High resolution studies of low-energy electron attachment to SF5Cl: Product anions and absolute cross sections

Low energy electron attachment to SF$_5$Cl was studied at high energy resolution by mass spectrometric detection of the product anions. Two variants of the laser photoelectron attachment (LPA) technique (Kaiserslautern) were used for determining the threshold behaviour of the yield for SF$_5^-$ formation at about 1 meV resolution, and to investigate the relative cross sections for Cl$^-$, FCl$^-$, and SF$_5^-$ formation towards higher energies (up to 1 eV) at about 20 meV resolution. Thermal swarm measurements (Birmingham) were used to place the relative LPA cross sections on an absolute scale. A trochoidal electron monochromator (Innsbruck) was used for survey measurements of the relative cross sections for the different product anions over the energy range of 0-14 eV with a resolution of 0.30 eV. Combined with earlier beam data (taken at Berlin, J. Chem. Phys. 88 (1988) 149), the present experimental results provide a detailed set of partial cross sections for anion formation in low-energy electron collisions with SF$_5$Cl

Índice de estresse hídrico da cultura (IEHC) combinado com a temperatura de estresse diário (TED) em feijoeiro (Phaseolus vulgaris L.) submetido a diferentes frequências de irrigação.

O objetivo do presente trabalho foi estimar valores do indice de estresse hidrico da cultura combinado com a temperatura de estresse diario (IEHCc) em feijoeiro (Phaseolus vulgaris L.) submetido a cinco frequencias de irrigacao 2, 4, 8, 12 e 16 dias. Os tratamentos foram estabelecidos em blocos casualizados com 4 repeticoes. As temperaturas da copa vegetal (Tc) foram medidas, atraves do termometro a infravermelho em dois periodos de manha (entre 10 e 11 horas) e de tarde (entre 13 e 14 horas). A maior producao de graos (2755kg.ha4) foi obtida na frequencia de irrigacao de 2 dias, com perdas relativas de 0,181; 16,7; 42,5 e 61,6%, para as frequencias de 4, 8, 12 e 16 dias, respectivamente. Nao houve diferenca estatistica entre as frequencias de 2, 4 e 8 dias, para a producao. As laminas totais de agua aplicadas foram de 482,0; 439,6; 385,6; 326,5 e 290,4mm, para as frequencias de 2, 4, 8, 12 e 16 dias, respectivamente. Os valores do IEHCc estimados para o periodo da manha acompanharam os da tarde, porem, os maximos ocorreram a tarde, sendo esse o periodo recomendavel para as leituras de Tc. Um valor limite de 0,15 para o IEHCc pode ser o estipulado alem do qual havera perda significativa de rendimento da cultura do feijoeiro

Design of a LNA in the frequency band 1.8-2.2GHz in 0.13μm CMOS Technology

The subject of this work is a low noise amplifier (LNA), operating in the frequency range 1.8-2.1GHz. The CMOS 0.13μm technology is used in respect to the low cost of the final device. Among the specifications, a variable gain and an adjustable working frequency are required. In particular, four different working modes are provided: 1.8, 1.9 and 2.1GHz high gain and 2.1GHz low gain. The amplifier is designed to be used as first stage of a receiver for mobile telephony. For this reason low power consumption is taken into consideration (low supply voltage and low drain currents). A simple digital circuit, integrated on-chip, is used to select the operating mode of the LNA by means of two input pins. A Noise figure of 1dB is obtained with a supply voltage of 0.8V

Measurement of focusing properties for high numerical aperture optics using an automated submicron beamprofiler

The focusing properties of three aspheric lenses with numerical aperture (NA) between 0.53 and 0.68 were directly measured using an interferometrically referenced scanning knife-edge beam profiler with sub-micron resolution. The results obtained for two of the three lenses tested were in agreement with paraxial gaussian beam theory. It was also found that the highest NA aspheric lens which was designed for 830nm was not diffraction limited at 633nm. This process was automated using motorized translation stages and provides a direct method for testing the design specifications of high numerical aperture optics.Comment: 6 pages 4 figure

Crop water stress index for beans obtained from temperature difference between canopy and air.

Canopy temperature (Tc), besides serving as a parameter to estimate crop evapotranspiration (ETc), can also be used to define water stress indexes that have the advantage to serve as a reference for the rational scheduling for irrigation for a crop. One of these indexes, which has been well disseminated, is the crop water stress index (CWSI), based on the ratio between crop resistance and aerodynamic resistance (rc/ra), whose value can be estimated by the difference between the cropy canopy and the air (Tc - Ta). A study was carried out with the objective of obtaining CWSI values for beans (Phaseolus vulgaris L.), under field conditions, in which the crop was under different irrigation scheduling; 2, 4, 8, 12 and 16 day intervals. The experiment was conducted at Sete Lagoas, Minas Gerais State, Brazil, in the period from July through October, 1995. Tc values were measured by means of infrared thermometry at two times of the day; between 10:00 and 11:00 am, and between 01:00 and 02:00 p.m. The obtained results pointed to a limit of 0,15 as a reference for the beginning of water stress to occur, which is consistent with other work and other index obtained under similar conditions

Estimativa da evapotranspiração máxima do feijoeiro (Phaseolus vulgaris L.) em função do índice de área foliar e da evaporação da água do tanque classe A.

Um metodo simples que tem sido amplamente usado na obtencao da evapotranspiracao da cultura (ET) e o padronizado pela FAO. Esse se baseia em medir a evaporacao de agua do tanque Classe A (ECA) e multiplicar por coeficientes ( do tanque e da cultura) que geracao a ET. No entanto, a estimativa dos referidos coeficientes (K, e K,) nem sempre retrata de forma satisfatoria as condicoes da cultura. Procurando-se vencer essa dificuldade, tornando-se desnecessario o uso de tais coeficientes, foi objetivo deste trabalho comporvar a boa concordancia entre a ET, calculada pelo metodo de Penman-Monteith, e o indice de area foliar (IAF) e a ECA e entre a ET, unicamente com o IAF, atraves da analise de regressao linear multipla, para o feijoeiro. A melhor relacao encontrada foi a que considerou o fator biologico (IAF) conjuntamente com o ambiental (ECA), isto e, ET = -1.304 + 0,8368.iaf + 0,5537.ECA (r2 = 0,854), comprovando a metodologia como de boa eficiencia para predizer a ET

Kinin-B1 receptors in ischaemia-induced pancreatitis: Functional importance and cellular localisation

In this study we compare the role of kininB1 and B2 receptors during ischaemia/reperfusion of rat pancreas. Our investigations were prompted by the observation that infusion of a kininB2 receptor antagonist produced significant improvement in acute experimental pancreatitis. In an acute model with two hours of ischaemia/two hours of reperfusion, application of the kininB1 receptor antagonist (CP-0298) alone, or in combination with kininB2 receptor antagonist (CP-0597), significantly reduced the number of adherent leukocytes in postcapillary venules. In a chronic model with five days of reperfusion, the continuous application of kininB1 receptor antagonist or a combination of kininB1 and B2 receptor antagonists markedly reduced the survival rate. In kininreceptor binding studies kininB1 receptor showed a 22-fold increase in expression during the time of ischaemia/ reperfusion. Carboxypeptidase M activity was upregulated 10-fold following two hours of ischaemia and two hours of reperfusion, provided the appropriate specific ligand, desArg10-kallidin and/or desArg9-bradykinin, was used. The occurrence of kininB1 receptor binding sites on acinar cell membranes was demonstrated by microautoradiography. With a specific antibody, the localisation of kininB1 receptor protein was confirmed at the same sites. In conclusion, we have demonstrated the upregulation of the pancreatic acinar cell kininB1 receptors during ischaemia/reperfusion. The novel functional finding was that antagonism of the kininB1 receptors decreased the survival rate in an experimental model of pancreatitis

Eficiência do uso da água em cultivares de beterraba submetidas a diferentes tensões de água no solo.

A limitação hídrica é a principal causa de redução na produtividade das plantas, e reduz a exploração agrícola durante o período de estiagens. Assim, um experimento foi conduzido em casa de vegetação na FCA UNESP, campus de Botucatu, para verificar a eficiência de uso da água na cultura da beterraba. Utilizou-se o delineamento em blocos casualizados com 4 repetições. Os tratamentos compreendiam 6 níveis de tensões de água no solo (-15, -25, -35, -45, -55, -65 KPa) e 2 cultivares de beterraba (Early Wonder e Itapuã 202) totalizando 48 parcelas experimentais. Foram avaliados durante o experimento o número de folhas, a eficiência do uso de água e a massa fresca total das plantas. As plantas que se desenvolveram a tensão de água no solo de -15 kPa apresentaram maiores valores das variáveis estudadas. A eficiência do uso da água pelas plantas foi reduzida em 5,34 Kg ha-1 mm-1 e a massa fresca total das plantas apresentou redução de 0,44g (cv. Eearly Wonder) e 0,47 g (cv. Itapuã 202), a medida que a tensão de água no solo aumentou