In situ characterization of interface-microstructure dynamics in 3D-Directional Solidification of model transparent alloys

Microstructure plays a central role in determining properties of materials so that the fundamental understanding of the physics of microstructure selection is critical in the design of materials. Under terrestrial conditions fluid flow effects are dominant in bulk samples which preclude precise characterization of fundamental physics of microstructure selection. Experiments in thin samples, carried out to obtain diffusive growth, give microstructures that are neither 2D nor 3D. Rigorous theoretical models, using the phase-field method, have shown that the fundamental physics of pattern selection in 2D and 3D is significantly different. A benchmark experimental study is required in bulk samples under low gravity conditions. Also, the selection of microstructure occurs during the dynamical growth process so that in situ observations of spatio-temporal evolution of the interface shapes are required. Microgravity experiments on ISS are thus planned in a model transparent system by using a new Directional Solidification Insert (DSI), designed for use in the DECLIC facility of CNES and to be adapted to also fit ESA experiments. The critical aspects of hardware design, the key fundamental issues identified through 1g-experiments, the proposed experimental study on ISS, and the results of rigorous theoretical modeling are presented.     

Finding the Next Computational Model: Experience with the UCSC Kestrel

Architects and industry have been searching for the next durable computational model, the next step beyond the standard CPU. Graphics co-processors, though ubiquitous and powerful, can only be effectively used on a limited range of stream-based applications. The UCSC Kestrel parallel processor is part of a continuum of parallel processing architectures, stretching from the application-specific through the application-specialized to the application-unspecific. Kestrel combines an ALU, multiplier, and local memory, with Systolic Shared Registers for seamless merging of communication and computation, and an innovative condition stack for rapid conditionals. The result has been a readily programmable and efficient co-processor for a wide range of applications, including biological sequence analysis, image processing, and irregular problems. Experience with Kestrel indicates that programmable systolic processing, and its natural combination with the Single Instruction-Multiple Data (SIMD) parallel architecture, is the most powerful, flexible, and power-efficient computational model available for a large group of applications. Unlike other approaches that try to displace or replace the standard serial processor, our model recognizes that the expansion in the application landscape and performance requirements simply imply that the most efficient solution is the combination of more than one type of processor. We propose a model in which the CPU and the GPU are complemented by “the third big chip,” a massively-parallel SIMD processor.     

New equations for the calculation of the horizon brightness irradiance in the model of Perez

In this technical note authors propose new expressions to calculate the diffuse irradiance coming from the horizon brightness band on a tilted plane. As in the model of Perez, it is assumed that the radiance from this band is a constant. New expressions are more exact than previous ones as they eliminate some of the simplifications considered in the model of Perez. For small slope angles new expressions give irradiance values up to 32.98% higher than with the cited model. Notwithstanding, when slope angle increases obtained differences sharply decrease at the beginning and this decrease becomes practically linear from about 40° on.     

Simulations of cascades in pure and alumina doped magnesia

Atomic scale molecular dynamics simulations of displacement cascades are carried out in an initially defect-free MgO lattice and in a lattice where 0.2% of the Mg²⁺ ions have been replaced by Al³⁺ ions, charge compensated by magnesium vacancies. Results show that the properties of the cascade in the perfect lattice exhibit considerable anisotropy with respect to the direction of the incident primary knock-on atom (PKA). We find that a different anisotropy of equivalent magnitude occurs as a consequence of the (random) distribution of defects in the vicinity of the cascade. This suggests that the details of damage production during a cascade event can depend sensitively on the distribution of dopants and impurity atoms around the PKA.     

Airport electric vehicle powered by fuel cell

Nowadays, new technologies and breakthroughs in the field of energy efficiency, alternative fuels and added-value electronics are leading to bigger, more sustainable and green thinking applications. Within the Automotive Industry, there is a clear declaration of commitment with the environment and natural resources. The presence of passenger vehicles of hybrid architecture, public transport powered by cleaner fuels, non-aggressive utility vehicles and an encouraging social awareness, are bringing to light a new scenario where conventional and advanced solutions will be in force.     

Refining a descriptive structure of personality attributes in the Italian language: The abridged Big Three circumplex structure.

Factor structure and circumplex approaches were integrated to develop a refined structure of personality attributes in Italian. In Study 1, the factor analytic approach was applied on the data set. The 3-factor solution, resembling the Big Three, was the most stable among others; the Big Five were not replicated. In Study 2, it was verified that differences in language and culture were relevant for the failure of the Big Five in Italian. In Study 3, the 3-factor solution was developed into 3 circumplexes, thus generating the abridged Big Three circumplex (AB3C) structure. Each 2-factor space had circumplex properties. In Study 4, the AB3C structure was shown to account for relevant proportions of variance in most of the scales of 4 well-established measures of personality. Findings indicate that the AB3C structure provides a parsimonious representation of the conceptual organization of most of the personality attributes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quality of life after radical prostatectomy

OBJECTIVE: To evaluate the quality of life of our prostatectomized patients relative to the following factors: continence, mictional quality, sexual potency and psychological repercussion. MATERIAL AND METHODS: The study includes a series of 204 patients undergoing radical prostatectomy between June 1986 and October 1996, where a personal questionnaire was administered to 112 of them. The questionnaire consisted of 25 questions dealing with various aspects related to their quality of life. RESULTS: The overall rating on continence shows the following results: total continence 59.8%, minimal incontinence grade I 17.8%, moderate incontinence grade II 13.3% and total incontinence grade III 8%. Only 2.6% retains sexual potency after surgery. 29.3% of impotent patients consulted for their dysfunction. 91% declared to be satisfied with the results of the surgical procedure. CONCLUSIONS: In our experience, continence (total + grade I incontinence) is acceptable for 77.6%, the level of mictional satisfaction being very high. There is a high index of impotence after surgery. However, most patients appear to be impervious to this fact. Overall, quality of life of our patients has not changed significantly as a result of the intervention.     

Determination of sterols by capillary column gas chromatography. Differentiation among different types of olive oil: Virgin,refined, and solvent-extracted

Compositional analysis of the sterol fraction of olive oil can be used to assess the degree of purity of the oil and the absence of admixture with other plant oils. This determination also permits characterization of the type of olive oil in question: virgin, refined, or solvent-extracted. In the present work, 130 samples of olive oil were analyzed, the sterol fractions were separated from the unsaponifiable fraction by silica gel plate chromatography, and later they were analyzed as the trimethylsilyl ether derivatives by capillary column gas chromatography. From the results obtained, it was concluded that this methodology is able to differentiate among virgin, refined, and solvent-extracted olive oils. Stigmasterol, clerosterol, Δ5-avenasterol, Δ7-stigmasterol, and Δ7-avenasterol permit the differentiation of the three types of oil from one another. Campesterol, Δ5, 23-stigmastadienol, β-sitosterol, and Δ5,24-stigmastadienol permit the differentiation of only two oils from each other but confirm the conclusions obtained for other sterols. Correlations between the different sterols of virgin, refined, and solven-extracted olive oil also have been obtained.