Phase diagram of the mixed spin-2 and spin-5/2 Ising system with two different single-ion anisotropies

AbstractWe study the effect of two different single-ion anisotropies in the phase diagram and in the compensation temperature of mixed spin-2 and spin-5/2 Ising ferrimagnetic system. We employed the mean-field theory based on the Bogoliubov inequality for Gibbs free energy. We use the Landau expansion of free energy in the order parameter to describe the phase diagram. In the temperature versus single-ion anisotropy plane the phase diagram displays tricritical behavior. The critical and compensation temperatures increase with increasing values of the single-ion anisotropies

Microscopic mechanisms of spin-dependent electric polarization in 3d oxides

We present a short critical overview of different microscopic models for nonrelativistic and relativistic magnetoelectric coupling including the so-called "spin current scenario", ab-initio calculations, and several recent microscopic approaches to a spin-dependent electric polarization in 3d oxides.Comment: 8 pages, 3 figure

Integrated utilization of grape skins from white grape pomaces

An approach for the integrated utilization of grape skins from white grape pomaces has been proposed. This consists of consecutive or simultaneous extraction of grape skins with neutral organic solvent and water under reflux. Organic extract is a valuable raw material for the isolation of oleanolic acid. The aqueous extract (ca 50%, w/w) is composed of essentially hexoses and suitable for the high yield (till 51%) bioethanol production at a maximum specific cell growth rate (μmax) of 0.29 h−1. The remained extracted grape skins are the complex of structural polysaccharides embedded into cutinous matrix. Extracted grape skins were shown to be a prospective raw material for the production of low-density boards (d ≤ 0.40) for insulation needs. The boards produced from grape skins and bind of 8% urea–formaldehyde resin revealed reasonable tensile strength (0.4 MPa) and a low thermal conductivity (0.09–0.12 W (m K)−1) over a wide range of temperatures (40–200 °C).info:eu-repo/semantics/publishedVersio

A Pulsating Gaussian Wave Packet

A pulsating Gaussian wave packet for the harmonic oscillator is explicitly constructed. The mechanism for that behaviour is pointed out. © 1999 IOP Publishing Ltd.201L19L20Tsuru, H., (1992) J. Phys. Soc. Jpn., 61, p. 2595Goldman, I.I., Krivchenkov, V.D., Kogan, Galitskii, (1960) Selected Problems in Quantum Mechanics, , transl D ter Haar (London: Infosearch)Feynman, R.P., Hibbs, A.R., (1965) Quantum Mechanics and Path Integrals, , New York: McGraw-Hil

Particle motion and gravitational lensing in the metric of a dilaton black hole in a de Sitter universe

We consider the metric exterior to a charged dilaton black hole in a de Sitter universe. We study the motion of a test particle in this metric. Conserved quantities are identified and the Hamilton-Jacobi method is employed for the solutions of the equations of motion. At large distances from the black hole the Hubble expansion of the universe modifies the effective potential such that bound orbits could exist up to an upper limit of the angular momentum per mass for the orbiting test particle. We then study the phenomenon of strong field gravitational lensing by these black holes by extending the standard formalism of strong lensing to the non-asymptotically flat dilaton-de Sitter metric. Expressions for the various lensing quantities are obtained in terms of the metric coefficients.Comment: 8 pages, RevTex, 1 eps figures; discussion improved; typos corrected; references adde

OCORRÊNCIA DA FORMIGA CORTADEIRA ATTA SEXDENS (L.) (HYMENOPTERA: FORMICIDAE) RELACIONADA A ESTRADAS NÃO-PAVIMENTADAS EM DUAS ÁREAS DO SEMIÁRIDO BRASILEIRO COM GRAUS DE PERTURBAÇÃO CONTRASTANTES

In the semiarid Brazilian Caatinga, we compared the occurrence of leaf-cutting ant nests (Atta sexdens) at two areas in Contendas do Sincorá, Bahia State: one single disturbed area subjected to cattle overgrazing (Fazenda Lagoa das Covas: FLC) and one protected area characterized by well-preserved patches of caatinga (Floresta Nacional Contendas do Sincorá: FNCS). We also tested if A. sexdens nests were more abundant near roads. No nest was observed in the FNCS, whereas 35 nests were recorded in the FLC (3.6 colonies ha-1). The number of A. sexdens nests clearly decreased with increasing road distance, which varied from zero to about 140 m. Nests were also observed on roads outside FLC and FNCS. We suggest that roads may be facilitating the expansion of A. sexdens range in the Caatinga vegetation at Contendas do Sincorá. We expect that A. sexdens presence will maintain or even increase the disturbing effects of cattle overgrazing on FLC vegetation. If A. sexdens also succeed to establish in FNCS, this protected area will experience a possible process of flora homogenization and impoverishment, favoring the establishment of plant species associated to anthropogenic disturbances. It is possible that other Caatinga areas are being subjected to the same process of Atta invasion favored by the establishment of paved and unpaved roads.Na Caatinga, semiárido brasileiro, nós comparamos a ocorrência de ninhos da formiga cortadeira (Atta sexdens) em duas áreas do município de Contendas do Sincorá, estado da Bahia: uma área perturbada por pecuária (Fazenda Lagoa das Covas: FLC), e uma protegida e com áreas preservadas de Caatinga (Floresta Nacional Contendas do Sincorá: FNCS). Nós também testamos se os ninhos de A. sexdens são mais abundantes próximos às estradas não pavimentadas. Nenhum ninho foi registrado na FNCS, em contraste, 35 ninhos foram registrados na FLC (3,6 colônias ha-1). O número de ninhos de A. sexdens claramente diminuiu com o aumento da distância da estrada, que variou de 0 a 140 m. Ninhos também foram observados nas estradas do lado de fora da FLC e da FNCS. Nós sugerimos que estradas podem estar facilitando a expansão de A. sexdens nas áreas de caatinga do município de Contendas do Sincorá. Nós esperamos que a presença de A. sexdens irá manter ou mesmo aumentar os efeitos dos distúrbios promovidos pelo gado na vegetação da FLC. Se o estabelecimento de A. sexdens na FNCS também for bem sucedido, nesta área protegida poderá ocorrer um processo de homogeneização e empobrecimento, favorecendo o estabelecimento de espécies de plantas associadas a perturbações antrópicas. É possível que outras áreas da Caatinga estejam sendo submetidas ao mesmo processo de invasão por Atta favorrecido por estradas pavimentadas e não-pavimentadas

Health risk assessment from exposure to particles during packing in working environments

Packing of raw materials in work environments is a known source of potential health impacts (respiratory, cardiovascular) due to exposure to airborne particles. This activity was selected to test different exposure and risk assessment tools, aiming to understand the effectiveness of source enclosure as a strategy to mitigate particle release. Worker exposure to particle mass and number concentrations was monitored during packing of 7 ceramic materials in 3 packing lines in different settings, with low (L), medium (M) and high (H) degrees of source enclosure. Results showed that packing lines L and M significantly increased exposure concentrations (119-609 μg m-3 respirable, 1150-4705 μg m-3 inhalable, 24755-51645 cm-3 particle number), while nonsignificant increases were detected in line H. These results evidence the effectiveness of source enclosure as a mitigation strategy, in the case of packing of ceramic materials. Total deposited particle surface area during packing ranged between 5.4-11.8x105 μm2 min-1, with particles depositing mainly in the alveoli (51-64%) followed by head airways (27-41%) and trachea bronchi (7-10%). The comparison between the results from different risk assessment tools (Stoffenmanager, ART, NanoSafer) and the actual measured exposure concentrations evidenced that all of the tools overestimated exposure concentrations, by factors of 1.5-8. Further research is necessary to bridge the current gap between measured and modelled health risk assessments

Identification, review, and use of health state utilities in cost-effectiveness models: An ISPOR good practices for outcomes research task force report

Cost-effectiveness models that present results in terms of cost per quality-adjusted life-year for health technologies are used to inform policy decisions in many parts of the world. Health state utilities (HSUs) are required to calculate the quality-adjusted life-years. Even when clinical studies assessing the effectiveness of health technologies collect data on HSUs to populate a cost-effectiveness model, which rarely happens, analysts typically need to identify at least some additional HSUs from alternative sources. When possible, HSUs are identified by a systematic review of the literature, but, again, this rarely happens. In 2014, ISPOR established a Good Practices for Outcome Research Task Force to address the use of HSUs in cost-effectiveness models. This task force report provides recommendations for researchers who identify, review, and synthesize HSUs for use in cost-effectiveness models; analysts who use the results in models; and reviewers who critically appraise the suitability and validity of the HSUs selected for use in models. The associated Minimum Reporting Standards of Systematic Review of Utilities for Cost-Effectiveness checklist created by the task force provides criteria to judge the appropriateness of the HSUs selected for use in cost-effectiveness models and is suitable for use in different international settings

Potential for macro and micronutrients extraction from tomato plants with different soil water stresses

Different tomato cultivars may present differentiated water needs, making it indispensable to study water demand. Thus, the objective of this work was to evaluate the influence of six water stresses in the soil on the extraction potential of macro and micronutrients in the aerial part of tomato in vegetative stage, cultivar ‘Dominador’ F1, under protected cultivation and drip. The experiment was installed in a greenhouse with a randomized block design with four replications. The treatments consisted of six soil water stresses as indicative of the time of irrigation. The preset stresses were 20, 45, 70, 95, 120 and 145 kPa at 20 cm depth. At 140 days after transplanting, the variables evaluated were: the macro and micronutrient content of shoots. The results showed that to obtain higher levels of macro (P and S) and micronutrients (B and Cu) of the total aerial part of the ‘Dominador’ tomato plant F1, it was obtained at a voltage of 20 kPa, and its value was reduced linearly with the increase of the water tension in the soil