Numerical Simulation of Magnetic Interactions in Polycrystalline YFeO3

The magnetic behavior of polycrystalline yttrium orthoferrite was studied from the experimental and theoretical points of view. Magnetization measurements up to 170 kOe were carried out on a single-phase YFeO3 sample synthesized from heterobimetallic alkoxides. The complex interplay between weak-ferromagnetic and antiferromagnetic interactions, observed in the experimental M(H) curves, was successfully simulated by locally minimizing the magnetic energy of two interacting Fe sublattices. The resulting values of exchange field (H_E = 5590 kOe), anisotropy field (H_A = 0.5 kOe) and Dzyaloshinsky-Moriya antisymmetric field (H_D = 149 kOe) are in good agreement with previous reports on this system.Comment: 26 pages, 9 figure

Características químicas e físicas de um solo cascalhento e suas implicações para o manejo sustentável desse solo.

Nesse trabalho foi coletado e analisado um solo cascalhento sob campo cerrado de Sete Lagoas - MG, visando obter subsídios para sua classificação e seu manejo. O solo foi analisado pelos métodos de rotina para fertilidade, química e física. Os resultados indicam que o solo é dominado pelas frações grosseiras, que perfazem mais de 80% da massa dos horizontes. O solo também apresenta acidez trocável elevada e baixos teores de nutrientes, exceto no horizonte superficial. Os testes de infiltração indicam condutividade hidráulica alta. O solo apresenta relativa resistência à erosão, mas de difícil manejo em caso de intervenção. Palavras-chave: granulornetria, fração grosseira, infiltração não saturad

Correlation between the soil classification Brazilian system (2006), WRB (ISSSWG RB, 2006) and soil taxonomy (USDA, 1999) of Indian Dark Earth of Western Amazonia.

Correlation of differents soils profiles with anthropic horizon of cities in Amazon State/Brazil through of Soils Classification Brazilian System (SiBCS), of World Reference Base for Soil Resources (WRB) and Soil Taxonomy (ST)

Estudo comparativo entre número de perfilhos no cultivo da pupunheira sem espinhos (Bactris gasipaes Kunth) para produção de palmito.

Dois diferentes numeros de perfilhos de pupunheira foram estudados para producao de palmito nas condicoes edafoclimaticas do municio de Rio Preto da Eva (AM). O Espacamento utilizado foi de 2,5m x 1m, deixando-se dois perfilhos por cova. O que apresentou melhores resultados foi de dois perfilhos/cova, que produziu 713kg/ha/ano de palmito comestivel de primeira (tambem denominado creme), dos quais foram aproveitados 87%, um envasamento de 2067 frascos de vidro de 300g de peso drenado. O diametro medio do palmito creme (2,44cm), obtido por criterios fixados para abate das plantas, atendem a exigencia industrial. Foram taambem produzidas 40t/ha/ano de restos vegetais, proprios para arracoamento de ruminantes. A composicao centesimal do palmito creme, revelou que o mesmo pode usado como componente de dieta alimentar para emagrecimento.bitstream/CPAA-2009-09/2324/1/BP_5.pd

MERCURY PHYTOTOXICITY IN COMMON BEANS IN SOILS OF MINAS GERAIS, BRAZIL

INTRODUCTION: Problems caused by contaminated areas have been increasingly found around the world. Mercury (Hg) is a trace element potentially toxic to humans and the environment. Thus, monitoring Hg levels in the environment has great importance. The transfer of trace elements from soils to plants is a complex process, that depends on soil attributes such as pH, cation exchange capacity, texture, and mineralogy and also plant attributes, such as root system lenght and others. In Brazil, agricultural areas with levels of Hg higher than 12 mg kg-1 are considered contaminated, since such levels of Hg are likely to come from non-natural sources. The State of Minas Gerais is the third largest producer of common beans in Brazil (2015/2016 farming year). The area planted with common beans is estimated in 339,000 hectares. The soil most used for such crop in the State of Minas Gerais is classified as Latosol (Oxisol). The plants of Phaseolus vulgaris L. cv. BRSMG Madrepérola have indeterminate growth habit, low tolerance to lodging, and can be classified as an early-season variety. This variety has high yield potential and resistance to diseases, such as the common mosaic virose and anthracnose. P. vulgaris is one of the preferred plant species for using in ecotoxicological tests to evaluate the potential effect of toxic substances. The objective of this work was to evaluate the emergence and early development of common bean variety BRSMG Madrepérola under doses of mercury chloride (HgCl2), in two Latosols (Oxisols)

MERCURY PHYTOTOXICITY IN COMMON BEANS IN SOILS OF MINAS GERAIS, BRAZIL

INTRODUCTION: Problems caused by contaminated areas have been increasingly found around the world. Mercury (Hg) is a trace element potentially toxic to humans and the environment. Thus, monitoring Hg levels in the environment has great importance. The transfer of trace elements from soils to plants is a complex process, that depends on soil attributes such as pH, cation exchange capacity, texture, and mineralogy and also plant attributes, such as root system lenght and others. In Brazil, agricultural areas with levels of Hg higher than 12 mg kg-1 are considered contaminated, since such levels of Hg are likely to come from non-natural sources. The State of Minas Gerais is the third largest producer of common beans in Brazil (2015/2016 farming year). The area planted with common beans is estimated in 339,000 hectares. The soil most used for such crop in the State of Minas Gerais is classified as Latosol (Oxisol). The plants of Phaseolus vulgaris L. cv. BRSMG Madrepérola have indeterminate growth habit, low tolerance to lodging, and can be classified as an early-season variety. This variety has high yield potential and resistance to diseases, such as the common mosaic virose and anthracnose. P. vulgaris is one of the preferred plant species for using in ecotoxicological tests to evaluate the potential effect of toxic substances. The objective of this work was to evaluate the emergence and early development of common bean variety BRSMG Madrepérola under doses of mercury chloride (HgCl2), in two Latosols (Oxisols)

Anharmonic transitions in nearly dry L-cysteine I

Two special dynamical transitions of universal character have been recently observed in macromolecules at $T_{D}\sim 180 - 220$ K and $T^{*}\sim 100$ K. Despite their relevance, a complete understanding of the nature of these transitions and their consequences for the bio-activity of the macromolecule is still lacking. Our results and analysis concerning the temperature dependence of structural, vibrational and thermodynamical properties of the orthorhombic polymorph of the amino acid L-cysteine (at a hydration level of 3.5%) indicated that the two referred temperatures define the triggering of very simple and specific events that govern all the biochemical interactions of the biomolecule: activation of rigid rotors ($T<T^{*}$), phonon-phonon interactions with phonons of water dimer ($T^{*}<T<T_{D}$), and water rotational barriers surpassing ($T>T_{D}$).Comment: 4 pages, 4 figures, submitted to Physical Review Letter