It is shown that the standard sp n hybrid orbitals are orthogonal orbitals that minimize the total quadratic spread. This is done in a concise way that may improve the understanding of hybrid orbitals. The fact that maximally localized Wannier functions of crystalline materials may resemble hybrid orbitals is discussed.
Neste trabalho abordamos a caracterização de soluções de sulfato de cobre II penta-hidratado (CuSO4.5H2O) utilizando a técnica de espectroscopia no UV-Vis. Empregando a Lei de Beer, foi possível calcular o coeficiente de extinção molar do CuSO4 em solução. Estes parâmetros são úteis para determinações quantitativas de cobre em solução. Os espectros analisados apresentaram uma única banda de absorção centrada em 810nm e transparência na região correspondente à cor azul no espectro eletromagnético. DOI:http://dx.doi.org/10.30609/JETI.2018-2.5930
Resumo -O objetivo deste trabalho foi avaliar o potencial predatório de besouros adultos de Carabidae e Staphylinidae (Coleoptera) sobre lagartas de quarto instar da lagarta-da-soja, em laboratório. Inicialmente, avaliou-se a capacidade de consumir uma lagarta por 24 horas. Para as espécies que causaram ≥80% de mortalidade da presa, determinou-se a taxa de consumo, tendo-se oferecido uma lagarta por 24 horas, durante quatro dias consecutivos. Os carabídeos Calosoma granulatum, Cynthidia croceipes, Odontocheila nodicornis e Pseudabarys sp. 1; as espécies dos gêneros Galerita, Scarites e Tetracha; e os estafilinídeos Eulissus chalybaeus, Glenus cyanicollis e Xenopygus sp. 2 apresentam elevado potencial predatório.Termos para indexação: Anticarsia gemmatalis, consumo de presa, controle biológico, predadores.
Predatory potential of Carabidae and Staphylinidae (Coleoptera) on the velvetbean caterpillarAbstract -The objective of this work was to evaluate the predatory potential of adult Carabidae and Staphylinidae (Coleoptera) beetles on fourth-instar larvae of the velvetbean caterpillar, in the laboratory. Initially, the capacity to consume one caterpillar during 24 hours was evaluated. For species that caused ≥80% mortality of the prey, the consumption rate was determined, by offering one caterpillar during 24 hours for four consecutive days. The carabids Calosoma granulatum, Cynthidia croceipes, Odontocheila nodicornis, and Pseudabarys sp. 1; the species of the Galerita, Scarites, and Tetracha genera; and the staphylinids Eulissus chalybaeus, Glenus cyanicollis, and Xenopygus sp. 2 show great predatory potential.
The aim of this study was to evaluate the influence of surface topography of gutta-percha (GP) cones and plasticized disks of GP on the initial adhesion of Enterococcus faecalis (E. faecalis). The GP cones (Tanari and Dentsply brands) were cut 3 mm from the apical portion and fixed on a glass slide. To make the disks, the cones were thermoplasticized in standardized molds. The specimens were divided into groups according to the shape of the GP and the presence or absence of the bacteria. For contamination, the strain of E. faecalis (ATCC 29212) was used. The surface topography was analyzed using an atomic force microscope (AFM). The surface, roughness, and waviness parameters were evaluated by the Kruskal–Wallis and Dunn test. The comparison between disks and cones showed significant differences, where the cones were rougher, with a higher value attributed to the Dentsply cone (DC group). The same was observed for the waviness. After contamination, there was greater bacterial accumulation in cones, especially in their valleys, but both the surface and the topography became more homogeneous and smoother, with no differences between disks and cones of both brands. The topographic surface of the GP, at the micro and nanoscale, influences the initial adhesion of E. faecalis, with a greater tendency for contamination in regions associated with the presence of roughness and waviness. In this context, plasticization of GP is indicated, as it reduces surface irregularities compared to cones, contributing to less retention of bacteria.
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