1,637 research outputs found
O PLANO DE CAPACITAÇÃO DE UMA UNIVERSIDADE FEDERAL JUNTO A SEUS SERVIDORES
No contexto da gestão do conhecimento, levando-se em consideração a sua criação e o seu compartilhamento, citam-se as universidades, as quais têm sido reconhecidas como as avenidas para o ensino e a consequente aprendizagem, a pesquisa e a descoberta, bem como provedores de serviços à sociedade via aplicação do conhecimento. O presente trabalho objetivou a análise da influência da criação e do compartilhamento do conhecimento na aprendizagem, por meio do plano de capacitação de uma universidade federal, junto aos seus servidores. A abordagem utilizada foi a quantitativa, sendo a pesquisa descritiva. Foram coletados dados primários e secundários em um universo de 1732 servidores que realizaram algum curso de capacitação entre 2011/1 e 2011/2. Entre os participantes da pesquisa conseguiu-se o retorno de 233 questionários. Desta forma, foi possível obter resposta ao questionamento elaborado, cujo tema central foi responder qual a influência da criação e do compartilhamento do conhecimento na aprendizagem por meio do plano de capacitação de uma universidade federal no sul do país. Verificou-se ainda por intermédio dos pontos levantados que a capacitação da referida universidade federal utiliza em seus cursos de aprimoramento meios de geração e compartilhamento do conhecimento como forma de ampliar a aprendizagem, como pode ser constatado quando 51% dos entrevistados concordam parcialmente e 23% concordam totalmente que os cursos de capacitação permitem a criação de laços sociais (amizade) entre os seus participantes. Observou-se que 45% concordam parcialmente e 41% concordam totalmente que trabalhar em grupo ajuda a maior obtenção de conhecimento. Quanto ao quesito de comentar com outros servidores sobre as satisfações/frustrações a respeito dos cursos de capacitação, os percentuais 39% e 36% respectivamente para os indicadores de concorda parcialmente e totalmente. Finalizando, constatou-se que 51% concordam parcialmente que os cursos de capacitação, na forma como são ministrados, geram desenvolvimento de confiança mútua entre os participantes
Rapid thermally annealed plasma deposited SiNx : H thin films: Application to metal-insulator-semiconductor structures with Si, In0.53Ga0.47As, and InP
We present in this article a comprehensive study of rapid thermal annealing (RTA) effects on the physical properties of SiNx:H thin films deposited by the electron cyclotron resonance plasma method. Films of different as-deposited compositions (defined in this article as the nitrogen to silicon ratio, x=N/Si) were analyzed: from Si-rich (x=0.97) to N-rich (x=1.6) films. The evolution of the composition, bonding configuration, and paramagnetic defects with the annealing temperature are explained by means of different network bond reactions that take place depending on the as-deposited film composition. All the analyzed films release hydrogen, while Si-rich and near-stoichiometric (x=1.43) ones also lose nitrogen upon annealing. These films were used to make Al/SiNx:H/semiconductor devices with Si, In0.53Ga0.47As, and InP. After RTA treatments, the electrical properties of the three different SiNx:H/semiconductor interfaces can be explained, noting the microstructural modifications that SiNx:H experiences upon annealing
Optical and structural properties of SiOxNyHz films deposited by electron cyclotron resonance and their correlation with composition
SiOxNyHz films were deposited from O-2, N-2, and SiH4 gas mixtures at room temperature using the electron cyclotron resonance plasma method. The absolute concentrations of all the species present in the films (Si, O, N, and H) were measured with high precision by heavy-ion elastic recoil detection analysis. The composition of the films was controlled over the whole composition range by adjusting the precursor-gases flow ratio during deposition. The relative incorporation of O and N is determined by the ratio Q = phi(O-2)/(phi(SiH4) and the relative content of Si is determined by R =[phi(O-2)+phi(N-2)]/phi(SiH4) where phi(SiH4), phi(O-2), and phi(N-2) are the SiH4, O-2, and N-2 gas flows, respectively. The optical properties (infrared absorption and refractive index) and the density of paramagnetic defects were analyzed in dependence on the film composition. Single-phase homogeneous films were obtained at low SiH4 partial pressure during deposition; while those samples deposited at high SiH4 partial pressure show evidence of separation of two phases. The refractive index was controlled over the whole range between silicon nitride and silicon oxide, with values slightly lower than in stoichiometric films due to the incorporation of H, which results in a lower density of the films. The most important paramagnetic defects detected in the films were the K center and the E' center. Defects related to N were also detected in some samples. The total density of defects in SiOxNyHz films was higher than in SiO2 and lower than in silicon nitride films
Thermally induced modifications on bonding configuration and density of defects of plasma deposited SiOx : H films
The bonding configuration, hydrogen evolution, and defect content of rapid thermally annealed (RTA) SiOx:H films of different compositions were studied. Infrared absorption measurements showed that all the hydrogen present in the films is lost at annealing temperatures below 600 degreesC without any change in the oxygen to silicon ratio of the films. The activation energy of the hydrogen release is in the 0.21-0.41 eV range independently of film composition, suggesting that the process occurs via network bond reactions. For annealing temperatures higher than 700 degreesC, a change in the Si-O-Si stretching wave number from the initial unannealed value to the 1070-1080 cm(-1) range was promoted, independently of the initial film composition. Electron spin resonance measurements showed that all the films contain two type of bulk paramagnetic defects: the E-' center (.Si=O-3) and the silicon dangling bond center (.Si=Si-3). The RTA process promotes a general decrease of defect concentration for annealing temperatures below 400 degreesC. At higher temperatures, E' center disappears, and the .Si=Si-3 center increases its concentration up to the 10(17)-10(18) cm(-3) range. This suggests that the RTA at higher temperatures promotes the formation of a high-quality, almost defect-free, SiO2 matrix in which highly defective Si nanocrystals are also formed, where the .Si=Si-3 centers are located
Microstructural modifications induced by rapid thermal annealing in plasma deposited SiOxNyHz films
The effect of rapid thermal annealing (RTA) processes on the structural properties of SiOxNyHz films was investigated. The samples were deposited by the electron cyclotron resonance plasma method, using SiH4, O-2 and N-2 as precursor gases. For SiOxNyHz films with composition close to that of SiO2, which have a very low H content, RTA induces thermal relaxation of the lattice and improvement of the structural order. For films of intermediate composition and of compositions close to SiNyHz, the main effect of RTA is the release of H at high temperatures (T>700degreesC). This H release is more significant in films containing both Si-H and N-H bonds, due to cooperative reactions between both kinds of bonds. In these films the degradation of structural order associated to H release prevails over thermal relaxation, while in those films with only N-H bonds, thermal relaxation predominates. For annealing temperatures in the 500-700degreesC range, the passivation of dangling bonds by the nonbonded H in the films and the transition from the paramagnetic state to the diamagnetic state of the K center result in a decrease of the density of paramagnetic defects. The H release observed at high annealing temperatures is accompanied by an increase of density of paramagnetic defects
Effect of lubricant on mechanical and rheological properties of compatibilized PP/sawdust composites
AbstractAn investigation was performed regarding the effect of compatibilizer and lubricant concentrations on the mechanical and rheological properties of polypropylene/sawdust composites using two-level factorial central composite design. Maleic anhydride grafted PP (PP-g-MA) was used as compatibilizer and the lubricant used was Struktol TPW 113. Composites without these additives were also prepared. Processing was carried out in a co-rotating twin-screw extruder coupled to a Haake rheometer. Mechanical properties were assessed from tensile tests and rheological properties were evaluated by oscillatory measurements and melt flow index (MFI) test. Tensile strength improved with increasing compatibilizer concentration in the composites and reached a maximum value in the absence of lubricant. When both additives were present tensile strength decreased, suggesting a possible interaction between lubricant and compatibilizer, reducing efficiency of the latter. The general trend observed for rheological results was a decrease in complex viscosity, storage modulus and MFI when both additives were present
A Day-4 Lille Model Predicts Response to Corticosteroids and Mortality in Severe Alcoholic Hepatitis
OBJECTIVES: Prednisolone therapy increases the risk of infections in patients with severe alcoholic hepatitis (SAH). We evaluated whether the use of the Lille Model at day 4 (LM4) is useful to predict response to prednisolone compared with the classic day 7 (LM7) in order to limit a futile exposure to corticosteroids.
METHODS: We performed a retrospective analysis of a large multinational cohort of patients with SAH with Maddrey's discriminant function (DF) ≥32. Response to corticosteroids was assessed with LM4 and LM7, according to the validated cutoff value (CUV>0.45). Receiver operating characteristics (ROC) curves were constructed to determine the optimal CUV for LM4 and to compare accuracy between LM4, LM7, MELD (Model for End-Stage Liver Disease), and ABIC (age, bilirubin, international normalized ratio, and creatinine). Logistic regression models were constructed to predict 28- and 90-day mortality. Cox regression analysis was performed to assess long-term survival.
RESULTS: A total of 163 (62.7%) out of 260 patients received corticosteroids. The median DF for the patients treated with corticosteroids was 64.1 (47.9-81.3). Overall 90-day mortality was 35.9%. The median LM4 and LM7 for the patients who received treatment was 0.39 (0.19-0.83) and 0.36 (0.13-0.77). LM4 was a strong independent predictor of 28-day mortality (OR 25.4, (95% confidence interval (CI) 5.1-126.8), P0.45, 28- and 90-day survival was significantly higher for responders (90% and 76%) than non-responders (66% and 40%), P<0.001. Importantly, the area under the ROC curve for predicting mortality for LM4 was similar than the classic LM7 (0.77 vs. 0.75, respectively: P=0.558).
CONCLUSIONS: LM4 is as accurate as LM7 in predicting response to corticosteroids, as well as 28- and 90-day mortality. Assessing the efficacy of prednisolone at an earlier time point can avoid a more prolonged futile use of this therapy
CD45 expression discriminates waves of embryonic megakaryocytes in the mouse
Embryonic megakaryopoiesis starts in the yolk sac on gestational day 7.5 as part of the primitive wave of hematopoiesis, and it continues in the fetal liver when this organ is colonized by hematopoietic progenitors between day 9.5 and 10.5, as the definitive hematopoiesis wave. We characterized the precise phenotype of embryo megakaryocytes in the liver at gestational day 11.5, identifying them as CD41++CD45-CD9++CD61+MPL+CD42c+ tetraploid cells that express megakaryocyte-specific transcripts and display differential traits when compared to those present in the yolk sac at the same age. In contrast to megakaryocytes from adult bone marrow, embryo megakaryocytes are CD45- until day 13.5 of gestation, as are both the megakaryocyte progenitors and megakaryocyte/erythroid-committed progenitors. At gestational day 11.5, liver and yolk sac also contain CD41+CD45+ and CD41+CD45- cells. These populations, and that of CD41++CD45-CD42c+ cells, isolated from liver, differentiate in culture into CD41++CD45-CD42c+ proplatelet-bearing megakaryocytes. Also present at this time are CD41-CD45++CD11b+ cells, which produce low numbers of CD41++CD45-CD42c+ megakaryocytes in vitro, as do fetal liver cells expressing the macrophage-specific Csf receptor-1 (Csf1r/CD115) from MaFIA transgenic mice, which give rise poorly to CD41++CD45-CD42c+ embryo megakaryocytes both in vivo and in vitro In contrast, around 30% of adult megakaryocytes (CD41++CD45++CD9++CD42c+) from C57BL/6 and MaFIA mice express CD115. We propose that differential pathways operating in the mouse embryo liver at gestational day 11.5 beget CD41++CD45-CD42c+ embryo megakaryocytes that can be produced from CD41+CD45- or from CD41+CD45+ cells, at difference from those from bone marrow.This work was supported by grants from the Ministerio de Ciencia e Innovacion (MICINN SAF2009-12596) and from the Ministerio de Economia y Competitividad (MINECO SAF2012-33916 and SAF2015-70880-R MINECO/FEDER). NS was the recipient of a fellowship from the Centro de Biologia Molecular Severo Ochoa (CBMSO) and IC received a fellowship from the MICINN. The CBMSO receives institutional funding from Fundacion Ramon Areces. The CNIC is supported by the MEIC and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505).S
Si oxidation processes by electron cyclotron resonance plasmas
National Congress of Materials (7. 2002. Madrid). © Sociedad Española de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas. Licencia Creative Commons 3.0 España (by-nc). Los autores agradecen al C.A.I. de Implantación Iónica (U.C.M.) por las labores técnicas de apoyo, y al C.A.I. de Espectroscopía (U.C.M.) por la disponibilidad del espectrómetro FTIR. Éste trabajo fue parcialmente financiado por el CICYT bajo contrato TIC 01‑1253.Se han fabricado estructuras MIS sobre Si (100) mediante un proceso en dos pasos: una primera exposición del sustrato de Si a un plasma ECR de oxígeno, que da lugar a la obtención de una capa de SiOx (en adelante PO-SiOx), seguido de un depósito de nitruro de silicio (SiN1.55:H) mediante plasma ECR. La estructura MIS resultante es de la forma Al/SiN1.55:H/PO‑SiOx/Si. Los dispositivos han sido caracterizados mediante la medida simultánea de las capacidades a alta y baja frecuencia, lo que permite conocer la calidad de la intercara PO‑SiOx/Si, calcular los espesores de la capa de PO‑SiOx y la velocidad de crecimiento del SiNx:H. Para caracterizar el proceso de oxidación se realizaron varias series de muestras variando en cada una un parámetro del proceso. Estos parámetros fueron: el tiempo de depósito del SiNx:H, el tiempo de oxidación, la temperatura del sustrato y el flujo total de O2. Asimismo, se ha estudiado la estructura de enlaces del dieléctrico apilado mediante espectroscopia infrarroja. El espectro del dieléctrico apilado mostró la superposición de dos picos: uno de menor intensidad asociado al PO‑SiOx con el máximo en 1056 cm-1, y otro debido al SiN1.55:H con máximo en 860 cm-1. Estas medidas mostraron que la ley que rige el crecimiento del PO‑SiOx es dSiO = 2.7 tox 0.26 nm donde dSiO es el espesor de la capa de PO-SiOx y tox es el tiempo de oxidación en min. Por lo que respecta a las características eléctricas, las estructuras presentaron mínimos de la densidad de trampas en la intercara (Dit) cercanos a 1011 eV-1cm-2. Este valor es inferior al que presentaron las estructuras sin oxidar, del tipo SiN1.55:H/Si. Además, los dispositivos apilados mostraron un barrido del nivel de Fermi mayor y una histéresis prácticamente despreciable.MIS structures have been fabricated on Si (111) by a two-step process: first an exposition of the Si substrates to an ECR oxygen plasma was performed, which yields a layer of SiOx (in the following PO-SiOx); this process was followed by an ECR plasma silicon nitride deposition (SiN1.55:H). The resulting MIS structure is Al/SiN1.55:H/PO-SiOx/Si. Devices have been characterized by the simultaneous measurement of the capacitance at high and low frequencies. This measurement lets us know the PO-SiOx/Si interface quality, calculate the thickness of the PO-SiOx layer and the growth rate of SiN1.55:H. To characterize the oxidation process some series of samples were prepared. In each series a process parameter was varied. These parameters were: the SiN1.55:H deposition time, the ECR plasma oxidation duration, the substrate temperature and the total oxygen flux. The bonding structure of the stacked dielectric has been studied by infrared spectroscopy. The stacked dielectrics spectra showed the super-position of two peaks: a less intense peak associated to the PO-SiOx layer with its maximum in 1056 cm(-1), and another one due to the SiN1.55:H film with its maximum in 860 cm(-1). These measurements showed that the PO-SiOx growth law is d(SiO) = 2.71 t(ox)(026) nm where d(SiO) is the PO-SiOx layer thickness and t(ox) is the oxidation time in min. Concerning electrical characteristics, stacked MIS devices showed interface trap density minimums (D-u) close to 10(11) eV(-1)cm(-2). This value is inferior to the one that non-oxydized devices (Al/SiN1.55:H/Si) show. Also, stacked devices presented higher Fermi level sweeps and an electrical hysteresis almost insignificant.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUECICYT of Spainpu
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