On the 2D Dirac oscillator in the presence of vector and scalar potentials in the cosmic string spacetime in the context of spin and pseudospin symmetries

The Dirac equation with both scalar and vector couplings describing the dynamics of a two-dimensional Dirac oscillator in the cosmic string spacetime is considered. We derive the Dirac-Pauli equation and solve it in the limit of the spin and the pseudo-spin symmetries. We analyze the presence of cylindrical symmetric scalar potentials which allows us to provide analytic solutions for the resultant field equation. By using an appropriate ansatz, we find that the radial equation is a biconfluent Heun-like differential equation. The solution of this equation provides us with more than one expression for the energy eigenvalues of the oscillator. We investigate these energies and find that there is a quantum condition between them. We study this condition in detail and find that it requires the fixation of one of the physical parameters involved in the problem. Expressions for the energy of the oscillator are obtained for some values of the quantum number $n$. Some particular cases which lead to known physical systems are also addressed.Comment: 15 pages, 8 figures, matches published versio

The influence of teaching environment on music teacher self-efficacy perceptions

The purpose of this study was to examine the experiences of music teachers who teach or have taught in environments outside their personal backgrounds in order to understand how working in environments dissimilar from their personal backgrounds might influence feelings of teacher self-efficacy. The constituent elements of music teacher participants' personal backgrounds considered in the study included socioeconomic status, racial or ethnic identity, and perspectives of public education with regard to classroom management, expectations, and student achievement. One of the main themes throughout the study included cultural differences between teachers and students and the way these differences might affect student engagement in the classroom and teachers’ sense of self-efficacy. Study participants included two early-career teachers with less than five years’ experience and three experienced teachers with more than five years' experience and represented a demographically diverse cross-section of music teachers currently teaching in the public school system in Northern California. Bandura (1997) advanced Social Cognitive Theory and the subset of self-efficacy, which served as the theoretical framework for the current study. The methodological approach of case study was employed and expanded into a modified multi-case study analysis with an accompanying cross-case analysis. Study results revealed challenges that teachers experience when teaching in culturally unfamiliar environments, but also revealed that these challenges could be minimized by engaging with students, making connections, and developing mutually beneficial rapport between themselves and their students. The music teachers in the current study acknowledged that music teaching and learning can be used as a vehicle to make connections with culturally diverse student groups and that appealing to students’ home culture through music can enhance student engagement and academic achievement resulting in an increase in teacher self-efficacy. Teacher self-efficacy is related to health, job satisfaction, burnout, and attrition and the current study sought to add to the body of research that supports the notion that teacher self-efficacy is a critical aspect of success for teachers and learners

Industrial Automation Self-Learning Through the Develoment of Didactic Industrial Processes

Trabalho apresentado no 20th International Conference on Interactive Collaborative Learning, 27-29 de setembro 2017, Budapeste, HungriaTeaching industrial automation is a complex mission. The classical approach is based on lectures and laboratories assisted by teachers. Nevertheless, teaching industrial automation using the classical approach is not easy because this multidisciplinary area requires knowledge in control, energy, electronics, robotics and computer engineering, among others. In this way, this paper presents an approach to teach Industrial Automation based on a self learning strategy. Instead of using the classical approach, students must develop a research work and a didactic automation prototype. The results of this methodology indicate that students increase the interest about industrial automation and clarify important aspects of assembly, commissioning, parameterization and programming of electric and electronic devices. Additionally this methodology seems to increase self-confidence of students and give them the necessary background to face the challenge of working in the real world.N/

Does Eating Slowly Influence Appetite and Energy Intake when Water Intake is Controlled?

Background: Slow eating has been associated with enhanced satiation, but also with increased water intake. Therefore, the role of water ingestion in regard to eating rate needs to be discerned. This study examined the influence of eating rate on appetite regulation and energy intake when water intake is controlled. Methods: In a randomized design, slow and fast eating rates were compared on two occasions, in 30 women (22.7±1.2y; BMI=22.4±0.4kg/m2) who consumed an ad libitum mixed-macronutrient lunch with water (300 mL). Satiation was examined as the main outcome by measuring energy intake during meals. At designated times, subjects rated hunger, satiety, desire-to-eat, thirst, and meal palatability on visual analogue scales. Paired t-tests were used to compare hypothesis-driven outcomes. Appetite ratings were compared across time points and conditions by repeated measures analysis of variance (ANOVA) using a within-subject model. Results: Energy intake and appetite ratings did not differ between conditions at meal completion. However, subjects rated less hunger and tended to rate lower desire-to-eat and greater satiety at 1 hour following the slow condition. Conclusions: Results tend to support a role of slow eating on decreased hunger and higher inter-meal satiety when water intake is controlled. However, the lack of significant differences in energy intake under these conditions indicates that water intake may account for the effects of eating rate on appetite regulation

Using Genetic Algorithms to Improve Support Vector Regression in the Analysis of Atomic Spectra of Lubricant Oils

[Abstract] Purpose – The purpose of this paper is to assess the quality of commercial lubricant oils. A spectroscopic method was used in combination with multivariate regression techniques (ordinary multivariate multiple regression, principal components analysis, partial least squares, and support vector regression (SVR)). Design/methodology/approach – The rationale behind the use of SVR was the fuzzy characteristics of the signal and its inherent ability to find nonlinear, global solutions in highly complex dimensional input spaces. Thus, SVR allows extracting useful information from calibration samples that makes it possible to characterize physical-chemical properties of the lubricant oils. Findings – A dataset of 42 spectra measured from oil standards was studied to assess the concentration of copper into the oils and, thus, evaluate the wearing of the machinery. It was found that the use of SVR was very advantageous to get a regression model. Originality/value – The use of genetic algorithms coupled to SVR was considered in order to reduce the time needed to find the optimal parameters required to get a suitable prediction model

An unusual cause of intra-abdominal calcification: A lithopedion

AbstractWe report a case of a 77-year-old female who was admitted to the emergency department complaining of diffuse abdominal pain for five days, associated with nausea, vomiting and constipation.Physical examination disclosed a large incarcerated umbilical hernia, which was readily apparent on supine abdominal plain films. These also showed a calcified heterogeneous mass in the mid-abdominal region, which was further characterized by CT as a lithopedion (calcified ectopic pregnancy). This is one of the few cases studied on a MDCT equipment, and it clearly enhances the post-processing abilities of this imaging method which allows diagnostic high-quality MIP images.Lithopedion is a rare entity, with less than 300 cases previously described in the medical literature. However, many reported cases corresponded to cases of skeletonization or collections of fetal bone fragments discovered encysted in the pelvic region at surgery or autopsy. It is thus estimated that true lithopedion is a much rarer entity.The diagnosis may be reached by a suggestive clinical history and a palpable mass on physical examination, while the value of modern cross-sectional techniques is still virtually unknown. Ultrasonography may depict an empty uterine cavity and a calcified abdominal mass of non-specific characteristics, and computed tomography or magnetic resonance imaging are able to reach a conclusive diagnosis and may additionally define the involvement of adjacent structures.The differential diagnosis includes other calcified pathologic situations, including ovarian tumors, uterine fibroids, urinary tract neoplasms, inflammatory masses or epiploic calcifications