Position-dependent effective mass Dirac equations with PT-symmetric and non-PT-symmetric potentials

We present a new procedure to construct the one-dimensional non-Hermitian imaginary potential with a real energy spectrum in the context of the position-dependent effective mass Dirac equation with the vector-coupling scheme in 1 + 1 dimensions. In the first example, we consider a case for which the mass distribution combines linear and inversely linear forms, the Dirac problem with a PT-symmetric potential is mapped into the exactly solvable Schrodinger-like equation problem with the isotonic oscillator by using the local scaling of the wavefunction. In the second example, we take a mass distribution with smooth step shape, the Dirac problem with a non-PT-symmetric imaginary potential is mapped into the exactly solvable Schrodinger-like equation problem with the Rosen-Morse potential. The real relativistic energy levels and corresponding wavefunctions for the bound states are obtained in terms of the supersymmetric quantum mechanics approach and the function analysis method.

Extension of PT-symmetric quantum mechanics to the Dirac theory with position-dependent mass

We present a new method to construct the exactly solvable PT-symmetric potentials within the framework of the position-dependent effective mass Dirac equation with the vector potential coupling scheme in 1 + 1 dimensions. In order to illustrate the procedure, we produce three PT-symmetric potentials as examples, which are PT-symmetric harmonic oscillator-like potential, PT-symmetric potential with the form of a linear potential plus an inversely linear potential, and PT-symmetric kink-like potential, respectively. The real relativistic energy levels and corresponding spinor components for the bound states are obtained by using the basic concepts of the supersymmetric quantum mechanics formalism and function analysis method. (C) 2007 Elsevier B.V. All rights reserved.

Weathering degradation of polyester and polypropylene geotextiles

This paper presents results of physical and mechanical tests in polyester (PET) and polypropilene (PP) nonwoven geotextiles that were exposed to weathering conditions (solar radiation, humidity, wind, rain) after some specific periods of exposure (1, 2, 3 and 4 months). ASTM D5970 and Brazilian standards (NBR) recommendation were followed in this research. Results show variations in tensile properties and in the mass per unit area. Variations in the deformations were more significant in the PP geotextile when compared to the PET geotextile.

UV exposure of polymeric geomembranes

The break of polymer chemical bonds may occur due to penetration of sun short wavelengths. In sanitary landfills for instance, ultraviolet radiation affects uncovered materials and can be dangerous during the installation of the liner and before the placement of the waste. Only the ultraviolet part of the light is harmful to the geosynthetic materials, moreover, each material is sensitive to a particular wavelength. This article evaluates the effects of UV degradation and condensation in black HDPE (1.0 and 1.5 mm) and white HDPE (textured - 1.0 mm) geomembrane that were tested in laboratory during 6 months. The tests were performed using a weatherometer assembled at EESC-USP in accordance to ASTM G154. The results have shown variations in punction and tear resistance after each period of exposure.

Evaluation of geomembrane UV degradation using melt flow index and oxidative induction time tests

Many factors such as the sunlight, intensity of radiation, temperature, and moisture may influence the degradation process of geosynthetics. UV stabilizers are used especially in polyolefin geomembrane to prevent the degradation process. In these geomembranes the service lifetime is initially governed by the consumption of antioxidants. Tests like MFI and OIT are a alternative to detect the oxidative degradation in polyolefins. This article evaluates HDPE geomembrane degradation after UV exposure through the results of MFI and OIT tests. Two kinds of geomembranes were evaluated: a black and smooth (0.8, 1.0, 1.5, 2.5 mm) and a white and textured (1.0 mm). MFI test showed some levels of superficial degradation (crosslink) in HDPE geomembrane.

Biliary tract reconstruction using jejunal tube: an experimental study in dogs

BACKGROUND: To physiologically reconstruct the biliary tract, Crema et al suggested the application of the Monti principle to the biliary tract, already used in humans for the urinary tract. With this technique, a jejunal segment is transversely retubularized. This study aimed to evaluate the efficacy of jejunal tube interposition between the common bile duct and duodenum in dogs.METHODS: Thirteen dogs underwent a laparoscopic common bile duct ligature, followed by a biliodigestive connection by jejunal tube interposition after one week. The levels of glutamic-pyruvic and glutamic-oxalacetic transaminases, total bilirubins, alkaline phosphatase and gamma-glutamyltransferase were assessed before surgery and thereafter weekly until euthanasia, which was performed 6 weeks after biliodigestive connection.RESULTS: Data on 9 dogs were analyzed statistically. The dogs presented with obstructive jaundice after common bile duct ligature, as confirmed by biochemical examination. They showed a statistically significant reduction in cholestasis after biliodigestive connection by jejunal tube interposition and were healthy until the end of the experiment.CONCLUSION: A statistically significant reduction was seen in total bilirubin and canalicular enzymes (alkaline phosphatase and gamma-glutamyltransferase) in the 9 dogs 6 weeks after biliodigestive conviction by jejunal tube interposition.

Multi-wavelength holographic profilometry - art. no. 60272L

A novel method for surface profilometry by holography is presented. We used a diode laser emitting at many wavelengths simultaneously as the light source and a Bi12TiO20 (BTO) crystal as the holographic medium in single exposure processes. The employ of multi-wavelength, large free spectral range (FSR) lasers leads to holographic images covered of interference fringes corresponding to the contour lines of the studied surface. In order to obtain the relief of the studied surface, the fringe analysis was performed by the phase stepping technique (PST) and the phase unwrapping was carried out by the Cellular-automata method. We analysed the relief of a tilted flat metallic bar and a tooth prosthesis.

Avaliação da capacidade funcional e força muscular respiratória associada ao exercício físico em pacientes com doença renal crônica que realizam hemodiálise

A Doença Renal Crônica (DRC) é considerada um problema mundial de saúde pública. O paciente com DRC apresenta baixa tolerância ao exercício físico e como conseqüência apresenta limitações na capacidade funcional e força muscular respiratória. O paciente com DRC em programa de hemodiálise pode sofrer impactos negativos na sua capacidade funcional. Objetivo: Avaliar a capacidade funcional e a força muscular respiratória associada ao exercício físico em pacientes com doença renal crônica que realizam hemodiálise. Metodologia: 28 pacientes de ambos os sexos com idade entre 40 e 60 anos participaram do estudo, em programa de hemodiálise no Instituto do Rim da Santa Casa de Misericórdia de Presidente Prudente-SP. Os pacientes foram avaliados pela força muscular inspiratória (PImax) e força muscular expiratória (PEmax) pela manovacuometria e Teste de Caminhada de Seis Minutos (TC6’) para avaliar a capacidade funcional. Após as avaliações, os pacientes iniciaram o programa de atividade física, com duração de oito semanas, realizado 3 vezes por semana durante 40 minutos na hemodiálise. Ao final do programa de exercícios físicos, os pacientes foram reavaliados. Resultados: Na avaliação da força muscular respiratória o valor da PImax pós foi significativamente maior que o valor obtido na avaliação pré programa (p<0,05), para a variável PEmax não foi encontrada diferença significativa entre os momentos pré e pós intervenção (p<0,05). As avaliações da capacidade funcional ou Teste de Caminhada de Seis Minutos (TC6’) inicial e após o programa de exercícios, não apresentaram diferenças significativas (p<0,05). Dados da Escala de Borg indicaram redução significativa do cansaço e dispnéia (p<0,05), após o programa de exercícios. Os indicadores relativos à dor foram reduzidos, após o programa, em relação ao pré (p<0,05). Conclusão:... (Resumo completo, clicar acesso eletrônico abaixo)

Avaliação funcional pré e pós programa de exercício físico de pacientes em hemodialise

Model Study: An experimental study Introduction: Chronic Kidney Disease (CKD) refers to a syndromic diagnosis which leads to a progressive and irreversible loss of renal function. A hemodialysis patient may have limitations in functional capacity, pulmonary function and respiratory musclular strength impacting in quality of life. Objective: To evaluate the effects of an exercise program on pulmonary function, functional capacity, quality of life and pain in patients undergoing hemodialysis. Methodology: The study included 28 patients of both genders, women and men aged between 40 and 60 years undergoing dialysis at the Kidney Institute, Santa Casa de Misericordia in Presidente Prudente-SP. Primary outcomes included respiratory muscular strength measurements assessed by manovacuometry. The functional capacity was evaluated by a six minute walking test. A life quality questionnaire was applied to evaluate quality of life (SF36-KDQOL). Lung function was evaluated by spirometry. Pain was assessed by a visual analogue scale. The exercise program consisted of training 3 times a week for 40 minutes on hemodialysis during eight weeks. At the end of the program all patients were reassessed. Results: There was no significant difference in the values of FVC and FEV1 before and after the exercise program as well as the index Tiffenau. The value of post MIP was significantly higher than the value obtained in the pre program. For variable MEP no significant difference was found. Functional capacity evaluations showed that there were no significant differences (p> 0.05). The evaluation of quality of life, about the domains of specific areas of CKD showed statistical significance when comparing the list of symptoms and problems with overloading of renal disease and professional role. Indicators related to pain were significantly reduced after the program (P <0.05). Discussion: A chronic kidney patient faces complex situations of physical, social and financial aspects. Although no statistically significant results were found in all variables, the study corroborates to others found in the literature, which suggests that an exercise program can be positive for this population. Conclusion: Although lung capacity and functional capacity did not submit changes to the end of the study, reduced levels of pain, fatigue and dyspnea suggest improvement in functional performance after exercise programs.