250 research outputs found

    Experimental bending tests of partially encased beams at elevated temperatures

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    This paper presents the result of an experimental research about the lateral torsional buckling instability during bending tests of Partially Encased Beams (PEB) at elevated temperature. A set of twenty seven four-point bending tests, grouped in ten series, were carried out to analyse the influence of relative slenderness, beam temperature and the shear bond conditions between concrete and steel in bending. In addition, this study compares the behaviour of PEB and bare steel beam under bending at room temperature. PEB specimens are based on IPE100 steel profiles, with two different lengths 2.4 m (medium series) and 3.9 m (large series), tested in bending using simple supporting conditions and exposed to different temperatures levels of 200 °C, 400 °C, and 600 °C. Two different shear bond conditions, between steel profile and lateral concrete, were analysed at 400 °C: one series with connectors formed by welded stirrups to the web and another series with natural adherence between steel and concrete, not welded stirrups. PEB attained lateral torsional buckling as deformed failure mode at the ultimate limit state, except for the case of PEB tested at 600 °C that results in a plastic hinge failure. The bending resistance was determined for the maximum load event (F u ) and for the displacement limit corresponding to L/30 (F L/30 ) and compared with the results of the Eurocode 3 part 1–2 simple calculation method, considering an adaptation of its formulae to PEB. The expected reduction in bending resistance at elevated temperature is in good agreement with the experimental reduction factor, when the deformation criterion is used.Authors acknowledge material support to the following companies and institutions: Arcelor – Mittal (Spain), J. Soares Correia (Portugal), Fepronor (Portugal), Hierros Furquet (Spain) and D. Samuel Solorzano Barruso Memorial Foundation-University of Salamanca (Spain).info:eu-repo/semantics/publishedVersio

    Configured distribution of the celiac artery in blue-fronted amazon (Amazona aestiva)

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    Foram descritas a origem e a distribuição da artéria celíaca em 20 papagaios-verdadeiros (Amazona aestiva), por meio do preenchimento do sistema arterial com solução de látex corado, fixado em solução de formol, para posterior dissecação de seus ramos colaterais. Como primeiro ramo, a artéria célica emitiu a artéria proventricular dorsal, que seguiu para o ventrículo como artéria gástrica dorsal e, em seguida, enviou a artéria proventricular ventral, que em 85% dos exemplares se originou diretamente da artéria celíaca, ou do seu ramo esquerdo em 15%. Em 25% dos casos, a artéria esplênica foi emitida antes da bifurcação em ramo esquerdo e direito. O ramo esquerdo foi responsável pela origem de ramos proventriculares, ramos pilóricos, artéria esplênica e artéria proventricular ventral, a qual emitiu ramos ao proventrículo e ao esôfago. A artéria celíaca também originou as artérias gástrica ventral e gástrica esquerda, que foram responsáveis pela emissão da artéria hepática esquerda. O ramo direito emitiu artérias esplênicas − que variaram de uma a sete −, duodenal − destinada ao segmento mais caudal da alça ascendente do duodeno, hepática direita − para o lobo direito do fígado. Em seu segmento terminal, o ramo direito dividiu-se em artérias gástrica direita − para o ventrículo −, pancreaticoduodenal − para o pâncreas, alças ascendente e descendente do duodeno e segmentos cranial do íleo e caudal do jejuno. A irrigação determinada pela artéria celíaca nos papagaios segue o que é proposto para aves de outros gêneros, apresentando divergências como ausência das artérias vesicular e ileocecal, bem como da vesícula biliar e ceco. _________________________________________________________________________________ ABSTRACTThis research was performed aiming to describe the origin and the distribution of the celiac artery in 20 blue fronted amazon (Amazona aestiva), through the completion of their circulatory system with an aqueous solution of colored latex, followed by fixation in formol for later dissection of the collateral branches. The first branch emitted the proventricular dorsal artery that headed to the ventricle as gastric dorsal artery and next emitted the proventricular ventral artery which originated on the celiac artery in 85% of the cases and in 15% had its origin on the left branch of the celiac artery. In 25% of the cases the splenic artery was emitted before the bifurcation on left and right branches. The left branch was responsible for the origin of the proventricular branches, piloric branches, splenic artery and proventricular artery, which emitted branches to the proventricle and esophagus. The celiac artery also emitted the gastric ventral artery and left gastric. The right branch emitted splenic arteries (that varied from a number of seven); duodenal bound for the more caudal segment of the ascendant segment of the duodenum and the right hepatica to the right liver lobe. On its terminal segment the right branch was divided into right gastric arteries to the ventricle and pancreaticduodenal to the pancreas, ascendant and descendant braces of the duodenum and to the cranial segments of the ileum and caudal of the jejune. The irrigation provided by the celiac artery in parrots remains the same as described for other bird genders showing as divergences: the lack of vesicular arteries and ileocecal as well the gall bladder and the cecos

    Classical analogous of quantum cosmological perfect fluid models

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    Quantization in the mini-superspace of a gravity system coupled to a perfect fluid, leads to a solvable model which implies singularity free solutions through the construction of a superposition of the wavefunctions. We show that such models are equivalent to a classical system where, besides the perfect fluid, a repulsive fluid with an equation of state pQ=ρQp_Q = \rho_Q is present. This leads to speculate on the true nature of this quantization procedure. A perturbative analysis of the classical system reveals the condition for the stability of the classical system in terms of the existence of an anti-gravity phase.Comment: Latex file, 10 pages, 3 figure

    Quantum cosmological perfect fluid model and its classical analogue

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    The quantization of gravity coupled to a perfect fluid model leads to a Schr\"odinger-like equation, where the matter variable plays the role of time. The wave function can be determined, in the flat case, for an arbitrary barotropic equation of state p=αρp = \alpha\rho; solutions can also be found for the radiative non-flat case. The wave packets are constructed, from which the expectation value for the scale factor is determined. The quantum scenarios reveal a bouncing Universe, free from singularity. We show that such quantum cosmological perfect fluid models admit a universal classical analogue, represented by the addition, to the ordinary classical model, of a repulsive stiff matter fluid. The meaning of the existence of this universal classical analogue is discussed. The quantum cosmological perfect fluid model is, for a flat spatial section, formally equivalent to a free particle in ordinary quantum mechanics, for any value of α\alpha, while the radiative non-flat case is equivalent to the harmonic oscillator. The repulsive fluid needed to reproduce the quantum results is the same in both cases.Comment: Latex file, 13 page

    Validation of a cable speedometer for butterfly evaluation

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    Getting fast results from the evaluation of swimmers is one of the most important goals to achieve with technological development in the field. The purpose of this study was to validate a real-time velocimetric device (speedometer) through the comparison of their results with computer assisted videogrametry. The sample included 7 international level swimmers (3 females and 4 males). Each swimmer performed four 25m trials, two at 200m race pace and two at 50m race pace. For each trial, two stroke cycles were studied, resulting on a total of 28 cycles SWIMMING EVALUATION, ADVICE AND BIOFEEDBACK Rev Port Cien Desp 6(Supl.2) 201–282 237 analysed. Hip v(t) curves obtained from speedometer and videogrametry were compared, as well as the speedometer hip curve with the one of the centre of mass (CM). The higher mean correlation obtained was between vhip1 and vhip2 (0.955±0.028), followed by vhip1 with vCM (0.920±0.049). The lower correlation was vhip2 vs. vCM (0.878±0.053). It was concluded that the speedometer is a reliable, fast and interactive tool for training advice

    Psychosocial factors and T lymphocyte counts in Brazilian peacekeepers

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    OBJECTIVE: To investigate the associations between psychosocial factors and peripheral blood CD4 and CD8 T lymphocyte numbers in Brazilian peacekeepers. METHODS: Venous blood was collected from 759 peacekeepers who had just returned from a peace mission in Haiti. Among the 759 soldiers, 642 individuals completed the psychosocial measures. CD4 and CD8 T lymphocyte counts were measured by flow cytometry using a commercially available kit. Psychosocial factors, including military peace force stressors, clinical stress, anxiety and depression, were recorded. As a reference for T lymphocyte numbers, we measured T lymphocyte counts in 75 blood donors from the Instituto de Biologia do Exército, Rio de Janeiro. RESULTS: The median numbers of CD4 and CD8 T lymphocytes in the blood donors were 819 cells/µl and 496 cells/µl, respectively, with a CD4:CD8 ratio of 1.6. Significantly (

    Time limit at the minimum velocity of VO2max and intracyclic variation of the velocity of the centre of mass

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    The purpose of this study was to analyse the relationship between time limit at the minimum velocity that elicits maximal oxygen consumption (TLim-vVO2max) and intra-cyclic variations of the velocity of the centre of mass (dv) in the four competitive swimming techniques. Twelve elite male swimmers SWIMMING BIOENERGETICS Rev Port Cien Desp 190 6(Supl.2) 185–197 swam their own best technique until exhaustion at their previously determined v O2max to assess TLim-v O2max. The test was videotaped in the sagittal plan and the APAS software was used to evaluate the horizontal velocity of the centre of mass (Vcm) and its intra-cyclic variation (dv) per swimming technique. Results pointed out that the strokes that presented higher intra-cyclic variations also presented larger values of TLim. Intra-cyclic speed fluctuations (dv) decreased during the TLim test in the four strokes studied, probably due to fatigue. Key words: VO2, intra-cyclic velocity variations, time limit, centre of mass.Authors want to express their gratitude to the Portuguese National Team, and the Portuguese Swimming Federation, for their cooperation

    Heavy metals and micronutrients in soils under dairy grazing right on top of the river Paranaíba basin in the state of Goiás, Brazil

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    In Brazil, the agricultural activity is among the most competitive sectors of national economy, in which milk production has a very significant contribution. Concern about environmental contamination by this activity is related to the fact that dairy cattle manure heavy metals present in the constitution; the creation of such animals in the grazing system directly questions the possibility of any contamination by these metals in the watery, area where these animals congregate at certain times of day for drinking water and where they defecate. This study aimed to evaluate the content of copper, iron, manganese, zinc, cadmium, lead and chromium in watery areas and in conservation areas (control) of 28 properties, grouped into six “otto-basins” forming the upper basin of the Paranaíba River in the State of Goiás. The simple soil samples were collected at three depths (0-10, 10-20 and 20-30 cm) obtained from such a composite sample for each depth in the areas watered and preserved. The analysis of PCA metals pollutants in soils watery areas analyzed did not indicate the occurrence of contamination in these environments when compared to the preserved area. Observed random distribution of average levels of metals in the three studied depths in all treatments, which complicates the definition of the potential for soil contamination by feces of dairy farming originated in watery areas, under rotational grazing.A preocupação quanto à contaminação do ambiente por meio da atividade leiteira está relacionada ao fato dos dejetos destes bovinos apresentarem metais poluentes em sua constituição; na criação desses animais no sistema de pastejo direto questiona-se a possibilidade da ocorrência de contaminação por estes metais nas aguadas, área onde esses animais se aglomeram em determinados períodos do dia para beberem água e onde defecam. O presente estudo objetivou avaliar os teores dos metais cobre, ferro, manganês, zinco, cádmio, chumbo e cromo em áreas de aguadas e em áreas preservadas (testemunha) de 28 propriedades, agrupadas em seis Ottobacias hidrográficas formadoras do alto da bacia do Rio Paranaíba, no Estado de Goiás. As amostras simples de solos foram coletadas em três profundidades (0-10, 10-20 e 20-30 cm), a partir destas foram obtidas uma amostra composta para cada profundidade nas áreas de aguadas e preservadas. Pela análise de PCA os metais poluentes analisados nos solos de aguada não indicou a ocorrência de contaminação nestes ambientes quando comparados à área preservada. A distribuição aleatória dos teores médios dos metais nas três profundidades estudadas em todos os tratamentos dificulta a definição do potencial de contaminação do solo pelos dejetos originados da atividade leiteira em áreas de aguadas, sob pastejo direto3052582590Alvarenga, M.I.N., Davide, A.C., Características físicas e químicas de um Latossolo Vermelho-Escuro e a sustentabilidade de agroecossistemas (1999) Revista Brasileira de Ciência do Solo, 23 (4), pp. 933-942. , ViçosaByers, H.L., Cabrera, M.L., Matthews, M., Franklin, D.H., Andrae, J.G., Radcliffe, D.E., McCann, M.A., Calvert Jr, V.H., Phosphorus, sediment and Escherichia coli loads in unfenced streams of the Georgia Piedmont, USA (2005) Journal of Environmental Quality, 34 (11), pp. 2293-2300. , MadisonCorreia, P.R.M., Ferreira, M.M.C., Reconhecimento de padrões por métodos não supervisionados: Explorando procedimentos quimiométricos para o tratamento de dados analíticos (2007) Revista Química Nova, 30 (2), pp. 48-487. , São PauloEMBRAPA-Embrapa Informação Tecnológica, (2003) Pesquisa, desenvolvimento e inovação para o agronegócio brasileiro: Cenários 2002-2012, 92p. , Embrapa/Secretaria de Gestão e Estratégia. Brasília: Embrapa Informação TecnológicaIBGE-Instituto Brasileiro de Geografia e Estatística. Indicadores: Produção pecuária, , http://www.ibge.gov.br/home/mapa_site/mapa_site.php, Disponível em, Acesso em: 02 abr. 2012McGechan, M.B., Topp, C.F.E., Modelling environmental impacts of deposition of excreted nitrogen by grazing dairy cows (2004) Agriculture, Ecossystems e Environment, 103 (1), pp. 149-164. , AmsterdamMoura, M.C.S., Lopes, A.N.C., Moita, G.C., Moita Neto, J.M., Estudo multivariado de solos urbanos da cidade de Teresina (2006) Revista Química Nova, 29 (3), pp. 429-435. , São PauloOliver, M.A., Soil and human health: A review (1997) Journal Science Soil, 48 (4), pp. 573-592. , OxfordPereira, A.A., Borges, J.D., Leandro, W.M., Metais poluentes e micronutrientes no solo e em folhas de brachiaria decumbens às margens de rodovias (2010) Bioscience Journal, 26 (3), pp. 347-357. , UberlândiaPfafstetter, O., (1989) Classificação de bacias hidrográficas: Metodologia de codificação, 19p. , Rio de Janeiro, RJ: Departamento Nacional de Obras de Saneamento (DNOS), Trabalho não publicadoQuaggio, J.A., van Raij, B., Comparação de métodos rápidos para determinação da matéria orgânica em solo (1979) Revista Brasileira de. Ciência do Solo, 3 (3), pp. 184-187. , CampinasSEPIN-Superintendência de Pesquisa e Informação, (2012) Anuário Estatístico do Estado de Goiás-2005, , http://www.segplan.go.gov.br/, Disponível em: Acesso em: 22 junWijewardena, J.D.H., Gunaratne, S.P., Heavy metal in commonly used animal manure (2004) Annals of the Sri Lanka Dapartment of agriculture, 6 (2), pp. 245-253. , BombuwelaIn Brazil, the agricultural activity is among the most competitive sectors of national economy, in which milk production has a very significant contribution. Concern about environmental contamination by this activity is related to the fact that dairy cattle manure heavy metals present in the constitution; the creation of such animals in the grazing system directly questions the possibility of any contamination by these metals in the watery, area where these animals congregate at certain times of day for drinking water and where they defecate. This study aimed to evaluate the content of copper, iron, manganese, zinc, cadmium, lead and chromium in watery areas and in conservation areas (control) of 28 properties, grouped into six “otto-basins” forming the upper basin of the Paranaíba River in the State of Goiás. The simple soil samples were collected at three depths (0-10, 10-20 and 20-30 cm) obtained from such a composite sample for each depth in the areas watered and preserved. The analysis of PCA metals pollutants in soils watery areas analyzed did not indicate the occurrence of contamination in these environments when compared to the preserved area. Observed random distribution of average levels of metals in the three studied depths in all treatments, which complicates the definition of the potential for soil contamination by feces of dairy farming originated in watery areas, under rotational grazin

    Acute effects of the use of a biofeedback system for the technical training in breaststroke swimming

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    The purpose of this research was to develop, validate, and evaluate a biofeedback system for the technical training in breaststroke swimming. The system lied on the assessment of speed fluctuation curves of an anatomical landmark of the swimmer(hip)

    Epidemiological situation of bovine brucellosis in the State of Rio Grande do Sul, Brazil

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    Realizou-se um estudo para caracterizar a situação epidemiológica da brucelose bovina. O Estado foi dividido em sete regiões. Em cada região foram amostradas aleatoriamente cerca de 300 propriedades, e dentro dessas foi escolhido de forma aleatória um número pré-estabelecido de animais, dos quais foi obtida uma amostra de sangue. No total foram amostrados 16.072 animais, provenientes de 1.957 propriedades. Em cada propriedade amostrada foi aplicado um questionário epidemiológico para verificar o tipo de exploração e as práticas zootécnicas e sanitárias que poderiam estar associadas ao risco de infecção pela doença. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado e o reteste dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal foi reagente às duas provas sorológicas. Para o Estado, as prevalências de focos e de animais infectados foram, respectivamente, 2,1% [1,5-2,6%] e 1,0% [0,60-1,4%]. Para os circuitos, a prevalência de focos e a de animais foram, respectivamente: circuito 1, 3,1% [1,4-5,7%] e 0,95% [0,0-2,0%]; circuito 2, 7,7% [4,9-11,3%] e 1,0% [0,40-1,7%]; circuito 3, 5,7% [3,4-8,8%] e 2,1% [0,41-3,8%]; circuito 4, 0,66% [0,08-2,4%] e 0,66% [0,0-1,8%]; circuito 5, 0,66% [0,08-2,4%] e 0,05% [0,0-0,13%]; circuito 6, 0,0% [0,0-1,3%] e 0,0% [0,0-0,25%]; circuito 7, 5,4% [2,5-10,1%] e 2,9% [0,49-5,3%]. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: exploração de corte (OR= 4,27 [1,82-10,01]) e histórico de aborto (OR=3,27,1,71-6,25]). ____________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological status of bovine brucellosis was carried out in the State of Rio Grande do Sul. The State was divided in seven regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 16,072 serum samples from 1,957 herds, were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test and all positive sera were re-tested by the 2-mercaptoethanol test. The herd was considered positive if at least one animal was positive on both tests. The prevalences of infected herds and animals in the State were, respectively 2.1% [1.5-2.6%] and 1.0% [0.60-1.4%]. In the regions, the prevalences of infected herds and animals were, respectively: region 1, 3.1% [1.4-5.7%] and 0.95% [0.0-2.0%]; region 2, 7.7% [4.9-11.3%] and 1.0% [0.40-1.7%]; region 3, 5.7% [3.4-8.8%] and 2.1% [0.41-3.8%]; region 4, 0.66% [0.08-2.4%] and 0.66% [0.0-1.8%]; region 5, 0.66% [0.08-2.4%] and 0.05% [0.0-0.13%]; region 6, 0.0% [0.0-1.3%] and 0.0% [0.0-0.25%]; and region 7, 5.4% [2.5-10.1%] and 2.9% [0.49-5.3%]. The risk factors (odds ratio, OR) associated with the presence of infection were: beef herd (OR= 4.27 [1.82-10.01]) and recent history of abortion (OR= 3.27-1.71-6.25])
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