1,470 research outputs found
Aplicação da interferometria holografia subaquática para análise de estruturas
Pretende-se com este trabalho estudar a aplicação das técnicas de interferometria
holográfica à análise estrutural em ambiente subaquático. Estas técnicas estão hoje bem
divulgadas e com aplicações em diversas áreas. No entanto, a sua aplicação em ambientes subaquáticos, apresenta alguns desafios. Neste trabalho estuda-se a aplicação de duas tĂ©cnicas, ESPI e holografia digital, comparando-as e apresentando vantagens e desvantagens de cada uma delas. Faz-se um breve estudo sobre a influĂŞncia das instabilidades resultantes da turbulĂŞncia das águas e da presença de partĂculas em suspensĂŁo bem como possĂveis soluções para minimizar estes problemas
Strain field analysis of cancellous bone under compression by image correlation
Experimental mechanical analysis of cancellous bone has been performed to capture the global strain field of
specimens under compression. One major objective is to assess the test procedure and obtain the cancellous bone
mechanical properties. Now a day, several techniques are available for the experimental measurement of the field
displacement. Among them, the Cross-Correlation is one of most simple’s techniques and can be applied to several studies cases. Based on the correlation of random speckle pattern between two images, the spatial displacement fields can be
accessed. A simple digital camera or video recorder can be used without special light to capture the surface intensity pattern
in each instant. If several images are taken during a test loading, the displacement field can be fallowed and subsequently
the strain can be obtain by the spatial differentiation. Because of random surface pattern, the image can be divided in small
areas, each of them pattern independent. By cross-correlating each of one between the two images, the relative displacement is obtained
A graph-based design framework for services
Service-oriented systems rely on software applications that offer services through the orchestration of activities performed by external services procured on the fly when they are needed. This paper presents an overview of a graph-based framework developed around the notions of service and activity module for supporting the design of service-oriented systems in a way that is independent of execution languages and deployment platforms. The framework supports both behaviour and quality-of-service constraints for the discovery, ranking and selection of external services. Service instantiation and binding are captured as algebraic operations on configuration graphs. © 2012 Springer-Verlag
CURRENT TOPICS IN LOCOMOTION PHYSIOLOGY: A) MUSCLE EFFICIENCY IN HEAVILY LOADED GRADIENT WALKING AND B) HEART RATE OFF-KINETICS AS A PREDICTOR OF VO2MAX
The human locomotion has been constantly analysed from both bioenergetics and biomechanical point of views (Saibene & Minetti, 2003; Cavagna, 2010). Since earliest times, hunting for food and escaping from predators already has proven how important is to comprehend this complex engineering that is our locomotor machine.
Gradient locomotion has been investigated in the past, and the concept of the optimum gradient for walking, running and mountain paths are well known in the literature. The existence of an optimum gradient is based on the different partitioning between positive and negative mechanical work (that mirrors concentric and eccentric muscular activity) and the related metabolic demand. In the literature, the ratio between negative and positive work efficiency during unloaded locomotion was found to be 5/1. The purpose of this new study is to analyse the mechanical, metabolic and electromyography parameters during gradient loaded walking in order to understand how an extra-load can affect locomotion and especially the efficiency of positive and negative work.
Still, another important topic referred to the human locomotion physiology is about the cardiovascular system. Related to this, oxygen uptake (V'O2) refers to the product of cardiac output and the volume of oxygen extracted from the blood, and its maximal value (V'O2peak) strengthen the maximal capacity of the cardiovascular system to provide O2 to muscle cells during continued exercise, being the most widely used measure of physical fitness (Plasqui & Westerterp, 2005; Koeneman et al., 2011). Although there is a large genetic component, it is mainly determined by a person\u2019s activity level, and inversely related to several health outcomes such as cardiovascular disease (Daanen et al., 2012).
Besides of heart rate (HR) control and its relationship with V'O2, the HR recovery (off transient, after exercise) has received more attention by current researchers (Myers et al., 2007; Dupuy et al., 2012; Haddad et al., 2012). The rate of decline in HR following termination of exercise, which is regulated by the autonomic nervous system and thereby, provides information concerning sympathetic and parasympathetic activity (Daanen et al., 2012). In general, the more rapid the HR recovery, the better the fitness (Daanen et al., 2012; Buchheit, 2014).
While exercise-training studies usually report HR values at a given time during the recovery period (Daanen et al., 2012), in most clinical studies, HR recovery is defined as the difference between HR at the end of exercise and HR at a given time during the recovery period (Otsuki et al., 2007; Dupuy et al., 2012). Moreover, in some studies a mono-exponential model fit the HR off-kinetics to derive global parameters of HR recovery kinetics such as the time constant or the asymptotic value (Stanley et al., 2013; Peinado et al., 2014).
Based on these results and the growing interest in new smart devices for health monitoring, here we aimed to estimate V'O2peak from a short test (60 m) with variables that can be detected by the smart sensors. We ask to 25 healthy subjects to perform a maximal sprint over 60-m. Beat-by-beat HR was recorded by a chest belt during the whole test including resting period before and recovery post sprint. (n = 25). HR off kinetics was fitted by a mono-exponential function and tau value was calculated in order to obtain a velocity of HR decrement post exercise. V'O2peak was then estimate with a multiple regression analysis: V'O2peak = 7.46 19vtest + 261.4 19voff - 0.19 19 06HR (R2= 0.65, p<0.001). Where vtest represents the velocity performed during the 60-m test, voff corresponds to the velocity of HR decreasing during off-transient (recovery phase), and " 06HR" is the difference of HR during on-transient of exercise and it is the difference between maximum and the resting value.
This new equation does not aim to replace the laboratory-standard protocols for V'O2peak determination, but it can give an insight about fitness level to laymen that use smart devices for monitoring their physical activity. Whenever these new models (smart watches) would perform a beat-by-beat analysis this equation could be introduced to the software and give a first general estimate of the user's fitness level
Fundamental Strings and Black Holes
We propose a black hole thermodynamic description of highly excited charged
and uncharged perturbative string states in 3+1 dimensional type II and 4+1
dimensional heterotic string theory. We also discuss the generalization to
extremal and non-extremal black holes carrying magnetic charges.Comment: 25 pages, harvmac; V2: Added reference
Are biological species and higher-ranking categories real? Fish folk taxonomy on Brazil’s Atlantic Forest coast and in the Amazon
Analysis of Brazilian fishers' classifications of 24 marine (Atlantic coast) and 24 freshwater (Amazon) fish species reveals that fishers from the Atlantic coast identify fish mainly through generic names (primary lexemes), while riverine Amazonian fishers typically identify them through binomials. The similarity of Amazonian fish species seems to contribute to the detailed folk taxonomy used by riverine fishers. High-ranking groups called "relatives" or "cousins" are sorted by fishers in terms of similarities of habitat, diet, and morphology and, secondarily, behavior. The general correspondence between the folk and scientific taxonomies reinforces the reality of both the supracategories used by these fishers and the biological groups as discontinuities in nature. Given the urgency of biological inventories and the lack of knowledge of high-biodiversity environments such as the Atlantic Forest and the Amazon, these results suggest that fisher knowledge and experience could contribute to scientific research.49229130
An architecture for message exchange in pervasive healthcare based on the use of intelligent agents
Aims: This paper proposes an architecture for the exchange of context-aware messages in Pervasive Healthcare environments.\ud
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Materials and methods: In Pervasive Healthcare, novel information and communication technologies are applied to support the provision of health services anywhere, at anytime, and to anyone. Ubiquitous Computing technologies allow efficient and safe information exchange amongst caregivers and their patients in communities, homes and hospitals. Since health systems may offer their health records in various electronic formats, the openEHR foundation has proposed a dual model to achieve semantic interoperability between such systems. Intelligent Agents is a technology that has been applied to simulate human skills in healthcare procedures. This architecture is based on technologies from Ubiquitous Computing and Intelligent Agents, and complies with the openEHR dual model.\ud
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Results: This architecture was demonstrated and evaluated in a controlled experiment that we conducted in the cardiology department of a hospital located in the city of MarĂlia (SĂŁo Paulo, Brazil).\ud
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Conclusion: An application was developed to evaluate this architecture, and the results showed that the architecture is suitable for facilitating the development of healthcare systems by offering generic resources and powerful solution to integrate these systems
Travelling waves for the Gross-Pitaevskii equation II
The purpose of this paper is to provide a rigorous mathematical proof of the
existence of travelling wave solutions to the Gross-Pitaevskii equation in
dimensions two and three. Our arguments, based on minimization under
constraints, yield a full branch of solutions, and extend earlier results,
where only a part of the branch was built. In dimension three, we also show
that there are no travelling wave solutions of small energy.Comment: Final version accepted for publication in Communications in
Mathematical Physics with a few minor corrections and added remark
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