379 research outputs found

    Lipid oxidation kinetics of ozone-processed shrimp during iced storage using peroxide value measurements

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    In this research, in situ generated ozone exposure/wash cycles of 1, 3, and 5 min applied to shrimp samples either before (BIS) or during iced storage (DIS) has been used to study the lipid oxidation kinetics using the peroxide values (PV). The induction period (IP) as well as PV at end of the IP (PVIP) have been obtained. The rate constants (k) as well as half-lives (t1/2) of hydroperoxides formation for different oxidation stages were calculated. The results showed that both IP and PVIP were lower with BIS (IP between 4.35±0.09 and 5.08±0.23 days; PVIP between 2.92±0.06 and 3.40±0.18 mEq kg−1) compared with DIS (IP between 5.92±0.12 and 6.14±0.09 days; PVIP between 4.49±0.17 and 4.56±0.10 mEq kg−1). The k value for DIS seemed to be the greater compared to BIS. In addition, whilst decreases and increases in t1/2 were found at propagation, respectively, for BIS and DIS, decreases and increases were only found at the induction of oxidation stage(s) for BIS. Further, the PV of ozone-processed samples would fit first order lipid oxidation kinetics independent of duration of ozone exposures. For the first time, PV measurements and fundamental kinetic principles have been used to describe how increasing ozone exposures positively affects the different oxidation stages responsible for the formation of hydroperoxides in ozone-processed shrimp

    Considerando a questão da interoperabilidade

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    This article concerns the path taken during my scientific research related to the construction and management of digital assets for the design, development, and management of databases, within the scope of the INET-md in Portugal. Its general objective is to facilitate the interoperability, Web dissemination, search, and retrieval of the INET-md's digital collections. This investigation aims to reinforce the alliance between the areas of Information Science and Computer Science. From the Information Science, it brings the applications used for organization, management, and publication of digital assets collections on the Web; and from the Computer Science, it brings syntactic concepts (metadata and protocols) to communicate and exchange data and semantic concepts (ontologies and semantic annotations) to describe data. Both types of concepts can promote interoperability between distinct digital repositories and platforms, providing improvements in information search and retrieval activities.Este artigo diz respeito ao caminho percorrido durante a minha investigação científica relacionada à construção e gestão de ativos digitais para a conceção, desenvolvimento e gestão de bases de dados, no âmbito do INET-md em Portugal. Seu objetivo geral é facilitar a interoperabilidade, disseminação na Web, busca e recuperação das coleções digitais do INET-md. Esta investigação visa reforçar a aliança entre as áreas de Ciência da Informação e Ciência da Computação. Da Ciência da Informação, traz os aplicativos utilizados para organização, gestão e publicação de acervos de ativos digitais na Web; e da Ciência da Computação, traz conceitos sintáticos (metadados e protocolos) para comunicar e trocar dados e conceitos semânticos (ontologias e anotações semânticas) para descrever dados. Ambos os tipos de conceitos podem promover a interoperabilidade entre distintos repositórios e plataformas digitais, proporcionando melhorias nas atividades de busca e recuperação de informações.publishe

    Moisture effect on the separation of CO2/CH4 mixtures with amine-functionalised porous silicas

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    The effect of minor amounts of water on the CO2 and CH4 adsorption on primary and secondary amine-functionalised mesoporous silicas (APTES@SBA-15 and DEAPTES@SBA15, respectively) was studied with a combination of high-pressure gas adsorption, solid state NMR of labelled 13CO2 and density functional theory (DFT) calculations. Known amounts of water were pre-adsorbed on the materials (0.047 to 0.157 mmol∙g−1) and the adsorption performance for CO2 and CH4 was compared to the performance of the dry samples. We observed that even when only minor amounts of water are present, the tertiary amine-functionalised material revealed a significant enhancement of the selectivity for CO2 (from ca. 5.8 to 208) while the one with primary amine maintained the same adsorption properties. This is related to the change in the adsorption mechanism in DEAPTES@SBA15 when water is present since water participates in the reaction of the tertiary amine with CO2 to produce bicarbonate (confirmed by NMR and DFT results). Such species was not observed in APTES@SBA-15 with water. From a broader perspective, the results presented in this work are relevant to confirm the suitability of this type of hybrid adsorbents in industrial applications related with CO2 adsorption, where minor amounts of water may be present in the process streams, such as during bio, landfill, or natural gas upgrading, or also in carbon capture applications.publishe

    Simulation and Training of Gynaecological Skills

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    In order to offer our patients, the "state of the art" treatment in gynaecology, we need a structured teaching program for trainees concerning the gynaecological skills. In recent years, training and education in endoscopic surgery has been critically reviewed. Clinicians, both surgeons as gynaecologists who perform endoscopic surgery without proper training of the specific psychomotor skills, are at higher risk to increased patient morbidity and mortality. The traditional apprentice-tutor model is no longer valid for developing all skills necessary in gynaecological surgery, particularly in endoscopy. Endoscopic training should happen at both the theoretical and the practical skill level. The acquisition of the correct knowledge regarding general laparoscopy, hysteroscopy and standard level procedures is as important as learning the necessary psychomotor skills to successfully perform endoscopic manipulations. Training in the operating room can only start when it is proven that knowledge and skills are present. To learn and train total abdominal hysterectomy by laparotomy there are inexpensive simple models that can be used, which are easy to reproduce. The development, construction, cost, and utility of a low-cost and anatomically representative vaginal hysterectomy simulator also has been described. The complexity of modern surgery has increased the demands and challenges to surgical education and the quality control.info:eu-repo/semantics/publishedVersio

    Functional and sensory properties of jam with different proportions of pineapple, cucumber, and Jatropha leaf

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    Introduction. Fruits and vegetables are vital for healthy food consumption. Conservation is the only option to prolong their shelf life. Nigeria is currently experiencing an increase in production of fruit jams that incorporate vegetables. Cucumbers, Jatropha tanjorensis L. leaf, and pineapples have a lot of health benefits, which makes them very promising for jam making. The present research featured the effect of cucumber, pineapple, and Jatropha leaf in different proportions on the functional and sensory properties of composite jam. Study objects and methods. The technology of jam making followed standard procedures. Pineapple jam without cucumbers and Jatropha leaf served as control (pineapple:cucumber:Jatropha leaf = 100:0:0). The experimental jam samples had increasing amounts of Jatropha leaf (J), decreasing amounts of pineapple pulps (P), and a constant amount of cucumber (C), i.e. P:C:J = 85:10:5, 80:10:10, 75:10:15, and 70:10:20. The functional analysis involved chemical and proximate aspects, whereas the sensory evaluation involved appearance, aroma, taste, spreadability, and overall liking. Results and discussion. The experimental samples showed a significant difference (P 0.05). Compared to the control sample, the sensory properties of the experimental samples differed significantly (P 0.05) taste and overall liking. Conclusion. The obtained functional and sensory data proved that the new pineapple jam with cucumber and Jatropha leaf is a promising functional product

    O tema mudança global e a sua importancia para o desenvolvimento de futuros cidadaos: uma proposta didáctica implementada numa escola básica em Portugal

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    Ponencia presentada en: XXIX Jornadas Científicas de la AME y el VII Encuentro Hispano Luso de Meteorología celebrado en Pamplona, del 24 al 26 de abril de 2006

    D=4, N=1 orientifolds with vector structure

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    We construct compact type IIB orientifolds with discrete groups Z_4, Z_6, Z_6', Z_8, Z_12 and Z_12'. These models are N=1 supersymmetric in D=4 and have vector structure. The possibility of having vector structure in Z_N orientifolds with even N arises due to an alternative Omega-projection in the twisted sectors. Some of the models without vector structure are known to be inconsistent because of uncancelled tadpoles. We show that vector structure leads to a sign flip in the twisted Klein bottle contribution. As a consequence, all the tadpoles can be cancelled by introducing D9-branes and D5-branes.Comment: Latex, 44 pages, 2 figures, v2: misprints and an error concerning Omega^2_{95} corrected, a comment on D5-branes with negative NSNS charge added, references and acknowledgements adde
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