1,079 research outputs found
Evidence for partial rotation alignment in proton emitting 121Pr
Abstract Using nonadiabatic quasiparticle calculations we reproduce the experimental half-life for proton radioactivity in 121Pr assuming that the decaying state has angular momentum J π = 7 / 2 − , thus showing for the first time clear evidence for partial rotation alignment in a proton emitting nucleus. The treatment of the pairing interaction in the BCS approach produces profound changes in the ordering of energy levels, and at high deformation, the state 7 / 2 − coming from the h 11 / 2 spherical shell becomes the bandhead
Lack of mutations of exon 2 of the MEN1 gene in endocrine and nonendocrine sporadic tumors
In addition to the mutations that underlie most cases of the multiple endocrine neoplasia type 1 (MEN1) syndrome, somatic mutations of the MEN1 gene have also been described in sporadic tumors like gastrinomas, insulinomas and bronchial carcinoid neoplasm. We examined exon 2 of this gene, where most of the mutations have been described, in 148 endocrine and nonendocrine sporadic tumors. DNA was obtained by phenol/chloroform extraction and ethanol precipitation from 92 formalin-fixed, paraffin-embedded samples, and from 40 fresh tumor tissue samples. We used 5 pairs of primers to encompass the complete coding sequence of exon 2 of the MEN1 gene that was screened by the polymerase chain reaction-single-stranded conformation polymorphism (PCR-SSCP) technique in 78 sporadic thyroid cancers: 28 follicular adenomas, 35 papillary carcinomas, 14 follicular carcinomas, and 1 anaplastic thyroid carcinoma. We also examined 46 adrenal lesions (3 hyperplasias, 3 adenomas and 35 adrenocortical carcinomas, 2 pheochromocytomas, 2 ganglioneuroblastomas, and 1 lymphoma) and 24 breast cancers (6 noninvasive, 16 infiltrating ductal, and 2 invasive lobular tumors). The PCR product of 5 tumors suspected to present band shifts by SSCP was cloned. Direct sense and antisense sequencing did not identify mutations. These results suggest that the MEN1 gene is not important in breast, thyroid or adrenal sporadic tumorigenesis. Because the frequency of mutations varies significantly among tumor subgroups and allelic deletions are frequently observed at 11q13 in thyroid and adrenal cancers, another tumor suppressor gene residing in this region is likely to be involved in the tumorigenesis of these neoplasms.86186
Computational Fluid Dynamics Modeling of Ammonia Concentration in a Commercial Broiler Building
In the present study, a numerical model was developed to predict the flow pattern inside a broiler building. The model intends to predict the velocities fields inside the domain and am-monia (NH3) emitted or released by litter from poultry housing. The numerical model developed in Computational Fluid Dynamics (CFD) commercial code, intends to represent a commercial broiler building, and intends to simulate the 3D and heat transfer, in steady state flow. The evaporative cooling pads were also included in the model. The validation of the model was based in experimental measurements obtained in previous studies. The simulations were fo-cused on Summer, Winter and also Mid-Season situation. The numerical results of NH3 concen-tration were compared with the experimental measurements, and a quite good agreement was verified. The numerical results allowed the characterization of: the inside flow pattern devel-oped for the summer and winter situation; the inside NH3 distribution, and the velocity field distribution inside the broiler building. It was found that NH3 concentration increases along the tunnel, especially in low flow rate imposed from the exhaust fan. Also, it was verified that the low velocities inside domain are no sufficient to remove the gaseous pollutants.info:eu-repo/semantics/publishedVersio
Modelação numérica da encurvadura lateral de vigas em aço inoxidável sujeitas a temperaturas elevadas
A utilização de elementos estruturais em aço inoxidável tem vindo a crescer nos últimos anos, devido quer à sua maior resistência à corrosão quer à sua maior resistência mecânica ao fogo, quando comparado com o aço carbono.
Com o objectivo de modelar pelo Método dos Elementos Finitos a encurvadura lateral de vigas I em aço inoxidável sujeitas a altas temperaturas, introduziram-se as leis constitutivas de diferentes tipos de aço inoxidável no programa SAFIR. Trata-se de um programa de elementos finitos para análise não-linear geométrica e material, especialmente desenvolvido na Universidade de Liège para o estudo de estruturas sujeitas à acção do fogo.
Neste trabalho pretende-se efectuar uma breve comparação das propriedades mecânicas do aço carbono com as do aço inoxidável a altas temperaturas e os resultados numéricos obtidos com esta nova versão do programa SAFIR, adaptado para tratar o aço inoxidável, com resultados obtidos com o programa comercial ANSYS, utilizando elementos finitos de viga e de casca
Numerical modelling of the behaviour of a stainless steel portal frame subjected to fire
It is known that stainless steel has a better fire performance than carbon steel, which
can lead to a growing utilization of this kind of steel in structures. In fact, although more
expensive than the carbon steel, structures in stainless steel can be competitive because of its
smaller thermal protection need.
With the purpose of modelling by Finite Element Method the behaviour of a stainless
steel framed structure, without any protection, submitted to fire, has been introduced in the
SAFIR program, the material properties of the stainless steel. SAFIR is a finite element
program with geometrical and material non-linear analysis, specially developed in the
University of Liège for studying structures subjected to fire. The thermal and mechanical
properties of the stainless steel, introduced in the SAFIR program are temperature dependent,
according to the Eurocode 3. The stress strain relationship, the thermal conductivity and the
specific heat are the most important material properties for the structure analysis at high
temperatures. These properties in stainless steel are considerable different from carbon steel.
The behaviour of the structure will be compared in the two different materials:
stainless steel 1.4301 (also known as 304) and carbon steel S235. The benefits of using
stainless steel in the fire resistance of the structure, which is 3 times higher than the one obtained with carbon steel, avoiding any fire protection material needed to fulfil the necessary
fire requirements will be shown
Modelação numérica do comportamento ao fogo de uma estrutura em aço inoxidável em situação de incêndio
O aço inoxidável tem reconhecidamente uma resistência ao fogo superior ao aço
carbono pelo que é de prever uma crescente utilização deste tipo de aço para fins estruturais.
De facto, embora mais caro que o aço carbono, o aço inoxidável pode conduzir a estruturas
competitivas em virtude de necessitarem de uma menor quantidade de material de protecção
térmica ou mesmo, em alguns casos, não ser necessária protecção contra incêndio, como
sucede na estrutura apresentada neste artigo.
Com o objectivo de modelar pelo Método dos Elementos Finitos o comportamento de
uma estrutura porticada de um edifício em aço inoxidável em situação de incêndio,
introduziu-se a sua lei constitutiva no programa SAFIR, um programa de elementos finitos
para análise não-linear geométrica e material, especialmente desenvolvido na Universidade de
Liège para estudo de estruturas sujeitas à acção do fogo. Neste programa as propriedades
térmicas e mecânicas do aço são função da temperatura, de acordo com o Eurocódigo 3.
Compara-se o comportamento da estrutura em aço inoxidável 1.4301 (também
conhecido como 304) com o comportamento que teria se a estrutura fosse em aço carbono
S235 e realçam-se os benefícios da utilização do aço inoxidável resultantes da sua maior
resistência ao fogo
Modelação numérica de elementos estruturais em aço inoxidável com secções esbeltas em situação de incêndio
Neste trabalho, a resposta estrutural de elementos esbeltos em aço inoxidável
submetidos a incêndio é analisada numericamente através de programas de elementos
finitos geométrica e materialmente não lineares. Com o intuito de realizar estas
simulações, foram necessárias duas alterações no programa SAFIR: i) foi introduzida a
lei constitutiva 2D do aço inoxidável, para ser usada em elementos de casca e ii) foi
introduzida a possibilidade do programa considerar tensões residuais em elementos
finitos de casca. A lei constitutiva utilizada do aço inoxidável foi a apresentada na parte
1.2 do Eurocódigo 3. Para modelar o endurecimento exibido pelos aços inoxidáveis,
usando a formulação de elementos de casca, foi necessária uma aproximação à referida
lei constitutiva do Eurocódigo 3. Imperfeições geométricas locais e globais foram
consideradas nas simulações numéricas. Por fim, este trabalho mostrará também a
influência das tensões residuais na capacidade resistente em situação de incêndio, de
elementos estruturais esbeltos em aço inoxidável
Comparison of dimensionality reduction methods to predict genomic breeding values for carcass traits in pigs
A significant contribution of molecular genetics is the direct use of DNA information to identify genetically superior individuals. With this approach, genome-wide selection (GWS) can be used for this purpose. GWS consists of analyzing a large number of single nucleotide polymorphism markers widely distributed in the
genome; however, because the number of markers is much larger than the number of genotyped individuals, and such markers are highly correlated, special statistical methods are widely required. Among these methods, independent component regression, principal component regression, partial least squares, and partial principal components stand
out. Thus, the aim of this study was to propose an application of the methods of dimensionality reduction to GWS of carcass traits in an F2 (Piau x commercial line) pig population. The results show similarities between the principal and the independent component methods and provided the most accurate genomic breeding estimates for most
carcass traits in pigs
Use of multivariate analysis to evaluate genetic groups of pigs for dry-cured ham production
AbstractRecords of a pig population used for dry-cured ham production were used to evaluate genetic groups by multivariate analysis. The investigated genetic groups were as follows: DULL=Duroc×(Landrace×Large White), DULA=Duroc×Landrace, DUWI=Duroc×Large White, WIWI=Large White and DUDU=Duroc. Two groups were obtained for the carcass traits hot carcass weight (HCW), backfat thickness (BT) and loin depth (LD), with the groups including 597 and 341 animals harvested at 130kg and at 160kg weights, respectively. Two groups were also found for ham traits gross ham weight (GHW), trimmed ham weight (THW), ham inner layer fat thickness (HIFT), ham outer layer fat thickness (HOFT), pH (PH), and Göfo value, with 393 and 91 animals harvested at 130kg and 160kg weights, respectively. The analysis was performed within each group of traits and harvest weights, and the animals without records were excluded. The first and the second canonical variables explained 97.5% and 93.6% of the total variation for the carcass traits at 130kg and 160kg, respectively, and 88.8% of ham traits at 130kg. In the dispersion graph concerning the canonical means, a significant distance was observed between the genetic groups DUDU and WIWI for the carcass traits at 130kg and 160kg and the ham traits at 130kg. The 50% Duroc animals exhibited little dispersion regarding the carcass traits at 130kg and 160kg and were not divergent from the DUDU genetic group for the ham traits at 130kg. In a cluster analysis using the single linkage method, DULL, DULA and DUWI were grouped with a high similarity level for the carcass traits at 130kg and 160kg and ham traits at 130kg. Using the Tocher optimization method, 50% Duroc crossbred and 100% Duroc purebred animals were grouped for the ham traits at 130kg, suggesting that for ham traits, 50% Duroc animals were similar to 100% Duroc purebred animals. In this context, the genetic groups Duroc×Large White, Duroc×Landrace and Duroc×(Landrace×Large White) are recommended for use in producing dry-cured ham
Traçando mapas: a teoria histórico-cultural e as contribuições para a pesquisa com crianças e suas espacialidades
Este texto busca fazer uma reflexão sobre as pesquisas sistematizadas no campo da infância, tendo como enfoque principal as estratégias de pesquisas “com crianças”. O recorte ao qual nos dedicamos são as relações que as crianças estabelecem com o meio, tendo como foco principal as suas espacialidades. A partir das contribuições de pesquisas que se aportam em estratégias de natureza qualitativas e fundamentadas nos aportes da teoria históricas cultural, elege-se o conceito de vivência (perejivanie) como mote em torno do qual nossos trabalhos são desenvolvidos. Para isso, traça-se, inicialmente, a origem da pesquisa com base em paradigmas positivistas e evidenciam-se alguns caminhos que buscaram romper com essa perspectiva: os postulados etnográficos de Malinovky e Boas; o Interacionismo simbólico, cujo precursor é George Herbert Mead; a Etnometodologia de Harold Garfinkel; as contribuições de Marx e os princípios estabelecidos por Vigotski e seus colaboradores.</p
- …