2,595,472 research outputs found

    UPS for Computer Systems Protection Electricity

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    Computers are a means for people to help all kinds of human activities in accordance with its use. Anyone used these facilities both individuals, corporate organizations, government installations and by those who use computers. But what if the computer's performance is affected by the lack of protection against electricity. In this case developed a device that UPS needed to overcome the problem of electricity computers. With UPS is expected to minimize all forms of electricity shortages on the computer used

    A dynamic modelling environment for the evaluation of wide area protection systems

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    This paper introduces the concept of dynamic modelling for wide area and adaptive power system protection. Although not limited to these types of protection schemes, these were chosen due to their potential role in solving a multitude of protection challenges facing future power systems. The dynamic modelling will be implemented using a bespoke simulation environment. This tool allows for a fully integrated testing methodology which enables the validation of protection solutions prior to their operational deployment. Furthermore the paper suggests a distributed protection architecture, which when applied to existing and future protection schemes, has the potential to enhance their functionality and avoid mal-operation given that safety and reliability of power systems are paramount. This architecture also provides a means to better understand the underlying dynamics of the aforementioned protection schemes and will be rigorously validated using the modelling environment

    Improving practice : child protection as a systems problem

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    This paper argues for treating the task of improving the child protection services as a systems problem, and for adopting the system-focused approach to investigating errors that has been developed in areas of medicine and engineering where safety is a high priority. It outlines how this approach differs from the traditional way of examining errors and how it leads to different types of solutions. Traditional inquiries tend to stop once human error has been found whereas a systems approach treats human error as the starting point and examines the whole context in which the operator was working to see how this impacted on their ability to perform well. The article outlines some factors that seem particularly problematic and worthy of closer analysis in current child protection services. A better understanding of the factors that are adversely effecting practitioners’ level of performance offers the potential for identifying more effective solutions. These typically take the form of modifying the tasks so that they make more realistic and feasible demands on human cognitive and emotional abilities

    Machine Protection and Interlock Systems for Circular Machines - Example for LHC

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    This paper introduces the protection of circular particle accelerators from accidental beam losses. Already the energy stored in the beams for accelerators such as the TEVATRON at Fermilab and Super Proton Synchrotron (SPS) at CERN could cause serious damage in case of uncontrolled beam loss. With the CERN Large Hadron Collider (LHC), the energy stored in particle beams has reached a value two orders of magnitude above previous accelerators and poses new threats with respect to hazards from the energy stored in the particle beams. A single accident damaging vital parts of the accelerator could interrupt operation for years. Protection of equipment from beam accidents is mandatory. Designing a machine protection system requires an excellent understanding of accelerator physics and operation to anticipate possible failures that could lead to damage. Machine protection includes beam and equipment monitoring, a system to safely stop beam operation (e.g. extraction of the beam towards a dedicated beam dump block or stopping the beam at low energy) and an interlock system providing the glue between these systems. This lecture will provide an overview of the design of protection systems for accelerators and introduce various protection systems. The principles are illustrated with examples from LHC.Comment: 23 pages, contribution to the 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14 Nov 201

    Determination of protection system requirements for DC UAV electrical power networks for enhanced capability and survivability

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    A growing number of designs of future Unmanned Aerial Vehicle (UAV) applications utilise dc for the primary power distribution method. Such systems typically employ large numbers of power electronic converters as interfaces for novel loads and generators. The characteristic behaviour of these systems under electrical fault conditions, and in particular their natural response, can produce particularly demanding protection requirements. Whilst a number of protection methods for multi-terminal dc networks have been proposed in literature, these are not universally applicable and will not meet the specific protection challenges associated with the aerospace domain. Through extensive analysis, this paper seeks to determine the operating requirements of protection systems for compact dc networks proposed for future UAV applications, with particular emphasis on dealing with the issues of capacitive discharge in these compact networks. The capability of existing multi-terminal dc network protection methods and technologies are then assessed against these criteria in order to determine their suitability for UAV applications. Recommendations for best protection practice are then proposed and key inhibiting research challenges are discussed

    Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010

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    The Eyjafjallajökull volcano in Iceland erupted on 14 April 2010 emitting a volcanic ash plume that spread across the United Kingdom and mainland Europe. The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health during the incident: there were no particularly unusual increases in any of the monitored conditions. This incident has again demonstrated the use of syndromic surveillance systems for monitoring community health in real time

    The Political Economy of Corporate Governance

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    We analyze the political determinants of investor and employment protection. Our model predicts that proportional electoral systems are conducive to weaker investor protection and stronger employment protection than majoritarian systems. This prediction is consistent with international panel data evidence. The proportionality of the voting system is significantly and negatively correlated with shareholder protection in a panel of 45 countries, and positively correlated with employment protection in a panel of 21 OECD countries. Also other political variables appear to affect regulatory outcomes, especially for the labor market. The origin of the legal system has some additional explanatory power only for employment protection.political economy, shareholder protection, corporate governance, employment legislation, takeovers, mergers and acquisitions.

    Survey of aircraft electrical power systems

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    Areas investigated include: (1) load analysis; (2) power distribution, conversion techniques and generation; (3) design criteria and performance capabilities of hydraulic and pneumatic systems; (4) system control and protection methods; (5) component and heat transfer systems cooling; and (6) electrical system reliability

    Effect of organic, low-input and conventional production systems on pesticide and growth regulator residues in wheat, potato and cabbage

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    The Nafferton factorial systems comparison (NFSC) experiments facilitate the investigation of effects of, and interaction between, three production system components - a) rotational position, b) fertility and c) crop protection management - in organic, conventional and low-input crop management systems. This paper presents first results on pesticide and growth regulator residues observed over a period of two years. Residues were only detected for three (Chlormequat, Chlorothalonil and Aldicarb) of the 28 pesticides used in the experiments. As expected, residue levels were affected by the crop protection practices, but significant effects of fertility management practices were also detected. This indicates that the human health risks associated with pesticide residues may increase in low input systems which attempt to reduce the environmental impact of conventional farming systems by switching to organic matter based fertilisation regimes
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