Experimental analysis of the cyclic response of traditional timber joints and their influence on the seismic capacity of timber frame structures

Timber connections represent the crucial part of a timber structure and a great variability exists in terms of types of connections and mechanisms. Taking as case study the widespread traditional timber frame structures, in particular the Portuguese Pombalino buildings, one of the most common timber connection is the half-lap joint. Connections play a major role in the overall behaviour of a structure, particularly when assessing their seismic response, since damage is concentrated at the connections. For this reason, an experimental campaign was designed and distinct types of tests were carried out on traditional half-lap joints to assess their in-plane response. In particular, pull-out and in-plane cyclic tests were carried out on real scale unreinforced connections. Subsequently, the connections were retrofitted, using strengthening techniques such as self-tapping screws, steel plates and GFRP sheets. The tests chosen were meant to capture the hysteretic behaviour and dissipative capacity of the connections and characterise their response and, therefore, their influence on the seismic response of timber frame walls, particularly concerning their uplifting and rotation capacity, that could lead to rocking in the walls. In this paper, the results of the experimental campaign are presented in terms of hysteretic curves, dissipated energy and equivalent viscous damping ratio. Moreover, recommendations are provided on the most appropriate retrofitting solutions.

Analysis of polydicyclopentadiene-metal hybrid adhesive joints for automotive exterior body applications

An exterior body panel solution containing a polydicyclopentadiene skin attached to an interior metallic reinforcement through adhesive bonding is being studied to be applied in the MobiCar bonnet. With this solution is expected to achieve lightness, adequate structural integrity and cost-efficiency. However, there is uncertainty regarding to the bonnet adhesiveness since different metallic materials and adhesive types are being considered for its development. Thus, in this paper, several samples are tested through shear loading with the aim of understanding the loading magnitude expected by using polydicyclopentadiene, steel DC04+ZE and aluminum alloy AW5754-H111 as substrates adhesively bonded by an epoxy or a methacrylate. Methacrylate adhesive have shown greater shear strength in all types of adhesive joints. PDCPD joints presented the highest displacements. Surface degradation was considered adequate over abrading once none strength difference was seen between the different surface treatments. Steel treated by cataphoresis has shown the highest joint interface strength.

Symptoms and signs in rigid gas permeable lens wearers during adaptation period

Objectives: To evaluate neophyte contact lens wearers’ fitting to rigid gas permeable (RGP) contact lenses in terms of wearing time, tear volume, stability, corneal staining, and subjective ratings, over a 1-month period of time. Methods: Twenty-two young healthy subjects were enrolled for wearing RGP on a daily wear basis. The participants included in this study never wore contact lenses and showed a value under 10 in McMonnies Questionnaire. Contact Lens Dry Eye Questionnaire, Visual Analog Scales, Schirmer test, tear film break-up time (BUT), and corneal staining grading were performed. Follow-up visits were scheduled at 1, 7, 15, and 28 days. Results: Six subjects dropped out due to discomfort from the study before 1 month (27% of discontinuation rate). Successful RGP wearers (16 participants) achieved high levels of subjective vision and reported comfort scores of approximately 9 of 10 between 10 and 15 days. They reported wearing their lenses for an average of 10.1262.43 hr after 1 month of wear. Conversely, unsuccessful wearers discontinued wearing the lenses after the first 10 to 15 days, showing comfort scores and wearing time significantly lower compared with the first day of wear. Schirmer test showed a signifi- cant increase at 10 days (P,0.001), and the BUT trends decreased after the first week of wear in unsuccessful group. Conclusions: Symptomatology related with dryness and discomfort, detected during the first 10 days of the adaptation, may help the clinician to predict those participants who will potentially fail to adapt to RGP lens wear.

Características bioquímicas e hematológicas do pirarucu Arapaima gigas Schinz, 1822 (Arapaimidae) de cultivo semi-intensivo na Amazônia

O presente estudo comparou os níveis plasmáticos de glicose, proteínas totais, uréia, triglicerídeos e colesterol, a contagem de eritrócitos, leucócitos e trombócitos entre alevinos e juvenis de Arapaima gigas (Osteoglociformes, Arapaimidae) de uma piscicultura semi-intensiva de Manaus, estado do Amazonas, Brasil. Os alevinos de A. gigas apresentaram níveis significativamente (p<0,05) menores de proteínas totais, triglicerídeos, uréia e Volume Corpuscular Médio (VCM) e maior concentração de glicose, colesterol e hemoglobina, contagem de eritrócitos, hematócrito e Concentração da Hemoglobina Corpuscular Média (CHCM) quando comparados aos juvenis. Porém, não houve diferença significativa (p>0,05) no número de trombócitos e leucócitos totais entre alevinos e juvenis. Os juvenis de A. gigas apresentaram menor quantidade de linfócitos e maior quantidade de monócitos, neutrófilos e eosinófilos, quando comparados aos alevinos. Em estudos futuros, espécimes de A. gigas com outras idades também deverão ser comparados para melhor entendimento dos efeitos da idade neste peixe amazônico, pois estas informações, além de possibilitarem uma melhor compreensão da fisiologia desta espécie, poderão auxiliar no estabelecimento de estratégias para seu manejo.

Intermetallic layer formation and influence in solder joints reliability

Dissertação de mestrado integrado em Materials Engineering

Fundamental concepts in multibody dynamics

In this chapter, the fundamental ingredients related to formulation of the equations of motion for multibody systems are described. In particular, aspects such as degrees of freedom, types of coordinates, basic kinematics joints and types of analysis in multibody systems are briefly characterized. Illustrative examples of application are also presented to better clarify the fundamental issues for spatial rigid multibody systems, which are of crucial importance in the formulation development of mathematical models of mechanical systems, as well as its computational implementation.

Kinematic joints constraints

"Series title: Springerbriefs in applied sciences and technology, ISSN 2191-530X"

Racionalidades e ambiguidades da organização instituto federal: o caso do Rio Grande do Norte

Tese de Doutoramento em Ciências da Educação (área de especialização em Organização e Administração Escolar).

Quantificação da massa infartada do ventrículo esquerdo pela ressonância magnética cardíaca: comparação entre a planimetria e o método de escore visual semi-quantitativo

OBJETIVO: Validar um novo método de escore visual semi-quantitativo contra a planimetria digital quantitativa para a determinação da massa infartada do ventrículo esquerdo pela ressonância magnética cardíaca com técnica de realce tardio. MÉTODO: Estudados 77 pacientes com infarto miocárdico prévio em aparelho de ressonância magnética de 1,5T utilizando técnica de realce tardio para avaliação da viabilidade miocárdica e cálculo da massa infartada. Para avaliação da função ventricular esquerda pelo método de Simpson utilizamos técnica de cine-ressonância. O cálculo da massa infartada foi realizado nas imagens de realce tardio de duas formas: planimetria e método de escore. Utilizamos métodos de regressão linear simples, correlação e concordância entre métodos e observadores segundo a análise de Bland-Altman. RESULTADOS: Em todos os 77 pacientes as áreas de infarto foram detectadas pela ressonância magnética cardíaca utilizando a técnica de realce tardio. O tamanho do infarto medido pela planimetria foi semelhante ao obtido pelo método de escore, com a média das diferenças entres as medidas de apenas 1,03% da massa do ventrículo esquerdo. As variabilidades inter (0,41%) e intra-observador (0,34%) evidenciaram excelente reprodutibilidade do método de escore. A massa infartada apresentou boa correlação com a fração de ejeção e volumes distólico e sistólico finais indexados, r=-0,76, r=0,63 e r=0,67, respectivamente. CONCLUSÃO: A avaliação de pacientes com infarto agudo do miocárdio prévio pela ressonância magnética cardíaca, utilizando a técnica de realce tardio, permite a determinação reprodutível do tamanho do infarto, tanto pelo método de planimetria, quanto pelo modelo semi-quantitativo de escore.

A monograph of the free and semi-parasitic Copepoda of the British islands. By G. Stewardson Brady.

2

A monograph of the free and semi-parasitic Copepoda of the British islands. By G. Stewardson Brady.

3

A monograph of the free and semi-parasitic Copepoda of the British islands. By G. Stewardson Brady.

1

Development of a semi-automatic self learning pattern recognition system for the control of electronic boards

This project was funded under the Applied Research Grants Scheme administered by Enterprise Ireland. The project was a partnership between Galway - Mayo Institute of Technology and an industrial company, Tyco/Mallinckrodt Galway. The project aimed to develop a semi - automatic, self - learning pattern recognition system capable of detecting defects on the printed circuits boards such as component vacancy, component misalignment, component orientation, component error, and component weld. The research was conducted in three directions: image acquisition, image filtering/recognition and software development. Image acquisition studied the process of forming and digitizing images and some fundamental aspects regarding the human visual perception. The importance of choosing the right camera and illumination system for a certain type of problem has been highlighted. Probably the most important step towards image recognition is image filtering, The filters are used to correct and enhance images in order to prepare them for recognition. Convolution, histogram equalisation, filters based on Boolean mathematics, noise reduction, edge detection, geometrical filters, cross-correlation filters and image compression are some examples of the filters that have been studied and successfully implemented in the software application. The software application developed during the research is customized in order to meet the requirements of the industrial partner. The application is able to analyze pictures, perform the filtering, build libraries, process images and generate log files. It incorporates most of the filters studied and together with the illumination system and the camera it provides a fully integrated framework able to analyze defects on printed circuit boards.

Numerical simulations of Lamb waves in plates using a semi-analytical finite element method

Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2011