Annual evolution of global, direct and diffuse radiation and fractions in tilted surfaces

Avaliou-se a evolução anual das componentes global, direta e difusa da radiação solar incidente em superfícies inclinadas a 12,85; 22,85 e 32,85º, com face voltada ao Norte, em Botucatu-SP. Foram obtidas frações radiométricas para cada componente da radiação nas superfícies supracitadas, através de razões com a radiação global e a do topo da atmosfera. A sazonalidade foi avaliada através das médias mensais dos valores diários. As medidas ocorreram entre 04/1998 e 07/2001, em 22,85º; 08/2001 e 02/2003, em 12,85º; e de 03/2003 a 12/2007, em 32,85º, com medidas concomitantes no plano horizontal (referência). Os níveis das radiações global e direta nos planos inclinados foram inferiores no período de verão e superiores entre os equinócios, quando comparadas ao plano horizontal. A radiação difusa nas superfícies inclinadas foi inferior na maioria dos meses, com perdas de até 65%. Ocorreu uma tendência de aumento das diferenças entre as superfícies horizontal e inclinada com o incremento do ângulo em todas as componentes e frações da radiação incidente. A evolução anual das precipitações pluviométricas e da razão de nebulosidade afetou diretamente a transmissividade atmosférica das componentes direta e difusa na região.

CP trajectory diagram - a tool for a pictorial representation of CP and matter effects in neutrino oscillations

We introduce a CP trajectory diagram in bi-probability space as a powerful tool for a pictorial representation of the genuine CP and the matter effects in neutrino oscillations. The existence of correlated ambiguity in the B is uncovered. The principles of tuning the beam energy for a determination of CP-violating phase delta and the sign of Deltam(13)(2) given baseline distance are proposed to resolve the ambiguity and to maximize the CP-odd effect. We finally point out, quite contrary to what is usually believed, that the ambiguity may be resolved with similar to 50% chance in the super-JHF experiment despite its relatively short baseline of 300 km. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Duality of coordinates and matter fields in curved spacetime

We show that there exists a duality between the local coordinates and the solutions of the Klein-Gerdon equation in curved spacetime in the same sense as in the Minkowski spacetime. However, the duality in curved spacetime does not have the same generality as in flat spacetime and it holds only if the system satisfies certain constraints. We derive these constraints and the basic equations of duality and discuss the implications in the quantum theory. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Gravity and duality between coordinates and matter fields

We use the duality between the local Cartezian coordinates and the solutions of the Klein-Gordon equation to parametrize locally the spacetime in terms of wave functions and prepotentials. The components of metric, metric connection, curvature as well as the Einstein equation are given in this parametrization. We also discuss the local duality between coordinates and quantum fields and the metric in this later reparametrization. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Interaction of Hawking radiation and a static electric charge

We investigate whether the equality found for the response of static scalar sources interacting (i) with Hawking radiation in Schwarzschild spacetime and (ii) with the Fulling-Davies-Unruh thermal bath in the Rindler wedge is maintained in the case of electric charges. We find a finite result in the Schwarzschild case, which is computed exactly, in contrast with the divergent result associated with the infrared catastrophe in the Rindler case, i.e., in the case of uniformly accelerated charges in Minkowski spacetime. Thus the equality found for scalar sources does not hold for electric charges.

Effects of ionizing radiation and preservation on biomechanical properties of human costal cartilage

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ratios of UV, PAR and NIR components to global solar radiation measured at Botucatu site in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultraviolet-B and water stress effects on growth, gas exchange and oxidative stress in sunflower plants

The effects and interaction of drought and UV-B radiation were studied in sunflower plants (Helianthus annuus L. var. Catissol-01), growing in a greenhouse under natural photoperiod conditions. The plants received approximately 1.7 W m(-2) (controls) or 8.6 W m(-2) (+UV-B) of UV-B radiation for 7 h per day. The UV-B and water stress treatments started 18 days after sowing. After a period of 12 days of stress, half of the water-stressed plants (including both UV-B irradiated or non-irradiated) were rehydrated. Both drought and UV-B radiation treatments resulted in lower shoot dry matter per plant, but there was no significant interaction between the two treatments. Water stress and UV-B radiation reduced photosynthesis, stomatal conductance and transpiration. However, the amplitude of the effects of both stressors was dependent on the interactions. This resulted in alleviation of the negative effect of drought on photosynthesis and transpiration by UV-B radiation as the water stress intensified. Intercelluar CO(2) concentration was initially reduced in all treatments compared to control plants but it increased with time. Photosynthetic pigments were not affected by UV-B radiation. Water stress reduced photosynthetic pigments only under high UV-B radiation. The decrease was more accentuated for chlorophyll a than for chlorophyll b. As a measure for the maximum efficiency of photosystem II in darkness F (v)/F (m) was used, which was not affected by drought stress but initially reduced by UV-B radiation. Independent of water supply, UV-B radiation increased the activity of pirogalol peroxidase and did not increase the level of malondialdehyde. on the other hand, water stress did not alter the activity of pirogalol peroxidase and caused membrane damage as assessed by lipid peroxidation. The application of UV-B radiation together with drought seemed to have a protective effect by lowering the intensity of lipid peroxidation caused by water stress. The content of proline was not affected by UV-B radiation but was increased by water stress under both low and high UV-B radiation. After 24 h of rehydration, most of the parameters analyzed recovered to the same level as the unstressed plants.

Determination of jet energy calibration and transverse momentum resolution in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Performance of tau-lepton reconstruction and identification in CMS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

EFFECT OF APIS-MELLIFERA BEE VENOM AND GAMMA-RADIATION ON BONE-MARROW CELLS OF WISTAR RATS TREATED INVIVO

To determine whether the venom of Apis mellifera can exert a radioprotective effect, by reducing the frequency of chromosome aberrations induced by radiation, five different experiments were performed on bone marrow cells of Wistar rats.Animals weighing about 100 g were injected intraperitoneally with different venom concentrations (1.0 or 0.5 mul) 1 or 24 h before, or 30 min after being submitted to 3 or 4 Gy of gamma radiation, and sacrificed 24 h after the last treatment. For each experiment in addition to the group of animals submitted to combined treatment (venom + radiation) and to their control, there was also one group treated with radiation only and another treated with venom only. A decrease in the frequency of chromosome aberrations, and fragments in particular, as well as in the number of cells with aberrations was observed in the experiments in which venom was administered 24 h before irradiation, and the effect was more marked at the higher venom concentration (1 mul/100 g weight).

Doping of polyaniline and derivatives induced by X-ray radiation

Thin films of chemically synthesized polyaniline and poly(o-methoxyaniline) were exposed to ionizing X-ray radiation and characterized by radiation induced conductivity measurements, ultraviolet-visible spectroscopy, electron paramagnetic resonance, electrical conductivity and solubility measurements. Samples irradiated in vacuum or dry Oxygen atmosphere did not have their electronic spectra changed. However, under humid atmosphere the energy of the excitonic transition was decreased and accompanied by a great conductivity increase. The results indicate that doping of polyaniline can be induced by X-ray radiation which might be of great interest for applications on lithography and microelectronics.

Distribution of Ra-226, Th-232 and K-40 in soils and sugar cane crops at Corumbatai river basin, São Paulo State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estimativa do fluxo de calor latente pelo balanço de energia em cultivo protegido de pimentão

O objetivo deste trabalho foi caracterizar e relacionar a radiação líquida com o calor latente equivalente, em mm de água, nos cultivos protegido e de campo, na cultura de pimentão. O experimento foi feito em Botucatu, SP. A estimativa do fluxo de calor latente foi feita pelo método do balanço de energia, por meio da razão de Bowen. Foram feitas medidas instantâneas da radiação líquida (Rn), dos fluxos convectivos de calor latente (LE) e sensível (H), do fluxo de calor no solo (G), e dos gradientes psicrométricos sobre a cultura. O cultivo protegido, apesar de receber menor quantidade de radiação solar global, foi mais eficiente na conversão da radiação líquida disponível em matéria seca total e na produtividade de frutos. No balanço de energia, o cultivo protegido apresentou razões G/Rn e LE/Rn inferiores e H/Rn superior, com um fluxo de calor latente, equivalente em milímetros, 45,43% menor que no cultivo no campo. Apresentou, ainda, menor quantidade de radiação líquida disponível e menores perdas de energia, mostrando-se mais eficiente no uso da água.