20,934 research outputs found
Human Trafficking and Terrorism: Utilizing National Security Resources to Prevent Human Trafficking in the Islamic State
This is a report of a Masterâs thesis done in behalf of the local network in Stockholm, under Fortum Distribution AB. The thesis was to conduct a review of a distribution station named Fs MyrĂ€ngen located in TĂ€by. A model was created for the 11 kV network linked to the secondary side of Fs MyrĂ€ngen. Based on this model and using symmetrical components, theoretical fault currents (short circuit and ground fault) could be calculated. The results of these fault currents are used to investigate and develop new settings for relay protection and ground equipment in the station. The results of the calculated fault currents were also used to investigate unwanted voltages that occurs for grounded parts due to earth faults. The value of these unwanted voltages was then compared to heavy current regulations developed by the Electrical Safety Authority in Sweden. Another element of the work was to create a rehabilitation plan for the structure on the 11 kV side of Fs MyrĂ€ngen, the main goal regarding the rehabilitation plan was to investigate the advantages and disadvantages that exist at a possible transition to numerical protection relays. This was done by making a market overview of the different types of numerical protection relays and compare these with the existing analog protective device in Fs MyrĂ€ngen. The study showed that protective relay settings should be revised according to the recommendations in the report, ground equipment should be replaced with a self-regulating type, transformers should be replaced due to age and capacity limitations. Regarding a switch to numerical protection relays the type REF615 from ABB was recommended, in that case the control board in the station should be replaced to a station computer. Furthermore should current transformers be replaced to recive a desired sensitivity regarding detection of ground faults. The report also showed that Fs MyrĂ€ngen meets the regulations of unwanted voltages over grounded parts in distribution stations due to earth faults.Detta Ă€r en rapport av ett examensarbete utfört i uppdrag av lokalnĂ€t Stockholm under Fortum Distribution AB. Examensarbetet gick ut pĂ„ att göra en översyn av en fördelningsstation vid namn Fs MyrĂ€ngen som Ă€r belĂ€gen i TĂ€by. En modell skapades av 11 kV nĂ€tet kopplat till Fs MyrĂ€ngen, utifrĂ„n denna modell samt med hjĂ€lp av symmetriska komponenter berĂ€knades teoretiska felströmmar bĂ„de för kortslutning och jordslutning. Resultaten av dessa felströmmar anvĂ€ndes för att utreda och ta fram instĂ€llningar pĂ„ relĂ€skydd och nollpunktsutrustning i stationen. Resultaten pĂ„ framrĂ€knade jordfelsströmmar anvĂ€ndes Ă€ven för att utreda vilken spĂ€nningssĂ€ttning som uppstĂ„r vid jordfel, i de nĂ€tstationer som matas av Fs MyrĂ€ngen. SpĂ€nningssĂ€ttningen pĂ„ nĂ€tstationerna jĂ€mfördes sedan med de starkströmsföreskrifter som Ă€r framtagna av elsĂ€kerhetsverket. Ett annat moment i arbetet var att skapa en upprustningsplan för skyddsanordningen pĂ„ 11 kV sidan i Fs MyrĂ€ngen, huvudmĂ„let för den biten var att utreda vilka fördelar och nackdelar som finns vid en eventuell övergĂ„ng till numeriska skydd. Detta gjordes genom att göra en marknadsöversikt över olika typer av numeriska relĂ€skydd, samt jĂ€mföra dessa med den befintliga skyddsanordningen i MyrĂ€ngen som Ă€r av analog typ. Studien visade att relĂ€skyddsinstĂ€llningar bör ses över enligt rekommendationer i rapporten, nollpunktsutrustningen bör bytas ut till sjĂ€lvreglerande typ, transformatorerna bör bytas ut p.g.a. Ă„lder och kapacitetsbegrĂ€nsning. GĂ€llande skyddsanordningen rekommenderas en övergĂ„ng till numeriska skydd av typen REF615, och i samband med detta byta ut den befintliga kontrolltavlan i stationen till en stationsdator. Vidare bör Ă€ven strömtransformatorer för jordfelsskydden bytas ut för att uppnĂ„ önskad kĂ€nslighet gĂ€llande detektering av jordfel. För spĂ€nningssĂ€ttning av nĂ€tstationer vid jordfel, visar resultaten att stationen uppfyller kraven enligt starkströmsföreskrifterna frĂ„n elsĂ€kerhetsverket
THE BIOLOGICAL AND STRUCTURAL CHARACTERIZATION OF TRANSFERABLE BACTEROIDES R PLASMIDS
In this literature review I will briefly describe the general biology of transferable antibiotic resistance in bacteria, the genetic elements involved (plasmids) and several specific plasmid associated phenotypes. This will be followed with a review of the general biology of Bacteroides, the information known concerning its plasmid reservoir and finally a review of the information documenting the emergence of transferable clindamycin resistance in Bacteroides. The latter aspect represents the central focus of research described in this thesis
Implications of skeletal muscle loss for public health nutrition messages:a brief report
Age-related skeletal muscle loss, sarcopenia, cachexia and wider malnutrition (under nutrition) are complex in aetiology with interaction of clinical, social and economic factors. Weight loss and loss of skeletal muscle mass in older people are associated with increased morbidity and mortality with implications for increasing health and social care costs. There is insufficient evidence to identify the ideal treatment options. However, preventing weight loss and loss of skeletal muscle in older age will be keys to reducing morbidity and mortality. This will require all those coming into contact with older people to identify and address weight loss early, including through diet, improving physical activity and increasing social interaction. Public health messages on diet should, in the main, continue to focus on older people achieving current UK dietary recommendations for their age as visually depicted in the eatwell plate together with associated messages regarding dietary supplements where appropriate
Evaluation of Composite Materials for Use on Launch Complexes
Commercially available composite structural shapes were evaluated for use. These composites, fiberglass-reinforced polyester and vinylester resin materials are being used extensively in the fabrication and construction of low maintenance, corrosion resistant structures. The evaluation found that in many applications these composite materials can be successfully used at the space center. These composite materials should not be used where they will be exposed to the hot exhaust plume/cloud of the launch vehicle during the liftoff, and caution should be taken in their use in areas where electrostatic discharge and hypergolic propellant compatibility are primary concerns
The credibility and performance of unilateral target zones: a comparison of the Mexican and Chilean cases
Foreign exchange rates ; Mexico ; Latin America
Contribution of cod liver oil-related nutrients (vitamins A, D, E and eicosapentaenoic acid and docosahexaenoic acid) to daily nutrient intake and their associations with plasma concentrations in the EPIC-Norfolk cohort
Total nutrient intake (TNI) is intake from food and supplements. This provides an assessment of nutrient adequacy and the prevalence of excessive intake, as well as the response with respect to biomarkers. Cod liver oil (CLO) is the most frequently consumed supplement in the UK, containing nutrients that might have varying influences on health. We calculated TNI for vitamins A, D and E, as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and assessed associations with the respective blood concentrations
An adaptive, hanging-node, discontinuous isogeometric analysis method for the first-order form of the neutron transport equation with discrete ordinate (SN) angular discretisation
In this paper a discontinuous, hanging-node, isogeometric analysis (IGA) method is developed and applied to the first-order form of the neutron transport equation with a discrete ordinate (SN) angular discretisation in two-dimensional space. The complexities involved in upwinding across curved element boundaries that contain hanging-nodes have been addressed to ensure that the scheme remains conservative. A robust algorithm for cycle-breaking has also been introduced in order to develop a unique sweep ordering of the elements for each discrete ordinates direction. The convergence rate of the scheme has been verified using the method of manufactured solutions (MMS) with a smooth solution. Heuristic error indicators have been used to drive an adaptive mesh refinement (AMR) algorithm to take advantage of the hanging-node discretisation. The effectiveness of this method is demonstrated for three test cases. The first is a homogeneous square in a vacuum with varying mean free path and a prescribed extraneous unit source. The second test case is a radiation shielding problem and the third is a 3Ă3 âsupercellâ featuring a burnable absorber. In the final test case, comparisons are made to the discontinuous Galerkin finite element method (DGFEM) using both straight-sided and curved quadratic finite elements
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