Sheet metal forming by numerical simulations: 2D and 3D axisymmetric deformation of a cylindrical piece

Until few years ago, design of sheet metal forming was based on knowledge through work experience and expensive trial and error process. Nowadays the use of numerical simulations in different phases of the sheet metal forming process are performed using finite element analysis (Ranganath et al, 2012). Different codes are available for finite element analysis in metal forming such as Abaqus, Dynaform, Nike 2D, Ansys, etc. Deep drawing is the metalworking process used for stamping flat sheets into cup-shaped forms, where the metal is subjected to different types of deformations (Dieter, 1961). The aim of this work is conduct numerical simulations to verify the deep drawing process and the shape of the final stamping component of a simple profile of a sheet metal geometry. To evaluate the design of sheet metal forming, a nonlinear dynamic explicit numerical model was developed using two models: a 3D quarter and a 2D axisymmetric finite element model, due the geometry and loading conditions symmetry to reduce the computational time processing. The numerical simulations showed the shape deformation occurring after start the process and provided detailed quantitative information about expected weakness of the resulting piece.info:eu-repo/semantics/publishedVersio

Alterações químicas durante o desenvolvimento e maturação de manga Tommy Atkins cultivada no Vale do São Francisco.

O objetivo deste trabalho foi caracterizar alterações químicas relacionadas à qualidade da manga Tommy Atkins, durante o desenvolvimento e maturação, nas condições de cultivo do Vale do São Francisco. A manga Tommy Atkins madura apresentou o máximo teor de sólidos solúveis totais (SST), porém os teores de vitamina C e de carotenóides totais da polpa foram inferiores aos dos frutos em estádio inicial de maturação. As mudanças na acidez total titulável e nos teores de SST e carotenóides totais da polpa foram indicativas da evolução da maturação

Estimativa do tamanho do genoma em cultivares de capim-andropogon (Andropogon gayanus Kunth).

Resumo ? Experimentos de montagem de genomas dependem de estimativas iniciais do conteúdo de DNA nuclear de uma espécie alvo. A citometria de fluxo é uma ferramenta de baixo custo, utilizada em rotina, para estimar o tamanho do genoma a partir do conteúdo de DNA nuclear de plantas. O capim-andropogon (Andropogon gayanus Kunth) é uma gramínea perene, tetraploide (2n = 4x = 40), resistente a solos de baixa fertilidade e com baixa disponibilidade hídrica. Há potencial de dinamização do processo de desenvolvimento de cultivares pelo uso de ferramentas genômicas. O tamanho do genoma de três cultivares de capim-andropogon foi estimado por citometria de fluxo. O tamanho médio estimado para o genoma haploide de capim-andropogon foi de 1,5 Gpb C-1 e 770 Mpb Cx-1. Os resultados obtidos neste trabalho são inéditos para cultivares dessa espécie e guiarão os esforços de sequenciamento para montagem do seu genoma.bitstream/item/224864/1/Estimativa-do-tamanho-do-genoma-Boletim-372.pd

Food color is in the eye of the beholder: the role of human trichromatic vision in food evaluation

Non-human primates evaluate food quality based on brightness of red and green shades of color, with red signaling higher energy or greater protein content in fruits and leafs. Despite the strong association between food and other sensory modalities, humans, too, estimate critical food features, such as calorie content, from vision. Previous research primarily focused on the effects of color on taste/flavor identification and intensity judgments. However, whether evaluation of perceived calorie content and arousal in humans are biased by color has received comparatively less attention. In this study we showed that color content of food images predicts arousal and perceived calorie content reported when viewing food even when confounding variables were controlled for. Specifically, arousal positively co-varied with red-brightness, while green-brightness was negatively associated with arousal and perceived calorie content. This result holds for a large array of food comprising of natural food - where color likely predicts calorie content - and of transformed food where, instead, color is poorly diagnostic of energy content. Importantly, this pattern does not emerged with nonfood items. We conclude that in humans visual inspection of food is central to its evaluation and seems to partially engage the same basic system as non-human primates

Zero-inflated Poisson regression models for QTL mapping applied to tick-resistance in a Gyr × Holstein F2 population

Now a days, an important and interesting alternative in the control of tick-infestation in cattle is to select resistant animals, and identify the respective quantitative trait loci (QTLs) and DNA markers, for posterior use in breeding programs. The number of ticks/animal is characterized as a discrete-counting trait, which could potentially follow Poisson distribution. However, in the case of an excess of zeros, due to the occurrence of several noninfected animals, zero-inflated Poisson and generalized zero-inflated distribution (GZIP) may provide a better description of the data. Thus, the objective here was to compare through simulation, Poisson and ZIP models (simple and generalized) with classical approaches, for QTL mapping with counting phenotypes under different scenarios, and to apply these approaches to a QTL study of tick resistance in an F2 cattle (Gyr × Holstein) population. It was concluded that, when working with zero-inflated data, it is recommendable to use the generalized and simple ZIP model for analysis. On the other hand, when working with data with zeros, but not zero-inflated, the Poisson model or a data-transformation-approach, such as square-root or Box-Cox transformation, are applicable

A computational method for the identification of dengue, zika and chikungunya virus species and genotypes

In recent years, an increasing number of outbreaks of Dengue, Chikungunya and Zika viruses have been reported in Asia and the Americas. Monitoring virus genotype diversity is crucial to understand the emergence and spread of outbreaks, both aspects that are vital to develop effective prevention and treatment strategies. Hence, we developed an efficient method to classify virus sequences with respect to their species and sub-species (i.e. serotype and/or genotype). This tool provides an easy-to-use software implementation of this new method and was validated on a large dataset assessing the classification performance with respect to whole-genome sequences and partial-genome sequences.publishersversionpublishe

Covariance functions under B-spline polynomials to model Polled Nellore cattle growth.

B-spline functions have been used in random regression models (RRM) to model animal weight from birth to adulthood because they are less vulnerable to common difficulties of other methods. However, its application to model growth traits of Polled Nellore cattle has been little studied. Therefore, this study aimed to evaluate polynomial functions of different orders and segment numbers to model effects associated with the Polled Nellore cattle growth curve. For this purpose, we used 15,148 weight records of 3,115 animals aged between 1 and 660 days and reared in northern Brazil and born between 1995 and 2010. Random effects were modeled using B-spline polynomials. As random effects, we considered the direct and maternal genetic additives, as well as direct and maternal permanent environments. As fixed effects were included contemporary group, cow age at calving (linear and quadratic) and fourth order Legendre polynomials to represent average growth curve. The residue was modeled by considering seven age classes. The bestfitted model was the one that considered cubic B-spline functions with four knots for direct additive genetic effects and three knots for maternal genetic, animal permanent environment, and maternal permanent environment effects (C6555). Therefore, covariance functions under B-spline polynomials are efficient and can be used to model the growth curve of Polled Nellore cattle from birth to 660 days of age

Phytochemical characterization, antioxidant potential and antibacterial activity of the Croton argyrophylloides Muell. Arg. (Euphorbiaceae).

Croton argyrophylloides Muell. Arg., from the Euphorbiaceae family, popularly known as marmeleiro prateado or sacatinga, is a plant from the Caatinga biome commonly found in Brazil?s northeastern region. The present study aimed to evaluate the antioxidant activity of the species. The phytochemical study was performed through qualitative analysis of chemical constituents and quantitative determination of the total phenol content through the Folin-Ciocalteu test. The qualitative and quantitative antioxidant tests were performed using the DPPH method (2.2 diphenyl-1-picryl hydrazil) and ferric reducing antioxidant power (FRAP). The minimum inhibitory concentration (MIC) was determined by microdilution in 96-well plates. The ethanolic extract of the leaves of C. argyrophylloides manifested antioxidant action in the quantitative DPPH test with a significant bioactivity of 84.70 AAO% in 500 µg/mL, with an EC50 of 236.79. The content of total phenolic compounds was 946.06 mg of gallic acid equivalents/g of sample, and total flavonoids was 58.11 mg of quercetin equivalents/g of sample, the result obtained for FRAP was 15294.44 µM Trolox/g of sample and ABTS was 718 μM Trolox of sample. The prospecting of the chemical constituents of the leaves of C. argyrophylloides revealed the presence of the main compounds that manifests the antioxidant activity and it was proven by the DPPH method that there is antioxidant activity in the analyzed sample, in addition to demonstrating a significant content of phenolic compounds and total flavonoid content in the species, which corroborates the antioxidant activity of the plant sample. The leaf extracts presented growth inhibition halos of 10 and 12 mm upon Staphylococcus aureus ATCC 25923

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males