate
experiments due to their high electroluminescence yields and radiopurity. In
this work, the VUV light responses of the Gas Electron Multiplier and of the
Micro-Hole Strip Plate, working with pure xenon, are simulated and studied in
detail using a new and versatile C++ toolkit. It is shown that the solid angle
subtended by a photosensor placed below the microstructures depends on the
operating conditions. The obtained absolute EL yields, determined for different
gas pressures and as functions of the applied voltage, are compared with those
determined experimentally.Comment: Accepted for publication in Journal of Instrumentatio
A dynamic method for charging-up calculations: the case of GEM
The simulation of Micro Pattern Gaseous Detectors (MPGDs) signal response is
an important and powerful tool for the design and optimization of such
detectors. However, several attempts to simulate exactly the effective charge
gain have not been completely successful. Namely, the gain stability over time
has not been fully understood. Charging-up of the insulator surfaces have been
pointed as one of the responsible for the difference between experimental and
Monte Carlo results. This work describes two iterative methods to simulate the
charging-up in one MPGD device, the Gas Electron Multiplier (GEM). The first
method uses a constant step for avalanches time evolution, very detailed, but
slower to compute. The second method uses a dynamic step that improves the
computing time. Good agreement between both methods was reached. Despite of
comparison with experimental results shows that charging-up plays an important
role in detectors operation, should not be the only responsible for the
difference between simulated and measured effective gain, but explains the time
evolution in the effective gain.Comment: Minor changes in grammatical statements and inclusion of some
important information about experimental setup at section "Comparison with
experimental results
Fatores de Risco para o Desenvolvimento de Síndrome Pós-Quimioembolização após Quimioembolização Hepática para Tratamento de Hepatocarcinoma
Introduction: Hepatic transarterial chemoembolization is a widely used technique for the treatment of hepatocellular carcinoma. The most common complication of this procedure is postembolization syndrome. The main objective of this study was to assess risk factors for the development of postembolization syndrome.
Material and Methods: Single-centre retrospective analysis of 563 hepatic transarterial chemoembolization procedures from January 1st, 2014 – December 31st, 2015. Hepatic transarterial chemoembolization was performed with ½ - 2 vials of 100 - 300 μm microspheres loaded with doxorubicin. Patients who experienced postembolization syndrome were identified based on prolongation of hospitalization due to pain, fever, nausea and/or vomiting. A control group with the patients who did not have postembolization syndrome was randomly created (three controls for one case). Descriptive analysis and multivariate logistic regression were performed.
Results: The overall prevalence of postembolization syndrome was 6.2%. Hepatic transarterial chemoembolization with doxorubicin dosage above 75 mg (more than one vial), the size of the largest nodule and female gender had statistically significant relation with development of postembolization syndrome (p = 0.030, p = 0.046 and p = 0.037, respectively).
Discussion: Doxorrubicin dosage above 75 mg is associated with a higher risk of postembolization syndrome. This result can be helpful for decision-making in clinical practice, whenever it is possible to avoid a higher dose without compromising the efficacy of the treatment. The size of the largest nodule and female gender also constitute risk factors for postembolization syndrome. The other variables studied were not related to the development of postembolization syndrome.
Conclusion: The dose of doxorrubicin, the size of the largest nodule treated and female gender are potential risk factors for the development of postembolization syndrome after hepatic transarterial chemoembolization for hepatocellular carcinoma.info:eu-repo/semantics/publishedVersio
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