1,888 research outputs found
Understanding UV Sensor Performance in ZnO TFTs Through the Application of Multivariate Analysis
Zinc oxide (ZnO) thin film transistors are well suited to UV sensing application because they absorb predominantly in the UV region due to the wide bandgap (Eg = 3.37 eV) and possess a large exciton binding energy (60 meV) with high radiation hardness. When operated as a transistor, many device performance parameters alter such as threshold Voltage, on-off current and channel mobility. As a result, it is to distinguish between changes in electrical performance induced by UV light and environmental effects that add noise to the sensor performance. In this work, the UV response of zinc oxide thin film transistors (ZnO TFTs) is examined using Taguchi Design of Experiment (DOE) method. By using this multivariate analysis approach, it is possible to reduce the number of calibration tests required for the sensor to accurately assess UV irradiation It is observed that different input conditions (UV power, exposure time, temperature, bias conditions) affect different TFT performance parameters more or less significantly. From the perspective of UV sensing, ON current in the saturation region appears to be the best performance parameter in a ZnO TFT for examining differences in UV exposure
Optimization of the Anodization Processing for Aluminum Oxide Gate Dielectrics in ZnO Thin Film Transistors by Multivariate Analysis
The
present study reports a two-level multivariate analysis to
optimize the production of anodized aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) dielectric films for zinc oxide thin-film transistors
(TFTs). Fourteen performance parameters were measured and analysis
of variance (ANOVA) of the combined responses has been applied to
identify how the Al<sub>2</sub>O<sub>3</sub> dielectric fabrication
process influences the electrical properties of the TFTs. Using this
approach, the levels for the manufacturing factors to achieve optimal
overall device performance have been identified and ranked. The cross-checked
analysis of the TFT performance parameters demonstrated that the appropriate
control of the anodization process can have a higher impact on TFT
performance than the use of traditional methods of surface treatment
of the dielectric layer. Flexible electronics applications are expected
to grow substantially over the next 10 years. Given the complexity
and challenges of new flexible electronics components, this “multivariate”
approach could be adopted more widely by the industry to improve the
reliability and performance of such devices
Main neoplasic processes in psittacines birds kept in captivity
Um estudo anatomopatológico envolvendo 130 psitacídeos oriundos de centros de triagens, zoológicos e criadouros, visando a determinação da causa de morte destes animais, revelou a presença de neoplasias em sete animais, totalizando 5,4% dos casos. Os processos neoplasicos foram caracterizados como colangiocarcinoma, colangioma, linfoma, hemangiossarcoma e carcinoma renal primário, sendo o colangiocarcinoma o mais freqüentemente encontrado, presente em três animais. Este trabalho descreve estas neoplasias, levando em consideração os aspectos macro e microscópicos, meios de diagnósticos e espécies acometidas.An anatomopathologic study of 130 captivy psittacines from zoos, breeders and rehabilitation centers showed the presence of neoplastic disease in seven birds, totalizing 5.4% of the cases. The neoplasms were identified like cholangiocarcinoma, cholangioma, lymphoma, haemangiosarcoma and renal cell carcinoma. The cholangiocarcinoma was the tumor most commonly observed. it was present in birds. This study describes the macro and microscopic findings of these tumors; also reports diagnostic methods employed to identify these neoplasms.Fundação de Amparo à Pesquis
Improvement of the deep UV sensor performance of a β-Ga2O3 photodiode by coupling of two planar diodes
β -Ga 2 O 3 is one of the promising semiconductor materials that has been widely used in power electronics and ultraviolet (UV) detectors due to its wide bandgap and high sensitivity to UV light. Specifically, for the UV detection application, it has been reported that the photocurrent was in the scale of microamps ( μA ), which normally requires sophisticated signal processing units. In this work, a novel approach based upon coupling of two Schottky diodes is reported, leads to a substantial increase in photocurrent (~186 times) when benchmarked against a conventional planar UV photodiode. The detectivity and responsivity of the new device have also been significantly increased; the rectification ratio of this device was measured to be 1.7×107 with ultralow dark current, when measured in the reverse bias. The results confirm that the approach of coupling two Schottky diodes has enormous potential for improving the optical performance of deep UV sensors
UV phototransistors based upon spray coated and sputter deposited ZnO TFTs
A comparison of Zinc Oxide (ZnO) phototransistors prepared by spray and sputter coating process is presented. The work shows that spray coated layers provide significant advantages in sensor response over ZnO phototransistors made by physical vapour deposition and we show that spray deposited ZnO phototransistors can exhibit state-of-the-art performances for UV photodetectors. Topographic images of the samples surface shows that there is increase in surface roughness in spray coated samples indicating increasing grain sizes, which is considered the source of the greater sensor responsivity. X-ray photoelectron spectroscopy (XPS) is also used to understand the root cause of the greater UV responsivity. It was observed that sprayed ZnO TFTs are more sensitive to UV radiation due to higher adsorption of oxygen level. Responsivity and external quantum efficiency (EQE) of the sprayed and sputtered ZnO TFTs are also evaluated
Sistema de Controle da Frota (SCF)
Este trabalho tem por objetivo apresentar o desenvolvimento do Sistema de Controle de Frota (SCF) que será utilizado pelo Centro Universitário de Brasília – UniCEUB, para o controle e gerenciamento da frota institucional que é realizado pelo Setor de Transporte. Para o desenvolvimento dos trabalhos foram empregados os conhecimentos adquiridos no decorrer do curso, como técnicas de elicitação, reuniões e entrevistas, modelagem de dados, documentação e implementação. O estudo e análise deste projeto foram baseados nas rotinas já estabelecidas pelo atual gestor do Setor de Transporte, o qual contribuiu na elucidação e mapeamento dos processos, atuais e propostos, possibilitando assim a construção de uma ferramenta de auxilio e controle dos processos realizados no departamento. O Sistema possui funcionalidades que se referem a consumo, manutenção e controle efetivo da frota, que auxiliam as tomadas de decisões por parte do gestor visando melhorar os processos do Setor de transporte
Decreased gait speed and health outcomes in older adults: Rede FIBRA’s data
La velocidad de la marcha (VM) se ha considerado un marcador de salud en los ancianos capaz de predecir resultados adversos en la salud, pero la comprensión de sus factores asociados todavía es limitada y controvertida. El presente estudio tiene como objetivo identificar los resultados adversos para la salud relacionados con la disminución de la velocidad de la marcha en los ancianos comunitarios. Se trata de un estudio transversal y multicéntrico, el que evaluó el autoinforme de enfermedades crónicas y de la hospitalización en el último año, la polifarmacia y la velocidad de la marcha. Se utilizó el análisis de regresión logística para estimar los efectos de cada variable independiente sobre la posibilidad de que los ancianos presenten una disminución más baja en la velocidad de la marcha (VM<0,8 m/s) (α=0,05). Participaron en el estudio 5.501 ancianos. La velocidad de marcha más baja estuvo asociada a portadores de enfermedades cardíacas (OR=2,06; IC: 1,67-2,54), respiratorias (OR=3,25; IC: 2,02-5,29), reumáticas (OR=2,16; IC: 1,79-2,52) y/o depresión (OR=2,51; IC: 2,10-3,14), hospitalizados en el último año (OR=1,51; IC: 1,21- 1,85) y polifarmacia (OR=2,14; IC: 1,80-2,54). De esta manera, los resultados indicaron que los ancianos con velocidades de marcha por debajo de 0,8m/s presentan un mayor riesgo de eventos adversos para la salud. Por lo tanto, se sugiere que la velocidad de la marcha no debe ser descuidada en la evaluación de ancianos comunitarios, incluso en la atención primaria.Gait speed (GS) can predict adverse health outcomes. However, an understanding of its associated factors is still limited and with some controversy. The objective of this study was to identify adverse health outcomes related to the decline in gait speed in community-dwelling older adults. This is a cross-sectional study that evaluated records of chronic diseases and hospitalization in the last year, polypharmacy, and gait speed. Logistic regression analysis was used to estimate the effects of each independent variable on the chance of older adults presenting a decline in gait speed (GS<0.8 m/s) (α=5%). In total, 5,501 older adults participated. Brazilian older adults with heart diseases (OR=2.06; 1.67-2.54 CI), respiratory diseases (OR=3.25; 2.02-5.29 CI), rheumatic (OR=2.16; 1.79-2.52 CI) and/ or depression diseases (OR=2.51; 2.10-3.14 CI); hospitalized in the last year (OR=1.51; 1.21-1.85 CI) and under polypharmacy (OR=2.14; 1.80-2.54 CI) were associated with lower gait speed. Thus, the results showed that those with gait speed lower than 0.8 m/s are at higher risk of some adverse health events. Therefore, it is suggested that gait speed should not be neglected in the evaluation in community-dwelling older adults, including basic health care.A velocidade da marcha (VM) tem sido considerada um marcador de saúde em idosos capaz de predizer desfechos adversos de saúde, mas a compreensão de fatores associados a ela ainda é limitada e controversa. O objetivo deste trabalho é identificar desfechos adversos de saúde relacionados ao declínio da velocidade de marcha em idosos comunitários. Trata-se de estudo transversal e multicêntrico, que avaliou o autorrelato de doenças crônicas e de hospitalização no último ano, polifarmácia e velocidade de marcha. Utilizou-se análise de regressão logística para estimar os efeitos de cada variável independente na chance de os idosos apresentarem declínio na velocidade de marcha inferior (VM<0,8m/s) (α=0,05). Participaram da pesquisa 5.501 idosos. A menor velocidade da marcha mostrou-se associada a portadores de doenças cardíacas (OR=2,06; IC: 1,67-2,54), respiratórias (OR=3,25; IC: 2,02-5,29), reumáticas (OR=2,16; IC: 1,79-2,52) e/ou depressão (OR=2,51; IC: 2,10-3,14), hospitalizados no último ano (OR=1,51; IC: 1,21-1,85) e polifarmácia (OR=2,14; IC: 1,80-2,54). Assim, os resultados indicaram que idosos com velocidade de marcha menor que 0,8m/s apresentam maior risco de eventos adversos de saúde. Dessa forma, sugere-se que a velocidade de marcha não seja negligenciada na avaliação de idosos comunitários, inclusive na atenção básica
[association Between Insomnia Symptoms, Daytime Napping, And Falls In Community-dwelling Elderly].
This study focused on associations between insomnia symptoms, daytime napping, and falls in community-dwelling elderly, using a population-based cross-sectional design and probability sample with 689 community-dwelling elders. The protocol consisted of self-reported and physical performance variables. The study used univariate and multivariate logistic regression analysis with statistical significance set at p 80 (OR = 3.48; 95%CI: 1.54-7.85), napping (OR = 2.24; 95%CI: 1.24-4.05), and depressive symptoms (OR = 1.98; 95%CI: 1.11-3.53). The association between daytime napping and falls corroborates data from international research. Identifying modifiable risk factors may help programs to prevent falls in the elderly.29535-4
Saúde Mental de Universitários: Levantamento de Transtornos Mentais Comuns em Estudantes de uma Universidade Brasileira
Transtornos mentais comuns causam prejuízos à vida social e acadêmica de estudantes universitários. Este estudo teve como objetivo levantar as prevalências de sintomas de Transtornos Mentais Comuns de estudantes de graduação de uma universidade pública, avaliando variáveis relacionadas ao gênero, à área e ao curso. Trata-se de pesquisa quantitativa de corte transversal e caráter descritivo. A coleta de dados foi realizada por meio de instrumento online, composto por questionário sociodemográfico e pelo Self-Reporting Questionnaire (SRQ-20). Participaram da pesquisa 7.177 estudantes (62,1% mulheres, 37,6% homens, e 0,3% não declararam, M idade = 25,6 anos) de 77 cursos de uma universidade federal. Os resultados indicaram prevalência de 71,52% de sintomas de Transtornos Mentais Comuns. Mulheres apresentaram piores indicativos de saúde mental. Das áreas de curso, os Bacharelados Interdisciplinares obtiveram maiores prevalências de Transtornos Mentais Comuns (76,2 %). Tais achados indicam a necessidade do desenvolvimento de programas de atenção à saúde mental estudantil
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