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Sample records for unit failures maintenance

  1. Optimal oppor tunistic maintenance model of multi-unit systems

    Institute of Scientific and Technical Information of China (English)

    Zhijun Cheng; Zheng Yang; Bo Guo

    2013-01-01

    An opportunistic maintenance model is presented for a continuously deteriorating series system with economical de-pendence. The system consists of two kinds of units, which are respectively subjected to the deterioration failure described by Gamma process and the random failure described by Poisson process. A two-level opportunistic policy defined by three decision parameters is proposed to coordinate the different maintenance actions and minimize the long-run maintenance cost rate of the system. A computable expression of the average cost rate is es-tablished by using the renewal property of the stochastic process of the maintained system state. The optimal values of three deci-sion parameters are derived by an iteration approach based on the characteristic of Gamma process. The behavior of the proposed policy is il ustrated through a numerical experiment. Comparative study with the widely used corrective maintenance policy demon-strates the advantage of the proposed opportunistic maintenance method in significantly reducing the maintenance cost. Simultane-ously, the applicable area of this opportunistic model is discussed by the sensitivity analysis of the set-up cost and random failure rate.

  2. Utility-scale system preventive and failure-related maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, C.; Hutchinson, P.

    1995-11-01

    This paper describes the design and performance background on PVUSA utility-scale systems at Davis and Kerman, California, and reports on a preventative and failure-related maintenance approach and costs.

  3. Reducing costs by clustering maintenance activities for multiple critical units

    NARCIS (Netherlands)

    de Jonge, Bram; Klingenberg, Warse; Teunter, Ruud; Tinga, Tiedo

    Advances in sensor technology have enabled companies to make significant progress towards achieving condition-based maintenance (CBM). CBM provides the opportunity to perform maintenance actions more effectively. However, scheduling maintenance at the unit level may imply a high maintenance

  4. Managing Highway Maintenance: Maintenance Activities, Work Units, and Classifying Work, Unit 6, Level 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit explains how maintenance work should be described, measured, and classified. It is designed for supervisors who need to know the mechanics of describing work. The format is a programed, self-instruction approach in which information is presented in progressive segments or…

  5. A Costing Analysis for Decision Making Grid Model in Failure-Based Maintenance

    Directory of Open Access Journals (Sweden)

    Burhanuddin M. A.

    2011-01-01

    Full Text Available Background. In current economic downturn, industries have to set good control on production cost, to maintain their profit margin. Maintenance department as an imperative unit in industries should attain all maintenance data, process information instantaneously, and subsequently transform it into a useful decision. Then act on the alternative to reduce production cost. Decision Making Grid model is used to identify strategies for maintenance decision. However, the model has limitation as it consider two factors only, that is, downtime and frequency of failures. We consider third factor, cost, in this study for failure-based maintenance. The objective of this paper is to introduce the formulae to estimate maintenance cost. Methods. Fish bone analysis conducted with Ishikawa model and Decision Making Grid methods are used in this study to reveal some underlying risk factors that delay failure-based maintenance. The goal of the study is to estimate the risk factor that is, repair cost to fit in the Decision Making Grid model. Decision Making grid model consider two variables, frequency of failure and downtime in the analysis. This paper introduces third variable, repair cost for Decision Making Grid model. This approaches give better result to categorize the machines, reduce cost, and boost the earning for the manufacturing plant. Results. We collected data from one of the food processing factories in Malaysia. From our empirical result, Machine C, Machine D, Machine F, and Machine I must be in the Decision Making Grid model even though their frequency of failures and downtime are less than Machine B and Machine N, based on the costing analysis. The case study and experimental results show that the cost analysis in Decision Making Grid model gives more promising strategies in failure-based maintenance. Conclusions. The improvement of Decision Making Grid model for decision analysis with costing analysis is our contribution in this paper for

  6. Joint Maintenance Policies for a Stored System with Two Units

    Institute of Scientific and Technical Information of China (English)

    XIE Jun; WANG Hong-wei

    2009-01-01

    Failure of a stored system can only be detected after inspection and its reliability can be resumed by replacement of failed components. A maintenance policy of combining periodic inspection and preventive replacement is proposed to improve its availability. To coordinate component replacement and spare provision, an ordering policy of (0,1) is considered jointly. Thus, the joint maintenance policy contains inspection, replacement and spare provision. A programming model based on the joint maintenance policy is established, whose objective function is average expected cost, containing maintenance cost and inventory cost, and the constraint is system availability. Applying renewal theorem, the performance indexes are deduced under the condition that the stored system obeys the common life distribution. Numerical examples are given for a stored system with two different units, where unit 1 probability degrades with time and unit 2 probability degrades at each test. The effect of reliability parameters on the policies is discussed. The results indicate that the joint policy is very close to the independent policy.

  7. Mitochondrial maintenance failure in aging and role of sexual dimorphism

    OpenAIRE

    Tower, John

    2014-01-01

    Gene expression changes during aging are partly conserved across species, and suggest that oxidative stress, inflammation and proteotoxicity result from mitochondrial malfunction and abnormal mitochondrial-nuclear signaling. Mitochondrial maintenance failure may result from trade-offs between mitochondrial turnover versus growth and reproduction, sexual antagonistic pleiotropy and genetic conflicts resulting from uni-parental mitochondrial transmission, as well as mitochondrial and nuclear mu...

  8. Optimal maintenance of a multi-unit system under dependencies

    Science.gov (United States)

    Sung, Ho-Joon

    The availability, or reliability, of an engineering component greatly influences the operational cost and safety characteristics of a modern system over its life-cycle. Until recently, the reliance on past empirical data has been the industry-standard practice to develop maintenance policies that provide the minimum level of system reliability. Because such empirically-derived policies are vulnerable to unforeseen or fast-changing external factors, recent advancements in the study of topic on maintenance, which is known as optimal maintenance problem, has gained considerable interest as a legitimate area of research. An extensive body of applicable work is available, ranging from those concerned with identifying maintenance policies aimed at providing required system availability at minimum possible cost, to topics on imperfect maintenance of multi-unit system under dependencies. Nonetheless, these existing mathematical approaches to solve for optimal maintenance policies must be treated with caution when considered for broader applications, as they are accompanied by specialized treatments to ease the mathematical derivation of unknown functions in both objective function and constraint for a given optimal maintenance problem. These unknown functions are defined as reliability measures in this thesis, and theses measures (e.g., expected number of failures, system renewal cycle, expected system up time, etc.) do not often lend themselves to possess closed-form formulas. It is thus quite common to impose simplifying assumptions on input probability distributions of components' lifetime or repair policies. Simplifying the complex structure of a multi-unit system to a k-out-of-n system by neglecting any sources of dependencies is another commonly practiced technique intended to increase the mathematical tractability of a particular model. This dissertation presents a proposal for an alternative methodology to solve optimal maintenance problems by aiming to achieve the

  9. A maintenance policy for two-unit parallel systems based on imperfect monitoring information

    Energy Technology Data Exchange (ETDEWEB)

    Barros, Anne [Department Genie des Systems Industiels (GSI), Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes, Cedex (France)]. E-mail: anne.barros@utt.fr; Berenguer, Christophe [Department Genie des Systems Industiels (GSI), Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes, Cedex (France); Grall, Antoine [Department Genie des Systems Industiels (GSI), Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes, Cedex (France)

    2006-02-01

    In this paper a maintenance policy is optimised for a two-unit system with a parallel structure and stochastic dependences. Monitoring problems are taken into account in the optimisation scheme: the failure time of each unit can be not detected with a given probability. Conditions on the system parameters (unit failure rates) and on the non-detection probabilities must be verified to make the optimisation scheme valid. These conditions are clearly identified. Numerical experiments allow to show the relevance of taking into account monitoring problems in the maintenance model.

  10. Mitochondrial maintenance failure in aging and role of sexual dimorphism.

    Science.gov (United States)

    Tower, John

    2015-06-15

    Gene expression changes during aging are partly conserved across species, and suggest that oxidative stress, inflammation and proteotoxicity result from mitochondrial malfunction and abnormal mitochondrial-nuclear signaling. Mitochondrial maintenance failure may result from trade-offs between mitochondrial turnover versus growth and reproduction, sexual antagonistic pleiotropy and genetic conflicts resulting from uni-parental mitochondrial transmission, as well as mitochondrial and nuclear mutations and loss of epigenetic regulation. Aging phenotypes and interventions are often sex-specific, indicating that both male and female sexual differentiation promote mitochondrial failure and aging. Studies in mammals and invertebrates implicate autophagy, apoptosis, AKT, PARP, p53 and FOXO in mediating sex-specific differences in stress resistance and aging. The data support a model where the genes Sxl in Drosophila, sdc-2 in Caenorhabditis elegans, and Xist in mammals regulate mitochondrial maintenance across generations and in aging. Several interventions that increase life span cause a mitochondrial unfolded protein response (UPRmt), and UPRmt is also observed during normal aging, indicating hormesis. The UPRmt may increase life span by stimulating mitochondrial turnover through autophagy, and/or by inhibiting the production of hormones and toxic metabolites. The data suggest that metazoan life span interventions may act through a common hormesis mechanism involving liver UPRmt, mitochondrial maintenance and sexual differentiation.

  11. Managing Highway Maintenance: Standards for Maintenance Work, Part 2, Unit 8, Level 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit describes the ways maintenance standards are developed and some of the factors which are considered in setting standards; the preceding unit on standards (part 1) should be completed before reading this unit. The format is a programed, self-instruction approach in which…

  12. Managing Highway Maintenance: Maintenance Management--by Objectives, Unit 10, Level 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit deals with management by objectives--its definition, how it works, and necessary steps for application. It is designed for maintenance supervisors who are familiar with maintenance management systems. The format is a programed, self-instructional approach in which questions are…

  13. Managing Highway Maintenance: Standards for Maintenance Work, Part 1, Unit 8, Level 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit is about maintenance standards and is designed for superintendents and senior foremen who are responsible for scheduling and controlling routine maintenance. It describes different kinds of standards, why and how standards are developed, and how standards are to be used and…

  14. An Enhanced Preventive Maintenance Optimization Model Based on a Three-Stage Failure Process

    Directory of Open Access Journals (Sweden)

    Ruifeng Yang

    2015-01-01

    Full Text Available Nuclear power plants are highly complex systems and the issues related to their safety are of primary importance. Probabilistic safety assessment is regarded as the most widespread methodology for studying the safety of nuclear power plants. As maintenance is one of the most important factors for affecting the reliability and safety, an enhanced preventive maintenance optimization model based on a three-stage failure process is proposed. Preventive maintenance is still a dominant maintenance policy due to its easy implementation. In order to correspond to the three-color scheme commonly used in practice, the lifetime of system before failure is divided into three stages, namely, normal, minor defective, and severe defective stages. When the minor defective stage is identified, two measures are considered for comparison: one is that halving the inspection interval only when the minor defective stage is identified at the first time; the other one is that if only identifying the minor defective stage, the subsequent inspection interval is halved. Maintenance is implemented immediately once the severe defective stage is identified. Minimizing the expected cost per unit time is our objective function to optimize the inspection interval. Finally, a numerical example is presented to illustrate the effectiveness of the proposed models.

  15. Portable suction unit failure in a rural EMS system.

    Science.gov (United States)

    Risavi, Brian L; Sabotchick, K J; Heile, Christopher J

    2013-08-01

    Portable suction units used by EMS personnel are utilized infrequently and often are powered by batteries. Lack of use and inspection often results in failure of the device when it is needed. The purpose of this study was to examine the incidence of portable suction unit failure in a rural EMS system and to identify the reasons for failures. A convenience sample was obtained through both random inspections by the staff of a regional EMS council and data from twice monthly checks reported by respective EMS agencies following a standard protocol for each unit. A standard protocol was used, including checking the vacuum level on each suction unit and inspecting the tubing, canister, and battery. Each inspector assessed whether the unit was capable of achieving 300 mmHg of suction within four seconds. Also, the unit was inspected for any signs of misalignment or dry rot of the gasket, kinking of suction hose, damage to the suction canister, weak/dead battery, or defective pump. Findings were recorded. Over a two-year period, 9,631 suction unit inspections were completed. There were 233 failures (2.4%) noted. The majority (126, 54.1%) were due to battery failure. Seventy-three units failed due to other reasons (not recorded, switch failure, battery not seated). Ten inspections failed due to incorrect assembly. Nineteen inspections failed due to defects with the suction canister. Five inspections failed due to kinked/disconnected suction tubing. Only a relatively small percentage of inspections of suction units revealed failures (4.6% Advanced Life Support, 8.6% Basic Life Support) using the above-stated criteria. However, given the importance of airway management and potential complications associated with airway compromise, including aspiration pneumonia, hypoxia, and hemodynamic instability, this is of concern relative to the morbidity and mortality that could be related to airway failure. Due to the relative infrequency of use and the nature of portable suction units

  16. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT IX, ENGINE COMPONENTS.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION, FUNCTION, AND MAINTENANCE OF DIESEL ENGINE CRANKSHAFTS, CAMSHAFTS, AND ASSOCIATED BEARINGS. TOPICS ARE SHAFTS AND BEARINGS, CAMSHAFTS, BEARINGS AND THEIR MAINTENANCE, AND DETECTING FAILURE. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED…

  17. Managing Highway Maintenance: Standards for Maintenance Work, Part 3, Unit 8, Level 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit explains various uses of maintenance standards and how standards should be interpreted and communicated to formen and crew leaders. Several examples are given of the decisions made when applying the standards to routine work. The preceding units on standards (parts 1 and 2)…

  18. Contraceptive failure in the United States.

    Science.gov (United States)

    Trussell, James

    2011-05-01

    This review provides an update of previous estimates of first-year probabilities of contraceptive failure for all methods of contraception available in the United States. Estimates are provided of probabilities of failure during typical use (which includes both incorrect and inconsistent use) and during perfect use (correct and consistent use). The difference between these two probabilities reveals the consequences of imperfect use; it depends both on how unforgiving of imperfect use a method is and on how hard it is to use that method perfectly. These revisions reflect new research on contraceptive failure both during perfect use and during typical use.

  19. Concepts for measuring maintenance performance and methods for analysing competing failure modes

    DEFF Research Database (Denmark)

    Cooke, R.; Paulsen, J.L.

    1997-01-01

    competing failure modes. This article examines ways to assess maintenance performance without introducing statistical assumptions, then introduces a plausible statistical model for describing the interaction of preventive and corrective maintenance, and finally illustrates these with examples from...

  20. Periodic imperfect preventive maintenance with two categories of competing failure modes

    Energy Technology Data Exchange (ETDEWEB)

    Zequeira, R.I. [ISTIT FRE CNRS 2732-Equipe LM2S, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes (France)]. E-mail: romulo.zequeira@utt.fr; Berenguer, C. [ISTIT FRE CNRS 2732-Equipe LM2S, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes (France)]. E-mail: christophe.berenguer@utt.fr

    2006-04-15

    A maintenance policy is studied for a system with two types of failure modes: maintainable and non-maintainable. The quality of maintenance actions is modelled by its effect on the system failure rate. Preventive maintenance actions restore the system to a condition between as good as new and as bad as immediately before the maintenance action. The model presented permits to study the equipment condition improvement (improvement factor) as a function of the time of the preventive maintenance action. The determination of the maintenance policy, which minimizes the cost rate for an infinite time span, is examined. Conditions are given under which a unique optimal policy exists.

  1. Insuring unit failures in electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Pineda, S.; Conejo, A.J.; Carrion, M. [Univ. Castilla-La Mancha (Spain)

    2010-11-15

    An electric energy producer participates in futures markets in the hope of hedging the risk of trading in the pool. However, this producer is required to supply the energy associated with all its signed forward contracts even if some of its units are forced out due to unexpected failures. In this case, the producer must purchase some of the energy needed to meet its futures market commitments in the pool, which may result in high losses if the pool prices happen to be higher than the forward contract prices. To mitigate these losses, the producer can take out insurance against the forced outages of its units. Using a stochastic programming model, this paper analyzes the convenience of signing an insurance against unit failure by an electric energy producer and its impact on forward contracting decisions. Results from a realistic case study are provided and analyzed. (author)

  2. Managing Highway Maintenance: Budget Preparation, Unit 9, Level 3.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit describes the essential steps in developing a maintenance budget, or performance budget, based on the work to be done. It is designed for field engineers and supervisors who assist department officials in preparing work programs and budgets. The format is a programed,…

  3. A Maintenance Model Based on Phase Type Distribution for Equipment under Two Types of Failures

    Institute of Scientific and Technical Information of China (English)

    YIN Xiao-hu; WEN Xi-sen; YANG Yong-min; QIAN Yan-ling

    2007-01-01

    A maintenance model is put forward for equipment, which is subjected to internal and external failures. In the model, two maintenance policies-perfect minimal repair and replacement are considered. The operational time has a phase type distribution (PH distribution). Failures' arrival follows a Markovian Arrival Process (MAP). Some failures require the replacement of the system, and others minimal repairs. The performance measures-the mean number of minimal repairs and replacements are analyzed and calculated.

  4. The study of Influencing Maintenance Factors on Failures of Two gypsum Kilns by Failure Modes and Effects Analysis (FMEA

    Directory of Open Access Journals (Sweden)

    Iraj Alimohammadi

    2014-06-01

    Full Text Available Developing technology and using equipment in Iranian industries caused that maintenance system would be more important to use. Using proper management techniques not only increase the performance of production system but also reduce the failures and costs. The aim of this study was to determine the quality of maintenance system and the effects of its components on failures of kilns in two gypsum production companies using Failure Modes and Effects Analysis (FMEA. Furthermore the costs of failures were studied. After the study of gypsum production steps in the factories, FMEA was conducted by the determination of analysis insight, information gathering, making list of kilns’ component and filling up the FMEA’s tables. The effects of failures on production, how to fail, failure rate, failure severity, and control measures were studied. The evaluation of maintenance system was studied by a check list including questions related to system components. The costs of failures were determined by refer in accounting notebooks and interview with the head of accounting department. It was found the total qualities of maintenance system in NO.1 was more than NO.2 but because of lower quality of NO.1’s kiln design, number of failures and their costs were more. In addition it was determined that repair costs in NO.2’s kiln were about one third of NO.1’s. The low severity failures caused the most costs in comparison to the moderate and low ones. The technical characteristics of kilns were appeared to be the most important factors in reducing of failures and costs.

  5. Principles of loads and failure mechanisms applications in maintenance, reliability and design

    CERN Document Server

    Tinga, T

    2013-01-01

    Failure of components or systems must be prevented by both designers and operators of systems, but knowledge of the underlying mechanisms is often lacking. Since the relation between the expected usage of a system and its failure behavior is unknown, unexpected failures often occur, with possibly serious financial and safety consequences. Principles of Loads and Failure Mechanisms.  Applications in Maintenance, Reliability and Design provides a complete overview of all relevant failure mechanisms, ranging from mechanical failures like fatigue and creep to corrosion and electric failures. Both qualitative and quantitative descriptions of the mechanisms and their governing loads enable a solid assessment of a system’s reliability in a given or assumed operational context. Moreover, a unique range of applications of this knowledge in the fields of maintenance, reliability and design are presented. The benefits of understanding the physics of failure are demonstrated for subjects like condition monitoring, pre...

  6. Modified iterative aggregation procedure for maintenance optimisation of multi-component systems with failure interaction

    Science.gov (United States)

    Zhang, Zhuoqi; Wu, Su; Lee, Seungchul; Ni, Jun

    2014-12-01

    This paper studies maintenance policies for multi-component systems which have failure interaction among their components. Component failure might accelerate deterioration processes or induce instantaneous failures of the remaining components. We formulate this maintenance problem as a Markov decision process (MDP) with an objective of minimising a total discounted maintenance cost. However, the action set and state space in MDP exponentially grow as the number of components increases. This makes traditional approaches computationally intractable. To deal with this curse of dimensionality, a modified iterative aggregation procedure (MIAP) is proposed. We mathematically prove that iterations in MIAP guarantee the convergence and the policy obtained is optimal. Numerical case studies find that failure interaction should not be ignored in a maintenance policy decision making and the proposed MIAP is faster and requires less computational memory size than that of linear programming.

  7. Failure mode and effect analysis in asset maintenance : a multiple case study in the process industry

    NARCIS (Netherlands)

    Braaksma, Jan; Klingenberg, W.; Veldman, J.

    2013-01-01

    Failure mode and effect analysis (FMEA) is an important method for designing and prioritising preventive maintenance activities and is often used as the basis for preventive maintenance planning. Although FMEA was studied extensively, most of the published work so far covers FMEA concept design. Lit

  8. Failure mode and effect analysis in asset maintenance: a multiple case study in the process industry

    NARCIS (Netherlands)

    Braaksma, A.J.J.; Klingenberg, W.; Veldman, J.

    2013-01-01

    Failure mode and effect analysis (FMEA) is an important method for designing and prioritising preventive maintenance activities and is often used as the basis for preventive maintenance planning. Although FMEA was studied extensively, most of the published work so far covers FMEA concept design. Lit

  9. Managing Highway Maintenance: Instructor's Manual for Management by Objectives Review, Unit 11, All Levels.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit is designed for the training group leader and contains selected highlights and suggested discussion questions from six units of training: maintenance activities, work units, and classifying work; maintenance feature inventories; how to conduct a maintenance feature inventory;…

  10. AUTOMOTIVE MAINTENANCE PLAN IMPROVEMENT BASED ON DISTRIBUTION OF FAILURE TIMES

    Directory of Open Access Journals (Sweden)

    Alexandru BOROIU

    2016-05-01

    Full Text Available In accordance with the concept of "RCM - Reliability Centered Maintenance", the paper presents a study on the possibility to improve maintenance plan for the most frequently replaced parts from a sample of cars, followed during the operation period: front/rear brake pads. After analyzing the reliability of these components, it is found that there is the possibility of introducing the obligatory replacement operation of brake pads who have reached the third technical inspection without being replaced, sacrificing resource exploitation of them, but improving the benefits for the client - the automotive availability.

  11. Effectivness Of The Failure Rate On Maintenance Costs Of The City Buses

    Directory of Open Access Journals (Sweden)

    Ignaciuk Piotr

    2015-11-01

    Full Text Available The purpose of this paper was to present a failure rate and maintenance cost comparison for two types of city transport buses. The paper presents in detail a case study of well known bus brands used at Municipal Transport Company in Lublin. A failure index of all functional and constructional systems of the vehicles and their technical availability with regards to calendar time was determined. The paper also presents analysis of the factors related to maintenance costs of buses, including costs of fluids, repair costs and maintenance service. It has been demonstrated, that both analyzed buses generate similar maintenance costs, while their failures and technical availability differ significantly in operational practice. These differences are particularly evident in relation to the cumulative costs of repairs.

  12. IMPROVEMENT DIRECTIONS OF MAINTENANCE SYSTEM OF MULTIPLE UNIT

    Directory of Open Access Journals (Sweden)

    O. S. Krasheninin

    2014-07-01

    Full Text Available Purpose. Efficiency of function multiple units park (MUP as a complex system considerably depends on the modes and conditions of its operation, which is defined as the state of their eigenstate and state of the system content. The purpose is the decision scientifically - a technical problem of system of the content of maintenance operation and repair of a rolling stock. Methodology. Article is devoted to a question of the maintenance operation and repair of a rolling stock of Ukraine. On the basis of theoretical probe, the situation which has developed on maintenance operation and repair of MVPS is analysed. The comparative analysis of a railway, motor and air transportation is provided. On the basis of the analysis and comparison by authors it is offered transition from scheduled preventive to system of service of railway transport to service on an actual state. Findings. According to given theoretical comparison of the put perspective in different types of transport it is possible to note that experience and features of operation rolling stock in allied industries is the base for revision and improvement of system of the maintenance rolling stock, including at various stages of its operation. Originality. This article provides the comparative theoretical analysis, concerning contents and repair system between railway, automobile and by air. Practical value. Introduction new approaches of the maintenance operation and rolling stocks repair will allow carrying out gradual transition from maintenance operation and repairing existing scheduled preventive system in repair system «on an actual state». Thus it is possible maximum cutting-down of number of sudden refusals in operation, providing high coefficient of operational readiness of a rolling stock (to 0.95. A comparative analysis of the maintenance system and repair is the basis of the transition feasibility.

  13. An estimate of maintenance efficiency in Brown-Proschan imperfect repair model with bathtub failure intensity

    Directory of Open Access Journals (Sweden)

    Makram Krit

    2012-06-01

    Full Text Available Purpose: Estimate the maintenance efficiency in the Brown-Proschan model with the bathtub failure intensity.Design/methodology/approach: Empirical research through which we propose a framework to establish the characteristics of failure process and its influence on maintenance process.Findings: The main contribution of the present study is the reformulation of the Brown and Proschan model using the bathtub failure intensityPractical implications: Our model is defined by BP reformulation one using bathtub failure intensity. This form of intensity is presented like superposition of two NHPP and Homogeneous Poisson one.Originality/value: This is the follow on research on the study that employed the power-law-process type of failure intensity.

  14. Design Failure Affecting Maintenance Management on Public Higher Education Institution in Malaysia

    Directory of Open Access Journals (Sweden)

    Agus Salim Nuzaihan Aras

    2016-01-01

    Full Text Available The issue of government building defect is keeping on reporting in the media and arising since 2007. These issues of building defects, maintenance and management have existing and it is deliberated up to the parliament level. The government keep continue increased the maintenance allowance in National Budgetary in every year. However, the building disasters and failures keep going develop their number of cases in Malaysia. Most of the issues are related with a weak maintenance management and faulty in design. This reflects to a poorly building condition, create discomfort and danger environment to the building users. Besides, it will result to a low quality building condition and reflect to a weak building maintenance management. Building defects arise through inappropriate or poor design, specification, construction and it will give an impact to maintenance management itself [1]. Errors in the design of the building are being debated and becoming a reason of major factor in building defect reproduction [2]. Thus, this issue will discover the major cause in building design failure that develop the building defects and verify the impact of design defects towards building maintenance management. The study involved with the public higher education institution in Malaysia focusing on main campuses and the distribution of questionnaire to the facility and maintenance management department. This research is aimed to produce a better understanding on the impact of building design failure towards the institution facilities’ condition.

  15. Generating unit maintenance scheduling under competitive market environments

    Energy Technology Data Exchange (ETDEWEB)

    Jin Ho Kim [Pusan National Univ. (Korea, Republic of). Dept. of Electrical and Communication Engineering; Jong Bae Park [Konkuk Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering; Jong Keun Park [Seoul National Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering; Yeung Han Chun [HongIlk Univ., Seoul (Korea, Republic of). Dept. of Electrical Engineering

    2005-03-01

    A novel approach to a generating unit maintenance scheduling problem in competitive electricity markets is presented in this paper. The objective is to develop a game-theoretic framework for analyzing strategic behaviors of generating companies (Gencos) from the standpoint of the generating unit maintenance scheduling (GMS) game and for obtaining the equilibrium solution for the GMS game. The GMS problem is formulated as a dynamic non-cooperative game with complete information. The players correspond to profit maximizing individual Gencos, and the payoff of each player is defined as the profits from the energy market. The optimal schedule is defined by Nash equilibrium (equilibriums) of the game. Numerical results for two-Genco system are used to demonstrate that the proposed framework can be successfully applied to analyzing the strategic behaviors of each Genco and to obtaining the corresponding Nash equilibrium. The result indicates that generating unit maintenance schedule is one of the major strategic behaviors whereby Genco maximize their profits in a competitive market environment. (author)

  16. Economic Statistical Design of integrated X-bar-S control chart with Preventive Maintenance and general failure distribution.

    Science.gov (United States)

    Caballero Morales, Santiago Omar

    2013-01-01

    The application of Preventive Maintenance (PM) and Statistical Process Control (SPC) are important practices to achieve high product quality, small frequency of failures, and cost reduction in a production process. However there are some points that have not been explored in depth about its joint application. First, most SPC is performed with the X-bar control chart which does not fully consider the variability of the production process. Second, many studies of design of control charts consider just the economic aspect while statistical restrictions must be considered to achieve charts with low probabilities of false detection of failures. Third, the effect of PM on processes with different failure probability distributions has not been studied. Hence, this paper covers these points, presenting the Economic Statistical Design (ESD) of joint X-bar-S control charts with a cost model that integrates PM with general failure distribution. Experiments showed statistically significant reductions in costs when PM is performed on processes with high failure rates and reductions in the sampling frequency of units for testing under SPC.

  17. Remote Maintenance Design Guide for Compact Processing Units

    Energy Technology Data Exchange (ETDEWEB)

    Draper, J.V.

    2000-07-13

    Oak Ridge National Laboratory (ORNL) Robotics and Process Systems (RPSD) personnel have extensive experience working with remotely operated and maintained systems. These systems require expert knowledge in teleoperation, human factors, telerobotics, and other robotic devices so that remote equipment may be manipulated, operated, serviced, surveyed, and moved about in a hazardous environment. The RPSD staff has a wealth of experience in this area, including knowledge in the broad topics of human factors, modular electronics, modular mechanical systems, hardware design, and specialized tooling. Examples of projects that illustrate and highlight RPSD's unique experience in remote systems design and application include the following: (1) design of a remote shear and remote dissolver systems in support of U.S. Department of Energy (DOE) fuel recycling research and nuclear power missions; (2) building remotely operated mobile systems for metrology and characterizing hazardous facilities in support of remote operations within those facilities; (3) construction of modular robotic arms, including the Laboratory Telerobotic Manipulator, which was designed for the National Aeronautics and Space Administration (NASA) and the Advanced ServoManipulator, which was designed for the DOE; (4) design of remotely operated laboratories, including chemical analysis and biochemical processing laboratories; (5) construction of remote systems for environmental clean up and characterization, including underwater, buried waste, underground storage tank (UST) and decontamination and dismantlement (D&D) applications. Remote maintenance has played a significant role in fuel reprocessing because of combined chemical and radiological contamination. Furthermore, remote maintenance is expected to play a strong role in future waste remediation. The compact processing units (CPUs) being designed for use in underground waste storage tank remediation are examples of improvements in systems

  18. User experience network. Supply gas failure alarm on Cardinal Health Infant Flow SiPAP units may not activate.

    Science.gov (United States)

    2009-07-01

    The supply gas failure alarm on Cardinal Health Infant Flow SiPAP units manufactured before April 2009 may not activate in the event of a gas supply loss if the device's silencer accessory is attached. However, the unit's FiO2 (fraction of inspired oxygen) and low-airway-pressure alarms will activate in such cases. If both of these alarms activate simultaneously, users should suspect a failure of the gas supply pressure. Identifying affected units requires testing that can be conducted during the device's next scheduled maintenance.

  19. Effects of a 14-month low-cost maintenance training program in patients with chronic systolic heart failure

    DEFF Research Database (Denmark)

    Prescott, Eva; Hjardem-Hansen, Rasmus; Ørkild, Bodil;

    2009-01-01

    Exercise training is known to be beneficial in chronic heart failure (CHF) patients but there is a lack of studies following patient groups for longer duration with maintenance training programs to defer deconditioning.......Exercise training is known to be beneficial in chronic heart failure (CHF) patients but there is a lack of studies following patient groups for longer duration with maintenance training programs to defer deconditioning....

  20. Electrical. Teacher's Guide. Building Maintenance Units of Instruction.

    Science.gov (United States)

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    This teaching guide on electrical building maintenance, one in a series of six publications designed for building maintenance instructors in Texas, is designed to give students an understanding of electricity in order to know how to make basic repairs to the electrical systems in a building. Introductory material provides teachers with information…

  1. Access to Care for Methadone Maintenance Patients in the United States

    Science.gov (United States)

    Hettema, Jennifer E.; Sorensen, James L.

    2009-01-01

    This policy commentary addresses a significant access to care issue that faces methadone maintenance patients seeking residential treatment in the United States. Methadone maintenance therapy (MMT) has demonstrated strong efficacy in the outpatient treatment of opiate dependence. However, many opiate dependent patients are also in need of more…

  2. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT II, MECHANICAL TRANSMISSIONS.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF TRANSMISSIONS, (2) RATIO DIFFERENCE, (3) CONSTANT MESH TRANSMISSIONS, (4) FOUR-SPEED TRUCK TRANSMISSION POWER FLOW, AND (5) TRANSMISSION TROUBLESHOOTING.…

  3. Developing a United States Marine Corps Organizational and Intermediate Level Maintenance Performance Cost Model

    Science.gov (United States)

    2009-12-01

    Marine Corps Integrated Maintenance Management System MIPR Military Interdepartmental Purchase Request MLG Marine Corps Logistics Unit MOSIS ...D. (1997). An examination of the Marine Operating and Support Information System ( MOSIS ) as a mechanism for linking resources to readiness for

  4. VALIDATION OF SPRING OPERATED PRESSURE RELIEF VALVE TIME TO FAILURE AND THE IMPORTANCE OF STATISTICALLY SUPPORTED MAINTENANCE INTERVALS

    Energy Technology Data Exchange (ETDEWEB)

    Gross, R; Stephen Harris, S

    2009-02-18

    The Savannah River Site operates a Relief Valve Repair Shop certified by the National Board of Pressure Vessel Inspectors to NB-23, The National Board Inspection Code. Local maintenance forces perform inspection, testing, and repair of approximately 1200 spring-operated relief valves (SORV) each year as the valves are cycled in from the field. The Site now has over 7000 certified test records in the Computerized Maintenance Management System (CMMS); a summary of that data is presented in this paper. In previous papers, several statistical techniques were used to investigate failure on demand and failure rates including a quantal response method for predicting the failure probability as a function of time in service. The non-conservative failure mode for SORV is commonly termed 'stuck shut'; industry defined as the valve opening at greater than or equal to 1.5 times the cold set pressure. Actual time to failure is typically not known, only that failure occurred some time since the last proof test (censored data). This paper attempts to validate the assumptions underlying the statistical lifetime prediction results using Monte Carlo simulation. It employs an aging model for lift pressure as a function of set pressure, valve manufacturer, and a time-related aging effect. This paper attempts to answer two questions: (1) what is the predicted failure rate over the chosen maintenance/ inspection interval; and do we understand aging sufficient enough to estimate risk when basing proof test intervals on proof test results?

  5. Future plans for performance analysis and maintenance/inspection optimization of shutoff rods based on the case study of Bruce Power Unit-3 Shutoff Rod 5 inspection

    Energy Technology Data Exchange (ETDEWEB)

    Nasimi, E. [Bruce Power LLP, Tiverton, Ontario (Canada); Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada); Gabbar, H.A. [Univ. of Ontario Inst. of Technology, Oshawa, Ontario (Canada)

    2011-07-01

    Shutdown System 1 (SDS1) is a preferred method for a quick shutdown of nuclear fission process in CANDU (CANada Deuterium Uranium) reactor units. Failure of a routine SDS1 safety test during Fall 2009 outage resulted in the need to develop and execute a new methodology for Shutoff Rod inspection and re-evaluate the known degradation mechanisms and failure modes. This paper describes the development of this methodology and the obtained results. It also proposes several alternative solutions for the future performance analysis and maintenance/inspection optimization for SDS1 Shutoff Rods based on the Bruce Power Unit-3 Shutoff Rod 5 case study. (author)

  6. Characteristics of organizational culture at the maintenance units of two Nordic nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, Teemu [VTT Industrial Systems, P.O. Box 1301, FIN-02044 VTT (Finland)]. E-mail: teemu.reiman@vtt.fi; Oedewald, Pia [VTT Industrial Systems, P.O. Box 1301, FIN-02044 VTT (Finland); Rollenhagen, Carl [Maelardalen University, P.O. Box 325, SE-631 05 Eskilstuna (Sweden)

    2005-09-01

    This study aims to characterize and assess the organizational cultures of two Nordic nuclear power plant (NPP) maintenance units. The research consisted of NPP maintenance units of Forsmark (Sweden) and Olkiluoto (Finland). The study strives to anticipate the consequences of the current practices, conceptions and assumptions in the given organizations to their ability and willingness to fulfill the organizational core task. The methods utilized in the study were organizational culture and core task questionnaire (CULTURE02) and semi-structured interviews. Similarities and differences in the perceived organizational values, conceptions of one's own work, conceptions of the demands of the maintenance task and organizational practices at the maintenance units were explored. The maintenance units at Olkiluoto and Forsmark had quite different organizational cultures, but they also shared a set of dimensions such as strong personal emphasis placed on safety. The authors propose that different cultural features and organizational practices may be equally effective from the perspective of the core task. The results show that due to the complexity of the maintenance work, the case organizations tend to emphasize some aspects of the maintenance task more than others. The reliability consequences of these cultural solutions to the maintenance task are discussed. The authors propose that the organizational core task, in this case the maintenance task, should be clear for all the workers. The results give implications that this has been a challenge recently as the maintenance work has been changing. The concepts of organizational core task and organizational culture could be useful as management tools to anticipate the consequences of organizational changes.

  7. Annual preventive maintenance scheduling for thermal units in an electric power system

    Directory of Open Access Journals (Sweden)

    Tonić Rodoljub

    2010-01-01

    Full Text Available The system approach to the problem of preventive maintenance scheduling for thermal units in a large scale electric power system is considered in this paper. The maintenance scheduling program determines a set of thermal units maintenance switch off for a time period of one year. This paper considers the application of dynamic programming and successive approximations method in determination of annual thermal unit maintenance schedules. The objective function is multiple component and consists of system operation costs and system reliability indices (loss-of-load-probability and expected unserved energy. The evaluation of these costs is performed through a simulation method which uses a cumulant load model. The software package, developed in FORTRAN and integrated with an ORACLE data base, produces many useful outputs.

  8. Impact of mechanical- and maintenance-induced failures of main reactor coolant pump seals on plant safety

    Energy Technology Data Exchange (ETDEWEB)

    Azarm, M A; Boccio, J L; Mitra, S

    1985-12-01

    This document presents an investigation of the safety impact resulting from mechanical- and maintenance-induced reactor coolant pump (RCP) seal failures in nuclear power plants. A data survey of the pump seal failures for existing nuclear power plants in the US from several available sources was performed. The annual frequency of pump seal failures in a nuclear power plant was estimated based on the concept of hazard rate and dependency evaluation. The conditional probability of various sizes of leak rates given seal failures was then evaluated. The safety impact of RCP seal failures, in terms of contribution to plant core-melt frequency, was also evaluated for three nuclear power plants. For leak rates below the normal makeup capacity and the impact of plant safety were discussed qualitatively, whereas for leak rates beyond the normal make up capacity, formal PRA methodologies were applied. 22 refs., 17 figs., 19 tabs.

  9. Judeo-Spanish Language Maintenance Efforts in the United States.

    Science.gov (United States)

    Malinowski, Arlene

    The aim of the paper is to ascertain the size and cultural vitality of the Sephardic component of the 50 Sephardic congregations and communities in the United States. Particular attention is focused on the extent to which Judeo-Spanish, the language of the Sephardim, continues to play a role within the group. The history of Sephardic expulsion and…

  10. Analyzing planned maintenance (PM) inspection data by failure mode and effect analysis methodology.

    Science.gov (United States)

    Ridgway, Malcolm

    2003-01-01

    There is no question that medical devices are becoming more reliable. However, we have had some difficulty finding a satisfactory method for providing persuasive documentary evidence that this improved reliability will allow us to relax our traditional planned maintenance (PM) practices without compromising patient safety. The acceptance and increasing use of Failure Mode and Effect Analysis (FMEA) by several of the oversight agencies, including the Joint Commission on Accreditation of Healthcare Organizations, provides us with an important opportunity to take another shot at this vexing problem. Using this proven FMEA methodology and some relatively simple rules to quantify the results of the routine PM inspections that all healthcare providers are still performing in considerable abundance, we have developed a method that allows us to reduce the test results to a simple, single measure (the Risk Score) that can be used to characterize the effectiveness and levels of safety of our current PM regimens. When tested on theoretical data and a sample of real PM inspection results, the method provides answers that seem reasonable. Although it will probably require some modification as we begin the standardized data gathering and gain working experience, it is our hope that this new approach will become generally accepted within the industry. This kind of positive response should enable us to persuade the various accrediting and licensing agencies to similarly accept the concept.

  11. Acute renal failure in the intensive care unit.

    Science.gov (United States)

    Weisbord, Steven D; Palevsky, Paul M

    2006-06-01

    Acute renal failure (ARF) is a common complication in critically ill patients, with ARF requiring renal replacement therapy (RRT) developing in approximately 5 to 10% of intensive care unit (ICU) patients. Epidemiological studies have demonstrated that ARF is an independent risk factor for mortality. Interventions to prevent the development of ARF are currently limited to a small number of settings, primarily radiocontrast nephropathy and rhabdomyolysis. There are no effective pharmacological agents for the treatment of established ARF. Renal replacement therapy remains the primary treatment for patients with severe ARF; however, the data guiding selection of modality of RRT and the optimal timing of initiation and dose of therapy are inconclusive. This review focuses on the epidemiology and diagnostic approach to ARF in the ICU and summarizes our current understanding of therapeutic approaches including RRT.

  12. Managing Highway Maintenance: Instructor's Manual for Work Programs and Budgets, Unit 9, Levels 1 and 2.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit covers the purpose of developing work programs and budgets; a review of the program and budget development process (activity descriptions, feature inventories and quality standards, estimated work quantities, and dollar requirements); and typical calculations for work programs,…

  13. Forecasting the Impact of Heart Failure in the United States

    Science.gov (United States)

    Heidenreich, Paul A.; Albert, Nancy M.; Allen, Larry A.; Bluemke, David A.; Butler, Javed; Fonarow, Gregg C.; Ikonomidis, John S.; Khavjou, Olga; Konstam, Marvin A.; Maddox, Thomas M.; Nichol, Graham; Pham, Michael; Piña, Ileana L.; Trogdon, Justin G.

    2013-01-01

    Background Heart failure (HF) is an important contributor to both the burden and cost of national healthcare expenditures, with more older Americans hospitalized for HF than for any other medical condition. With the aging of the population, the impact of HF is expected to increase substantially. Methods and Results We estimated future costs of HF by adapting a methodology developed by the American Heart Association to project the epidemiology and future costs of HF from 2012 to 2030 without double counting the costs attributed to comorbid conditions. The model assumes that HF prevalence will remain constant by age, sex, and race/ethnicity and that rising costs and technological innovation will continue at the same rate. By 2030, >8 million people in the United States (1 in every 33) will have HF. Between 2012 and 2030, real (2010$) total direct medical costs of HF are projected to increase from $21 billion to $53 billion. Total costs, including indirect costs for HF, are estimated to increase from $31 billion in 2012 to $70 billion in 2030. If one assumes all costs of cardiac care for HF patients are attributable to HF (no cost attribution to comorbid conditions), the 2030 projected cost estimates of treating patients with HF will be 3-fold higher ($160 billion in direct costs). Conclusions The estimated prevalence and cost of care for HF will increase markedly because of aging of the population. Strategies to prevent HF and improve the efficiency of care are needed. PMID:23616602

  14. Maintenance and operation of a hydroelectric unit of energy in a power system using virtual reality

    Energy Technology Data Exchange (ETDEWEB)

    de Sousa, Marcos Paulo Alves [Federal University of Para, Faculty of Engineering Computing, Augusto Correa Street, No. 1, Belem, Para (Brazil); Emilio Goeldi Museum, Service Data Processing Department, Perimetral Avenue No. 1901, Belem, Para (Brazil); Filho, Manoel Ribeiro; Nunes, Marcus Vinicius Alves; Lopes, Andrey da Costa [Federal University of Para, Faculty of Engineering Computing, Augusto Correa Street, No. 1, Belem, Para (Brazil)

    2010-07-15

    This paper presents a new approach to training for hydroelectric unit of energy (HUE) by using virtual reality Non-immersive techniques. The software offers two modules of training: maintenance and operation. The first module, maintenance, uses the learning approach based on practice and offers different training levels, divided into three modes: automatic, guided, and exploratory, in which these modes are accessed according to the acquired degree of knowledge by the trainee in relation to maintenance procedures. The second module, allows the trainee to visualize the operation of HUE during a certain event as the electromechanical dynamics of the turbine-generator assemblage in the virtual world by the visualization of several requisite conditions before the startup-shutdown procedure of HUE. (author)

  15. A United Allocation Method of Spare Parts and Ground Maintenance Equipment for Civil Aircraft

    Directory of Open Access Journals (Sweden)

    Li Yongkai

    2017-01-01

    Full Text Available Aimed at multi-echelon inventory allocation problem with finite repair capacity for civil aircraft,a united planning method based on queuing theory and Vari-Metric model is presented to deploy the aircraft spare parts and ground maintenance equipment. Through the analysis of actual engineering, the effect of repair time is quantified by the number of maintenance equipment. On this basis, the available of fleet and the cost expense are selected as the objective and constraint respectively, marginal analysis method is set as the optimization, a new allocation scheme which was suit to civil aircraft’s maintenance resources is put forward. By applied examples analysis, it is shows that this method is reasonable and feasible.

  16. Depression and self-care maintenance in patients with heart failure: A moderated mediation model of self-care confidence and resilience.

    Science.gov (United States)

    Chang, Ling-Yin; Wu, Shan-Ying; Chiang, Chern-En; Tsai, Pei-Shan

    2017-06-01

    Despite the recognition of the negative effects of depressive symptoms on self-care confidence and self-care maintenance in patients with heart failure, little is known about the moderating role of resilience underlying these relations. To explore whether depressive symptoms affect self-care maintenance through self-care confidence and whether this mediating process was moderated by resilience. The sample comprised 201 community-dwelling and medically stable patients with echocardiographically documented heart failure. A moderated mediation model was conducted to test whether self-care confidence mediated the association between depressive symptoms and self-care maintenance, and whether resilience moderated the direct and indirect effects of depressive symptoms after adjustment for covariates. Depressive symptoms reduced self-care maintenance indirectly by decreasing self-care confidence (indirect effect: -0.22, 95% confidence interval: -0.36, -0.11), and this pathway was only significant for patients with moderate and high levels and not with low levels of resilience. Resilience also moderated the direct effects of depressive symptoms on self-care maintenance such that the negative association between depressive symptoms and self-care maintenance was reversed by the existence of high resilience. Resilience moderated the direct and indirect effects of depressive symptoms through self-care confidence on self-care maintenance in heart failure patients. Efforts to improve self-care maintenance by targeting depressive symptoms may be more effective when considering self-care confidence in patients with moderate to high levels of resilience.

  17. Evaluation of the european heart failure self-care behaviour scale in a united kingdom population

    NARCIS (Netherlands)

    Shuldham, Caroline; Theaker, Chris; Jaarsma, Tiny; Cowie, Martin R.

    2007-01-01

    Title. Evaluation of the European Heart Failure Self-care Behaviour Scale in a United Kingdom population Aim. This paper is a report of a study to test the internal consistency, reliability and validity of the 12-item European Heart Failure Self-care Behaviour Scale in an English-speaking sample in

  18. Evaluation of the european heart failure self-care behaviour scale in a united kingdom population

    NARCIS (Netherlands)

    Shuldham, Caroline; Theaker, Chris; Jaarsma, Tiny; Cowie, Martin R.

    2007-01-01

    Title. Evaluation of the European Heart Failure Self-care Behaviour Scale in a United Kingdom population Aim. This paper is a report of a study to test the internal consistency, reliability and validity of the 12-item European Heart Failure Self-care Behaviour Scale in an English-speaking sample in

  19. Classification and Quality Standards of Heart Failure Units: Scientific Consensus of the Spanish Society of Cardiology.

    Science.gov (United States)

    Anguita Sánchez, Manuel; Lambert Rodríguez, José Luis; Bover Freire, Ramón; Comín Colet, Josep; Crespo Leiro, María G; González Vílchez, Francisco; Manito Lorite, Nicolás; Segovia Cubero, Javier; Ruiz Mateas, Francisco; Elola Somoza, Francisco Javier; Íñiguez Romo, Andrés

    2016-10-01

    The prevalence of heart failure remains high and represents the highest disease burden in Spain. Heart failure units have been developed to systematize the diagnosis, treatment, and clinical follow-up of heart failure patients, provide a structure to coordinate the actions of various entities and personnel involved in patient care, and improve prognosis and quality of life. There is ample evidence on the benefits of heart failure units or programs, which have become widespread in Spain. One of the challenges to the analysis of heart failure units is standardization of their classification, by determining which "programs" can be identified as heart failure "units" and by characterizing their complexity level. The aim of this article was to present the standards developed by the Spanish Society of Cardiology to classify and establish the requirements for heart failure units within the SEC-Excellence project. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  20. Water Ingress Failure Analysis of Whistler II Unit

    Science.gov (United States)

    2014-08-01

    be addressed to reduce the risk of water ingress. 15. SUBJECT TERMS Failure Analysis, Water Ingress, Ingress Protection, Rain Test 16. SECURITY...conversion coated and should not have been subject to corrosion with exposure to ordinary rain water . The batteries were highly corroded, and some...steel/chromate conversion coated. Corrosion of the star washers was greater than would be expected by normal rain water at normal temperatures

  1. Angiogenesis and cardiac hypertrophy: maintenance of cardiac function and causative roles in heart failure.

    Science.gov (United States)

    Oka, Toru; Akazawa, Hiroshi; Naito, Atsuhiko T; Komuro, Issei

    2014-01-31

    Cardiac hypertrophy is an adaptive response to physiological and pathological overload. In response to the overload, individual cardiac myocytes become mechanically stretched and activate intracellular hypertrophic signaling pathways to re-use embryonic transcription factors and to increase the synthesis of various proteins, such as structural and contractile proteins. These hypertrophic responses increase oxygen demand and promote myocardial angiogenesis to dissolve the hypoxic situation and to maintain cardiac contractile function; thus, these responses suggest crosstalk between cardiac myocytes and microvasculature. However, sustained pathological overload induces maladaptation and cardiac remodeling, resulting in heart failure. In recent years, specific understanding has increased with regard to the molecular processes and cell-cell interactions that coordinate myocardial growth and angiogenesis. In this review, we summarize recent advances in understanding the regulatory mechanisms of coordinated myocardial growth and angiogenesis in the pathophysiology of cardiac hypertrophy and heart failure.

  2. A condition-based maintenance policy with non-periodic inspections for a two-unit series system

    Energy Technology Data Exchange (ETDEWEB)

    Castanier, B. [IRCCyN/Ecole des Mines de Nantes, Departement Automatique et Productique, 4 rue Alfred Kastler, F-44307 Nantes (France)]. E-mail: bruno.castanier@emn.fr; Grall, A. [Universite de Technologie de Troyes, ISTIT-CNRS FRE 2732, Equipe Modelisation et Surete des Systemes, 12, rue Marie Curie, BP 2060-10010 Troyes Cedex (France)]. E-mail: antoine.grall@utt.fr; Berenguer, C. [Universite de Technologie de Troyes, ISTIT-CNRS FRE 2732, Equipe Modelisation et Surete des Systemes, 12, rue Marie Curie, BP 2060-10010 Troyes Cedex (France)]. E-mail: christophe.berenguer@utt.fr

    2005-01-01

    This paper considers a condition-based maintenance policy for a two-unit deteriorating system. Each unit is subject to gradual deterioration and is monitored by sequential non-periodic inspections. It can be maintained by good as new preventive or corrective replacements. Every inspection or replacement entails a set-up cost and a component-specific unit cost but if actions on the two components are combined, the set-up cost is charged only once. A parametric maintenance decision framework is proposed to coordinate inspection/replacement of the two components and minimize the long-run maintenance cost of the system. A stochastic model is developed on the basis of the semi-regenerative properties of the maintained system state and the associated cost model is used to assess and optimize the performance of the maintenance model. Numerical experiments emphasize the interest of a control of the operation groupings.

  3. Early Detection of Plant Equipment Failures: A Case Study in Just-in-Time Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Parlos, Alexander G.; Kim, Kyusung; Bharadwaj, Raj M.

    2001-06-17

    The development and testing of a model-based fault detection system for electric motors is briefly presented. The fault detection system was developed using only motor nameplate information. The fault detection results presented utilize only motor voltage and current sensor information, minimizing the need for expensive or intrusive sensors. Dynamic recurrent neural networks are used to predict the input-output response of a three-phase induction motor while using an estimate of the motor speed signal. Multiresolution (or wavelet) signal-processing techniques are used in combination with more traditional methods to estimate fault features for use in winding insulation and motor mechanical and electromechanical failure detection.

  4. Determinants of Heart Failure Self-Care Maintenance and Management in Patients and Caregivers: A Dyadic Analysis.

    Science.gov (United States)

    Bidwell, Julie T; Vellone, Ercole; Lyons, Karen S; D'Agostino, Fabio; Riegel, Barbara; Juárez-Vela, Raúl; Hiatt, Shirin O; Alvaro, Rosaria; Lee, Christopher S

    2015-10-01

    Disease self-management is a critical component of maintaining clinical stability for patients with chronic illness. This is particularly evident in the context of heart failure (HF), which is the leading cause of hospitalization for older adults. HF self-management, commonly known as HF self-care, is often performed with the support of informal caregivers. However, little is known about how a HF dyad manages the patient's care together. The purpose of this study was to identify determinants of patient and caregiver contributions to HF self-care maintenance (daily adherence and symptom monitoring) and management (appropriate recognition and response to symptoms), utilizing an approach that controls for dyadic interdependence. This was a secondary analysis of cross-sectional data from 364 dyads of Italian HF patients and caregivers. Multilevel modeling was used to identify determinants of HF self-care within patient-caregiver dyads. Patients averaged 76.2 (SD = 10.7) years old, and a slight majority (56.9%) was male, whereas caregivers averaged 57.4 (SD = 14.6) years old, and about half (48.1%) were male. Most caregivers were adult children (48.4%) or spouses (32.7%) of patients. Both patients and caregivers reported low levels of HF maintenance and management behaviors. Significant individual and dyadic determinants of self-care maintenance and self-care management included gender, quality of life, comorbid burden, impaired ADLs, cognition, hospitalizations, HF duration, relationship type, relationship quality, and social support. These comprehensive dyadic models assist in elucidating the complex nature of patient-caregiver relationships and their influence on HF self-care, leading to more effective ways to intervene and optimize outcomes.

  5. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXX, I--CATERPILLAR DIESEL ENGINE MAINTENANCE SUMMARY, II--REIEWING FACTS ABOUT ALTERNATORS.

    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 PROVIDE A SUMMARY OF DIESEL ENGINE MAINTENANCE FACTORS AND A REVIEW OF DIESEL ENGINE ALTERNATOR OPERATION. THE SEVEN SECTIONS COVER DIESEL ENGINE TROUBLESHOOTING AND THE OPERATION, TESTING, AND ADJUSTING OF ALTERNATORS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM…

  6. 拖拉机故障分析与维修%Tractor Failure Analysis and Maintenance

    Institute of Scientific and Technical Information of China (English)

    何家潮

    2013-01-01

    The tractor is to have the largest number of agricultural machinery, one of the most versatile machines. The course of the tractor, as parts wear, variations and other reasons, causing decreased performance, affect normal use, ie a failure occurs tractor. Tractor out of the failure to timely repair, do not let the machine work sick, or small problems will cause major accidents, outweigh the benefits. Article mainly discusses the tractor fault repair analysis.%拖拉机是农业机械中拥有量最多、用途最广泛的机械之一。在拖拉机使用过程中,由于零件磨损,变型等原因,引起使用性能下降,影响正常使用,也就是说拖拉机产生了故障。拖拉机出了故障要及时进行修理,不能让机器带病作业,否则小毛病就会造成大事故,得不偿失。文章主要对拖拉机的故障维修进行探讨分析。

  7. Modeling preventive maintenance using subjective data

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Presents the optimal preventive maintenance model establishedwith the target function given through technical economic analysis, and failure rate and delay time distribution estimated from subjective data, which describes the relationship between the total downtime and the preventive maintenance and can be used to determine the rational inspection interval and to minimize the total expected downtime per unit time.

  8. Four Generations of Maintenance Resource Management Programs in the United States: An Analysis of the Past, Present, and Future

    Science.gov (United States)

    Taylor, James C.; Patankar, Manoj S.

    2001-01-01

    This paper analyzes four generations of Maintenance Resource Management (MRM) programs implemented by aviation maintenance organizations in the United States. Data collected from over ten years of survey research and field observations are used for this analysis; they are presented in a case-study format. The first three generations of MRM programs were episodic efforts to increase safety through teamwork, focus group discussions, and awareness courses, respectively. Now, the fourth generation programs, characterized by a commitment to long-term communication and behavioral changes in maintenance, are set to build on those earlier generations, toward a culture of mutual trust between mechanics, their managers, and regulators.

  9. Influence of light curing units on failure of directcomposite restorations

    Directory of Open Access Journals (Sweden)

    Sameer Jadhav

    2011-01-01

    Full Text Available Light polymerizable tooth colored restorative materials are most widely preferred for advantages such as esthetics, improved physical properties and operator′s control over the working time. Since the introduction of these light polymerizable restorative materials, there has been a concern about the depth of appropriate cure throughout the restoration. Photopolymerization of the composite is of fundamental importance because adequate polymerization is a crucial factor for optimization of the physical and mechanical properties and clinical results of the composite material. Inadequate polymerization results in greater deterioration at the margins of the restoration, decreased bond strength between the tooth and the restoration, greater cytotoxicity, and reduced hardness. Therefore, the dentist must use a light curing unit that delivers adequate and sufficient energy to optimize composite polymerization. Varying light intensity affects the degree of conversion of monomer to polymer and depth of cure.

  10. Does the United States economy affect heart failure readmissions? A single metropolitan center analysis.

    Science.gov (United States)

    Thompson, Keith A; Morrissey, Ryan P; Phan, Anita; Schwarz, Ernst R

    2012-08-01

    To determine the effects of the US economy on heart failure hospitalization rates. The recession was associated with worsening unemployment, loss of private insurance and prescription medication benefits, medication nonadherence, and ultimately increased rates of hospitalization for heart failure. We compared hospitalization rates at a large, single, academic medical center from July 1, 2006 to February 28, 2007, a time of economic stability, and July 1, 2008 to February 28, 2009, a time of economic recession in the United States. Significantly fewer patients had private medical insurance during the economic recession than during the control period (36.5% vs 46%; P = 0.04). Despite this, there were no differences in the heart failure hospitalization or readmission rates, length of hospitalization, need for admission to an intensive care unit, in-hospital mortality, or use of guideline-recommended heart failure medications between the 2 study periods. We conclude that despite significant effects on medical insurance coverage, rates of heart failure hospitalization at our institution were not significantly affected by the recession. Additional large-scale population-based research is needed to better understand the effects of fluctuations in the US economy on heart failure hospitalization rates. © 2012 Wiley Periodicals, Inc.

  11. A Study of the Unsafe Actions of Staff in the Maintenance and Overhaul Unit at a Petrochemical Complex and the Presentation of Control Strategies

    Directory of Open Access Journals (Sweden)

    Mousavipour

    2016-02-01

    Full Text Available Background Today, oil, gas, and petrochemical industries are of strategic significance in the macro-development of oil-rich countries. These industries, given the nature of the work and the technical complexity of the various processes, are hazardous and susceptible to occupational accidents. More than 90% of the accidents are related to the faults and unsafe actions of personnel, either directly or indirectly. Objectives The aim of this study is to investigate the unsafe actions of staff working in the maintenance unit of a petrochemical complex. Materials and Methods This is a descriptive and analytical study conducted on 167 morning-shift workers at the Mahshahr petrochemical complex. The data were collected based on a checklist of unsafe actions prepared through a direct observation of their activities and an analysis of work instructions, documents, and incident reports. SPSS statistical software was also used for data analysis and relevant testing. Results According to the results of this study, the mean number of unsafe actions performed by the employees was 42%. The highest number of unsafe actions achieved in the maintenance mechanical unit was 52.8%, 47.1% in repair services, and 43.8% in machinery. The highest frequency of unsafe actions were caused by indiscretion and negligence, a failure to use a face shield and goggles, and non-compliance with safety principles. Conclusions According to the findings, there has been a rise in the number of unsafe actions in machinery and maintenance service units compared to other maintenance units. As such, training courses based on the behavior-based safety principles at the beginning of employment, close monitoring of health safety environment (HSE officials on the implementation of regulations, and provision of appropriate scheduling based on weather conditions and the nature of maintenance services are recommended. In addition, a refrainment from hastiness in performing duties, enhanced

  12. Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

    NARCIS (Netherlands)

    Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

    2015-01-01

    Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based

  13. Clustering condition-based maintenance for a multi-unit system with aperiodic inspections

    NARCIS (Netherlands)

    Olde Keizer, Minou C.A.; Teunter, Ruud H.; Podofillini, Luca; Sudret, Bruno; Stojadinović, Božidar; Zio, Enrico; Kröger, Wolfgang

    2015-01-01

    Condition-Based Maintenance (CBM) is a predictive maintenance strategy, which bases the maintenance scheduling on condition measurements of the components. In this paper, we continue work on the CBM optimization approach proposed by Castanier, B., A. Grall & C. Bérenguer (2005). A condition-based ma

  14. Optimization and maintenance tests considering multiple failure modes, aging and imperfect maintenance; Optimizacion de las pruebas y mantenimiento considerando multiples modos de fallo, envejecimiento y mantenimiento imperfecto

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, S.; Marton, I.; Sanchez, A.; Carlos, S.

    2014-07-01

    The paper focuses on the optimization of the test and maintenance intervals under the criteria of unavailability or cost including the effect of the aging of the components and models of imperfect maintenance. The results obtained in the case of application, which focuses on a system of safety of a nuclear power station, show differences, mainly in the outage when you consider the aging. (Author)

  15. ITALIAN LANGUAGE MAINTENANCE EFFORTS IN THE UNITED STATES AND THE TEACHER OF ITALIAN IN AMERICAN HIGH SCHOOLS AND COLLEGES.

    Science.gov (United States)

    FISHMAN, JOSHUA A.

    A STRONG INFLUENCE ON THE NATURE OF ITALIAN INSTRUCTION TODAY IN THE UNITED STATES IS THE FACT THAT ITALO-AMERICANS SHOW LESS ORGANIZED INTEREST IN THEIR LANGUAGE THAN DO OTHER ETHNIC GROUPS, AS EVIDENCED BY COMPARING NEWSPAPER PUBLICATIONS IN DIFFERENT MOTHER TONGUES, RADIO LANGUAGE PROGRAMS, AND LANGUAGE MAINTENANCE ASSOCIATIONS WHERE, IN EACH…

  16. Effects of distance between residence and hemodialysis unit on cardiovascular complications and treatments of maintenance hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    袁静

    2013-01-01

    Objective To explore the effects of etiological classification and the distance between residence and hemodialysis unit on cardiovascular complications and treatments in maintenance hemodialysis (MHD) patients.Methods A total of 756 MHD patients were collected from 12 hemodialysis centers of Guiyang,China between January

  17. Effects of a 14-month low-cost maintenance training program in patients with chronic systolic heart failure: a randomized study

    DEFF Research Database (Denmark)

    Prescott, Eva; Hjardem-Hansen, Rasmus; Dela, Flemming;

    2009-01-01

    BACKGROUND: Exercise training is known to be beneficial in chronic heart failure (CHF) patients but there is a lack of studies following patient groups for longer duration with maintenance training programs to defer deconditioning. METHODS: Study base consisted of all patients diagnosed with CHF...... in a 3-year period. Sixty-six patients with systolic CHF (ejection fraction Heart Association II-III) were randomized to 12 months of either usual care orhome-based maintenance exercise with group training sessions every 2 weeks after an initial 8-week training program. The primary endpoint...

  18. 浅谈机床电气的故障分析与检修%A Brief Discussion on Failure Analysis and Maintenance of Machine Tool Electric

    Institute of Scientific and Technical Information of China (English)

    刘予鲁

    2013-01-01

    In order to ensure the normal operation of machine tool equipment, the electrical maintenance staff should understand electric schematic diagram, enable to analyze common failures of electrical controlling circuits, and grasp circuit maintenance methods.%为确保机床设备能正常运行,电气维修人员必须读懂电路原理图,会分析常见的电气控制线路故障现象,掌握电路检修方法。

  19. Feasibility of using adaptive logic networks to predict compressor unit failure

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, W.W.; Chungying Chu; Thomas, M.M. [Dendronic Decisions Limited, Edmonton (Canada)] [and others

    1995-12-31

    In this feasibility study, an adaptive logic network (ALN) was trained to predict failures of turbine-driven compressor units using a large database of measurements. No expert knowledge about compressor systems was involved. The predictions used only the statistical properties of the measurements and the indications of failure types. A fuzzy set was used to model measurements typical of normal operation. It was constrained by a requirement imposed during ALN training, that it should have a shape similar to a Gaussian density, more precisely, that its logarithm should be convex-up. Initial results obtained using this approach to knowledge discovery in the database were encouraging.

  20. A practical procedure for the selection of time-to-failure models based on the assessment of trends in maintenance data

    Energy Technology Data Exchange (ETDEWEB)

    Louit, D.M. [Komatsu Chile, Av. Americo Vespucio 0631, Quilicura, Santiago (Chile)], E-mail: rpascual@ing.puc.cl; Pascual, R. [Centro de Mineria, Pontificia Universidad Catolica de Chile, Av. Vicuna Mackenna 4860, Santiago (Chile); Jardine, A.K.S. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ont., M5S 3G8 (Canada)

    2009-10-15

    Many times, reliability studies rely on false premises such as independent and identically distributed time between failures assumption (renewal process). This can lead to erroneous model selection for the time to failure of a particular component or system, which can in turn lead to wrong conclusions and decisions. A strong statistical focus, a lack of a systematic approach and sometimes inadequate theoretical background seem to have made it difficult for maintenance analysts to adopt the necessary stage of data testing before the selection of a suitable model. In this paper, a framework for model selection to represent the failure process for a component or system is presented, based on a review of available trend tests. The paper focuses only on single-time-variable models and is primarily directed to analysts responsible for reliability analyses in an industrial maintenance environment. The model selection framework is directed towards the discrimination between the use of statistical distributions to represent the time to failure ('renewal approach'); and the use of stochastic point processes ('repairable systems approach'), when there may be the presence of system ageing or reliability growth. An illustrative example based on failure data from a fleet of backhoes is included.

  1. Failure factors in non-life insurance companies in United Kingdom

    Science.gov (United States)

    Samsudin, Humaida Banu

    2013-04-01

    Failure in insurance company is a condition of financial distress where a company has difficulty paying off its financial obligations to its creditors. This study continues the research from the study in identifying the determinants for run-off non-life insurance companies in United Kingdom. The analysis continues to identify other variables that could lead companies to financial distress that is macroeconomic factors (GDP rates, inflation rates and interest rates); total companies failed a year before and average size for failed companies'. The result from the analysis indicates that inflation rates, interest rates, total companies failed a year before and average sizes for failed companies are the best predictors. An early detection of failure can prevent companies from bankruptcy and allow management to take action to reduce the failure costs.

  2. Failure time series prediction in industrial maintenance using neural networks; Previsao de series temporais de falhas em manutencao industrial usando redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Torres Junior, Rubiao G.; Machado, Maria Augusta S. [Instituto Brasileiro de Mercado de Capitais (IBMEC), Rio de Janeiro, RJ (Brazil); Souza, Reinaldo C. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The objective of this work is the application of two failure prediction models in industrial maintenance with the use of Artificial Neural Networks (ANN). A characteristic of the modern industrial environment is a strong competition which leads companies to search for costs minimization methods. Thus, dada gathering and maintenance dada treatment becomes extremely important in this scenario for it aims the equipment and plant systems real repair necessity. Therefore, the objective becomes the widening of the system's full activity in a continuous manner, in the required period, without problems in their integrating parts. A daily time series is modeled based on maintenance interventions pauses dada from a five years period derived form many productive systems in the finalization areas of PETROFLEX Ind. and Com. S.A. Thus, the purpose is to introduce models based on neural networks and verify its system's pauses prediction capacity, so as to intervene with adequate timing before the system fails, extend the operational period and consequently increase its availability. The results obtained in this work demonstrate the employment of Neural Networks in the prediction of pauses in PETROFLEX industrial area maintenance. The ANN's prediction capacity in a group of dada with strong non-linear component where other statistical techniques have shown little efficient has also been confirmed. Discover neural models to predict failure systems time series has enable a breakthrough in the research field, especially due to the market demand. It's no doubt a technique that will evolve in the industrial maintenance area financing important managing decision. Prediction techniques, such as the ones illustrated in this study, work side by side maintenance planning and if carefully implemented and followed up can in the medium run supply a substantial increase in the available operational hours. (author)

  3. AUTOMOTIVE DIESEL MAINTENANCE, UNIT V, MAINTAINING THE LUBRICATION SYSTEM--DETROIT DIESEL ENGINE.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE LUBRICATION SYSTEM. TOPICS ARE LUBE OILS USED, MAINTENANCE OF THE LUBRICATION SYSTEM, AND CRANKCASE VENTILATION COMPONENTS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILM "BASIC ENGINE…

  4. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT III, MAINTAINING THE FUEL SYSTEM--DETROIT DIESEL ENGINE.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM. TOPICS ARE (1) PURPOSE OF THE FUEL SYSTEM, (2) TRACING THE FUEL FLOW, (3) MINOR COMPONENTS OF THE FUEL SYSTEM, (4) MAINTENANCE TIPS, (5) CONSTRUCTION AND FUNCTION OF THE FUEL INJECTORS, AND (6)…

  5. Noninvasive ventilation for acute hypercapnic respiratory failure: intubation rate in an experienced unit.

    Science.gov (United States)

    Contou, Damien; Fragnoli, Chiara; Córdoba-Izquierdo, Ana; Boissier, Florence; Brun-Buisson, Christian; Thille, Arnaud W

    2013-12-01

    Failure of noninvasive ventilation (NIV) is common in patients with COPD admitted to the ICU for acute hypercapnic respiratory failure (AHRF). We aimed to assess the rate of NIV failure and to identify early predictors of intubation under NIV in patients admitted for AHRF of all origins in an experienced unit. This was an observational cohort study using data prospectively collected over a 3-year period after the implementation of a nurse-driven NIV protocol in a 24-bed medical ICU of a French university hospital. Among 242 subjects receiving NIV for AHRF (P(aCO2) > 45 mm Hg), 67 had cardiogenic pulmonary edema (CPE), 146 had acute-on-chronic respiratory failure (AOCRF) (including 99 subjects with COPD and 47 with other chronic respiratory diseases), and 29 had non-AOCRF (mostly pneumonia). Overall, the rates of intubation and ICU mortality were respectively 15% and 5%. The intubation rates were 4% in CPE, 15% in AOCRF, and 38% in non-AOCRF (P intubation rate was reduced to 15% in patients receiving NIV for AHRF, with a mortality rate of only 5%. Whereas the risk of NIV failure is associated with hypoxemia and acidosis after initiation of NIV, it is also markedly influenced by the presence or absence of an underlying chronic respiratory disease.

  6. The United States Government Interagency Process and the Failure of Institution Building in Iraq

    Science.gov (United States)

    2008-06-12

    LTG Martin Dempsey, to make the case for an increase in the investment by the United States Government (USG) in the development of a self-sufficient...the exception of 5 Feil , Scott R. “The Failure of Incrementalism: Interagency Coordination Challenges and Responses.” In The Interagency and...society invested in establishing a stable democratic, and economically viable Iraq.” (SIGIR-06-045, 2007) 35 Interview, Scott Feil , 27 November 2007. 22

  7. Tempo ótimo entre manutenções preventivas para sistemas sujeitos a mais de um tipo de evento aleatório Optimal maintenance time for repairable systems in more than one type of failure

    Directory of Open Access Journals (Sweden)

    Wagner Baracho dos Santos

    2007-04-01

    Full Text Available Um sistema reparável opera sob uma política de manutenção que especifica reparos preventivos em tempos pré-determinados e reparos mínimos quando ocorre uma falha. O processo de Poisson não-homogêneo é um modelo adequado para as falhas aleatórias que são tratadas por reparo mínimo. Assumindo um único tipo de falha e uma forma paramétrica para a função de intensidade deste processo, pode-se encontrar uma política ótima de manutenção preventiva que minimiza o custo médio por unidade de tempo. Este artigo foi motivado por uma situação envolvendo chaves seccionadoras de uma empresa de energia elétrica. Neste sistema existem dois tipos diferentes de eventos aleatórios, caracterizados por distintas causas de falhas. Uma política ótima de manutenção preventiva é obtida estendendo-se os resultados da situação envolvendo um único evento aleatório.A repairable system operates under a maintenance strategy that calls for complete preventive repair actions at pre-scheduled times and minimal repair actions whenever a failure occurs. Under minimal repair, failures are modeled according to a non-homogeneous Poisson process. When the intensity function is assumed to grow proportional to a power of time, this process is called the Power Law Process. The motivation for this paper was a maintenance data set related to power switch disconnectors. Two different types of failures could be observed for these systems according to their causes. The major differences between these types of failures are their costs. Assuming that the system will be in operation for an infinite time, we found the expected cost per unit of time for each preventive maintenance policy and hence obtained the optimal strategy as a function of the intensity function of the process. Large sample procedures to estimate the optimal maintenance check points for the Power Law Process are also discussed. The results are applied in the power switch disconnector data set.

  8. Failure mechanisms of additively manufactured porous biomaterials: Effects of porosity and type of unit cell.

    Science.gov (United States)

    Kadkhodapour, J; Montazerian, H; Darabi, A Ch; Anaraki, A P; Ahmadi, S M; Zadpoor, A A; Schmauder, S

    2015-10-01

    Since the advent of additive manufacturing techniques, regular porous biomaterials have emerged as promising candidates for tissue engineering scaffolds owing to their controllable pore architecture and feasibility in producing scaffolds from a variety of biomaterials. The architecture of scaffolds could be designed to achieve similar mechanical properties as in the host bone tissue, thereby avoiding issues such as stress shielding in bone replacement procedure. In this paper, the deformation and failure mechanisms of porous titanium (Ti6Al4V) biomaterials manufactured by selective laser melting from two different types of repeating unit cells, namely cubic and diamond lattice structures, with four different porosities are studied. The mechanical behavior of the above-mentioned porous biomaterials was studied using finite element models. The computational results were compared with the experimental findings from a previous study of ours. The Johnson-Cook plasticity and damage model was implemented in the finite element models to simulate the failure of the additively manufactured scaffolds under compression. The computationally predicted stress-strain curves were compared with the experimental ones. The computational models incorporating the Johnson-Cook damage model could predict the plateau stress and maximum stress at the first peak with less than 18% error. Moreover, the computationally predicted deformation modes were in good agreement with the results of scaling law analysis. A layer-by-layer failure mechanism was found for the stretch-dominated structures, i.e. structures made from the cubic unit cell, while the failure of the bending-dominated structures, i.e. structures made from the diamond unit cells, was accompanied by the shearing bands of 45°.

  9. Developing the concept of maintenance and repairs in projects of power units for new-generation nuclear power stations

    Science.gov (United States)

    Gurinovich, V. D.; Yanchenko, Yu. A.

    2012-05-01

    Results from conceptual elaboration of individual requirements for the system of maintenance and repairs that must be implemented in the projects of new-generation nuclear power stations are presented taking as an example the power unit project for a nuclear power station equipped with a standard optimized VVER reactor with enhanced information support (the so-called VVER TOI reactor). Implementation of these concepts will help to achieve competitiveness of such nuclear power stations in the domestic and international markets.

  10. Failures of foreseeability: Risk management considerations in reducing allegations of sexual violence in psychiatric units.

    Science.gov (United States)

    Banja, John D

    2017-01-01

    This article begins with a brief discussion of findings on causal factors leading to allegations of sexual violence in health care facilities and then offers the author's account of 4 such cases that he reviewed, 3 of which occurred in psychiatric units. These cases show remarkably similar variables, especially involving decisions to allow male and female patients to commingle, the inadequate physical layout of the units, poor or absent video surveillance, and staff unacquainted with institutional policies on patient safety or refusing to enforce relevant rules. These variables arguably amount to "failures of foreseeability" that reasonably cautious health care personnel should recognize as facilitating or enabling sexual violence. As such, the proactive message of this article for health care risk management urges critical and robust attention paid to a unit's environmental/physical design as well as to performance factors among personnel so as to prevent sexual attacks and diminish the probability of malpractice actions.

  11. Failure analysis of corrosion cracking and simulated testing for a fluid catalytic cracking unit

    Institute of Scientific and Technical Information of China (English)

    Hua Chen; Xiaogang Li; Chaofang Dong; Ming Li; Jinwen Yang

    2005-01-01

    The failure of a fluid catalysis and cracking unit (FCCU) in a Chinese refinery was investigated by using nondestructive detection methods, fracture surface examination, hardness measurement, chemical composition and corrosion products analysis. The results showed that the failure was caused by the dew point nitrate stress corrosion cracking. For a long operation period, the wall temperature of the regenerator in the FCCU was below the fume dew point. As a result, an acid fume NOx-SOx-H2O medium presented on the surface, resulting in stress corrosion cracking of the component with high residual stress. In order to confirm the relative conclusion, simulated testing was conducted in laboratory, and the results showed similar cracking characteristics. Finally, some suggestions have been made to prevent the stress corrosion cracking of an FCCU from re-occurring in the future.

  12. 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.

  13. Solid Waste Management Units And Areas Of Concern Annual Long-Term Monitoring & Maintenance Report For Calendar Year 2016.

    Energy Technology Data Exchange (ETDEWEB)

    Dotson, Patrick Wells [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Little, Bonnie Colleen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-02-01

    Long-term controls were maintained at 21 Solid Waste Management Units (SWMUs) and Areas of Concern (AOCs) in accordance with the requirements of the “Long-Term Monitoring and Maintenance Plan for SWMUs and AOCs Granted Corrective Action Complete with Controls” in Attachment M of the Resource Conservation and Recovery Act Facility Operating Permit, which took effect February 26, 2015. Maintenance and controls at these SWMUs and AOCs are described and documented in this report. Conditions requiring maintenance or repair activities were not identified for any of the inspected SWMUs or AOCs. Based upon the inspections performed and site conditions observed, the administrative and physical institutional controls in place at the SWMUs and AOCs are effectively providing continued protection of human health and the environment. This report does not present monitoring and maintenance activities for SWMU 76, the Mixed Waste Landfill; those activities adhere to the approved MWL LTMM Plan, Section 4.8.1 requiring a separate annual report which will be submitted to the NMED by June 30, 2017.

  14. Integrated Logistics Support Analysis of the International Space Station Alpha, Background and Summary of Mathematical Modeling and Failure Density Distributions Pertaining to Maintenance Time Dependent Parameters

    Science.gov (United States)

    Sepehry-Fard, F.; Coulthard, Maurice H.

    1995-01-01

    The process of predicting the values of maintenance time dependent variable parameters such as mean time between failures (MTBF) over time must be one that will not in turn introduce uncontrolled deviation in the results of the ILS analysis such as life cycle costs, spares calculation, etc. A minor deviation in the values of the maintenance time dependent variable parameters such as MTBF over time will have a significant impact on the logistics resources demands, International Space Station availability and maintenance support costs. There are two types of parameters in the logistics and maintenance world: a. Fixed; b. Variable Fixed parameters, such as cost per man hour, are relatively easy to predict and forecast. These parameters normally follow a linear path and they do not change randomly. However, the variable parameters subject to the study in this report such as MTBF do not follow a linear path and they normally fall within the distribution curves which are discussed in this publication. The very challenging task then becomes the utilization of statistical techniques to accurately forecast the future non-linear time dependent variable arisings and events with a high confidence level. This, in turn, shall translate in tremendous cost savings and improved availability all around.

  15. Integrated Logistics Support Analysis of the International Space Station Alpha, Background and Summary of Mathematical Modeling and Failure Density Distributions Pertaining to Maintenance Time Dependent Parameters

    Science.gov (United States)

    Sepehry-Fard, F.; Coulthard, Maurice H.

    1995-01-01

    The process of predicting the values of maintenance time dependent variable parameters such as mean time between failures (MTBF) over time must be one that will not in turn introduce uncontrolled deviation in the results of the ILS analysis such as life cycle costs, spares calculation, etc. A minor deviation in the values of the maintenance time dependent variable parameters such as MTBF over time will have a significant impact on the logistics resources demands, International Space Station availability and maintenance support costs. There are two types of parameters in the logistics and maintenance world: a. Fixed; b. Variable Fixed parameters, such as cost per man hour, are relatively easy to predict and forecast. These parameters normally follow a linear path and they do not change randomly. However, the variable parameters subject to the study in this report such as MTBF do not follow a linear path and they normally fall within the distribution curves which are discussed in this publication. The very challenging task then becomes the utilization of statistical techniques to accurately forecast the future non-linear time dependent variable arisings and events with a high confidence level. This, in turn, shall translate in tremendous cost savings and improved availability all around.

  16. Maintenance of the Lightning Strike Failure of EL - type Contact Anemometer indicator%1EL型电接风向风速计指示器遭雷击故障维修

    Institute of Scientific and Technical Information of China (English)

    韦健; 梁继晗

    2011-01-01

    介绍了EL型电接风向风速计指示器电路工作原理,通过对EL型电接风向风速计指示器遭雷击故障分析,介绍指示器电源电路、风向指示电路的检修方法,为基层台站业务人员在工作中提供帮助。%Presented the theory of EL-type contact anemometer Indicator. Based on an analysis of the lightning strike failure of EL-type con- tact anemometer Indicator, introduced the maintenance methods of indicator circuit and wind direction indicator circuit help for the personnel of grass-roots unit in their work.

  17. ANALYSIS OF A TWO UNIT STANDBY SYSTEM WITH CORRELATED FAILURE AND REPAIR AND RANDOM APPEARANCE AND DISAPPEARANCE OF REPAIRMAN

    Directory of Open Access Journals (Sweden)

    Rakesh Gupta

    2010-01-01

    Full Text Available The paper deals with the stochastic analysis of a two non-identical unit standbysystem model. The one unit is considered as priority (p unit and the other as ordinary (o unit.The p-unit gets priority in operation. A single repair facility appears in and disappears from thesystem randomly with constant rates. The repair discipline of units is FCFS. The joint distributionof failure and repair times for each unit is taken to be bivariate exponential. Using regenerativepoint technique various measures of system effectiveness useful to industrial managers areobtained.

  18. End-of-life Heart Failure Care in the United States.

    Science.gov (United States)

    Buggey, Jonathan; Mentz, Robert J; Galanos, Anthony N

    2015-10-01

    Heart failure (HF) is increasingly common in the United States and is associated with a high degree of morbidity and mortality. As patients approach the end of life there is a significant increase in health care resource use. Patients with end-stage HF have a unique set of needs at the end of life, including symptoms such as dyspnea, uremia, and depression, as well as potentially deactivating implantable defibrillators and mechanical circulatory support devices. Improved palliative care services for patients with HF may improve quality of life and decrease health care resource use near the end of life.

  19. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXII, I--MAINTAINING THE FUEL SYSTEM (PART I)--CUMMINS DIESEL ENGINE, II--UNDERSTANDING THE DIFFERENTIAL.

    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 FUNCTION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM AND DIFFERENTIAL DRIVE UNITS USED IN DIESEL POWERED VEHICLES. TOPICS ARE (1) FUEL SYSTEM COMPARISONS, (2) FUEL SYSTEM SUPPLY COMPONENTS, (3) FUEL SUPPLY SECTION MAINTENANCE, (4) FUNCTION OF THE DIFFERENTIAL,…

  20. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VIII. ENGINE COMPONENTS--PART I.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION AND MAINTENANCE OF DIESEL ENGINE CYLINDER HEADS AND CYLINDER ASSEMBLIES. TOPICS ARE CYLINDER ASSEMBLY (LINERS), CYLINDER HEADS, VALVES AND VALVE MECHANISMS, AND PISTON AND PISTON RINGS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

  1. Using Data Envelopment Analysis to Evaluate Technical Training Program for Maintenance Units

    Directory of Open Access Journals (Sweden)

    Nai-Chieh Wei and Shui-Cheung Cham

    2015-05-01

    Full Text Available Applying data envelope analysis (DEA, this study focuses on the influences of objectivity and subjectivity on aircraft maintenance supervision evaluation and inspection procedure; the aim is to improve overall logistic operation and training efficiency. Moreover, the results of this analysis will be helpful for making decisions in training, management, capability and competitiveness

  2. Cross-Linguistic Analysis of Vietnamese and English with Implications for Vietnamese Language Acquisition and Maintenance in the United States

    Directory of Open Access Journals (Sweden)

    Giang Tang

    2007-01-01

    Full Text Available Two overall goals of this paper are a to provide a linguistic basis for promoting first language maintenance of Vietnamese in a larger United States context and b to stimulate future research in language acquisition of Vietnamese-English speakers. This paper is divided into three sections. Section 1 discusses previous studies on first language (L1 maintenance among Vietnamese Americans. Section 2 presents a cross-linguistic comparison of Vietnamese and English across speech-sound, word, and grammatical language levels. A cross-linguistic analysis may help educators better understand speaking patterns of Vietnamese American students. Based on this cross-linguistic comparison, Section 3 presents potential bi-directional interactions between Vietnamese and English within an individual speaker. These predictions are intended to provide a framework for future empirical studies related to bilingual development.

  3. Cholera gravis associated with acute renal failure in a traveler from Haiti to the United States.

    Science.gov (United States)

    Reyes-Corcho, Andrés; Pinsker, Richard W; Sarkar, Samir; Bagheri, Farshad; Patel, Mahendra C; Lam, Pablo; González, Argentina

    2012-09-01

    Cholera is a gastroenteric disease caused by epidemic or pandemic Vibrio cholerae which still is responsible for over 100,000 annual deaths worldwide. Since October 2010, Haiti experienced a cholera outbreak affecting more than 300,000 persons. Few imported cases related to the Haitian epidemic have been reported so far in the United States and Canada. We presented a patient who developed cholera gravis soon after arrival at New York City from Haiti. The patient needed admission to an Intensive Care Unit, for vigorous intravenous hydration, antibiotic therapy, and hemodialysis due to refractory oliguric renal failure. The patient was discharged the day 6 after admission and V. cholerae O1 was isolated from the stool culture. Cholera can be a life-threatening disease; early recognition based on travel history and clinical features is the corner stone for successful management. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. A Case of Biotinidase Deficiency in an Adult with Respiratory Failure in the Intensive Care Unit

    Science.gov (United States)

    Demirtürk, Zerrin; Şentürk, Evren; Köse, Abbas; Özcan, Perihan Ergin; Telci, Lütfi

    2016-01-01

    Background: Biotinidase deficiency (BD) is a rare, inherited autosomal recessive disorder that is treatable within childhood. We present a patient with pneumonia and respiratory acidosis who was not diagnosed with any systemic disorders; the patient was finally diagnosed as BD. Case Report: A thirty-year-old woman was admitted to the emergency department with respiratory failure that had persisted for a few days and progressively weakening over the previous six months. Then, the patient was admitted to the intensive care unit with marked respiratory acidosis, respiratory failure and alterations in consciousness. At the follow-up, the patient was not diagnosed with a systematic disorder. Rather, the patient’s historical clinical findings suggested a metabolic disorder. Finally, the patient was diagnosed with biotinidase deficiency. Conclusion: Even though biotinidase deficiency is not frequently seen in the intensive care unit, metabolic syndromes such as biotinidase deficiency should be considered. Patients should be evaluated holistically with attention to medical history, family history and clinical findings. PMID:27761288

  5. Extracorporeal liver support therapy with Prometheus in patients with liver failure in the intensive care unit.

    Science.gov (United States)

    Oppert, Michael; Rademacher, Sibylle; Petrasch, Kathrin; Jörres, Achim

    2009-10-01

    Acute liver failure (ALF) and acute-on-chronic liver failure (AoCLF) are associated with a high mortality. In these patients an accumulation of both water-soluble and water-insoluble, protein-bound, metabolic waste products occurs. Conventional extracorporeal blood purification techniques based on diffusion and/or convection such as hemodialysis or hemofiltration may only eliminate small molecular weight, water-soluble compounds. In recent years, fractionated plasma separation and adsorption (FPSA) with the Prometheus system has been introduced for extracorporeal liver support therapy. To date, however, only limited data is available regarding the effect of this treatment on mortality and outcome of patients with advanced liver disease. Here we report on our experience with 23 patients with severe liver failure who were treated with Prometheus in our medical intensive care unit. Fourteen patients had AoCLF, and nine patients experienced ALF. The median bilirubin level at the start of Prometheus therapy was 30.5 mg/dL and the median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 26. During 40 individual treatment sessions lasting 5-6 h, Prometheus therapy reduced serum bilirubin levels from 23.7 mg/dL to 15.0 mg/dL (median values) (P Prometheus therapy was well tolerated without relevant side-effects. In conclusion, extracorporeal liver support therapy with Prometheus is a novel and safe treatment option in patients with severe liver failure. In this series, patients with ALF showed a significantly better outcome with Prometheus therapy compared to AoCLF patients.

  6. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT VI, AUTOMATIC TRANSMISSIONS--PLANETARY GEARING.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO ACQUAINT THE TRAINEE WITH THE OPERATION OF PLANETARY GEARS IN AUTOMATIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF PLANETARY GEARING, (2) POWER TRANSMISSION THROUGH A PLANETARY SYSTEM, (3) HYDRAMATIC TRANSMISSION, (4) HYDRAULIC SYSTEM, AND (5) GEAR FAILURE AND…

  7. Bridging the conservation design and delivery gap for wetland bird habitat maintenance and restoration in the Midwestern United States

    Science.gov (United States)

    Thogmartin, W.E.; Potter, B.; Soulliere, G.

    2011-01-01

    The U.S. Fish and Wildlife Service's adoption of Strategic Habitat Conservation is intended to increase the effectiveness and efficiency of conservation delivery by targeting effort in areas where biological benefits are greatest. Conservation funding has not often been allocated in accordance with explicit biological endpoints, and the gap between conservation design (the identification of conservation priority areas) and delivery needs to be bridged to better meet conservation goals for multiple species and landscapes. We introduce a regional prioritization scheme for North American Wetlands Conservation Act funding which explicitly addresses Midwest regional goals for wetland-dependent birds. We developed decision-support maps to guide conservation of breeding and non-breeding wetland bird habitat. This exercise suggested ~55% of the Midwest consists of potential wetland bird habitat, and areas suited for maintenance (protection) were distinguished from those most suited to restoration. Areas with greater maintenance focus were identified for central Minnesota, southeastern Wisconsin, the Upper Mississippi and Illinois rivers, and the shore of western Lake Erie and Saginaw Bay. The shores of Lakes Michigan and Superior accommodated fewer waterbird species overall, but were also important for wetland bird habitat maintenance. Abundant areas suited for wetland restoration occurred in agricultural regions of central Illinois, western Iowa, and northern Indiana and Ohio. Use of this prioritization scheme can increase effectiveness, efficiency, transparency, and credibility to land and water conservation efforts for wetland birds in the Midwestern United States.

  8. 电磁阀的失效模式及维修策略%Solenoid Valve Failure Mode and Maintenance Strategy

    Institute of Scientific and Technical Information of China (English)

    蒋道福

    2012-01-01

    大亚湾和岭澳核电站使用了很多进口电磁阀.随着服役时间不断增加,大量电磁阀出现了漏气、漏油和生锈等故障现象;对这些故障现象进行分类,并结合相关资料分析了电磁阀的工作原理,总结出电磁阀的失效模式;参考法国电力公司(EDF)的维修方法,提出了大亚湾与岭澳核电站电磁阀的维修策略,对相关核电厂电磁阀的维修具有一定的参考价值.%Many solenoid valves were imported from France for Daya Bay and Ling'Ao nuclear power plants. Some phenomena of leaking air or oil and rustiness occurred in solenoid valves with the serve time increases. All malfunction phenomena were classified, operation principle of the solenoid valve was analyzed in combination with relevant information, and the failure mode was summarized. The maintenance strategy of the solenoid valve for Daya Bay and Ling'Ao nuclear power plants was put forward, with reference to the maintenance methods of EDF. It could be served as reference for solenoid valve maintenance in nuclear power plants of similar kind.

  9. Strong Magnetic Units for a Wind Power Tower Inspection and Maintenance Robot

    Directory of Open Access Journals (Sweden)

    Xueshan Gao

    2012-11-01

    Full Text Available For developing a climbing robot which is used to inspect and maintain a wind power tower, the magnetic unit is one of the key components. Based on analysis of the working conditions of the robot, the approach in this paper is to use four common kinds of magnetic units for adapting to the conical surface. The magnetic circuit of these units is given by theory analysis and is simulated using ANSYS. Moreover, the magnetic force is analysed in detail and the results prove that the magnetic force is greatly influenced by the gap between the unit and the wall surface. In this paper, the design procedures and selection criteria based on the analytical results are given. Meanwhile, these units are compared with each other with the aid of ANSYS. From the results of this comparison, it can be ascertained that the unit using Installation C has the better performance. Furthermore, the effectiveness of the magnetic unit using Installation C is verified by a prototype. The simulations and experiments show that the magnetic unit can allow the robot to keep in contact with the conical wall surface as well as the plane wall surface.

  10. TMI-2 (Three-Mile Island-Unit 2) rail cask and railcar maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Tyacke, M.J.; Ayers, A.L., Jr.; Ball, L.J.; Anselmo, A.A.

    1988-02-01

    This paper describes the NuPac 125-B cask system (i.e., cask and railcar), and the maintenance and inspection requirements for that system. The paper discusses the operations being done to satisfy those requirements and how, in some cases, it has been efficient for the operations to be more rigorous than the requirements. Finally, this paper discusses the experiences gained from those operations and how specific hardware and procedural enhancements have resulted in a reliable and continuous shipping campaign. 2 refs., 2 figs.

  11. Concept and methodology for evaluating core damage frequency considering failure correlation at multi units and sites and its application

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, K.; Teragaki, T.; Nomura, S. [Former Incorporated Administrative Agency, Japan Nuclear Safety Organization (Japan); Abe, H., E-mail: Hiroshi_abe@nsr.go.jp [Former Incorporated Administrative Agency, Japan Nuclear Safety Organization (Japan); Shigemori, M.; Shimomoto, M. [Mizuho Information & Research Institute, 2-3, Kanda-Nishikicho, Chiyoda-ku, Tokyo (Japan)

    2015-07-15

    Highlights: • We develop a method to evaluate CDF considering failure correlation at multi units. • We develop a procedure to evaluate correlation coefficient between multi components. • We evaluate CDF at two different BWR units using correlation coefficients. • We confirm the validity of method and correlation coefficient through the evaluation. - Abstract: The Tohoku earthquake (Mw9.0) occurred on March 11, 2011 and caused a large tsunami. The Fukushima Daiichi Nuclear Power Plant with six units were overwhelmed by the tsunami and core damage occurred. Authors proposed the concept and method for evaluating core damage frequency (CDF) considering failure correlation at the multi units and sites. Based on the above method, one of authors developed the procedure for evaluating the failure correlation coefficient and response correlation coefficient between the multi components under the strong seismic motion. These method and failure correlation coefficients were applied to two different BWR units and their CDF was evaluated by seismic probabilistic risk assessment technology. Through this quantitative evaluation, the validity of the method and failure correlation coefficient was confirmed.

  12. Environmental Assessment Rehabilitation and Maintenance of Wetlands Unit 3 Prime Hook National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — For management purposes, Prime Hook is divided into four units using highways which transect the refuge. This proposal concerns the rehabilitation of wetlands...

  13. Diagnosis methodology applied to the preventive maintenance of power generation units in isolated sites; Methodologie de diagnostic appliquee a la maintenance preventive d'unites de production d'electricite en sites isoles

    Energy Technology Data Exchange (ETDEWEB)

    Marie-Joseph, M.

    2003-04-01

    Todays, overseas territories gather more than 25% of the photovoltaic systems of the French territory. More than 600 kWc of this photovoltaic park is located in French Guiana and 75% in isolated areas. This leads to the problem of implementation of a convenient maintenance policy mainly because of the problem of supply of replacement parts, of the lack of qualified local manpower, and of the complexity of a fast diagnosis of the installations. Therefore, the development of a diagnosis tool for the different kinds of failures and defects that can occur on a photovoltaic power system is of prime importance. Starting from the elements of preventive maintenance philosophy developed in the thesis of S. Salvat, this work describes the development of a functional simulation tool allowing the validation of these first results. Using models for the simulation of each sub-part of the system, involving a statistical modeling of the solar resource and of the connected load, a detailed analysis of the operation defects is presented. This tool, which is a key element of the elaboration of the diagnosis, allows the use of detection methods based on pattern recognition principle. The supervised learning makes a classification using the search for a parametric discriminating function minimizing the quadratic error on the base. The algorithms performing the real-time monitoring of the system in the presence of defects are fitted in an experimental kit representing the production of an individual generator at a reduced scale. The experimental detection procedures are then tested on production and regulation defects and then compared to those obtained from simulations performed in the same operating conditions. (J.S.)

  14. DUSTMS-D: DISPOSAL UNIT SOURCE TERM - MULTIPLE SPECIES - DISTRIBUTED FAILURE DATA INPUT GUIDE.

    Energy Technology Data Exchange (ETDEWEB)

    SULLIVAN, T.M.

    2006-01-01

    Performance assessment of a low-level waste (LLW) disposal facility begins with an estimation of the rate at which radionuclides migrate out of the facility (i.e., the source term). The focus of this work is to develop a methodology for calculating the source term. In general, the source term is influenced by the radionuclide inventory, the wasteforms and containers used to dispose of the inventory, and the physical processes that lead to release from the facility (fluid flow, container degradation, wasteform leaching, and radionuclide transport). Many of these physical processes are influenced by the design of the disposal facility (e.g., how the engineered barriers control infiltration of water). The complexity of the problem and the absence of appropriate data prevent development of an entirely mechanistic representation of radionuclide release from a disposal facility. Typically, a number of assumptions, based on knowledge of the disposal system, are used to simplify the problem. This has been done and the resulting models have been incorporated into the computer code DUST-MS (Disposal Unit Source Term-Multiple Species). The DUST-MS computer code is designed to model water flow, container degradation, release of contaminants from the wasteform to the contacting solution and transport through the subsurface media. Water flow through the facility over time is modeled using tabular input. Container degradation models include three types of failure rates: (a) instantaneous (all containers in a control volume fail at once), (b) uniformly distributed failures (containers fail at a linear rate between a specified starting and ending time), and (c) gaussian failure rates (containers fail at a rate determined by a mean failure time, standard deviation and gaussian distribution). Wasteform release models include four release mechanisms: (a) rinse with partitioning (inventory is released instantly upon container failure subject to equilibrium partitioning (sorption) with

  15. Performance deterioration modeling and optimal preventive maintenance strategy under scheduled servicing subject to mission time

    Directory of Open Access Journals (Sweden)

    Li Dawei

    2014-08-01

    Full Text Available Servicing is applied periodically in practice with the aim of restoring the system state and prolonging the lifetime. It is generally seen as an imperfect maintenance action which has a chief influence on the maintenance strategy. In order to model the maintenance effect of servicing, this study analyzes the deterioration characteristics of system under scheduled servicing. And then the deterioration model is established from the failure mechanism by compound Poisson process. On the basis of the system damage value and failure mechanism, the failure rate refresh factor is proposed to describe the maintenance effect of servicing. A maintenance strategy is developed which combines the benefits of scheduled servicing and preventive maintenance. Then the optimization model is given to determine the optimal servicing period and preventive maintenance time, with an objective to minimize the system expected life-cycle cost per unit time and a constraint on system survival probability for the duration of mission time. Subject to mission time, it can control the ability of accomplishing the mission at any time so as to ensure the high dependability. An example of water pump rotor relating to scheduled servicing is introduced to illustrate the failure rate refresh factor and the proposed maintenance strategy. Compared with traditional methods, the numerical results show that the failure rate refresh factor can describe the maintenance effect of servicing more intuitively and objectively. It also demonstrates that this maintenance strategy can prolong the lifetime, reduce the total lifetime maintenance cost and guarantee the dependability of system.

  16. [A Case of Crohn's Disease Showing Favorable Response to Induction and Maintenance Therapy with Methotrexate after Failure of Anti-tumor Necrosis Factor Therapy].

    Science.gov (United States)

    Choi, Jung Ran; Yun, Gak Won; Park, Yoo Mi; Kim, Jie Hyun; Youn, Young Hoon; Park, Hyo Jin; Park, Jae Jun

    2015-10-01

    Thanks to the introduction of immumomodulators and biologics, therapeutic approaches in Crohn's disease have changed significantly during the past decade. Although new biologic therapy has dramatically improved the treatment of Crohn's disease, a substantial number of patients are refractory to these therapies or lose their initial response. Methotrexate (MTX) is a structural analogue of folic acid that can competitively inhibit the binding of dihydrofolic acid to the enzyme dihydrofolate reductase and has been widely used as immunomodulator in rheumatology area for patients with rheumatoid arthritis and psoriasis. Although MTX has also been shown to be an effective agent for remission induction and maintenance of remission in Crohn's disease, the use of MTX in Crohn's disease has not yet been reported in Korea. Herein, we report a case of Crohn's disease patient who was successfully treated with MTX after treatment failure with thiopurine and anti-tumor necrosis factor.

  17. Variation exists in rates of admission to intensive care units for heart failure patients across hospitals in the United States

    Science.gov (United States)

    Safavi, Kyan C.; Dharmarajan, Kumar; Kim, Nancy; Strait, Kelly M.; Li, Shu-Xia; Chen, Serene I.; Lagu, Tara; Krumholz, Harlan M.

    2013-01-01

    Background Despite increasing attention on reducing relatively costly hospital practices while maintaining the quality of care, few studies have examined how hospitals use the intensive care unit (ICU), a high-cost setting, for patients admitted with heart failure (HF). We characterized hospital patterns of ICU admission for patients with HF and determined their association with the use of ICU-level therapies and patient outcomes. Methods and Results We identified 166,224 HF discharges from 341 hospitals in the 2009–10 Premier Perspective® database. We excluded hospitals with transfers. We defined ICU as including medical ICU, coronary ICU, and surgical ICU. We calculated the percent of patients admitted directly to an ICU. We compared hospitals in the top-quartile (high ICU admission) with the remaining quartiles. The median percentage of ICU admission was 10% (Interquartile Range 6% to 16%; range 0% to 88%). In top-quartile hospitals, treatments requiring an ICU were used less often: percentage of ICU days receiving mechanical ventilation (6% top quartile versus 15% others), non-invasive positive pressure ventilation (8% versus 19%), vasopressors and/or inotropes (9% versus 16%), vasodilators (6% versus 12%), and any of these interventions (26% versus 51%). Overall HF in-hospital risk standardized mortality was similar (3.4% versus 3.5%; P = 0.2). Conclusions ICU admission rates for HF varied markedly across hospitals and lacked association with in-hospital risk-standardized mortality. Greater ICU use correlated with fewer patients receiving ICU interventions. Judicious ICU use could reduce resource consumption without diminishing patient outcomes. PMID:23355624

  18. Production and postharvest quality maintenance of single unit and bunching broccoli in Virginia

    OpenAIRE

    Jett, Lewis W.

    1990-01-01

    Broccoli (Brassica oleracea L. var. italica) has become an increasingly popular vegetable with American consumers. Much of the attractiveness of fresh broccoli is derived from this vegetable's high nutrition and excellent organoleptic properties. In a consumer response survey, Virginia Master Gardeners indicated a preference for broccoli that has less stalk and more florets by weight. The objectives of this research were to produce single unit broccoli, and to examine vac...

  19. PROACTIVE STRATEGY MAINTENANCE

    Directory of Open Access Journals (Sweden)

    Stanisław RADKOWSKI

    2014-03-01

    Full Text Available Given challenging competition of today service providers are required to be more proactive in satisfying the environmental conditions and customer needs. Proactive maintenance should start at the design stage with establishing the functions, functional failures and failure modes. The understanding the failure behavior, especially the relationship between potential failures, functional failures and diagnostic parameters is the most important task. In the next step the designer have to explore the maintenance activities as they have to apply to the design criteria. The models and frameworks have been presented in the paper also a comprehensive review of literature and some results of laboratory investigations.

  20. Challenges to United States Tactical Air Force Aircraft Maintenance Personnel: Past, Present and Future

    Science.gov (United States)

    1991-09-01

    Korean War. MS thesis, AFIT/GSM/L/88S-7. School of Systems and Logistics, Air Force Institute of Technology, Wright-Patterson APB OH, September 1988 (AD...1.5-billion program, MSIP is upgrading 15 line replaceable units (LRUs) in the Hughes APG-63 radar and other key avionics systems to extend the...1980. 11. Forney, Captain James I. Logistics Of Aircrnt Mmintenance During The Korean War. MS thesis, AFIT/GSM/LS/88S-7. School of Systems and Logistics

  1. Dual-stream modulation failure: a novel hypothesis for the formation and maintenance of delusions in schizophrenia.

    Science.gov (United States)

    Speechley, William J; Ngan, Elton T C

    2008-01-01

    Delusions, a cardinal feature of schizophrenia, are characterized by the development and preservation of false beliefs despite reason and evidence to the contrary. A number of cognitive models have made important contributions to our understanding of delusions, though it remains unclear which core cognitive processes are malfunctioning to enable individuals with delusions to form and maintain erroneous beliefs. We propose a modified dual-stream processing model that provides a viable and testable mechanism that can account for this debilitating symptom. Dual-stream models divide decision-making into two streams: a fast, intuitive and automatic form of processing (Stream 1); and a slower, conscious and deliberative process (Stream 2). Our novel model proposes two key influences on the way these streams interact in everyday decision-making: conflict and emotion. Conflict: in most decision-making scenarios one obvious answer presents itself and the two streams converge onto the same conclusion. However, in instances where there are competing alternative possibilities, an individual often experiences dissonance, or a sense of conflict. The detection of this conflict biases processing towards the more deliberative Stream 2. Emotion: highly emotional states can result in behavior that is reflexive and action-oriented. This may be due to the power of emotionally valenced stimuli to bias reasoning towards Stream 1. We propose that in schizophrenia, an abnormal response to these two influences results in a pathological schism between Stream 1 and Stream 2, enabling erroneous intuitive explanations to coexist with contrary logical explanations of the same event. Specifically, we suggest that delusions are the result of a failure to reconcile the two streams due to both a failure of conflict to bias decision-making towards Stream 2 and an accentuated emotional bias towards Stream 1.

  2. Maintenance of Radar Transmitter Filament Power Failure%雷达发射机灯丝电源故障维修

    Institute of Scientific and Technical Information of China (English)

    弓宇恒; 李庆君; 蔺汝罡

    2013-01-01

    The filament supply is an AC stabilized-voltage supply,powering the klystron filament through a filament intermediate transformer,the pulse transformer located in the fuel tank,and the filament transformer.On 18 July 2011,at the Tongliao weather radar station,Inner Mongolia,the CINRAD/CB radar transmitter recurred filament power supply failure:there was no high voltage,leading to radar shutdown.By careful troubleshooting,the radar failure was removed successfully.The failure reasons are analyzed in detail,and the results are suggestive for the maintenance staff at radar stations%灯丝电源是一个交流稳压电源,通过灯丝中间变压器和位于油箱中的脉冲变压器及灯丝变压器,为速调管灯丝供电.2011年7月18日,内蒙古气象局通辽天气雷达站的CINRAD/CB雷达发射机反复出现灯丝电源故障,且无法加高压导致雷达停机,经分析和排查故障原因,最终排除了雷达故障.就此次故障的出现,分析其原因,举一反三,对雷达台站在今后的工作中加强备件的管理和测试数据的管理有一定的启示.

  3. Maintenance of CO2 level in a BLSS by controlling solid waste treatment unit

    Science.gov (United States)

    Dong, Yingying; Li, Leyuan; Liu, Hong; Fu, Yuming; Xie, Beizhen; Hu, Dawei; Liu, Dianlei; Dong, Chen; Liu, Guanghui

    A bioregenerative life support system (BLSS) is an artificial closed ecosystem for providing basic human life support for long-duration, far-distance space explorations such as lunar bases. In such a system, the circulation of gases is one of the main factor for realizing a higher closure degree. O2 produced by higher plants goes to humans, as well as microorganisms for the treatment of inedible plant biomass and human wastes; CO2 produced by the crew and microorganisms is provided for plant growth. During this process, an excessively high CO2 level will depress plant growth and may be harmful to human health; and if the CO2 level is too low, plant growth will also be affected. Thus, keeping the balance between CO2 and O2 levels is a crucial problem. In this study, a high-efficiency, controllable solid waste treatment unit is constructed, which adopts microbial fermentation of the mixture of inedible biomass and human wastes. CO2 production during the fermentation process is controlled by adjusting fermentation temperature, aeration rate, moisture, etc., so as to meet the CO2 requirement of plants

  4. A Case Study on Improving Intensive Care Unit (ICU) Services Reliability: By Using Process Failure Mode and Effects Analysis (PFMEA)

    Science.gov (United States)

    Yousefinezhadi, Taraneh; Jannesar Nobari, Farnaz Attar; Goodari, Faranak Behzadi; Arab, Mohammad

    2016-01-01

    Introduction: In any complex human system, human error is inevitable and shows that can’t be eliminated by blaming wrong doers. So with the aim of improving Intensive Care Units (ICU) reliability in hospitals, this research tries to identify and analyze ICU’s process failure modes at the point of systematic approach to errors. Methods: In this descriptive research, data was gathered qualitatively by observations, document reviews, and Focus Group Discussions (FGDs) with the process owners in two selected ICUs in Tehran in 2014. But, data analysis was quantitative, based on failures’ Risk Priority Number (RPN) at the base of Failure Modes and Effects Analysis (FMEA) method used. Besides, some causes of failures were analyzed by qualitative Eindhoven Classification Model (ECM). Results: Through FMEA methodology, 378 potential failure modes from 180 ICU activities in hospital A and 184 potential failures from 99 ICU activities in hospital B were identified and evaluated. Then with 90% reliability (RPN≥100), totally 18 failures in hospital A and 42 ones in hospital B were identified as non-acceptable risks and then their causes were analyzed by ECM. Conclusions: Applying of modified PFMEA for improving two selected ICUs’ processes reliability in two different kinds of hospitals shows that this method empowers staff to identify, evaluate, prioritize and analyze all potential failure modes and also make them eager to identify their causes, recommend corrective actions and even participate in improving process without feeling blamed by top management. Moreover, by combining FMEA and ECM, team members can easily identify failure causes at the point of health care perspectives. PMID:27157162

  5. Post partum heart failure: a rare presentation to the intensive care unit of a teaching hospital in Ghana

    Directory of Open Access Journals (Sweden)

    Owusu IK

    2012-06-01

    Full Text Available Isaac Kofi Owusu,1 Charles Anane,1 Kwame Ohene Buabeng,21Komfo Anokye Teaching Hospital, 2Clinical and Social Pharmacy Department, Kwame Nkrumah University Of Science and Technology, Kumasi, GhanaAbstract: A patient with a devastating form of heart failure that sometimes afflicts women in late pregnancy or after delivery presented to the intensive care unit of the Komfo Anokye Teaching Hospital, Kumasi, Ghana, in September 2010. The patient was a 37-year-old farmer and mother of six children, and was admitted with symptoms of heart failure five months after the delivery of her last child. After clinical evaluation, post partum cardiomyopathy was diagnosed. She responded well to treatment and was discharged on day 10 following admission, to be followed up at the cardiac clinic.Keywords: heart failure, cardiomyopathy, late pregnancy, post partum, Ghana

  6. Instrument Automation Equipment Failures and Maintenance Technology%仪表自动化设备故障与维护技术

    Institute of Scientific and Technical Information of China (English)

    赵明

    2015-01-01

    随着经济的发展,我国石油化工企业的作用越来越重要,油气运输的相关技术和设备也更加先进,在石油化工企业运行的过程中,仪表自动化设备能够很好地提高其生产效率。我们必须做好自动化设备故障维修方面的工作,提高其工作效率。%With the development of economy, the role of China’s petrochemical enterprises increasingly important oil and gas-related technologies and equipment transportation are also more advanced in the process of petrochemical companies operating in instrument automation equipment can well improve its production efficiency . We must do a good job of automation equipment maintenance failures, improve their work efficiency.

  7. Optical Fiber Line Equipment Failures and Maintenance Measures%光纤线路设备故障分析及维护措施

    Institute of Scientific and Technical Information of China (English)

    王海

    2012-01-01

    近年来,随着科学技术的快速发展,光纤通信系统在各个行业领域中都有着较为广泛的应用.光纤通信技术的普及与发展为人们的生产与生活带了极大的便利,其逐步朝着智能化、数字化以及集成化的方向发展,在实际的光纤设备运行过程难免会出现各种各样的故障问题,这就需要采取相应的故障分析以及维护措施进行问题的有效解决.%In recent years, with the rapid development of science and technology, optical fiber communication systems in various industries have a relatively wide range of applications. Optical fiber communication technology popularization and development of production and life of people with a great convenience, gradually moving in the direction of intelligent, digital and integrated development of the actual fiber optic equipment is running, there will inevitably be a variety of failure problems, which need to take the corresponding fault analysis and maintenance of measures to effectively solve the problem.

  8. 清梳联设备状态维修管理体会%Experience of Blowing-carding Unit State Maintenance and Management

    Institute of Scientific and Technical Information of China (English)

    潘荣昌; 李海霞; 徐林岚

    2011-01-01

    探讨清梳联设备进行状态维修的管理要点.针对当前清梳联设备的性能特点,在设备管理方面采取状态维修与周期保养揩检相结合,以状态维修为主的包机制管理模式,通过加强员工队伍建设、建立健全设备维护保养制度、细化清梳联设备的维修保养周期和范围、充分发挥试验仪器和测试仪表的作用等手段,充分调动了人员积极性,降低了机物料消耗,提高了设备的运行质量,使清梳联设备的性能得到了充分发挥.%Key points of blowing-carding unit state maintenance and management were discussed. According to blowing-carding unit characteristics, periodic maintenance and state maintenance were combined. Contract management mode was adopted. Staff structure was enhanced, equipment maintenance system was established, maintenance periodic and range of blowing-carding unit were subdivided, function of test instruments were used fully, staff positive attitude were mobilized fully, machine material consumption were reduced, machine operational quality were improved, finally performance of blowing-carding unit were used fully.

  9. Comparative Business Failures of Foreign-Controlled Firms in the United States

    OpenAIRE

    Jiatao Li; Stephen Guisinger

    1991-01-01

    We explore the comparative business failures of foreign-owned or controlled firms and domestically owned firms. Original data are collected regarding foreign-controlled firms in the U.S. that filed for bankruptcy protection, were involuntarily liquidated or ceased operations mainly due to poor financial performance during the 1978-1988 period. Our results show that foreign-controlled firms fail less often than domestically owned firms. The patterns of foreign-controlled business failures and ...

  10. Therapeutic education unit for heart failure: setting-up and difficulties. Initial evaluation of the I-CARE programme.

    Science.gov (United States)

    Juillière, Yves; Jourdain, Patrick; Roncalli, Jérome; Boireau, Amélie; Guibert, Hélène; Lambert, Hélène; Spinazze, Laure; Jondeau, Guillaume; Sonnier, Pierre; Rouanne, Céline; Bidet, Angélique; Sandrin-Berthon, Brigitte; Trochu, Jean-Nöel

    2009-01-01

    Education programmes are required in chronic diseases. The insuffisance cardiaque : éducation thérapeutique (I-CARE) programme was developed in France to promote the setting-up of therapeutic education units for chronic heart failure. To evaluate the setting-up of such units, assessing the influence of training on the creation and organization of the unit, the problems encountered and the contribution of the dedicated educational tools. We submitted a questionnaire to the first 136 trained centres. The questionnaire was divided into two sections: one section dealing with educational practices and the other with the advantages and disadvantages of the tools provided. The participation rate reached 69.1%. Seventy-four centres (78.7%) declared themselves to be active in therapeutic education. Unit educational activities determined an educational diagnosis (89.2% of the centres) and provided education by means of collective workshops (73.0%) or one-to-one teaching sessions (75.7%). A complete education programme for a patient consisted of a median of four sessions (25th-75th percentile, 2-5 sessions) and lasted for a median of 6 h (25th-75th percentile, 4-10 h). The education team was multidisciplinary and usually included a nurse (93.2%), a dietician (78.4%), a cardiologist (71.6%) and a physiotherapist (40.5%). Heart failure educational tools were used only in part in most centres (89.2%). All advantages and disadvantages were recorded. This first evaluation of the setting-up of therapeutic education units in the I-CARE programme has yielded promising results, despite expected difficulties. The effects of therapeutic education on the behaviour of heart failure patients remain to be determined.

  11. Importance of RIFLE (Risk, Injury, Failure, Loss, and End-Stage Renal Failure) and AKIN (Acute Kidney Injury Network) in Hemodialysis Initiation and Intensive Care Unit Mortality.

    Science.gov (United States)

    Kara, Iskender; Yildirim, Fatma; Kayacan, Esra; Bilaloğlu, Burcu; Turkoglu, Melda; Aygencel, Gülbin

    2017-07-01

    Our study evaluated the differences between early and late hemodialysis (HD) initiation in the intensive care unit (ICU) according to the RIFLE (Risk, Injury, Failure, Loss, and End-stage renal failure) and AKIN (Acute Kidney Injury Network) classifications. On the assumption that early initiation of HD in critical patients according to the RIFLE and AKIN criteria decreases mortality, we retrospectively evaluated the medical records of 68 patients in our medical ICU and divided the patients into 2 groups: Those undergoing HD in no risk, risk, or injury stage according to RIFLE and in stage 0, I, or II according to AKIN were defined as early HD and those in failure stage according to RIFLE and in stage III according to AKIN were defined as late HD. The median age of the patients was 66.5 years, and 56.5% were male. HD was started in 25% and 39.7% of the patients in the early stage in the RIFLE and AKIN classification, respectively. According to RIFLE, HD was started in 61.5% of the surviving patients in the early stage; this rate was 16.4% in the deceased patients (P=0.001). HD was commenced in 69.2% of the surviving patients in AKIN stages 0, I, and II and in 32.7% of the deceased patients (P=0.026). Sepsis (61.5% vs. 94.5%; P=0.001) and mechanical ventilation (30.8% vs. 87.3%; PRIFLE decreased ICU mortality (61.5% vs. 16.4%; P=0.001). In conclusion, in critically ill patients, HD initiation in the early stages according to the RIFLE classification decreased our ICU mortality.

  12. Efforts to Reduce International Space Station Crew Maintenance for the Management of the Extravehicular Mobility Unit Transport Loop Water Quality

    Science.gov (United States)

    Steele, John W.; Etter, David; Rector, Tony; Boyle, Robert; Vandezande, Christopher

    2013-01-01

    The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with on-orbit ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post-Shuttle 6-year service life.

  13. Mechanisms of virologic failure in previously untreated HIV-infected patients from a trial of induction-maintenance therapy. Trilège (Agence Nationale de Recherches sur le SIDA 072) Study Team).

    Science.gov (United States)

    Descamps, D; Flandre, P; Calvez, V; Peytavin, G; Meiffredy, V; Collin, G; Delaugerre, C; Robert-Delmas, S; Bazin, B; Aboulker, J P; Pialoux, G; Raffi, F; Brun-Vézinet, F

    2000-01-12

    In the Trilège trial, following induction with a zidovudine, lamivudine, and indinavir regimen, human immunodeficiency virus (HIV) replication was less suppressed by 2-drug maintenance therapy than by triple-drug therapy. To identify mechanisms of virologic failure in the 3 arms of the Trilège trial. Case-control study conducted from February to October 1998. Three urban hospitals in Paris, France. Fifty-eight case patients with virologic failure (HIV RNA rebound to >500 copies/mL in 2 consecutive samples) randomized to 3 therapy groups: triple drug (zidovudine, lamivudine, and indinavir), 8; zidovudine-lamivudine, 29; and zidovudine-indinavir, 21; the case patients were randomly matched with 58 control patients with sustained viral suppression. At virologic failure (S1 sample) and 6 weeks later (S2 sample), assessment of protease and reverse transcriptase gene mutations, plasma indinavir level, and degree of viral load rebound; pill count during induction and maintenance periods. Only 1 primary resistance mutation, M184V, was detected in S1 plasma samples from 4 of 6 patients in the triple-drug and in all 22 in the zidovudine-lamivudine therapy groups and in S2 plasma samples from 3 of 6 in the triple-drug and 20 of 21 in the zidovudine-lamivudine groups. Of controls, M184V was detected in 11 of 13 S1 plasma samples and in 10 of 11 S2 plasma samples. Indinavir levels were undetectable in all S1 samples but 2 in 7 triple-drug cases tested and in the expected range in 11 of 18 S1 and 5 of 12 S2 zidovudine-indinavir case plasma samples tested. Maintenance adherence rates were lower for cases vs controls for zidovudine (P = .05) and indinavir (P = .05). Low indinavir levels, lower adherence rates for zidovudine (P = .04) and lamivudine (P = .03), and rebound to near-baseline values suggested adherence as cause of early failure for 4 of 8 triple-drug cases. In the zidovudine-lamivudine arm, for which case and control adherence rates did not differ significantly (P

  14. Positive predictive value and impact of misdiagnosis of a heart failure diagnosis in administrative registers among patients admitted to a University Hospital cardiac care unit

    DEFF Research Database (Denmark)

    Mard, Shan; Nielsen, Finn Erland

    2010-01-01

    To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF.......To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF....

  15. [Use of enoximone in patients with acute and subacute heart failure in the intensive care unit].

    Science.gov (United States)

    Holubarsch, C; Pieske, B; Hasenfuss, G; Just, H

    1994-01-01

    The phosphodiesterase inhibitor enoximone has both vasodilating and positive inotropic pharmacological properties. The balance between vasodilation and positive inotropism may be different between the various types of heart failure as well as the various stages of heart failure. Therefore, we investigated the effect of intravenous application of enoximone (1 mg/kg body weight) in a cohort of patients (n = 10) suffering from acute or subacute heart failure mainly due to ischemia or hypoxia. All patients had high left ventricular filling pressure, low cardiac output and were pretreated with intravenous dobutamine. Enoximone increased cardiac output from 3.2 +/- 1.2 to 5.5 +/- 2.2 l/min, increased heart rate from 94 +/- 20 to 100 +/- 18 beats/min, decreased systemic peripheral resistance from 1770 +/- 861 to 931 +/- 340 dyn.sec.cm-5 and decreased pulmonary wedge pressure from 24 +/- 5 to 20 +/- 6 mmHg, significantly. However, systolic aortic pressure, systolic pulmonary pressure and right atrial pressure were not significantly altered. We conclude that in a selected group of patients enoximone-given intravenously and acutely in the intensive care unity-can induce beneficial effects on central hemodynamics without critical falls in perfusion pressure.

  16. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL)

    Science.gov (United States)

    1996-01-01

    This Failure Modes and Effects Analysis (FMEA) is for the Advanced Microwave Sounding Unit-A (AMSU-A) instruments that are being designed and manufactured for the Meteorological Satellites Project (METSAT) and the Earth Observing System (EOS) integrated programs. The FMEA analyzes the design of the METSAT and EOS instruments as they currently exist. This FMEA is intended to identify METSAT and EOS failure modes and their effect on spacecraft-instrument and instrument-component interfaces. The prime objective of this FMEA is to identify potential catastrophic and critical failures so that susceptibility to the failures and their effects can be eliminated from the METSAT/EOS instruments.

  17. Improving the Estimates of International Space Station (ISS) Induced K-Factor Failure Rates for On-Orbit Replacement Unit (ORU) Supportability Analyses

    Science.gov (United States)

    Anderson, Leif F.; Harrington, Sean P.; Omeke, Ojei, II; Schwaab, Douglas G.

    2009-01-01

    This is a case study on revised estimates of induced failure for International Space Station (ISS) on-orbit replacement units (ORUs). We devise a heuristic to leverage operational experience data by aggregating ORU, associated function (vehicle sub -system), and vehicle effective' k-factors using actual failure experience. With this input, we determine a significant failure threshold and minimize the difference between the actual and predicted failure rates. We conclude with a discussion on both qualitative and quantitative improvements the heuristic methods and potential benefits to ISS supportability engineering analysis.

  18. 考虑需求弹性的发电检修协调方法%Unit maintenance coordination method considering demand elasticity

    Institute of Scientific and Technical Information of China (English)

    方陈; 夏清; 孙欣

    2011-01-01

    随着智能电网的发展,用户的需求响应能力进一步增强,对发电检修的协调安排带来了新的影响.提出了机组检修协调意愿费用曲线,建立了考虑需求价格弹性的发电检修决策协调模型.在此基础上,深入分析市场环境下中长期发电检修决策对短期市场供求关系及出清价格的影响.建立了用户电力需求随电价而弹性变化、最终受中长期发电检修决策影响的函数关系;通过函数分段参数的讨论与约束的合并变换,将非线性混合整数规划模型转化为线性整数规划模型;根据智能电网下不同需求响应场景模拟,评估分析了需求弹性对发电检修决策产生的影响与效益.%With the development of smart grid, demand response capacity is further enhanced, which influences the coordination of unit maintenance scheduling. Maintenance coordination cost curve is proposed, and unit maintenance coordination model is established considering the elasticity of demand price. On this basis, influence of long-term maintenance scheduling on short-term market demand-supply relationship and further on market cleating prices is analyzed. The function of load demand elastically changing with price and ultimately influenced by medium and long term maintenance scheduling is established. Accordingly, the nonlinear mixed integer programming model is simplified into linear integer programming model by function segment parameters discussion and constraints merging transformation. Finally, according to the simulation of different demand response scenarios of smart grid, the impact and benefit of demand elasticity on unit maintenance scheduling is assessed and analyzed.This work is supported by National Natural Science Foundation of China (No.50877041).

  19. Electrical Maintenance Technician.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document contains 30 units to consider for use in a tech prep competency profile for the occupation of electrical maintenance technician. All the units listed will not necessarily apply to every situation or tech prep consortium, nor will all the competencies within each unit be appropriate. Several units appear within each specific…

  20. Collective consciousness and its pathologies: understanding the failure of AIDS control and treatment in the United States.

    Science.gov (United States)

    Wallace, Rodrick M; Fullilove, Mindy T; Fullilove, Robert E; Wallace, Deborah N

    2007-02-26

    We address themes of distributed cognition by extending recent formal developments in the theory of individual consciousness. While single minds appear biologically limited to one dynamic structure of linked cognitive submodules instantiating consciousness, organizations, by contrast, can support several, sometimes many, such constructs simultaneously, although these usually operate relatively slowly. System behavior remains, however, constrained not only by culture, but by a developmental path dependence generated by organizational history, in the context of market selection pressures. Such highly parallel multitasking--essentially an institutional collective consciousness--while capable of reducing inattentional blindness and the consequences of failures within individual workspaces, does not eliminate them, and introduces new characteristic malfunctions involving the distortion of information sent between workspaces and the possibility of pathological resilience--dysfunctional institutional lock-in. Consequently, organizations remain subject to canonical and idiosyncratic failures analogous to, but more complicated than, those afflicting individuals. Remediation is made difficult by the manner in which pathological externalities can write images of themselves onto both institutional function and corrective intervention. The perspective is applied to the failure of AIDS control and treatment in the United States.

  1. Collective consciousness and its pathologies: Understanding the failure of AIDS control and treatment in the United States

    Directory of Open Access Journals (Sweden)

    Fullilove Robert E

    2007-02-01

    Full Text Available Abstract We address themes of distributed cognition by extending recent formal developments in the theory of individual consciousness. While single minds appear biologically limited to one dynamic structure of linked cognitive submodules instantiating consciousness, organizations, by contrast, can support several, sometimes many, such constructs simultaneously, although these usually operate relatively slowly. System behavior remains, however, constrained not only by culture, but by a developmental path dependence generated by organizational history, in the context of market selection pressures. Such highly parallel multitasking – essentially an institutional collective consciousness – while capable of reducing inattentional blindness and the consequences of failures within individual workspaces, does not eliminate them, and introduces new characteristic malfunctions involving the distortion of information sent between workspaces and the possibility of pathological resilience – dysfunctional institutional lock-in. Consequently, organizations remain subject to canonical and idiosyncratic failures analogous to, but more complicated than, those afflicting individuals. Remediation is made difficult by the manner in which pathological externalities can write images of themselves onto both institutional function and corrective intervention. The perspective is applied to the failure of AIDS control and treatment in the United States.

  2. Insomnia Self-Management in Heart Failure

    Science.gov (United States)

    2016-12-07

    Cardiac Failure; Heart Failure; Congestive Heart Failure; Heart Failure, Congestive; Sleep Initiation and Maintenance Disorders; Chronic Insomnia; Disorders of Initiating and Maintaining Sleep; Fatigue; Pain; Depressive Symptoms; Sleep Disorders; Anxiety

  3. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT VII, AUTOMATIC TRANSMISSIONS--ALLISON, TORQUMATIC SERIES 5960 AND 6060 (PART I).

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF SPECIFIC MODELS OF AUTOMATIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) GENERAL SPECIFICATION DATA, (2) OPTIONS FOR VARIOUS APPLICATIONS, (3) ROAD TEST INSTRUCTIONS, (4) IDENTIFICATION AND SPECIFICATION DATA, (5) ALLISON…

  4. The Design of Treatment Wetlands in the United Kingdom: Successes, Failures, and Alternative Approaches

    Institute of Scientific and Technical Information of China (English)

    SUN Guangzhi; ZHANG Guangxin

    2008-01-01

    Constructed wetland was first introduced into the United Kingdom in the middle of 1980s, following a visit by a group of scientist to Western Germany. In the past 2 decades, the applications of constructed wetlands in this country have expanded substantially, due to the demand for green technologies and rising cost of fossil fuel energies. This paper reported a statistical investigation of the performances of 78 horizontal flow wetlands, representatives of such system in the United Kingdom. Alternative design equations, based on organic matter removal efficiency, have been developed from Monod kinetics, and the accuracy and reliability of current and alternative design approaches have been examined.

  5. AUTOMOTIVE DIESEL MAINTENANCE L. UNIT XII, PART I--MAINTAINING THE FUEL SYSTEM (PART II), CUMMINS DIESEL ENGINE, PART II--UNIT INSTALLATION (ENGINE).

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM AND THE PROCEDURES FOR DIESEL ENGINE INSTALLATION. TOPICS ARE FUEL FLOW CHARACTERISTICS, PTG FUEL PUMP, PREPARATION FOR INSTALLATION, AND INSTALLING ENGINE. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH…

  6. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XI, PART I--MAINTAINING THE FUEL SYSTEM (PART I), CUMMINS DIESEL ENGINES, PART II--UNIT REPLACEMENT (ENGINE).

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF DIFFERENCES BETWEEN TWO AND FOUR CYCLE ENGINES, THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL SYSTEM, AND THE PROCEDURES FOR DIESEL ENGINE REMOVAL. TOPICS ARE (1) REVIEW OF TWO CYCLE AND FOUR CYCLE CONCEPT, (2) SOME BASIC CHARACTERISTICS OF FOUR CYCLE ENGINES,…

  7. Predictive maintenance policy for a gradually deteriorating system subject to stress

    Energy Technology Data Exchange (ETDEWEB)

    Deloux, E. [IRCCyN/Ecole des Mines de Nantes, Nantes (France); Castanier, B. [IRCCyN/Ecole des Mines de Nantes, Nantes (France)], E-mail: bruno.castanier@emn.fr; Berenguer, C. [Universite de Technologie de Troyes/CNRS, Troyes (France)

    2009-02-15

    This paper deals with a predictive maintenance policy for a continuously deteriorating system subject to stress. We consider a system with two failure mechanisms which are, respectively, due to an excessive deterioration level and a shock. To optimize the maintenance policy of the system, an approach combining statistical process control (SPC) and condition-based maintenance (CBM) is proposed. CBM policy is used to inspect and replace the system according to the observed deterioration level. SPC is used to monitor the stress covariate. In order to assess the performance of the proposed maintenance policy and to minimize the long-run expected maintenance cost per unit of time, a mathematical model for the maintained system cost is derived. Analysis based on numerical results are conducted to highlight the properties of the proposed maintenance policy in respect to the different maintenance parameters.

  8. Performance deterioration modeling and optimal preventive maintenance strategy under scheduled servicing subject to mission time

    Institute of Scientific and Technical Information of China (English)

    Li Dawei; Zhang Zhihua; Zhong Qianghui; Zhai Yali

    2014-01-01

    Servicing is applied periodically in practice with the aim of restoring the system state and prolonging the lifetime. It is generally seen as an imperfect maintenance action which has a chief influ-ence on the maintenance strategy. In order to model the maintenance effect of servicing, this study analyzes the deterioration characteristics of system under scheduled servicing. And then the deterio-ration model is established from the failure mechanism by compound Poisson process. On the basis of the system damage value and failure mechanism, the failure rate refresh factor is proposed to describe the maintenance effect of servicing. A maintenance strategy is developed which combines the benefits of scheduled servicing and preventive maintenance. Then the optimization model is given to determine the optimal servicing period and preventive maintenance time, with an objective to minimize the sys-tem expected life-cycle cost per unit time and a constraint on system survival probability for the dura-tion of mission time. Subject to mission time, it can control the ability of accomplishing the mission at any time so as to ensure the high dependability. An example of water pump rotor relating to scheduled servicing is introduced to illustrate the failure rate refresh factor and the proposed maintenance strat-egy. Compared with traditional methods, the numerical results show that the failure rate refresh factor can describe the maintenance effect of servicing more intuitively and objectively. It also demonstrates that this maintenance strategy can prolong the lifetime, reduce the total lifetime maintenance cost and guarantee the dependability of system.

  9. 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.)

  10. Environmental risk assessment of low density polyethylene unit using the method of failure mode and effect analysis

    Directory of Open Access Journals (Sweden)

    Salati Parinaz

    2012-01-01

    Full Text Available The ninth olefin plan of Arya Sasol Petrochemical Company (A.S.P.C. is regarded the largest gas Olefin Unit located on Pars Special Economic Energy Zone (P.S.E.E.Z. Considering the importance of the petrochemical unit, its environmental assessment seems necessary to identify and reduce potential hazards. For this purpose, after determining the scope of the study area, identification and measurement of the environmental parameters, environmental risk assessment of the unit was carried out using Environment Failure Mode and Effect Analysis (EFMEA. Using the noted method, sources causing environmental risks were identified, rated and prioritized. Beside, the impacts of the environmental aspects derived from the unit activities as well as their consequences were also analyzed. Furthermore, the identified impacts were prioritized based on Risk Priority Number (RPN and severity level of the consequences imposed on the affected environment. After performing statistical calculations, it was found that the environmental aspects owing the risk priority number higher than 15 have a high level of risk. Results obtained from Low Density Polyethylene Unit revealed that the highest risk belongs to the emergency vent system with risk priority number equal to 48. It is occurred due to imperfect performance of the reactor safety system leading to the emissions of ethylene gas, particles, and radioactive steam as well as air and noise pollutions. Results derived from secondary assessment of the environmental aspects, through difference in calculated RPN and activities risk levels showed that employing modern methods and risk assessment are have remarkably reduced the severity of risk and consequently detracted the damages and losses incurred on the environment.

  11. Congenital Heart Disease Requiring Maintenance of Ductus Arteriosus in Critically Ill Newborns Admitted at A Tertiary Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Cucerea Manuela

    2016-10-01

    Full Text Available Introduction: Congenital heart diseases (CHD have been reported to be responsible for 30 to 50% of infant mortality caused by congenital disabilities. In critical cases, survival of newborns with CHD depends on the patency of the ductus arteriosus (PDA, for maintaining the systemic or pulmonary circulation. The aim of the study was to assess the efficacy and side effects of PGE (prostaglandin E administration in newborns with critical congenital heart disease requiring maintenance of the ductus arteriosus.

  12. Atrial Fibrillation on Intensive Care Unit Admission Independently Increases the Risk of Weaning Failure in Nonheart Failure Mechanically Ventilated Patients in a Medical Intensive Care Unit: A Retrospective Case-Control Study.

    Science.gov (United States)

    Tseng, Yen-Han; Ko, Hsin-Kuo; Tseng, Yen-Chiang; Lin, Yi-Hsuan; Kou, Yu Ru

    2016-05-01

    Atrial fibrillation (AF) is one of the most frequent arrhythmias in clinical practice. Previous studies have reported the influence of AF on patients with heart failure (HF). The effect of AF on the non-HF critically ill patients in a medical intensive care unit (ICU) remains largely unclear. The study aimed to investigate the impact of AF presenting on ICU admission on the weaning outcome of non-HF mechanically ventilated patients in a medical ICU.A retrospective observational case-control study was conducted over a 1-year period in a medical ICU at Taipei Veterans General Hospital, a tertiary medical center in north Taiwan. Non-HF mechanically ventilated patients who were successful in their spontaneous breathing trial and underwent ventilator discontinuation were enrolled. The primary outcome measure was the ventilator status after the first episode of ventilator discontinuation.A total of 285 non-HF patients enrolled were divided into AF (n = 62) and non-AF (n = 223) groups. Compared with the non-AF patients, the AF patients were significantly associated with old age (P = 0.002), a higher rate of acute respiratory distress syndrome causing respiratory failure (P = 0.015), a higher percentage of sepsis before liberation from mechanical ventilation (MV) (P = 0.004), and a higher serum level of blood urea nitrogen on the day of liberation from MV (P = 0.003). Multivariate logistic regression analysis demonstrated that AF independently increased the risk of weaning failure [adjusted odds ratio (AOR), 3.268; 95% confidence interval (CI), 1.254-8.517; P = 0.015]. Furthermore, the AF patients were found to be independently associated with a high rate of ventilator dependence (log rank test, P = 0.026), prolonged total ventilator use (AOR, 1.979; 95% CI, 1.032-3.794; P = 0.040), increased length of ICU stay (AOR, 2.256; 95% CI, 1.049-4.849; P = 0.037), increased length of hospital stay (AOR, 2.921; 95% CI, 1.363-6.260; P = 0

  13. [APACHE II and ATN-ISS in acute renal failure (ARF) in intensive care unit (ICU) and non-ICU].

    Science.gov (United States)

    Fernandes, Natáia Maria da Silva; Pinto, Patrícia dos Santos; Lacet, Thiago Bento de Paiva; Rodrigues, Dominique Fonseca; Bastos, Marcus Gomes; Stella, Sérgio Reinaldo; Cendoroglo Neto, Miguel

    2009-01-01

    Acute renal failure (ARF) remains highly prevalent with a high rate of morbidity and mortality. of this study was to compare use of the APACHE II scoring prognosis with that of the ATN-ISS to determine whether the APACHE II could be used for patients with ARF outside the ICU. For this purpose, 205 patients with ARF were accompanied in a prospective cohort. Demographic data, preexisting conditions, organ failure and characteristics of ARF were analyzed. The prognostic scores were performed with the assessment of a nephrologist. The mean age was 52 +/- 18 years, 50% were male, 69% were white, 45% were treated in ICU and 55% in other units. Mortality in the ICU group was 85% and in the non-ICU group 18%. Factors that correlated with higher mortality were more prevalent in the ICU group: age, male, hospitalization with ARF, organ failure, sepsis, septic IRA, oliguria and need of dialysis. Overall, the prognostic markers were the same for both the ICU and non-ICU groups. The discrimination with the APACHE II was similar in both, ICU and non-ICU groups and calibration was better in the non-ICU group. The ATN-ISS achieved good discrimination in both the ICU and non-ICU groups, but, regarding calibration, there was a discreet over estimating of mortality in the non-ICU group. The ATN-ISS showed a greater capacity for discrimination than the APACHE II in both the ICU and non-ICU groups. It was concluded that the APACHE II and ATN-ISS scores could be used for stratification of risk in patients with ARF treated outside of the ICU in Brazil.

  14. An Emergency Unit Support System to Diagnose Chronic Heart Failure Embedded with SWRL and Bayesian Network

    Directory of Open Access Journals (Sweden)

    Baydaa Al-Hamadani

    2016-07-01

    Full Text Available In all the regions of the world, heart failure is common and on raise caused by several aetiologies. Although the development of the treatment is fast, there are still lots of cases that lose their lives in emergence sections because of slow response to treat these cases. In this paper we propose an expert system that can help the practitioners in the emergency rooms to fast diagnose the disease and advise them with the appropriate operations that should be taken to save the patient’s life. Based on the mostly binary information given to the system, Bayesian Network model was selected to support the process of reasoning under uncertain or missing information. The domain concepts and the relations between them were building by using ontology supported by the Semantic Web Rule Language to code the rules. The system was tested on 105 patients and several classification functions were tested and showed remarkable results in the accuracy and sensitivity of the system.

  15. Transformer failure and common-mode loss of instrument power at Nine Mile Point Unit 2 on August 13, 1991

    Energy Technology Data Exchange (ETDEWEB)

    1991-10-01

    On August 13, 1991, at Nine Mile Point Unit 2 nuclear power plant, located near Scriba, New York, on Lake Ontario, the main transformer experienced an internal failure that resulted in degraded voltage which caused the simultaneous loss of five uninterruptible power supplies, which in turn caused the loss of several nonsafety systems, including reactor control rod position indication, some reactor power and water indication, control room annunciators, the plant communications system, the plant process computer, and lighting at some locations. The reactor was subsequently brought to a safe shutdown. Following this event, the US Nuclear Regulatory Commission dispatched an Incident Investigation Team to the site to determine what happened, to identify the probable causes, and to make appropriate findings and conclusions. This report describes the incident, the methodology used by the team in its investigation, and presents and the team's findings and conclusions. 59 figs., 14 tabs.

  16. Incidence, risk factors and prognostic factors of acute renal failure in patients admitted to an intensive care unit

    Directory of Open Access Journals (Sweden)

    S.E. Mataloun

    2006-10-01

    Full Text Available The objective of the present study was to assess the incidence, risk factors and outcome of patients who develop acute renal failure (ARF in intensive care units. In this prospective observational study, 221 patients with a 48-h minimum stay, 18-year-old minimum age and absence of overt acute or chronic renal failure were included. Exclusion criteria were organ donors and renal transplantation patients. ARF was defined as a creatinine level above 1.5 mg/dL. Statistics were performed using Pearsons' chi2 test, Student t-test, and Wilcoxon test. Multivariate analysis was run using all variables with P < 0.1 in the univariate analysis. ARF developed in 19.0% of the patients, with 76.19% resulting in death. Main risk factors (univariate analysis were: higher intra-operative hydration and bleeding, higher death risk by APACHE II score, logist organ dysfunction system on the first day, mechanical ventilation, shock due to systemic inflammatory response syndrome (SIRS/sepsis, noradrenaline use, and plasma creatinine and urea levels on admission. Heart rate on admission (OR = 1.023 (1.002-1.044, male gender (OR = 4.275 (1.340-13642, shock due to SIRS/sepsis (OR = 8.590 (2.710-27.229, higher intra-operative hydration (OR = 1.002 (1.000-1004, and plasma urea on admission (OR = 1.012 (0.980-1044 remained significant (multivariate analysis. The mortality risk factors (univariate analysis were shock due to SIRS/sepsis, mechanical ventilation, blood stream infection, potassium and bicarbonate levels. Only potassium levels remained significant (P = 0.037. In conclusion, ARF has a high incidence, morbidity and mortality when it occurs in intensive care unit. There is a very close association with hemodynamic status and multiple organ dysfunction.

  17. On Problems of Multicomponent System Maintenance Modelling

    Institute of Scientific and Technical Information of China (English)

    Tomasz Nowakowski; Sylwia Werbinka

    2009-01-01

    We present an overview of some recent developments in the area of mathematical modeling of maintenance decisions for multi-unit systems. The emphasis is on three main groups of multicomponent maintenance optimization models: the block replacement models, group maintenance models, and opportunistic maintenance models. Moreover, an example of a two-unit system maintenance process is provided in order to compare various maintenance policies.

  18. Positive predictive value and impact of misdiagnosis of a heart failure diagnosis in administrative registers among patients admitted to a University Hospital cardiac care unit

    DEFF Research Database (Denmark)

    Mard, Shan; Nielsen, Finn Erland

    2010-01-01

    patients with heart failure from July 1, 2005 to June 30, 2007. Heart failure was defined in accordance with European Society of Cardiology (ESC) guidelines. The recorded diagnoses from the NRP were compared with clinical data from the medical records. RESULTS: We identified 758 patients with a diagnosis......OBJECTIVE: To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF. DESIGN: The NRP was used to identify...... of heart failure in the NRP. The PPV of a heart failure discharge diagnosis was 84.0% (95% confidence interval: 81.2-86.6). Patients with a discharge diagnosis of HF in the NRP without fulfilling the ESC criteria for HF had a better survival rate, a lower rate of rehospitalization, none were followed...

  19. Rol del fallo mecánico en la optimización del mantenimiento en una central nuclear//Role of the mechanical failure during the maintenance optimization in the nuclear power plant

    Directory of Open Access Journals (Sweden)

    Antonio Torres-Valle

    2012-05-01

    Full Text Available Entre las más recientes aplicaciones del Análisis Probabilista de Seguridad (1997 – 2003 de la Central Nuclear Embalse en Argentina, está el Programa de Mantenimiento Orientado a la Seguridad (2006– 2009 el cual se ha desarrollado con el empleo de la metodología de Mantenimiento Centrado en la Confiabilidad (RCM en inglés. El objetivo general del artículo es demostrar la alta contribución de los fallos mecánicos en el diseño de las políticas de mantenimiento de varios sistemas de la instalación a través del empleo de la metodología RCM. La composición, estructura y políticas de explotación de los sistemas tecnológicos de muchas instalaciones con riesgo asociado, similares a las de los sistemas analizados en este estudio, permite inferir que los resultados que se obtendrán serán equivalentes de aplicarse la metodología RCM en dichas instalaciones. Palabras claves: mantenimiento centrado en la confiabilidad, mantenimiento predictivo, mantenimiento preventivo, fallo mecánico, seguridad, confiabilidad, riesgo.______________________________________________________________________________ Abstract One of the most recent applications of Probabilistic Safety Analysis (1997 – 2003 to Embalse Nuclear Power Plant in Argentina, is the Safety Oriented Maintenance Program (2006 – 2009 developed with employment of the Reliability Centered Maintenance (RCM methodology. The general objective of the paper is to demonstrate the high contribution of the mechanical failures in the maintenance program design through the RCM methodology. The composition, structure and operation strategies of the technological systems of many risk associated facilities, similar to the analysed systems included in this study, allow deduce that the results will equivalent in case of application of RCM methodology in such facilities. Key words: reliability centered maintenance (RCM, predictive maintenance, preventive maintenance, mechanical failure, safety

  20. 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 mai

  1. 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

  2. Development and Pilot of a Checklist for Management of Acute Liver Failure in the Intensive Care Unit.

    Directory of Open Access Journals (Sweden)

    Oren K Fix

    Full Text Available Acute liver failure (ALF is an ideal condition for use of a checklist. Our aims were to develop a checklist for the management of ALF in the intensive care unit (ICU and assess the usability of the checklist among multiple providers.The initial checklist was developed from published guidelines and expert opinion. The checklist underwent pilot testing at 11 academic liver transplant centers in the US and Canada. An anonymous, written survey was used to assess the usability and quality of the checklist. Written comments were used to improve the checklist following the pilot testing period.We received 81 surveys involving the management of 116 patients during the pilot testing period. The overall quality of the checklist was judged to be above average to excellent by 94% of users. On a 5-point Likert scale, the majority of survey respondents agreed or agreed strongly with the following checklist characteristics: the checklist was easy to read (99% agreed/agreed strongly, easy to use (97%, items are categorized logically (98%, time to complete the checklist did not interfere with delivery of appropriate and safe patient care (94% and was not excessively burdensome (92%, the checklist allowed the user the freedom to use his or her clinical judgment (80%, it is a useful tool in the management of acute liver failure (98%. Web-based and mobile apps were developed for use of the checklist at the point of care.The checklist for the management of ALF in the ICU was shown in this pilot study to be easy to use, helpful and accepted by a wide variety of practitioners at multiple sites in the US and Canada.

  3. Risk-Based Predictive Maintenance for Safety-Critical Systems by Using Probabilistic Inference

    Directory of Open Access Journals (Sweden)

    Tianhua Xu

    2013-01-01

    Full Text Available Risk-based maintenance (RBM aims to improve maintenance planning and decision making by reducing the probability and consequences of failure of equipment. A new predictive maintenance strategy that integrates dynamic evolution model and risk assessment is proposed which can be used to calculate the optimal maintenance time with minimal cost and safety constraints. The dynamic evolution model provides qualified risks by using probabilistic inference with bucket elimination and gives the prospective degradation trend of a complex system. Based on the degradation trend, an optimal maintenance time can be determined by minimizing the expected maintenance cost per time unit. The effectiveness of the proposed method is validated and demonstrated by a collision accident of high-speed trains with obstacles in the presence of safety and cost constrains.

  4. Operation and maintenance engineering support of the Angra Unit 1 in Brasil; Presentacion de servicios de operacion y mantenimiento en la unidad 1 de la Central Nuclear de Angra (Brasil)

    Energy Technology Data Exchange (ETDEWEB)

    Castanos, E.

    2001-07-01

    Iberinco has developed during the last four years a major task in regards to the Operation and Maintenance of the Angra unit 1 plant in Brasil, by means of being awarded in the 1996 international licitation for the following activities. Operation and Maintenance engineering support - Material Procurement - Refuelling services In this article the most relevant activities performed during this period are shown as well as the organisation in charge to carry them out. (Author)

  5. Modern Maintenance Strategy of Electronic Equipment in Complex Electromechanical System

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-fang; CHEN Gui-ming; YANG Bao-li; ZHANG Xue-tao; WANG Han-gong

    2004-01-01

    In this paper, the failure mechanism of electronic equipment was analysed. Aiming at the limitation of traditional maintenance modes, moderu maintenance strategy was put forward on the basis of reliability-centered maintenance (RCM) combined with condition-based maintenance (CBM)aud maintenance efficiency review (MER). A maintenance management information system was constructed for electronic equipment for the purpose of failure analysis, reliability evaluation, and maintenance decisions such as time, mode, and plan. The best maintenance time could be predicted with failure analysis and reliability evaluation, which was mainly influenced by environmental stress. Suitable maintenance modes should be determined fiom equipment importance, failure aftereffect, maintenance condition, and economical power so as to ensure equipment reliability and decrease the requirement of the maintenance source.

  6. Comparison of management and outcomes of ED patients with acute decompensated heart failure between the Canadian and United States' settings.

    Science.gov (United States)

    Lai, Anita; Tenpenny, Elliott; Nestler, David; Hess, Erik; Stiell, Ian G

    2016-03-01

    Introduction The objective of this study was to compare the emergency department (ED) management and rate of admission of acute decompensated heart failure (ADHF) between two hospitals in Canada and the United States and to compare the outcomes of these patients. This was a health records review of adults presenting with ADHF to two EDs in Canada and the United States between January 1 and April 30, 2010. Outcome measures were admission to the hospital, myocardial infarction (MI), and death or relapse rates to the ED. Data were analysed using descriptive, univariate and multivariate analyses. In total, 394 cases were reviewed and 73 were excluded. Comparing 156 Canadian to 165 U.S. patients, respectively, mean age was 76.0 and 75.8 years; male sex was 54.5% and 52.1%. Canadian and U.S. ED treatments were noninvasive ventilation 7.7% v. 12.8% (p=0.13); IV diuretics 77.6% v. 36.0% (p<0.001); IV nitrates 4.5% v. 6.7% (p=0.39). There were significant differences in rate of admission (50.6% v. 95.2%, p<0.001) and length of stay in ED (6.7 v. 3.0 hours, p<0.001). Proportion of Canadian and U.S. patients who died within 30 days of the ED visit was 5.1% v. 9.7% (p=0.12); relapsed to the ED within 30 days was 20.8% v. 17.5% (p=0.5); and had MI within 30 days was 2.0% v. 1.9% (p=1.0). The U.S. and Canadian centres saw ADHF patients with similar characteristics. Although the U.S. site had almost double the admission rate, the outcomes were similar between the sites, which question the necessity of routine admission for patients with ADHF.

  7. A study on maintenance rule program and its application at Korean NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Mee Jeong; Kim, Kil Yoo; Kang, Dae Il; Yang, Joon Eon; Ha, Jae Joo

    2000-11-01

    The objective of the Maintenance Rule is to require monitoring of the overall continuing effectiveness of licensee maintenance programs to ensure that safety related and certain nonsafety-related SSCs are capable of performing their intended functions and, for nonsafety-related equipment failures will not occur that prevent the fulfillment of safety-related functions, and failures resulting in scrams and unnecessary actuations of safety-related systems are minimized. That is, proper maintenance is essential to plant safety. U.S. Maintenance Rule, which was effective July 1996 in USA., was not officially adopted in Korea by Korean regulatory body. However, since many PSA and IPE have been performed for NPPs, the philosophy and usefulness of the Maintenance Rule as well as performance-based regulation are being acceptable. We survey the Maintenance Rule program and applications in the USA, and also developed the Maintenance Rule program to apply to Korean NPPs. In addition, we applied the Maintenance Rule Program apply to Ulchin 3,4 Units roughly with the Maintenance Rule Program developed in this project.

  8. Streamlined Approach for Environmental Restoration Plan for Corrective Action Unit 113: Reactor Maintenance, Assembly, and Disassembly Building Nevada Test Site, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J. L. Smith

    2001-01-01

    This Streamlined Approach for Environmental Restoration (SAFER) Plan addresses the action necessary for the closure in place of Corrective Action Unit (CAU) 113 Area 25 Reactor Maintenance, Assembly, and Disassembly Facility (R-MAD). CAU 113 is currently listed in Appendix III of the Federal Facility Agreement and Consent Order (FFACO) (NDEP, 1996). The CAU is located in Area 25 of the Nevada Test Site (NTS) and consists of Corrective Action Site (CAS) 25-04-01, R-MAD Facility (Figures 1-2). This plan provides the methodology for closure in place of CAU 113. The site contains radiologically impacted and hazardous material. Based on preassessment field work, there is sufficient process knowledge to close in place CAU 113 using the SAFER process. At a future date when funding becomes available, the R-MAD Building (25-3110) will be demolished and inaccessible radiologic waste will be properly disposed in the Area 3 Radiological Waste Management Site (RWMS).

  9. The use of Seabees to perform maintenance and repair on Naval facilities in the continental United States

    OpenAIRE

    LeNoir, Walter M.

    1996-01-01

    A masters report on the use of Seabees to supplement the other facility management assets that Navy Public Works Officers and Staff Civil Engineers have at their disposal. Every tool possible must be utilized to effectively manage and maintain the Navy's facility assets totaling 171 billion dollars. The paper will discuss Naval Mobile Construction Battalions, Construction Battalion Units, and individual Seabees assigned to shore installations. Chapter 1 of this report provides an introduction...

  10. Hospital Modular Air Handling Units Maintenance%医院组合式空气处理机组的维护保养

    Institute of Scientific and Technical Information of China (English)

    林锡德

    2015-01-01

    In the hospital renovation and remodeling work, built a large number of various types of operating room and purification function rooms. And to strengthen the purification system equipment maintenance and repair work has become the focus of the current hospital. This paper proposes the following measures to strengthen the daily management of the hospital air handling units and maintenance. Such as maintaining a clean environment purification equipment room clean, and orderly use of established norms, the implementation of an effective security mechanism, the maintenance, material supply logistics flow, regular inspection and timely replacement of fan belts, periodic inspection of bearings and shaft, regularly check the equipment operating parameters, timely replacement of the beginning, in effect filters, regular inspection of air purification unit and other processing segments.%随着医院改造及改建工作的不断推进,新建了众多各类净化手术室和净化功能室。而加强对净化系统设备的维护和保养成为当前医院工作的重点。本文提出从保持净化机房的洁净环境干净整洁,建立有序的使用规范,实行有效的保障机制,保持维护材料的供应物流畅通,定期检查和及时更换风机传动皮带,定期检查对轴承和转轴,经常性地检查设备各项运行参数,及时更换初、中效过滤器,定期检查净化机组的空气处理段等方面,以加强针对组合式空气处理机组的特点,提出了医院组合式空气处理机组的日常管理和维护保养。

  11. Loss of the SPHF homologue Slr1768 leads to a catastrophic failure in the maintenance of thylakoid membranes in Synechocystis sp. PCC 6803.

    Directory of Open Access Journals (Sweden)

    Samantha J Bryan

    Full Text Available BACKGROUND: In cyanobacteria the photosystems are localised to, and maintained in, specialist membranes called the thylakoids. The mechanism driving the biogenesis of the thylakoid membranes is still an open question, with only two potential biogenesis factors, Vipp1 and Alb3 currently identified. METHODOLOGY/PRINCIPAL FINDINGS: We generated a slr1768 knockout using the pGEM T-easy vector and REDIRECT. By comparing growth and pigment content (chlorophyll a fluoresence of the Δslr1768 mutant with the wild-type, we found that Δslr1768 has a conditional phenotype; specifically under high light conditions (130 µmol m(-2 s(-1 thylakoid biogenesis is disrupted leading to cell death on a scale of days. The thylakoids show considerable disruption, with loss of both structure and density, while chlorophyll a density decreases with the loss of thylakoids, although photosynthetic efficiency is unaffected. Under low light (30 µmol m(-2 s(-1 the phenotype is significantly reduced, with a growth rate similar to the wild-type and only a low frequency of cells with evident thylakoid disruption. CONCLUSIONS/SIGNIFICANCE: This is the first example of a gene that affects the maintenance of the thylakoid membranes specifically under high light, and which displays a phenotype dependent on light intensity. Our results demonstrate that Slr1768 has a leading role in acclimatisation, linking light damage with maintenance of the thylakoids.

  12. The Analysis and Maintenance of Power Failure in Power Communication System%电力通信网中通信电源故障的分析与维护

    Institute of Scientific and Technical Information of China (English)

    赵倩

    2009-01-01

    通信电源的稳定是保证通信网安全稳定运行的根本.文中结合工程实践,分析了实际应用中通信电源出现故障的原因.并给出了相应解决方案.对电力系统通信电源的维护工作具有一定的借鉴意义.%The stability of the power supply is the basis of the power communication system. Combing with the prac-tice, the reasons of power failure are analyzed and the corresponding solutions are given. All these can provide some sug-gest for maintenance of the power supply.

  13. Mobile network maintenance (GSM)

    CERN Multimedia

    IT Department

    2009-01-01

    Maintenance work will be carried out on the CERN mobile network infrastructure (GSM) on the 23 and 24 July from 6 p.m. to 6 a.m. in order to replace discontinued equipment and to increase the bandwidth capacity of the GSM mobile network. All CERN GSM emitters (40 units) will be moved one by one to the new infrastructure during the maintenance. The call of a user connected to an emitter at the time of its maintenance will be cut off. However, the general overlapping of the GSM radio coverage should mean that users are able immediately to call again should their call be interrupted. IT/CS/CS

  14. Barriers to kidney transplantation among adult Sudanese patients on maintenance hemodialysis in dialysis units in Khartoum state

    Directory of Open Access Journals (Sweden)

    Hisham H Abdelwahab

    2013-01-01

    Full Text Available Kidney transplantation remains the preferred modality of treatment for patients with end-stage renal disease. In Sudan, kidney transplantation accounted for 28% of the total provided renal replacement therapies. A cross-sectional, hospital-based study was conducted in hemodialysis (HD units in Khartoum State during the period from September 2010 to January 2011. It aimed to determine the main reasons for the currently low renal transplantation rate. Data were obtained by direct interviewing using a specifically pre-coded and pre-tested questionnaire following a pilot study. A total of 462 adult HD patients were randomly selected from the various HD units in Khartoum State; these patients accounted for 16.9% of the total HD population in Khartoum State. The mean age of the study patients was 48.5 ± 23.6 years and 312 (67.5% were males. Upon interviewing, only 316 patients (68.4% said that they had been counseled for kidney transplantation. One hundred and twenty-two patients (26.4% were on the active transplant list; of these, 50% preferred to have their kidney transplantation performed abroad, mostly due to the availability of commercial transplantation and/or a presumed better outcome. The low renal transplantation rate was due to financial constraints in 112 patients (24.2%, lack of medical fitness in 97 patients (21% and absence of a suitable kidney donor in 92 patients (20%, while 56 patients (12% were still having misperceptions regarding transplantation and preferred to continue on dialysis. To improve the kidney transplantation rate in Khartoum State, the Sudan program for organ transplantation is expected to take more initiatives to promote and improve the outcome of kidney transplants inside the country and, accordingly, regain the patients′ confidence on the health system.

  15. Study on Secondary Device Maintenance and Failure Isolation Measures in Smart Substation%智能变电站二次设备检修及故障隔离措施研究

    Institute of Scientific and Technical Information of China (English)

    宋会平; 杨东熏; 王友怀; 周虎兵; 杨铭; 张侃君

    2016-01-01

    Aiming at the problem of highly security risk during secondary device maintenance and failure isolation in smart substation, the corresponding manipulation principle of smart substation secondary device software plate is proposed in the paper. And a 220 kV smart substation is taken for example, the concrete plate operation method of transmission line, main transform and bus bar secondary device during maintenance and failure isolation are analyzed, then plate manipulation se⁃quence and secondary device outage measure are proposed. They will play an important role in sec⁃ondary device manipulating and operation order sheet design, and the probability of mistrip or forced outage probability of primary equipment caused by human errors can be reduced.%针对智能变电站二次设备检修和故障隔离工作安全风险较高的问题,本文提出了智能变电站二次设备检修和故障隔离过程中的压板操作原则,并以一座220 kV智能变电站为例,对线路、主变压器、母线二次设备检修及故障隔离的具体操作进行分析,提出明确的操作顺序及设备陪停措施,可用于指导变电运行维护人员开展操作以及检修人员编制二次安全措施票,降低因人为失误造成的一次设备误跳闸或强迫停运事故发生的概率。

  16. Effect of Correlations of Component Failures and Cross-Connections of EDGs on Seismically Induced Core Damages of a Multi-Unit Site

    Science.gov (United States)

    Muramatsu, Ken; Liu, Qiao; Uchiyama, Tomoaki

    Aiming at proposing effective applications of seismic probabilistic safety assessment (PSA) for design and risk management of nuclear facilities, we conducted a preliminary seismic PSA study for a multi-unit site to examine core damage frequency (CDF) and core damage sequences with consideration of the effect of correlations of component failures. In addition, we also examined the effectiveness of an accident management measure, namely, cross-connections of emergency diesel generators (EDGs) between adjacent units in this study. Twin BWR-5 units of the same design were hypothesized to be located at the same site in this study and the CDF as well as the accident sequences of this two-unit site were analyzed by using SECOM2, a system reliability analysis code for seismic PSA. The results showed that the calculated CDF was dependent on the assumptions on the correlations of component failures. When the rules for assigning correlation coefficients of component responses defined in the NUREG-1150 program were adopted, the CDF of a single unit, the CDF of this two-unit site (the frequency of core damages of at least one unit at this site) and the frequency of simultaneous core damages of both units increased by factors of about 1.3, 1.2 and 2.3, respectively. In addition, it might be possible that the simultaneous core damages of both units are caused by different accident sequence pairs as well as the same sequence pairs. When cross-connections of EDGs between two units were available, the CDF of a single unit, the CDF of this two-unit site as well as the frequency of simultaneous core damages of both units decreased. In addition, the CDF of this two-unit site was smaller than the CDF of a single unit site. These results show that cross-connections of EDGs might be beneficial for a multi-unit site if the rules for assigning correlation coefficients defined in NUREG-1150 program are reasonable.

  17. The effect of the United States Great Lakes on the maintenance of derecho-producing mesoscale convective systems.

    Science.gov (United States)

    Bentley, M.; Sparks, J.; Graham, R.

    2003-04-01

    The primary aim of this research is to investigate the influence of the United States Great Lakes on the intensity of mesoscale convective systems (MCSs). One of the greatest nowcast challenges during the warm season is anticipating the impact of the Great Lakes on severe convection, particularly MCSs capable of producing damaging widespread windstorms known as derechos. Since a major derecho activity corridor lies over the Great Lakes region, it is important to understand the effects of the Lakes on the intensity and propagation of severe wind producing MCSs. Specific objectives of the research include: 1) The development of a short-term climatology of MCS events that have impacted the Great Lakes region over the past seven years; 2) An analysis of radar, satellite, surface (including buoy and lighthouse observations), and lake surface temperature data to determine the environmental conditions impacting the evolution of MCSs passing over a Great Lake; 3) An examination of MCS initiation times and seasonal frequencies of occurrence to delineate temporal consistencies in MCS evolution due to changing lake surface temperatures; and 4) The development of conceptual and forecast models to help anticipate MCS intensity and morphology as these systems interact with the Great Lakes environment.

  18. Intercultural Dating at Predominantly White Universities in the United States: The Maintenance and Crossing of Group Borders

    Directory of Open Access Journals (Sweden)

    Micere Keels

    2014-06-01

    Full Text Available The increased representation of minority students on the campuses of predominantly White universities in the United States presents increased opportunities for intercultural contact. Studying dating experiences across racial and ethnic lines has been used to determine the existence of a post-racial America. While most previous research has examined general racial/ethnic and gender differences in intercultural college dating experiences, this study analyzes precollege and college-going friendship diversity and skin tone as factors accounting for romantic distance between racial/ethnic groups among a recent cohort of college students. Hierarchical linear modeling analyses were conducted on a 4-year longitudinal sample of 2804 undergraduate students from 24 colleges and universities. Results confirm that White students continue to be the group most likely to engage in intragroup dating relationships, Latino/a students were the most likely to date interculturally, and that Black men were significantly more likely to date interculturally than Black women. For Black students there were significant within group differences in intercultural dating based on skin tone.

  19. Bituminous Pavement Failures

    Directory of Open Access Journals (Sweden)

    Surajo Abubakar Wada

    2016-02-01

    Full Text Available Pavement deterioration is a serious problem for road and traffic sector in almost every country, the most affecting causes of bituminous pavement failures have been studied in this paper. The paper describes the lessons learnt from pavement failures and problems experienced. Failures of bituminous pavements are caused due to many reasons or combination of reasons. Application of correction in the existing surface will enhance the life of maintenance works as well as that of strengthening layer. Along with the maintenance techniques there are various methods for pavement preservation which will help in enhancing the life of pavement and delaying of its failure.This paper discusses the possible causes of pavement failures, and recommendbetter ways to minimize and hopefully eliminate the causes of failures in bituminous pavements.

  20. Severe encephalopathy after ingestion of star fruit juice in a patient with chronic renal failure admitted to the intensive care unit.

    Science.gov (United States)

    Auxiliadora-Martins, Maria; Alkmin Teixeira, Gil Cezar; da Silva, Graciana Soares; Viana, Jaciara Machado; Nicolini, Edson Antônio; Martins-Filho, Olindo Assis; Basile-Filho, Anibal

    2010-01-01

    Star fruit (Averrhoa carambola) is a popular tropical fruit that is usually consumed as fresh fruit or fruit juice. Consumption of star fruit by patients with chronic renal failure can lead to neurologic symptoms. The present report describes the clinical course, management, and outcome of a patient with chronic renal failure admitted to an intensive care unit after ingestion of star fruit juice 2 days before hospital admission. A case of nausea, vomiting, intractable hiccups, and severe encephalopathy along with mental confusion, disorientation, agitation, and seizures in a 53-year-old woman is presented. The patient's ventilatory pattern worsened, with development of dyspnea and tachypnea, which resulted in her transfer to an intensive care unit. Although hemodialysis was performed and the septic shock was adequately treated, the patient died on the fifth day after hospital admission. The susceptibility of patients with chronic renal failure to star fruit and the severity of intoxication are poorly known by intensivists. This case demonstrates that star fruit consumption should be considered as a cause of rapid deterioration in the renal function of patients with underlying chronic renal failure, potentially resulting in a fatal outcome.

  1. Serum 1H-NMR metabolomic fingerprints of acute-on-chronic liver failure in intensive care unit patients with alcoholic cirrhosis.

    Directory of Open Access Journals (Sweden)

    Roland Amathieu

    Full Text Available INTRODUCTION: Acute-on-chronic liver failure is characterized by acute deterioration of liver function in patients with compensated or decompensated, but stable, cirrhosis. However, there is no accurate definition of acute-on-chronic liver failure and physicians often use this term to describe different clinical entities. Metabolomics investigates metabolic changes in biological systems and identifies the biomarkers or metabolic profiles. Our study assessed the metabolomic profile of serum using proton nuclear magnetic resonance ((1H-NMR spectroscopy to identify metabolic changes related to acute-on-chronic liver failure. PATIENTS: Ninety-three patients with compensated or decompensated cirrhosis (CLF group but stable liver function and 30 patients with cirrhosis and hospitalized for the management of an acute event who may be responsible of acute-on-chronic liver failure (ACLF group, were fully analyzed. Blood samples were drawn at admission, and sera were separated and stored at -80°C until (1H-NMR spectral analysis. Using orthogonal projection to latent-structure discriminant analyses, various metabolites contribute to the complete separation between these both groups. RESULTS: The predictability of the model was 0.73 (Q(2 Y and the explained variance was 0.63 (R(2 Y. The main metabolites that had increased signals related to acute-on-chronic liver failure were lactate, pyruvate, ketone bodies, glutamine, phenylalanine, tyrosine, and creatinine. High-density lipids were lower in the ALCF group than in CLF group. CONCLUSION: A serum metabolite fingerprint for acute-on-chronic liver failure, obtained with (1H-NMR, was identified. Metabolomic profiling may aid clinical evaluation of patients with cirrhosis admitted into intensive care units with acute-on-chronic liver failure, and provide new insights into the metabolic processes involved in acute impairment of hepatic function.

  2. Patterns of scheduled follow-up appointments following hospitalization for heart failure: insights from an urban medical center in the United States

    Science.gov (United States)

    Goyal, Parag; Sterling, Madeline R; Beecy, Ashley N; Ruffino, John T; Mehta, Sonal S; Jones, Erica C; Lachs, Mark S; Horn, Evelyn M

    2016-01-01

    Objectives Although postdischarge outpatient follow-up appointments after a hospitalization for heart failure represent a potentially effective strategy to prevent heart failure readmissions, patterns of scheduled follow-up appointments upon discharge are poorly described. We aimed to characterize real-world patterns of scheduled follow-up appointments among adult patients with heart failure upon hospital discharge. Patients and methods This was a retrospective cohort study performed at a large urban academic center in the United States among adults hospitalized with a principal diagnosis of congestive heart failure between January 1, 2013, and December 31, 2014. Patient demographics, administrative data, clinical parameters, echocardiographic indices, and scheduled postdischarge outpatient follow-up appointments were collected. Results Of the 796 patients hospitalized for heart failure, just over half of the cohort had a scheduled follow-up appointment upon discharge. Follow-up appointments were less likely among patients who were white and had heart failure with preserved ejection fraction and more likely among patients with Medicaid and chronic obstructive pulmonary disease. In an adjusted multivariable regression model, age ≥65 years was inversely associated with a scheduled follow-up appointment upon hospital discharge, despite higher rates of several cardiovascular and noncardiovascular comorbidities. Conclusion Just half of the patients discharged home following a hospitalization for heart failure had a follow-up appointment scheduled, representing a missed opportunity to provide a recommended care transition intervention. Despite a greater burden of both cardiovascular and noncardiovascular comorbidities, older adults (age ≥65 years) were less likely to have a follow-up appointment scheduled upon discharge compared with younger adults, revealing a disparity that warrants further investigation. PMID:27713623

  3. Optimization of Equipment Maintenance Strategy Based on Availability

    Institute of Scientific and Technical Information of China (English)

    张友诚

    2001-01-01

    It is very important to optimize maintenance strategy in maintenance plan. Proper parameters play a decisive role for the optimization. In the opinion of writer, availability is a basic parameter, failure consequence cost and failure characteristic are also important parameters. Maintenance strategy can be optimized on the base by means of quantitative analysis and diagram.

  4. Software Maintenance.

    Science.gov (United States)

    Cannon, Glenn; Jobe, Holly

    Proper cleaning and storage of audiovisual aids is outlined in this brief guide. Materials and equipment needed for first line maintenance are listed, as well as maintenance procedures for records, audio and video tape, film, filmstrips, slides, realia, models, prints, graphics, maps, and overhead transparencies. A 15-item quiz on software…

  5. ISS ECLSS: 3 Years of Logistics for Maintenance

    Science.gov (United States)

    Shkedi, Brienne; Thompson, Dean

    2004-01-01

    The International Space Station (ISS) Environmental Control and Life Support System (ECLSS) is designed to be maintainable. During the 3 years since the ISS US Lab became operational, there have been numerous ECLSS Orbital Replacement Units (ORUs) launched and returned to Maintain the ECLSS operation in the US segments. The maintenance logistics have provided tools for maintenance, replaced limited life ORUs and failed ORUs, upgraded ECLSS hardware to improve reliability and placed critical spares onboard prior to need. In most cases, the removed ORUs have been returned for either failure analysis and repair or refurbishment. This paper describes the ECLSS manifesting history and maintenance events and quantifies the numbers of ECLSS items, weights, and volumes.

  6. Industrial Mechanical Maintenance.

    Science.gov (United States)

    Hendrix, Laborn J.

    This manual was developed to assist teachers in Oklahoma in preparing students for industrial mechanical maintenance. The materials in this teacher's guide are organized in 14 units of instruction covering the following four areas: receiving and setting equipment; equipment hookup and operation; equipment layout, anchoring, and setup; and…

  7. The influence of condition-based maintenance on workforce planning and maintenance scheduling

    NARCIS (Netherlands)

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

    2013-01-01

    Condition-based maintenance (CBM) is generally considered an attractive maintenance policy for a single component: it uses the operating condition of the component to predict a failure event and therefore tries to avoid any unplanned downtime and unnecessary maintenance activities. However,

  8. Condition-based maintenance for complex systems : Coordinating maintenance and logistics planning for the process industries

    NARCIS (Netherlands)

    Olde Keizer, Minou Catharina Anselma

    2016-01-01

    Maintenance planning in the process industries is extremely complex for various reasons. Plants often run nonstop, allowing little time for performing preventive maintenance. Failures should be prevented, however, as they can lead to system downtime and high losses of revenue. Corrective maintenance

  9. New-onset heart failure due to heart muscle disease in childhood: a prospective study in the United kingdom and Ireland.

    Science.gov (United States)

    Andrews, Rachel E; Fenton, Matthew J; Ridout, Deborah A; Burch, Michael

    2008-01-01

    We undertook the first prospective, national, multicenter study to describe the incidence and outcome of heart muscle disease-induced heart failure in children. Data were collected on patients admitted to a hospital through 2003 with a first episode of heart failure in the absence of congenital heart disease. All 17 pediatric cardiac centers in the United Kingdom and Ireland participated. Follow-up data were obtained to a minimum of 1 year. The incidence was 0.87/100,000 population Heart Association class III to IV. Causes of heart failure included dilated cardiomyopathy (50 idiopathic, 8 familial), probable myocarditis (23), occult arrhythmia (7), anthracycline toxicity (5), metabolic disease (4), left ventricular noncompaction (3), and other (4). Overall 1-year survival was 82%, and event (death or transplantation)-free survival was 66%. Regression analysis showed older age and reduced systolic function on admission echocardiogram increased the event risk. Only 8% of event-free survivors (n=69) remained in New York Heart Association class III to IV, but 35 required readmission during the study period, and all but 8 remained on medication. This first national prospective study of new-onset heart failure in children has shown an incidence of 0.87/100,000. Multivariable analysis of survival data indicates a better outcome for younger children and for those with better systolic function at presentation, but overall, one third of children die or require transplantation within 1 year of presentation.

  10. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXV, I--CATERPILLAR DIESEL ENGINE COOLING SYSTEM D-8 AND 824 MODELS, II--TIRES AND TIRE HARDWARE.

    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 OPERATION AND MAINTENANCE OF THE DIESEL ENGINE COOLING SYSTEM AND TO PROVIDE A DESCRIPTION OF HEAVY TIRES AND WHEELS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) THEORY OF THE COOLING SYSTEM, (2) COOLING SYSTEM COMPONENTS, (3) MAINTENANCE TIPS (COOLING SYSTEM), (4)…

  11. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXIV, I--MAINTAINING THE FUEL SYSTEM PART III--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING THE VOLTAGE REGULATOR/ALTERNATOR.

    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 OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL AND BATTERY CHARGING SYSTEM. TOPICS ARE (1) INJECTION TIMING CONTROLS, (2) GOVERNOR, (3) FUEL SYSTEM MAINTENANCE TIPS, (4) THE CHARGING SYSTEM, (5) REGULATING THE GENERATOR/ALTERNATOR, AND (6) CHARGING SYSTEM SERVICE…

  12. Patterns of scheduled follow-up appointments following hospitalization for heart failure: insights from an urban medical center in the United States

    Directory of Open Access Journals (Sweden)

    Goyal P

    2016-09-01

    Full Text Available Parag Goyal,1 Madeline R Sterling,2 Ashley N Beecy,2 John T Ruffino,2 Sonal S Mehta,3 Erica C Jones,1 Mark S Lachs,3 Evelyn M Horn1 1Division of Cardiology, Department of Medicine, 2Department of Medicine, 3Division of Geriatrics, Department of Medicine, Weill Cornell Medicine, New York, NY, USA Objectives: Although postdischarge outpatient follow-up appointments after a hospitalization for heart failure represent a potentially effective strategy to prevent heart failure readmissions, patterns of scheduled follow-up appointments upon discharge are poorly described. We aimed to characterize real-world patterns of scheduled follow-up appointments among adult patients with heart failure upon hospital discharge.Patients and methods: This was a retrospective cohort study performed at a large urban academic center in the United States among adults hospitalized with a principal diagnosis of congestive heart failure between January 1, 2013, and December 31, 2014. Patient demographics, administrative data, clinical parameters, echocardiographic indices, and scheduled postdischarge outpatient follow-up appointments were collected.Results: Of the 796 patients hospitalized for heart failure, just over half of the cohort had a scheduled follow-up appointment upon discharge. Follow-up appointments were less likely among patients who were white and had heart failure with preserved ejection fraction and more likely among patients with Medicaid and chronic obstructive pulmonary disease. In an adjusted multivariable regression model, age ≥65 years was inversely associated with a scheduled follow-up appointment upon hospital discharge, despite higher rates of several cardiovascular and noncardiovascular comorbidities.Conclusion: Just half of the patients discharged home following a hospitalization for heart failure had a follow-up appointment scheduled, representing a missed opportunity to provide a recommended care transition intervention. Despite a greater

  13. The Method of Mission Oriented Maintenance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In a real application, equipment in good condition sometimes have to be repairedbecause the equipment does not satisfy the requirements of the mission; However, it is notnecessary to repair some equipment with failures because the failures do not affect the mission completion. In these cases, maintenance activity guided by present maintenance methodsmay sometimes affect the mission completion in time or bring about extra maintenance. To overcome the shortage of present maintenance methods, we propose an idea and method of missionoriented maintenance (MOM) to deal with the maintenance policy on these kinds of problems. This method can work out different maintenance policies corresponding to differentmissions with full consideration of missions and mission requirements for the equipment.

  14. Gastrointestinal failure in intensive care: a retrospective clinical study in three different intensive care units in Germany and Estonia

    Directory of Open Access Journals (Sweden)

    Starkopf Joel

    2006-06-01

    Full Text Available Abstract Background While gastrointestinal problems are common in ICU patients with multiple organ failure, gastrointestinal failure has not been given the consideration other organ systems receive. The aim of this study was to evaluate the incidence of gastrointestinal failure (GIF, to identify its risk factors, and to determine its association with ICU mortality. Methods A retrospective analysis of adult patients (n = 2588 admitted to three different ICUs (two ICUs at the university hospital Charité-Universitätsmedizin Berlin, Germany and one at Tartu University Clinics, Estonia during the year 2002 was performed. Data recorded in a computerized database were used in Berlin. In Tartu, the data documented in the patients' charts was retrospectively transferred into a similar database. GIF was defined as documented gastrointestinal problems (food intolerance, gastrointestinal haemorrhage, and/or ileus in the patient data at any period of their ICU stay. ICU mortality, length of stay, and duration of mechanical ventilation were assessed as outcome parameters. Results GIF was identified in 252 patients (9.7% of all patients. Only 20% of GIF patients were identifiable at admission. GIF was related to significantly higher mortality (43.7% vs. 5.3% in patients without GIF, as well as prolonged length of ICU stay (10 vs. 2 days and mechanical ventilation (8 vs. 1 day, p Conclusion Gastrointestinal failure represents a relevant clinical problem accompanied by an increased mortality, longer ICU stay and mechanical ventilation.

  15. Efforts to Reduce International Space Station Crew Maintenance Time in the Management of the Extravehicular Mobility Unit Transport Loop Water Quality

    Science.gov (United States)

    Etter,David; Rector, Tony; Boyle, robert; Zande, Chris Vande

    2012-01-01

    The EMU (Extravehicular Mobility Unit) contains a semi-closed-loop re-circulating water circuit (Transport Loop) to absorb heat into a LCVG (Liquid Coolant and Ventilation Garment) worn by the astronaut. A second, single-pass water circuit (Feed-water Loop) provides water to a cooling device (Sublimator) containing porous plates, and that water sublimates through the porous plates to space vacuum. The cooling effect from the sublimation of this water translates to a cooling of the LCVG water that circulates through the Sublimator. The quality of the EMU Transport Loop water is maintained through the use of a water processing kit (ALCLR - Airlock Cooling Loop Remediation) that is used to periodically clean and disinfect the water circuit. Opportunities to reduce crew time associated with ALCLR operations include a detailed review of the historical water quality data for evidence to support an extension to the implementation cycle. Furthermore, an EMU returned after 2-years of use on the ISS (International Space Station) is being used as a test bed to evaluate the results of extended and repeated ALCLR implementation cycles. Finally, design, use and on-orbit location enhancements to the ALCLR kit components are being considered to allow the implementation cycle to occur in parallel with other EMU maintenance and check-out activities, and to extend the life of the ALCLR kit components. These efforts are undertaken to reduce the crew-time and logistics burdens for the EMU, while ensuring the long-term health of the EMU water circuits for a post- Shuttle 6-year service life.

  16. Paranal maintenance and CMMS experience

    Science.gov (United States)

    Montano, Nelson

    2004-10-01

    During the last four years of operations, low technical downtime has been one of the relevant records of the Paranal Observatory. From the beginning of the Very Large Telescope (VLT) project, European Southern Observatory (ESO) has considered the implementation of a proper maintenance strategy a fundamental point in order to ensure low technical down time and preserve the Observatory's assets. The implementation of the maintenance strategy was based on the following aspects: - Strong maintenance sense during the design stage. Line Replacement Unit (LRU) concept, standardization and modularity of the Observatory equipment - Creation of a dedicated team for Maintenance - The implementation of a Computerized Maintenance Management System After four operational years, the result of these aspects has exceeded the expectations; the Observatory has been operating with high availability under a sustainable strategy. The strengths of the maintenance strategy have been based on modern maintenance concepts applied by regular production companies, where any minute of down time involves high cost. The operation of the actual Paranal Maintenance System is based mainly on proactive activities, such as regular inspections, preventive maintenance (PM) and predictive maintenance (PdM) plans. Nevertheless, it has been necessary to implement a strong plan for corrective maintenance (CM). The Spare Parts Strategy has also been an important point linked to the Maintenance Strategy and CMMS implementation. At present, almost 4,000 items related to the Observatory spare parts are loaded into the CMMS database. Currently, we are studying the implementation of a Reliability Centered Maintenance (RCM) project in one of our critical systems The following document presents the actual status of the Paranal Maintenance Strategy and which have been the motivations to implement the established strategy.

  17. Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning.

    Science.gov (United States)

    Tsai, Stephanie B; Liu, Hongtao; Shore, Tsiporah; Fan, Yun; Bishop, Michael; Cushing, Melissa M; Gergis, Usama; Godley, Lucy; Kline, Justin; Larson, Richard A; Martinez, Guadalupe; Mayer, Sebastian; Odenike, Olatoyosi; Stock, Wendy; Wickrema, Amittha; van Besien, Koen; Artz, Andrew S

    2016-06-01

    Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34(+) selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

  18. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  19. Evaluation of the Implementation of an educational intervention nurse in patients treated at the Heart Failure Unit at the University Hospital Puerta de Hierro

    Directory of Open Access Journals (Sweden)

    Aurora Hernández Rivas

    2012-11-01

    Full Text Available Objective: To evaluate the effectiveness of the implementation of a nurse educational intervention in patients with heart failure in relation to the level of knowledge about their disease, level of self-care, treatment adherence, perceived satisfaction, fewer hospital readmissions and improved quality of life. Methods: Quasi-experimental study with two groups: control group (consisting of patients treated according to standard practice and experimental group (consisting of patients who will apply the nursing educational intervention proposal. It included all patients (= 18 years, good cognitive, literacy, sign informed consent with a diagnosis of heart failure (HF of recent (3-6 months or new onset, coming first in the Heart Failure Unit of Hospital Universitario Puerta de Hierro from May 2008. Sample: 68 patients per group. Nurse educational intervention will consist of four teaching sessions of 20 minutes before discharge, will be given a boost educational DVD, complete with brochures and explanatory guide, it will reinforce the information a month by telephone. Monitoring: baseline visit (inclusion and follow-up after 15 days, at 3 and 6 months. Outcomes/Instruments: demographic and clinical/exploration and medical history; quality of life, knowledge, self-care and medication adherence/validated questionnaires. Analysis: measures of central tendency and dispersion. Analysis by treatment assignment.

  20. Maintenance Optimization based on Mathematical Modeling

    NARCIS (Netherlands)

    de Jonge, Bram

    2017-01-01

    Due to an increasingly competitive marketplace and an ongoing shift from labor intensive to technology intensive industries, the importance of effectively planned and performed maintenance activities is growing. Because consequences of equipment failures are often severe, it is generally preferred

  1. Maintenance Therapy in IBD

    Science.gov (United States)

    ... Help Center Home > Resources > Maintenance Therapy Go Back Maintenance Therapy Email Print + Share The term "maintenance therapy" ... are referred to as "maintenance therapies." Why is Maintenance Therapy Needed in IBD? Both Crohn's disease and ...

  2. Maintenance Therapy in IBD

    Science.gov (United States)

    ... Help Center Home > Resources > Maintenance Therapy Go Back Maintenance Therapy Email Print + Share The term "maintenance therapy" ... are referred to as "maintenance therapies." Why is Maintenance Therapy Needed in IBD? Both Crohn's disease and ...

  3. Establishing maintenance intervals based on measurement reliability of engineering endpoints.

    Science.gov (United States)

    James, P J

    2000-01-01

    Methods developed by the metrological community and principles used by the research community were integrated to provide a basis for a periodic maintenance interval analysis system. Engineering endpoints are used as measurement attributes on which to base two primary quality indicators: accuracy and reliability. Also key to establishing appropriate maintenance intervals is the ability to recognize two primary failure modes: random failure and time-related failure. The primary objective of the maintenance program is to avert predictable and preventable device failure, and understanding time-related failures enables service personnel to set intervals accordingly.

  4. Operation and maintenance strategies for wave energy converters

    DEFF Research Database (Denmark)

    Ambühl, Simon; Marquis, Laurent; Kofoed, Jens Peter;

    2015-01-01

    Inspection and maintenance costs are a significant contributor to the cost of energy for wave energy converters. There are different operation and maintenance strategies for wave energy converters. Maintenance can be performed after failure (corrective) or before a breakdown (preventive) occurs...... and maintenance costs estimations for wave energy converter applications including real weather data and damage accumulation. Furthermore, uncertainties related with costs, structural damage accumulation, inspection accuracy and different maintenance strategies can be included. This article contains a case study...

  5. Machinery prognostics and prognosis oriented maintenance management

    CERN Document Server

    Yan, Jihong

    2014-01-01

    This book gives a complete presentatin of the basic essentials of machinery prognostics and prognosis oriented maintenance management, and takes a look at the cutting-edge discipline of intelligent failure prognosis technologies for condition-based maintenance.  Latest research results and application methods are introduced for signal processing, reliability moelling, deterioration evaluation, residual life prediction and maintenance-optimization as well as applications of these methods.

  6. PFP MICON maintenance manual. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Silvan, G.R.

    1995-01-25

    This manual covers the use of maintenance displays, maintenance procedures, system alarms and common system failures. This manual is intended to supplement the MICON maintenance training not replace it. It also assumes that the user is familiar with the normal operation of the MICON A/S system. The MICON system is a distributed control computer and, among other things, controls the HVAC system for the Plutonium Finishing Plant.

  7. Reliability-centered maintenance for ground-based large optical telescopes and radio antenna arrays

    Science.gov (United States)

    Marchiori, G.; Formentin, F.; Rampini, F.

    2014-07-01

    the logic is completed for all the analyzed items, the resulting Maintenance Program is compiled in order to preserve all the system important functions and to rationalize the tasks periodicities. Lastly, the RCM is kept alive throughout the entire life of the telescope, where the effectiveness of the maintenance is constantly reviewed and adjusted on the basis of the "lesson learned". In addition to the RCM analysis methodology, a second basic concept is applied for the telescope maintenance: to design and install components in such a manner to restore a failure and to perform servicing procedures as close as possible to the telescope, maximizing the replacement of Line Replaceable Units (LRUs) or Shop Replaceable Units (SRUs), rather than repair on-equipment.

  8. A Grounded Theory Study of Aircraft Maintenance Technician Decision-Making

    Science.gov (United States)

    Norcross, Robert

    Aircraft maintenance technician decision-making and actions have resulted in aircraft system errors causing aircraft incidents and accidents. Aircraft accident investigators and researchers examined the factors that influence aircraft maintenance technician errors and categorized the types of errors in an attempt to prevent similar occurrences. New aircraft technology introduced to improve aviation safety and efficiency incur failures that have no information contained in the aircraft maintenance manuals. According to the Federal Aviation Administration, aircraft maintenance technicians must use only approved aircraft maintenance documents to repair, modify, and service aircraft. This qualitative research used a grounded theory approach to explore the decision-making processes and actions taken by aircraft maintenance technicians when confronted with an aircraft problem not contained in the aircraft maintenance manuals. The target population for the research was Federal Aviation Administration licensed aircraft and power plant mechanics from across the United States. Nonprobability purposeful sampling was used to obtain aircraft maintenance technicians with the experience sought in the study problem. The sample population recruitment yielded 19 participants for eight focus group sessions to obtain opinions, perceptions, and experiences related to the study problem. All data collected was entered into the Atlas ti qualitative analysis software. The emergence of Aircraft Maintenance Technician decision-making themes regarding Aircraft Maintenance Manual content, Aircraft Maintenance Technician experience, and legal implications of not following Aircraft Maintenance Manuals surfaced. Conclusions from this study suggest Aircraft Maintenance Technician decision-making were influenced by experience, gaps in the Aircraft Maintenance Manuals, reliance on others, realizing the impact of decisions concerning aircraft airworthiness, management pressures, and legal concerns

  9. Treatment of S109FA Gas Power Unit Direct Current Oil Pump Failure%S109FA燃气机组直流油泵自动启动失败的处理方法

    Institute of Scientific and Technical Information of China (English)

    王平

    2015-01-01

    S109FA燃气机组正常运行时由380 V交流润滑油泵提供轴系润滑油和发电机氢气密封油;2台交流润滑油泵都故障时,直流润滑油泵自动启动代替交流润滑油泵工作;当发电机氢气密封油压力低于设定值时直流密封油泵自动启动,使发电机氢气密封油的油压力维持在合格的范围之内。本文介绍了直流润滑油泵和直流密封油泵在自动启动失败的紧急情况下的处理方法,为S109FA燃气机组和其它型号的燃气机组处理类似的故障提供参考。%S109FA gas power unit was provided by the 380V alternating current lubricant pump to fasten lubricant and generator hydro-gen to seal completely oil while it ran normally.While two alternating current lubricant pumps all broke down, the direct current lubri-cant pump automatic start instead of the alternating current lubricant pump.While the oil pressure of generator hydrogen seals was less than initial value, the direct current seal oil pump automatic start, which made the oil pressure in the qualified scope.This paper intro-duced direct current lubricant the pump and direct current seal completely an oil pump under the urgent circumstance that auto start failure of treatment.It can be a reference for the S109 FA gas power unit and other similar of the breakdown unit.

  10. Failure to Validate a Multivariable Clinical Prediction Model to Identify Pediatric Intensive Care Unit Patients at High Risk for Candidemia.

    Science.gov (United States)

    Fisher, Brian T; Ross, Rachael K; Roilides, Emmanuel; Palazzi, Debra L; Abzug, Mark J; Hoffman, Jill A; Berman, David M; Prasad, Priya A; Localio, A Russell; Steinbach, William J; Vogiatzi, Lambrini; Dutta, Ankhi; Zaoutis, Theoklis E

    2016-12-01

    We attempted to validate a previously derived clinical prediction rule for candidemia in the pediatric intensive care unit. This multicenter case control study did not identify significant association of candidemia with most of the previously identified predictors. Additional study in larger cohorts with other predictor variables is needed. © The Author 2015. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  11. Crusted ("Norwegian") scabies in a specialist HIV unit: successful use of ivermectin and failure to prevent nosocomial transmission.

    OpenAIRE

    Corbett, E. L.; Crossley, I; Holton, J; Levell, N; Miller, R.; De Cock, K M

    1996-01-01

    A nosocomial outbreak of scabies in a specialist inpatient HIV unit resulted from a patient admitted with crusted scabies. Treatment of his infestation with topical scabicides alone failed and he remained infectious for several weeks. His infestation was then eradicated with combined topical treatment and oral ivermectin. In total, 14 (88%) out of 19 ward staff became symptomatic, and 4 (21%) had evidence of scabies on potassium hydroxide examination of skin scrapings. The ward infection cont...

  12. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXI, I--MAINTAINING THE AIR SYSTEM--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING REAR END SUSPENSION.

    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 OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM AND REAR AXLE SUSPENSION USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) AIR INDUCTION AND EXHAUST SYSTEM, (2) VALVE MECHANISM, (3) TROUBLESHOOTING THE AIR SYSTEM, (4) PURPOSE OF VEHICLE SUSPENSION, (5) TANDEM…

  13. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XIII, I--MAINTAINING THE FUEL SYSTEM (PART III), CUMMINS DIESEL ENGINES, II--RADIATOR SHUTTER SYSTEM.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION, OPERATION, AND MAINTENANCE OF THE DIESEL ENGINE FUEL AND RADIATOR SHUTTER SYSTEMS. TOPICS ARE (1) MORE ABOUT THE CUMMINS FUEL SYSTEM, (2) CALIBRATING THE PT FUEL PUMP, (3) CALIBRATING THE FUEL INJECTORS, (4) UNDERSTANDING THE SHUTTER SYSTEM, (5) THE…

  14. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXIII, I--MAINTAINING THE FUEL SYSTEM, PART II--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING STEERING SYSTEMS.

    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 OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL INJECTION SYSTEM AND THE STEERING SYSTEM OF DIESEL POWERED VEHICLES. TOPICS ARE FUEL INJECTION SECTION, AND DESCRIPTION OF THE STEERING SYSTEM. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

  15. Inspection-replacement policy of system under predictive maintenance

    Institute of Scientific and Technical Information of China (English)

    LIU Bao-you; FANG You-tong; WEI Jin-xiang; WANG Yong-liang

    2007-01-01

    In general, every system is in one of the three states: normal, abnormal, or failure state. When the system is diagnosed as abnormal state, it needs predictive maintenance. If the system fails, an identical new one will replace it. The predictive maintenance cannot make the system "as good as new". Under these assumptions, the reliability index and the inspection-replacement policy of a system were studied. The explicit expression of the reliability index and the average income rate (i.e., the long-runaverage income per unit time) are derived by using probability analysis and vector Markov process method. The criterion of feasibility for the optimal inspection-replacement policy under the maximum average income rate is obtained. The numerical example shows the optimal inspection-replacement policy can raise the average income rate when the optimal inspection-replacement policy is feasible.

  16. 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...

  17. 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

  18. 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

  19. Reliability centered maintenance applied to gas turbines, a deeper methodological study; Optimisation de la maintenance par la fiabilite appliquee aux turbines a combustion: approfondissement methodologique

    Energy Technology Data Exchange (ETDEWEB)

    Despujols, A.; Delbos, J.P.; Zuliani, G.

    1995-12-31

    The 9000E`combustion turbine study is unique in that it applied he RCM procedure to a power station before construction had begun on it. This has resulted in a maintenance programme being determined from the outset, rather than an existing programme being improved. The analysis begins with a search of the functions required by the unit, its operating states and its failure modes, then moves on to look at different systems to establish functional trees followed by failure trees. The lowest leaves on these graphs correspond respectively to functions carried out by important equipment nd their failure modes. Following on from this hierarchical procedure, each of the items of equipment are studies in an analysis of the failures modes, their effects and their criticality. The absence of feedback on this machine, the lack of data on the technology and the small size of the equipment (by comparison with those encountered in a nuclear unit), all contribute to limiting the level of decomposition. Tables are thus obtained which show the failure modes of an item of equipment, their origin, their effects on a system and unit level, the potential damage they cause, their severity, expert estimates of the frequency with they are likely to appear, their criticality and their evidence. The next step is a crucial one since it produces the results expected from the previous stages. It relies on task selection logic which has been honed to better take account of the obvious or hidden character of the failures. Not only must preventive operations to stop critical failure modes from occurring be suggested, but certain operations must be prescribed in order for breakdowns to be revealed. In practice, the state of the redundant or protective equipment has to be known when some of their failure modes remain hidden from the operator. The risk of a double failure with serious consequences becomes a probability when their breakdown state is not detected. (authors) 15 refs.

  20. Managing aging in nuclear power plants: Insights from NRC maintenance team inspection reports

    Energy Technology Data Exchange (ETDEWEB)

    Fresco, A.; Subudhi, M.; Gunther, W.; Grove, E.; Taylor, J. [Brookhaven National Lab., Upton, NY (United States)

    1993-12-01

    A plant`s maintenance program is the principal vehicle through which age-related degradation is managed. From 1988 to 1991, the NRC evaluated the maintenance program of every nuclear power plant in the United States. Forty-four out of a total of 67 of the reports issued on these in-depth team inspections were reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant systems, structures, and components. Relevant information was extracted from these inspection reports and sorted into several categories, including Specific Aging Insights, Preventive Maintenance, Predictive Maintenance and Condition Monitoring, Post Maintenance Testing, Failure Trending, Root Cause Analysis and Usage of Probabilistic Risk Assessment in the Maintenance Process. Specific examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging have been identified. The information also was sorted according to systems and components, including: Auxiliary Feedwater, Main Feedwater, High Pressure Injection for both BWRs and PWRs, Service Water, Instrument Air, and Emergency Diesel Generator Air Start Systems, and Emergency Diesel Generators Air Start Systems, emergency diesel generators, electrical components such as switchgear, breakers, relays, and motor control centers, motor operated valves and check valves. This information was compared to insights gained from the Nuclear Plant Aging Research (NPAR) Program. Attributes of plant maintenance programs where the NRC inspectors felt that improvement was needed to properly address the aging issue also are discussed.

  1. Comparative evaluation of maintenance performance using subsurvival functions

    DEFF Research Database (Denmark)

    Paulsen, J.L.; Cooke, R.; Nyman, R.

    1997-01-01

    Subsurvival functions are applied to operational data for the control rod drive systems of Nordic nuclear reactors to evaluate maintenance performance. Competing failure modes are preventive and corrective maintenance. Maintenance indicators are defined and evaluated for 8 plants. (C) 1997 Elsevier...

  2. 探讨炼油装置自动化检测仪表的安装与维护%Installation and maintenance of automatic detecting instruments in refining units

    Institute of Scientific and Technical Information of China (English)

    高嗣晟

    2015-01-01

    The automatic detecting instruments applied in refining units are introduced in this paper along with related installation processes. The potential faults are analyzed as well to provide maintenance measures.%本文首先对炼油装置自动化检测仪表进行简单的介绍,然后说明自动化检测仪表的安装过程,最后针对可能出现的事故进行分析,提出相应的维护措施.

  3. An enterprise risk management framework for evaluation of eMaintenance

    OpenAIRE

    Söderholm, Peter; Karim, Ramin

    2010-01-01

    Maintenance is one approach to manage risk by a reduction of the probability of failure of technical systems and/or the consequences of their failure. However, history has shown that erroneous maintenance also can lead to reduced quality, incidents and accidents with extensive losses. Today, eMaintenance promises great opportunities for a paradigm shift from a rather narrow condition-based maintenance approach with focus on technical system health to a true risk-based maintenance approach tha...

  4. Safety Management of a Clinical Process Using Failure Mode and Effect Analysis: Continuous Renal Replacement Therapies in Intensive Care Unit Patients.

    Science.gov (United States)

    Sanchez-Izquierdo-Riera, Jose Angel; Molano-Alvarez, Esteban; Saez-de la Fuente, Ignacio; Maynar-Moliner, Javier; Marín-Mateos, Helena; Chacón-Alves, Silvia

    2016-01-01

    The failure mode and effect analysis (FMEA) may improve the safety of the continuous renal replacement therapies (CRRT) in the intensive care unit. We use this tool in three phases: 1) Retrospective observational study. 2) A process FMEA, with implementation of the improvement measures identified. 3) Cohort study after FMEA. We included 54 patients in the pre-FMEA group and 72 patients in the post-FMEA group. Comparing the risks frequencies per patient in both groups, we got less cases of under 24 hours of filter survival time in the post-FMEA group (31 patients 57.4% vs. 21 patients 29.6%; p < 0.05); less patients suffered circuit coagulation with inability to return the blood to the patient (25 patients [46.3%] vs. 16 patients [22.2%]; p < 0.05); 54 patients (100%) versus 5 (6.94%) did not get phosphorus levels monitoring (p < 0.05); in 14 patients (25.9%) versus 0 (0%), the CRRT prescription did not appear on medical orders. As a measure of improvement, we adopt a dynamic dosage management. After the process FMEA, there were several improvements in the management of intensive care unit patients receiving CRRT, and we consider it a useful tool for improving the safety of critically ill patients.

  5. Early Mobilization Reduces Duration of Mechanical Ventilation and Intensive Care Unit Stay in Patients With Acute Respiratory Failure.

    Science.gov (United States)

    Lai, Chih-Cheng; Chou, Willy; Chan, Khee-Siang; Cheng, Kuo-Chen; Yuan, Kuo-Shu; Chao, Chien-Ming; Chen, Chin-Ming

    2017-05-01

    To evaluate the effects of a quality improvement program to introduce early mobilization on the outcomes of patients with mechanical ventilation (MV) in the intensive care unit (ICU). A retrospective observational study. Nineteen-bed ICU at a medical center. Adults patients with MV (N=153) admitted to a medical ICU. A multidisciplinary team (critical care nurse, nursing assistant, respiratory therapist, physical therapist, patient's family) initiated the protocol within 72 hours of MV when patients become hemodynamically stable. We did early mobilization twice daily, 5d/wk during family visits (30min each time), and cooperated with family, if possible. MV duration, rate of successful weaning, and length of ICU and hospital stay. We enrolled 63 patients in the before protocol group and 90 in the after protocol group. The 2 groups were well matched in age, sex, body height, body weight, body mass index, disease severity, cause of intubation, number of comorbidities, and most underlying diseases. After protocol group patients had shorter MV durations (4.7d vs 7.5d; PICU stays (6.9d vs 9.9d; P=.001) than did before protocol group patients. Early mobilization was negatively associated with the duration of MV (β=-.269; PICU shortened MV durations and ICU stays. A multidisciplinary team that includes the patient's family can work together to improve the patient's clinical outcomes. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  6. 14 CFR 183.27 - Designated aircraft maintenance inspectors.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Designated aircraft maintenance inspectors...: Privileges § 183.27 Designated aircraft maintenance inspectors. A designated aircraft maintenance inspector (DAMI) may approve maintenance on civil aircraft used by United States military flying clubs in foreign...

  7. Turnley Unit

    Data.gov (United States)

    Federal Laboratory Consortium — Facilities at this unit include cattle working pens, hydraulic squeeze chute and electronic scale, a maintenance building, and four hay storage sheds. There is one...

  8. A joint spare part and maintenance inspection optimisation model using the Delay-Time concept

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wenbin, E-mail: wangwb@ustb.edu.cn [Dongling School of Economics and Management, University of Science and Technology Beijing (China)

    2011-11-15

    Spare parts and maintenance are closely related logistics activities where maintenance generates the need for spare parts. When preventive maintenance is present, it may need more spare parts at one time because of the planned preventive maintenance activities. This paper considers the joint optimisation of three decision variables, e.g., the ordering quantity, ordering interval and inspection interval. The model is constructed using the well-known Delay-Time concept where the failure process is divided into a two-stage process. The objective function is the long run expected cost per unit time in terms of the three decision variables to be optimised. Here we use a block-based inspection policy where all components are inspected at the same time regardless of the ages of the components. This creates a situation that the time to failure since the immediate previous inspection is random and has to be modelled by a distribution. This time is called the forward time and a limiting but closed form of such distribution is obtained. We develop an algorithm for the optimal solution of the decision process using a combination of analytical and enumeration approaches. The model is demonstrated by a numerical example. - Highlights: > Joint optimisation of maintenance and spare part inventory. > The use of the Delay-Time concept. > Block-based inspection. > Fixed order interval but variable order quantity.

  9. Managing Postoperative Analgesic Failure: Tramadol Versus Morphine for Refractory Pain in the Post-Operative Recovery Unit.

    Science.gov (United States)

    Byrne, Kelly; Nolan, Aoife; Barnard, John; Tozer, Megan; Harris, David; Sleigh, Jamie

    2017-02-01

    This study aimed to discover whether co-analgesia with tramadol or additional morphine was more effective for patients who still had severe pain despite being given 10 mg intravenous morphine in the post-anesthesia care unit (PACU). All eligible patients were consented and recruited to the trial pre-operatively, but only a small subgroup – whose pain was not successfully controlled (pain score 6/10 or more) after receiving 10 mg of morphine in the PACU—were then randomized to enter the trial and receive, in a double blinded fashion, the analgesic study drug; which consisted of either a further 10 mg of morphine, or 100 mg of tramadol, titrated intravenously to control their pain. The groups were compared as to: the time to readiness for discharge, the patient’s pain scores over time, and the presence of side effects. There was no statistically significant difference in any of the outcomes measured. The time to readiness for discharge from PACU was 119 minutes in the morphine group and 120 minutes in the tramadol group. However in approximately half the cases who entered the trial (i.e., where pain had not been controlled with the pre-enrollment baseline 10 mg of morphine in PACU) neither a further 10 mg of morphine nor 100 mg of tramadol effectively relieved the patient’s pain. We found no difference between additional morphine and co-analgesia with tramadol in this study. Patients who don’t respond to reasonable doses of opioids in PACU are very likely to be unresponsive to further opioids, and other non-opioid analgesic techniques (such as regional anesthesia) should be considered early in this group of patients.

  10. Opportunistic maintenance and adaptation of warranty maintenance tasks for Power Plant equipment

    Directory of Open Access Journals (Sweden)

    P. McGibney

    2016-08-01

    Full Text Available This paper makes a link between opportunistic maintenance literature and warranty analysis of a power plant. A new plant warranty maintenance tasks are observed over a two year period. The main aim is to see how opportunistic maintenance could be incorporated when the warranty period has elapsed. The paper examine the warranty period maintenance task list and propose adequate methods for assessing opportunistic maintenance as a preventive maintenance task in order to ensure reliability and availability of the plant equipment. Statistical approach is used to give an insight to the plant equipment status and a modeling approach is proposed to also assess maintenance information defined by experts in the context of actual operating regimes. This study focuses on the power plant‟s critical equipment. Failure Mode and Effect Analysis (FMEA is conducted on the power plant Booster Fans. This gives an insight about equipment failure mode patterns and maintenance requirements. A simulation example is presented based in the failure modes results obtained and a graphical display of optimum preventive maintenance schedule cost curves is also presented.

  11. Contingent post-closure plan, hazardous waste management units at selected maintenance facilities, US Army National Training Center, Fort Irwin, California

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The National Training Center (NTC) at Fort Irwin, California, is a US Army training installation that provides tactical experience for battalion/task forces and squadrons in a mid- to high-intensity combat scenario. Through joint exercises with US Air Force and other services, the NTC also provides a data source for improvements of training doctrines, organization, and equipment. To meet the training and operational needs of the NTC, several maintenance facilities provide general and direct support for mechanical devices, equipment, and vehicles. Maintenance products used at these facilities include fuels, petroleum-based oils, lubricating grease, various degreasing solvents, antifreeze (ethylene glycol), transmission fluid, brake fluid, and hydraulic oil. Used or spent petroleum-based products generated at the maintenance facilities are temporarily accumulated in underground storage tanks (USTs), collected by the NTC hazardous waste management contractor (HAZCO), and stored at the Petroleum, Oil, and Lubricant (POL) Storage Facility, Building 630, until shipped off site to be recovered, reused, and/or reclaimed. Spent degreasing solvents and other hazardous wastes are containerized and stored on-base for up to 90 days at the NTC`s Hazardous Waste Storage Facility, Building 703. The US Environmental Protection Agency (EPA) performed an inspection and reviewed the hazardous waste management operations of the NTC. Inspections indicated that the NTC had violated one or more requirements of Subtitle C of the Resource Conservation and Recovery Act (RCRA) and as a result of these violations was issued a Notice of Noncompliance, Notice of Necessity for Conference, and Proposed Compliance Schedule (NON) dated October 13, 1989. The following post-closure plan is the compliance-based approach for the NTC to respond to the regulatory violations cited in the NON.

  12. Contingent post-closure plan, hazardous waste management units at selected maintenance facilities, US Army National Training Center, Fort Irwin, California

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The National Training Center (NTC) at Fort Irwin, California, is a US Army training installation that provides tactical experience for battalion/task forces and squadrons in a mid- to high-intensity combat scenario. Through joint exercises with US Air Force and other services, the NTC also provides a data source for improvements of training doctrines, organization, and equipment. To meet the training and operational needs of the NTC, several maintenance facilities provide general and direct support for mechanical devices, equipment, and vehicles. Maintenance products used at these facilities include fuels, petroleum-based oils, lubricating grease, various degreasing solvents, antifreeze (ethylene glycol), transmission fluid, brake fluid, and hydraulic oil. Used or spent petroleum-based products generated at the maintenance facilities are temporarily accumulated in underground storage tanks (USTs), collected by the NTC hazardous waste management contractor (HAZCO), and stored at the Petroleum, Oil, and Lubricant (POL) Storage Facility, Building 630, until shipped off site to be recovered, reused, and/or reclaimed. Spent degreasing solvents and other hazardous wastes are containerized and stored on-base for up to 90 days at the NTC's Hazardous Waste Storage Facility, Building 703. The US Environmental Protection Agency (EPA) performed an inspection and reviewed the hazardous waste management operations of the NTC. Inspections indicated that the NTC had violated one or more requirements of Subtitle C of the Resource Conservation and Recovery Act (RCRA) and as a result of these violations was issued a Notice of Noncompliance, Notice of Necessity for Conference, and Proposed Compliance Schedule (NON) dated October 13, 1989. The following post-closure plan is the compliance-based approach for the NTC to respond to the regulatory violations cited in the NON.

  13. Characterization of obstetric patients with multiple organ failure in the intensive care unit of a Havana teaching hospital, 1998 to 2006.

    Science.gov (United States)

    Pérez, Albadio; Acevedo, Omar; Tamayo, Felicia del Consuelo; Oviedo, Regino

    2010-01-01

    Most obstetric patients admitted to intensive care units (ICU) present life-threatening complications of pregnancy, delivery, and postpartum, often leading to multiple organ failure (MOF), considered the main cause of death in ICUs. Although maternal mortality is an important indicator of health status in women and nations, few studies have analyzed MOF in obstetric ICU patients. The Sequential Organ Failure Assessment (SOFA) scale is a prognostic tool for ranking organ dysfunction in critically ill patients and correlating scores with outcome. Characterize obstetric patients diagnosed with MOF in the ICU of the Enrique Cabrera General Teaching Hospital, Havana, Cuba, between January 1, 1998 and December 31, 2006. A descriptive observational study was conducted of obstetric patients admitted to the ICU for >24 hours during the study period and diagnosed with MOF. Of 422 obstetric patients admitted, 58 met inclusion criteria. Patients' clinical characteristics, chronic diseases, diagnoses, Acute Physiology and Chronic Health Evaluation (APACHE II) scores, SOFA scores and discharge status were recorded in a data collection form. Day 1, Day 3, and maximum APACHE II and SOFA scores were calculated, and 3 prognostic groups were formed based on the difference between SOFA Day 1 and Day 3 scores (SOFAd 3-1: 0, poor prognosis). Data was entered in an EXCEL database and processed using SPSS 13.0 software. Quantitative variables were described by mean and standard deviation; qualitative variables by totals and percentages. A chi-square test was used to analyze associations between these variables and discharge status (alive or deceased) with significance level p 0 score with an unfavorable prognosis (84.0% mortality). Respiratory and cardiovascular systems were the most affected (75.9% each). Further studies analyzing MOF in obstetric patients are urgently needed in order to adopt more effective strategies for reducing maternal mortality in Cuba.

  14. Non-invasive positive pressure ventilation in acute hypercapnic respiratory failure: ten-year’s clinical experience of a Respiratory Semi-Intensive Care Unit (VERSIONE IN ITALIANO

    Directory of Open Access Journals (Sweden)

    Mario Naldi

    2007-12-01

    Full Text Available BackgroundAlthough several prospective controlled randomizedtrials demonstrated the success of non-invasive positive pressure ventilation (NIV in selected cases of acute hypercapnic respiratory failure (IRA in setting with different care levels, clinical practice data about the use of NIV in the “real world” are limited.AimTo report the results of our clinical experience in NIV applied for IRA in the Respiratory Semi-Intensive Care Unit (UTSIR allocated within the Respiratory Division of Arezzo in the years 1996-2006 in terms of: tolerance, effects upon arterial blood gases, success rate and predictors of failure.MethodsThree hundred filthy of the 1484 patients (23.6% consecutively admitted for IRA to our RespiratoryDivision during the study period received NIV in addition to standard therapy, according to the pre-defined routinely used criteria.ResultsEight patients (2.3% did not tolerated NIV becauseof mask discomfort, while the remaining 342 (M: 240, F: 102; median (interquartiles age: 74.0 (68.0-79.3 yrs; COPD: 69.3% were ventilatedfor >1 hour. Arterial blood gases significantlyimproved after two hours of NIV (mean (standard deviation pH: 7.33 (0.07 versus 7.28 (7.25-7.31, p 48 hrs of ventilation after an initial positive response.ConclusionsAs results of our ten-year’s clinical experience performed in a UTSIR, NIV is confirmed to be well tolerated, effective in improving arterial blood gases and useful in avoiding intubation in most IRA episodes non-responder to standard therapy.

  15. Non-Invasive Positive Pressure Ventilation in Acute Hypercapnic Respiratory Failure: Ten-Year’s Clinical Experience of a Respiratory Semi-Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Raffaele Scala, M.D., esp.

    2007-12-01

    Full Text Available BackgroundAlthough several prospective controlled randomizedtrials demonstrated the success of non-invasive positive pressure ventilation (NIPPV in selected cases of acute hypercapnic respiratory failure (ARF in setting with different care levels, clinical practice data about the use of VNI in the “real world” are limited.AimTo report the results of our clinical experiencein NIPPV applied for ARF in the Respiratory Semi-Intensive Care Unit (UTSIR allocated within the Respiratory Division of Arezzo betweenthe years 1996-2006 in terms of: patient tolerance, effects upon arterial blood gases, successrate and predictors of failure. Methods: Three hundred and filthy out of the 1484 patients (23.6% consecutively admittedfor ARF to our Respiratory Division during the study period received NIPPV in addition to standard therapy, according to the predeterminedroutinely used criteria. Results: Eight patients (2.3% did not tolerateNIPPV because of mask discomfort, while the remaining 342 (M: 240, F: 102; median (interquartilesage: 74.0 (68.0-79.3 yrs; COPD: 69.3% were ventilated for >1 hour. Arterial blood gases significantly improved after two hours of NIPPV (mean (standard deviation pH: 7.33 (0.07 versus 7.28 (7.25-7.31, p 48 hrs of ventilation after an initial positive response. Conclusions: As results of ten years of clinicalexperience at our UTSIR, NIPPV was shown to be well tolerated, effective in improving arterialblood gases and useful in avoiding intubationin most ARF episodes non-responsive to standard therapy.

  16. A periodic inspection and replacement policy for systems subject to competing failure modes due to degradation and traumatic events

    Energy Technology Data Exchange (ETDEWEB)

    Huynh, K.T., E-mail: tuan.huynh@utt.f [Universite de technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279-12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Barros, A., E-mail: anne.barros@utt.f [Universite de technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279-12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Berenguer, C., E-mail: christophe.berenguer@utt.f [Universite de technologie de Troyes, Institut Charles Delaunay and STMR UMR CNRS 6279-12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Castro, I.T., E-mail: inmatorres@unex.e [Departamento de Matematicas, Escuela Politecnica, 10071 Caceres (Spain)

    2011-04-15

    This paper deals with the condition-based maintenance of single-unit systems which are subject to the competing and dependent failures due deterioration and traumatic shock events. The main aim is to provide a model to assess the value of condition monitoring information for the maintenance decision-making. A condition-based periodic inspection/replacement policy is developed and compared with a benchmark time-based block replacement policy. Numerical results show that it is indeed useful to follow closely the actual evolution of the system to adapt the maintenance decisions to the true system state to improve the performance of maintenance policies. The analysis of the maintenance costs savings can be used to justify or not the choice to implement a policy based on condition monitoring information and to invest in condition monitoring devices.

  17. Analysis on the Failure of Computer Network Hardware Maintenance Strategy%关于计算机网络硬件的故障维护策略分析

    Institute of Scientific and Technical Information of China (English)

    罗林

    2014-01-01

    随着科技的快速发展,计算机的应用已经深入到社会的各个角落,无论是企业、学校还是一些小型单位,计算机网络已经成为人们生活和工作中不可缺少的一部分,发挥着越来越重要的作用。但是,计算机给人们生活和工作带来极大便利的同时,也出现了诸多问题,如计算机硬件故障给使用者带来的不便,甚至数据的丢失。该文针对计算机网络硬件中常见的故障进行了简单分析,并对此提出相应的维护措施。%With the rapid development of science and technology, Computer application is embedded in every corner of society, both the businesses, schools and the small units, computer networks have become an integral part of people's life and work, play an increasingly important role. However, the computer brings us a great convenience in living and working, there have been many problems, such as computer hardware failure inconvenience to the consumer, even data loss. This article analyses the com⁃mon faults of computer network hardware, and provide appropriate solutions.

  18. 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.

  19. Data mining and statistical process control for condition-based maintenance; Datamining und statistische Prozesskontrolle zur zustandsorientierten Instandhaltung

    Energy Technology Data Exchange (ETDEWEB)

    Deeskow, Peter; Steinmetz, Urs; Hay, Martin [Evonik Energy Services, Essen (Germany)

    2008-07-01

    Optimum, condition-based maintenance should balance the commercial consequences of an efficiency loss or a component failure and the cost of maintenance. This requires an early and highly reliable detection of abnormalities of the component/unit behaviour. For this purpose key performance indicators (KPIs) can be used which are online calculated from operational measurements and which solely depend on the component condition and do not depend on other influencing factors such as operation mode, load or ambient conditions. Software tools using data mining methods can facilitate the definition and calculation of such KPIs. (orig.)

  20. Patterns of 6-mercaptopurine and azathioprine maintenance therapy among a cohort of commercially insured individuals diagnosed with Crohn's disease in the United States

    Directory of Open Access Journals (Sweden)

    Lund JL

    2013-12-01

    Full Text Available Jennifer L Lund,1 Suzanne F Cook,2 Jeffery K Allen,2 Charlotte F Carroll,2 Michael D Kappelman3 1Department of Clinical Epidemiology, Aarhus University, Aarhus, Denmark; 2Worldwide Epidemiology, GlaxoSmithKline, Research Triangle Park, NC, USA; 3Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA Background and aims: Thiopurines, including 6-mercaptopurine (6-MP and azathioprine (AZA, are the mainstay of maintenance therapy for Crohn's disease (CD. However, studies examining their effectiveness in routine practice among diverse patient populations are lacking. Among a cohort of new users of 6MP/AZA, we described treatment patterns and changes in subsequent therapy. Methods: Using the Truven Health Analytics databases, we identified all individuals diagnosed with CD and initiating 6-MP/AZA monotherapy from 2001–2008 (n=3,657. We estimated the proportion of CD patients remaining on 6-MP/AZA monotherapy, using Kaplan–Meier methods, and identified predictors of treatment noncontinuation, using multivariable Cox regression. Among the “noncontinuers,” we described subsequent patterns of maintenance therapy and summarized the diagnosis and procedure codes and prescription drug claims preceding treatment discontinuation. Results: The 1-year 6-MP/AZA treatment continuation rate was 42%. Children (age ≤18 years and individuals with no prior anti-tumor necrosis factor (TNF use were more likely to continue 6-MP/AZA, while those dispensed more (>4 outpatient prescriptions for any drug before initiation of 6-MP/AZA were less likely to continue maintenance treatment. Overall, 1,128 (39% and 105 (4% individuals experienced a clinical event potentially indicating active disease or 6-MP/AZA-intolerance prior to discontinuation, respectively. Most patients discontinued therapy; among the remaining patients who failed to continue 6-MP/AZA, most augmented with an anti-TNF. Conclusion: Most patients initiating 6-MP

  1. On the hazard rate process for imperfectly monitored multi-unit systems

    Energy Technology Data Exchange (ETDEWEB)

    Barros, A. [Institut des Sciences et Techonologies de l' Information de Troyes (ISTIT-CNRS), Equipe de Modelisation et Surete des Systemes, Universite de Technologie de Troyes (UTT), 12, rue Marie Curie, BP2060, 10010 Troyes cedex (France)]. E-mail: anne.barros@utt.fr; Berenguer, C. [Institut des Sciences et Techonologies de l' Information de Troyes (ISTIT-CNRS), Equipe de Modelisation et Surete des Systemes, Universite de Technologie de Troyes (UTT), 12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Grall, A. [Institut des Sciences et Techonologies de l' Information de Troyes (ISTIT-CNRS), Equipe de Modelisation et Surete des Systemes, Universite de Technologie de Troyes (UTT), 12, rue Marie Curie, BP2060, 10010 Troyes cedex (France)

    2005-12-01

    The aim of this paper is to present a stochastic model to characterize the failure distribution of multi-unit systems when the current units state is imperfectly monitored. The definition of the hazard rate process existing with perfect monitoring is extended to the realistic case where the units failure time are not always detected (non-detection events). The so defined observed hazard rate process gives a better representation of the system behavior than the classical failure rate calculated without any information on the units state and than the hazard rate process based on perfect monitoring information. The quality of this representation is, however, conditioned by the monotony property of the process. This problem is mainly discussed and illustrated on a practical example (two parallel units). The results obtained motivate the use of the observed hazard rate process to characterize the stochastic behavior of the multi-unit systems and to optimize for example preventive maintenance policies.

  2. Predictors of mortality of patients with acute respiratory failure secondary to chronic obstructive pulmonary disease admitted to an intensive care unit: A one year study

    Directory of Open Access Journals (Sweden)

    Banga Amit

    2004-11-01

    Full Text Available Abstract Background Patients with acute exacerbation of chronic obstructive pulmonary disease (COPD commonly require hospitalization and admission to intensive care unit (ICU. It is useful to identify patients at the time of admission who are likely to have poor outcome. This study was carried out to define the predictors of mortality in patients with acute exacerbation of COPD and to device a scoring system using the baseline physiological variables for prognosticating these patients. Methods Eighty-two patients with acute respiratory failure secondary to COPD admitted to medical ICU over a one-year period were included. Clinical and demographic profile at the time of admission to ICU including APACHE II score and Glasgow coma scale were recorded at the time of admission to ICU. In addition, acid base disorders, renal functions, liver functions and serum albumin, were recorded at the time of presentation. Primary outcome measure was hospital mortality. Results Invasive ventilation was required in 69 patients (84.1%. Fifty-two patients survived to hospital discharge (63.4%. APACHE II score at the time of admission to ICU {odds ratio (95 % CI: 1.32 (1.138–1.532; p Conclusion APACHE II score at admission and SA levels with in 24 hrs after admission are independent predictors of mortality for patients with COPD admitted to ICU. The equation derived from these two parameters is useful for predicting outcome of these patients.

  3. Trends and Perspective in Industrial Maintenance Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    With increased global competition for manufacturing, many companies are seeking ways to gain competitative advanges with respect to cost, service, quality and on-time deliveries. The role that effective maintenance management plays in contributing to overall organizational productivity has received...... increased attention. Trends and perspective in industrial maintenance are presented. The result of benchmarking studies from Scandinavia and United States are also presented and compared. Case studies that examine maintenance methods, knowledge, organization and information systems in three Danish...

  4. Trends and Perspective in Industrial Maintenance Management

    DEFF Research Database (Denmark)

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

    1997-01-01

    With increased global competition for manufacturing, many companies are seeking ways to gain competitative advanges with respect to cost, service, quality and on-time deliveries. The role that effective maintenance management plays in contributing to overall organizational productivity has received...... increased attention. Trends and perspective in industrial maintenance are presented. The result of benchmarking studies from Scandinavia and United States are also presented and compared. Case studies that examine maintenance methods, knowledge, organization and information systems in three Danish...

  5. Reliability centered maintenance applied to the control rod drives of a nuclear power reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lyytikaeinen, A.; Holmberg, J. (Technical Research Centre of Finland, Espoo (Finland)); Unga, E. (Teollisuuden Voima Oy, Olkiluoto (Finland))

    1990-12-01

    Reliability Centered Maintenance (RCM) offers a hybrid reliability analysis methodology to evaluate the level of maintenance and direct the resources in an effective manner. The RCM analysis consists of several steps, including a Logic Tree Analysis (LTA) for identification of applicable and efficient preventive maintenance task. As a result of the analysis the total amount of maintenance of equipment is decreased or increased, depending on whether the failures are potential having adverse effects on plant safety, availability or economics. A RCM analysis results thus in an improved preventive maintenance program, which is supposed to decrease the maintenance and outage costs and at the same time increase the system safety and reliability. A problem is the relatively large and slow analysis effort, the fact which tends to inhibit the large scale and continuous application of this useful method. A case study is described, in which the control rod equipment at the TVO I/II nuclear units was analyzed and the problematics of the RCM-method is discussed. (au).

  6. Failure Probabilities and MR Performance Criteria versus variation in Surveillance Interval

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Tae Young; Yeom, Dong Un; Cho, Kung Su [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2010-10-15

    As a part of efforts to develop a fleet-wide Maintenance Rule program of Korea Hydro and Nuclear Power Co. (KHNP), we are developing a CANDU program. Three CANDU reactors were connected to the grid between July 1997 and October 1999. Initially, the same design and Technical Specifications were applied. One reactor (Unit A) has been operated by Plant 1 organization while the other two reactors (Units B and C) have been operated by a different organization of Plant 2. Each organization has different operating procedures and surveillance intervals, which influence the component reliabilities and Maintenance Rule performance criteria according to the variation in surveillance test intervals (STIs). This paper evaluates the influence of different surveillance test intervals on the Maintenance Rule program and component failure probability and recommends some considerations to prevent these problems

  7. Laboratory Maintenance of Acinetobacter baumannii.

    Science.gov (United States)

    Jacobs, Anna C; Zurawski, Daniel V

    2014-11-03

    Acinetobacter baumannii has recently drawn great interest in the microbiology research community due to the increase in clinical antibiotic resistance of this organism, and persistence of this bacterial species in the hospital environment. This unit outlines protocols for the growth and maintenance of A. baumannii in the laboratory.

  8. Time between failures model and failure analysis of CNC system

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hai-bo; JIA Ya-zhou; ZHOU Guang-wen

    2007-01-01

    To provide basis for the reliability improvement design of CNC system, the failure data of a type of CNC system in one year are collected under field conditions in workshops. The distribution model parameters of time between failures are estimated by least square method and hypothesis testing is done by d-test method. It is proved that the time between failures of the CNC system follows Weibull distribution and the system has entered into the wear-out failure period. The failure positions and failure causes are analyzed further to indicate the weak subsystems of the CNC system. It can be found that servo unit, electrical system, detecting unit and power supply are principal failure positions and the main failure cause is breakage of components. The corresponding improvement measures are put forward. The paper provides a reference to reliability design and analysis of CNC system for the manufacturer and has great guidance to using and maintaining CNC system for the user.

  9. A Review of Software Maintenance Technology.

    Science.gov (United States)

    1980-02-01

    is a concept that must be formalized. Class differentiation in this context implies that there are varying maintenance requirements among the classes...has been developed using a number of fundamental equations which relate failures experienced, present MTTF, MTTF objective, and time required to meet...34Scheduled Maintenance of Applications Software,’ Datamation, Volume 19, Number 5, May 1973, pp. 64-67. Liskov, B. and Zilles , S., "Specification

  10. Gearbox Typical Failure Modes, Detection, and Mitigation Methods (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, S.

    2014-01-01

    This presentation was given at the AWEA Operations & Maintenance and Safety Seminar and focused on what the typical gearbox failure modes are, how to detect them using detection techniques, and strategies that help mitigate these failures.

  11. AIRCRAFT MAINTENANCE HANGAR

    National Research Council Canada - National Science Library

    GEAMBASU Gabriel George

    2017-01-01

    .... 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...

  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. Standardized Curriculum for General Industrial Maintenance Trades.

    Science.gov (United States)

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    Standardized vocational education course titles and core contents for two courses in Mississippi are provided: general industrial maintenance trades I and II. The first course contains the following units: (1) orientation and leadership activities; (2) safety; (3) blueprint reading; (4) oxyacetylene cutting; (5) preventative maintenance; (6)…

  14. Planification de la maintenance d'un parc de turbines-alternateurs par programmation mathematique

    Science.gov (United States)

    Aoudjit, Hakim

    A growing number of Hydro-Quebec's hydro generators are at the end of their useful life and maintenance managers fear to face a number of overhauls exceeding what can be handled. Maintenance crews and budgets are limited and these withdrawals may take up to a full year and mobilize significant resources in addition to the loss of electricity production. In addition, increased export sales forecasts and severe production patterns are expected to speed up wear that can lead to halting many units at the same time. Currently, expert judgment is at the heart of withdrawals which rely primarily on periodic inspections and in-situ measurements and the results are sent to the maintenance planning team who coordinate all the withdrawals decisions. The degradations phenomena taking place is random in nature and the prediction capability of wear using only inspections is limited to short-term at best. A long term planning of major overhauls is sought by managers for the sake of justifying and rationalizing budgets and resources. The maintenance managers are able to provide a huge amount of data. Among them, is the hourly production of each unit for several years, the repairs history on each part of a unit as well as major withdrawals since the 1950's. In this research, we tackle the problem of long term maintenance planning for a fleet of 90 hydro generators at Hydro-Quebec over a 50 years planning horizon period. We lay a scientific and rational framework to support withdrawals decisions by using part of the available data and maintenance history while fulfilling a set of technical and economic constraints. We propose a planning approach based on a constrained optimization framework. We begin by decomposing and sorting hydro generator components to highlight the most influential parts. A failure rate model is developed to take into account the technical characteristics and unit utilization. Then, replacement and repair policies are evaluated for each of the components then

  15. VT Maintenance District Boundaries

    Data.gov (United States)

    Vermont Center for Geographic Information — Vermont has eight transportation maintenance districts which are responsible for all maintenance activities on state highways, and for providing technical assistance...

  16. Steam saving during maintenance of the 50-MW Unit 7 at Los Azufres geothermal field, Michoacan; Ahorro de vapor durante el mantenimiento de la Unidad 7 de 50 MW en el campo geotermico de Los Azufres, Michoacan

    Energy Technology Data Exchange (ETDEWEB)

    Medina Barajas, Elvia Nohemi; Ruiz Lemus, Alejandro [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres, Morelia, Michoacan (Mexico)]. E-mail: elvia-medina@cfe.gob.mx

    2011-07-15

    Commercial-steam production in the southern area of Los Azufres, Mich., Mexico, Geothermal Field began in 1982 with the operation of Unit 2, the backpressure 5-MW unit, and continued in 1988 when the 50-MW condensing Unit 7 was commissioned. Today to supply steam to Unit 7, it is necessary to gather steam from 15 production wells, amounting 450 tons per hour (t/h) under operating conditions. During maintenance periods for Unit 7, production wells are removed from the steam-supply system but continue producing steam that is discharged to the atmosphere-a loss affecting the economic life of the geothermal reservoir. Therefore several actions have been proposed and tried to save the steam and preserve the geothermal resource. This paper presents the results of the actions and the technical and economic benefits obtained from them. [Spanish] La produccion de vapor con fines comerciales en la zona sur del campo geotermico de Los Azufres, Mich., Mexico, empezo en 1982 con la puesta en marcha de la Unidad 2 de 5 MW a contrapresion, para continuar en 1988 con la Unidad 7 de 50 MW a condensacion. Para cumplir con el suministro de vapor a la U-7, a la fecha es necesario integrar la produccion de 15 pozos productores, que producen un total de 450 toneladas por hora (t/h) a condiciones de operacion. Durante los periodos de mantenimiento de la U-7 los pozos son desintegrados del sistema de suministro, pero continuan produciendo vapor, el cual es descargado a la atmosfera sin ningun provecho, lo que representa una perdida que afecta la vida util del yacimiento geotermico. Por ello se han propuesto y aplicado diversas acciones operativas en cada uno de esos pozos con el objetivo de ahorrar vapor y preservar el recurso geotermico. En este trabajo se presentan los resultados de esas acciones y los beneficios tecnicos y economicos obtenidos.

  17. Application of improved technologies for ensuring high quality in safety, maintenance and operation activities of units 5 and 6 of Kozloduy - a successful project

    Energy Technology Data Exchange (ETDEWEB)

    Naydenov, N. [Kozloduy NPP Units 5 and 6 Modernization Program, Kozloduy (Bulgaria); Hoch, G. [Kozloduy NPP Units 5 and 6 Modernization Program, AREVA NP GmbH, Erlangen (Germany); Krasnocharov, A. [Kozloduy NPP Units 5 and 6 Modernization Program, Dept. Manager, Kozloduy (Bulgaria)

    2007-07-01

    The Units 5 and 6 of Kozloduy Nuclear Power Plant (KNPP) became operative in 1987 and 1991, respectively. These units, consisting of a VVER-1000/320 type reactor, have design characteristics, basically elaborated in accordance with Russian rules and standards in force at the time of the design. In order to reach a full compliance with the international safety standards that evolved over the last two decades KNPP decided to introduce the Kozloduy Units 5 and 6 Modernization Program to upgrade the plant, with the main objective to bring the installation to a safety level compatible with current international practices. The Program comprises 212 individual modifications aimed at enhancing safety, reliability and operational conditions of both units. Some of the measures implemented are as follows: -) the replacement of the thermal insulation of equipment and pipelines in the containment, -) the replacement of the turbine condenser tube bundles with stainless steel tubes, -) the replacement of the in-core monitoring system, -) the implementation of new gas fire extinguishing system for the electronic cabinets, -) the implementation of protective measures and the enhancement of the supports of the main steam and feed water lines, -) the installation of a filtered ventilation system, -) the upgrading of the electrical equipment, and -) the installation of new technologies and equipment for facility status monitoring and preventive detection. The installation of the above mentioned systems is not only a change in design but is a long and complicated process that involves the achievement of thorough analysis of design condition and of the integration on new equipment in existing configuration. The Report draws special attention to the value of the experience gained upon the management and implementation of such large-scale and complex designs in the nuclear field.

  18. Maintenance Optimization of High Voltage Substation Model

    Directory of Open Access Journals (Sweden)

    Jan Gala

    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.

  19. Reliability-Based Maintenance and Inspection Planning for Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2004-01-01

    , local buckling of main tower, and failure of the foundation. This paper considers reliability-based optimal inspection and maintenance planning of wind turbines. Different formulations are considered of the objective function including benefits, building costs of the wind turbine, inspection...... and maintenance costs, and failure costs. Different reconstruction policies in case of failure are considered, including systematic reconstruction in case of failure, no reconstruction and failure of the control system. The concept of generic inspection and maintenance planning coupled with information from...... continuous monitoring is presented and illustrated. Illustrative examples for offshore wind turbines are presented, and as a part of the results optimal reliability levels for the different failure modes are obtained....

  20. Maintenance management at La Silla Paranal Observatory

    Science.gov (United States)

    Montano, Nelson

    2008-07-01

    From the beginning of the VLT project, the European Southern Observatory (ESO) considered the application of a competent maintenance strategy a fundamental aspect for future operations of the Paranal Observatory. For that purpose, a special maintenance philosophy was developed during the project stage and applied during the initial years of operations. The merging of the La Silla and Paranal Observatories in 2005 added a new managerial challenge to the regular operational requirements (high availability and reliability) which motivated ESO Management to develop a stronger strategy for the operations of the new merged Observatory. Part of the new strategy considered the creation of a dedicated department for the management of all maintenance activities, separating this support from the traditional scheme where the Engineering Department had the responsibility for the entire technical support to operations. In order to keep a competent level of maintenance operations for the new unified Observatory, the La Silla Paranal (LSP) Maintenance Department has been using a well known maintenance management model used in various industrial applications as a guide. Today the operations of the Maintenance Department are concentrated on developing and implementing practices regarding concepts such as Maintenance Tactics, Planning, Data Management, Performance Indicators and Material Management. In addition to that, advances related to Reliability Analysis been taken in order to reach a superior level of excellence. The results achieved by the LSP Maintenance Department are reflected in a reduced rate of functional failures, allowing uninterrupted operations of the Observation sites.

  1. 柔性制造系统(FMS)故障预测与健康管理视情维修系统研究%Research on Condition-based Maintenance System for Failure Prediction and Health Management in Flexible Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    赵中敏; 王茂凡

    2012-01-01

    现有的视情维修系统研究中缺乏对处于正常运行阶段的设备因加工过程操作不当所引起的运行故障进行预测维修.为提高柔性制造系统的使用寿命及使用效率,提出预测与健康管理视情维修的体系结构,构建柔性制造系统视情维修系统的功能框图并分析其工作流程;通过对设备运行状态信息融合,借助人工智能推理对柔性制造系统的状态监测、健康评估和故障预测方法进行了具体分析.该方案能够实现柔性制造系统故障的提前预测和剩余寿命计算,具有重要的工业推广价值.%In view of the lack of the capacity of prediction maintenance in existing condition-based maintenance system research, and considering this situation that, in normal operation phase, with wrong operation, equipments malfunction also occurred, the system structure of a modified condition-based maintenance system based on failure prediction and health management was proposed to increase service life and efficiency of flexible manufacturing system. Functional block diagram of the modified condition-based maintenance system was established and workflow was elaborated. Using data fusion technology and artificial intelligence reasoning, condition monitoring, health assessment and failure prediction were all analyzed in detail. The failure can be predicted in advance adopting the modified condition-based system, and the residual life can be calculated. So it has promotion value in industry.

  2. Designing a scrubber for maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Mahlmeister, M.E.; Baron, E.S. [New York State Electric and Gas Corp., Binghamton, NY (United States); Watts, J. [USDOE Pittsburgh Energy Technology Center, PA (United States)

    1996-12-01

    Under Round 4 of the U.S. Department of Energy`s (DOE) Clean Coal Technology program, New York State Electric & Gas Corporation (NYSEG), in partnership with Saarberg-Holter-Umwelttechnik (SHU), Consolidation Coal Company and Stebbins Engineering and Manufacturing Company, has retrofitted a formic acid enhanced forced oxidation wet limestone scrubber on Units I and 2 at the Milliken Steam Electric Station. Units I and 2 are 1950s vintage Combustion Engineering tangentially fired pulverized coal units, which are rated at nominal 150 MW each and operate in balanced draft mode. The Flue Gas Desulfurization (FGD) system for Unit 2 was placed into operation in January 1995 and the Unit I system in June 1995. The project incorporates several unique aspects: low pH operation; a ceramic tile-lined cocurrent/countercurrent, split module absorber; a wet stack supported on the roof of the FGD building; and closed loop, zero liquid discharge operation that produces commercial grade gypsum and calcium chloride brine. The project objectives include 98% SO{sub 2} removal efficiency while burning high sulfur coal, the production of marketable byproducts to minimize solid waste disposal, zero wastewater discharge, space-saving design, and minimization of maintenance requirements of a wet scrubber. The paper provides a brief overview of the project scrubber design relating to maintenance considerations. A discussion of the early results of the maintenance history is also provided. Repair techniques that have been developed and tested for ceramic tile lined modules are included. 1 fig.

  3. An advanced maintenance advisory and surveillance system for boiler tubes - AMASS

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, A.B. [ERA Technology Ltd, Leatherhead (United Kingdom)

    1998-12-31

    In a recently completed European collaborative project, the aim was to address the issue of boiler tube failures and thereby plant availability. The reduction of forced outages due to component failures and the reduction of planned outages for preventative maintenance can both contribute in this respect. It has been possible to assess tube degradation due to erosion, corrosion and overheating through the use of on-line techniques (thin layer activation, corrosion probes and novel temperature sensors) and off-line techniques (cold air velocity measurements, laser shearography and measurements of steam side oxide) which have been developed in the project. These techniques have been demonstrated on an oil fired boiler in Portugal and a coal fired unit in Spain. The output from the monitoring techniques has been integrated in the AMASS maintenance advisory and surveillance system. This is a computerised system comprising a spatial database with add-on tools designed to assess data from individual monitors and to provide the user with information on tube life utilisation rates and the probability of tube failure occurring. A description of the monitoring techniques will be described along with some of the results of demonstrating them in the field. Also an overview of the computerized system and the way in which it works will be given along with examples of how it can be used to assist with preventative maintenance and to help avoid unplanned outages. (orig.) 10 refs.

  4. Maintenance planning and organisation at Appin Colliery

    Energy Technology Data Exchange (ETDEWEB)

    Dawkins, G.; O`Brien, B. [Appin Colliery, Appin, NSW (Australia)

    1994-12-31

    At the modern Appin Colliery 2.5 million tonnes are produced per year by 390 employees from one longwall and four development units. The maintenance organisation has both mechanical and electrical departments. Recent BHP Collieries improvement initiatives have benefitted the maintenance organisation at Appin in many ways, particularly with senior management support, an effective maintenance business plan and documented programme. With accent on skills and teamwork, maintenance times, and therefore costs have been reduced. Heightened communication has led to more acute condition monitoring.

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

    OpenAIRE

    Mana Sezdi

    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...

  6. 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....

  7. 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....

  8. Maintenance and Condition-Based Maintenance

    Institute of Scientific and Technical Information of China (English)

    DING Jin-hua; WANG Xue-Jun; ZHOU Rong; LIN Min; Olsson Erland

    2005-01-01

    The evolution of maintenance management is briefly introduced in this paper, from corrective maintenance to preventive maintenance. First, a range of condition monitoring and fault diagnosis techniques developed in different industries are surveyed; Second, many methods of condition monitoring are presented; Third, mathematical methods used in condition monitoring are given; Then the merits and shortcomings are discussed.Efficient maintenance policies are of fundamental importance in system engineering because of their fallbacks into the safety and economics of plant operation. Applying condition-based maintenance to a system can reduce the cost and extend the availability of facilities. With the advent of personal computers as fast and cost effective machines for data acquisition and processing of multiple signals some shortcomings mentioned in condition monitoring could be solved or reduced to some extent. These PCs can be a solution as a condition monitoring based maintenance system.

  9. Heart Failure

    Science.gov (United States)

    ... heart failure due to systolic dysfunction. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ... patient with heart failure or cardiomyopathy. http://www.uptodate.com/home. Accessed Sept. 26, 2014. Colucci WS. ...

  10. DFTCalc: Reliability centered maintenance via fault tree analysis (tool paper)

    NARCIS (Netherlands)

    Guck, Dennis; Spel, Jip; Stoelinga, Mariëlle Ida Antoinette; Butler, Michael; Conchon, Sylvain; Zaïdi, Fatiha

    2015-01-01

    Reliability, availability, maintenance and safety (RAMS) analysis is essential in the evaluation of safety critical systems like nuclear power plants and the railway infrastructure. A widely used methodology within RAMS analysis are fault trees, representing failure propagations throughout a system.

  11. DFTCalc: reliability centered maintenance via fault tree analysis (tool paper)

    NARCIS (Netherlands)

    Guck, Dennis; Spel, Jip; Stoelinga, Mariëlle; Butler, Michael; Conchon, Sylvain; Zaïdi, Fatiha

    2015-01-01

    Reliability, availability, maintenance and safety (RAMS) analysis is essential in the evaluation of safety critical systems like nuclear power plants and the railway infrastructure. A widely used methodology within RAMS analysis are fault trees, representing failure propagations throughout a system.

  12. Operating and maintenance experience in tritium environments

    Energy Technology Data Exchange (ETDEWEB)

    Tuer, G.L.

    1987-01-01

    This presentation is a summary of practical experience gained over more than twenty years from analyzing failures of process equipment operated in tritium and deuterium environments. Significant improvements have been achieved in design and procurement of new equipment, testing and selection of materials, and gradually more favorable maintenance experience. Preferred materials and inspection methods are described. 6 tabs.

  13. Optimal condition-based maintenance strategy under periodic inspections for traction motor insulations

    Institute of Scientific and Technical Information of China (English)

    Jian ZHANG; Ji-en MA; Xiao-yan HUANG; You-tong FANG; He ZHANG

    2015-01-01

    目的:充分利用寿命信息,并考虑冲击效应对维修策略的影响,提出符合牵引电机绝缘运行特征的最优视情维修策略。  方法:1.采用正常状态、潜在故障状态与功能故障状态描述牵引电机绝缘运行状况;2.应用泊松过程描述随机高电压冲击;3.以单位时间的运行成本为目标函数,以监测间隔和预防性维修寿命阈值为优化变量,建立最优视情维修决策模型。  结论:该模型能显著降低牵引电机绝缘功能故障的风险,同时降低单位时间运行成本。%Insulation failure is a crucial failure mode of traction motors. Insulation deteriorates under both fatigue load and shock. This paper focuses on proposing an optimal insulation condition-based maintenance strategy. By combining the infor-mation obtained from periodic inspections with historic life information, an integrated model of time-based maintenance and condition-based model is proposed, in which random shocks following Poisson process are also taken into account. In this model we define that insulation has three states: normal state, latent failure state, and functional failure state. Normal state and latent failure state differ in their operating cost, proneness to functional failure, and survival probability under extreme shocks. Preven-tive maintenance (PM) will be launched if an inspection result exceeds the threshold or if the operating time reaches the critical age. One operating cycle ends as soon as a preventive maintenance or a corrective maintenance is completed. Moreover, an op-timization model is established, which takes minimal cost per unit time as the objective, and inspection interval and critical age as the optimization variables. Finally, a numerical example illustrates the analytic results.

  14. 76 FR 55364 - Rules for Patent Maintenance Fees

    Science.gov (United States)

    2011-09-07

    ... United States Patent and Trademark Office Rules for Patent Maintenance Fees ACTION: Proposed collection... or after December 12, 1980. Payment of these maintenance fees is due at 3\\1/2\\, 7\\1/2\\, and 11\\1/2... maintenance fee and any applicable surcharge within a grace period of six months following each of the...

  15. 78 FR 20619 - Customer Account Registration and Maintenance

    Science.gov (United States)

    2013-04-05

    ... United States Patent and Trademark Office Customer Account Registration and Maintenance ACTION: Proposed... Maintenance'' in the subject line of the message. Mail: Susan K. Fawcett, Records Officer, Office of the Chief... Customer Profile Account Request and 12 minutes 5,000 1,000 Maintenance. Correspondence and...

  16. Proactive maintenance for mechanical systems

    CERN Document Server

    Fitch, EC

    1992-01-01

    Written by Dr. E.C. Fitch, the book contains over 340 double column pages which include 400 figures and tables, a comprehensive bibliography, and index. There is no root cause of mechanical failure, known to the author, that has been ignored or left out. Nowhere in the world is this information put together in such a concise and comprehensive manner, and the book will serve as a reference and guide to designers, practising engineers, maintenance technicians, plant managers and operators who must design, maintain and operate fluid-dependent mechanical systems.

  17. Autonomous and professional maintenance in metallurgical enterprise as activities within total productive maintenance

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2014-04-01

    Full Text Available The content of this publication consists of notions connected with Total Productive Maintenance (TPM in metallurgical enterprise. The basic areas of devices condition management through Autonomous and Professional Maintenance are described here. Mentioned areas of activities are performed in metallurgical enterprise ArcelorMittal Poland within pillars of World Class Manufacturing (WCM. The aims of UR programs are to maintain the basic functionality of the devices and decrease the number of failures in order to reach improvement of production efficiency.

  18. Predictive maintenance of maritime systems : models and challenges

    NARCIS (Netherlands)

    Tinga, T.; Tiddens, W.W.; Amoiralis, F.; Politis, M.; Cepin, Marko; Bris, Radim

    2017-01-01

    To reduce maintenance and logistic costs and increase the asset availability, a predictive maintenance concept for maritime systems is developed. In the present paper, the physics-of-failure based prognostic methods will be introduced, but also other issues related to the development and application

  19. RELIABILITY EVALUATION AS A MEANS OF INCREASING THE EFFICIENCY OF EQUIPMENT MAINTENANCE

    OpenAIRE

    Vladimír Stuchlý; Roman Poprocký; Malgorzata Kaczmarek

    2016-01-01

    Quality assurance of production and the associated maintenance systems have changed a lot for recent decades and are subject to change requirements for reliability – Reliability and Availability of machinery and equipment subject to the optimal maintenance costs. The paper deals with design options and assessment of the maintenance system intended method of reliability-oriented maintenance and maintenance costs. They use the methods of statistical and probabilistic analyzes of data on failure...

  20. Nuclear Power Plant Maintenance Optimization with Heuristic Algorithm

    OpenAIRE

    Andrija Volkanovski; Leon Cizelj

    2014-01-01

    The test and maintenance activities are conducted in the nuclear power plants in order to prevent or limit failures resulting from the ageing or deterioration. The components and systems are partially or fully unavailable during the maintenance activities. This is especially important for the safety systems and corresponding equipment because they are important contributors to the overall nuclear power plant safety. A novel method for optimization of the maintenance activities in the nuclear ...

  1. Positioning embedded software maintenance within industrial maintenance

    OpenAIRE

    Karim, Ramin; Kajko-Mattsson, Mira; Söderholm, Peter; Candell, Olov; Tyrbern, Tommy; Öhlund, Hans; Johansson, Jan

    2008-01-01

    Little is known about of how software embedded in complex industrial technical systems is maintained. In this paper, we identify industrial maintenance process steps and position software maintenance activities within them. We do this in the context of JAS 39 Gripen, a multi-role combat aircraft developed by Saab.

  2. An Improved Logic Diagram of RCM with the Proactive Maintenance

    Institute of Scientific and Technical Information of China (English)

    SONG Wenyuan; KANG Jianshe; WEN Liang; HONG Qing

    2006-01-01

    For some repeatedly occurring failure with root cause, the reliability centered maintenance (RCM) can't deal with them effectively. So, the logic diagram of RCM was improved by combining it with proactive maintenance technology. First, root cause analysis is used to build a key result-cause chain of the repeatedly occur failure. Then, a reasonable link in the chain, which work station is suitable to be monitored and repaired, should be selected. Finally, the corresponding proactive maintenance measure should be adopted to prevent the matter occur on the chain and broken the key result-cause chain, and the repeatedly occur failure is to be prevent at a deeper level or from the root cause. By doing this, a system engineering method comes into being, not only it can determine the needs of preventive maintenance for equipment, but also determine the proactive maintenance needs for equipment. The analysis result of reliability centered maintenance and the analysis result considering proactive maintenance are combined to form a maintenance guideline containing proactive maintenance strategy.

  3. 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.

  4. Evaluation of Common Maintenance Methods for Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Asma T. Ibraheem

    2011-01-01

    Full Text Available Problem statement: With the increasing use and awareness of pavement management systems and the growing emphasis on asset management of pavement infrastructure, it is important to strengthen the maintenance components of these systems and particularly the preventive maintenance component. Iraqi Roads don’t receive an effective and proper maintenance during their service life until they reach the state of major failure that requires rehabilitation. Roads in Iraq are being lost. Approach: In this study, a study of the status of maintenance methods for road pavements in Iraq with special reference to flexible pavements is presented. For this purpose, open and closed questionnaires were executed in Baghdad to investigate the status of road pavement maintenance in Iraq. Road maintenance offices as (Ministry of construction and Housing, State Corporation for Roads and Bridges, Amanat Baghdad, Project office, were included in the questionnaire to arrive at the level of maintenance and techniques followed to maintain paved road in Iraq. Results: The interviews carried out reveal that maintenance in Iraq has secondary importance, apparently with no special budget allocated for such important works. In addition the maintenance methods and techniques followed do not comply the developments and modern techniques. Conclusion/Recommendations: Poor and miss-management of maintenance works and activities leading to delays and accumulation of failure in the highway network that require unusual expenditures to repair and maintain the accumulated damages. Also shortages in resources allocated for maintenance works and this leads to the diversion of significant portion of the allocated fund for maintenance works toward purchasing of new, or additional equipment to be used for the construction of new roads. It is strongly recommended to design a planning system for management pavement maintenance of road network in Iraq and develop a particular failure criterion

  5. Rural road maintenance management

    OpenAIRE

    Johannessen, B.

    1999-01-01

    This manual summarizes relevant Cambodian government policies regarding rural road maintenance. Chapter 2 defines the various components of road maintenance and describes an effective strategy and organization which addresses the maintenance requirements of rural roads in Cambodia. Chapter 3 is a brief description of the planning, implementation and reporting cycle required in an effective road maintenance management system. Chapter 4 summarizes the contracts management procedures, and finall...

  6. CONTEXT DRIVEN MAINTENANCE: AN eMAINTENANCE APPROACH

    Directory of Open Access Journals (Sweden)

    Diego GALAR

    2014-07-01

    Full Text Available All assets necessarily suffer wear and tear during operation. Prognostics can assess the current health of a system and predict its remaining life based on features capturing the gradual degradation of its operational capabilities. Prognostics are critical to improve safety, plan successful work, schedule maintenance, and reduce maintenance costs and down time. Prognosis is a relatively new area but has become an important part of Condition‐based Maintenance (CBM of systems. As there are many prognostic techniques, usage must be attuned to particular applications. Broadly stated, prognostic methods are either data‐driven, rule based, or model‐based. Each approach has advantages and disadvantages; consequently, they are often combined in hybrid applications. A hybrid model can combine some or all model types; thus, more complete information can be gathered, leading to more accurate recognition of the fault state. This approach is especially relevant in systems where the maintainer and operator know some of the failure mechanisms, but the sheer complexity of the assets precludes the development of a complete model‐based approach. The paper addresses the process of data aggregation into a contextual awareness hybrid model to get RUL values within logical confidence intervals so that the life cycle of assets can be managed and optimised.

  7. Systems failure.

    OpenAIRE

    Macleod, Anna

    1998-01-01

    Systems Failure A solo exhibition of new work by Anna Macleod developed in conversation with curator Liz Burns. The Dock, Carrick on Shannon, Co Leitrim. Ireland. 12th February – 17th April 2010. The works for the exhibition Systems Failure include drawings, prints and small constructions that examine the delicate balance that exists between need and aspects of failure rooted in the relationship between humanity and land use. The work seeks to question the relationship between scient...

  8. 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…

  9. SCOPE : an intelligent maintenance system for supporting crew operations

    NARCIS (Netherlands)

    Bos, A.; Breebaart, L.; Neerincx, M.A.; Wolff, M.

    2004-01-01

    This paper describes an intelligent maintenance system for Supporting Crew OPErations (SCOPE). SCOPE supports the astronauts onboard the ISS and helps them to maximize the availability of complex payload systems. SCOPE detects system failures, guides the isolation of the root causes of failure, and

  10. 浅谈自动包装机在医药行业的作用与维护保养%Function and Maintenance of Automatic Packaging Unit for the Pharmaceuticals Industry

    Institute of Scientific and Technical Information of China (English)

    焦海智

    2014-01-01

    自动定量包装机是目前医药行业比较常用的新型包装设备,该机性能稳定、结构紧凑、造型美观、自动化程度高,适用于胶襄、片剂等药品的泡罩式铝塑复合密封包装。根据工作经验浅谈自动定量包装机的作用与维护保养,希望能为相关人员提供有效借鉴。%Automatic quantitative packaging machine is the new packaging unit that are widely used in the pharmaceutical industry . This machine has stable performance ,compact structure ,beautiful appearance and high automation degree ,which is suitable for capsule , tablet and other pharmaceutical blister type aluminum-plastic composite seal packing . According to the working experience ,this paper discusses functions of automatic quantitative packaging machine maintenance , which hopes to provide effective references .

  11. Effective maintenance practices to manage system aging

    Science.gov (United States)

    Chockie, Alan; Bjorkelo, Kenneth

    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 of maintenance programs on addressing the system and component aging degradation issues. An effective maintenance program was found to be essential to the management of system and component aging. Four key elements of an effective maintenance program that are important to an aging management were identified: (1) the selection of critical systems and components; (2) the development of an understanding of aging through the collection and analysis of equipment performance information; (3) the development of appropriate preventive and predictive maintenance tasks to manage equipment and system aging degradation; and (4) 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.

  12. [Guidelines for specialized nutritional and metabolic support in the critically-ill patient. Update. Consensus of the Spanish Society of Intensive Care Medicine and Coronary Units-Spanish Society of Parenteral and Enteral Nutrition (SEMICYUC-SENPE): respiratory failure].

    Science.gov (United States)

    Grau Carmona, T; López Martínez, J; Vila García, B

    2011-11-01

    Severe acute respiratory failure requiring mechanical ventilation is one of the most frequent reasons for admission to the intensive care unit. Among the most frequent causes for admission are exacerbation of chronic obstructive pulmonary disease and acute respiratory failure with acute lung injury (ALI) or with criteria of acute respiratory distress syndrome (ARDS). These patients have a high risk of malnutrition due to the underlying disease, their altered catabolism and the use of mechanical ventilation. Consequently, nutritional evaluation and the use of specialized nutritional support are required. This support should alleviate the catabolic effects of the disease, avoid calorie overload and, in selected patients, to use omega-3 fatty acid- and antioxidant-enriched diets, which could improve outcome.

  13. 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

  14. 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.

  15. 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.)

  16. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  17. Determination of Time for Conducting Preventive Maintenance Using Hybrid Analysis

    Institute of Scientific and Technical Information of China (English)

    SUN Yong; Lin MA; Joseph Mathew

    2004-01-01

    It becomes a common practice to determine time for conducting preventive maintenance (PM) using a hazard function and an alarm limit on a specified failure rate. In this paper, the authors argue that using both hazard and reliability functions can improve the accuracy of the result, especially when the whole-life characteristic failure is modelled using different failure distributions. The PM time predicted based on the hazard function should be checked against reliability.

  18. Orem自理模式在维持性血液透析并发心力衰竭护理中的应用%The Application of Orem Self-care Model in the Maintenance Hemodialysis Concurrent Heart Failure Care

    Institute of Scientific and Technical Information of China (English)

    陆娟

    2012-01-01

      目的探讨 Orem 自护理论在维持性血液透析并发心力衰竭护理中的作用。方法对维持性透析并发心力衰竭6例患者分别通过全补偿系统、部分补偿系统、支持—教育系统进行护理。结果4例患者能下床且生活自理,1例患者在床上自理,1例患者因经济原因自动出院。结论运用 Orem 自护理论指导血液透析并发心力衰竭患者的护理,有效提高其自理能力和自我管理能力,减轻抑郁,提高其生活质量。%  Objective To investigate the Orem of self-care theory in patients with maintenance hemodialysis complicated with heart failure care in rats. Methods for maintaining hemodialysis complicated with heart failure in 6 patients respectively through the compensation system, compensation system, support and education system for nursing. Results 4 patients could get out of bed and self-care,1 patients in bed and self-care,1 patients because of economic reasons automatic discharge. Conclusion the application of Orem self-care theory to guide the hemodialysis nursing care for patients with heart failure, effectively improve the self-care ability and self management ability, alleviate depression, improve their quality of life.

  19. Spare parts inventory risk for decision making in plant maintenance

    Science.gov (United States)

    Sharif, Kamal Imran; Ibrahim, Jafni Azhan; Udin, Zulkifli Mohamed

    2016-08-01

    Equipment breakdown due to unavailability of spare parts is really disastrous in plant maintenance. The failure increase the cost of repair and production downtime. Therefore, it is important to understand the maintenance and inventory function in order to ensure the plant operate accordingly. Moreover, it is necessary for the plant maintenance to balance the issue of shortage and excess of inventory in plant maintenance. In view of this situation, the spare parts become a critical matters and it is good starting point to tackle the issues from looking at the perspective of spare parts inventory risk. This paper describes the development of risk technique for plant maintenance decision making purposes using the Shortage and Excess Impact Table. It also used the Breakdown Probability Table to quantify the risk for the spare part failure.

  20. Technical information report: Plasma melter operation, reliability, and maintenance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, D.W. [ed.

    1995-03-14

    This document provides a technical report of operability, reliability, and maintenance of a plasma melter for low-level waste vitrification, in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. A process description is provided that minimizes maintenance and downtime and includes material and energy balances, equipment sizes and arrangement, startup/operation/maintence/shutdown cycle descriptions, and basis for scale-up to a 200 metric ton/day production facility. Operational requirements are provided including utilities, feeds, labor, and maintenance. Equipment reliability estimates and maintenance requirements are provided which includes a list of failure modes, responses, and consequences.

  1. 合成氨装置变换单元减温器开裂失效分析%ANALYSIS OF CAUSES FOR CRACKING FAILURE OF DESUPERHEATERIN SHIFT-CONVERSION UNIT OF AMMONIA PLANT

    Institute of Scientific and Technical Information of China (English)

    左清; 周群群

    2011-01-01

    Causes for cracking failure of desuperheater in shift-conversion unit of ammonia plant are analyzed based on both macro-check and micro detection and necessary solutions adopted to ensure a safe running of desuperheater.%从宏观检查和微观检测分析了合成氨装置变换单元减温器开裂失效的原因,采取必要的解决措施,保证了减温器安全运行。

  2. Studying the Advance Maintenance Practice & Computerised Maintenance

    Directory of Open Access Journals (Sweden)

    Eng Hamdy Ibrahim Mohamed Mahmoud

    2016-02-01

    Full Text Available Many companieѕ think of maintenance aѕ an inevitable ѕource of coѕt. For theѕe companieѕ maintenance operationѕ have a corrective function and are only executed in emergency conditionѕ. Today, thiѕ form of intervention iѕ no longer acceptable becauѕe of certain critical elementѕ ѕuch aѕ product quality, plant ѕafety, and the increaѕe in maintenance department coѕtѕ which can repreѕent from 15 to 70% of total production coѕtѕ. The managerѕ have to ѕelect the beѕt maintenance policy for each piece of equipment or ѕyѕtem from a ѕet of poѕѕible alternativeѕ. For example, corrective, preventive, opportuniѕtic, condition-baѕed and predictive maintenance policieѕ are conѕidered in thiѕ paper.

  3. Analysis of Emergency Diesel Generators Failure Incidents in Nuclear Power Plants

    Science.gov (United States)

    Hunt, Ronderio LaDavis

    In early years of operation, emergency diesel generators have had a minimal rate of demand failures. Emergency diesel generators are designed to operate as a backup when the main source of electricity has been disrupted. As of late, EDGs (emergency diesel generators) have been failing at NPPs (nuclear power plants) around the United States causing either station blackouts or loss of onsite and offsite power. These failures occurred from a specific type called demand failures. This thesis evaluated the current problem that raised concern in the nuclear industry which was averaging 1 EDG demand failure/year in 1997 to having an excessive event of 4 EDG demand failure year which occurred in 2011. To determine the next occurrence of the extreme event and possible cause to an event of such happening, two analyses were conducted, the statistical and root cause analysis. Considering the statistical analysis in which an extreme event probability approach was applied to determine the next occurrence year of an excessive event as well as, the probability of that excessive event occurring. Using the root cause analysis in which the potential causes of the excessive event occurred by evaluating, the EDG manufacturers, aging, policy changes/ maintenance practices and failure components. The root cause analysis investigated the correlation between demand failure data and historical data. Final results from the statistical analysis showed expectations of an excessive event occurring in a fixed range of probability and a wider range of probability from the extreme event probability approach. The root-cause analysis of the demand failure data followed historical statistics for the EDG manufacturer, aging and policy changes/ maintenance practices but, indicated a possible cause regarding the excessive event with the failure components. Conclusions showed the next excessive demand failure year, prediction of the probability and the next occurrence year of such failures, with an

  4. 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...

  5. Framework for Maintenance Planning

    DEFF Research Database (Denmark)

    Soares, C. Guedes; Duarte, J. Caldeira; Garbatov, Y.;

    2010-01-01

    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...... 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...... 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...

  6. Framework for Maintenance Planning

    DEFF Research Database (Denmark)

    Duarte, J. Caldeira; Garbatov, Y.; Zio, E.

    2010-01-01

    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...... 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...... 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...

  7. 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)

  8. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008275 Relationship of calcineure in mRNA level in peripheral blood and cardiac muscle of patients with heart failure.WANG Mengmeng(王萌萌),et al.Dept Cardiol,Shandong Prov Hosp,Shandong Univ,Jinan 250021.Chin Cir J 2008;23(2):113-116.Objective To study the relationship of calcineurin mRNA level between peripheral lymphocytes and cardiac muscles of patients with chronic heart failure.Methods

  9. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008037 Factors associated with efficacy of cardiac resynchronization therapy for patients with congestive heart failure. SHI Haoying(史浩颖), et al. Dept Cardiol, Zhongshan Hosp Fudan Univ, Shanghai 200032. Chin J Cardiol 2007;35(12):1099-1163. Objective The efficacy of cardiac resynchronization therapy (CRT) in patients with congestive heart failure and the potential factors associated with responder or nonresponder were investigated. Methods Fifty

  10. 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...

  11. Examining maintenance responsibilities.

    Science.gov (United States)

    Lam, K C

    2001-06-01

    This paper has examined the important responsibilities of the two organisations involved in the provision of maintenance service for the vital building services in many of our highly serviced buildings. The issues raised could be put to beneficial use in both clients and maintenance providers. All in all, the clients should work closely with their maintenance providers. Engineering services in buildings will not perform satisfactorily and efficiently if both parties do not work together and understand the maintenance tasks based on a business partnering mode. Put forward is the view that the management of the activities involved in the operation and maintenance process is a "shared commitment/involvement" between the client and the maintenance provider. It is obvious that many factors can influence the continued effectiveness of a quality maintenance scheme set up by client and provider. Some of these factors are: Change in key personnel Updates in technology Amendments to engineering practice Implementation of legislative requirements Changes in operation by client or provider Change of use of building Passage of time These factors must be fully reviewed by both parties from time to time, and necessary actions taken. A cooperative team working relationship and improved communication should be fostered by the client and his provider for the best management of services maintenance. This arrangement will contribute to better building services systems with continuous improvement; improved value for clients and higher return for the maintenance provider.

  12. Software Maintenance Success Recipes

    CERN Document Server

    Reifer, Donald J

    2011-01-01

    Dispelling much of the folklore surrounding software maintenance, Software Maintenance Success Recipes identifies actionable formulas for success based on in-depth analysis of more than 200 real-world maintenance projects. It details the set of factors that are usually present when effective software maintenance teams do their work and instructs on the methods required to achieve success. Donald J. Reifer--an award winner for his contributions to the field of software engineering and whose experience includes managing the DoD Software Initiatives Office--provides step-by-step guidance on how t

  13. Based on DCS System Failure Analysis of the Nuclear Island Fast Maintenance Strategy%基于DCS故障分析的核岛系统快速维护策略

    Institute of Scientific and Technical Information of China (English)

    赵鸿斌; 宫爱成; 王争光

    2015-01-01

    由于DCS的故障和维修时间对核电站的影响范围较大,所以研究核岛工艺系统在DCS故障下快速维护,尽量缩短DCS不可用时间就十分有意义.核岛工艺设计者通过对DCS和IO卡件技术原理的学习,研究DCS IO卡件故障原理,基于单一设备故障的假设,综合考虑DCS缺省值及系统失电分析的研究成果,分析得出卡件故障后状态及对核岛工艺系统的影响.另外还可假设特定工况,将相关影响进行叠加,最终得出各类卡件在单一故障或特定故障下对核岛工艺系统的影响以及对应DCS卡件的快速维护及恢复的策略.此策略可以用于指导运行维修人员对DCS 卡件故障的快速维修和恢复,也可以用于开发基于专用计算机的DCS卡件的维修平台.%Current nuclear technology has entered the third generation technology, The DCS is the logo of nuclear power advanced technology. It's Widely used in the nuclear power plant digital control system today, the study of the nuclear island systems under specified fault conditions in the DCS system, based on the results of the impact analysis of DCS fault, the research of DCS quickly maintenance and restoration to the normal state strategies has great signification , it can increasing the reliability of nuclear power plant operation and improving the economics of nuclear power plants.

  14. Determinación de las Prioridades de Mantenimiento en Turbogeneradores “Elektrosila TBФ-100-3600-T3” a partir del Comportamiento de sus Fallos; Determination of Maintenance Priorities in Turbogenerators “Elektrosila TBФ- 100-3600-T3” Based on their Failure

    Directory of Open Access Journals (Sweden)

    Odalys Martínez Rodríguez

    2012-11-01

    Full Text Available Los generadores de potencia son de gran importancia para la producción de electricidad. Un fallo en un generador ocasiona la interrupción de su servicio, limitaciones o pérdida total de la energía generada, tiene efectos negativos sobre la economía y afecta la calidad de la vida de la sociedad. Ello conduce a la necesidad un control estricto de los generadores y sus sistemas, tal que faciliten la detección temprana de desviaciones en sus parámetros de operación e intervenir apropiadamente para impedir la ocurrencia de una avería. Este trabajo tiene como objetivo presentar los resultados de tres variantes empleadas en la determinación de las prioridades de mantenimiento de los turbogeneradores “ELEKTROSILA TBФ-100-3600-T3”, las variantes estudiadas fueron: el comportamiento histórico de los fallos, el comportamiento histórico de la energía indisponible debido a los fallos y el análisis de criticidad; los resultados, sustentados en seis años de estudio, descartaron la utilización del criterio de energía indisponible.  The power generators are very important for the electricity production. A failure in a generator causes the interruption of service, limitations or the complete loss of the generated energy, has negative effects on theeconomy and it harms quality of life of the society. This leads to the necessity of a strict control of the generators as in their systems, such that facilitates the early detection of any deviation on their operationparameters to intervene appropriately and avoid the occurrence of a failure. This paper has the objective to present the results of three variants used in the determination of the priorities of maintenance of theturbogenerators "ELEKTROSILA TBФ-100-3600-T3", the analyzed variants were: the historical behavior of failures, the historical behavior of the unavailable energy due to failures and the analysis of criticality; theobtained results, supported in six years of study, discard

  15. Risk-Based Operation and Maintenance of Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Nielsen, Jannie Sønderkær

    maintenance costs, and many studies have also been published for preventive maintenance. However, an important part is the modeling of the relationship between maintenance and reliability, which is typically not modeled in a consistent way. Therefore, the methods cannot be used directly for optimal......For offshore wind turbines, maintenance costs are substantial due to a large number of component failures. In addition to the repair costs, equipment costs and lost production costs are large due to limited accessibility to the turbines. In order to reduce the costs, preventive methods can be used......, but presently maintenance is not planned using advanced methods taking all available information into account in a consistent manner. Maintenance decisions can be made based on risk-based methods, where the total expected life cycle costs are minimized. Methods have been developed for assessing the corrective...

  16. Survey of maintenance policies for the Last 50 Years

    Directory of Open Access Journals (Sweden)

    Asis Sarkar

    2011-08-01

    Full Text Available In the past several decades, maintenance and replacement problems have been extensively studied inthe literature. Thousands of maintenance and replacement models have been created. However, all thesemodels can fall into some categories of maintenance policies: age replacement policy, block replacementpolicy, periodic preventive maintenance policy, failure limit policy, sequential preventive maintenancepolicy, repair cost limit policy, repair time limit policy, repair number counting policy, reference timepolicy, mixed age policy, group maintenance policy, opportunistic maintenance policy, etc. Each kind ofpolicy has different characteristics, advantages and disadvantages with lot of contributions fromResearch scientist, Technologists... This survey summarizes, classifies, and compares various existingmaintenance policies Around 170 Authors and their research works are presented in the Referencesection. It will help to look into the different policies which is appropriate to the organization and forfurther study the reference section will be helpful for the researchers for further knowledge

  17. Optimal interval for major maintenance actions in electricity distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Louit, Darko; Pascual, Rodrigo [Centro de Mineria, Pontificia Universidad Catolica de Chile, Av. Vicuna MacKenna, 4860 Santiago (Chile); Banjevic, Dragan [Centre for Maintenance Optimization and Reliability Engineering, University of Toronto, 5 King' s College Rd., Toronto, Ontario (Canada)

    2009-09-15

    Many systems require the periodic undertaking of major (preventive) maintenance actions (MMAs) such as overhauls in mechanical equipment, reconditioning of train lines, resurfacing of roads, etc. In the long term, these actions contribute to achieving a lower rate of occurrence of failures, though in many cases they increase the intensity of the failure process shortly after performed, resulting in a non-monotonic trend for failure intensity. Also, in the special case of distributed assets such as communications and energy networks, pipelines, etc., it is likely that the maintenance action takes place sequentially over an extended period of time, implying that different sections of the network underwent the MMAs at different periods. This forces the development of a model based on a relative time scale (i.e. time since last major maintenance event) and the combination of data from different sections of a grid, under a normalization scheme. Additionally, extended maintenance times and sequential execution of the MMAs make it difficult to identify failures occurring before and after the preventive maintenance action. This results in the loss of important information for the characterization of the failure process. A simple model is introduced to determine the optimal MMA interval considering such restrictions. Furthermore, a case study illustrates the optimal tree trimming interval around an electricity distribution network. (author)

  18. Assessment of the Reliability ofFractionator Column of the Kaduna Refinery using Failure Modes Effects and Criticality Analysis (FMECA

    Directory of Open Access Journals (Sweden)

    Ibrahim A

    2016-06-01

    Full Text Available —The reliability of a process equipment is the probability that an item will perform a required function under stated condition(s. It is an important issue in any process industry. Failure to assess the reliability of most process equipment had led to huge financial losses. As a result, this research aims at assessing the reliability of the Fractionator column of the Kaduna Refining and Petrochemicals (KRPC, Fluid Catalytic Cracking Unit (FCCU, using the Failure mode, effects and criticality analysis (FMECA. The failure mode effects analysis (FMEA was firstused to identify failure modes, mechanisms, cause, effects severity of the fractionator column through its fourteen (14 sub-units(fractionator primary condenser, bottoms product cooler, debutanizer oil condenser, main fractionator, main fractionator oil drum, main fractionator reflux drum, heavy naphtha exchanger, heavy cycle oil exchanger, bottoms exchanger, BFW heater, steam generator, stripper reboiler, debutanizer reboiler, top reflux pumps. Both quantitative and qualitative criticality analyses (CA were used to determine the effectiveness and reliability of the unit (Fractionator column. For the qualitative analysis, items risk priority number (RPN were computed and it was found that, six (6 of the sub-units (feed/ main fractionator bottoms exchanger, main fractionator reflux drum, main fractionator bottoms pumps, feed/ heavy naphtha exchanger, main fractionator, and main fractionator bottoms/BFW heater had their RPN>300, with feed/ main fractionator bottoms exchanger having the highest RPN of 460. For the quantitative analysis, items criticality number (Cr were computed and it was found that most of the sub-units had their Cr>0.002. In addition, the results of the criticality matrix showed that, fifteen (15 out of the twenty nine (29 failure modes identifiedwere above or closely below the criticality line. Therefore, the effectiveness and reliability of the unit is low. As such, sub-units

  19. Stochastic maintenance optimization at Candu power plants

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, E.K. [Bruce Power, Tiverton (Canada); Duchesne, T. [Departement de mathematiques et de statistique, Universite Laval, Quebec (Canada); Lee, C.G. [Department of Mechanical and Industrial Engineering, University of Toronto (Canada); Cho, D.I. [Faculty of Business, Brock University, St. Catherines, (Canada)

    2004-07-01

    The use of various innovative maintenance optimization techniques at Bruce has lead to cost effective preventive maintenance applications for complex systems as previously reported at ICONE 6 in New Orleans (1996). Further refinement of the station maintenance strategy was evaluated via the applicability of statistical analysis of historical failure data. The viability of stochastic methods in Candu maintenance was illustrated at ICONE 10 in Washington DC (2002). The next phase consists of investigating the validity of using subjective elicitation techniques to obtain component lifetime distributions. This technique provides access to the elusive failure statistics, the lack of which is often referred to in the literature as the principal impediment preventing the use of stochastic methods in large industry. At the same time the technique allows very valuable information to be captured from the fast retiring 'baby boom generation'. Initial indications have been quite positive. The current reality of global competition necessitates the pursuit of all financial optimizers. The next construction phase in the power generation industry will soon begin on a worldwide basis. With the relatively high initial capital cost of new nuclear generation all possible avenues of financial optimization must be evaluated and implemented. (authors)

  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. School failure.

    Science.gov (United States)

    Dworkin, P H

    1989-04-01

    Numerous factors may contribute to a child's failure to learn. Certain causes of school failure, such as specific learning disabilities, mental retardation, sensory impairment, and chronic illness may be regarded as intrinsic characteristics of the child. Other causes, such as family dysfunction, social problems, and ineffective schooling, are characteristics of the child's environment. Still other influences on school performance, such as temperamental dysfunction, attention deficits, and emotional illness, may be viewed as the consequence of the interaction between the child and his or her environment. The reasons for a child's school failure must not be considered in isolation but rather within the context of social and environmental circumstances. Evaluation must consider the myriad of reasons for a child's school failure and attempt to identify "clusters" of adverse influences on school performance. Detailed information must be sought from the student, parents, and school system through the history and physical examination. Questionnaires are useful in data gathering. Ancillary methods of assessment that may be of value include neurodevelopmental screening and laboratory studies. Further investigations and referrals, particularly psychoeducational evaluation, are of major importance. Traditional roles of the pediatrician in school failure include the treatment of underlying medical conditions, counseling, the coordination of further investigations and referrals, and the facilitation of communication with community services and resources. Participation with other disciplines in the development of a child's educational plan is feasible and useful.

  2. Mitochondrial DNA maintenance: an appraisal.

    Science.gov (United States)

    Akhmedov, Alexander T; Marín-García, José

    2015-11-01

    Mitochondria play a crucial role in a variety of cellular processes ranging from energy metabolism, generation of reactive oxygen species (ROS), and Ca(2+) handling to stress responses, cell survival, and death. Malfunction of the organelle may contribute to the pathogenesis of neuromuscular disorders, cancer, premature aging, and cardiovascular diseases, including myocardial ischemia, cardiomyopathy, and heart failure. Mitochondria are unique as they contain their own genome organized into DNA-protein complexes, so-called mitochondrial nucleoids, along with multiprotein machineries, which promote mitochondrial DNA (mtDNA) replication, transcription, and repair. Although the organelle possesses almost all known nuclear DNA repair pathways, including base excision repair, mismatch repair, and recombinational repair, the proximity of mtDNA to the main sites of ROS production and the lack of protective histones may result in increased susceptibility to oxidative stress and other types of mtDNA damage. Defects in the components of these highly organized machineries, which mediate mtDNA maintenance (replication and repair), may result in accumulation of point mutations and/or deletions in mtDNA and decreased mtDNA copy number impairing mitochondrial function. This review will focus on the mechanisms of mtDNA maintenance with emphasis on the proteins implicated in these processes and their functional role in various disease conditions and aging.

  3. Determination of Pareto frontier in multi-objective maintenance optimization

    Energy Technology Data Exchange (ETDEWEB)

    Certa, Antonella [Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo 90128 Palermo (Italy); Galante, Giacomo, E-mail: galante@dtpm.unipa.i [Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo 90128 Palermo (Italy); Lupo, Toni; Passannanti, Gianfranco [Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo 90128 Palermo (Italy)

    2011-07-15

    The objective of a maintenance policy generally is the global maintenance cost minimization that involves not only the direct costs for both the maintenance actions and the spare parts, but also those ones due to the system stop for preventive maintenance and the downtime for failure. For some operating systems, the failure event can be dangerous so that they are asked to operate assuring a very high reliability level between two consecutive fixed stops. The present paper attempts to individuate the set of elements on which performing maintenance actions so that the system can assure the required reliability level until the next fixed stop for maintenance, minimizing both the global maintenance cost and the total maintenance time. In order to solve the previous constrained multi-objective optimization problem, an effective approach is proposed to obtain the best solutions (that is the Pareto optimal frontier) among which the decision maker will choose the more suitable one. As well known, describing the whole Pareto optimal frontier generally is a troublesome task. The paper proposes an algorithm able to rapidly overcome this problem and its effectiveness is shown by an application to a case study regarding a complex series-parallel system.

  4. Maintenance Process Strategic Analysis

    Science.gov (United States)

    Jasiulewicz-Kaczmarek, M.; Stachowiak, A.

    2016-08-01

    The performance and competitiveness of manufacturing companies is dependent on the availability, reliability and productivity of their production facilities. Low productivity, downtime, and poor machine performance is often linked to inadequate plant maintenance, which in turn can lead to reduced production levels, increasing costs, lost market opportunities, and lower profits. These pressures have given firms worldwide the motivation to explore and embrace proactive maintenance strategies over the traditional reactive firefighting methods. The traditional view of maintenance has shifted into one of an overall view that encompasses Overall Equipment Efficiency, Stakeholders Management and Life Cycle assessment. From practical point of view it requires changes in approach to maintenance represented by managers and changes in actions performed within maintenance area. Managers have to understand that maintenance is not only about repairs and conservations of machines and devices, but also actions striving for more efficient resources management and care for safety and health of employees. The purpose of the work is to present strategic analysis based on SWOT analysis to identify the opportunities and strengths of maintenance process, to benefit from them as much as possible, as well as to identify weaknesses and threats, so that they could be eliminated or minimized.

  5. Wind Turbine Failures - Tackling current Problems in Failure Data Analysis

    Science.gov (United States)

    Reder, M. D.; Gonzalez, E.; Melero, J. J.

    2016-09-01

    The wind industry has been growing significantly over the past decades, resulting in a remarkable increase in installed wind power capacity. Turbine technologies are rapidly evolving in terms of complexity and size, and there is an urgent need for cost effective operation and maintenance (O&M) strategies. Especially unplanned downtime represents one of the main cost drivers of a modern wind farm. Here, reliability and failure prediction models can enable operators to apply preventive O&M strategies rather than corrective actions. In order to develop these models, the failure rates and downtimes of wind turbine (WT) components have to be understood profoundly. This paper is focused on tackling three of the main issues related to WT failure analyses. These are, the non-uniform data treatment, the scarcity of available failure analyses, and the lack of investigation on alternative data sources. For this, a modernised form of an existing WT taxonomy is introduced. Additionally, an extensive analysis of historical failure and downtime data of more than 4300 turbines is presented. Finally, the possibilities to encounter the lack of available failure data by complementing historical databases with Supervisory Control and Data Acquisition (SCADA) alarms are evaluated.

  6. Planning for recall of maintenance manpower

    OpenAIRE

    Poh, Yang Siang Kelvin

    2015-01-01

    Approved for public release; distribution is unlimited Mission availability is a key component of system effectiveness wherein manpower forms a critical part of the resource requirements. Within the United States Air Force, military technicians supplement essential maintenance and logistics support for fighter aircraft. Under certain conditions, the placement of these technicians in their roles as reserve personnel creates disproportionate economic loss for the parent unit and the reserve ...

  7. Respiratory failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970318 A study on evoked potentials in cor pul-monale patients with chronic respiratory failure.QIAO Hui(乔慧), et al. Beijing Neurosurg Instit,Beijing, 100050. Chin J Geriatr 1997; 16(1): 43-45. Objective: Evoked protential was used to detect thechange of brain function in cor pulmonale patients with

  8. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    2009170 Curcumin attenuates left ventricular dysfunction and remodeling in rabbits with chronic heart failure. TANG Yanhong(唐艳红),et al.Dept Cardiol,Renmin Hosp,Wuhan Univ,Wuhan 430060.Chin J Cardiol,2009;37(3):262-267.

  9. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008411 Expression of S100B during heart failure in rats. JIANG Zhenni(蒋珍妮), et al. Dept Cardiol, 2nd Affili Hosp, Zhejiang Univ, Coll Med Hangzhou 310009. Chin J Emerg Med 2008;17(5):475-478. Objective To evaluate the value of S100B gene on cardiovascular remodeling in rats with abdominal aorta coarctation.

  10. Heart failure

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    970284 Effects of enalapril on heart rate variabilityin patients with congestive heart failure. ZHANGYouhua(章友华), et a1. Dept Cardiol, Cardiovasc Instit& Fuwai Hosp, CAMS & PUMC, Beijing, 100037. ChinCir J 1996; 11(2): 729-732.

  11. Failure Modes

    DEFF Research Database (Denmark)

    Jakobsen, K. P.; Burcharth, H. F.; Ibsen, Lars Bo;

    1999-01-01

    The present appendix contains the derivation of ten different limit state equations divided on three different failure modes. Five of the limit state equations can be used independently of the characteristics of the subsoil, whereas the remaining five can be used for either drained or undrained...

  12. Industrial Maintenance. Ohio's Competency Analysis Profile.

    Science.gov (United States)

    Ohio State Univ., Columbus. Vocational Instructional Materials Lab.

    Developed through a modified DACUM (Developing a Curriculum) process involving business, industry, labor, and community agency representatives in Ohio, this document is a comprehensive and verified employer competency profile for industrial maintenance occupations. The list contains units (with and without subunits), competencies, and competency…

  13. Powerful drivers for maintenance.

    Science.gov (United States)

    Mason, Steve

    2013-10-01

    A UPS system is the central building block of a Power Continuity Plan in medical facilities, but such equipment requires careful maintenance to continue fulfilling its vital role in delivering power resilience, and avoid catastrophic downtime, and potentially tens of thousands of pounds in costs to rectify the issues caused by poor maintenance. In our latest technical guidance article, Steve Mason, MD at Bender UK, one of the leading providers of isolated power supplies, theatre control panels, UPS systems, and Steris surgical products, and a turnkey provider of solutions for safe handling of electrical power and advanced provision of critical care products, examines some of the issue surrounding UPS maintenance.

  14. Failure Analysis of Drainage System Under the LP Heater in A 600MW Unit%600MW机组低压加热器疏水系统故障原因浅析

    Institute of Scientific and Technical Information of China (English)

    王波; 吴喜

    2012-01-01

    某600MW机组低压加热器系统由于原设计缺陷,在机组升负荷过程中,其6号低加至7号低加正常疏水逐级自流不畅,使机组冷源损失增大,直接影响了机组热经济性.通过详细分析并加以实验验证,找到了导致低加疏水系统故障的根本原因,提出了技术改造方案以供工程应用参考.%Because the original design of drainage system under the LP heater system in a 600MW unit was defective, it resulted the gravity step by step of the normal drainage from 6 LP heater to 7 LP heater was poor when the unit load was increasing. It increased the cold source loss and directly impacted on the thermal economy of the unit. By careful analysis and experimental verification, the essential reasons leading to drainage system failure had been found and technological transformation programs had been proposed for engineering reference.

  15. Hydrodynamic film thickness measurements and CFD analysis identify the root causes of repetitive thrust bearing failures on a 45 MW hydro generating unit at Hydro-Québec

    Science.gov (United States)

    Gauvin, P.; Huard, P.

    2016-11-01

    High temperature level recorded on the thrust bearing of a 45 MW hydro generating unit was resulting in frequent production stoppage. In spite of improvements brought to the oil cooling system since the rehabilitation in 2008, the operator had to activate the bearing oil lift system to keep the temperature below acceptable limits. Primary root cause analysis first pointed to the design of the shoe that was centrally pivoted, not allowing the formation of a thick hydrodynamic film. The removal of a strip of the soft metal layer near the trailing edge of the shoe resulted in a significant surface temperature reduction (about 15 deg. C), as predicted by a CFD model of the oil film. The goal of this machining was to increase the pivoting angle by moving the centre of hydrodynamic pressure. Proximity sensors were installed at each corner of the redesigned shoe to measure the film thickness and the bearing attitude. Signal analysis revealed a step of a magnitude close to the oil film thickness between the two halves of the rotating thrust block. This was the cause of another failure few hours since restarting the unit. The lessons learnt through these measurements and analyses were carefully applied to the ultimate build. The unit now runs with a robust thrust bearing and even survived a significant cooling flow reduction event. This paper presents the CFD analysis results and the measurements acquired during these events.

  16. Effectiveness of Condition-Based Maintenance in Army Aviation

    Science.gov (United States)

    2009-06-12

    quickly moved ahead with applying these new technologies to maintenance programs. Aviation maintainers started utilizing magnetic flux, ultrasound ...was mission abort rate. A mission abort occurs when an operational aircraft assigned to perform a mission, becomes unable to perform its assigned...a failure occur during mission execution. A study from AMRDEC in January 2009 referenced the mean time between maintenance abort for a handful of

  17. A New Route Maintenance in Dynamic Source Routing Protocol

    CERN Document Server

    Shukla, Ashish

    2010-01-01

    Mobile ad-hoc network (MANET) is infrastructureless, self-organizable, multi hop packet switched network. A number of routing protocols for MANETs have been proposed in recent years. Dynamic Source Routing (DSR) protocol is one of the most popular routing protocol for ad hoc networks. This paper presents a novel method to enhance route maintenance part of DSR protocol. Our proposed route maintenance significantly increases the efficiency of the protocol at the time of route failures.

  18. Performance-based inspection and maintenance strategies

    Energy Technology Data Exchange (ETDEWEB)

    Vesely, W.E.

    1995-04-01

    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 {open_quotes}high degradation{close_quotes}, {open_quotes}moderate degradation{close_quotes}, or {open_quotes}low degradation{close_quotes}. 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.

  19. V-TECS Guide for Industrial Maintenance Mechanic.

    Science.gov (United States)

    Meyer, Calvin F.; Benson, Robert T.

    This guide is intended to assist vocational teachers who are teaching a course in industrial machinery maintenance and repair; electromechanical, hydraulic, and pneumatic instrument repair; or building maintenance. Addressed in the individual units of the course outline are the following topics: assembling and disassembling machine mechanisms;…

  20. 10 CFR 35.605 - Installation, maintenance, adjustment, and repair.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Installation, maintenance, adjustment, and repair. 35.605... Installation, maintenance, adjustment, and repair. (a) Only a person specifically licensed by the Commission or an Agreement State shall install, maintain, adjust, or repair a remote afterloader unit,...

  1. Through Thick and Thin: Identifying Barriers to Bariatric Surgery, Weight Loss Maintenance, and Tailoring Obesity Treatment for the Future

    Directory of Open Access Journals (Sweden)

    Donevan Westerveld

    2016-01-01

    Full Text Available More than one-third of the adults in the United States are obese. This complex metabolic disorder is associated with multiple comorbidities and increased all-cause mortality. Bariatric surgery has been shown to be more effective than medical therapy and has been associated with weight loss maintenance and decreased mortality. In spite of these well-established benefits, less than 1% of candidates undergo surgery due to multiple factors, such as patient and physician perceptions and attitudes, patient-physician interaction, lack of resources, and cost burden. Furthermore, even in patients who do undergo bariatric surgery and/or alternate weight loss interventions, long-term weight control is associated with high-risk failure and weight regain. In this review, we highlight some of the current barriers to bariatric surgery and long-term weight loss maintenance and underscore the importance of an individualized multidisciplinary longitudinal strategy for the treatment of obesity.

  2. 检修人力资源在不同生产单元的开发与应用%Development and Application of Human Resources for Maintenance in Different Production Units

    Institute of Scientific and Technical Information of China (English)

    王华胜

    2014-01-01

    A maintenance engineering company was founded in Jinan Steel through reintegration of the maintenance human resources, breaking the maintenance mode used for many years, which realized sharing of personnel, materials, technology and resources and not only ensured stable production operation but also achieved external benefit.%介绍了济钢检修人力资源通过整合成立检修工程公司,打破济钢多年来检修模式,实现检修人力、物力、技术、资源的共享,既保证了产线稳定运行,又实现了外部创效。

  3. Just In-Time Maintenance of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    DR. Alexander G. Parlos

    2002-01-22

    The goal of this project has been to develop and demonstrate the feasibility of a new technology for maintenance engineering: a Just-In-Time Maintenance (JITM) system for rotating machines. The JITM system is based on several key developments at Texas A and M over the past ten years in emerging intelligent information technologies, which if integrated into a single system could provide a revolutionary approach in the way maintenance is performed. Rotating machines, such as induction motors, range from a few horse power (hp) to several thousand hp in size, and they are widely used in nuclear power plants and in other industries. Forced outages caused by induction motor failures are the reason for as much as 15% - 40% of production costs to be attributable to maintenance, whereas plant shutdowns caused by induction motor failures result in daily financial losses to the utility and process industries of $1 M or more. The basic components of the JITM system are the available machine sensors, that is electric current sensors and accelerometers, and the computational algorithms used in the analysis and interpretation of the occurring incipient failures. The JITM system can reduce the costs attributable to maintenance by about 40% and it can lower the maintenance budgets of power and process plants by about 35%, while requiring no additional sensor installation. As a result, the JITM system can improve the competitiveness of US nuclear utilities at minimal additional cost.

  4. Aging based maintenance and reinvestment scheduling of electric distribution

    Energy Technology Data Exchange (ETDEWEB)

    Korpijarvi, J.

    2012-07-01

    The maintenance of electric distribution network is a topical question for distribution system operators because of increasing significance of failure costs. In this dissertation the maintenance practices of the distribution system operators are analyzed and a theory for scheduling maintenance activities and reinvestment of distribution components is created. The scheduling is based on the deterioration of components and the increasing failure rates due to aging. The dynamic programming algorithm is used as a solving method to maintenance problem which is caused by the increasing failure rates of the network. The other impacts of network maintenance like environmental and regulation reasons are not included to the scope of this thesis. Further the tree trimming of the corridors and the major disturbance of the network are not included to the problem optimized in this thesis. For optimizing, four dynamic programming models are presented and the models are tested. Programming is made in VBA-language to the computer. For testing two different kinds of test networks are used. Because electric distribution system operators want to operate with bigger component groups, optimal timing for component groups is also analyzed. A maintenance software package is created to apply the presented theories in practice. An overview of the program is presented (orig.)

  5. Health Maintenance Restaurant

    Institute of Scientific and Technical Information of China (English)

    JANE SHAW

    1994-01-01

    Arestaurant named "Health Maintenance Restaurant" which serves dishes cooked with traditional Chinese medicine recently opened at Xiyuan Hotel in western Beijing. Entering the restaurant, you’ll see the god of longevity on the

  6. Statistical analysis of the reliability of complex systems for maintenance planning

    DEFF Research Database (Denmark)

    Pedersen, Thomas Espelund

    2003-01-01

    is to analyze failure and maintenance data using mathematical and statistical models in order to improve maintenance procedures in the Danish Defence. The first part of the report introduces the maintenance planning problem and presents an overview of models for reliability, failure processes, and maintenance...... planning. This overview is structured to highlight the process of choosing a proper model for a given data set, focusing on different measures of time and the data requirements for the different models. The second part of the report describes the analysis of two data sets from the Danish Defence. The data...

  7. RENEW v3.2 user's manual, maintenance estimation simulation for Space Station Freedom Program

    Science.gov (United States)

    Bream, Bruce L.

    1993-04-01

    RENEW is a maintenance event estimation simulation program developed in support of the Space Station Freedom Program (SSFP). This simulation uses reliability and maintainability (R&M) and logistics data to estimate both average and time dependent maintenance demands. The simulation uses Monte Carlo techniques to generate failure and repair times as a function of the R&M and logistics parameters. The estimates are generated for a single type of orbital replacement unit (ORU). The simulation has been in use by the SSFP Work Package 4 prime contractor, Rocketdyne, since January 1991. The RENEW simulation gives closer estimates of performance since it uses a time dependent approach and depicts more factors affecting ORU failure and repair than steady state average calculations. RENEW gives both average and time dependent demand values. Graphs of failures over the mission period and yearly failure occurrences are generated. The averages demand rate for the ORU over the mission period is also calculated. While RENEW displays the results in graphs, the results are also available in a data file for further use by spreadsheets or other programs. The process of using RENEW starts with keyboard entry of the R&M and operational data. Once entered, the data may be saved in a data file for later retrieval. The parameters may be viewed and changed after entry using RENEW. The simulation program runs the number of Monte Carlo simulations requested by the operator. Plots and tables of the results can be viewed on the screen or sent to a printer. The results of the simulation are saved along with the input data. Help screens are provided with each menu and data entry screen.

  8. RENEW v3.2 user's manual, maintenance estimation simulation for Space Station Freedom Program

    Science.gov (United States)

    Bream, Bruce L.

    1993-01-01

    RENEW is a maintenance event estimation simulation program developed in support of the Space Station Freedom Program (SSFP). This simulation uses reliability and maintainability (R&M) and logistics data to estimate both average and time dependent maintenance demands. The simulation uses Monte Carlo techniques to generate failure and repair times as a function of the R&M and logistics parameters. The estimates are generated for a single type of orbital replacement unit (ORU). The simulation has been in use by the SSFP Work Package 4 prime contractor, Rocketdyne, since January 1991. The RENEW simulation gives closer estimates of performance since it uses a time dependent approach and depicts more factors affecting ORU failure and repair than steady state average calculations. RENEW gives both average and time dependent demand values. Graphs of failures over the mission period and yearly failure occurrences are generated. The averages demand rate for the ORU over the mission period is also calculated. While RENEW displays the results in graphs, the results are also available in a data file for further use by spreadsheets or other programs. The process of using RENEW starts with keyboard entry of the R&M and operational data. Once entered, the data may be saved in a data file for later retrieval. The parameters may be viewed and changed after entry using RENEW. The simulation program runs the number of Monte Carlo simulations requested by the operator. Plots and tables of the results can be viewed on the screen or sent to a printer. The results of the simulation are saved along with the input data. Help screens are provided with each menu and data entry screen.

  9. Lessons Learned in Robotic Support of the Maintenance and Repair of the International Space Station

    Science.gov (United States)

    Dyer, J.; Lucier, L.

    With the completion of International Space Station (ISS) assembly, planning and daily activities are transitioning from construction to maintenance and repair. Previously, the ISS programme has relied heavily on the Space Shuttle programme to aid these tasks due to its ability to deliver equipment on relatively short notice together with crewmembers recently trained on execution of specific tasks. In 2007, a study was performed to identify and develop preliminary removal and replacement (R&R) timelines for those Orbital Replaceable Units (ORUs) that would cause a loss of redundancy to ISS power or life support capability [1]. This study identified 14 such ORUs and the team was challenged to demonstrate that the various Extra Vehicular Activity (EVA) tasks required to repair or replace these units could be performed without the support of the Space Station Remote Manipulator System (SSRMS or Canadarm2) due to potential lack of redundancy in the robotic system due to either the failed ORU or safe-guards put in place for its R&R. This philosophy was recently challenged upon failure of an external cooling loop pump, the repair of which relied heavily on Canadarm2 support. This paper will discuss the challenges associated with the planning and execution of R&R tasks onboard the ISS post Space Shuttle retirement, focusing on robotics support and using the 2010 failure of an external cooling loop pump module as context. A timeline of events from failure to recovery will be laid out, highlighting lessons learned. Specific challenges associated with this activity included developing products to complete three EVAs in two weeks, preparing crewmembers to perform a specific task for which they had not been trained, and the late decision to rely heavily on use of Canadarm2 for its completion. Attention will also be given to the change in philosophy regarding use of the SSRMS as it applies to the continued maintenance and repair of the International Space Station.

  10. Comparison of maintenance scheme effects on power transformer reliability performance

    Directory of Open Access Journals (Sweden)

    I. C. Durán

    2015-11-01

    Full Text Available Power transformer failures have a significant impact on electrical systems reliability, as they compromise the electricity delivery. Failures impact the operational cost of electric utilities as they endanger the accomplishment of power commitments. Power transformer failure rate can be modeled from its health condition, which is determined from different condition parameters. This paper is aimed to compare different maintenance schemes that allow the asset to be available the longest possible time. The power transformer operation is represented considering actual electric load profiles and temperature. Electrical and thermal transformer parameters are taken from manufacturer tests and technical standards. An electrical-thermal model is employed to estimate the life span reduction and temperature changes. From life span and loading, the health condition is determined, so as the effects of different maintenance schemes. The failure rates are calculated for unmaintained conditions and different maintained schemes, allowing to determine their effects on transformer reliability. Optimal maintenance schemes are determined and the expected benefits in failure rate reduction, asset reliability and life span extension are presented. As a result, it was found that certain time-based maintenance schemes provide better transformer reliability performance in comparison to condition based schemes, allowing to reduce the interruptions and extending the life of the transformer.

  11. Definition, Detection, and Recovery of Single-Page Failures, a Fourth Class of Database Failures

    CERN Document Server

    Graefe, Goetz

    2012-01-01

    The three traditional failure classes are system, media, and transaction failures. Sometimes, however, modern storage exhibits failures that differ from all of those. In order to capture and describe such cases, single-page failures are introduced as a fourth failure class. This class encompasses all failures to read a data page correctly and with plausible contents despite all correction attempts in lower system levels. Efficient recovery seems to require a new data structure called the page recovery index. Its transactional maintenance can be accomplished writing the same number of log records as today's efficient implementations of logging and recovery. Detection and recovery of a single-page failure can be sufficiently fast that the affected data access is merely delayed, without the need to abort the transaction.

  12. Renal failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930150 Epidermal growth factor and its recep-tor in the renal tissue of patients with acute re-nal failure and normal persons.LIU Zhihong(刘志红),et al.Jinling Hosp,Nanjing,210002.Natl Med J China 1992;72(10):593-595.Epidermal growth factor(EGF)and its receptor(EGF-R)were identified by immunohis-tochemical method(4 layer PAP)in the renaltissue specimens obtained from 11 normal kid-neys and 17 cases of acute renal failure(ARF).The quantitative EGF and EGF-R in the tissuewere expressed as positive tubules per mm~2.The amount of EGF and EGF-R in renal tissue

  13. Heart failure

    Institute of Scientific and Technical Information of China (English)

    1992-01-01

    920647 Comparative effects of commonvasodilators on experimental cardiac fai-lure. LI Zhijian (李志坚), et al. Dept Cardiol,2nd Hosp, Tianjin Med Coll. Tianjin Med J1992; 20(8): 456-458. A 9×9 latin square design was employed forcomparing the effects of (1) placebo, (2) nitr-oprusside, (3) phentolamine, (4) isosorbide dini-trate. (5) captopril, (6) captopril-isosorbide

  14. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    2005186 The diagnostic application of bedside measurement of plasma brain natriuretic in patients with heart failure. SHAO Le-wen (邵乐文) , Advanced Ward Dept, 1st Hosp, Med Sch, Zhejiang Univ, Hangzhou 310003. Chin J Intern Med, 2005;44(2): 99-101. Objective: To investigate differential diagnosis value of ultra-rapid bedside measurement of brain na-triuretic peptide (BNP) in patients with dyspnea.

  15. Heart failure

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010316 Tissue doppler imaging observation on effect of long-term use of gingko biloba tabtet on left ventricular function in patients with chronic heart failure. ZHANG Hui(张辉),et al. Dept Cardiovasc Med, 2nd Hosp, Hebei Med Univ,Shijiazhuang 050000. Chin J Integr Tradit & West Med 2010;30(5):478-481. Objective To quantitatively observe the effect of long-term

  16. Renal failure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008463 Protective effect of recombination rat augmenter of liver regeneration on kidney in acute renal failure rats. TANG Xiaopeng(唐晓鹏), et al. Dept Nephrol, 2nd Affili Hosp Chongqing Med Univ, Chongqing 400010.Chin J Nephrol 2008;24(6):417-421. Objective To investigate the protective effects of recombination rat augmenter of liver regeneration (rrALR) on tubular cell injury and renal dysfunction

  17. A Functional Inspection Model for the Immeasurable Potential Failure State

    Institute of Scientific and Technical Information of China (English)

    ZHU Wen-ge; LI Shi-qi; ZHAO Di

    2008-01-01

    Functional inspection is a type of preventive maintenance of Reliability Centered Maintenance (RCM). We, in this paper, establish a functional inspection model(FIM)--the cost model and the availability model for the immeasurable potential failure state based on the delay time concept. This model can be used to determine the appropriate Functional Inspection Interval(FII) to achieve the goal of specific cost and availability and to assist in maintenance decision making.

  18. Functional Problems and Maintenance Operations of Hydraulic Turbines

    Directory of Open Access Journals (Sweden)

    Liliana Topliceanu

    2016-02-01

    Full Text Available The exploitation in good conditions of the hydroelectric power plant imposes a rigorous maintenance of equipment and operating facilities, primarily of the turbine. The efficiency of the turbine is strongly affected by any defects which could occur during the operation. The paper makes a synthesis of the most frequent failures which have occurred during the functioning of Kaplan turbines plant and the required maintenance plan that has to be adopted. The maintenance rules for the optimal working of these turbines are also emphasized.

  19. Reliability Centered Maintenance in Schedule Improvement of Automotive Assembly Industry

    Directory of Open Access Journals (Sweden)

    Rizauddin Ramli

    2012-01-01

    Full Text Available Problem statement: Today, in many automotive manufacturing companies, maintenance management is an important factor to maintain the plant operation and production equipments. Approach: In this study, we present an implementation of Reliability Centered Maintenance (RCM practice in one of the automotive manufacturing company in Malaysia. The RCM practice was used to assist the company in focusing their maintenance activities based on the criticalities of the equipments by applying the Failure Modes and Effects Analysis (FMEA. The implementation of RCM was carried out in 4 stages; preparation, system analysis, decision making and feedback. The aim of RCM was to reduce the number of maintenance checklist and to improve significantly the integrity of maintenance practice. Results: As a result, the new RCM framework was generated where Class A equipment was at the top of the monthly maintenance frequency priority, followed by Class B and Class C equipment which had lesser critical value. Conclusion: The new RCM framework is used to conduct visible guideline and propose a new maintenance schedule. The guideline is useful for future maintenance strategy improvement. After the implementation, it can be ascertained that our proposed RCM is useful in reducing maintenance personnel burden and this leads to improvement of productivity.

  20. Determination of Preventive Maintenance Lead Time Using Hybrid Analysis

    Institute of Scientific and Technical Information of China (English)

    SUN Yong; MA Lin; Joseph Mathew; ZHANG Sheng

    2005-01-01

    The time for conducting Preventive Maintenance (PM) on an asset is often determined using a predefined alarm limit based on trends of a hazard function. In this paper, the authors propose using both hazard and reliability functions to improve the accuracy of the prediction particularly when the failure characteristic of the asset whole life is modelled using different failure distributions for the different stages of the life of the asset. The proposed method is validated using simulations and case studies.

  1. Differing antidepressant maintenance methodologies.

    Science.gov (United States)

    Safer, Daniel J

    2017-10-01

    The principle evidence that antidepressant medication (ADM) is an effective maintenance treatment for adults with major depressive disorder (MDD) is from placebo substitution trials. These trials enter responders from ADM efficacy trials into randomized, double-blind placebo-controlled (RDBPC) effectiveness trials to measure the rate of MDD relapse over time. However, other randomized maintenance trial methodologies merit consideration and comparison. A systematic review of ADM randomized maintenance trials included research reports from multiple databases. Relapse rate was the main effectiveness outcome assessed. Five ADM randomized maintenance methodologies for MDD responders are described and compared for outcome. These effectiveness trials include: placebo-substitution, ADM/placebo extension, ADM extension, ADM vs. psychotherapy, and treatment as usual. The placebo-substitution trials for those abruptly switched to placebo resulted in unusually high (46%) rates of relapse over 6-12months, twice the continuing ADM rate. These trials were characterized by selective screening, high attrition, an anxious anticipation of a switch to placebo, and a risk of drug withdrawal symptoms. Selectively screened ADM efficacy responders who entered into 4-12month extension trials experienced relapse rates averaging ~10% with a low attrition rate. Non-industry sponsored randomized trials of adults with multiple prior MDD episodes who were treated with ADM maintenance for 1-2years experienced relapse rates averaging 40%. Placebo substitution trial methodology represents only one approach to assess ADM maintenance. Antidepressant maintenance research for adults with MDD should be evaluated for industry sponsorship, attrition, the impact of the switch to placebo, and major relapse differences in MDD subpopulations. Copyright © 2017. Published by Elsevier Inc.

  2. PROFIT ANALYSIS OF A COMPLEX SYSTEM WITH CORRELATION IN TIME TO PREVENTIVE MAINTENANCE AND TIME TAKEN IN PREVENTIVE MAINTENANCE

    Directory of Open Access Journals (Sweden)

    Alka Chaudhury

    2010-01-01

    Full Text Available This paper deals with the cost benefit analysis of a complex system with correlationin time to preventive maintenance and time taken in preventive maintenance. The systemconsists of two subsystems, say A & B, connected in series. Subsystem A consists of twoidentical units while subsystem B consist only one unit. The operation of only one unit ofsubsystem A with subsystem B is sufficient to do the job. The joint distribution of time topreventive maintenance and time taken in preventive maintenance are taken bivariateexponential. Each repaired unit works as good as new. Various measures of system effectivenessof interest to system designers and operation managers are obtained by using regenerative pointtechnique. The graphical behaviors of MTSF and profit function have also been studied.

  3. Feasibility study: Application of RCM techniques for substation maintenance at the Bonneville Power Administration. [Reliability Centered Maintenance (RCM)

    Energy Technology Data Exchange (ETDEWEB)

    Purucker, S.L.; Tonn, B.E.; Goeltz, R.T.; James, R.D.; Kercel, S.; Rizy, D.T.; Simpson, M.L.; Van Dyke, J.W.

    1992-05-28

    This feasibility study examines reliability centered maintenance (RCM) as it applies to Bonneville Power Administrations (BPA) substation maintenance program. Reliability techniques are examined in evaluated. Existing BPA equipment maintenance procedures are documented. Equipment failure history is considered. Economic impacts are estimated. Various equipment instrumentation methods are reviewed. Based on this analysis a prototype system is proposed. The prototype will be implemented in two phases. Phase 1 is to be completed in 1992, it includes instrumenting one power transformer and one oil circuit breaker. Software development will focus on displaying data. Phase 2 is to be completed the following year. The remaining transformers and breakers will be instrumented during the second phase. Software development will focus on predictive maintenance techniques and maintenance decision support.

  4. Heart failure - tests

    Science.gov (United States)

    CHF - tests; Congestive heart failure - tests; Cardiomyopathy - tests; HF - tests ... the best test to: Identify which type of heart failure (systolic versus diastolic, valvular) Monitor your heart failure ...

  5. Heart failure - home monitoring

    Science.gov (United States)

    ... failure - discharge Heart failure - fluids and diuretics Heart failure - what to ask ... Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David Zieve, MD, ...

  6. A Unit Maintenance Scheduling Model Considering Peak Regulation Pressure Balance for Power System Containing Wind Farms%含风电场的电力系统中考虑调峰压力平衡的机组检修规划模型

    Institute of Scientific and Technical Information of China (English)

    吴耀武; 邴焕帅; 娄素华

    2012-01-01

    Grid-connection of large-scale wind power system brings new challenge to peak regulation of power grid and the maintenance outage of wind power generators has a certain effect on peak regulation ability of power grid. Along with the increase of the scale of grid-connected wind farm the coordination of power grid peak regulation ability should be considered in unit maintenance scheduling. A medium- and long-term unit maintenance scheduling, in which the economy of maintenance, reliability and balance of peak regulation pressure is synthetically taken into account, is proposed for power grid containing wind farms. Combining with the influence of grid-connected wind farms on peak regulation of power grid and peak regulation ability of different types of units, an index to measure peak regulation pressure for power grid containing wind power systems is proposed. On this basis, a method to balance the peak regulation pressure in maintenance scheduling is researched. According to different peak regulation abilities of units and the intensity of peak regulation pressure in different time intervals the unit maintenance is reasonably scheduled to balance peak regulation pressure of power grid; the constraint of maximum peak regulation of power grid is added in constraint conditions to ensure that after the maintenance scheduling is drafted the peak regulation pressure of power grid can be kept to a reasonable level. The proposed model is solved by genetic algorithm. The availability of the proposed model is verified by results of calculation example.%大规模风电并网给电力系统的调峰带来新的挑战,发电机组检修停运将对系统的调峰能力产生一定的影响,随着并网风电规模地加大,机组检修规划需要考虑系统的调峰能力协调问题.在含风电场的电力系统中,提出了综合考虑检修经济性、可靠性和调峰压力平衡的中长期机组检修规划模型.结合风电接入后对系统调峰的影响及不同

  7. 33 CFR 164.82 - Maintenance, failure, and reporting.

    Science.gov (United States)

    2010-07-01

    ... board the vessel likely to impair navigation, such as shortage of personnel or lack of current nautical charts or maps, or publications; and (3) Any characteristics of the vessel that affect or restrict...

  8. Present and future techniques for automated power facility maintenance. Maintenance techniques for power transmission facilities

    Energy Technology Data Exchange (ETDEWEB)

    Taneichi, Takeshi; Takada, Nobuyuki

    1988-09-15

    Present automated information acquisition system of the maintenance services for overhead transmission lines is outlined, and in addition, the fault localization system with optical fiber composite overhead ground wires (OPGW) and fault locators, automated ice or snow coating monitoring system, and transmission tower site monitoring system are presented. As maintenance equipment, the automatic fitting equipment of low-snow coating rings, and remote measuring with a helicopter are presented. More applications of OPGW and more uses of robots for the maintenance services are pointed out as future trends. Present automated maintenance services for underground transmission lines are outlined, and in addition, the communication system of the oil leakage information of OF cables or failure information of cooling facilities, the automatic operation and monitoring system for cooling facilities, and the duct monitoring system to collect and montor operation, failure and control imformation are presented. The use of inspection robots and a computerized total facility management system are pointed out as future trends. (7 figs, 3 tabs, 3 refs)

  9. General Course of Failure Distributions at Complex Machineries

    Directory of Open Access Journals (Sweden)

    Naqib Daneshjo

    2017-02-01

    Full Text Available In the process of maintenance management of machinery and devices there is necessity to keep in the mind "construction technologicity” (ability of construction technology. This term is used in evaluating of machinery construction, their groups and components in terms of production. The aim of management and planning maintenance of machinery is the failure-free operation in the application process. The range of machinery maintenance machines from routine one and inspection to general repairs is important to organize in a way to prevent unplanned idle time and failures or very likely to accidents.

  10. Research on the Reliability Centered Maintenance Plan of a Launching System

    Institute of Scientific and Technical Information of China (English)

    XIE Chao; SUN Ming-fang; DU Jun-min

    2011-01-01

    Aiming at the shortcomings of the traditional maintenance plan of a launching system, an analysis was made on the development of the reliability centered maintenance methods (RCM) and the basic models for reliability centered maintenance of a launching system are presented in this paper. The common methods for functional impor- tant product determination, failure modes and effect analysis ( FMEA ) and logic decision analysis were illustrated and the basic methods for maintenance interval calculation models were studied based on availability. According to the research, the reliability centered maintenance plan of a certain launching system was given.

  11. A quantitative method for Failure Mode and Effects Analysis

    NARCIS (Netherlands)

    Braaksma, A.J.J.; Meesters, A.J.; Klingenberg, W.; Hicks, C.

    2012-01-01

    Failure Mode and Effects Analysis (FMEA) is commonly used for designing maintenance routines by analysing potential failures, predicting their effect and facilitating preventive action. It is used to make decisions on operational and capital expenditure. The literature has reported that despite its

  12. The Modern Approach to Industrial Maintenance Management

    Directory of Open Access Journals (Sweden)

    Vasile DEAC

    2010-01-01

    Full Text Available The maintenance activity isn’t a purpose in itself, it’s a necessity of which "the production suffers" and the financial agent “considers too expensive”. It often exists a conflict between the production units and the maintenance department, not only for a short term, but, sometimes, for a long term, imposing a rigorous definition of each person’s responsibilities. Considering the mutations in the industrial equipments’ technical complexity and the accidental failures’ catastrophic consequences from the economic and/or social point of view, it should be assigned a new dimension to the maintenance activity. One of the imperatives imposed to this action is represented by modern means of informing through the maintenance’s operational computerization.

  13. 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.

  14. Failure Effects Evaluation for ATC Automation System

    Directory of Open Access Journals (Sweden)

    Rui Li

    2017-01-01

    Full Text Available ATC (air traffic control automation system is a complex system, which helps maintain the air traffic order, guarantee the flight interval, and prevent aircraft collision. It is essential to ensure the safety of air traffic. Failure effects evaluation is an important part of ATC automation system reliability engineering. The failure effects evaluation of ATC automation system is aimed at the effects of modules or components which affect the performance and functionality of the system. By analyzing and evaluating the failure modes and their causes and effects, some reasonable improvement measures and preventive maintenance plans can be established. In this paper, the failure effects evaluation framework considering performance and functionality of the system is established on the basis of reliability theory. Some algorithms for the quantitative evaluation of failure effects on performance of ATC automation system are proposed. According to the algorithms, the quantitative evaluation of reliability, availability, maintainability, and other assessment indicators can be calculated.

  15. Increased reliability through assessment of standard components with life cycle units

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, A.; Seliger, G. [Inst. fuer Werkzeugmaschinen und Fabrikbetrieb, Fachgebiet Montagetechnik und Fabrikbetrieb - PTZ 2, Berlin (Germany); Middendorf, A.; Reichl, H. [Research Center for Microperipheric Technologies of the TU-Berlin, Berlin (Germany); Ray, P.

    2004-07-01

    Products and their components underlie constant devaluation by their usage which sooner or later leads to a failure. As manufacturers of complex technical products are confronted with increasing demands regarding product availability and reliability, the assessment of the product's condition is desirable. Existing microelectronic technology enables a constant supervision of standard components in their usage to initiate timely adaptation processes like maintenance and repair. The Life Cycle Unit is presented as a modular microelectronic system for product supervision and assessment. Life Cycle Units have been prototypically implemented in various application examples using SMD technology and microsystem technology. (orig.)

  16. SCADA alarms processing for wind turbine component failure detection

    Science.gov (United States)

    Gonzalez, E.; Reder, M.; Melero, J. J.

    2016-09-01

    Wind turbine failure and downtime can often compromise the profitability of a wind farm due to their high impact on the operation and maintenance (O&M) costs. Early detection of failures can facilitate the changeover from corrective maintenance towards a predictive approach. This paper presents a cost-effective methodology to combine various alarm analysis techniques, using data from the Supervisory Control and Data Acquisition (SCADA) system, in order to detect component failures. The approach categorises the alarms according to a reviewed taxonomy, turning overwhelming data into valuable information to assess component status. Then, different alarms analysis techniques are applied for two purposes: the evaluation of the SCADA alarm system capability to detect failures, and the investigation of the relation between components faults being followed by failure occurrences in others. Various case studies are presented and discussed. The study highlights the relationship between faulty behaviour in different components and between failures and adverse environmental conditions.

  17. Application of Percutaneous Dilatational Tracheostomy in Patients with Acute Respiratory Failure in Intensive Care Units%经皮气管切开术在重症监护病房呼吸衰竭患者中的应用

    Institute of Scientific and Technical Information of China (English)

    王霞(综述); 张恒(审校)

    2015-01-01

    Patients with acute respiratory failure account for the majority of critically ill patients in the intensive care unit.Initial intubation with an endotracheal tube through the larynx resolves acute respiratory failure.However, if long-term ventilator dependence is required, the tracheostomy is necessary.With the development of medical technology with regards to patient safety,research has continued on more effective and simple methods.One such method is percutaneous tracheostomy,which can be performed directly at the patient′s bedside which greatly improves efficiency with lower complication and mortality rate .Here is to make a review of the development, steps, indications, contraindications, and complications of percutaneous dilatational tracheostomy,and comparison to the traditional tracheostomy.%重症患者中,急性呼吸衰竭者比例高,初期可经喉插管置入气管保证换气,如需要长期使用呼吸器,推荐行气管切开术。随着医疗技术的发展与进步,为了患者的安全及保证医疗效率,经皮气管切开术得到发展。研究表明,与传统外科气管切开术相比,经皮气管切开术的并发症及手术相关病死率低。经皮气管切开术可直接在患者床边进行,提高效率。现就经皮气管切开术的发展史,执行步骤、适应证、禁忌证、相关并发症及与传统气管切开术的比较等进行综述。

  18. Causes of weaning failure in 58 patients receiving mechanical ventilation and related weaning strategies in intensive care unit%ICU 58例机械通气撤机失败原因分析与对策

    Institute of Scientific and Technical Information of China (English)

    王存真; 康焰; 谢傲

    2010-01-01

    目的 分析机械通气患者撤机失败原因,总结相关撤机成功经验,提高脱机成功率.方法 对本院ICU 收住的58 例机械通气脱机失败患者的临床资料进行回顾性分析.结果 58例中共有81例次撤机失败,其中自主呼吸试验失败73例次(90.1%),其具体表现为神经系统的控制问题8例次(9.6%), 呼吸系统问题52例次(71.2%),心血管系统问题9例次(13.7%),心理障碍6例次(5.5%).8例拔管后48 h内再次插管,其中3例系因原发疾病加重,2例拔管过于激进,1例发生脑卒中昏迷致无法自主咳痰,1例发生严重谵妄.治疗原发病,采用合理的撤机策略,55例(94.8%)患者实现成功撤机,3例患者未能实现撤机,2例放弃治疗,1例患者原发病恶化而死亡.结论 机械通气撤机失败的原因多样.机械通气患者脱机时应在积极治疗患者原发病的情况下,采用合适的撤机策略;脱机后亦应及时评估患者呼吸状况.%Objective Analyzing the causes of weaning failure and summarizing related weaning strategies in intensive care unit (ICU), to promote the rate of weaning success. Methods The information of 58 patients suffering from weaning failure in ICU were investigated. Results Eighty-one unsuccessful weaning cases in all patients happened,including 73 cases of failured spontaneous breathing trial.The causes of failured spontaneous breathing trial were as follows, the question of nervous system accounted for 9.6% (8 cases), too large respiratory load for 71.2% (52 cases),insufficient function of circulation system for 13.7% (9 cases),and psychologic obstacle for 5.5%(6 cases).Eight patients were reintubated 48 hours after extubation because of aggravated primary disease,radical extubation,insufficient ablity of expectoration and severe delirium.By treating primary disease and adopting proper weaning strategies,55 patients weaned sucessfully.In 3 patients who could not wean from mechanical ventilation finally,2 were because of

  19. In sync. Benefits accrue through reliability-centered maintenance.

    Science.gov (United States)

    Waier, Phil

    2002-06-01

    Reliability-centered maintenance (RCM) programs establish best practices to determine the condition of equipment as well as find root causes that signal imminent system or product failures. The reliability-centered approach monitors the conditions of systems, limiting the frequency of inspections. The reduced labor can often lead to significant bottom-line cost savings.

  20. Reliability and maintenance simulation of the Hubble Space Telescope

    Science.gov (United States)

    Pizzano, F.

    1986-01-01

    An analytical approach is presented which was developed and implemented at MSFC specifically for the Space Telescope Program to provide comparisons of critical item failures, system downstates, on-orbit servicing versus return for ground maintenance, overall system downtime, and to obtain a measure of expected uptime for science functions.

  1. Coordinated planning of preventive maintenance in hierarchical production systems

    NARCIS (Netherlands)

    van Dijkhuizen, G.C.; van Harten, Aart

    1997-01-01

    We consider a technical system consisting of multiple different components, which are all subject to failure. Creating an occasion for preventive maintenance on one of these components requires a collection of preparatory set-up activities to be carried out in advance, with corresponding set-up

  2. Tennessee Valley Authority validation experience with substation reliability centered maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, S.M.; Graziano, J.A. [Tennessee Valley Authority, Chattanooga, TN (United States)

    1996-08-01

    This paper discusses the approach the Tennessee Valley Authority (TVA) used in the application of the Reliability Centered Maintenance (RCM) process during the evaluation of a Delle air blast circuit breaker. It discusses the selection of a system, establishing system boundaries, and the problems encountered in reviewing test data and personnel interviews. This paper also shows the functional failure analysis process, critical failure mode causes and resulting tasks. From the failure mode causes a task comparison is developed. The results from the RCM evaluation are shown as a cost savings. Finally, from this evaluation a list of conclusions and recommendations concerning the RCM validation process is provided.

  3. A case of scrub typhus requiring maintenance hemodialysis

    Directory of Open Access Journals (Sweden)

    Dae-Yeon Kim

    2013-12-01

    Full Text Available Renal failure caused by scrub typhus is known to be reversible. In most cases, renal function is almost fully restored after appropriate antibiotic treatment. A 71-year-old man was diagnosed with scrub typhus complicated by renal failure. A renal biopsy revealed histopathologic findings consistent with acute tubulointerstitial nephritis. Renal function did not improve 18 months after discharge and the patient required continuous hemodialysis. Although severe renal failure requiring dialysis is a rare complication of scrub typhus, we describe a case of scrub typhus requiring maintenance hemodialysis. To the best of our knowledge, this is the first such report.

  4. Reliability Simulation and Design Optimization for Mechanical Maintenance

    Institute of Scientific and Technical Information of China (English)

    LIU Deshun; HUANG Liangpei; YUE Wenhui; XU Xiaoyan

    2009-01-01

    Reliability model of a mechanical product system will be newly reconstructed and maintenance cost will increase because failed parts can be replaced with new components during service, which should be accounted for in system design. In this paper, a reliability model and reliability-based design optimization methodology for maintenance are presented. First, based on the time-to-failure density function of the part of the system, the age distributions of all parts of the system during service are investigated, a reliability model of the mechanical system for maintenance is developed. Then, reliability simulations of the systems with Weibull probability density functions are performed, the system minimum reliability and steady reliability for maintenance are defined based on reliability simulation during the life cycle of the system. Thirdly, a maintenance cost model is developed based on replacement rates of the parts, a reliability-based design optimization model for maintenance is presented, in which total life cycle cost is considered as design objective and system reliability as design constrain. Finally, the reliability-based design optimization methodology for maintenance is used to design of a link ring for the chain conveyor, which shows that optimal design with the lowest maintenance cost can be obtained, and minimum reliability and steady reliability of the system can satisfy requirement of system reliability during service of the chain conveyor.

  5. Maintenance and hazardous substances

    NARCIS (Netherlands)

    Kuhl, K.; Terwoert, J.; Cabecas, J.J.M.

    2012-01-01

    Maintenance workers come into close contact with a broad variety of often hazardous chemicals. Depending on the specific type, these chemicals may not only cause diseases like skin sores or cancer, but many of them are highly flammable and explosive. This e-facts focuses on the specific risks relate

  6. Maintenance: problem and solution

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    Equipment that is often unique, machines that are as old as the Laboratory, continuous and demanding performance requirements: these are the challenges faced by CERN’s accelerator maintenance teams. There are some twenty such teams, attached to different departments. A new project aims to standardise their procedures to make their work easier, and you can be a part of it.   “For the past year or so, the Accelerator and Technologies Sector and the GS Department have been working together on identifying the needs of the different teams that perform maintenance on CERN’s equipment. We are now ready to provide computer support with detailed specifics about the processes that need to be set up,” explains Goran Perinić, one of the leaders in CERN’s new Maintenance Management project (MMP). Since the LHC entered operation, the responsibilities of the technical teams have been broadened to cover maintenance of the collider and that of its injectors...

  7. Operations and maintenance philosophy

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN, G.P.

    1999-10-28

    This Operations and Maintenance (O&M) Philosophy document is intended to establish a future O&M vision, with an increased focus on minimizing worker exposure, ensuring uninterrupted retrieval operations, and minimizing operation life-cycle cost. It is intended that this document would incorporate O&M lessons learned into on-going and future project upgrades.

  8. Telephone Exchange Maintenance

    CERN Multimedia

    2005-01-01

    Urgent maintenance work on CERN telephone exchanges will be performed on 24 March from 6 a.m. to 8 a.m. Telephone services may be disrupted or even interrupted during this time. For more details, please contact us by email at Standard.Telephone@cern.ch.

  9. Maintenance in sustainable manufacturing

    Directory of Open Access Journals (Sweden)

    Vladimir Stuchly

    2014-09-01

    Full Text Available Background: Sustainable development is about reaching a balance between economic, social, and environmental goals, as well as people's participation in the planning process in order to gain their input and support. For a company, sustainable development means adoption of such business strategy and actions that contribute to satisfying present needs of company and stakeholders, as well as simultaneous protection, maintenance and strengthening of human and environmental potential which will be needed in the future. This new approach forces manufacturing companies to change their previous management paradigms. New management paradigm should include new issues and develop innovative methods, practices and technologies striving for solving problem of shortages of resources, softening environment overload and enabling development of environment-friendly lifecycle of products. Hence, its realization requires updating existing production models as they are based on previously accepted paradigm of unlimited resources and unlimited regeneration capabilities. Maintenance plays a crucial role because of its impact on availability, reliability, quality and life cycle cost, thus it should be one of the main pillars of new business running model.  Material and methods: The following paper is a result of research on the literature and observation of practices undertaken by a company within maintenance area. Results and conclusions: The main message is that considering sustainable manufacturing requires considerable expanding range of analysis and focusing on supporting processes. Maintenance offers numerous opportunities of decreasing influence of business processes on natural environment and more efficient resources utilization. The goal of maintenance processes realizing sustainable development strategy is increased profitability of exploitation and optimization of total lifecycle cost without disturbing safety and environmental issues. 

  10. Wind turbine blade life-time assessment model for preventive planning of operation and maintenance

    DEFF Research Database (Denmark)

    Florian, Mihai; Sørensen, John Dalsgaard

    2014-01-01

    Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...

  11. Wind Turbine Blade Life-Time Assessment Model for Preventive Planning of Operation and Maintenance

    DEFF Research Database (Denmark)

    Florian, Mihai; Sørensen, John Dalsgaard

    2015-01-01

    Out of the total wind turbine failure events, blade damage accounts for a substantial part, with some studies estimating it at around 23%. Current operation and maintenance (O&M) practices typically make use of corrective type maintenance as the basic approach, implying high costs for repair...

  12. Analysis of the ITER ECH Upper Port Launcher remote maintenance using virtual reality

    NARCIS (Netherlands)

    Elzendoorn, B.; Baar, M. de; Chavan, R.; Goodman, T.; Heemskerk, C.; Heidinger, R.; Kleefeldt, K.; Koning, J.; Sanders, S.; Späh, P.; Strauss, D.; Verhoeven, T.; Vreede, F. de

    2009-01-01

    All ITER sub-systems of remote handling (RH) classes 1 and 2 have to be remotely maintainable. The maintenance strategy for these components has to ensure system availability after failure or scheduled maintenance. This paper shows how virtual reality (VR) simulation [1] can be used as a tool to ana

  13. Modelling the failure behaviour of wind turbines

    Science.gov (United States)

    Faulstich, S.; Berkhout, V.; Mayer, J.; Siebenlist, D.

    2016-09-01

    Modelling the failure behaviour of wind turbines is an essential part of offshore wind farm simulation software as it leads to optimized decision making when specifying the necessary resources for the operation and maintenance of wind farms. In order to optimize O&M strategies, a thorough understanding of a wind turbine's failure behaviour is vital and is therefore being developed at Fraunhofer IWES. Within this article, first the failure models of existing offshore O&M tools are presented to show the state of the art and strengths and weaknesses of the respective models are briefly discussed. Then a conceptual framework for modelling different failure mechanisms of wind turbines is being presented. This framework takes into account the different wind turbine subsystems and structures as well as the failure modes of a component by applying several influencing factors representing wear and break failure mechanisms. A failure function is being set up for the rotor blade as exemplary component and simulation results have been compared to a constant failure rate and to empirical wind turbine fleet data as a reference. The comparison and the breakdown of specific failure categories demonstrate the overall plausibility of the model.

  14. Model-based fault diagnosis framework for effective predictive maintenance / B.B. Akindele

    OpenAIRE

    Akindele, Babatunde Babajide

    2010-01-01

    Predictive maintenance is a proactive maintenance strategy that is aimed at preventing the unexpected failure of equipment through condition monitoring of the health and performance of the equipment. Incessant equipment outage resulting in low availability of production facilities is a major issue in the Nigerian manufacturing environment. Improving equipment availability in Nigeria industry through institution of a full featured predictive maintenance has been suggested by many authors. T...

  15. Failure in imperfect anisotropic materials

    DEFF Research Database (Denmark)

    Legarth, Brian Nyvang

    2005-01-01

    The fundamental cause of crack growth, namely nucleation and growth of voids, is investigated numerically for a two phase imperfect anisotropic material. A unit cell approach is adopted from which the overall stress strain is evaluated. Failure is observed as a sudden stress drop and depending...

  16. Maintenance and fabrication of electronic equipment

    CERN Document Server

    Chung, C E; Kim, J B; Kim, Y K; Moon, B S

    2001-01-01

    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.

  17. 加氢裂化装置往复压缩机填料密封故障分析与改造%Failure Analysis and Transformation on Reciprocating Compressor Packing Seal of Hydrocracking Unit

    Institute of Scientific and Technical Information of China (English)

    莫才颂; 吴海智

    2012-01-01

    针对加氢裂化装置C102新型往复压缩机填料密封存在的泄漏问题,对压缩机气缸活塞填料密封结构、密封原理及其密封条件进行研究,在对密封填料函结构和填料受力等讨论的基础上,分析压缩机气缸填料密封失效的主要原因,提出改进填料密封环结构、冷却系统、规范密封环加工工艺程序及优化安装等措施.实践证明,改造后密封效果显著提高,设备使用寿命延长.%According to the packing seal leakage problems existed at new reciprocating compressor of C102 hydrocrac-king unit,the compressor cylinder piston filler sealing structure,sealing principle and sealing condition were studied. Based on discussion to the seal stuffing box structure and packing stress and etc. ,the main reason resulting in compressor cylinder packing seal failure was analyzed. Some measures including improving the filler sealing ring structure and cooling system, regulating the processing technology and optimizing the program of sealing ring installation were put forward. Practice proves,after the transformation,the sealing effect is significantly enhanced,unit use has longer life spans.

  18. Interval of Routine Maintenance and Maintenance Performance: A Literature Review

    Directory of Open Access Journals (Sweden)

    Au-Yong Cheong Peng

    2016-01-01

    Full Text Available In high-rise residential buildings, the quality of facilities management services is significant to the normal operation of the facilities. Unfortunately, lack of concern towards building maintenance, especially preventive maintenance, happens in domestic housing industry in Malaysia. Majority of the maintenance operations of condominiums suffer from lack of planning, lack of proactive maintenance plan, and lack of proper implementation. Thus, this paper reviews the implementation of preventive maintenance strategy, routine maintenance in specific. An extensive review of literature published in 1987 to 2014 is performed for the purpose of this research. The publications are sourced from journal articles, conference proceedings and books. The literature analysis confirms that the routine maintenance of facilities and building services is vital and it can be influential towards the maintenance performance. Subsequently, a theoretical framework is developed, which shows the relationship between routine maintenance of building facilities & services and maintenance performance. The building facilities & services are divided into two categories. They are essential facilities & services that ensure the safety, health, habitability, and operability of buildings; while value-added facilities & services deal with property value, return on investment, and quality living of buildings. Based on the findings, a future research is proposed, which aims to identify the appropriate routine of maintenance for the facilities and services in high-rise residential buildings to improve the maintenance performance.

  19. DLG5 in cell polarity maintenance and cancer development.

    Science.gov (United States)

    Liu, Jie; Li, Juan; Ren, Yu; Liu, Peijun

    2014-01-01

    Failure in establishment and maintenance of epithelial cell polarity contributes to tumorigenesis. Loss of expression and function of cell polarity proteins is directly related to epithelial cell polarity maintenance. The polarity protein discs large homolog 5 (DLG5) belongs to a family of molecular scaffolding proteins called Membrane Associated Guanylate Kinases (MAGUKs). As the other family members, DLG5 contains the multi-PDZ, SH3 and GUK domains. DLG5 has evolved in the same manner as DLG1 and ZO1, two well-studied MAGUKs proteins. Just like DLG1 and ZO1, DLG5 plays a role in cell migration, cell adhesion, precursor cell division, cell proliferation, epithelial cell polarity maintenance, and transmission of extracellular signals to the membrane and cytoskeleton. Since the roles of DLG5 in inflammatory bowel disease (IBD) and Crohn's disease (CD) have been reviewed, here, our review focuses on the roles of DLG5 in epithelial cell polarity maintenance and cancer development.

  20. Respiratory failure

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    930118 Facial or nasal mask pressure supportventilation in managing acute exacerbation ofchronic respiratory failure in COPD patients.CHEN Rongchang(陈荣昌),et al.GuangzhouInstit Respir Dis,Guangzhou 510120.Chin Tu-berc & Respir Dis 1992;15(5)285-287.Eleven COPD patients(age:65±9 yrs)withacute exacerbation of chronic respiratory failure(PaCO2 11.3±1.1kPa)were treated with maskpressure support ventilation,another 10 similarpatients(age:68±12yrs)served as controls.Bi-PAP ventilator was used with the followingmodifications:(1)Non-rehreathing valve set-in proximal to mask;(2)5 LPM oxygen flow de-livered into mask to reduce the dead space ef-fect.Mask ventilation was given 2-3 hours ev-ery time and 1-2 times daily for 7 days.Syn-

  1. Maintenance of Occupational Control: The Case of Professions.

    Science.gov (United States)

    Child, John; Fulk, Janet

    1982-01-01

    Contemporary conditions relevant to the maintenance of occupational control are examined for five professions (accounting, architecture, civil engineering, law, and medicine) in the United Kingdom and the United States as an impetus for the analysis of control by occupations in general. (Author/CT)

  2. 19 CFR 10.514 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free Trade Agreement Import Requirements § 10.514 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good imported into the United States under § 10.510(a) of this subpart...

  3. 19 CFR 10.415 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Chile Free Trade Agreement Import Requirements § 10.415 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good imported into the United States must maintain, for five years...

  4. 19 CFR 10.587 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ...-United States Free Trade Agreement Import Requirements § 10.587 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good imported into the United States under § 10.583(b..., all records and documents that the importer has demonstrating that the good qualifies for...

  5. Predictors of weight maintenance

    NARCIS (Netherlands)

    Pasman, W.J.; Saris, W.H.M.; Westerterp-Plantenga, M.S.

    1999-01-01

    Objective: To obtain predictors of weight maintenance after a weight-loss intervention. Research Methods and Procedures: An overall analysis of data from two-long intervention studies [n = 67 women; age: 37.9±1.0 years; body weight (BW): 87.0±1.2 kg; body mass index: 32.1±0.5 kg·m-2; % body fat: 42.

  6. Predictors of weight maintenance

    NARCIS (Netherlands)

    Pasman, W.J.; Saris, W.H.M.; Westerterp-Plantenga, M.S.

    1999-01-01

    Objective: To obtain predictors of weight maintenance after a weight-loss intervention. Research Methods and Procedures: An overall analysis of data from two-long intervention studies [n = 67 women; age: 37.9±1.0 years; body weight (BW): 87.0±1.2 kg; body mass index: 32.1±0.5 kg·m-2; % body fat: 42.

  7. Missile Maintenance Career Ladder

    Science.gov (United States)

    1994-01-01

    K696 INSPECT GENERAL PURPOSE EQUIPMENT 48 E176 LOCATE INFORMATION IN TOs 44 F235 PERFORM PREOPERATIONAL CHECKS ON MECHANICAL 42 MAINTENANCE SUPPORT...ON COLORIMETRIC GAS DETECTORS 24 27 TABLE 9 REPRESENTATIVE TASKS PERFORMED BY 2M052A PERSONNEL PERCENT MEMBERS PERFORMING TASKS (N=436) E176 LOCATE...AS STAFF MEETINGS, 67 BRIEFINGS, CONFERENCES, OR WORKSHOPS B30 CONDUCT PERFORMANCE FEEDBACK WORKSHEET SESSIONS 64 E176 LOCATE INFORMATION IN TOs 57

  8. Predictors of weight maintenance

    NARCIS (Netherlands)

    Pasman, W.J.; Saris, W.H.M.; Westerterp-Plantenga, M.S.

    1999-01-01

    Objective: To obtain predictors of weight maintenance after a weight-loss intervention. Research Methods and Procedures: An overall analysis of data from two-long intervention studies [n = 67 women; age: 37.9±1.0 years; body weight (BW): 87.0±1.2 kg; body mass index: 32.1±0.5 kg·m-2; % body fat:

  9. SCR maintenance fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Wicker, K.; Staudt, J.

    2004-06-01

    The latest round of NOx emissions rules in the USA may afford power plant operators more flexibility in meeting air-quality standards. But complying with the rules can be somewhat confusing. Because a selective catalytic reduction (SCR) system is the first line of defence against excessive NOx emission, its proper maintenance is critical. This article explains how to monitor an SCR system for ammonia slip and manage its catalysts in a way that optimizes the system's performance. 9 figs.

  10. Global Outsourcing of Aircraft Maintenance

    OpenAIRE

    McFadden, Michael; Worrells, D. Scott

    2012-01-01

    Before the airlines were deregulated, the majority of air carriers conducted their maintenance in-house. After deregulation, with competitive pressures mounting and airlines failing and starting up seemingly simultaneously, the outsourcing of maintenance became more prevalent. Not restricted to U.S. airlines, outsourcing maintenance has become a global practice. Factors involved in the outsourcing decision range from a startup not having the capital to develop their own in-house maintenance p...

  11. 49 CFR 214.529 - In-service failure of primary braking system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  12. 49 CFR Appendix E to Part 238 - General Principles of Reliability-Based Maintenance Programs

    Science.gov (United States)

    2010-10-01

    ... altered only by basic changes in the design. Safety consequences can, in nearly all cases, be reduced to... that a failure has occurred); (3) The visibility of reduced resistance to failure (evidence that a... operating life of the equipment. Management of the ongoing maintenance program requires an organized...

  13. Sensor Technology Baseline Study for Enabling Condition Based Maintenance Plus in Army Ground Vehicles

    Science.gov (United States)

    2012-03-01

    and mechanisms are identified. Based on this analysis, baselines sensor technologies are determined to prognosticate these types failure causes early...Current/voltage sensor measured at sensor terminals; Fluid level sensor Excessive slippage and clutch chatter Internal transmission failure ... TYPE Final 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Sensor Technology Baseline Study for Enabling Condition Based Maintenance Plus in

  14. Improvement in renal function after everolimus introduction and calcineurin inhibitor reduction in maintenance thoracic transplant recipients

    DEFF Research Database (Denmark)

    Arora, Satish; Gude, Einar; Sigurdardottir, Vilborg

    2012-01-01

    The NOCTET (NOrdic Certican Trial in HEart and lung Transplantation) trial demonstrated that everolimus improves renal function in maintenance thoracic transplant (TTx) recipients. Nevertheless, introduction of everolimus is not recommended for patients with advanced renal failure. We evaluated...... NOCTET data to assess everolimus introduction amongst TTx recipients with advanced renal failure....

  15. New Maintenance Strategies for Generating Companies in Power Market

    Institute of Scientific and Technical Information of China (English)

    JIA De-xiang; CHENG Hao-zhong; YAN Jian-yong; CHEN Ming; HAN Jing

    2007-01-01

    A new approach to maintenance scheduling of generating units (MSU) in competitive electricity markets was presented, which was formulated as a noncooperative game with complete information. The payoff of each generating company (Genco) was defined as the profit from the energy auction market minus maintenance cost and risk loss. The compensation fee of interruptible load was a part of the maintenance cost when the permitted maintenance capacity in the system was insufficient. Hourly energy auction was incorporated in the computation of both revenues from energy market and risk loss of maintenance strategy as a nested game. A new heuristic search algorithm for the calculation of the game equilibrium of MSU was presented, which coordinates the solutions of nonequilibrium, unique equilibrium and multiple equilibria. Numerical results for a two-Genco system and a realistic system were used to demonstrate the basic ideas and the applicability of the proposed method, as well as its computational efficiency.

  16. Effect of Maintenance on Computer Network Reliability

    Directory of Open Access Journals (Sweden)

    Rima Oudjedi Damerdji

    2014-08-01

    Full Text Available At the time of the new information technologies, computer networks are inescapable in any large organization, where they are organized so as to form powerful internal means of communication. In a context of dependability, the reliability parameter proves to be fundamental to evaluate the performances of such systems. In this paper, we study the reliability evaluation of a real computer network, through three reliability models. The computer network considered (set of PCs and server interconnected is localized in a company established in the west of Algeria and dedicated to the production of ammonia and fertilizers. The result permits to compare between the three models to determine the most appropriate reliability model to the studied network, and thus, contribute to improving the quality of the network. In order to anticipate system failures as well as improve the reliability and availability of the latter, we must put in place a policy of adequate and effective maintenance based on a new model of the most common competing risks in maintenance, Alert-Delay model. At the end, dependability measures such as MTBF and reliability are calculated to assess the effectiveness of maintenance strategies and thus, validate the alert delay model.

  17. Optimal Maintenance Management of Offshore Wind Farms

    Directory of Open Access Journals (Sweden)

    Alberto Pliego Marugán

    2016-01-01

    Full Text Available Nowadays offshore wind energy is the renewable energy source with the highest growth. Offshore wind farms are composed of large and complex wind turbines, requiring a high level of reliability, availability, maintainability and safety (RAMS. Firms are employing robust remote condition monitoring systems in order to improve RAMS, considering the difficulty to access the wind farm. The main objective of this research work is to optimise the maintenance management of wind farms through the fault probability of each wind turbine. The probability has been calculated by Fault Tree Analysis (FTA employing the Binary Decision Diagram (BDD in order to reduce the computational cost. The fault tree presented in this paper has been designed and validated based on qualitative data from the literature and expert from important European collaborative research projects. The basic events of the fault tree have been prioritized employing the criticality method in order to use resources efficiently. Exogenous variables, e.g., weather conditions, have been also considered in this research work. The results provided by the dynamic probability of failure and the importance measures have been employed to develop a scheduled maintenance that contributes to improve the decision making and, consequently, to reduce the maintenance costs.

  18. Imperfect preventive maintenance for numerical control machine tools with log-linear virtual age process

    Institute of Scientific and Technical Information of China (English)

    郭俊锋; 芮执元; 冯瑞成; 魏兴春

    2014-01-01

    Based on the log-linear virtual age process, an imperfect preventive maintenance policy for numerical control (NC) machine tools with random maintenance quality is proposed. The proposed model is a combination of the Kijima type virtual age model and the failure intensity adjustment model. Maintenance intervals of the proposed hybrid model are derived when the failure intensity increase factor and the restoration factor are both random variables with uniform distribution. The optimal maintenance policy in infinite time horizon is presented. A numerical example is given when the failures of NC machine tools are described by the log-linear process. Finally, a discussion is presented to show how the optimal results depend on the different cost parameters.

  19. Kidney (Renal) Failure

    Science.gov (United States)

    ... How is kidney failure treated? What is kidney (renal) failure? The kidneys are designed to maintain proper fluid ... marrow and strengthen the bones. The term kidney (renal) failure describes a situation in which the kidneys have ...

  20. Acute kidney failure

    Science.gov (United States)

    Kidney failure; Renal failure; Renal failure - acute; ARF; Kidney injury - acute ... There are many possible causes of kidney damage. They include: ... cholesterol (cholesterol emboli) Decreased blood flow due to very ...

  1. Living with Heart Failure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Living With Heart Failure Currently, heart failure has no cure. You'll ... avoid harmful side effects. Take Steps To Prevent Heart Failure From Getting Worse Certain actions can worsen your ...

  2. Classes of Heart Failure

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Classes of Heart Failure Updated:Sep 28,2016 Doctors usually classify patients' ... Blood Pressure Tracker Find additional helpful resources here Heart Failure • Home • About Heart Failure Introduction Types of Heart ...

  3. About Heart Failure

    Science.gov (United States)

    ... talk about your health and the medicines About Heart Failure Heart failure is a disease where the heart cannot do ... very important for your health. common causes of heart failure are diseases or conditions that damage the heart. ...

  4. What Is Heart Failure?

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Heart Failure? Heart failure is a condition in which the heart can' ... force. Some people have both problems. The term "heart failure" doesn't mean that your heart has stopped ...

  5. Acute Kidney Failure

    Science.gov (United States)

    ... out of balance. Acute kidney failure — also called acute renal failure or acute kidney injury — develops rapidly over ... 2015. Palevsky PM. Definition of acute kidney injury (acute renal failure). http://www.uptodate.com/home. Accessed April ...

  6. Fatigue of Concrete Armour Units

    DEFF Research Database (Denmark)

    Sørensen, N. B.; Burcharth, H. F.; Liu, Z.

    1995-01-01

    In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed.......In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed....

  7. Fatigue of Concrete Armour Units

    DEFF Research Database (Denmark)

    Sørensen, N. B.; Burcharth, H. F.; Liu, Z.

    1995-01-01

    In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed.......In the present article fatigue as a possible reason for failure of Dolosse armour units made of plain concrete is discussed....

  8. Factors Influencing Army Maintenance

    Science.gov (United States)

    1989-01-01

    battle damage cannot be eliminated in the design process, but fault isolation and repair, as well as routine and preventive maintenance, can be...documentation does not meet thebe requirements, the efficiency of the xmaintainer’s performance will be reduced. It Is often the case that documentation...sustain battle damage of various levels of severity; and 3) systems experience relatively high ube latES I- Obat. C..L. LI= C 4LILCLr42 L C LI=%-t I- iC

  9. Motorway maintenance work

    CERN Document Server

    2005-01-01

    Built 20 years ago, the airport section of the Geneva motorway bypass is now in need of maintenance work and alterations to bring it into line with the new standards. Two-lane traffic will be maintained in both directions during the work, which will be carried out in 2006 and 2007, but there will be various temporary special traffic arrangements in force. We should like to thank you in advance for your understanding. Civil Engineering Department, DAEL, State of Geneva More information: tel. 163 or www.autoroute-aeroport.ch Fewer cars, fewer traffic jams, with www.covoiturage.ch

  10. The Fault Interpretation and Maintenance of the Traction Drive System for CRH5 Multiple-unit Train%CRH5型动车组牵引传动系统故障解析及维护保养

    Institute of Scientific and Technical Information of China (English)

    张旭永

    2015-01-01

    动车组传动系统为动车组的动力传输装置,CRH5型动车组牵引传动装置区别于其他高速动车组传动系统,独具特点。CRH5型动车组牵引传动系统由牵引电机、万向轴、齿轮箱三大部件组成。牵引电机产生的牵引力通过万向轴及齿轮箱传导至车轮上,最终产生了牵引作用。本文通过牵引系统常见故障的分析,研究出可行性的预防方法,可以有效地规避动车组运行风险。%The drive system is the power transfer unit for multi-ple-unit trains. The traction drive system of CRH5 multiple-unit train differs from the drive system of other multiple-unit trains and has its own features. The traction and drive system of CRH5 multiple-unit train consists of such three major parts as traction motor, cardan shaft and gear case. The tractive force produced by the traction motor is transferred to the wheels through the cardan shaft and gear case, finally generating the function of traction. By analyzing common faults in the traction system, this paper studies feasible prevention methods which can effectively avoid the risks in the working of multiple-unit trains.

  11. THE EFFECTS OF MAINTENANCE ACTIONS ON THE PFDavg OF SPRING OPERATED PRESSURE RELIEF VALVES

    Energy Technology Data Exchange (ETDEWEB)

    Harris, S.; Gross, R.

    2014-04-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

  12. Model for heart failure education.

    Science.gov (United States)

    Baldonado, Analiza; Dutra, Danette; Abriam-Yago, Katherine

    2014-01-01

    Heart failure (HF) is the heart's inability to meet the body's need for blood and oxygen. According to the American Heart Association 2013 update, approximately 5.1 million people are diagnosed with HF in the United States in 2006. Heart failure is the most common diagnosis for hospitalization. In the United States, the HF direct and indirect costs are estimated to be US $39.2 billion in 2010. To address this issue, nursing educators designed innovative teaching frameworks on HF management both in academia and in clinical settings. The model was based on 2 resources: the American Association of Heart Failure Nurses (2012) national nursing certification and the award-winning Pierce County Responsive Care Coordination Program. The HF educational program is divided into 4 modules. The initial modules offer foundational levels of Bloom's Taxonomy then progress to incorporate higher-levels of learning when modules 3 and 4 are reached. The applicability of the key components within each module allows formatting to enhance learning in all areas of nursing, from the emergency department to intensive care units to the medical-surgical step-down units. Also applicable would be to provide specific aspects of the modules to nurses who care for HF patients in skilled nursing facility, rehabilitation centers, and in the home-health care setting.

  13. THE FAILURE OF COLLECTIVE SECURITY IN THE POST WORLD WARS I AND II INTERNATIONAL SYSTEM

    Directory of Open Access Journals (Sweden)

    JOSEPH C. EBEGBULEM

    2012-05-01

    Full Text Available The League of Nations and the United Nations Organization were two post-World War (World War I and World War II organizations established for the maintenance of peace and security in the international system. One of the cardinal objectives of these organizations was the promotion of a Collective Security System which was considered as vital in the pursuit of global peace and security. In other words, Collective Security is an institutional mechanism established to address a comprehensive list of major threats to peace and security around the world. With the escalation of conflicts and wars in different parts of the world, there is therefore the need for collective responses at global, regional and national levels in conflict situations. The achievement of collective security in the international system would be based on the principle that any attack on any member of the United Nations would be considered as an attack on all the members. After a panoramic discourse of the meaning and nature of Collective Security, the paper also examines the problems of collective security in the international system; its failure under the League of Nations and the United Nations. The paper concludes that the weaknesses inherent in the system do not make it unuseful as it is a relevant factor in the maintenance of international peace and security.

  14. Reducing maintenance costs in agreement with CNC machine tools reliability

    Science.gov (United States)

    Ungureanu, A. L.; Stan, G.; Butunoi, P. A.

    2016-08-01

    Aligning maintenance strategy with reliability is a challenge due to the need to find an optimal balance between them. Because the various methods described in the relevant literature involve laborious calculations or use of software that can be costly, this paper proposes a method that is easier to implement on CNC machine tools. The new method, called the Consequence of Failure Analysis (CFA) is based on technical and economic optimization, aimed at obtaining a level of required performance with minimum investment and maintenance costs.

  15. TRIZ method application for improving the special vehicles maintenance

    Directory of Open Access Journals (Sweden)

    Petrović Saša

    2014-01-01

    Full Text Available TRIZ methodology provides an opportunity for improving the classical engineering approach based on personal knowledge and experience. This paper presents the application of TRIZ methods for improving vehicle maintenance where special equipment is installed. A specific problem is the maintenance of the periscopes with heating system. Protective glass panels with heating system are rectangular glass elements. Their purpose is to perform mechanical protection of built-in prisms and provide heating of the prisms. Aging and long-term use leads to failure of these elements. The practice requires solutions in order to extend the lifetime of the system. New solution is evaluated by simulation and experiment.

  16. Augmented reality application utility for aviation maintenance work instruction

    Science.gov (United States)

    Pourcho, John Bryan

    Current aviation maintenance work instructions do not display information effectively enough to prevent costly errors and safety concerns. Aircraft are complex assemblies of highly interrelated components that confound troubleshooting and can make the maintenance procedure difficult (Drury & Gramopadhye, 2001). The sophisticated nature of aircraft maintenance necessitates a revolutionized training intervention for aviation maintenance technicians (United States General Accounting Office, 2003). Quite simply, the paper based job task cards fall short of offering rapid access to technical data and the system or component visualization necessary for working on complex integrated aircraft systems. Possible solutions to this problem include upgraded standards for paper based task cards and the use of integrated 3D product definition used on various mobile platforms (Ropp, Thomas, Lee, Broyles, Lewin, Andreychek, & Nicol, 2013). Previous studies have shown that incorporation of 3D graphics in work instructions allow the user to more efficiently and accurately interpret maintenance information (Jackson & Batstone, 2008). For aircraft maintenance workers, the use of mobile 3D model-based task cards could make current paper task card standards obsolete with their ability to deliver relevant, synchronized information to and from the hangar. Unlike previous versions of 3D model-based definition task cards and paper task cards, which are currently used in the maintenance industry, 3D model based definition task cards have the potential to be more mobile and accessible. Utilizing augmented reality applications on mobile devices to seamlessly deliver 3D product definition on mobile devices could increase the efficiency, accuracy, and reduce the mental workload for technicians when performing maintenance tasks (Macchiarella, 2004). This proposal will serve as a literary review of the aviation maintenance industry, the spatial ability of maintenance technicians, and benefits of

  17. Maintenance Optimization Model for One kind of Three-Dimensional Radar Antenna Array

    Science.gov (United States)

    Wang, Min; Yang, Jiang-ping; Wang, Yong-pan; Liu, Wei-jian

    2017-07-01

    For three-dimensional radar, maintenance cost is high and maintenance time is difficult to be determined. What’s more, model simulation computing is significantly complex. The subject of this paper is a new generation of meter wave active, phased array 3D radar. We put forth a concept that maintenance should be done after dividing into several regions to the asymmetrical distribution planar array antenna. First, a failure model of array elements is built to analyze the influence from the element to antenna. Second, the maintenance optimization model is established. Finally, computer simulations are conducted to verify the feasibility and effectiveness of the proposed model.

  18. Wind Turbine Gearbox Failure Modes - A Brief (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, S.; McDade, M.; Errichello, R.

    2011-10-01

    Wind turbine gearboxes are not always meeting 20-year design life. Premature failure of gearboxes increases cost of energy, turbine downtime, unplanned maintenance, gearbox replacement and rebuild, and increased warranty reserves. The problem is widespread, affects most Original Equipment Manufacturers, and is not caused by manufacturing practices. There is a need to improve gearbox reliability and reduce turbine downtime. The topics of this presentation are: GRC (Gearbox Reliability Collaborative) technical approach; Gearbox failure database; Recorded incidents summary; Top failure modes for bearings; Top failure modes for gears; GRC test gearbox; Bearing nomenclature; Test history; Real damage; Gear sets; Bearings; Observations; and Summary. 5 refs.

  19. A Combined Maintenance Strategy for Offshore Wind Turbine Considering Accessibility%考虑可及性的海上风机综合维护策略

    Institute of Scientific and Technical Information of China (English)

    郑小霞; 赵华; 刘璐洁; 符杨

    2014-01-01

    Accessibility is one of key factors related to the operation and maintenance of offshore wind turbine generation units. A model of maintenance strategy for offshore wind turbines, in which the accessibility is taken into account, is constructed. Firstly, the weather condition such as wind speed and so on is described by Markov chain model, and the influences of the wind speed and the duration of maintenance on the waiting time of accessible window are further analyzed. Considering the fact that adverse offshore weather conditions more likely lead to instable failure rate of wind turbines, a censored data based Weibull proportional hazards model (WPHM) is constructed to describe wind turbine failures, and combining with acquired condition based maintenance (CBM) data the CBM threshold curve is plotted. Meanwhile, taking the minimum overall maintenance cost and the maximum reliability of offshore wind turbines as objectives of the optimized maintenance strategy, the optimal preventive replacement cycle and the time intervals of unequal periodic incomplete maintenance can be obtained. Finally, taking a certain offshore wind farm as the case, the correctness and the availability of the proposed maintenance strategy are validated.%可及性是海上风电机组运行维护的关键因素之一。构建了考虑可及性的海上风机综合维护策略模型。首先采用马尔科夫法描述风速等,进而分析风速、维护持续时间对可及窗口等待时间的影响。考虑到海上恶劣气候条件易导致风机故障率不稳定,构建截尾数据下威布尔比例失效模型描述风机故障,结合状态检修的采集数据绘制状态检修阈值曲线。同时以海上风机总维护费用最小、可靠度最大为目标优化维护策略,得到最优的预防性更换周期和非等周期不完全维护的时间间隔。最后,以某海上风机为例,验证了该维护策略的正确性和有效性。

  20. Musculoskeletal disorders in hemodialysis patients and its impact on physical function (Zagazig University Nephrology Unit, Egypt

    Directory of Open Access Journals (Sweden)

    Amany R El-Najjar

    2014-01-01

    Conclusion Musculoskeletal system involvement remains a common problem that limits the physical function of patients with renal failure, in particular, those treated with long-term maintenance dialysis.

  1. METHODOLOGICAL FUNDAMENTALS OF DETERMINATION OF UNPOWERED ROLLING STOCK MAINTENANCE CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    L. A. Muradian

    2016-02-01

    Full Text Available Purpose. The paper involves: 1 confirmation of the technical characteristics of cars and their modifications, as well as indicators of unfailing work probability during the time between overhauls or service hours; 2 improving the methodological approaches to assess the maintenance characteristics of new and modernized equipment of rail transport on the example of not self-propelled rolling stock, namely, railway freight cars; 3 solution of scientific and applied problems in assessment the maintenance characteristics of the new and modernized railway equipment. Methodology. The basic methodological approaches to the assessment of the maintenance characteristics on the example of not self-propelled rolling stock, namely, railway freight cars were considered. The analysis of the reliability of the car, which is considered as a complex mechanical system, where all system elements are connected in series, wherein each element includes m is serially connected parts. The failure of each part of the calculation will result in refusal of the car. Thus, the car is a system without redundancy. Findings. The evaluation technic of the maintenance characteristics of freight cars in controlled operation with taking into account the features of the new generation of cars was improved. Specified: the duration of the tests, the frequency of inspection of the control group of cars controlled by the parameters of the car, the reasons for the early termination of controlled operation. Identified failures in the process of controlled operation are divided according to their nature. Originality. The authors proposed a method of assessing the maintenance characteristics of railway equipment in trial operation as an example of a new generation of freight cars. Practical value. The results allow assessing the maintenance characteristics of new and modernized rail transport equipment during the maintenance test.

  2. Ciprofloxacin-Induced Renal Failure

    Directory of Open Access Journals (Sweden)

    Audra Fuller

    2015-10-01

    Full Text Available Acute renal failure (ARF is a common diagnosis in hospitalized patients, particularly in intensive care units (ICU. Determining the cause and contributing factors associated with ARF is crucial during treatment. The etiology is complex, and several factors often contribute to its development. Medications can cause acute tubular necrosis, acute interstitial nephritis, and crystal-induced or post-obstructive nephropathy. There have been several case reports of ARF secondary to fluoroquinolones. Here we report the development of acute renal failure within a few days of initiating oral ciprofloxacin therapy and briefly describe the different types of renal failure secondary to fluoroquinolone administration. Clinical studies demonstrate that using fluoroquinolones with other potentially nephrotoxic medications requires monitoring of renal function to limit the renal toxicity with these medications. Also, the risk-benefit profile of patients requiring fluoroquinolones should be considered.

  3. Dynamic environment for training for maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, F.; Gonzalez, F.; Marti, F. [Tecnatom, s.a., Madrid (Spain)

    2001-07-01

    The governing board of TECNATOM approved a project for creating a maintenance training center in 1995. The objective was to cover training necessities identified in the maintenance area, mainly in issues related with continuous training, recycling and professional development. A team of instructors in the 3 specialties: mechanical, electrical and instrumentation, was selected. Written training material has been developed. New facilities and adequate mock-ups for training has been acquired, more than 100 didactical units have been developed. The mock-ups are real components from nuclear power plants, they have been adapted to fulfill the didactical function. New courses and mock-ups are being developed as new customer necessities are being identified. (A.C.)

  4. Actinomadura Species: Laboratory Maintenance and Ribosome Engineering.

    Science.gov (United States)

    Dhakal, Dipesh; Chung, Nguyen Thanh; Rayamajhi, Vijay; Sohng, Jae Kyung

    2017-02-06

    Actinomadura spp. are aerobic, Gram-positive, catalase-positive, non-acid fast, non-motile actinomycetes. Some species of Actinomadura are associated with opportunistic infections in humans. However, many bioactive compounds with pharmaceutical applications can be isolated from various Actinomadura spp. This unit includes general protocols for the laboratory maintenance of Actinomadura spp., including growth in liquid medium, growth on solid agar, long-term storage, and generation of a higher producing strain by ribosome engineering. Actinomadura hibisca P157-2 is used as a prototype for explaining the considerations for efficient laboratory maintenance of Actinomadura spp. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  5. Performance enhancement for crystallization unit of a sugar plant using genetic algorithm technique

    Science.gov (United States)

    Tewari, P. C.; Khanduja, Rajiv; Gupta, Mahesh

    2012-05-01

    This paper deals with the performance enhancement for crystallization unit of a sugar plant using genetic algorithm. The crystallization unit of a sugar industry has three main subsystems arranged in series. Considering exponential distribution for the probable failures and repairs, the mathematical formulation of the problem is done using probabilistic approach, and differential equations are developed on the basis of Markov birth-death process. These equations are then solved using normalizing conditions so as to determine the steady-state availability of the crystallization unit. The performance of each subsystem of crystallization unit in a sugar plant has also been optimized using genetic algorithm. Thus, the findings of the present paper will be highly useful to the plant management for the timely execution of proper maintenance decisions and, hence, to enhance the system performance.

  6. Role of supportive maintenance therapy on implant survival: a university-based 17 years retrospective analysis.

    Science.gov (United States)

    Gay, I C; Tran, D T; Weltman, R; Parthasarathy, K; Diaz-Rodriguez, J; Walji, M; Fu, Y; Friedman, L

    2016-11-01

    The objective of this study was to determine whether professional maintenance appointments were related to a decrease on dental implant loss. We performed a retrospective review (1995-2012) of 1020 patient dental charts to collect data including a cadre of different variables such as age, gender, race, diabetes, osteoporosis, jaw location, implant dimensions and professional maintenance therapy. As a patient may have multiple implants which are correlated, we selected one random implant per patient to assure independence of observations assumption of the Cox proportional hazards regression model. Data analysis was performed using Kaplan-Meier survival curves and multivariate analysis using Cox proportional hazards regression analysis. Our results demonstrate that subjects with no maintenance had the lowest cumulative survival rate as compared to subjects with regular maintenance. In a multivariate Cox regression model, regular maintenance patients had the dental implant failure rate reduced by 90% as compared to no maintenance (P = 0.001). If patients had less than one maintenance visit per year, the failure rate was reduced by 60% as compared to no maintenance, but the difference was not statistically significant (P = 0.08). From this research, we conclude that a professional administered periodontal maintenance at least on an annual basis is a critical factor for implant survival. © 2015 The Authors. International Journal of Dental Hygiene Published by John Wiley & Sons Ltd.

  7. Plasma Glutamine Concentrations in Liver Failure.

    Directory of Open Access Journals (Sweden)

    Gunnel Helling

    Full Text Available Higher than normal plasma glutamine concentration at admission to an intensive care unit is associated with an unfavorable outcome. Very high plasma glutamine levels are sometimes seen in both acute and chronic liver failure. We aimed to systematically explore the relation between different types of liver failure and plasma glutamine concentrations.Four different groups of patients were studies; chronic liver failure (n = 40, acute on chronic liver failure (n = 20, acute fulminant liver failure (n = 20, and post-hepatectomy liver failure (n = 20. Child-Pugh and Model for End-stage Liver Disease (MELD scores were assessed as indices of liver function. All groups except the chronic liver failure group were followed longitudinally during hospitalisation. Outcomes were recorded up to 48 months after study inclusion.All groups had individuals with very high plasma glutamine concentrations. In the total group of patients (n = 100, severity of liver failure correlated significantly with plasma glutamine concentration, but the correlation was not strong.Liver failure, regardless of severity and course of illness, may be associated with a high plasma glutamine concentration. Further studies are needed to understand whether high glutamine levels should be regarded as a biomarker or as a contributor to symptomatology in liver failure.

  8. Types of Heart Failure

    Science.gov (United States)

    ... Disease Venous Thromboembolism Aortic Aneurysm More Types of Heart Failure Updated:Feb 9,2017 Left-sided heart failure ... making. This content was last reviewed April 2015. Heart Failure • Home • About Heart Failure Introduction Types of Heart ...

  9. Buildings Lean Maintenance Implementation Model

    Science.gov (United States)

    Abreu, Antonio; Calado, João; Requeijo, José

    2016-11-01

    Nowadays, companies in global markets have to achieve high levels of performance and competitiveness to stay "alive".Within this assumption, the building maintenance cannot be done in a casual and improvised way due to the costs related. Starting with some discussion about lean management and building maintenance, this paper introduces a model to support the Lean Building Maintenance (LBM) approach. Finally based on a real case study from a Portuguese company, the benefits, challenges and difficulties are presented and discussed.

  10. Entretian Model for Software Maintenance

    Directory of Open Access Journals (Sweden)

    Priya K Betala

    2013-10-01

    Full Text Available Maintenance refers to the act of modifying the software after putting in use in order to maintain its usability.[1]. In other words, Software maintenance can be defined as; it is the process of providing services to the customers after the delivery of the software. Despite the fact that maintaining software is very challenging, it is the most important routine that must be carried out in the development cycle. If the software is not maintained efficiently it may lead to the death of the software. Maintenance of software may be carried out in two ways. The first one is called „In-house maintenance‟ and the second one is called „Transition maintenance‟. The latter faces the drastic challenges when compared to former, as one team may not provide complete source code to the other, leading to unstructured code, lack of appropriate technique and knowledge about the functioning of the current software. There are a few aspects of software maintenance that set it apart from the other phases. Software maintenance cost comprises more than half of the total software development cost. Also, without software maintenance, it is impossible to change the problems within the product after its release, and many disasters can happen because of immature software. Recognising the importance of software maintenance, this paper proposes a model called “ENTRETIAN MODEL” (Entretian, a French word meaning Maintenance which consists of six basic steps to follow while maintaining software system. This model overcomes certain misconceptions about maintenance phase and it is highly beneficial to the Maintenance Support Team (MST to handle their maintenance activities systematically and efficiently. By employing the proposed model, the MST is able to overcome the technical and managerial issues that are faced earlier in the maintenance phase. The advantage of using “Entretian Model” is best illustrated in this paper with the help of the ERP package.

  11. DCSP hardware maintenance system

    Energy Technology Data Exchange (ETDEWEB)

    Pazmino, M.

    1995-11-01

    This paper discusses the necessary changes to be implemented on the hardware side of the DCSP database. DCSP is currently tracking hardware maintenance costs in six separate databases. The goal is to develop a system that combines all data and works off a single database. Some of the tasks that will be discussed in this paper include adding the capability for report generation, creating a help package and preparing a users guide, testing the executable file, and populating the new database with data taken from the old database. A brief description of the basic process used in developing the system will also be discussed. Conclusions about the future of the database and the delivery of the final product are then addressed, based on research and the desired use of the system.

  12. Failure to thrive: an update.

    Science.gov (United States)

    Cole, Sarah Z; Lanham, Jason S

    2011-04-01

    Failure to thrive in childhood is a state of undernutrition due to inadequate caloric intake, inadequate caloric absorption, or excessive caloric expenditure. In the United States, it is seen in 5 to 10 percent of children in primary care settings. Although failure to thrive is often defined as a weight for age that falls below the 5th percentile on multiple occasions or weight deceleration that crosses two major percentile lines on a growth chart, use of any single indicator has a low positive predictive value. Most cases of failure to thrive involve inadequate caloric intake caused by behavioral or psychosocial issues. The most important part of the outpatient evaluation is obtaining an accurate account of a child's eating habits and caloric intake. Routine laboratory testing rarely identifies a cause and is not generally recommended. Reasons to hospitalize a child for further evaluation include failure of outpatient management, suspicion of abuse or neglect, or severe psychosocial impairment of the caregiver. A multidisciplinary approach to treatment, including home nursing visits and nutritional counseling, has been shown to improve weight gain, parent-child relationships, and cognitive development. The long-term effects of failure to thrive on cognitive development and future academic performance are unclear.

  13. Is Maintenance Therapy for Everyone?

    Science.gov (United States)

    Nooka, Ajay K; Lonial, Sagar

    2016-08-01

    Although myeloma remains an incurable disease among majority of myeloma patients, the prognosis has significantly improved after the introduction of novel agents. While more agents are being explored for their anti-myeloma activity, the more familiar agents with a better tolerability profile have been tested in the maintenance arena. Lenalidomide and bortezomib so far have shown promise as effective maintenance agents in prolonging PFS, and also OS in some studies. The current review aims at describing the clinical data supporting various maintenance therapies and also at providing some clarity to a few concerns associated with maintenance therapies.

  14. 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)

  15. Understanding chronic heart failure

    OpenAIRE

    Fenton, Matthew; Burch, Michael

    2007-01-01

    The key principles of chronic heart failure and the development of clinical management strategies are described. The physiological changes in chronic heart failure and the clinical management of children with heart failure are considered, but the treatment of heart failure related to congenital heart disease or the intensive care management of heart failure are not mentioned as both topics require consideration in their own right. A greater understanding of the maladaptive responses to chroni...

  16. Immune mediated liver failure

    OpenAIRE

    Wang, Xiaojing; Ning, Qin

    2014-01-01

    Liver failure is a clinical syndrome of various etiologies, manifesting as jaundice, encephalopathy, coagulopathy and circulatory dysfunction, which result in subsequent multiorgan failure. Clinically, liver failure is classified into four categories: acute, subacute, acute-on-chronic and chronic liver failure. Massive hepatocyte death is considered to be the core event in the development of liver failure, which occurs when the extent of hepatocyte death is beyond the liver regenerative capac...

  17. Understanding contraceptive failure

    OpenAIRE

    Trussell, James

    2009-01-01

    Contraceptive failure is a major source of unintended pregnancy. This chapter will review sources of data and measurement of contraceptive failure, summarize results from the literature on the risks of contraceptive failure during typical and perfect use for available methods of contraception, provide a tool for communicating risks of contraceptive failure to clients, examine determinants of contraceptive failure, and identify methodological pitfalls in the published literature.

  18. On the application of copula in modeling maintenance contract

    Science.gov (United States)

    Iskandar, B. P.; Husniah, H.

    2016-02-01

    This paper deals with the application of copula in maintenance contracts for a nonrepayable item. Failures of the item are modeled using a two dimensional approach where age and usage of the item and this requires a bi-variate distribution to modelling failures. When the item fails then corrective maintenance (CM) is minimally repaired. CM can be outsourced to an external agent or done in house. The decision problem for the owner is to find the maximum total profit whilst for the agent is to determine the optimal price of the contract. We obtain the mathematical models of the decision problems for the owner as well as the agent using a Nash game theory formulation.

  19. Illinois Occupational Skill Standards: Industrial Maintenance General Maintenance Cluster.

    Science.gov (United States)

    Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

    These skill standards for the industrial maintenance general maintenance cluster are intended to be a guide to workforce preparation program providers in defining content for their programs and to employers to establish the skills and standards necessary for job acquisition. An introduction provides the Illinois perspective; Illinois Occupational…

  20. Maintenance performance improvement with System Dynamics: A Corrective Maintenance showcase

    NARCIS (Netherlands)

    Deenen, R.E.M.; Van Daalen, C.E.; Koene, E.G.C.

    2008-01-01

    This paper presents a case study of an analysis of a Corrective Maintenance process to realize performance improvement. The Corrective Maintenance process is supported by SAP, which has indicated the performance realisation problem. System Dynamics is used in a Group Model Building process to

  1. Condition-based dynamic maintenance operations planning and grouping. Application to commercial heavy vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Bouvard, K., E-mail: keomany.bouvard@volvo.co [Volvo Technology, 99 route de Lyon, 69806 Saint Priest cedex (France); Laboratoire d' Automatique de Genie Informatique et Signal - FRE3303 - Polytech' Lille, 59655 Villeneuve d' Ascq (France); Artus, S., E-mail: samuel.artus@volvo.co [Volvo Technology, 99 route de Lyon, 69806 Saint Priest cedex (France); Berenguer, C., E-mail: christophe.berenguer@utt.f [Universite de technologie de Troyes - Institut Charles Delaunay and UMR CNRS 6279 - 12, rue Marie Curie, BP2060, 10010 Troyes cedex (France); Cocquempot, V., E-mail: vincent.cocquempot@univ-lille1.f [Laboratoire d' Automatique de Genie Informatique et Signal - FRE3303 - Polytech' Lille, 59655 Villeneuve d' Ascq (France)

    2011-06-15

    This paper aims at presenting a method to optimize the maintenance planning for a commercial heavy vehicle. Such a vehicle may be considered as a multi-components system. Grouping maintenance operations related to each component reduces the global maintenance cost of the system. Classically, the optimization problem is solved using a priori reliability characteristics of components. Two types of methods may be used, i.e. static or dynamic methods. Static methods provide a fixed maintenance planning, whereas dynamic methods redefine the groups of maintenance operations at each decision time. Dynamic procedures can incorporate component information such as component states or detected failures. For deteriorating systems, reliability characteristics of each component may be estimated thanks to deterioration models and may be updated when a degradation measure is available. This additional information on degradation features allows to better follow the real state of each component and to improve the maintenance planning.

  2. Human Factors Issues In Aircraft Maintenance And Inspection

    Science.gov (United States)

    1990-11-01

    reliability data system ( NPRDS ) " Maintenance personnel performance simulation (MAPPS) * Cognitive environment simulation (CES) * Criteria for equating...System ( NPRDS ) The Nuclear Plant Reliability Data System is a voluntary reporting system sponsored and maintained by the U.S. commercial nuclear power...to 1974. NPRDS data can be recalled by hardware description, vendor, plant, type of failure, source, timeframe, or combinations for use in risk

  3. 冲击环境下租赁设备预防维护策略优化研究%Preventive Maintenance Policy Optimization Based on Shock Model for the Leasing Equipment

    Institute of Scientific and Technical Information of China (English)

    李林; 周晓军; 金琳

    2012-01-01

    从租赁设备的工作环境出发,提出了一种基于冲击模型的故障建模方法,综合考虑改善因子与预防维护成本的制约关系以及租赁条件下的故障惩罚机制,建立了一种面向租赁设备的等周期预防维护策略,并以最小化期望总成本率为决策目标得到租赁设备的优化维护计划.算例分析显示,该策略符合一般租赁设备维护的实际情况,能为服务制造商提供有效的维护解决方案.%In this paper,a periodic preventive maintenance strategy was proposed lor the leasing equipment based on the shock model by comprehensively considering the failure punishment mechanism and the relationship between the improvement factor and preventive maintenance cost. The optimal maintenance plan for the leasing equipment was achieved by minimizing the expected total long-run cost per unit time. The numerical results show that the proposed maintenance strategy is practical and it can provide efficient decision support for the maintenance optimization of the leasing equipment.

  4. 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.

  5. RENEW - MAINTENANCE ESTIMATION SIMULATION MODEL FOR SPACE STATION FREEDOM PROGRAM, VERSION 3.2

    Science.gov (United States)

    Bream, B. L.

    1994-01-01

    RENEW is a maintenance event estimation simulation program developed in support of the Space Station Freedom Program (SSFP) Work Package 4 at NASA Lewis Research Center. This simulation uses reliability and maintainability (R&M) data as well as logistics data to estimate both average and time dependent maintenance demands. RENEW uses Monte Carlo techniques to generate failure and repair times as a function of the R&M and logistics parameters. The estimates are generated for a single type of orbital replacement unit (ORU). The RENEW simulation gives closer estimates of performance than steady-state average calculations since it uses a time dependent approach and depicts more factors affecting ORU failure and repair. RENEW gives both average and time dependent demand values, and generates graphs of both failures over the mission period and yearly failure occurrences. The average demand rate for the ORU over the mission period is also calculated. While RENEW displays the results in graphs, the results are also available in data tables. The process of using RENEW starts with keyboard entry of the R&M and operational data. Once entered, the data may be saved in a data file for later retrieval, and the parameters may be viewed and changed. The simulation program runs the number of Monte Carlo simulations requested by the operator. Plots and tables of the results can be viewed on the screen or sent to a printer. The results of the simulation are saved along with the input data. Help screens are provided with each menu and data entry screen. RENEW is written in BASIC and assembly language for IBM PC series and compatible computers running MS-DOS. Microsoft's QuickBasic Professional Development System and Crescent Software's QuickPak Professional are required to compile the source code. A CGA or VGA monitor is required. A sample executable is provided on the distribution media. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette

  6. Qualitative Maintenance Experience Handbook

    Science.gov (United States)

    1975-10-20

    possible damare to radome during removal and 7 installation. Also, w4hen radar dish’iz present , there is a very Zood chance that IsomethinG on the dish...for the removal arid replaeanent of the =mit. Access * to the bolts, securing the unit to the shelf, is gained through the lover copart- menit ( gum

  7. Achieving world class maintenance status

    Energy Technology Data Exchange (ETDEWEB)

    Tomlingson, P.D. [Paul D. Tomingson Associates (United States)

    2007-08-15

    The article written by a management consultant, discusses the art of successful planning and operation of maintenance in mines considering factors such as benchmaking, key performance indices (KPIs) and frequency of procedures which can help achieve 'world class maintenance'. 1 fig.

  8. The Nordic maintenance care program

    DEFF Research Database (Denmark)

    Myburgh, Corrie; Brandborg-Olsen, Dorthe; Albert, Hanne;

    2013-01-01

    To describe and interpret Danish Chiropractors' perspectives regarding the purpose and rationale for using MC (maintenance care), its content, course and patient characteristics.......To describe and interpret Danish Chiropractors' perspectives regarding the purpose and rationale for using MC (maintenance care), its content, course and patient characteristics....

  9. Truth Maintenance in Automatic Planning.

    Science.gov (United States)

    The objective of this project was to explore the usefulness of incorporating truth maintenance system (TMS) technology into the design of planning...in the report. The six appendices describe the underlying research contributing to the design of the prototype system. Keywords: Truth maintenance, Planning search, Replanning, Nonmonotonic reasoning, Defeasible reasoning.

  10. Recent Research on Language Maintenance.

    Science.gov (United States)

    Garcia, MaryEllen

    2003-01-01

    Describes recent research on language maintenance to provide broad, worldwide coverage of different language contact situations. Surveys various countries in which research within ethnic and minority language communities illuminates language maintenance or shift, or revitalization, for that group. (Author/VWL)

  11. Latent-failure risk estimates for computer control

    Science.gov (United States)

    Dunn, William R.; Folsom, Rolfe A.; Green, Owen R.

    1991-01-01

    It is shown that critical computer controls employing unmonitored safety circuits are unsafe. Analysis supporting this result leads to two additional, important conclusions: (1) annual maintenance checks of safety circuit function do not, as widely believed, eliminate latent failure risk; (2) safety risk remains even if multiple, series-connected protection circuits are employed. Finally, it is shown analytically that latent failure risk is eliminated when continuous monitoring is employed.

  12. Electrical failure during cardiopulmonary bypass: an evaluation of incidence, causes, management and guidelines for preventative measures.

    LENUS (Irish Health Repository)

    Hargrove, M

    2012-02-03

    The incidence of electrical failure during cardiopulmonary bypass (CPB) has been reported to occur in approximately 1 per 1000 cases. While the resultant morbidity and mortality is low, electrical failure is a life-threatening scenario. We report three major electrical failures during CPB in a patient population of 3500 over a 15-year period. These cases involved mains failure and generator shut down, mains failure and generator power surge, and failure of the uninterruptable power supply (UPS), which caused protected sockets to shut down. Protocols for preventative maintenance, necessary equipment, battery backup and guidelines for the successful management of such accidents during CPB are discussed.

  13. Optimal Maintenance of a Production System with Intermediate Buffers

    Directory of Open Access Journals (Sweden)

    Constantinos C. Karamatsoukis

    2012-01-01

    Full Text Available We consider a production-inventory system that consists of an input-generating installation, a production unit and L intermediate buffers. It is assumed that the installation transfers the raw material to buffer and the production unit pulls the raw material from buffer We consider the problem of the optimal preventive maintenance of the installation if the installation deteriorates stochastically with usage and the production unit is always in operative condition. We also consider the problem of the optimal preventive maintenance of the production unit if the production unit deteriorates stochastically with usage and the installation is always in operative condition. Under a suitable cost structure and for given contents of the buffers, it is proved that the average-cost optimal policy for the first (second problem initiates a preventive maintenance of the installation (production unit if and only if the degree of deterioration of the installation (production unit exceeds some critical level. Numerical results are presented for both problems.

  14. Predictors of extubation failure in myasthenic crisis.

    Science.gov (United States)

    Seneviratne, Janaka; Mandrekar, Jay; Wijdicks, Eelco F M; Rabinstein, Alejandro A

    2008-07-01

    The ideal timing for extubation of patients with myasthenic crisis (MC) and the factors that influence extubation outcome are not well established. To assess the risk of extubation failure in MC and to identify predictors of extubation failure. We reviewed consecutive episodes of MC treated with endotracheal intubation from January 1, 1987, through December 31, 2006. Mayo Clinic. Patients Forty patients with 46 episodes of MC underwent endotracheal intubation and mechanical ventilation. The main outcome measures were extubation failure and reintubation. Extubation failure was defined as reintubation, tracheostomy, or death while intubated. Reintubation was also analyzed as a separate end point. Univariate logistic regression was used to identify predictors of extubation failure and reintubation. Of the 46 episodes of MC, extubation failure occurred in 20 (44%), including 9 of 35 episodes (26%) of reintubation. Male sex, history of previous crisis, atelectasis, and intubation for more than 10 days were associated with extubation failure. Lower pH and lower forced vital capacity on the time of extubation, atelectasis, and bilevel intermittent positive airway pressure use after extubation predicted the need for reintubation. Atelectasis showed the strongest association with both end points. Extubation failure and reintubation were associated with significant prolongation in intensive care unit and hospital length of stay. Extubation failure is relatively common in patients with MC. Atelectasis is the strongest predictor of this complication.

  15. Our experience with deceased organ donor maintenance

    Directory of Open Access Journals (Sweden)

    Kumar Meena

    2007-01-01

    Full Text Available Deceased organ donors in an intensive care unit (ICU are the richest source of organs for transplantation. Careful donor maintenance plays a vital role in the successful functioning of the organ in the recipient. Aims : Early identification of brain stem death (BSD in the ICU, problems and management in donor maintenance till retrieval are the main objectives. Materials and Methods : BSD was identified in a level I trauma center over a period of eight years (1996-2004 using UK code. After screening for fitness, they were maintained to achieve normothermia, systolic BP > 90 mm Hg, CVP 8-10 cm water, urine output > 80 ml/hour and normal acid base balance. Results: 168 cases of BSD were maintained, 30 with identity unknown. Common transient complications noted were hypotension (68%, hypokalemia (62%, hypothermia (12%, diabetes insipidus (70%. Brain stem death was identified early and resuscitated to maintain normal tissue perfusion. 17 (12.3% consent for organ donation was obtained. Organs (24 kidneys and one liver were retrieved from 12 donors. Four donors sustained cardiac arrest before retrieval. Conclusion: Early recognition of brain stem death and prompty correction of hemodyanamic instability is the key to deceased donor maintenance. Optimal care of potential donor translates to care of multiple recipients.

  16. Robots for Aircraft Maintenance

    Science.gov (United States)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  17. Subcontracting Railway Maintenance

    DEFF Research Database (Denmark)

    Thommesen, Jacob

    2010-01-01

    In several European countries, national railway operators have been dismantled and partly privatized to create new contractual relations where operations originally performed internally are now outsourced to several companies. Breaking up work across several independent organizational and commerc......In several European countries, national railway operators have been dismantled and partly privatized to create new contractual relations where operations originally performed internally are now outsourced to several companies. Breaking up work across several independent organizational...... railway infrastructure manager (InfraMan), whichis subcontracting maintenance tasks to other companies. InfraMan has implemented various central elements in managing their subcontractors. The latter are required to present a safety plan as part of their bid, they must be approved if they are to be awarded...... a contract, and the competencies of their employees working on the railway are controlled and provided by InfraMan. However, this regime faces a number of further challenges, including uncertainties related to the safety plans, contested responsibility for the education program, difficulties in controlling...

  18. Construction, repair and maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Hinger, R. [Terasen Pipelines, Calgary, AB (Canada); Wong, P. [KC Integrity Corp., Calgary, AB (Canada); Yeomans, M.; Glover, A. [TransCanada PipeLines Ltd., Calgary, AB (Canada)

    2003-07-01

    The presentations by Working Group 4 focused on construction, repair and maintenance of pipelines with particular reference to high-strength steels and their applications for natural gas transmission pipelines. Discussions focused on how technology can be used to provide cost-effective design and construction solutions for long distance pipelines in a manner that does not compromise safety and reliability. The role that carbon plays in increasing the toughness of steel was also discussed. A few fundamental changes in steel production technology and a reduction in carbon content can result in a simultaneous increase in strength and toughness of steels. The cost impact of this technology was summarized. It was concluded that high strength steels offer effective solutions to deliver cost-effective pipelines to transport natural gas from northern basins. This session also presented pipeline routes that transport diluted bitumens from the Athabasca Oil Sands Project and the Muskeg River Mine to upgrader facilities in Alberta. Construction issues included design conservatism, water course crossings, winter construction, winter ditching, and public consultation. Examples of high strength steel pipe applications were also included with reference to experience gained by TransCanada and Corridor Pipeline. tabs., figs.

  19. Technical analysis of failure of catalyst support of reformer furnace tube of a hydrogen generation unit%制氢装置转化炉炉管催化剂支托失效分析

    Institute of Scientific and Technical Information of China (English)

    齐庆轩; 冯岩

    2012-01-01

    The damages of catalyst support of reformer furnace tubes of No. 1 hydrogen generation unit in SINOPEC Shijiazhuang Refining & Chemical Co. , Ltd. in two maintenances were introduced. The composition analysis of catalyst support, the study on the macroscopic photo, the analysis of damaged surface of catalyst support of Incoloy800H, the metallographic analysis, energy dispersion spectrum (EDS) analysis, and scanning electron microscope analysis of support' s section area as well as study on the anti-caburization performances of Cr25Ni20 and Incoloy800H materials have concluded the following: The damages of catalyst support was caused by surface carburization of catalyst support material under high temperature in the presence of hydrogen, which led to phase changes of material surface structure, material stratification, loosening and bulging of surface material structure, large amount of micro-crackings in grain boundary at surface area and eduction of large amount of carbides. All these will reduce the ductility and plasticity of material. Therefore, it is difficult for the catalyst support to restore its original state after thermal expansion, which explains why there are some bulges on the tube of failed support. The anti-carburization performance is greatly improved after application of Cr25Ni20 steel material.%对两次检修中所发现的中国石油化工股份有限公司石家庄炼化分公司l号制氢装置转化炉炉管催化剂支托出现损坏的情况做了介绍,并对两种批次的催化剂支托进行了成分分析,对使用Incoloy800H材料、损坏严重的催化剂支托表面宏观照片进行了分析,对损伤支托的横截面进行金相、电镜及能谱检验分析.通过对Cr25Ni20和lncoloy800H两种材料的抗渗碳能力的比较,得出了以下结论:催化剂支托损伤的原因是材料在含氢高温环境下发生了表面渗碳现象,直接导致材料表面组织相变、材料分层、表现材料组织疏松和隆起,

  20. Rotating Machinery Predictive Maintenance Through Expert System

    Directory of Open Access Journals (Sweden)

    M. Sarath Kumar

    2000-01-01

    Full Text Available Modern rotating machines such as turbomachines, either produce or absorb huge amount of power. Some of the common applications are: steam turbine-generator and gas turbine-compressor-generator trains produce power and machines, such as pumps, centrifugal compressors, motors, generators, machine tool spindles, etc., are being used in industrial applications. Condition-based maintenance of rotating machinery is a common practice where the machine's condition is monitored constantly, so that timely maintenance can be done. Since modern machines are complex and the amount of data to be interpreted is huge, we need precise and fast methods in order to arrive at the best recommendations to prevent catastrophic failure and to prolong the life of the equipment. In the present work using vibration characteristics of a rotor-bearing system, the condition of a rotating machinery (electrical rotor is predicted using an off-line expert system. The analysis of the problem is carried out in an Object Oriented Programming (OOP framework using the finite element method. The expert system which is also developed in an OOP paradigm gives the type of the malfunctions, suggestions and recommendations. The system is implemented in C++.

  1. Analysis of Maintenance Service Contracts for Dump Trucks Used in Mining Industry with Simulation Approach

    Science.gov (United States)

    Dymasius, A.; Wangsaputra, R.; Iskandar, B. P.

    2016-02-01

    A mining company needs high availability of dump trucks used to haul mining materials. As a result, an effective maintenance action is required to keep the dump trucks in a good condition and hence reducing failure and downtime of the dump trucks. To carry out maintenance in-house requires a high intensive maintenance facility and high skilled maintenance specialists. Often, outsourcing maintenance is an economic option for the company. An external agent takes a proactive action with offering some maintenance contract options to the owner. The decision problem for the owner is to decide the best option and for the agent is to determine the optimal price for each option offered. A non-cooperative game-theory is used to formulate the decision problems for the owner and the agent. We consider that failure pattern of each truck follows a non-homogeneous Poisson process (NHPP) and a queueing theory with multiple servers is used to estimate the downtime. As it involves high complexity to model downtime using a queueing theory, then in this paper we use a simulation method. Furthermore, we conduct experiment to seek for the best number of maintenance facilities (servers) which minimises maintenance and penalty costs incurred to the agent.

  2. Condition based maintenance optimization for wind power generation systems under continuous monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhigang; Wu, Bairong; Ding, Fangfang [Concordia Institute for Information Systems Engineering, Concordia University, 1515 Ste-Catherine Street, West EV-7.637, Montreal (Canada); Jin, Tongdan [Ingram School of Engineering, Texas State University (United States)

    2011-05-15

    By utilizing condition monitoring information collected from wind turbine components, condition based maintenance (CBM) strategy can be used to reduce the operation and maintenance costs of wind power generation systems. The existing CBM methods for wind power generation systems deal with wind turbine components separately, that is, maintenance decisions are made on individual components, rather than the whole system. However, a wind farm generally consists of multiple wind turbines, and each wind turbine has multiple components including main bearing, gearbox, generator, etc. There are economic dependencies among wind turbines and their components. That is, once a maintenance team is sent to the wind farm, it may be more economical to take the opportunity to maintain multiple turbines, and when a turbine is stopped for maintenance, it may be more cost-effective to simultaneously replace multiple components which show relatively high risks. In this paper, we develop an optimal CBM solution to the above-mentioned issues. The proposed maintenance policy is defined by two failure probability threshold values at the wind turbine level. Based on the condition monitoring and prognostics information, the failure probability values at the component and the turbine levels can be calculated, and the optimal CBM decisions can be made accordingly. A simulation method is developed to evaluate the cost of the CBM policy. A numerical example is provided to illustrate the proposed CBM approach. A comparative study based on commonly used constant-interval maintenance policy demonstrates the advantage of the proposed CBM approach in reducing the maintenance cost. (author)

  3. Research on Selection of Equipment Maintenance Modes

    Institute of Scientific and Technical Information of China (English)

    SHANG Wen-li; SHI Hai-bo; HE Bai-tao

    2006-01-01

    The development of equipment maintenance management is introduced, and equipment maintenance concept is defined. Equipment maintenance modes are classified, analyzed and compared, which merits and demerits are pointed out. At last, a decision-making frame to select equipment maintenance modes is advanced, and steps to select and implement equipment maintenance are given.

  4. [Understanding heart failure].

    Science.gov (United States)

    Boo, José Fernando Guadalajara

    2006-01-01

    Heart failure is a disease with several definitions. The term "heart failure" is used by has brougth about confusion in the terminology. For this reason, the value of the ejection fraction (< 0.40 or < 0.35) is used in most meganalyses on the treatment of heart failure, avoiding the term "heart failure" that is a confounding concept. In this paper we carefully analyze the meaning of contractility, ventricular function or performance, preload, afterload, heart failure, compensation mechanisms in heart failure, myocardial oxygen consumption, inadequate, adequate and inappropriate hypertrophy, systole, diastole, compliance, problems of relaxation, and diastolic dysfunction. Their definitions are supported by the original scientific descriptions in an attempt to clarify the concepts about ventricular function and heart failure and, in this way, use the same scientific language about the meaning of ventricular function, heart failure, and diastolic dysfunction.

  5. Real System Failures

    Data.gov (United States)

    National Aeronautics and Space Administration — This resource area contains descriptions of actual electronic systems failure scenarios with an emphasis on the diversity of failure modes and effects that can...

  6. Contraceptive failure in China.

    Science.gov (United States)

    Wang, Duolao

    2002-09-01

    This study examines patterns and differentials of contraceptive failure rates by method and characteristics of users, using the Chinese Two-per-Thousand Fertility Survey data. The results show that contraceptive failure rates for modern methods including sterilization are some of the highest in the world. The first year failure rates are 4.2% for male sterilization, 0.7% for female sterilization, 10.3% for IUD, 14.5% for pill, and 19.0% for condom. There are also some differentials in contraceptive failure rates by users' sociodemographic and fertility characteristics. Contraceptive failure rate declines with women's age for all reversible methods. Rural women have higher sterilization, IUD, and condom contraceptive failure rates than urban women. Women with two or more children have a higher failure rate for sterilization methods but have lower failure rates for other methods.

  7. Ivabradine, heart failure and chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Luca Di Lullo

    2015-12-01

    Full Text Available The incidence and prevalence of congestive heart failure are actually increasing worldwide, especially in Western countries. In Europe and the United States, congestive heart failure represents a disabling clinical disease, accountable for increased hospitalization and health care costs. European guidelines have underlined the importance of pharmacological treatment to improve both patients’ outcomes and quality of life. The latest clinical trials to evaluate ivabradine’s efficacy have underlined its usefulness as a stand-alone medication and in combination with conventional congestive heart failure therapy, including in chronic kidney disease patients.

  8. Acute liver failure

    DEFF Research Database (Denmark)

    Larsen, Fin Stolze; Bjerring, Peter Nissen

    2011-01-01

    Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these.......Acute liver failure (ALF) results in a multitude of serious complications that often lead to multi-organ failure. This brief review focuses on the pathophysiological processes in ALF and how to manage these....

  9. Evaluating the Impacts of Technology Education on Military Maintenance Students

    Science.gov (United States)

    Jordan, Jeremy D.; Curtis, Christopher

    2010-01-01

    The United States Air Force (USAF) provides career and technical education (CTE) to a wide variety of specialty career fields. Training airmen to carry out the mission while honoring the USAF core values of integrity first, service before self, and excellence in all we do is the top priority of military leaders and trainers. Vehicle maintenance is…

  10. Industrial Maintenance, Volume II-B. Post Secondary Curriculum Guide.

    Science.gov (United States)

    Butler, Raymond H.; And Others

    This volume is the third of four volumes that comprise a curriculum guide for a postsecondary industrial maintenance program. It contains part of section 3 of the guide which contains the unit guides for 10 of the 12 duties included in the course. Each of the 247 tasks included in these 10 duties is presented on a separate page and contains the…

  11. Industrial Maintenance, Volume II-A. Post Secondary Curriculum Guide.

    Science.gov (United States)

    Butler, Raymond H.; And Others

    This volume is the second of four volumes that comprise a curriculum guide for a postsecondary industrial maintenance program. It contains part of section 3 of the guide which contains the unit guides for two of the 12 duties included in the course. Each of the 197 tasks included in these two duties is presented on a separate page and contains the…

  12. Impacts of the Fleet Response Plan on Surface Combatant Maintenance

    Science.gov (United States)

    2006-01-01

    Plan on Surface Combatant Maintenance Roland J. Yardley, Raj Raman, Jessie Riposo, James Chiesa, John F. Schank Prepared for the United States Navy...Command; CDR Robert Johnson, Kevin Alexander, and LCDR Tony Glover of Commander, Naval Surface Forces Atlantic; and CAPT Larry Olsen and Steve Reynolds

  13. Managing Highway Maintenance--Training Guide and Catalog.

    Science.gov (United States)

    Burke, Clyde A.

    A model curriculum is reported for training personnel who are responsible for managing highway maintenance field operations. The training is organized and sequenced by five broad areas--management problems, management by objective, work planning, work control and management systems. In each area, one or more training units are provided for each of…

  14. 19 CFR 10.707 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Jordan Free Trade Agreement Import Requirements § 10.707 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good under § 10.703 of this subpart must maintain, for five years after...

  15. 19 CFR 10.807 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Bahrain Free Trade Agreement Import Requirements § 10.807 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good under § 10.803 of this subpart must maintain, for five years after...

  16. 19 CFR 10.767 - Maintenance of records.

    Science.gov (United States)

    2010-04-01

    ... TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Morocco Free Trade Agreement Import Requirements § 10.767 Maintenance of records. (a) General. An importer claiming preferential tariff treatment for a good under § 10.763 of this subpart must maintain, for five years after...

  17. Implementation of an agile maintenance mechanic assignment methodology

    Science.gov (United States)

    Jimenez, Jesus A.; Quintana, Rolando

    2000-10-01

    The objective of this research was to develop a decision support system (DSS) to study the impact of introducing new equipment into a medical apparel plant from a maintenance organizational structure perspective. This system will enable the company to determine if their capacity is sufficient to meet current maintenance challenges. The DSS contains two database sets that describe equipment and maintenance resource profiles. The equipment profile specifies data such as mean time to failures, mean time to repairs, and minimum mechanic skill level required to fix each machine group. Similarly, maintenance-resource profile reports information about the mechanic staff, such as number and type of certifications received, education level, and experience. The DSS will then use this information to minimize machine downtime by assigning the highest skilled mechanics to machines with higher complexity and product value. A modified version of the simplex method, the transportation problem, was used to perform the optimization. The DSS was built using the Visual Basic for Applications (VBA) language contained in the Microsoft Excel environment. A case study was developed from current existing data. The analysis consisted of forty-two machine groups and six mechanic categories with ten skill levels. Results showed that only 56% of the mechanic workforce was utilized. Thus, the company had available resources for meeting future maintenance requirements.

  18. Nuclear Power Plant Maintenance Optimization with Heuristic Algorithm

    Directory of Open Access Journals (Sweden)

    Andrija Volkanovski

    2014-01-01

    Full Text Available The test and maintenance activities are conducted in the nuclear power plants in order to prevent or limit failures resulting from the ageing or deterioration. The components and systems are partially or fully unavailable during the maintenance activities. This is especially important for the safety systems and corresponding equipment because they are important contributors to the overall nuclear power plant safety. A novel method for optimization of the maintenance activities in the nuclear power plant considering the plant safety is developed and presented. The objective function of the optimization is the mean value of the selected risk measure. The risk measure is assessed from the minimal cut sets identified in the Probabilistic Safety Assessment. The optimal solution of the objective function is estimated with genetic algorithm. The proposed method is applied on probabilistic safety analysis model of the selected safety system of the reference nuclear power plant. Obtained results show that optimization of maintenance decreases the risk and thus improves the plant safety. The implications of the consideration of different constraints on the obtained results are investigated and presented. The future prospects for the optimization of the maintenance activities in the nuclear power plants with the presented method are discussed.

  19. Dofetilide in patients with congestive heart failure and left ventricular dysfunction: safety aspects and effect on atrial fibrillation. The Danish Investigators of Arrhythmia and Mortality on Dofetilide (DIAMOND) Study Group

    DEFF Research Database (Denmark)

    Møller, M; Torp-Pedersen, C T; Køber, L

    2002-01-01

    and reduced left ventricular systolic function were randomized to receive either placebo or a new class III antiarrhythmic drug, dofetilide. The dose of dofetilide was adjusted according to the presence of atrial fibrillation, the length of the QT interval, and renal function. Patients were continuously......INTRODUCTION. Atrial fibrillation is a frequent cause of worsening of symptoms in patients with congestive heart failure. The drugs currently available for maintenance of sinus rhythm all have major side effects. METHODS. In 34 Danish coronary care units, 1518 patients with congestive heart failure......, 0.81-1.11). Treatment with dofetilide reduced worsening of heart failure significantly (hazard ratio, 0.75; 0.63-0.89). After 1 year, 61% of patients with atrial fibrillation at the start of the study had converted to sinus rhythm on dofetilide, vs. 33% in the placebo group. After conversion...

  20. System reliability in design and maintenance of fixed offshore structures

    Energy Technology Data Exchange (ETDEWEB)

    Dalane, J.I.

    1993-05-01

    Offshore structures are usually redundant, and several components must fail before structural collapse occurs. This work deals with system reliability for fatigue and overload of typical steel truss and frame structure such as jackets and jack-ups. The application of system reliability in design and maintenance is addressed. A formulation for a failure sequence of fatigue and overload is presented. The basic failure event for fatigue, is defined in terms of time to section failure. For overload, realistic failure criteria are applied. After an overload failure, the member replacement technique is used to account for the post collapse behavior. The branch and bound algorithm is used to identify important failure sequences, and system failure occur if any of these collapse sequences occur. The first order reliability methods are efficiently used to calculate the failure probabilities. In this work the importance of uncertainties in load and ultimate strength for a jacket and a jack-up structure is discussed. A joint environmental model for wave and current loading is applied. Ultimate capacity is calculated by nonlinear pushover analysis, and the uncertainties identified by Monte Carlo simulation. Fatigue may be an important failure mode for offshore structure, and in-service inspections are frequently performed. Underwater inspections are, however, very expensive and it is therefore important that the inspections are performed in such a way that they significantly increase our knowledge about the safety of the structure. In this work an inspection importance factor is defined. This importance factor can be used to identify the most important members in the system from an inspection point of view. Inspection for unexpected damages are also discussed. 122 refs., 72 figs., 50 tabs.