Combined High Power and High Frequency Operation of InGaAsP/InP Lasers at 1.3μm

A simultaneous operation of a semiconductor laser at high power and high speed was demonstrated in a buried crescent laser on a P-InP substrate. In a cavity length of 300μm, a maximum CW power of 130mW at room temperature was obtained in a junction-up mounting configuration. A 3dB bandwidth in excess of 12GHz at an output power of 52mW was observed

Densification and preservation of ceramic nanocrystalline character by spark plasma sintering

Spark plasma sintering is a hot pressing technique where rapid heating by dc electric pulses is used simultaneously with applied pressure. Thus, spark plasma sintering is highly suitable for rapid densification of ceramic nanoparticles and preservation of the final nanostructure. A considerable portion of the shrinkage during densification of the green compact of nanoparticles in the first and intermediate stages of sintering occurs during heating by particle rearrangement by sliding and rotation. Further densification to the final stage of sintering takes place by either plastic yield or diffusional processes. Full densification in the final stage of sintering is associated with diffusional processes only. Nanoparticle sliding and rotation during heating may also lead to grain coalescence, with much faster kinetics than normal grain growth at higher temperatures. Based on existing models for particle rearrangement and sliding, the contributions of these processes in conjunction with nanoparticle properties and process parameters were highlighted

Monolithic integration of a very low threshold GaInAsP laser and metal-insulator-semiconductor field-effect transistor on semi-insulating InP

Monolithic integration of 1.3-µm groove lasers and metal-insulator-semiconductor field-effect transistors (MISFET) is achieved by a simple single liquid phase epitaxy (LPE) growth process. Laser thresholds as low as 14 mA for 300-µm cavity length are obtained. MIS depletion mode FET's with n channels on LPE grown InP layer show typical transconductance of 5–10 mmho. Laser modulation by the FET current is demonstrated at up to twice the threshold current

Reganho de peso em mulheres após cirurgia metabólica e bariátrica: estudo qualitativo no Brasil

Introduction: Due to the increased number of bariatric surgeries over the years, aspects contributing or hindering the achievement of outcomes, among them weight regain, have acquired increased significance. Psychological factors directly influence on this unwanted situation, but there are few studies and controversies about the degree of participation of these factors. We propose a qualitative investigation to analyze the meanings of weight regain after surgery among women and how these factors influence this outcome. Method: This study uses the clinical-qualitative method, by means of a semi-structured interview with open questions in an intentional sample, closed by saturation, with eight women who underwent surgery at the Bariatric Surgery Outpatient Clinic of Hospital das Clínicas, Universidade Estadual de Campinas (UNICAMP), in the state of São Paulo, Brazil. Results: A feeling of defeat and failure emerges with weight regain, which contributes to social isolation; there is no regret, but gratitude for the surgery; among patients, there is a sense of feeling rejected greater than a rejection that actually exists. Conclusion: We found out the need for further qualitative studies that help the health team to better understand the dynamic psychological factors involved in the meaning of weight regain after bariatric surgery among women, in order to adopt appropriate conducts to deal with this problem.Due to the increased number of bariatric surgeries over the years, aspects contributing or hindering the achievement of outcomes, among them weight regain, have acquired increased significance. Psychological factors directly influence on this unwanted sit363140146sem informaçãosem informaçã

Recent developments in monolithic integration of InGaAsP/InP optoelectronic devices

Monolithically integrated optoelectronic circuits combine optical devices such as light sources (injection lasers and light emitting diodes) and optical detectors with solid-state semiconductor devices such as field effect transistors, bipolar transistors, and others on a single semiconductor crystal. Here we review some of the integrated circuits that have been realized and discuss the laser structures suited for integration with emphasis on the InGaAsP/InP material system. Some results of high frequency modulation and performance of integrated devices are discussed

Validação de método para estudo de deposição de inseticidas biológicos em florestas.

Tem sido dada muito pouca atenção aos estudos da deposição de inseticidas biológicos, os quais tem sido aplicados com equipamento desenvolvido para uso com químicos. O objetivo desta pesquisa foi avaliar um método para a analise da deposição de agrotóxicos em florestas de eucaliptos, caracterizado pelo uso de uma calda de pulverização marcada com traçador e uma técnica especial de amostragem. Empregou-se o cobre como traçador, na forma de fungicida, cuja analise espectrofotométrica e de baixo custo, fácil de execução, alem de possibilitar um excelente nível de recuperação das plantas. Utilizaram-se cartões de papel mata-borrão como alvo artificial para amostrar as gotas. Cartões grampeados em barbantes, em distancias preestabelecidas, foram colocados sobre as plantas, possibilitando uma amostragem estratificada por alturas. Para o solo, os cartões foram colocados em discos de Petri e distribuídos sob a copa das arvores, entre plantas e entre as linhas de plantio. Os resultados indicam que 61% do produto aplicado ficaram retidos nas plantas, 31% atingiram o solo e 8% podem ter sido perdidos através da "exo-deriva".bitstream/item/143340/1/CNPMA-BOLET.-PESQ.-4-99.pd

Pulverização eletrostática.

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Utilizando a API HTTPUnit no Sistema Agritempo.

Este trabalho apresenta o uso da API HTTPUnit para recuperar dados de previsão do tempo utilizados na geração dos mapas a partir do site www.somarmeteorologia.com.brbitstream/CNPTIA/10190/1/comtec51.pdfAcesso em: 28 maio 2008