351 research outputs found
QUALIDADE DA CARNE SUÍNA APÓS DOIS TEMPOS DE DESCANSO NO FRIGORÍFICO
Existem vários fatores estressantes que podem afetar a qualidade da carne e também
há falta de informação sobre a quantidade de horas mínimas e máximas ideais de descanso no
frigorífico para a reposição do esgotamento físico dos animais após o transporte. O presente trabalho
teve como objetivo estudar o efeito da redução do tempo de permanência na pocilga do frigorífico
sobre a qualidade da carne suína, avaliando-se as seguintes características: pH; capacidade de
retenção de água (WHC). A redução de descanso de 9 horas para 3 horas de descanso no frigorífico
não alteraram de modo significativo a qualidade da carne suína nas variáveis pH 45 minutos, pH 24
horas pós abate e na capacidade de retenção de água (WHC) pelos métodos Drip Loss e papel de
filtro prensado de GRAU e HAMM, mas com a redução do tempo de descanso no frigorífico, pôdese
obter outros ganhos (redução do estresse, escoriações de pele, hematomas, fraturas e outros)
e em qualidade da carne.
Pork meat quality after two times of lairage in slaugther
Abstract
There are several stressing factors that can affect the meat quality, and also a lack of
information on the minimum and maximum ideal lairage time in the slaugther for the replacement of
animal physical exhaustion after transportation. The reduction of 9 to 3 hours of lairage in the preslaugther
did not significantly alter the pork meat quality in the variables pH 45 min, pH 24 h postslaugther,
water-holding capacity (WHC) for the methods Drip Loss and filter paper press of GRAU
& HAMM. However, with the reduction lairage time in the slaugther, other gains could be obtained
(reduction of stress, skin excoriations, hematomas, fractures and others) as well as increase in meat
quality
A low-cost platinum film deposited direct on glass substrate for electrochemical counter electrodes
AbstractThe preparation and characterization of platinum electrodes on glass substrates obtained by the Pechini method for a potential application as a counter electrode is presented in this paper. This method is based on the dissolution of citric acid (CA) and hexachloride platinum acid (H2PtCl6) in ethylene glycol (EG), and then calcinated in an appropriated temperature to produce the desired metallic film. Characterization was carried out by X-ray diffraction, scanning electron and atomic force microscopy and cyclic voltammetry. X-ray patterns of platinum on glass substrate showed the same features of the platinum bulk metal as well as its voltammetric profile. In order to determine the stability of the electrode, the electrode was subjected to 5000 voltammetric cycles and polarized at constant current of 100 mA cm−2 for at least 200 h, showing no considerable differences compared with the as synthesized electrode. Moreover, the main advantage of the electrode is the low cost (US$ 0.03 cm−2) of the prepared samples
Genetic evaluation of Jatropha curcas: an important oilseed for biodiesel production
Jatropha curcas, internationally and locally known, respectively, as physic nut and pinhão manso, is a highly promising
species for biodiesel production in Brazil and other countries in the tropics. It is rustic, grows in warm regions and is easily cultivated. These characteristics and high-quality oil yields from the seeds have made this plant a priority for biodiesel programs in Brazil. Consequently, this species merits genetic investigations aimed at improving yields. Some studies have detected genetic variability in accessions in Africa and Asia.
We have made the first genetic evaluation of J. curcas collected from Brazil. Our objective was to quantify genetic diversity and to estimate genetic parameters for growth and production traits and seed oil content. We evaluated 75 J. curcas progenies collected from Brazil and three from Cambodia. The mean oil content in the seeds was 31%, ranging from 16 to 45%. No genetic correlation between growth traits and seed
oil content was found. However, high coefficients of genetic variation were found for plant height, number of branches, height of branches, and stem diameter. The highest individual narrow-sense heritabilities were found for leaf length (0.35) and width (0.34), stem diameter (0.24) and height of branches (0.21). We used a clustering algorithm to genetically identify the closest and most distant progenies, to assist in the development of new cultivars. Geographical diversity did not
necessarily represent the genetic diversity among the accessions collected. These results are important for the continuity of breeding programs, aimed at obtaining cultivars with high grain yield and high oil content in seeds
Uma nota didáctica breve no uso esclarecido de procedimentos estatísticos em análise de dados repetidos no tempo. Um estudo guiado para investigadores em Ciências do Desporto
Este texto pretende ser um auxiliar didáctico no uso esclarecido de procedimentos estatísticos relativos à análise longitudinal de dados. Servir-nos-emos de um exemplo ilustrativo de
complexidade crescente para introduzir a estrutura de um delineamento de grupo único e da essência do ensaio de hipóteses
estatísticas. De seguida apresentamos os principais resultados do uso de teste t e da análise de variância de medidas repetidas.
Os resultados são interpretados de modo formal e substantivo, introduzindo um pensamento alternativo à estrutura binária do resultado do ensaio de hipóteses. O recurso a procedimentos gráficos é fortemente explorado. Finalmente, recorremos
à modelação hierárquica para salientar a sua riqueza e flexibilidade interpretativa no estudo de dados longitudinais
Hydrothermal synthesis to water-stable luminescent carbon dots from acerola fruit for photoluminescent composites preparation and its application as sensors
Carbon dots (C-dots) possess the attractive properties of high stability, low toxicity, good water solubility, simple synthetic routes as well as size and excitation-dependent photoluminescence (PL).The aim of this work was to synthesize photoluminescent C-dots by hydrothermal method using acerola fruit (Malpighiaemarginata) as a row material, since this fruit contains large number of organic molecules. Studies about the optimal synthesis conditions were performed, where these organic molecules were converted into C-dots by hydrothermal carbonization at 180 ºC for 18 h. The C-dots exhibited a green emission light at 459 nm when excited under UV-light (λ ex= 370 nm). These nanomaterials were also successfully used to prepare C-dots/poly (vinyl alcohol) luminescent composites (C-dots/PVA). Both C-dots and C-dots/PVA composite films were investigated by using colorimetric visual sensor for Fe3+ metal ions detection. The results show that the prepared C-dots and C-dots/poly presented strong green emission light. The emission spectra of above materials were quenched in the presence of Fe3+ ions. Thus, highly specific “turn off” fluorescence sensing of Fe3+ was achieved using fluorescent C-dots. Regarding, this work describe that the polymeric films as sensors of metallic ions in aqueous solution appears as a new perspectives to design new composite materials22
Dados longitudinais e modelação hierárquica. Um tutorial para investigadores das Ciências do Desporto
Este texto pretende ser um auxiliar didáctico sobre modos de olhar informação de natureza longitudinal.
O seu propósito fundamental é auxiliar os investigadores a recorrerem à Modelação Hierárquica ou Multinível
(MHMN) para extraírem dos dados toda a sua riqueza. Na primeira parte apresentaremos as ideias fundamentais
da MHMN aplicadas a dados longitudinais. De seguida recorreremos a um exemplo complexo para apresentar
todos os passos da MHMN, interpretando de modo substantivo as principais estatísticas produzidas pelo software
HLM 6.0
Análise e interpretação dos níveis de actividade física de crianças: um tutorial baseado na modelação hierárquica ou multinível
Este tutorial pretende apresentar, de modo didáctico, uma forma alternativa de análise de dados sobre os níveis de actividade física de crianças a partir da modelação hierárquica ou multinível. São mencionadas as diferentes etapas da modelação, os resultados são interpretados com base nos output's do software utilizado – o HLM 6.02. Em cada etapa do percurso são lançadas as hipóteses mais importantes em grau de complexidade crescente. A sua importância é referida a partir dos resultados disponíveis
Indirect search for dark matter: prospects for GLAST
Possible indirect detection of neutralino, through its gamma-ray annihilation
product, by the forthcoming GLAST satellite from our galactic halo, M31, M87
and the dwarf galaxies Draco and Sagittarius is studied. Gamma-ray fluxes are
evaluated for the two representative energy thresholds, 0.1 GeV and 1.0 GeV, at
which the spatial resolution of GLAST varies considerably. Apart from dwarfs
which are described either by a modified Plummer profile or by a
tidally-truncated King profiles, fluxes are compared for halos with central
cusps and cores. It is demonstrated that substructures, irrespective of their
profiles, enhance the gamma-ray emission only marginally. The expected
gamma-ray intensity above 1 GeV at high galactic latitudes is consistent with
the residual emission derived from EGRET data if the density profile has a
central core and the neutralino mass is less than 50 GeV, whereas for a central
cusp only a substantial enhancement would explain the observations. From M31,
the flux can be detected above 0.1 GeV and 1.0 GeV by GLAST only if the
neutralino mass is below 300 GeV and if the density profile has a central cusp,
case in which a significant boost in the gamma-ray emission is produced by the
central black hole. For Sagittarius, the flux above 0.1 GeV is detectable by
GLAST provided the neutralino mass is below 50 GeV. From M87 and Draco the
fluxes are always below the sensitivity limit of GLAST.Comment: 14 Pages, 7 Figures, 3 Tables, version to appear on Physical Review
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