Orthostasis test in the practice of the cardiologist

The orthostasis test makes it possible to evaluate neurohumoral regulation and reaction of the circulatory system and to detect changes in the function of a number of internal organs (especially the kidney). Simultaneous recording of the ECG in an orthostatic position despite nonspecificity, makes it possible to detect hidden damage (organic or metabolic) or increased sensitivity of the myocardium to stressor sympathetico-adrenal effects, stability of therapeutic effect, and the action mechanism of a number of drugs

The near wall effect of synthetic jets in a boundary layer

Copyright @ 2007 Elsevier Inc. All rights reserved.An experimental investigation to analyse the qualitative near wall effect of synthetic jets in a laminar boundary layer has been undertaken for the purpose of identifying the types of vortical structures likely to have delayed separation on a 2D circular cylinder model described in this paper. In the first instance, dye visualisation of the synthetic jet was facilitated in conjunction with a stereoscopic imaging system to provide a unique quasi three-dimensional identification of the vortical structures. Secondly, the impact of synthetic jet structures along the wall was analysed using a thermochromic liquid crystal-based convective heat transfer sensing system in which, liquid crystals change colour in response to the thermal footprints of a passing flow structure. Of the different vortical structures produced as a result of varying actuator operating and freestream conditions, the footprints of hairpin vortices and stretched vortex rings revealed a marked similarity with the oil flow pattern of a vortex pair interacting with the separation line on the cylinder hence suggesting that either of these structures was responsible in delaying separation. Conditions were established for the formation of the different synthetic jet structures in non-dimensional parameter space

State of gas exchange in recumbent and orthostatic positions and under physical load in healthy persons of varying age, sex and body build

Age effect on gas exchange was studied in the recumbent and orthostatic positions and under physical load. In the case of the older age group and for normal as compared with hypersthenic persons, oxygen consumption during rest and during moderate physical overload diminishes. When the vertical position is assumed oxygen consumption in persons of various age groups is distinctly increased, particularly in the elderly group. There is a reduction in the amount of oxygen consumption, oxygen pulse, recovery coefficient, and work efficiency under moderate overload. In persons over 50, physical labor induces a large oxygen requirement and a sharp rise in the level of lactic acid and the blood's lactate/pyruvate ratio. No distinct difference was noted in the amount of oxygen consumed during rest and during physical overload in men and women of the same physical development and age

Analysis of structure-phase states in-a-bulk hardened and a head-hardened rails

A layer-by-layer analysis along the central axis and over the fillet of rails for low-temperature service, rails with enhanced wear resistance and contact fatigue resistance, and for senior-grade rails, bulk oil hardened and DT 350 rails head-hardened under different conditions has been carried out by modern material science methods. Quantitative variables have been established and a comparison of structure-phase states, defective substructure and internal stress fields has been made

Pesquisa de História do Brasil: trabalhos em realização

Em fins de 1970, sob a orientação do Profesor Dr. Frédéric Mauro, o Setor de Documentação iniciou um fichário de teses e trabalhos sôbre História do Brasil. Êste fichário contém o levantamento das pesquisas realizadas desde 1935, e as que ainda se encontram em andamento.

Microstructure and crystallographic texture of silicon iron modified by torsion under quasihydrostatic pressure

The electron backscatter diffraction, X-ray diffraction analysis, electromotive force instantaneous measurement, microhardness and coercive force measurement techniques are used to explore the development of the microstructure, crystallographic texture and physico-mechanical properties of silicon iron (Fe-3% Si) alloy under quasi-hydrostatic pressure in a Bridgman anvil. It is found that the alloy deformation is accompanied by its significant hardenin

Virtual Shaping on NACA 0015 by Means of a High Momentum Coefficient Synthetic Jet

Results concerning flow control on a NACA 0015 airfoil using high power synthetic jets are presented for low incidences and for Reynolds numbers ranging from 132000 to 425000. The forcing was operated through a spanwise slit positioned near the leading edge at x/c=1.25% or at x/c=10% on the upper surface. Static pressure distribution measurements around the airfoil, wake surveys and smoke flow visualizations were performed. Pressure distributions were significantly modified around the injection location, showing an area of intense suction which increased the lift and strongly affected the drag. Flow visualizations highlighted that the intense suction was due to a virtual shaping effect caused by the formation of a recirculation bubble capable of displacing the streamlines. Low momentum deficits in the wake velocity distributions and, in certain conditions, jet-like flow was observed for the forced cases. Finally, a scaling law relating the bubble size to the forcing intensity is propose

Point-by-point inscription of apodized fiber Bragg gratings

We demonstrate apodized fiber Bragg gratings inscribed with a point-by-point technique. We tailor the grating phase and coupling amplitude through precise control over the longitudinal and transverse position of each laser-inscribed modification. This method of apodization is facilitated by the highly-localized, high-contrast modifications generated by focussed IR femtosecond laser inscription. Our technique provides a simple method for the design and implementation of point-by-point fiber Bragg gratings with complex apodization profiles.Comment: 6 pages, 4 figures, article in revie

DIRECTIONS FOR SUSTAINABILITY: I. ALTERNATIVE ENERGY

Concern with the future of planet Earth, its sustainability and conservation of life (both human and of the several species) has resulted in several debates and socioeconomic changes in the past decades. The ongoing and systematic gas emission (especially CO2) arising out of the growing need for energy for the many social sectors has been blamed as the main villain in this story. Is it possible to go back in time and recover nature’s balance without giving up the technologies that improved the quality of life of most people in the past century? How can we control nature’s fury, consequence of the many climate changes? Answers are to be found in collaboration, once the awareness of each individual is raised via simple and clear information concerning the phenomena involved, the technology available and to be developed. In view of the above, Parque CienTec, the Science and Technology Park of the University of São Paulo, created exhibits in scale and promotes monitored activities on the type and use of the alternative energies and how to put them into practice. This study is part of a larger project involving biological sciences and social activities.Nas últimas décadas, a grande preocupação com o futuro do planeta Terra, sua sustentabilidade e a conservação da vida humana e das várias espécies, tem provocado variadas discussões e propostas de mudanças sociais e econômicas. Como principal vilã dessa história, foi eleita a intensa e contínua emissão de gases (principalmente CO2) derivada da crescente necessidade de energia pelos diversos segmentos sociais. Como retroagir no tempo para recuperar o equilíbrio da natureza sem abrir mão das tecnologias que melhoraram a qualidade de vida da maioria das populações no último século? Como estancar a fúria da natureza provocada pelas mudanças climáticas? As respostas encontram-se na colaboração após a conscientização de cada indivíduo através da informação simples e clara dos fenômenos envolvidos e das tecnologias já disponíveis e a serem desenvolvidas. Neste intuito, o Parque CienTec criou peças de exposição em escala real e promove atividades monitoradas sobre o tipo e uso de energias alternativas, de forma interativa e lúdica, para todas as idades e formações. Após um breve histórico, apresentam-se a seguir algumas alternativas e a forma de colocá-las em prática. O presente trabalho é parte de um projeto maior que envolve ciências biológicas e atividades sociais.