845 research outputs found
Estudo da taxa de degradação de vitamina C em alguns sucos de frutas.
A vitamina C é uma vitamina de extrema importância para o ser humano não somente por sua atividade antiescorbútica, mas também pelas inúmeras atividades fisiológicas e antioxidantes que exerce. Este trabalho visa desmistificar o senso comum estabelecido de que a vitamina C é destruída pouco depois que um suco de frutas é preparado. Para isto, um breve estudo utilizando alguns sucos de frutas foi realizado. Tal estudo consistiu de extrações da vitamina C dos sucos preparados inicialmente e também após 2, 4 e 6 horas de exposição destes à temperatura ambiente. Os resultados obtidos mostraram que após seis horas o suco que obteve a maior perda de vitamina C foi o suco de laranja, mas tratou-se de perda inferior a 22% do teor inicial
Residual feed intake and its effect on carcass and meat characteristics of feedlot Zebu cattle.
the objective of this study was to evaluate the residual feed intake (RFI) and its relation with performance, carcass and meat characteristics of Zebu animals. A total of 40 Zebu steers with initial age of 18 months and initial live weight of 350 kg were confined in feedlot for 112 days. The average daily gain (ADG) and dry matter intake (DMI) were obtained every 14 days. Residual feed intake was determined by the difference between observed and predicted DMI, based on the metabolic weight and the ADG. Animals were classified into the RFI groups: high (>0.5 standard deviation of the mean - least efficient), medium (±0.5 standard deviation of the mean) and low (<0.5 standard deviation of the mean - most efficient). Daily cost with feeding and per kilogram of weight gain was determined. Characteristics of carcass (weight, yield, subcutaneous fat) meat (pH, shear force and color) were assessed. Animals with low RFI presented lower DMI. The variation in DMI between the low and the high RFI groups promoted difference in the daily cost with feeding and per kilogram of weight gain, with animals of low RFI presenting costs 5 and 9% lower, respectively. Carcass and meat characteristics differed over the RFI groups. The knowledge of the RFI of the animals enables a more efficient system, with reduction in the costs with feeding, without promoting alterations on the performance and carcass characteristics of the meat from Zebu animals
Desenvolvimento de dendezeiro em área reabilitada com leguminosas arbóreas.
O objetivo desse trabalho foi avaliar o desenvolvimento de 8 cultivares de dendê, plantadas em tanques de deposição de rejeito de bauxita, anteriormente com um substrato de cerca de 50 cm de cinza vegetal e revegetado com leguminosas arbóreas fixadoras de nitrogênio
"Narrow" Graphene Nanoribbons Made Easier by Partial Hydrogenation
It is a challenge to synthesize graphene nanoribbons (GNRs) with narrow
widths and smooth edges in large scale. Our first principles study on the
hydrogenation of GNRs shows that the hydrogenation starts from the edges of
GNRs and proceeds gradually toward the middle of the GNRs so as to maximize the
number of carbon-carbon - bonds. Furthermore, the partially
hydrogenated wide GNRs have similar electronic and magnetic properties as those
of narrow GNRs. Therefore, it is not necessary to directly produce narrow GNRs
for realistic applications because partial hydrogenation could make wide GNRs
"narrower"
Reactivity, performance, color and tenderness of meat from Zebu cattle finished in feedlot.
The objective of this study was to study the animal reactivity and correlate it with performance and meat quality of cattle finished in feedlots. A total of 20 animals of the Tabapuã breed and 20 animals of the Nellore breed were confined for 112 days: 28 days of adaptation and 84 days of data collection. Performance was determined by the average daily weight gain (ADG) and average dry matter intake (DMI) estimated through the use of indicators. On the 1st, 42nd and 84th days of the experiment, two methods were used to measure the animal reactivity: animal reactivity in mobile cage and visual reactivity during handling. The characteristics of meat quality were evaluated by the color, shear force and pH24 after slaughter (pH24). Through the study of correlation, the degree and direction of linear association on animal reactivity, performance and meat quality were established. Regression equations were generated for the parameters evaluated according to the values of animal reactivity. Correlations between mobile cage and visual reactivity were 0.77, 0.56 and 0.45 in the 1st, 2nd and 3rd evaluations, respectively. There was no correlation between animal reactivity and DMI. The correlations between ADG, pH24, and color with animal reactivity were -0.31, 0.40, 0.47 and -0.34, and -0.33 for mobile cage, 0.74, 0.71 and -0.51, for visual reactivity, respectively. The parameters of meat quality varied according to the reactivity. Undesirable values of pH24, animal reactivity and color were found when mobile cage reactivity was higher than 780, 590 and 540, respectively. In general, animals that show greater reactivity tend to have lower daily weight gain and lower meat quality. The reactivity can be used in animal breeding programs, in order to improve performance and meat quality of Zebu cattle finished in feedlot
NASirt: AutoML based learning with instance-level complexity information
Designing adequate and precise neural architectures is a challenging task,
often done by highly specialized personnel. AutoML is a machine learning field
that aims to generate good performing models in an automated way. Spectral data
such as those obtained from biological analysis have generally a lot of
important information, and these data are specifically well suited to
Convolutional Neural Networks (CNN) due to their image-like shape. In this work
we present NASirt, an AutoML methodology based on Neural Architecture Search
(NAS) that finds high accuracy CNN architectures for spectral datasets. The
proposed methodology relies on the Item Response Theory (IRT) for obtaining
characteristics from an instance level, such as discrimination and difficulty,
and it is able to define a rank of top performing submodels. Several
experiments are performed in order to demonstrate the methodology's performance
with different spectral datasets. Accuracy results are compared to other
benchmarks methods, such as a high performing, manually crafted CNN and the
Auto-Keras AutoML tool. The results show that our method performs, in most
cases, better than the benchmarks, achieving average accuracy as high as
97.40%.Comment: to be publishe
BRS Fronteira: cultivar de arroz irrigado para os Estados do Rio Grande do Sul e São Paulo.
O lançamento desta cultivar tem como objetivo aumentar a diversidade genética e dar maior opção aos produtores gaúchos e paulistas.344, realizado pela Embrapa Arroz e Feijão em 1990.bitstream/CNPAF/25386/1/comt_124.pd
Sumário Nacional de Touros da Raça Holandesa - 2012.
bitstream/item/90335/1/DOC-158-Completo-Touros-Holand-2012.pd
Projeto mecatrõnico de um rover para aplicação na análise de solos usando tecnologia LIBS - Parte I.
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