89 resultados para HVDC-VSC


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Calbindin-D28K and/or parvalbumin appear to influence the selective vulnerability of motoneurons in amyotrophic lateral sclerosis (ALS). Their immunoreactivity is undetectable in motoneurons readily damaged in human ALS, and in differentiated motoneuron hybrid cells [ventral spinal cord (VSC 4.1 cells)] that undergo calcium-dependent apoptotic cell death in the presence of ALS immunoglobulins. To provide additional evidence for the role of calcium-binding proteins in motoneuron vulnerability, VSC 4.1 cells were infected with a retrovirus carrying calbindin-D28K cDNA under the control of the promoter of the phosphoglycerate kinase gene. Differentiated calbindin-D28K cDNA-infected cells expressed high calbindin-D28K and demonstrated increased resistance to ALS IgG-mediated toxicity. Treatment with calbindin-D28K antisense oligodeoxynucleotides, which significantly decreased calbindin-D28K expression, rendered these cells vulnerable again to ALS IgG toxicity.

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Upper Devonian rocks of the Iberian Pyrite Belt (IPB) in southwest Spain, comprising the Phyllite-Quartzite Group (PQ) and the lower part of the overlying Volcano-Sedimentary Complex (VSC), contain a diversity of terrestrial and marine palynomorphs (miospores and organic-walled microphytoplankton, respectively), which constitute the basis of this biostratigraphically oriented research project. Part One of the report has previously detailed the miospore content of the constituent 117 palyniferous samples. In the present paper (i.e., the concluding Part Two), the organic-walled microphytoplankton (acritarchs and prasinophyte phycomata) are systematically described and illustrated, and their occurrence in the study material is fully documented. The acritarchs are represented by 23 species (including one species complex) allocated among 14 genera (one of which, Dupliciradiatum, is newly established), together with a very rare and novel category (informally termed Gen. nov. A). The following new acritarch species are formally instituted: Dupliciradiatum crassum (type species), D. tenue, Histopalla languida, and Winwaloeusia repagulata. Five genera allied with the prasinophycean algae are identified; these accommodate a total of 15 species of which two - Cymatiosphaera tenuimembrana and Maranhites multioculus - are formally proposed as new. In addition, representatives of the prasinophyte genera Leiosphaeridia and Tasmanites are recorded but are not discriminated at species level. The microphytoplankton suite is clearly consonant, from previously published occurrences in other regions, with a Late Devonian dating. However, most of the species are known to be relatively long ranging through (and in some cases beyond) that epoch and hence are not amenable to detailed biozonal subdivision of the IPB succession. Moreover, the distribution of the species therein tends to be erratic in comparison with the more consistently occurring miospores, possibly due to stress factors induced by fluctuating conditions in the IPBs Upper Devonian marine environment. By contrast, the land-derived (miospore) assemblages are readily applicable in a blostratigraphic context: they can be correlated precisely with the Devonian miospore biozonation scheme for Western Europe. In those terms, the sampled PQ strata are assignable to the Diducites versabilis-Grandispora cornuta (VCo) Biozone of late Famennian age; while the samples from the anoxic sequence at the base of the VSC belong to the Retispora lepidophyta-Verrucosisporites nitidus (LN) Biozone (latest Famennian = latest Devonian). The biochronostratigraphic data, in conjunction with the findings from earlier IPB studies, imply two appreciable palynostratigraphic breaks within the PQ. These are representative, respectively, of the lower Frasnian-middle Famennian interval and of part of the Strunian/upper Famennian. Speculation currently remains as to whether the inferred gaps are more apparent than real; i.e., whether one or both represent actual hiatuses in IPB sedimentation or are simply a manifestation of hitherto unsampled and/or non-palyniferous PQ strata.

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This thesis describes an investigation of methods by which both repetitive and non-repetitive electrical transients in an HVDC converter station may be controlled for minimum overall cost. Several methods of inrush control are proposed and studied. The preferred method, whose development is reported in this thesis, would utilize two magnetic materials, one of which is assumed to be lossless and the other has controlled eddy-current losses. Mathematical studies are performed to assess the optimum characteristics of these materials, such that inrush current is suitably controlled for a minimum saturation flux requirement. Subsequent evaluation of the cost of hardware and capitalized losses of the proposed inrush control, indicate that a cost reduction of approximately 50% is achieved, in comparison with the inrush control hardware for the Sellindge converter station. Further mathematical studies are carried out to prove the adequacy of the proposed inrush control characteristics for controlling voltage and current transients during both repetitive and non-repetitive operating conditions. The results of these proving studies indicate that no change in the proposed characteristics is required to ensure that integrity of the thyristors is maintained.

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Power system simulation software is a useful tool for teaching the fundamentals of power system design and operation. However, existing commercial packages are not ideal for teaching work-based students because of high-cost, complexity of the software and licensing restrictions. This paper describes a set of power systems libraries that have been developed for use with the free, student-edition of a Micro-Cap Spice that overcomes these problems. In addition, these libraries are easily adapted to include power electronic converter based components into the simulation, such as HVDC, FACTS and smart-grid devices, as well as advanced system control functions. These types of technology are set to become more widespread throughout existing power networks, and their inclusion into a power engineering degree course is therefore becoming increasingly important.

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Volunteered Service Composition (VSC) refers to the process of composing volunteered services and resources. These services are typically published to a pool of voluntary resources. The composition aims at satisfying some objectives (e.g. Utilizing storage and eliminating waste, sharing space and optimizing for energy, reducing computational cost etc.). In cases when a single volunteered service does not satisfy a request, VSC will be required. In this paper, we contribute to three approaches for composing volunteered services: these are exhaustive, naïve and utility-based search approach to VSC. The proposed new utility-based approach, for instance, is based on measuring the utility that each volunteered service can provide to each request and systematically selects the one with the highest utility. We found that the utility-based approach tend to be more effective and efficient when selecting services, while minimizing resource waste when compared to the other two approaches.

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This paper provides a discussion on future direct current (DC) network development in terms of system protection under DC-side fault scenarios. The argument between appropriate DC circuit breaker and new DC fault-tolerant converters is discussed after a review on DC technology development and bottleneck issues that require proper solutions. The overcurrent/cost curve of power-electronic DC circuit breakers (CB) superimposed to voltage-source converter (VSC) systems is derived and compared with other possible fault-tolerant power conversion options. This in-advance planning of protection capability is essential for the future development of DC networks.

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Volunteered Service Composition (VSC) refers to the process of composing volunteered services and resources. These services are typically published to a pool of voluntary resources. Selection and composition decisions tend to encounter numerous uncertainties: service consumers and applications have little control of these services and tend to be uncertain about their level of support for the desired functionalities and non-functionalities. In this paper, we contribute to a self-awareness framework that implements two levels of awareness, Stimulus-awareness and Time-awareness. The former responds to basic changes in the environment while the latter takes into consideration the historical performance of the services. We have used volunteer service computing as an example to demonstrate the benefits that self-awareness can introduce to self-adaptation. We have compared the Stimulus-and Time-awareness approaches with a recent Ranking approach from the literature. The results show that the Time-awareness level has the advantage of satisfying higher number of requests with lower time cost.

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This project is funded by European Research Council in FP7; grant no 259328, 2010 and EPSRC grant no EP/K006428/1, 2013.

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This project is funded by European Research Council in FP7; grant no 259328, 2010 and EPSRC grant no EP/K006428/1, 2013.

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Experiments in the authors’ laboratory are supported by the Wellcome Trust (grant no. 109680/Z/15/Z), the Royal Society (grant no. RG150386), and Tenovus Scotland (grant no. G14/19) to SS. VSC is recipient of a European Union’s Horizon 2020 research and innovation programme Marie Sklodowska Curie Fellowship (grant no. 706040).

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Software deployment, eller mjukvarudistribution översatt till svenska kan ses som processen där alla aktiviteter ingår för att göra en mjukvara tillgänglig för användare utan en manuell installation på användarens dator eller annan maskin. Det finns ett flertal software deployment-verktyg, som hanterar automatiska installationer, tillgängliga för företag på marknaden idag.  Avdelningen HVDC på ABB i Ludvika har behov att börja använda ett verktyg för automatiserade installationer av mjukvaror då installationer idag utförs manuellt och är tidsödande. Som Microsoftpartners vill ABB se hur Microsofts verktyg för mjukvarudistribution skulle kunna hjälpa för detta behov.  Vår studie syftade till att undersöka hur arbetet med installationer av mjukvara ser ut idag, samt hitta förbättringsmöjligheter för installationer som inte kan automatiseras i nuläget. I studien ingick även att ta fram ett generellt ramverk för hur verksamheter kan gå tillväga när de vill börja använda sig utav software deployment-verktyg. I ramverket ingår en utformad kravspecifikation som ska utvärderas mot Microsofts verktyg.  För att skapa en uppfattning om hur arbetet i verksamheten ser ut idag har vi utfört enkätundersökning och intervjuer med personal på HVDC. För att utveckla ett ramverk har vi använt oss av insamlade data från de intervjuer, enkätundersökning och gruppintervju som utförts, detta för att identifiera krav och önskemål från personalen hos ett software deployment-verktyg. Litteraturstudier utfördes för att skapa en teoretisk referensram att utgå ifrån vid utvecklande av ramverket och kravspecifikationen.  Studien har resulterat i en beskrivning av software deployment, förbättringsmöjligheter i arbetet med installationer av mjukvara samt ett generellt ramverk som beskriver hur verksamheter kan gå tillväga när de ska börja använda ett software deployment-verktyg. Ramverket innehåller också en kravspecifikation som använts för att utvärdera Microsofts verktyg för mjukvarudistribution. I vår studie har vi inte sett att någon tidigare har tagit fram ett generellt ramverk och kravspecifikation som verksamheter kan använda sig av som underlag när de ska börja använda ett software deployment-verktyg. Vårt resultat av studien kan täcka upp detta kunskapsgap.    

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A halitose é uma condição ou alteração do hálito, sendo caracterizada por um hálito desagradável emitido pela expiração. Segundo a Organização Mundial de Saúde (OMS), é considerado um problema de saúde, visto que afeta cerca de 40% da população mundial. Este problema causa desconforto e constrangimento social, sendo assim um limitador da qualidade de vida e da autoestima de quem a padece. Atualmente sabe-se que a halitose pode ser caracterizada como verdadeira, pseudo-halitose ou halitofobia. A halitose verdadeira pode ser uma halitose patológica ou fisiológica. A sua etiologia é multifatorial e o seu tratamento é multidisciplinar. Por outro lado, tanto a pseudo-halitose como a halitofobia provêm do foro psicológico, sendo necessário a ajuda de um psicólogo ou psiquiatra. Existem vários testes de diagnóstico (halímetro, cromatografia gasosa, BANA, entre outros) para avaliar a presença e a severidade desta patologia. O tratamento desta patologia consiste na eliminação das cáries e doenças periodontais, dando instruções de higiene oral para reforçar a escovagem dentária, o uso do fio dentário e a higiene das próteses. O aconselhamento dietético e a limpeza da língua também são essenciais, como também o controlo do biofilme com anti-séticos orais (Abreu et alii., 2011; Machado et alii., 2008). O objetivo desta revisão bibliográfica assenta na determinação de diversas possibilidades de prevenção e tratamento bem como a sua eficácia, sendo esta fundamental para o reconhecimento e correta interpretação da halitose. A pesquisa bibliográfica sobre o tema “Halitose: da etiologia ao tratamento” foi realizada essencialmente em motores de busca como o Pubmed e a Scielo, em três idiomas, Português, Inglês e Espanhol. selecionando artigos na sua maioria entre os anos 2006-2016. O médico médico dentista tem como função, na maioria dos casos, de tratar esta patologia ou então, quando não está associada à cavidade oral, reencaminhar o paciente para a especialidade médica adequada. Contudo, é de salientar que o paciente também possui um papel ativo no tratamento e na manutenção da halitose.

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DCDC transformadore erresonante isolatu baten prototipoaren fabrikazioa

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La tesi tratta del metodo PEA per la misura della carica di spazio. Viene fatta una valutazione sull'applicazione del metodo e sul significato dei risultati per le prove sui cavi modello. Utilizzando quanto ottenuto dalle prove si fa poi una riflessione su come sia più sensato calcolare il campo elettrico, partendo dalla distribuzione di carica ottenuta. Infine verra mostrata una prova su un cavo full size (progetto IFA2) per avere un riscontro degli studi fatti in laboratorio su un test di fabbrica. Le conclusioni si concentreranno sui problemi attuali relativi al sistema di misura e sulle possibili migliorie future.