Aharonov-Bohm Effect on Noncommutative Plane: A Coherent State Approach

We apply the coherent state approach to study Aharonov-Bohm effect in the field theory context. We verify that, contrarily to the commutative result, the scattering amplitude is ultraviolet finite. However, we have logarithmic singularities as the noncommutative parameter tends to zero. Thus, the inclusion of a quartic self-interaction for the scalar field is necessary to obtain a smooth commutative limit.Comment: 14 pages, 4 figures, minor correction

Long-Term Evaluation of the Influence of Mechanical Pruning on Olive Growing

In Portugal, olive (Olea europaea L.) groves with the traditional tree density of around 100 trees ha -1, necessitate increasing pruning costs every year. As a result farmers tend to lengthen pruning intervals. With the purpose of studying a mechanised alternative to the expensive, labor-intensive manual pruning practice, the authors established in 1997 field trials with the following three treatments: i) manual pruning with a chain saw; ii) mechanical pruning, performed by a tractor mounted cutting bar provided with 6 circular disc-saws; and iii) mechanical pruning, as in the mechanical pruning treatment, followed by a manual pruning complement. The effect of the above treatments on olive production and on harvesting efficiency was evaluated every year for 8 yr. The harvesting was performed by a trunk shaker, and the remaining non-detached fruits were collected manually. The pruning rate of mechanical pruning (487 trees hour-1man-1) was substantially higher than the values of manual pruning and mechanical+manual pruning, which were the same (20 trees hour-1man-1). Over the 8-yr period, mechanical pruning had an average yield of 36,4 kg tree-1 year-1 which was significantly higher than the 30,1 kg tree-1 year-1 of manual pruning and no significantly different from the 34,1 kg tree-1 year-1 of mechanical+manual pruning. The shaker efficiency was significantly influenced by the year, ranging from 72% to 96%; no significant differences were found between treatments in terms of harvesting efficiency. These tests indicate that after mechanized pruning (horizontal cut at the uppermost part of the canopy) trees can be kept for at least 8 years without any significant loss in olive yield per tree and no effect in harvesting efficiency, therefore reducing costs. Selective manual complement to the mechanized pruning, performed in the same year, does not provide any further advantages in olive yield nor in shaker performance and consequently increasing production costs

Quantum-corrected self-dual black hole entropy in tunneling formalism with GUP

In this paper we focus on the Hamilton-Jacobi method to determine the entropy of a self-dual black hole by using linear and quadratic GUPs(generalized uncertainty principles). We have obtained the Bekenstein-Hawking entropy of self-dual black holes and its quantum corrections that are logarithm and also of several other types.Comment: Latex, 7 pages, no figure. Version to appear in PLB. arXiv admin note: substantial text overlap with arXiv:1502.0017

Gravitational Aharonov-Bohm effect due to noncommutative BTZ black hole

In this paper we consider the scattering of massless planar scalar waves by a noncommutative BTZ black hole. We compute the differential cross section via the partial wave approach, and we mainly show that the scattering of planar waves leads to a modified Aharonov-Bohm effect due to spacetime noncommutativityComment: 6 pages, latex, no figures. To appear in PLB. arXiv admin note: substantial text overlap with arXiv:1210.773

Notas para una fil(m)osofía

El interés de la filosofía por el cine, si bien se ha acentuado en los últimos años, ya estaba presente en las últimas décadas. Desde el momento en que la filosofía abandonó la pretensión de constituirse en un saber sustantivo y se convirtió en una reflexión en torno a otros saberes y actividades humanas, la preocupación por indagar diferentes discursos acabará siendo su tarea principal. Entre esos discursos no podía faltar el cine: el lenguaje de las imágenes (y en especial el de las imágenes en movimiento) devendrá. desde posiciones críticas y analíticas, motivo de reflexión de los filósofos. No sólo por razones de pura supervivencia corporativa, como sugiere algún crítico, sino fundamentalmente por la convicción de que la escisión entre el mito y el logos, entre las imágenes y los conceptos, responde a una concepción hiperracionalista de la filosofía que parece necesario revisar

La pregunta adecuada

En el contexto tan hostil del campo de concentración de Dachau, la entrega de Nico Rost a la literatura no cumple sólo una función autoafirmativa, psicohigiénica, sino también política, de apertura a un inmediato futuro en el que se haya erradicado el fascismo, ya que, como afirma el 22 de octubre de 1944: «Si después de la guerra queremos conocernos y entendernos mejor –cosa que será más que deseable y urgente–, a mi juicio, uno de los mejores medios es tener un conocimiento profundo de las respectivas literaturas» (p. 157)