78 research outputs found

    Integração de Esquemas Relacionais e XML com realização de Consultas na Base de Dados Integrada

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    A modelagem de estrutura de dados em um Sistema Gerenciador de Banco de Dados (SGBD) normalmente é feita de acordo com as regras de negócio da realidade que está sendo representada. Organizações que possuem o mesmo negócio nem sempre terão as mesmas estruturas de dados, por terem sido modeladas por pessoas diferentes e também para atender a necessidades diferentes. Atualmente, a identificação da correspondência existente entre esquemas relacionais é feita manualmente na maioria dos casos e tem sido tema de muitas pesquisas na área de Banco de Dados. Este processo é fundamental para possibilitar a integração de esquemas criados de forma independente e de bases de dados diferentes, uma vez que o problema da integração é o transporte de dados armazenados de um esquema para o outro. A proposta para este trabalho é desenvolver uma interface que, após a identificação dos atributos correspondentes entre os esquemas selecionados, realize a integração dos esquemas permitindo a busca de dados na base integrada. Mesmo com o processo de integração e casamento criado, a correspondência entre os esquemas é semi-automática porque os atributos podem ser relacionados sem possuir similaridade real

    Investigation of corrosion-erosion phenomena in the primary cooling system of SPIDER

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    SPIDER dedicated cooling plant has to remove up to 10 MW thermal power from in-vessel components and auxiliary systems. The circuit is characterized by three main heat transfer systems: primary, secondary and tertiary systems. The primary system is made of four circuits, with only three operating so far, these are called PC01, PC02 and PC03. These three circuits respectively cool SPIDER power supplies and the beam source components using ultrapure water. During 2019 SPIDER experimental campaigns, it was observed that electrical resistivity of water degraded considerably and more quickly (∼25 MΩ cm h−1 in PC01) than estimated by design. To overcome this issue, water had to be restored very frequently to maintain the desired characteristics and avoid possible detrimental leakage currents throughout the circuit. The reason for this severe water degradation has to be better understood before issues such as abrupt failures may arise. This work presents a preliminary analysis of the two main circuits (PC01 and PC02) where an estimation of water degradation induced by general corrosion of stainless steels and copper components was made. This preliminary estimation showed that PC01 could be more prone to general corrosion than PC02; however, the rate of water conductivity increase was 5.3 times smaller than that observed during experiments in 2019 and 2020

    Start of SPIDER operation towards ITER neutral beams

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    Heating Neutral Beam (HNB) Injectors will constitute the main plasma heating and current drive tool both in ITER and JT60-SA, which are the next major experimental steps for demonstrating nuclear fusion as viable energy source. In ITER, in order to achieve the required thermonuclear fusion power gain Q=10 for short pulse operation and Q=5 for long pulse operation (up to 3600s), two HNB injectors will be needed [1], each delivering a total power of about 16.5 MW into the magnetically-confined plasma, by means of neutral hydrogen or deuterium particles having a specific energy of about 1 MeV. Since only negatively charged particles can be efficiently neutralized at such energy, the ITER HNB injectors [2] will be based on negative ions, generated by caesium-catalysed surface conversion of atoms in a radio-frequency driven plasma source. A negative deuterium ion current of more than 40 A will be extracted, accelerated and focused in a multi-aperture, multi-stage electrostatic accelerator, having 1280 apertures (~ 14 mm diam.) and 5 acceleration stages (~200 kV each) [3]. After passing through a narrow gas-cell neutralizer, the residual ions will be deflected and discarded, whereas the neutralized particles will continue their trajectory through a duct into the tokamak vessels to deliver the required heating power to the ITER plasma for a pulse duration of about 3600 s. Although the operating principles and the implementation of the most critical parts of the injector have been tested in different experiments, the ITER NBI requirements have never been simultaneously attained. In order to reduce the risks and to optimize the design and operating procedures of the HNB for ITER, a dedicated Neutral Beam Test Facility (NBTF) [4] has been promoted by the ITER Organization with the contribution of the European Union\u2019s Joint Undertaking for ITER and of the Italian Government, with the participation of the Japanese and Indian Domestic Agencies (JADA and INDA) and of several European laboratories, such as IPP-Garching, KIT-Karlsruhe, CCFE-Culham, CEA-Cadarache. The NBTF, nicknamed PRIMA, has been set up at Consorzio RFX in Padova, Italy [5]. The planned experiments will verify continuous HNB operation for one hour, under stringent requirements for beam divergence (< 7 mrad) and aiming (within 2 mrad). To study and optimise HNB performances, the NBTF includes two experiments: MITICA, full-scale NBI prototype with 1 MeV particle energy and SPIDER, with 100 keV particle energy and 40 A current, aiming at testing and optimizing the full-scale ion source. SPIDER will focus on source uniformity, negative ion current density and beam optics. In June 2018 the experimental operation of SPIDER has started

    Management of hydrocele in adolescent patients

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    Hydrocele is defined as an abnormal collection of serous fluid in the potential space between the parietal and visceral layers of the tunica vaginalis. In the majority of affected adolescents, hydrocele is acquired and is idiopathic in origin. The pathogenesis of idiopathic hydrocele is thought to be an imbalance in the normal process of fluid production and reabsorption. The diagnosis is usually clinical. Taking a thorough history is essential to rule out any fluctuation in size, which is an indication of a patent processus vaginalis. Scrotal ultrasonography is mandatory in nonpalpable testicles to rule out a subtending testicular solid mass requiring inguinal exploration. Otherwise, open hydrocelectomy via a scrotal incision is the standard treatment of idiopathic hydroceles. The second most common cause of hydrocele in adolescents is varicocelectomy. The risk of hydrocele formation is higher with non-artery-sparing procedures or those performed without microsurgical aid, and in surgery requiring cord dissection. If hydrocele occurs after varicocelectomy, initial management should include observation with or without hydrocele aspiration. Large persistent hydroceles are best served by open hydrocelectomy

    Development of advanced control strategies for a dynamic triaxial soil testing machine

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    As civil engineering projects become increasingly ambitious, the earthworks that form a significant part of these projects become increasingly critical. Geotechnical engineering is concerned with the measurement , modelling and simulation of soil under various conditions for the application within civil engineering. In triaxial testing, an actuator applies a force or displacement to a soil sample. Dynamic triaxial testing is concerned with applying forces conforming to a rapidly changing pattern. The simplest case is concerned with applying a force in a sinusoidal pattern. The accuracy of models produced during triaxial testing depends largely on the accuracy of the equipment used for testing. As such, the control of the applied force is of great importance. The response of the soil sample directly influences the closed loop behaviour of the system. The soil sample response is unknown at the start of the test , can vary throughout a test and depends on various parameters, many of which are unobservable. This research investigates the issues faced in developing accurate control of dynamic triaxial testing equipment. Models of the load frame and various nonlinear soil sample responses are built for the purpose of simulation and controller design. Various control strategies are developed, implemented and tested, including the use of PID control, adaptive repetitive control and sliding mode control techniques. The recursive least squares algorithm is investigated and used for online identification in order to compensate for unknown and time varying plant parameters. Simulation and testing methods are investigated and several control methods are tested in simulation, on the target triaxial load frame using and finally using embedded processing hardware. Development and implementation techniques are also used including rapid prototyping and hardware-in-the-loop testing.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Cooperative nanosystems

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    Multivalent systems are well known for their enhanced ability to bind multivalent counterparts. This contribution addresses the question whether they can also behave as cooperative catalysts. Analyzing examples from our own laboratory we show that self-assembled systems obtained by covering gold nanoclusters with thiol-terminated amino acids and peptides behave indeed as cooperative catalysts. By comparing their activity profiles with those of discrete, multivalent systems we show what are minimal conditions to elicit cooperativity in multivalent systems. Reactions taken into considerations for our analysis are the hydrolyses of carboxylate- and phosphate esters. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd

    Raman spectroscopy application in frozen carrot cooked in different ways and the relationship with carotenoids

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    BACKGROUND: Raman spectroscopy, in its confocal micro-Raman variation, has been recently proposed as a spatially resolved method to identify carotenoids in various food matrices, being faster, non-destructive, and avoiding sample extraction, but no data are present in the literature concerning its application to the evaluation of carotenoid pattern changes after thermal treatment of carrots. RESULTS: The effect of three cooking methods (i.e. boiling, steaming and microwaving) was evaluated on frozen carrot, comparing changes on carotenoid profiles measured by means of Raman spectroscopy with their high-performance liquid chromatographic determination and colour. A more pronounced detrimental effect on carotenoids was detected in steamed carrots, in accordance with colour data. Conversely, boiling and, to a lesser extent, microwaving caused an increase in carotenoid concentration. Cooking procedures affected the Raman spectral features of carotenoids, causing a shift of vibration frequencies towards a higher energy, increase in the spectral baseline and peak intensities as well as a broadening of their width, probably in relation to the thermal degradation of longer carotenoids (i.e. the all-trans form) and the isomerization process. In particular, steamed samples showed a significantly higher increase of centre frequency, in accordance with amore pronounced isomerization and changes in colour parameters. CONCLUSION: This work showed that the evolution of Raman spectral parameters could provide information on carotenoid bioaccessibility for carrots cooked using various methods. This paves the way for a future use of this technique to monitor and optimize cooking processes aimed at maximizing carotenoid bioaccessibility and bioavailability
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