304 research outputs found
An overview on armor research for the laser fusion project HiPER
During the current preparatory phase of the European laser fusion project HiPER, an intensive effort has being placed to identify an armour material able to protect the internal walls of the chamber against the high thermal loads and high fluxes of x-rays and ions produced during the fusion explosions. This poster addresses the different threats and limitations of a poly-crystalline Tungsten armour. The analysis is carried out under the conditions of an experimental chamber hypothetically constructed to demonstrate laser fusion in a repetitive mode, subjected to a few thousand 48MJ shock ignition shots during its entire lifetime. If compared to the literature, an extrapolation of the thermomechanical and atomistic effects obtained from the simulations of the experimental chamber to the conditions of a Demo reactor (working 24/7 at hundreds of MW) or a future power plant (producing GW) suggests that âstandardâ tungsten will not be a suitable armour. Thus, new materials based on nano-structured W and C are being investigated as possible candidates. The research programme launched by the HiPER material team is introduced
Seminal quality, testicle and epididymis morphology of bulls fed a diet containing gossypol
The objective was to evaluate the effect of intake of free gossypol on sperm quality and morphology of the testicles and epididymis of Nelore bulls. Twelve bulls were fed diets containing 3.3g of free gossypol/bull/day (cottonseed) (Group 1, n = 6) and a diet free of gossypol (Group 2, n = 6), respectively. Semen samples were collected in the beginning and end of the experiment which lasted 73 days. In the end of the study the testes and epididymis of bulls were removed to study the effect of free gossypol on histological characteristics. The average consumption of 3.3g of free gossypol/bull/day (mean 7.1mg of free gossypol/kg/day) reduced motility and sperm concentration and increased the percentage of major and total sperm defects, as well as the animals showing testes with seminiferous tubules of smaller thickness, fewer layers of spermatogenic lineage cells, smaller epididymal epithelium thickness and smaller number of sperm within the epididymal ducts, compared to animals with a diet free of gossypol (Group 2). The consumption of 3.3g of free gossypol/bull/day led to changes in morphology and morphometry of the testes and epididymis and reduced sperm quality of bulls.Objetivou-se avaliar o efeito da ingestĂŁo de gossipol livre sobre a qualidade espermĂĄtica e a morfologia dos testĂculos e dos epidĂdimos de touros da raça Nelore. Doze touros receberam dieta contendo 3,3g de gossipol livre/touro/dia (caroço de algodĂŁo) (Grupo 1, n=6) e dieta isenta de gossipol (Grupo 2, n=6), respectivamente. Foram realizadas coletas de sĂŞmen no inĂcio e no final do experimento, que teve duração de 73 dias. Ao final do estudo, foram retirados os testĂculos e os epidĂdimos dos touros para se estudar o efeito do gossipol livre sobre as caracterĂsticas histolĂłgicas. O consumo mĂŠdio de 3,3g de gossipol livre/touro/dia (mĂŠdia 7,1mg de gossipol livre/kg/dia) reduziu a motilidade e a concentração espermĂĄtica e aumentou a porcentagem de defeitos espermĂĄticos maiores e totais. AlĂŠm disso, os animais apresentaram testĂculos com tĂşbulos seminĂferos de menor espessura de parede, menor nĂşmero de camadas de cĂŠlulas espermatogĂŞnicas, menor espessura do epitĂŠlio epididimĂĄrio e menor nĂşmero de espermatozoide no interior dos ductos epidĂdimĂĄrios, em relação aos animais com dieta isenta de gossipol (Grupo 2). O consumo de 3,3g de gossipol livre/touro/dia acarretou alteraçþes na morfologia e na morfometria dos testĂculos e dos epidĂdimos e reduziu a qualidade espermĂĄtica dos touros.Universidade de CuiabĂĄ Faculdade de Medicina VeterinĂĄriaUFMS Faculdade de Medicina VeterinĂĄria e ZootecniaEpamigUniversidade Federal do Mato GrossoUNIFESP-EPMUNIFESP, EPMSciEL
Temperature Evolution and Light Species Diffusion in Armor and Structural Material for Inertial Fusion Reactor Chambers: a Case for HiPER 4a
One of the most advance designs for HiPER fusion reactor is a spherical chamber 10 m in diameter based on dry wall concept. In this system, the first wall will have to withstand short energy pulses of 5 to 20 MJ at a repetition rate of 0.5-10 Hz mostly in form of X-rays and charged particles. To avoid melting of the inner surface, the first wall consists on a thin armor attached to the structural material. Thickness (th) and material of each layer have to be chosen to assure the proper functioning of the facility during its planned lifetime
Diffusion Issues of Heat and Light Species in Laser Fusion Devices
There are several heat and mass diffusion problems which affect to the IFC chamber design. New simulation models and experiments are needed to take into account the extreme conditions due to ignition pulses and neutron flu
Assessment of the behaviour of hidrogen isotopes and helio in the W armor for inertial confinement
After 10s the 90-99% of particles are released from the tungsten wall, mostly, towards the chamber. No element crosses the tungsten wall to the cooler. With 1x1022p/m2of He inside the W wall, He starts occasioning damages in the material. For case HiPER4a that is not a proble
Anålise retrospectiva dos fatores associados à distribuição da tuberculose bovina no estado do Rio de Janeiro
Qualidade de cortes congelados de tambaqui cultivado
The objective of this work was to determine the proximate composition, yield, the influence of frozen storage time on the quality, and the cut type x shelf life relation of rib, tenderloin and flitch cuts of tambaqui (Colossoma macropomum) reared in a fish farm, during 180 days of cold storage. The cuts were stored in polyethylene bags and frozen at -25oC. Sensory, physicochemical and microbiological analyses were carried out. The pH, total volatile basic nitrogen, and thiobarbituric acid-reactive substance values, as well as the results of the microbiological analyses, proved to be good indexes for freshness evaluation along the storage time. The cut rib was more susceptible to oxidation than the other cuts. However, the cuts remained appropriate for consumption during the experiment, under correct handling and good hygienic practices between harvest and storage
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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