Effects on the proton production from explosions of hydrogen clusters subjected to intense femtosecond laser fields

The dependence of the maximum and average energies of protons, which were produced in the interaction of an intense laser pulse (similar to 1 x 10(16) W cm(-2), 65 fs) with hydrogen clusters in a gas jet backed up to 80 bar at liquid nitrogen temperature (similar to 80 K), on the backing pressure has been studied. The general trend of the proton energy dependence on the square of the average cluster radius, which is determined by a calibrated Rayleigh scattering measurement, is similar to that described by theory under the single size approximation. Calculations are made to fit the experimental results under a simplified model by taking into account both a log-normal cluster size distribution and the laser intensity attenuation in the interaction volume. A very good agreement between the experimental proton energy spectra and the calculations is obtained in the high- energy part of the proton energy distributions, but a discrepancy of the fits is revealed in the low-energy part at higher backing pressures which are associated with denser flows. A possible mechanism which would be responsible for this discrepancy is discussed. Finally, from the fits, a variation of the cluster size distributions was revealed to be dependent on the gas backing pressure as well as on the evolving time of the gas flow of clusters.

Climate change impacts on the water services in Costa Rica: a production function for the hydroenergy sector

23 p.

Freshwater prawn fry production and delivery process: key to sustainable aquaculture development for Bangladesh

This study was conducted to identify a functioning fingerlings production and delivery system for a sustainable aquaculture development. Data were collected from 234 respondents randomly sampled from a population of 600 fish farmers. Results indicated that farmer-to-farmer was the major source of fingerlings production and distribution system. Although this source accessed disadvantaged groups like the rural based, resource poor, less educated and women, it lacked knowledge on how to produce good quality fingerlings. These results suggest that a decentralized and privatized fingerlings production and delivery system should be promoted. For this system to operate effectively the aquaculture department should first identify potential zones for aquaculture growth and profit motivated fingerlings producers and distributors. Furthermore, the institutional mechanism through which farmer-to-farmer will operate should be identified and strengthened through short and long term training programmes. The government should support the system by providing guidelines for good quality fingerlings management; maintain brood stock parents and technical training in Bangladesh.

Bareback: reflexões sobre a normalização das condutas sexuais

Refletindo sobre homossexualidade, Aids e seus desdobramentos sociais e subjetivos nos últimos 30 anos, procuramos nesta dissertação discutir o fenômeno bareback sexo sem camisinha - nomeado nos Estados Unidos na segunda metade da década de 1990. Sua disseminação na mídia tem causado, com frequência, reações que reconectam a homossexualidade a loucura, doença e morte. Devido à restrita produção acadêmica no Brasil, objetivamos contribuir por meio deste trabalho com algumas considerações essenciais ao debate. Percorremos alguns deslocamentos historicamente importantes relativos à homossexualidade, a condução das condutas - práticas de governo, risco, Aids e ao próprio bareback. Neste sentido, o trabalho associa um estudo teórico sobre este objeto a entrevistas realizadas na cidade do Rio de Janeiro. A pesquisa empírica exploratoria recolheu dados e discursos sobre este fenômeno em nossa realidade e contexto, tendo como terreno a Associação Brasileira Interdisciplinar de Aids (ABIA) e o Grupo Pela Vidda-RJ, duas organizações não-governamentais que trabalham com a Aids, e no Grupo Arco-íris, ONG integrante do Movimento LGBT. Duas pessoas de cada uma destas ONGs foram entrevistadas. Buscamos entender como essas instituições, locais privilegiados de nossa incursão, vêm abordando o fenômeno, quais suas posições e impressões. Paralelamente, contactamos alguns voluntários adeptos do sexo bareback, por considerarmos seus discursos indispensáveis e capazes de tornar este trabalho mais rico e diverso, no entendimento do bareback, a partir de suas experiências individuais. Para tal, utilizamos dois sites de bareback internacionais (barebackrt.com e bareback.com) que hospedam perfis de brasileiros, alguns residentes na cidade do Rio de Janeiro, onde três praticantes foram integrados à pesquisa. Nossa hipótese é que as tentativas em decifrar o bareback, dar-lhe um sentido, uma verdade, acabam percorrendo trilhas normativas que têm seus limites expostos à medida que percebemos que a diversidade das práticas erótico-sexuais, da singularidade e subjetividade dos sujeitos transcendem qualquer tentativa de normatização / normalização. Assim, acreditamos que o que chamamos de bareback, seja fenômeno, subcultura, prática ou comportamento, não pode ser definido enquanto conjunto coeso de discursos, fantasias e práticas erótico-sexuais, mas pelo contrário, apresenta-se por meio de múltiplas faces ainda mais variadas, restando apenas à alusão que lhe é característica: o sexo sem camisinha, que nem sempre significará sexo sem proteção. Desta forma, tendo como perspectiva a noção de condução das condutas e cuidado de si proposta por Michel Foucault, discutimos o significado das práticas sexuais dissidentes e as questões referentes a normalização, patologização e formas de resistência.

Radiative tau production and decay

A study of the muon decay channel of the τ lepton with the presence of a photon has been carried out to verify theoretical predictions for the production rate of e⁺e^- → τ⁺τ^-γ and for the branching ratio of τ^- → ν_τ µ^-ν_µγ. Included in this study is the first direct measurement of radiative tau decay. Using e⁺e^- annihilation data taken at 29 GeV center-of-mass energy with the Mark II detector, we find the ratio of the measured τ^- → ν_τ µ^-ν_µγ branching fraction to the expected value from QED to be 1.03 ± 0.42. The ratio of measured-to-predicted number of events from radiative T production, e⁺e^- → τ⁺τ^-γ, where one of the τ's decay to μνν is found to be 0.91 ± 0.20. We have not seen an indication of anomalous behavior in radiative tau events.

Production of the chironomids of the Uchinsk Reservoir. [Translation of: Methods for the estimation of production of aquatic animals. (Handbook and papers) (ed. G. G. Vinberg) p226-239. Minsk, Vysheishaya Shkola, 1968]

The method of E.V. Borutski was used for determining the production of chironomids, that is, the dynamics of the number and biomass of the larvae were analysed, their death, a calculation of emergence and the number of deposited egg layings was carried out. In addition to the method of Borutski, the authors also calculated the seasonal dynamics of the number of larvae of the younger age stages in the microbenthos.

On methods of evaluation of bacterial production. [Translation from: Lietuvas TSR Mokslu Akademijos Darbai, C Serija 2(55) 3-9, 1971.]

By now a great deal of work is known concerning the methods of determining the production of bacteria or similar questions; among these the problems of a common terminology is discussed. The article discusses formulae of production of bacterial populations over time.

Glycocalyx production in teleosts [Translation from: Verhandlungen der Deutschen Zoologischen Gesellschaft, p.286, 1970]

Shielding the organism against harmful effects from the environment is one of the most important tasks of the outer covering of all animals. The epidermis of primarily aquatic organisms and the epithelia of organs which are exposed to water, such as the digestive or the urinary system, possess a film of glycoproteins and mucopolysaccharides, the glycocalyx. This short paper examines the relationship of the mucus cells with the glycocalyx.

Flood circulation in oligomictic lakes: an undervalued reason for restriction of zooplankton production [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 22 9-52, 1967]

Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.