A generalized treatment of the order-disorder transformation in alloys and its effects on their magnetic properties

A theory of the order-disorder transformation is developed in complete generality. The general theory is used to calculate long range order parameters, short range order parameters, energy, and phase diagrams for a face centered cubic binary alloy. The theoretical results are compared to the experimental determination of the copper-gold system, Values for the two adjustable parameters are obtained.

An explanation for the behavior of magnetic alloys is developed, Curie temperatures and magnetic moments of the first transition series elements and their alloys in both the ordered and disordered states are predicted. Experimental agreement is excellent in most cases. It is predicted that the state of order can effect the magnetic properties of an alloy to a considerable extent in alloys such as Ni₃Mn. The values of the adjustable parameter used to fix the level of the Curie temperature, and the adjustable parameter that expresses the effect of ordering on the Curie temperature are obtained.

Absolute left-handed behaviors in a triangular elliptical-rod photonic crystal

In this paper we theoretically study the left-handed behaviors in a two-dimensional triangular photonic crystal made of elliptical rods in air. An absolute left-handed region is found in the second photonic band by using the plane wave expansion method to analyze the photonic band structure and equifrequency contours. Typical left-handed behaviors such as negative refraction, flat superlensing and plano-concave lensing are demonstrated by the finite-difference time-domain simulations. These behaviors are also compared with the quasi-negative refraction and the resulted focusing effects in a square-lattice two-dimensional photonic crystal. (c) 2005 Optical Society of America

Spatiotemporal behaviors and singularity of ultrashort pulsed Elegant Hermite-Gaussian beams

Analytical propagation expressions of ultrashort pulsed Elegant Hermite-Gaussian beams are derived and spatiotemporal properties of the pulses with different transverse modes are studied. Singularity of the complex amplitude envelope solution of the pulses obtained under slowly varying envelope approximation is analyzed in detail. The rigorous analytical solution of the pulse is deduced and no singularity emerges in the solution. The obtained results indicate that the transverse mode affects not only the spatiotemporal properties but also the singularity of the pulses. Time delay of the off-axis maximum intensity is more obvious and the singularity is located nearer to the z-axis for the pulse with higher transverse modes. (C) 2007 Elsevier GmbH. All rights reserved.

Effect of the A cation size disorder and synthesis conditions on the properties of an iron perovskite series

Póster presentado en The Energy and Materials Research Conference - EMR2015 celebrado en Madrid (España) entre el 25-27 de febrero de 2015

Bipolar disorder comorbid with alcohol use disorder: Focus on neurocognitive correlates

Bipolar disorder (BD) and alcohol use disorders (AUDs) are usually comorbid, and both have been associated with significant neurocognitive impairment. Patients with the BD-AUD comorbidity (dual diagnosis) may have more severe neurocognitive deficits than those with a single diagnosis, but there is paucity of research in this area. To explore this hypothesis more thoroughly, we carried out a systematic literature review through January 2015. Eight studies have examined the effect of AUDs on the neurocognitive functioning of BD patients. Most studies found that BD patients with current or past history of comorbid AUDs show more severe impairments, especially in verbal memory and executive cognition, than their non-dual counterparts. Greater neurocognitive dysfunction is another facet of this severe comorbid presentation. Implications for clinical practice and research are discussed. Specifically, the application of holistic approaches, such as clinical staging and systems biology, may open new avenues of discoveries related to the BD-AUD comorbidity.

Investigations on valence-change behaviors of europium ions in Eu-doped aluminate and silicate phosphors

Compounds of Sr3Al2O6: Eu, Sr4Al14O25: Eu, and BaZnSiO4: Eu were synthesized by high-temperature solid state reactions. The doping Eu3+ ions were partially reduced to Eu2+ in Sr4Al14O25: Eu and BaZnSiO4: Eu prepared in an oxidizing atmosphere, N-2 + O-2. However, such an abnormal reduction process could not be performed in Sr3Al2O6: Eu, which was also prepared in an atmosphere of N-2 + O-2. Moreover, even though Sr3Al2O6: Eu was synthesized in a reducing condition CO, only part of the Eu3+ ions was reduced to Eu2+. The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3+ to Eu2+.

Spectroscopic and fluorescence decay behaviors of Yb3+ -doped SiO2-PbO-Na2O-K2O glass

The spectroscopic and fluorescent decay behaviors of Yb3+-doped SiO2-PbO-Na2O-K2O glass is reported in this work. Yb2O3 contents of 1, 1.5 and 2mol% are added into the glass. Through the measurement of absorption and fluorescence spectra, and fluorescent decay rate at room temperature and at low temperature (18 K), it is found that the nonradiative decay rate of Yb3+ ions is mainly determined by the interaction between residual hydroxyl groups and Yb3+ ions. Concentration quenching effect can be omitted in this glass up to the Yb3+ ion concentration of 8.98 x 10(20)/cm(3). Multiphonon decay rate is also very small because of the large energy gap between F-2(5/2) and F-2(7/2) levels of Yb3+ ions. (c) 2004 Elsevier B.V. All rights reserved.

Trabalho técnico-administrativo em uma instituição federal de ensino superior: análise do trabalho e das condições de saúde

O presente estudo tem por tema central a análise do trabalho dos técnico-administrativos em educação, ocupantes do cargo de assistente em administração na Universidade Federal do Maranhão (UFMA), bem como os impactos dessa atividade na saúde e nos modos de ser desses profissionais. O referencial teórico-metodológico para o desenvolvimento desse estudo assenta-se nos princípios do materialismo histórico-dialético, implicando o entendimento do sujeito como ser social e histórico, que intervém na realidade na qual está inserido e sofre as determinações dessa mesma realidade. Esse paradigma busca ultrapassar a aparência do fenômeno, entendendo as mediações que o determinam. Conceitos da abordagem da psicodinâmica do trabalho também são priorizados e articulados na fundamentação teórica. No contexto organizacional em questão, a partir da análise de cinquenta questionários e de vinte e uma entrevistas semiestruturadas identificou-se um número significativo de técnicos com potenciais subutilizados, normalmente colocados à margem dos processos de decisão, funcionando como mero apoio às atividades acadêmicas, vivenciando, por conseguinte, sentimentos de invisibilidade e desprestígio. O modelo de organização burocrático a que estão submetidos gera frustração ao impor a execução de atividades predominantemente rotineiras, prescritas, atreladas a normas, que quase sempre os impedem de lançar mão de alternativas para a realização de um atendimento ao público mais ágil e eficaz. Observa que esse cenário cria um terreno fértil para o surgimento de estratégias defensivas, de sofrimento patogênico e, possivelmente, de menor engajamento e mobilização. Questiona as análises superficiais que não identificam a complexidade desse emaranhado de sentimentos e comportamentos suscitados, provavelmente, pelas dificuldades que permeiam o cotidiano laboral do assistente em administração. Aponta a necessidade de se desconstruir a ideia de que toda acomodação é fruto de malandragem e má fé dos servidores, inferindo que o imobilismo e a apatia podem ser sinais de sofrimento psíquico ou até mesmo de um processo de adoecimento, fruto de uma dinâmica organizacional que reserva um lugar de anonimato ao profissional. Alerta sobre a importância da criação de espaços laborais para os assistentes em administração que favoreçam: valorização, participação e negociação, viabilizando-se, então, uma oportunidade para a atividade laboral ser um fim em si mesma, constituindo-se em uma atividade significativa para o sujeito, para a universidade e para a sociedade. Conclui que o trabalho, assim considerado, pode assumir sentidos de crescimento, utilidade, coerência e realização, emprestando, talvez, significado para todo o sofrimento experimentado diante do enfrentamento das adversidades tão presentes no mundo do trabalho.

Convivência da pessoa idosa com diabetes buscando autonomia para o autocuidado: estudo sociopoético

Este trabalho refere-se ao educar/cuidar/pesquisar centrado na orientação de enfermagem para o autocuidado da pessoa idosa, com diabetes, visando seu bem-estar; visto a evidência do crescimento demográfico da população idosa em todo o mundo e, em especial, no Brasil. Tem como objetivo aplicar, no contexto de um curso de autocuidado ministrado em oficina sociopoética, o Diagrama de Nola Pender como instrumento de produção de dados sobre a construção de ações e apresentação de propostas de comportamentos de saúde, visando o bem-estar de pessoas. O marco teórico enfoca a Teoria de promoção da saúde de Nola Pender, que defende o processo de capacitação da comunidade para buscar sua qualidade de vida e saúde, incluindo maior participação e controle deste processo. O marco teórico metodológico é a sociopoética, que fundamenta um estudo qualitativo, descritivo, desenvolvido em 2012, após aprovação do Comitê de Ética da Universidade do Estado do Rio de Janeiro, mediante a instituição do Grupo Pesquisador, dispositivo analítico, deste método, composto por 10 sujeitos, aplicando-se as técnicas de pesquisa de sensibilidade e artísticas. São resultados da técnica Vivência de Lugares Geomíticos a delimitação das categorias temáticas, a saber: Medo do desconhecido; Transcendendo a convivência com a diabetes através da aceitação; O autocuidado como resolução dos problemas a serem enfrentados; Busca da cura da diabetes através de uma vida saudável; e Expectativas para o futuro. Na técnica Corpo como território mínimo emergiram os temas: Insegurança; Fragilidade; Dificuldade no controle da glicemia; Controle; Autocuidado; Otimismo; Perseverança; Dificuldade no controle da alimentação; Tranquilidade; Dependência; Conformação; Revolta; Equilíbrio; Desânimo; Autoestima; Autoimagem e Descuidado. Aplicando o Diagrama de Nola Pender constatou-se entre os membros do Grupo Pesquisador (GP) os fatores pessoais que influenciam a conduta prévia à adoção do autocuidado, os benefícios de ações percebidas durante o ensino do autocuidado, e as demandas de competência para assumi-lo, visando à promoção da saúde. Conclui-se, que a conduta de promoção de saúde é a variável que conduz a um olhar através de ações dirigidas que tenham resultados positivos para o bem-estar e o equilíbrio das dimensões corporais. Entre as condutas de promoção da saúde adotadas pelo GP estão: ter compromisso na realização de atividades físicas; alimentação saudável, uso de medicação diariamente e regularmente, além do autocuidado com o corpo e mente, através de práticas de atividade física e de lazer.

Study of thermal behaviors in CO2 laser irradiated glass

To understand mechanisms underlying laser-induced damage of BK7 and fused silica, we calculate the temperature field of the substrates with CO2 laser irradiating at a given laser power and beam radius. We find that the two glasses show different thermal behaviors. A model is developed for estimating the time t to heat the surface of the substrates up to a particular temperature T with cw CO2 laser irradiation. We calculate theoretically the duration t that the samples are irradiated, from the beginning to visual catastrophic damage, with the assumption of damage threshold determined by the critical temperature. The duration t that the samples are irradiated, from the beginning to visual catastrophic damage, is investigated experimentally as well. Here we take the melting point or softening point as the critical temperature, given the thermomechanical coupling properties, which is enough to cause damage for BK7. Damage features are characterized by the sound of visual cracks. Finally, we calculate stresses induced by laser heating. The analysis of stress indicates that the damage of BK7 is due to the stresses induced by laser heating. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

Study of thermal behaviors in CO2 laser irradiated glass

To understand mechanisms underlying laser-induced damage of BK7 and fused silica, we calculate the temperature field of the substrates with CO2 laser irradiating at a given laser power and beam radius. We find that the two glasses show different thermal behaviors. A model is developed for estimating the time t to heat the surface of the substrates up to a particular temperature T with cw CO2 laser irradiation. We calculate theoretically the duration t that the samples are irradiated, from the beginning to visual catastrophic damage, with the assumption of damage threshold determined by the critical temperature. The duration t that the samples are irradiated, from the beginning to visual catastrophic damage, is investigated experimentally as well. Here we take the melting point or softening point as the critical temperature, given the thermomechanical coupling properties, which is enough to cause damage for BK7. Damage features are characterized by the sound of visual cracks. Finally, we calculate stresses induced by laser heating. The analysis of stress indicates that the damage of BK7 is due to the stresses induced by laser heating. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

Efficacy of a cognitive and behavioural psychotherapy applied by primary care psychologists in patients with mixed anxiety-depressive disorder: a research protocol

Background: In contrast with the recommendations of clinical practice guidelines, the most common treatment for anxiety and depressive disorders in primary care is pharmacological. The aim of this study is to assess the efficacy of a cognitive-behavioural psychological intervention, delivered by primary care psychologists in patients with mixed anxiety-depressive disorder compared to usual care. Methods/Design: This is an open-label, multicentre, randomized, and controlled study with two parallel groups. A random sample of 246 patients will be recruited with mild-to-moderate mixed anxiety-depressive disorder, from the target population on the lists of 41 primary care doctors. Patients will be randomly assigned to the intervention group, who will receive standardised cognitive-behavioural therapy delivered by psychologists together with usual care, or to a control group, who will receive usual care alone. The cognitive-behavioural therapy intervention is composed of eight individual 60-minute face-to face sessions conducted in eight consecutive weeks. A follow-up session will be conducted over the telephone, for reinforcement or referral as appropriate, 6 months after the intervention, as required. The primary outcome variable will be the change in scores on the Short Form-36 General Health Survey. We will also measure the change in the frequency and intensity of anxiety symptoms (State-Trait Anxiety Inventory) and depression (Beck Depression Inventory) at baseline, and 3, 6 and 12 months later. Additionally, we will collect information on the use of drugs and health care services. Discussion: The aim of this study is to assess the efficacy of a primary care-based cognitive-behavioural psychological intervention in patients with mixed anxiety-depressive disorder. The international scientific evidence has demonstrated the need for psychologists in primary care. However, given the differences between health policies and health services, it is important to test the effect of these psychological interventions in our geographical setting.

Response of the topological surface state to surface disorder in TlBiSe2

Through a combination of experimental techniques we show that the topmost layer of the topological insulator TlBiSe2 as prepared by cleavage is formed by irregularly shaped Tl islands at cryogenic temperatures and by mobile Tl atoms at room temperature. No trivial surface states are observed in photoemission at low temperatures, which suggests that these islands cannot be regarded as a clear surface termination. The topological surface state is, however, clearly resolved in photoemission experiments. This is interpreted as direct evidence of its topological self-protection and shows the robust nature of the Dirac cone-like surface state. Our results can also help explain the apparent mass acquisition in S-doped TlBiSe2.

Courtship and spawning behaviors of carangid species in Belize

Many species of reef f ish agg regate seasonally in large numbers to spawn at predictable times and sites (Johannes, 1978; Sadovy, 1996; Domeier and Colin, 1997). Although spawning behavior has been observed for many reef fish in the wild (Wicklund, 1969; Smith, 1972; Johannes, 1978; Sadovy et al., 1994; Aguilar Perera and Aguilar Davila, 1996), few records exist of observations on the courtship or natural spawning for the commercially important family Carangidae (jacks) (von Westernhagen, 1974; Johannes, 1981; Sala et al., 2003). In this study, we present the first observations on the natural spawning behavior of the economically-valuable permit (Trachinotus falcatus)(Linnaeus, 1758) from the full to new moon period at reef promontories in Belize, with notes on the spawning of the yellow jack (Carangoides bartholomaei) (Cuvier, 1833), and the courtship of five other carangid species.