Current-driven and field-driven domain walls at nonzero temperature

We present a model for the dynamics of current- and field-driven domain-wall lines at nonzero temperature. We compute thermally-averaged drift velocities from the Fokker-Planck equation that describes the nonzero-temperature dynamics of the domain wall. As special limits of this general description, we describe rigid domain walls as well as vortex domain walls. In these limits, we determine also depinning times of the domain wall from an extrinsic pinning potential. We compare our theory with previous theoretical and experimental work

Model for erosion-deposition patterns

We investigate through computational simulations with a pore network model the formation of patterns caused by erosion-deposition mechanisms. In this model, the geometry of the pore space changes dynamically as a consequence of the coupling between the fluid flow and the movement of particles due to local drag forces. Our results for this irreversible process show that the model is capable to reproduce typical natural patterns caused by well known erosion processes. Moreover, we observe that, within a certain range of porosity values, the grains form clusters that are tilted with respect to the horizontal with a characteristic angle. We compare our results to recent experiments for granular material in flowing water and show that they present a satisfactory agreement.Comment: 8 pages, 12 figures, submitted to Phys. Rev.

Fases fenológicas do feijão-caupi e tolerância ao fomesafen.

O objetivo deste trabalho foi o de avaliar a tolerância do feijão-caupi, variedade BRS Guariba, ao herbicida fomesafen, conduzido em casa de vegetação na Embrapa Amazônia Ocidental

Estimativa dos teores de nutrientes foliares em feijão-caupi utilizando clorofilômetro.

Uso do clorofilômetro para estimar o status nutricional pelo método não destrutivo. O Estudo. Correlação do clorofilômetro com os teores de macronutrientes. Correlação do clorofilômetro com os teores de micronutrientes. Análise de regressão para os valores SPAD e os nutrientes foliares.bitstream/item/88776/1/Circ-Tec-40.pd

Tolerância de clones de guaranazeiros a herbicidas.

O objetivo deste trabalho foi o de avaliar a seletividade de herbicidas para clones de guaranazeiro (Paullinia cupana), BRS Amazonas e BRS Maués, em condição de viveiro de mudas no estado do Amazonas

Effect of carotenoid source and dietary lipid content on blood astaxanthin concentration in rainbow trout (Oncorhynchus mykiss)

Astaxanthin concentration in the blood of rainbow trout was studied in a feeding trial with two different astaxanthin sources: green algae Haematococcus pluvialis and commercial beadlets of 8% astaxanthin content (CAROPHYLL® Pink), and two different dietary lipid levels. The green algae contained 1.4% of carotenoids on a dry matter basis: free astaxanthin (<1%), astaxanthin monoester (24.3%); astaxanthin diester (70.2%) and lutein (4.8%). Algal biomass was mechanically ground to disrupt the cell wall before incorporation in the feed. Hydrolysis of astaxanthin esters from algae occurred during the pelletization even at a low process temperature (43°C). Rainbow trout with an initial mean body weight of 150 g were fed experimental diets supplemented at a rate of 100 mg pigment/kg diet combined with two different lipid levels (9 and 24%) during 5 days. Astaxanthin concentration in the serum ranged from 5.3 μg/ml (8.9 nmol/ml) to 9.0 μg/ml (15.1 nmol/ml). Astaxanthin concentration in the serum was higher for fish fed high lipid level diets, independently of the astaxanthin source. No differences in the astaxanthin serum concentration were found for fish fed diets supplemented with either natural or synthetic astaxanthin, respectively 9.0±1.9 and 8.4±2.4 μg astaxanthin/ml serum, when dietary lipid level was high (24%). On the other hand, there was a higher blood astaxanthin concentration in fish fed diets supplemented with algal biomass (7.0±2.4 μg astaxanthin/ml serum) compared to synthetic astaxanthin (5.3±2.0 μg astaxanthin/ml serum) when dietary lipid level was low (9%

Agronomic performance of eight corn genotypes in two sowing periods.

Os fatores climáticos de uma região determinam os períodos críticos de desenvolvimento da cultura do milho e afetam o planejamento da semeadura de forma a reduzir os efeitos negativos sobre a produtividade. Assim, objetivou-se com este trabalho avaliar o desempenho agronômico de oito genótipos de milho e duas épocas de semeadura nas condições edafoclimáticas de Manaus, Amazonas.Título em Português: Desempenho agronômico de genótipos de milho em duas épocas de semeadura