ASCA Slew Survey

We are systematically analyzing ASCA GIS data taken during the satellite attitude maneuver operation. Our motivation is to search for serendipitous hard X-ray sources and make the ASCA Slew Survey catalog. During its operational life from 1993 February to 2000 July, ASCA carried out more than 2,500 maneuver operations, and total exposure time during the maneuver was ~415 ksec after data screening. Preliminary results are briefly reported.Comment: Proceedings for "X-ray surveys in the light of new observations", Santander (Spain), 2002 September. 1 pag

Aclimatação e quarentena: manejos muitas vezes esquecidos - quando não realizados, podem representar grandes perdas.

Quem nunca comprou um peixe e ao chegar em casa colocouo direto no aquário e, em um período compreendido entre quatro e sete dias, ele morreu ou todos os peixes do aquário começam a adoecer? Bom, esse é um cenário bem mais comum do que se imagina. Isso ocorre principalmente devido à falta de cuidados e de manejos adequados para a manutenção desse animal em cativeiro.bitstream/item/123109/1/12-aclimatacao-e-quarentena.pd

Nambu-Goldstone Mechanism in Real-Time Thermal Field Theory

In a one-generation fermion condensate scheme of electroweak symmetry breaking, it is proven based on Schwinger-Dyson equation in the real-time thermal field theory in the fermion bubble diagram approximation that, at finite temperature $T$ below the symmetry restoration temperature $T_c$, a massive Higgs boson and three massless Nambu-Goldstone bosons could emerge from the spontaneous breaking of electroweak group $SU_L(2)\times U_Y(1) \to U_Q(1)$ if the two fermion flavors in the one generation are mass-degenerate, thus Goldstone Theorem is rigorously valid in this case. However, if the two fermion flavors have unequal masses, owing to "thermal flactuation", the Goldstone Theorem will be true only approximately for a very large momentum cut-off $\Lambda$ in zero temperature fermion loop or for low energy scales. All possible pinch singularities are proven to cancel each other, as is expected in a real-time thermal field theory.Comment: 11 pages, revtex, no figure, Phys. Rev. D, to appea

Identity of the imaginary-time and real-time thermal propagators for scalar bound states in a one-generation Nambu-Jona-Lasinio model

By rigorous reanalysis of the results, we have proven that the propagators at finite temperature for scalar bound states in one-generation fermion condensate scheme of electroweak symmetry breaking are in fact identical in the imaginary-time and the real-time formalism. This dismisses the doubt about possible discrepancy between the two formalisms in this problem. Identity of the derived thermal transformation matrices of the real-time matrix propagators for scalar bound states without and with chemical potential and the ones for corresponding elementary scalar particles shows similarity of thermodynamic property between the two types of particles. Only one former inference is modified, i.e. when the two flavors of fermions have unequal nonzero masses, the amplitude of the composite Higgs particle will decay instead grow in time.Comment: 5 pages, revtex4, no figure

Aumentar a produção de peixes ornamentais cultivados: um desafio ambiental e econômico

O comércio internacional de organismos aquáticos ornamentais cresce, desde 1985, a uma taxa média anual de 14%. Mundialmente os maiores produtores de peixes ornamentais em cativeiro estão localizados em Singapura, Malásia, Hong Kong,Tailândia, Indonésia, Japão, Israel e sul dos Estados Unidos, que contribuem com cerca de 90% deste setor no comércio.bitstream/item/123077/1/07-Aumentar-a-producao.pd

Isolamento e caracterização de Flavobacterium columnare de tambaqui (Colossoma macropomum).

O objetivo deste estudo foi de realizar o isolamento e a caracterização de Flavobacterium columnare de tambaqui (Colossoma macropomum) criado em tanques escavados na região de Rio Preto da Eva - AM

Locating the Warm-Hot Intergalactic Medium in the Simulated Local Universe

We present an analysis of mock spectral observation of warm-hot intergalactic medium (WHIM) using a constrained simulation of the local universe. The simulated map of oxygen emission lines from local WHIM reproduces well the observed structures traced by galaxies in the real local universe. We further attempt to perform mock observations of outer parts of simulated Coma cluster and A3627 adopting the expected performance of DIOS (Diffuse Intergalactic Oxygen Surveyor), which is proposed as a dedicated soft X-ray mission to search for cosmic missing baryons. We find that WHIMs surrounding nearby clusters are detectable with a typical exposure time of a day, and thus constitute realistic and promising targets for DIOS. We also find that an X-ray emitting clump in front of Coma cluster, recently reported in the XMM-Newton observation, has a counterpart in the simulated local universe, and its observed spectrum can be well reproduced in the simulated local universe if the gas temperature is set to the observationally estimated value.Comment: 25 pages, 3 tables, 16 figures. Accepted for publication in PASJ. High resolution PS/PDF files are available at http://www-utap.phys.s.u-tokyo.ac.jp/~kohji/research/x-ray/index.htm