ACUMULAÇÃO DE METAIS PESADOS E ALTERAÇÃO DAS PROPRIEDADES FÍSICAS E QUÍMICAS DE AREIAS DE DUNAS LITORÂNEAS

Nos dois últimos séculos, na orla costeira de Portugal, generalizou-se a prática agrícola em areias de duna com a aplicação de agroquímicos, sem controlo técnico, de onde resultaram alterações da composição físico-química e acumulação de metais pesados nas areias. Com o objetivo de avaliar os efeitos do manejo agrícola foram coletadas e caracterizadas, do ponto de vista físico e químico, amostras das dunas, entre os 0,0 cm e os 20 cm de profundidade, com e sem prática agrícola. Foi determinada, por ensaio de peneiramento, a fração fina (partículas com diâmetro inferior a 0,074 mm) e pelo método MAB – Peróxido a composição em matéria orgânica. Foi estimada a umidade das amostras e determinado, pelo método eletroquímico, o pH, a condutividade elétrica e o potencial de oxirredução. A composição química foi analisada por fluorescência de raios-x. Verificou-se que o manejo agrícola das dunas resultou no aumento da fração fina, da matéria orgânica, da umidade, da condutividade elétrica e do potencial de oxirredução das areias. O pH diminuiu, de básico para valores próximos de neutro, aumentando o risco de acumulação e mobilização de Fe, Mn, Cu, Zn, Pb, As, Zr, Th, Rb, Cr, V, Ni, Hg, Co e U

Contaminação/descontaminação de solos com gasolina : Influência das características dos solos

Tese elaborada no Laboratório Nacional de Engenharia Civil para obtenção do grau de Doutor em Ciências de Engenharia pela Faculdade de Engenharia da Universidade do Port

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Surgeons’ practice and preferences for the anal fissure treatment: results from an international survey

The best nonoperative or operative anal fissure (AF) treatment is not yet established, and several options have been proposed. Aim is to report the surgeons' practice for the AF treatment. Thirty-four multiple-choice questions were developed. Seven questions were about to participants' demographics and, 27 questions about their clinical practice. Based on the specialty (general surgeon and colorectal surgeon), obtained data were divided and compared between two groups. Five-hundred surgeons were included (321 general and 179 colorectal surgeons). For both groups, duration of symptoms for at least 6 weeks is the most important factor for AF diagnosis (30.6%). Type of AF (acute vs chronic) is the most important factor which guide the therapeutic plan (44.4%). The first treatment of choice for acute AF is ointment application for both groups (59.6%). For the treatment of chronic AF, this data is confirmed by colorectal surgeons (57%), but not by the general surgeons who prefer the lateral internal sphincterotomy (LIS) (31.8%) (p = 0.0001). Botulin toxin injection is most performed by colorectal surgeons (58.7%) in comparison to general surgeons (20.9%) (p = 0.0001). Anal flap is mostly performed by colorectal surgeons (37.4%) in comparison to general surgeons (28.3%) (p = 0.0001). Fissurectomy alone is statistically significantly most performed by general surgeons in comparison to colorectal surgeons (57.9% and 43.6%, respectively) (p = 0.0020). This analysis provides useful information about the clinical practice for the management of a debated topic such as AF treatment. Shared guidelines and consensus especially focused on operative management are required to standardize the treatment and to improve postoperative results