Thermal properties of a solid through q-deformed algebra

We address the study of the thermodynamics of a crystalline solid by applying q-deformed algebras. We based part of our study by considering both Einstein and Debye models. We have mainly explored the q-deformed thermal and electric conductivities as a function of the Debye specific heat. The results led to the interpretation of the q-deformation acting as a factor of disorder or impurity modifying the characteristics of a crystalline structure as, for example, in the case of semiconductors.Comment: 8 pages, twocolumn, 12 figures, Latex, version to appear in Physica

Test Fixture for Determination of Energy Absorbing Capabilities of Composite Materials

The present invention provides a fixture for supporting an elongated specimen for crush testing. The fixture comprises a base plate. four guiding rods, a sliding plate, four support rods and two collars. The guiding rods connect to the base plate and extend in a direction substantially perpendicular to the base plate. The sliding plate has linear bearings which encircle the guiding rods and enable translation of the sliding plate along the axis of each guiding rod. The four supporting rods mount to the base plate and also extend in a direction substantially perpendicular to the base plate. Each support rod has a keyway for a wedge which contacts the elongated specimen and holds the specimen in place during crushing. Each collar lies above the sliding plate and holds a pair of support rods on their ends opposite the ends connected to the base plate. A spherical bearing sits on top of the sliding plate and transfers an applied load to the sliding plate, which moves downward and crushes the elongated specimen

Test fixture for determination of energy absorbing capabilities of composite materials

The present invention provides a fixture for supporting an elongated specimen for crush testing. The fixture comprises a base plate, four guiding rods, a sliding plate, four support rods and two collars. The guiding rods connect to the base plate and extend in a direction substantially perpendicular to the base plate. The sliding plate has linear bearings which encircle the guiding rods and enable translation of the sliding plate along the axis of each guiding rod. The four supporting rods mount to the base plate and also extend in a direction substantially perpendicular to the base plate. Each support rod has a keyway for a wedge which contacts the elongated specimen and holds the specimen in place during crushing. Each collar lies above the sliding plate and holds a pair of support rods on their ends opposite the ends connected to the base plate. A spherical bearing sits on top of the sliding plate and transfers an applied load to the sliding plate, which moves downward and crushes the elongated specimen

ASTRO Journals' Data Sharing Policy and Recommended Best Practices.

Transparency, openness, and reproducibility are important characteristics in scientific publishing. Although many researchers embrace these characteristics, data sharing has yet to become common practice. Nevertheless, data sharing is becoming an increasingly important topic among societies, publishers, researchers, patient advocates, and funders, especially as it pertains to data from clinical trials. In response, ASTRO developed a data policy and guide to best practices for authors submitting to its journals. ASTRO's data sharing policy is that authors should indicate, in data availability statements, if the data are being shared and if so, how the data may be accessed

Cornelius Lanczos's derivation of the usual action integral of classical electrodynamics

The usual action integral of classical electrodynamics is derived starting from Lanczos's electrodynamics -- a pure field theory in which charged particles are identified with singularities of the homogeneous Maxwell's equations interpreted as a generalization of the Cauchy-Riemann regularity conditions from complex to biquaternion functions of four complex variables. It is shown that contrary to the usual theory based on the inhomogeneous Maxwell's equations, in which charged particles are identified with the sources, there is no divergence in the self-interaction so that the mass is finite, and that the only approximation made in the derivation are the usual conditions required for the internal consistency of classical electrodynamics. Moreover, it is found that the radius of the boundary surface enclosing a singularity interpreted as an electron is on the same order as that of the hypothetical "bag" confining the quarks in a hadron, so that Lanczos's electrodynamics is engaging the reconsideration of many fundamental concepts related to the nature of elementary particles.Comment: 16 pages. Final version to be published in "Foundations of Physics

Cognitive processes underlying anticipation in a context-oriented task

Cognitive processes underlying anticipation in a context-oriented tas

New Solutions For Household Refrigerator Performance Improvement

This paper presents some experimental results of two alternative solutions to improve household refrigerators energy consumption, the flooded evaporator architecture and the pulse width modulation (PWM) control logic for a variable capacity compressor. The experiments were carried out in a 360-liters bottom-mounted refrigerator-freezer, with natural draft evaporators, at two different ambient temperatures: 16°C and 32°C. The flooded evaporator solution can imply the same performance of the parallel circuit but with the simplicity of the serial-hybrid circuit, demanding no check valve nor need for pump out. The flooded evaporator circuit has a liquid accumulator connecting the evaporator’s outlet, which allows working with high evaporating temperatures during refrigerator compartment cooling. The liquid accumulator construction jeopardizes the compressor oil to return therefore it can be trapped in the circuit; hence the solution requires an oiless compressor oil to operate. The PWM control solution may lead to compressor performance improvement at low cooling capacity, so it is especially applicable to compressors which have lower COP at smaller capacities. The PWM solution works through short on-off cycles – on period has high input power and high capacity, and along the off period the compressor has zero capacity at lowest power input – which overall results in higher COP with low cooling capacity. The experiments were set to modulate compressor cooling capacity according to the compressor power input, small cycle period and duty cycle. The experimental results indicate the flooded evaporator solution lead to a reduction in energy consumption of 4.7% at 32°C and the PWM solution implied a reduction in energy consumption of 2.7% at 32°C and 7% at 16°C

Contextual information and perceptual-cognitive expertise in a dynamic, temporally-constrained task

Skilled performers extract and process postural information from an opponent during anticipation more effectively than their less-skilled counterparts. In contrast, the role and importance of contextual information in anticipation has received only minimal attention. We evaluate the importance of contextual information in anticipation and examine the underlying perceptual-cognitive processes. We present skilled and less-skilled tennis players with normal video or animated footage of the same rallies. In the animated condition, sequences were created using player movement and ball trajectory data, and postural information from the players was removed, constraining participants to anticipate based on contextual information alone. Participants judged ball bounce location of the opponent’s final occluded shot. The two groups were more accurate than chance in both display conditions with skilled being more accurate than less-skilled (Exp. 1) participants. When anticipating based on contextual information alone, skilled participants employed different gaze behaviors to less-skilled counterparts and provided verbal reports of thoughts which were indicative of more thorough evaluation of contextual information (Exp. 2). Findings highlight the importance of both postural and contextual information in anticipation and indicate that perceptual-cognitive expertise is underpinned by processes that facilitate more effective processing of contextual information, in the absence of postural information