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Glucose Monitoring System based on Osmotic Pressure Measurements

Calibration Agent for Ecological Simulations: A Metaheuristic Approach

This paper presents an approach to the calibration of ecological models, using intelligent agents with learning skills and optimization techniques. Model calibration, in complex ecological simulations is tipically performed by comparing observed with predicted data and it reveals as a key phase in the modeling process. It is an interactive process, because after each simulation, the agent acquires more informat...

Aplicação e integração das "novas tecnologias" à produção de uma longa-metragem...

A presente tese de doutoramento pretende em primeiro lugar estabelecer uma aproximação à problemática que a introdução das novas tecnologias tem gerado na indústria da animação mundial, numa altura em que o clássico formato cinematográfico de longa-metragem ganha crescente importância. Em segundo lugar, pretende avançar na análise de um caso particular como mola para o desenvolvimento de uma investigação nesta ...

Concept study of an implantable microsystem for electrical resistance and tempe...

In cattle breeding industry, where artificial insemination techniques are employed, the successful detection of estrus onset leads to considerable cost-saving in herd management. One of the most reliable approaches is based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate is used in a chemical-binding reaction to direct...

An implantable microsystem for electrical resistance and temperature measuremen...

In the cattle breeding industry, where artificial insemination techniques are employed, the successful detection of oestrus onset leads to considerable cost saving in herd management. One of the most reliable approaches is based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate is used in a chemical binding reaction to, ...

A Headspace Solid Phase Microextraction (HS-SPME) method for the chromatographi...

A Headspace Solid Phase Microextraction (HS-SPME) procedure for isolation and determination of alkylpyrazines in cocoa liquor, using Gas Chromatography with Flame Ionization Detection (GC-FID) for the separation and detection of the analytes, is presented here. The HS-SPME operational conditions were optimized using extractions of samples spiked with known amounts of alkylpyrazines typically found on cocoa prod...

Microextração por fase sólida

Fundamental aspects of Solid Phase Micro-Extraction (SPME) are discussed in the present paper. The application of SPME as a microtechnique of sample preparation for gas chromatographic analysis is considered and related to existing theoretical models. Both research prototypes and commercial SPME devices are considered.

Extração e pré-concentração de compostos orgânicos voláteis por permeação em me...

This work discusses sample preparation processes for gas chromatography (GC) based on the technique of extraction through membrane permeation (MPE). The MPE technique may be easily coupled to GC via a relatively simple device, which is a module that holds the membrane and is directly connected to the GC column. The possibility of operational errors due to sample handling is substantially reduced in an MPE-GC sy...

As artes plásticas na Madeira (1910-1990): conjunturas, factos e protagonistas ...

Modificação de um micro-extrator de vidro para pré-enriquecimento de traços de ...

Two models of a glass micro-extractor were constructed after modification of a model proposed in the literature. The two models were used for the simultaneous extraction and enrichment of organochlorinated pesticides from aqueous matrixes to an organic solution appropriate for the gas chromatographic analysis of the pesticide. It was established that the performance of one of the modified micro-extractors permi...