Bringing Together Gravity and the Quanta

Due to its underlying gauge structure, teleparallel gravity achieves a separation between inertial and gravitational effects. It can, in consequence, describe the isolated gravitational interaction without resorting to the equivalence principle, and is able to provide a tensorial definition for the energy-momentum density of the gravitational field. Considering the conceptual conflict between the local equivalence principle and the nonlocal uncertainty principle, the replacement of general relativity by its teleparallel equivalent can be considered an important step towards a prospective reconciliation between gravitation and quantum mechanics.Comment: 9 pages. Contribution to the proceedings of the Albert Einstein Century International Conference, Paris, 18-22 July, 200

The managerial and economic effects of celebrity endorsement on consumer purchasing intentions

Despite the fact that celebrity endorsement brings up some risks, it has been used quite extensively in the present era and it is a method to reach competitive advantage by companies. The economic effects for companies are obvious. This study focuses on examining the relationship between a set of variables (gender, credibility, attractiveness, type, multiple endorsements and multiple product endorsement) that were identified during the literature review as characteristics of the TV advertisings and consumers purchasing intentions. A questionnaire survey was applied. This study is based on a sample of 285 young respondents. Respondents answered two sets of questions after viewing an advertisement of a specific product featuring one or more endorsers. A quantitative approach has been adopted to investigate the relationship between the purchase intentions and the perceptions of the six characteristics of celebrity endorsement mentioned above. Results revealed that all the characteristics of celebrity endorsement analyzed had a positive impact in consumers purchasing intentions, however some of them were quite low. This study has an approach with relevant consequences for companies, either economic or managerial, bringing room to analyze and to discuss the related coming up managerial implications.info:eu-repo/semantics/publishedVersio

Adsorção de fósforo em solos de argila de atividade baixa.

Neste estudo foram avaliadas possíveis correlações entre atributos físicos e químicos do solo e a capacidade máxima de adsorção de fósforo (CMAP) em solos com argila de atividade baixa de diferentes regiões do Brasil, sendo utilizadas amostras de horizontes superficiais (A) e subsuperficiais (B) de 16 perfis de solos. As doses para a determinação da CMAP foram calculadas com base no teor de fósforo remanescente e variaram de 0 a 135 mg.L-1. A partir dos dados obtidos foram então construídas isotermas de adsorção de Langmuir. Foram feitas correlações entre CMAP e os teores de argila, de carbono orgânico, ki, kr, superfície específica, teor de alumínio determinado por ataque sulfúrico e teores das diferentes formas de ferro extraível. Foi observada grande variação nos valores de CMAP para o horizonte superficial (48 a 1429 mg.kg-1) e para o horizonte subsuperficial (455 e 1.667 mg.kg-1). Os coeficientes de correlação demonstraram haver uma associação significativa entre a CMAP e o teor de argila dos solos, ferro e alumínio, determinados pelo ataque sulfúrico e ferro aos valores da CMAP com base em atributos dos solos estudados

Vortices in the presence of a nonmagnetic atom impurity in 2D XY ferromagnets

Using a model of nonmagnetic impurity potential, we have examined the behavior of planar vortex solutions in the classical two-dimensional XY ferromagnets in the presence of a spin vacancy localized out of the vortex core. Our results show that a spinless atom impurity gives rise to an effective potential that repels the vortex structure.Comment: 6 pages, 2 figures, RevTex