191 research outputs found

    Design and development of a feeding aid device to assist people with deficiency

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    The present work intends to design new devices of aid to the feeding for individuals with deficiency. Like this, along this paper they are referred the most relevant pathologies, which affect the autonomy of the patient’s feeding, as well as some existent devices in the market. Based on the characteristics of these devices, this research was performed with the main objective of finding the most appropriate actuation system. Furthermore, it was made the analysis and discussion of the performance specifications, essential stage in the design process of the feeding aid device for this to assure all the demanded requirements. Afterward, they are pointed some possible solutions, in the sense of creating more and better on behalf of the patient's need. Finally, for the solution selected, it was being later developed a model, in the advanced software Working Model for the simulation of the mechanical system of aid feeding

    Seismic performance of the St. George of the Latins church : lessons learned from studying masonry ruins

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    This work addresses the seismic safety of the remainings of one church in Famagusta (Cyprus), including also a historical survey, inspection and diagnosis. The seismic safety is studied in detail, using limit analysis of collapse mechanisms as preliminary safety assessment. Then, a finite element model was prepared and updated using dynamic identification results. The updated model was subjected to non-linear static (pushover) analysis in different directions (global and principal) using two lateral load patterns: proportional to the mass and proportional to the modal shapes of the structure. Finally, a time history analysis is also performed. The results allow to conclude that: (a) limit analysis of collapse mechanism can be adequately employed for the seismic assessment of masonry ruins, as they provide comparable results to more sophisticated analysis; (b) load patterns proportional to the mode shapes in pushover analysis of complex masonry structures should be carefully considered, as they can provide too conservative results; (c) the ruins of the church exhibit a low seismic safety.This work was partly funded by project FP7-ENV-2009-1-244123-NIKER of the 7th Framework Programme of the European Commission Project

    A formal approach for aerospace systems control considering SFC specification and C programming language

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    The C programming language is one of the most used in critical embedded real-time controllers applied at aerospace systems. Despite its potential, it is a very general language, with many maintenance problems and with a little or without graphical structure. The absence of formal verification techniques - even if it is possible to find some works associated to C programming language formal verification - is a fact. In this paper, it is proposed a methodology, that is divided in two main steps, and has, as main goal, to obtain safe C program code from a SFC specification: in first step some tools and techniques are used in order to assure the quality of the SFC specification and, on the second step, the goal is to translate (in a systematic way) the safe SFC specification to C code considering crucial aspects like taking into account aspects related with time specification

    Desempenho sĂ­smico de um minarete de alvenaria

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    Esta comunicação apresenta a avaliação do desempenho sísmico do Qutb Minar, minarete em Nova Deli, Índia. A modelação numérica foi realizada com recurso a três modelos diferentes, calibrados através de ensaios de identificação dinâmica. A combinação de resultados dos modelos permitiu compreender melhor o comportamento do minarete e validar os modelos mais simples. No estudo do desempenho sísmico da estrutura foram consideradas a análise não-linear estática e a análise não-linear dinâmica com integração no tempo. As técnicas de análise conduziram a resultados diferentes em termos de capacidade e mecanismo de colapso, indicando que o uso de análises estáticas para a avaliação do desempenho sísmico de construções históricas de alvenaria deve ser realizado com precaução. Os resultados da análise não-linear dinâmica estão de acordo com os danos causados por sismos no passado e com os modos identificados experimentalmente, concluindo-se que os dois últimos pisos correspondem à parte mais vulnerável do minarete

    Uso de Pediococcus parvulus para a degradação e destoxificação biológica de ocratoxina A, respetivo método e kit

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    National Patent (INPI)A presente invenção refere-se ao uso de um microrganismo para a degradação e destoxificação biológica de micotoxinas, mais especificamente para a degradação da ocratoxina A em ocratoxina a. Concretamente, relaciona-se com o uso de Pediococcus parvulus para a destoxificação de alimentos e rações. Outro aspeto da presente invenção relaciona-se com o método de destoxificação e a sua aplicação a um kit. A invenção insere-se na área farmacêutica, alimentar e veterinária.info:eu-repo/semantics/publishedVersio

    Survey and dynamic behaviour of the Our Lady of Conception Church, Portugal

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    The Our Lady of Conception church is located in village of Monforte (Portugal) and is not in use nowadays. The church presents structural damage and, consequently, a study was carried out. The study involved the survey of the damage, dynamic identification tests under ambient vibration and the numerical analysis. The church is constituted by the central nave, the chancel, the sacristy and the corridor to access the pulpit. The masonry walls present different thickness, namely 0.65 m in the chancel, 0.70 m in the sacristy, 0.92 in the central nave and 0.65 m in the corridor. The masonry walls present 8 buttresses with different dimensions. The total longitudinal and transversal dimensions of the church are equal to 21.10 m and 14.26 m, respectively. The survey of the damage showed that, in general, the masonry walls are in good conditions, with exception of the transversal walls of the nave, which present severe cracks. The arches of the vault presents also severe cracks along the central nave. As consequence, the infiltrations have increased the degradation of the vault and paintings. Furthermore, the foundations present settlements in the Southwest direction. The dynamic identification test were carried out under the action of ambient excitation of the wind and using 12 piezoelectric accelerometers of high sensitivity. The dynamic identification tests allowed to estimate the dynamic properties of the church, namely frequencies, mode shapes and damping ratios. A FEM numerical model was prepared and calibrated, based on the first four experimental modes estimated in the dynamic identification tests. The average error between the experimental and numerical frequencies of the first four modes is equal to 5%. After calibration of the numerical model, pushover analyses with a load pattern proportional to the mass, in the transversal and longitudinal direction of the church, were performed. The results of the analysis numerical allow to conclude that the most vulnerable direction of the church is in the transversal one and the maximum load factor is equal to 0.35

    Stone masonry buildings: shaking table testing and advanced methods of analysis

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    The paper presents the main results of experimental tests concerning the reduction of the seismic vulnerability of stone masonry buildings with flexible floors. Two mock-ups (original condition and repaired) were tested in a 3D shaking table. The results show that the adopted measures are efficient. A set of non-linear static analyses (pushover) were considered, together with time integration analysis. The non-linear dynamic analyses reproduced the seismic behavior observed in the seismic tests. However, the pushover analyses did not simulate correctly all the failure mode of the structure and should be used with caution.This work was partly funded by project FP7-ENV-2009-1-244123-NIKER of the 7th Framework Programme of the European Commission Project

    Air quality in the North of Portugal.

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    Air pollution in urban areas is a major topic of concern in many large cities. In Portugal, a monitoring network measures relevant pollutants for zones and agglomerations. The measurements of two zones and four agglomerations located in the North of Portugal were used to diagnose the pollution level and the relative air quality. It was found that, despite the need for densification of the network of monitoring stations, ozone (O3) and particulate matter (PM10) reach significant levels in a number of days during the year. Some recommendations are made regarding the inclusion of planning and mitigation actions in the Regional and Municipal Master Plan

    Particle Swarm Optimization for damage identification in beam-like structures

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    The main objectives of Structural Health Monitoring (SHM) are the characterization and the assessment of the health condition of structural systems. Combined with appropriate Damage Identification (DI) strategies, SHM aims to provide reliable information about the localization and quantification of the structural damage by using an inverse formulation approach, with the damage parameters being estimated from parametric changes in dynamic properties. Mathematically, an inverse problem consists of the optimization of a function which represents the "distance" between the experimental and the numerically-simulated features of the system. Such process requires the development of a mock-up numerical model fairly representative of the system and iteratively updated until a response, as close as possible to the experimental one, is provided. The minimization of the difference between measured and predicted features' values is the objective function, whose global minimum corresponds to the best adjustment of the model variables. Metaheuristics represent a large class of global methods for optimization purposes able to outperformtraditional methods in the following aspects: ease of implementation, time consumption, suitability for non-linear phenomena, black-box and high-dimensional problems. The present paper analyses, through a numerical experimentation approach, the suitability of one of the best-known metaheuristics, i.e. the Particle Swarm Optimization (PSO) algorithm, for DI of beam-like structures. Modal properties are used to define the objective function and various algorithm instances are tested across different problem instances to assess robustness and influence of the algorithm parameters.This work was supported by FCT (Portuguese Foundation for Science and Technology), within ISISE, scholarship SFRH/BD/115188/2016. This work was also financed by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT - Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007633

    Application of a classification algorithm to the early-stage damage detection of a masonry arch

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    The early-stage identification of structural damage still represents a relevant challenge in civil engineering. Localized damages if not readily detected can lead to disruption or even collapse, involving hazard to people and economical losses. Although the final goal of the identification is to localize and quantify the damage, a reliable discrimination between normal and abnormal states of the structure in the very early stage of the damage onset is not an easy task. In the field of Structural Health Monitoring (SHM) great attention has been paid to the development of damage detection methods based on continuous and automatic registration of the system response to unknown ambient inputs. The numerical algorithms exploited must be: (1) easy to implement and computationally inexpensive, eventually being embedded in the sensors; (2) as much independent on human decision as possible; (3) robust to the many sources of uncertainties affecting the monitoring; (4) able to detect small damage extents in order to provide an early warning; (5) suitable for the application in the case of few and sparse measurements collected only in the normal condition. The performance of a novel version of Negative Selection Algorithm, recently developed by the authors, is here analyzed with attention to these issues. The algorithm is tested against data collected on a segmental masonry arch built in the laboratory of the University of Minho and subject to progressive lateral displacement of one support.- (undefined
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