354 research outputs found
A computational study of the configurational and vibrational contributions to the thermodynamics of substitutional alloys: the Ni3Al case
We have developed a methodology to study the thermodynamics of order-disorder
transformations in n-component substitutional alloys that combines
nonequilibrium methods, which can efficiently compute free energies, with Monte
Carlo simulations, in which configurational and vibrational degrees of freedom
are simultaneously considered on an equal footing basis. Furthermore, by
appropriately constraining the system, we were able to compute the
contributions to the vibrational entropy due to bond proportion, atomic size
mismatch, and bulk volume effects. We have applied this methodology to
calculate configurational and vibrational contributions to the entropy of the
Ni3Al alloy as functions of temperature. We found that the bond proportion
effect reduces the vibrational entropy at the order-disorder transition, while
the size mismatch and the bond proportion effects combined do not change the
vibrational entropy at the transition. We also found that the volume increase
at the order-disorder transition causes a vibrational entropy increase of 0.08
kB/atom, which is significant when compared to the configurational entropy
increase of 0.27 kB/atom. Our calculations indicate that the inclusion of
vibrations reduces in about 30 percent the order-disorder transition
temperature determined solely considering the configurational degrees of
freedom.Comment: Already submitte
Lateral branch induction at nursery with growth regulators in ?maxi gala? apple trees grafted on four rootstocks.
Apple production in Southern Brazil has been increasing along the past decade, and part of this was due to the introduction of more adapted dwarfing rootstocks and consequently increased tree density in the orchards. Looking for obtaining early beariness, the use of branched nursery trees is one of the most important steps. The objective of this experiment was to determine the effects of plant the growth regulators Benzyladenine (BA), Benzyladenine + Gibberellic acid4+7, Thidiazuron, and Cyclanilide + Ethephon on the induction of lateral branches of ?Maxi Gala? apple trees at nursery, grafted on the rootstocks G.202, G.213, M.9, and Marubakaido with M.9 interstem. The growth regulators Benzyladenine (BA), and Benzyladenine + Gibberellic acid4+7 are the most effective on improving tree?s architecture and on increasing the number of spurs, for all scion-rootstock combinations tested. Plant growth regulators at elevated doses strongly interrupt apical dominance and stimulate an elevated number of lateral branches with narrower crotch angles
Composição celular de microalgas obtidas da ficorremediação de efluentes suinícolas.
A remoção do nitrogênio e fósforo do digestato utilizando processos de ficorremediação foi demonstrada. A composição celular das microalgas cultivadas foi avaliada. Dois tipos de efluentes foram utilizados: do UASB e de reator aeróbio para nitrificação-desnitrificação (RBA). Fotobiorreatores (FBRs) em escala de laboratório foram utilizados para os testes. A amônia e o fósforo foram eficientemente removidos (> 99%) após 100 dias de experimento. A biomassa de microalgas foi constituída por 50, 41 e 1% de proteínas, carboidratos e lipídios, respectivamente. Os resultados sugerem que a ficorremediação pode ser promissora como tratamento terciário. Além disso, a produção excedente da biomassa de microalgas pode ter valor agregado nas diversas aplicações biotecnológicas, incluindo a de uso para nutrição animal
Effect of stocking density and use of environmental enrichment materials on the welfare and the performance of pigs in the growth and finishing phases
Aim of study: To evaluate the effects of stocking density and the use of environmental enrichment (EE) objects on the welfare and the performance of pigs in the growing and finishing phases.Area of study: The southern region of Brazil.Material and methods: A total of 240 pigs, 120 immunocastrated males and 120 females, with an initial weight of 22.38 ± 2.38 kg and mean age of 65 days, were submitted to two stocking densities conditions (0.85 and 1.28 m²pig) with and without EE for 117 days. The experimental design was a 2×2×2 factorial (two categories, two densities, and two EE conditions), with six replicates. Performance variables and behavior were evaluated.Main results: For stocking density, there was a significant difference in the finishing phase from 148 to 161 days of age for the final weight (FW), average daily weight gain (ADWG), and feed conversion rate (FCR). For the EE factor, there was no difference in any of the phases or in the overall period. In the overall period, the higher availability of space improved the results of FW (140.56 kg vs 136.63 kg), ADWG (1.005 kg vs 0.974 kg), and FCR (2.05 vs 2.10). There was no effect of EE, stocking densities, or their interaction on the frequency of different behaviors of the pigs in the growth and finishing phases.Research highlights: There was no effect of interactions between enriched environments, stocking densities, and sex for animal performance and behavioral frequencies; however, differences between the factors were observed separately. The higher availability of space improved the results of FW, ADWG, and FCR
Impact of management and luminosity on morphological composition of giant missionary grass (Axonopus catharinensis Valls.).
Resumo.Zootecnia Brasil 2018
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