First test of a high voltage feedthrough for liquid Argon TPCs connected to a 300 kV power supply

Voltages above a hundred kilo-volt will be required to generate the drift field of future very large liquid Argon Time Projection Chambers. The most delicate component is the feedthrough whose role is to safely deliver the very high voltage to the cathode through the thick insulating walls of the cryostat without compromising the purity of the argon inside. This requires a feedthrough that is typically meters long and carefully designed to be vacuum tight and have small heat input. Furthermore, all materials should be carefully chosen to allow operation in cryogenic conditions. In addition, electric fields in liquid argon should be kept below a threshold to reduce risks of discharges. The combination of all above requirements represents significant challenges from the design and manufacturing perspective. In this paper, we report on the successful operation of a feedthrough satisfying all the above requirements. The details of the feedthrough design and its manufacturing steps are provided. Very high voltages up to unprecedented voltages of -300 kV could be applied during long periods repeatedly. A source of instability was observed, which was specific to the setup configuration which was used for the test and not due to the feedthrough itself.Comment: 13 pages, 9 figure

Underground Neutrino Detectors for Particle and Astroparticle Science: the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER)

The current focus of the CERN program is the Large Hadron Collider (LHC), however, CERN is engaged in long baseline neutrino physics with the CNGS project and supports T2K as recognized CERN RE13, and for good reasons: a number of observed phenomena in high-energy physics and cosmology lack their resolution within the Standard Model of particle physics; these puzzles include the origin of neutrino masses, CP-violation in the leptonic sector, and baryon asymmetry of the Universe. They will only partially be addressed at LHC. A positive measurement of $\sin^22\theta_{13}>0.01$ would certainly give a tremendous boost to neutrino physics by opening the possibility to study CP violation in the lepton sector and the determination of the neutrino mass hierarchy with upgraded conventional super-beams. These experiments (so called ``Phase II'') require, in addition to an upgraded beam power, next generation very massive neutrino detectors with excellent energy resolution and high detection efficiency in a wide neutrino energy range, to cover 1st and 2nd oscillation maxima, and excellent particle identification and $\pi^0$ background suppression. Two generations of large water Cherenkov detectors at Kamioka (Kamiokande and Super-Kamiokande) have been extremely successful. And there are good reasons to consider a third generation water Cherenkov detector with an order of magnitude larger mass than Super-Kamiokande for both non-accelerator (proton decay, supernovae, ...) and accelerator-based physics. On the other hand, a very massive underground liquid Argon detector of about 100 kton could represent a credible alternative for the precision measurements of ``Phase II'' and aim at significantly new results in neutrino astroparticle and non-accelerator-based particle physics (e.g. proton decay).Comment: 31 pages, 14 figure

Descritores epidérmicos de gramíneas (Poaceae): um guia para identificação da dieta de herbívoros usando o programa Delta.

Este guia tem como objetivo auxiliar os técnicos nas leituras de lâminas fecais a partir da definição de decritores anatômicos da epiderme foliar de gramíneas que foram inseridos no sistema DELTADIET, desenvolvido pela Embrapa Pantanal, Royal Zoological Society of Scotland e apoio de outras Instituições. Essas informações serão úteis não apenas como guia para a identificação da dieta dos animais do Pantanal como também para animais de outras regiões, além de contribuir para a caracterização das forrageiras nativas da região.bitstream/item/79824/1/BP95.pd

Efeito de diferentes ordenhadores sobre o comportamento de ordenha de vacas Jersey no estado do Rio Grande do Sul.

ZOOTEC 2011

The Zeeman effect in the G band

We investigate the possibility of measuring magnetic field strength in G-band bright points through the analysis of Zeeman polarization in molecular CH lines. To this end we solve the equations of polarized radiative transfer in the G band through a standard plane-parallel model of the solar atmosphere with an imposed magnetic field, and through a more realistic snapshot from a simulation of solar magneto-convection. This region of the spectrum is crowded with many atomic and molecular lines. Nevertheless, we find several instances of isolated groups of CH lines that are predicted to produce a measurable Stokes V signal in the presence of magnetic fields. In part this is possible because the effective Land\'{e} factors of lines in the stronger main branch of the CH A$^{2}\Delta$--X$^{2}\Pi$ transition tend to zero rather quickly for increasing total angular momentum $J$, resulting in a Stokes $V$ spectrum of the G band that is less crowded than the corresponding Stokes $I$ spectrum. We indicate that, by contrast, the effective Land\'{e} factors of the $R$ and $P$ satellite sub-branches of this transition tend to $\pm 1$ for increasing $J$. However, these lines are in general considerably weaker, and do not contribute significantly to the polarization signal. In one wavelength location near 430.4 nm the overlap of several magnetically sensitive and non-sensitive CH lines is predicted to result in a single-lobed Stokes $V$ profile, raising the possibility of high spatial-resolution narrow-band polarimetric imaging. In the magneto-convection snapshot we find circular polarization signals of the order of 1% prompting us to conclude that measuring magnetic field strength in small-scale elements through the Zeeman effect in CH lines is a realistic prospect.Comment: 22 pages, 6 figures. To be published in the Astrophysical Journa

Modificação do fenótipo linfocitário e aumento da sobrevida do enxerto de pele após a terapia com FTY720 + FK506

The development of new drugs to be associated with calcineurin inhibitors and promote additional immunosuppression with fewer side effects is the goal in transplantation. FTY720 is a new synthetic compound which presents immunomodulatory properties which are not fully understood. It has been reported that the main mechanism of action of FTY720 is to reduce the peripheral lymphocyte count by redirecting these cells toward secondary lymphoid organs. Skin allograft transplantation in a fully mismatched strain combination was used to investigate the potential of FTY720 alone or in combination with a calcineurin inhibitor - FK506 - in preventing rejection. The number and phenotype of immune system cells was also evaluated. FTY720 alone or in combination with FK506 provided significant skin allograft survival. FTY720+FK506 therapy was associated with decreases of total lymphocyte numbers in spleen and blood, and increases in apoptosis levels in splenocytes. In FTY720 isolated treatment, a significant decrease in the CD4 expression and significantly lower expressions of MHC II and ICAM-1 molecules were observed in spleen lymphocytes. Despite of allograft survival being the same in both FTY720 and FTY720+FK506 treated groups, the association of drugs was associated with the absence of macroscopic skin necrosis for a longer period than the other treatments (FTY720, FK506) and histology showed less cell infiltration. Our results suggest that a decrease of effector T cells due to elevated levels of apoptosis and impairment in the appearance of antigens were events associated with FTY720+FK506 administration.O objetivo na área dos transplantes é o desenvolvimento de novas drogas que possam ser associadas a inibidores da calcineurina para evitar o processo de rejeição e causar menos efeitos colaterais. FTY720 é um novo composto sintético que apresenta propriedades imunomoduladoras não completamente elucidadas. Foi relatado que o principal mecanismo de ação do FTY720 é a redução do número de linfócitos periféricos através do redirecionamento dessas células para órgãos linfóides secundários. O alotransplante de pele entre linhagens de camundongos completamente incompatíveis quanto ao MHC foi usado para investigar o potencial de FTY720 isolado ou em combinação com um inibidor da calcineurina - FK506 - na prevenção da rejeição. Também foram avaliados o número e fenótipo das células do sistema imune. A administração de FTY720 como monoterapia ou FTY720+FK506 associou-se a uma diminuição do número total de linfócitos no baço e no sangue e aumento dos níveis de apoptose nos esplenócitos. No grupo tratado somente com FTY720, foi observada uma diminuição mais importante da expressão de CD4 e expressão significativamente menor de moléculas de MHC II e ICAM-1. Apesar de a sobrevida do aloenxerto ter sido igual para os grupos tratados com FTY720 ou FTY720 +FK506, a associação das drogas promoveu ausência de necrose macroscópica da pele por um período maior do que os outros tratamentos (FTY720, FK506) e os achados histológicos mostraram menor infiltrado celular. Nossos resultados sugerem que uma diminuição do número de células T efetoras devido a elevados níveis de apoptose e o prejuízo da apresentação de antígenos foram os eventos associados à administração de FTY720+FK506.Faculdade de Medicina de São José do Rio PretoUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Descritores epidérmicos de cyperaceae forrageiras - guia para identificação da dieta de herbívoros usando o programa Delta.

Este Boletim de Pesquisa lista os descritores anatômicos da epiderme das folhas das forrageiras de Cyperaceae. Esta família constitui uma das três famílias de forrageiras mais importantes do Pantanal, com aproximadamente 90 espécies. Como muitas dessas espécies fazem parte da dieta dos diferentes herbívoros domésticos e silvestres que habitam o Pantanal, a definição desses descritores epidérmicos para uso no sistema Delta é de fundamental importância para a leitura de lâminas fecais visando a identificação da dieta. Esta publicação, junto com os boletins de pesquisa números 95 e 96, vai facilitar o uso do programa Delta para estudos da dieta de herbívoros no Pantanal, e também para o desenvolvimento de adaptação para estudos desse tipo em outras regiões do país.bitstream/item/79826/1/BP97.pd

Inflection Point Inflation and Time Dependent Potentials in String Theory

We consider models of inflection point inflation. The main drawback of such models is that they suffer from the overshoot problem. Namely the initial condition should be fine tuned to be near the inflection point for the universe to inflate. We show that stringy realizations of inflection point inflation are common and offer a natural resolution to the overshoot problem.Comment: 15 pages, 2 figures, refs. adde