Study of the one dimensional and transient bioheat transfer equation: Multi-layer solution development and applications

: In this work we derive an analytical solution given by Bessel series to the transient and one-dimensional (1D) bioheat transfer equation in a multi-layer region with spatially dependent heat sources. Each region represents an independent biological tissue characterized by temperature-invariant physiological parameters and a linearly temperature dependent metabolic heat generation. Moreover, 1D Cartesian, cylindrical or spherical coordinates are used to define the geometry and temperature boundary conditions of first, second and third kinds are assumed at the inner and outer surfaces. We present two examples of clinical applications for the developed solution. In the first one, we investigate two different heat source terms to simulate the heating in a tumor and its surrounding tissue, induced during a magnetic fluid hyperthermia technique used for cancer treatment. To obtain an accurate analytical solution, we determine the error associated with the truncated Bessel series that defines the transient solution. In the second application, we explore the potential of this model to study the effect of different environmental conditions in a multi-layered human head model (brain, bone and scalp). The convective heat transfer effect of a large blood vessel located inside the brain is also investigated. The results are further compared with a numerical solution obtained by the Finite Element Method and computed with COMSOL Multi-physics v4.1 (c). (c) 2013 Elsevier Ltd. All rights reserved.

An application of structural equation modeling of test dispositional optimism as mediator or moderator in quality of life in patients with chronic disease

The aim of the present study was to test a hypothetical model to examine if dispositional optimism exerts a moderating or a mediating effect between personality traits and quality of life, in Portuguese patients with chronic diseases. A sample of 540 patients was recruited from central hospitals in various districts of Portugal. All patients completed self-reported questionnaires assessing socio-demographic and clinical variables, personality, dispositional optimism, and quality of life. Structural equation modeling (SEM) was used to analyze the moderating and mediating effects. Results suggest that dispositional optimism exerts a mediator rather than a moderator role between personality traits and quality of life, suggesting that “the expectation that good things will happen” contributes to a better general well-being and better mental functioning.

Remediation of sandy soils contaminated with hydrocarbons and halogenated hydrocarbons by soil vapour extraction

This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%.

Sequential application of soil vapor extraction and bioremediation processes for the remediation of ethylbenzene-contaminated soils

Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application of these technologies is presented as a valid option but is not yet entirely studied. This work presents the study of the remediation of ethylbenzene (EB)-contaminated soils, with different soil water and natural organic matter (NOMC) contents, using sequential SVE and BR. The obtained results allow the conclusion that: (1) SVE was sufficient to reach the cleanup goals in 63% of the experiments (all the soils with NOMC below 4%), (2) higher NOMCs led to longer SVE remediation times, (3) BR showed to be a possible and cost-effective option when EB concentrations were lower than 335 mg kgsoil −1, and (4) concentrations of EB above 438 mg kgsoil −1 showed to be inhibitory for microbial activity.

Determination of total petroleum hydrocarbons in soil from different locations using infrared spectrophotometry and gas chromatography

Total petroleum hydrocarbons (TPH) are important environmental contaminants which are toxic to human and environmental receptors. Several analytical methods have been used to quantify TPH levels in contaminated soils, specifically through infrared spectrometry (IR) and gas chromatography (GC). Despite being two of the most used techniques, some issues remain that have been inadequately studied: a) applicability of both techniques to soils contaminated with two distinct types of fuel (petrol and diesel), b) influence of the soil natural organic matter content on the results achieved by various analytical methods, and c) evaluation of the performance of both techniques in analyses of soils with different levels of contamination (presumably non-contaminated and potentially contaminated). The main objectives of this work were to answer these questions and to provide more complete information about the potentials and limitations of GC and IR techniques. The results led us to the following conclusions: a) IR analysis of soils contaminated with petrol is not suitable due to volatilisation losses, b) there is a significant influence of organic matter in IR analysis, and c) both techniques demonstrated the capacity to accurately quantify TPH in soils, irrespective of their contamination levels.

Formação em Universal Design for Learning

Na qualidade de Diretora Regional das Comunidades, fomos responsável pela redação dos artigos e coordenação da página "Comunidades", integrada no jornal Açoriano Oriental, servindo a mesma para a divulgação das atividades realizadas pela Direção Regional Das Comunidades do Governo dos Açores.

Açores recebe Congresso Internacional de Universal Design for Learning

Na qualidade de Diretora Regional das Comunidades, fomos responsável pela redação dos artigos e coordenação da página "Comunidades Açorianas no Mundo", integrada no jornal Mundo Português, servindo a mesma para a divulgação das atividades realizadas pela Direção Regional Das Comunidades do Governo dos Açores.

Localização ótima de apoios em estruturas do tipo viga utilizando o método dos algoritmos genéticos

Dissertação de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica Ramo de Manutenção e Produção

Implementação do rastreio auditivo neonatal universal de surdez no Hospital CUF Porto

A incidência de perda auditiva bilateral é de 1 a 3 por cada recém-nascidos saudáveis e de 30 a 40 por 1000 recém-nascidos de risco. No Hospital Cuf Porto (HCP) o Rastreio Auditivo Neonatal Universal (RANU) teve inicio em Dezembro de 2010 em paralelo com abertura dos serviços de Obstetrícia / Neonatologia. As otoemissões acústicas (OEA) são o teste utilizado pois são reconhecidas como um método de rastreio auditivo simples, seguro e bem aceite. O objectivo deste trabalho é salientar a importância do RANU na identificação da perda auditiva antes da alta hospitalar, apresentando as suas vantagens na detecção e intervenção precoce minimizando as consequências da perda auditiva. Este trabalho, pretende ainda demonstrar as vantagens do RANU como estratégia fundamental no planeamento e na introdução de medidas de diagnóstico e terapêutica. É assim apresentada uma análise retrospectiva dos resultados obtidos nas OEA por produtos de distorção (OEAPD) entre Janeiro de 2011 e Dezembro de 2012, com uma amostra constituída por n=572. Os resultados revelam uma percentagem de “PASS” (OEAPD presentes) na primeira fase do rastreio, com um valor de 88,8% relativamente ao número total de rastreios efectuados. Relativamente à percentagem de “REFER” (OEAPD ausentes) – na mesma fase do rastreio- obtiveram-se 11,2% de situações face ao total de rastreados. Destes – que correspondem a um n=64 – 42.2% das situações referem-se a “REFER” bilateral (n=27). Relativamente às situações de “REFER” unilateral (n=37), encontramos uma percentagem de 57,8% dos casos. De acordo com a casuística apresentada, correspondente aos resultados obtidos e atendendo à realidade da população rastreada (dado que até ao momento não se confirmou perda auditiva em nenhum dos indivíduos rastreados), pode-se concluir que os OEA podem ser um método de rastreio simples e fiável, fundamental para a detecção e intervenção precoce nas perdas auditivas.

Planeamento e balanceamento de uma linha de montagem universal para formação

Este trabalho teve o intuito de criar uma linha de montagem universal através da qual será dada formação aos atuais operadores e a novos que possam vir a pertencer ao departamento de montagem na empresa Grohe Portugal. Para tal era necessário saber realizar um estudo de métodos e um estudo de tempos sobre os vários processos existentes no departamento de montagem. Com esse intuito foi elaborada uma pesquisa sobre as referidas temáticas, onde ficou evidente a sua importância e a sua imprescindibilidade. Inicialmente houve também um acompanhamento das montagens dos produtos nas várias linhas, de forma a adquirir conhecimento sobre as características dos processos de montagem existentes no departamento. Os pontos mais importantes durante o estudo de métodos e tempos realizado foram a definição de toda a estrutura do processo, das ferramentas e materiais a utilizar, não esquecendo a relação entre o operador e as suas ferramentas e a medição de tempos de todas as tarefas necessárias para cada processo de montagem. A linha de montagem, cujo projeto se desenvolveu, é composta por três bancadas e consiste num conjunto de postos de trabalho onde são executadas as operações através de máquinas, do trabalho humano, ou da sua conjugação, dispostos numa determinada sequência, sendo alguns deles amovíveis. Para a realização e conclusão deste projeto foram superadas diversas etapas, sendo que as mais relevantes foram:  a análise dos processos de montagem;  estudo de tempos de todas as famílias de produtos a serem implementados na linha de formação; - Definição da estrutura da linha de montagem; - Definição das rampas e dos tubos de abastecimento da linha; - Desenho da linha de montagem em 3D no software SolidWorks. Paralelamente foram também desenvolvidos estudos de tempos sobre alguns produtos com o intuito de serem implementadas melhorias, ou apenas para o controlo de tempos necessários para a realização das operações Por último, foi também elaborada uma recolha de ferramentas existentes no departamento de montagem para serem elaborados manuais de instruções das ferramentas fabricadas internamente, com o objetivo de obter a certificação OSHAS 180001 e de criar documentos com a listagem de materiais necessários para cada produto.

Soil vapor extraction in sandy soils: influence of airflow rate

Airflow rate is one of the most important parameters for the soil vapor extraction of contaminated sites, due to its direct influence on the mass transfer occurring during the remediation process. This work reports the study of airflow rate influence on soil vapor extractions, performed in sandy soils contaminated with benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene. The objectives were: (i) to analyze the influence of airflow rate on the process; (ii) to develop a methodology to predict the remediation time and the remediation efficiency; and (iii) to select the most efficient airflow rate. For dry sandy soils with negligible contents of clay and natural organic matter, containing the contaminants previously cited, it was concluded that: (i) if equilibrium between the pollutants and the different phases present in the soil matrix was reached and if slow diffusion effects did not occur, higher airflow rates exhibited the fastest remediations, (ii) it was possible to predict the remediation time and the efficiency of remediation with errors below 14%; and (iii) the most efficient remediation were reached with airflow rates below 1.2 cm3 s 1 standard temperature and pressure conditions.

Dual augmentation for aerobic bioremediation of MTBE and TCE pollution in heavy metal-contaminated soil

In this work we isolated from soil and characterized several bacterial strains capable of either resisting high concentrations of heavy metals (Cd2+ or Hg2+ or Pb2+) or degrading the common soil and groundwater pollutants MTBE (methyl-tertbutyl ether) or TCE (trichloroethylene). We then used soil microcosms exposed to MTBE (50 mg/l) or TCE (50 mg/l) in the presence of one heavy metal (Cd 10 ppm or Hg 5 ppm or Pb 50 or 100 ppm) and two bacterial isolates at a time, a degrader plus a metalresistant strain. Some of these two-membered consortia showed degradation efficiencies well higher (49–182% higher) than those expected under the conditions employed, demonstrating the occurrence of a synergetic relationship between the strains used. Our results show the efficacy of the dual augmentation strategy for MTBE and TCE bioremediation in the presence of heavy metals.

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.

Soil remediation time to achieve clean-up goals I: influence of soil water content

The current models are not simple enough to allow a quick estimation of the remediation time. This work reports the development of an easy and relatively rapid procedure for the forecasting of the remediation time using vapour extraction. Sandy soils contaminated with cyclohexane and prepared with different water contents were studied. The remediation times estimated through the mathematical fitting of experimental results were compared with those of real soils. The main objectives were: (i) to predict, through a simple mathematical fitting, the remediation time of soils with water contents different from those used in the experiments; (ii) to analyse the influence of soil water content on the: (ii1) remediation time; (ii2) remediation efficiency; and (ii3) distribution of contaminants in the different phases present into the soil matrix after the remediation process. For sandy soils with negligible contents of clay and natural organic matter, artificially contaminated with cyclohexane before vapour extraction, it was concluded that (i) if the soil water content belonged to the range considered in the experiments with the prepared soils, then the remediation time of real soils of similar characteristics could be successfully predicted, with relative differences not higher than 10%, through a simple mathematical fitting of experimental results; (ii) increasing soil water content from 0% to 6% had the following consequences: (ii1) increased remediation time (1.8–4.9 h, respectively); (ii2) decreased remediation efficiency (99–97%, respectively); and (ii3) decreased the amount of contaminant adsorbed onto the soil and in the non-aqueous liquid phase, thus increasing the amount of contaminant in the aqueous and gaseous phases.

Soil remediation time to achieve clean-up goals II: influence of natural organic matter and water contents

This work reports a relatively rapid procedure for the forecasting of the remediation time (RT) of sandy soils contaminated with cyclohexane using vapour extraction. The RT estimated through the mathematical fitting of experimental results was compared with that of real soils. The main objectives were: (i) to predict the RT of soils with natural organic matter (NOM) and water contents different from those used in experiments; and (ii) to analyse the time and efficiency of remediation, and the distribution of contaminants into the soil matrix after the remediation process, according to the soil contents of: (ii1) NOM; and (ii2) water. For sandy soils with negligible clay contents, artificially contaminated with cyclohexane before vapour extraction, it was concluded that: (i) if the NOM and water contents belonged to the range of the prepared soils, the RT of real soils could be predicted with relative differences not higher than 12%; (ii1) the increase of NOM content from 0% to 7.5% increased the RT (1.8–13 h) and decreased the remediation efficiency (RE) (99–90%) and (ii2) the increase of soil water content from 0% to 6% increased the RT (1.8–4.9 h) and decreased the RE (99–97%). NOM increases the monolayer capacity leading to a higher sorption into the solid phase. Increasing of soil water content reduces the mass transfer coefficient between phases. Concluding, NOM and water contents influence negatively the remediation process, turning it less efficient and more time consuming, and consequently more expensive.