WorldWideScience

Sample records for circuit components maintenance

  1. Circuit arrangement of an electronic component for the design of fail-safe protective circuits

    International Nuclear Information System (INIS)

    Centmaier, W.; Bernhard, U.; Friederich, B.; Heisecke, I.

    1974-01-01

    The critical parameters of reactors are controlled by safety circuits. These circuits are controlled designed as logic modules operating by the 'n-out-of-m' selection principle. In most cases, a combination of a '1-out-of-3' circuit with a '2-out-of-3' circuit and separate indication is sufficient for a dynamic fail-safe circuit. The basic logic elements are AND and OR gate circuits, respectively, which are triggered by pulse trains and in which the failure of a pulse train is indicated as an error at the output. The module allows the design of safety circuits offering various degrees of safety. If the indication of an error is made on the modules, faulty components can be exchanged by the maintenance crew right away. (DG) [de

  2. Active components for integrated plasmonic circuits

    DEFF Research Database (Denmark)

    Krasavin, A.V.; Bolger, P.M.; Zayats, A.V.

    2009-01-01

    We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides.......We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides....

  3. Power electronics handbook components, circuits and applications

    CERN Document Server

    Mazda, F F

    1993-01-01

    Power Electronics Handbook: Components, Circuits, and Applications is a collection of materials about power components, circuit design, and applications. Presented in a practical form, theoretical information is given as formulae. The book is divided into three parts. Part 1 deals with the usual components found in power electronics such as semiconductor devices and power semiconductor control components, their electronic compatibility, and protection. Part 2 tackles parts and principles related to circuits such as switches; link frequency chargers; converters; and AC line control, and Part 3

  4. Circuit bridging of components by smoke

    International Nuclear Information System (INIS)

    Tanaka, T.J.; Nowlen, S.P.; Anderson, D.J.

    1996-10-01

    Smoke can adversely affect digital electronics; in the short term, it can lead to circuit bridging and in the long term to corrosion of metal parts. This report is a summary of the work to date and component-level tests by Sandia National Laboratories for the Nuclear Regulatory Commission to determine the impact of smoke on digital instrumentation and control equipment. The component tests focused on short-term effects such as circuit bridging in typical components and the factors that can influence how much the smoke will affect them. These factors include the component technology and packaging, physical board protection, and environmental conditions such as the amount of smoke, temperature of burn, and humidity level. The likelihood of circuit bridging was tested by measuring leakage currents and converting those currents to resistance in ohms. Hermetically sealed ceramic packages were more resistant to smoke than plastic packages. Coating the boards with an acrylic spray provided some protection against circuit bridging. The smoke generation factors that affect the resistance the most are humidity, fuel level, and burn temperature. The use of CO 2 as a fire suppressant, the presence of galvanic metal, and the presence of PVC did not significantly affect the outcome of these results

  5. Components of the primary circuit of LWRs

    International Nuclear Information System (INIS)

    1980-01-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673 K (400 C). The primary circuit as the pressure containment of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives. (orig.) [de

  6. Breaker Maintenance: Volume 3, Molded-Case circuit breakers

    International Nuclear Information System (INIS)

    Davis, E.L.; Funk, D.L.

    1991-09-01

    Modeled-case circuit breakers (MCCBs) provide power and circuit protection in nuclear plant electrical distribution systems. Thus, their proper operation is essential to the safe and reliable operation of plant electrical distribution systems. This guide for both nuclear and non-nuclear power generating facilities will help improve the maintenance and reliability of MCCBs. The authors developed this guide to establish a working-level understanding of hardware performance trends, reliability, and failure modes from which maintenance practices could be specified. The first step in preparing this guide was an in-depth review of available operating experience and failure data, which was obtained from nuclear information sources such as EPRI's Nuclear Maintenance Applications Center. In addition, they evaluated some nonnuclear reliability data. Next, they investigated current industry practices, including a review of manufacturer's recommendations and numerous industry standards. Finally, they used the collective information to develop programmatic recommendations and, where appropriate, detailed inspection and test guidance. This guide offers many recommendations applicable to MCCB maintenance, such as an engineering description of MCCBs and their operation; an overview of reliability and failure data; programmatic recommendations, including inspection and test periodicity; detailed inspection and test guidance; and corrective maintenance recommendations. Supplementary information includes an overview of industry standards, a discussion of regulatory issues, and sample data sheets. An evaluation of operating experience indicates that a maintenance program need not be overly complicated to detect the predominant failure modes associated with MCCBs. Those implementating an MCCB maintenance and testing program, however, must recognize the inherent limitations associated with field-testing of these devices. 42 refs., 17 figs., 7 tabs

  7. Design, maintenance and lifetime of nuclear components

    International Nuclear Information System (INIS)

    Noel, R.L.; Eisenhut, D.G.; Carey, J.J.; Reynes, L.J.

    1989-01-01

    Division D of SMiRT deals with experience feedback relating to the in-service behavior of nuclear components, the design and construction of this equipment, its maintenance and the evaluation and management of its lifetime. The nuclear industry now having reached maturity, with more than 300 units in service worldwide, these problems are now of predominant importance to the activity of the industry and in its development programs. This applies particularly to the problems relating to the lifetime of nuclear plants, problems which are rightly of such concern both to the utilities, in view of the enormous investments involved, and also to the safety authorities. These contributions have been reviewed for the purpose of analyzing the essential points. This analysis highlights the considerable advances achieved during the recent decades in design and maintenance methods and practices. It also identifies the areas in which progress still remains to be made

  8. Microwaves photonic links components and circuits

    CERN Document Server

    Rumelhard, Christian; Billabert, Anne-Laure

    2013-01-01

    This book presents the electrical models for the different elements of a photonic microwave link like lasers, external modulators, optical fibers, photodiodes and phototransistors. The future trends of these components are also introduced: lasers to VCSEL, external modulators to electro-absorption modulators, glass optical fibers to plastic optical fibers, photodiodes to UTC photodiodes or phototransistors. It also describes an original methodology to evaluate the performance of a microwave photonic link, based on the developed elcetrical models, that can be easily incorporated in

  9. Manipulator techniques and problems of their application in primary circuit maintenance

    International Nuclear Information System (INIS)

    Kertscher, F.; Popp, P.

    1985-01-01

    The fundamental structure and specifications of manipulators (in particular of industrial robots) are presented in order to derive the application conditions and fields for manipulators in primary circuit maintenance. The necessity of applying process-specific manipulator technique in the primary circuit maintenance is based on nuclear safety requirements and on decreasing of the radiation exposure of maintenance personnel. Synchronous manipulators and industrial robots are the types of manipulators used in materials testing, repairing and scrapping. The technical requirements of manipulators are discussed

  10. Feasibility study of component risk ranking for plant maintenance

    International Nuclear Information System (INIS)

    Ushijima, Koji; Yonebayashi, Kenji; Narumiya, Yoshiyuki; Sakata, Kaoru; Kumano, Tetsuji

    1999-01-01

    Nuclear power is the base load electricity source in Japan, and reduction of operation and maintenance cost maintaining or improving plant safety is one of the major issues. Recently, Risk Informed Management (RIM) is focused as a solution. In this paper, the outline regarding feasibility study of component risk ranking for plant maintenance for a typical Japanese PWR plant is described. A feasibility study of component risk raking for plant maintenance optimization is performed on check valves and motor-operated valves. Risk ranking is performed in two steps using probabilistic analysis (quantitative method) for risk ranking of components, and deterministic examination (qualitative method) for component review. In this study, plant components are ranked from the viewpoint of plant safety / reliability, and the applicability for maintenance is assessed. As a result, distribution of maintenance resources using risk ranking is considered effective. (author)

  11. Optimization of Reliability Centered Maintenance Bassed on Maintenance Costs and Reliability with Consideration of Location of Components

    Directory of Open Access Journals (Sweden)

    Mahdi Karbasian

    2011-03-01

    Full Text Available The reliability of designing systems such as electrical and electronic circuits, power generation/ distribution networks and mechanical systems, in which the failure of a component may cause the whole system failure, and even the reliability of cellular manufacturing systems that their machines are connected to as series are critically important. So far approaches for improving the reliability of these systems have been mainly based on the enhancement of inherent reliability of any system component or increasing system reliability based on maintenance strategies. Also in some of the resources, only the influence of the location of systems' components on reliability is studied. Therefore, it seems other approaches have been rarely applied. In this paper, a multi criteria model has been proposed to perform a balance among a system's reliability, location costs, and its system maintenance. Finally, a numerical example has been presented and solved by the Lingo software.

  12. Remote maintenance systems requirements are being developed to provide design guidelines for machine components, to define maintenance interfaces, and to quantify maintenance equipment and procedures needed

    International Nuclear Information System (INIS)

    Spampinato, P.T.; Tabor, M.A.

    1988-01-01

    Remote maintenance systems requirements are being developed to provide design guidelines for machine components, to define maintenance interfaces, and to quantify maintenance equipment and procedures needed

  13. Optimal maintenance of multi-component systems: a review

    NARCIS (Netherlands)

    R.P. Nicolai (Robin); R. Dekker (Rommert)

    2006-01-01

    textabstractIn this article we give an overview of the literature on multi-component maintenance optimization. We focus on work appearing since the 1991 survey "A survey of maintenance models for multi-unit systems" by Cho and Parlar. This paper builds forth on the review article by Dekker et al.

  14. Multi-level predictive maintenance for multi-component systems

    International Nuclear Information System (INIS)

    Nguyen, Kim-Anh; Do, Phuc; Grall, Antoine

    2015-01-01

    In this paper, a novel predictive maintenance policy with multi-level decision-making is proposed for multi-component system with complex structure. The main idea is to propose a decision-making process considered on two levels: system level and component one. The goal of the decision rules at the system level is to address if preventive maintenance actions are needed regarding the predictive reliability of the system. At component level the decision rules aim at identifying optimally a group of several components to be preventively maintained when preventive maintenance is trigged due to the system level decision. Selecting optimal components is based on a cost-based group improvement factor taking into account the predictive reliability of the components, the economic dependencies as well as the location of the components in the system. Moreover, a cost model is developed to find the optimal maintenance decision variables. A 14-component system is finally introduced to illustrate the use and the performance of the proposed predictive maintenance policy. Different sensitivity analysis are also investigated and discussed. Indeed, the proposed policy provides more flexibility in maintenance decision-making for complex structure systems, hence leading to significant profits in terms of maintenance cost when compared with existing policies. - Highlights: • A predictive maintenance policy for complex structure systems is proposed. • Multi-level decision process based on prognostic results is proposed. • A cost-based group importance measure is introduced for decision-making. • Both positive and negative dependencies between components are investigated. • A cost model and Monte Carlo simulation are developed for optimization process.

  15. Manual on maintenance of systems and components important to safety

    International Nuclear Information System (INIS)

    1986-01-01

    The Manual should serve as guidance at the plant management level for the maintenance of systems and components important to safety. It includes a detailed description of management systems, administrative controls and procedures. The Annexes contain examples of documents and practices adopted by Operating Organizations of some Member States. It is not the intention of this Manual to address the technical problem of how to maintain a particular component but rather to cover the programmatic aspects of maintenance. It also contains some aspects of surveillance and verification activities. The Manual makes only general statements about radiation protection provisions in connection with maintenance; detailed guidance can be found in other IAEA documents

  16. Components of the LWR primary circuit. Pt. 2

    International Nuclear Information System (INIS)

    1984-01-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673 K (400 0 C). The primary circuit as the pressure containment of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives. (orig.) [de

  17. Guidelines for Remote Handling Maintenance of ITER Neutral Beam Components

    International Nuclear Information System (INIS)

    Cordier, J.-J.; Hemsworth, R.; Bayetti, P.

    2006-01-01

    Remote handling maintenance of ITER components is one of the main challenges of the ITER project. This type of maintenance shall be operational for the nuclear phase of exploitation of ITER, and be considered at a very early stage since it significantly impacts on the components design, interfaces management and integration business. A large part of the R/H equipment will be procured by the EU partner, in particular the whole Neutral Beam Remote Handling (RH) equipment package. A great deal of work has already been done in this field during the EDA phase of ITER project, but improvements and alternative option that are now proposed by ITER lead to added RH and maintenance engineering studies. The Neutral Beam Heating -and- Current Drive system 1 is being revisited by the ITER project. The vertical maintenance scheme that is presently considered by ITER, may significantly impact on the reference design of the Neutral Beam (NB) system and associated components and lead to new design of the NB box itself. In addition, revision of both NB cell radiation level zoning and remote handling classification of the beam line injector will also significantly impact on components design and maintenance. Based on the experience gained on the vertical maintenance scheme, developed in detail for the ITER Neutral Beam Test Facility 2 to be built in Europe in a near future, guidelines for the revision of the design and preliminary feasibility study of the remote handling vertical maintenance scheme of beam line components are described in the paper. A maintenance option for the SINGAP3 accelerator is also presented. (author)

  18. Electronic zero-point fluctuation forces inside circuit components

    Science.gov (United States)

    Leonhardt, Ulf

    2018-01-01

    One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies. PMID:29719863

  19. Electronic zero-point fluctuation forces inside circuit components.

    Science.gov (United States)

    Shahmoon, Ephraim; Leonhardt, Ulf

    2018-04-01

    One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies.

  20. A Study on the Maintenance Effectiveness Assessment for Active Components

    International Nuclear Information System (INIS)

    Lim, Woo Sang; Oh, Seung Jong

    2006-01-01

    One of the key tasks in the periodic safety review (PSR) of nuclear power plant is to assess the aging management of structures, systems and components (SSC). The evaluation can be categorized by two parts, passive and active components. Unlike the passive components, active components are periodically maintained and replaced with new components, so the evaluation of aging mechanism of the passive components such as erosion, corrosion is not applicable to the evaluation of active components of nuclear power plant. For active components, they will maintain capability to fulfill its design function if preventive maintenance effectiveness is proper. In this paper, the assessment based on the reliability and availability of the active components of the domestic nuclear power plants is examined

  1. Measuring compliance during aircraft (Component) redeliveries at KLM engineering & maintenance

    NARCIS (Netherlands)

    Burhani, Shahir; Verhagen, W.J.C.; Curran, Ricky

    2016-01-01

    Aircraft and aircraft components are redelivered to the next operator or owner during the phase-out process. During this process the operator is required by law and contract requirements to show compliance with maintenance procedures. At KLM E&M the phase-out documentation process is under

  2. Identification of Optimal Preventive Maintenance Decisions for Composite Components

    NARCIS (Netherlands)

    Laks, P.; Verhagen, W.J.C.; Gherman, B.; Porumbel, I.

    2018-01-01

    This research proposes a decision support tool which identifies cost-optimal maintenance decisions for a given planning period. Simultaneously, the reliability state of the component is kept at or below a given reliability threshold: a failure limit policy applies. The tool is developed to support

  3. 76 FR 58041 - Certain Digital Televisions Containing Integrated Circuit Devices and Components Thereof; Notice...

    Science.gov (United States)

    2011-09-19

    ... Integrated Circuit Devices and Components Thereof; Notice of Institution of Investigation; Institution of... integrated circuit devices and components thereof by reason of infringement of certain claims of U.S. Patent... after importation of certain digital televisions containing integrated circuit devices and components...

  4. Component aging illustrated in maintenance histories from IPRDS

    International Nuclear Information System (INIS)

    Kahl, W.K.; Borkowski, R.J.

    1984-01-01

    The centerpiece of the In-Plant Reliability Data (IPRD) program is a nuclear power plant component data base developed from corrective maintenance records. The primary objective of this program is to establish a comprehensive source of information for reliability analyses, including the compilation of maintenance histories for failure statistics. The IPRD program is currently a pilot effort that has 36 reactor-years of data on pumps, valves, diesel generators, batteries, battery chargers and inverters from five nuclear plants. The data are collected under the auspices of the Institute of Electrical and Electronics Engineers (IEEE) to certify anonymity of the participating plants, and is funded by the Nuclear Regulatory Commission

  5. Laser-Based Maintenance and Repair Technologies for Reactor Components

    International Nuclear Information System (INIS)

    Masaki Yoda; Naruhiko Mukai; Makoto Ochiai; Masataka Tamura; Satoshi Okada; Katsuhiko Sato; Motohiko Kimura; Yuji Sano; Noboru Saito; Seishi Shima; Tetsuo Yamamoto

    2004-01-01

    Toshiba has developed various laser-based maintenance and repair technologies and applied them to existing nuclear power plants. Laser-based technology is considered to be the best tool for remote processing in nuclear power plants, and particularly so for the maintenance and repair of reactor core components. Accessibility could be drastically improved by a simple handling system owing to the absence of reactive force against laser irradiation and the flexible optical fiber. For the preventive maintenance, laser peening (LP) technology was developed and applied to reactor components in operating BWR plants. LP is a novel process to improve residual stress from tensile to compressive on material surface layer by irradiating focused high-power laser pulses in water. We have developed a fiber-delivered LP system as a preventive maintenance measure against stress corrosion cracking (SCC). Laser ultrasonic testing (LUT) has a great potential to be applied to the remote inspection of reactor components. Laser-induced surface acoustic wave (SAW) inspection system was developed using a compact probe with a multi-mode optical fiber and an interferometer. The developed system successfully detected a micro slit of 0.5 mm depth on weld metal and heat-affected zone (HAZ). An artificial SCC was also detected by the system. We are developing a new LP system combined with LUT to treat the inner surface of bottom-mounted instruments (BMI) of PWR plants. Underwater laser seal welding (LSW) technology was also developed to apply surface crack. LSW is expected to isolate the crack tip from corrosive water environment and to stop the propagation of the crack. Rapid heating and cooling of the process minimize the heat effect, which extends the applicability to neutron-irradiated material. This paper describes recent advances in the development and application of such laser-based technologies. (authors)

  6. The maintenance optimization of structural components in nuclear power plants

    International Nuclear Information System (INIS)

    Bryla, P.; Ardorino, F.; Aufort, P.; Jacquot, J.P.; Magne, L.; Pitner, P.; Verite, B.; Villain, B.; Monnier, B.

    1997-10-01

    An optimization process, called 'OMF-Structures', is developed by Electricite de France (EDF) in order to extend the current 'OMF' Reliability Centered Maintenance to piping structural components. The Auxiliary Feedwater System of a 900 MW French nuclear plant has been studied in order to lay the foundations of the method. This paper presents the currently proposed principles of the process. The principles of the OMF-Structures process include 'Risk-Based Inspection' concepts within an RCM process. Two main phases are identified: The purpose of the first phase is to select the risk-significant failure modes and associated elements. This phase consists of two major steps: potential consequences evaluation and reliability performance evaluation. The second phase consists of the definition of preventive maintenance programs for piping elements that are associated with risk-significant failure modes. (author)

  7. Condition monitoring a key component in the preventive maintenance

    International Nuclear Information System (INIS)

    Isar, C.

    2006-01-01

    The preventive maintenance programs are necessary to ensure that nuclear safety significant equipment will function when it is supposed to. Diesel generator, pumps, motor operated valves and air operated control valves are typically operated every three months. When you drive a car, you depend on lot of sounds, the feel of the steering wheel and gauges to determine if the car is running correctly. Similarly with operating equipment for a power plant - sounds or vibration of the equipment or the gauges and test equipment indicate a problem or degradation, actions are taken to correct the deficiency. Due to safety and economical reason diagnostic and monitoring systems are of growing interest in all complex industrial production. Diagnostic systems are requested to detect, diagnose and localize faulty operating conditions at an early stage in order to prevent severe failures and to enable predictive and condition oriented maintenance. In this context it is a need for using various on-line and off-line condition monitoring and diagnostics, non-destructive inspection techniques and surveillance. The condition monitoring technique used in nuclear power plant Cernavoda are presented in this paper. The selection of components and parameters to be monitored, monitoring and diagnostics techniques used are incorporated into a preventive maintenance program. Modern measurement technique in combination with advanced computerized data processing and acquisition show new ways in the field of machine surveillance. The diagnostic capabilities of predictive maintenance technologies have increased recently year with advances made in sensor technologies. The paper will focus on the following condition monitoring technique: - oil analysis - acoustic leakage monitoring - thermography - valve diagnostics: motor operated valve, air operated valve and check valve - motor current signature - vibration monitoring and rotating machine monitoring and diagnostics For each condition monitoring

  8. Development of radiation hardness components for ITER remote maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Ito, Akira [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yagi, Toshiaki; Morita, Yousuke

    1998-04-01

    In the ITER, in-vessel remote handling is required to assemble and maintain in-vessel components in DT operations. Since in-vessel remote handling systems must operate under intense gamma ray radiation exceeding 30 kGy/h, their components must have sufficiently high radiation hardness to allow maintenance long enough in ITER in-vessel environments. Thus, extensive radiation tests and quality improvement, including optimization of material compositions, have been conducted through the ITER R and D program to develop radiation hardness components that meet radiation doses from 10 to 100 MGy at 10 kGy/h. This paper presents the latest on radiation hardness component development conducted by the Japan Home Team as a contribution to the ITER. The remote handling components tested are categorized for use in robotic or viewing systems, or as common components. Radiation tests have been conducted on commercially available products for screening, on modified products, and on new products to improve the radiation hardness. (author)

  9. Development of radiation hardness components for ITER remote maintenance

    International Nuclear Information System (INIS)

    Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi; Ito, Akira; Yagi, Toshiaki; Morita, Yousuke

    1998-01-01

    In the ITER, in-vessel remote handling is required to assemble and maintain in-vessel components in DT operations. Since in-vessel remote handling systems must operate under intense gamma ray radiation exceeding 30 kGy/h, their components must have sufficiently high radiation hardness to allow maintenance long enough in ITER in-vessel environments. Thus, extensive radiation tests and quality improvement, including optimization of material compositions, have been conducted through the ITER R and D program to develop radiation hardness components that meet radiation doses from 10 to 100 MGy at 10 kGy/h. This paper presents the latest on radiation hardness component development conducted by the Japan Home Team as a contribution to the ITER. The remote handling components tested are categorized for use in robotic or viewing systems, or as common components. Radiation tests have been conducted on commercially available products for screening, on modified products, and on new products to improve the radiation hardness. (author)

  10. A dynamic predictive maintenance policy for complex multi-component systems

    International Nuclear Information System (INIS)

    Van Horenbeek, Adriaan; Pintelon, Liliane

    2013-01-01

    The use of prognostic methods in maintenance in order to predict remaining useful life is receiving more attention over the past years. The use of these techniques in maintenance decision making and optimization in multi-component systems is however a still underexplored area. The objective of this paper is to optimally plan maintenance for a multi-component system based on prognostic/predictive information while considering different component dependencies (i.e. economic, structural and stochastic dependence). Consequently, this paper presents a dynamic predictive maintenance policy for multi-component systems that minimizes the long-term mean maintenance cost per unit time. The proposed maintenance policy is a dynamic method as the maintenance schedule is updated when new information on the degradation and remaining useful life of components becomes available. The performance, regarding the objective of minimal long-term mean cost per unit time, of the developed dynamic predictive maintenance policy is compared to five other conventional maintenance policies, these are: block-based maintenance, age-based maintenance, age-based maintenance with grouping, inspection condition-based maintenance and continuous condition-based maintenance. The ability of the predictive maintenance policy to react to changing component deterioration and dependencies within a multi-component system is quantified and the results show significant cost savings

  11. Influence of Non-safety Important Component on Maintenance Rule

    International Nuclear Information System (INIS)

    Ju, Tae Young; Kim, Wang Bae

    2016-01-01

    The Maintenance Rule (MR) programs in KHNP have been implemented since Jan 2009. KHNP is currently developing MR program for new built plant which has been constructed from December 2011. It is required to utilize plant-specific probabilistic safety analysis (PSA) result as risk significant criteria to determine which components are significantly important to safety. The criteria consist of three PSA risk values which are risk reduction worth (RRW), risk achievement worth (RAW) and core damage frequency (CDF) contribution. Most safety related components are classified as high risk significant, and non-safety related components as low safety significant in MR program. This paper presents the influence of the non-safety related component which has high PSA risk value on MR program of new built plant. It is considered that safety related system has at least one or more safety functions and some non-safety functions, but non-safety system doesn't have any safety function. The safety functions are defined as three functions which are required to maintain 1) integrity of reactor coolant pressure boundary, 2) capability to shut-down the reactor and maintain it in a safe shutdown, and 3) capability to prevent or mitigate the accident that could result in potential offsite exposure. The Maintenance Rule program is developed based on PSA result. Safety functions have high risk value in PSA program and considered HSS function in MR program. On the contrary, non-safety functions are generally has low risk value in PSA program and they are determined as LSS function in MR program. The AAC DG and its supporting systems are designed as non-safety systems which mean they don't have any safety function. But, AAC DG is treated as an important measure to mitigate accident in PSA program. It is determined as HSS function in MR program because it has high risk value in PSA program. AAC DG supporting systems does not have high risk value in operating plant's PSA program

  12. EBR-II facility for cleaning and maintenance of LMR components

    International Nuclear Information System (INIS)

    Washburn, R.A.

    1986-01-01

    The cleaning and maintenance of EBR-II sodium wetted components is accomplished in a separate hands-on maintenance facility known as the Sodium Components Maintenance Shop (SCMS). Sodium removal is mostly done using alcohol but steam or water is used. The SCMS has three alcohol cleaning systems: one for small nonradioactive components, one for small radioactive components, and one for large radioactive components. The SCMS also has a water-wash station for the removal of sodium with steam or water. An Alcohol Recovery Facility removes radioactive contaminants from the alcohol and reclaims the alcohol for reuse. Associated with the large components cleaning system is a major component handling system

  13. Suitability of Co as an alloy material for components of the primary circuit of HTR reactors

    International Nuclear Information System (INIS)

    Iniotakis, N.

    1977-02-01

    For high temperature reactors it is of interest if Co-alloys could be used for the different components of the primary cooling circuit. It has been investigated in detail to what amount the Co-60 created by neutron activation of Co-59 contained in the material of the components could possibly contribute to the contamination of the primary cooling circuit of the reactor. The result of these investigations is compared with the contamination of the cooling circuit by fission and activation products like Co-137, Cs-134, Ag-11om etc. For pebble bed reactors with an OTTO-type fuel management it could be shown that there is no limitation for the use of cobalt in alloys for materials of the components in the primary cooling circuit. The only boundary condition is that the local Thermal Flux at the position of the components should be less than phisub(th) 7 n/cm 2 . sec. (orig.) [de

  14. Voltage-Mode All-Pass Filters Including Minimum Component Count Circuits

    Directory of Open Access Journals (Sweden)

    Sudhanshu Maheshwari

    2007-01-01

    Full Text Available This paper presents two new first-order voltage-mode all-pass filters using a single-current differencing buffered amplifier and four passive components. Each circuit is compatible to a current-controlled current differencing buffered amplifier with only two passive elements, thus resulting in two more circuits, which employ a capacitor, a resistor, and an active element, thus using a minimum of active and passive component counts. The proposed circuits possess low output impedance, and hence can be easily cascaded for voltage-mode systems. PSPICE simulation results are given to confirm the theory.

  15. Development of large components for the fusion reactor vacuum circuits

    International Nuclear Information System (INIS)

    Perinic, D.; Lorrain, C.

    1986-06-01

    The Commission of the European Communities appointed in mid-1983 the Centre d'Etudes Nucleaires de Saclay and the Kernforschungszentrum Karlsruhe GmbH to investigate whether large vacuum components for use in the fusion machine can be built. The following individual targets have been defined for studies under this project: - Elaboration of technical specifications for large components. - Investigation of the feasibility. - Specification of the tests required and planning of a testing facility. The plasma chamber pumping system is essentially concerned

  16. NPP component maintenance and life management in Russia

    International Nuclear Information System (INIS)

    Tutnov, I.; Lyssakov, V.

    2002-01-01

    This report represents the conceptual strategies (ideas) on life management programs for nuclear power plants. Use of the optimum programs for NPP's NDE, maintenance service, operation and service life can provide the best economic benefit for the utilities. The paper presents general approaches to life management, maintenance service, and risks of operating and service life of NPPs in Russia. The report offers some optimized ways for the solution of these important tasks

  17. On Different Maintenance Strategies for Casted Components of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Ambühl, Simon; Sørensen, John Dalsgaard

    . This maintenance tool uses Crude Monte Carlo Simulations to estimate the expected maintenance costs. Corrective and preventive maintenance strategies with a constant inspection interval or a condition monitoring system are considered. Furthermore, transportation from shore to the wind turbines by boat...... and transportation strategy. The case study shows that the maintenance expenses of casted components correspond to roughly 5% of the overall expected maintenance costs when using a corrective maintenance strategy. This amount can be decreased to roughly 2% when using a condition monitoring system and following...

  18. Current status of research and development on remote maintenance for fusion components

    International Nuclear Information System (INIS)

    Takeda, Nobukazu; Kakudate, Satoshi; Nakahira, Masataka; Shibanuma, Kiyoshi

    2008-01-01

    There is a growing attention to remote maintenance of nuclear fusion reactors. Remote maintenance is planned in ITER tokamak to keep the health of in-vessel components like blankets and divertors. In this article, current status of the development in the remote maintenance equipments and methods, especially for ITER tokamak are reviewed. The newly developed vehicle type and boom type maintenance devices, manipulator, and transfer cask are illustrated. (J.P.N.)

  19. Maintenance Management Support Systems for component aging estimation at nuclear power plants

    International Nuclear Information System (INIS)

    Shimizu, Shunichi; Ando, Yasumasa; Morioka, Toshihiko; Okuzumi, Naoaki

    1991-01-01

    Maintenance Management Support Systems (MMSSs) for nuclear power plants have been developed using component aging estimation methods and decision tree analysis for maintenance planning. The former evaluates actual component reliability through statistical analysis on field maintenance data. The latter provides preventive maintenance (PM) planning guidance using heuristic expert knowledge and estimated reliability parameters. The following aspects have been investigated: (1) A systematic and effective method of managing components/parts design information and field maintenance data (2) A method for estimating component aging based on a statistical analysis of field maintenance data (3) A method for providing PM planning guidance using estimated component reliability/performance parameters and decision tree analysis. Based on these investigations, two MMSSs were developed. One deals with 'general maintenance data', which are common to all component types and are amenable to common data handling. The other system deals with 'specific maintenance data', which are specific to an individual component type. Both systems provide PM planning guidance for PM cycles propriety and the PM work priority. The function of these systems were verified using simulated maintenance data. (author)

  20. Component-Based Data-Driven Predictive Maintenance to Reduce Unscheduled Maintenance Events

    NARCIS (Netherlands)

    Verhagen, W.J.C.; Curran, R.; de Boer, L.W.M.; Chen, C.H.; Trappey, A.C.; Peruzzini, M.; Stjepandić, J.; Wognum, N.

    2017-01-01

    Costs associated with unscheduled and preventive maintenance can contribute significantly to an airline's expenditure. Reliability analysis can help to identify and plan for maintenance events. Reliability analysis in industry is often limited to statistically based

  1. Stochastic Simulation of Integrated Circuits with Nonlinear Black-Box Components via Augmented Deterministic Equivalents

    Directory of Open Access Journals (Sweden)

    MANFREDI, P.

    2014-11-01

    Full Text Available This paper extends recent literature results concerning the statistical simulation of circuits affected by random electrical parameters by means of the polynomial chaos framework. With respect to previous implementations, based on the generation and simulation of augmented and deterministic circuit equivalents, the modeling is extended to generic and ?black-box? multi-terminal nonlinear subcircuits describing complex devices, like those found in integrated circuits. Moreover, based on recently-published works in this field, a more effective approach to generate the deterministic circuit equivalents is implemented, thus yielding more compact and efficient models for nonlinear components. The approach is fully compatible with commercial (e.g., SPICE-type circuit simulators and is thoroughly validated through the statistical analysis of a realistic interconnect structure with a 16-bit memory chip. The accuracy and the comparison against previous approaches are also carefully established.

  2. Maintenance of the electrical and electronic components and quality assurance

    International Nuclear Information System (INIS)

    Foletto, A.

    1992-01-01

    Quality assurance in the area of maintenance must satisfy certain requirements which concern the materials to be replaced, the working and requalification documentation and the qualifications of the persons carrying out the work. The test systems described in the last section of this article have a dual aim - quality of the work and reduced duration. tabs

  3. Estimation of component redundancy in optimal age maintenance

    OpenAIRE

    Siopa, Jorge; Garção, José; Silva, Júlio

    2012-01-01

    The classical Optimal Age-Replacement defines the maintenance strategy based on the equipment failure consequences. For severe consequences an early equipment replacement is recommended. For minor consequences the repair after failure is proposed. One way of reducing the failure consequences is the use of redundancies, especially if the equipment failure rate is decreasing over time, since in this case the preventive replacement does not reduce the risk of failure. The estimation of an ac...

  4. Neural circuit components of the Drosophila OFF motion vision pathway.

    Science.gov (United States)

    Meier, Matthias; Serbe, Etienne; Maisak, Matthew S; Haag, Jürgen; Dickson, Barry J; Borst, Alexander

    2014-02-17

    Detecting the direction of visual motion is an essential task of the early visual system. The Reichardt detector has been proven to be a faithful description of the underlying computation in insects. A series of recent studies addressed the neural implementation of the Reichardt detector in Drosophila revealing the overall layout in parallel ON and OFF channels, its input neurons from the lamina (L1→ON, and L2→OFF), and the respective output neurons to the lobula plate (ON→T4, and OFF→T5). While anatomical studies showed that T4 cells receive input from L1 via Mi1 and Tm3 cells, the neurons connecting L2 to T5 cells have not been identified so far. It is, however, known that L2 contacts, among others, two neurons, called Tm2 and L4, which show a pronounced directionality in their wiring. We characterized the visual response properties of both Tm2 and L4 neurons via Ca(2+) imaging. We found that Tm2 and L4 cells respond with an increase in activity to moving OFF edges in a direction-unselective manner. To investigate their participation in motion vision, we blocked their output while recording from downstream tangential cells in the lobula plate. Silencing of Tm2 and L4 completely abolishes the response to moving OFF edges. Our results demonstrate that both cell types are essential components of the Drosophila OFF motion vision pathway, prior to the computation of directionality in the dendrites of T5 cells. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A condition-based maintenance policy for multi-component systems with a high maintenance setup cost

    NARCIS (Netherlands)

    Zhu, Q.; Peng, H.; Houtum, van G.J.J.A.N.

    2015-01-01

    Condition-based maintenance (CBM) is becoming increasingly important due to the development of advanced sensor and information technology, which facilitates the remote collection of condition data. We propose a new CBM policy for multi-component systems with continuous stochastic deteriorations. To

  6. A condition-based maintenance policy for multi-component systems with a high maintenance setup cost

    NARCIS (Netherlands)

    Zhu, Q.; Peng, H.; Houtum, van G.J.J.A.N.

    2012-01-01

    Condition-based maintenance (CBM) is becoming increasingly important due to the development of advanced sensor and ICT technology, so that the condition data can be collected remotely. We propose a new CBM policy for multi-component systems with continuous stochastic deteriorations. To reduce the

  7. Detection of circuit-board components with an adaptive multiclass correlation filter

    Science.gov (United States)

    Diaz-Ramirez, Victor H.; Kober, Vitaly

    2008-08-01

    A new method for reliable detection of circuit-board components is proposed. The method is based on an adaptive multiclass composite correlation filter. The filter is designed with the help of an iterative algorithm using complex synthetic discriminant functions. The impulse response of the filter contains information needed to localize and classify geometrically distorted circuit-board components belonging to different classes. Computer simulation results obtained with the proposed method are provided and compared with those of known multiclass correlation based techniques in terms of performance criteria for recognition and classification of objects.

  8. In-service inspection of electronics components, circuits and nuclear radiation detectors

    International Nuclear Information System (INIS)

    Darbhe, M.D.

    2002-01-01

    A nuclear reactor is a complex process plant. Like a nuclear power plant, the research reactors also employ various nuclear and process systems, the scope and number of such systems being plant-specific. In-service inspection of these systems is an important requirement and is applied at various levels of their constituent units such as detectors, electronics components, circuits and integrated systems. The sensors used cover a wide range such as neutronic, radiation, process (pressure, temperature, flow, level) and many others. The present discussion is limited to neutronic and radiation detectors. The electronic components used normally consist of passive components like resistors, capacitors, semiconductor components like diodes, transistors, analog integrated circuits and digital integrated circuits and electromagnetic relays, to name a few. In order to have a comprehensive surveillance and ISI plan, over the entire plant life, it is necessary to understand various mechanisms, which degrade the performance of these systems. These are discussed initially and later various ISI methods that are used on component-circuit or system level, to ensure optimum system performance, are discussed. The computerised systems, because of hardware and software considerations, have to be given special attention, and the same are discussed briefly

  9. Development of radiation hard components for remote maintenance

    International Nuclear Information System (INIS)

    Oka, Kiyoshi; Obara, Kenjiro; Kakudate, Satoshi; Tominaga, Ryuichiro; Akada, Tamio; Morita, Hirosuke.

    1997-01-01

    In International Thermonuclear Experimental Reactor (ITER), in-vessel remote-handling is inevitably required to assemble and maintain activated in-vessel components due to D-T operation. The components of the in-vessel remote-handling system must have sufficient radiation hardness to allow for operation under an intense gamma-ray radiation of over 30 kGy/h for periods up to more than 1,000 hours. To this end, extensive irradiation tests and quality improvements including the optimization of material composition have been conducted through the ITER R and D program in order to develop radiation hard components which satisfy radiation doses from 10 MGy to 100 MGy at the dose rate of 10 kGy/h. This paper outlines the latest status of the radiation hard component development that has been conducted as the Japan Home Team's contribution to ITER. The remote-handling components tested are categorized into either robotics, viewing systems or common components. The irradiation tests include commercial base products for screening both modified and newly developed products to improve their radiation hardness. (author)

  10. Irradiation of electronic components and circuits at the Portuguese Research Reactor: Lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Marques, J.G.; Ramos, A.R.; Fernandes, A.C.; Santos, J.P. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS (Portugal)

    2015-07-01

    The behavior of electronic components and circuits under radiation is a concern shared by the nuclear industry, the space community and the high-energy physics community. Standard commercial components are used as much as possible instead of radiation hard components, since they are easier to obtain and allow a significant reduction of costs. However, these standard components need to be tested in order to determine their radiation tolerance. The Portuguese Research Reactor (RPI) is a 1 MW pool-type reactor, operating since 1961. The irradiation of electronic components and circuits is one area where a 1 MW reactor can be competitive, since the fast neutron fluences required for testing are in most cases well below 10{sup 16} n/cm{sup 2}. A program was started in 1999 to test electronics components and circuits for the LHC facility at CERN, initially using a dedicated in-pool irradiation device and later a beam line with tailored neutron and gamma filters. Neutron filters are essential to reduce the intensity of the thermal neutron flux, which does not produce significant defects in electronic components but produces unwanted radiation from activation of contacts and packages of integrated circuits and also of the printed circuit boards. In irradiations performed within the line-of-sight of the core of a fission reactor there is simultaneous gamma radiation which complicates testing in some cases. Filters can be used to reduce its importance and separate testing with a pure gamma radiation source can contribute to clarify some irradiation results. Practice has shown the need to introduce several improvements to the procedures and facilities over the years. We will review improvements done in the following areas: - Optimization of neutron and gamma filters; - Dosimetry procedures in mixed neutron / gamma fields; - Determination of hardness parameter and 1 MeV-equivalent neutron fluence; - Temperature measurement and control during irradiation; - Follow-up of reactor

  11. Influence of the secondary circuit chemistry on the characteristics of the filmed carbon steel components

    International Nuclear Information System (INIS)

    Radulescu, M.; Pirvan, I.; Dinu, A.; Fulger, M.; Lucan, D.; Anghel, C.

    2001-01-01

    Some correlations are established between the characteristics of the superficial films formed on the carbon steel components in some operation conditions of a secondary circuit from Nuclear Power Station (NPS), and the specific parameters of the aqueous environment in which these films were formed. The main parameters studied, specific to a secondary circuit environment, are: the value of pH and the substances used to regulate it and, respectively, the oxygen concentration dissolved in the aqueous environment. These filmed samples by autoclaving were studied by: X rays diffraction method; metallographic microscopy and electrochemical methods such as: potentiodynamic and electrochemical impedance spectroscopy (E.I.S.). (R.P.)

  12. Assembling surface mounted components on ink-jet printed double sided paper circuit board

    International Nuclear Information System (INIS)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Sidén, Johan; Nilsson, Hans-Erik; Hummelgård, Magnus; Olin, Håkan; Hummelgård, Christine

    2014-01-01

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed. (paper)

  13. Assembling surface mounted components on ink-jet printed double sided paper circuit board.

    Science.gov (United States)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Hummelgård, Magnus; Sidén, Johan; Hummelgård, Christine; Olin, Håkan; Nilsson, Hans-Erik

    2014-03-07

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed.

  14. Assembling surface mounted components on ink-jet printed double sided paper circuit board

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Henrik A; Manuilskiy, Anatoliy; Haller, Stefan; Sidén, Johan; Nilsson, Hans-Erik [Department of Electronics Design, Mid Sweden University, SE-851 70 Sundsvall (Sweden); Hummelgård, Magnus; Olin, Håkan [Department of Natural Science, Mid Sweden University, SE-851 70 Sundsvall (Sweden); Hummelgård, Christine [Acreo Swedish ICT AB, Håstaholmen 4, SE-824 42 Hudiksvall (Sweden)

    2014-03-07

    Printed electronics is a rapidly developing field where many components can already be manufactured on flexible substrates by printing or by other high speed manufacturing methods. However, the functionality of even the most inexpensive microcontroller or other integrated circuit is, at the present time and for the foreseeable future, out of reach by means of fully printed components. Therefore, it is of interest to investigate hybrid printed electronics, where regular electrical components are mounted on flexible substrates to achieve high functionality at a low cost. Moreover, the use of paper as a substrate for printed electronics is of growing interest because it is an environmentally friendly and renewable material and is, additionally, the main material used for many packages in which electronics functionalities could be integrated. One of the challenges for such hybrid printed electronics is the mounting of the components and the interconnection between layers on flexible substrates with printed conductive tracks that should provide as low a resistance as possible while still being able to be used in a high speed manufacturing process. In this article, several conductive adhesives are evaluated as well as soldering for mounting surface mounted components on a paper circuit board with ink-jet printed tracks and, in addition, a double sided Arduino compatible circuit board is manufactured and programmed. (paper)

  15. Preventive maintenance optimization for a multi-component system under changing job shop schedule

    International Nuclear Information System (INIS)

    Zhou Xiaojun; Lu Zhiqiang; Xi Lifeng

    2012-01-01

    Variability and small lot size is a common feature for many discrete manufacturing processes designed to meet a wide array of customer needs. Because of this, job shop schedule often has to be continuously updated in reaction to changes in production plan. Generally, the aim of preventive maintenance is to ensure production effectiveness and therefore the preventive maintenance models must have the ability to be adaptive to changes in job shop schedule. In this paper, a dynamic opportunistic preventive maintenance model is developed for a multi-component system with considering changes in job shop schedule. Whenever a job is completed, preventive maintenance opportunities arise for all the components in the system. An optimal maintenance practice is dynamically determined by maximizing the short-term cumulative opportunistic maintenance cost savings for the system. The numerical example shows that the scheme obtained by the proposed model can effectively address the preventive maintenance scheduling problem caused by the changes in job shop schedule and is more efficient than the ones based on two other commonly used preventive maintenance models.

  16. Optimization of the preventive maintenance plan of a series components system

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Jose A. Caldeira [Mathematical Department, Instituto Politecnico de Setubal/Escola Superior de Tecnologia de Setubal, Campus do IPS, Estefanilha, 2914-508 Setubal (Portugal)]. E-mail: jduarte@est.ips.pt; Craveiro, Joao C. Taborda A. [MIIT, Manutencao Industrial Informatizada e Tecnologia, Lda, Av. Elias Garcia, 123, 5o, Lisbon (Portugal); Trigo, Tomas Pedro [MIIT, Manutencao Industrial Informatizada e Tecnologia, Lda, Av. Elias Garcia, 123, 5o, Lisbon (Portugal)

    2006-04-15

    One of the most critical problems in preventive maintenance is the determination of the optimum frequency to perform preventive maintenance in equipment, in order to ensure its availability. In this paper, we propose an algorithm to solve the previous problem for equipment that exhibit linearly increasing hazard rate and constant repair rate. Based on this algorithm, we have developed another one to solve the problem of maintenance management of a series system based on preventive maintenance over the different system components. We assume that all components of the system still exhibit linearly increasing hazard rate and constant repair rate and that preventive maintenance would bring the system to the as good as new condition. We define a cost function for maintenance tasks (preventive and corrective) for the system. The algorithm calculates the interval of time between preventive maintenance actions for each component, minimizing the costs, and in such a way that the total downtime, in a certain period of time, does not exceed a predetermined value.

  17. Components of the LWR primary circuit. Pt. 2. Komponenten des Primaerkreises von Leichtwasserreaktoren. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673 K (400/sup 0/C). The primary circuit as the pressure containment of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives.

  18. Components of the LWR primary circuit. Pt. 2. Design, construction and calculation. Draft

    International Nuclear Information System (INIS)

    1995-01-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673 K (400 deg C). The primary circuit as the pressure containment of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives. (orig.) [de

  19. Chemistry of the aqueous medium - Determining factor of corrosion in carbon steel components of secondary circuit

    International Nuclear Information System (INIS)

    Radulescu, M.; Pirvan, I.; Dinu, A.; Velciu, L.

    2003-01-01

    The interplay of chemistry of aqueous medium and corrosion processes followed by deposition and/or release of corrosion products determines both formation and growth of superficial films as well as the kinetics of ion release from materials into the aqueous medium. Material corrosion in the secondary circuit of a NPP can be minimized by choosing the materials of the components and by a rigorous inspection of the chemistry of aqueous agent. The chemical inspection helps in minimizing: - the corrosion of the components immersed in feedwater and vapor and of Steam Generator components; - 'dirtying' of the systems particularly of the surfaces implied in heat transfer; - the amount of insoluble chemical species resulting in corrosion process and carried along the circuit; - the corrosion of secondary circuit components during revisions or outages. An important role among the chemical parameters of the fluids circulated in NPP tubing appears to be the pH. In CANDU reactors it must be kept within the range of 8.7 to 9.4 by treating the medium with volatile amines (morpholine and cyclohexylamine). A plot is presented giving the corrosion rate of carbon steels as a function of the pH of the medium. Besides, the oxygen concentration dissolved in the aqueous medium must be maintained under 5 μg per water kg. Other factors determining the corrosion rates are also discussed. The paper gives the results of the experiments done with various materials, solutions and analysis methods

  20. A condition-based maintenance policy for multi-component systems with Lévy copulas dependence

    International Nuclear Information System (INIS)

    Li, Heping; Deloux, Estelle; Dieulle, Laurence

    2016-01-01

    In this paper, we propose a new condition-based maintenance policy for multi-component systems taking into account stochastic and economic dependences. The stochastic dependence between components due to common environment is modelled by Lévy copulas. Its influence on the maintenance optimization is investigated with different dependence degrees. On the issue of economic dependence providing opportunities to group maintenance activities, a new maintenance decision rule is proposed which permits maintenance grouping. In order to evaluate the performance of the proposed maintenance policy, we compare it to the classical maintenance policies. - Highlights: • A new adaptive maintenance policy for grouping maintenance actions is proposed. • The impacts of both economic and stochastic dependences are investigated. • The performance of the proposed maintenance policy is evaluated under different system configurations. • The stochastic dependence is modelled by Lévy copulas. • The proposed maintenance decision rule can take full advantage of economic and stochastic dependences.

  1. Circuit card failures and industry mitigation strategy

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, U. [Candu Owners Group, Toronto, Ontario (Canada)

    2012-07-01

    In recent years the nuclear industry has experienced an increase in circuit card failures due to ageing of components, inadequate Preventive Maintenance (PM), lack of effective circuit card health monitoring, etc. Circuit card failures have caused loss of critical equipment, e.g., electro hydraulic governors, Safety Systems, resulting in loss of function and in some cases loss of generation. INPO completed a root cause analysis of 40 Reactor Trips/Scrams in US reactors and has recommended several actions to mitigate Circuit Card failures. Obsolescence of discrete components has posed many challenges in conducting effective preventative maintenance on circuit cards. In many cases, repairs have resulted in installation of components that compromise performance of the circuit cards. Improper termination and worn edge connectors have caused intermittent contacts contributing to circuit card failures. Traditionally, little attention is paid to relay functions and preventative maintenance of relay. Relays contribute significantly to circuit card failures and have dominated loss of generation across the power industry. The INPO study recommended a number of actions to mitigate circuit card failures, such as; identification of critical components and single point vulnerabilities; strategic preventative maintenance; protection of circuit boards against electrostatic discharge; limiting power cycles; performing an effective burn-in prior to commissioning of the circuit cards; monitoring performance of DC power supplies; limiting cabinet temperatures; managing of component aging/degradation mechanism, etc. A subcommittee has been set up under INPO sponsorship to understand the causes of circuit card failure and to develop an effective mitigation strategy. (author)

  2. Maintenance grouping strategy for multi-component systems with dynamic contexts

    International Nuclear Information System (INIS)

    Vu, Hai Canh; Do, Phuc; Barros, Anne; Bérenguer, Christophe

    2014-01-01

    This paper presents a dynamic maintenance grouping strategy for multi-component systems with both “positive” and “negative” economic dependencies. Positive dependencies are commonly due to setup cost whereas negative dependencies are related to shutdown cost. Actually, grouping maintenance activities can save part of the setup cost, but can also in the same time increase the shutdown cost. Until now, both types of dependencies have been jointly taken into account only for simple system structures as pure series. The first aim of this paper is to investigate the case of systems with any combination of basic structures (series, parallel or k-out-of n structures). A cost model and a heuristic optimization scheme are proposed since the optimization of maintenance grouping strategy for such multi-component systems leads to a NP-complete problem. Then the second objective is to propose a finite horizon (dynamic) model in order to optimize online the maintenance strategy in the presence of dynamic contexts (change of the environment, the working condition, the production process, etc). A numerical example of a 16-component system is finally introduced to illustrate the use and the advantages of the proposed approach in the maintenance optimization framework. - Highlights: • A dynamic grouping maintenance strategy for complex structure systems is proposed. • Impacts of the system structure on grouping maintenance are investigated. • A grouping approach based on the rolling horizon and GA algorithm is proposed. • Different dynamic contexts and their impacts on grouping maintenance are studied. • The proposed approach can help to update the maintenance planning in dynamic contexts

  3. Field analysis and enhancement of multi-pole magnetic components fabricated on printed circuit board

    International Nuclear Information System (INIS)

    Chiu, K.-C.; Chen, C.-S.

    2007-01-01

    A multi-pole magnetic component magnetized with a fine magnetic pole pitch of less than 1 mm is very difficult to achieve by using traditional methods. Moreover, it requires a precise mechanical process and a complicated magnetization system. Different fine magnetic pole pitches of 300, 350 and 400 μm have been accomplished on 9-pole magnetic components through the printed circuit board (PCB) manufacturing technology. Additionally, another fine magnetic pole pitch of 500 μm was also fabricated on a dual-layered (DL) wire circuit structure to investigate the field enhancement. After measurements, a gain factor of 1.37 was obtained in the field strength. The field variations among different magnetic pole pitches were analyzed in this paper

  4. Control-limit preventive maintenance policies for components subject to imperfect preventive maintenance and variable operational conditions

    International Nuclear Information System (INIS)

    You Mingyi; Li Hongguang; Meng Guang

    2011-01-01

    This paper develops two component-level control-limit preventive maintenance (PM) policies for systems subject to the joint effect of partial recovery PM acts (imperfect PM acts) and variable operational conditions, and investigates the properties of the proposed policies. The extended proportional hazards model (EPHM) is used to model the system failure likelihood influenced by both factors. Several numerical experiments are conducted for policy property analysis, using real lifetime and operational condition data and typical characterization of imperfect PM acts and maintenance durations. The experimental results demonstrate the necessity of considering both factors when they do exist, characterize the joint effect of the two factors on the performance of an optimized PM policy, and explore the influence of the loading sequence of time-varying operational conditions on the performance of an optimized PM policy. The proposed policies extend the applicability of PM optimization techniques.

  5. 30 CFR 75.1508 - Training and records for examination, maintenance and repair of refuge alternatives and components.

    Science.gov (United States)

    2010-07-01

    ... repair, the person conducting the maintenance or repair shall make a record of all corrective action..., maintenance and repair of refuge alternatives and components. 75.1508 Section 75.1508 Mineral Resources MINE..., maintenance and repair of refuge alternatives and components. (a) Persons examining, maintaining, or repairing...

  6. An approach to integrating surveillance and maintenance tasks to prevent the dominant failure causes of critical components

    International Nuclear Information System (INIS)

    Martorell, S.; Munoz, A.; Serradell, V.

    1995-01-01

    Surveillance requirements and maintenance activities in a nuclear power plant aim to preserve components' inherent reliability. Up to now, predictive and preventive maintenance mainly concerned plant staff, but the US Nuclear Regulatory Commission Maintenance Rule released in July 1991 will have significant impact on how nuclear power plants perform and document this maintenance. Reliability Centered Maintenance (RCM) is a systematic methodology to establish maintenance tasks for critical components in plant with a high degree of compliance with the goals of the Rule. RCM pursues the identification of applicable and efficient tasks to prevent these components from developing their dominant failure causes, and, in turn, towards achieving proper levels of components availability with low cost. In this paper, we present an approach for identifying the most suitable set of tasks to achieve this goal, which involves the integration of maintenance activities and surveillance requirements for each critical component based on the unavailability and cost associated with each individual task which is performed on it

  7. Performance of Water Recirculation Loop Maintenance Components for the Advanced Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Rector, Tony; Peyton, Barbara M.; Steele, John W.; Makinen, Janice; Bue, Grant C.; Campbell, Colin

    2014-01-01

    Water loop maintenance components to maintain the water quality of the Advanced Spacesuit Water Membrane Evaporation (SWME) water recirculation loop have undergone a comparative performance evaluation with a second SWME water recirculation loop with no water quality maintenance. Results show the benefits of periodic water maintenance. The SWME is a heat rejection device under development at the NASA Johnson Space Center to perform thermal control for advanced spacesuits. One advantage to this technology is the potential for a significantly greater degree of tolerance to contamination when compared to the existing Sublimator technology. The driver for the evaluation of water recirculation maintenance components was to further enhance this advantage through the leveraging of fluid loop management lessons learned from the International Space Station (ISS). A bed design that was developed for a UTAS military application, and considered for a potential ISS application with the Urine Processor Assembly, provided a low pressure drop means for water maintenance in a recirculation loop. The bed design is coupled with high capacity ion exchange resins, organic adsorbents, and a cyclic methodology developed for the Extravehicular Mobility Unit (EMU) Transport Water loop. The maintenance cycle included the use of a biocide delivery component developed for ISS to introduce a biocide in a microgravity compatible manner for the Internal Active Thermal Control System (IATCS). The leveraging of these water maintenance technologies to the SWME recirculation loop is a unique demonstration of applying the valuable lessons learned on the ISS to the next generation of manned spaceflight Environmental Control and Life Support System (ECLSS) hardware.

  8. Methods for designing building envelope components prepared for repair and maintenance

    DEFF Research Database (Denmark)

    Rudbeck, Claus Christian

    2000-01-01

    the deterministic and probabilistic approach. Based on an investigation of the data-requirement, user-friendliness and supposed accuracy (the accuracy of the different methods has not been evaluated due to the absence of field data) the method which combines the deterministic factor method with statistical...... to be prepared for repair and maintenance. Both of these components are insulation systems for flat roofs and low slope roofs; components where repair or replacement is very expensive if the roofing material fails in its function. The principle of both roofing insulation systems is that the insulation can...... of issues which are specified below:Further development of methods for designing building envelope components prepared for repair and maintenance, and ways of tracking and predicting performance through time once the components have been designed, implemented in a building design and built...

  9. A review of multi-component maintenance models with economic dependence

    NARCIS (Netherlands)

    R. Dekker (Rommert); R.E. Wildeman (Ralph); F.A. van der Duyn Schouten (Frank)

    1997-01-01

    textabstractIn this paper we review the literature on multi-component maintenance models with economic dependence. The emphasis is on papers that appeared after 1991, but there is an overlap with Section 2 of the most recent review paper by Cho and Parlar (1991). We distinguish between stationary

  10. A model for determining condition-based maintenance policies for deteriorating multi-component systems

    NARCIS (Netherlands)

    Hontelez, J.A.M.; Wijnmalen, D.J.D.

    1993-01-01

    We discuss a method to determine strategies for preventive maintenance of systems consisting of gradually deteriorating components. A model has been developed to compute not only the range of conditions inducing a repair action, but also inspection moments based on the last known condition value so

  11. Control of Series Resonant Converter with Robust Performance Against Load and Power Circuit Components Uncertainties

    Directory of Open Access Journals (Sweden)

    A. Mohammadpour

    2009-12-01

    Full Text Available Robust performance controller design for duty-cycle controlled series resonant converter (SRC is proposed in this paper. The uncertainties of the converter are analyzed with load variation and power circuit components tolerances are taken into consideration. Additionally, a nominal performance (NP controller is designed. Closed-loop system is simulated with Orcad and simulation results of robust controller are compared with nominal performance controller. Although nominal performance controller has better performance for nominal plant, the robust performance controller is advantageous in dealing with uncertainties.

  12. On risk-based operation and maintenance of offshore wind turbine components

    DEFF Research Database (Denmark)

    Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

    2011-01-01

    Operation and maintenance are significant contributors to the cost of energy for offshore wind turbines. Optimal planning could rationally be based on Bayesian pre-posterior decision theory, and all costs through the lifetime of the structures should be included. This paper contains a study...... of a generic case where the costs are evaluated for a single wind turbine with a single component. Costs due to inspections, repairs, and lost production are included in the model. The costs are compared for two distinct maintenance strategies, namely with and without inclusion of periodic imperfect...

  13. The right maintenance on the right components, at the right time, with the right parts: maintaining high plant reliability through an effective maintenance program

    International Nuclear Information System (INIS)

    Von Hatten, P.

    2008-01-01

    The objective of the maintenance program at a Nuclear Power Plant is to be proactive and prevent unexpected failures of equipment that can impact on Nuclear or Conventional Safety and Plant Production. This does not mean that all equipment failures will be prevented; in a number of cases the most cost effective solution is to allow equipment to run to failure. Deciding what components are critical to the plant is the first step. The industry uses guidance from INPO Advanced Process, AP913, to classify components as Critical, Non Critical or Run to Failure based on the consequence of the failure. Once this is complete, then the right maintenance program needs to be specified. This is done through utilization of experience from the industry based on the type of component. Maintenance strategies and templates have been produced for most power plant components. Each station or fleet needs then to apply the criteria, with exceptions as required, to determine the maintenance requirements and frequency for their components. This includes predictive and preventative maintenance. The more critical the component is the more rigorous the maintenance requirements. Once the maintenance program is defined it can be implemented. This requires that the Preventative Maintenance (PM's) are updated to ensure the correct tasks are in place and the frequency is correct. Work Management will group the PM's so they can scheduled efficiently and to minimize equipment down time. The last element is to ensure that the required parts are specified and are stocked or readily available for the maintenance when it is scheduled. This is an ongoing effort since components become obsolete or suppliers go out of business or change hands. (author)

  14. Analyses of component degradation to evaluate maintenance effectiveness and aging effects

    International Nuclear Information System (INIS)

    Samanta, P.K.; Hsu, F.; Subudhi, M.; Vesely, W.E.

    1991-01-01

    This paper describes degradation modeling, an approach for analyzing degradation and failure of components to understand the aging process of components. As used in our study, degradation modeling is the analysis of information on degradation of components for developing models of the degradation process and its implications. This modeling focuses on the analysis of the times of degradations of components, to model how the rate of degradation changes with the age of the component. With this methodology we also determine the effectiveness of maintenance as applicable to aging evaluations. The specific applications which are performed show quantitative models of degradation rates of components and failure rates of components from plant-specific data. The statistical techniques allow aging trends to be identified in the degradation data and in the failure data. Initial estimates of the effectiveness of maintenance in limiting degradations from becoming failures are developed. These results are important first steps in degradation modeling, and show that degradation can be modeled to identify aging trends. 2 refs., 8 figs., 1 tab

  15. A maintenance policy for a system with multi-state components: an approximate solution

    International Nuclear Information System (INIS)

    Guerler, Uelkue; Kaya, Alev

    2002-01-01

    For maintenance and quality assessment purposes, various performance levels for both systems and components are identified, usually as a function of the deterioration. In this study, we consider a multicomponent system where the lifetime of each component is described by several stages, (0,...,S), which are further classified as good, doubtful, preventive maintenance due (PM due) and down. A control policy is suggested where the system is replaced when a component enters a PM due or a down state and the number of components in the doubtful states (K,...,S-2) is at least N. All maintenance activities are assumed to take negligible time. The exact description of the underlying stochastic model under the policy is very complicated. We therefore propose some approximations, which allow an explicit expression for the long run average cost function, which is minimized w.r.t. (K,N) by numerical methods. Sensitivity of the model to system parameters and the performance of the approximation are investigated through several examples

  16. Maintenance service for major component of PWR plant. Replacement of pressurizer safe end weld

    International Nuclear Information System (INIS)

    Miyoshi, Yoshiyuki; Kobayashi, Yuki; Yamamoto, Kazuhide; Ueda, Takeshi; Suda, Naoki; Shintani, Takashi

    2017-01-01

    In October 2016, MHI completed the replacement of safe end weld of pressurizer (Pz) of Ringhals unit 3, which was the first maintenance work for main component of pressurized water reactor (PWR) plant in Europe. For higher reliability and longer lifetime of PWR plant, MHI has conducted many kinds of maintenance works of main components of PWR plants in Japan against stress corrosion cracking due to aging degradation. Technical process for replacement of Pz safe end weld were established by MHI. MHI has experienced the work for 21 PWR units in Japan. That of Ringhals unit 3 was planned and conducted based on the experiences. In this work, Alloy 600 used for welds of nozzles of Pz was replaced with Alloy 690. Alloy 690 is more corrosive-resistant than Alloy 600. Specially designed equipment and technical process were developed and established by MHI to replace safe end weld of Pz and applied for the Ringhals unit 3 as a first application in Europe. The application had been performed in success and achieved the planned replacement work duration and total radiation dose by using sophisticated machining and welding equipment designed to meet the requirements to be small, lightweight and remote-controlled and operating by well skilled MHI personnel experienced in maintenance activities for major components of PWR plant in Japan. The success shows that the experience, activities and technology developed in Japan for main components of PWR plant shall be applicable to contribute reliable operations of nuclear power plants in Europe and other countries. (author)

  17. Determining optimal preventive maintenance interval for component of Well Barrier Element in an Oil & Gas Company

    Science.gov (United States)

    Siswanto, A.; Kurniati, N.

    2018-04-01

    An oil and gas company has 2,268 oil and gas wells. Well Barrier Element (WBE) is installed in a well to protect human, prevent asset damage and minimize harm to the environment. The primary WBE component is Surface Controlled Subsurface Safety Valve (SCSSV). The secondary WBE component is Christmas Tree Valves that consist of four valves i.e. Lower Master Valve (LMV), Upper Master Valve (UMV), Swab Valve (SV) and Wing Valve (WV). Current practice on WBE Preventive Maintenance (PM) program is conducted by considering the suggested schedule as stated on manual. Corrective Maintenance (CM) program is conducted when the component fails unexpectedly. Both PM and CM need cost and may cause production loss. This paper attempts to analyze the failure data and reliability based on historical data. Optimal PM interval is determined in order to minimize the total cost of maintenance per unit time. The optimal PM interval for SCSSV is 730 days, LMV is 985 days, UMV is 910 days, SV is 900 days and WV is 780 days. In average of all components, the cost reduction by implementing the suggested interval is 52%, while the reliability is improved by 4% and the availability is increased by 5%.

  18. Password Based Distribution Panel and Circuit Breaker Operation for the Safety of Lineman during Maintenance Work

    OpenAIRE

    Hudedmani, Mallikarjun G; Ummannanavar, Nitin; Mudaliar, Mani Dheeraj; Sooji, Chandana; Bogar, Mala

    2017-01-01

    Security is the prime concern in our day to day life while performing any activity. In the current scenario, accidental death of lineman is often read and evidenced. In this direction, a safety measure to safe guard the operator is found very necessary looking into the present working style. The electric lineman safety system is designed to control the control panel doors and circuit breaker by using a password for the safety. Critical electrical accidents to lineman are on the rise during el...

  19. Pressurized and radioactivity-containing components of systems outside the primary circuit. Pt. 1

    International Nuclear Information System (INIS)

    1990-01-01

    This document lays down the requirements on: a) Organisations involved in manufacturing; b) manufacture of materials and moulds, their chemical composition, mechanical and engineering properties, physical properties, heat treatment and further machining; c) verification procedures and controls for the achievement and maintenance of specified quality standards for materials and moulds, plus destructive and non-destructive testing; d) the provision of documents for the documentary files on test results. The following components fall under the remit of this rule: a) pressure vessel, b) piping and pipe sections/fittings, c) pumps, d) valves. (orig./HP) [de

  20. Pressurized and radioactivity-containing components of systems outside the primary circuit. Pt. 1

    International Nuclear Information System (INIS)

    1991-01-01

    This document lays down the requirements on: a) Organisations involved in manufacturing; b) Manufacture of materials and moulds, their chemical composition, mechanical and engineering properties, physical properties, heat treatment and further machining; c) Verification procedures and controls for the achievement and maintenance of specified quality standards for materials and moulds, plus destructive and non-destructive testing; d) The provision of documents for the documentary files on test results. The following components fall under the remit of this rule: a) pressure vessel, b) piping and pipe sections/fittings, c) pumps, d) valves. (orig.) [de

  1. Automatic ultrasonic pre-service, and in-service inspection of pressurized components of the primary circuit of nuclear power stations

    International Nuclear Information System (INIS)

    Muller, G.P.; Hallermeier, L.; Heinrich, D.; Grabendorfer, W.; Rebrmann, M.

    1985-01-01

    Ultrasonic pre-service and especially in-service inspection activities on the primary circuit of nuclear power stations form an essential part of the maintenance work that must be performed throughout the lifetime to ensure plant integrity. Consequently, the equipment required to carry out these inspections must be continuously improved in respect of reliability, safety, accuracy and ease of handling in order to minimize disturbances and repairs and reduce radiation exposure of the personnel. The authors' discussion of technique, equipment and performance of automated ultrasonic inspection is based on 15 years of experience in the testing of components of the primary circuit in nuclear power stations. To cover all inspection areas of the RPV of a PWR, four different manipulators are required, two for the closure head, one for the studs and one for the cylindrical shell and bottom closure. The use of the newly developed equipment, which naturally meets all the recommendations of the licensing authorities, allows for the automatic inspection of the components of primary circuit of nuclear power stations and the thus helps to substantially decrease the radiation exposure of the personnel. All the manipulators and their control consoles were designed and manufactured by M.A.N., Nuremberg while the ultrasonic electronic system was developed by Krautkramer, Cologne

  2. A multi-level maintenance policy for a multi-component and multifailure mode system with two independent failure modes

    International Nuclear Information System (INIS)

    Zhu, Wenjin; Fouladirad, Mitra; Bérenguer, Christophe

    2016-01-01

    This paper studies the maintenance modelling of a multi-component system with two independent failure modes with imperfect prediction signal in the context of a system of systems. Each individual system consists of multiple series components and the failure modes of all the components are divided into two classes due to their consequences: hard failure and soft failure, where the former causes system failure while the later results in inferior performance (production reduction) of system. Besides, the system is monitored and can be alerted by imperfect prediction signal before hard failure. Based on an illustration example of offshore wind farm, in this paper three maintenance strategies are considered: periodic routine, reactive and opportunistic maintenance. The periodic routine maintenance is scheduled at fixed period for each individual system in the perspective of system of systems. Between two successive routine maintenances, the reactive maintenance is instructed by the imperfect prediction signal according to two criterion proposed in this study for the system components. Due to the high setup cost and practical restraints of implementing maintenance activities, both routine and reactive maintenance can create the opportunities of maintenance for the other components of an individual system. The life cycle of the system and the cost of the proposed maintenance policies are analytically derived. Restrained by the complexity from both the system failure modelling and maintenance strategies, the performances and application scope of the proposed maintenance model are evaluated by numerical simulations. - Highlights: • We study the life behavior of a complex system with two failure modes. • We consider the imperfect prediction signal of potential failure by monitoring. • We propose an integrated maintenance policy with three levels based on wind turbine. • We derive the mathematical cost formulations for the proposed maintenance policy.

  3. Quality Control Activities Related to Mechanical Maintenance of Safety Related Components at Krsko NPP

    International Nuclear Information System (INIS)

    Djakovic, D.

    2016-01-01

    For successful, safe and reliable operation of nuclear power plant, maintenance processes have to be systematically controlled and procedures for quality control of maintenance activities shall be established. This is requested by the quality assurance program, which shall provide control over activities affecting the quality of structures, systems, and components, considering their importance to safety. As a part of Quality and Nuclear Oversight Division (QNOD; SKV), the Quality Control Department (QC) provides quality control activities, which are deeply involved in maintenance processes at Krsko NPP, both on safety related and non-safety related (non-nuclear safety) components. QC activities on safety related components have to fulfil all requirements, which will enable the components to perform their intended safety functions. This paper describes quality control activities related to mechanical maintenance of safety related components at Krsko NPP and significant role of the Krsko plant QC Department in three particular maintenance cases connected with safety related components. In these three specific cases, the QC has confirmed its importance in compliance with quality assurance program and presented its significant added value in providing safe and reliable operation of the plant. The first maintenance activity was installation of nozzle check valves in the scope of a modification for improving regulation of spent fuel pit pumps. The QC Department performed receipt inspection of the valves. Using non-destructive examination methods and X-ray spectrometry, it was found out that the valve diffuser was made of improper material, which could cause progressive corrosion of the valve diffuser in borated water and consequently a loss of safety function of the valves followed by long-term consequences. The second one was the receipt inspection of containment ventilation fan coolers. The coolers were claimed and sent back to the supplier because the QC Department

  4. Influence of hydrazine primary water chemistry on corrosion of fuel cladding and primary circuit components

    International Nuclear Information System (INIS)

    Iourmanov, V.; Pashevich, V.; Bogancs, J.; Tilky, P.; Schunk, J.; Pinter, T.

    1999-01-01

    Earlier at Paks 1-4 NPP standard ammonia chemistry was in use. The following station performance indicators were improved when hydrazine primary water chemistry was introduced: occupational radiation exposures of personnel; gamma-radiation dose rates near primary system components during refuelling and maintenance outages. The reduction of radiation exposures and radiation fields were achieved without significant expenses. Recent results of experimental studies allowed to explain the mechanism of hydrazine dosing influence on: corrosion rate of structure materials in primary coolant; behaviour of soluble and insoluble corrosion products including long-life corrosion-induced radionuclides in primary system during steady-state and transient operation modes; radiolytic generation of oxidising radiolytic products in core and its corrosion activity in primary system; radiation situation during refuelling and maintenance outages; foreign material degradation and removal (including corrosion active oxidant species) from primary system during abnormal events. Operational experience and experimental data have shown that hydrazine primary water chemistry allows to reduce corrosion wear and thereby makes it possible to extend the life-time of plant components in primary system. (author)

  5. Musical molecules: the molecular junction as an active component in audio distortion circuits

    Science.gov (United States)

    Bergren, Adam Johan; Zeer-Wanklyn, Lucas; Semple, Mitchell; Pekas, Nikola; Szeto, Bryan; McCreery, Richard L.

    2016-03-01

    Molecular junctions that have a non-linear current-voltage characteristic consistent with quantum mechanical tunneling are demonstrated as analog audio clipping elements in overdrive circuits widely used in electronic music, particularly with electric guitars. The performance of large-area molecular junctions fabricated at the wafer level is compared to currently standard semiconductor diode clippers, showing a difference in the sound character. The harmonic distributions resulting from the use of traditional and molecular clipping elements are reported and discussed, and differences in performance are noted that result from the underlying physics that controls the electronic properties of each clipping component. In addition, the ability to tune the sound using the molecular junction is demonstrated. Finally, the hybrid circuit is compared to an overdriven tube amplifier, which has been the standard reference electric guitar clipped tone for over 60 years. In order to investigate the feasibility of manufacturing molecular junctions for use in commercial applications, devices are fabricated using a low-density format at the wafer level, where 38 dies per wafer, each containing two molecular junctions, are made with exceptional non-shorted yield (99.4%, representing 718 out of 722 tested devices) without requiring clean room facilities.

  6. Musical molecules: the molecular junction as an active component in audio distortion circuits

    International Nuclear Information System (INIS)

    Bergren, Adam Johan; Zeer-Wanklyn, Lucas; Pekas, Nikola; Szeto, Bryan; McCreery, Richard L; Semple, Mitchell

    2016-01-01

    Molecular junctions that have a non-linear current–voltage characteristic consistent with quantum mechanical tunneling are demonstrated as analog audio clipping elements in overdrive circuits widely used in electronic music, particularly with electric guitars. The performance of large-area molecular junctions fabricated at the wafer level is compared to currently standard semiconductor diode clippers, showing a difference in the sound character. The harmonic distributions resulting from the use of traditional and molecular clipping elements are reported and discussed, and differences in performance are noted that result from the underlying physics that controls the electronic properties of each clipping component. In addition, the ability to tune the sound using the molecular junction is demonstrated. Finally, the hybrid circuit is compared to an overdriven tube amplifier, which has been the standard reference electric guitar clipped tone for over 60 years. In order to investigate the feasibility of manufacturing molecular junctions for use in commercial applications, devices are fabricated using a low-density format at the wafer level, where 38 dies per wafer, each containing two molecular junctions, are made with exceptional non-shorted yield (99.4%, representing 718 out of 722 tested devices) without requiring clean room facilities. (paper)

  7. Maintenance implications of critical components in ITER CXRS upper port plug design

    International Nuclear Information System (INIS)

    Koning, Jarich; Jaspers, Roger; Doornink, Jan; Ouwehand, Bernard; Klinkhamer, Friso; Snijders, Bart; Sadakov, Sergey; Heemskerk, Cock

    2009-01-01

    Already in the early phase of a design for ITER, the maintenance aspects should be taken into account, since they might have serious implications. This paper presents the arguments in support of the case for the maintainability of the design, notably if this maintenance is to be performed by advanced remote methods. This structure is compliant to the evolving maintenance strategy of ITER. Initial results of a Failure Mode Effects and Criticality Analysis (FMECA) and a development risk analysis for the ITER upper port plug no. 3, housing the Charge Exchange Recombination Spectroscopy (CXRS) diagnostic, are employed for the definition of the maintenance strategy. The CXRS upper port plug is essentially an optical system which transfers visible light from the plasma into a fiber bundle. The most critical component in this path is the first mirror (M1) whose reflectivity degrades during operation due to deposition and/or erosion dominated effects. Amongst other measures to mitigate these effects, the strategy is to allow for a replacement of this mirror. Therefore it is mounted on a retractable central tube. The main purpose of this tube is to make frequent replacements possible without hindering operation. The maintenance method in terms of time, geometry and spare part policy has a large impact on cost of the system and time usage in the hot cell. Replacement of the tube under vacuum and magnetic field seems infeasible due to the operational risk involved. The preferred solution is to have a spare tube available which is replaced in parallel with other maintenance operations on the vessel, as to avoid any interference in the hot cell with the shutdown scheduling. This avoids having to refurbish a full port plug and also allows for a more frequent replacement of M1, as we can replace the mirror anytime the vacuum vessel is vented, estimated to be once a year.

  8. Optimal condition-based maintenance decisions for systems with dependent stochastic degradation of components

    International Nuclear Information System (INIS)

    Hong, H.P.; Zhou, W.; Zhang, S.; Ye, W.

    2014-01-01

    Components in engineered systems are subjected to stochastic deterioration due to the operating environmental conditions, and the uncertainty in material properties. The components need to be inspected and possibly replaced based on preventive or failure replacement criteria to provide the intended and safe operation of the system. In the present study, we investigate the influence of dependent stochastic degradation of multiple components on the optimal maintenance decisions. We use copula to model the dependent stochastic degradation of components, and formulate the optimal decision problem based on the minimum expected cost rule and the stochastic dominance rules. The latter is used to cope with decision maker's risk attitude. We illustrate the developed probabilistic analysis approach and the influence of the dependency of the stochastic degradation on the preferred decisions through numerical examples

  9. Enrichment of the metallic components from waste printed circuit boards by a mechanical separation process using a stamp mill

    International Nuclear Information System (INIS)

    Yoo, Jae-Min; Jeong, Jinki; Yoo, Kyoungkeun; Lee, Jae-chun; Kim, Wonbaek

    2009-01-01

    Printed circuit boards incorporated in most electrical and electronic equipment contain valuable metals such as Cu, Ni, Au, Ag, Pd, Fe, Sn, and Pb. In order to employ a hydrometallurgical route for the recycling of valuable metals from printed circuit boards, a mechanical pre-treatment step is needed. In this study, the metallic components from waste printed circuit boards have been enriched using a mechanical separation process. Waste printed circuit boards shredded to 5.0 mm. The fractions of milled printed circuit boards of size 5.0 mm fraction and the heavy fraction were subjected to two-step magnetic separation. Through the first magnetic separation at 700 Gauss, 83% of the nickel and iron, based on the whole printed circuit boards, was recovered in the magnetic fraction, and 92% of the copper was recovered in the non-magnetic fraction. The cumulative recovery of nickel-iron concentrate was increased by a second magnetic separation at 3000 Gauss, but the grade of the concentrate decreased remarkably from 76% to 56%. The cumulative recovery of copper concentrate decreased, but the grade increased slightly from 71.6% to 75.4%. This study has demonstrated the feasibility of the mechanical separation process consisting of milling/size classification/gravity separation/two-step magnetic separation for enriching metallic components such as Cu, Ni, Al, and Fe from waste printed circuit boards

  10. Mechanization devices for maintenance of technological components of nuclear power plant primary circuit

    International Nuclear Information System (INIS)

    Palicka, L.; Blazek, J.

    1987-01-01

    Selected mechanization devices are described, developed for assembly and repair jobs and for decontamination of the steam generator, the main closing valve and the main circulating pump of a WWER-440 nuclear power plant. (author). 8 figs., 3 tabs., 10 refs

  11. On risk-based operation and maintenance of offshore wind turbine components

    International Nuclear Information System (INIS)

    Jessen Nielsen, Jannie; Dalsgaard Sorensen, John

    2011-01-01

    Operation and maintenance are significant contributors to the cost of energy for offshore wind turbines. Optimal planning could rationally be based on Bayesian pre-posterior decision theory, and all costs through the lifetime of the structures should be included. This paper contains a study of a generic case where the costs are evaluated for a single wind turbine with a single component. Costs due to inspections, repairs, and lost production are included in the model. The costs are compared for two distinct maintenance strategies, namely with and without inclusion of periodic imperfect inspections. Finally the influence of different important parameters, e.g. failure rate, reliability of inspections, inspection interval, and decision rule for repairs, is evaluated.

  12. Two Independent Mushroom Body Output Circuits Retrieve the Six Discrete Components of Drosophila Aversive Memory

    Directory of Open Access Journals (Sweden)

    Emna Bouzaiane

    2015-05-01

    Full Text Available Understanding how the various memory components are encoded and how they interact to guide behavior requires knowledge of the underlying neural circuits. Currently, aversive olfactory memory in Drosophila is behaviorally subdivided into four discrete phases. Among these, short- and long-term memories rely, respectively, on the γ and α/β Kenyon cells (KCs, two distinct subsets of the ∼2,000 neurons in the mushroom body (MB. Whereas V2 efferent neurons retrieve memory from α/β KCs, the neurons that retrieve short-term memory are unknown. We identified a specific pair of MB efferent neurons, named M6, that retrieve memory from γ KCs. Moreover, our network analysis revealed that six discrete memory phases actually exist, three of which have been conflated in the past. At each time point, two distinct memory components separately recruit either V2 or M6 output pathways. Memory retrieval thus features a dramatic convergence from KCs to MB efferent neurons.

  13. Utilisation of symmetrical components in a communication-based protection for loop MV feeders with variable short-circuit power

    DEFF Research Database (Denmark)

    Ciontea, Catalin-Iosif; Bak, Claus Leth; Blaabjerg, Frede

    2018-01-01

    -circuit power is presented. It relies on utilisation of symmetrical components of the short-circuit currents and on communication between the protection relays. The proposed method addresses the Single Phase to Ground (SPG) faults occurring in directly grounded distribution networks, with focus on closed......Variability of the available short-circuit power also implies variation of the fault level, which can potentially cause several protection problems in the electric networks. In this paper, a novel protection method that is insensitive to the fault level changes caused by variable short......-loop Medium Voltage (MV) feeders. Case studies are presented, which demonstrate that the proposed protection scheme is capable of effectively detecting the SPG faults in closed-loop feeders with variable short-circuit power....

  14. Reliability-based optimization of maintenance scheduling of mechanical components under fatigue

    Science.gov (United States)

    Beaurepaire, P.; Valdebenito, M.A.; Schuëller, G.I.; Jensen, H.A.

    2012-01-01

    This study presents the optimization of the maintenance scheduling of mechanical components under fatigue loading. The cracks of damaged structures may be detected during non-destructive inspection and subsequently repaired. Fatigue crack initiation and growth show inherent variability, and as well the outcome of inspection activities. The problem is addressed under the framework of reliability based optimization. The initiation and propagation of fatigue cracks are efficiently modeled using cohesive zone elements. The applicability of the method is demonstrated by a numerical example, which involves a plate with two holes subject to alternating stress. PMID:23564979

  15. Active component modeling for analog integrated circuit design. Model parametrization and implementation in the SPICE-PAC circuit simulator

    International Nuclear Information System (INIS)

    Marchal, Xavier

    1992-01-01

    In order to use CAD efficiently in the analysis and design of electronic Integrated circuits, adequate modeling of active non-linear devices such as MOSFET transistors must be available to the designer. Many mathematical forms can be given to those models, such as explicit relations, or implicit equations to be solved. A major requirement in developing MOS transistor models for IC simulation is the availability of electrical characteristic curves over a wide range of channel width and length, including the sub-micrometer range. To account in a convenient way for bulk charge influence on I_D_S = f(V_D_S, V_G_S, v_B_S) device characteristics, all 3 standard SPICE MOS models use an empirical fitting parameter called the 'charge sharing factor'. Unfortunately, this formulation produces models which only describe correctly either some of the short channel phenomena, or some particular operating conditions (low injection, avalanche effect, etc.). We present here a cellular model (CDM = Charge Distributed Model) implemented in the open modular SPICE-PAC Simulator; this model is derived from the 4-terminal WANG charge controlled MOSFET model, using the charge sheet approximation. The CDM model describes device characteristics in ail operating regions without introducing drain current discontinuities and without requiring a 'charge sharing factor'. A usual problem to be faced by designers when they simulate MOS ICs is to find a reliable source of model parameters. Though most models have a physical basis, some of their parameters cannot be easily estimated from physical considerations. It can also happen that physically determined parameters values do not produce a good fit to measured device characteristics. Thus it is generally necessary to extract model parameters from measured transistor data, to ensure that model equations approximate measured curves accurately enough. Model parameters extraction can be done in 2 different ways, exposed in this thesis. The first

  16. On the optimal scheduling of periodic tests and maintenance for reliable redundant components

    International Nuclear Information System (INIS)

    Courtois, Pierre-Jacques; Delsarte, Philippe

    2006-01-01

    Periodically, some m of the n redundant components of a dependable system may have to be taken out of service for inspection, testing or preventive maintenance. The system is then constrained to operate with lower (n-m) redundancy and thus with less reliability during these periods. However, more frequent periodic inspections decrease the probability that a component fail undetected in the time interval between successive inspections. An optimal time schedule of periodic preventive operations arises from these two conflicting factors, balancing the loss of redundancy during inspections against the reliability benefits of more frequent inspections. Considering no other factor than this decreased redundancy at inspection time, this paper demonstrates the existence of an optimal interval between inspections, which maximizes the mean time between system failures. By suitable transformations and variable identifications, an analytic closed form expression of the optimum is obtained for the general (m, n) case. The optimum is shown to be unique within the ranges of parameter values valid in practice; its expression is easy to evaluate and shown to be useful to analyze and understand the influence of these parameters. Inspections are assumed to be perfect, i.e. they cause no component failure by themselves and leave no failure undetected. In this sense, the optimum determines a lowest bound for the system failure rate that can be achieved by a system of n-redundant components, m of which require for inspection or maintenance recurrent periods of unavailability of length t. The model and its general closed form solution are believed to be new . Previous work had computed optimal values for an estimation of a time average of system unavailability, but by numerical procedures only and with different numerical approximations, other objectives and model assumptions (one component only inspected at a time), and taking into account failures caused by testing itself, repair and

  17. Anticipation of maintenance of EDF nuclear power plants: the studying of the feasibility of big components repair or replacement

    International Nuclear Information System (INIS)

    Dubreuil Chambardel, A.

    2001-01-01

    Maintaining the technical-economic performance of nuclear power stations is in the first place provided by standard preventive maintenance. These are operations of test, monitoring or maintenance performed periodically on the components, providing the guarantee of a level of safety and availability of the NPPs at the lowest possible cost. To this standard maintenance is added exceptional maintenance which covers important operations of maintenance to be performed (generally only once) on a large number of units, the achievement of which may have a strong impact in terms of resources and availability. As an example can be quoted replacement of steam generators. The second level of anticipation of maintenance consists of having a prospective vision of major degradations which could affect components, of identifying exceptional operations of maintenance which should ''probably'' be performed some day, and of making certain that measures are taken in order that, if needed, their implementation affects as little as possible the performance of the EDF nuclear power stations. EDF has developed these two levels of anticipation since the onset of running its NPPs. However it has turned out to be necessary to intensify the preceding actions in particular with regard to the possibilities to repair or replace components, by identifying as completely as possible the equipment which could create problems and by assessing the interest to implement solutions with a view of making the best use of allocated resources. (author)

  18. Anticipation of maintenance of EDF nuclear power plants: the studying of the feasibility of big components repair or replacement

    Energy Technology Data Exchange (ETDEWEB)

    Dubreuil Chambardel, A. [Electricite de France (EDF), Div. Production Nucleaire, 93 - Saint-Denis (France)

    2001-07-01

    Maintaining the technical-economic performance of nuclear power stations is in the first place provided by standard preventive maintenance. These are operations of test, monitoring or maintenance performed periodically on the components, providing the guarantee of a level of safety and availability of the NPPs at the lowest possible cost. To this standard maintenance is added exceptional maintenance which covers important operations of maintenance to be performed (generally only once) on a large number of units, the achievement of which may have a strong impact in terms of resources and availability. As an example can be quoted replacement of steam generators. The second level of anticipation of maintenance consists of having a prospective vision of major degradations which could affect components, of identifying exceptional operations of maintenance which should ''probably'' be performed some day, and of making certain that measures are taken in order that, if needed, their implementation affects as little as possible the performance of the EDF nuclear power stations. EDF has developed these two levels of anticipation since the onset of running its NPPs. However it has turned out to be necessary to intensify the preceding actions in particular with regard to the possibilities to repair or replace components, by identifying as completely as possible the equipment which could create problems and by assessing the interest to implement solutions with a view of making the best use of allocated resources. (author)

  19. Disassembly and physical separation of electric/electronic components layered in printed circuit boards (PCB).

    Science.gov (United States)

    Lee, Jaeryeong; Kim, Youngjin; Lee, Jae-chun

    2012-11-30

    Although printed circuit boards (PCBs) contain various elements, only the major elements (i.e., those with content levels in wt% or over grade) of and precious metals (e.g., Ag, Au, and platinum groups) contained within PCBs can be recycled. To recover other elements from PCBs, the PCBs should be properly disassembled as the first step of the recycling process. The recovery of these other elements would be beneficial for efforts to conserve scarce resources, reuse electric/electronic components (EECs), and eliminate environmental problems. This paper examines the disassembly of EECs from wasted PCBs (WPCBs) and the physical separation of these EECs using a self-designed disassembling apparatus and a 3-step separation process of sieving, magnetic separation, and dense medium separation. The disassembling efficiencies were evaluated by using the ratio of grinding area (E(area)) and the weight ratio of the detached EECs (E(weight)). In the disassembly treatment, these efficiencies were improved with an increase of grinder speed and grinder height. 97.7% (E(area)) and 98% (E(weight)) could be accomplished ultimately by 3 repetitive treatments at a grinder speed of 5500 rpm and a grinder height of 1.5mm. Through a series of physical separations, most groups of the EECs (except for the diode, transistor, and IC chip groups) could be sorted at a relatively high separation efficiency of about 75% or more. To evaluate the separation efficiency with regard to the elemental composition, the distribution ratio (R(dis)) and the concentration ratio (R(conc)) were used. 15 elements could be separated with the highest R(dis) and R(conc) in the same separated division. This result implies that the recyclability of the elements is highly feasible, even though the initial content in EECs is lower than several tens of mg/kg. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Fabrication of nuclear ship reactor MRX model and study on inspection and maintenance of components

    International Nuclear Information System (INIS)

    Kasahara, Yoshiyuki; Nakazawa, Toshio; Kusunoki, Tsuyoshi; Takahashi, Hiroki; Yoritsune, Tsutomu.

    1997-10-01

    The MRX (Marine Reactor X) is an integral type small reactor adopting passive safety systems. As for an integral type reactor, primary system components are installed in the reactor vessel. It is therefor important to establish the appropriate procedure for construction, inspection and maintenance, dismauntling, etc., for all components in the reactor vessel as well as in the reactor containment, because inspection space is limited. To study these subjects, a one-fifth model of the MRX was fabricated and operation capabilities were studied. As a result of studies, the following results are obtained. (1) Manufacturing and installing problems of the reactor pressure vessel, the containment vessel and internal components are basically not abserved. (2) Heat transfer tube structures of the steam generator and the heat exchangers of emergency decay heat removal system and containment water cooler were not seen of any problem for fabrication. However, due consideration is required in the detailed design of supports of heat transfer tubes. (3) Further studies should be needed for designs of flange penetrations and leak countermeasures for pipes instrument cables. (4) Arrangements of equipments in the containment should be taken in consideration in detail because the space is narrow. (5) Further discussion is required for installation methods of instruments and cables. (author)

  1. Review of Maintenance and Repair Times for Components in Technological Facilities

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader

    2012-11-01

    This report is a compilation of some unique component repair time data and it also presents citations of more extensive reports where lists of repair times can be found. This collection of information should support analysts who seek to quantify maintainability and availability of high technology and nuclear energy production systems. While there are newer sources of repair time information, most, if not all, of the newer sources are proprietary and cannot be shared. This report offers data that, while older, is openly accessible and can serve as reasonable estimates of repair times, at least for initial studies. Some times were found for maintenance times in radiation environments, and some guidance for multiplicative factors to use to account for work in contamination areas.

  2. Components of the primary circuit of LWRs. Design, construction and calculation. Komponenten des Primaerkreises von Leichtwasserreaktoren. Auslegung, Konstruktion und Berechnung

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673 K (400 C). The primary circuit as the pressure containment of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives.

  3. Design and test of component circuits of an integrated quantum voltage noise source for Johnson noise thermometry

    International Nuclear Information System (INIS)

    Yamada, Takahiro; Maezawa, Masaaki; Urano, Chiharu

    2015-01-01

    Highlights: • We demonstrated RSFQ digital components of a new quantum voltage noise source. • A pseudo-random number generator and variable pulse number multiplier are designed. • Fabrication process is based on four Nb wiring layers and Nb/AlOx/Nb junctions. • The circuits successfully operated with wide dc bias current margins, 80–120%. - Abstract: We present design and testing of a pseudo-random number generator (PRNG) and a variable pulse number multiplier (VPNM) which are digital circuit subsystems in an integrated quantum voltage noise source for Jonson noise thermometry. Well-defined, calculable pseudo-random patterns of single flux quantum pulses are synthesized with the PRNG and multiplied digitally with the VPNM. The circuit implementation on rapid single flux quantum technology required practical circuit scales and bias currents, 279 junctions and 33 mA for the PRNG, and 1677 junctions and 218 mA for the VPNM. We confirmed the circuit operation with sufficiently wide margins, 80–120%, with respect to the designed bias currents.

  4. Design and test of component circuits of an integrated quantum voltage noise source for Johnson noise thermometry

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Takahiro, E-mail: yamada-takahiro@aist.go.jp [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568 (Japan); Maezawa, Masaaki [Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568 (Japan); Urano, Chiharu [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology, Central 3, Umezono 1-1-1, Tsukuba, Ibaraki 305-8563 (Japan)

    2015-11-15

    Highlights: • We demonstrated RSFQ digital components of a new quantum voltage noise source. • A pseudo-random number generator and variable pulse number multiplier are designed. • Fabrication process is based on four Nb wiring layers and Nb/AlOx/Nb junctions. • The circuits successfully operated with wide dc bias current margins, 80–120%. - Abstract: We present design and testing of a pseudo-random number generator (PRNG) and a variable pulse number multiplier (VPNM) which are digital circuit subsystems in an integrated quantum voltage noise source for Jonson noise thermometry. Well-defined, calculable pseudo-random patterns of single flux quantum pulses are synthesized with the PRNG and multiplied digitally with the VPNM. The circuit implementation on rapid single flux quantum technology required practical circuit scales and bias currents, 279 junctions and 33 mA for the PRNG, and 1677 junctions and 218 mA for the VPNM. We confirmed the circuit operation with sufficiently wide margins, 80–120%, with respect to the designed bias currents.

  5. Guidelines for remote handling maintenance of ITER neutral beam line components: Proposal of an alternate supporting system

    International Nuclear Information System (INIS)

    Cordier, J.J.; Bayetti, P.; Hemsworth, R.; David, O.; Friconneau, J.P.

    2007-01-01

    Remote handling (R/H) maintenance of ITER components is one of the main challenges of the ITER project. This type of maintenance shall be operational for the assembly and nuclear phase of exploitation of ITER. It must be considered at a very early stage since it significantly impacts on the components design, interfaces management, assembly, maintenance and integration aspects. A large part of the R/H equipment will be procured by the EU Participating Team, including the whole Neutral Beam R/H Equipment. The Neutral Beam Heating and Current Drive system (NB and CD) design is being revisited by the ITER project. A vertical maintenance scheme is presently considered which may significantly impact on the reference design and associated components and lead to a new design of the NB and CD vacuum tank. In addition, NB line components remote handling solutions are being studied. The neutral beam test facility ITER to be built in Europe in the near future is also based on the vertical NB maintenance scheme of beam line components. New design guidelines compliant for both the ITER NB and CD system and the NB test facility proposed by the CEA association are described in the paper

  6. New Role of Thermal Mapping in Winter Maintenance with Principal Components Analysis

    Directory of Open Access Journals (Sweden)

    Mario Marchetti

    2014-01-01

    Full Text Available Thermal mapping uses IR thermometry to measure road pavement temperature at a high resolution to identify and to map sections of the road network prone to ice occurrence. However, measurements are time-consuming and ultimately only provide a snapshot of road conditions at the time of the survey. As such, there is a need for surveys to be restricted to a series of specific climatic conditions during winter. Typically, five to six surveys are used, but it is questionable whether the full range of atmospheric conditions is adequately covered. This work investigates the role of statistics in adding value to thermal mapping data. Principal components analysis is used to interpolate between individual thermal mapping surveys to build a thermal map (or even a road surface temperature forecast, for a wider range of climatic conditions than that permitted by traditional surveys. The results indicate that when this approach is used, fewer thermal mapping surveys are actually required. Furthermore, comparisons with numerical models indicate that this approach could yield a suitable verification method for the spatial component of road weather forecasts—a key issue currently in winter road maintenance.

  7. The Plateau de Bure ASTEP Platform Test in natural radiation environment of electronic components and circuits

    International Nuclear Information System (INIS)

    Autran, J.L.; Munteanu, D.; Sauze, S.; Roche, Ph.; Gasiot, G.; Borel, J.

    2010-01-01

    Reducing the size of microelectronic devices and increasing the integration density of circuits lead (following the famous Moore's law) to an increased sensitivity of circuits to natural terrestrial radiation environment. - Such sensitivity to atmospheric particles (mainly neutrons) can cause non-destructive (soft-errors) or destructive (latch-up) failures in most electronic circuits, including volatile static memories (SRAM), object of the research work carried out since 2004 on the European Test Platform ASTER. - This paper presents in details the ASTEP platform, its location, the instruments (neutron monitor of the Plateau de Bure) and the experiences (memory tester) currently installed on the Plateau de Bure. In a second part, we also report a synthesis of the key results concerning the natural radiation sensitivity of SRAM fabricated in 130 nm and 65 nm bulk silicon technologies. (authors)

  8. Maintenance and manipulation of information in schizophrenia: further evidence for impairment in the central executive component of working memory.

    Science.gov (United States)

    Kim, Junghoon; Glahn, David C; Nuechterlein, Keith H; Cannon, Tyrone D

    2004-06-01

    Impairments in working memory (WM) have been proposed to underlie various cognitive and functional impairments in schizophrenia. However, the nature and extent of the dysfunction remain unclear. The present study attempted to examine the integrity of sub-components of working memory in schizophrenia within the framework of the multiple-component working memory model proposed by Baddeley. Two sets of visuospatial and verbal delayed-response tasks were developed which had comparable formats and difficulties across domains. In Experiment 1, demands on the central executive (CE) were manipulated by requiring subjects either (1) to simultaneously maintain and transform information (maintenance-and-manipulation condition) or (2) just to maintain this information (maintenance-only condition). In Experiment 2, the amount of information to be maintained over the delay was parametrically varied to evaluate demands on the temporary maintenance component of working memory. Patients (N=16) performed worse than controls (N=16) in both conditions of Experiment 1; however, simultaneous maintenance and manipulation was associated with a significantly greater performance reduction in the patients. In Experiment 2, both patients (N=15) and controls (N=15) declined in performance, at equivalent rates, with increasing memory load. Parallel findings were observed for the verbal and visuospatial tasks. These results suggest that while both maintenance and central executive aspects of working memory are impaired in schizophrenic patients, the central executive may be more severely affected.

  9. Study of a simplified method of evaluating the economic maintenance importance of components in nuclear power plant system

    International Nuclear Information System (INIS)

    Aoki, Takayuki; Takagi, Toshiyuki; Kodama, Noriko

    2014-01-01

    Safety risk importance of components in nuclear power plants has been evaluated based on the probabilistic risk assessment and used for the decisions in various plant managements. But economic risk importance of the components has not been discussed very much. Therefore, this paper discusses risk importance of the components from the viewpoint of plant economic efficiency and proposes a simplified evaluation method of the economic risk importance (or economic maintenance importance). As a result of consideration, the followings were obtained. (1) A unit cost of power generation is selected as a performance indicator and can be related to a failure rate of components in nuclear power plant which is a result of maintenance. (2) The economic maintenance importance has to major factors, i.e. repair cost at component failure and production loss associated with plant outage due to component failure. (3) The developed method enables easy understanding of economic impacts of plant shutdown or power reduction due to component failures on the plane which adopts the repair cost in vertical axis and the production loss in horizontal axis. (author)

  10. Micro-coolers fabricated as a component in an integrated circuit

    International Nuclear Information System (INIS)

    Glover, James; Oxley, Chris H; Khalid, Ata; Cumming, David; Stephen, Alex; Dunn, Geoff

    2015-01-01

    The packing density and power capacity of integrated electronics is increasing resulting in higher thermal flux densities. Improved thermal management techniques are required and one approach is to include thermoelectric coolers as part of the integrated circuit. An analysis will be described showing that the supporting substrate will have a large influence on the cooling capacity of the thermoelectric cooler. In particular, for materials with a low ZT figure of merit (for example gallium arsenide (GaAs) based compounds) the substrate will have to be substantially thinned to obtain cooling, which may preclude the use of thermoelectric coolers, for example, as part of a GaAs based integrated circuit. Further, using experimental techniques to measure only the small positive cooling temperature difference (ΔT) between the anode (T h ) and the cathode (T c ) contacts can be misinterpreted as cooling when in fact it is heating. (paper)

  11. Integrated circuits and molecular components for stress and feeding: implications for eating disorders.

    Science.gov (United States)

    Hardaway, J A; Crowley, N A; Bulik, C M; Kash, T L

    2015-01-01

    Eating disorders are complex brain disorders that afflict millions of individuals worldwide. The etiology of these diseases is not fully understood, but a growing body of literature suggests that stress and anxiety may play a critical role in their development. As our understanding of the genetic and environmental factors that contribute to disease in clinical populations like anorexia nervosa, bulimia nervosa and binge eating disorder continue to grow, neuroscientists are using animal models to understand the neurobiology of stress and feeding. We hypothesize that eating disorder clinical phenotypes may result from stress-induced maladaptive alterations in neural circuits that regulate feeding, and that these circuits can be neurochemically isolated using animal model of eating disorders. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  12. Design and characterization of integrated components for SiN photonic quantum circuits.

    Science.gov (United States)

    Poot, Menno; Schuck, Carsten; Ma, Xiao-Song; Guo, Xiang; Tang, Hong X

    2016-04-04

    The design, fabrication, and detailed calibration of essential building blocks towards fully integrated linear-optics quantum computation are discussed. Photonic devices are made from silicon nitride rib waveguides, where measurements on ring resonators show small propagation losses. Directional couplers are designed to be insensitive to fabrication variations. Their offset and coupling lengths are measured, as well as the phase difference between the transmitted and reflected light. With careful calibrations, the insertion loss of the directional couplers is found to be small. Finally, an integrated controlled-NOT circuit is characterized by measuring the transmission through different combinations of inputs and outputs. The gate fidelity for the CNOT operation with this circuit is estimated to be 99.81% after post selection. This high fidelity is due to our robust design, good fabrication reproducibility, and extensive characterizations.

  13. Reactor pressure vessel and reactor coolant circuit cast duplex stainless steel components contribution of the expertise for life management studies

    International Nuclear Information System (INIS)

    Bezdikian, Georges

    2006-09-01

    The life management of French Nuclear Power Plants is a major stake from an economic and a technical point of view considering the aging management assessment of the key components of the plant. The actual life evaluation is the result of prediction of life assessment from important program of expertise for the 3-loop PWR and 4-loop PWR plants in operation. To optimize the strategic policy in order to achieve the best possible performance and to prepare the technical and economical choice and decision, the paper presents the association of life management strategy and the program of expertise considering: - the identification of degradation for different components and prediction criteria proposed; - the large database from cast reactor coolant and component removed from nuclear power plants and expertise studies to confirm the prediction; - the life evaluation of RPV with radiation surveillance program based on the expertise of irradiation capsules, it is particularly shown how the expertise is in the center of the strategic choice. The French utility has organized the life management of nuclear plant as a function of several programs of expertise of knowledge on the long term experience feedback and the maintenance program for life. This paper shows updated on RPV and reactor coolant equipment activities engaged by utility on: - periodic maintenance and volume of expertise; - Alternative maintenance actions; - Large volume of expertise and how are managed these results to predict the aging management. (author)

  14. A new multi-objective optimization model for preventive maintenance and replacement scheduling of multi-component systems

    Science.gov (United States)

    Moghaddam, Kamran S.; Usher, John S.

    2011-07-01

    In this article, a new multi-objective optimization model is developed to determine the optimal preventive maintenance and replacement schedules in a repairable and maintainable multi-component system. In this model, the planning horizon is divided into discrete and equally-sized periods in which three possible actions must be planned for each component, namely maintenance, replacement, or do nothing. The objective is to determine a plan of actions for each component in the system while minimizing the total cost and maximizing overall system reliability simultaneously over the planning horizon. Because of the complexity, combinatorial and highly nonlinear structure of the mathematical model, two metaheuristic solution methods, generational genetic algorithm, and a simulated annealing are applied to tackle the problem. The Pareto optimal solutions that provide good tradeoffs between the total cost and the overall reliability of the system can be obtained by the solution approach. Such a modeling approach should be useful for maintenance planners and engineers tasked with the problem of developing recommended maintenance plans for complex systems of components.

  15. Maintenance implications of critical components in ITER CXRS upper port plug design

    NARCIS (Netherlands)

    Koning, J.; Jaspers, R.; Doornink, J.; Ouwehand, B.; Klinkhamer, J.F.F.; Snijders, B.; Sadakov, S.; Heemskerk, C.

    2009-01-01

    Already in the early phase of a design for ITER, the maintenance aspects should be taken into account, since they might have serious implications. This paper presents the arguments in support of the case for the maintainability of the design, notably if this maintenance is to be performed by

  16. Maintenance of Structures, Systems and Components of the RSG-GAS Reactor as an Implementation of BAPETEN Regulation No. 5 Year 2011

    International Nuclear Information System (INIS)

    Aep Saepudin Catur; Dede Solehudin Fauzi; Djunaidi

    2012-01-01

    Maintenance activities for structures, systems and components of the reactor, consider prerequisites for the operation of the non power reactor. This activity is intended to ensure that the structures, systems and components function properly. Implementation of reactor maintenance carried out starting from programs establishment, scheduling, maintenance accomplishment and maintenance report. This paper will describe the implementation of reactor maintenance non power as required by BAPETEN regulation no.5, year 2011. By understanding correctly of this regulation, it is expected that maintenance activity of structures, systems and components of the reactor can be successfully performed. The RSG-GAS reactor has implemented various types of reactor maintenance based on BAPETEN regulation no.5 year 2011 properly. As a result failure of the structures, systems and components of the reactor can be minimized then they can be kept reliable. (author)

  17. Crack Growth-Based Predictive Methodology for the Maintenance of the Structural Integrity of Repaired and Nonrepaired Aging Engine Stationary Components

    National Research Council Canada - National Science Library

    Barron, Michael

    1999-01-01

    .... Specifically, the FAA's goal was to develop "Crack Growth-Based Predictive Methodologies for the Maintenance of the Structural Integrity of Repaired and Nonrepaired Aging Engine Stationary Components...

  18. Application of the regulations on pressurized components or light water reactor primary coolant circuits

    International Nuclear Information System (INIS)

    Barthelemy, F.; Menjon, G.

    1977-01-01

    This paper describes the philosophy and the provisions of the Order of 26 February 1974 concerning application of the regulations on pressurized components for light water reactor steam supply systems. The aim is to show how these regulations which differ from other regulations on pressurized components and is more detailed on many points, is applied in practice in France in the various stages of the design, construction and operation of PWRs. (NEA) [fr

  19. Radiation tolerance qualification for maintenance tasks in the future fusion reactors: from fibre-optic components to robust data links

    International Nuclear Information System (INIS)

    Uffelen, M. van; Fernandez, A. Fernandez; Brichard, B.; Berghmans, F.; Decreton, M.

    2003-01-01

    The future International Thermonuclear Experimental Reactor (ITER) requires remote handling tools for its maintenance that will operate in a harsh environment. The numerous instrumentation cables for this maintenance equipment call for (de)multiplexing solutions, in order to reduce the umbilical size. Fibre-optic data links, using commercial-off-the-shelf (COTS) components, are seriously considered as a radiation tolerant solution, offering wavelength encoded multiplexing possibilities. However, an adapted modus operandi for a reliable assessment of this evolving technology is needed, to enable their long-term implementation in a radiation environment. In this paper, we present a methodology towards qualification methods for these instrumentation data links, and illustrate it with results obtained for different individual components. These results should enable the future design of robust architectures for communication links

  20. Water chemistry and corrosion control of cladding and primary circuit components. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    1999-12-01

    Corrosion is the principal life limiting degradation mechanism in nuclear steam supply systems, especially taking into account the trends to increase fuel burnup, thermal rate and cycle length. Primary circuit components of water cooled power reactors have an impact on Zr-based alloys behaviour due to crud (primary circuit corrosion products) formation, transport and deposition on heat transfer surfaces. Crud deposits influence water chemistry, radiation and thermal hydraulic conditions near cladding surface, and by this way-Zr-based alloy corrosion. During the last decade, significant improvements were achieved in the reduction of the corrosion and dose rates by changing the cladding material for one more resistant to corrosion or by the improvement of water chemistry conditions. However, taking into account the above mentioned tendency for heavier fuel duties, corrosion and water chemistry, control will remain a serious task to work with for nuclear power plant operators and scientists, as well as development of generally accepted corrosion model of Zr-based alloys in a water environment in a new millennium. Upon the recommendation of the International Working Group on Water Reactor Fuel Performance and Technology, water chemistry and corrosion of cladding and primary circuit components are in the focus of the IAEA activities in the area of fuel technology and performance. At present the IAEA performs two co-ordinated research projects (CRPs): on On-line High Temperature Monitoring of Water Chemistry and Corrosion (WACOL) and on Activity Transport in Primary Circuits. Two CRPs deal with hydrogen and hydride degradation of the Zr-based alloys. A state-of-the-art review entitled: 'Waterside Corrosion of Zirconium Alloys in Nuclear Power Plants' was published in 1998. Technical Committee meetings on the subject were held in 1985 (Cadarache, France), 1989 (Portland, USA), 1993 (Rez, Czech Republic). During the last few years extensive exchange of experience in

  1. Coherent quantum phase slip in two-component bosonic atomtronic circuits

    International Nuclear Information System (INIS)

    Gallemí, A; Mateo, A Muñoz; Mayol, R; Guilleumas, M

    2016-01-01

    Coherent quantum phase slip consists in the coherent transfer of vortices in superfluids. We investigate this phenomenon in two miscible coherently coupled components of a spinor Bose gas confined in a toroidal trap. After imprinting different vortex states, i.e. states with quantized circulation, on each component, we demonstrate that during the whole dynamics the system remains in a linear superposition of two current states in spite of the nonlinearity, and can be mapped onto a linear Josephson problem. We propose this system as a good candidate for the realization of a Mooij–Harmans qubit and remark its feasibility for implementation in current experiments with 87 Rb, since we have used values for the physical parameters currently available in laboratories. (paper)

  2. Packaging strategies for printed circuit board components. Volume I, materials & thermal stresses.

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Michael K. (Kansas City Plant, Kansas City, MO); Austin, Kevin N.; Adolf, Douglas Brian; Spangler, Scott W.; Neidigk, Matthew Aaron; Chambers, Robert S.

    2011-09-01

    Decisions on material selections for electronics packaging can be quite complicated by the need to balance the criteria to withstand severe impacts yet survive deep thermal cycles intact. Many times, material choices are based on historical precedence perhaps ignorant of whether those initial choices were carefully investigated or whether the requirements on the new component match those of previous units. The goal of this program focuses on developing both increased intuition for generic packaging guidelines and computational methodologies for optimizing packaging in specific components. Initial efforts centered on characterization of classes of materials common to packaging strategies and computational analyses of stresses generated during thermal cycling to identify strengths and weaknesses of various material choices. Future studies will analyze the same example problems incorporating the effects of curing stresses as needed and analyzing dynamic loadings to compare trends with the quasi-static conclusions.

  3. Dynamic simulation of natural convection bypass two-circuit cycle refrigerator-freezer and its application Part I: Component models

    International Nuclear Information System (INIS)

    Ding Guoliang; Zhang Chunlu; Lu Zhili

    2004-01-01

    In order to reduce the greenhouse gas emissions, efficient household refrigerator/freezers (RFs) are required. Bypass two-circuit cycle RFs with one compressor are proved to be more efficient than two-evaporator in series cycle RFs. In order to study the characteristics and improve the design of bypass two-circuit cycle RFs, a dynamic model is developed in this paper. In part I, the mathematic models of all components are presented, considering not only the accuracy of the models but also the computation stability and speed to solve the models. An efficiency model that requires a single calorimeter data point at the standard test condition is employed for compressor. A multi-zone model is employed for condenser and for evaporator, with its wall thermal capacity considered by effective metal method. The approximate integral analytic model is employed for adiabatic capillary tube, and the effective inlet enthalpy method is used to transfer the non-adiabatic capillary tube to adiabatic capillary tube. The z-transfer function model is employed for cabinet load calculation

  4. Analytical modeling of multi-layered printed circuit board using multi-stacked via clusters as component heat spreader

    Directory of Open Access Journals (Sweden)

    Monier-Vinard Eric

    2016-01-01

    Full Text Available In order to help the electronic designer to early determine the limits of the power dissipation of electronic component, an analytical model was established to allow a fast insight of relevant design parameters of a multi-layered electronic board constitution. The proposed steady-state approach based on Fourier series method promotes a practical solution to quickly investigate the potential gain of multi-layered thermal via clusters. Generally, it has been shown a good agreement between the results obtained by the proposed analytical model and those given by electronics cooling software widely used in industry. Some results highlight the fact that the conventional practices for Printed Circuit Board modeling can be dramatically underestimate source temperatures, in particular with smaller sources. Moreover, the analytic solution could be applied to optimize the heat spreading in the board structure with a local modification of the effective thermal conductivity layers.

  5. The use of the acoustic emission for the components of the primary circuit of the nuclear power plants

    International Nuclear Information System (INIS)

    Svoboda, V.

    1992-01-01

    Full text: The Modrany Engineering Works (Modranske strojirny) is a producer and a final supplier of the main connecting piping circuit systems and valves for the nuclear power plants (type VVER 440 and VVER 1000) built in Czechoslovakia. Besides the delivery and assembly of valves and components methods there were developed for a monitoring of the stated equipment ability of a service in the Material and Diagnostic Laboratory, which is a part of the company. An important object of this work is to obtain a sufficient set of data and to work out suitable methods, on the basis of which it would be possible to perform a serious estimation of residual service life of the main piping components after certain service operation of the nuclear power plant. During the operation of a nuclear power station a failure of the main piping circuit could happen in either of two possible modes: 1.) A sudden break - by an unstable defect propagation leading to a. final fracture of the piping; 2) A fatigue failure - which is characterised by a gradual subcritical growth of defect in relation to the loading parameters. This process is frequently accelerated by further processes, e.g. corrosion. It is therefore suitable to use such physical and mechanical quantities, which characterize the material damage. Acoustic emission signals belongs to these quantities. A knowledge of the response of these signals in relation to the damage of the material gives us the possibility to evaluate the residual life of the piping containing defects. The importance of this is increasing mainly after a long period of service. She paper deals in details with experience gained in application of acoustic emission, during pressure tests of primary circuit components (elbow, welds, T- junction etc) in laboratory conditions which imitate those in service. There are shown some results of cyclic fatigue tests by internal pressure on prototypes models and specimen. Acoustic emission method represents the

  6. Fatigue evaluation including environmental effects for primary circuit components in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Seichter, Johannes [Siempelkamp Pruef- und Gutachter-Gesellschaft mbH, Dresden (Germany); Reese, Sven H.; Klucke, Dietmar [E.ON Kernkraft GmbH, Hannover (Germany). Component Technology

    2013-06-01

    The influence of LWR coolant environment to the lifetime of materials in nuclear power plants is being discussed internationally. Environmental phenomena had been investigated in laboratory tests and published in recent years. The discussion is mainly focused both on the transition from laboratory to real plant components and on numerical calculation procedures. Since publishing of the NUREG/CR-6909 report in 2007, formulae for calculating the Fen factors have been modified several times. Various calculation procedures are discussed and recommendations are made how to avoid extremely conservative results. (orig.)

  7. Remote maintenance of in-vessel components in Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Loesser, G.D.; Heitzenroeder, P.; Kungl, D.; Dylla, H.F.; Cerdan, G.

    1990-01-01

    The Tokamak Fusion Test Reactor (TFTR) will generate a total of 3 x 10 21 neutrons during its planned D-T operational period. A maintenance manipulator has been designed and tested to minimize personnel radiation during in-vessel maintenance activities. Its functions include visual inspection, first-wall tile replacement, cleaning, diagnostics calibrations and leak detection. To meet these objectives, the TFTR maintenance manipulator is required to be operable in the TFTR high vacuum environment, typically -8 torr, ( -6 Pa). Geometrically, the manipulator must extend 180 0 in either direction around the torus to assure complete coverage of the vessel first-wall. The manipulator consists of a movable carriage, and movable articulated link sections which are driven by electrical actuators. The boom has vertical load capacity of 455 kg and lateral load capacity of 46 kg. The boom can either be fitted with a general inspection arm or dextrous slave arms. The general inspection arm is designed to hold the leak detector and an inspection camera; it is capable of rotation along two axes and has a linkage system which permits motion normal to the vacuum vessel wall. All systems except the dextrous slave arms are operable in a vacuum. (author)

  8. Component-Level Electronic-Assembly Repair (CLEAR) Spacecraft Circuit Diagnostics by Analog and Complex Signature Analysis

    Science.gov (United States)

    Oeftering, Richard C.; Wade, Raymond P.; Izadnegahdar, Alain

    2011-01-01

    The Component-Level Electronic-Assembly Repair (CLEAR) project at the NASA Glenn Research Center is aimed at developing technologies that will enable space-flight crews to perform in situ component-level repair of electronics on Moon and Mars outposts, where there is no existing infrastructure for logistics spares. These technologies must provide effective repair capabilities yet meet the payload and operational constraints of space facilities. Effective repair depends on a diagnostic capability that is versatile but easy to use by crew members that have limited training in electronics. CLEAR studied two techniques that involve extensive precharacterization of "known good" circuits to produce graphical signatures that provide an easy-to-use comparison method to quickly identify faulty components. Analog Signature Analysis (ASA) allows relatively rapid diagnostics of complex electronics by technicians with limited experience. Because of frequency limits and the growing dependence on broadband technologies, ASA must be augmented with other capabilities. To meet this challenge while preserving ease of use, CLEAR proposed an alternative called Complex Signature Analysis (CSA). Tests of ASA and CSA were used to compare capabilities and to determine if the techniques provided an overlapping or complementary capability. The results showed that the methods are complementary.

  9. A cholinergic-regulated circuit coordinates the maintenance and bi-stable states of a sensory-motor behavior during Caenorhabditis elegans male copulation.

    Directory of Open Access Journals (Sweden)

    Yishi Liu

    2011-03-01

    Full Text Available Penetration of a male copulatory organ into a suitable mate is a conserved and necessary behavioral step for most terrestrial matings; however, the detailed molecular and cellular mechanisms for this distinct social interaction have not been elucidated in any animal. During mating, the Caenorhabditis elegans male cloaca is maintained over the hermaphrodite's vulva as he attempts to insert his copulatory spicules. Rhythmic spicule thrusts cease when insertion is sensed. Circuit components consisting of sensory/motor neurons and sex muscles for these steps have been previously identified, but it was unclear how their outputs are integrated to generate a coordinated behavior pattern. Here, we show that cholinergic signaling between the cloacal sensory/motor neurons and the posterior sex muscles sustains genital contact between the sexes. Simultaneously, via gap junctions, signaling from these muscles is transmitted to the spicule muscles, thus coupling repeated spicule thrusts with vulval contact. To transit from rhythmic to sustained muscle contraction during penetration, the SPC sensory-motor neurons integrate the signal of spicule's position in the vulva with inputs from the hook and cloacal sensilla. The UNC-103 K(+ channel maintains a high excitability threshold in the circuit, so that sustained spicule muscle contraction is not stimulated by fewer inputs. We demonstrate that coordination of sensory inputs and motor outputs used to initiate, maintain, self-monitor, and complete an innate behavior is accomplished via the coupling of a few circuit components.

  10. Data Collection for Current U.S. Wind Energy Projects: Component Costs, Financing, Operations, and Maintenance; January 2011 - September 2011

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Tretton, M.; Reha, M.; Drunsic, M.; Keim, M.

    2012-01-01

    DNV Renewables (USA) Inc. (DNV) used an Operations and Maintenance (O&M) Cost Model to evaluate ten distinct cost scenarios encountered under variations in wind turbine component failure rates. The analysis considers: (1) a Reference Scenario using the default part failure rates within the O&M Cost Model, (2) High Failure Rate Scenarios that increase the failure rates of three major components (blades, gearboxes, and generators) individually, (3) 100% Replacement Scenarios that model full replacement of these components over a 20 year operating life, and (4) Serial Failure Scenarios that model full replacement of blades, gearboxes, and generators in years 4 to 6 of the wind project. DNV selected these scenarios to represent a broad range of possible operational experiences. Also in this report, DNV summarizes the predominant financing arrangements used to develop wind energy projects over the past several years and provides summary data on various financial metrics describing those arrangements.

  11. Fatigue evaluation including environmental effects for primary circuit components in nuclear power plants

    International Nuclear Information System (INIS)

    Seichter, Johannes; Reese, Sven H.; Klucke, Dietmar

    2013-01-01

    The influence of LWR coolant environment to the lifetime of materials in Nuclear Power Plants is in discussion internationally. Environmental phenomena were investigated in laboratory tests and published in recent years. The discussion is mainly focused both on the transition from laboratory to real plant components and on numerical calculation procedures. Since publishing of the NUREG/CR-6909 report in 2007, formulae for calculating the Fen factors have been modified several times. Various calculation procedures like the so called 'Strain-integrated Method' and 'Simplified Approach' have been published while each approach yields to different results. The recent revision of the calculation procedure, proposed by ANL in 2012, is presented and discussed with regard to possible variations in the results depending on the assumptions made. In German KTA Rules the effect of environmentally assisted fatigue (EAF) is taken into account by means of so called attention thresholds. If the threshold value is exceeded, further measures like NDT, in-service inspections including fracture mechanical evaluations or detailed assessment procedures have to be performed. One way to handle those measures is to apply sophisticated procedures and to show that the calculated CUF is below the defined attention thresholds. On the basis of a practical example, methods and approaches will be discussed and recommendations in terms of avoiding over-conservatism and misinterpretation will be presented.

  12. Fatigue evaluation including environmental effects for primary circuit components in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Seichter, Johannes [Siempelkamp Pruef- und Gutachter-Gesellschaft mbH, Dresden (Germany); Reese, Sven H.; Klucke, Dietmar [Component Technology Global Unit Generation, E.ON Kernkraft GmbH, Hannover (Germany)

    2013-05-15

    The influence of LWR coolant environment to the lifetime of materials in Nuclear Power Plants is in discussion internationally. Environmental phenomena were investigated in laboratory tests and published in recent years. The discussion is mainly focused both on the transition from laboratory to real plant components and on numerical calculation procedures. Since publishing of the NUREG/CR-6909 report in 2007, formulae for calculating the Fen factors have been modified several times. Various calculation procedures like the so called 'Strain-integrated Method' and 'Simplified Approach' have been published while each approach yields to different results. The recent revision of the calculation procedure, proposed by ANL in 2012, is presented and discussed with regard to possible variations in the results depending on the assumptions made. In German KTA Rules the effect of environmentally assisted fatigue (EAF) is taken into account by means of so called attention thresholds. If the threshold value is exceeded, further measures like NDT, in-service inspections including fracture mechanical evaluations or detailed assessment procedures have to be performed. One way to handle those measures is to apply sophisticated procedures and to show that the calculated CUF is below the defined attention thresholds. On the basis of a practical example, methods and approaches will be discussed and recommendations in terms of avoiding over-conservatism and misinterpretation will be presented.

  13. Development of HWVP melter/turntable components for canyon-remote maintenance and replacement

    International Nuclear Information System (INIS)

    Siemens, D.H.; Beary, M.M.; Berger, D.N.; Heath, W.O.; Larson, D.E.

    1985-03-01

    Remote operability and maintainability of vitrification equipment were assessed under shielded-cell conditions. The equipment tested will be applied to immobilize high-level and transuranic liquid waste slurries that resulted from plutonium production for defense weapons. Equipment tested included: (1) a turntable for handling waste canisters under the melter; (2) a removable discharge cone in the melter overflow section; (3) a thermocouple jumper that extends into a shielded cell; (4) remote instrument and electrical connectors; (5) remote, mechanical, and heat transfer aspects of the melter glass overflow section; (6) a reamer to clean out plugged nozzles in the melter top; (7) a closed circuit camera to view the melter interior; and (8) a device to retrieve samples of the glass product. 14 figs

  14. Use of Influence Diagrams and Fuzzy Theory to Develop Assessment Method of Organizational Influences on Component Maintenance

    International Nuclear Information System (INIS)

    Yoonik Kim; Kwang-Won Ahn; Chang-Hyun Chung; Kil Yoo Kim; Joon-Eon Yang

    2002-01-01

    Organization can make influences on all the systems. Especially in case of nuclear power plants in which safety is established to be one of the most important operating goals, there have been a lot of research efforts for the hardware advancement. However in recent years, it has been widely recognized that organizational factors in nuclear power plants have an important influence on the safety attitudes and the safe behavior of individuals. Until now, any means to include assessments of organizational structure in probabilistic risk assessments have not been universally accepted. The objective of this work is to develop a method to assess organizational influences on component maintenance. Influence diagrams are introduced in this method as a decision making tool and fuzzy theory is used to reflect the vagueness in considering relevance of human activities in maintenance tasks. Introducing fuzzy theory to assess the organizational factors is deemed to a somewhat new trial, which makes it possible to convert linguistic vague descriptions into mathematical ones. Fuzzy linguistic descriptions offer an alternative and often complementary language to conventional, i.e., analytic approaches to modeling systems. Among the existing methodologies to assess organizational factors, the concept of the ω-factor model is utilized and the mechanism that organizational factors have influences on component maintenance is evaluated through composing influence diagrams. These influences go to failure rates and eventually affect component unavailability. Further study will make it possible that the influences of organizational factors on human error probabilities are incorporated into human reliability analysis and furthermore probabilistic safety assessment. (authors)

  15. Structural analysis and incipient failure detection of primary circuit components based on correlation-analysis and finite-element models

    International Nuclear Information System (INIS)

    Olma, B.J.

    1977-01-01

    A method is presented to compute vibrational power spectral densities (VPSD's) of primary circuit components based on a finite-element representation of the primary circuit. First this method has been applied to the sodium cooled reactor KNK, Karlsruhe. Now a further application is being developed for a BWR-nuclear power plant. The experimentally determined VPSD's can be considered as the output of a multiple input-output system. They have to be explained as the frequency response of a multidimensional mechanical system, which is excited by stochastic and deterministic mechanical driving forces. The stochastic mechanical forces are generated by the dynamic pressure fluctuations of the fluid. The deterministic mechanical forces are caused by the pressure fluctuations, which are induced by the main coolant pumps or by standing waves. The excitation matrix can be obtained from measured pressure fluctuations. The vibration transfer function matrix can be computed from the mass matrix, damping matrix and stiffness matrix of a theoretical finite-element model or mass-spring model. Based on this theory the computer code 'STAMPO' has been established. This program has been applied to the KNK reactor. The excitation matrix was created from measured jet-noise pressure fluctuations. The mass-, stiffness- and damping matrix has been extracted from a SAP-IV-model of the primary system. Sequentially for each frequency point the complete VPSD matrix has been computed. The diagonal elements of this matrix represent the vibrational auto-power spectral densities, the off-diagonal elements represent the vibrational cross-power spectral densities. The calculations give good agreement with measured VPSD's. The comparison shows that the measured jet-noise pressure fluctuations act nearly uncorrelated on the structure, whereas the output VPSD's are well correlated

  16. An Approach to Integrating Tactical Decision-Making in Industrial Maintenance Balance Scorecards Using Principal Components Analysis and Machine Learning

    Directory of Open Access Journals (Sweden)

    Néstor Rodríguez-Padial

    2017-01-01

    Full Text Available The uncertainty of demand has led production systems to become increasingly complex; this can affect the availability of the machines and thus their maintenance. Therefore, it is necessary to adequately manage the information that facilitates decision-making. This paper presents a system for making decisions related to the design of customized maintenance plans in a production plant. This paper addresses this tactical goal and aims to provide greater knowledge and better predictions by projecting reliable behavior in the medium-term, integrating this new functionality into classic Balance Scorecards, and making it possible to extend their current measuring function to a new aptitude: predicting evolution based on historical data. In the proposed Custom Balance Scorecard design, an exploratory data phase is integrated with another analysis and prediction phase using Principal Component Analysis algorithms and Machine Learning that uses Artificial Neural Network algorithms. This new extension allows better control over the maintenance function of an industrial plant in the medium-term with a yearly horizon taken over monthly intervals which allows the measurement of the indicators of strategic productive areas and the discovery of hidden behavior patterns in work orders. In addition, this extension enables the prediction of indicator outcomes such as overall equipment efficiency and mean time to failure.

  17. Remote maintenance of future fusion reactors - a challenge for rad-hard components and smart control strategies

    International Nuclear Information System (INIS)

    Decreton, M.; Geeter, J. De

    1996-01-01

    The future fusion reactor will need frequent maintenance turns, involving inspection, repair and parts replacement inside the vacuum vessel. These operations will require high payload manipulations in constrained space under very high gamma-radiation dose-rates and temperature. Present research is being undertaken to qualify the components of the handling machine under representative conditions, in the framework of the ITER international consortium. Simultaneously, challenging control strategies will be needed to achieve reliable tasking under very poor viewing conditions and elementary sensing help. The paper reviews the present state of the art on both issues and present results of the ongoing research themes among the partners of the ITER programme. In particular, SCK''centre-dot''CEN coordinates the ITER T252 task on Radiation Tolerance Assessment of Remote Handling Components. (UK)

  18. Maintenance of HVAC-systems and components: How to prevent pollution from HVAC-systems?

    NARCIS (Netherlands)

    Müller, B.; Björkroth, M.; Plitt, U.; Bluyssen, P.M.

    2000-01-01

    In the beginning of 1998 a three-year European project, AIRLESS, was started to develop strategies, principles and protocols to improve and control the performance of HVAC-systems and its components for incorporation in codes and guidelines. Twelve institutes, universities and companies, from seven

  19. Susquehanna SES maintenance supervisor training and certification

    International Nuclear Information System (INIS)

    Deckman, M.

    1991-01-01

    Susquehanna's program targets all Supervisors, Supervisor Candidates, and Temporary Supervisors that are responsible for in-plant maintenance or maintenance support activities, including: mechanical maintenance; electrical maintenance; maintenance support (labor support, radwaste, etc.); mobile construction support (mechanical and electrical); chemistry; health physics; maintenance planning; and instrument and controls. The program integrates the three major areas of direct Supervisory responsibilities: (1) Leadership and Management - Skills that require interpersonal activities that are typically humanistic and subjective; such as coaching, motivating, communications, etc. (2) Technical and Administrative - Knowledge that is directly related to the job of Supervising from the production, regulatory, accountability perspective. These topics are very objective and include training on topics such as workpackages, plant chemistry parameters, radiological concerns, etc. (3) Technical Skills - Ensure each Supervisor is technically competent in the plant systems, components, or equipment he/she is tasked with maintaining or overseeing. Typical skills found in this area are, circuit breaker maintenance, primary system sampling, or overhauling pumps

  20. Evaluation of components and systems of RSG-GAS and developing of maintenance evaluation software

    International Nuclear Information System (INIS)

    Pane, Jupiter-Sitorus; Kadarusmanto

    2003-01-01

    In order to enhance the evaluation of components and systems, inventarization of failure and repair data has been performed. The evaluation was done by calculating distribution function of failure, failure rate, MTTF, MTTR, and unavailability. The evaluation was comprehend in a code program of SYSCOM-RSG-GAS, that are able to performed statistical analysis, reliability parameters, and Fault Tree Analysis. This paper will describe some results of the program

  1. To the application of TV and optical equipment for in-service inspection of reactor vessel and primary circuit component materials

    International Nuclear Information System (INIS)

    Afonin, Eh.M.; Bachelis, I.M.; Tokarev, E.A.; Yastrebov, V.E.

    1985-01-01

    Some problems of application of TV and optical equipment for inspection of reactor vessel and primary circuit component materials are considered taking the most widespread WWER-440 type reactor as an example. The most advanrageous objects of the inspection and typical zones of equipment arrangement are shown. Methods and peculiarities of the inspection with the use of TV and optical equipment are presented. Recommendations on rational application of the equipment for the inspection of WWER-440 reactor vessel components are given

  2. Effect of amplifier component maintenance on laser system availability and reliability for the US National Ignition Facility

    International Nuclear Information System (INIS)

    Erlandson, A.C.; Lambert, H.; Zapata, L.E.

    1996-12-01

    We have analyzed the availability and reliability of the flashlamp-pumped, Nd:glass amplifiers that, as a part of a laser now being designed for future experiments, in inertial confinement fusion (ICF), will be used in the National Ignition Facility (NIF). Clearly , in order for large ICF systems such as the NIF to operate effectively as a whole, all components must meet demanding availability and reliability requirements. Accordingly, the NIF amplifiers can achieve high reliability and availability by using reliable parts, and by using a cassette-based maintenance design that allows most key amplifier parts to be 1744 replaced within a few hours. In this way, parts that degrade slowly, as the laser slabs, silver reflectors, and blastshields can be expected to do, based on previous experience, can be replaced either between shots or during scheduled maintenance periods, with no effect on availability or reliability. In contrast, parts that fail rapidly, such as the flashlamps, can and do cause unavailability or unreliability. Our analysis demonstrates that the amplifiers for the NIF will meet availability and reliability goals, respectively, of 99.8% and 99.4%, provided that the 7680 NIF flashlamps in NIF have failure rates of less than, or equal to, those experienced on Nova, a 5000-lamp laser at Lawrence Livermore National Laboratory (LLNL)

  3. Workers' exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations.

    Science.gov (United States)

    Korpinen, Leena; Pääkkönen, Rauno

    2018-02-26

    The objective of the study was to investigate occupational exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations. The aim was also to compare the results to Directive 2013/35/EU. At 16 substations, 255 electric field measurements were performed. The highest mean value of the electric fields was 9.6 kV⋅m -1 . At 63% of substations the maximum values were over 10.0 kV⋅m -1 , and at 31% of the substations the 75th percentiles were over 10.0 kV⋅m -1 , which is the low action level (AL) according to Directive 2013/35/EU. All measured values were below the high AL (20.0 kV⋅m -1 ). In the future, it is important to take into account that the measurements were only taken at Finnish 110-kV substations; therefore, it is not possible to generalize these results to other countries and different types of substations.

  4. Design and test of component circuits of an integrated quantum voltage noise source for Johnson noise thermometry

    Science.gov (United States)

    Yamada, Takahiro; Maezawa, Masaaki; Urano, Chiharu

    2015-11-01

    We present design and testing of a pseudo-random number generator (PRNG) and a variable pulse number multiplier (VPNM) which are digital circuit subsystems in an integrated quantum voltage noise source for Jonson noise thermometry. Well-defined, calculable pseudo-random patterns of single flux quantum pulses are synthesized with the PRNG and multiplied digitally with the VPNM. The circuit implementation on rapid single flux quantum technology required practical circuit scales and bias currents, 279 junctions and 33 mA for the PRNG, and 1677 junctions and 218 mA for the VPNM. We confirmed the circuit operation with sufficiently wide margins, 80-120%, with respect to the designed bias currents.

  5. Components of the primary circuit of LWRs. Design, construction and calculation. Draft. Komponenten des Primaerkreises von Leichtwasserreaktoren. Auslegung, Konstruktion und Berechnung. Entwurf

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    This standard is to be applied to components made of metallic materials, operated at design temperatures of up to 673/sup 0/K (400/sup 0/C). The primary circuit as the pressure continement of the reactor coolant comprises: Reactor pressure vessel (without internals), steam generator (primary loop), pressurizer, reactor coolant pump housing, interconnecting pipings between the components mentioned above and appropriate various valve and instrument casings, pipings branding off from the above components and interconnecting pipings, including the appropriate instrument casings, up to and including the first isolating valve, pressure shielding of control rod drives.

  6. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  7. Determination of the necessary parameters for a protection insulation disk of sodium circuit weighing system for thermomechanical and small component tests

    International Nuclear Information System (INIS)

    Bloch, M.; Cesar, S.B.G.

    1985-01-01

    The parameters requisited for a plastic disk used as thermal insulation, between feeding tank and weghing system, where the tank is supported are defined. The tank and weghing system are component parts of sodium circuit for thermomechanical and small component tests. During the circuit operation the temperature at tank reaches 600 0 C, however the temperature at weghing system should not reach 50 0 C. The temperature distribution in insulation disk is obtained by finit element method in function of thickness and thermal conductivity of material. The results obtained indicate for thickness E = 32 mm should be K 0 C and for E = 48 mm the thermal conductivity should be K 0 C. In both cases the pressure is σ > 14.5 Kgf/mm 2 . (M.C.K.) [pt

  8. Optimizing preventive maintenance with maintenance templates

    International Nuclear Information System (INIS)

    Dozier, I.J.

    1996-01-01

    Rising operating costs has caused maintenance professionals to rethink their strategy for preventive maintenance (PM) programs. Maintenance Templates are pre-engineered PM task recommendations for a component type based on application of the component. Development of the maintenance template considers the dominant failure cause of the component and the type of preventive maintenance that can predict or prevent the failure from occurring. Maintenance template development also attempts to replace fixed frequency tasks with condition monitoring tasks such as vibration analysis or thermography. For those components that have fixed frequency PM intervals, consideration is given to the maintenance drivers such as criticality, environment and usage. This helps to maximize the PM frequency intervals and maximize the component availability. Maintenance Templates have been used at PECO Energy's Limerick Generating Station during the Reliability Centered Maintenance (RCM) Process to optimize their PM program. This paper describes the development and uses of the maintenance templates

  9. Spinal glutamatergic neurons defined by EphA4 signaling are essential components of normal locomotor circuits

    DEFF Research Database (Denmark)

    Borgius, Lotta; Nishimaru, Hiroshi; Caldeira, Vanessa

    2014-01-01

    EphA4 signaling is essential for the spatiotemporal organization of neuronal circuit formation. In mice, deletion of this signaling pathway causes aberrant midline crossing of axons from both brain and spinal neurons and the complete knock-outs (KOs) exhibit a pronounced change in motor behavior...

  10. Microwave Photonic Architecture for Direction Finding of LPI Emitters: Front End Analog Circuit Design and Component Characterization

    Science.gov (United States)

    2016-09-01

    into two parts. The design, development, and testing efforts of the front-end microwave photonics circuit design and the system integration with the...miniature microwave - photonic phase-sampling DF technique is investigated in this thesis. This front-end design uses a combination of integrated optical...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release. Distribution is unlimited. MICROWAVE

  11. Reliability Analysis and Optimal Release Problem Considering Maintenance Time of Software Components for an Embedded OSS Porting Phase

    Science.gov (United States)

    Tamura, Yoshinobu; Yamada, Shigeru

    OSS (open source software) systems which serve as key components of critical infrastructures in our social life are still ever-expanding now. Especially, embedded OSS systems have been gaining a lot of attention in the embedded system area, i.e., Android, BusyBox, TRON, etc. However, the poor handling of quality problem and customer support prohibit the progress of embedded OSS. Also, it is difficult for developers to assess the reliability and portability of embedded OSS on a single-board computer. In this paper, we propose a method of software reliability assessment based on flexible hazard rates for the embedded OSS. Also, we analyze actual data of software failure-occurrence time-intervals to show numerical examples of software reliability assessment for the embedded OSS. Moreover, we compare the proposed hazard rate model for the embedded OSS with the typical conventional hazard rate models by using the comparison criteria of goodness-of-fit. Furthermore, we discuss the optimal software release problem for the porting-phase based on the total expected software maintenance cost.

  12. Maintenance Business Plans.

    Science.gov (United States)

    Adams, Matt

    2002-01-01

    Discusses maintenance business plans, statements which provide accountability for facilities maintenance organizations' considerable budgets. Discusses the plan's components: statement of plan objectives, macro and detailed description of the facility assets, maintenance function descriptions, description of key performance indicators, milestone…

  13. Opportune maintenance and predictive maintenance decision support

    OpenAIRE

    Thomas , Edouard; Levrat , Eric; Iung , Benoît; Cocheteux , Pierre

    2009-01-01

    International audience; Conventional maintenance strategies on a single component are being phased out in favour of more predictive maintenance actions. These new kinds of actions are performed in order to control the global performances of the whole industrial system. They are anticipative in nature, which allows a maintenance expert to consider non-already-planned maintenance actions. Two questions naturally emerge: when to perform a predictive maintenance action; how a maintenance expert c...

  14. Overall Equipment Efficiency (OEE Enhancement in Manufacture of Electronic Components & Boards Industry through Total Productive Maintenance Practices

    Directory of Open Access Journals (Sweden)

    Fam Soo-Fen

    2018-01-01

    Full Text Available In an environment of intense global competition, both creative and proven strategies need to be considered in order to bring about the effectiveness and efficiency in manufacturing operation. Total Productive Maintenance (TPM is one of the effective maintenance strategy in enhancing the equipment effectiveness and to achieve a significant competitive advantage. This research paper addresses the impact of three TPM pillars namely planned maintenance (PM, autonomous maintenance (AM and focused maintenance (FM on overall equipment effectiveness (OEE of die attach equipment in the production line of semiconductor industry. The effect of TPM on the OEE is also investigated depending on the equipment types, in where die attach process consist of two models-CANON and ESEC. The primary data was collected from an organization's database and was analysed by SPSS V23. The preliminary results of the analysis showed that the performance of OEE in ESEC is better than the CANON after the implementation of TPM. The analysis also showed that out of the three TPM practices deployed, planned maintenance of equipment by production and maintenance team played the biggest role in increasing the equipment effectiveness. In conclusion, this study provides insights the importance of implementing TPM in order to succeed in a highly demanding market arena.

  15. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    1991-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  16. Development of standardized component\\0x2010based equipment specifications and transition plan into a predictive maintenance strategy.

    Science.gov (United States)

    2015-12-01

    This project investigated INDOT equipment records and equipment industry standards to produce standard equipment specifications : and a predictive maintenance schedule for the more than 1100 single and tandem axle trucks in use at INDOT. The research...

  17. Development of standardized component\\0x2010based equipment specifications and transition plan into a predictive maintenance strategy : final report.

    Science.gov (United States)

    2015-12-01

    This project investigated INDOT equipment records and equipment industry standards to produce standard equipment specifications : and a predictive maintenance schedule for the more than 1100 single and tandem axle trucks in use at INDOT. The research...

  18. Activity in neurons of a putative protocerebral circuit representing information about a ten component plant odour blend in Heliothis virescens.

    Directory of Open Access Journals (Sweden)

    Bjarte Bye Løfaldli

    2012-09-01

    Full Text Available The olfactory pathway in the insect brain is anatomically well described from the antennal lobe to the mushroom bodies and the lateral protocerebrum in several species. Less is known about the further connections of the olfactory network in protocerebrum and how information about relevant plant odorants and mixtures are represented in this network, resulting in output information mediated by descending neurons. In the present study we have recorded intracellularly followed by dye injections from neurons in the lateral- and superior protocerebrum of the moth, Heliothis virescens. As relevant stimuli, we have used selected primary plant odorants and mixtures of them. The results provide the morphology and physiological responses of neurons involved in a putative circuit connecting the mushroom body lobes, the superior and the lateral protocerebrum, as well as input to superior and lateral protocerebrum by one multiglomerular antennal lobe neuron and output from the lateral protocerebrum by one descending neuron. All neurons responded to one particular mixture of ten primary plant odorants, some of them also to single odorants of the mixture. Altogether, the physiological data indicate integration in protocerebral neurons of information from several of the receptor neuron types functionally described in this species.

  19. Sodium confluent rates of flow values, on 0,5 mixer, of a sodium italian SS-050 circuit component

    International Nuclear Information System (INIS)

    Walsh, L.M.

    1987-01-01

    Sodium lines on different temperatures, during an emergency drainage on 0,5 mixer was found. To future valuation by DIMEC of tensions that occurs on that component of SS-050, the confluent rates of flow values were calculated. (L.M.J.) [pt

  20. Probabilistic risk analysis of aging components which fail on demand. A Bayesian model. Application to maintenance optimization of Diesel engine linings

    International Nuclear Information System (INIS)

    Procaccia, H.; Lannoy, A.; Clarotti, C.A.

    1997-01-01

    The optimization of preventive maintenance of aging materials can be well modelled through the application of the two-parameters Weibull law. Unfortunately there is no theoretical model describing the aging of components implied in emergency interventions which may fail in very moment of demand. These components are relevant to the safety of Nuclear Power Plants and the main problem with them is the optimization of the maintenance and the test schedule. Indeed the effect of any test is twofold, namely: the test reveals failures which otherwise would occur when the Power Plant would need urgent intervention but at the same time it causes the aging process to step up. The aging process is suspected to affect certain safeguard equipment, but it does not exist a theoretical model of component aging in function of demands. Sections 2.1 and 2.2 of the paper are devoted to the description of a Bayesian model of discrete aging, deriving the likelihood function of the model (data modelling) and to selecting 'the best prior' (Analyst knowledge) that can be associated to the likelihood, respectively. The aspects of numerical integration relative to assessing the predictive reliability of the aging components are discussed in Section 2.3. Section 3 reports a Reliability Centered Maintenance application of the model to cylinders of emergency electrical generators of the NPP nuclear sectors. These components are subjected to an annual endoscopic checking and to a systematical replacement at every 5 years. The statistical Bayesian decision theory was applied to determine an optimal period of cylinder replacement based on the aging model presented in this paper. It is shown that the optimal value is between 10 to 12 years. (author)

  1. A Component-Minimized Single-Phase Active Power Decoupling Circuit with Reduced Current Stress to Semiconductor Switches

    DEFF Research Database (Denmark)

    Tang, Yi; Blaabjerg, Frede

    2015-01-01

    inductor. With such a configuration, this leg can control the current going into the two output capacitors connected in series for power decoupling, and the other leg can control the line current according to active and reactive power requirement. The proposed topology does not require additional passive...... component, e.g. inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced...

  2. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVI, I--CATERPILLAR LUBRICATION SYSTEMS AND COMPONENTS, II--LEARNING ABOUT BRAKES (PART I).

    Science.gov (United States)

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE FUNCTIONS OF DIESEL ENGINE LUBRICATION SYSTEMS AND COMPONENTS AND THE PRINCIPLES OF OPERATION OF BRAKE SYSTEMS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) THE NEED FOR OIL, (2) SERVICE CLASSIFICATION OF OILS, (3) CATERPILLAR LUBRICATION SYSTEM COMPONENTS (4)…

  3. Age-dependent risk-based methodology and its application to prioritization of nuclear power plant components and to maintenance for managing aging using PRAs

    International Nuclear Information System (INIS)

    Levy, I.S.; Vesely, W.E.

    1990-01-01

    This paper is based on a study to demonstrate several important ways that the age-dependent risk-based methodology developed by the Nuclear Plant Aging Research (NPAR) Program may be applied to resolving important issues related to the aging of nuclear power plant systems, structures, and components (SSCs). The study was sponsored by the NPAR Program of the Division of Engineering, Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission (NRC). Initiated on the basis of a Users Need Request, the age-dependent risk-based methodology has been under development by the NPAR Program for several years. In this methodology, the time-dependent change in a component's risk contribution is the product of two factors: (1) the risk importance of the component (e.g., the change in its risk contribution when it is assumed to be totally unavailable to perform its intended safety function) and (2) the change in its unavailability with time. This change in the component's unavailability with time is a function of the component's aging rate and plant inspection and maintenance practices. The methodology permits evaluations of the age-dependent risk contributions from both single- and multiple-components. Principal results and conclusions generated by the methodology demonstrations are discussed

  4. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  5. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  6. Measuring circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings

  7. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    Science.gov (United States)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  8. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  9. Remote Maintenance Monitoring System -

    Data.gov (United States)

    Department of Transportation — The Remote Maintenance and Monitoring System (RMMS) is a collection of subsystems that includes telecommunication components, hardware, and software, which serve to...

  10. The problem of maintenance of strength, lifetime and safety of the structural components operational NPP from items of a system approach

    International Nuclear Information System (INIS)

    Getman, A.F.

    2005-01-01

    The strength of the structural components and pipelines NPP determines largely their lifetime, radiation and nuclear safety. As shows world experience of operation NPP, in a series of cases during operation the local damages, breaks and destructions of elements of the equipment and pipelines emerge. These cases force maintaining organizations to execute on NPP large volumes of the control, repair and modernizing of the equipment and pipelines. These activities require large material inputs (net less than 50% of the cost of operation NPP), however not always are effective and in a series of cases do not allow to reach required of level reliability and safety. The reason of such condition of a problem is that the measures executed on NPP, developed on stretch of long time and under influence of the diverse factors. Besides until now there is no unified scientific methodology of a case study of maintenance of strength, lifetime and safety of the operational equipment and pipelines NPP. The application of a system approach to a problem of maintenance of strength, lifetime and safety of the equipment and pipelines operational NPP allows to consider a problem as a whole, from unified items, to define the most fast and effective paths it of the solution and to decide problems in as much as possible short times at minimum material inputs. The experience of practical application of a system approach at the solution of separate problems of operation NPP has allowed to develop a lot of effective new techniques, technologies and means, which application allows essentially to increase reliability and gamma percentage lifetime of elements NPP, to which they were applied. As an example in the report the outcomes of application of a system approach for maintenance of SG tubes integrity of reactors of a type WWER are adduced. The application of a system approach for all elements of the equipment and pipelines NPP will allow to increase it reliability and safety not less, than on 10

  11. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  12. Maintenance of nuclear medicine instruments

    Energy Technology Data Exchange (ETDEWEB)

    Ambro, P

    1993-12-31

    Maintenance of instruments is generally of two kinds: (a) corrective maintenance, on a non-scheduled basis, to restore equipment to a functional status by repairs; (b) preventive maintenance, to keep equipment in a specified functional condition by providing systematic inspection, quality control, detection and correction of early malfunctions. Most of the instruments used in nuclear medicine are rather complex systems built from mechanical, electrical and electronic parts. Any one of these components is liable to fail at some time or other. Repair could be done only by a specialist who is able to evaluate the condition of the various parts ranging from cables to connectors, from scintillators to photomultipliers, from microprocessors to microswitches. The knowledge of the intricacies of the various electronic components required for their repairs is quite wide and varied. The electronics industry turns out more and more multi-purpose chips which can carry out the functions of many parts used in the instruments of the earlier generation. This provides protection against unauthorized copying of the circuits but it serves another purpose as well of inhibiting repairs by non-factory personnel. These trends of the instrument design should be taken into consideration when a policy has to be developed for the repairs of the hospital based equipment 1 fig., 1 tab

  13. Maintenance of nuclear medicine instruments

    International Nuclear Information System (INIS)

    Ambro, P.

    1992-01-01

    Maintenance of instruments is generally of two kinds: (a) corrective maintenance, on a non-scheduled basis, to restore equipment to a functional status by repairs; (b) preventive maintenance, to keep equipment in a specified functional condition by providing systematic inspection, quality control, detection and correction of early malfunctions. Most of the instruments used in nuclear medicine are rather complex systems built from mechanical, electrical and electronic parts. Any one of these components is liable to fail at some time or other. Repair could be done only by a specialist who is able to evaluate the condition of the various parts ranging from cables to connectors, from scintillators to photomultipliers, from microprocessors to microswitches. The knowledge of the intricacies of the various electronic components required for their repairs is quite wide and varied. The electronics industry turns out more and more multi-purpose chips which can carry out the functions of many parts used in the instruments of the earlier generation. This provides protection against unauthorized copying of the circuits but it serves another purpose as well of inhibiting repairs by non-factory personnel. These trends of the instrument design should be taken into consideration when a policy has to be developed for the repairs of the hospital based equipment

  14. 49 CFR 236.721 - Circuit, control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates. ...

  15. Electronic Circuit Analysis Language (ECAL)

    Science.gov (United States)

    Chenghang, C.

    1983-03-01

    The computer aided design technique is an important development in computer applications and it is an important component of computer science. The special language for electronic circuit analysis is the foundation of computer aided design or computer aided circuit analysis (abbreviated as CACD and CACA) of simulated circuits. Electronic circuit analysis language (ECAL) is a comparatively simple and easy to use circuit analysis special language which uses the FORTRAN language to carry out the explanatory executions. It is capable of conducting dc analysis, ac analysis, and transient analysis of a circuit. Futhermore, the results of the dc analysis can be used directly as the initial conditions for the ac and transient analyses.

  16. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1998-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  17. Knowledge based maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, A. [Hamburgische Electacitaets-Werke AG Hamburg (Germany)

    1997-12-31

    The establishment of maintenance strategies is of crucial significance for the reliability of a plant and the economic efficiency of maintenance measures. Knowledge about the condition of components and plants from the technical and business management point of view therefore becomes one of the fundamental questions and the key to efficient management and maintenance. A new way to determine the maintenance strategy can be called: Knowledge Based Maintenance. A simple method for determining strategies while taking the technical condition of the components of the production process into account to the greatest possible degree which can be shown. A software with an algorithm for Knowledge Based Maintenance leads the user during complex work to the determination of maintenance strategies for this complex plant components. (orig.)

  18. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  19. Physico-topological methods of increasing stability of the VLSI circuit components to irradiation. Fiziko-topologhicheskie sposoby uluchsheniya radiatsionnoj stojkosti komponentov BIS

    Energy Technology Data Exchange (ETDEWEB)

    Pereshenkov, V S [MIFI, Moscow, (Russian Federation); Shishianu, F S; Rusanovskij, V I [S. Lazo KPI, Chisinau, (Moldova, Republic of)

    1992-01-01

    The paper presents the method used and the experimental results obtained for 8-bit microprocessor irradiated with [gamma]-rays and neutrons. The correlation between the electrical and technological parameters with the irradiation ones is revealed. The influence of leakage current between devices incorporated in VLSI circuits was studied. The obtained results create the possibility to determine the technological parameters necessary for designing the circuit able to work at predetermined doses. The necessary substrate doping concentration for isolation which eliminates the leakage current between devices prevents the VLSI circuit break down was determined. (Author).

  20. Principles of MONJU maintenance. Characteristic of MONJU maintenance and reflection of LWR maintenance experience to FBR

    International Nuclear Information System (INIS)

    Nakai, Satoru; Nishio, Ryuichi; Uchihashi, Masaya; Kaneko, Yoshihisa; Yamashita, Hironobu; Yamaguchi, Atsunori; Aoki, Takayuki

    2014-01-01

    A sodium cooled fast breeder reactor (FBR) has unique systems and components and different degradation mechanism from light water reactor (LWR) so that need to establish maintenance technology in accordance with its features. The examination of the FBR maintenance technology is carried out in the special committee for considering the maintenance for Monju established in the Japan Society of Maintenology (JSM). As a result of the study such as extraction of Monju maintenance feature, maintenance technology benchmark between Monju and LWR components and survey of LWR maintenance experience, it is clear that principles of maintenance are same as LWR, necessity of LWR maintenance experience reflection and points to be considered in Monju maintenance. The road map to establish a FBR maintenance technology in the technical aspect became clear and it is vital to acquire operation and maintenance experience of the plant to implement this road map, and to establish a fast reactor maintenance. (author)

  1. Aircraft Maintenance Expert Systems.

    Science.gov (United States)

    1983-11-01

    PARA 2 -104)) 44: (( JETCAL ANALYSIS SHOWS SYSTEM READS CORRECT) (REPLACE FAULTY PARTS)) 45: ((OVERTEMP EXCEEDED SERVICE LIMITS) 46: I(ENGINE CONTROL...CIRCUITS WITHIN LIMITS ON JETCAL ) (REPLACE FAULTY PARTS)) 47: (ADJUST EST AT AMPLIFIER AND CHECK TENP)) (SEND ENGINE TO HIGHER LEVEL MAINTENANCE)) 48: 2

  2. Numerical study of inventory management under various maintenance policies

    NARCIS (Netherlands)

    Poppe, J.; Basten, R.J.I.; Boute, R.N.; Lambrecht, M.R.

    2017-01-01

    Capital assets, such as manufacturing equipment, require maintenance to remain functioning. Maintenance can be performed when a component breaks down and needs replacement (i.e., corrective maintenance), or the maintenance and part replacement can be performed preventively. Preventive maintenance

  3. Developing a Domain Model for Relay Circuits

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth

    2009-01-01

    In this paper we stepwise develop a domain model for relay circuits as used in railway control systems. First we provide an abstract, property-oriented model of networks consisting of components that can be glued together with connectors. This model is strongly inspired by a network model...... for railways madeby Bjørner et.al., however our model is more general: the components can be of any kind and can later be refined to e.g. railway components or circuit components. Then we show how the abstract network model can be refined into an explicit model for relay circuits. The circuit model describes...... the statics as well as the dynamics of relay circuits, i.e. how a relay circuit can be composed legally from electrical components as well as how the components may change state over time. Finally the circuit model is transformed into an executable model, and we show how a concrete circuit can be defined...

  4. A Methodology for Modeling Nuclear Power Plant Passive Component Aging in Probabilistic Risk Assessment under the Impact of Operating Conditions, Surveillance and Maintenance Activities

    Science.gov (United States)

    Guler Yigitoglu, Askin

    In the context of long operation of nuclear power plants (NPPs) (i.e., 60-80 years, and beyond), investigation of the aging of passive systems, structures and components (SSCs) is important to assess safety margins and to decide on reactor life extension as indicated within the U.S. Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) Program. In the traditional probabilistic risk assessment (PRA) methodology, evaluating the potential significance of aging of passive SSCs on plant risk is challenging. Although passive SSC failure rates can be added as initiating event frequencies or basic event failure rates in the traditional event-tree/fault-tree methodology, these failure rates are generally based on generic plant failure data which means that the true state of a specific plant is not reflected in a realistic manner on aging effects. Dynamic PRA methodologies have gained attention recently due to their capability to account for the plant state and thus address the difficulties in the traditional PRA modeling of aging effects of passive components using physics-based models (and also in the modeling of digital instrumentation and control systems). Physics-based models can capture the impact of complex aging processes (e.g., fatigue, stress corrosion cracking, flow-accelerated corrosion, etc.) on SSCs and can be utilized to estimate passive SSC failure rates using realistic NPP data from reactor simulation, as well as considering effects of surveillance and maintenance activities. The objectives of this dissertation are twofold: The development of a methodology for the incorporation of aging modeling of passive SSC into a reactor simulation environment to provide a framework for evaluation of their risk contribution in both the dynamic and traditional PRA; and the demonstration of the methodology through its application to pressurizer surge line pipe weld and steam generator tubes in commercial nuclear power plants. In the proposed methodology, a

  5. Trigger circuit

    International Nuclear Information System (INIS)

    Verity, P.R.; Chaplain, M.D.; Turner, G.D.J.

    1984-01-01

    A monostable trigger circuit comprises transistors TR2 and TR3 arranged with their collectors and bases interconnected. The collector of the transistor TR2 is connected to the base of transistor TR3 via a capacitor C2 the main current path of a grounded base transistor TR1 and resistive means R2,R3. The collector of transistor TR3 is connected to the base of transistor TR2 via resistive means R6, R7. In the stable state all the transistors are OFF, the capacitor C2 is charged, and the output is LOW. A positive pulse input to the base of TR2 switches it ON, which in turn lowers the voltage at points A and B and so switches TR1 ON so that C2 can discharge via R2, R3, which in turn switches TR3 ON making the output high. Thus all three transistors are latched ON. When C2 has discharged sufficiently TR1 switches OFF, followed by TR3 (making the output low again) and TR2. The components C1, C3 and R4 serve to reduce noise, and the diode D1 is optional. (author)

  6. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  7. Preventive maintenance and reliability-centered maintenance

    International Nuclear Information System (INIS)

    Anderson, J.G.

    1989-01-01

    In the recent past, the primary function of the preventive maintenance program at a nuclear power plant was to maintain the operability and reliability of the plant. Reducing overall maintenance costs by performing effective preventive maintenance, instead of more costly and disruptive corrective maintenance, instead of more costly and disruptive corrective maintenance, was a secondary consideration. In today's operating environment, the preventive maintenance program must meet the test of cost-effectiveness as well as many new standards for performance that are being required by rate regulators. The preventive maintenance program must be able to withstand the challenge of independent audit to a new standard of technical adequacy and compliance with recommendations from component vendors. In this new environment, the standard that is being applied at the San Onofre nuclear generating station (SONGS) is that the preventive maintenance program must meet the test of cost-effectiveness, improve equipment performance, support increased plant availability, and (a) literally implement the recommendations of the vendor, (b) provide other compensation for the vendor recommendation, or (c) provide technical justification for the deviation. The subject of this paper is the way that reliability-centered maintenance (RCM) is helping SONGS meet these challenges

  8. Turbine maintenance and modernization

    Energy Technology Data Exchange (ETDEWEB)

    Unga, E. [Teollisuuden Voima Oy, Olkiluoto (Finland)

    1998-12-31

    The disturbance-free operation of the turbine plant plays an important role in reaching good production results. In the turbine maintenance of the Olkiluoto nuclear power plant the lifetime and efficiency of turbine components and the lifetime costs are taken into account in determining the turbine maintenance and modernization/improvement program. The turbine maintenance program and improvement/modernization measures taken in the plant units are described in this presentation. (orig.)

  9. Turbine maintenance and modernization

    Energy Technology Data Exchange (ETDEWEB)

    Unga, E [Teollisuuden Voima Oy, Olkiluoto (Finland)

    1999-12-31

    The disturbance-free operation of the turbine plant plays an important role in reaching good production results. In the turbine maintenance of the Olkiluoto nuclear power plant the lifetime and efficiency of turbine components and the lifetime costs are taken into account in determining the turbine maintenance and modernization/improvement program. The turbine maintenance program and improvement/modernization measures taken in the plant units are described in this presentation. (orig.)

  10. Electronic circuit encyclopedia 2

    International Nuclear Information System (INIS)

    Park, Sun Ho

    1992-10-01

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  11. Electronic circuit encyclopedia 2

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Ho

    1992-10-15

    This book is composed of 15 chapters, which are amplification of weak signal and measurement circuit audio control and power amplification circuit, data transmission and wireless system, forwarding and isolation, signal converting circuit, counter and comparator, discriminator circuit, oscillation circuit and synthesizer, digital and circuit on computer image processing circuit, sensor drive circuit temperature sensor circuit, magnetic control and application circuit, motor driver circuit, measuring instrument and check tool and power control and stability circuit.

  12. A possible mechanism of the enhancement and maintenance of the shear magnetic field component in the current sheet of the Earth’s magnetotail

    International Nuclear Information System (INIS)

    Grigorenko, E. E.; Malova, H. V.; Malykhin, A. Yu.; Zelenyi, L. M.

    2015-01-01

    The influence of the shear magnetic field component, which is directed along the electric current in the current sheet (CS) of the Earth’s magnetotail and enhanced near the neutral plane of the CS, on the nonadiabatic dynamics of ions interacting with the CS is studied. The results of simulation of the nonadiabatic ion motion in the prescribed magnetic configuration similar to that observed in the magnetotail CS by the CLUSTER spacecraft demonstrated that, in the presence of some initial shear magnetic field, the north-south asymmetry in the ion reflection/refraction in the CS is observed. This asymmetry leads to the formation of an additional current system formed by the oppositely directed electric currents flowing in the northern and southern parts of the plasma sheet in the planes tangential to the CS plane and in the direction perpendicular to the direction of the electric current in the CS. The formation of this current system perhaps is responsible for the enhancement and further maintenance of the shear magnetic field near the neutral plane of the CS. The CS structure and ion dynamics observed in 17 intervals of the CS crossings by the CLUSTER spacecraft is analyzed. In these intervals, the shear magnetic field was increased near the neutral plane of the CS, so that the bell-shaped spatial distribution of this field across the CS plane was observed. The results of the present analysis confirm the suggested scenario of the enhancement of the shear magnetic field near the neutral plane of the CS due to the peculiarities of the nonadiabatic ion dynamics

  13. A possible mechanism of the enhancement and maintenance of the shear magnetic field component in the current sheet of the Earth’s magnetotail

    Energy Technology Data Exchange (ETDEWEB)

    Grigorenko, E. E., E-mail: elenagrigorenko2003@yahoo.com; Malova, H. V., E-mail: hmalova@yandex.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation); Malykhin, A. Yu., E-mail: anmaurdreg@gmail.com [Moscow Institute of Physics and Technology (Russian Federation); Zelenyi, L. M., E-mail: lzelenyi@iki.rssi.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2015-01-15

    The influence of the shear magnetic field component, which is directed along the electric current in the current sheet (CS) of the Earth’s magnetotail and enhanced near the neutral plane of the CS, on the nonadiabatic dynamics of ions interacting with the CS is studied. The results of simulation of the nonadiabatic ion motion in the prescribed magnetic configuration similar to that observed in the magnetotail CS by the CLUSTER spacecraft demonstrated that, in the presence of some initial shear magnetic field, the north-south asymmetry in the ion reflection/refraction in the CS is observed. This asymmetry leads to the formation of an additional current system formed by the oppositely directed electric currents flowing in the northern and southern parts of the plasma sheet in the planes tangential to the CS plane and in the direction perpendicular to the direction of the electric current in the CS. The formation of this current system perhaps is responsible for the enhancement and further maintenance of the shear magnetic field near the neutral plane of the CS. The CS structure and ion dynamics observed in 17 intervals of the CS crossings by the CLUSTER spacecraft is analyzed. In these intervals, the shear magnetic field was increased near the neutral plane of the CS, so that the bell-shaped spatial distribution of this field across the CS plane was observed. The results of the present analysis confirm the suggested scenario of the enhancement of the shear magnetic field near the neutral plane of the CS due to the peculiarities of the nonadiabatic ion dynamics.

  14. Advances in safety related maintenance

    International Nuclear Information System (INIS)

    2000-03-01

    The maintenance of systems, structures and components in nuclear power plants (NPPs) plays an important role in assuring their safe and reliable operation. Worldwide, NPP maintenance managers are seeking to reduce overall maintenance costs while maintaining or improving the levels of safety and reliability. Thus, the issue of NPP maintenance is one of the most challenging aspects of nuclear power generation. There is a direct relation between safety and maintenance. While maintenance alone (apart from modifications) will not make a plant safer than its original design, deficient maintenance may result in either an increased number of transients and challenges to safety systems or reduced reliability and availability of safety systems. The confidence that NPP structures, systems and components will function as designed is ultimately based on programmes which monitor both their reliability and availability to perform their intended safety function. Because of this, approaches to monitor the effectiveness of maintenance are also necessary. An effective maintenance programme ensures that there is a balance between the improvement in component reliability to be achieved and the loss of component function due to maintenance downtime. This implies that the safety level of an NPP should not be adversely affected by maintenance performed during operation. The nuclear industry widely acknowledges the importance of maintenance in NPP safety and operation and therefore devotes great efforts to develop techniques, methods and tools to aid in maintenance planning, follow-up and optimization, and in assuring the effectiveness of maintenance

  15. Compact Circuit Preprocesses Accelerometer Output

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1993-01-01

    Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.

  16. Enhancement of Linear Circuit Program

    DEFF Research Database (Denmark)

    Gaunholt, Hans; Dabu, Mihaela; Beldiman, Octavian

    1996-01-01

    In this report a preliminary user friendly interface has been added to the LCP2 program making it possible to describe an electronic circuit by actually drawing the circuit on the screen. Component values and other options and parameters can easily be set by the aid of the interface. The interface...

  17. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: A case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2015-03-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification (Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  18. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  19. Radiation-sensitive switching circuits

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.H.; Cockshott, C.P.

    1976-03-16

    A radiation-sensitive switching circuit has a light emitting diode which supplies light to a photo-transistor, the light being interrupted from time to time. When the photo-transistor is illuminated, current builds up and when this current reaches a predetermined value, a trigger circuit changes state. The peak output of the photo-transistor is measured and the trigger circuit is arranged to change state when the output of the device is a set proportion of the peak output, so as to allow for aging of the components. The circuit is designed to control the ignition system in an automobile engine.

  20. Primer printed circuit boards

    CERN Document Server

    Argyle, Andrew

    2009-01-01

    Step-by-step instructions for making your own PCBs at home. Making your own printed circuit board (PCB) might seem a daunting task, but once you master the steps, it's easy to attain professional-looking results. Printed circuit boards, which connect chips and other components, are what make almost all modern electronic devices possible. PCBs are made from sheets of fiberglass clad with copper, usually in multiplelayers. Cut a computer motherboard in two, for instance, and you'll often see five or more differently patterned layers. Making boards at home is relatively easy

  1. Reduction of adhesive stain defect in flexible printed circuit board on hot pressing process: a case study of electronic component factory

    Directory of Open Access Journals (Sweden)

    Sakulkaew Srisang

    2014-09-01

    Full Text Available The objective of this research is a reduction of an adhesive stain defect in flexible printed circuit board in hot pressing process, the electronic factory. The manufacturing have been processing by sheet type of products with ninety-six pieces of flexible printed circuit boards. Causes of the problem include the before and internal hot pressing process. In process beginning times, the most right row of products between the cooling plate and the hot pressing machine has temperature 71.2◦C that is higher than glass transition temperature (Tg 60◦C. Those products’ temperature lead to evaporate a polyimide adhesive before hot pressing process beginning. The internal hot pressing process include the preheat times and the pressure time. In the preheat time the problem is a gap between lower and upper plate, was under specification(Under 1 mm and leaded to adhesive polyimide stain. In the actuality this time requires temperature and low pressure that mean a gap within 1 – 2 mm (between lower and upper plate. In pressure times the hot pressing plate surface is not flat and products are pressed by insufficient force that it lead to generate an adhesive stain on flexible printed circuit boards. That force is measured by the pre-scale paper and a result, RGB color, is provided. And then color density (From standard color sample and RGB color (From pre-scale paper is found out the relation by Photoshop program and multiple regression theory using. The formula is applied to compare with defect so as to find out the suitable color density (Defects reducing. The solving solutions is provided including the gap reduced adjustment between cooling plate and hot pressing machine before hot pressing process, the plate adjustment within specification in the preheat time and the pressing plate polishing in the pressure time. Results of study and solving are provide defect reduction from 24.4 percentage to 7.2 percentage of total study product.

  2. Overview of catastrophic failures of freewheeling diodes in power electronic circuits

    DEFF Research Database (Denmark)

    Wu, Rui; Blaabjerg, Frede; Wang, Huai

    2013-01-01

    Emerging applications (e.g. electric vehicles, renewable energy systems, more electric aircrafts, etc.) have brought more stringent reliability constrains into power electronic products because of safety requirements and maintenance cost issues. To improve the reliability of power electronics......, better understanding of failure modes and failure mechanisms of reliability–critical components in power electronic circuits are needed. Many efforts have been devoted to the reduction of IGBT failures, while the study on the failures of freewheeling diodes is less impressive. It is of importance...... to investigate the catastrophic failures of freewheeling diodes as they could induce the malfunction of other components and eventually the whole power electronic circuits. This paper presents an overview of those catastrophic failures and gives examples of the corresponding consequences to the circuits....

  3. The Maplin electronic circuits handbook

    CERN Document Server

    Tooley, Michael

    1990-01-01

    The Maplin Electronic Circuits Handbook provides pertinent data, formula, explanation, practical guidance, theory and practical guidance in the design, testing, and construction of electronic circuits. This book discusses the developments in electronics technology techniques.Organized into 11 chapters, this book begins with an overview of the common types of passive component. This text then provides the reader with sufficient information to make a correct selection of passive components for use in the circuits. Other chapters consider the various types of the most commonly used semiconductor

  4. Perencanaan Kegiatan Maintenance Dengan Metode Reability Centered Maintenance (Rcm) II

    OpenAIRE

    Rachmad Hidayat; Nachnul Ansori; Ali Imron

    2010-01-01

    Maintenance Activity Planning by Reability Centered Maintenance (RCM) II Method. This research discussmaintenance activity by using RCM II method to determine failure function risk at compresor screw. Calculation isgiven to magnitude optimum time maintenance interval by considering the cost maintenance and the cost reparation.From the research results with RPN points out that critical component that needs to get main priority in givemaintenance on compresor screw are bust logistic on timeworn...

  5. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  6. Circuit Training.

    Science.gov (United States)

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  7. Implementation of Chua's circuit using simulated inductance

    Science.gov (United States)

    Gopakumar, K.; Premlet, B.; Gopchandran, K. G.

    2011-05-01

    In this study we describe how to build an inductorless version of the classic Chua's circuit. A suitable inductor for Chua's circuit is often hard to procure. The required inductor for the circuit is designed using simple circuit elements such as resistors, capacitors and operational amplifiers. The complete circuit can be implemented by using off-the-shelf components, and it can readily be integrated on a single chip. This design of Chua's circuit allows the original dynamics to be slowed down to just a few hertz, enabling implementation of sophisticated control schemes without severe time restrictions. Another novel feature of the circuit is that losses associated with capacitors due to leakages can easily be compensated by providing negative resistance using the same setup. The chaotic behaviour of the circuit is verified by PSpice and Multisim simulation and also by experimental study on a circuit breadboard. The results give excellent agreement with each other and with the results of previous investigators.

  8. [Work accidents and automatic circuit reclosers in the electricity sector: beyond the immediate causes].

    Science.gov (United States)

    Silva, Alessandro Jose Nunes da; Almeida, Ildeberto Muniz de; Vilela, Rodolfo Andrade de Gouveia; Mendes, Renata Wey Berti; Hurtado, Sandra Lorena Beltran

    2018-05-10

    The Brazilian electricity sector has recorded high work-related mortality rates that have been associated with outsourcing, used to cut costs. In order to decrease the power outage time for consumers, the industry adopted the automatic circuit recloser as the technical solution. The device has hazardous implications for maintenance workers. The aim of this study was to analyze the origins and consequences of work accidents in power systems with automatic circuit recloser, using the Accident Analysis and Prevention (AAP) model. The AAP model was used to investigate two work accidents, aimed to explore the events' organizational origins. Case 1 - when changing a deenergized secondary line, a worker received a shock from the energized primary cable (13.8kV). The system reclosed three times, causing severe injury to the worker (amputation of a lower limb). Case 2 - a fatal work accident occurred during installation of a new crosshead on a partially insulated energized line. The tip of a metal cross arm section strap touched the energized secondary line and electrocuted the maintenance operator. The circuit breaker component of the automatic circuit recloser failed. The analyses revealed how business management logic can participate in the root causes of work accidents through failures in maintenance management, outsourced workforce management, and especially safety management in systems with reclosers. Decisions to adopt automation to guarantee power distribution should not overlook the risks to workers in overhead power lines or fail to acknowledge the importance of ensuring safe conditions.

  9. Maintenance methods

    International Nuclear Information System (INIS)

    Sanchis, H.; Aucher, P.

    1990-01-01

    The maintenance method applied at the Hague is summarized. The method was developed in order to solve problems relating to: the different specialist fields, the need for homogeneity in the maintenance work, the equipment diversity, the increase of the materials used at the Hague's new facilities. The aim of the method is to create a knowhow formalism, to facilitate maintenance, to ensure the running of the operations and to improve the estimation of the maintenance cost. One of the method's difficulties is the demonstration of the profitability of the maintenance operations [fr

  10. Parameter Estimation of a Reliability Model of Demand-Caused and Standby-Related Failures of Safety Components Exposed to Degradation by Demand Stress and Ageing That Undergo Imperfect Maintenance

    Directory of Open Access Journals (Sweden)

    S. Martorell

    2017-01-01

    Full Text Available One can find many reliability, availability, and maintainability (RAM models proposed in the literature. However, such models become more complex day after day, as there is an attempt to capture equipment performance in a more realistic way, such as, explicitly addressing the effect of component ageing and degradation, surveillance activities, and corrective and preventive maintenance policies. Then, there is a need to fit the best model to real data by estimating the model parameters using an appropriate tool. This problem is not easy to solve in some cases since the number of parameters is large and the available data is scarce. This paper considers two main failure models commonly adopted to represent the probability of failure on demand (PFD of safety equipment: (1 by demand-caused and (2 standby-related failures. It proposes a maximum likelihood estimation (MLE approach for parameter estimation of a reliability model of demand-caused and standby-related failures of safety components exposed to degradation by demand stress and ageing that undergo imperfect maintenance. The case study considers real failure, test, and maintenance data for a typical motor-operated valve in a nuclear power plant. The results of the parameters estimation and the adoption of the best model are discussed.

  11. Integrated circuit structure

    International Nuclear Information System (INIS)

    1981-01-01

    The invention describes the fabrication of integrated circuit structures, such as read-only memory components of field-effect transistors, which may be fabricated and then maintained in inventory, and later selectively modified in accordance with a desired pattern. It is claimed that MOS depletion-mode devices in accordance with the invention can be fabricated at lower cost and at higher yields. (U.K.)

  12. New fast switches for the Tore Supra ohmic heating circuit

    International Nuclear Information System (INIS)

    Zunino, K.; Bruneth, J.; Cara, P.; Louart, A.; Santagiustina, A.; Emelyanova, I.; Filippov, F.; Mikailov, N.

    2003-01-01

    The Tore-Supra ohmic heating circuit is equipped with four fast make switches and one fast opening switch. After many years of operation, it became necessary to substitute this equipment by modern components with similar ratings. An extensive research has been undertaken to find fast switches able to withstand more than 2500 operations per year without maintenance, at a make current of 54 kA, a voltage of 12 kV and with a closing time of less than 15 ms. At the end of the investigation, it was decided to replace the old components by fast mechanical switches proposed by the Efremov Institute and based on a prototype developed for ITER. This paper presents the technical requirements and the characteristics of the switches and describes the operational experience gained with these components during operating campaigns of 2002 and 2003. (authors)

  13. Regulatory oversight of maintenance activities at nuclear power plants in France

    International Nuclear Information System (INIS)

    Bouton, J.P.; Lallement, J.

    1997-01-01

    In France the nuclear safety authority sets out the main safety objectives but the operator remains the first responsible for the NPP safety. During the operation, operators have to demonstrate that the safety level remains the same as defined in the design studies. Maintenance contributes to meet this objective. The French regulation insists on the quality of the safety related components maintenance, especially in the 1984 order. All gap between results and requirements have to be analyzed by operator who provide feedback measures to avoid similar failure to occur. This gap have to be mentioned to regulators. The use of probabilistic safety analysis (PSA) and reliability centered maintenance (RCM) methods is not well developed in France to optimize maintenance. For the French regulatory, the major difficulties in the use of PSA are: The impossibility to detect unanticipated failure mode; the validity of the input data; the validity of model use, based on ''engineering judgement''. For the specific case of passive components inspection, such as the vessel of the primary circuit, the French regulator has already indicated to the operator that the optimization of maintenance by use of PSA cannot be used, for the following reasons: The safety analysis does not take into account the failure of the vessel; unanticipated failure modes have already damaged part of the primary circuit; the use of defense in depth concept requires a systematic detection of any defect on the vessel. (author)

  14. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  15. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  16. Radiation-sensitive switching circuits

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.H.; Cockshott, C.P.

    1976-03-16

    A radiation-sensitive switching circuit includes a light emitting diode which from time to time illuminates a photo-transistor, the photo-transistor serving when its output reaches a predetermined value to operate a trigger circuit. In order to allow for aging of the components, the current flow through the diode is increased when the output from the transistor falls below a known level. Conveniently, this is achieved by having a transistor in parallel with the diode, and turning the transistor off when the output from the phototransistor becomes too low. The circuit is designed to control the ignition system in an automobile engine.

  17. Fast Flux Test Facility (FFTF) maintenance provisions

    International Nuclear Information System (INIS)

    Marshall, J.L.

    1981-05-01

    The Fast Flux Test Facility (FFTF) was designed with maintainability as a primary parameter, and facilities and provisions were designed into the plant to accommodate the maintenance function. This paper describes the FFTF and its systems. Special maintenance equipment and facilities for performing maintenance on radioactive components are discussed. Maintenance provisions designed into the plant to enhance maintainability are also described

  18. Quasi-Linear Circuit

    Science.gov (United States)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  19. Remote maintenance development for ITER

    International Nuclear Information System (INIS)

    Tada, Eisuke; Shibanuma, Kiyoshi

    1998-01-01

    This paper describes the overall ITER remote maintenance design concept developed mainly for in-vessel components such as diverters and blankets, and outlines the ITER R and D program to develop remote handling equipment and radiation hard components. Reactor structures inside the ITER cryostat must be maintained remotely due to DT operation, making remote handling technology basic to reactor design. The overall maintenance scenario and design concepts have been developed, and maintenance design feasibility, including fabrication and testing of full-scale in-vessel remote maintenance handling equipment and tool, is being verified. (author)

  20. Remote maintenance development for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Eisuke [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Shibanuma, Kiyoshi

    1998-04-01

    This paper describes the overall ITER remote maintenance design concept developed mainly for in-vessel components such as diverters and blankets, and outlines the ITER R and D program to develop remote handling equipment and radiation hard components. Reactor structures inside the ITER cryostat must be maintained remotely due to DT operation, making remote handling technology basic to reactor design. The overall maintenance scenario and design concepts have been developed, and maintenance design feasibility, including fabrication and testing of full-scale in-vessel remote maintenance handling equipment and tool, is being verified. (author)

  1. Annual report of the group for maintenance of electronic equipment

    International Nuclear Information System (INIS)

    Popovic, B.

    1965-01-01

    Maintenance and repair of the RA reactor control and safety systems were uniformly distributed during the whole year and were done according to the annual plan. A series of repairs of he electronic equipment as well as exchange of electronic components and elec tonic tubes. The testing and calibration of control and protection circuits were done regularly according to the needs and operation state of the reactor and according to the instructions. Inspections, repairs and reconstructions well as operating characteristics of individual elements as well as complete electronic circuits during 1965 have shown da the systems of control and safety are still in good condition. Somewhat higher number of failures due to aging of electronic tubes is a regular consequence of equipment and instrumentation aging [sr

  2. Preventative Maintenance.

    Science.gov (United States)

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  3. LOGIC CIRCUIT

    Science.gov (United States)

    Strong, G.H.; Faught, M.L.

    1963-12-24

    A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)

  4. Excellence through maintenance mastering

    International Nuclear Information System (INIS)

    Lamarche, M.; Guillot, M.; Monier, M.

    1987-01-01

    To improve the overall availability factor of nuclear power plants you have to cut either the forced outage role and the planned outage time or you need to reduce simultaneously the failures and the efforts devoted to avoiding them. Among other results, this goal leads to a decrease in the number of real or anticipated problems. Electricite de France policy, in this matter, is to focus on decreasing the compoents' maintenance needs through a comprehensive modification program, targeted to eliminating the weak points as revealed by the operation. Thereby one may reach, for simple equipment, a nearly maintenance-free condition in which the only maintenance needed is surveillance, which provides assurance that everything is operating properly. A good example of this type of equipment is the family of static components, drums, and pipes whose corrective maintenance is almost nil when their initial condition is good

  5. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  6. Design concept of conducting shell and in-vessel components suitable for plasma vertical stability and remote maintenance scheme in DEMO reactor

    Energy Technology Data Exchange (ETDEWEB)

    Utoh, Hiroyasu, E-mail: uto.hiroyasu@jaea.go.jp [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Takase, Haruhiko [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Sakamoto, Yoshiteru; Tobita, Kenji [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); Mori, Kazuo; Kudo, Tatsuya [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan); International Fusion Energy Research Centre, 2-166, Obuchi, Rokkasho, Aomori 039-3212 (Japan); Someya, Youji; Asakura, Nobuyuki; Hoshino, Kazuo; Nakamura, Makoto; Tokunaga, Shinsuke [Japan Atomic Energy Agency, Obuchi, Rokkasho-mura, Aomori-ken 039-3212 (Japan)

    2016-02-15

    Highlights: • Conceptual design of in-vessel component including conducting shell has been investigated. • The conducting shell design for plasma vertical stability was clarified from the plasma vertical stability analysis. • The calculation results showed that the double-loop shell has the most effect on plasma vertical stability. - Abstract: In order to realize a feasible DEMO, we designed an in-vessel component including the conducting shell. The project is affiliated with the broader approach DEMO design activities and is conceptualized from a plasma vertical stability and engineering viewpoint. The dependence of the plasma vertical stability on the conducing shell parameters and the electromagnetic force at plasma disruption were investigated in numerical simulations (programmed in the 3D eddy current analysis code and a plasma position control code). The simulations assumed the actual shape and position of the vacuum vessel and in-vessel components. The plasma vertical stability was most effectively maintained by the double-loop shell.

  7. Support to NPP operation and maintenance technology risk management. A concept for establishing criteria and procedure for the selection of components with respect to their importance. Stage 3.1. NPP equipment reliability management

    International Nuclear Information System (INIS)

    Stvan, F.

    2003-12-01

    A proposal was developed for a procedure using the deterministic approach to the assessment of components from the operational point of view and other aspects that cannot be directly and readily quantified and of the probabilistic approach for the assessment of component importance with respect to nuclear safety. A specific PSA study performed for the Dukovany NPP was employed. The structure of the report is as follows: (1) Aspects of component selection; (2) Introductory procedure; (3) Criteria for the selection of components with respect to their importance (4) Assessing the priority of use of the assets - effect on production, safety, and profit; (5) Assessment of the risk aspect of the assets - effect on major processes; (6) Assessment of the level of use of the assets; (7) Assessment of the structure of the assets - optimal structure for maintenance in relation to the major processes; (8) Assessment of the criteria for estimating the importance of the components; (9) Probabilistic assessment of importance from the safety aspect by means of PSA; and (10) Deterministic assessment of importance from the safety aspect. (P.A.)

  8. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    1987-02-01

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  9. Collective of mechatronics circuit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-02-15

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  10. Maintenance of electronic equipment at the Saclay Nuclear Research Centre

    International Nuclear Information System (INIS)

    Chicheportiche, Armand; Raoult, Norbert.

    1975-06-01

    The Test-Repair Group of the Saclay Electronics Services ensures the maintenance of electronic equipment available to users of the Saclay site. The more and more frequent use of microelectronics in these instruments increases the electronic operator density and the working and data transmission sequences are becoming difficult to understand. This leads to complications in the adjustment, testing and repairs. Ways and means are studied to facilitate maintenance while reducing the immobilization time of the equipment and the repair costs. The Saclay Electronics Services have developed a method of systematic test sequence formulation and breakdown diagnosis based on the properties of binary analysis. This method is used by a supplier of the CEA which has built the corresponding test equipment. Owing to the test programmmes established for each component of an apparatus it is possible for example to locate a faulty element on a plan including more than 100 integrated circuits and to replace it in no more than 10 minutes [fr

  11. Circuit parties.

    Science.gov (United States)

    Guzman, R

    2000-03-01

    Circuit parties are extended celebrations, lasting from a day to a week, primarily attended by gay and bisexual men in their thirties and forties. These large-scale dance parties move from city to city and draw thousands of participants. The risks for contracting HIV during these parties include recreational drug use and unsafe sex. Limited data exists on the level of risk at these parties, and participants are skeptical of outside help because of past criticism of these events. Health care and HIV advocates can promote risk-reduction strategies with the cooperation of party planners and can counsel individuals to personally reduce their own risk. To convey the message, HIV prevention workers should emphasize positive and community-centered aspects of the parties, such as taking care of friends and avoiding overdose.

  12. Remote handling maintenance of ITER

    International Nuclear Information System (INIS)

    Haange, R.

    1999-01-01

    The remote maintenance strategy and the associated component design of the International Thermonuclear Experimental Reactor (ITER) have reached a high degree of completeness, especially with respect to those components that are expected to require frequent or occasional remote maintenance. Large-scale test stands, to demonstrate the principle feasibility of the remote maintenance procedures and to develop the required equipment and tools, were operational at the end of the Engineering Design Activities (EDA) phase. The initial results are highly encouraging: major remote equipment deployment and component replacement operations have been successfully demonstrated. (author)

  13. CANDU plant maintenance: Recent developments

    International Nuclear Information System (INIS)

    Charlebois, P.

    2000-01-01

    CANDU units have long been recognized for their exceptional safety and reliability. Continuing development in the maintenance area has played a key role in achieving this performance level. For over two decades, safety system availability has been monitored closely and system maintenance programs adjusted accordingly to maintain high levels of performance. But as the plants approach mid life in a more competitive environment and component aging becomes a concern, new methods and techniques are necessary. As a result, recent developments are moving the maintenance program largely from a corrective and preventive approach to predictive and condition based maintenance. The application of these techniques is also being extended to safety related systems. These recent developments include use of reliability centred methods to define system maintenance requirements and strategies. This approach has been implemented on a number of systems at Canadian CANDU plants with positive results. The pilot projects demonstrated that the overall maintenance effort remained relatively constant while the system performance improved. It was also possible to schedule some of the redundant component maintenance during plant operation without adverse impact on system availability. The probabilistic safety assessment was found to be useful in determining the safety implications of component outages. These new maintenance strategies are now making use of predictive and condition based maintenance techniques to anticipate equipment breakdown and schedule preventive maintenance as the need arises rather than time based. Some of these techniques include valve diagnostics, vibration monitoring, oil analysis, thermography. Of course, these tools and techniques must form part of an overall maintenance management system to ensure that maintenance becomes a living program. To facilitate this process and contain costs, new information technology tools are being introduced to provide system engineers

  14. Condition based maintenance in the context of opportunistic maintenance

    NARCIS (Netherlands)

    Koochaki, Javid; Bokhorst, Jos A. C.; Wortmann, Hans; Klingenberg, Warse

    2012-01-01

    Condition based maintenance (CBM) uses the operating condition of a component to predict a failure event. Compared to age based replacement (ABR), CBM usually results in higher availability and lower maintenance costs, since it tries to prevent unplanned downtime and avoid unnecessary preventive

  15. Active component modeling for analog integrated circuit design. Model parametrization and implementation in the SPICE-PAC circuit simulator; Modelisation de composants actifs pour la CAO de circuits integres analogiques. Parametrage et implantation de modeles dans le simulateur SPICE-PAC

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, Xavier

    1992-06-19

    In order to use CAD efficiently in the analysis and design of electronic Integrated circuits, adequate modeling of active non-linear devices such as MOSFET transistors must be available to the designer. Many mathematical forms can be given to those models, such as explicit relations, or implicit equations to be solved. A major requirement in developing MOS transistor models for IC simulation is the availability of electrical characteristic curves over a wide range of channel width and length, including the sub-micrometer range. To account in a convenient way for bulk charge influence on I{sub DS} = f(V{sub DS}, V{sub GS}, v{sub BS}) device characteristics, all 3 standard SPICE MOS models use an empirical fitting parameter called the 'charge sharing factor'. Unfortunately, this formulation produces models which only describe correctly either some of the short channel phenomena, or some particular operating conditions (low injection, avalanche effect, etc.). We present here a cellular model (CDM = Charge Distributed Model) implemented in the open modular SPICE-PAC Simulator; this model is derived from the 4-terminal WANG charge controlled MOSFET model, using the charge sheet approximation. The CDM model describes device characteristics in ail operating regions without introducing drain current discontinuities and without requiring a 'charge sharing factor'. A usual problem to be faced by designers when they simulate MOS ICs is to find a reliable source of model parameters. Though most models have a physical basis, some of their parameters cannot be easily estimated from physical considerations. It can also happen that physically determined parameters values do not produce a good fit to measured device characteristics. Thus it is generally necessary to extract model parameters from measured transistor data, to ensure that model equations approximate measured curves accurately enough. Model parameters extraction can be done in 2 different ways, exposed in this thesis

  16. Maintenance Mentor

    National Research Council Canada - National Science Library

    Jacobs, John

    2003-01-01

    Maintenance Mentor (MXM) is a research effort conducted by a joint AFRL/HESR and Northrop Grumman Information Technology team to identify the basic, high-level requirements necessary for improving flight line diagnostic capabilities...

  17. Maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    1982-01-01

    This Guide covers the organizational and procedural aspects of maintenance but does not give detailed technical advice on the maintenance of particular plant items. It gives guidance on preventive and remedial measures necessary to ensure that all structures, systems and components important to safety are capable of performing as intended. The Guide covers the organizational and administrative requirements for establishing and implementing preventive maintenance schedules, repairing defective plant items, providing maintenance facilities and equipment, procuring stores and spare parts, selecting and training maintenance personnel, reviewing and controlling plant modifications arising from maintenance, and for generating, collecting and retaining maintenance records. Maintenance shall be subject to quality assurance in all aspects important to safety. Because quality assurance has been dealt with in detail in other Safety Guides, it is only included here in specific instances where emphasis is required. Maintenance is considered to include functional and performance testing of plant, surveillance and in-service inspection, where these are necessary either to support other maintenance activities or to ensure continuing capability of structures, systems and components important to safety to perform their intended functions

  18. Instrumentation maintenance

    International Nuclear Information System (INIS)

    Mack, D.A.

    1976-09-01

    It is essential to any research activity that accurate and efficient measurements be made for the experimental parameters under consideration for each individual experiment or test. Satisfactory measurements in turn depend upon having the necessary instruments and the capability of ensuring that they are performing within their intended specifications. This latter requirement can only be achieved by providing an adequate maintenance facility, staffed with personnel competent to understand the problems associated with instrument adjustment and repair. The Instrument Repair Shop at the Lawrence Berkeley Laboratory is designed to achieve this end. The organization, staffing and operation of this system is discussed. Maintenance policy should be based on studies of (1) preventive vs. catastrophic maintenance, (2) records indicating when equipment should be replaced rather than repaired and (3) priorities established to indicate the order in which equipment should be repaired. Upon establishing a workable maintenance policy, the staff should be instructed so that they may provide appropriate scheduled preventive maintenance, calibration and corrective procedures, and emergency repairs. The education, training and experience of the maintenance staff is discussed along with the organization for an efficient operation. The layout of the various repair shops is described in the light of laboratory space and financial constraints

  19. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  20. Digital logic circuit test

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Gil Jung; Yang, Hong Young

    2011-03-15

    This book is about digital logic circuit test, which lists the digital basic theory, basic gate like and, or And Not gate, NAND/NOR gate such as NAND gate, NOR gate, AND and OR, logic function, EX-OR gate, adder and subtractor, decoder and encoder, multiplexer, demultiplexer, flip-flop, counter such as up/down counter modulus N counter and Reset type counter, shift register, D/A and A/D converter and two supplements list of using components and TTL manual and CMOS manual.

  1. Irradiation properties of T0 chopper components

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Shinichi, E-mail: shinichi.itoh@kek.jp [Neutron Science Division, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba 305-0801 (Japan); Ueno, Kenji; Ohkubo, Ryuji [Mechanical Engineering Center, Applied Research Laboratory, High Energy Accelerator Research Organization, Tsukuba 305-0801 (Japan); Sagehashi, Hidenori [Neutron Science Division, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba 305-0801 (Japan); Funahashi, Yoshisato [Mechanical Engineering Center, Applied Research Laboratory, High Energy Accelerator Research Organization, Tsukuba 305-0801 (Japan); Yokoo, Tetsuya [Neutron Science Division, Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba 305-0801 (Japan)

    2011-10-21

    We investigated the irradiation properties of the components of a T0 chopper. The organic materials in the rotor bearing grease, the magnetic fluids in seals, and the rubber in the timing belt, as well as the semiconductor materials in the rotation sensor and motor encoder, were all irradiated with high-energy {gamma}-rays up to 100 kGy. No significant damage that shortens the lifetime of a T0 chopper was observed for the mechanical components. However, the semiconductor components were damaged by the irradiation. For the rotation sensor system detecting the rotor phase, the signal from a marker on the rotor shaft was transmitted outside the shielding by an optical fiber with radiation-proofing and the electrical circuits were removed from the beamline shielding. The lifetime of the motor encoder possibly meets the requirement for the maintenance period of the T0 chopper.

  2. Maintenance of extra high voltage circuit breakers and switches by own and contracted teams; Manutencao de disjuntores e seccionadores de extra alta tensao com utilizacao de equipes proprias e contratadas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose Flavio; Santiago Junior, Martin G.; Siecola, Paulo Roberto C.; Betio, Ivan [Companhia Energetica de Sao Paulo (CESP), SP (Brazil)

    1995-12-31

    This work presents CESP`s experience in the maintenance of electric power substation equipment by a team contracted to do the work out of the risk area in conjunction to the company`s own teams which perform the activities in the electric power substation areas. the several contract types are discussed as well as the adopted procedures in order to achieve quality improvement and costs reduction

  3. Improving the TRIGA facility maintenance by predictive maintenance techniques

    International Nuclear Information System (INIS)

    Preda, M.; Sabau, C.; Barbalata, E.

    1997-01-01

    This work deals with the specific operation of equipment in radioactive environment or in conditions allowing radioactive contamination. The requirements of remote operation ensuring the operators' protection are presented. Also, the requirements of international standards issued by IAEA-Vienna are reviewed. The organizational withdraws of the maintenance activities, based on the standards and maintenance and repair directives still in force, are shown. It is emphasized the fact that this type of maintenance was adequate to a given level of technical development, characteristic for pre-computerized industry, but, at present, it is obsolete and uneconomic both in utilization and maintenance. Such a system constitutes already a burden hindering the efforts of maximizing the availability, maintenance, prolongation the service life of equipment and utilities, finally, of increasing the efficiency of complex installations. Moreover, the predictive maintenance techniques are strongly requested by the character of radioactive installations precluding the direct access in given zones (a potential risk of irradiation or radioactive contamination) of installations during operation. The results obtained by applying the predictive maintenance techniques in the operation of the double circuit irradiation loop, used in the TRIGA reactors, are presented

  4. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  5. PUZZLE - A program for computer-aided design of printed circuit artwork

    Science.gov (United States)

    Harrell, D. A. W.; Zane, R.

    1971-01-01

    Program assists in solving spacing problems encountered in printed circuit /PC/ design. It is intended to have maximum use for two-sided PC boards carrying integrated circuits, and also aids design of discrete component circuits.

  6. Maintenance - a design perspective

    International Nuclear Information System (INIS)

    Hedges, K.R.

    1992-01-01

    The paper describes how the CANDU-3 has incorporated, at the design stage, maintenance requirements such as component accessibility, standardization, ease of replacement, reduction in the number of components, and simplified component design. AECL is also active in the planned rehabilitation of the four units at Ontario Hydro's Bruce A nuclear generating station. In addition to conceptual design and development, detailed design and analysis, procurement and site assistance, AECL's Sheridan Park Laboratory will provide important development and mockup facilities. An AECL research and development program on reactor maintenance includes the identification and characterization of aging and degrading mechanisms, the tailoring of developed products to plant requirements, and the identification of areas of international cooperation and information exchange. 3 tabs., 1 fig

  7. Proceedings of the fourth international conference on CANDU maintenance

    International Nuclear Information System (INIS)

    1997-01-01

    These proceedings record the information presented at the 4th International Conference on CANDU Maintenance held November 16-18,1997 in Toronto, Canada. The papers for these proceedings were prepared on component maintenance, human performance, steam generator leak detection, fuel channel inspections, rotating equipment maintenance, surveillance programs, inspection techniques, valve maintenance, steam generator repairs and performance, reactor aging management and preventative maintenance

  8. Proceedings of the fourth international conference on CANDU maintenance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    These proceedings record the information presented at the 4th International Conference on CANDU Maintenance held November 16-18,1997 in Toronto, Canada. The papers for these proceedings were prepared on component maintenance, human performance, steam generator leak detection, fuel channel inspections, rotating equipment maintenance, surveillance programs, inspection techniques, valve maintenance, steam generator repairs and performance, reactor aging management and preventative maintenance.

  9. DEVICES FOR COOLING ELECTRONIC CIRCUIT BOARDS

    OpenAIRE

    T. A. Ismailov; D. V. Evdulov; A. G. Mustafaev; D. K. Ramazanova

    2014-01-01

    In the work described structural variants of devices for cooling electronic circuit boards, made on the basis of thermoelectric batteries and consumable working substances, implementing uneven process of removing heat from heat-generating components. A comparison of temperature fields of electronic circuit simulator with his uniform and non-uniform cooling. 

  10. DEVICES FOR COOLING ELECTRONIC CIRCUIT BOARDS

    Directory of Open Access Journals (Sweden)

    T. A. Ismailov

    2014-01-01

    Full Text Available In the work described structural variants of devices for cooling electronic circuit boards, made on the basis of thermoelectric batteries and consumable working substances, implementing uneven process of removing heat from heat-generating components. A comparison of temperature fields of electronic circuit simulator with his uniform and non-uniform cooling. 

  11. Remote maintenance development for ITER

    International Nuclear Information System (INIS)

    Tada, Eisuke; Shibanuma, Kiyoshi

    1997-01-01

    This paper both describes the overall design concept of the ITER remote maintenance system, which has been developed mainly for use with in-vessel components such as divertor and blanket, and outlines of the ITER R and D program, which has been established to develop remote handling equipment/tools and radiation hard components. In ITER, the reactor structures inside cryostat have to be maintained remotely because of activation due to DT operation. Therefore, remote-handling technology is fundamental, and the reactor-structure design must be made consistent with remote maintainability. The overall maintenance scenario and design concepts of the required remote handling equipment/tools have been developed according to their maintenance classification. Technologies are also being developed to verify the feasibility of the maintenance design and include fabrication and testing of a fullscale remote-handling equipment/tools for in-vessel maintenance. (author)

  12. Radiation-hardened CMOS integrated circuits

    International Nuclear Information System (INIS)

    Derbenwick, G.F.; Hughes, R.C.

    1977-01-01

    Electronic circuits that operate properly after exposure to ionizing radiation are necessary for nuclear weapon systems, satellites, and apparatus designed for use in radiation environments. The program to develop and theoretically model radiation-tolerant integrated circuit components has resulted in devices that show an improvement in hardness up to a factor of ten thousand over earlier devices. An inverter circuit produced functions properly after an exposure of 10 6 Gy (Si) which, as far as is known, is the record for an integrated circuit

  13. Intrinsic neuromodulation: altering neuronal circuits from within.

    Science.gov (United States)

    Katz, P S; Frost, W N

    1996-02-01

    There are two sources of neuromodulation for neuronal circuits: extrinsic inputs and intrinsic components of the circuits themselves. Extrinsic neuromodulation is known to be pervasive in nervous systems, but intrinsic neuromodulation is less recognized, despite the fact that it has now been demonstrated in sensory and neuromuscular circuits and in central pattern generators. By its nature, intrinsic neuromodulation produces local changes in neuronal computation, whereas extrinsic neuromodulation can cause global changes, often affecting many circuits simultaneously. Studies in a number of systems are defining the different properties of these two forms of neuromodulation.

  14. Maintenance for life management

    International Nuclear Information System (INIS)

    Hevia, F.

    1997-01-01

    Life Management is based on the detection, monitoring and control of long-term degradation that affects individual plant components and important populations. Experience has shown that in many cases current maintenance practices do not attend to ageing directly; instead they deal with the consequences when it is already too late, when good Life Management is no longer practical. This has brought about the need for specific Maintenance Evaluation and Improvement Programmes to adjust to the basic objective of Life Management which is to project against, monitor and mitigate ageing that can affect the safe and profitable operating life of the facility. New regulatory requirements for ageing monitoring and effective maintenance to ensure safety (Maintenance Rule) have made it even more necessary to implement the Maintenance Evaluation Programme to cope with ageing, and to integrate that tasks in both programmes to optimise effort and use of tools. This paper presents a brief description of the objectives and methodologies of these Programmes which has been applied to plants around the world and in Spain at the Garona and Vandellos II plants in Spain as part of the PIE project for developing a Remanent Life Evaluation System for nuclear power plants. (Author)

  15. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  16. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  17. Current limiter circuit system

    Science.gov (United States)

    Witcher, Joseph Brandon; Bredemann, Michael V.

    2017-09-05

    An apparatus comprising a steady state sensing circuit, a switching circuit, and a detection circuit. The steady state sensing circuit is connected to a first, a second and a third node. The first node is connected to a first device, the second node is connected to a second device, and the steady state sensing circuit causes a scaled current to flow at the third node. The scaled current is proportional to a voltage difference between the first and second node. The switching circuit limits an amount of current that flows between the first and second device. The detection circuit is connected to the third node and the switching circuit. The detection circuit monitors the scaled current at the third node and controls the switching circuit to limit the amount of the current that flows between the first and second device when the scaled current is greater than a desired level.

  18. Residual life management. Maintenance improvement

    International Nuclear Information System (INIS)

    Sainero Garcia, J.; Hevia Ruperez, F.

    1995-01-01

    The terms Residual Life Management, Life Cycle Management and Long-Term Management are synonymous with a concept which aims to establish efficient maintenance for the profitable and safe operation of a power plant for as long as possible. A Residual Life Management programme comprises a number of stages, of which Maintenance Evaluation focuses on how power plant maintenance practices allow the mitigation and control of component ageing. with this objective in mind, a methodology has been developed for the analysis of potential degradative phenomena acting on critical components in terms of normal power plant maintenance practices. This methodology applied to maintenance evaluation enables the setting out of a maintenance programme based on the Life Management concept, and the programme's subsequent up-dating to allow for new techniques and methods. Initial applications have shown that although, in general terms, power plant maintenance is efficient, the way in which Residual Life Management is approached requires changes in maintenance practices. These changes range from modifications to existing inspection and surveillance methods or the establishment of new ones, to the monitoring of trends or the performance of additional studies, the purpose of which is to provide an accurate evaluation of the condition of the installations and the possibility of life extension. (Author)

  19. Development of blanket remote maintenance system

    International Nuclear Information System (INIS)

    Kakudate, Satoshi; Nakahira, Masataka; Oka, Kiyoshi; Taguchi, Kou

    1998-01-01

    ITER in-vessel components such as blankets are scheduled maintenance components, including complete shield blanket replacement for breeding blankets. In-vessel components are activated by 14 MeV neutrons, so blanket maintenance requires remote handling equipment and tools able to handle heavy payloads of about 4 tons within a positioning accuracy of 2 mm under intense gamma radiation. To facilitate remote maintenance, blankets are segmented into 730 modules and rail-mounted vehicle remote maintenance was developed. According to the ITER R and D program, critical technology related to blanket maintenance was developed extensively through joint efforts of the Japan, EU, and U.S. home teams. This paper summarizes current blanket maintenance technology conducted by the Japan Home Team, including development of full-scale remote handling equipment and tools for blanket maintenance. (author)

  20. Development of blanket remote maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Kakudate, Satoshi; Nakahira, Masataka; Oka, Kiyoshi; Taguchi, Kou [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    ITER in-vessel components such as blankets are scheduled maintenance components, including complete shield blanket replacement for breeding blankets. In-vessel components are activated by 14 MeV neutrons, so blanket maintenance requires remote handling equipment and tools able to handle heavy payloads of about 4 tons within a positioning accuracy of 2 mm under intense gamma radiation. To facilitate remote maintenance, blankets are segmented into 730 modules and rail-mounted vehicle remote maintenance was developed. According to the ITER R and D program, critical technology related to blanket maintenance was developed extensively through joint efforts of the Japan, EU, and U.S. home teams. This paper summarizes current blanket maintenance technology conducted by the Japan Home Team, including development of full-scale remote handling equipment and tools for blanket maintenance. (author)

  1. TPX remote maintenance and shielding

    International Nuclear Information System (INIS)

    Rennich, M.J.; Nelson, B.E.

    1994-01-01

    The Tokamak Physics Experiment machine design incorporates comprehensive planning for efficient and safe component maintenance. Three programmatic decisions have been made to insure the successful implementation of this objective. First, the tokamak incorporates radiation shielding to reduce activation of components and limit the dose rate to personnel working on the outside of the machine. This allows most of the ex-vessel equipment to be maintained through conventional ''hands-on'' procedures. Second, to the maximum extent possible, low activation materials will be used inside the shielding volume. This resulted in the selection of Titanium (Ti-6Al-4V) for the vacuum vessel and PFC structures. The third decision stipulated that the primary in-vessel components will be replaced or repaired via remote maintenance tools specifically provided for the task. The component designers have been given the responsibility of incorporating maintenance design and for proving the maintainability of the design concepts in full-scale mockup tests prior to the initiation of final fabrication. Remote maintenance of the TPX machine is facilitated by general purpose tools provided by a special purpose design team. Major tools will include an in-vessel transporter, a vessel transfer system and a large component transfer container. In addition, tools such as manipulators and remotely operable impact wrenches will be made available to the component designers by this group. Maintenance systems will also provide the necessary controls for this equipment

  2. Resistor Extends Life Of Battery In Clocked CMOS Circuit

    Science.gov (United States)

    Wells, George H., Jr.

    1991-01-01

    Addition of fixed resistor between battery and clocked complementary metal oxide/semiconductor (CMOS) circuit reduces current drawn from battery. Basic idea to minimize current drawn from battery by operating CMOS circuit at lowest possible current consistent with use of simple, fixed off-the-shelf components. Prolongs lives of batteries in such low-power CMOS circuits as watches and calculators.

  3. General Tokamak Circuit Simulation Program-GTCSP

    International Nuclear Information System (INIS)

    Matsukawa, Makoto; Miura, Yushi; Aoyagi, Tetsuo.

    1997-05-01

    General Tokamak Circuit Simulation Program (GTCSP) was originally developed for the design work of JT-60 Power Supply System in JAERI. Therefore the prepared models (components) to be analyzed are generator, thyristor converter and coils. This is one of the unique points of GTCSP in comparison with other conventional electric circuit analysis program, because they make a circuit from the small devices such as resister, coil, condenser, transistor and so on. However, GTCSP is also clearly conventional because it is possible to construct an electric circuit freely with the prepared components. Moreover, a similar function could be realized by addition a new component to GTCSP. This report is assumed to be used as an User Manual of the GTCSP, not only to present the development and the analytical functions. Then some useful examples are described, and how to get graphic outputs are also mentioned. (author)

  4. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  5. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  6. Remote maintenance development, July 1975--July 1976

    International Nuclear Information System (INIS)

    Fletcher, R.D.

    1977-04-01

    The results of the second year's efforts on remote handling development and studies for remote maintenance of failure-prone areas of the New Waste Calcining Facility (NWCF) are presented. Test arrangements and results for specific viewing situations and component remote installation and removal in the Remote Maintenance Development Facility (RMDF) and component material evaluations are discussed

  7. Network maintenance

    CERN Multimedia

    GS Department

    2009-01-01

    A site-wide network maintenance operation has been scheduled for Saturday 28 February. Most of the network devices of the general purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites throughout the day. This upgrade will not affect the Computer Centre itself, Building 613, the Technical Network and the LHC experiments, dedicated networks at the pits. For further details of this intervention, please contact Netops by phone 74927 or e-mail mailto:Netops@cern.ch. IT/CS Group

  8. Network maintenance

    CERN Multimedia

    IT Department

    2009-01-01

    A site wide network maintenance has been scheduled for Saturday 28 February. Most of the network devices of the General Purpose network will be upgraded to a newer software version, in order to improve our network monitoring capabilities. This will result in a series of short (2-5 minutes) random interruptions everywhere on the CERN sites along this day. This upgrade will not affect: the Computer centre itself, building 613, the Technical Network and the LHC experiments dedicated networks at the pits. Should you need more details on this intervention, please contact Netops by phone 74927 or email mailto:Netops@cern.ch. IT/CS Group

  9. Maintenance and environmental qualification

    International Nuclear Information System (INIS)

    Martin, R.S.; Austin, D.G.

    1995-01-01

    The design of today's nuclear generating plants involves many detailed design considerations. This includes comprehensive look at aging effects on plant components over their expected lifetimes. This is important to ensuring that the plant operates safely throughout its life. The effects of aging are required to be documented in detail in today's designs. This documentation provides assurance that safe operating conditions are maintained throughout the station life cycle. This requirement is analogous to the longer standing requirement to ensure pressure boundary integrity. The pressure boundary integrity requirement has existed in the industry since its inception. The subject of plant aging effects and the maintenance of functionality is known as Environmental Qualification (EQ). This paper will attempt to explain the wisdom of EQ and the potential for optimizing maintenance activities (to move from reactive to proactive activities), within the context of the overall maintenance program. It is the author's intent to encourage the active involvement of maintenance professionals in the effective implementation of the ongoing EQ program so that the benefits are maximized

  10. Optimizing preventive maintenance

    International Nuclear Information System (INIS)

    DiCola, F.E.

    1988-01-01

    The traditional approach to preventive maintenance (PM) is based on adherence to manufacturers's requirements and recommended frequencies. When equipment fails, either new procedures are established or the frequency is increased. This leads to an increase in the number of PM activities, overloading not only maintenance resources, but support as well. There is no correlation between more PM and an increase in equipment reliability. More PM may actually induce failures. Reliability-centered maintenance, a new concept in utility maintenance, is based on identifying system/subsystem functions, failures, and dominant failure modes to develop or revise PM tasks. The activities described in this paper are based on actual implementation of this concept on an ongoing project to upgrade the PM program at one of the largest electric utilities in the country. Optimum PM activities are those that, when implemented, will minimize factors that c cause equipment to fail. One technique described illustrates how equipment performance, failure modes, and causes can be related to minimize the occurrence of failures. Operating history and service life of a component are key factors in determining the most effective PM activities, provided that the factors are related to failure modes and causes

  11. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  12. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  13. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  14. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  15. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of

  16. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  17. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, S.M.; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital

  18. Development of a standard methodology for optimizing remote visual display for nuclear maintenance tasks

    Science.gov (United States)

    Clarke, M. M.; Garin, J.; Prestonanderson, A.

    A fuel recycle facility being designed at Oak Ridge National Laboratory involves the Remotex concept: advanced servo-controlled master/slave manipulators, with remote television viewing, will totally replace direct human contact with the radioactive environment. The design of optimal viewing conditions is a critical component of the overall man/machine system. A methodology was developed for optimizing remote visual displays for nuclear maintenance tasks. The usefulness of this approach was demonstrated by preliminary specification of optimal closed circuit TV systems for such tasks.

  19. Designing Novel Quaternary Quantum Reversible Subtractor Circuits

    Science.gov (United States)

    Haghparast, Majid; Monfared, Asma Taheri

    2018-01-01

    Reversible logic synthesis is an important area of current research because of its ability to reduce energy dissipation. In recent years, multiple valued logic has received great attention due to its ability to reduce the width of the reversible circuit which is a main requirement in quantum technology. Subtractor circuits are between major components used in quantum computers. In this paper, we will discuss the design of a quaternary quantum reversible half subtractor circuit using quaternary 1-qudit, 2-qudit Muthukrishnan-Stroud and 3-qudit controlled gates and a 2-qudit Generalized quaternary gate. Then a design of a quaternary quantum reversible full subtractor circuit based on the quaternary half subtractor will be presenting. The designs shall then be evaluated in terms of quantum cost, constant input, garbage output, and hardware complexity. The proposed quaternary quantum reversible circuits are the first attempt in the designing of the aforementioned subtractor.

  20. GRAPHICAL MODELS OF THE AIRCRAFT MAINTENANCE PROCESS

    Directory of Open Access Journals (Sweden)

    Stanislav Vladimirovich Daletskiy

    2017-01-01

    Full Text Available The aircraft maintenance is realized by a rapid sequence of maintenance organizational and technical states, its re- search and analysis are carried out by statistical methods. The maintenance process concludes aircraft technical states con- nected with the objective patterns of technical qualities changes of the aircraft as a maintenance object and organizational states which determine the subjective organization and planning process of aircraft using. The objective maintenance pro- cess is realized in Maintenance and Repair System which does not include maintenance organization and planning and is a set of related elements: aircraft, Maintenance and Repair measures, executors and documentation that sets rules of their interaction for maintaining of the aircraft reliability and readiness for flight. The aircraft organizational and technical states are considered, their characteristics and heuristic estimates of connection in knots and arcs of graphs and of aircraft organi- zational states during regular maintenance and at technical state failure are given. It is shown that in real conditions of air- craft maintenance, planned aircraft technical state control and maintenance control through it, is only defined by Mainte- nance and Repair conditions at a given Maintenance and Repair type and form structures, and correspondingly by setting principles of Maintenance and Repair work types to the execution, due to maintenance, by aircraft and all its units mainte- nance and reconstruction strategies. The realization of planned Maintenance and Repair process determines the one of the constant maintenance component. The proposed graphical models allow to reveal quantitative correlations between graph knots to improve maintenance processes by statistical research methods, what reduces manning, timetable and expenses for providing safe civil aviation aircraft maintenance.

  1. Plant inspection and maintenance technology

    International Nuclear Information System (INIS)

    Miyahara, Masatoshi; Kanazawa, Masafumi

    1995-01-01

    The article reports on information systems and related tools that support routine inspection and preventive maintenance activities, which contribute to safer plant operation and increase plant operating duty. Tools include the Mitsubishi Electric Reliability and Availability Upgrade Program-Nuclear (MELRAP-N), which supports the general evolution of industry operating experiences, periodic component replacement management, management of discontinued and modified components, periodic inspection item management, and periodic inspection workplace management. The article also introduces a comprehensive preventive maintenance management system currently under development. (author)

  2. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  3. Quality assurance for the maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Modemann, G.

    1985-01-01

    In order to maintain the quality of a nuclear power plant, it is essential that the numerous participants involved in maintenance work consistently fulfil their specified tasks, and that the quality control circuit is closed and functions smoothly. First of all, the report briefly explains the significance of the operational organization of a nuclear power plant and the role of the supervisory authority with the consulted experts. The quality control circuit for maintenance illustrates the tasks and cooperation of the participants. An idea is given of the testing and monitoring criteria which are implemented to assure the quality of the different types of maintenance and the procurement of supplies. (orig.) [de

  4. Maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Migaud, D.; Hutin, J.P.; Jouette, I.; Eymond, P.; Devie, P.; Cudelou, C.; Magnier, S.; Frydman, M.

    2016-01-01

    This document gathers different articles concerning the maintenance of the French nuclear power plants. The first article analyses the impact of the recent law on the energetic transition that sets the share of nuclear power at 50% of the electricity produced by 2025. A consequence may be the decommissioning of 17 to 20 reactors by 2025 and the huge maintenance program called 'Grand Carenage' whose aim is to extend operating life over 40 years will have to be re-considered in order to avoid useless expenses. The second article shows that in 2015 the French nuclear reactor fleet got very good results in terms of availability and safety. There were 49 scheduled outages and among them some ended ahead of time. The third article describes the specificities of the maintenance of a nuclear power plant, for instance the redundancy of some systems implies that maintenance has to deal with systems that have never functioned but must be ready to operate at any moment. Another specificity is the complexity of a nuclear power plant that implies an essential phase of preparation for maintenance operations. Because of safety requirements any maintenance operation has to be controlled, checked and may provide feedback. The fourth article presents the 'Grand Carenage' maintenance program that involves the following operations: the replacement of steam generators, the re-tubing of condensers, the replacement of the filtering drums used for cooling water, the testing of the reactor building, the hydraulic test of the primary circuit and the inspection of the reactor vessel. The fifth article focuses on the organization of the work-site for maintenance operations and the example of the Belleville-sur-Loire is described in the sixth article. Important maintenance operations like 'Grand Carenage' requires a strong collaboration with a network of specialized enterprises and as no reactor (except Flamanville EPR) is being built in France, maintenance

  5. A guide to printed circuit board design

    CERN Document Server

    Hamilton, Charles

    1984-01-01

    A Guide to Printed Circuit Board Design discusses the basic design principles of printed circuit board (PCB). The book consists of nine chapters; each chapter provides both text discussion and illustration relevant to the topic being discussed. Chapter 1 talks about understanding the circuit diagram, and Chapter 2 covers how to compile component information file. Chapter 3 deals with the design layout, while Chapter 4 talks about preparing the master artworks. The book also covers generating computer aided design (CAD) master patterns, and then discusses how to prepare the production drawing a

  6. Effective maintenance practices to manage system aging

    International Nuclear Information System (INIS)

    Chockie, A.; Bjorkelo, K.

    1992-01-01

    For a variety of economic and technical reasons, there has been a growing concern with the aging of complex systems and components and the role that maintenance can play in reducing this degradation. A study for the Nuclear Regulatory Commission was recently undertaken to identify effective maintenance practices that could be adapted by the nuclear industry in the United States to assist in managing the aging degradation of plant systems and components. Four organizations were examined to assess the influence that their maintenance programs have on their ability to address the systems and component aging degradation issues. An effective maintenance program was found to be essential to the management of system and component aging. The four key elements of an effective maintenance program that are important to an aging management program were identified. These are: the selection of critical systems and components; the development of an understanding of aging through the collection and analysis of equipment performance information; the development of appropriate preventive and predictive maintenance tasks to manage equipment and system aging degradation; the use of feedback mechanisms to continuously improve the management of aging systems and components. These elements were found to be common to all four organizations. In examining how the four organizations have structured their maintenance programs to include these key elements provides valuable lessons not only for the nuclear power industry, but also for any industrial organization that is concerned with the management of system and component aging degradation. This document provides detail, of these studies

  7. The TFTR maintenance manipulator

    International Nuclear Information System (INIS)

    Kungl, D.; Loesser, D.; Heitzenroeder, P.; Cerdan, G.

    1989-01-01

    TFTR plans to begin D-T experiments in mid 1990. The D-T experimental program will produce approximately one hundred shots, with a neutron generation rate of 10 19 neutrons per shot. This will result in high levels of activation in TFTR, especially in the vacuum vessel. The primary purpose of the Maintenance Manipulator is to provide a means of remotely performing certain defined maintenance and inspection tasks inside the vacuum torus so as to minimize personnel exposure to radiation. The manipulator consists of a six-link folding boom connected to a fixed boom on a movable carriage. The entire manipulator is housed in a vacuum antechamber connected to the vacuum torus, through a port formerly used for a vacuum pumping duct. The configuration extends 180 0 in either direction to provide complete coverage of the torus. The four 3500 l/s turbopumps which were formerly used in the pumping duct will be mounted on the antechamber. The manipulator will utilize two end effectors. The first, called a General Inspection Arm (GIA) provides a movable platform to an inspection camera and an in-vacuum leak detector. The second is a bilateral, force-reflecting pair of slave arms which utilize specially developed tools to perform several maintenance functions. All components except the slave arms are capable of operating in TFTR's vacuum environment and during 150 0 C bakeout of the torus. (orig.)

  8. Reducing maintenance costs

    International Nuclear Information System (INIS)

    Zaiss, W.; Reuschle, K.; Baier, B.

    2002-01-01

    The increasingly more expensive maintenance measures, cuts in the cost budget, and the loss of know-how on the part of vendors all require a change of policy with respect to maintenance concepts of the part of operators. This also applies to the existing valve concepts, the drives included. Under these aspects, the current drive, which is self-actuated and actuated by outside media, for a parallel-plate valve of a nomial width of 700 was reconsidered. The effort served to reduce maintenance costs and, at the same time, simplify the drive concept as well as cut back on the number of in-service inspections. Moreover, the number of active components were to be minimized and installation conditions in the plant were to be improved. When the boundary conditions to be observed with respect to process technology had been laid down, the competent technical department developed a concept of modification of the drive. A major constituent part was the demonstration of the functioning capability of the new drive under accident conditions. It was achieved mainly by an analytical approach. In the resultant drive concept, the same control valves are employed to actuate a driving cylinder by means of self-actuation or by an outside medium as a function of pressure. (orig.) [de

  9. Digital signal processing in power electronics control circuits

    CERN Document Server

    Sozanski, Krzysztof

    2013-01-01

    Many digital control circuits in current literature are described using analog transmittance. This may not always be acceptable, especially if the sampling frequency and power transistor switching frequencies are close to the band of interest. Therefore, a digital circuit is considered as a digital controller rather than an analog circuit. This helps to avoid errors and instability in high frequency components. Digital Signal Processing in Power Electronics Control Circuits covers problems concerning the design and realization of digital control algorithms for power electronics circuits using

  10. Quantum Effects of Mesoscopic Inductance and Capacity Coupling Circuits

    International Nuclear Information System (INIS)

    Liu Jianxin; Yan Zhanyuan; Song Yonghua

    2006-01-01

    Using the quantum theory for a mesoscopic circuit based on the discretenes of electric charges, the finite-difference Schroedinger equation of the non-dissipative mesoscopic inductance and capacity coupling circuit is achieved. The Coulomb blockade effect, which is caused by the discreteness of electric charges, is studied. Appropriately choose the components in the circuits, the finite-difference Schroedinger equation can be divided into two Mathieu equations in p-circumflex representation. With the WKBJ method, the currents quantum fluctuations in the ground states of the two circuits are calculated. The results show that the currents quantum zero-point fluctuations of the two circuits are exist and correlated.

  11. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  12. Electric circuits and signals

    CERN Document Server

    Sabah, Nassir H

    2007-01-01

    Circuit Variables and Elements Overview Learning Objectives Electric Current Voltage Electric Power and Energy Assigned Positive Directions Active and Passive Circuit Elements Voltage and Current Sources The Resistor The Capacitor The Inductor Concluding Remarks Summary of Main Concepts and Results Learning Outcomes Supplementary Topics on CD Problems and Exercises Basic Circuit Connections and Laws Overview Learning Objectives Circuit Terminology Kirchhoff's Laws Voltage Division and Series Connection of Resistors Current Division and Parallel Connection of Resistors D-Y Transformation Source Equivalence and Transformation Reduced-Voltage Supply Summary of Main Concepts and Results Learning Outcomes Supplementary Topics and Examples on CD Problems and Exercises Basic Analysis of Resistive Circuits Overview Learning Objectives Number of Independent Circuit Equations Node-Voltage Analysis Special Considerations in Node-Voltage Analysis Mesh-Current Analysis Special Conside...

  13. [Shunt and short circuit].

    Science.gov (United States)

    Rangel-Abundis, Alberto

    2006-01-01

    Shunt and short circuit are antonyms. In French, the term shunt has been adopted to denote the alternative pathway of blood flow. However, in French, as well as in Spanish, the word short circuit (court-circuit and cortocircuito) is synonymous with shunt, giving rise to a linguistic and scientific inconsistency. Scientific because shunt and short circuit made reference to a phenomenon that occurs in the field of the physics. Because shunt and short circuit are antonyms, it is necessary to clarify that shunt is an alternative pathway of flow from a net of high resistance to a net of low resistance, maintaining the stream. Short circuit is the interruption of the flow, because a high resistance impeaches the flood. This concept is applied to electrical and cardiovascular physiology, as well as to the metabolic pathways.

  14. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts...... amplifier architectures. In addition, distortion analysis and power combining techniques are considered. Another key element in most microwave systems is a signal generator. It forms the heart of all kinds of communication and radar systems. The fourth part of this book is dedicated to signal generators...... push currently available technologies to the limits. Some considerations to meet the growing requirements are provided in the fifth part of this book. The following part deals with circuits based on LTCC and MEMS technologies. The book concludes with chapters considering application of microwaves...

  15. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  16. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  17. Condition-based maintenance at both scheduled and unscheduled opportunities

    NARCIS (Netherlands)

    Kalosi, S.; Kapodistria, S.; Resing, J.A.C.

    2016-01-01

    Motivated by original equipment manufacturer (OEM) service and maintenance practices we consider a single component subject to replacements at failure instances and two types of preventive maintenance opportunities: scheduled, which occur due to periodic system reviews of the equipment, and

  18. Development of divertor remote maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Nobukazu; Oka, Kiyoshi; Akou, Kentaro; Takiguchi, Yuji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-04-01

    The ITER divertor is categorized as a scheduled maintenance component because of extreme heat and particle loads it is exposed to by plasma. It is also highly activated by 14 MeV neutrons. Reliable remote handling equipment and tools are required for divertor maintenance under intense gamma radiation. To facilitate remote maintenance, the divertor is segmented into 60 cassettes, and each cassette weighing about 25 tons and maintained and replaced through four maintenance ports each 90 degrees. Divertor cassettes must be transported toroidally and radially for replacement through maintenance ports. Remote handling involving cassette movers and carriers for toroidal and radial transport has been developed. Under the ITER R and D program, technology critical to divertor cassette maintenance is being developed jointly by Japan, E.U., and U.S. home teams. This paper summarizes divertor remote maintenance design and the status of technology development by the Japan Home Team. (author)

  19. Development of divertor remote maintenance system

    International Nuclear Information System (INIS)

    Takeda, Nobukazu; Oka, Kiyoshi; Akou, Kentaro; Takiguchi, Yuji

    1998-01-01

    The ITER divertor is categorized as a scheduled maintenance component because of extreme heat and particle loads it is exposed to by plasma. It is also highly activated by 14 MeV neutrons. Reliable remote handling equipment and tools are required for divertor maintenance under intense gamma radiation. To facilitate remote maintenance, the divertor is segmented into 60 cassettes, and each cassette weighing about 25 tons and maintained and replaced through four maintenance ports each 90 degrees. Divertor cassettes must be transported toroidally and radially for replacement through maintenance ports. Remote handling involving cassette movers and carriers for toroidal and radial transport has been developed. Under the ITER R and D program, technology critical to divertor cassette maintenance is being developed jointly by Japan, E.U., and U.S. home teams. This paper summarizes divertor remote maintenance design and the status of technology development by the Japan Home Team. (author)

  20. Primary circuit water chemistry during shutdown period at Kalinin NPP

    International Nuclear Information System (INIS)

    Gorbatenko, S.; Otchenashev, G.; Yurmanov, V.

    2005-01-01

    The primary circuit water chemistry feature at Kalinin NPP is using of special up-dated regime during the period of unit shutdown for refueling. The main objective of up-dated regime is removing from the circuit long time living corrosion products on SVO-2 ion exchange filters with the purpose of dose rates reduction from the equipment and in such a way reduction of maintenance personnel overexposure. (N.T.)

  1. CMOS circuits manual

    CERN Document Server

    Marston, R M

    1995-01-01

    CMOS Circuits Manual is a user's guide for CMOS. The book emphasizes the practical aspects of CMOS and provides circuits, tables, and graphs to further relate the fundamentals with the applications. The text first discusses the basic principles and characteristics of the CMOS devices. The succeeding chapters detail the types of CMOS IC, including simple inverter, gate and logic ICs and circuits, and complex counters and decoders. The last chapter presents a miscellaneous collection of two dozen useful CMOS circuits. The book will be useful to researchers and professionals who employ CMOS circu

  2. Timergenerator circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Timer/Generator Circuits Manual is an 11-chapter text that deals mainly with waveform generator techniques and circuits. Each chapter starts with an explanation of the basic principles of its subject followed by a wide range of practical circuit designs. This work presents a total of over 300 practical circuits, diagrams, and tables.Chapter 1 outlines the basic principles and the different types of generator. Chapters 2 to 9 deal with a specific type of waveform generator, including sine, square, triangular, sawtooth, and special waveform generators pulse. These chapters also include pulse gen

  3. Maximum Acceleration Recording Circuit

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1995-01-01

    Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

  4. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  5. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  6. Security electronics circuits manual

    CERN Document Server

    MARSTON, R M

    1998-01-01

    Security Electronics Circuits Manual is an invaluable guide for engineers and technicians in the security industry. It will also prove to be a useful guide for students and experimenters, as well as providing experienced amateurs and DIY enthusiasts with numerous ideas to protect their homes, businesses and properties.As with all Ray Marston's Circuits Manuals, the style is easy-to-read and non-mathematical, with the emphasis firmly on practical applications, circuits and design ideas. The ICs and other devices used in the practical circuits are modestly priced and readily available ty

  7. On-Line Maintenance Methodology Development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo Won; Kim, Jae Ho; Jae, Moo Sung [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    Most of domestic maintenance activities for nuclear power plants are performed while overhaul. Therefore, On-Line Maintenance (OLM) is one of the proper risks informed application techniques for diffusing maintenance burden during overhaul with safety of the plant is secured. The NUMARC 93-01 (Rev.3) presents the OLM state of the art and it provides methodology. This study adopts NUMARC 93-01 (Rev.3) and present OLM. The reference component is Emergency Diesel Generator (EDG) of Ulchin 3, 4

  8. Reflection of centrifugal pumps maintenance

    International Nuclear Information System (INIS)

    Mozos Fernandez, V.

    2010-01-01

    The aim of this work is to prove that is not necessary a deep and complex knowledge to manage the centrifugal pumps maintenance. According to the author, only deep but single technical knowledge about causes of breakdowns in the different and simple component parts of the pumps, are required. (Author)

  9. Electrical, Magnetic, Thermal Modeling and Analysis of a 5000A Solid-State Switch Module and Its Application as a DC Circuit Breaker

    OpenAIRE

    Zhou, Xigen

    2005-01-01

    This dissertation presents a systematic design and demonstration of a novel solid-state DC circuit breaker. The mechanical circuit breaker is widely used in power systems to protect industrial equipment during fault or abnormal conditions. Compared with the slow and high-maintenance mechanical circuit breaker, the solid-state circuit breaker is capable of high-speed interruption of high currents without generating an arc, hence it is maintenance-free. Both the switch and the tripping unit ...

  10. Maintenance Management Update.

    Science.gov (United States)

    Sternloff, Robert E.

    1987-01-01

    Current trends in park maintenance are overviewed, including maintenance impact statements, avoidance of cost through efficient use and national resource conservation, horticultural accomplishments that influence maintenance management, and vandalism prevention. (CB)

  11. RCM and component evaluation logic

    International Nuclear Information System (INIS)

    Davis, B.; Anderson, J.

    1991-01-01

    This paper reports on the prevention maintenance program at Palo Verde Nuclear Generating Station (PVNGS), initially developed based on recommendations found in vendor technical manuals and accepted industry standards. The method was used until there was sufficient operating history to justify changes. The Reliability Centered Maintenance (RCM) project was started to provide another approach to the implementation of preventive maintenance. RCM evaluations were performed on nine systems. RCM was then suspended since it was found during implementation that additional documentation was necessary. RCM was selected as a preventive maintenance development process because it provides a documented analytical approach to establishing a preventive maintenance program. It is also being developed throughout the industry as a standard approach to preventive maintenance. PVNGS became interested in performing RCM analyses primarily to ensure that system and component reliability is maintained at the highest level possible and that hidden or rare failures are addressed by appropriate and effective maintenance. A secondary reason was to save maintenance expenditures

  12. Information-Based Maintenance Optimization with Focus on Predictive Maintenance (Informatiegebaseerde onderhoudsoptimalisatie met focus op predictief onderhoud)

    OpenAIRE

    Van Horenbeek, Adriaan

    2013-01-01

    This dissertation presents an information-based maintenance optimization methodology for physical assets; with focus on, but not limited to, predictive maintenance (PdM). The overall concept of information-based maintenance is that of updating maintenance decisions based on evolving knowledge of operation history and anticipated usage of the machinery, as well as the physics and dynamics of material degradation in critical machinery components. Within this concept, predictive maintenance is a...

  13. Pulse generator circuit triggerable by nuclear radiation

    International Nuclear Information System (INIS)

    Fredrickson, P.B.

    1980-01-01

    A pulse generator circuit triggerable by a pulse of nuclear radiation is described. The pulse generator circuit includes a pair of transistors arranged, together with other electrical components, in the topology of a standard monostable multivibrator circuit. The circuit differs most significantly from a standard monostable multivibrator circuit in that the circuit is adapted to be triggered by a pulse of nuclear radiation rather than electrically and the transistors have substantially different sensitivities to radiation, due to different physical and electrical characteristics and parameters. One of the transistors is employed principally as a radiation detector and is in a normally non-conducting state and the other transistor is normally in a conducting state. When the circuit is exposed to a pulse of nuclear radiation, currents are induced in the collector-base junctions of both transistors but, due to the different radiation sensitivities of the transistors, the current induced in the collector-base junction of the radiation-detecting transistor is substantially greater than that induced in the collector-base junction of the other transistor. The pulse of radiation causes the radiation-detecting transistor to operate in its conducting state, causing the other transistor to operate in its non-conducting state. As the radiation-detecting transistor operates in its conducting state, an output signal is produced at an output terminal connected to the radiation-detecting transistor indicating the presence of a predetermined intensity of nuclear radiation

  14. Experience based reliability centered maintenance

    International Nuclear Information System (INIS)

    Haenninen, S.; Laakso, K.

    1993-03-01

    The systematic analysis and documentation of operating experiences should be included in a living NPP life management program. Failure mode and effects and maintenance effects analyses are suitable methods for analysis of the failure and corrective maintenance experiences of equipment. Combined use of the information on occurred functional failures and the decision tree logic of the reliability centered maintenance identifies applicable and effective preventive maintenance tasks of equipment in an old plant. In this study the electrical motor drives of closing and isolation valves (MOV) of TVO and Loviisa nuclear power plants were selected to serve as pilot study objects. The study was limited to valve drives having actuators manufactured by AUMA in Germany. The fault and maintenance history of MOVs from 1981 up to and including October 1991 in different safety and process systems at TVO 1 and 2 nuclear power units was at first analyzed in a systematic way. The scope of the components studied was 81 MOVs in safety-related systems and 127 other MOVs per each TVO unit. In the case of the Loviisa plant, the observation period was limited to three years, i.e. from February 1989 up to February 1992. The scope of the Loviisa 1 and 2 components studied was 44 respectively 95 MOVs. (25 refs., 22 figs., 8 tabs.)

  15. The ITER remote maintenance system

    International Nuclear Information System (INIS)

    Tesini, A.; Palmer, J.

    2008-01-01

    The aim of this paper is to summarize the ITER approach to machine components maintenance. A major objective of the ITER project is to demonstrate that a future power producing fusion device can be maintained effectively and offer practical levels of plant availability. During its operational lifetime, many systems of the ITER machine will require maintenance and modification; this can be achieved using remote handling methods. The need for timely, safe and effective remote operations on a machine as complex as ITER and within one of the world's most hostile remote handling environments represents a major challenge at every level of the ITER Project organization, engineering and technology. The basic principles of fusion reactor maintenance are presented. An updated description of the ITER remote maintenance system is provided. This includes the maintenance equipment used inside the vacuum vessel, inside the hot cell and the hot cell itself. The correlation between the functions of the remote handling equipment, of the hot cell and of the radwaste processing system is also described. The paper concludes that ITER has equipped itself with a good platform to tackle the challenges presented by its own maintenance and upgrade needs

  16. Decreasing inventory of a cement factory roller mill parts using reliability centered maintenance method

    Science.gov (United States)

    Witantyo; Rindiyah, Anita

    2018-03-01

    According to data from maintenance planning and control, it was obtained that highest inventory value is non-routine components. Maintenance components are components which procured based on maintenance activities. The problem happens because there is no synchronization between maintenance activities and the components required. Reliability Centered Maintenance method is used to overcome the problem by reevaluating maintenance activities required components. The case chosen is roller mill system because it has the highest unscheduled downtime record. Components required for each maintenance activities will be determined by its failure distribution, so the number of components needed could be predicted. Moreover, those components will be reclassified from routine component to be non-routine component, so the procurement could be carried out regularly. Based on the conducted analysis, failure happens in almost every maintenance task are classified to become scheduled on condition task, scheduled discard task, schedule restoration task and no schedule maintenance. From 87 used components for maintenance activities are evaluated and there 19 components that experience reclassification from non-routine components to routine components. Then the reliability and need of those components were calculated for one-year operation period. Based on this invention, it is suggested to change all of the components in overhaul activity to increase the reliability of roller mill system. Besides, the inventory system should follow maintenance schedule and the number of required components in maintenance activity so the value of procurement will be decreased and the reliability system will increase.

  17. Circuits on Cylinders

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro; Vinay, V

    2006-01-01

    We consider the computational power of constant width polynomial size cylindrical circuits and nondeterministic branching programs. We show that every function computed by a Pi2 o MOD o AC0 circuit can also be computed by a constant width polynomial size cylindrical nondeterministic branching pro...

  18. Microwave integrated circuits for space applications

    Science.gov (United States)

    Leonard, Regis F.; Romanofsky, Robert R.

    1991-01-01

    Monolithic microwave integrated circuits (MMIC), which incorporate all the elements of a microwave circuit on a single semiconductor substrate, offer the potential for drastic reductions in circuit weight and volume and increased reliability, all of which make many new concepts in electronic circuitry for space applications feasible, including phased array antennas. NASA has undertaken an extensive program aimed at development of MMICs for space applications. The first such circuits targeted for development were an extension of work in hybrid (discrete component) technology in support of the Advanced Communication Technology Satellite (ACTS). It focused on power amplifiers, receivers, and switches at ACTS frequencies. More recent work, however, focused on frequencies appropriate for other NASA programs and emphasizes advanced materials in an effort to enhance efficiency, power handling capability, and frequency of operation or noise figure to meet the requirements of space systems.

  19. Improved Battery Charger Circuit Utilizing Reduced DC-link Capacitors

    Directory of Open Access Journals (Sweden)

    Vencislav Valchev

    2017-11-01

    Full Text Available The article presents a comparison of advantages and disadvantages of a battery charger circuit with and without the use of DC-link capacitors in it. The specific application requirements, namely ultra-light electric vehicles, are set as lightness, efficiency and robustness of the design. Prove of greater reliability and improvement on maintenance costs without significant decrease in the quality of charging process with the removal of DC-link capacitors in rectifier and boost converter circuits is accomplished. The proposed circuit parameters are analyzed by carried out simulations.

  20. CMOS analog circuit design

    CERN Document Server

    Allen, Phillip E

    1987-01-01

    This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

  1. Electric motor predictive and preventive maintenance guide

    International Nuclear Information System (INIS)

    Oliver, J.A.

    1992-07-01

    Electric motor performance is vital to the reliable and efficient operation of power plants. The failure of one or more critical motors could cause lost capacity and excessive repair and maintenance cost. However, existing maintenance recommendations proposed by vendors for electric motors have sometimes encouraged many overly conservative maintenance practices. These practices have lead to excessive maintenance activities and costs which have provided no extra margin of operability. EPRI has sponsored RP2814-35 to develop a guide which provides power plants with information and guidance for establishing an effective maintenance program which will aid in preventing unexpected motor failures and assist in planning motor maintenance efforts. The guide includes a technical description which summarizes technical data relative to the four basic types of motors and their components in general use in power plants. The significant causes of motor failures are investigated and described in detail and methods to optimize service life and minimize maintenance cost through appropriate preventive maintenance and conditioning program are presented. This guide provides a foundation for an effective electric motor maintenance program and simplifies the selection of predictive and preventive maintenance tasks. Its use will enable maintenance personnel in nuclear and fossil plants to plan motor repairs during scheduled outages and avoid costly unexpected failures

  2. Modularity Design Approach for Preventive Machine Maintenance

    Science.gov (United States)

    Ernawati, D.; Pudji, E.; Ngatilah, Y.; Handoyo, R.

    2018-01-01

    In a company, machine maintenance system will be very influential in production process activity. The company should have a scheduled engine maintenance system that does not require high costs when repairing and replacing machine parts. Modularity Design method is able to provide solutions to the engine maintenance scheduling system and can prevent fatal damage to the engine components. It can minimize the cost of repair and replacement of these machine components.The paper provides a solution to machine maintenance problems. The paper is also completed with case study of milling machines. That case studies can give us a real description about impact implementation of modularity design to prevent fatal damage to components and minimize the cost of repair and replacement of components of the machine.

  3. TRUPACT-II container maintenance program plan

    International Nuclear Information System (INIS)

    1990-01-01

    This document details the maintenance/repair and replacement of components, as well as the documentation required and the procedures to be followed to maintain the integrity of the TRUPACT-II container

  4. Predictive maintenance: A new approach in maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Benvenuto, F.; Ferrari, L.

    2005-01-01

    The maintenance services for a Nuclear Power Plant are in general aimed at reaching the following goals: - Increase component availability and consequently decrease intervention frequency; - Reduce unexpected costs from unexpected repairs; - Progressively decrease the time of each intervention; - Improve the spare parts supply efficiency; - Improve spare parts and consumable warehouse managing; - Decrease maintenance costs. Most of the currently used maintenance activities refer to run-to-failure or preventive approaches: - Run-to-failure or Corrective Maintenance means that work is only carried out when a component or system is faulty and unable to perform its critical function. Non critical components such as filters or components with spare may be maintained in this way; - Preventive or Scheduled Maintenance involves a regular pre-set schedule programme of maintenance work. Programme outlined by the manufacturer of the component in question based on the design life of the component and based on past experience by operation. One step further than Preventive Maintenance is represented by Predictive Maintenance. Whereas Preventive Maintenance bases its schedules on past performance data, a predictive system acquires condition data from the machine to be maintained whilst the machine is in operation. The information obtained from this analysis indicates the condition in real time, provides a diagnosis of wear and shows any trend towards critical conditions. Predictive maintenance mainly consists of the following interventions: - Lubricant analysis; - Collection / analysis of functional parameters, such as motor absorption, flow rate, pressure, temperature, noise, vibration of rotating equipment, thermal efficiency, etc; - Periodical test of lifting systems; - Other operations to acquire sensitive equipment parameters. Predictive Maintenance can reduce the accidental intervention and extend the components life, and, in the end, is increasing the global availability

  5. Advantages of condition-based maintenance approach

    International Nuclear Information System (INIS)

    Bareiss, J.; Roos, E.; Jovanovic, A.; Perunicic, M.; Balos, D.

    2004-01-01

    Pilot applications in EnBW steam boiler components and high-pressure pipe systems in the context of the European research project RIMAP (''Risk Based Inspection and Maintenance Procedures for European Industry'') showed that application of a risk-based maintenance strategy (e.g. RIMAP) will make the decision process more transparent and enable better condition-oriented maintenance. With regard to life management of the systems (availability, product quality), this appears to be more important than than the aspect of cost reduction in the maintenance sector, although the latter may not be unwelcome. (orig.) [de

  6. Evaluations of maintenance effectiveness on unavailability and risk

    International Nuclear Information System (INIS)

    Vesely, W.E.

    1993-01-01

    A methodology is presented for quantifying the effectiveness of maintenance on unavailability and on risk. The methodology is based on standard Markov modeling principles. What is new is the application to quantify maintenance effectiveness by explicitly quantifying maintenance benefits as well as maintenance's negative contributions. Maintenance effects are quantified by defining a degraded state for the component in addition to an operational state and a failed state which are usually defined. The maintenance model which is developed is a natural extension of the standard models used in reliability analysis and in Probabilistic Risk Assessments (PRAs). The results which are obtained can be directly used in PRAs. Applications of the methodology are presented by quantifying maintenance effectiveness on component performance and component unavailability for specific maintenance schedules

  7. Performance-based inspection and maintenance strategies

    International Nuclear Information System (INIS)

    Vesely, W.E.

    1995-01-01

    Performance-based inspection and maintenance strategies utilize measures of equipment performance to help guide inspection and maintenance activities. A relevant measure of performance for safety system components is component unavailability. The component unavailability can also be input into a plant risk model such as a Probabilistic Risk Assessment (PRA) to determine the associated plant risk performance. Based on the present and projected unavailability performance, or the present and projected risk performance, the effectiveness of current maintenance activities can be evaluated and this information can be used to plan future maintenance activities. A significant amount of information other than downtimes or failure times is collected or can be collected when an inspection or maintenance is conducted which can be used to estimate the component unavailability. This information generally involves observations on the condition or state of the component or component piecepart. The information can be detailed such as the amount of corrosion buildup or can be general such as the general state of the component described as ' high degradation', ' moderate degradation', or ' low degradation'. Much of the information collected in maintenance logs is qualitative and fuzzy. As part of an NRC Research program on performance-based engineering modeling, approaches have been developed to apply Fuzzy Set Theory to information collected on the state of the component to determine the implied component or component piecepart unavailability. Demonstrations of the applications of Fuzzy Set Theory are presented utilizing information from plant maintenance logs. The demonstrations show the power of Fuzzy Set Theory in translating engineering information to reliability and risk implications

  8. A Situational Maintenance Model

    DEFF Research Database (Denmark)

    Luxhoj, James T.; Thorsteinsson, Uffe; Riis, Jens Ove

    1997-01-01

    An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance.......An overview of trend in maintenance management and presentation of a situational model and an analytical tools for identification of managerial efforts in maintenance....

  9. Approximate circuits for increased reliability

    Science.gov (United States)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  10. Estimating the short-circuit impedance

    DEFF Research Database (Denmark)

    Nielsen, Arne Hejde; Pedersen, Knud Ole Helgesen; Poulsen, Niels Kjølstad

    1997-01-01

    A method for establishing a complex value of the short-circuit impedance from naturally occurring variations in voltage and current is discussed. It is the symmetrical three phase impedance at the fundamental grid frequency there is looked for. The positive sequence components in voltage...... and current are derived each period, and the short-circuit impedance is estimated from variations in these components created by load changes in the grid. Due to the noisy and dynamic grid with high harmonic distortion it is necessary to threat the calculated values statistical. This is done recursively...... through a RLS-algorithm. The algorithms have been tested and implemented on a PC at a 132 kV substation supplying a rolling mill. Knowing the short-circuit impedance gives the rolling mill an opportunity to adjust the arc furnace operation to keep flicker below a certain level. Therefore, the PC performs...

  11. Modular thought in the circuit analysis

    Science.gov (United States)

    Wang, Feng

    2018-04-01

    Applied to solve the problem of modular thought, provides a whole for simplification's method, the complex problems have become of, and the study of circuit is similar to the above problems: the complex connection between components, make the whole circuit topic solution seems to be more complex, and actually components the connection between the have rules to follow, this article mainly tells the story of study on the application of the circuit modular thought. First of all, this paper introduces the definition of two-terminal network and the concept of two-terminal network equivalent conversion, then summarizes the common source resistance hybrid network modular approach, containing controlled source network modular processing method, lists the common module, typical examples analysis.

  12. Selective maintenance of multi-state systems with structural dependence

    International Nuclear Information System (INIS)

    Dao, Cuong D.; Zuo, Ming J.

    2017-01-01

    This paper studies the selective maintenance problem for multi-state systems with structural dependence. Each component can be in one of multiple working levels and several maintenance actions are possible to a component in a maintenance break. The components structurally form multiple hierarchical levels and dependence groups. A directed graph is used to represent the precedence relations of components in the system. A selective maintenance optimization model is developed to maximize the system reliability in the next mission under time and cost constraints. A backward search algorithm is used to determine the assembly sequence for a selective maintenance scenario. The maintenance model helps maintenance managers in determining the best combination of maintenance activities to maximize the probability of successfully completing the next mission. Examples showing the use of the proposed method are presented. - Highlights: • A selective maintenance model for multi-state systems is proposed considering both economic and structural dependence. • Structural dependence is modeled as precedence relationship when disassembling components for maintenance. • Resources for disassembly and maintenance are evaluated using a backward search algorithm. • Maintenance strategies with and without structural dependence are analyzed. • Ignoring structural dependence may lead to over-estimation of system reliability.

  13. Maintenance and fabrication of electronic equipment

    International Nuclear Information System (INIS)

    Chung, Chong Eun; Moon, Byung Soo; Hong, Suk Boong; Kim, Yong Keun; Kim, Jung Bok

    2001-12-01

    Providing technical support to the maintenance and repair problems of electronic instruments, we have assisted the research and development work, and made it done effectively in KAERI. In addition, we have improved the performance of the alarming system of the unit211 in PIEF and the lamp control module(IND100) in RWTF using PLCs. And also, electronic circuit modules for MAFF system which is an instrument for airborne monitoring in radiation area have been designed and fabricated

  14. Modern TTL circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Modern TTL Circuits Manual provides an introduction to the basic principles of Transistor-Transistor Logic (TTL). This book outlines the major features of the 74 series of integrated circuits (ICs) and introduces the various sub-groups of the TTL family.Organized into seven chapters, this book begins with an overview of the basics of digital ICs. This text then examines the symbology and mathematics of digital logic. Other chapters consider a variety of topics, including waveform generator circuitry, clocked flip-flop and counter circuits, special counter/dividers, registers, data latches, com

  15. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  16. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

  17. 'Speedy' superconducting circuits

    International Nuclear Information System (INIS)

    Holst, T.

    1994-01-01

    The most promising concept for realizing ultra-fast superconducting digital circuits is the Rapid Single Flux Quantum (RSFQ) logic. The basic physical principle behind RSFQ logic, which include the storage and transfer of individual magnetic flux quanta in Superconducting Quantum Interference Devices (SQUIDs), is explained. A Set-Reset flip-flop is used as an example of the implementation of an RSFQ based circuit. Finally, the outlook for high-temperature superconducting materials in connection with RSFQ circuits is discussed in some details. (au)

  18. ITER assembly and maintenance

    International Nuclear Information System (INIS)

    Honda, T.; Davis, F.; Lousteau, D.

    1991-01-01

    This document is intended to describe the work conducted by the ITER Assembly and Maintenance (A and M) Design Unit and the supporting home teams during the ITER Conceptual Design Activities, carried out from 1988 through 1990. Its content consists of two main sections, i.e., Chapter III, which describes the identified tasks to be performed by the A and M system and a general description of the required equipment; and Chapter IV, which provides a more detailed description of the equipment proposed to perform the assigned tasks. A two-stage R and D program is now planned, i.e., (1) a prototype equipment functional tests using full scale mock-ups and (2) a full scale integration demonstration test facility with real components (vacuum vessel with ports, blanket modules, divertor modules, armor tiles, etc.). Crucial in-vessel and ex-vessel operations and the associated remote handling equipment, including handling of divertor plates and blanket modules will be demonstrated in the first phase, whereby the database needed to proceed with the engineering phase will be acquired. The second phase will demonstrate the ability of the overall system to execute the required maintenance procedures and evaluate the performance of the prototype equipment

  19. Multi-qubit circuit quantum electrodynamics

    International Nuclear Information System (INIS)

    Viehmann, Oliver

    2013-01-01

    Circuit QED systems are macroscopic, man-made quantum systems in which superconducting artificial atoms, also called Josephson qubits, interact with a quantized electromagnetic field. These systems have been devised to mimic the physics of elementary quantum optical systems with real atoms in a scalable and more flexible framework. This opens up a variety of possible applications of circuit QED systems. For instance, they provide a promising platform for processing quantum information. Recent years have seen rapid experimental progress on these systems, and experiments with multi-component circuit QED architectures are currently starting to come within reach. In this thesis, circuit QED systems with multiple Josephson qubits are studied theoretically. We focus on simple and experimentally realistic extensions of the currently operated circuit QED setups and pursue investigations in two main directions. First, we consider the equilibrium behavior of circuit QED systems containing a large number of mutually noninteracting Josephson charge qubits. The currently accepted standard description of circuit QED predicts the possibility of superradiant phase transitions in such systems. However, a full microscopic treatment shows that a no-go theorem for superradiant phase transitions known from atomic physics applies to circuit QED systems as well. This reveals previously unknown limitations of the applicability of the standard theory of circuit QED to multi-qubit systems. Second, we explore the potential of circuit QED for quantum simulations of interacting quantum many-body systems. We propose and analyze a circuit QED architecture that implements the quantum Ising chain in a time-dependent transverse magnetic field. Our setup can be used to study quench dynamics, the propagation of localized excitations, and other non-equilibrium features in this paradigmatic model in the theory of non-equilibrium thermodynamics and quantumcritical phenomena. The setup is based on a

  20. Multi-qubit circuit quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Viehmann, Oliver

    2013-09-03

    Circuit QED systems are macroscopic, man-made quantum systems in which superconducting artificial atoms, also called Josephson qubits, interact with a quantized electromagnetic field. These systems have been devised to mimic the physics of elementary quantum optical systems with real atoms in a scalable and more flexible framework. This opens up a variety of possible applications of circuit QED systems. For instance, they provide a promising platform for processing quantum information. Recent years have seen rapid experimental progress on these systems, and experiments with multi-component circuit QED architectures are currently starting to come within reach. In this thesis, circuit QED systems with multiple Josephson qubits are studied theoretically. We focus on simple and experimentally realistic extensions of the currently operated circuit QED setups and pursue investigations in two main directions. First, we consider the equilibrium behavior of circuit QED systems containing a large number of mutually noninteracting Josephson charge qubits. The currently accepted standard description of circuit QED predicts the possibility of superradiant phase transitions in such systems. However, a full microscopic treatment shows that a no-go theorem for superradiant phase transitions known from atomic physics applies to circuit QED systems as well. This reveals previously unknown limitations of the applicability of the standard theory of circuit QED to multi-qubit systems. Second, we explore the potential of circuit QED for quantum simulations of interacting quantum many-body systems. We propose and analyze a circuit QED architecture that implements the quantum Ising chain in a time-dependent transverse magnetic field. Our setup can be used to study quench dynamics, the propagation of localized excitations, and other non-equilibrium features in this paradigmatic model in the theory of non-equilibrium thermodynamics and quantumcritical phenomena. The setup is based on a

  1. A preventive maintenance lubricant

    Energy Technology Data Exchange (ETDEWEB)

    Chapaykina, S A; Ol' kov, P L; Pertsev, A N; Rodzevillo, I T; Rogacheva, O I; Zinov' yev, A P

    1980-02-15

    A method is disclosed to lower the adherence of materials by reducing the viscosity of a preventive maintenance lubricant against adhesion of moist, freeflowing materials, containing extract of selective cleaning of oil fractions and asphalt. Gas oil of catalytic cracking is added having a boiling point of 190-300 degrees, with the following ratio of components (%): selective cleaning extract, 43-50; asphalt, 14-16; and gas oil of catalytic cracking, the remainder, Treating a surface with the proposed lubricant lowers the specific resistance to shift of rock compared with the prototype (g/cm/sup 2/): sand (moisture content, 18%) from 3.82 to 1.55; and clay (moisture content 16%), from 5.41 to 3.51.

  2. LC Circuits for Diagnosing Embedded Piezoelectric Devices

    Science.gov (United States)

    Chattin, Richard L.; Fox, Robert Lee; Moses, Robert W.; Shams, Qamar A.

    2005-01-01

    A recently invented method of nonintrusively detecting faults in piezoelectric devices involves measurement of the resonance frequencies of inductor capacitor (LC) resonant circuits. The method is intended especially to enable diagnosis of piezoelectric sensors, actuators, and sensor/actuators that are embedded in structures and/or are components of multilayer composite material structures.

  3. Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices.

    Science.gov (United States)

    Sezdi, Mana

    2016-01-01

    A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older technology devices and predictive maintenance for newer high-tech devices. For preventive maintenance development, 589 older technology devices were subjected to performance verification and safety testing (PVST). For predictive maintenance development, the manufacturers' recommendations were used for 134 high-tech devices. These strategies were evaluated in terms of device reliability. This study recommends the use of two different maintenance strategies for old and new devices at hospitals in developing countries. Thus, older technology devices that applied only corrective maintenance will be included in maintenance like high-tech devices.

  4. Analogue circuits simulation

    Energy Technology Data Exchange (ETDEWEB)

    Mendo, C

    1988-09-01

    Most analogue simulators have evolved from SPICE. The history and description of SPICE-like simulators are given. From a mathematical formulation of the electronic circuit the following analysis are possible: DC, AC, transient, noise, distortion, Worst Case and Statistical.

  5. Printed circuit for ATLAS

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A printed circuit board made by scientists in the ATLAS collaboration for the transition radiaton tracker (TRT). This will read data produced when a high energy particle crosses the boundary between two materials with different electrical properties.

  6. Magnonic logic circuits

    International Nuclear Information System (INIS)

    Khitun, Alexander; Bao Mingqiang; Wang, Kang L

    2010-01-01

    We describe and analyse possible approaches to magnonic logic circuits and basic elements required for circuit construction. A distinctive feature of the magnonic circuitry is that information is transmitted by spin waves propagating in the magnetic waveguides without the use of electric current. The latter makes it possible to exploit spin wave phenomena for more efficient data transfer and enhanced logic functionality. We describe possible schemes for general computing and special task data processing. The functional throughput of the magnonic logic gates is estimated and compared with the conventional transistor-based approach. Magnonic logic circuits allow scaling down to the deep submicrometre range and THz frequency operation. The scaling is in favour of the magnonic circuits offering a significant functional advantage over the traditional approach. The disadvantages and problems of the spin wave devices are also discussed.

  7. Advanced maintenance research programs

    International Nuclear Information System (INIS)

    Marston, T.U.; Gelhaus, F.; Burke, R.

    1985-01-01

    The purpose of this paper is to provide the reader with an idea of the advanced maintenance research program at the Electric Power Research Institute (EPRI). A brief description of the maintenance-related activities is provided as a foundation for the advanced maintenance research projects. The projects can be divided into maintenance planning, preventive maintenance program development and implementation, predictive (or conditional) maintenance, and innovative maintenance techniques. The projects include hardware and software development, human factors considerations, and technology promotion and implementation. The advanced concepts include: the incorporation of artificial intelligence into outage planning; turbine and pump maintenance; rotating equipment monitoring and diagnostics with the aid of expert systems; and the development of mobile robots for nuclear power plant maintenance

  8. Peak reading detector circuit

    International Nuclear Information System (INIS)

    Courtin, E.; Grund, K.; Traub, S.; Zeeb, H.

    1975-01-01

    The peak reading detector circuit serves for picking up the instants during which peaks of a given polarity occur in sequences of signals in which the extreme values, their time intervals, and the curve shape of the signals vary. The signal sequences appear in measuring the foetal heart beat frequence from amplitude-modulated ultrasonic, electrocardiagram, and blood pressure signals. In order to prevent undesired emission of output signals from, e. g., disturbing intermediate extreme values, the circuit consists of the series connections of a circuit to simulate an ideal diode, a strong unit, a discriminator for the direction of charging current, a time-delay circuit, and an electronic switch lying in the decharging circuit of the storage unit. The time-delay circuit thereby causes storing of a preliminary maximum value being used only after a certain time delay for the emission of the output signal. If a larger extreme value occurs during the delay time the preliminary maximum value is cleared and the delay time starts running anew. (DG/PB) [de

  9. Color Coding of Circuit Quantities in Introductory Circuit Analysis Instruction

    Science.gov (United States)

    Reisslein, Jana; Johnson, Amy M.; Reisslein, Martin

    2015-01-01

    Learning the analysis of electrical circuits represented by circuit diagrams is often challenging for novice students. An open research question in electrical circuit analysis instruction is whether color coding of the mathematical symbols (variables) that denote electrical quantities can improve circuit analysis learning. The present study…

  10. Project Circuits in a Basic Electric Circuits Course

    Science.gov (United States)

    Becker, James P.; Plumb, Carolyn; Revia, Richard A.

    2014-01-01

    The use of project circuits (a photoplethysmograph circuit and a simple audio amplifier), introduced in a sophomore-level electric circuits course utilizing active learning and inquiry-based methods, is described. The development of the project circuits was initiated to promote enhanced engagement and deeper understanding of course content among…

  11. Application of reliability analysis methods to the comparison of two safety circuits

    International Nuclear Information System (INIS)

    Signoret, J.-P.

    1975-01-01

    Two circuits of different design, intended for assuming the ''Low Pressure Safety Injection'' function in PWR reactors are analyzed using reliability methods. The reliability analysis of these circuits allows the failure trees to be established and the failure probability derived. The dependence of these results on test use and maintenance is emphasized as well as critical paths. The great number of results obtained may allow a well-informed choice taking account of the reliability wanted for the type of circuits [fr

  12. Development of maintenance engineering system

    International Nuclear Information System (INIS)

    1995-03-01

    Department of JMTR project has developed the Maintenance Engineering System which evaluates the aging tendency of the facilities. The system is used for the repair plan and the replace period of parts, components, equipments or facilities. The system has the data-base which consists of the check data, the inspection data, the trouble data and the repair data at the JMTR since the virgin criticality. The system is utilized maintenance works and concludes the maintenance procedures for the failure components, equipments and facilities. This system has the following characteristics. (1) Anybody can operate the system as easily as word processor. (2) Data are put into by man-machine-interface. (3) The data sheets are with light color and the recognizable arrangements. (4) The system is cost-efficient using commercial personal computers and applications. The research card and the layouts of the input data sheet had been formatted. Data has been begun to be put into the system and to check its functions. The result demonstrates that the system is available for preventive maintenance at the JMTR. (author)

  13. Maintenance analysis method and operational feedback: a comprehensive maintenance management

    International Nuclear Information System (INIS)

    Mathieu Riou; Victor Planchon

    2006-01-01

    components instead of cask. Safety Analysis Reports have now exhaustive periodic upkeep program, listing all the inspections mandatory to guarantee transportations safety and cask's conformity with current approval certificates. Some inspections have been deleted, leading to a radiation exposure reduction. Some criteria have been widened, leading to replacement component optimization. It is currently too early to have a precise estimation of waste optimization, as the relation between waste quantity and maintenance operations. This methodology will be applied on the other casks of the COGEMA LOGISTICS fleet. As soon as the new procedures are applicable, an assessment will be carried out. (authors)

  14. Effects of smoke on functional circuits

    International Nuclear Information System (INIS)

    Tanaka, T.J.

    1997-10-01

    Nuclear power plants are converting to digital instrumentation and control systems; however, the effects of abnormal environments such as fire and smoke on such systems are not known. There are no standard tests for smoke, but previous smoke exposure tests at Sandia National Laboratories have shown that digital communications can be temporarily interrupted during a smoke exposure. Another concern is the long-term corrosion of metals exposed to the acidic gases produced by a cable fire. This report documents measurements of basic functional circuits during and up to 1 day after exposure to smoke created by burning cable insulation. Printed wiring boards were exposed to the smoke in an enclosed chamber for 1 hour. For high-resistance circuits, the smoke lowered the resistance of the surface of the board and caused the circuits to short during the exposure. These circuits recovered after the smoke was vented. For low-resistance circuits, the smoke caused their resistance to increase slightly. A polyurethane conformal coating substantially reduced the effects of smoke. A high-speed digital circuit was unaffected. A second experiment on different logic chip technologies showed that the critical shunt resistance that would cause failure was dependent on the chip technology and that the components used in the smoke exposures were some of the most smoke tolerant. The smoke densities in these tests were high enough to cause changes in high impedance (resistance) circuits during exposure, but did not affect most of the other circuits. Conformal coatings and the characteristics of chip technologies should be considered when designing circuitry for nuclear power plant safety systems, which must be highly reliable under a variety of operating and accident conditions. 10 refs., 34 figs., 18 tabs

  15. Safety of steel vessel Magnox pressure circuits

    International Nuclear Information System (INIS)

    Stokoe, T.Y.; Bolton, C.J.; Heffer, P.J.H.

    1991-01-01

    The maintenance of pressure circuit integrity is fundamental to nuclear safety at the steel vessel Magnox stations. To confirm continued pressure circuit integrity the CEGB, as part of the Long Term Safety Review, has carried out extensive assessment and inspection in recent years. The assessment methods and inspection techniques employed are based on the most modern available. Reactor pressure vessel integrity is confirmed by a combination of arguments including safety factors inferred from the successful pre-service overpressure test, leak-before-break analysis and probabilistic assessment. In the case of other parts of the pressure circuits that are more accessible, comprising the boiler shells and interconnecting gas duct work, in-service inspection is a major element of the safety substantiation. The assessment and inspection techniques and the materials property data have been underpinned for many years by extensive research and development programmes and in-reactor monitoring of representative samples has also been undertaken. The paper summarises the work carried out to demonstrate the long term integrity of the Magnox pressure circuits and provides examples of the results obtained. (author)

  16. Maintenance of nuclear power plants

    International Nuclear Information System (INIS)

    Lashgari, Farbod.

    1995-01-01

    This paper is about maintenance of nuclear power plants. In part one, the outage management of nuclear power plants has described. Meaning of the outage and objectives of outage management is given in introduction. The necessity of a long-term outage strategy is shown in chapter one. The main parts of an outage are as follows: Planning; Preparation; Execution, Each of them and also post-outage review have been explained in the followed chapters. Part two deals with technical details of main primary components of nuclear power plant type WWER. After an introduction about WWER reactors, in each chapter first the general and detailed description of main primary components has given and then their maintenance schedules and procedures. Chapter about reactor and steam generator is related to both types of WWER-440 and WWER-1000, but chapter about reactor coolant pump has specified to WWER-1000 to be more in details.(author)

  17. Maintenance cost models in deregulated power systems under opportunity costs

    International Nuclear Information System (INIS)

    Al-Arfaj, K.; Dahal, K.; Azaiez, M.N.

    2007-01-01

    In a centralized power system, the operator is responsible for scheduling maintenance. There are different types of maintenance, including corrective maintenance; predictive maintenance; preventive maintenance; and reliability-centred maintenance. The main cause of power failures is poor maintenance. As such, maintenance costs play a significant role in deregulated power systems. They include direct costs associated with material and labor costs as well as indirect costs associated with spare parts inventory, shipment, test equipment, indirect labor, opportunity costs and cost of failure. In maintenance scheduling and planning, the cost function is the only component of the objective function. This paper presented the results of a study in which different components of maintenance costs were modeled. The maintenance models were formulated as an optimization problem with single and multiple objectives and a set of constraints. The maintenance costs models could be used to schedule the maintenance activities of power generators more accurately and to identify the best maintenance strategies over a period of time as they consider failure and opportunity costs in a deregulated environment. 32 refs., 4 tabs., 4 figs

  18. A process for risk-focused maintenance

    International Nuclear Information System (INIS)

    Lofgren, E.V.; Cooper, S.E.; Kurth, R.E.; Phillips, L.B.

    1991-03-01

    This report presents a process for focusing maintenance resources on components that enable nuclear plant systems to perform their essential functions and on components whose failure may initiate challenges to safety systems, so as to have the greatest impact in decreasing risk. The process provides criteria, based on risk, for deciding which components are critical to risk and determining what maintenance activities are required to ensure reliable operation of those risk-critical components. Two approaches are provided for selection of risk-critical components. One approach uses the results of a Probabilistic Risk Assessment (PRA); the other is based on the methodology developed for this report, which has a basis in PRA although it does not use the results of a PRA study. Following identification of risk-critical components, both approaches use a single methodology for determining what maintenance activities are required to ensure reliable operation of the identified components. The report also provides demonstrations of application of the two approaches to selection of risk-critical components and demonstrations of application of the methodology for determining what maintenance activities are required to an active standby safety system, a normally operating system, and passive components. 5 refs., 11 figs., 1 tab

  19. A process for risk-focused maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Lofgren, E.V.; Cooper, S.E.; Kurth, R.E.; Phillips, L.B. (Science Applications International Corp., McLean, VA (USA))

    1991-03-01

    This report presents a process for focusing maintenance resources on components that enable nuclear plant systems to perform their essential functions and on components whose failure may initiate challenges to safety systems, so as to have the greatest impact in decreasing risk. The process provides criteria, based on risk, for deciding which components are critical to risk and determining what maintenance activities are required to ensure reliable operation of those risk-critical components. Two approaches are provided for selection of risk-critical components. One approach uses the results of a Probabilistic Risk Assessment (PRA); the other is based on the methodology developed for this report, which has a basis in PRA although it does not use the results of a PRA study. Following identification of risk-critical components, both approaches use a single methodology for determining what maintenance activities are required to ensure reliable operation of the identified components. The report also provides demonstrations of application of the two approaches to selection of risk-critical components and demonstrations of application of the methodology for determining what maintenance activities are required to an active standby safety system, a normally operating system, and passive components. 5 refs., 11 figs., 1 tab.

  20. Improving nuclear power plant reliability through predictive maintenance

    International Nuclear Information System (INIS)

    Geilhausen, R.; Kunze, U.

    1996-01-01

    Maintenance strategies can be assigned to one of three categories: failure maintenance, periodic maintenance or condition-oriented maintenance. The optimum maintenance scheme can be selected on the basis of a cost-benefit analysis but the safety of life and limb or the political climate for NPP can hardly expressed in numbers. The implementation of preventive maintenance needs two preconditions: high-performance instrumentation in the form of stationary and mobile monitoring systems for the determination of the condition of the nuclear power plant components and provision of a tool that can handle both the organization of the work and the evaluation of the results obtained. (authors)

  1. Design for maintenance during operation

    International Nuclear Information System (INIS)

    Barton, P.H.; Lyerly, H.D.

    1976-01-01

    Design of a nuclear power plant for safe, reliable and efficient operation involves much more than theory, regulations, regulatory guides, procedures, inspectors, and even quality assurance. It also involves a full knowledge and understanding of the activities which must be carried out to operate and maintain the plant. It must be remembered that a nuclear power plant is different from fossil designs and the designer must constantly keep in mind that access by people to every component is required for maintenance

  2. High-precision analog circuit technology for power supply integrated circuits; Dengen IC yo koseido anarogu kairo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamori, A.; Suzuki, T.; Mizoe, K. [Fuji Electric Corporate Research and Development,Ltd., Kanagawa (Japan)

    2000-08-10

    With the recent rapid spread of portable electronic appliances, specification requirements such as compact power supply and long operation with batteries have become severer. Power supply ICs (integrated circuits) are required to reduce power consumption in the circuit and perform high-precision control. To meet these requirements, Fuji Electric develops high-precision CMOS (complementary metal-oxide semiconductor) analog technology. This paper describes three analog circuit technologies of a voltage reference, an operational amplifier and a comparator as circuit components particularly important for the precision of power supply ICs. (author)

  3. A fast charge integrating and shaping circuit

    International Nuclear Information System (INIS)

    Kulka, Z.; Szoncso, F.

    1990-01-01

    The development of a low cost fast charge integrating and shaping circuit (FCISC) was motivated by the need for an interface between the photomultipliers of an existing hadronic calorimeter and recently developed new readout electronics designed to match the output of small ionization chambers for the upgraded UA1 detector at the CERN proton-antiproton collider. This paper describes the design principles of gated and ungated charge integrating and shaping circuits. An FCISC prototype using discrete components was made and its properties were determined with a computerized test setup. Finally an SMD implementation of the FCISC is presented and the performance is reported. (orig.)

  4. Electromagnetic compatibility methods, analysis, circuits, and measurement

    CERN Document Server

    Weston, David A

    2016-01-01

    Revised, updated, and expanded, Electromagnetic Compatibility: Methods, Analysis, Circuits, and Measurement, Third Edition provides comprehensive practical coverage of the design, problem solving, and testing of electromagnetic compatibility (EMC) in electrical and electronic equipment and systems. This new edition provides novel information on theory, applications, evaluations, electromagnetic computational programs, and prediction techniques available. With sixty-nine schematics providing examples for circuit level electromagnetic interference (EMI) hardening and cost effective EMI problem solving, this book also includes 1130 illustrations and tables. Including extensive data on components and their correct implementation, the myths, misapplication, misconceptions, and fallacies that are common when discussing EMC/EMI will also be addressed and corrected.

  5. RF and microwave coupled-line circuits

    CERN Document Server

    Mongia, R K; Bhartia, P; Hong, J; Gupta, K C

    2007-01-01

    This extensively revised edition of the 1999 Artech House classic, RF and Microwave Coupled-Line Circuits, offers you a thoroughly up-to-date understanding of coupled line fundamentals, explaining their applications in designing microwave and millimeter-wave components used in today's communications, microwave, and radar systems. The Second Edition includes a wealth of new material, particularly relating to applications. You find brand new discussions on a novel simple design technique for multilayer coupled circuits, high pass filters using coupled lines, software packages used for filter des

  6. Low latency asynchronous interface circuits

    Science.gov (United States)

    Sadowski, Greg

    2017-06-20

    In one form, a logic circuit includes an asynchronous logic circuit, a synchronous logic circuit, and an interface circuit coupled between the asynchronous logic circuit and the synchronous logic circuit. The asynchronous logic circuit has a plurality of asynchronous outputs for providing a corresponding plurality of asynchronous signals. The synchronous logic circuit has a plurality of synchronous inputs corresponding to the plurality of asynchronous outputs, a stretch input for receiving a stretch signal, and a clock output for providing a clock signal. The synchronous logic circuit provides the clock signal as a periodic signal but prolongs a predetermined state of the clock signal while the stretch signal is active. The asynchronous interface detects whether metastability could occur when latching any of the plurality of the asynchronous outputs of the asynchronous logic circuit using said clock signal, and activates the stretch signal while the metastability could occur.

  7. A New Simple Chaotic Circuit Based on Memristor

    Science.gov (United States)

    Wu, Renping; Wang, Chunhua

    In this paper, a new memristor is proposed, and then an emulator built from off-the-shelf solid state components imitating the behavior of the proposed memristor is presented. Multisim simulation and breadboard experiment are done on the emulator, exhibiting a pinched hysteresis loop in the voltage-current plane when the emulator is driven by a periodic excitation voltage. In addition, a new simple chaotic circuit is designed by using the proposed memristor and other circuit elements. It is exciting that this circuit with only a linear negative resistor, a capacitor, an inductor and a memristor can generate a chaotic attractor. The dynamical behaviors of the proposed chaotic system are analyzed by Lyapunov exponents, phase portraits and bifurcation diagrams. Finally, an electronic circuit is designed to implement the chaotic system. For the sake of simple circuit topology, the proposed chaotic circuit can be easily manufactured at low cost.

  8. Maintenance work management system

    International Nuclear Information System (INIS)

    Kanai, T.; Takahashi, Y.; Takahashi, K.; Nishino, M.; Takeshige, R.

    2000-01-01

    The maintenance work management system supports the efficient drawing up of various documents for the maintenance work at nuclear power stations and the speeding up of the permission procedure. In addition, it improves the quality assurance of the safety and reliability of the maintenance work. Key merits of the system are: 1. Efficiently drawing up various documents for the maintenance work by using the stored data for the previous maintenance work and the pipe and instrument diagram (P and ID) data. 2. Supporting the management work for the completion of maintenance work safety by using the isolation information stored on the computer system. 3. Speeding up the permission procedure by electronic mail and electronic permission. 4. Displaying additional information such as the specifications of equipment, maintenance result, and maintenance plan by linking up with the database of another system. 5. Reducing the cost of hardware devices by using client/server network configurations of personal computers and a personal computer server. (author)

  9. Unsurfaced Road Maintenance Management

    Science.gov (United States)

    1992-12-01

    This draft manual describes an unsurfaced road maintenance management system for use on military installations. This system is available in either a manual or computerized mode (Micro PAVER). The maintenance standards prescribed should protect Govern...

  10. Winter maintenance performance measure.

    Science.gov (United States)

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  11. Large remote manipulator operating and maintenance experience at IEM cell

    International Nuclear Information System (INIS)

    Hicks, D.F.; McGuinness, P.W.

    1985-01-01

    The Interim Examination and Maintenance (IEM) Cell at the Fast Flux Test Facility (FFTF) has two large Electro-Mechanical Manipulators (EMM's). These manipulators are used for cell operations (processing of reactor core components) as well as general cell maintenance. From our eleven years of operation and maintenance experience with these large EMM's, we have learned many lessons concerning manipulator design. This paper describes the IEM Cell EMM design features and discusses operating and maintenance experience at the IEM Cell

  12. Competence within Maintenance

    OpenAIRE

    Nerland, Annette Smørholm

    2010-01-01

    Maintenance can be a contributing factor to unwanted events, as well as desired events and states. Human competence can be defined as the ability to perform a specific task, action or function successfully, and is therefore a key factor to proper execution of maintenance tasks. Hence,maintenance will have negative consequences if done wrong, and give positive results when done right. The purpose of this report is to study the many aspects of maintenance competence. Endeavoring to improve ...

  13. Implementation of chaotic secure communication systems based on OPA circuits

    International Nuclear Information System (INIS)

    Huang, C.-K.; Tsay, S.-C.; Wu, Y.-R.

    2005-01-01

    In this paper, we proposed a novel three-order autonomous circuit to construct a chaotic circuit with double scroll characteristic. The design idea is to use RLC elements and a nonlinear resistor. The one of salient features of the chaotic circuit is that the circuit with two flexible breakpoints of nonlinear element, and the advantage of the flexible breakpoint is that it increased complexity of the dynamical performance. Here, if we take a large and suitable breakpoint value, then the chaotic state can masking a large input signal in the circuit. Furthermore, we proposed a secure communication hyperchaotic system based on the proposed chaotic circuits, where the chaotic communication system is constituted by a chaotic transmitter and a chaotic receiver. To achieve the synchronization between the transmitter and the receiver, we are using a suitable Lyapunov function and Lyapunov theorem to design the feedback control gain. Thus, the transmitting message masked by chaotic state in the transmitter can be guaranteed to perfectly recover in the receiver. To achieve the systems performance, some basic components containing OPA, resistor and capacitor elements are used to implement the proposed communication scheme. From the viewpoints of circuit implementation, this proposed chaotic circuit is superior to the Chua chaotic circuits. Finally, the test results containing simulation and the circuit measurement are shown to demonstrate that the proposed method is correct and feasible

  14. Using the system maintenance datastore to characterize lifetime maintenance for PLiM

    International Nuclear Information System (INIS)

    Watson, P.; Dam, R.; Nickerson, J.

    2004-01-01

    A comprehensive Plant Life Management (PLiM) program involves evaluating a large amount of information. For any plant, there are numerous maintenance, surveillance and inspection programs for the important systems, structures and components. There is extensive industry experience on component failure modes, degradation mechanisms and recommended maintenance practices. This information forms the basis of the aging assessment work, through which improvements to these plant programs are identified. AECL has developed several tools to manage the quantities of information required in aging assessment studies, such as the SYSTMS (SYtematic approach for the development of STrategy for Maintenance and Surveillance) tool and the System Maintenance Datastore (SMD). The SMD has been developed to serve as a hub to a Systematic based Adaptive Maintenance Program (SAMP), by storing maintenance resource requirements for recommended maintenance tasks for use by the other processes in a SAMP. The SMD can be used to (a) quantify the savings or cost of optimising a maintenance program, (b) characterize and understand long term trends in condition-based maintenance due to component aging, (c) quantify the resource savings due to optimum timing of component replacement or general plant refurbishment, and (d) provide aging assessment cost information for input to plant asset evaluation. The SMD contains data for regular maintenance program tasks, plant condition assessment recommendations, and equipment refurbishment costs. A prototype SMD has been developed with data tables populated with information from operating CANDU stations. The SMD is now available to be used either with a SYSTMS evaluation or with a plant's database of maintenance tasks. (author)

  15. Machine Maintenance Scheduling with Reliability Engineering Method and Maintenance Value Stream Mapping

    Science.gov (United States)

    Sembiring, N.; Nasution, A. H.

    2018-02-01

    Corrective maintenance i.e replacing or repairing the machine component after machine break down always done in a manufacturing company. It causes the production process must be stopped. Production time will decrease due to the maintenance team must replace or repair the damage machine component. This paper proposes a preventive maintenance’s schedule for a critical component of a critical machine of an crude palm oil and kernel company due to increase maintenance efficiency. The Reliability Engineering & Maintenance Value Stream Mapping is used as a method and a tool to analize the reliability of the component and reduce the wastage in any process by segregating value added and non value added activities.

  16. Optimization of reliability centered predictive maintenance scheme for inertial navigation system

    International Nuclear Information System (INIS)

    Jiang, Xiuhong; Duan, Fuhai; Tian, Heng; Wei, Xuedong

    2015-01-01

    The goal of this study is to propose a reliability centered predictive maintenance scheme for a complex structure Inertial Navigation System (INS) with several redundant components. GO Methodology is applied to build the INS reliability analysis model—GO chart. Components Remaining Useful Life (RUL) and system reliability are updated dynamically based on the combination of components lifetime distribution function, stress samples, and the system GO chart. Considering the redundant design in INS, maintenance time is based not only on components RUL, but also (and mainly) on the timing of when system reliability fails to meet the set threshold. The definition of components maintenance priority balances three factors: components importance to system, risk degree, and detection difficulty. Maintenance Priority Number (MPN) is introduced, which may provide quantitative maintenance priority results for all components. A maintenance unit time cost model is built based on components MPN, components RUL predictive model and maintenance intervals for the optimization of maintenance scope. The proposed scheme can be applied to serve as the reference for INS maintenance. Finally, three numerical examples prove the proposed predictive maintenance scheme is feasible and effective. - Highlights: • A dynamic PdM with a rolling horizon is proposed for INS with redundant components. • GO Methodology is applied to build the system reliability analysis model. • A concept of MPN is proposed to quantify the maintenance sequence of components. • An optimization model is built to select the optimal group of maintenance components. • The optimization goal is minimizing the cost of maintaining system reliability

  17. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  18. Optimization of surface maintenance

    International Nuclear Information System (INIS)

    Oeverland, E.

    1990-01-01

    The present conference paper deals with methods of optimizing the surface maintenance of steel-made offshore installations. The paper aims at identifying important approaches to the problems regarding the long-range planning of an economical and cost effective maintenance program. The methods of optimization are based on the obtained experiences from the maintenance of installations on the Norwegian continental shelf. 3 figs

  19. Dukovany NPP maintenance management

    International Nuclear Information System (INIS)

    Siegel, F.

    2005-01-01

    Maintenance planning and management for the technological equipment of the Dukovany NPP are described. A Maintenance Control and Evaluation System has been developed and is in use to help manage the complex maintenance issue. Practical examples of outputs of the System, with a comprehensive use of the cost, reliability and safety related data, are presented. (author)

  20. Advice for the repair and maintenance of industrial refrigeration plants with screw compressors; Hinweise fuer die Wartung und Instandhaltung von Industriekaelteanlagen mit Schraubenverdichtern

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, R. [Johnson Controls Systems and Service GmbH, Mannheim (Germany)

    2007-07-01

    Apart from the mentioned advice several special focuses are of particular importance for the corresponding plant when repair and maintenance works are carried out at industrial refrigeration plants with screw compressors. Apart from the plant components in the engine room like compressor, separators, pumps, circuit plants and safety devices the other plant components up to the corresponding steamer, like main pipelines, valve stations, bushings for roof and walls, mountings require particular attention. Problems with under-cooling the coolants, lack of coolants, low levels in collectors can lead to a malfunctioning of the coolant pumps. Coolant shifts and badly adjusted control valves are causes to strive for improving the availability and the energy efficiency of the plant operation. Hence we recommend to the user to develop tailored repair and maintenance concepts for special refrigeration plants with his expert service company. These concepts should include the latest state of technology and regular training of the operating personnel. (orig.)

  1. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  2. Implementation of a Computerized Maintenance Management System

    Science.gov (United States)

    Shen, Yong-Hong; Askari, Bruce

    1994-01-01

    A primer Computerized Maintenance Management System (CMMS) has been established for NASA Ames pressure component certification program. The CMMS takes full advantage of the latest computer technology and SQL relational database to perform periodic services for vital pressure components. The Ames certification program is briefly described and the aspects of the CMMS implementation are discussed as they are related to the certification objectives.

  3. design of preventive maintenance scheduling model for ...

    African Journals Online (AJOL)

    connected in parallel, Rj(ti) is the reliability of the jth unit at ith time interval, n is the to- tal number of systems (components or units) connected in parallel. Equations (3) and (4) enable us to deter- mine the reliability of all components, units or sub-systems in an industry. 5. System Reliability with Preventive. Maintenance. Fig.

  4. A trolley mounted magazine for reactor maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, P.J.; Madani, M.; Ridgway, G.H. [GE Hitachi Nuclear Energy Canada, Peterborough, Ontario (Canada)], E-mail: patrick1.brennan@ge.com, mehdi.madani@ge.com, guy.ridgway@ge.com; Lundy, E.; Knight, D. [IM and CS (Inspection, Maintenance and Commerical Services), Ontario Power Generation, Ajax, Ontario (Canada)], E-mail: erroll.lundy@opg.com, david.knight@opg.com

    2009-03-15

    This paper describes the design of a mechanism incorporating a rotary magazine to be mounted on a fuelling machine transport trolley for use at a Darlington reactor during a feeder replacement or maintenance outage. The magazine stores reactor channel maintenance components, such as channel isolation plugs and vented closure plugs, in twelve available magazine channels. Use of the magazine rather than a fuelling machine reduces the time required to transfer such components between the Central Service Area and reactor channels. Component transfers are accomplished by locking the fuelling machine onto one of the magazine channels and using a local controller to execute commands received from the fuel handling control system. (author)

  5. A trolley mounted magazine for reactor maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, P.J.; Madani, M.; Ridgway, G.H., E-mail: patrick1.brennan@ge.com, E-mail: mehdi.madani@ge.com, E-mail: guy.ridgway@ge.com [GE Hitachi Nuclear Energy Canada, Peterborough, Ontario (Canada); Lundy, E.; Knight, D., E-mail: erroll.lundy@opg.com, E-mail: david.knight@opg.com [Ontario Power Generation, Inspection, Maintenance and Commercial Services, Ajax, Ontario (Canada)

    2008-07-01

    This paper describes the design of a mechanism incorporating a rotary magazine to be mounted on a fuelling machine transport trolley for use at a Darlington reactor during a feeder replacement or maintenance outage. The magazine stores reactor channel maintenance components, such as channel isolation plugs and vented closure plugs, in twelve available magazine channels. Use of the magazine rather than a fuelling machine reduces the time required to transfer such components between the Central Service Area and reactor channels. Component transfers are accomplished by locking the fuelling machine onto one of the magazine channels and using a local controller to execute commands received from the fuel handling control system. (author)

  6. A trolley mounted magazine for reactor maintenance

    International Nuclear Information System (INIS)

    Brennan, P.J.; Madani, M.; Ridgway, G.H.; Lundy, E.; Knight, D.

    2009-01-01

    This paper describes the design of a mechanism incorporating a rotary magazine to be mounted on a fuelling machine transport trolley for use at a Darlington reactor during a feeder replacement or maintenance outage. The magazine stores reactor channel maintenance components, such as channel isolation plugs and vented closure plugs, in twelve available magazine channels. Use of the magazine rather than a fuelling machine reduces the time required to transfer such components between the Central Service Area and reactor channels. Component transfers are accomplished by locking the fuelling machine onto one of the magazine channels and using a local controller to execute commands received from the fuel handling control system. (author)

  7. A trolley mounted magazine for reactor maintenance

    International Nuclear Information System (INIS)

    Brennan, P.J.; Madani, M.; Ridgway, G.H.; Lundy, E.; Knight, D.

    2008-01-01

    This paper describes the design of a mechanism incorporating a rotary magazine to be mounted on a fuelling machine transport trolley for use at a Darlington reactor during a feeder replacement or maintenance outage. The magazine stores reactor channel maintenance components, such as channel isolation plugs and vented closure plugs, in twelve available magazine channels. Use of the magazine rather than a fuelling machine reduces the time required to transfer such components between the Central Service Area and reactor channels. Component transfers are accomplished by locking the fuelling machine onto one of the magazine channels and using a local controller to execute commands received from the fuel handling control system. (author)

  8. Junction and circuit fabrication

    International Nuclear Information System (INIS)

    Jackel, L.D.

    1980-01-01

    Great strides have been made in Josephson junction fabrication in the four years since the first IC SQUID meeting. Advances in lithography have allowed the production of devices with planar dimensions as small as a few hundred angstroms. Improved technology has provided ultra-high sensitivity SQUIDS, high-efficiency low-noise mixers, and complex integrated circuits. This review highlights some of the new fabrication procedures. The review consists of three parts. Part 1 is a short summary of the requirements on junctions for various applications. Part 2 reviews intergrated circuit fabrication, including tunnel junction logic circuits made at IBM and Bell Labs, and microbridge radiation sources made at SUNY at Stony Brook. Part 3 describes new junction fabrication techniques, the major emphasis of this review. This part includes a discussion of small oxide-barrier tunnel junctions, semiconductor barrier junctions, and microbridge junctions. Part 3 concludes by considering very fine lithography and limitations to miniaturization. (orig.)

  9. Fuse Modeling for Reliability Study of Power Electronic Circuits

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    This paper describes a comprehensive modeling approach on reliability of fuses used in power electronic circuits. When fuses are subjected to current pulses, cyclic temperature stress is introduced to the fuse element and will wear out the component. Furthermore, the fuse may be used in a large......, and rated voltage/current are opposed to shift in time to effect early breaking during the normal operation of the circuit. Therefore, in such cases, a reliable protection required for the other circuit components will not be achieved. The thermo-mechanical models, fatigue analysis and thermo...

  10. Improved Navy Maintenance Through Corrosion-Fatigue Assessment Program

    National Research Council Canada - National Science Library

    Hoppe, Wally

    2008-01-01

    ... to evaluate issues relevant to corrosion-fatigue of aircraft components. In this multi-year, multi-contract program, tools have been developed to assist in the establishment of maintenance options for corroded components...

  11. Small circuits for cryptography.

    Energy Technology Data Exchange (ETDEWEB)

    Torgerson, Mark Dolan; Draelos, Timothy John; Schroeppel, Richard Crabtree; Miller, Russell D.; Anderson, William Erik

    2005-10-01

    This report examines a number of hardware circuit design issues associated with implementing certain functions in FPGA and ASIC technologies. Here we show circuit designs for AES and SHA-1 that have an extremely small hardware footprint, yet show reasonably good performance characteristics as compared to the state of the art designs found in the literature. Our AES performance numbers are fueled by an optimized composite field S-box design for the Stratix chipset. Our SHA-1 designs use register packing and feedback functionalities of the Stratix LE, which reduce the logic element usage by as much as 72% as compared to other SHA-1 designs.

  12. Silicon integrated circuit process

    International Nuclear Information System (INIS)

    Lee, Jong Duck

    1985-12-01

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  13. Silicon integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Duck

    1985-12-15

    This book introduces the process of silicon integrated circuit. It is composed of seven parts, which are oxidation process, diffusion process, ion implantation process such as ion implantation equipment, damage, annealing and influence on manufacture of integrated circuit and device, chemical vapor deposition process like silicon Epitaxy LPCVD and PECVD, photolithography process, including a sensitizer, spin, harden bake, reflection of light and problems related process, infrared light bake, wet-etch, dry etch, special etch and problems of etching, metal process like metal process like metal-silicon connection, aluminum process, credibility of aluminum and test process.

  14. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  15. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  16. EPR design for maintenance

    International Nuclear Information System (INIS)

    Krugmann, U.

    1998-01-01

    Preventive maintenance is very important in achieving high plant availability. For the European Pressurized Reactor (EPR) preventive maintenance has been carefully addressed in the design stage. This is particularly necessary because of the traditionally different maintenance strategies employed in France and Germany. This paper emphasizes the following features introduced in the ERP design to minimize the duration of the refueling outage: (1) containment accessibility during power operation; (2) overall plant layout to facilitate inspections and maintenances within the containment; and (3) safety system design for enabling preventive maintenance during power operation. (author)

  17. Modern electronic maintenance principles

    CERN Document Server

    Garland, DJ

    2013-01-01

    Modern Electronic Maintenance Principles reviews the principles of maintaining modern, complex electronic equipment, with emphasis on preventive and corrective maintenance. Unfamiliar subjects such as the half-split method of fault location, functional diagrams, and fault finding guides are explained. This book consists of 12 chapters and begins by stressing the need for maintenance principles and discussing the problem of complexity as well as the requirements for a maintenance technician. The next chapter deals with the connection between reliability and maintenance and defines the terms fai

  18. Managing nuclear maintenance

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    For utilities operating nuclear powerplants, the rules of the game continue to change. Conflicting regulatory pressures and a tougher competitive environment will make management's job more complicated and difficult in the 1990s. Dealing with these pressures successfully requires greater attention to maintenance effectiveness. Utilities can help shape their future environment by developing a well-planned strategy to guide their actions. Parts of the strategy that are discussed include developing a sound maintenance philosophy, selecting a service company, radiation exposure, and managing spare parts. This article also addresses the Swedish experience in maintenance, German philosophy regarding maintenance and the current maintenance practices of the Electricite de France

  19. AIRCRAFT MAINTENANCE HANGAR

    Directory of Open Access Journals (Sweden)

    GEAMBASU Gabriel George

    2017-05-01

    Full Text Available The paper presents the maintenance process that is done on an airplane, at a certain period of time, or after a number of flight hours or cycles and describes the checks performed behind each inspection. The first part of research describes the aircraft maintenance process that has to be done after an updated maintenance manual according with aircraft type, followed by a short introduction about maintenance hangar. The second part of the paper presents a hangar design with a foldable roof and walls, which can be folded or extended, over an airplane when a maintenance process is done, or depending on weather condition.

  20. Sensor/signal monitoring and plant maintenance

    International Nuclear Information System (INIS)

    Ciftcioglu, Oe.; Tuerkcan, E.

    1994-02-01

    Nuclear Power Plant (NPO) availability is determined by the intended functionality of safety related system and components. Therefore, maintenance is an important issue in a power plant connected to the plant's reliability and safety. The traditional maintenance policies proved to be rather costly and even not effectively addressing NPP requirements. Referring to these drawbacks, in the last decade, in the nuclear reliability centered maintenance (RCM) gained substantial interest due to its merits. In the formal implementation of RCM, apparently, predictive maintenance is not considered. However, with the impact of modern real-time and on-line surveillance and monitoring methodologies, the predictive maintenance procedures like sensor/signal verification and validation are to be included into RCM. (orig.)

  1. Maintenance considerations of the Starfire Commercial Tokamak

    International Nuclear Information System (INIS)

    Trachael, C.A.; Zahn, H.S.; Field, R.E.; Stevens, H.C.

    1979-01-01

    An initial reactor design has been developed for the Starfire Tokamak reactor that incorporates maintenance features to permit reactor and plant operation with a 75% availability. All components of the reactor can be replaced utilizing highly automated remote maintenance techniques. Provisions for contact maintenance are included but would only be utilized on a contingency basis since it is believed that allowable dose rates will be decreased in future years. A modular design approach is used for the reactor and auxiliary subsystems to permit efficient use of remote maintenance. The modular approach minimizes the number of different maintenance operations required and can result in use of simple tasks such as push, pull, turn, etc., maneuvers for module removal. Fault isolation is provided for each replaceable module

  2. Circuit architecture derivation starting from a formal requirements specification considering a DDS as example

    Science.gov (United States)

    Garbe, H.; Richter, R.; Jentschel, H.-J.

    2004-05-01

    Based on a formal specification of a direct digital synthesis (DDS) and assuming the availability of a set of possible circuit architectures we derive a customised system configuration. e calculate the design parameters that can be used for the specification to synthesise the circuit components. We show how the derived parameters and the selected IC technology influence the complexity of the circuit implementation.

  3. A novel ambulatory closed circuit breathing system for use during exercise

    NARCIS (Netherlands)

    McMorrow, R. C. N.; Windsor, J. S.; Mythen, M. G.; Grocott, M. P. W.; Ahuja, V.; Aref-Adib, G.; Burnham, R.; Chisholm, A.; Clarke, K.; Coates, D.; Coates, M.; Cook, D.; Cox, M.; Dhillon, S.; Dougall, C.; Doyle, P.; Duncan, P.; Edsell, M.; Edwards, L.; Evans, L.; Gardiner, P.; Grocott, M.; Gunning, P.; Hart, N.; Harrington, J.; Harvey, J.; Holloway, C.; Howard, D.; Hurlbut, D.; Imray, C.; Ince, C.; Jonas, M.; van der Kaaij, J.; Khosravi, M.; Kolfschoten, N.; Levett, D.; Luery, H.; Luks, A.; Martin, D.; McMorrow, R.; Meale, P.; Mitchell, K.; Montgomery, H.; Morgan, G.; Morgan, J.; Murray, A.; Mythen, M.; Newman, S.; O'Dwyer, M.; Pate, J.

    2011-01-01

    P>We describe a unique ambulatory closed circuit for delivering high fractions of inspired oxygen to an exercising user who does not require isolation from their environment. We describe the major components and their function and suggest potential applications for such a circuit. This circuit may

  4. Guide for generic application of Reliability Centered Maintenance (RCM) recommendations

    International Nuclear Information System (INIS)

    Schwan, C.A.; Toomey, G.E.; Morgan, T.A.; Darling, S.S.

    1991-02-01

    Previously completed reliability centered maintenance (RCM) studies form the basis for developing or refining a preventive maintenance program. This report describes a generic methodology that will help utilities optimize nuclear plant maintenance programs using RCM techniques. This guide addresses the following areas: history of the generic methodology development process, and use of the generic methodology for conducting system-to-system and component-to-component evaluations. 2 refs., 2 figs., 5 tabs

  5. Feeding and purge systems of coolant primary circuit and coolant secondary circuit control of the I sup(123) target

    International Nuclear Information System (INIS)

    Almeida, G.L. de.

    1986-01-01

    The Radiation Protection Service of IEN (Brazilian-CNEN) detected three faults in sup(123)I target cooling system during operation process for producing sup(123)I: a) non hermetic vessel containing contaminated water from primary coolant circuit; possibility of increasing radioactivity in the vessel due to accumulation of contaminators in cooling water and; situation in region used for personnels to arrange and adjust equipments in nuclear physics area, to carried out maintenance of cyclotron and target coupling in irradiation room. The primary circuit was changed by secondary circuit for target coolant circulating through coil of tank, which receive weater from secondary circuit. This solution solved the three problems simultaneously. (M.C.K.)

  6. Maintenance management systems

    International Nuclear Information System (INIS)

    Rohan, M. de

    1989-01-01

    This paper is concerned principally with Maintenance Management systems and their effective introduction into organisations. Maintenance improvement is basically a problem of managing the maintenance department in the broadest sense. Improvement does not only lie in the area of special techniques, systems or procedures; although they are valuable tools, but rather in a balanced attack, carefully guided by management. Over recent years, maintenance systems have received the major emphasis and in many instances the selection of the system has become a pre-occupation, whereas the importance of each maintenance function must be recognised and good management practices applied to all maintenance activities. The ingredients for success in the implementation of maintenance management systems are summarised as: having a management committee, clear objectives, project approach using project management techniques and an enthusiastic leader, user managed and data processing supported project, realistic budget and an understanding of the financial audit requirements. (author)

  7. Electronic circuit design with HEP computational tools

    International Nuclear Information System (INIS)

    Vaz, Mario

    1996-01-01

    CPSPICE is an electronic circuit statistical simulation program developed to run in a parallel environment under UNIX operating system and TCP/IP communications protocol, using CPS - Cooperative Processes Software , SPICE program and CERNLIB software package. It is part of a set of tools being develop, intended to help electronic engineers to design, model and simulate complex systems and circuits for High Energy Physics detectors, based on statistical methods, using the same software and methodology used by HEP physicists for data analysis. CPSPICE simulates electronic circuits by Monte Carlo method, through several different processes running simultaneously SPICE in UNIX parallel computers or workstation farms. Data transfer between CPS processes for a modified version of SPICE2G6 is done by RAM memory, but can also be done through hard disk files if no source files are available for the simulator, and for bigger simulation outputs files. Simulation results are written in a HBOOK file as a NTUPLE, to be examined by HBOOK in batch model or graphics, and analyzed by statistical procedures available. The HBOOK file be stored on hard disk for small amount of data, or into Exabyte tape file for large amount of data. HEP tools also helps circuit or component modeling, like MINUT program from CERNLIB, that implements Nelder and Mead Simplex and Gradient with or without derivatives algorithms, and can be used for design optimization.This paper presents CPSPICE program implementation. The scheme adopted is suitable to make parallel other electronic circuit simulators. (author)

  8. Circuit for Communication Over Power Lines

    Science.gov (United States)

    Krasowski, Michael J.; Prokop, Normal F.; Greer, Lawrence C., III; Nappier, Jennifer

    2011-01-01

    Many distributed systems share common sensors and instruments along with a common power line supplying current to the system. A communication technique and circuit has been developed that allows for the simple inclusion of an instrument, sensor, or actuator node within any system containing a common power bus. Wherever power is available, a node can be added, which can then draw power for itself, its associated sensors, and actuators from the power bus all while communicating with other nodes on the power bus. The technique modulates a DC power bus through capacitive coupling using on-off keying (OOK), and receives and demodulates the signal from the DC power bus through the same capacitive coupling. The circuit acts as serial modem for the physical power line communication. The circuit and technique can be made of commercially available components or included in an application specific integrated circuit (ASIC) design, which allows for the circuit to be included in current designs with additional circuitry or embedded into new designs. This device and technique moves computational, sensing, and actuation abilities closer to the source, and allows for the networking of multiple similar nodes to each other and to a central processor. This technique also allows for reconfigurable systems by adding or removing nodes at any time. It can do so using nothing more than the in situ power wiring of the system.

  9. Circuit simulation and physical implementation for a memristor-based colpitts oscillator

    Science.gov (United States)

    Deng, Hongmin; Wang, Dongping

    2017-03-01

    This paper implements two kinds of memristor-based colpitts oscillators, namely, the circuit where the memristor is added into the feedback network of the oscillator in parallel and series, respectively. First, a MULTISIM simulation circuit for the memristive colpitts oscillator is built, where an emulator constructed by some off-the-shelf components is utilized to replace the memristor. Then the physical system is implemented in terms of the MULTISIM simulation circuit. Circuit simulation and experimental study show that this memristive colpitts oscillator can exhibit periodic, quasi-periodic, and chaotic behaviors with certain parameter's variances. Besides, in a sense, the circuit is robust with circuit parameters and device types.

  10. Light Sources and Ballast Circuits

    Science.gov (United States)

    Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

    According to the machinery statistics by Ministry of Economy, Trade and Industry (METI), the total of domestic light bulb production in 2006 was 1,101 million (88.5% year-on-year). Production for general purpose illumination light bulbs and halogen light bulbs accounted for 122 million (99.2% y/y) and 45 million (96.3% y/y), respectively. The total of fluorescent lamp production was 988 million (114.9%) and the production of general purpose fluorescent lamps excluding backlights accounted for 367 million (101.7% y/y). Further, HID lamp production was 10 million (106.3% y/y). What is noteworthy regarding such lamp production is that, similar to the previous year, the sales volume (amount) of lamps for general illumination exceeded 100% against the previous year, indicating a steady shift to high value added products. Major lighting exhibitions in 2006 included the Light + Building Trade Fair held in Frankfurt in April and the Light Fair International 2006 held in Las Vegas, U.S.A. in May, both of which demonstrated signs of acceleration toward energy saving, high efficiency and resource saving. As for incandescent lamps, products filled with larger atomic weight gases aiming at higher efficiency/longer life are becoming the mainstream. As for new technologies, it was experimentally demonstrated that infrared radiation can be suppressed by processing micro cavities to metal plates made of tungsten, tantalum, etc. For fluorescent lamps, straight and circular fluorescent lamps achieving a longer life/higher luminous flux maintenance factor continued to be widely developed/launched again this year. For compact fluorescent lamps, energy saving/high efficiency products, multifunctional type products combined with LED and new shaped products were launched. As to HID lamps, ceramic metal halide lamps with high efficiency, improved color rendering, longer life and higher luminous flux maintenance factor were commercialized one after another. Numerous studies and analyses, on

  11. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  12. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  13. The test of VLSI circuits

    Science.gov (United States)

    Baviere, Ph.

    Tests which have proven effective for evaluating VLSI circuits for space applications are described. It is recommended that circuits be examined after each manfacturing step to gain fast feedback on inadequacies in the production system. Data from failure modes which occur during operational lifetimes of circuits also permit redefinition of the manufacturing and quality control process to eliminate the defects identified. Other tests include determination of the operational envelope of the circuits, examination of the circuit response to controlled inputs, and the performance and functional speeds of ROM and RAM memories. Finally, it is desirable that all new circuits be designed with testing in mind.

  14. An integrated circuit switch

    Science.gov (United States)

    Bonin, E. L.

    1969-01-01

    Multi-chip integrated circuit switch consists of a GaAs photon-emitting diode in close proximity with S1 phototransistor. A high current gain is obtained when the transistor has a high forward common-emitter current gain.

  15. Automatic sweep circuit

    International Nuclear Information System (INIS)

    Keefe, D.J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input is described. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found

  16. Automatic sweep circuit

    Science.gov (United States)

    Keefe, Donald J.

    1980-01-01

    An automatically sweeping circuit for searching for an evoked response in an output signal in time with respect to a trigger input. Digital counters are used to activate a detector at precise intervals, and monitoring is repeated for statistical accuracy. If the response is not found then a different time window is examined until the signal is found.

  17. "Printed-circuit" rectenna

    Science.gov (United States)

    Dickinson, R. M.

    1977-01-01

    Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.

  18. Het onzichtbare circuit

    NARCIS (Netherlands)

    Nauta, Bram

    2013-01-01

    De chip, of geïntegreerde schakeling, heeft in een razend tempo ons leven ingrijpend veranderd. Het lijkt zo vanzelfsprekend dat er weer een nieuwe generatie smartphones, tablets of computers is. Maar dat is het niet. Prof.dr.ir. Bram Nauta, hoogleraar Integrated Circuit Design, laat in zijn rede

  19. Voltage regulating circuit

    NARCIS (Netherlands)

    2005-01-01

    A voltage regulating circuit comprising a rectifier (2) for receiving an AC voltage (Vmains) and for generating a rectified AC voltage (vrec), and a capacitor (3) connected in parallel with said rectified AC voltage for providing a DC voltage (VDC) over a load (5), characterized by a unidirectional

  20. Streaming Reduction Circuit

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Kuper, Jan; Kokkeler, Andre B.J.; Molenkamp, Egbert

    2009-01-01

    Reduction circuits are used to reduce rows of floating point values to single values. Binary floating point operators often have deep pipelines, which may cause hazards when many consecutive rows have to be reduced. We present an algorithm by which any number of consecutive rows of arbitrary lengths

  1. A Magnetic Circuit Demonstration.

    Science.gov (United States)

    Vanderkooy, John; Lowe, June

    1995-01-01

    Presents a demonstration designed to illustrate Faraday's, Ampere's, and Lenz's laws and to reinforce the concepts through the analysis of a two-loop magnetic circuit. Can be made dramatic and challenging for sophisticated students but is suitable for an introductory course in electricity and magnetism. (JRH)

  2. Maintenance Optimization of High Voltage Substation Model

    Directory of Open Access Journals (Sweden)

    Radim Bris

    2008-01-01

    Full Text Available The real system from practice is selected for optimization purpose in this paper. We describe the real scheme of a high voltage (HV substation in different work states. Model scheme of the HV substation 22 kV is demonstrated within the paper. The scheme serves as input model scheme for the maintenance optimization. The input reliability and cost parameters of all components are given: the preventive and corrective maintenance costs, the actual maintenance period (being optimized, the failure rate and mean time to repair - MTTR.

  3. Radwaste treatment complex. DRAWMACS planned maintenance system

    International Nuclear Information System (INIS)

    Keel, A.J.

    1992-07-01

    This document describes the operation of the Planned Maintenance System for the Radwaste Treatment Complex. The Planned Maintenance System forms part of the Decommissioning and Radwaste Management Computer System (DRAWMACS). Further detailed information about the data structure of the system is contained in Database Design for the DRAWMACS Planned Maintenance System (AEA-D and R-0285, 2nd issue, 25th February 1992). Information for other components of DRAWMACS is contained in Basic User Guide for the Radwaste Treatment Plant Computer System (AEA-D and R-0019, July 1990). (author)

  4. Reliability centered Maintenance (RCM) program for Chashma NPP (CHASNUPP)

    International Nuclear Information System (INIS)

    Khalid, S.; Khan, S.A.

    2000-01-01

    This paper describes the proposed Reliability Centered Maintenance (RCM) program for Chashma Nuclear Power Plant (CHASNUPP). Major steps are the identification of risk critical components and the implementation of RCM procedures. Identification of risk critical components is based upon the CHASNUPP level 1 PSA results (performed under IAEA TC Project PAK/9/019) which is near completion. The other requirements for implementation of RCM program is the qualitative analysis to be performed for identifying the dominant potential failure modes of each risk critical component and determination of the necessary maintenance activities, required to ensure reliable operation of the identified risk critical components. Implementation of RCM program for these components will lead to improvement in plant availability and safety together with reduction in the maintenance cost. Development - implementation of RCM program at this stage will help the CHASNUPP Maintenance department who is now developing the maintenance program - procedures for CHASNUPP. (author)

  5. Optimization of maintenance policy using the proportional hazard model

    Energy Technology Data Exchange (ETDEWEB)

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  6. Conductus makes high-Tc integrated circuit

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This paper reports that researchers at Conductus have successfully demonstrated what the company says is the world's first integrated circuit containing active devices made from high-temperature superconductors. The circuit is a SQUID magnetometer made from seven layers of material: three layers of yttrium-barium-copper oxide, two layers of insulating material, a seed layer to create grain boundaries for the Josephson junctions, and a layer of silver for making electrical contact to the device. The chip also contains vias, or pathways that make a superconducting contact between the superconducting layers otherwise separated by insulators. Conductus had previously announced the development of a SQUID magnetometer that featured a SQUID sensor and a flux transformer manufactured on separate chips. What makes this achievement important is that the company was able to put both components on the same chip, thus creating a simple integrated circuit on a single chip. This is still a long way from conventional semiconductor technology, with as many as a million components per chip, or even the sophisticated low-Tc superconducting chips made by the Japanese, but the SQUID magnetometer demonstrates all the elements and techniques necessary to build more complex high-temperature superconductor integrated circuits, making this an important first step

  7. Operations and Maintenance Manual, Atmospheric Contaminant Sensor, Revision B.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The sensor is a mass spectrometer system which continuously monitors the atmospheric constituents of hydrogen, water vapor, nitrogen, oxygen, and carbon dioxide, and monitors the Freons on a demand sampling basis. The manual provides a system description, operational procedures, and maintenance and troubleshooting instructions. Circuit diagrams…

  8. Condition based maintenance pilot projects at Pickering ND

    International Nuclear Information System (INIS)

    Zemdegs, R.T.

    1995-01-01

    Ontario Hydro has recognized that the approaches to maintenance have undergone significant changes to the past decades. The traditional break down maintenance approach has been replaced by preventative maintenance and more recently, by condition based maintenance. The nuclear plants of Ontario Hydro have evaluated on a number of alternative programs to improve their maintenance effectiveness and to reduce costs, including Reliability Centred Maintenance (RCM), call-up review, component-based PM programs, analysis of failure history and so on. Pickering ND (nuclear division) and Ontario Hydro's Nuclear Technologies Services Division, have embarked on a Condition Based Maintenance pilot project to address the above issues as a breakthrough solution for smarter maintenance. The Condition Based Maintenance pilot project will demonstrate an end-to-end process utilizing a Reliability Centred Maintenance structured approach to re-engineer and redefine the existing maintenance programs. The project emphasizes on-condition maintenance where justified, and utilizes an information management tool to provide the required records keeping and analysis infrastructure. This paper briefly describes the planned maintenance model at Pickering ND used to guide the CBM pilot, and an overview of the methodology used to develop on-condition equipment indicators as part of a re-engineered maintenance plan

  9. Circuit simulation and physical implementation for a memristor-based colpitts oscillator

    OpenAIRE

    Hongmin Deng; Dongping Wang

    2017-01-01

    This paper implements two kinds of memristor-based colpitts oscillators, namely, the circuit where the memristor is added into the feedback network of the oscillator in parallel and series, respectively. First, a MULTISIM simulation circuit for the memristive colpitts oscillator is built, where an emulator constructed by some off-the-shelf components is utilized to replace the memristor. Then the physical system is implemented in terms of the MULTISIM simulation circuit. Circuit simulation an...

  10. Configuration control during maintenance of safety related equipment

    International Nuclear Information System (INIS)

    Irish, C.S.

    2001-01-01

    Possibly the most important aspect of performing maintenance of safety related equipment is maintaining the component's original design basis. Assuring that the repaired item will perform the same safety function within the original performance and equipment qualification parameters is commonly referred to as configuration control. Maintaining configuration control of a technologically current well documented item is easy. Unfortunately, this does not describe most safety related items requiring maintenance within the global nuclear industry. Items such as motors, transformers, metal clad switchgear (low and medium voltage circuit breakers), refrigeration compressors, and electronic components (i.e. circuit boards, power supplies, regulators, etc.) which routinely require repair have been in service for twenty plus years. As a result, finding replacement parts and or material to repair the items to the original condition is becoming more and more difficult. An added difficulty is the lack of original technical documentation available on the item which is being repaired. The lack of technical documentation makes it difficult to identify replacement material and parts when the original part or material is not available. The lack of documentation also makes it difficult to test the repaired item to make sure that the original configuration has been maintained after the repair. The presentation will discuss the details of repairing various items including motors, metal clad switchgear, refrigeration compressors and power supplies and the controls which are necessary to maintain the configuration of the original item. The discussion will include the Quality Assurance and engineering necessary to identify and evaluate replacement material and parts necessary to perform repairs on safety related equipment when the original material or part is not available. Examples of repairs which required different parts or materials than the original to be used in the repair will be

  11. Configuration control during maintenance of safety related equipment

    International Nuclear Information System (INIS)

    Irish, C.S.

    2003-01-01

    Possibly the most important aspect of performing maintenance of safety related equipment is maintaining the component's original design basis. Assuring that the repaired item will perform the same safety function within the original performance and equipment qualification parameters is commonly referred to as configuration control. Maintaining configuration control of a technologically current well documented item is easy. Unfortunately, this does not describe most safety related items requiring maintenance within the global nuclear industry. Items such as motors, transformers, metal clad switchgear (low and medium voltage circuit breakers), refrigeration compressors, and electronic components (i.e. circuit boards, power supplies, regulators, etc.) which routinely require repair have been in service for twenty plus years. As a result, finding replacement parts and or material to repair the items to the original condition is becoming more and more difficult. An added difficulty is the lack of original technical documentation available on the item which is being repaired. The lack of technical documentation makes it difficult to identify replacement material and parts when the original part or material is not available. The lack of documentation also makes it difficult to test the repaired item to make sure that the original configuration has been maintained after the repair. The presentation will discuss the details of repairing various items including motors, metal clad switchgear, refrigeration compressors and power supplies and the controls which are necessary to maintain the configuration of the original item. The discussion will include the Quality Assurance and engineering necessary to identify and evaluate replacement material and parts necessary to perform repairs on safety related equipment when the original material or part is not available. Examples of repairs which required different parts or materials than the original to be used in the repair will be

  12. Solution of multiple circuits of steam cycle HTR system

    International Nuclear Information System (INIS)

    Li, Fu; Wang, Dengying; Hao, Chen; Zheng, Yanhua

    2014-01-01

    In order to analyze the dynamic operation performance and safety characteristics of the steam cycle high temperature gas cooled reactor (HTR) systems, it is necessary to find the solution of the whole HTR systems with all coupled circuits, including the primary circuit, the secondary circuit, and the residual heat removal system (RHRS). Considering that those circuits have their own individual fluidity and characteristics, some existing code packages for independent circuits themselves have been developed, for example THEMRIX and TINTE code for the primary circuit of the pebble bed reactor, BLAST for once through steam generator. To solve the coupled steam cycle HTR systems, a feasible way is to develop coupling method to integrate these independent code packages. This paper presents several coupling methods, e.g. the equivalent component method between the primary circuit and steam generator which reflect the close coupling relationship, the overlapping domain decomposition method between the primary circuit and the passive RHRS which reflects the loose coupling relationship. Through this way, the whole steam cycle HTR system with multiple circuits can be easily and efficiently solved by integration of several existing code packages. Based on this methodology, a code package TINTE–BLAST–RHRS was developed. Using this code package, some operation performance of HTR–PM was analyzed, such as the start-up process of the plant, and the depressurized loss of forced cooling accident when different number of residual heat removal trains is operated

  13. LHC Report: superconducting circuit powering tests

    CERN Multimedia

    Mirko Pojer

    2015-01-01

    After the long maintenance and consolidation campaign carried out during LS1, the machine is getting ready to start operation with beam at 6.5 TeV… the physics community can’t wait! Prior to this, all hardware and software systems have to be tested to assess their correct and safe operation.   Most of the cold circuits (those with high current/stored energy) possess a sophisticated magnet protection system that is crucial to detect a transition of the coil from the superconducting to the normal state (a quench) and safely extract the energy stored in the circuits (about 1 GJ per dipole circuit at nominal current). LHC operation relies on 1232 superconducting dipoles with a field of up to 8.33 T operating in superfluid helium at 1.9 K, along with more than 500 superconducting quadrupoles operating at 4.2 or 1.9 K. Besides, many other superconducting and normal resistive magnets are used to guarantee the possibility of correcting all beam parameters, for a total of mo...

  14. Alternative cask maintenance facility concepts

    International Nuclear Information System (INIS)

    Attaway, C.R.; Pope, R.B.; Wiliamson, A.C.; Medley, L.G.; Shappert, L.B.

    1992-01-01

    In this paper, the results of three trade-off studies of alternative concepts for performing cask maintenance for Civilian Radioactive Waste Management System casks are presented. An earlier study resulted in a recommendation that a submerged pool concept for cask internal component removal be used in the design of a Cask Maintenance Facility. The first trade-off study resulted in confirming the previous recommendation that a submerged pool concept be used rather than an isolation cell; the basis for this continued recommendation is discussed. The second study provides an evaluation of the previously proposed facility for the capability of handling an increased quantity of OCRWM casks. The third study provides a preliminary concept for adding the capability to repaint the exterior cylindrical portions of casks

  15. Maintenance facilities, stores and records

    International Nuclear Information System (INIS)

    Fischer, K.

    1986-01-01

    The topics of this report are: on-site or off-site facilities. On-site facilities: workshops and special facilities. KWU's Service Center, a typical off-site supporting facility in Germany, capabilities and activities. A pool for special tools and equipment: devices for plugging of nozzles, for handling of RPU-studs and RPU internals etc. Devices for and management of radiological protection on-site for typical outage work. Spare parts and spare part management on site, typical examples. KWU's centralized spare part pools for components, generators and turbines etc. A computerized system for spare parts storage and maintenance planning. A system for mutual exchange of operational experience with respect to maintenance and repair activities. Systematic evaluation of failures and statistical results. (orig./GL)

  16. The LMT circuit and SPICE

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamacevicius, Arunas

    2006-01-01

    The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented....

  17. Resistor Combinations for Parallel Circuits.

    Science.gov (United States)

    McTernan, James P.

    1978-01-01

    To help simplify both teaching and learning of parallel circuits, a high school electricity/electronics teacher presents and illustrates the use of tables of values for parallel resistive circuits in which total resistances are whole numbers. (MF)

  18. Detecting short circuits during assembly

    Science.gov (United States)

    Deboo, G. J.

    1980-01-01

    Detector circuit identifies shorts between bus bars of electronic equipment being wired. Detector sounds alarm and indicates which planes are shorted. Power and ground bus bars are scanned continuously until short circuit occurs.

  19. BR-5 primary circuit decontamination

    International Nuclear Information System (INIS)

    Efimov, I.A.; Nikulin, M.P.; Smirnov-Averin, A.P.; Tymosh, B.S.; Shereshkov, V.S.

    1976-01-01

    Results and methodology of steam-water and acid decontamination of the primary coolant circuit SBR-5 reactor in 1971 are discussed. Regeneration process in a cold trap of the primary coolant circuit is discussed

  20. Random maintenance policies

    CERN Document Server

    Nakagawa, Toshio

    2014-01-01

    Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

  1. Framework for Maintenance Planning

    DEFF Research Database (Denmark)

    Soares, C. Guedes; Duarte, J. Caldeira; Garbatov, Y.

    2010-01-01

    the design and during the whole life span of operational use, within an integrated framework founded on risk and reliability based techniques. The document addresses designers, decision makers and professionals responsible for or involved in establishing maintenance plans. The purpose of this document......The present document presents a framework for maintenance planning. Maintenance plays a fundamental role in counteracting degradation effects, which are present in all infrastructure and industrial products. Therefore, maintenance planning is a very critical aspect to consider both during...... is to present maintenance as an integrated approach that needs to be planned, designed, engineered, and controlled by proper qualitative and quantitative techniques. This document outlines the basic premises for maintenance planning and provides the general philosophies that can be followed and points to a best...

  2. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  3. Design and Characterization of DNA Strand-Displacement Circuits in Serum-Supplemented Cell Medium.

    Science.gov (United States)

    Fern, Joshua; Schulman, Rebecca

    2017-09-15

    The functional stability and lifetimes of synthetic molecular circuits in biological environments are important for long-term, stable sensors or controllers of cell or tissue behavior. DNA-based molecular circuits, in particular DNA strand-displacement circuits, provide simple and effective biocompatible control mechanisms and sensors, but are vulnerable to digestion by nucleases present in living tissues and serum-supplemented cell culture. The stability of double-stranded and single-stranded DNA circuit components in serum-supplemented cell medium and the corresponding effect of nuclease-mediated degradation on circuit performance were characterized to determine the major routes of degradation and DNA strand-displacement circuit failure. Simple circuit design choices, such as the use of 5' toeholds within the DNA complexes used as reactants in the strand-displacement reactions and the termination of single-stranded components with DNA hairpin domains at the 3' termini, significantly increase the functional lifetime of the circuit components in the presence of nucleases. Simulations of multireaction circuits, guided by the experimentally measured operation of single-reaction circuits, enable predictive realization of multilayer and competitive-reaction circuit behavior. Together, these results provide a basic route to increased DNA circuit stability in cell culture environments.

  4. Software evolution and maintenance

    CERN Document Server

    Tripathy, Priyadarshi

    2014-01-01

    Software Evolution and Maintenance: A Practitioner's Approach is an accessible textbook for students and professionals, which collates the advances in software development and provides the most current models and techniques in maintenance.Explains two maintenance standards: IEEE/EIA 1219 and ISO/IEC14764Discusses several commercial reverse and domain engineering toolkitsSlides for instructors are available onlineInformation is based on the IEEE SWEBOK (Software Engineering Body of Knowledge)

  5. Status of fusion maintenance

    International Nuclear Information System (INIS)

    Fuller, G.M.

    1984-01-01

    Effective maintenance will be an essential ingredient in determining fusion system productivity. This level of productivity will result only after close attention is paid to the entire system as an entity and appropriate integration of the elements is made. The status of fusion maintenance is reviewed in the context of the entire system. While there are many challenging developmental tasks ahead in fusion maintenance, the required technologies are available in several high-technology industries, including nuclear fission

  6. Laboratory equipment maintenance contracts.

    Science.gov (United States)

    Boudreau, D A; Scheer, W D; Catrou, P G

    1985-12-01

    The increasing level of technical sophistication and complexity found in clinical laboratory instrumentation today more than ever demands careful attention to maintenance service needs. The time-worn caution for careful definition of requirements for acquisition of a system should also carry over to acquisition of maintenance service. Guidelines are presented for specifications of terms and conditions for maintenance service from the perspective of the laboratorian in the automated clinical laboratory.

  7. Interactive videodisc in maintenance

    International Nuclear Information System (INIS)

    Zwingelstein, G.; Nguyen Van Nghi, B.

    1986-01-01

    After a recall of the videodisc characteristics, this paper presents its utilization by Electricite de France in the framework of training and maintenance. The SICMA (Interactive Communication System in Maintenance) developed and tested by Electricte de France is presented as also its utilization. It has been tested on the sites of Dampierre and Paluel in the cases of training and maintenance (deconnexion of drive rods of control elements); the conclusions of this experimentation are finally given. 4 refs [fr

  8. MOS voltage automatic tuning circuit

    OpenAIRE

    李, 田茂; 中田, 辰則; 松本, 寛樹

    2004-01-01

    Abstract ###Automatic tuning circuit adjusts frequency performance to compensate for the process variation. Phase locked ###loop (PLL) is a suitable oscillator for the integrated circuit. It is a feedback system that compares the input ###phase with the output phase. It can make the output frequency equal to the input frequency. In this paper, PLL ###fomed of MOSFET's is presented.The presented circuit consists of XOR circuit, Low-pass filter and Relaxation ###Oscillator. On PSPICE simulation...

  9. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  10. Selected collection of circuit drawings

    International Nuclear Information System (INIS)

    1977-01-01

    The many electronics circuits have been constracted in the Electronics Shop for use in nuclear experiments or other purposes of this Institute. The types of these circuits amount to about 500 items in total since 1968. This report describes the electronics circuit diagrams selected from this collection. The circuit details are not presented in this report, because these are already been published in the other technical reports. (auth.)

  11. Using systematic aging assessments to improve effectiveness of plant maintenance programs

    International Nuclear Information System (INIS)

    Watson, P.; Yang, J.X.; Dam, R.F.; Nickerson, J.H.

    2003-01-01

    Nuclear plant equipment aging assessment studies provided by AECL include life assessments, condition assessments or systematic assessments of maintenance. AECL has developed several tools to apply the results of aging assessment studies to improve the effectiveness of actual plant maintenance programs. The Systematic Assessment of Maintenance and the SYSTMS tool generate maintenance tasks for a system. The System Maintenance Datastore tool assesses the maintenance resources on a system basis, and can thus quantify the savings realized by optimizing the maintenance program. Long term trends in condition-based maintenance due to component aging can be predicted, and resource savings due to optimum timing of component replacement or general plant refurbishment can be quantified. The System based Adaptive Maintenance Process ensures the maintenance program is continually updated to reflect the latest plant equipment condition and maintenance strategy information. (author)

  12. Area-efficient physically unclonable function circuit architecture

    Science.gov (United States)

    Gurrieri, Thomas; Hamlet, Jason; Bauer, Todd; Helinski, Ryan; Pierson, Lyndon G

    2015-04-28

    Generating a physically a physically unclonable function ("PUF") circuit value includes comparing each of first identification components in a first bank to each of second identification components in a second bank. A given first identification component in the first bank is not compared to another first identification component in the first bank and a given second identification component in the second bank is not compared to another second identification component in the second bank. A digital bit value is generated for each comparison made while comparing each of the first identification components to each of the second identification components. A PUF circuit value is generated from the digital bit values from each comparison made.

  13. Industrial Maintenance Strategies

    International Nuclear Information System (INIS)

    Sajjad Akbar

    2006-01-01

    Industrial plants have become more complex due to technological advancement. This has made the task of maintenance more difficult. The maintenance costs in terms of resources and downtime loss are so high that maintenance function has become a critical factor in a plant's profitability. Industry should devote as much forethought to the management of maintenance function as to production. Maintenance has grown from an art to a precise, technical engineering science. Planning, organizing scheduling and control of maintenance using modern techniques pays dividends in the form of reduced costs and increased reliability. The magnitude and the dimension of maintenance have multiplied due to development in the engineering technologies. Production cost and capacities are directly affected by the breakdown time. Total operating cost including the maintenance cost plays an important role in replacement dimension. The integrated system approach would bring forth the desired results of high maintenance standards. The standards once achieved and sustained, would add to the reliability of the plan and relieve heavy stresses and strains on the engineering logistic support. (author)

  14. Analysis of maintenance strategies

    International Nuclear Information System (INIS)

    Laakso, K.; Simola, K.

    1998-01-01

    The main topics of the presentation include: (1) an analysis model and methods to evaluate maintenance action programs and the support decision to make changes in them and (2) to understand the maintenance strategies in a systems perspective as a basis for future developments. The subproject showed how systematic models for maintenance analysis and decision support, utilising computerised and statistical tool packages, can be taken into use for evaluation and optimisation of maintenance of active systems from the safety and economic point of view

  15. Army Maintenance System Transformation

    National Research Council Canada - National Science Library

    Gilbertson, Frank V

    2006-01-01

    .... Used in conjunction with pertinent historical data and developed with Army transformation goals in mind, General Systems thinking can provide the framework for guiding maintenance transformation...

  16. Analysis of Bernstein's factorization circuit

    NARCIS (Netherlands)

    Lenstra, A.K.; Shamir, A.; Tomlinson, J.; Tromer, E.; Zheng, Y.

    2002-01-01

    In [1], Bernstein proposed a circuit-based implementation of the matrix step of the number field sieve factorization algorithm. These circuits offer an asymptotic cost reduction under the measure "construction cost x run time". We evaluate the cost of these circuits, in agreement with [1], but argue

  17. High voltage MOSFET switching circuit

    Science.gov (United States)

    McEwan, Thomas E.

    1994-01-01

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  18. MIMS circuit scrapbook V.I.

    CERN Document Server

    Mims, Forrest

    2000-01-01

    Here it is--a collection of Forrest Mims's classic work from the original Popular Electronics magazine! Using commonly available components and remarkable ingenuity, Forrest shows you how to build and experiment with circuits like these:analog computers color organs digital phase-locked loops frequency-to-voltage and voltage-to-frequency converters interval timers LED oscilloscopes light wave communicators magnetic field sensors optoelectronics pseudorandom number generators tone sequencers and much, much, more!

  19. Micro-circuits for high energy physics

    International Nuclear Information System (INIS)

    Kunz, P.F.

    1978-01-01

    Microprogramming is an inherently elegant method for implementing many digital systems. It is a mixture of hardware and software techniques with the logic subsystems controlled by 'instructions' stored in a memory. In the past, designing microprogrammed systems was difficult, tedious, and expensive because the available components were capable of only limited number of functions. Today, however, large blocks of microprogrammed systems have been incorporated into a single integrated circuit, thus microprogramming has become a simple, practical method. (Auth.)

  20. Maintenance and Outage Management Assessment (MOMA)

    International Nuclear Information System (INIS)

    2005-01-01

    The competitive environment has significant implications for nuclear power plant (NPP) operations, which include, inter alia, the need for efficient use of resources and effective management of plant activities of maintenance and outages. The purpose of NPP maintenance and outages is to allow NPPs to use all those functions necessary for safe and reliable power production by keeping them available and adequate maintenance programme is essential. The maintenance programme covers all preventive and remedial measures, both administrative and technical, necessary to identify and mitigate degradation of a functioning system, structure or component, or restore the design functions of a failed system, structure or component to an acceptable level. In response to the needs of MSs, NPES (Nuclear Power Section, Division of Nuclear Power, IAEA) plans to strengthen its services. NPES services will not only continue to provide its 'traditional' products of publications of nuclear industrial best practices and technical implementation of TC projects on plant maintenance and outage management, but also be expanded to deliver, in a timely manner, technical support missions as requested by MSs for NPPs. One of many services is Maintenance and Outage Management Assessment (MOMA). The NPP can obtain support and assistance in assessment and optimisation of its maintenance program and/or outage management. It aims to help the NPP improve its performance of maintenance and outage in a competitive nuclear power business environment. The specific benefits of the assessment are as follows: a) disseminate nuclear industrial best practices on maintenance program and outage management in the world, b) benchmark, evaluate and optimise the approach of maintenance program and outage management and c) identify solutions to known problems at nuclear power plants, if any. MOMA is conducted at the request of NPPs of any IAEA Member States. MOMA consists in a technical mission/visit for 1-3 weeks by

  1. Neuromorphic Silicon Neuron Circuits

    Science.gov (United States)

    Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena

    2011-01-01

    Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754

  2. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.

  3. Regulatory control of maintenance activities in Argentine nuclear power plants

    International Nuclear Information System (INIS)

    Calvo, J.C.; Caruso, G.

    2000-01-01

    The main maintenance objective is to assure that the safety features of structures, components and systems of nuclear power plants are kept as designed. Therefore, there is a direct relationship between safety and maintenance. Owing to the above mentioned, maintenance activities are considered a relevant regulatory issue for the Argentine Nuclear Regulatory Authority (ARN). This paper describes the regulatory control to maintenance activities of Argentine nuclear power plants. It also addresses essential elements for maintenance control, routine inspections, special inspections during planned outages, audits and license conditions and requirements. (author)

  4. Nuclear maintenance strategy and first steps for preliminary maintenance plan of the EU HCLL & HCPB Test Blanket Systems

    Energy Technology Data Exchange (ETDEWEB)

    Galabert, Jose, E-mail: jose.galabert@f4e.europa.eu [F4E Fusion for Energy, EU Domestic Agency, c/Josep Pla, 2. B3, 08019, Barcelona (Spain); Hopper, Dave [AMEC Foster Wheeler, Faraday Street, Birchwood Park, WA3 6GN (United Kingdom); Neviere, Jean-Cristophe [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, 13067, St. Paul Lez Durance Cedex (France); Nodwell, David [CCFE, Culham Science Centre, Abingdon, OX14 3DB, Oxfordshire (United Kingdom); Pascal, Romain [ITER Organization, Route de Vinon-sur-Verdon, CS 90046, 13067, St. Paul Lez Durance Cedex (France); Poitevin, Yves; Ricapito, Italo [F4E Fusion for Energy, EU Domestic Agency, c/Josep Pla, 2. B3, 08019, Barcelona (Spain); White, Gareth [AMEC Foster Wheeler, Faraday Street, Birchwood Park, WA3 6GN (United Kingdom)

    2017-03-15

    Highlights: • Nuclear maintenance strategy for the two European (EU) Test Blanket Systems (TBS): i/. Helium Cooled Lead Lithium (HCLL) and ii/. Helium Cooled Pebble Bed (HCPB). • Preliminary identification of maintenance tasks for most relevant components of the EU HCLL & HCPB TBS. • Preliminary feasibility analysis for hands-on maintenance tasks of some relevant components of the European Test Blanket Systems. • Design recommendations for enhancement of the European Test Blanket Systems maintainability. - Abstract: This paper gives an overview of nuclear maintenance strategy to be followed for the European HCLL & HCPB Test Blanket Systems (TBS) to be installed in ITER. One of the several core documents to prepare in view of their licensing is their respective ‘Maintenance Plan’. This document is fundamental for ensuring sound performance and safety of the TBS during ITER’s operational phase and shall include, amongst others, relevant information on: maintenance organization, preventive and corrective maintenance task procedures, condition monitoring for key components, maintenance work planning, and a spare parts plan, just to mention some of the key topics. In compliance with the ITER Plant Maintenance policy, first steps have been taken aimed at defining nuclear maintenance strategy for some of the most relevant HCLL & HCPB TBS components, conducted by F4E in collaboration with industry. After a brief recall of maintenance strategy of the TBM Program (PBS-56), this paper analyses main features of EU HCLL & HCPB TBS maintainability and identifies, at their conceptual design phase, a preliminary list of maintenance tasks to be developed for their most representative components. In addition, the paper also presents the first nuclear maintenance studies conducted for replacement of the Q{sub 2} Getter Beds, identifying some design recommendations for their sound maintainability.

  5. Nuclear maintenance strategy and first steps for preliminary maintenance plan of the EU HCLL & HCPB Test Blanket Systems

    International Nuclear Information System (INIS)

    Galabert, Jose; Hopper, Dave; Neviere, Jean-Cristophe; Nodwell, David; Pascal, Romain; Poitevin, Yves; Ricapito, Italo; White, Gareth

    2017-01-01

    Highlights: • Nuclear maintenance strategy for the two European (EU) Test Blanket Systems (TBS): i/. Helium Cooled Lead Lithium (HCLL) and ii/. Helium Cooled Pebble Bed (HCPB). • Preliminary identification of maintenance tasks for most relevant components of the EU HCLL & HCPB TBS. • Preliminary feasibility analysis for hands-on maintenance tasks of some relevant components of the European Test Blanket Systems. • Design recommendations for enhancement of the European Test Blanket Systems maintainability. - Abstract: This paper gives an overview of nuclear maintenance strategy to be followed for the European HCLL & HCPB Test Blanket Systems (TBS) to be installed in ITER. One of the several core documents to prepare in view of their licensing is their respective ‘Maintenance Plan’. This document is fundamental for ensuring sound performance and safety of the TBS during ITER’s operational phase and shall include, amongst others, relevant information on: maintenance organization, preventive and corrective maintenance task procedures, condition monitoring for key components, maintenance work planning, and a spare parts plan, just to mention some of the key topics. In compliance with the ITER Plant Maintenance policy, first steps have been taken aimed at defining nuclear maintenance strategy for some of the most relevant HCLL & HCPB TBS components, conducted by F4E in collaboration with industry. After a brief recall of maintenance strategy of the TBM Program (PBS-56), this paper analyses main features of EU HCLL & HCPB TBS maintainability and identifies, at their conceptual design phase, a preliminary list of maintenance tasks to be developed for their most representative components. In addition, the paper also presents the first nuclear maintenance studies conducted for replacement of the Q_2 Getter Beds, identifying some design recommendations for their sound maintainability.

  6. Integrated Circuit Immunity

    Science.gov (United States)

    Sketoe, J. G.; Clark, Anthony

    2000-01-01

    This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.

  7. Integrated coincidence circuits

    International Nuclear Information System (INIS)

    Borejko, V.F.; Grebenyuk, V.M.; Zinov, V.G.

    1976-01-01

    The description is given of two coincidence units employing integral circuits in the VISHNYA standard. The units are distinguished for the coincidence selection element which is essentially a combination of a tunnel diode and microcircuits. The output fast response of the units is at least 90 MHz in the mode of the output signal unshaped in duration and 50 MHz minimum in the mode of the output signal shaping. The resolution time of the units is dependent upon the duration of input signals

  8. Adaptive noise reduction circuit for a sound reproduction system

    Science.gov (United States)

    Engebretson, A. Maynard (Inventor); O'Connell, Michael P. (Inventor)

    1995-01-01

    A noise reduction circuit for a hearing aid having an adaptive filter for producing a signal which estimates the noise components present in an input signal. The circuit includes a second filter for receiving the noise-estimating signal and modifying it as a function of a user's preference or as a function of an expected noise environment. The circuit also includes a gain control for adjusting the magnitude of the modified noise-estimating signal, thereby allowing for the adjustment of the magnitude of the circuit response. The circuit also includes a signal combiner for combining the input signal with the adjusted noise-estimating signal to produce a noise reduced output signal.

  9. Semiconductor integrated circuits

    International Nuclear Information System (INIS)

    Michel, A.E.; Schwenker, R.O.; Ziegler, J.F.

    1979-01-01

    An improved method involving ion implantation to form non-epitaxial semiconductor integrated circuits. These are made by forming a silicon substrate of one conductivity type with a recessed silicon dioxide region extending into the substrate and enclosing a portion of the silicon substrate. A beam of ions of opposite conductivity type impurity is directed at the substrate at an energy and dosage level sufficient to form a first region of opposite conductivity within the silicon dioxide region. This impurity having a concentration peak below the surface of the substrate forms a region of the one conductivity type which extends from the substrate surface into the first opposite type region to a depth between the concentration peak and the surface and forms a second region of opposite conductivity type. The method, materials and ion beam conditions are detailed. Vertical bipolar integrated circuits can be made this way when the first opposite type conductivity region will function as a collector. Also circuits with inverted bipolar devices when this first region functions as a 'buried'' emitter region. (U.K.)

  10. Two Different Maintenance Strategies in the Hospital Environment: Preventive Maintenance for Older Technology Devices and Predictive Maintenance for Newer High-Tech Devices

    OpenAIRE

    Sezdi, Mana

    2016-01-01

    A maintenance program generated through the consideration of characteristics and failures of medical equipment is an important component of technology management. However, older technology devices and newer high-tech devices cannot be efficiently managed using the same strategies because of their different characteristics. This study aimed to generate a maintenance program comprising two different strategies to increase the efficiency of device management: preventive maintenance for older tec...

  11. Development and application of degradation modeling to define maintenance practices

    International Nuclear Information System (INIS)

    Stock, D.; Samanta, P.; Vesely, W.

    1994-06-01

    This report presents the development and application of component degradation modeling to analyze degradation effects on reliability and to identify aspects of maintenance practices that mitigate degradation and aging effects. Using continuous time Markov approaches, a component degradation model is discussed that includes information about degradation and maintenance. The component model commonly used in probabilistic risk assessments is a simple case of this general model. The parameters used in the general model have engineering interpretations and can be estimated using data and engineering experience. The generation of equations for specific models, the solution of these equations, and a methodology for estimating the needed parameters are all discussed. Applications in this report show how these models can be used to quantitatively assess the benefits that are expected from maintaining a component, the effects of different maintenance efficiencies, the merits of different maintenance policies, and the interaction of surveillance test intervals with maintenance practices

  12. The ITER remote maintenance system

    International Nuclear Information System (INIS)

    Tesini, A.; Palmer, J.

    2007-01-01

    ITER is a joint international research and development project that aims to demonstrate the scientific and technological feasibility of fusion power. As soon as the plasma operation begins using tritium, the replacement of the vacuum vessel internal components will need to be done with remote handling techniques. To accomplish these operations ITER has equipped itself with a Remote Maintenance System; this includes the Remote Handling equipment set and the Hot Cell facility. Both need to work in a cooperative way, with the aim of minimizing the machine shutdown periods and to maximize the machine availability. The ITER Remote Handling equipment set is required to be available, robust, reliable and retrievable. The machine components, to be remotely handle-able, are required to be designed simply so as to ease their maintenance. The baseline ITER Remote Handling equipment is described. The ITER Hot Cell Facility is required to provide a controlled and shielded area for the execution of repair operations (carried out using dedicated remote handling equipment) on those activated components which need to be returned to service, inside the vacuum vessel. The Hot Cell provides also the equipment and space for the processing and temporary storage of the operational and decommissioning radwaste. A conceptual ITER Hot Cell Facility is described. (orig.)

  13. Development of a standard methodology for optimizing remote visual display for nuclear-maintenance tasks

    International Nuclear Information System (INIS)

    Clarke, M.M.; Garin, J.; Preston-Anderson, A.

    1981-01-01

    The aim of the present study is to develop a methodology for optimizing remote viewing systems for a fuel recycle facility (HEF) being designed at Oak Ridge National Laboratory (ORNL). An important feature of this design involves the Remotex concept: advanced servo-controlled master/slave manipulators, with remote television viewing, will totally replace direct human contact with the radioactive environment. Therefore, the design of optimal viewing conditions is a critical component of the overall man/machine system. A methodology has been developed for optimizing remote visual displays for nuclear maintenance tasks. The usefulness of this approach has been demonstrated by preliminary specification of optimal closed circuit TV systems for such tasks

  14. Reliability-based maintenance evaluations and standard preventive maintenance programs

    International Nuclear Information System (INIS)

    Varno, M.; McKinley, M.

    1993-01-01

    Due to recent issuance of 10CFR50.65, the U.S. Nuclear Regulatory Commission maintenance rule (Rule), and the open-quotes Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plantsclose quotes prepared by the Nuclear Management and Resources Council, many utilities are undertaking review or evaluation of current preventive maintenance (PM) programs. Although PM optimization and documentation are not specifically required by the Rule, an appropriate and effective PM program (PMP) will be the cornerstone of the successful and cost-effective implementation of the Rule. Currently, a project is being conducted at the Vermont Yankee Nuclear Power Station (VYNPS) in conjunction with Quadrex Energy Services to evaluate, optimize, and document the PMP. The project began in March 1993 and is scheduled for completion in mid-1995. The initial scope for the project is the evaluation of those structures, systems, and components that are within the scope of the Rule. Because of the number of systems to be evaluated (∼50), the desired completion schedule, and cost considerations, a streamlined approach to PM optimization and documentation is being utilized

  15. Circuit theoretical methods for efficient solution of finite element structural mechanics problems

    OpenAIRE

    Ekinci, Ahmet Suat

    1999-01-01

    Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent Univ., 1999. Thesis (Ph.D.) -- Bilkent University, 1999. Includes bibliographical references leaves 78-84. Shrinking device dimensions in integrated circuit technology made integrated circuits with millions of components a reality. As a result of this advance, electrical circuit simulators that can handle very large number of components have emerged. These...

  16. Interface Circuit For Printer Port

    Science.gov (United States)

    Tucker, Jerry H.; Yadlowsky, Ann B.

    1991-01-01

    Electronic circuit, called printer-port interface circuit (PPI) developed to overcome certain disadvantages of previous methods for connecting IBM PC or PC-compatible computer to other equipment. Has both reading and writing modes of operation. Very simple, requiring only six integrated circuits. Provides for moderately fast rates of transfer of data and uses existing unmodified circuit card in IBM PC. When used with appropriate software, circuit converts printer port on IBM PC, XT, AT, or compatible personal computer to general purpose, 8-bit-data, 16-bit address bus that connects to multitude of devices.

  17. Changes to the shuttle circuits

    CERN Multimedia

    GS Department

    2011-01-01

    To fit with passengers expectation, there will be some changes to the shuttle circuits as from Monday 10 October. See details on http://cern.ch/ShuttleService (on line on 7 October). Circuit No. 5 is cancelled as circuit No. 1 also stops at Bldg. 33. In order to guarantee shorter travel times, circuit No. 1 will circulate on Meyrin site only and circuit No. 2, with departures from Bldg. 33 and 500, on Prévessin site only. Site Services Section

  18. Thermionic integrated circuits: electronics for hostile environments

    International Nuclear Information System (INIS)

    Lynn, D.K.; McCormick, J.B.; MacRoberts, M.D.J.; Wilde, D.K.; Dooley, G.R.; Brown, D.R.

    1985-01-01

    Thermionic integrated circuits combine vacuum tube technology with integrated circuit techniques to form integrated vacuum triode circuits. These circuits are capable of extended operation in both high-temperature and high-radiation environments

  19. Power system with an integrated lubrication circuit

    Science.gov (United States)

    Hoff, Brian D [East Peoria, IL; Akasam, Sivaprasad [Peoria, IL; Algrain, Marcelo C [Peoria, IL; Johnson, Kris W [Washington, IL; Lane, William H [Chillicothe, IL

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  20. Maintenance Trades Guidelines

    Science.gov (United States)

    Weidner, Theodore J.

    2008-01-01

    In 2002, APPA published "Maintenance Staffing Guidelines for Educational Facilities," the first building maintenance trades staffing guideline designed to assist educational facilities professionals with their staffing needs. addresses how facilities professionals can determine the appropriate size and mix of their organization. Contents…

  1. Advanced engineering materials and thick film hybrid circuit technology

    International Nuclear Information System (INIS)

    Faisal, S.; Aslam, M.; Mehmood, K.

    2006-01-01

    The use of Thick Film hybrid Technology to manufacture electronic circuits and passive components continues to grow at rapid rate. Thick Film Technology can be viewed as a means of packaging active devices, spanning the gap between monolithic integrated circuit chips and printed circuit boards with attached active and passive components. An advancement in engineering materials has moved from a formulating art to a base of greater understanding of relationship of material chemistry to the details of electrical and mechanical performance. This amazing advancement in the field of engineering materials has brought us up to a magnificent standard that we are able to manufacture small size, low cost and sophisticated electronic circuits of Military, Satellite systems, Robotics, Medical and Telecommunications. (author)

  2. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    Ryu, C.; Boshier, M. G.

    2015-01-01

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  3. Helium impurities in a PNP-primary coolant circuit

    International Nuclear Information System (INIS)

    Reif, M.

    1981-01-01

    The concentration of impurities to be expected have been defined in consideration of recent findings concerning the rates of infiltration and formation and the reaction mechanisms of the impurity components in the circuit. The data obtained correspond with the requirements on the metallic high-temperature components as well as with the requirements of limited graphite corrosion. (DG) [de

  4. Maintenance improvement program

    International Nuclear Information System (INIS)

    Derbonne, D.R.; Plunkett, T.F.; Simpson, J.R.

    1989-01-01

    During fuel cycle 1 at River Bend station, considerable effort was expended to reduce corrective maintenance work orders (MWOs) to <1,000. This was done by complementing the plant staff with costly contract personnel. Coming out of the first refueling outage, most contract personnel were released. The change in MWO backlog started a steady rise. It became readily apparent that to avoid costly contract staff time, a maintenance improvement program (MIP) was necessary. The MIP Was primarily directed at two areas: crew efficiency improvements and improved preplanned MWO packages. The overall effect of the MIP was to achieve significant productivity improvements with reduced operation and maintenance cost by providing frequent accountability to all levels of maintenance supervision. The MIP also produced a feeling of pride among the maintenance department employees that had not really existed before. This was the best benefit of all

  5. Integrated Circuit Electromagnetic Immunity Handbook

    Science.gov (United States)

    Sketoe, J. G.

    2000-08-01

    This handbook presents the results of the Boeing Company effort for NASA under contract NAS8-98217. Immunity level data for certain integrated circuit parts are discussed herein, along with analytical techniques for applying the data to electronics systems. This handbook is built heavily on the one produced in the seventies by McDonnell Douglas Astronautics Company (MDAC, MDC Report E1929 of 1 August 1978, entitled Integrated Circuit Electromagnetic Susceptibility Handbook, known commonly as the ICES Handbook, which has served countless systems designers for over 20 years). Sections 2 and 3 supplement the device susceptibility data presented in section 4 by presenting information on related material required to use the IC susceptibility information. Section 2 concerns itself with electromagnetic susceptibility analysis and serves as a guide in using the information contained in the rest of the handbook. A suggested system hardening requirements is presented in this chapter. Section 3 briefly discusses coupling and shielding considerations. For conservatism and simplicity, a worst case approach is advocated to determine the maximum amount of RF power picked up from a given field. This handbook expands the scope of the immunity data in this Handbook is to of 10 MHz to 10 GHz. However, the analytical techniques provided are applicable to much higher frequencies as well. It is expected however, that the upper frequency limit of concern is near 10 GHz. This is due to two factors; the pickup of microwave energy on system cables and wiring falls off as the square of the wavelength, and component response falls off at a rapid rate due to the effects of parasitic shunt paths for the RF energy. It should be noted also that the pickup on wires and cables does not approach infinity as the frequency decreases (as would be expected by extrapolating the square law dependence of the high frequency roll-off to lower frequencies) but levels off due to mismatch effects.

  6. Implementation of maintenance rule for structures

    International Nuclear Information System (INIS)

    Ashar, H.; Bagchi, G.

    1999-01-01

    The maintenance rule, 10 CFR 50.65, 'Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants', was published by the Nuclear Regulatory Commission (NRC) in the Federal Register (56 FR 31324) on July 10, 1991. The rule became effective on July 10, 1996, giving nuclear power plant licensees 5 years to implement it. During 1994-1995, NRC staff visited nine nuclear power plant sites to observe licensees' preparations for implementation of the rule. The teams found that most of the licensees had not established goals, or performance criteria for monitoring structures at their sites. The licensees contended that the structures were inherently reliable and required no monitoring under the maintenance rule. On the basis of earlier site visits performed by NRC staff to assess the condition of structures, the NRC staff could not accept this contention, and clarified its position in Revision 1 of Regulatory Guide 1.160, 'Monitoring the Effectiveness of Maintenance at Nuclear Power Plants'. This paper discusses the applicability of the maintenance rule criteria for structures and its usefulness in ensuring that the structures, systems, and components within the scope of the maintenance rule are capable of fulfilling their intended functions. Also discussed are the aspects of maintenance rule efforts that could be useful for license renewal applications. (orig.)

  7. Quantitative Analysis of Criteria in University Building Maintenance in Malaysia

    Directory of Open Access Journals (Sweden)

    Olanrewaju Ashola Abdul-Lateef

    2010-10-01

    Full Text Available University buildings are a significant part of university assets and considerable resources are committed to their design, construction and maintenance. The core of maintenance management is to optimize productivity and user satisfaction with optimum resources. An important segment in the maintenance management system is the analysis of criteria that influence building maintenance. Therefore, this paper aims to identify quantify, rank and discuss the criteria that influence maintenance costs, maintenance backlogs, productivity and user satisfaction in Malaysian university buildings. The paper reviews the related literature and presents the outcomes of a questionnaire survey. Questionnaires were administered on 50 university maintenance organizations. Thirty-one criteria were addressed to the university maintenance organizations to evaluate the degree to which each of the criteria influences building maintenance management. With a 66% response rate, it was concluded that the consideration of the criteria is critical to the university building maintenance management system. The quality of components and materials, budget constraints and the age of the building were found to be the most influential criteria but information on user performance satisfaction, problems associated with in-house workforce and shortage of materials and components were the least influential criteria. The paper also outlined that maintenance management is a strategic function in university administration.

  8. Early implementation of the Maintenance Rule

    International Nuclear Information System (INIS)

    Green, J.R.

    1995-01-01

    On July 10, 1991, the U.S. Nuclear Regulatory Commission (NRC) published the Maintenance Rule as Section 50.65 of 10 CFR 50. The purpose of the Maintenance Rule is to ensure that the effectiveness of maintenance activities is assessed on an ongoing basis in a manner that ensures key structures, systems, and components are capable of performing their intended function. Full implementation of the rule is required by July 10, 1996. On May 31, 1994, the NRC published Generic Letter 94-01, which allowed removal of technical specification accelerated testing and special reporting requirements for emergency diesel generators provided a program is implemented for monitoring and maintaining emergency diesel generator performance consistent with the provisions of the Maintenance Rule

  9. Analysis and modeling of rail maintenance costs

    Directory of Open Access Journals (Sweden)

    Amir Ali Bakhshi

    2012-01-01

    Full Text Available Railroad maintenance engineering plays an important role on availability of roads and reducing the cost of railroad incidents. Rail is of the most important parts of railroad industry, which needs regular maintenance since it covers a significant part of total maintenance cost. Any attempt on optimizing total cost of maintenance could substantially reduce the cost of railroad system and it can reduce total cost of the industry. The paper presents a new method to estimate the cost of rail failure using different cost components such as cost of inspection and cost of risk associated with possible accidents. The proposed model of this paper is used for a real-world case study of railroad transportation of Tehran region and the results have been analyzed.

  10. LS1 Report: short-circuit tests

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    As the LS1 draws to an end, teams move from installation projects to a phase of intense testing. Among these are the so-called 'short-circuit tests'. Currently under way at Point 7, these tests verify the cables, the interlocks, the energy extraction systems, the power converters that provide current to the superconducting magnets and the cooling system.   Thermal camera images taken during tests at point 4 (IP4). Before putting beam into the LHC, all of the machine's hardware components need to be put to the test. Out of these, the most complicated are the superconducting circuits, which have a myriad of different failure modes with interlock and control systems. While these will be tested at cold - during powering tests to be done in August - work can still be done beforehand. "While the circuits in the magnets themselves cannot be tested at warm, what we can do is verify the power converter and the circuits right up to the place the cables go into the magn...

  11. Operation and maintenance requirements of system design bases

    International Nuclear Information System (INIS)

    Banerjee, A.K.; Hanley, N.E.

    1989-01-01

    All system designs make assumptions about system operation testing, inspection, and maintenance. Existing industry codes and standards explicitly address design requirements of new systems, while issues related to system and plant reliability, life, design margins, effects of service conditions, operation, maintenance, etc., usually are implicit. However, system/component design documents of existing power plants often address the code requirements without considering the operation, maintenance, inspection, and testing (OMIT) requirements. The nuclear industry is expending major efforts at most nuclear power plants to reassemble and/or reconstitute system design bases. Stone ampersand Webster Engineering Corporation (SWEC) recently addressed the OMIT requirements of system/component design as an integral part of a utility's preventive maintenance program. For each component, SWEC reviewed vendor recommendations, NPRDS data/industry experience, the existing maintenance program, component service conditions, and actual plant experience. A maintenance program that considers component service conditions and plant experience ensures a connection between maintenance and design basis. Root cause analysis of failure and engineering evaluation of service condition are part of the program. System/component OMIT requirements also are compared against system design, service condition, degradation mechanism, etc., through system/component life-cycle evaluation

  12. Activities of maintenance and outage

    International Nuclear Information System (INIS)

    Gracia-Orellan, J. M.; Gonzalez, P. L.; Verdu, M. F.; Fernandez, J. A.

    2004-01-01

    Iberinco Nuclear Generation Department have wanted to promote service activities in nuclear power plants for years besides its dedication to engineering activities. for it, in 1997 Nuclear Services Management was created to complement engineering activities and to be able to make an offer for products and turn key services. People involved in this Management have an extensive experience in Services Area, so that all type of maintenance works are promoted, as well other services like dismantling, fallout management and new equipment's for nuclear power plants services. Iberinco's experience in Support Services in Nuclear Power Plants allows to answer effectively to special workers during operation cycle and outages periods. These activities have been made in spanish nuclear power plants and Angra I and II plants, both of them in Brazil. In this area we provide Technical Consulting Management and Supervision to develop the following activities: - Improvement Maintenance Programs based in PSA: Implantation of Maintenance Rule in the plants. - Supervision and Assembly of design modifications in structures, systems and components. - Fulfilment of efficiency tests, inspection and turbo-group modification. - Noise and vibrations analysis. - Valves and rotative equipment calculations and diagnosis tests. Iberinco develop these outage activities itself or as contractors coordinator under its management. A lot of them have been working with Iberinco for many years and have a great experience in the Service Area they are developing. In this article, the main outage activities developed for Iberinco are detailed. (Author)

  13. Enabling complex genetic circuits to respond to extrinsic environmental signals.

    Science.gov (United States)

    Hoynes-O'Connor, Allison; Shopera, Tatenda; Hinman, Kristina; Creamer, John Philip; Moon, Tae Seok

    2017-07-01

    Genetic circuits have the potential to improve a broad range of metabolic engineering processes and address a variety of medical and environmental challenges. However, in order to engineer genetic circuits that can meet the needs of these real-world applications, genetic sensors that respond to relevant extrinsic and intrinsic signals must be implemented in complex genetic circuits. In this work, we construct the first AND and NAND gates that respond to temperature and pH, two signals that have relevance in a variety of real-world applications. A previously identified pH-responsive promoter and a temperature-responsive promoter were extracted from the E. coli genome, characterized, and modified to suit the needs of the genetic circuits. These promoters were combined with components of the type III secretion system in Salmonella typhimurium and used to construct a set of AND gates with up to 23-fold change. Next, an antisense RNA was integrated into the circuit architecture to invert the logic of the AND gate and generate a set of NAND gates with up to 1168-fold change. These circuits provide the first demonstration of complex pH- and temperature-responsive genetic circuits, and lay the groundwork for the use of similar circuits in real-world applications. Biotechnol. Bioeng. 2017;114: 1626-1631. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Model for transient simulation in a PWR steam circuit

    International Nuclear Information System (INIS)

    Mello, L.A. de.

    1982-11-01

    A computer code (SURF) was developed and used to simulate pressure losses along the tubes of the main steam circuit of a PWR nuclear power plant, and the steam flow through relief and safety valves when pressure reactors its thresholds values. A thermodynamic model of turbines (high and low pressure), and its associated components are simulated too. The SURF computer code was coupled to the GEVAP computer code, complementing the simulation of a PWR nuclear power plant main steam circuit. (Author) [pt

  15. Silicon-based optical integrated circuits for terabit communication networks

    International Nuclear Information System (INIS)

    Svidzinsky, K K

    2003-01-01

    A brief review is presented of the development of silicon-based optical integrated circuits used as components in modern all-optical communication networks with the terabit-per-second transmission capacity. The designs and technologies for manufacturing these circuits are described and the problems related to their development and application in WDM communication systems are considered. (special issue devoted to the memory of academician a m prokhorov)

  16. Integrated maintenance program (IMP)

    International Nuclear Information System (INIS)

    Zemdegs, R.T.; Chout, Q.B.

    1998-01-01

    Approaches to the maintenance of nuclear power plants have undergone significant change in the past several decades. The traditional breakdown approach has been displaced by preventive (calendar-based) maintenance and more recently, by condition-based maintenance (CBM). This is largely driven by the fact that traditional maintenance programs, derived primarily from equipment vendor recommendations, are generally unsuccessful in controlling maintenance costs or equipment failures. Many advances in the maintenance field have taken place since the maintenance plans for Ontario Hydro's nuclear plants were initially established. Ontario Hydro nuclear plant operating costs can be substantially reduced and Incapability Factor improved with the application of modern maintenance processes and tools. Pickering is designated as the lead station for IMP. Of immediate concern is the fact that Pickering Nuclear Division has been experiencing a significant backlog of Operating Preventive Maintenance Callups. This backlog, over 2000, is unacceptable to both station management and the nuclear regulator, the Atomic Energy Control Board. In addition there are over 500 callups in various stages of revision (in hyperspace) without an adequate control nor reporting system to manage their completion. There is also considerable confusion about the classification of l icensing c allups, e.g. callups which are mandatory as a result of legal requirements. Furthermore the ineffectiveness of the Preventive Maintenance (PM) has been the subject of peer audits and Atomic Energy Control Board (AECB) findings over the past several years. The current preventive maintenance ratio PM2 /(PM+CM3) at Pickering ND is less than 20%, due to the current high load of equipment breakdown. This past summer, an Independent Integrated Performance Assessment (IIPA) review at Ontario Hydro confirmed these concerns. Over the past several years, Ontario Hydro nuclear staff have evaluated several programs to improve

  17. A genetic algorithm solution for a nuclear power plant risk-cost maintenance model

    International Nuclear Information System (INIS)

    Tong Jiejuan; Mao Dingyuan; Xue Dazhi

    2004-01-01

    Reliability Centered Maintenance (RCM) is one of the popular maintenance optimization methods according to certain kinds of priorities. Traditional RCM usually analyzes and optimizes the maintenance strategy from the viewpoint of component instead of the whole maintenance program impact. Research presented in this paper is a pilot study using PSA techniques in RCM. How to reflect the effect on component unavailability by the maintenance activities such as surveillance testing and preventive maintenance in PSA model is discussed firstly. Based on the discussion, a maintenance risk-cost model is established for global maintenance optimization in a nuclear power plant, and a genetic algorithm (GA) is applied to solve such a model to get the global optimized maintenance strategy. Finally, the result got from a simple test case based on a risk-cost model consisting of 10 components is presented

  18. Dynamic pulse difference circuit

    International Nuclear Information System (INIS)

    Erickson, G.L.

    1978-01-01

    A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry is disclosed which comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter

  19. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  20. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av