Tunneling Rate for Superparamagnetic Particles by the Instanton Method

We derive the tunneling rate for paramagnetic molecules in the context of a collective spin model. By means of path integral methods an analytical expression is derived. Given the very large spins in question (s ~ 3000 hbar), the observation of magnetization changes due to pure unitary tunnel effects is unlikely.Comment: 16 pages, 2 figure

Association of gamma glutamyltransferase, metabolic syndrome and cardiovascular risk

Serum gamma-glutamyl transferase (GGT) has been used as a marker of alcohol induced liver disease. Recent epidemiology and pathology studies have suggested its independent role in the pathogenesis and clinical evolution of cardiovascular diseases (CVD) promoting atherosclerosis through an oxidative process leading, within the atherosclerotic plaque, to LDL oxidation, metalloproteinase activation, cell proliferation and apoptosis. Besides it is known that GGT levels rise even in the normal range, with obesity and hepatic steatosis occurs, it is thought, which originates insulin resistance (IR). Being sure that IR is important in the development of type 2 diabetes and CVD, both very prevalent in Portugal, the authors considered as relevant to study the association of GGT with markers of multiple metabolic derangements: insulin-resistance (hyperinsulinemia, hyperglicemia, IR-HOMA = 3), obesity and dyslipidemia. So, a Portuguese sample population, consisted of 123 subjects (52 male and 71 female) was organized. As results were observed: elevation of GGT serum levels with the increasing risk of every marker and the same happened with metabolic syndrome and its components; compared with non obese the group of obese subjects exhibited elevated prevalence of risk factors, though in non obese subjects the percentages of insulin-resistance and dyslipidemias were high (hypercholesterolemia in both sexes, hypertriglyceridemia and low concentrations of HDL-c in men); association of serum GGT levels with every risk factor and metabolic syndrome. Though, as the association with the insulin-resistance state was particularly strong, it is thought that a high prevalence of non-alcoholic fatty liver disease (NAFLD) was present in the studied population. As serum determination of GGT activity is a low-cost, highly sensitive, accurate and frequently used laboratory test and there is association of this enzyme with the most important risk factors of diabetes type 2 and CVD, its serum levels should be considered as a marker of insulin-resistance when NAFLD is supposed to be present or there is obesity

Symmetric Differentiation on Time Scales

We define a symmetric derivative on an arbitrary nonempty closed subset of the real numbers and derive some of its properties. It is shown that real-valued functions defined on time scales that are neither delta nor nabla differentiable can be symmetric differentiable.Comment: This is a preprint of a paper whose final and definite form will be published in Applied Mathematics Letters. Submitted 30-Jul-2012; revised 07-Sept-2012; accepted 10-Sept-201

Ensaios experimentais para avaliar a utilização de adjuvantes tecnológicos na extracção de azeite virgem.

Comunicação da qual só está disponível o resumo.No processamento de produtos vegetais, a utilização de adjuvantes tecnológicos para melhorar o rendimento e a qualidade dos alimentos tem uma vasta aplicação industrial. No entanto, no processo de extracção de azeite virgem a utilização de adjuvantes tecnológicos tem ainda uma utilização muito residual. Por sua vez, tal aplicação pode ter uma importância determinante no aumento do rendimento industrial, nomeadamente quando no lagar se apresentam azeitonas com características de pastas de difícil extração. No presente trabalho apresentam-se alguns ensaios realizados no lagar experimental do Laboratório de Tecnologia Alimentar da ESACB, aplicando diferentes sistemas enzimáticos e microtalco natural na operação de termobatedura. Os ensaios realizaram-se com azeitona das cultivares ‘Galega Vulgar’ e ‘Cobrançosa’ colhidas com índices de maturação bem definidos. A extracção de azeite foi efectuada em equipamento constituído por moinho de martelos (3000 rpm), termobatedeira (50 rpm) e centrifugadora (3500 rpm). Apresentam-se ainda resultados de optimização das condições de operação do equipamento utilizando um delineamento Placket-Burman para seleccionar as variáveis significativas, seguido por um delineamento descrito por uma matriz central compósita rotativa (CCRD) em função dessas variáveis. Avaliaram-se o rendimento e o índice de extractabilidade da azeitona; no azeite, avaliaram-se os critérios de qualidade, os fenóis totais e os pigmentos clorofilinos. As respostas relacionadas com o rendimento de extracção podem ser descritas por modelos polinomiais de segundo grau com um elevado ajuste aos dados experimentais (r> 0,8). Em todos os ensaios efectuados com adição de adjuvantes, verificou-se um aumento no rendimento e consequentemente do índice de extractabilidade, relativamente aos ensaios sem qualquer adjuvante de extracção. Os ensaios permitem concluir que a adição de adjuvantes tecnológicos não provocou quaisquer alterações nos teores de compostos fenólicos, nos pigmentos clorofilinos nem nos parâmetros de qualidade dos azeites obtidos.info:eu-repo/semantics/publishedVersio

Persistent currents in n-fold twisted Moebius strips

We investigate the influence of the topology on generic features of the persistent current in n-fold twisted Moebius strips formed of quasi one--dimensional mesoscopic rings, both for free electrons and in the weakly disordered regime. We find that there is no generic difference between the persistent current for untwisted rings and for Moebius strips with an arbitrary number of twists.Comment: 7 pages, 2 figure

Water quality on small ruminants’ dairy farms in Castelo Branco region

The importance of providing quality water for cleaning milking machines and other equipment is perhaps one of the most overlooked factors in ensuring milk quality on most dairy farms. Water for cleaning in the dairy barn is used for different situations, including for the process of milking, which requires cleaning and disinfection of the milking equipment, the milking parlour, and the milk cooling tank. Many factors on dairy farms can contribute to contamination of the raw milk, and one of the major factors responsible for this contamination is the water used to clean the milking and storage equipment.This work was financially supported by QRural Research Unit/IPCB and CERNAS-IPCB (UIDB/00681/2020, FCT).info:eu-repo/semantics/publishedVersio

Prototype implementation of a smart locker

Smart lockers are intelligent storage units that are increasingly being adopted to help solving the last mile problem. This paper focuses on the concept of an individual smart locker that can be installed at the entrance of a residential house. First, the operational principle and advantages of this concept are discussed. Then, the design, development and implementation of a functional prototype is demonstrated. The prototype was submitted to tests and can be used as a proof of concept.info:eu-repo/semantics/publishedVersio

A moenda da azeitona e as características físico-químicas dos azeites virgens

Comunicação apresentada no III Simpósio Nacional de Olivicultura que decorreu em Castelo Branco na Escola Superior Agrária do Instituto Politécnico de Castelo Branco, de 29 a 31 de Outubro de 2003.No presente trabalho estudou-se a influência do tipo de moenda da azeitona nas características do azeite virgem, comparando os azeites obtidos extraídos por moinho de pedras e por moinho metálico de martelos (com grelhas 5 e 7 mm de diâmetro). A azeitona foi processada numa linha Rapanelli . A qualidade dos azeites foi avaliada por determinação de: acidez, índice de peróxido, absorvâncias no UV, composição em ácidos gordos, estabilidade oxidativa, K225, pigmentos clorofilinos, cor (L*a*b*) e polifenóis totais. Em geral, a moenda não influencia os parâmetros de qualidade dos azeites, dependendo mais das cultivares constituintes dos lotes. Os resultados mostram que quando se utilizam moinhos de martelos se obtêm azeites virgens com um teor superior de pigmentos clorofilinos

Effect of sodium and nitrogen on yield function of irrigated maize in Southern Portugal

Salinization and nitrate leaching are two of the leading threats to the environment of the European Mediterranean regions. Inefficient use of water and fertilizers has led to a nitrate increase in the aquifers and reduction in crop yields caused by salts. In this study, a triple emitter source irrigation system delivers water, salt (Na+), and fertilizer (N) applications to maize (Zea mays L.). The objective of the study was to evaluate the combined effect of saline water and nitrogen application on crop yields in two different textured soils of Alentejo (Portugal) and to assess if increasing salinity levels of the irrigation water can be compensated by application of nitrogen while still obtaining acceptable crop yield. Maximum yield was obtained from both soils with an application of 13 g m−2 of nitrogen. Yield response to Na+ application was different in the two studied soils and depended on the total amount of Na+ or irrigation water applied. No significant interaction was found between nitrogen and sodium, but a positive effect on maize yield was observed in the medium textured soil for amounts of Na+ less than 905 g m−2 when applied in the irrigation water

Respiratory evaluation through volumetric capnography among grade III obese and eutrophic individuals: a comparative study

sem informaçãoExcess trunk body fat in obese individuals influences respiratory physiological function. The of this study were to compare volumetric capnography findings (VCap) between severely obese patients and normal-weight subjects and to assess whether there is a1372177183sem informaçãosem informaçãosem informaçã