Statistical Multifragmentation in Central Au+Au Collisions at 35 MeV/u

Multifragment disintegrations, measured for central Au + Au collisions at E/A = 35 MeV, are analyzed with the Statistical Multifragmentation Model. Charge distributions, mean fragment energies, and two-fragment correlation functions are well reproduced by the statistical breakup of a large, diluted and thermalized system slightly above the multifragmentation threshold.Comment: Latex file, 8 pages + 4 postscript figures available upon request from [email protected]

Multifragment production in Au+Au at 35 MeV/u

Multifragment disintegration has been measured with a high efficiency detection system for the reaction $Au + Au$ at $E/A = 35\ MeV$. From the event shape analysis and the comparison with the predictions of a many-body trajectories calculation the data, for central collisions, are compatible with a fast emission from a unique fragment source.Comment: 9 pages, LaTex file, 4 postscript figures available upon request from [email protected]. - to appear in Phys. Lett.

Nuclear temperature measurements with helium isotopes

Temperatures extracted with the family of (He-3, He-4) isotope ratio thermometers, T-He, have been studied and cross-checked with temperatures, T(He-4*) constructed from excited and ground state populations of He-4. Empirical correction factors provide baseline corrections for sequential decay effects for T-He < 4.5 MeV, independent of projectile, target and incident energies. After corrections for fluctuations due to sequential decay, statistical calculations predict that T-He, and T(He-4*) should agree. (C) 1998 Published by Elsevier Science B.V. All rights reserved

Thermal source parameters in Au+Au central collisions at 35 A MeV

31Central Au+Au collisions at 35 A MeV are analyzed to find the characteristics of a thermal source, in the framework of the statistical multifragmentation model SMM. A recently introduced backtracing protocol provides an effective comparison of theory and experiment. For the first time the distributions of the central source parameters (density, mass number, excitation energy) are found. The collective energy of primary fragments is also deduced. It is shown that the backtracing procedure allows an estimation of the pre-equilibrium emission. (C) 1998 Published by Elsevier Science B.V.nonenoneP. Désesquelles;M. D'Agostino;A.S. Botvina;M. Bruno;N. Colonna;A. Ferrero;M.L. Fiandri;E. Fuschini;F. Gramegna;I. Iori;G.V. Margagliotti;P.F. Mastinu;P.M. Milazzo;A. Moroni;F. Petruzzelli;R. Rui;G. Vannini;J.D. Dinius;C.K. Gelbke;T. Glasmacher;D.O. Handzy;W.C. Hsi;M. Huang;M.A. Lisa;W.G. Lynch;C.P. Montoya;G.F. Peaslee;L. Phair;C. Schwarz;M.B. Tsang;C. WilliamsP., Désesquelles; M., D'Agostino; A. S., Botvina; M., Bruno; N., Colonna; A., Ferrero; M. L., Fiandri; E., Fuschini; F., Gramegna; I., Iori; Margagliotti, Giacomo; P. F., Mastinu; P. M., Milazzo; A., Moroni; F., Petruzzelli; Rui, Rinaldo; Vannini, Gianni; J. D., Dinius; C. K., Gelbke; T., Glasmacher; D. O., Handzy; W. C., Hsi; M., Huang; M. A., Lisa; W. G., Lynch; C. P., Montoya; G. F., Peaslee; L., Phair; C., Schwarz; M. B., Tsang; C., William

Fermentação da proteína de seis alimentos por microrganismos ruminais, incubados puros ou com monensina ou rumensin® Protein fermentation of six food souces by ruminal microorganisms, incubated alone or with monensin or rumensin®

Avaliaram-se os efeitos da fermentação in vitro de seis alimentos: fubá de milho (FM), farelo de soja (FS), farelo de trigo (FT), sorgo (SO), glúten de milho (GM) e uréia (UR), incubados puros ou com o antibiótico monensina, esse na forma pura para análise (Monensina) ou comercial (Rumensin®). O experimento constituiu-se de 18 unidades experimentais [três alimentos energéticos ou protéicos × três tratamentos (controle, monensina ou rumensin) × duas repetições], em que foram analisados os parâmetros ruminais: pH, produção de amônia (NH3), proteína bacteriana (PM), proteína solúvel (PS) e degradabilidade da proteína. As incubações foram feitas por 96 horas, em que as amostras foram coletadas às zero, 24, 48, 72 e 96 horas de fermentação. A leitura do pH foi realizada por um potenciômetro, enquanto as análises de amônia, proteínas microbiana e solúvel foram analisadas por técnicas colorimétricas. Não houve variações significativas no pH ao longo das incubações (6,94 inicial e 7,03 final). Não houve diferença entre as duas fontes de ionóforo testadas, contudo houve efeitos de interação entre antibiótico e alimento. A maior produção de NH3 nos alimentos protéicos foi encontrada para a UR, seguida do FS e GM, sendo reduzida na presença do ionóforo. A PS foi semelhante para os alimentos protéicos, aumentada pelo uso do ionóforo, exceto para a uréia. A PM decresceu para a UR e o FS, porém aumentou para o GM, sem ocorrer efeito de ionóforo. Nos alimentos energéticos a PM foi semelhante para os três alimentos e os ionóforos apenas reduziram a PM do SO. A maior produção de NH3 nos alimentos energéticos, foi encontrada para o FT, seguida do FM e SO. A PS foi semelhante para os alimentos energéticos. Houve correlações significativas das concentrações de NH3 com o pH final e %PB dos alimentos.<br>The in vitro fermentation of the following food sources were evaluated: corn meal (CM), soybean meal (SM), wheat meaddlings (WM), sorghum (SO), corn gluten feed (CG) and urea (UR), incubated alone or with monensin, pure for analysis or comercial (Rumensin®). The experiment constituted of 18 experimental units (three energetic or proteic food sources × three antibiotic (control, monensin or rumensin) × two duplicates), and the following fermentation parameters were analyzed: pH, ammonia production, microbial protein, soluble protein and protein degradability. The incubations were developed in 96 hours and samples were collected at 0, 24, 48, 72 and 96 hours of fermentation. The pH was measured in glass electrode and ammonia, microbial protein and soluble protein by colorimetry. The was no pH variation along the incubations (initial = 6.94 and final = 7.03). There was no difference between the two ionophore sources, but there was interactions between antibiotic and food sources. The greater ammonia production in the proteic sources was observed with UR, followed by SM and CG, being reduced by the ionophores. The soluble protein was similar for proteic food sources and increased by the ionophores, except for UR. The microbial protein decreased for UR and SM, but increased for CG, with no ionophore effect. In the energetic sources the ionophores only decreased microbial protein of SO. Greater ammonia production in the energetic sources was observed with WM, followed by CM and SO. The soluble protein and microbial protein were similar for all three food sources. Ammonia concentration in all incubations correlated with the final pH and %CP of the food sources