Information about the polarization of x-ray photons can be determined by probing the direction of emission of photoelectrons and the profile of the electron cloud produced in the detecting medium. In this work we present Monte Carlo results for the electron clouds produced in xenon by the absorption of x-rays, considering a simplenon-relativistic dipole approach to the angular differential photoionization cross...
Descreve-se um método de isolamento de mitocôndrias acopladas de tilápia-do-nilo Oreochromis niloticus, isoladas de células hepáticas de peixes adultos. As mitocôndrias estavam metabolicamente ativas, sendo capazes de realizarem fosforilação oxidativa, de acordo com os valores do quociente de controle respiratório. Os valores de controle respiratório obtidos com malato/piruvato (complexo I) e com succinato (com...
The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%), nalidixic acid (64%), ampicilin (41%), sulfamethoxazole/trimethoprin (36%), sulfonamide (34%), cloranphenicol (274%)...
Synthesis of new 2-aminobenzimidazole-1-carbamates was accomplished by carbamoylation of 2-aminobenzimidazole using different substituted phenyl chloroformates. The aqueous hydrolysis of the new compounds was examined in the pH range 1-13 at 25 ºC. The evaluated kinetic parameters led to the conclusion that up to pH 4 reaction proceeds by a bimolecular attack of water to the N-protonated substrate. This is the ...
2007
2006
Com o objectivo de obter informação sobre as espécies de coccinelídeos associadas ao olival da Beira Interior, em 2003 e 2004 efectuaram-se amostragens em dois olivais considerados 401 representativos das condições da região. As amostragens decorreram entre Maio e Outubro de cada um dos anos, a uma periodicidade aproximadamente quinzenal, tendo consistido no batimento de dois ramos por árvore em cada uma de 25 ...
The results of an experimental determination of the pulse-height distortion in soft X-ray spectra in gaseous xenon detectors are presented. The study confirms previous Monte Carlo simulation results and emphasizes the importance of the electric field in the drift region in reducing spectral degradation while the effect of a strong magnetic field in the same region is shown to be negligible ; JNICT (Junta Nac...
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