Stochastic ground motion simulation with geological site effects in damage asessment

Damage assessment of structures with a mechanical non linear model demands the representation of seismic action in terms of an accelerogram (dynamic analysis) or a response spectrum (pushover analysis). Stochastic ground motion simulation is largely used in regions where seismic strong-motion records are available in insufficient number. In this work we present a variation of the stochastic finite-fault method with dynamic corner frequency that includes the geological site effects. The method was implemented in a computer program named SIMULSIS that generate time series (accelerograms) and response spectra. The program was tested with the MW= 7.3 Landers earthquake (June 28, 1992) and managed to reproduce its effects. In the present work we used it to reproduce the effects of the 1980’s Azores earthquake (January 1, 1980) in several islands, with different possible local site conditions. In those places, the response spectra are presented and compared with the buildings damage observed.

GIS on tourism planning: preventing the impacts caused by the developing tourism activity in a specific site

The environment is one of the greatest concerns of humankind. Nowadays, the activities which improve or destroy it must be assessed and controlled by efficient means which should permit the control of environmental impact caused by the development of these activities. This document presents an information system implementation, as a Decision Support system, allowing the Decision Maker to evaluate, foresee and control the future environmental impact of Tourism through consultation, the management and the presentation of decision schemes based on defined measures of a regional tourism planning.

Comparison of AGNES (absence of gradients and Nernstian equilibrium stripping) and SSCP (scanned stripping chronopotentiometry) for trace metal speciation analysis

The free metal ion concentrations obtained by SSCP (stripping chronopotentiometry at scanned deposition potential) and by AGNES (absence of gradients and Nernstian equilibrium stripping) techniques have been compared and the usefulness of the combination of both techniques in the same electrochemical cell for trace metal speciation analysis is assessed. The free metal ion concentrations and the stability constants obtained for lead(II) and cadmium(II) complexation by pyridinedicarboxylic acid, by 40 nm radius carboxylated latex nanospheres and by a humic acid extracted from an ombrotrophic peat bog were determined. Whenever possible, the free metal ion concentrations were compared with the theoretical predictions of the code MEDUSA and with the free metal ion concentrations estimated from ion selective electrodes (ISE). SSCP values were in agreement with the ones obtained by AGNES, and both of them agreed reasonably with the ISE values and the theoretical predictions. For the lead(II)-humic acid, it was not possible to obtain the stability constants by SSCP due to the heterogeneity effect. However, using AGNES it is possible to obtain, for these heterogeneous systems, the free bulk metal concentration, which allows us to retrieve the stability constant at bulk conditions.

Application of permeation liquid membrane and scanned stripping chronopotentiometry to metal speciation analysis of colloidal complexes

The potential of permeation liquid membrane (PLM) to obtain dynamic metal speciation information for colloidal complexes is evaluated by measurements of lead(II) and copper(II) complexation by carboxyl modified latex nanospheres of different radii (15, 35, 40 and 65 nm). The results are compared with those obtained by a well characterized technique: stripping chronopotentiometry at scanned deposition potential (SSCP). Under the PLM conditions employed, and for large particles or macromolecular ligands, membrane diffusion is the rate-limiting step. That is, the flux is proportional to the free metal ion concentration with only a small contribution from labile complexes. In the absence of ligand aggregation in the PLM channels, good agreement was obtained between the stability constants determined by PLM and SSCP for both metals.

Efeitos do tipo de web site, conteúdo VS. contexto, no fluxo percepcionado, na avaliação do produto e na experiência virtual com o produto

Cada vez mais a experiência dos utilizadores num ambiente virtual deve ser alvo de novas investigações. A crescente evolução da tecnologia, a modernização da forma como comunicamos e recebemos informações, bem como realizamos as nossas compras em novos ambientes online, constituem um novo espaço de pesquisa. A Experiência de Fluxo online, descrita como um estado em que o utilizador se sente cognitivamente eficiente, motivado e feliz, parece contribuir para a navegação dos utilizadores num site, maximizando a eficácia comercial de um produto apresentado nesse mesmo site. Nós acreditamos que no mundo virtual da internet, a experiência de fluxo dos utilizadores pode ser potenciada através da melhor interação humano-computador, nos sites em que o utilizador navega, oferecendo aos utilizadores experiências virtuais mais envolventes com um produto. Esta pesquisa tem como objetivo verificar em que modelo de site, conteúdo versus contexto, os visitantes experienciam níveis mais elevadores de fluxo online, com implicações a nível da sua experiência de consumo, aceitação do próprio produto, experiência virtual e intenção comportamental de uso para com o produto. Características individuais dos utilizadores, como a sua inovação na disponibilidade para a tecnologia também serão alvo de estudo. O produto tecnológico utilizado foram os Óculos da Google. Foram utilizados estudantes em laboratório, de ambos os géneros, num plano experimental 2 (site conteúdo versus site contexto) que foram solicitados a responder a um questionário após a navegação num destes sites, sempre imersos num ambiente virtual. Os resultados mostram que no site de contexto, os participantes experienciaram maiores níveis de fluxo online, sentimentos mais agradáveis durante a sua navegação, uma maior utilidade percebida do produto, avaliaram mais positivamente os Óculos da Google, manifestaram uma atitude ao uso do produto tendencialmente maior e navegaram durante mais tempo neste site em detrimento do site de conteúdo. Os resultados revelaram ainda existir um efeito de interação entre a inovação na disponibilidade para a tecnologia e o tipo de site para com a intenção de uso do produto, com aplicações a nível do marketing e publicidade online.

A construção de conhecimento, através do desenvolvimento de um site de Economia, numa turma do 10º ano de Economia A

Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino da Economia e Contabilidade, Universidade de Lisboa, Instituto de Educação, 2014

Defining Spatial and Temporal Hydromorphological Sampling Strategies for the Leigh Brook River Site

Detailed surveys of depth and velocity are undertaken to describe hydro-ecological status of rivers. Fieldwork for these surveys is time consuming and expensive. This paper aims to describe the methodology applied in order to determine the most suitable depth sampling strategy for effective field data collection and river representation in time and space at the Leigh Brook river site, Worcester, UK. The accuracy of three different sampling strategies for predicting depth at non-measured points has been compared and the mesohabitats that better characterise depth changes due to variations in discharge have been identified. The results show that depth changes due to discharge change are mainly located at shallow and deep glide mesohabitat types. The analysis for the comparison of sampling strategies indicates that grid sampling strategies give better results than regular transects. Since the results also show that higher errors in predictions are obtained in the deepest areas, higher sampling densities should be applied in these locations.

Site level cost benefit analysis of renewable energy in the near-shore environment

Senior thesis written for Oceanography 445

Determination of chlorfenvinphos in soils by microwave-assisted extraction and stripping voltammetry with an ultramicroelectrode

A methodology for the determination of the pesticide chlorfenvinphos by microwave-assisted solvent extraction and square-wave cathodic stripping voltammetry at a mercury film ultramicroelectrode in soil samples is proposed. Optimization of microwave solvent extraction performed with two soils, selected for having significantly different properties, indicated that the optimum solvent for extracting chlorfenvinphos is hexane-acetone (1:1, v/v). The voltammetric procedure is based on controlled adsorptive accumulation of the insecticide at the potential of -0.60 V (vs. Ag/AgCl) in the presence of Britton-Robinson buffer (pH 6.2). The detection limit obtained for a 10 s collection time was 3.0 x 10-8 mol l-1. The validity of the developed methodology was assessed by recovery experiments at the 0.100 µg g-1 level. The average recoveries and standard deviations for the global procedure reached byMASE-square-wave voltammetry were 90.2±2.8% and 92.1±3.4% for type I (soil rich in organic matter) and type II (sandy soil) samples, respectively. These results are in accordance to the expected values which show that the method has a good accuracy.

Adsorptive stripping voltammetric determination of venlafaxine in urine with a mercury film microelectrode

An adsorptive stripping voltammetric procedure for the determination of the antidepressant venlafaxine in urine using a mercury film microelectrode wasdeveloped. The method is based on controlled adsorptive accumulation of the drug at the potential of 1.00V (vs. Ag/AgCl) in the presence of 1.25 x10 -2 molL- 1 borate buffer (pH 8.7). Urine samples were analyzed directly after performing a ten-fold dilution with the supporting electrolyte but without other pretreatment. The limit of detection obtained for a 30 s collection time was 0.693x 10- 6 mol L -1. Recovery experimentsgave good results at the 10 -6 mol L- 1 level (bias less 5% were obtained).

Anodic adsorptive stripping voltammetric determination of atrazine in spiked soil samples with a gold microelectrode

Microwave-assisted solvent extraction was combined with anodic adsorptive stripping voltammetry at a gold microelectrode to extract and quantify the herbicide atrazine in spiked soil samples. A systematic study of the experimental parameters affecting the stripping response was carried out by square-wave voltammetry. The voltammetric procedure is based on controlled adsorptive accumulation of atrazine at the potential of 0.35V (versus Ag/AgCl) in the presence of Britton–Robinson buffer pH (2.0). The limit of detection obtained for a 30 sec collection time was 4.3x10-7 mol L-1. Recovery experiments, at the 1µgg-1 level of spiking, gave good results for the global procedure, and the values found were comparable to those obtained by HPLC.

Electrochemical determination of citalopram by adsorptive stripping voltammetry–determination in pharmaceutical products

The electrochemical behavior of citalopram was studied by square-wave and square-wave adsorptive-stripping voltammetry (SWAdSV). Citalopram can be reduced and accumulated at a mercury drop electrode, with a maximum peak current intensity being obtained at a potential of approximately -1.25V vs. AgCl/Ag, in an aqueous electrolyte solution of pH 12. A SWAdSV method has been developed for the determination of citalopram in pharmaceutical preparations. The method shows a linear range between 1.0x10-7 and 2.0x10-6 mol L-1 with a limit of detection of 5x10-8 mol L-1 for an accumulation time of 30 s. The precision of the method was evaluated by assessing the repeatability and intermediate precision, achieving good relative standard deviations in all cases (≤2.3%). The proposed method was applied to the determination of citalopram in five pharmaceutical products and the results obtained are in good agreement with the labeled values.

Determination of ametryn in soils via microwave-assisted solvent extraction coupled to anodic stripping voltammetry with a gold ultramicroelectrode

An extraction-anodic adsorptive stripping voltammetric procedure using microwave-assisted solvent extraction and a gold ultramicroelectrode was developed for determining the pesticide ametryn in soil samples. The method is based on the use of acetonitrile as extraction solvent and on controlled adsorptive accumulation of the herbicide at the potential of 0.50 V (vs. Ag/AgCl) in the presence of Britton-Robinson buffer (pH 3.3). Soil sample extracts were analysed directly after drying and redissolution with the supporting electrolyte but without other pre-treatment. The limit of detection obtained for a 10 s collection time was 0.021 µg g-1. Recovery experiments for the global procedure, at the 0.500 µg g-1 level, gave satisfactory mean and standard deviation results which were comparable to those obtained by HPLC with UV detection.

Um site, um conteúdo e incontáveis dispositivos: as estratégias de design utilizadas para ambientes multiplataformas

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Audiovisual e Multimédia.

Benchmarking de identificação de ano: criação de um site para benchmarking de técnicas de identificação de dano

Dissertação para obtenção do grau de Mestre em Engenharia Mecânica na Área de Manutenção e Produção