Hermitian Dirac Hamiltonian in time dependent gravitational field

It is shown by a straightforward argument that the Hamiltonian generating the time evolution of the Dirac wave function in relativistic quantum mechanics is not hermitian with respect to the covariantly defined inner product whenever the background metric is time dependent. An alternative, hermitian, Hamiltonian is found and is shown to be directly related to the canonical field Hamiltonian used in quantum field theory.Comment: 9 pages, final version, to appear in Class. Quant. Gra

On dual canonical bases

The dual basis of the canonical basis of the modified quantized enveloping algebra is studied, in particular for type $A$. The construction of a basis for the coordinate algebra of the $n\times n$ quantum matrices is appropriate for the study the multiplicative property. It is shown that this basis is invariant under multiplication by certain quantum minors including the quantum determinant. Then a basis of quantum SL(n) is obtained by setting the quantum determinant to one. This basis turns out to be equivalent to the dual canonical basis

Manual do Sistema Balanço Hídrico e Calendário Agrícola.

Manual do Sistema Balanço Hídrico; Explicação e observações sobre os termos empregados nas tabelas do Balanço Hídrico; Modelo Entidade Relacionamento (MER); Objetivo operacional do sistema; Diferenciamento das duas maneiras de processamento do sistema; Funcionamento; Módulo arquivos; Módulo Balanço Hídrico; Módulo Utilitário; Módulo Sobre.bitstream/item/116808/1/834.pd

Projection-based measurement and identification

A recently developed Projection-based Digital Image Correlation (P-DVC) method is here extended to 4D (space and time) displacement field measurement and mechanical identification based on a single radiograph per loading step instead of volumes as in standard DVC methods. Two levels of data reductions are exploited, namely, reduction of the data acquisition (and time) by a factor of 1000 and reduction of the solution space by exploiting model reduction techniques. The analysis of a complete tensile elastoplastic test composed of 127 loading steps performed in 6 minutes is presented. The 4D displacement field as well as the elastoplastic constitutive law are identified. Keywords: Image-based identification, Model reduction, Fast 4D identification, In-situ tomography measurements. INTRODUCTION Identification and validation of increasingly complex mechanical models is a major concern in experimental solid mechanics. The recent developments of computed tomography coupled with in-situ tests provide extremely rich and non-destructive analyses [1]. In the latter cases, the sample was imaged inside a tomograph, either with interrupted mechanical load or with a continuously evolving loading and on-the-fly acquisitions (as ultra-fast X-ray synchrotron tomography, namely, 20 Hz full scan acquisition for the study of crack propagation [2]). Visualization of fast transformations, crack openings, or unsteady behavior become accessible. Combined with full-field measurements, in-situ tests offer a quantitative basis for identifying a broad range of mechanical behavior.Comment: SEM 2019, Jun 2019, Reno, United State

Sistema de Balanço Hídrico: manual do desenvolvedor.

O Sistema Balanço Hídrico, elaborado pela Unidade, completa o Sistema AgroCast desenvolvido e divulgado pela Agência Estado. O AgroCast disponibiliza diversas informações para o AgroNegócio, como commodities, previsão de tempo, taxas etc. Já o sistema desenvolvido pela Unidade, disponibiliza na internet dados sobre o Balanço Hídrico para diversos estados de São Paulo, com a possibilidade de gerar dados especificamente para os tipos de solos existente na região.bitstream/item/116952/1/898.PD

Situational Precipitators and Interactive Forces in Sexual Crime Events Involving Adult Offenders

We investigated the role of situational precipitators in sexual offenses in relation to the use of physical force by offenders, penetration of the victim, and physical injuries to the victim. We used self-report data obtained from a Canadian sample of 553 incarcerated adult male sexual offenders. All data used in this study were gathered through a semi-structured interview conducted with each participant. First, we found that 75.8% of sexual crime events were somehow precipitated, or characterized, by the presence of precipitators before crime. Second, the relationship between each precipitator and the type of offense was statistically significant except for one precipitator. Third, although a number of precipitators were associated with the dependent variables, we also found two interaction effects that illuminated the complexity of the role of precipitators in sexual offenses. Interaction analysis can increase our understanding of sexual crime events and better inform prevention practices, such as relapse prevention

Lightweight Carbon Fiber Mirrors for Solar Concentrator Applications

Lightweight parabolic mirrors for solar concentrators have been fabricated using carbon fiber reinforced polymer (CFRP) and a nanometer scale optical surface smoothing technique. The smoothing technique improved the surface roughness of the CFRP surface from ~3 {\mu}m root mean square (RMS) for as-cast to ~5 nm RMS after smoothing. The surfaces were then coated with metal, which retained the sub-wavelength surface roughness, to produce a high-quality specular reflector. The mirrors were tested in an 11x geometrical concentrator configuration and achieved an optical efficiency of 78% under an AM0 solar simulator. With further development, lightweight CFRP mirrors will enable dramatic improvements in the specific power, power per unit mass, achievable for concentrated photovoltaics in space.Comment: IEEE Photovoltaic Specialist Conference (PVSC), DC, USA, 201

Effects of Individual and Work-related Factors on Incidence of Shoulder Pain in a Large Working Population

Objectives: The aim of this study was to assess the effects of individual and work-related factors on the incidence of shoulder pain in a large French working population. Methods: A total of 3,710 workers of a French region were randomly included in a cross-sectional study between 2002 and 2005. They completed a self-administered questionnaire about musculoskeletal symptoms, individual factors and exposure to work constraints. In 2007, 2,332 responded to a follow-up questionnaire. The Nordic questionnaire was used both times to assess shoulder pain during the preceding 7 days. Associations between incident shoulder pain and individual and work-related factors at baseline were studied by multivariate logistic regression for both genders. Results: A total of 946 men and 709 women without shoulder pain at baseline were eligible for the analyses. At follow-up, 105 men (11.1%) and 145 women (20.5%) reported shoulder pain. For men, age (OR 3.3, 95% CI, 1.7–6.5 for ≥50 yr), working with arms above the shoulder (1.5; 1.0–2.3) and high perceived physical exertion (1.6; 1.0–2.5) increased the risk of incident shoulder pain. For women, the factors associated with incident shoulder pain were age (2.9; 1.5–5.8 for ≥50 yr), obesity (2.5; 1.4–4.5), temporary employment (2.1; 1.1–3.7), high perceived physical exertion (2.2; 1.4–3.5) and low decision latitude (1.6; 1.0–2.3). Conclusion: Age was the strongest predictor of incident shoulder pain in both genders. BMI and biomechanical and psychosocial factors were also identified as risk factors, whereas no factor related to work organization remained in the final models