Oscillating holograms recorded in photorefractive crystals by a frequency detuned feedback loop

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aplicação dos conceitos de RCM e a ferramenta FMEA no aumento de confiabilidade em equipamentos de uma indústria química

The growing demand for quality at competitive prices and fast production process put to the test function in the industrial Maintenance. The need for equipment with high availability to fit this fierce competitiveness makes maintenance becomes essentially reliable. Despite this current context, many companies still have an old view of maintenance, focused only on corrective services, and proposals for change are often neglected due to the sense of urgency day to day. Thus, this study aims to demonstrate through theoretical applicability of simple tool, but of great value in increasing reliability within the maintenance sector of an industry, applying the concepts of Reliability Centered Maintenance – RCM and Analysis tool Failure Modes and Effects – FMEA in equipment of a chemical company directly involved in the manufacturing process of the brake fluid, which this product is used in vehicles around the country. That way, you can identify the types, occurrence and criticality of each failure and evaluate assertively decision making for each device, avoiding unnecessary downtime and potential failures of the same

An inverse method to estimate the moving heat source in machining process

The present work propounds an inverse method to estimate the heat sources in the transient two-dimensional heat conduction problem in a rectangular domain with convective bounders. The non homogeneous partial differential equation (PDE) is solved using the Integral Transform Method. The test function for the heat generation term is obtained by the chip geometry and thermomechanical cutting. Then the heat generation term is estimated by the conjugated gradient method (CGM) with adjoint problem for parameter estimation. The experimental trials were organized to perform six different conditions to provide heat sources of different intensities. This method was compared with others in the literature and advantages are discussed. (C) 2012 Elsevier Ltd. All rights reserved.

From transient to steady state deformation and grain size: A thermodynamic approach using elasto-visco-plastic numerical modeling

Numerical simulation experiments give insight into the evolving energy partitioning during high-strain torsion experiments of calcite. Our numerical experiments are designed to derive a generic macroscopic grain size sensitive flow law capable of describing the full evolution from the transient regime to steady state. The transient regime is crucial for understanding the importance of micro structural processes that may lead to strain localization phenomena in deforming materials. This is particularly important in geological and geodynamic applications where the phenomenon of strain localization happens outside the time frame that can be observed under controlled laboratory conditions. Ourmethod is based on an extension of the paleowattmeter approach to the transient regime. We add an empirical hardening law using the Ramberg-Osgood approximation and assess the experiments by an evolution test function of stored over dissipated energy (lambda factor). Parameter studies of, strain hardening, dislocation creep parameter, strain rates, temperature, and lambda factor as well asmesh sensitivity are presented to explore the sensitivity of the newly derived transient/steady state flow law. Our analysis can be seen as one of the first steps in a hybrid computational-laboratory-field modeling workflow. The analysis could be improved through independent verifications by thermographic analysis in physical laboratory experiments to independently assess lambda factor evolution under laboratory conditions.

Tutoriales multimedia para sistemas de telecomunicación

Este Proyecto Fin de Carrera está destinado a la ilustración y aprendizaje del uso de varios dispositivos de los laboratorios del Departamento de Ingeniería Audiovisual y Comunicaciones, de la Escuela Universitaria de Ingeniería Técnica de Telecomunicación, de la Universidad Politécnica de Madrid, en forma de vídeos tutoriales basados en mediciones y prácticas habituales de las asignaturas del departamento para que puedan ser utilizados por los alumnos de la escuela como apoyo a las explicaciones del profesor en ocasiones puntuales. En concreto se han realizado hasta seis vídeos tutoriales en los que se explica: el diseño de un circuito impreso y la creación y fabricación de éste. Por otro lado, también se ha explicado el fenómeno del ruido de fase y cómo es el proceso de su medida, como una de las muchas características de un analizador de espectros. A modo de análisis, se ha realizado otro tutorial acerca de la modulación en FM, sus características y sus aplicaciones. Por último se ha hecho un estudio del comportamiento de un analizador de redes, exponiendo su funcionamiento y explicando su proceso de calibración. Para la realización de estos tutoriales se han utilizado diferentes aplicaciones sobre creación de vídeos multimedia, animación, producción de audio y narración. En especial se han usado: Sprint-Layout 5.0, Adobe Flash Professional CS5.5, Camtasia studio 7, Corel VideoStudio Pro X4, Loquendo TTS7 y WinPlot. Para el apartado de las grabaciones de las diferentes escenas se ha necesitado el uso de distintos instrumentos de medida del laboratorio tales como: analizador de espectros, analizador de redes, generador de señal, generador de funciones, osciloscopio y otros equipos adicionales como: cámara de vídeo y trípode del departamento. Para la composición de los diferentes tutoriales se ha comenzado creando un guion, para cada uno de ellos, estableciendo la aparición de las imágenes, vídeos, y locución. A continuación se exponen los diferentes temas en los que se han basado estos tutoriales de laboratorio, uno a uno. ABSTRACT. This Project is destined to learn the use of several devices at the laboratory of “Ingeniería Audiovisual y Comunicaciones” Department at “Escuela Universitaria de Ingeniería técnica de Telecomunicaciones” of “Universidad Politécnica de Madrid”, on the way as tutorial videos base on the subjects from this department to be used by the college students as help of the teacher’s explanations. In this project you will find up to six tutorial videos, showing: printed circuit design, printed circuit board manufacture. You can also find an explanation about the phenomenon of phase noise and how it’s its measurement process, as one of the many features of a spectrum analyzer. Another tutorial video is based on FM modulation, its features and applications. The last tutorial explains the networks analyzer functionalities and its calibration process. To carry out these tutorials different applications have been used to create multimedia videos, animation, audio production and storytelling. Such as Sprint Layout 5.0, Camtasia 7.0, Corel VideoStudio Pro X4, Adobe Flash Professional CS5.5, Loquendo TTS7 y WinPlot. About the recording side of the different scenes, several equipment have been required at the laboratory, such as spectrums analyzer, signal generator, oscilloscope, function generator, network analyzer and other additional devices, such as: a video camera with its tripod. The composition of the different tutorials has begun creating a script, for each of them, setting the times of appearance of images, video, speech and music. After this abstract, the different topics of the tutorials are showed, one by one.

A mathematical modelling technique for the analysis of the dynamics of a simple continuous EDA

This paper presents some initial attempts to mathematically model the dynamics of a continuous estimation of distribution algorithm (EDA) based on a Gaussian distribution and truncation selection. Case studies are conducted on both unimodal and multimodal problems to highlight the effectiveness of the proposed technique and explore some important properties of the EDA. With some general assumptions, we show that, for ID unimodal problems and with the (mu, lambda) scheme: (1). The behaviour of the EDA is dependent only on the general shape of the test function, rather than its specific form; (2). When initialized far from the global optimum, the EDA has a tendency to converge prematurely; (3). Given a certain selection pressure, there is a unique value for the proposed amplification parameter that could help the EDA achieve desirable performance; for ID multimodal problems: (1). The EDA could get stuck with the (mu, lambda) scheme; (2). The EDA will never get stuck with the (mu, lambda) scheme.

Automating Exersises Validation in e-Learning Environments

E-learning is supposing an innovation in teaching, raising from the development of new technologies. It is based in a set of educational resources, including, among others, multimedia or interactive contents accessible through Internet or Intranet networks. A whole spectrum of tools and services support e-learning, some of them include auto-evaluation and automated correction of test-like exercises, however, this sort of exercises are very constrained because of its nature: fixed contents and correct answers suppose a limit in the way teachers may evaluation students. In this paper we propose a new engine that allows validating complex exercises in the area of Data Structures and Algorithms. Correct solutions to exercises do not rely only in how good the execution of the code is, or if the results are same as expected. A set of criteria on algorithm complexity or correctness in the use of the data structures are required. The engine presented in this work covers a wide set of exercises with these characteristics allowing teachers to establish the set of requirements for a solution, and students to obtain a measure on the quality of their solution in the same terms that are later required for exams.

Generation of Testing Source Code for Object-Oriented Programs

Красимир Манев, Антон Желязков, Станимир Бойчев - В статията е представена имплементацията на последната фаза на автоматичен генератор на тестови данни за структурно тестване на софтуер, написан на обектно-ориентиран език за програмиране – генерирането на изходен код на тестващия модул. Някои детайли от имплементацията на останалите фази, които са важни за имплементацията на последната фаза, са представени първо. След това е описан и алгоритъмът за генериране на кода на тестващия модул.

Effect Of Exercise Test On Pulmonary Function Of Obese Adolescents.

to investigate the pulmonary response to exercise of non-morbidly obese adolescents, considering the gender. a prospective cross-sectional study was conducted with 92 adolescents (47 obese and 45 eutrophic), divided in four groups according to obesity and gender. Anthropometric parameters, pulmonary function (spirometry and oxygen saturation [SatO2]), heart rate (HR), blood pressure (BP), respiratory rate (RR), and respiratory muscle strength were measured. Pulmonary function parameters were measured before, during, and after the exercise test. BP and HR were higher in obese individuals during the exercise test (p = 0.0001). SatO2 values decreased during exercise in obese adolescents (p = 0.0001). Obese males had higher levels of maximum inspiratory and expiratory pressures (p = 0.0002) when compared to obese and eutrophic females. Obese males showed lower values of maximum voluntary ventilation, forced vital capacity, and forced expiratory volume in the first second when compared to eutrophic males, before and after exercise (p = 0.0005). Obese females had greater inspiratory capacity compared to eutrophic females (p = 0.0001). Expiratory reserve volume was lower in obese subjects when compared to controls (p ≤ 0,05). obese adolescents presented changes in pulmonary function at rest and these changes remained present during exercise. The spirometric and cardiorespiratory values were different in the four study groups. The present data demonstrated that, in spite of differences in lung growth, the model of fat distribution alters pulmonary function differently in obese female and male adolescents.

Measurement of the whole body clearance of infused glycerol as a test of liver function after major hepatectomy.

Major liver resection can be used in the treatment of liver cancer. The functional capacity of liver parenchyma needs to be evaluated preoperatively because it conditions the outcome. We assessed whether the whole body clearance of glycerol, a substrate essentially metabolized in liver cells, may be suitable as a simple test of liver function. Seven patients after major hepatectomy, six patients after colectomy and 12 healthy subjects were studied. Patients were investigated on the first day after surgery. All participants were studied during a 150-min basal period followed by a 120-min infusion of 16 mumol kg-1 min-1 13C-labelled glycerol. Whole body glycerol clearance was calculated from the change in plasma glycerol concentration. Whole body glucose production was measured with 6,6 2H2 glucose infused as a tracer in the basal state and during glycerol infusion. In addition, 13C glucose synthesis was monitored to quantitate gluconeogenesis from glycerol. Patients after liver resection had higher plasma glycerol concentrations and lower whole body glycerol clearance than healthy subjects and patients after colectomy. They also had higher plasma glucagon concentrations. Their fasting glucose production was mildly elevated in the fasting state and did not change after glycerol infusion, indicating a normal hepatic autoregulation of glucose production. These results indicate that whole body glycerol clearance can be simply determined from plasma glycerol concentrations during exogenous glycerol infusion. It is significantly reduced in patients after major hepatectomy, suggesting that it constitutes a sensitive test of hepatic function. Its use as a preoperative testing procedure remains to be evaluated.

Coronary vasomotor responses to isometric handgrip exercise are primarily mediated by nitric oxide: a noninvasive MRI test of coronary endothelial function.

Endothelial cell release of nitric oxide (NO) is a defining characteristic of nondiseased arteries, and abnormal endothelial NO release is both a marker of early atherosclerosis and a predictor of its progression and future events. Healthy coronaries respond to endothelial-dependent stressors with vasodilatation and increased coronary blood flow (CBF), but those with endothelial dysfunction respond with paradoxical vasoconstriction and reduced CBF. Recently, coronary MRI and isometric handgrip exercise (IHE) were reported to noninvasively quantify coronary endothelial function (CEF). However, it is not known whether the coronary response to IHE is actually mediated by NO and/or whether it is reproducible over weeks. To determine the contribution of NO, we studied the coronary response to IHE before and during infusion of N(G)-monomethyl-l-arginine (l-NMMA, 0.3 mg·kg(-1)·min(-1)), a NO-synthase inhibitor, in healthy volunteers. For reproducibility, we performed two MRI-IHE studies ∼8 wk apart in healthy subjects and patients with coronary artery disease (CAD). Changes from rest to IHE in coronary cross-sectional area (%CSA) and diastolic CBF (%CBF) were quantified. l-NMMA completely blocked normal coronary vasodilation during IHE [%CSA, 12.9 ± 2.5 (mean ± SE, placebo) vs. -0.3 ± 1.6% (l-NMMA); P < 0.001] and significantly blunted the increase in flow [%CBF, 47.7 ± 6.4 (placebo) vs. 10.6 ± 4.6% (l-NMMA); P < 0.001]. MRI-IHE measures obtained weeks apart strongly correlated for CSA (P < 0.0001) and CBF (P < 0.01). In conclusion, the normal human coronary vasoactive response to IHE is primarily mediated by NO. This noninvasive, reproducible MRI-IHE exam of NO-mediated CEF promises to be useful for studying CAD pathogenesis in low-risk populations and for evaluating translational strategies designed to alter CAD in patients.

Discrepancy between Visual Acuity and Microperimetry in AMD Patients: Visual Acuity Appears as an Inadequate Parameter to Test Macular Function.

BACKGROUND: Best corrected visual acuity (BCVA) of 0.8 or above in AMD patients can sometimes correspond to poor macular function inducing a serious visual handicap. Microperimetry can be used to objectivize this difference. PATIENTS AND METHODS: A retrospective study was undertaken on 233 files of AMD patients of whom 82 had had a microperimetry. BCVA was compared with microperimetry performance. All examinations were performed in an identical setting by the same team of 3 persons. RESULTS: Among the 82 patients included, 32 (39.0%) had a BCVA equal to or above 0.8 even though their microperimetry performance was lower than 200/560 db. 10 of them (12.2% of total) had an even poorer microperimetry below 120/560 db indicating poor macular function. CONCLUSIONS: More than a third of the AMD patients had a bad or very bad microperimetry performance in parallel with a good visual acuity. Microperimetry is a valuable tool to assess and follow real macular function in AMD patients when visual acuity alone can be misleading.

Standardization of a computerized method for calculating autonomic function test responses in healthy subjects and patients with diabetes mellitus

The objectives of the present study were 1) to compare results obtained by the traditional manual method of measuring heart rate (HR) and heart rate response (HRR) to the Valsalva maneuver, standing and deep breathing, with those obtained using a computerized data analysis system attached to a standard electrocardiograph machine; 2) to standardize the responses of healthy subjects to cardiovascular tests, and 3) to evaluate the response to these tests in a group of patients with diabetes mellitus (DM). In all subjects (97 healthy and 143 with DM) we evaluated HRR to deep breathing, HRR to standing, HRR to the Valsalva maneuver, and blood pressure response (BPR) to standing up and to a sustained handgrip. Since there was a strong positive correlation between the results obtained with the computerized method and the traditional method, we conclude that the new method can replace the traditional manual method for evaluating cardiovascular responses with the advantages of speed and objectivity. HRR and BPR of men and women did not differ. A correlation between age and HRR was observed for standing (r = -0.48, P<0.001) and deep breathing (r = -0.41, P<0.002). Abnormal BPR to standing was usually observed only in diabetic patients with definite and severe degrees of autonomic neuropathy.