196 research outputs found
Design of a Broadband Amplifier for High Speed Applications
This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal
Effect of Pruning Severity on Yield, Drying Time and Wages in Flame Seedless Dry-on-vine and Traditional Raisin Production Systems in Argentina
Raisin grapes are potentially more profitable than wine grapes in San Juan, Argentina, although the traditional system of grape drying requires an extensive use of costly labour. Production costs might be reduced by adopting the dry-on-vine (DOV) raisin-making system, but the feasibility of DOV in Argentina has not been assessed, and neither have the costs and pruning schemes. Thus we determined drying time and yields, estimated wages per hectare, and determined the influence of pruning severity on Flame Seedless raisin grapes. A completely random design with six treatments and six replicates was used in the 2013 to 2016 seasons. The treatments comprised differences in the nodes per cane, nodes per vine,distribution of nodes, and sugar content. Descriptive statistics and variance analysis were calculated for fresh fruit weight, dry fruit weight, drying ratio and drying time. The leaf area and its relationship with dried fruit weight also were calculated. These data were processed with the Infostat program. The DOV system demands between 11 and 31 additional days during the drying period and reduces labour costs by between 38% and 64% compared to the traditional system. Long pruning with the same load of buds is better. Furthermore, the DOV system is not associated with a lower production and thus appears to be a financially sustainable alternative to traditional production systems for Flame Seedless raisin grape producers in Argentina
A 43-Gbps Lithium Niobate Modulator Driver Module
This paper describes the realization of a 43-Gbps Lithium Niobate modulator driver module. The NRZ driver module utilizes four stages of GaAs p-HEMT MMIC amplifiers integrated with an output level detector and feedback loop to provide thermal stability and external control of the output swing. The bias and loop control circuitry are contained in the housing on a PC board external to the sealed MIC section. The integrated module (50.8 x 73.4 x 9.5 mm 3) provides 6.0 Vp-p controllable single-ended output voltage while dissipating only 4 watt
Cognitive approaches and optical multispectral data for semi-automated classification of landforms in a rugged mountainous area
This paper introduces a new open source, knowledge-based framework for automatic interpretation of remote sensing images, called InterIMAGE. This framework owns a flexible modular architecture, in which image processing operators can be associated to both root and leaf nodes of the semantic network, which constitutes a differential strategy in comparison to other object-based image analysis platforms currently available. The architecture, main features as well as an overview on the interpretation strategy implemented in InterIMAGE is presented. The paper also reports an experiment on the classification of landforms. Different geomorphometric and textural attributes obtained from ASTER/Terra images were combined with fuzzy logic and drove the interpretation semantic network. Object-based statistical agreement indices, estimated from a comparison between the classified scene and a reference map, were used to assess the classification accuracy. The InterIMAGE interpretation strategy yielded a classification result with strong agreement and proved to be effective for the extraction of landforms
Dificuldades e alternativas encontradas por licenciandos para o planejamento de atividades de ensino de óptica para alunos com deficiência visual
Spin density wave dislocation in chromium probed by coherent x-ray diffraction
We report on the study of a magnetic dislocation in pure chromium. Coherent
x-ray diffraction profiles obtained on the incommensurate Spin Density Wave
(SDW) reflection are consistent with the presence of a dislocation of the
magnetic order, embedded at a few micrometers from the surface of the sample.
Beyond the specific case of magnetic dislocations in chromium, this work may
open up a new method for the study of magnetic defects embedded in the bulk.Comment: 8 pages, 7 figure
Efeito de grupo versus produção de CO2 em operárias da formiga cortadeira Atta sexdens rubropilosa
Suscetibilidade de oito cultivares de bananeira à sigatoka-amarela na região de Marília (SP)
The microstructure and development of male genital organs of Spix's yellow-toothed cavy (Galea spixii) bred in captivity
O preá do semiárido nordestino (Galea spixii) é um roedor pertencente à família Caviidae. São encontrados nas regiões da Caatinga e do Cerrado Brasileiro e se reproduz ao longo do ano, apresentando um período de gestação de 48 dias e uma ninhada de 2 a 4 crias. O objetivo deste estudo foi caracterizar histologicamente os componentes estruturais dos órgãos genitais de preás machos relacionando com a evolução cronológica destes órgãos na espécie. Foram utilizados para análise animais ao nascimento e aos 15, 30, 45, 60, 75, 90, 105, 120 e aos 150 dias de idade. Fragmentos do epidídimo, ducto deferente, pênis e glândulas sexuais acessórias foram coletados, fixados e processados para descrição em microscopia de luz. O epidídimo apresentou epitélio colunar simples e em cada fase sexual notou-se diferença quanto ao tamanho do lúmen tubular e à presença de espermatozóides no lúmen aos 45 dias de idade. O epitélio do ducto deferente no preá mostrou-se pseudo-estratificado colunar com crescente presença de estereocilios com o avanço da idade. A glândula vesicular no preá apresentou uma mucosa com pregueamento variado, de acordo com a fase do desenvolvimento sexual. A próstata mostrou-se pouco desenvolvida, com lúmen pequeno nos preás ao nascimento e aos 15 dias de idade; aos 45 dias mostrou-se com um pregueamento do epitélio variável. Os órgãos genitais masculinos do preá passaram por transformações morfológicas no decorrer da idade e com o desenvolvimento sexual, isso colaborou para a determinação do início da fase da puberdade, que na espécie em estudo foi aos 45 dias de idade
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