Risk Based Maintenance of Offshore Wind Turbines Using Bayesian Networks

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2010-01-01

This paper presents how Bayesian networks can be used to make optimal decisions for repairs of offshore wind turbines. The Bayesian network is an efficient tool for updating a deterioration model whenever new information becomes available from inspections/monitoring. The optimal decision is found...... such that the preventive maintenance effort is balanced against the costs to corrective maintenance including indirect costs to reduced production. The basis for the optimization is the risk based Bayesian decision theory. The method is demonstrated through an application example....

Acid Balance, Dietary Acid Load, and Bone Effects—A Controversial Subject

Directory of Open Access Journals (Sweden)

Lynda Frassetto

2018-04-01

Full Text Available Modern Western diets, with higher contents of animal compared to fruits and vegetable products, have a greater content of acid precursors vs. base precursors, which results in a net acid load to the body. To prevent inexorable accumulation of acid in the body and progressively increasing degrees of metabolic acidosis, the body has multiple systems to buffer and titrate acid, including bone which contains large quantities of alkaline salts of calcium. Both in vitro and in vivo studies in animals and humans suggest that bone base helps neutralize part of the dietary net acid load. This raises the question of whether decades of eating a high acid diet might contribute to the loss of bone mass in osteoporosis. If this idea is true, then additional alkali ingestion in the form of net base-producing foods or alkalinizing salts could potentially prevent this acid-related loss of bone. Presently, data exists that support both the proponents as well as the opponents of this hypothesis. Recent literature reviews have tended to support either one side or the other. Assuming that the data cited by both sides is correct, we suggest a way to reconcile the discordant findings. This overview will first discuss dietary acids and bases and the idea of changes in acid balance with increasing age, then review the evidence for and against the usefulness of alkali therapy as a treatment for osteoporosis, and finally suggest a way of reconciling these two opposing points of view.

Effect of diet composition on acid-base balance in adolescents, young adults and elderly at rest and during exercise.

Science.gov (United States)

Hietavala, E-M; Stout, J R; Hulmi, J J; Suominen, H; Pitkänen, H; Puurtinen, R; Selänne, H; Kainulainen, H; Mero, A A

2015-03-01

Diets rich in animal protein and cereal grains and deficient in vegetables and fruits may cause low-grade metabolic acidosis, which may impact exercise and health. We hypothesized that (1) a normal-protein diet with high amount of vegetables and fruits (HV) induces more alkaline acid-base balance compared with a high-protein diet with no vegetables and fruits (HP) and (2) diet composition has a greater impact on acid-base balance in the elderly (ELD). In all, 12-15 (adolescents (ADO)), 25-35 (young adults (YAD)) and 60-75 (ELD)-year-old male and female subjects (n=88) followed a 7-day HV and a 7-day HP in a randomized order and at the end performed incremental cycle ergometer tests. We investigated the effect of diet composition and age on capillary (c-pH) and urine pH (u-pH), strong ion difference (SID), partial pressure of carbon dioxide (pCO2) and total concentration of weak acids (Atot). Linear regression analysis was used to examine the contribution of SID, pCO2 and Atot to c-pH. In YAD and ELD, c-pH (P⩽0.038) and u-pH (Pdiet-induced acid-base changes.

Knowledge based maintenance

Energy Technology Data Exchange (ETDEWEB)

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

1998-12-31

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

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.)

Threonine and lysine requirements for maintenance in chickens

African Journals Online (AJOL)

student

In order to describe the response of broiler breeder hens to dietary amino acids and to develop an ... containing energy, vitamins and minerals was made available ad libitum during the balance period, to ensure ... amino acid required for maintenance using response trials with populations of laying hens or growing birds.

Correlating multidimensional fetal heart rate variability analysis with acid-base balance at birth

International Nuclear Information System (INIS)

Frasch, Martin G; Durosier, Lucien D; Xu, Yawen; Wang, Xiaogang; Gao, Xin; Stampalija, Tamara; Herry, Christophe; Seely, Andrew JE; Casati, Daniela; Ferrazzi, Enrico; Alfirevic, Zarko

2014-01-01

Fetal monitoring during labour currently fails to accurately detect acidemia. We developed a method to assess the multidimensional properties of fetal heart rate variability (fHRV) from trans-abdominal fetal electrocardiogram (fECG) during labour. We aimed to assess this novel bioinformatics approach for correlation between fHRV and neonatal pH or base excess (BE) at birth. We enrolled a prospective pilot cohort of uncomplicated singleton pregnancies at 38–42 weeks’ gestation in Milan, Italy, and Liverpool, UK. Fetal monitoring was performed by standard cardiotocography. Simultaneously, with fECG (high sampling frequency) was recorded. To ensure clinician blinding, fECG information was not displayed. Data from the last 60 min preceding onset of second-stage labour were analyzed using clinically validated continuous individualized multiorgan variability analysis (CIMVA) software in 5 min overlapping windows. CIMVA allows simultaneous calculation of 101 fHRV measures across five fHRV signal analysis domains. We validated our mathematical prediction model internally with 80:20 cross-validation split, comparing results to cord pH and BE at birth. The cohort consisted of 60 women with neonatal pH values at birth ranging from 7.44 to 6.99 and BE from −0.3 to −18.7 mmol L −1 . Our model predicted pH from 30 fHRV measures (R 2 = 0.90, P < 0.001) and BE from 21 fHRV measures (R 2 = 0.77, P < 0.001). Novel bioinformatics approach (CIMVA) applied to fHRV derived from trans-abdominal fECG during labor correlated well with acid-base balance at birth. Further refinement and validation in larger cohorts are needed. These new measurements of fHRV might offer a new opportunity to predict fetal acid-base balance at birth. (fast track communication)

Recommended ingestion of indispensable amino acids to young men . A study using stable isotopes, plasmatic amino acids and nitrogen balance

International Nuclear Information System (INIS)

Marchini, J.S.

1992-01-01

It has been previously stated that the minimum physiological recommendations for the indispensable amino acids in health adults, as proposed by FAO/WHO/UNU in 1985, are far too low, except for the methionine. An amino acid stable isotopic kinetic study was conducted to seek further experimental support to this hypothesis. Twenty healthy young men received an l-amino acid based diet, supplying 140 mg N.kg -1 .d -1 , patterned on egg protein for 1 week, then for 3 weeks either i) a pattern based on current international recommendations (FAO diet, n=7), ii) a the tentative Laboratory of Human Nutrition of the Massachusetts Institute of Technology, new amino acid recommendation pattern (MIT diet, n=7) or iii) again the egg hen pattern (EGG diet, n=6). All subjects were again studied for one final, consecutive week of the egg diet. At the end of the initial week, at the first and third week with the three experimental diets,and after three days following the return of the egg diet, an 8 h primed continuous intravenous infusion with l- 13 C-leucine was conducted (3 h, fast, 5 h fed - while subjects received hourly meals supplying the equivalent of 5/12 total daily intake). Estimation of leucine balance were carried out with measurements plasma free amino acids changes. Daily nitrogen balances were obtained through the study. Interpretation of plasma amino acids profile, and changes of leucine kinetics balances, indicated that the FAO diet was not able to maintain amino acids homeostasis whereas the MIT and the egg diets sustained body amino acids equilibrium with a positive amino acid balance. nitrogen balances tended to be more negative with the FAO diet but failed to show statistically significant differences among the three diets. The finding point out that it would be prudent to use the new, tentative recommended amino acid pattern (MIT diet 0 as the minimum physiological amino acid needs of healthy human adults (author)

Maintenance management balancing performance maintenance and cost balance at reinforced concrete constructions of the fossil-fuel and nuclear power stations

International Nuclear Information System (INIS)

Ito, Hiroshi; Benno, Hiroshi; Ozaki, Mitsuhiro

2003-01-01

Life elongation of concrete constructions (CCs) is a very important needs for supporting future safe supply of electric power. However, some CCs constructed and used for a long term at fossil-fuel and nuclear power stations had reduction of their required performance by deterioration based on environmental and using conditions represented by salt-damage. As such constructions are anxious to increase in future, it is necessary to keep reliability of their establishments by providing desired rehabilitation to persist supplying effect of their facilities. On the other hand, as it is also essential to progress keeping and reducing cost of power generation together with development of recent liberalization of electric power, it is an important subject how to keep their performance maintenance and cost balance. Therefore, here were outlined on required performance setting method, inspection method, long-term deterioration forecasting and evaluating methods, selection method of countermeasure scenarios minimizing LCC, inspection period setting method, introduction of database and deterioration forecasting system, and so on, to economically maintain and manage already built reinforced concrete constructions at suitable materials and places to elongate their lives. (G.K.)

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to sodium and potassium salts of citric acid and maintenance of normal bone (ID 330) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

claims in relation to sodium and potassium salts of citric acid and maintenance of normal bone. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly...... from stakeholders. The food constituents that are the subject of the health claim are sodium and potassium salts of citric acid. The Panel considers that sodium and potassium salts of citric acid are sufficiently characterised. The claimed effect is “acid-base balance and bone health”. The target...... using a higher dose of potassium citrate did not show an effect on bone mineral density. On the basis of the data presented, the Panel concludes that a cause and effect relationship has not been established between the dietary intake of potassium or sodium salts of citric acid and maintenance of normal...

[Acid-base imbalance in acute obstructive uropathies].

Science.gov (United States)

Belyĭ, L E

2007-01-01

The aim of this study was to evaluate impairment of acid-base balance (ABB) in acute obstructive uropathies. Evaluation of acid-base balance was performed by pH, partial carbon dioxide pressure, plasma bicarbonate concentration, buffer bases, basis excess, hydrogen ion concentration. An automatic gas analyzer was used, plasma anion gap was calculated. Characteristic ABB alterations in different acute obstructive uropathies were detected. Acidotic shifts in acute obstruction of the upper urinary tracts and its inflammatory complications were assessed pathophysiologically. A comparative study of pathological acid-base disorders in acute supra- and infravesical obstructive uropathies was performed.

Whole body acid-base modeling revisited.

Science.gov (United States)

Ring, Troels; Nielsen, Søren

2017-04-01

The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis. Copyright © 2017 the American Physiological Society.

Fatty acid composition of adipose tissue triglycerides after weight loss and weight maintenance

DEFF Research Database (Denmark)

Kunešová, M; Hlavatý, P; Tvrzická, E

2012-01-01

Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants...... of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP....../HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7...

Effects of xylazine on acid-base balance and arterial blood-gas tensions in goats under different environmental temperature and humidity conditions

Directory of Open Access Journals (Sweden)

E.G.M. Mogoa

2000-07-01

Full Text Available The effects of acute exposure to 3 different temperature and humidity conditions on arterial blood-gas and acid-base balance in goats were investigated after intravenous bolus administration of xylazine at a dose of 0.1 mg/kg. Significant (P < 0.05 changes in the variables occurred under all 3 environmental conditions. Decreases in pH, partial pressure of oxygen and oxyhaemoglobin saturation were observed, and the minimum values for oxygen tension and oxyhaemoglobin saturation were observed within 5 min of xylazine administration. The pH decreased to its minimum values between 5 and 15 min. Thereafter, the variables started to return towards baseline, but did not reach baseline values at the end of the 60 min observation period. Increases in the partial pressure of carbon dioxide, total carbon dioxide content, bicarbonate ion concentration, and the actual base excess were observed. The maximum increase in the carbon dioxide tension occurred within 5 min of xylazine administration. The increase in the actual base excess only became significant after 30 min in all 3 environments, and maximal increases were observed at 60 min. There were no significant differences between the variables in the 3 different environments. It was concluded that intravenous xylazine administration in goats resulted in significant changes in arterial blood-gas and acid-base balance that were associated with hypoxaemia and respiratory acidosis, followed by metabolic alkalosis that continued for the duration of the observation period. Acute exposure to different environmental temperature and humidity conditions after xylazine administration did not influence the changes in arterial blood-gas and acid-base balance.

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

Directory of Open Access Journals (Sweden)

Néstor Rodríguez-Padial

2017-01-01

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

Acid-base equilibrium: The best clinical approach

OpenAIRE

Aristizábal-Salazar, Raúl E; Calvo-Torres, L. Felipe; Valencia-Arango, Luis Alfonso; Montoya-Canon, Mauricio; Barbosa-Gantiva, Oscar; Hincapié-Baena, Vanessa

2015-01-01

Acid-base balance disorders can be found in a primary or secondary form in patients with a disease process such as Diabetes Mellitus or acute renal failure, among others. The objective of this article is to explain and guide the correlation ship between the clinical findings in the patient and the parameters of arterial blood gases in a simple and precise manner, in order to make the correct acid-base balance diagnosis and adequate therapeutic interventions. A non-systematic review of the sci...

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

Synthesis of Polystyrene-Based Random Copolymers with Balanced Number of Basic or Acidic Functional Groups

DEFF Research Database (Denmark)

Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

2010-01-01

for the functionalization were applied. The first one involved direct functionalization of the template backbone through alkylation of the phenolic groups with suitable reagents. The second modification approach was based on "click" chemistry, where the introduction of alkyne groups onto the template backbone was followed......Pairs of polystyrene-based random copolymers with balanced number of pendant basic or acidic groups were synthesized utilizing the template strategy. The same poly[(4-hydroxystyrene)-ran-styrene] was used as a template backbone for modification. Two different synthetic approaches...... by copper-catalyzed 1,3 cycloaddition of aliphatic sulfonate- or amine-contaning azides. Both synthetic approaches proved to be highly efficient as evidenced by H-1-NMR analyses. The thermal properties were evaluated by differential scanning calorimetry and thermal gravimetric analyses and were influenced...

Changes in oxygen content and acid-base balance in arterial and portal blood in response to the dietary electrolyte balance in pigs during a 9-h period after a meal

NARCIS (Netherlands)

Dersjant-Li, Y.; Verstegen, M.W.A.; Jansman, A.; Schulze, H.; Schrama, J.W.; Verreth, J.A.J.

2002-01-01

The effect of two dietary electrolyte balance (dEB, Na K - Cl-) levels on arterial and portal blood oxygen content, blood pH, and acid-base status in pigs was studied during a 9-h period after a meal, using a crossover experimental design. The dEB levels were established by changing the Cl- level in

Gentilly 2 maintenance in a total quality environment

Energy Technology Data Exchange (ETDEWEB)

Ross, M H; Marois, H [Hydro-Quebec, Gentilly (Canada). Gentilly Generating Station

1993-12-31

Comprehensive preventive maintenance programs at Gentilly-2 Nuclear Generating Station are based on a policy that seeks to balance requirements against resources. A commitment to total quality aims at performance improvement and total customer satisfaction. To improve overall performance to an annual availability factor of 90%, planned outages must be limited to 21 days per year, and the preventive maintenance program must be upgraded. A quality improvement team is involved in supporting this initiative. This team will seek to bring a new balance to the program, and eventually optimize it, using reliability-centred maintenance techniques. 24 figs.

Risk-based maintenance-Techniques and applications

International Nuclear Information System (INIS)

Arunraj, N.S.; Maiti, J.

2007-01-01

Plant and equipment, however well designed, will not remain safe or reliable if it is not maintained. The general objective of the maintenance process is to make use of the knowledge of failures and accidents to achieve the possible safety with the lowest possible cost. The concept of risk-based maintenance was developed to inspect the high-risk components usually with greater frequency and thoroughness and to maintain in a greater manner, to achieve tolerable risk criteria. Risk-based maintenance methodology provides a tool for maintenance planning and decision making to reduce the probability of failure of equipment and the consequences of failure. In this paper, the risk analysis and risk-based maintenance methodologies were identified and classified into suitable classes. The factors affecting the quality of risk analysis were identified and analyzed. The applications, input data and output data were studied to understand their functioning and efficiency. The review showed that there is no unique way to perform risk analysis and risk-based maintenance. The use of suitable techniques and methodologies, careful investigation during the risk analysis phase, and its detailed and structured results are necessary to make proper risk-based maintenance decisions

Some comments upon acid-base balance in teleost fishes and its relationship to environmental temperature

Energy Technology Data Exchange (ETDEWEB)

Houston, A.H.

1971-01-01

It has been hypothesized that acid-base regulation in mammalian species is directed toward stabilization of body fluid pH, whereas among the poikilotherms control centers upon the maintenance of relative alkalinity. Consequently, given the known relationship between temperature and the dissociation constant of water reductions in mammalian body temperature should be accompanied by decreases in the OH/sup -//H/sup +/ ratio while, under similar circumstances, the pH of the poikilothermic tetrapods, extension of the concept of relative alkalinity regulation to teleost fishes is not wholly consistent with the data presently available. Recorded blood and plasma pH values for teleost fishes are generally below those reported for amphibians and reptiles, tending to fall within or below the levels observed in mammals under comparable thermal conditions. Moreover, they seemingly display little tendency to vary in an inverse fashion wth temperature.

Hemorheological changes, the state of microcirculation, and blood acid-base balance in rats under conditions of a 30-day limiting of the motor activity

Science.gov (United States)

Shtykhno, Y. M.; Udovichenko, V. I.

1980-01-01

Changes were expressed in reduction in number of true capillaries, the appearance of nonfunctioning empty vessels and in the opening of the arteriolo-venular shunts. Changes in the acid-base balance in the direction of reduction of buffer blood content were also noted.

Multiple functions of the crustacean gill: osmotic/ionic regulation, acid-base balance, ammonia excretion, and bioaccumulation of toxic metals

Science.gov (United States)

Henry, Raymond P.; Lucu, Čedomil; Onken, Horst; Weihrauch, Dirk

2012-01-01

The crustacean gill is a multi-functional organ, and it is the site of a number of physiological processes, including ion transport, which is the basis for hemolymph osmoregulation; acid-base balance; and ammonia excretion. The gill is also the site by which many toxic metals are taken up by aquatic crustaceans, and thus it plays an important role in the toxicology of these species. This review provides a comprehensive overview of the ecology, physiology, biochemistry, and molecular biology of the mechanisms of osmotic and ionic regulation performed by the gill. The current concepts of the mechanisms of ion transport, the structural, biochemical, and molecular bases of systemic physiology, and the history of their development are discussed. The relationship between branchial ion transport and hemolymph acid-base regulation is also treated. In addition, the mechanisms of ammonia transport and excretion across the gill are discussed. And finally, the toxicology of heavy metal accumulation via the gill is reviewed in detail. PMID:23162474

Neurologic complications of electrolyte disturbances and acid-base balance.

Science.gov (United States)

Espay, Alberto J

2014-01-01

Electrolyte and acid-base disturbances are common occurrences in daily clinical practice. Although these abnormalities can be readily ascertained from routine laboratory findings, only specific clinical correlates may attest as to their significance. Among a wide phenotypic spectrum, acute electrolyte and acid-base disturbances may affect the peripheral nervous system as arreflexic weakness (hypermagnesemia, hyperkalemia, and hypophosphatemia), the central nervous system as epileptic encephalopathies (hypomagnesemia, dysnatremias, and hypocalcemia), or both as a mixture of encephalopathy and weakness or paresthesias (hypocalcemia, alkalosis). Disabling complications may develop not only when these derangements are overlooked and left untreated (e.g., visual loss from intracranial hypertension in respiratory or metabolic acidosis; quadriplegia with respiratory insufficiency in hypermagnesemia) but also when they are inappropriately managed (e.g., central pontine myelinolisis when rapidly correcting hyponatremia; cardiac arrhythmias when aggressively correcting hypo- or hyperkalemia). Therefore prompt identification of the specific neurometabolic syndromes is critical to correct the causative electrolyte or acid-base disturbances and prevent permanent central or peripheral nervous system injury. This chapter reviews the pathophysiology, clinical investigations, clinical phenotypes, and current management strategies in disorders resulting from alterations in the plasma concentration of sodium, potassium, calcium, magnesium, and phosphorus as well as from acidemia and alkalemia. © 2014 Elsevier B.V. All rights reserved.

Acid-base balance in rainbow trout (Salmo gairdneri) subjected to acid stresses

Energy Technology Data Exchange (ETDEWEB)

Eddy, F.B.

1976-01-01

The respiratory properties of rainbow-trout blood were investigated in acid-stressed fish. In the first group acid was introduced into the bloodstream and in the second the carbon dioxide content of the ambient water was increased. Initially the introduction of the acid to the blood caused a decrease in blood pH and bicarbonate, and increases in oxygen uptake and ventilation volume. After 2 to 3 h these values had returned to the control levels. Trout subjected to high ambient CO/sub 2/ (about 10 mmHg) showed a decrease in blood pH while PCO/sub 2/ and bicarbonate increased. After 8 h the trout began to show signs of compensation to the acidosis. In each experiment the blood PO/sub 2/ was little changed but blood O/sub 2/ content was decreased and tended not to resume the control value even after several hours. The results are discussed in terms of the various acid-base mechanisms thought to be available to the fish. These include branchial ion exchanges and the possible buffering roles of the extracellular and intracellular fluids.

Influence of an acetate- and a lactate-based balanced infusion solution on acid base physiology and hemodynamics: an observational pilot study.

Science.gov (United States)

Hofmann-Kiefer, Klaus F; Chappell, Daniel; Kammerer, Tobias; Jacob, Matthias; Paptistella, Michaela; Conzen, Peter; Rehm, Markus

2012-07-06

The current pilot study compares the impact of an intravenous infusion of Ringer's lactate to an acetate-based solution with regard to acid-base balance. The study design included the variables of the Stewart approach and focused on the effective strong ion difference. Because adverse hemodynamic effects have been reported when using acetate buffered solutions in hemodialysis, hemodynamics were also evaluated. Twenty-four women who had undergone abdominal gynecologic surgery and who had received either Ringer's lactate (Strong Ion Difference 28 mmol/L; n = 12) or an acetate-based solution (Strong Ion Difference 36.8 mmol/L; n = 12) according to an established clinical protocol and its precursor were included in the investigation. After induction of general anesthesia, a set of acid-base variables, hemodynamic values and serum electrolytes was measured three times during the next 120 minutes. Patients received a mean dose of 4,054 ± 450 ml of either one or the other of the solutions. In terms of mean arterial blood pressure and norepinephrine requirements there were no differences to observe between the study groups. pH and serum HCO3- concentration decreased slightly but significantly only with Ringer's lactate. In addition, the acetate-based solution kept the plasma effective strong ion difference more stable than Ringer's lactate. Both of the solutions provided hemodynamic stability. Concerning consistency of acid base parameters none of the solutions seemed to be inferior, either. Whether the slight advantages observed for the acetate-buffered solution in terms of stability of pH and plasma HCO3- are clinically relevant, needs to be investigated in a larger randomized controlled trial.

Exposure to acute severe hypoxia leads to increased urea loss and disruptions in acid-base and ionoregulatory balance in dogfish sharks (Squalus acanthias).

Science.gov (United States)

Zimmer, Alex M; Wood, Chris M

2014-01-01

The effects of acute moderate (20% air O2 saturation; 6-h exposure) and severe (5% air O2 saturation; 4-h exposure) hypoxia on N-waste, acid-base, and ion balance in dogfish sharks (Squalus acanthias suckleyi) were evaluated. We predicted that the synthesis and/or retention of urea, which are active processes, would be inhibited by hypoxia. Exposure to moderate hypoxia had negligible effects on N-waste fluxes or systemic physiology, except for a modest rise in plasma lactate. Exposure to severe hypoxia led to a significant increase in urea excretion (Jurea), while plasma, liver, and muscle urea concentrations were unchanged, suggesting a loss of urea retention. Ammonia excretion (Jamm) was elevated during normoxic recovery. Moreover, severe hypoxia led to disruptions in acid-base balance, indicated by a large increase in plasma [lactate] and substantial decreases in arterial pHa and plasma [Formula: see text], as well as loss of ionic homeostasis, indicated by increases in plasma [Mg(2+)], [Ca(2+)], and [Na(+)]. We suggest that severe hypoxia in dogfish sharks leads to a reduction in active gill homeostatic processes, such as urea retention, acid-base regulation and ionoregulation, and/or an osmoregulatory compromise due to increased functional gill surface area. Overall, the results provide a comprehensive picture of the physiological responses to a severe degree of hypoxia in an ancient fish species.

A proactive condition-based maintenance strategy with both perfect and imperfect maintenance actions

International Nuclear Information System (INIS)

Do, Phuc; Voisin, Alexandre; Levrat, Eric; Iung, Benoit

2015-01-01

This paper deals with a proactive condition-based maintenance (CBM) considering both perfect and imperfect maintenance actions for a deteriorating system. Perfect maintenance actions restore completely the system to the ‘as good as new’ state. Their related cost are however often high. The first objective of the paper is to investigate the impacts of imperfect maintenance actions. In fact, both positive and negative impacts are considered. Positive impact means that the imperfect maintenance cost is usually low. Negative impact implies that (i) the imperfect maintenance restores a system to a state between good-as-new and bad-as-old and (ii) each imperfect preventive action may accelerate the speed of the system's deterioration process. The second objective of the paper is to propose an adaptive maintenance policy which can help to select optimally maintenance actions (perfect or imperfect actions), if needed, at each inspection time. Moreover, the time interval between two successive inspection points is determined according to a remaining useful life (RUL) based-inspection policy. To illustrate the use of the proposed maintenance policy, a numerical example finally is introduced. - Highlights: • A new imperfect maintenance model for deterioration system is proposed. • Both positive and negative impacts of an imperfect maintenance action are investigated. • An adaptive condition-based maintenance policy is introduced. • The optimal number of useful imperfect maintenance actions for each life cycle is optimally provided

Uric acid is associated with nutritional status in maintenance hemodialysis patients

Directory of Open Access Journals (Sweden)

Ji Eun Lee

2012-06-01

Full Text Available Purines, mainly contained in meats, are metabolized finally to uric acid in humans. Although digestion of meat is impaired in end-stage renal disease patients on hemodialysis owing to anorexia and decreased taste, hyperuricemia is common in these patients. In this cross-sectional study, we analyzed demographic characteristics, normalized protein nitrogen appearance (nPNA, serum albumin concentration, and serum uric acid levels and other laboratory parameters in sixty patients on maintenance hemodialysis. There were 33 (55% males and 27 (45% females. The mean age was 62.9±14.3 years and the mean body mass index was 22.7±3.8 kg/m2. The mean serum uric acid level was 7.2±1.2 mg/dL, with the range of 5.1–10.8 mg/dL. There was a statistically significant correlation between serum uric level and nPNA (p < 0.05. The serum uric acid level was also positively correlated with blood urea nitrogen level (p < 0.01 and serum phosphorus level (p < 0.05. Our results suggest that serum uric acid level is associated with nutritional status, and might be a possible marker for protein nutrition in maintenance hemodialysis patients.

Advantages of condition-based maintenance approach

International Nuclear Information System (INIS)

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

2004-01-01

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

Carbonic anhydrase 5 regulates acid-base homeostasis in zebrafish.

Directory of Open Access Journals (Sweden)

Ruben Postel

Full Text Available The regulation of the acid-base balance in cells is essential for proper cellular homeostasis. Disturbed acid-base balance directly affects cellular physiology, which often results in various pathological conditions. In every living organism, the protein family of carbonic anhydrases regulate a broad variety of homeostatic processes. Here we describe the identification, mapping and cloning of a zebrafish carbonic anhydrase 5 (ca5 mutation, collapse of fins (cof, which causes initially a collapse of the medial fins followed by necrosis and rapid degeneration of the embryo. These phenotypical characteristics can be mimicked in wild-type embryos by acetazolamide treatment, suggesting that CA5 activity in zebrafish is essential for a proper development. In addition we show that CA5 regulates acid-base balance during embryonic development, since lowering the pH can compensate for the loss of CA5 activity. Identification of selective modulators of CA5 activity could have a major impact on the development of new therapeutics involved in the treatment of a variety of disorders.

System of Thermal Balance Maintenance in Modern Test Benches for Centrifugal Pumps

Directory of Open Access Journals (Sweden)

A. I. Petrov

2015-01-01

Full Text Available The article “Systems of the heat balance maintenance in modern test benches for centrifugal pumps” makes the case to include cooling systems of a working fluid (heat setting in test bench for impeller pumps. It briefly summarizes an experience of bench building to test centrifugal pumps, developed at the BMSTU Department E-10 over the last 10 years. The article gives the formulas and the algorithm to calculate the heat capacity of different types of impeller pumps when tested at the bench as ell as to determine the heating time of the liquid in the bench without external cooling. Based on analysis of the power balance of a centrifugal pump, it is shown that about 90% of the pump unit-consumed electric power in terminals is used for heating up the working fluid in the loop of the test bench. The article gives examples of elementary heat calculation of the pump operation within the test bench. It presents the main types of systems to maintain thermal balance, their advantages, disadvantages and possible applications. The cooling system schemes for open and closed version of the benches both with built-in and with an independent cooling circuit are analysed. The paper separately considers options of such systems for large benches using the cooling tower as a cooling device in the loop, and to test the pumps using the hydraulic fluids other than water, including those at high temperatures of working fluids; in the latter case a diagram of dual-circuit cooling system "liquid-liquid-air" is shown. The paper depicts a necessity to use ethylene glycol coolant in the two-loop cooling bench. It provides an example of combining the functions of cooling and filtration in a single cooling circuit. Criteria for effectiveness of these systems are stated. Possible ways for developing systems to maintain a thermal balance, modern methods of regulation and control are described. In particular, the paper shows the efficiency of frequency control of the

Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood.

Science.gov (United States)

Hussein, H A; Aamer, A A

2013-01-01

The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10), at RT of about 22-25 ºC (Group II, n = 10) and in an incubator adjusted to 37 ºC (Group III, n = 10) for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0), there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (ppO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (preference range and it may be of clinical diagnostic use for up to 6 h.

Condition based maintenance pilot projects at Pickering ND

International Nuclear Information System (INIS)

Zemdegs, R.T.

1995-01-01

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

Collaborative learning in condition based maintenance

NARCIS (Netherlands)

Koochaki, J.; Ao, SI; Gelman, L; Hukins, DWL; Hunter, A; Korsunsky, AM

2009-01-01

In recent years, the importance of reliable and consistent production equipments has increased. As a result, companies are shifting their maintenance policy from preventive maintenance towards Condition Based Maintenance (CBM). Despite the growing trend in this area and success stories of CBM

A STEPPING STONE TOWARDS KNOWLEDGE BASED MAINTENANCE

OpenAIRE

G. Waeyenbergh; L. Pintelon; L. Gelders

2012-01-01

Maintenance decision making becomes more and more a management concern. Some decades ago, maintenance was still often considered as an unavoidable side effect of production. The perception of maintenance has evolved considerably. One of the current issues is the maintenance concept, being the mix of maintenance interventions and the general framework for determining this mix. In this paper we describe a modular framework, called Knowledge Based Maintenance, for developing a customised mainten...

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.)

A method for accounting for maintenance costs in flux balance analysis improves the prediction of plant cell metabolic phenotypes under stress conditions.

Science.gov (United States)

Cheung, C Y Maurice; Williams, Thomas C R; Poolman, Mark G; Fell, David A; Ratcliffe, R George; Sweetlove, Lee J

2013-09-01

Flux balance models of metabolism generally utilize synthesis of biomass as the main determinant of intracellular fluxes. However, the biomass constraint alone is not sufficient to predict realistic fluxes in central heterotrophic metabolism of plant cells because of the major demand on the energy budget due to transport costs and cell maintenance. This major limitation can be addressed by incorporating transport steps into the metabolic model and by implementing a procedure that uses Pareto optimality analysis to explore the trade-off between ATP and NADPH production for maintenance. This leads to a method for predicting cell maintenance costs on the basis of the measured flux ratio between the oxidative steps of the oxidative pentose phosphate pathway and glycolysis. We show that accounting for transport and maintenance costs substantially improves the accuracy of fluxes predicted from a flux balance model of heterotrophic Arabidopsis cells in culture, irrespective of the objective function used in the analysis. Moreover, when the new method was applied to cells under control, elevated temperature and hyper-osmotic conditions, only elevated temperature led to a substantial increase in cell maintenance costs. It is concluded that the hyper-osmotic conditions tested did not impose a metabolic stress, in as much as the metabolic network is not forced to devote more resources to cell maintenance. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

Equipment Maintenance management support system based on statistical analysis of maintenance history data

International Nuclear Information System (INIS)

Shimizu, S.; Ando, Y.; Morioka, T.

1990-01-01

Plant maintenance is recently becoming important with the increase in the number of nuclear power stations and in plant operating time. Various kinds of requirements for plant maintenance, such as countermeasures for equipment degradation and saving maintenance costs while keeping up plant reliability and productivity, are proposed. For this purpose, plant maintenance programs should be improved based on equipment reliability estimated by field data. In order to meet these requirements, it is planned to develop an equipment maintenance management support system for nuclear power plants based on statistical analysis of equipment maintenance history data. The large difference between this proposed new method and current similar methods is to evaluate not only failure data but maintenance data, which includes normal termination data and some degree of degradation or functional disorder data for equipment and parts. So, it is possible to utilize these field data for improving maintenance schedules and to evaluate actual equipment and parts reliability under the current maintenance schedule. In the present paper, the authors show the objectives of this system, an outline of this system and its functions, and the basic technique for collecting and managing of maintenance history data on statistical analysis. It is shown, from the results of feasibility tests using simulation data of maintenance history, that this system has the ability to provide useful information for maintenance and the design enhancement

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

OpenAIRE

Van Horenbeek, Adriaan

2013-01-01

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

Maintenance Staffing Standards for Zero-Based Budgeting.

Science.gov (United States)

Adams, Matthew C.; And Others

1998-01-01

Discusses school preventive maintenance and the variables associated with maintenance staffing standards that address a zero-based budgeting environment. Explores preventive-maintenance measurement for staffing requirements, defines staffing levels and job descriptions, and outlines the factors to consider when creating a maintenance program and…

Case Based Asset Maintenance for the Electric Equipment

International Nuclear Information System (INIS)

Kim, Ji-Hyeon; Jung, Jae-Cheon; Chang, Young-Woo; Chang, Hoon-Seon; Kim, Jae-Cheol; Kim, Hang-Bae; Kim, Kyu-Ho; Hur, Yong; Lee, Dong-Chul

2006-01-01

The electric equipment maintenance strategies are changing from PM(Preventive Maintenance) or CM(Corrective Maintenance) to CBM(Condition Based Maintenance). The main benefits of CBM are reduced possibility of service failures of critical equipment and reduced costs or maintenance work. In CBM, the equipment status need to be monitored continuously and a decision should be made whether an equipment need to be repaired or replaced. For the maintenance decision making, the CBR(Case Base Reasoning) system is introduced. The CBR system receives the current equipment status and retrieves the case based historic database to determine any possible equipment failure under current conditions. In retrieving the case based historic data, the suggested DSS(Decision Support System) uses a reasoning engine with an equipment/asset ontology that describes the equipment subsumption relationships

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

NARCIS (Netherlands)

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

2017-01-01

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

Time since injury limits but does not prevent improvement and maintenance of gains in balance in chronic stroke.

Science.gov (United States)

Llorens, Roberto; Noé, Enrique; Alcañiz, Mariano; Deutsch, Judith E

2018-01-01

To determine the influence of time since injury on the efficacy and maintenance of gains of rehabilitation of balance after stroke. Forty-seven participants were assigned to a least (6-12 months), a moderate (12-24 months), or a most chronic (>24 months) group. Participants trained for 20 one-hour sessions, administered three to five times a week, combining conventional physical therapy and visual feedback-based exercises that trained the ankle and hip strategies. Participants were assessed before, after the intervention, and one month later with a posturography test (Sway Speed and Limits of Stability) and clinical scales. In contrast to other subjects, the most chronic participants failed to improve their sway and to maintain the benefits detected in the Limits of Stability after the intervention. Although all the participants improved in those clinical tests that better matched the trained skills, time since injury limited the improvement, and over all, the maintenance of gains. Time since injury limits but does not prevent improvement in chronic stages post-stroke, and this effect appears to be more pronounced with maintaining gains. These findings support that training duration and intensity as well as type of therapy may need to be adjusted based on time post-stroke.

The role of the restructured Mobile Remote Service Base System (MBS) in support of Space Station maintenance and servicing

Science.gov (United States)

Darlington, T.; Krukewich, K.

1992-08-01

The critical parameters resulting from the restructuring of Space Station Freedom which necessitated the redesign of the Mobile Remote Service Base System (MBS) are described. These include optimization of robotic attachment locations for access to the Space Station truss-mounted orbital replacement units, transport of logistics carriers to the maintenance sites, minimization of EVA overhead associated with maintenance, self-maintenance of other mobile servicing system (MSS) elements on the MBS, and balancing of station EVA and extravehicular robotics in a complementary fashion to minimize maintenance overhead in general. Consideration is given to the configuration of the resulting MBS, which provides the program with maximum flexibility to utilize the assets of the MSS and optimizes end-to-end maintenance with regard to the use of station resources such as crew time and power. Maintenance and servicing scenarios which are instrumental to the reconfigured MBS as well as the results of improved maintenance capability are presented.

[Acid-base status in patients treated with peritoneal dialysis].

Science.gov (United States)

Katalinić, Lea; Blaslov, Kristina; Pasini, Eva; Kes, Petar; Bašić-Jukić, Nikolina

2014-04-01

When compared to hemodialysis, peritoneal dialysis is very simple yet low cost method of renal replacement therapy. Series of studies have shown its superiority in preserving residual renal function, postponing uremic complications, maintaining the acid-base balance and achieving better post-transplant outcome in patients treated with this method. Despite obvious advantages, its role in the treatment of chronic kidney disease is still not as important as it should be. Metabolic acidosis is an inevitable complication associated with progressive loss of kidney function. Its impact on mineral and muscle metabolism, residual renal function, allograft function and anemia is very complex but can be successfully managed. The aim of our study was to evaluate the efficiency in preserving the acid-base balance in patients undergoing peritoneal dialysis at Zagreb University Hospital Center. Twenty-eight patients were enrolled in the study. The mean time spent on the treatment was 32.39 ± 43.43 months. Only lactate-buffered peritoneal dialysis fluids were used in the treatment. Acid-base balance was completely maintained in 73.07% of patients; 11.54% of patients were found in the state of mild metabolic acidosis, and the same percentage of patients were in the state of mild metabolic alkalosis. In one patient, mixed alkalosis with respiratory and metabolic component was present. The results of this study showed that acid-base balance could be maintained successfully in patients undergoing peritoneal dialysis, even only with lactate-buffered solutions included in the treatment, although they were continuously proclaimed as inferior in comparison with bicarbonate-buffered ones. In well educated and informed patients who carefully use this method, accompanied by the attentive and thorough care of their physicians, this method can provide quality continuous replacement of lost renal function as well as better quality of life.

Mechanisms of n-3 fatty acid-mediated development and maintenance of learning memory performance.

Science.gov (United States)

Su, Hui-Min

2010-05-01

Docosahexaenoic acid (DHA, 22:6n-3) is specifically enriched in the brain and mainly anchored in the neuronal membrane, where it is involved in the maintenance of normal neurological function. Most DHA accumulation in the brain takes place during brain development in the perinatal period. However, hippocampal DHA levels decrease with age and in the brain disorder Alzheimer's disease (AD), and this decrease is associated with reduced hippocampal-dependent spatial learning memory ability. A potential mechanism is proposed by which the n-3 fatty acids DHA and eicosapentaenoic acid (20:5n-3) aid the development and maintenance of spatial learning memory performance. The developing brain or hippocampal neurons can synthesize and take up DHA and incorporate it into membrane phospholipids, especially phosphatidylethanolamine, resulting in enhanced neurite outgrowth, synaptogenesis and neurogenesis. Exposure to n-3 fatty acids enhances synaptic plasticity by increasing long-term potentiation and synaptic protein expression to increase the dendritic spine density, number of c-Fos-positive neurons and neurogenesis in the hippocampus for learning memory processing. In aged rats, n-3 fatty acid supplementation reverses age-related changes and maintains learning memory performance. n-3 fatty acids have anti-oxidative stress, anti-inflammation, and anti-apoptosis effects, leading to neuron protection in the aged, damaged, and AD brain. Retinoid signaling may be involved in the effects of DHA on learning memory performance. Estrogen has similar effects to n-3 fatty acids on hippocampal function. It would be interesting to know if there is any interaction between DHA and estrogen so as to provide a better strategy for the development and maintenance of learning memory. Copyright 2010 Elsevier Inc. All rights reserved.

Performance-based inspection and maintenance strategies

International Nuclear Information System (INIS)

Vesely, W.E.

1995-01-01

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

Cost savings from performance-based maintenance contracting

NARCIS (Netherlands)

Straub, A.

2009-01-01

New procurement approaches combined with performance-based building approaches should reduce costs, but empirical qualitative and quantitative studies are lacking. Performance-based maintenance contracts give maintenance suppliers incentives to improve their way of working. Innovative,

A STEPPING STONE TOWARDS KNOWLEDGE BASED MAINTENANCE

Directory of Open Access Journals (Sweden)

G. Waeyenbergh

2012-01-01

Full Text Available Maintenance decision making becomes more and more a management concern. Some decades ago, maintenance was still often considered as an unavoidable side effect of production. The perception of maintenance has evolved considerably. One of the current issues is the maintenance concept, being the mix of maintenance interventions and the general framework for determining this mix. In this paper we describe a modular framework, called Knowledge Based Maintenance, for developing a customised maintenance concept. After describing the general framework and its decision support use, some case experiences are given. This experience covers some elements of the proposed framework.

Impacts of ocean acidification on respiratory gas exchange and acid-base balance in a marine teleost, Opsanus beta.

Science.gov (United States)

Esbaugh, Andrew J; Heuer, Rachael; Grosell, Martin

2012-10-01

The oceanic carbonate system is changing rapidly due to rising atmospheric CO(2), with current levels expected to rise to between 750 and 1,000 μatm by 2100, and over 1,900 μatm by year 2300. The effects of elevated CO(2) on marine calcifying organisms have been extensively studied; however, effects of imminent CO(2) levels on teleost acid-base and respiratory physiology have yet to be examined. Examination of these physiological processes, using a paired experimental design, showed that 24 h exposure to 1,000 and 1,900 μatm CO(2) resulted in a characteristic compensated respiratory acidosis response in the gulf toadfish (Opsanus beta). Time course experiments showed the onset of acidosis occurred after 15 min of exposure to 1,900 and 1,000 μatm CO(2), with full compensation by 2 and 4 h, respectively. 1,900-μatm exposure also resulted in significantly increased intracellular white muscle pH after 24 h. No effect of 1,900 μatm was observed on branchial acid flux; however, exposure to hypercapnia and HCO(3)(-) free seawater compromised compensation. This suggests branchial HCO(3)(-) uptake rather than acid extrusion is part of the compensatory response to low-level hypercapnia. Exposure to 1,900 μatm resulted in downregulation in branchial carbonic anhydrase and slc4a2 expression, as well as decreased Na(+)/K(+) ATPase activity after 24 h of exposure. Infusion of bovine carbonic anhydrase had no effect on blood acid-base status during 1,900 μatm exposures, but eliminated the respiratory impacts of 1,000 μatm CO(2). The results of the current study clearly show that predicted near-future CO(2) levels impact respiratory gas transport and acid-base balance. While the full physiological impacts of increased blood HCO(3)(-) are not known, it seems likely that chronically elevated blood HCO(3)(-) levels could compromise several physiological systems and furthermore may explain recent reports of increased otolith growth during exposure to elevated CO(2).

Discounted cost model for condition-based maintenance optimization

International Nuclear Information System (INIS)

Weide, J.A.M. van der; Pandey, M.D.; Noortwijk, J.M. van

2010-01-01

This paper presents methods to evaluate the reliability and optimize the maintenance of engineering systems that are damaged by shocks or transients arriving randomly in time and overall degradation is modeled as a cumulative stochastic point process. The paper presents a conceptually clear and comprehensive derivation of formulas for computing the discounted cost associated with a maintenance policy combining both condition-based and age-based criteria for preventive maintenance. The proposed discounted cost model provides a more realistic basis for optimizing the maintenance policies than those based on the asymptotic, non-discounted cost rate criterion.

The acid-base balance in women with neoplasmatic process of the genitals and the effect of Co60 therapy

International Nuclear Information System (INIS)

Tomaszkiewicz, T.; Markowska, J.; Glogowska, Z.; Simm, S.; Herwichowska, K.

1980-01-01

The acid-base balance parameters were determined in 34 women with neoplasmatic process in the genital organs (2 and 3 stage of development) before and after Co 60 therapy. Blood gasometery (capillary blood samples were drawn from the finger, ear-lobe and neoplasm-involved uterine cervix) served as basis for the study. After treatment an increase of the pCo 2 bicarbonates and base reserve values were noted in the capillary blood samples collected from the finger or ear-lobe and a decrease of the hydrogen ions concentration in the capillary blood drawn from the uterine cervix were met. The changes in electroneutrality of organism fluids were tested considering the treatment effects. After Co 60 treatment an increase of the pO 2 was demonstrated in both examined groups. (author)

Maintenance evaluation using risk based criteria

International Nuclear Information System (INIS)

Torres Valle, A.

1996-01-01

The maintenance evaluation is currently performed by using economic and, in some case, technical equipment failure criteria, however this is done to a specific equipment level. In general, when statistics are used the analysis for maintenance optimization are made isolated and whit a post mortem character; The integration provided by mean of Probabilistic Safety assessment (PSA) together with the possibilities of its applications, allow for evaluation of maintenance on the basis of broader scope criteria in regard to those traditionally used. The evaluate maintenance using risk based criteria, is necessary to follow a dynamic and systematic approach, in studying the maintenance strategy, to allow for updating the initial probabilistic models, for including operational changes that often take place during operation of complex facilities. This paper proposes a dynamic evaluation system of maintenance task. The system is illustrated by means of a practical example

Influence of different storage times and temperatures on blood gas and acid-base balance in ovine venous blood

Directory of Open Access Journals (Sweden)

H.A. Hussein

2013-01-01

Full Text Available The present study was designed to investigate the effects of storage temperature and time on blood gas and acid-base balance of ovine venous blood. Ten clinically healthy sheep were used in this study. A total number of 30 blood samples, were divided into three different groups, and were stored in a refrigerator adjusted to +4 ºC (Group I, n = 10, at RT of about 22-25 ºC (Group II, n = 10 and in an incubator adjusted to 37 ºC (Group III, n = 10 for up to 48 h. Blood samples were analysed for blood gas and acid-base indices at 0, 1, 2, 3, 4, 5, 6, 12, 24 and 48 h of storage. In comparison to the baseline value (0, there were significant decreases of blood pH of samples stored at RT and in the incubator after 1 h (p<0.05, the pH value of refrigerated blood samples exhibited insignificant changes during the study (p<0.05. Mean values of pCO2 showed a significant increase in Group I and Group III after 1 h then a progressive decrease after 12 h in all Groups. Mean pO2 values were significantly higher for Group I after 2 h and for Groups II and III after 1 h (p<0.05. In general, base excess decreased significantly for all the groups during the study especially in Groups II and III. In comparison with baseline values, in all groups, bicarbonate (HCO3 increased between 1 h and 6 h (p<0.05, and later decreased at the end of the study (p<0.05. In conclusion, status of acid-base indices of the samples stored at refrigerator and RT were found within normal reference range and it may be of clinical diagnostic use for up to 6 h.

Ageing Management Based Maintenance at ETRR-II

Energy Technology Data Exchange (ETDEWEB)

Kamoon, A.; Ali, A., E-mail: akamoun2004@yahoo.com [Inshas Nuclear Research Centre, Egyptian Atomic Energy Authority (EAEA), Cairo (Egypt)

2014-08-15

The second research reactor of Egypt, ETRR-II, is an open pool type multi-purpose reactor of 22 MW that has been in operation since 1998. The main purposes of ETRR-II are the production of radioisotopes, personnel training, research and development. Ageing management of ETRR-II is based on the maintenance programme. This programme was planned to have a proactive maintenance strategy that mainly depends on adequate preventive and predictive maintenance. Screening of SSCs is based on safety classes, needs and quality levels. The operation condition and maintenance history are the basis to assess the level of degradation. The ultimate aim of the maintenance team is to perform adequate maintenance work only when it is really necessary. The objectives of the ageing management based maintenance are to maintain and improve equipment availability, confirm compliance with operational limits and conditions, and detect and correct any abnormal condition that might affect reactor safety. The programme also helps to detect trends in ageing so that a plan for mitigating ageing effects can be prepared and implemented. Reactor service conditions are monitored through many parameters and conditions such as conductivity and pH of coolant water, water radiochemical analysis, thermal and hydraulic parameters, a leak detection system, corrosion rate of piping, vibration level of rotating equipment and control rod drop time.

Evaporation and NARS Nitric Acid Mass Balance Summary: 2000--2005

International Nuclear Information System (INIS)

Kreutzberg, B.D.; Ames, R.L.; Hansel, K.M.

2005-01-01

A compilation of the historical nitric acid processing data for the evaporation and nitric acid recycle system (NARS) in TA-55 has provided general acid mass balance trends, as well as the location of missing information in both the evaporation system and NARS data logs. The data were accumulated during the calendar years 2000 to 2005. After making a number of processing assumptions, the empirical system information was used to create an interactive spreadsheet that predicts, with moderate accuracy, some of the various stream variables for the combined evaporation and acid recycle processes. Empirical data and interactive calculations were compared to an Aspen Plus(trademark) simulation of the process

An Intelligent Fleet Condition-Based Maintenance Decision Making Method Based on Multi-Agent

OpenAIRE

Bo Sun; Qiang Feng; Songjie Li

2012-01-01

According to the demand for condition-based maintenance online decision making among a mission oriented fleet, an intelligent maintenance decision making method based on Multi-agent and heuristic rules is proposed. The process of condition-based maintenance within an aircraft fleet (each containing one or more Line Replaceable Modules) based on multiple maintenance thresholds is analyzed. Then the process is abstracted into a Multi-Agent Model, a 2-layer model structure containing host negoti...

An Intelligent Fleet Condition-Based Maintenance Decision Making Method Based on Multi-Agent

Directory of Open Access Journals (Sweden)

Bo Sun

2012-01-01

Full Text Available According to the demand for condition-based maintenance online decision making among a mission oriented fleet, an intelligent maintenance decision making method based on Multi-agent and heuristic rules is proposed. The process of condition-based maintenance within an aircraft fleet (each containing one or more Line Replaceable Modules based on multiple maintenance thresholds is analyzed. Then the process is abstracted into a Multi-Agent Model, a 2-layer model structure containing host negotiation and independent negotiation is established, and the heuristic rules applied to global and local maintenance decision making is proposed. Based on Contract Net Protocol and the heuristic rules, the maintenance decision making algorithm is put forward. Finally, a fleet consisting of 10 aircrafts on a 3-wave continuous mission is illustrated to verify this method. Simulation results indicate that this method can improve the availability of the fleet, meet mission demands, rationalize the utilization of support resources and provide support for online maintenance decision making among a mission oriented fleet.

Dry period cooling ameliorates physiological variables and blood acid base balance, improving milk production in murrah buffaloes

Science.gov (United States)

Aarif, Ovais; Aggarwal, Anjali

2016-03-01

This study aimed to evaluate the impact of evaporative cooling during late gestation on physiological responses, blood gas and acid base balance and subsequent milk production of Murrah buffaloes. To investigate this study sixteen healthy pregnant dry Murrah buffaloes (second to fourth parity) at sixty days prepartum were selected in the months of May to June and divided into two groups of eight animals each. One group of buffaloes (Cooled/CL) was managed under fan and mist cooling system during dry period. Group second buffaloes (Noncooled/NCL) remained as control without provision of cooling during dry period. The physiological responses viz. Rectal temperature (RT), Respiratory rate (RR) and Pulse rate were significantly ( P Milk yield, FCM, fat yield, lactose yield and total solid yield was significantly higher ( P < 0.05) in cooled group of Murrah buffaloes.

On condition based maintenance policy

Directory of Open Access Journals (Sweden)

Jong-Ho Shin

2015-04-01

Full Text Available In the case of a high-valuable asset, the Operation and Maintenance (O&M phase requires heavy charges and more efforts than the installation (construction phase, because it has long usage life and any accident of an asset during this period causes catastrophic damage to an industry. Recently, with the advent of emerging Information Communication Technologies (ICTs, we can get the visibility of asset status information during its usage period. It gives us new challenging issues for improving the efficiency of asset operations. One issue is to implement the Condition-Based Maintenance (CBM approach that makes a diagnosis of the asset status based on wire or wireless monitored data, predicts the assets abnormality, and executes suitable maintenance actions such as repair and replacement before serious problems happen. In this study, we have addressed several aspects of CBM approach: definition, related international standards, procedure, and techniques with the introduction of some relevant case studies that we have carried out.

Molecular Mechanisms Underlying Abscisic Acid/Gibberellin Balance in the Control of Seed Dormancy and Germination in Cereals

Directory of Open Access Journals (Sweden)

Pham A. Tuan

2018-05-01

Full Text Available Seed dormancy is an adaptive trait that does not allow the germination of an intact viable seed under favorable environmental conditions. Non-dormant seeds or seeds with low level of dormancy can germinate readily under optimal environmental conditions, and such a trait leads to preharvest sprouting, germination of seeds on the mother plant prior to harvest, which significantly reduces the yield and quality of cereal crops. High level of dormancy, on the other hand, may lead to non-uniform germination and seedling establishment. Therefore, intermediate dormancy is considered to be a desirable trait as it prevents the problems of sprouting and allows uniformity of postharvest germination of seeds. Induction, maintenance, and release of seed dormancy are complex physiological processes that are influenced by a wide range of endogenous and environmental factors. Plant hormones, mainly abscisic acid (ABA and gibberellin (GA, are the major endogenous factors that act antagonistically in the control of seed dormancy and germination; ABA positively regulates the induction and maintenance of dormancy, while GA enhances germination. Significant progress has been made in recent years in the elucidation of molecular mechanisms regulating ABA/GA balance and thereby dormancy and germination in cereal seeds, and this review summarizes the current state of knowledge on the topic.

Molecular Mechanisms Underlying Abscisic Acid/Gibberellin Balance in the Control of Seed Dormancy and Germination in Cereals

Science.gov (United States)

Tuan, Pham A.; Kumar, Rohit; Rehal, Pawanpuneet K.; Toora, Parneet K.; Ayele, Belay T.

2018-01-01

Seed dormancy is an adaptive trait that does not allow the germination of an intact viable seed under favorable environmental conditions. Non-dormant seeds or seeds with low level of dormancy can germinate readily under optimal environmental conditions, and such a trait leads to preharvest sprouting, germination of seeds on the mother plant prior to harvest, which significantly reduces the yield and quality of cereal crops. High level of dormancy, on the other hand, may lead to non-uniform germination and seedling establishment. Therefore, intermediate dormancy is considered to be a desirable trait as it prevents the problems of sprouting and allows uniformity of postharvest germination of seeds. Induction, maintenance, and release of seed dormancy are complex physiological processes that are influenced by a wide range of endogenous and environmental factors. Plant hormones, mainly abscisic acid (ABA) and gibberellin (GA), are the major endogenous factors that act antagonistically in the control of seed dormancy and germination; ABA positively regulates the induction and maintenance of dormancy, while GA enhances germination. Significant progress has been made in recent years in the elucidation of molecular mechanisms regulating ABA/GA balance and thereby dormancy and germination in cereal seeds, and this review summarizes the current state of knowledge on the topic. PMID:29875780

A knowledge-based assistant for valve maintenance planning

International Nuclear Information System (INIS)

Winter, M.J.; Danofsky, R.A.; Spinrad, B.I.; Howard, K.

1987-01-01

A knowledge-based program is being developed to assist engineers in maintenance planning for safety related, motor-operated valves at a boiling water reactor. The purpose of this project is to develop the general framework for a prototype system that demonstrates the capabilities for diagnosing valve symptoms and prescribing corrective maintenance, completing a portion of the Corrective Maintenance Action Request (CMAR) form which must be prepared for each job, and managing an interactive valve data base. Minimizing user input and providing output in a form that is familiar to the maintenance planning engineer are important goals for the program. This paper describes the present features of the valve maintenance advisory system which is currently being tested

Elevated CO2-mitigation of high temperature stress associated with maintenance of positive carbon balance and carbohydrate accumulation in Kentucky bluegrass.

Science.gov (United States)

Song, Yali; Yu, Jingjin; Huang, Bingru

2014-01-01

Elevated CO2 concentration may promote plant growth while high temperature is inhibitory for C3 plant species. The interactive effects of elevated CO2 and high temperatures on C3 perennial grass growth and carbon metabolism are not well documented. Kentucky bluegrass (Poa pratensis) plants were exposed to two CO2 levels (400 and 800 μmol mol-1) and five temperatures (15/12, 20/17, 25/22, 30/27, 35/32°C, day/night) in growth chambers. Increasing temperatures to 25°C and above inhibited leaf photosynthetic rate (Pn) and shoot and root growth, but increased leaf respiration rate (R), leading to a negative carbon balance and a decline in soluble sugar content under ambient CO2. Elevated CO2 did not cause shift of optimal temperatures in Kentucky bluegrass, but promoted Pn, shoot and root growth under all levels of temperature (15, 20, 25, 30, and 35°C) and mitigated the adverse effects of severe high temperatures (30 and 35°C). Elevated CO2-mitigation of adverse effects of high temperatures on Kentucky bluegrass growth could be associated with the maintenance of a positive carbon balance and the accumulation of soluble sugars and total nonstructural carbohydrates through stimulation of Pn and suppression of R and respiratory organic acid metabolism.

Advances in safety related maintenance

International Nuclear Information System (INIS)

2000-03-01

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

Geochemical mass balance for sulfur- and nitrogen-bearing acid components: Eastern United States

International Nuclear Information System (INIS)

Bischoff, W.D.; Mackenzie, F.T.; Paterson, V.L.

1984-01-01

The impact on a geographical region of SO 2 and nitrogen oxides (NO /SUB x/ ) emissions to the atmosphere because of man's activities (e.g., burning of fossil fuels and smelting of sulfide ores) usually has not been considered in terms of a regional geochemical mass balance model. Mass balance models, however, have been employed extensively on a global scale. The models evaluate reservoir sizes, processes and fluxes associated with the transfer of a substance within a system of interest. The models may be steady- or transient-state, and include assessment of historical (geologic), present and future data and processes. In this chapter a geochemical mass balance model is applied to constituents of acid precipitation (H + , NO - 3 and SO 2- ) to evaluate the impact of acid precipitation on the eastern United States

Correction of the acid-base balance in the presence of the hypoxic-ischemic brain damage in newborns

Directory of Open Access Journals (Sweden)

K. S. Kiriakov

2018-01-01

Full Text Available One of the current problems of perinatal neurology is the hypoxic-ischemic brain damage in newborns associated with the influence of the hypoxia upon the fetus, intranatal and postnatal asphyxia on one hand and a lack of the efficient therapy schemes on the other hand. Due to this, the purpose of this pilotstudy isto identify the effects of drug Cytoflavin, included into the complex therapy scheme for the newborns with the cerebral ischemia of II-III stages, on the blood acid-base balance. A retrospective analysis of the results of the complex therapy for 16 newborns with the moderate (14 children and severe (2 children brain ischemia was performed. Cytoflavin was included in the standard therapy schemes for all children at a dose of 2 ml/kg per day at a dilution of 5% glucose solution at the ratio of 1:5, intravenously, microfluidically for 20 hours for 3 days. In addition to the standard examination, the blood acid-base balance assessment using the follow-up microgasometric method was included (after 60 min and then every 6 hours until 72 hours of observation. All children had positive tendency to the arresting of the metabolic acidosis (in the form of the decrease of the base deficiency after 24 hours and increase of pH level (the level of 7.30 was reached by 12 hours of age in full-term newborns and 24 hour of age in the preterm newborns. The revealed positive changes in the time of the metabolic acidosis arresting along with the small volumes of the infusion and good tolerability are the cause for the planning of the subsequent, more large-scale studies. 

Reliability-based performance simulation for optimized pavement maintenance

International Nuclear Information System (INIS)

Chou, Jui-Sheng; Le, Thanh-Son

2011-01-01

Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: →A novel algorithm using multi-objective particle swarm optimization technique. → Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. → A probabilistic model for regression parameters is employed to assess reliability-based performance. → The proposed approach can help decision makers to optimize roadway maintenance plans.

Reliability-based performance simulation for optimized pavement maintenance

Energy Technology Data Exchange (ETDEWEB)

Chou, Jui-Sheng, E-mail: jschou@mail.ntust.edu.tw [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China); Le, Thanh-Son [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China)

2011-10-15

Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: > A novel algorithm using multi-objective particle swarm optimization technique. > Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. > A probabilistic model for regression parameters is employed to assess reliability-based performance. > The proposed approach can help decision makers to optimize roadway maintenance plans.

Intracellular pH regulation by acid-base transporters in mammalian neurons

Science.gov (United States)

Ruffin, Vernon A.; Salameh, Ahlam I.; Boron, Walter F.; Parker, Mark D.

2014-01-01

Intracellular pH (pHi) regulation in the brain is important in both physiological and physiopathological conditions because changes in pHi generally result in altered neuronal excitability. In this review, we will cover 4 major areas: (1) The effect of pHi on cellular processes in the brain, including channel activity and neuronal excitability. (2) pHi homeostasis and how it is determined by the balance between rates of acid loading (JL) and extrusion (JE). The balance between JE and JL determine steady-state pHi, as well as the ability of the cell to defend pHi in the face of extracellular acid-base disturbances (e.g., metabolic acidosis). (3) The properties and importance of members of the SLC4 and SLC9 families of acid-base transporters expressed in the brain that contribute to JL (namely the Cl-HCO3 exchanger AE3) and JE (the Na-H exchangers NHE1, NHE3, and NHE5 as well as the Na+- coupled HCO3− transporters NBCe1, NBCn1, NDCBE, and NBCn2). (4) The effect of acid-base disturbances on neuronal function and the roles of acid-base transporters in defending neuronal pHi under physiopathologic conditions. PMID:24592239

Mobile Clinical Decision Support System for Acid-base Balance Diagnosis and Treatment Recommendation.

Science.gov (United States)

Mandzuka, Mensur; Begic, Edin; Boskovic, Dusanka; Begic, Zijo; Masic, Izet

2017-06-01

This paper presents mobile application implementing a decision support system for acid-base disorder diagnosis and treatment recommendation. The application was developed using the official integrated development environment for the Android platform (to maximize availability and minimize investments in specialized hardware) called Android Studio. The application identifies disorder, based on the blood gas analysis, evaluates whether the disorder has been compensated, and based on additional input related to electrolyte imbalance, provides recommendations for treatment. The application is a tool in the hands of the user, which provides assistance during acid-base disorders treatment. The application will assist the physician in clinical practice and is focused on the treatment in intensive care.

Application of condition based maintenance to nuclear power plants

International Nuclear Information System (INIS)

Sonoda, Yukio; Nakano, Tomohito; Shimizu, Shunichi; Iida, Jun; Atomura, Masakazu; Abe, Masahiro

2002-01-01

Device Karte management system which supports application of condition based maintenance to nuclear power plants has been developed. The purpose of this system is to support maintenance personnel in device inspection scheduling based on operating condition monitoring and maintenance histories. There are four functions: field database, degradation estimation, inspection time decision and maintenance planning. The authors have been applying this system to dozens of devices of Onagawa Nuclear Power Station Unit No. 1 for one year. This paper represents the system concept and its application experiences. (author)

Maintenance management systems

International Nuclear Information System (INIS)

Rohan, M. de

1989-01-01

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

[Impact of a simultaneous application of anionic salts and rumen buffer on acid-base-balance and mineral metabolism in dairy cows].

Science.gov (United States)

Gelfert, Carl-Christian; Hauser, Simone; Löptien, Antje; Montag, Nicole; Passmann, Mareike; Baumgartner, Walter; Staufenbiel, Rudolf

2006-01-01

In this study, the influence of simultaneous application of anionic salts (AS) and rumen buffer (RB) on the metabolism of dairy cows was examined. Eleven rumen fistulated, non-pregnant and non-lactating dairy cows received equal amounts of one AS (CaCl2 or CaSO4) and one RB (NaHCO3 or KHCO3) via rumen cannula during feeding time over a period of eight days. Before the first application of AS and RB and on day eight of the treatment period, blood, urine and rumen fluid samples were taken. The following parameters were measured: whole blood: pH, base excess, bicarbonate; serum: sodium, potassium, chloride, calcium; urine: pH, net acid base excretion, sodium, potassium, chloride, calcium; rumen fluid: pH. The changes of each parameter were compared via ANOVA. The changes in acid-base balance on day eight were very small, although significant. But p-values showed that the statistical evidence was low. The most changes occurred when NaHCO3 was fed in combination with one of the AS used. In this case a small acidogenic load was seen in blood (p buffer must not be fed, if anionic salts are given for prevention of parturient paresis.

Virtual maintenance technology for reactor system based on PPR technology

International Nuclear Information System (INIS)

Wu Yaxiang; Ma Baiyong

2009-01-01

Based on the Product, Process and Resources (PPR) technology, the establishing technology of virtual maintenance environment for the reactor system and the process structure tree for virtual maintenance is studied, and the flow for the maintainability design and simulation for reactor system is put forward. Based on the subsection simulation of maintenance process and layered design of maintenance actions, the leveled structure of the reactor system virtual maintenance task is studied. The relation for the data of product, process and resource is described by Plan Evaluation and Review Technology (PERT) diagram to define the maintenance operation. (authors)

Quantitative acid-base physiology using the Stewart model. Does it improve our understanding of what is really wrong?

NARCIS (Netherlands)

Derksen, R.; Scheffer, G.J.; Hoeven, J.G. van der

2006-01-01

Traditional theories of acid-base balance are based on the Henderson-Hasselbalch equation to calculate proton concentration. The recent revival of quantitative acid-base physiology using the Stewart model has increased our understanding of complicated acid-base disorders, but has also led to several

Liming Influences Growth and Nutrient Balances in Sugar Maple (Acer saccharum) Seedlings on an Acidic Forest Soil

Science.gov (United States)

Dudley J. Raynal

1998-01-01

Forests in the northeastern US have been limed to mitigate soil acidification and the acidity of surface waters and to improve soil base cation status. Much of the area considered for liming is within the range of sugar maple (Acer saccharum), but there is a poor understanding of how liming influences growth and nutrient balance of this species on...

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Sønderkær

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...... 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...

Restoration of Respiratory Gases and Acid-base Balance of Blood of Gamma Irradiated Rats Through Bone Marrow Transplantation

International Nuclear Information System (INIS)

Eissa, S.M.; Roushdy, H.M.; Khamis, F. I.; Abu-Zeid, N.M.

2000-01-01

The present investigation aimed at elucidating the role played by bone marrow transplantation as a biological treatment against the deleterious effect of ionizing radiation. The parameters tested were PO2; PCO2; TCO2 and acid base balance encountering pH and (HCO3) in blood. Investigations were conducted 1,3,7,14 and 21 days post whole body gamma exposure at the dose levels 2 and 6 Gy. The data obtained showed highly significant changes in all tested parameters after whole body gamma irradiation. A higher depressant effect was more pronounced after exposure to higher radiation dose. Bone marrow transplantation to irradiated rats resulted in partial restoration or the radiation induced changes in both PO2 and PCO2 as recorded on the first week post treatment and succeeded to ameliorate the radiation induced changes in pH values and (HCO3) in blood

Biofeedback-Based, Videogame Balance Training in Autism

Science.gov (United States)

Travers, Brittany G.; Mason, Andrea H.; Mrotek, Leigh Ann; Ellertson, Anthony; Dean, Douglas C., III; Engel, Courtney; Gomez, Andres; Dadalko, Olga I.; McLaughlin, Kristine

2018-01-01

The present study examined the effects of a visual-based biofeedback training on improving balance challenges in autism spectrum disorder (ASD). Twenty-nine youth with ASD (7-17 years) completed an intensive 6-week biofeedback-based videogame balance training. Participants exhibited training-related balance improvements that significantly…

A randomized controlled study on the effects of acetate-free biofiltration on organic anions and acid-base balance in hemodialysis patients.

Science.gov (United States)

Sánchez-Canel, Juan J; Hernández-Jaras, Julio; Pons-Prades, Ramón

2015-02-01

Metabolic acidosis correction is achieved by the transfer of bicarbonate and other buffer anions in dialysis. The aim of this study was to evaluate changes in the main anions of intermediary metabolism on standard hemodiafiltration (HDF) and on acetate-free biofiltration (AFB). A prospective, in-center, crossover study was carried out with 22 patients on maintenance dialysis. Patients were randomly assigned to start with 12 successive sessions of standard HDF with bicarbonate (34 mmol/L) and acetate dialysate (3 mmol/L) or 12 successive sessions of AFB without base in the dialysate. Acetate increased significantly during the standard HDF session from 0.078 ± 0.062 mmol/L to 0.156 ± 0.128 mmol/L (P acid-base equilibrium through a bicarbonate substitution fluid. It also prevents hyperacetatemia and restores internal homeostasis with less production of intermediary metabolites. © 2014 The Authors. Therapeutic Apheresis and Dialysis © 2014 International Society for Apheresis.

Influencing factors for condition-based maintenance in railway tracks using knowledge-based approach

NARCIS (Netherlands)

Jamshidi, A.; Hajizadeh, S.; Naeimi, M.; Nunez Vicencio, Alfredo; Li, Z.

2017-01-01

In this paper, we present a condition-based maintenance decision method using
knowledge-based approach for rail surface defects. A railway track may contain a considerable number of surface defects which influence track maintenance decisions. The proposed method is based on two sets of

Nitrogen balance, plasma free amino acid concentrations and urinary orotic acid excretion during long-term fasting in cats.

Science.gov (United States)

Biourge, V; Groff, J M; Fisher, C; Bee, D; Morris, J G; Rogers, Q R

1994-07-01

The purpose of this study was to ascertain the changes in nitrogen balance, plasma free amino acid concentrations, urinary orotic acid excretion and body weight during long-term fasting in adult obese cats. Results from eight cats that fasted rather than eat an unpalatable diet are reported. After 5 to 6 wk of weight loss, six of the eight cats developed signs of hepatic lipidosis, and the livers of all cats were severely infiltrated with lipids. Cats lost (mean +/- SE) 33.2 +/- 1.4% of their pre-fasting body weight. Mean nitrogen balance (+/- SE) was -547 +/- 54 mg.d-1.kg-2/3 for the first week, and then the net nitrogen losses decreased to a plateau (-303 +/- 52 mg.d-1.kg-2/3) after 4 wk. Fasting was associated with a decrease in plasma concentration of essential amino acids. When plasma amino acid concentrations were considered individually, concentrations of alanine, methionine, taurine, citrulline, arginine and tryptophan decreased the most (> or = 50%), whereas concentrations of glutamine, glutamate and ornithine significantly increased. Orotic acid was not detected in the urine during the fast. After 1 wk of fasting, obese cats had reduced nitrogen excretion, but not to the same extent as has been shown in obese humans or obese rats. It is suggested that the availability of several amino acids may become limiting for liver protein synthesis during fasting and that these deficiencies may contribute to the development of hepatic lipidosis. Orotic acid was not linked to hepatic lipidosis caused by fasting in cats.

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2009-01-01

For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based lifecycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue, corrosion...

Transformer oil maintenance

Energy Technology Data Exchange (ETDEWEB)

White, J. [A.F. White Ltd., Brantford, ON (Canada)

2002-08-01

Proactive treatment is required in the case of transformer oil, since the oil degrades over time, which could result in the potential failure of the transformer or costly repairs. A mineral-based oil is used for transformers because of its chemical properties and dielectric strength. Water and particulate are the main contaminants found in transformer oil, affecting the quality of the oil through reduced insulation. Acid that forms in the oil when reacting with oxygen is called oxidization. It reduces the heat dissipation of the transformer as the acid forms sludge which settles on the windings of the transformer. The first step in the preventive maintenance program associated with transformer oil is the testing of the oil. The base line is established through initial testing, and subsequent annual testing identifies any changes. The minimal requirements are: (1) dielectric breakdown, a measure of the voltage conducted by the oil; (2) neutralization/acid number, which detects the level of acid present in the oil; (3) interfacial tension, which identifies the presence of polar compounds; (4) colour, which displays quality, aging and the presence of contaminants; and (5) water, which decreases the dielectric breakdown voltage. The analysis of the gases present in the oil is another useful tool in a maintenance program for the determination of a possible fault such as arcing, corona or overheated connections and is accomplished through Dissolved Gas Analysis (DGA). Remediation treatment includes upgrading the oil. Ideally, reclamation should be performed in the early stages of the acid buildup before sludging occurs. Onsite reclamation includes Fuller's earth processing and degasification, a process briefly described by the author.

Assessing Acid-Base Status: Physiologic Versus Physicochemical Approach.

Science.gov (United States)

Adrogué, Horacio J; Madias, Nicolaos E

2016-11-01

The physiologic approach has long been used in assessing acid-base status. This approach considers acids as hydrogen ion donors and bases as hydrogen ion acceptors and the acid-base status of the organism as reflecting the interaction of net hydrogen ion balance with body buffers. In the physiologic approach, the carbonic acid/bicarbonate buffer pair is used for assessing acid-base status and blood pH is determined by carbonic acid (ie, Paco 2 ) and serum bicarbonate levels. More recently, the physicochemical approach was introduced, which has gained popularity, particularly among intensivists and anesthesiologists. This approach posits that the acid-base status of body fluids is determined by changes in the dissociation of water that are driven by the interplay of 3 independent variables: the sum of strong (fully dissociated) cation concentrations minus the sum of strong anion concentrations (strong ion difference); the total concentration of weak acids; and Paco 2 . These 3 independent variables mechanistically determine both hydrogen ion concentration and bicarbonate concentration of body fluids, which are considered as dependent variables. Our experience indicates that the average practitioner is familiar with only one of these approaches and knows very little, if any, about the other approach. In the present Acid-Base and Electrolyte Teaching Case, we attempt to bridge this knowledge gap by contrasting the physiologic and physicochemical approaches to assessing acid-base status. We first outline the essential features, advantages, and limitations of each of the 2 approaches and then apply each approach to the same patient presentation. We conclude with our view about the optimal approach. Copyright © 2016 National Kidney Foundation, Inc. All rights reserved.

Preventive maintenance basis: Volume 24 -- Battery -- flooded lead-acid (lead-calcium, lead antimony, plante). Final report

International Nuclear Information System (INIS)

Worledge, D.; Hinchcliffe, G.

1997-12-01

US nuclear power plants are implementing preventive maintenance (PM) tasks with little documented basis beyond fundamental vendor information to support the tasks or their intervals. The Preventive Maintenance Basis project provides utilities with the technical basis for PM tasks and task intervals associated with 40 specific components such as valves, electric motors, pumps, and HVAC equipment. This document provides a program of preventive maintenance tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. This document provides a program of preventive maintenance (PM) tasks suitable for application to flooded lead-acid batteries. The PM tasks that are recommended provide a cost-effective way to intercept the causes and mechanisms that lead to degradation and failure. They can be used, in conjunction with material from other sources, to develop a complete PM program or to improve an existing program. Users of this information will be utility managers, supervisors, system engineers, craft technicians, and training instructors responsible for developing, optimizing, or fine-tuning PM programs

Risk-based Operation and Maintenance for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Nielsen, Jannie Jessen

2011-01-01

For offshore wind turbines, costs to Operation and Maintenance (OM) are substantial, and can be expected to increase when wind farms are placed at deeper water depths and in more harsh environments. Traditional strategies for OM include corrective and preventive (scheduled and condition...... statistics and costs of the different operations. The different OM strategies are described and compared in an illustrative example with focus on which types of information that are needed. Special focus is on comparison between risk-based maintenance strategies and the conventional maintenance planning...... and are often the driving mechanisms for failures / faults that need maintenance. Observations of the degree of damage can increase the reliability of predictions and decrease the costs of OM if integrated in a risk-based framework theoretically based on pre-posterior Bayesian decision theory. The mathematical...

Acid-base disorders in calves with chronic diarrhea.

Science.gov (United States)

Bednarski, M; Kupczyński, R; Sobiech, P

2015-01-01

The aim of this study was to analyze disorders of acid-base balance in calves with chronic diarrhea caused by mixed, viral, bacterial and Cryptosporydium parvum infection. We compared results ob- tained with the classic model (Henderson-Hasselbalch) and strong ion approach (the Steward model). The study included 36 calves aged between 14 and 21 days. The calves were allocated to three groups: I - (control) non-diarrheic calves, group II - animals with compensated acid-base imbalance and group III calves with compensated acid-base disorders and hypoalbuminemia. Plasma concentrations of Na+, K+, Cl-, C12+, Mg2+, P, albumin and lactate were measured. In the classic model, acid-base balance was determined on the basis of blood pH, pCO2, HCO3-, BE and anion gap. In the strong ion model, strong ion difference (SID), effective strong anion difference, total plasma concentration of nonvolatile buffers (A(Tot)) and strong ion gap (SIG) were measured. The control calves and the animals from groups II and III did not differ significantly in terms of their blood pH. The plasma concentration of HCO3-, BE and partial pressure of CO2 in animals from the two groups with chronic diarrhea were significantly higher than those found in the controls. The highest BE (6.03 mmol/l) was documented in calves from group II. The animals from this group presented compensation resulted from activation of metabolic mechanisms. The calves with hypoal- buminemia (group III) showed lower plasma concentrations of albumin (15.37 g/L), Cl (74.94 mmol/L), Mg2+ (0.53 mmol/L), P (1.41 mmol/L) and higher value of anion gap (39.03 mmol/L). This group III presented significantly higher SID3 (71.89 mmol/L), SID7 (72.92 mmol/L) and SIG (43.53 mmol/L) values than animals from the remaining groups (P acid-base disturbance in these cases suggests that classic model have some limitations. This model can not be recommended for use whenever serum albumin or phosphate concentrations are markedly abnormal.

Maintenance Decision Making based on different types of data fusion

OpenAIRE

Galar, D.; Gustafson, A.; Tormos Martínez, Bernardo Vicente; Berges, Luis

2012-01-01

[EN] Over the last decade, system integration is applied more as it allows organizations to streamline business processes. A recent development in the asset engineering management is to leverage the investment already made in process control systems. This allows the operations, maintenance, and process control teams to monitor and determine new alarm level based on the physical condition data of the critical machines. Condition-based maintenance (CBM) is a maintenance philosophy base...

26 CFR 1.430(f)-1 - Effect of prefunding balance and funding standard carryover balance.

Science.gov (United States)

2010-04-01

... Effect of prefunding balance and funding standard carryover balance. (a) In general—(1) Overview. This... were employed by a single employer. (b) Maintenance of balances—(1) Prefunding balance—(i) In general...) In general. If the plan sponsor of a plan elects to add to the plan's prefunding balance, as of the...

Optimizing block-based maintenance under random machine usage

NARCIS (Netherlands)

de Jonge, Bram; Jakobsons, Edgars

Existing studies on maintenance optimization generally assume that machines are either used continuously, or that times until failure do not depend on the actual usage. In practice, however, these assumptions are often not realistic. In this paper, we consider block-based maintenance optimization

The role of acid-base imbalance in statin-induced myotoxicity.

Science.gov (United States)

Taha, Dhiaa A; De Moor, Cornelia H; Barrett, David A; Lee, Jong Bong; Gandhi, Raj D; Hoo, Chee Wei; Gershkovich, Pavel

2016-08-01

Disturbances in acid-base balance, such as acidosis and alkalosis, have potential to alter the pharmacologic and toxicologic outcomes of statin therapy. Statins are commonly prescribed for elderly patients who have multiple comorbidities such as diabetes mellitus, cardiovascular, and renal diseases. These patients are at risk of developing acid-base imbalance. In the present study, the effect of disturbances in acid-base balance on the interconversion of simvastatin and pravastatin between lactone and hydroxy acid forms have been investigated in physiological buffers, human plasma, and cell culture medium over pH ranging from 6.8-7.8. The effects of such interconversion on cellular uptake and myotoxicity of statins were assessed in vitro using C2C12 skeletal muscle cells under conditions relevant to acidosis, alkalosis, and physiological pH. Results indicate that the conversion of the lactone forms of simvastatin and pravastatin to the corresponding hydroxy acid is strongly pH dependent. At physiological and alkaline pH, substantial proportions of simvastatin lactone (SVL; ∼87% and 99%, respectively) and pravastatin lactone (PVL; ∼98% and 99%, respectively) were converted to the active hydroxy acid forms after 24 hours of incubation at 37°C. At acidic pH, conversion occurs to a lower extent, resulting in greater proportion of statin remaining in the more lipophilic lactone form. However, pH alteration did not influence the conversion of the hydroxy acid forms of simvastatin and pravastatin to the corresponding lactones. Furthermore, acidosis has been shown to hinder the metabolism of the lactone form of statins by inhibiting hepatic microsomal enzyme activities. Lipophilic SVL was found to be more cytotoxic to undifferentiated and differentiated skeletal muscle cells compared with more hydrophilic simvastatin hydroxy acid, PVL, and pravastatin hydroxy acid. Enhanced cytotoxicity of statins was observed under acidic conditions and is attributed to increased

MOSEG code for safety oriented maintenance management Safety of management of maintenance oriented by MOSEG code

International Nuclear Information System (INIS)

Torres Valle, Antonio

2005-01-01

Full text: One of the main reasons that makes maintenance contribute highly when facing safety problems and facilities availability is the lack of maintenance management systems to solve these fields in a balanced way. Their main setbacks are shown in this paper. It briefly describes the development of an integrating algorithm for a safety and availability-oriented maintenance management by virtue of the MOSEG Win 1.0 code. (author)

Sensitivity of Risk-Based Maintenance Planning of Offshore Wind Turbine Farms

DEFF Research Database (Denmark)

Ambühl, Simon; Sørensen, John Dalsgaard

2017-01-01

Inspection and maintenance expenses cover a considerable part of the cost of energy from offshore wind turbines. Risk-based maintenance planning approaches are a powerful tool to optimize maintenance and inspection actions and decrease the total maintenance expenses. Risk-based planning is based...... on many input parameters, which are in reality often not completely known. This paper will assess the cost impact of this incomplete knowledge based on a case study following risk-based maintenance planning. The sensitivity study focuses on weather forecast uncertainties, incomplete knowledge about...... the needed repair time on the site as well as uncertainties about the operational range of the boat and helicopter used to access the broken wind turbine. The cost saving potential is estimated by running Crude Monte Carlo simulations. Furthermore, corrective and preventive (scheduled and condition...

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) and contribution to normal cognitive function (ID 532) and maintenance

DEFF Research Database (Denmark)

Tetens, Inge

claims in relation to docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) and contribution to normal cognitive function and maintenance of normal bone. The scientific substantiation is based on the information provided by the Member States in the consolidated list...... and fish oil”. From the references provided, the Panel assumes that the food constituents that are the subject of the claims are the n-6 fatty acid gamma-linolenic acid (GLA) in evening primrose oil and the n-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA...... of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders. The food constituents that are the subjects of the health claims are “omega-3 and omega-6 fatty acids (GLA)”, “gamma-linolenic acid + eicosapentaenoic acid (GLA+EPA)”, and “evening primrose oil...

The-Abstraction-Hierarchy-based Mobile PC Display Design for NPP Maintenance

International Nuclear Information System (INIS)

Kim, In; Kim, Bo Gyung; Seong, Poong Hyun; Ha, Jun Su

2010-01-01

Recently, the importance of effective maintenance in nuclear power plants (NPPs) has been emphasized and research into effective maintenance by adopting mobile maintenance aids (MMAs) have been attempted. For improved and effective use of an MMA display design method based on abstraction hierarchy (AH) is proposed and its design considerations are discussed in this study. Six levels of abstraction hierarchy are proposed in this paper to classify the maintenance information. By classifying and organizing maintenance information using AH, maintenance information can be used effectively by users with either high or low levels of expertise. When information classification has been finished, the information for MMA design is selected and designed. With the considerations of MMA design analysis and guidelines, AH-based MMA is designed for the maintenance tasks. An experiment is conducted using the AH-based MMA in order to estimate the effectiveness of the proposed method for the maintenance tasks and to identify design considerations to enhance the proposed MMAs. The result indicated that an AH-based manual was more effective than a conventional manual in terms of task completion time and number of errors. The workload for the AH-based manual was estimated less than the conventional manual for subjects with low level of expertise. As the level of expertise increases, subjects tended to follow more abstract information while the number of navigations decreased. It is believed that when mobile devices become pervasive in NPP maintenance fields, AH-model applied MMAs can be used as an effective maintenance supporting tool

Work-life balance: Does age matter?

Science.gov (United States)

Richert-Kaźmierska, Anita; Stankiewicz, Katarzyna

2016-11-22

Work-life balance is a priority of EU policies but at the same time demographic change affects the labour market. Employers have to deal with the ageing of their employees and adjust human resource management to maintain their competitiveness. The purpose of the article is to answer research questions: whether the age of workers determines their assessment of the work-life balance, and whether there is a relationship between the worker's age and their assessment of the activities undertaken by their employer to provide them with work-life balance. The article is based on the results of surveys conducted among 500 employees of the SME sector from Finland, Lithuania and Sweden. The results identified a statistically significant difference: employees representing older age groups are more likely to indicate the maintenance of WLB; older workers more frequently do not agree that all workers have equal opportunities to benefit from flexible solutions aimed at ensuring the maintenance of WLB. The results can be the inspiration for the decisions and actions of employers in the field of personnel management and for creating workplace conditions encouraging senior workers to continue working, even upon becoming entitled to old-age pension.

Using 3–6 differences in essential fatty acids rather than 3/6 ratios gives useful food balance scores

Directory of Open Access Journals (Sweden)

Lands Bill

2012-05-01

Full Text Available Abstract Background The vitamin-like omega-3 and omega-6 essential fatty acids are converted in the body to a large family of hormones which act at selective receptors that occur on nearly every cell and tissue. A relative omega-3 deficit allows overabundant actions of omega-6 hormones to develop into health disorders. People need simple, explicit information on the balance of essential fatty acids in their foods to avoid accumulating unintended imbalances in their tissue omega-3 and omega-6 fatty acids. Results We developed an Omega 3–6 Balance Food Score that summarizes in a single value the balance among eleven omega-3 and omega-6 essential fatty acids in a food. The value allows a quantitative estimate of the impact of each food item on the proportions of omega-3 and omega-6 that will accumulate in the 20- and 22-carbon highly unsaturated fatty acids of blood, which is an important health risk assessment biomarker. Conclusions The impact of an individual food item upon a useful health risk assessment biomarker is easily evident in a simple, explicit value for the balance among eleven essential fatty acids nutrients. Foods with more positive Omega 3–6 Balance Food Scores will increase the percent of omega-3 in the biomarker, whereas those with more negative Scores will increase the percent of omega-6 in the biomarker.

Risk based maintenance: Resource requirements and organizational challenges

International Nuclear Information System (INIS)

Weerakkody, S.D.

2000-01-01

10CFR50.65 'Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants' required licensees to monitor the performance or condition of structures, systems, or components (SSCs) against licensee established goals, in a manner sufficient to provide reasonable assurance that such SSCs are capable of fulfilling their intended functions. The goals were required to be commensurate with safety significance and operating experience. Northeast Utilities relied upon PRAs to implement 10CFR50.65, which is also referred to as the 'Maintenance Rule'. The Maintenance Rule changed some aspects of maintenance of structures, systems, and components (SSC) at nuclear power plants. One objective of the rule was to focus the maintenance resources based on risk significance of components. This paper will discuss the organizational challenges and resource requirements associated with implementation of the Maintenance Rule at nuclear facilities that are supported by the Northeast Utilities Services Company (NUSCo). The paper will discuss (a) how these challenges were addressed, (b) the resources required for ongoing efforts to support the Maintenance Rule, and (c) several key safety benefits derived from the implementation of the Maintenance Rule. (author)

Effect of a ten-week Nordic Walking exercise program on serum electrolyte concentration and plasma acid-base balance in postmenopausal women with overweight or obesity

OpenAIRE

Kałużny, Krystian; Kałużna, Anna; Budzyński, Jacek; Hagner, Wojciech; Kochański, Bartosz; Żukow, Walery; Bronisz, Agata; Hagner‑Derengowska, Magdalena

2016-01-01

Kałużny Krystian, Kałużna Anna, Budzyński Jacek, Hagner Wojciech, Kochański Bartosz, Żukow Walery, Bronisz Agata, Hagner‑Derengowska Magdalena. Effect of a ten-week Nordic Walking exercise program on serum electrolyte concentration and plasma acid-base balance in postmenopausal women with overweight or obesity. Journal of Education, Health and Sport. 2016;6(12):353-364. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.201929 http://ojs.ukw.edu.pl/index.php/johs/article/view/4065 ...

Using Field Data for Energy Efficiency Based on Maintenance and Operational Optimisation. A Step towards PHM in Process Plants

Directory of Open Access Journals (Sweden)

Micaela Demichela

2018-03-01

Full Text Available Energy saving is an important issue for any industrial sector; in particular, for the process industry, it can help to minimize both energy costs and environmental impact. Maintenance optimization and operational procedures can offer margins to increase energy efficiency in process plants, even if they are seldom explicitly taken into account in the predictive models guiding the energy saving policies. To ensure that the plant achieves the desired performance, maintenance operations and maintenance results should be monitored, and the connection between the inputs and the outcomes of the maintenance process, in terms of total contribution to manufacturing performance, should be explicit. In this study, a model for the energy efficiency analysis was developed, based on cost and benefits balance. It is aimed at supporting the decision making in terms of technical and operational solutions for energy efficiency, through the optimization of maintenance interventions and operational procedures. A case study is here described: the effects on energy efficiency of technical and operational optimization measures for bituminous materials production process equipment. The idea of the Conservation Supply Curve (CSC was used to capture both the cost effectiveness of the measures and the energy efficiency effectiveness. The optimization was thus based on the energy consumption data registered on-site: data collection and modelling of the relevant data were used as a base to implement a prognostic and health management (PHM policy in the company. Based on the results from the analysis, efficiency measures for the industrial case study were proposed, also in relation to maintenance optimization and operating procedures. In the end, the impacts of the implementation of energy saving measures on the performance of the system, in terms of technical and economic feasibility, were demonstrated. The results showed that maintenance optimization could help in reaching

Operation and maintenance of the technical installations in buildings

DEFF Research Database (Denmark)

Nielsen, O.(red.)

The report contains twelve papers from a seminar on operation and maintenance, held at the Danish Building Research Institute in October 1976. The papers deal, among other things, with dimensioning and balancing of pipesystems, design of ventilating systems for adequate operation and maintenance,......, cost and quality in maintenance, maintenance service companies, as well as organization and training for building services maintenance....

Balance maintenance as an acquired motor skill: Delayed gains and robust retention after a single session of training in a virtual environment.

Science.gov (United States)

Elion, Orit; Sela, Itamar; Bahat, Yotam; Siev-Ner, Itzhak; Weiss, Patrice L Tamar; Karni, Avi

2015-06-03

Does the learning of a balance and stability skill exhibit time-course phases and transfer limitations characteristic of the acquisition and consolidation of voluntary movement sequences? Here we followed the performance of young adults trained in maintaining balance while standing on a moving platform synchronized with a virtual reality road travel scene. The training protocol included eight 3 min long iterations of the road scene. Center of Pressure (CoP) displacements were analyzed for each task iteration within the training session, as well as during tests at 24h, 4 weeks and 12 weeks post-training to test for consolidation phase ("offline") gains and assess retention. In addition, CoP displacements in reaction to external perturbations were assessed before and after the training session and in the 3 subsequent post-training assessments (stability tests). There were significant reductions in CoP displacements as experience accumulated within session, with performance stabilizing by the end of the session. However, CoP displacements were further reduced at 24h post-training (delayed "offline" gains) and these gains were robustly retained. There was no transfer of the practice-related gains to performance in the stability tests. The time-course of learning the balance maintenance task, as well as the limitation on generalizing the gains to untrained conditions, are in line with the results of studies of manual movement skill learning. The current results support the conjecture that a similar repertoire of basic neuronal mechanisms of plasticity may underlay skill (procedural, "how to" knowledge) acquisition and skill memory consolidation in voluntary and balance maintenance tasks. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of a knowledge-based information management system for plant maintenance

International Nuclear Information System (INIS)

Yim, Hyung Sang; Park, Young Jae; Lee, Sang Min; Choi, Jae Boong; Kim, Young Jin; Roh, Eun Chul; Lee, Byung Ine

2003-01-01

Recently, the importance of Plant Maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as Risk-Based Inspection(RBI), Fitness For Service guidelines(FFS), Plant Lifecycle Management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system, which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance

Development of a knowledge-based information management system for plant maintenance

Energy Technology Data Exchange (ETDEWEB)

Yim, Hyung Sang; Park, Young Jae; Lee, Sang Min; Choi, Jae Boong; Kim, Young Jin [Sungkyunkwan Univ., Seoul (Korea, Republic of); Roh, Eun Chul; Lee, Byung Ine [Pohang Iron and Steel Company, Pohang (Korea, Republic of)

2003-07-01

Recently, the importance of Plant Maintenance(PM) was highly raised to provide efficient plant operation which highly affects the productivity. For this reason, a number of engineering methodologies, such as Risk-Based Inspection(RBI), Fitness For Service guidelines(FFS), Plant Lifecycle Management(PLM), have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP(Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there was no attempt to connect engineering methodologies to the ERP PM system. In this paper, a knowledge-based information system for the plant operation of steel making company has been proposed. This system, which is named as K-VRS(Knowledge-based Virtual Reality System), provides a connection between ERP plant maintenance module and knowledge-based engineering methodologies, and thus, enables network-based highly effective plant maintenance process. The developed system is expected to play a great role for more efficient and safer plant maintenance.

Input-output balances of acids, heavy metals and nutrients, and compartments of accumulation and depletion in forest ecosystems

International Nuclear Information System (INIS)

Mayer, R.

1989-01-01

Forest damage and decline are the consequence of several stress factors acting upon forest ecosystems in various combinations and degrees. Impact of atmospheric pollutants is certainly one of the most prominent of these factors. Regional comparion is facilitated by considering groups of atmospheric substances. We distinguish: 1. Acids and acidifying substances, 2. Heavy metals and 3. Nutrients: N, P, K, Ca, Mg, S. Forest decline has to be recognized as an expression of changes within the forest ecosystem, changes which must be accompanied by a non-steady state of the material balance. The best way to investigate changes in the material balance is to look at input and output of matter to the ecosystems. A positive balance (input > output) over a period of more than one year means accumulation, negative balance (input < output) means depletion of a substance. Based upon several case studies (Subjects I, K), we come to a typification of the material balance at any individual site which is defined by the immission/deposition situation on the one hand, by the geological-pedological site characteristics on the other hand. (orig.VT)

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

Comparison of two approaches for establishing performance criteria related to Maintenance Rule

International Nuclear Information System (INIS)

Jerng, Dong-Wook; Kim, Man Cheol

2015-01-01

Probabilistic safety assessment (PSA) serves as a tool for systemically analyzing the safety of nuclear power plants. This paper explains and compares two approaches for the establishment of performance criteria related to the Maintenance Rule: (1) the individual reliability-based approach, and (2) the PSA importance measure-based approach. Different characteristics of the two approaches were compared in a qualitative manner, while a quantitative comparison was performed through application of the two approaches to a nuclear power plant. It was observed that the individual reliability-based approach resulted in more conservative performance criteria, compared to the PSA importance measure-based approach. It is thus expected that the PSA importance measure-based approach will allow for more flexible maintenance policy under conditions of limited resources, while providing for a macroscopic view of overall plant safety. Based on insights derived through this analysis, we emphasize the importance of a balance between reliability and safety significance, and propose a balance measure accordingly. The conclusions of this analysis are likely to be applicable to other types of nuclear power plants. (author)

Weights in the balance: jasmonic acid and salicylic acid signaling in root-biotroph interactions.

Science.gov (United States)

Gutjahr, Caroline; Paszkowski, Uta

2009-07-01

Work on the interaction of aerial plant parts with pathogens has identified the signaling molecules jasmonic acid (JA) and salicylic acid (SA) as important players in induced defense of the plant against invading organisms. Much less is known about the role of JA and SA signaling in root infection. Recent progress has been made in research on plant interactions with biotrophic mutualists and parasites that exclusively associate with roots, namely arbuscular mycorrhizal and rhizobial symbioses on one hand and nematode and parasitic plant interactions on the other hand. Here, we review these recent advances relating JA and SA signaling to specific stages of root colonization and discuss how both signaling molecules contribute to a balance between compatibility and defense in mutualistic as well as parasitic biotroph-root interactions.

Dialysate bicarbonate variation in maintenance hemodiafiltration patients: Impact on serum bicarbonate, intradialytic hypotension and interdialytic weight gain.

Science.gov (United States)

Viegas, Márcio; Cândido, Cristina; Felgueiras, Joana; Clemente, José; Barros, Sara; Farbota, Rostislav; Vera, Filipa; Matos, Antero; Sousa, Francisco

2017-07-01

The dialysate bicarbonate (DB) influences the acid-base balance in dialysis patients. Very low and high serum bicarbonate (SB) have been related with a higher mortality. Acid-base balance also has been associated with hemodynamic effects in these patients. The trial aim was to compare the effect of DB concentration variation on SB levels in maintenance hemodiafiltration (HDF) patients and the effect on intradialytic hypotension and interdialytic weight gain. A prospective study, with 9 months of follow-up, involving 93 patients, divided in two groups: group 1 and group 2 with a DB of 34 mmol/L and 30 mmol/L, respectively, with monitoring of pre and post HDF SB, intradialytic hypotension, and interdialytic weight gain. Pre dialysis SB was higher in group 1: median concentration of 22.7 mmol/L vs. 21.1 mmol/L (P < 0.001). Post dialysis SB levels were higher in group 1: median concentration of 28.0 mmol/L vs. 25.3 mmol/L (P < 0.001). Post dialysis SB in alkalotic range was only detected in group 1 (51.2% of the patients). No significant differences were detected in intradialytic hypotension rate [28.0 vs. 27.4 episodes per 1000 sessions in group 1 and 2, respectively, (P = 0.906)] or in average interdialytic weight gain [2.9% vs. 3.0% in group 1 and 2, respectively, (P = 0.710)]. DB of 30 mmol/L appears to be associated with SB levels closer to physiological levels than 34 mmol/L. The bicarbonate dialysate, in the tested concentrations, did not appear to have a significant impact on intradialytic hypotension and interdialytic weight gain in maintenance HDF patients. © 2016 International Society for Hemodialysis.

The International Coal Statistics Data Base program maintenance guide

International Nuclear Information System (INIS)

1991-06-01

The International Coal Statistics Data Base (ICSD) is a microcomputer-based system which contains information related to international coal trade. This includes coal production, consumption, imports and exports information. The ICSD is a secondary data base, meaning that information contained therein is derived entirely from other primary sources. It uses dBase III+ and Lotus 1-2-3 to locate, report and display data. The system is used for analysis in preparing the Annual Prospects for World Coal Trade (DOE/EIA-0363) publication. The ICSD system is menu driven and also permits the user who is familiar with dBase and Lotus operations to leave the menu structure to perform independent queries. Documentation for the ICSD consists of three manuals -- the User's Guide, the Operations Manual, and the Program Maintenance Manual. This Program Maintenance Manual provides the information necessary to maintain and update the ICSD system. Two major types of program maintenance documentation are presented in this manual. The first is the source code for the dBase III+ routines and related non-dBase programs used in operating the ICSD. The second is listings of the major component database field structures. A third important consideration for dBase programming, the structure of index files, is presented in the listing of source code for the index maintenance program. 1 fig

Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

International Nuclear Information System (INIS)

Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

2013-01-01

A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt % or 2 wt %) were used at 55 deg C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results

Operation and maintenance requirements of system design bases

International Nuclear Information System (INIS)

Banerjee, A.K.; Hanley, N.E.

1989-01-01

All system designs make assumptions about system operation testing, inspection, and maintenance. Existing industry codes and standards explicitly address design requirements of new systems, while issues related to system and plant reliability, life, design margins, effects of service conditions, operation, maintenance, etc., usually are implicit. However, system/component design documents of existing power plants often address the code requirements without considering the operation, maintenance, inspection, and testing (OMIT) requirements. The nuclear industry is expending major efforts at most nuclear power plants to reassemble and/or reconstitute system design bases. Stone ampersand Webster Engineering Corporation (SWEC) recently addressed the OMIT requirements of system/component design as an integral part of a utility's preventive maintenance program. For each component, SWEC reviewed vendor recommendations, NPRDS data/industry experience, the existing maintenance program, component service conditions, and actual plant experience. A maintenance program that considers component service conditions and plant experience ensures a connection between maintenance and design basis. Root cause analysis of failure and engineering evaluation of service condition are part of the program. System/component OMIT requirements also are compared against system design, service condition, degradation mechanism, etc., through system/component life-cycle evaluation

Acid-base balance and cardiac index in SO2-bronchitic, papaine-emphysematous and paraquat-fibrotic rats after isoproterenol treatment.

Science.gov (United States)

Vértes, K; Debreczeni, L A

1990-01-01

SO2-bronchitis, papaine-emphysema and paraquat fibrosis were induced in Wistar rats. Blood pressure, cardiac index, total peripheral resistance, arterial blood gas values, parameters of acid-base balance were determined. Effects of 0.1 and 0.3 microgram.-1.min-1 isoproterenol iv. infusion were examined. Morphologic alterations of the lungs were verified by histopathological examinations. All the parameters investigated were found to be normal in the control rats. The treated groups differed from the normal ones: an increased blood pressure was observed in emphysema and fibrosis. A decreased cardiac index was characteristic of chronic bronchitis, high cardiac index of emphysema, high TPR of bronchitis and arterial hypoxaemy of fibrosis. The groups reacted differently to beta adrenergic stimulation: in bronchitic and fibrotic rats the cardiac index was augmented, whereas in emphysematous ones the increase proved to be smaller. The effects of isoproterenol infusion can be related to the altered beta-receptor function in the various experimental pulmonary diseases.

Maintenance metabolism and carbon fluxes in Bacillus species

Directory of Open Access Journals (Sweden)

Decasper Seraina

2008-06-01

Full Text Available Abstract Background Selection of an appropriate host organism is crucial for the economic success of biotechnological processes. A generally important selection criterion is a low maintenance energy metabolism to reduce non-productive consumption of substrate. We here investigated, whether various bacilli that are closely related to Bacillus subtilis are potential riboflavin production hosts with low maintenance metabolism. Results While B. subtilis exhibited indeed the highest maintenance energy coefficient, B. licheniformis and B. amyloliquefaciens exhibited only statistically insignificantly reduced maintenance metabolism. Both B. pumilus and B. subtilis (natto exhibited irregular growth patterns under glucose limitation such that the maintenance metabolism could not be determined. The sole exception with significantly reduced maintenance energy requirements was the B. licheniformis strain T380B. The frequently used spo0A mutation significantly increased the maintenance metabolism of B. subtilis. At the level of 13C-detected intracellular fluxes, all investigated bacilli exhibited a significant flux through the pentose phosphate pathway, a prerequisite for efficient riboflavin production. Different from all other species, B. subtilis featured high respiratory tricarboxylic acid cycle fluxes in batch and chemostat cultures. In particular under glucose-limited conditions, this led to significant excess formation of NADPH of B. subtilis, while anabolic consumption was rather balanced with catabolic NADPH formation in the other bacilli. Conclusion Despite its successful commercial production of riboflavin, B. subtilis does not seem to be the optimal cell factory from a bioenergetic point of view. The best choice of the investigated strains is the sporulation-deficient B. licheniformis T380B strain. Beside a low maintenance energy coefficient, this strain grows robustly under different conditions and exhibits only moderate acetate overflow, hence

Control of seed dormancy in Nicotiana plumbaginifolia: post-imbibition abscisic acid synthesis imposes dormancy maintenance.

Science.gov (United States)

Grappin, P; Bouinot, D; Sotta, B; Miginiac, E; Jullien, M

2000-01-01

The physiological characteristics of seed dormancy in Nicotiana plumbaginifolia Viv. are described. The level of seed dormancy is defined by the delay in seed germination (i.e the time required prior to germination) under favourable environmental conditions. A wild-type line shows a clear primary dormancy, which is suppressed by afterripening, whereas an abscisic acid (ABA)-deficient mutant shows a non-dormant phenotype. We have investigated the role of ABA and gibberellic acid (GA(3)) in the control of dormancy maintenance or breakage during imbibition in suitable conditions. It was found that fluridone, a carotenoid biosynthesis inhibitor, is almost as efficient as GA(3) in breaking dormancy. Dry dormant seeds contained more ABA than dry afterripened seeds and, during early imbibition, there was an accumulation of ABA in dormant seeds, but not in afterripened seeds. In addition, fluridone and exogenous GA(3) inhibited the accumulation of ABA in imbibed dormant seeds. This reveals an important role for ABA synthesis in dormancy maintenance in imbibed seeds.

Risk-Based Operation and Maintenance of Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Sønderkær

to oil and gas structures. In addition, condition monitoring systems are often available, and the information should be taken into account when making decisions. In this thesis, methods for risk-based maintenance planning using Bayesian methods are investigated, with the aim of making optimal decisions......, 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...... considering all available information. First, a theoretical damage model is formulated, the model is then updated using condition monitoring data, and the updated model is used as basis for risk-based decision making. Several approaches for solving the decision problems have been considered: various types...

Maintenance of energy expenditure on high-protein vs. high-carbohydrate diets at a constant body weight may prevent a positive energy balance.

Science.gov (United States)

Martens, E A; Gonnissen, H K; Gatta-Cherifi, B; Janssens, P L; Westerterp-Plantenga, M S

2015-10-01

Relatively high-protein diets are effective for body weight loss, and subsequent weight maintenance, yet it remains to be shown whether these diets would prevent a positive energy balance. Therefore, high-protein diet studies at a constant body weight are necessary. The objective was to determine fullness, energy expenditure, and macronutrient balances on a high-protein low-carbohydrate (HPLC) diet compared with a high-carbohydrate low-protein (HCLP) diet at a constant body weight, and to assess whether effects are transient or sustained after 12 weeks. A randomized parallel study was performed in 14 men and 18 women [mean ± SD age: 24 ± 5 y; BMI (in kg/m(2)): 22.8 ± 2.0] on diets containing 30/35/35 (HPLC) or 5/60/35 (HCLP) % of energy from protein/carbohydrate/fat. Significant interactions between dietary intervention and time on total energy expenditure (TEE) (P = 0.013), sleeping metabolic rate (SMR) (P = 0.040), and diet-induced thermogenesis (DIT) (P = 0.027) appeared from baseline to wk 12. TEE was maintained in the HPLC diet group, while it significantly decreased throughout the intervention period in the HCLP diet group (wk 1: P = 0.002; wk 12: P = 0.001). Energy balance was maintained in the HPLC diet group, and became positive in the HCLP diet group at wk 12 (P = 0.008). Protein balance varied directly according to the amount of protein in the diet, and diverged significantly between the diets (P = 0.001). Fullness ratings were significantly higher in the HPLC vs. the HCLP diet group at wk 1 (P = 0.034), but not at wk 12. Maintenance of energy expenditure on HPLC vs. HCLP diets at a constant body weight may prevent development of a positive energy balance, despite transiently higher fullness. The study was registered on clinicaltrials.gov with Identifier: NCT01551238. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Optimization of reliability centered predictive maintenance scheme for inertial navigation system

International Nuclear Information System (INIS)

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

2015-01-01

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

Maternal and Fetal Acid-Base Chemistry: A Major Determinant of ...

African Journals Online (AJOL)

Very small changes in pH may significantly affect the function of various fetal organ systems, such as the central nervous system, and the cardiovascular system with associated fetal distress and poor Apgar score. Review of existing data on maternal-fetal acid-base balance in pregnancy highlight the factors that are ...

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.

Mechatronics technology in predictive maintenance method

Science.gov (United States)

Majid, Nurul Afiqah A.; Muthalif, Asan G. A.

2017-11-01

This paper presents recent mechatronics technology that can help to implement predictive maintenance by combining intelligent and predictive maintenance instrument. Vibration Fault Simulation System (VFSS) is an example of mechatronics system. The focus of this study is the prediction on the use of critical machines to detect vibration. Vibration measurement is often used as the key indicator of the state of the machine. This paper shows the choice of the appropriate strategy in the vibration of diagnostic process of the mechanical system, especially rotating machines, in recognition of the failure during the working process. In this paper, the vibration signature analysis is implemented to detect faults in rotary machining that includes imbalance, mechanical looseness, bent shaft, misalignment, missing blade bearing fault, balancing mass and critical speed. In order to perform vibration signature analysis for rotating machinery faults, studies have been made on how mechatronics technology is used as predictive maintenance methods. Vibration Faults Simulation Rig (VFSR) is designed to simulate and understand faults signatures. These techniques are based on the processing of vibrational data in frequency-domain. The LabVIEW-based spectrum analyzer software is developed to acquire and extract frequency contents of faults signals. This system is successfully tested based on the unique vibration fault signatures that always occur in a rotating machinery.

Equilíbrio ácido-base e hidroeletrolítico em eqüinos com cólica Acid-base and hidroelectrolytic balance in colic horses

Directory of Open Access Journals (Sweden)

Paula Alessandra Di Filippo

2008-08-01

Full Text Available Foram utilizados setenta eqüinos distribuídos em três grupos experimentais, G1 (vinte eqüinos hígidos, G2 (vinte e cinco eqüinos com cólica, os quais passaram por tratamento clínico ou cirúrgico e sobreviveram e G3 (vinte e cinco eqüinos com cólica, os quais passaram por tratamento clínico ou cirúrgico e foram a óbito ou foram sacrificados. Amostras de sangue foram obtidas em dez diferentes momentos, mediante punção da jugular, para estudo do equilíbrio ácido-base e hidroeletrolítico. Os eqüinos com cólica apresentaram diminuição (PSeventy horses were distributed into three experimental groups ad follows: G1, twenty healthy animals; G2, twenty-five colic horses that survived after clinical or surgical treatment; and G3, twenty-five colic horses that were sacrificed or died after clinical or surgical treatment. Blood samples were taken from the jugular vein to assess acid-base balance and water-electrolyte balance. Colic horses had lower pH(v (P<0.05, mainly G3 animals. Acidosis was confirmed by the lower pH(v associated with decreased pCO2(v, cBase(v and cHCO-3(vP, which was probably due to an increased production of lactate during anaerobic glycolysis as a result from hypovolemia. Furthermore, hyponatremia, hypokalemia and hyperchloremia were detected. The presence and the extent of the imbalances contributed substantially to the prognosis of colic horses.

Preventive maintenance: optimization of time - based discard decisions at the bruce nuclear generating station

International Nuclear Information System (INIS)

Doyle, E.K.; Jardine, A.K.S.

2001-01-01

The use of various 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, several innovative practices reduced Reliability Centered Maintenance costs while maintaining the accuracy of the analysis. The optimization strategy has undergone further evolution and at the present an Integrated Maintenance Program (IMP) is in place where an Expert Panel consisting of all players/experts proceed through each system in a disciplined fashion and reach agreement on all items under a rigorous time frame. It is well known that there are essentially 3 maintenance based actions that can flow from a Maintenance Optimization Analysis: condition based maintenance, time based maintenance and time based discard. The present effort deals with time based discard decisions. Maintenance data from the Remote On-Power Fuel Changing System was used. (author)

DYMAC digital electronic balance

International Nuclear Information System (INIS)

Stephens, M.M.

1980-06-01

The Dynamic Materials Accountability (DYMAC) System at LASL integrates nondestructive assay (NDA) instruments with interactive data-processing equipment to provide near-real-time accountability of the nuclear material in the LASL Plutonium Processing Facility. The most widely used NDA instrument in the system is the DYMAC digital electronic balance. The DYMAC balance is a commercial instrument that has been modified at LASL for weighing material in gloveboxes and for transmitting the weight data directly to a central computer. This manual describes the balance components, details the LASL modifications, reviews a DYMAC measurement control program that monitors balance performance, and provides instructions for balance operation and maintenance

A condition-based maintenance policy for stochastically deteriorating systems

International Nuclear Information System (INIS)

Grall, A.; Berenguer, C.; Dieulle, L.

2002-01-01

We focus on the analytical modeling of a condition-based inspection/replacement policy for a stochastically and continuously deteriorating single-unit system. We consider both the replacement threshold and the inspection schedule as decision variables for this maintenance problem and we propose to implement the maintenance policy using a multi-level control-limit rule. In order to assess the performance of the proposed maintenance policy and to minimize the long run expected maintenance cost per unit time, a mathematical model for the maintained system cost is derived, supported by the existence of a stationary law for the maintained system state. Numerical experiments illustrate the performance of the proposed policy and confirm that the maintenance cost rate on an infinite horizon can be minimized by a joint optimization of the maintenance structure thresholds, or equivalently by a joint optimization of a system replacement threshold and the aperiodic inspection schedule

Skin Redox Balance Maintenance: The Need for an Nrf2-Activator Delivery System

Directory of Open Access Journals (Sweden)

Maya Ben-Yehuda Greenwald

2016-01-01

Full Text Available The skin, being the largest organ of the body, functions as a barrier between our body and the environment. It is consistently exposed to various exogenous and endogenous stressors (e.g., air pollutants, ionizing and non-ionizing irradiation, toxins, mitochondrial metabolism, enzyme activity, inflammatory process, etc. producing reactive oxygen species (ROS and physical damage (e.g., wounds, sunburns also resulting in reactive oxygen species production. Although skin is equipped with an array of defense mechanisms to counteract reactive oxygen species, augmented exposure and continued reactive oxygen species might result in excessive oxidative stress leading to many skin disorders including inflammatory diseases, pigmenting disorders and some types of cutaneous malignancy. The nuclear factor erythroid 2-related factor 2 (Nrf2 is an emerging regulator of cellular resistance and of defensive enzymes such as the phase II enzymes. Induction of the Keap1–Nrf2 pathway may have a beneficial effect in the treatment of a large number of skin disorders by stimulating an endogenous defense mechanism. However, prolonged and enhanced activation of this pathway is detrimental and, thus, limits the therapeutic potential of Keap1–Nrf2 modulators. Here, we review the consequences of oxidative stress to the skin, and the defense mechanisms that skin is equipped with. We describe the challenges of maintaining skin redox balance and its impact on skin status and function. Finally, we suggest a novel strategy for maintenance of skin redox homeostasis by modulating the Keap1–Nrf2 pathway using nanotechnology-based delivery systems.

Slc3a2 Mediates Branched-Chain Amino-Acid-Dependent Maintenance of Regulatory T Cells

Directory of Open Access Journals (Sweden)

Kayo Ikeda

2017-11-01

Full Text Available Summary: Foxp3+ regulatory T (Treg cells, which suppress immune responses, are highly proliferative in vivo. However, it remains unclear how the active replication of Treg cells is maintained in vivo. Here, we show that branched-chain amino acids (BCAAs, including isoleucine, are required for maintenance of the proliferative state of Treg cells via the amino acid transporter Slc3a2-dependent metabolic reprogramming. Mice fed BCAA-reduced diets showed decreased numbers of Foxp3+ Treg cells with defective in vivo proliferative capacity. Mice lacking Slc3a2 specifically in Foxp3+ Treg cells showed impaired in vivo replication and decreased numbers of Treg cells. Slc3a2-deficient Treg cells showed impaired isoleucine-induced activation of the mTORC1 pathway and an altered metabolic state. Slc3a2 mutant mice did not show an isoleucine-induced increase of Treg cells in vivo and exhibited multi-organ inflammation. Taken together, these findings demonstrate that BCAA controls Treg cell maintenance via Slc3a2-dependent metabolic regulation. : Treg cells regulate excess immune responses and are highly proliferative in vivo. Ikeda et al. find that branched-chain amino acids (BCAAs are essentially required to maintain expansion and the suppressive capacity of Treg cells via Slc3a2 and mTORC1. Keywords: Treg cells, amino acids, immunometabolism, immune regulation, transporter

Maintenance Decision Based on Data Fusion of Aero Engines

Directory of Open Access Journals (Sweden)

Huawei Wang

2013-01-01

Full Text Available Maintenance has gained a great importance as a support function for ensuring aero engine reliability and availability. Cost-effectiveness and risk control are two basic criteria for accurate maintenance. Given that aero engines have much condition monitoring data, this paper presents a new condition-based maintenance decision system that employs data fusion for improving accuracy of reliability evaluation. Bayesian linear model has been applied, so that the performance degradation evaluation of aero engines could be realized. A reliability evaluation model has been presented based on gamma process, which achieves the accurate evaluation by information fusion. In reliability evaluation model, the shape parameter is estimated by the performance degradation evaluation result, and the scale parameter is estimated by failure, inspection, and repair information. What is more, with such reliability evaluation as input variables and by using particle swarm optimization (PSO, a stochastic optimization of maintenance decision for aircraft engines has been presented, in which the effectiveness and the accuracy are demonstrated by a numerical example.

Model based decision support for planning of road maintenance

NARCIS (Netherlands)

van Harten, Aart; Worm, J.M.; Worm, J.M.

1996-01-01

In this article we describe a Decision Support Model, based on Operational Research methods, for the multi-period planning of maintenance of bituminous pavements. This model is a tool for the road manager to assist in generating an optimal maintenance plan for a road. Optimal means: minimising the

Nuclear power plant maintenance scheduling dilemma: a genetic algorithm approach

International Nuclear Information System (INIS)

Mahdavi, M.H.; Modarres, M.

2004-01-01

There are huge numbers of components scheduled for maintenance when a nuclear power plant is shut down. Among these components, a number of them are safety related which their operability as well as reliability when plant becomes up is main concerns. Not performing proper maintenance on this class of components/system would impose substantial risk on operating the NPP. In this paper a new approach based on genetic algorithms is presented to optimize the NPP maintenance schedule during shutdown. following this approach the cost incurred by maintenance activities for each schedule is balanced with the risk imposed by the maintenance scheduling plan to the plant operation status when it is up. The risk model implemented in the GA scheduler as its evaluation function is developed on the basis of the probabilistic risk assessment methodology. the Ga optimizers itself is shown to be superior compared to other optimization methods such as the monte carlo technique

Nutrient intake, acid base status and weight gain in water buffalo ...

African Journals Online (AJOL)

The impact of different dietary levels of sodium bicarbonate (NaHCO3) on nutrient intake, acid-base status, nitrogen balance and weight gain was examined in growing male buffalo (Bubalus bubalis) calves exposed to hot summer conditions. In a complete randomized block design 60 animals of similar age and weight ...

A basic condition-based maintenance strategy for air-cooled turbine generators

International Nuclear Information System (INIS)

Laird, T.; Griffith, G.; Hoof, M.

2005-01-01

This paper discusses the methods of using condition-based maintenance (CBM) for turbine generators. Even though it is focused on the maintenance strategy for air-cooled generators, all types of power producers can realize benefits from a better maintenance strategy at lower costs. A reliable assessment of the actual unit condition requires detailed knowledge of the unit design, operational weaknesses, cost of maintenance and operational capabilities. (author)

Optimal, Risk-based Operation and Maintenance Planning for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2008-01-01

For offshore wind turbines costs to operation and maintenance are substantial. This paper describes a risk-based life-cycle approach for optimal planning of operation and maintenance. The approach is based on pre-posterior Bayesian decision theory. Deterioration mechanisms such as fatigue...

Home-based balance training programme using Wii Fit with balance board for Parkinsons's disease: a pilot study.

Science.gov (United States)

Esculier, Jean-Francois; Vaudrin, Joanie; Bériault, Patrick; Gagnon, Karine; Tremblay, Louis E

2012-02-01

To evaluate the effects of a home-based balance training programme using visual feedback (Nintendo Wii Fit game with balance board) on balance and functional abilities in subjects with Parkinson's disease, and to compare the effects with a group of paired healthy subjects. Ten subjects with moderate Parkinson's disease and 8 healthy elderly subjects. Subjects participated in a 6-week home-based balance training programme using Nintendo Wii Fit and balance board. Baseline measures were taken before training for the Sit-to-Stand test (STST), Timed-Up-and-Go (TUG), Tinetti Performance Oriented Mobility Assessment (POMA), 10-m walk test, Community Balance and Mobility assessment (CBM), Activities-specific Balance and Confidence scale (ABC), unipodal stance duration, and a force platform. All measurements were taken again after 3 and 6 weeks of training. The Parkinson's disease group significantly improved their results in TUG, STST, unipodal stance, 10-m walk test, CBM, POMA and force platform at the end of the 6-week training programme. The healthy subjects group significantly improved in TUG, STST, unipodal stance and CBM. This pilot study suggests that a home-based balance programme using Wii Fit with balance board could improve static and dynamic balance, mobility and functional abilities of people affected by Parkinson's disease.

Balance-of-plant outage availability study. Phase I. Extension report

International Nuclear Information System (INIS)

Thomasson, F.R.

1978-09-01

After completion of the Phase 1 Refueling Outage Availability Study, Babcock and Wilcox and the U.S. Department of Energy entered into a supplemental agreement to perform a balance-of-plant maintenance, inspection, and test study with the cooperation of Duke Power Company and Arkansas Power and Light Company. The objectives were (1) to expand the Phase 1 data base, including balance-of-plant activities, to reduce outage time and increase plant availability and (2) to conduct an onsite review of plant maintenance, practices to complement the utility efforts in reducing outage time and increasing on-line operational time. Data were obtained from (1) observations during the 1977 refueling outage at Oconee 3, (2) review of maintenance practices during the Arkansas Nuclear One, Unit 1, operational cycle in 1977, and (3) selected observations of the 1978 refueling outage at ANO-1. Accumulated data were then reviewed and analyzed to produce a list of improvement recommendations for Oconee 3 and ANO-1 that can be generically applied to plants of similar design and construction

Performance-based maintenance of gas turbines for reliable control of degraded power systems

Science.gov (United States)

Mo, Huadong; Sansavini, Giovanni; Xie, Min

2018-03-01

Maintenance actions are necessary for ensuring proper operations of control systems under component degradation. However, current condition-based maintenance (CBM) models based on component health indices are not suitable for degraded control systems. Indeed, failures of control systems are only determined by the controller outputs, and the feedback mechanism compensates the control performance loss caused by the component deterioration. Thus, control systems may still operate normally even if the component health indices exceed failure thresholds. This work investigates the CBM model of control systems and employs the reduced control performance as a direct degradation measure for deciding maintenance activities. The reduced control performance depends on the underlying component degradation modelled as a Wiener process and the feedback mechanism. To this aim, the controller features are quantified by developing a dynamic and stochastic control block diagram-based simulation model, consisting of the degraded components and the control mechanism. At each inspection, the system receives a maintenance action if the control performance deterioration exceeds its preventive-maintenance or failure thresholds. Inspired by realistic cases, the component degradation model considers random start time and unit-to-unit variability. The cost analysis of maintenance model is conducted via Monte Carlo simulation. Optimal maintenance strategies are investigated to minimize the expected maintenance costs, which is a direct consequence of the control performance. The proposed framework is able to design preventive maintenance actions on a gas power plant, to ensuring required load frequency control performance against a sudden load increase. The optimization results identify the trade-off between system downtime and maintenance costs as a function of preventive maintenance thresholds and inspection frequency. Finally, the control performance-based maintenance model can reduce

Statistical Learning Framework with Adaptive Retraining for Condition-Based Maintenance

International Nuclear Information System (INIS)

An, Sang Ha; Chang, Soon Heung; Heo, Gyun Young; Seo, Ho Joon; Kim, Su Young

2009-01-01

As systems become more complex and more critical in our daily lives, the need for the maintenance based on the reliable monitoring and diagnosis has become more apparent. However, in reality, the general opinion has been that 'maintenance is a necessary evil' or 'nothing can be done to improve maintenance costs'. Perhaps these were true statements twenty years ago when many of the diagnostic technologies were not fully developed. The developments of microprocessor or computer based instrumentation that can be used to monitor the operating condition of plant equipment, machinery and systems have provided the means to manage the maintenance operation. They have provided the means to reduce or eliminate unnecessary repairs, prevent catastrophic machine failures and reduce the negative impact of the maintenance operation on the profitability of manufacturing and production plants. Condition-based maintenance (CBM) techniques help determine the condition of in-service equipment in order to predict when maintenance should be performed. Most of the statistical learning techniques are only valid as long as the physics of a system does not change. If any significant change such as the replacement of a component or equipment occurs in the system, the statistical learning model should be re-trained or re-developed to adapt the new system. In this research, authors will propose a statistical learning framework which can be applicable for various CBMs, and the concept of the adaptive retraining technique will be described to support the execution of the framework so that the monitoring system does not need to be re-developed or re-trained even though there are any significant changes in the system or component

Contracting, An Alarming Trend in Aviation Maintenance

National Research Council Canada - National Science Library

Brooke, J

1998-01-01

.... Aviation operational and maintenance units struggle to balance peacetime requirements for general military and technical training, organization and installation support, training and operational...

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.

A multi-agent based intelligent configuration method for aircraft fleet maintenance personnel

OpenAIRE

Feng, Qiang; Li, Songjie; Sun, Bo

2014-01-01

A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The maintenance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance...

Development of electromagnetic induction diagnostics technology for condition based maintenance

International Nuclear Information System (INIS)

Mawatari, Shingo; Oeda, Kaoru; Yatogi, Hideo; Fukuchi, Taira; Ueno, Tadashi

2008-01-01

In ROKKASHO Reprocessing Plant (below, called 'RRP'), we have applied Condition Based Maintenance to rotating equipment with vibration diagnostics technology. However, a few rotating equipment are difficult to diagnose definitely, because have structural problems which exercise vibrational noise to peripheral and be impossible to install vibratory sensor. Electromagnetic induction diagnostics technology which measure magnetic fields to eddy current which is induced to rotary through static magnetic field, diagnose deterioration behavior such as abrasion and crack. As a result, it has possibilities to clear above problems. Therefore, we started our basic researches with this technology for Condition Based Maintenance. In this paper, it introduces basic data about 'Non-seal pump' that have installed in RRP. As a result, this technology is a possibility that be able to detect Condition Based Maintenance. (author)

Acids and bases solvent effects on acid-base strenght

CERN Document Server

Cox, Brian G

2013-01-01

Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.

Concentration-Discharge Relationships, Nested Reaction Fronts, and the Balance of Oxidative and Acid-Base Weathering Fluxes in an Alpine Catchment, East River, Colorado

Science.gov (United States)

Winnick, M.; Carroll, R. W. H.; Williams, K. H.; Maxwell, R. M.; Maher, K.

2016-12-01

Although important for solute production and transport, the varied interactions between biogeochemical processes and subsurface hydrology remain poorly characterized. We investigate these couplings in the headwaters of the East River, CO, a high-elevation shale-dominated catchment system in the Rocky Mountains, using concentration-discharge (C-Q) relationships for major cations, anions, and organic carbon. Dissolved organic carbon (DOC) displays a positive C-Q relationship with well-defined clockwise hysteresis, indicating the mobilization and depletion of DOC in the upper soil horizons and highlighting the importance of shallow flowpaths through the snowmelt period. Cation and anion concentrations demonstrate that carbonate weathering, which dominates solute fluxes, is promoted by both carbonic acid and sulfuric acid derived from oxidation of pyrite in the shale bedrock. Sulfuric acid weathering in the deep subsurface dominates during base flow conditions when waters have infiltrated below the hypothesized pyrite oxidation front, whereas carbonic acid weathering plays a dominant role during the snowmelt period as a result of shallow flowpaths. Differential C-Q relationships between solutes suggest that infiltrating waters approach calcite saturation before reaching the pyrite oxidation front, after which sulfuric acid reduces carbonate alkalinity. This increase in CO2(aq) at the expense of HCO3- results in outgassing of CO2 when waters equilibrate to surface conditions, and reduces the export of carbon and alkalinity from the East River by roughly 33% annually. Future changes in snowmelt dynamics that control the balance of carbonic and sulfuric acid weathering therefore have the capacity to substantially alter the cycling of carbon in the East River catchment. Ultimately, we demonstrate that differential C-Q relationships between major solutes can provide unique insights into the complex subsurface flow and biogeochemical dynamics that operate at catchment scales.

Bayesian based Diagnostic Model for Condition based Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

Operation and maintenance costs are a major contributor to the Levelized Cost of Energy for electricity produced by offshore wind and can be significantly reduced if existing corrective actions are performed as efficiently as possible and if future corrective actions are avoided by performing...... sufficient preventive actions. This paper presents an applied and generic diagnostic model for fault detection and condition based maintenance of offshore wind components. The diagnostic model is based on two probabilistic matrices; first, a confidence matrix, representing the probability of detection using...... for a wind turbine component based on vibration, temperature, and oil particle fault detection methods. The last part of the paper will have a discussion of the case study results and present conclusions....

A multi-agent based intelligent configuration method for aircraft fleet maintenance personnel

Directory of Open Access Journals (Sweden)

Feng Qiang

2014-04-01

Full Text Available A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The maintenance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system (MAS model. A communication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol (CNP. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.

Fatty acid oxidation is required for active and quiescent brown adipose tissue maintenance and thermogenic programing

Directory of Open Access Journals (Sweden)

Elsie Gonzalez-Hurtado

2018-01-01

Full Text Available Objective: To determine the role of fatty acid oxidation on the cellular, molecular, and physiologic response of brown adipose tissue to disparate paradigms of chronic thermogenic stimulation. Methods: Mice with an adipose-specific loss of Carnitine Palmitoyltransferase 2 (Cpt2A−/−, that lack mitochondrial long chain fatty acid β-oxidation, were subjected to environmental and pharmacologic interventions known to promote thermogenic programming in adipose tissue. Results: Chronic administration of β3-adrenergic (CL-316243 or thyroid hormone (GC-1 agonists induced a loss of BAT morphology and UCP1 expression in Cpt2A−/− mice. Fatty acid oxidation was also required for the browning of white adipose tissue (WAT and the induction of UCP1 in WAT. In contrast, chronic cold (15 °C stimulation induced UCP1 and thermogenic programming in both control and Cpt2A−/− adipose tissue albeit to a lesser extent in Cpt2A−/− mice. However, thermoneutral housing also induced the loss of UCP1 and BAT morphology in Cpt2A−/− mice. Therefore, adipose fatty acid oxidation is required for both the acute agonist-induced activation of BAT and the maintenance of quiescent BAT. Consistent with this data, Cpt2A−/− BAT exhibited increased macrophage infiltration, inflammation and fibrosis irrespective of BAT activation. Finally, obese Cpt2A−/− mice housed at thermoneutrality exhibited a loss of interscapular BAT and were refractory to β3-adrenergic-induced energy expenditure and weight loss. Conclusion: Mitochondrial long chain fatty acid β-oxidation is critical for the maintenance of the brown adipocyte phenotype both during times of activation and quiescence. Keywords: Fatty acid oxidation, Brown adipose tissue, Cold induced thermogenesis, Adrenergic signaling, Adipose macrophage

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. 

Costs of performance based maintenance for local roads: Case study Albania

Science.gov (United States)

Jokanović, Igor; Grujić, Bojana; Zeljić, Dragana; Grujić, Žarko; Svilar, Mila

2017-12-01

The provision and maintenance of road infrastructure is a major global business, consequently it is essential that road maintenance services are provided in the most cost effective manner. Without regular maintenance, roads can rapidly fall into disrepair, preventing realization of the longer term impacts of road improvements on development, such as increased agricultural production and growth in school enrollment, which is of particular importance for a network of local (access) roads. Inadequate local roads maintenance in Albania is proposed to be solved by implementing performance based maintenance approach for which the costing exercise is presented within the paper.

Open system architecture for condition based maintenance applied to a hydroelectric power plant

Energy Technology Data Exchange (ETDEWEB)

Amaya, E.J.; Alvares, A.J. [University of Brasilia (UnB), DF (Brazil). Mechanical and Mechatronic Dept.], Emails: eamaya@unb.br, alvares@AlvaresTech.com; Gudwin, R.R. [State University of Campinas (UNICAMP), SP (Brazil). Computer Engineering and Industrial Automation Dept.], E-mail: gudwin@dca.fee.unicamp.br

2009-07-01

The hydroelectric power plant of Balbina is implementing a condition based maintenance system applying an open, modular and scalable integrated architecture to provide comprehensive solutions and support to the end users like operational and maintenance team. The system called SIMPREBAL (Predictive Maintenance System of Balbina) is advocate of open standards, in particular through collaborative research programmers. In the developing is clearly understands the need for both, industry standards and a simple to use software development tool chain, supporting the development of complex condition based maintenance systems with multiple partners. The Open System Architecture for Condition Based Maintenance (OSA-CBM) is a standard that consider seven hierarchic layers that represent a logic transition or performed data flow from the data acquisition layer, through the intermediates layers as signal processing, condition monitor, health assessment, prognostics and decision support, to arrive to the presentation layer. SIMPREBAL is being implementing as an OSA-CBM software framework and tool set that allows the creation of truly integrated, comprehensive maintenance solutions through the internet. This paper identifies specific benefits of the application of the OSA-CBM in comprehensive solutions of condition based maintenance for a hydroelectric power plant. (author)

Conference on the exploitation, maintenance and resale of ground-based photovoltaic plants

International Nuclear Information System (INIS)

Roesner, Sven; Christmann, Ralf; Bozonnat, Cedric; Le Pivert, Xavier; Vaassen, Willi; Dumoulin, Cedric; Kiefer, Klaus; Semmel, Andreas; Doose, Eckhard; Bion, Alain; Sanches, Frederico; Daval, Xavier; Pampouille, Antoine; Goetze, Holger; Stahl, Wolf-Ruediger; Merere, Karine

2017-11-01

This document gathers contributions and debate contents of a conference. A first set of contributions addressed the situation and recent developments of ground-based photovoltaic power plants in France and in Germany with presentations of legal frameworks in these both countries. The second set addressed the optimisation of such power plants: meteorological prediction and follow-up at the service of production, risks to which these power plants are exposed during operation, and the issue of right price and good practices for maintenance contracts for these plants. A round table addressed the issue of the balance between optimisation and established practices in a new economic framework. The next set of contributions addressed reasons for and effects of the resale of photovoltaic fleet during their exploitation: actors and financing solutions, value components, point of attention and legal view on re-financing contracts. A round table discussed trends and success factors for the re-financing of photovoltaic projects

Risk Based Maintenance in Electricity Network Organisations

NARCIS (Netherlands)

Mehairjan, R.P.Y.

2016-01-01

Presently, maintenance management of assets in infrastructure utilities such as electricity, gas and water are widely undergoing changes towards new working environments. These are mainly driven against the background of stringent regulatory regimes, an ageing asset base, increased customer demands

Fatty acid oxidation is required for active and quiescent brown adipose tissue maintenance and thermogenic programing.

Science.gov (United States)

Gonzalez-Hurtado, Elsie; Lee, Jieun; Choi, Joseph; Wolfgang, Michael J

2018-01-01

To determine the role of fatty acid oxidation on the cellular, molecular, and physiologic response of brown adipose tissue to disparate paradigms of chronic thermogenic stimulation. Mice with an adipose-specific loss of Carnitine Palmitoyltransferase 2 (Cpt2 A-/- ), that lack mitochondrial long chain fatty acid β-oxidation, were subjected to environmental and pharmacologic interventions known to promote thermogenic programming in adipose tissue. Chronic administration of β3-adrenergic (CL-316243) or thyroid hormone (GC-1) agonists induced a loss of BAT morphology and UCP1 expression in Cpt2 A-/- mice. Fatty acid oxidation was also required for the browning of white adipose tissue (WAT) and the induction of UCP1 in WAT. In contrast, chronic cold (15 °C) stimulation induced UCP1 and thermogenic programming in both control and Cpt2 A-/- adipose tissue albeit to a lesser extent in Cpt2 A-/- mice. However, thermoneutral housing also induced the loss of UCP1 and BAT morphology in Cpt2 A-/- mice. Therefore, adipose fatty acid oxidation is required for both the acute agonist-induced activation of BAT and the maintenance of quiescent BAT. Consistent with this data, Cpt2 A-/- BAT exhibited increased macrophage infiltration, inflammation and fibrosis irrespective of BAT activation. Finally, obese Cpt2 A-/- mice housed at thermoneutrality exhibited a loss of interscapular BAT and were refractory to β3-adrenergic-induced energy expenditure and weight loss. Mitochondrial long chain fatty acid β-oxidation is critical for the maintenance of the brown adipocyte phenotype both during times of activation and quiescence. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Optimizing preventive maintenance with maintenance templates

International Nuclear Information System (INIS)

Dozier, I.J.

1996-01-01

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

Advanced Maintenance Simulation by Means of Hand-Based Haptic Interfaces

Science.gov (United States)

Nappi, Michele; Paolino, Luca; Ricciardi, Stefano; Sebillo, Monica; Vitiello, Giuliana

Aerospace industry has been involved in virtual simulation for design and testing since the birth of virtual reality. Today this industry is showing a growing interest in the development of haptic-based maintenance training applications, which represent the most advanced way to simulate maintenance and repair tasks within a virtual environment by means of a visual-haptic approach. The goal is to allow the trainee to experiment the service procedures not only as a workflow reproduced at a visual level but also in terms of the kinaesthetic feedback involved with the manipulation of tools and components. This study, conducted in collaboration with aerospace industry specialists, is aimed to the development of an immersive virtual capable of immerging the trainees into a virtual environment where mechanics and technicians can perform maintenance simulation or training tasks by directly manipulating 3D virtual models of aircraft parts while perceiving force feedback through the haptic interface. The proposed system is based on ViRstperson, a virtual reality engine under development at the Italian Center for Aerospace Research (CIRA) to support engineering and technical activities such as design-time maintenance procedure validation, and maintenance training. This engine has been extended to support haptic-based interaction, enabling a more complete level of interaction, also in terms of impedance control, and thus fostering the development of haptic knowledge in the user. The user’s “sense of touch” within the immersive virtual environment is simulated through an Immersion CyberForce® hand-based force-feedback device. Preliminary testing of the proposed system seems encouraging.

Balance-of-plant outage availability study. Phase I. Extension report. [PWR

Energy Technology Data Exchange (ETDEWEB)

Thomasson, F.R.

1978-09-01

After completion of the Phase 1 Refueling Outage Availability Study, Babcock and Wilcox and the U.S. Department of Energy entered into a supplemental agreement to perform a balance-of-plant maintenance, inspection, and test study with the cooperation of Duke Power Company and Arkansas Power and Light Company. The objectives were (1) to expand the Phase 1 data base, including balance-of-plant activities, to reduce outage time and increase plant availability and (2) to conduct an onsite review of plant maintenance, practices to complement the utility efforts in reducing outage time and increasing on-line operational time. Data were obtained from (1) observations during the 1977 refueling outage at Oconee 3, (2) review of maintenance practices during the Arkansas Nuclear One, Unit 1, operational cycle in 1977, and (3) selected observations of the 1978 refueling outage at ANO-1. Accumulated data were then reviewed and analyzed to produce a list of improvement recommendations for Oconee 3 and ANO-1 that can be generically applied to plants of similar design and construction.

Acid-base balance of dairy cows and its relationship with alcoholic stability and mineral composition of milk

Directory of Open Access Journals (Sweden)

Rafael Fagnani

2014-05-01

Full Text Available This study aimed to associate the occurrence of acid-base disorders with the alcoholic stability of milk from animals in the field, and to evaluate differences between the mineral composition of milk that was both stable and unstable in alcohol. The sample comprised 96 dairy cows, where the milk and blood of each corresponding animal was collected. The mineral composition of stable and unstable milk in alcohol was different and may be related to acid-base disturbances. The average amount of phosphate was lower in the milk that was unstable in alcohol, while potassium was greater. Frequency of the alcoholically unstable milk cases was higher in the cows with acid-base disturbances. Respiratory alkalosis was the disorder that was most observed.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.

Protein feeding and balancing for amino acids in lactating dairy cattle.

Science.gov (United States)

Patton, Robert A; Hristov, Alexander N; Lapierre, Hélène

2014-11-01

This article summarizes the current literature as regards metabolizable protein (MP) and essential amino acid (EAA) nutrition of dairy cattle. Emphasis has been placed on research since the publication of the National Research Council Nutrient Requirements of Dairy Cattle, Seventh Revised Edition (2001). Postruminal metabolism of EAA is discussed in terms of the effect on requirements. This article suggests methods for practical application of MP and EAA balance in milking dairy cows. Copyright © 2014 Elsevier Inc. All rights reserved.

A Novel Assembly Line Balancing Method Based on PSO Algorithm

Directory of Open Access Journals (Sweden)

Xiaomei Hu

2014-01-01

Full Text Available Assembly line is widely used in manufacturing system. Assembly line balancing problem is a crucial question during design and management of assembly lines since it directly affects the productivity of the whole manufacturing system. The model of assembly line balancing problem is put forward and a general optimization method is proposed. The key data on assembly line balancing problem is confirmed, and the precedence relations diagram is described. A double objective optimization model based on takt time and smoothness index is built, and balance optimization scheme based on PSO algorithm is proposed. Through the simulation experiments of examples, the feasibility and validity of the assembly line balancing method based on PSO algorithm is proved.

Renal aquaporins and water balance disorders

DEFF Research Database (Denmark)

Kortenoeven, Marleen; Fenton, Robert A.

2013-01-01

BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, A......-solute diet and diuretics. GENERAL SIGNIFICANCE: In recent years, our understanding of the underlying mechanisms of water balance disorders has increased enormously, which has opened up several possible new treatment strategies.......BACKGROUND: Aquaporins (AQPs) are a family of proteins that can act as water channels. Regulation of AQPs is critical to osmoregulation and the maintenance of body water homeostasis. Eight AQPs are expressed in the kidney of which five have been shown to play a role in body water balance; AQP1, AQP......2, AQP3, AQP4 and AQP7. AQP2 in particular is regulated by vasopressin. SCOPE OF REVIEW: This review summarizes our current knowledge of the underlying mechanisms of various water balance disorders and their treatment strategies. MAJOR CONCLUSIONS: Dysfunctions of AQPs are involved in disorders...

Knowledge Management for Large Scale Condition Based Maintenance

Data.gov (United States)

National Aeronautics and Space Administration — This presentation will review the use of knowledge management in the development and support of Condition Based Maintenance (CBM) systems for complex systems with...

Risk-Based Operation and Maintenance Planning for Offshore Wind Turbines

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2010-01-01

Operation and maintenance (O&M) are large contributors to the cost of energy for offshore wind turbines. Optimal planning of O&M should include use of inspections and monitoring results to make decisions that minimize the expected costs through the lifetime of the structures. For offshore...... structures it is especially important because of the dependence on weather windows for inspections and repairs to be possible. A model has been developed to estimate the expected costs to corrective and condition based maintenance for a wind turbine with a single component. The deterioration of the component...... is simulated, and the expected costs are found for different strategies. An application example shows that condition based maintenance has the potential of reducing the costs, and a risk based approach can be used to find the optimal strategy for O&M. Further the influence of failure rate and damage parameters...

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.)

Structuring AHP-based maintenance policy selection

NARCIS (Netherlands)

Goossens, Adriaan; Basten, Robertus Johannes Ida; Hummel, J. Marjan; van der Wegen, Leonardus L.M.

2015-01-01

We aim to structure the maintenance policy selection process for ships, using the Analytic Hierarchy Process (AHP). Maintenance is an important contributor to reach the intended life-time of capital technical assets, and it is gaining increasing interest and relevance. A maintenance policy is a

PERFORMANCE-BASED CONTRACTING IN CONSTRUCTION PHASE AND MAINTENANCE PHASE OF PAVEMENT

Science.gov (United States)

Yoshida, Takeshi

Performance-based contracting for pavement in Japan started as performance warranties in construction phase, in 1999. Recently, road agencies have recognized the applicability of this type of contracting in outsourcing of maintenance activities. The objectives of this study are to clarify the issues of performance specifying in construction phase and maintenance phase of pavement, and to propose measures to be taken. This paper, with the recognition that the life of each pavement depends on performance standards for various attributes, reviews domestic and foreign examples of performance-based contracting. A performance standard based on the average of current practices can enhance product quality and service life with a warranty contract. Repair thresholds and response time for each deficiency should be considered as performance standards in maintenance phase.

Failure and Maintenance Analysis Using Web-Based Reliability Database System

International Nuclear Information System (INIS)

Hwang, Seok Won; Kim, Myoung Su; Seong, Ki Yeoul; Na, Jang Hwan; Jerng, Dong Wook

2007-01-01

Korea Hydro and Nuclear Power Company has lunched the development of a database system for PSA and Maintenance Rule implementation. It focuses on the easy processing of raw data into a credible and useful database for the risk-informed environment of nuclear power plant operation and maintenance. Even though KHNP had recently completed the PSA for all domestic NPPs as a requirement of the severe accident mitigation strategy, the component failure data were only gathered as a means of quantification purposes for the relevant project. So, the data were not efficient enough for the Living PSA or other generic purposes. Another reason to build a real time database is for the newly adopted Maintenance Rule, which requests the utility to continuously monitor the plant risk based on its operation and maintenance performance. Furthermore, as one of the pre-condition for the Risk Informed Regulation and Application, the nuclear regulatory agency of Korea requests the development and management of domestic database system. KHNP is stacking up data of operation and maintenance on the Enterprise Resource Planning (ERP) system since its first opening on July, 2003. But, so far a systematic review has not been performed to apply the component failure and maintenance history for PSA and other reliability analysis. The data stored in PUMAS before the ERP system is introduced also need to be converted and managed into the new database structure and methodology. This reliability database system is a web-based interface on a UNIX server with Oracle relational database. It is designed to be applicable for all domestic NPPs with a common database structure and the web interfaces, therefore additional program development would not be necessary for data acquisition and processing in the near future. Categorization standards for systems and components have been implemented to analyze all domestic NPPs. For example, SysCode (for a system code) and CpCode (for a component code) were newly

Design of Mobile Operation and Maintenance System Based on Power GIS and GPS

Directory of Open Access Journals (Sweden)

Jing TAO

2017-01-01

Full Text Available In order to solve the low efficiency of operation and maintenance and the problems of management coordination caused by the coexistence of off-line operation and maintenance and multi system coexistence in current power telecommunication operation and maintenance, this paper proposes a mobile operation and maintenance system based on power GIS and GPS location technology. The system is based on the C/S architecture, and the mobile operation and maintenance terminal is connected with the operation and maintenance management terminal through wireless and wired network. In addition to meeting basic business requirements, the system integrates power GIS functions to visually demonstrate communication resources, personnel, and failures. The staff can use the wireless mobile terminal which integrated GPS module for to operate and maintain, and can locate accurately in real time.

A novel integrated condition-based maintenance and stochastic flexible job shop scheduling problem

DEFF Research Database (Denmark)

Rahmati, Seyed Habib A.; Ahmadi, Abbas; Govindan, Kannan

2018-01-01

the level of the system optimization. By means of this equipment, managers can benefit from a condition-based maintenance (CBM) for monitoring and managing their system. The chief aim of the paper is to develop a stochastic maintenance problem based on CBM activities engaged with a complex applied......Integrated consideration of production planning and maintenance processes is a real world assumption. Specifically, by improving the monitoring equipment such as various sensors or product-embedded information devices in recent years, joint assessment of these processes is inevitable for enhancing...... production problem called flexible job shop scheduling problem (FJSP). This integrated problem considers two maintenance scenarios in terms of corrective maintenance (CM) and preventive maintenance (PM). The activation of scenario is done by monitoring the degradation condition of the system and comparing...

A COMPUTER BASED MAINTENANCE MANAGEMENT SYSTEM ...

African Journals Online (AJOL)

... programs to schedule for maintenance or replacement of machines has been designed such that it enables the maintenance department control all jobs associated with plant maintenance and breakdown. It predicts the time to failure of designated plants and caters for the replacement analysis of some capital equipment.

A review on condition-based maintenance optimization models for stochastically deteriorating system

International Nuclear Information System (INIS)

Alaswad, Suzan; Xiang, Yisha

2017-01-01

Condition-based maintenance (CBM) is a maintenance strategy that collects and assesses real-time information, and recommends maintenance decisions based on the current condition of the system. In recent decades, research on CBM has been rapidly growing due to the rapid development of computer-based monitoring technologies. Research studies have proven that CBM, if planned properly, can be effective in improving equipment reliability at reduced costs. This paper presents a review of CBM literature with emphasis on mathematical modeling and optimization approaches. We focus this review on important aspects of the CBM, such as optimization criteria, inspection frequency, maintenance degree, solution methodology, etc. Since the modeling choice for the stochastic deterioration process greatly influences CBM strategy decisions, this review classifies the literature on CBM models based on the underlying deterioration processes, namely discrete- and continuous-state deterioration, and proportional hazard model. CBM models for multi-unit systems are also reviewed in this paper. This paper provides useful references for CBM management professionals and researchers working on CBM modeling and optimization. - Highlights: • A review on Condition-based maintenance (CBM) optimization models is presented. • The CBM models are classified based on the underlying deterioration processes. • Existing CBM models for both single- and multi-unit systems are reviewed. • Future essential research directions on CBM are identified.

Complicated pregnancies in inherited distal renal tubular acidosis: importance of acid-base balance.

Science.gov (United States)

Seeger, Harald; Salfeld, Peter; Eisel, Rüdiger; Wagner, Carsten A; Mohebbi, Nilufar

2017-06-01

Inherited distal renal tubular acidosis (dRTA) is caused by impaired urinary acid excretion resulting in hyperchloremic metabolic acidosis. Although the glomerular filtration rate (GFR) is usually preserved, and hypertension and overt proteinuria are absent, it has to be considered that patients with dRTA also suffer from chronic kidney disease (CKD) with an increased risk for adverse pregnancy-related outcomes. Typical complications of dRTA include severe hypokalemia leading to cardiac arrhythmias and paralysis, nephrolithiasis and nephrocalcinosis. Several physiologic changes occur in normal pregnancy including alterations in acid-base and electrolyte homeostasis as well as in GFR. However, data on pregnancy in women with inherited dRTA are scarce. We report the course of pregnancy in three women with hereditary dRTA. Complications observed were severe metabolic acidosis, profound hypokalemia aggravated by hyperemesis gravidarum, recurrent urinary tract infection (UTI) and ureteric obstruction leading to renal failure. However, the outcome of all five pregnancies (1 pregnancy each for mothers n. 1 and 2; 3 pregnancies for mother n. 3) was excellent due to timely interventions. Our findings highlight the importance of close nephrologic monitoring of women with inherited dRTA during pregnancy. In addition to routine assessment of creatinine and proteinuria, caregivers should especially focus on acid-base status, plasma potassium and urinary tract infections. Patients should be screened for renal obstruction in the case of typical symptoms, UTI or renal failure. Furthermore, genetic identification of the underlying mutation may (a) support early nephrologic referral during pregnancy and a better management of the affected woman, and (b) help to avoid delayed diagnosis and reduce complications in affected newborns.

A computer vision based candidate for functional balance test.

Science.gov (United States)

Nalci, Alican; Khodamoradi, Alireza; Balkan, Ozgur; Nahab, Fatta; Garudadri, Harinath

2015-08-01

Balance in humans is a motor skill based on complex multimodal sensing, processing and control. Ability to maintain balance in activities of daily living (ADL) is compromised due to aging, diseases, injuries and environmental factors. Center for Disease Control and Prevention (CDC) estimate of the costs of falls among older adults was $34 billion in 2013 and is expected to reach $54.9 billion in 2020. In this paper, we present a brief review of balance impairments followed by subjective and objective tools currently used in clinical settings for human balance assessment. We propose a novel computer vision (CV) based approach as a candidate for functional balance test. The test will take less than a minute to administer and expected to be objective, repeatable and highly discriminative in quantifying ability to maintain posture and balance. We present an informal study with preliminary data from 10 healthy volunteers, and compare performance with a balance assessment system called BTrackS Balance Assessment Board. Our results show high degree of correlation with BTrackS. The proposed system promises to be a good candidate for objective functional balance tests and warrants further investigations to assess validity in clinical settings, including acute care, long term care and assisted living care facilities. Our long term goals include non-intrusive approaches to assess balance competence during ADL in independent living environments.

[Ocular surface acidity and buffering system (by studying the conjunctival sac)].

Science.gov (United States)

Avetisov, S É; Safonova, T N; Novikov, I A; Pateiuk, L S; Griboedova, I G

2014-01-01

As any mucous membrane the conjunctiva is characterized by a definite pH value which guarantees-physiological functioning of the ocular surface. The most commonly used method of assessment is potentiometric pH measurement with ion-specific glass microelectrodes. The results, however, can be affected by such factors, as conjunctival sac zoning, tissue acidity, epithelial trauma, and reflex tear secretion. Few data and hypotheses are available on mechanisms of maintaining the acid-base balance of the conjunctival sac (bicarbonate buffering system in particular). to study spatial variability of conjunctival tear fluid pH and possible mechanisms of its maintenance using original methods of acidity measurement and mineral content assessment. Tear pH was determined in 42 healthy participants (84 eyes) by means of litmus test strips and computer- aided colorimetry. Electron probe microanalysis in combination with energy dispersive spectrometry was performed in 8 healthy participants (8 eyes, 8 samples). In the group of 42 healthy participants (84 eyes) the pH value of conjunctival tear fluid varied from 6.30 to 7.23 with the average of 6.76 and pH mode 6.74. The pH value of conjunctival mucous discharge was measured in 25 healthy participants (28 eyes) and varied from 7.00 to 8.00 with the average of 7.26 and pH mode 7.30. The main mineral components of tear fluid are chlorine, sodium, potassium, and boron. Borate buffer is regarded as a mechanism of maintaining the acid-base balance of the ocular surface. The developed method of pH measurement ensuresreliable determination of conjunctival sac acidity in accordance with zoning and heterogeneity of its media as well as the complex structure of the tear film. In a healthy population, the acidity of tear significantly differs from that of conjunctival mucous discharge. Soluble chlorine, sodium, potassium, and boron compounds are the prevailing mineral components of tear fluid. Borate buffer appears to be the most stable of

Acidic deposition: State of science and technology. Report 10. Watershed and lake processes affecting surface-water acid-base chemistry. Final report

International Nuclear Information System (INIS)

Turner, R.S.; Cook, R.B.; Miegroet, H.V.; Johnson, D.W.; Elwood, J.W.

1990-09-01

The acid-base chemistry of surface waters is governed by the amount and chemistry of deposition and by the biogeochemical reactions that generate acidity or acid neutralizing capacity (ANC) along the hydrologic pathways that water follows through watersheds to streams and lakes. The amount of precipitation and it chemical loading depend on the area's climate and physiography, on it proximity to natural or industrial gaseous or particulate sources, and on local or regional air movements. Vegetation interacts with the atmosphere to enhance both wet and dry deposition of chemicals to a greater or lesser extent, depending on vegetation type. Vegetation naturally acidifies the environment in humid regions through processes of excess base cation uptake and generation of organic acids associated with many biological processes. Natural acid production and atmospheric deposition of acidic materials drive the acidification process. The lake or stream NAC represents a balance between the acidity-and ANC-generating processes that occur along different flow paths in the watershed and the relative importance of each flow path

Maternal and neonatal dietary intake of balanced n-6/n-3 fatty acids modulates experimental colitis in young adult rats.

Science.gov (United States)

Reddy, K Vijay Kumar; Naidu, K Akhilender

2016-08-01

The imbalance of n-6 and n-3 polyunsaturated fatty acids in the maternal diet impairs intestinal barrier development and sensitizes the colon response to inflammatory insults in the young rats. With a view to overcoming this issue, we designed this study to investigate the effect of maternal and neonatal intake of different proportions of n-6/n-3 fatty acids on colon inflammation in the young adult rats. Female Wistar rats were assigned into four groups, and each group fed one of four semisynthetic diets, namely n-6, low n-3, n-6/n-3 and n-3 fatty acids for 8 weeks prior to mating, during gestation and lactation periods. At weaning, the pups were separated from the dams and fed diet similar to the mothers. Colitis was induced on postnatal day 35, by administering 2 % dextran sulfate sodium in drinking water for 10 days. Colitis was assessed based on the clinical and inflammatory markers in the colon. Fatty acid analysis was done in liver, RBC, colon and spleen. A balanced n-6/n-3 PUFA diet significantly improved the body weight loss, rectal bleeding and mortality in rats. This was associated with lower myeloperoxidase activity, nitric oxide, prostaglandin E2, TNF-α and IL-6, IL-8, COX-2 and iNOS levels in the colon tissues. Fatty acid analysis has shown that the arachidonic acid/docosahexaenoic acid ratio was significantly lower in liver, RBC, colon and spleen in n-6/n-3 and n-3 diet groups. We demonstrate that balanced n-6/n-3 PUFA supplementation in maternal and neonatal diet alters systemic AA/DHA ratio and attenuates colon inflammation in the young adult rats.

The potential for adaptive maintenance of diversity in insect antimicrobial peptides.

Science.gov (United States)

Unckless, Robert L; Lazzaro, Brian P

2016-05-26

Genes involved in immune defence are among the fastest evolving in the genomes of many species. Interestingly, however, genes encoding antimicrobial peptides (AMPs) have shown little evidence for adaptive divergence in arthropods, despite the centrality of these peptides in direct killing of microbial pathogens. This observation, coupled with a failure to detect phenotypic consequence of genetic variation in AMPs, has led to the hypothesis that individual AMPs make minor contributions to overall immune defence and that AMPs instead act as a collective cocktail. Recent data, however, have suggested an alternative explanation for the apparent lack of adaptive divergence in AMP genes. Molecular evolutionary and phenotypic data have begun to suggest that variant AMP alleles may be maintained through balancing selection in invertebrates, a pattern similar to that observed in several vertebrate AMPs. Signatures of balancing selection include high rates of non-synonymous polymorphism, trans-species amino acid polymorphisms, and convergence of amino acid states across the phylogeny. In this review, we revisit published literature on insect AMP genes and analyse newly available population genomic datasets in Drosophila, finding enrichment for patterns consistent with adaptive maintenance of polymorphism.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Authors.

Contrasting nutritional acclimation of sugar maple (Acer saccharum Marsh. and red maple (Acer rubrum L. to increasing conifers and soil acidity as demonstrated by foliar nutrient balances

Directory of Open Access Journals (Sweden)

Alexandre Collin

2016-07-01

Full Text Available Sugar maple (Acer saccharum Marshall, SM is believed to be more sensitive to acidic and nutrient-poor soils associated with conifer-dominated stands than red maple (Acer rubrum L., RM. Greater foliar nutrient use efficiency (FNUE of RM is likely the cause for this difference. In the context of climate change, this greater FNUE could be key in favouring northward migration of RM over SM. We used the concept of foliar nutrient balances to study the nutrition of SM and RM seedlings along an increasing gradient in forest floor acidity conditioned by increasing proportions of conifers (pH values ranging from 4.39 under hardwoods, to 4.29 under mixed hardwood-conifer stands and 4.05 under conifer-dominated stands. Nutrients were subjected to isometric log-ratio (ilr transformation, which views the leaf as one closed system and considers interactions between nutrients. The ilr method eliminates numerical biases and weak statistical inferences based on raw or operationally’’ log-transformed data. We analyzed foliar nutrients of SM and RM seedlings and found that the [Ca,Mg,K|P,N] and [Ca,Mg|K] balances of SM seedlings were significantly different among soil acidity levels, whereas they did not vary for RM seedlings. For SM seedlings, these differences among soil acidity levels were due to a significant decrease in foliar Ca and Mg concentrations with increasing forest floor acidity. Similar differences in foliar balances were also found between healthy and declining SM stands estimated from literature values. Conversely, foliar balances of RM seedlings did not differ among soil acidity levels, even though untransformed foliar nutrient concentrations were significantly different. This result highlights the importance of using ilr transformation, since it provides more sensitive results than standard testing of untransformed nutrient concentrations. The lower nutrient requirements of RM and its greater capacity to maintain nutrient equilibrium are

The effects of water replacement by oral rehydration fluids with or without betaine supplementation on performance, acid-base balance, and water retention of heat-stressed broiler chickens.

Science.gov (United States)

Sayed, M A M; Downing, J

2011-01-01

Exposing broilers to a high temperature increases water and electrolyte K(+) and Na(+) excretion, which negatively affects the heat dissipation capacity and acid-base homeostasis, resulting in losses in growth performance. In this experiment, the efficacy of providing oral rehydration therapy and betaine on growth performance, acid-base balance, and water and electrolyte retention was evaluated. A total of 432 one-day-old broiler chicks (Cobb) were allocated to 72 metabolic cages and reared to 31 d of age under standard conditions. From 32 to 41 d of age, chicks were exposed to heat stress (ambient temperature, 32°C) and high RH (80 to 100% RH) for 9 h daily. The ameliorative effects of a 3 × 3 factorial array of treatments administered via drinking water were evaluated in 8 replicates of 6 chicks per cage for each treatment. Two oral rehydration therapy (ORT) fluids, based on either citrate or bicarbonate salts, were added to tap water. In addition, betaine was added to tap water at an inclusion rate of 0, 500, or 1,000 mg/L to complete the array of 9 liquid-based treatments. Growth performance was assessed at 32, 35, and 41 d of age. From 32 to 35 d of age, chicks receiving ORT fluids exhibited improved growth performance, water balance, and electrolyte (K(+), Na(+)) retention. In addition, the physiological response to stress was attenuated, as indicated by lower heterophil-to-lymphocyte ratios and blood glucose concentrations relative to the negative controls. The addition of betaine at an inclusion rate of 500 mg/L improved BW gain. From d 36 to 41, treatments did not significantly influence growth performance, which suggests that chicks receiving tap water were able to compensate and adapt to the heat-stress conditions. The results demonstrate that the beneficial effects of providing ORT fluids and 500 mg of betaine/L were observed only during the first 4 d of heat exposure. After this period, adaptation to the heat appears to occur, and none of the

Analytical method for optimization of maintenance policy based on available system failure data

International Nuclear Information System (INIS)

Coria, V.H.; Maximov, S.; Rivas-Dávalos, F.; Melchor, C.L.; Guardado, J.L.

2015-01-01

An analytical optimization method for preventive maintenance (PM) policy with minimal repair at failure, periodic maintenance, and replacement is proposed for systems with historical failure time data influenced by a current PM policy. The method includes a new imperfect PM model based on Weibull distribution and incorporates the current maintenance interval T 0 and the optimal maintenance interval T to be found. The Weibull parameters are analytically estimated using maximum likelihood estimation. Based on this model, the optimal number of PM and the optimal maintenance interval for minimizing the expected cost over an infinite time horizon are also analytically determined. A number of examples are presented involving different failure time data and current maintenance intervals to analyze how the proposed analytical optimization method for periodic PM policy performances in response to changes in the distribution of the failure data and the current maintenance interval. - Highlights: • An analytical optimization method for preventive maintenance (PM) policy is proposed. • A new imperfect PM model is developed. • The Weibull parameters are analytically estimated using maximum likelihood. • The optimal maintenance interval and number of PM are also analytically determined. • The model is validated by several numerical examples

Home-based virtual reality balance training and conventional balance training in Parkinson's disease: A randomized controlled trial

Directory of Open Access Journals (Sweden)

Wen-Chieh Yang

2016-09-01

Conclusion: This study did not find any difference between the effects of the home-based virtual reality balance training and conventional home balance training. The two training options were equally effective in improving balance, walking, and quality of life among community-dwelling patients with PD.

Risk-based equipment removal guide for on-line maintenance at PSE ampersand G

International Nuclear Information System (INIS)

Knoll, A.; Smith, C.; Pollock, J.

1995-01-01

On-line maintenance plays an important role in achieving safe and reliable power generation in a nuclear power plant. However, maintenance, if not properly planned and performed, may also be an important contributor to plant risk. Therefore, plant-specific procedures are needed for equipment removal from service to enhance the benefits of on-line maintenance and minimize the risks involved. The problem is to identify and implement the most effective on-line maintenance policy in the form of a proceduralized guide to assure plant safety under various operation and maintenance constraints. This paper presents a methodology to develop plant-specific on-line maintenance strategies and acceptance criteria using a multivariate safety approach based on risk assessment. Based on plant-specific data as modeled in the individual plant evaluation (IPE) and the updated probabilistic safety assessment (PSA), the risk-based methodology is currently being applied to the development of proceduralized equipment removal guides at Hope Creek and Salem units 1 and 2 of Public Service Electric and Gas Company (PSE ampersand G)

Heuristic hybrid game approach for fleet condition-based maintenance planning

International Nuclear Information System (INIS)

Feng, Qiang; Bi, Xiong; Zhao, Xiujie; Chen, Yiran; Sun, Bo

2017-01-01

The condition-based maintenance (CBM) method is commonly used to select appropriate maintenance opportunities according to equipment status over a period of time. The CBM of aircraft fleets is a fleet maintenance planning problem. In this problem, mission requirements, resource constraints, and aircraft statuses are considered to find an optimal strategy set. Given that the maintenance strategies for each aircraft are finite, fleet CBM can be treated as a combinatorial optimization problem. In this study, the process of making a decision on the CBM of military fleets is analyzed. The fleet CBM problem is treated as a two-stage dynamic decision-making problem. Aircraft are divided into dispatch and standby sets; thus, the problem scale is significantly reduced. A heuristic hybrid game (HHG) approach comprising a competition game and a cooperative game is proposed on the basis of heuristic rule. In the dispatch set, a competition game approach is proposed to search for a local optimal strategy matrix. A cooperative game method for the two sets is also proposed to ensure global optimization. Finally, a case study regarding a fleet comprising 20 aircraft is conducted, with the results proving that the approach efficiently generates outcomes that meet the mission risk-oriented schedule requirement. - Highlights: • A new heuristic hybrid game method for fleet condition-based maintenance is proposed. • The problem is simplified by hierarchical solving based on dispatch and standby set. • The local optimal solution is got by competition game algorithm for dispatch set. • The global optimal solution is got by cooperative game algorithm between two sets.

Effects of acid-base imbalance on vascular reactivity

Directory of Open Access Journals (Sweden)

A.C. Celotto

2008-06-01

Full Text Available Acid-base homeostasis maintains systemic arterial pH within a narrow range. Whereas the normal range of pH for clinical laboratories is 7.35-7.45, in vivo pH is maintained within a much narrower range. In clinical and experimental settings, blood pH can vary in response to respiratory or renal impairment. This altered pH promotes changes in vascular smooth muscle tone with impact on circulation and blood pressure control. Changes in pH can be divided into those occurring in the extracellular space (pHo and those occurring within the intracellular space (pHi, although, extracellular and intracellular compartments influence each other. Consistent with the multiple events involved in the changes in tone produced by altered pHo, including type of vascular bed, several factors and mechanisms, in addition to hydrogen ion concentration, have been suggested to be involved. The scientific literature has many reports concerning acid-base balance and endothelium function, but these concepts are not clear about acid-base disorders and their relations with the three known mechanisms of endothelium-dependent vascular reactivity: nitric oxide (NO/cGMP-dependent, prostacyclin (PGI2/cAMP-dependent and hyperpolarization. During the last decades, many studies have been published and have given rise to confronting data on acid-base disorder and endothelial function. Therefore, the main proposal of this review is to provide a critical analysis of the state of art and incentivate researchers to develop more studies about these issues.

The slice balance approach (SBA): a characteristic-based, multiple balance SN approach on unstructured polyhedral meshes

International Nuclear Information System (INIS)

Grove, R.E.

2005-01-01

The Slice Balance Approach (SBA) is an approach for solving geometrically-complex, neutral-particle transport problems within a multi-group discrete ordinates (S N ) framework. The salient feature is an angle-dependent spatial decomposition. We approximate general surfaces with arbitrary polygonal faces and mesh the geometry with arbitrarily-shaped polyhedral cells. A cell-local spatial decomposition divides cells into angle-dependent slices for each S N direction. This subdivision follows from a characteristic-based view of the transport problem. Most balance-based characteristic methods use it implicitly; we use it explicitly and exploit its properties. Our mathematical approach is a multiple balance approach using exact spatial moments balance equations on cells and slices along with auxiliary relations on slices. We call this the slice balance approach; it is a characteristic-based multiple balance approach. The SBA is intentionally general and can extend differencing schemes to arbitrary 2-D and 3-D meshes. This work contributes to development of general-geometry deterministic transport capability to complement Monte Carlo capability for large, geometrically-complex transport problems. The purpose of this paper is to describe the SBA. We describe the spatial decomposition and mathematical framework and highlight a few interesting properties. We sketch the derivation of two solution schemes, a step characteristic scheme and a diamond-difference-like scheme, to illustrate the approach and we present interesting results for a 2-D problem. (author)

Acid-base balance and changes in haemolymph properties of the South African rock lobsters, Jasus lalandii, a palinurid decapod, during chronic hypercapnia.

Science.gov (United States)

Knapp, Jarred L; Bridges, Christopher R; Krohn, Janina; Hoffman, Louwrens C; Auerswald, Lutz

2015-06-05

Few studies exist reporting on long-term exposure of crustaceans to hypercapnia. We exposed juvenile South African rock lobsters, Jasus lalandii, to hypercapnic conditions of pH 7.3 for 28 weeks and subsequently analysed changes in the extracellular fluid (haemolymph). Results revealed, for the first time, adjustments in the haemolymph of a palinurid crustacean during chronic hypercapnic exposure: 1) acid-base balance was adjusted and sustained by increased bicarbonate and 2) quantity and oxygen binding properties of haemocyanin changed. Compared with lobsters kept under normocapnic conditions (pH 8.0), during prolonged hypercapnia, juvenile lobsters increased bicarbonate buffering of haemolymph. This is necessary to provide optimum pH conditions for oxygen binding of haemocyanin and functioning of respiration in the presence of a strong Bohr Effect. Furthermore, modification of the intrinsic structure of the haemocyanin molecule, and not the presence of molecular modulators, seems to improve oxygen affinity under conditions of elevated pCO2. Copyright © 2015 Elsevier Inc. All rights reserved.

Analysis of Financial Position Based on the Balance Sheet

OpenAIRE

Spineanu-Georgescu Luciana

2011-01-01

Analysis of financial position based on the balance sheet is mainly aimed at assessing the extent to which financial structure chosen by the firm, namely, financial resources, covering the needs reflected in the balance sheet financed. This is done through an analysis known as horizontal analysis balance sheet financial imbalances.

Maintenance scheduling of a manufacturing system subject to deterioration

International Nuclear Information System (INIS)

Ahmadi, Reza; Newby, Martin

2011-01-01

This paper presents an integrated model for the joint determination of both optimal inspection strategy and optimal repair policy for a manufacturing system whose resulting output is subject to system state. An appropriate maintenance strategy is essential to optimize revenue from a manufacturing system which is in continuous operation and subject to deterioration. The optimum policy balances the amount of maintenance required to increase availability against the loss of revenue arising from the down time: insufficient maintenance leads to an increase in the number of defective items, low profit and low maintenance cost; excessive maintenance results in a reduction in the proportion of defective items, high profit and high maintenance cost. In this paper, an intensity control model adapted to partial information provides an optimal inspection intensity and repair degree of the system as an optimal control process to yield maximum revenue. The solution is obtained through formulating an equivalent deterministic Hamilton-Jacobi equation. A numerical example is provided to illustrate the behavior of the optimal control process. The optimal control process determines a solution to both optimum inspection frequency and optimal replacement policy which results in an optimal production run length of the system. - Highlights: → We develop an optimum asset management strategy based on the revenue generated by the asset. → The optimum strategy controls the intensity, rate of occurrence, of interruptions to service. → The decisions are based on partial observation of the system and do not need perfect information. There is no need for continuous monitoring of the system.

Disentangling the contribution of the paretic and non-paretic leg to balance control in stroke.

NARCIS (Netherlands)

van Asseldonk, Edwin H.F.; Buurke, Jaap; Bloem, Bastiaan R.; van der Helm, F.C.T.; Renzenbrink, Gerbert J.; van der Kooij, Herman; Nene, A.V.

2005-01-01

During stroke recovery, restoration of the paretic ankle and compensation in the non-paretic ankle may contribute to improved balance maintenance. We examine a new approach to disentangle these recovery mechanisms by objectively quantifying the contribution of each ankle to balance maintenance.

Energeia of maintenance. Knowledge resource maintenance and creation of new value

International Nuclear Information System (INIS)

Iwata, Shuichi

2011-01-01

After the Fukushima accident occurred in March 2011, the intellectual energeia of maintenology (motive force of implementation) - 'arrow of information' - could be obtained by trying to establish academic agenda from uniting 'arrow of time' and 'arrow of entropy' based on historical review and then dividing characteristics of maintenance objects needed from society in the future, into content, context and measures in order to overcome this chaos. Looking at contaminated area map around Chernobyl and comparing state of Ukraine elapsed 25 years after Chernobyl accident with that of Fukushima in great social anxiety at present, various 'arrow of information' could be enumerated such as (1) openness of content of accident information and evaluation of context, (2) safety and stability of social society, (3) perfect individual's care and human right for knowing risk, (4) data literacy, (5) various risks, (6) data dissemination and (7) utilization of outsider's view. Knowledge maintenology should be expanded in the area such as (1) preservation of global environment and maintenology, (2) problem of contaminated area with radioactive materials: data science and maintenology, (3) maintenance of large artificial product: experimental science, theoretical science, computational science and maintenology, (4) maintenance of knowledge related with events having complicated causality: design science responding to various risks. As for utilization of nuclear energy, maintenance technology, which shall balance its benefit and risk of society and establish science needed for security of all human being -a raison d'etre and energeia of maintenology-, should be considered for upper structure about global energy, environment, economics and politics (including military affairs) and human society, not for respective energy system in specific country or organization. Fundamentals of energeia of maintenology shall be implemented in the same spirit of 'Yui', small mutual aid organization

Research of nuclear power plant in-service maintenance based on virtual reality

International Nuclear Information System (INIS)

Wang Yong; Kuang Weijun

2015-01-01

This paper presents a method of constructing nuclear power plant in-service maintenance virtual simulation scene and virtual maintenance process. Taking air baffles dismantling process of CAP1400(China Advanced Passive 1400) nuclear power plant as an instance, this paper discusses ergonomics, space analysis, time assessment based on virtual reality in the process of in-service maintenance. It demonstrates the advantage of using VR technology to design and verify in-service maintenance process of nuclear power plant compared to the conventional way. (author)

Experience based reliability centered maintenance

International Nuclear Information System (INIS)

Haenninen, S.; Laakso, K.

1993-03-01

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

Efeito do tempo após a ingestão de leite sobre o equilíbrio ácido-básico de bezerros Effect of the time after milk feeding on the acid-base balance of calves

Directory of Open Access Journals (Sweden)

J.A.N. Lisbôa

2003-12-01

Full Text Available Blood pH, carbon dioxide and oxygen partial pressures, bicarbonate, total carbon dioxide, base excess, standard bicarbonate and oxygen saturation concentrations were measured by blood gas analyses in a study of assessment of the acid-base status in young calves. Venous blood samples were taken from 80 healthy female Holstein calves, from four to 30 days of age. The calves were divided in two groups based on the interval between the morning milk feeding and the blood sample collection (up to 30 minutes or over two hours. Greater alkali reserve and higher carbon dioxide pressure values were observed later than 2h after milk feeding, supporting the influence of the diet on the acid-base balance of calves during the milk feeding phase.

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

NARCIS (Netherlands)

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

2015-01-01

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

Developing Mobile- and BIM-Based Integrated Visual Facility Maintenance Management System

Directory of Open Access Journals (Sweden)

Yu-Cheng Lin

2013-01-01

Full Text Available Facility maintenance management (FMM has become an important topic for research on the operation phase of the construction life cycle. Managing FMM effectively is extremely difficult owing to various factors and environments. One of the difficulties is the performance of 2D graphics when depicting maintenance service. Building information modeling (BIM uses precise geometry and relevant data to support the maintenance service of facilities depicted in 3D object-oriented CAD. This paper proposes a new and practical methodology with application to FMM using BIM technology. Using BIM technology, this study proposes a BIM-based facility maintenance management (BIMFMM system for maintenance staff in the operation and maintenance phase. The BIMFMM system is then applied in selected case study of a commercial building project in Taiwan to verify the proposed methodology and demonstrate its effectiveness in FMM practice. Using the BIMFMM system, maintenance staff can access and review 3D BIM models for updating related maintenance records in a digital format. Moreover, this study presents a generic system architecture and its implementation. The combined results demonstrate that a BIMFMM-like system can be an effective visual FMM tool.

[Rehabilitation of patients with acid-base and fluid balance disorders with short bowel syndrome after ileostomies].

Science.gov (United States)

Söhngen, D; Balzer, C; Fuchs, M; Waldschmidt, D

2015-04-01

Patients with ileostomies regularly suffer from short bowel syndrome or high volume output associated with loss of absorptive surface and subsequent impairment of absorption for drugs and different nutrients resulting in electrolyte and fluid balance disorders as well as renal insufficiency. Adaptation of these fundamental functions of the gut with adequate fluid uptake, absorption of sufficient different nutrients and vitamins represents a major challenge to rehabilitate these patients shortly after surgery. Patients with ileostomy often develop metabolic acidosis with normal anion gap. In our retrospective study we would like to draw attention to these metabolic disorders in patients with ileostomy in comparison to patients with colostomy and patients undergoing gastrectomy for gastric cancer. In the period from 2005 to 2012 we examined 164 patients with ileostomy in our rehabilitation clinic, 109 patients with colostomy and 193 patients after surgery for gastric cancer of the possible presence of metabolic acidosis by using capillary blood gas analysis (metabolic acidosis was anticipated, if base excess was ≤- 3,0 mmol/l). Patients are treated as inpatients both in early stage and for follow-up rehabilitation. The length of time in our rehabilitation clinic lies in between 24-28 days. On the basis of random samples we tested blood samples in 19 patients with ileostomy in succession for ferritin, folic acid, zinc, selenium and vitamin B12. Statistical analysis comprised the classical intervals (mean and standard deviation, range and T-test for dependent and independent samples). In total we tested 164 inpatients with ileostomy in our rehabilitation clinic (median age 67.4 years, range 19-79 years). Surgery for ileostomy took place about 1.4 months on average ago (range ¼-56 months). 60 (36.5%) inpatients suffered from metabolic acidosis often combined with renal insufficiency. Supportive therapy intravenously administered in 10 patients and sodium bicarbonate

Maintenance management for nuclear power plant 'Integrated valve maintenance'

International Nuclear Information System (INIS)

Gerner, P.; Zanner, G.

2001-01-01

The deregulation of Europe's power market does force many utilities, and especially nuclear power plant operators, to introduce extensive cost-cutting measures in order to be able to compete within this new environment. The optimization of plant outages provides considerable potential for raising plant availability but can also lower operating costs by reducing e.g. expenditure on maintenance. Siemens Nuclear Power GmbH, in cooperation with plant operators, is currently implementing new and improved service concepts which can have a major effect on the way in which maintenance will be performed in the future. Innovative service packages for maintenance in nuclear power plants are available which can be used to perform a time- and cost-effective maintenance. The concepts encompass optimization of the overall sequence from planning in advance to the individual measures including reduction of the scope of maintenance activities, identification of cost cutting potential and bundling of maintenance activities. The main features of these maintenance activities are illustrated here using the examples of outage planning and integrated valve maintenance. In nuclear power plants approx. 5000 valves are periodically preventively, condition-based or breakdown-based maintained. Because of this large number of valves to be maintained a high potential of improvements and cost reductions can be achieved by performing an optimized, cost-effective maintenance based on innovative methods and tools. Siemens Nuclear Power GmbH has developed and qualified such tools which allow to reduce service costs while maintaining high standards of safety and availability. By changing from preventive to predictive (condition-based) maintenance - the number of valves to be maintained may be reduced considerably. The predictive maintenance is based on the Siemens Nuclear Power GmbH diagnostic and evaluation method (ADAM). ADAM is used to monitor the operability of valves by analytical verification of

A comprehensive approach to RCM-based preventive maintenance program development

International Nuclear Information System (INIS)

Hall, B.E.; Davis, T.; Pennington, A.J.

1988-01-01

In late 1986, Public Service Electric and Gas Company (PSE ampersand G) concluded that to support its vision and strategic planning it would be necessary to develop a consistent approach to maintenance for all nuclear units at the artificial island. General Physics Corporation was selected to lead a consultant team to support full-scale development of a preventive maintenance (PM) program for Salem and Hope Creek generating stations based on a reliability-centered maintenance (RCM) approach. RCM was selected because it represents a systematic approach to developing a PM program that provides a logical, consistent, and traceable methodology and produces a well-documented engineering basis for the program. Early in 1987, primary objectives for the PM program were defined. The Phase I tasks addressed key programmatic areas such as maintenance philosophy, procedures, condition monitoring, performance trending, equipment failure data base, ogranization, PM program effectiveness evaluation, RCM process, reliability/availability modeling, information management, training, spare parts, software/hardware, and commitments. Phase I of the PM program development project was completed in January 1988. Highlights of the Phase I work and the PM program manual are described

Game-Theoretic Models for Usage-based Maintenance Contract

Science.gov (United States)

Husniah, H.; Wangsaputra, R.; Cakravastia, A.; Iskandar, B. P.

2018-03-01

A usage-based maintenance contracts with coordination and non coordination between two parties is studied in this paper. The contract is applied to a dump truck operated in a mining industry. The situation under study is that an agent offers service contract to the owner of the truck after warranty ends. This contract has only a time limit but no usage limit. If the total usage per period exceeds the maximum usage allowed in the contract, then the owner will be charged an additional cost. In general, the agent (Original Equipment Manufacturer/OEM) provides a full coverage of maintenance, which includes PM and CM under the lease contract. The decision problem for the owner is to select the best option offered that fits to its requirement, and the decision problem for the agent is to find the optimal maintenance efforts for a given price of the service option offered. We first find the optimal decisions using coordination scheme and then with non coordination scheme for both parties.

Study of application properties of novel trisazo hetero bi-functional reactive dyes based on j-acid derivatives for cotton

International Nuclear Information System (INIS)

Mokhtari, Javad; Akbarzadeh, A; Phillips, D A S; Taylor, J A

2009-01-01

Three novel trisazo hetero bi-functional reactive dyes based on J-acid derivatives were prepared using the diazonium salt of [4-(4-sulphophenylazo-)-2,5-dimethylazobenzene-2-sulphonic acid] and a hetero bi-functional coupling component, derived from 1-hydroxy-6-aminonapthalene-3-sulphonic acid (J-acid), 1-hydroxy-6- methylaminonapthalene-3-sulphonic acid (methyl J-acid), and 1-hydroxy-6-aminonaphthalene-3,5-disulphonic acid (sulpho J-acid). On balance, the dye derived from sulpho J-acid displayed the most attractive set of technical properties, building up and fixing more efficiently than those derived from J-acid and methyl J-acid. In addition, the sulpho J-acid based dye offered better migration and, therefore, level dyeing and ease of wash off. (author)

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

Performance-based maintenance procurement by Dutch housing associations

NARCIS (Netherlands)

Straub, A.

2004-01-01

OTB Research institute has established a long-term research program to performance-based maintenance procurement in the technical management of housing stock. Stakeholders: housing associations, contractors and the Dutch Building Research Foundation are directly involved in this research program.

JRR-3 maintenance program utilizing accumulated maintenance data

International Nuclear Information System (INIS)

Izumo, Hironobu; Kato, Tomoaki; Kinase, Masami; Torii, Yoshiya; Murayama, Yoji

2007-07-01

JRR-3(Japan Research Reactor No.3) has been operated for more than 15 years after the modification, without significant troubles by carrying out maintenance such as the preventive maintenance (mainly time-based maintenance) for the safety-grade equipments and the breakdown maintenance for the non-safety-grade equipments. Unscheduled shutdowns causes by aged non-safety-grade equipments have been increasing, and the resources such as budgets have been decreasing year by year. In this situation, JRR-3 maintenance program was reviewed about safety, reliability and economic efficiency. This report offers the policy of the maintenance review and the future direction of maintenance programs. (author)

Development of maintenance tools based on tribology for nuclear power plant

International Nuclear Information System (INIS)

Iwai, Yoshiro; Honda, Tomomi; Yoshinaga, Shigeki

2007-01-01

Many tribological problems occur in the maintenance of nuclear power plants. In this paper, we introduced our developed maintenance tools based on tribology such as a particle counter and wear sensors. Their principals were shown briefly and their usefulness was clarified by the experiments on monitoring of wear. (author)

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

International Nuclear Information System (INIS)

Sanchez, Ana; Carlos, Sofia; Martorell, Sebastian; Villanueva, Jose F.

2009-01-01

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral

Addressing imperfect maintenance modelling uncertainty in unavailability and cost based optimization

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Ana [Department of Statistics and Operational Research, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Carlos, Sofia [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain); Martorell, Sebastian [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)], E-mail: smartore@iqn.upv.es; Villanueva, Jose F. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera, s/n, 46071 Valencia (Spain)

2009-01-15

Optimization of testing and maintenance activities performed in the different systems of a complex industrial plant is of great interest as the plant availability and economy strongly depend on the maintenance activities planned. Traditionally, two types of models, i.e. deterministic and probabilistic, have been considered to simulate the impact of testing and maintenance activities on equipment unavailability and the cost involved. Both models present uncertainties that are often categorized as either aleatory or epistemic uncertainties. The second group applies when there is limited knowledge on the proper model to represent a problem, and/or the values associated to the model parameters, so the results of the calculation performed with them incorporate uncertainty. This paper addresses the problem of testing and maintenance optimization based on unavailability and cost criteria and considering epistemic uncertainty in the imperfect maintenance modelling. It is framed as a multiple criteria decision making problem where unavailability and cost act as uncertain and conflicting decision criteria. A tolerance interval based approach is used to address uncertainty with regard to effectiveness parameter and imperfect maintenance model embedded within a multiple-objective genetic algorithm. A case of application for a stand-by safety related system of a nuclear power plant is presented. The results obtained in this application show the importance of considering uncertainties in the modelling of imperfect maintenance, as the optimal solutions found are associated with a large uncertainty that influences the final decision making depending on, for example, if the decision maker is risk averse or risk neutral.

Comparison of endogenous loss and maintenance need for minerals in rainbow trout (Oncorhynchus mykiss) fed fishmeal or plant ingredient-based diets.

Science.gov (United States)

Antony Jesu Prabhu, P; Kaushik, S J; Mariojouls, C; Surget, A; Fontagné-Dicharry, S; Schrama, J W; Geurden, I

2015-02-01

Mineral needs as affected by changes in dietary protein and oil sources were studied in rainbow trout. Duplicate groups (n = 30 fish per replicate) of rainbow trout (initial BW: 37 g) were fed either a fish meal/fish oil-based (M) or a complete plant ingredient (V)-based diet at four graded ration (R) levels [apparent satiation (AS), R75, R50 and R25 % of AS]; one treatment group was maintained under starvation. The feeding trial lasted 12 weeks at a water temperature of 17 °C. Dietary intake, apparent digestibility and initial and final whole-body composition data were used to calculate mineral gain which was regressed against digestible mineral intake (both expressed as mg or µg kg(-0.8) day(-1)). Starvation loss (SL), endogenous loss of fed fish (ELF, y-intercept at x = 0) and point of intake for zero balance (PZB, x-intercept at y = 0) were used as estimates of maintenance requirements. SL provided the lowest estimate, ELF provided the net requirement of a mineral for maintenance and PZB provided the digestible dietary intake required to meet maintenance (SL digestible mineral supply required for maintenance (PZB) for any of the minerals (P, Mg, K, Cu and Zn) studied. However, ELF of micro-minerals such as Cu and Zn were significantly affected. The ELF of Cu was significantly lower and that of Zn was significantly higher in V group compared with M-fed fish. Further studies on the effects of such changes in dietary formulations on micro-mineral metabolism are warranted.

The Importance of the Ionic Product for Water to Understand the Physiology of the Acid-Base Balance in Humans

Directory of Open Access Journals (Sweden)

María M. Adeva-Andany

2014-01-01

Full Text Available Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on the plasma ionic composition. Variations in the concentration of plasma ions that alter the relative proportion of anions and cations predictably lead to a change in the plasma concentration of hydrogen ions by driving adaptive adjustments in water ionization that allow plasma electroneutrality while maintaining constant the ionic product for water. The accumulation of plasma anions out of proportion of cations induces an electrical imbalance compensated by a fall of hydroxide ions that brings about a rise in hydrogen ions (acidosis. By contrast, the deficiency of chloride relative to sodium generates plasma alkalosis by increasing hydroxide ions. The adjustment of plasma bicarbonate concentration to these changes is an important compensatory mechanism that protects plasma pH from severe deviations.

An Abstraction Hierarchy based mobile PC display design in NPP maintenance considering the level of expertise

International Nuclear Information System (INIS)

Yim, Ho Bin; Kim, In; Seong, Poong Hyun

2011-01-01

Research highlights: → Six levels of Abstraction Hierarchy based information for maintenance were proposed. → Errors and workload with AH based information display were reduced for LL subjects. → Design concerns discovered can be applied to practical use of mobile maintenance aids. - Abstract: Recently, the importance of effective maintenance in nuclear power plants (NPPs) has been emphasized and research into effective maintenance by adopting mobile maintenance aids (MMAs) have been attempted. For improved and effective use of an MMA display design method based on the hierarchy is proposed and its design considerations are discussed in this study. Six levels of hierarchy are proposed in this paper to classify the maintenance information. By classifying and organizing maintenance information using the hierarchy, maintenance information can be used effectively by users with either high or low levels of expertise. When information classification has been finished, the information for MMA design is selected and designed. With the considerations of MMA design analysis and guidelines, a hierarchy-based MMA is designed for the maintenance tasks. An experiment is conducted using the hierarchy-based MMA in order to estimate the effectiveness of the proposed method for the maintenance tasks and to identify design considerations to enhance the proposed MMAs. The result indicated that a hierarchy-based manual was more effective than a conventional manual in terms of task completion time and number of errors. The workload for the hierarchy-based manual was estimated less than the conventional manual for subjects with low level of expertise. As the level of expertise increases, subjects tended to follow more abstract information while the number of navigations decreased. It is believed that when mobile devices become pervasive in NPP maintenance fields, the hierarchy model applied MMAs can be used as an effective maintenance supporting tool.

Methadone maintenance therapy as evidence based drug abuse ...

African Journals Online (AJOL)

Methadone maintenance therapy as evidence based drug abuse planning in ... drugs are being used as artificial problem-solvers such as frustrations, stress or ... Drug use is a problem to users when it begins to cause some damage to their ...

Reliability-based maintenance evaluations and standard preventive maintenance programs

International Nuclear Information System (INIS)

Varno, M.; McKinley, M.

1993-01-01

Due to recent issuance of 10CFR50.65, the U.S. Nuclear Regulatory Commission maintenance rule (Rule), and the open-quotes Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plantsclose quotes prepared by the Nuclear Management and Resources Council, many utilities are undertaking review or evaluation of current preventive maintenance (PM) programs. Although PM optimization and documentation are not specifically required by the Rule, an appropriate and effective PM program (PMP) will be the cornerstone of the successful and cost-effective implementation of the Rule. Currently, a project is being conducted at the Vermont Yankee Nuclear Power Station (VYNPS) in conjunction with Quadrex Energy Services to evaluate, optimize, and document the PMP. The project began in March 1993 and is scheduled for completion in mid-1995. The initial scope for the project is the evaluation of those structures, systems, and components that are within the scope of the Rule. Because of the number of systems to be evaluated (∼50), the desired completion schedule, and cost considerations, a streamlined approach to PM optimization and documentation is being utilized

Proper balance of omega-3 and omega-6 fatty acid supplements with topical cyclosporine attenuated contact lens-related dry eye syndrome.

Science.gov (United States)

Wang, Ling; Chen, Xi; Hao, Jingfang; Yang, Lu

2016-12-01

Essential fatty acids had been applied in the treatment of dry eye syndrome (DES), but the effects of different combinations of fatty acids have not been investigated. 360 long-term contact lens wearers were included in this double-blinded study. Omega-3 and omega-6 fatty acids were combined in different ratios and supplied to the participants that were randomly divided into six groups, and the effects of different essential fatty acids mixture on DES with or without topical cyclosporine were investigated. More than half of long-term contact lens wearers suffered from DES, which were found to be attenuated by oral supplement of properly balanced O3FA and O6FA fatty acid. The topical cyclosporine treatment considerably inhibited the production of cytokines compared to the cyclosporine negative groups, which further relieved DES. Proper balance of omega-3 and omega-6 fatty acid combination significantly alleviated contact lens-related DES.

Offshore wind energy : balancing risk and reward

International Nuclear Information System (INIS)

Nerland, C.

2010-01-01

Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.

Effect of a perturbation-based balance training program on compensatory stepping and grasping reactions in older adults: a randomized controlled trial.

Science.gov (United States)

Mansfield, Avril; Peters, Amy L; Liu, Barbara A; Maki, Brian E

2010-04-01

Compensatory stepping and grasping reactions are prevalent responses to sudden loss of balance and play a critical role in preventing falls. The ability to execute these reactions effectively is impaired in older adults. The purpose of this study was to evaluate a perturbation-based balance training program designed to target specific age-related impairments in compensatory stepping and grasping balance recovery reactions. This was a double-blind randomized controlled trial. The study was conducted at research laboratories in a large urban hospital. Thirty community-dwelling older adults (aged 64-80 years) with a recent history of falls or self-reported instability participated in the study. Participants were randomly assigned to receive either a 6-week perturbation-based (motion platform) balance training program or a 6-week control program involving flexibility and relaxation training. Features of balance reactions targeted by the perturbation-based program were: (1) multi-step reactions, (2) extra lateral steps following anteroposterior perturbations, (3) foot collisions following lateral perturbations, and (4) time to complete grasping reactions. The reactions were evoked during testing by highly unpredictable surface translation and cable pull perturbations, both of which differed from the perturbations used during training. /b> Compared with the control program, the perturbation-based training led to greater reductions in frequency of multi-step reactions and foot collisions that were statistically significant for surface translations but not cable pulls. The perturbation group also showed significantly greater reduction in handrail contact time compared with the control group for cable pulls and a possible trend in this direction for surface translations. Further work is needed to determine whether a maintenance program is needed to retain the training benefits and to assess whether these benefits reduce fall risk in daily life. Perturbation-based training

Disentangling the contribution of the paretic and non-paretic ankle to balance control in stroke patients.

NARCIS (Netherlands)

Asseldonk, E.H.F. van; Buurke, J.H.; Bloem, B.R.; Renzenbrink, G.J.; Nene, A.V.; Helm, F.C.T. van der; Kooij, H. van der

2006-01-01

During stroke recovery, restoration of the paretic ankle and compensation in the non-paretic ankle may contribute to improved balance maintenance. We examine a new approach to disentangle these recovery mechanisms by objectively quantifying the contribution of each ankle to balance maintenance.

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

NARCIS (Netherlands)

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

2012-01-01

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

Inherently balanced 4R four-bar based linkages

NARCIS (Netherlands)

van der Wijk, V.; Herder, Justus Laurens; Lenarcis, J.; Husty, M.

2012-01-01

Synthesis of mechanisms with their center of mass (CoM) at an invariant point on one of the elements is useful for the design of statically balanced and shaking-force balanced mechanisms and manipulators. For this purpose, a kinematic architecture based on a general 4R four-bar linkage is found by

Risk-Based Maintenance Assessment in the Manufacturing Industry: Minimisation of Suboptimal Prioritisation

Directory of Open Access Journals (Sweden)

Ratnayake R.M. Chandima

2017-03-01

Full Text Available Manufacturing firms continuously strive to increase the efficiency and effectiveness in the maintenance management processes. Focus is placed on eliminating the unexpected failures which cause unnecessary costs and the production losses. Risk-based maintenance (RBM strategies enable to address the above through the identification of probability and consequences of potential failures whilst providing a way for prioritisation of maintenance actions based on the risk of possible failures. Such prioritisations enable to identify the optimal maintenance strategy, intervals of maintenance tasks, and optimal level of spare parts inventory. However, the risk assessment activities are performed with the support of a risk matrix. Suboptimal classifications and/or prioritisations arise due to the inherent nature of the risk matrix. This is caused by the fact that there are no means to incorporate actual circumstances at the boundary of the input ranges or at the levels of linguistic data and risk categories. In this paper, a risk matrix is first developed in collaboration with one of the manufacturing firms in Poland. Then, it illustrates the use of fuzzy logic for minimisation of suboptimal prioritisation and/or classifications using a fuzzy inference system (FIS together with illustrative membership functions and a rule base. Finally, an illustrative risk assessment is also demonstrated to illustrate the methodology.

Prioritization of pavement maintenance sections using objective based Analytic Hierarchy Process

Directory of Open Access Journals (Sweden)

Sarfaraz Ahmed

2017-03-01

Full Text Available The application of Analytic Hierarchy Process (AHP method for the prioritization of pavement maintenance sections is widespread now-a-days. Although the evaluation of pavement maintenance section through AHP method is simple, where the relative importance (on Saaty’s scale assigned to each parameter in the hierarchy varies between the experts (transportation professionals consulted, which leads to discrepancies in the final rankings of the sections’, due to the subjectivity in the process. Further, experts base their decisions solely on their experience while consideration is not given to the actual quantitative physical condition of the roads. To overcome these difficulties an objective based AHP method is proposed in this study, where pairwise comparison values are assigned based on the collected field data from a road network in Mumbai city, consisting of 28 road sections. The final ranking list of candidate sections takes into consideration the priority weight of alternatives, which reflect the road conditions. The solution of priority ratings of AHP method is compared with the corresponding solution of road condition index method, a traditional pavement maintenance procedure. The findings of the present study suggest that objective based AHP method is more suitable for the prioritization of pavement maintenance of roads. Keywords: Prioritization, Analytic Hierarchy Process, Road condition index, Objective method, Rating and ranking

Analysis of the possibility of applying a condition-based maintenance model on an example of tank weapons

Directory of Open Access Journals (Sweden)

Igor J. Epler

2013-12-01

Full Text Available For any modern army it is very important to continuously maintain a high degree of operational (combat readiness (availability in order to maximize the effectiveness of the use of technical systems. Since determination and prediction of technical states and failures of technical systems in engineering, especially in armament, are difficult due to the impossibility of continuous condition monitoring with appropriate measuring equipment there is a need for a maintenance model that would be most helpful in taking timely action maintenance. In this paper, the subject of research is a model of maintenance of the M-84 tank  weapoons systems.   IntroductionThe M-84 tank is one of the most promising technical systems in the Serbian Army. Its use and modifications are foreseen in the next ten years. The  M-84 is characterized by good tactical and technical characteristics. It has a powerful 125 mm cannon, coupled 7.62 mm machine gun and 12.7 mm anti-aircraft machine gun. The M-84 tank has an automatic battery charger and a fire control system. The fire control system enables fast target tracking and stabilization of the cannon barrel, which is a prerequisite for timely and favorable effect on the target. There are certain ambiguities in the existing model of maintenance of tank weapons.   Technical diagnostics Technical diagnostics, as a part of the process of condition-based maintenance, should determine technical conditions of components or technical systems with certain accuracy at a point in time.   Maintenance strategy A maintenance strategy can be defined as a variant of a maintenance system determined by a concept, organization and character of maintenance procedures, as well as the relationship between the various levels at which maintenance is performed. It is defined for technical system parts, individual technical systems and for system maintenance as a whole. The basic maintenance strategies implemented today are: -      corrective

Sustainable Urban Regeneration Based on Energy Balance

Directory of Open Access Journals (Sweden)

Sacha Silvester

2012-07-01

Full Text Available In this paper, results are reported of a technology assessment of the use and integration of decentralized energy systems and storage devices in an urban renewal area. First the general context of a different approach based on 'rethinking' and the incorporation of ongoing integration of coming economical and environmental interests on infrastructure, in relation to the sustainable urban development and regeneration from the perspective of the tripod people, technology and design is elaborated. However, this is at different scales, starting mainly from the perspective of the urban dynamics. This approach includes a renewed look at the ‘urban metabolism’ and the role of environmental technology, urban ecology and environment behavior focus. Second, the potential benefits of strategic and balanced introduction and use of decentralized devices and electric vehicles (EVs, and attached generation based on renewables are investigated in more detail in the case study of the ‘Merwe-Vierhaven’ area (MW4 in the Rotterdam city port in the Netherlands. In order to optimize the energy balance of this urban renewal area, it is found to be impossible to do this by tuning the energy consumption. It is more effective to change the energy mix and related infrastructures. However, the problem in existing urban areas is that often these areas are restricted to a few energy sources due to lack of available space for integration. Besides this, energy consumption in most cases is relatively concentrated in (existing urban areas. This limits the potential of sustainable urban regeneration based on decentralized systems, because there is no balanced choice regarding the energy mix based on renewables and system optimization. Possible solutions to obtain a balanced energy profile can come from either the choice to not provide all energy locally, or by adding different types of storage devices to the systems. The use of energy balance based on renewables as a

Managed maintenance, the next step in power plant maintenance

International Nuclear Information System (INIS)

Butterworth, G.; Anderson, T.M.

1984-01-01

The Westinghouse Nuclear Services Integration Division managed maintenance services are described. Essential to the management and control of a total plant maintenance programme is the development of a comprehensive maintenance specification. During recent years Westinghouse has jointly developed total plant engineering-based maintenance specifications with a number of utilities. The process employed and the experience to date are described. To efficiently implement the maintenance programme Westinghouse has developed a computer software program specifically designed for day to day use at the power plant by maintenance personnel. This program retains an equipment maintenance history, schedules maintenance activities, issues work orders and performs a number of sophisticated analyses of the maintenance backlog and forecast, equipment failure rates, etc. The functions of this software program are described and details of Westinghouse efforts to support the utilities in reducing outage times through development of predefined outage plans for critical report maintenance activities are given. Also described is the experience gained in the training of specialized maintenance personnel, employing competency-based training techniques and equipment mock-ups, and the benefits experienced, in terms of improved quality and productivity of maintenance performed. The success experienced with these methods has caused Westinghouse to expand the use of these training techniques to the more routine skill areas of power plant maintenance. A significant reduction in the operating costs of nuclear power plants will only be brought about by a significant improvement in the quality of maintenance. Westinghouse intends to effect this change by expanding its international service capabilities and to make major investments in order to promote technological developments in the area of power plant maintenance. (author)

Guidance for the design and management of a maintenance plan to assure safety and improve the predictability of a DOE nuclear irradiation facility. Final report

International Nuclear Information System (INIS)

Booth, R.S.; Kryter, R.C.; Shepard, R.L.; Smith, O.L.; Upadhyaya, B.R.; Rowan, W.J.

1994-10-01

A program is recommended for planning the maintenance of DOE nuclear facilities that will help safety and enhance availability throughout a facility's life cycle. While investigating the requirements for maintenance activities, a major difference was identified between the strategy suitable for a conventional power reactor and one for a research reactor facility: the latter should provide a high degree of predicted availability (referred to hereafter as ''predictability'') to its users, whereas the former should maximize total energy production. These differing operating goals necessitate different maintenance strategies. A strategy for scheduling research reactor facility operation and shutdown for maintenance must balance safety, reliability,and predicted availability. The approach developed here is based on three major elements: (1) a probabilistic risk analysis of the balance between assured reliability and predictability (presented in Appendix C), (2) an assessment of the safety and operational impact of maintenance activities applied to various components of the facility, and (3) a data base of historical and operational information on the performance and requirements for maintenance of various components. These factors are integrated into a set of guidelines for designing a new highly maintainable facility, for preparing flexible schedules for improved maintenance of existing facilities, and for anticipating the maintenance required to extend the life of an aging facility. Although tailored to research reactor facilities, the methodology has broader applicability and may therefore be used to improved the maintenance of power reactors, particularly in anticipation of peak load demands

Preventive Maintenance Interval Prediction: a Spare Parts Inventory Cost and Lost Earning Based Model

Directory of Open Access Journals (Sweden)

O. A. Adebimpe

2015-06-01

Full Text Available In this paper, some preventive maintenance parameters in manufacturing firms were identified and used to develop cost based functions in terms of machine preventive maintenance. The proposed cost based model considers system’s reliability, cost of keeping spare parts inventory and lost earnings in deriving optimal maintenance interval. A case of a manufacturing firm in Nigeria was observed and the data was used to evaluate the model.

Cell phone based balance trainer

Directory of Open Access Journals (Sweden)

Lee Beom-Chan

2012-02-01

Full Text Available Abstract Background In their current laboratory-based form, existing vibrotactile sensory augmentation technologies that provide cues of body motion are impractical for home-based rehabilitation use due to their size, weight, complexity, calibration procedures, cost, and fragility. Methods We have designed and developed a cell phone based vibrotactile feedback system for potential use in balance rehabilitation training in clinical and home environments. It comprises an iPhone with an embedded tri-axial linear accelerometer, custom software to estimate body tilt, a "tactor bud" accessory that plugs into the headphone jack to provide vibrotactile cues of body tilt, and a battery. Five young healthy subjects (24 ± 2.8 yrs, 3 females and 2 males and four subjects with vestibular deficits (42.25 ± 13.5 yrs, 2 females and 2 males participated in a proof-of-concept study to evaluate the effectiveness of the system. Healthy subjects used the system with eyes closed during Romberg, semi-tandem Romberg, and tandem Romberg stances. Subjects with vestibular deficits used the system with both eyes-open and eyes-closed conditions during semi-tandem Romberg stance. Vibrotactile feedback was provided when the subject exceeded either an anterior-posterior (A/P or a medial-lateral (M/L body tilt threshold. Subjects were instructed to move away from the vibration. Results The system was capable of providing real-time vibrotactile cues that informed corrective postural responses. When feedback was available, both healthy subjects and those with vestibular deficits significantly reduced their A/P or M/L RMS sway (depending on the direction of feedback, had significantly smaller elliptical area fits to their sway trajectory, spent a significantly greater mean percentage time within the no feedback zone, and showed a significantly greater A/P or M/L mean power frequency. Conclusion The results suggest that the real-time feedback provided by this system can be used

Cell phone based balance trainer

Science.gov (United States)

2012-01-01

Background In their current laboratory-based form, existing vibrotactile sensory augmentation technologies that provide cues of body motion are impractical for home-based rehabilitation use due to their size, weight, complexity, calibration procedures, cost, and fragility. Methods We have designed and developed a cell phone based vibrotactile feedback system for potential use in balance rehabilitation training in clinical and home environments. It comprises an iPhone with an embedded tri-axial linear accelerometer, custom software to estimate body tilt, a "tactor bud" accessory that plugs into the headphone jack to provide vibrotactile cues of body tilt, and a battery. Five young healthy subjects (24 ± 2.8 yrs, 3 females and 2 males) and four subjects with vestibular deficits (42.25 ± 13.5 yrs, 2 females and 2 males) participated in a proof-of-concept study to evaluate the effectiveness of the system. Healthy subjects used the system with eyes closed during Romberg, semi-tandem Romberg, and tandem Romberg stances. Subjects with vestibular deficits used the system with both eyes-open and eyes-closed conditions during semi-tandem Romberg stance. Vibrotactile feedback was provided when the subject exceeded either an anterior-posterior (A/P) or a medial-lateral (M/L) body tilt threshold. Subjects were instructed to move away from the vibration. Results The system was capable of providing real-time vibrotactile cues that informed corrective postural responses. When feedback was available, both healthy subjects and those with vestibular deficits significantly reduced their A/P or M/L RMS sway (depending on the direction of feedback), had significantly smaller elliptical area fits to their sway trajectory, spent a significantly greater mean percentage time within the no feedback zone, and showed a significantly greater A/P or M/L mean power frequency. Conclusion The results suggest that the real-time feedback provided by this system can be used to reduce body sway. Its

Amino Acid Signatures to Evaluate the Beneficial Effects of Weight Loss

Directory of Open Access Journals (Sweden)

Nina Geidenstam

2017-01-01

Full Text Available Aims. We investigated the relationship between circulating amino acid levels and obesity; to what extent weight loss followed by weight maintenance can correct amino acid abnormalities; and whether amino acids are related to weight loss. Methods. Amino acids associated with waist circumference (WC and BMI were studied in 804 participants from the Malmö Diet and Cancer Cardiovascular Cohort (MDC-CC. Changes in amino acid levels were analyzed after weight loss and weight maintenance in 12 obese subjects and evaluated in a replication cohort (n=83. Results. Out of the eight identified BMI-associated amino acids from the MDC-CC, alanine, isoleucine, tyrosine, phenylalanine, and glutamate decreased after weight loss, while asparagine increased after weight maintenance. These changes were validated in the replication cohort. Scores that were constructed based on obesity-associated amino acids and known risk factors decreased in the ≥10% weight loss group with an associated change in BMI (R2=0.16–0.22, p<0.002, whereas the scores increased in the <10% weight loss group (p<0.0004. Conclusions. Weight loss followed by weight maintenance leads to differential changes in amino acid levels associated with obesity. Treatment modifiable scores based on epidemiological and interventional data may be used to evaluate the potential metabolic benefit of weight loss.

Using risk-informed asset management for feedwater system preventative maintenance optimization

International Nuclear Information System (INIS)

Kee, Ernest; Sun, Alice; Richards, Andrew; Grantom, Rick; Liming, James; Salter, James

2004-01-01

The initial development of a South Texas Project Nuclear Operating Company process for supporting preventative maintenance optimization by applying the Balance-Of-Plant model and Risk-Informed Asset Management alpha-level software applications is presented. Preventative maintenance activities are evaluated in the South Texas Project Risk-Informed Asset Management software while the plant maintains or improves upon high levels of nuclear safety. In the Balance-Of-Plant availability application, the level of detail in the feedwater system is enhanced to support plant decision-making at the component failure mode and human error mode level of indenture by elaborating on the current model at the super-component level of indenture. The enhanced model and modeling techniques are presented. Results of case studies in feedwater system preventative maintenance optimization sing plant-specific data are also presented. (author)

Laser-Based Maintenance and Repair Technologies for Reactor Components

International Nuclear Information System (INIS)

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

2004-01-01

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

Risk-Based Operation and Maintenance Using Bayesian Networks

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2011-01-01

This paper describes how risk-based decision making can be used for maintenance planning of components exposed to degradation such as fatigue in offshore wind turbines. In fatigue models, large epistemic uncertainties are usually present. These can be reduced if monitoring results are used to upd...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...... monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud; Sørensen, John Dalsgaard

2018-01-01

monitoring, fault prediction and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

Bayesian based Prognostic Model for Predictive Maintenance of Offshore Wind Farms

DEFF Research Database (Denmark)

Asgarpour, Masoud

2017-01-01

monitoring, fault detection and predictive maintenance of offshore wind components is defined. The diagnostic model defined in this paper is based on degradation, remaining useful lifetime and hybrid inspection threshold models. The defined degradation model is based on an exponential distribution......The operation and maintenance costs of offshore wind farms can be significantly reduced if existing corrective actions are performed as efficient as possible and if future corrective actions are avoided by performing sufficient preventive actions. In this paper a prognostic model for degradation...

The role of knowledge sharing and transactive memory system on condition based maintenance policy

NARCIS (Netherlands)

Koochaki, J.; Bouwhuis, I. M.

2008-01-01

Today, Condition Based Maintenance (CBM) has reached a sophisticated level in industry and the advantages of predictive maintenance are accepted globally. However, although lots of effort has been put into improving methods and techniques in CBM, most of predictive maintenance programs fail to

Remediation of Gremikha Coastal maintenance base - status of the project

International Nuclear Information System (INIS)

Pillette-Cousin, L.; Stepennov, B.S.; Gorbatchev, A.

2008-01-01

The former coastal maintenance base in Gremikha is located in the Kola Peninsula, along the Barents Sea, about 300 km east from Murmansk. There is no road or railway to get there, therefore the only possible connection is either by sea or by helicopter. Remediation of the Gremikha coastal maintenance base (CMB) is now one of the main priorities for Rosatom (the Agency for Atomic Energy of the Russian Federation) because nuclear and radioactive waste are currently stored in conditions which do not meet the up-to-date safety and regulatory requirements and it might represent an environmental hazard and a risk of misappropriation of the nuclear material stored there. (authors)

MOSEG code for safety oriented maintenance management Safety of management of maintenance oriented by MOSEG code; Codigo MOSEG para la gestion de mantenimiento orientada a la seguridad

Energy Technology Data Exchange (ETDEWEB)

Torres Valle, Antonio [Instituto Superior de Tecnologias y Ciencias Aplicadas, La Habana (Cuba). Dept. Ingenieria Nuclear]. E-mail: atorres@fctn.isctn.edu.cu; Rivero Oliva, Jose de Jesus [Centro de Gestion de la Informacion y Desarrollo de la Energia (CUBAENERGIA) (Cuba)]. E-mail: jose@cubaenergia.cu

2005-07-01

Full text: One of the main reasons that makes maintenance contribute highly when facing safety problems and facilities availability is the lack of maintenance management systems to solve these fields in a balanced way. Their main setbacks are shown in this paper. It briefly describes the development of an integrating algorithm for a safety and availability-oriented maintenance management by virtue of the MOSEG Win 1.0 code. (author)

[Brief disserting on the balance of internal environment in burn disease].

Science.gov (United States)

Han, C M; Wang, X G

2017-08-20

The essential internal environment in human being involves water, electrolyte, and acid-base balance, which is the basis of balance and stability of internal environment in other systems. For burn patients, the balance of internal environment, referring to metabolism, nutrition, inflammatory response, and immunoreaction, is one of the most important aspects in burn disease. This paper aims to briefly elaborate the balance of internal environment after burn, with the purpose to promote the basic and clinical research in this field.

The Acid-Base Titration of a Very Weak Acid: Boric Acid

Science.gov (United States)

Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

2012-01-01

A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

A preventive maintenance policy based on dependent two-stage deterioration and external shocks

International Nuclear Information System (INIS)

Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

2017-01-01

This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

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

International Nuclear Information System (INIS)

Hendrickson, D.W.

1995-01-01

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

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) balance in developmental outcomes.

Science.gov (United States)

Colombo, John; Jill Shaddy, D; Kerling, Elizabeth H; Gustafson, Kathleen M; Carlson, Susan E

2017-06-01

The DHA Intake and Measurement of Neural Development (DIAMOND) trial represents one of only a few studies of the long-term dose-response effects of LCPUFA-supplemented formula feeding during infancy. The trial contrasted the effects of four formulations: 0.00% docosahexaenoic acid (DHA)/0.00% arachidonic acid (ARA), 0.32% DHA/0.64% ARA, 0.64% DHA/0.64% ARA, and 0.96% DHA/0.64% ARA against a control condition (0.00% DHA/0.00% ARA). The results of this trial have been published elsewhere, and show improved cognitive outcomes for infants fed supplemented formulas, but a common finding among many of the outcomes show a reduction of benefit for the highest DHA dose (i.e., 0.96%DHA/0.64% ARA, that is, a DHA: ARA ratio 1.5:1.0). The current paper gathers and summarizes the evidence for the reduction of benefit at this dose, and in an attempt to account for this reduced benefit, presents for the first time data from infants' red blood cell (RBC) assays taken at 4 and 12 months of age. Those assays indicate that blood DHA levels generally rose with increased DHA supplementation, although those levels tended to plateau as the DHA-supplemented level exceeded 0.64%. Perhaps more importantly, ARA levels showed a strong inverted-U function in response to increased DHA supplementation; indeed, infants assigned to the formula with the highest dose of DHA (and highest DHA/ARA ratio) showed a reduction in blood ARA relative to more intermediate DHA doses. This finding raises the possibility that reduced ARA may be responsible for the reduction in benefit on cognitive outcomes seen at this dose. The findings implicate the DHA/ARA balance as an important variable in the contribution of LCPUFAs to cognitive and behavioral development in infancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Investigating ice cliff evolution and contribution to glacier mass-balance using a physically-based dynamic model

Science.gov (United States)

Buri, Pascal; Miles, Evan; Ragettli, Silvan; Brun, Fanny; Steiner, Jakob; Pellicciotti, Francesca

2016-04-01

, and then apply the model to the entirety of Lirung and Langtang glaciers to quantify the total contributions of cliffs to glacier mass balance. Observations and model results suggest a strong dependency of the cliffs' life cycle on supraglacial ponds, as the water body keeps the cliff geometry constant through a combination of backwasting and calving at the bottom and maintenance of steep slopes in the lowest sections. The absence of ponds causes the progressive flattening of the cliff, which finally leads to complete disappearance. Modelled volume losses from May to October 2013 range from 2650 to 9415 m3 w.e., in agreement with the estimates with the SfM-approach. Mean error of modelled elevation within the cliff outline ranges from -1.3 to 0.6m. This work sheds light on mechanisms of cliffs' changes by quantifying them for the first time with a physically-based, dynamic model, and presents the first complete estimate of the relevance of supraglacial ice-cliffs to total glacier mass-balance for two distinct glaciers.

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

International Nuclear Information System (INIS)

Li, Heping; Deloux, Estelle; Dieulle, Laurence

2016-01-01

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

Channels, pumps, and exchangers in the gill and kidney of freshwater fishes: their role in ionic and acid-base regulation.

Science.gov (United States)

Perry, S F; Shahsavarani, A; Georgalis, T; Bayaa, M; Furimsky, M; Thomas, S L Y

2003-11-01

In freshwater fishes, the gill and kidney are intricately involved in ionic and acid-base regulation owing to the presence of numerous ion channels, pumps, or exchangers. This review summarizes recent developments in branchial and renal ion transport physiology and presents several models that integrate epithelial ion and acid-base movements in freshwater fishes. At the gill, three cell types are potentially involved in ionic uptake: pavement cells, mitochondria-rich (MR) PNA(+) cells, and MR PNA(-) cells. The transfer of acidic or basic equivalents between the fish and its environment is accomplished largely by the gill and is appropriately regulated to correct acid-base imbalances. The kidney, while less important than the gill in overall acid or base excretion, has an essential role in regulating systemic acid-base balance by controlling HCO(3) (-) reabsorption from the filtrate. Copyright 2003 Wiley-Liss, Inc.

Battery pack state of charge balancing algorithm for cascaded H-Bridge multilevel converters

DEFF Research Database (Denmark)

Máthé, Lászlo; Burlacu, Paul Dan; Schaltz, Erik

2016-01-01

For most of the Multilevel Converter (MC) applications a commonly discussed issue is the maintenance of balance between the energy storage elements from the SubModules (SM). In applications where a battery pack is also part of the SM storage, such as STATCOMs or motor drives, the SM voltage...... is not in linear relation with the State Of Charge (SOC) of the entire battery; thus, the balancing becomes more cumbersome. A method to balance the SOC of the battery packs in a system using cascaded H-Bridge is proposed in this paper. The method uses nearest level control followed by sorting and selection based...... on the SOC of the battery packs. Based on the simulation results the number of switching is reduced considerably compared to the method where the phase shifted PWM is used. In addition, the time needed to achieve the balanced SOC is also reduced. The proposed method has been verified through experiments...

Multi-Objective Predictive Balancing Control of Battery Packs Based on Predictive Current

Directory of Open Access Journals (Sweden)

Wenbiao Li

2016-04-01

Full Text Available Various balancing topology and control methods have been proposed for the inconsistency problem of battery packs. However, these strategies only focus on a single objective, ignore the mutual interaction among various factors and are only based on the external performance of the battery pack inconsistency, such as voltage balancing and state of charge (SOC balancing. To solve these problems, multi-objective predictive balancing control (MOPBC based on predictive current is proposed in this paper, namely, in the driving process of an electric vehicle, using predictive control to predict the battery pack output current the next time. Based on this information, the impact of the battery pack temperature caused by the output current can be obtained. Then, the influence is added to the battery pack balancing control, which makes the present degradation, temperature, and SOC imbalance achieve balance automatically due to the change of the output current the next moment. According to MOPBC, the simulation model of the balancing circuit is built with four cells in Matlab/Simulink. The simulation results show that MOPBC is not only better than the other traditional balancing control strategies but also reduces the energy loss in the balancing process.

Performance based regulation - The maintenance rule

Energy Technology Data Exchange (ETDEWEB)

Correia, Richard P. [NRR/DOTS/TQMP, U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, M/S OWFN 10A19, Washington, D.C. 20555 (United States)

1997-07-01

The U.S. Nuclear Regulatory Commission has begun a transition from 'process-oriented' to 'results-oriented' regulations. The maintenance rule is a results-oriented rule that mandates consideration of risk and plant performance. The Maintenance Rule allows licensees to devise the most effective and efficient means of achieving the results described in the rule including the use of Probabilistic Risk (or Safety) Assessments. The NRC staff conducted a series of site visits to evaluate implementation of the Rule. Conclusions from the site visits indicated that the results-oriented Maintenance Rule can be successfully implemented and enforced. (author)

Performance based regulation - The maintenance rule

International Nuclear Information System (INIS)

Correia, Richard P.

1997-01-01

The U.S. Nuclear Regulatory Commission has begun a transition from 'process-oriented' to 'results-oriented' regulations. The maintenance rule is a results-oriented rule that mandates consideration of risk and plant performance. The Maintenance Rule allows licensees to devise the most effective and efficient means of achieving the results described in the rule including the use of Probabilistic Risk (or Safety) Assessments. The NRC staff conducted a series of site visits to evaluate implementation of the Rule. Conclusions from the site visits indicated that the results-oriented Maintenance Rule can be successfully implemented and enforced. (author)

Development the conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation

Science.gov (United States)

Milana; Khan, M. K.; Munive, J. E.

2014-07-01

The importance of maintenance has escalated significantly by the increasing of automation in manufacturing process. This condition switches traditional maintenance perspective of inevitable cost into the business competitive driver. Consequently, maintenance strategy and operation decision needs to be synchronized to business and manufacturing concerns. This paper shows the development of conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation (KBIMSO). The framework of KBIMSO is elaborated to show the process of how the KBIMSO works to reach the maintenance decision. By considering the multi-criteria of maintenance decision making, the KB system embedded with GAP and AHP to support integrated maintenance strategy and operation which is novel in this area. The KBIMSO is useful to review the existing maintenance system and give reasonable recommendation of maintenance decisions in respect to business and manufacturing perspective.

Development the conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation

International Nuclear Information System (INIS)

Milana; Khan, M K; Munive, J E

2014-01-01

The importance of maintenance has escalated significantly by the increasing of automation in manufacturing process. This condition switches traditional maintenance perspective of inevitable cost into the business competitive driver. Consequently, maintenance strategy and operation decision needs to be synchronized to business and manufacturing concerns. This paper shows the development of conceptual design of Knowledge Based System for Integrated Maintenance Strategy and Operation (KBIMSO). The framework of KBIMSO is elaborated to show the process of how the KBIMSO works to reach the maintenance decision. By considering the multi-criteria of maintenance decision making, the KB system embedded with GAP and AHP to support integrated maintenance strategy and operation which is novel in this area. The KBIMSO is useful to review the existing maintenance system and give reasonable recommendation of maintenance decisions in respect to business and manufacturing perspective

Corrosion Sensor Development for Condition-Based Maintenance of Aircraft

Directory of Open Access Journals (Sweden)

Gino Rinaldi

2012-01-01

Full Text Available Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

Relationships between energy balance and health traits of dairy cattle in early lactation.

Science.gov (United States)

Collard, B L; Boettcher, P J; Dekkers, J C; Petitclerc, D; Schaeffer, L R

2000-11-01

The objective of the study was to calculate phenotypic relationships between energy balance in early lactation and health and reproduction in that lactation. Data were 26,701 daily records of dry matter intake and milk production, periodic measures of milk composition and body weight, and all health and reproductive information from 140 multiparous Holstein cows. Daily energy balance was calculated by multiplying feed intake by the concentration of energy of the ration and subtracting the amount of energy required for maintenance (based on parity and body weight) and for milk production (based on yield and concentrations of fat, protein, and lactose). Six measures of energy balance were defined: mean daily energy balance during the first 20, 50, and 100 d of lactation; minimum daily energy balance; days in negative energy balance; and total energy deficit. Measures of health were the numbers of occurrences of each of the following during lactation: all udder problems, mastitis, all locomotive problems, laminitis, digestive problems, and reproductive problems. Reproductive traits were the number of days to first observed estrus and number of inseminations. Several significant relationships between energy balance and health were observed. Increased digestive and locomotive problems were associated with longer and more extreme periods of negative energy balance.

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to acetic acid and maintenance of normal blood pressure (ID 1447) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

that maintenance of normal blood pressure is a beneficial physiological effect. In weighing the evidence, the Panel took into account that although one animal study showed an effect of acetic acid administration on systolic blood pressure, results from two human intervention studies are conflicting...... claims in relation to acetic acid and maintenance of normal blood pressure. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from stakeholders....... The food that is the subject of the health claim is apple vinegar drink. From the references provided for the scientific substantiation of the claim, the Panel assumes that the food constituent which is responsible for the claimed effect is acetic acid. The Panel considers that acetic acid is sufficiently...

Maintenance management of railway infrastructures based on reliability analysis

International Nuclear Information System (INIS)

Macchi, Marco; Garetti, Marco; Centrone, Domenico; Fumagalli, Luca; Piero Pavirani, Gian

2012-01-01

Railway infrastructure maintenance plays a crucial role for rail transport. It aims at guaranteeing safety of operations and availability of railway tracks and related equipment for traffic regulation. Moreover, it is one major cost for rail transport operations. Thus, the increased competition in traffic market is asking for maintenance improvement, aiming at the reduction of maintenance expenditures while keeping the safety of operations. This issue is addressed by the methodology presented in the paper. The first step of the methodology consists of a family-based approach for the equipment reliability analysis; its purpose is the identification of families of railway items which can be given the same reliability targets. The second step builds the reliability model of the railway system for identifying the most critical items, given a required service level for the transportation system. The two methods have been implemented and tested in practical case studies, in the context of Rete Ferroviaria Italiana, the Italian public limited company for railway transportation.

40 CFR 63.1160 - Compliance dates and maintenance requirements.

Science.gov (United States)

2010-07-01

... corrective action within 1 working day of detection; and (iii) Maintenance of a daily record, signed by a... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Compliance dates and maintenance... Facilities and Hydrochloric Acid Regeneration Plants § 63.1160 Compliance dates and maintenance requirements...

14 CFR 119.47 - Maintaining a principal base of operations, main operations base, and main maintenance base...

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Maintaining a principal base of operations, main operations base, and main maintenance base; change of address. 119.47 Section 119.47 Aeronautics... Under Part 121 or Part 135 of This Chapter § 119.47 Maintaining a principal base of operations, main...

Optimizing Maintenance of Constraint-Based Database Caches

Science.gov (United States)

Klein, Joachim; Braun, Susanne

Caching data reduces user-perceived latency and often enhances availability in case of server crashes or network failures. DB caching aims at local processing of declarative queries in a DBMS-managed cache close to the application. Query evaluation must produce the same results as if done at the remote database backend, which implies that all data records needed to process such a query must be present and controlled by the cache, i. e., to achieve “predicate-specific” loading and unloading of such record sets. Hence, cache maintenance must be based on cache constraints such that “predicate completeness” of the caching units currently present can be guaranteed at any point in time. We explore how cache groups can be maintained to provide the data currently needed. Moreover, we design and optimize loading and unloading algorithms for sets of records keeping the caching units complete, before we empirically identify the costs involved in cache maintenance.

PRM-based patterns for knowledge formalisation of industrial systems to support maintenance strategies assessment

International Nuclear Information System (INIS)

Medina-Oliva, G.; Weber, P.; Iung, B.

2013-01-01

The production system and its maintenance system must be now developed on “system thinking” paradigm in order to guarantee that Key Performance Indicators (KPI) will be optimized all along the production system (operation) life. In a recursive way, maintenance system engineering has to integrate also KPI considerations with regards to its own enabling systems. Thus this paper develops a system-based methodology wherein a set of KPIs is computed in order to verify if the objectives of the production and maintenance systems are satisfied. In order to help the decision-making process for maintenance managers, a “unified” generic model have been developed. This model integrates (a) the interactions of the maintenance system with its enabling systems, (b) the impact of the maintenance strategies through the computation of some key performance indicators, and (c) different kinds of knowledge regarding the maintenance system and the system of interest, including quantitative and qualitative knowledge. This methodology is based on an executable unified model built with Probabilistic Relational Model (PRM). PRM allows a modular representation and inferences computation of large size models. The methodology added-value is shown on a test-bench

Joint optimization of condition-based maintenance and production lot-sizing

NARCIS (Netherlands)

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

2016-01-01

Due to the development of sensor technologies nowadays, condition-based maintenance (CBM) programs can be established and optimized based on the data collected through condition monitoring. The CBM activities can significantly increase the uptime of a machine. However, they should be conducted in a

A Systematic Review of Aquatic Exercise Programs on Balance Measures in Older Adults

OpenAIRE

Foster, Shayla Diane

2015-01-01

There are a variety of studies performed using aquatic exercise programs to evaluate balance measures using a case-control or pretest-posttest method on healthy young populations (Geytenbeek, 2002). Balance can be defined as either static; maintenance of an upright posture and stance or dynamic; posture adaption and maintenance control of movements and stability (Rose & Clark, 2000). An aquatic exercise program will henceforth be defined as any acute or chronic exercises performed in water wi...

Managing wind turbine reliability and maintenance via performance-based contract

DEFF Research Database (Denmark)

Jin, Tongdan; Ding, Yi; Guo, Huairui

2012-01-01

between system cost, reliability and spare parts stocking. This analytical insight into the system performance allows the turbine manufacturer to optimize design, production, and after-sales services. The study aims to create a theoretical basis to facilitate the transition of the maintenance paradigm......Performance-based contracting (PBC) is reshaping the acquisition, operation, and maintenance of capital equipment. Under the PBC scheme, we propose a holistic approach for lowering the cost of wind turbine ownership while meeting the availability requirement. Our effects are focused on integrated...... firms who design and market wind turbines, and also provide maintenance and repair service. PBC differs from conventional service contracts in that the wind farmers compensate the service provider for the system performance, not the spare parts and repair labor. We explore the analytical relationship...

Analyzing maintenance strategies by agent-based simulations: A feasibility study

International Nuclear Information System (INIS)

Kaegi, M.; Mock, R.; Kroeger, W.

2009-01-01

Thoroughly planned and implemented maintenance strategies save time and cost. However, the integration of maintenance work into reliability analysis is difficult as common modeling techniques are often not applicable due to state explosion which calls for restrictive model assumptions and oversimplification. From authors' point of view, agent-based modeling (ABM) of technical and organizational systems is a promising approach to overcome such problems. But since ABM is not well established in reliability analysis its feasibility in this area still has to be demonstrated. For this purpose ABM is compared with Markov chains, namely by analyzing the reliability of a maintained n-unit system with dependent repair events, applying both modeling approaches. Although ABM and Markov chains lead to the same numerical results, the former points out the potentiality of an improved system state handling. This is demonstrated by extending the ABM with operators as additional 'agents' featuring their location (x;y) availability (0;1) and different maintenance strategies. This extension highlights the capability of ABM to analyze complex emergent system behavior and allows a systematic refinement and optimization of the maintenance strategies.

[Development and practice evaluation of blood acid-base imbalance analysis software].

Science.gov (United States)

Chen, Bo; Huang, Haiying; Zhou, Qiang; Peng, Shan; Jia, Hongyu; Ji, Tianxing

2014-11-01

To develop a blood gas, acid-base imbalance analysis computer software to diagnose systematically, rapidly, accurately and automatically determine acid-base imbalance type, and evaluate the clinical application. Using VBA programming language, a computer aided diagnostic software for the judgment of acid-base balance was developed. The clinical data of 220 patients admitted to the Second Affiliated Hospital of Guangzhou Medical University were retrospectively analyzed. The arterial blood gas [pH value, HCO(3)(-), arterial partial pressure of carbon dioxide (PaCO₂)] and electrolytes included data (Na⁺ and Cl⁻) were collected. Data were entered into the software for acid-base imbalances judgment. At the same time the data generation was calculated manually by H-H compensation formula for determining the type of acid-base imbalance. The consistency of judgment results from software and manual calculation was evaluated, and the judgment time of two methods was compared. The clinical diagnosis of the types of acid-base imbalance for the 220 patients: 65 cases were normal, 90 cases with simple type, mixed type in 41 cases, and triplex type in 24 cases. The accuracy of the judgment results of the normal and triplex types from computer software compared with which were calculated manually was 100%, the accuracy of the simple type judgment was 98.9% and 78.0% for the mixed type, and the total accuracy was 95.5%. The Kappa value of judgment result from software and manual judgment was 0.935, P=0.000. It was demonstrated that the consistency was very good. The time for software to determine acid-base imbalances was significantly shorter than the manual judgment (seconds:18.14 ± 3.80 vs. 43.79 ± 23.86, t=7.466, P=0.000), so the method of software was much faster than the manual method. Software judgment can replace manual judgment with the characteristics of rapid, accurate and convenient, can improve work efficiency and quality of clinical doctors and has great

The effect of long-term acidifying feeding on digesta organic acids, mineral balance, and bone mineralization in growing pigs

DEFF Research Database (Denmark)

Nørgaard, Jan Værum; Højberg, Ole; Sørensen, Kristina Ulrich

2014-01-01

Acidification of slurry through dietary manipulation of urinary pH is a means of mitigating nitrogen emission from pig production, but long-term effects of diet acidification on bone mineralization and mineral balance is less investigated. The objective was therefore to study the long-term effects...... of feeding benzoic acid (BA) and calcium chloride (CaCl2) on the mineral balance and microbial activity in the gastrointestinal tract of pigs. Four diets containing the combinations of 0 or 10 g/kg BA and 0 or 20 g/kg CaCl2 were fed to 24 pigs in a factorial design. For the diets without CaCl2, calcium...... carbonate (CaCO3) was added to provide equimolar levels of Ca. The pigs were fed the diets from 36 kg until slaughter at 113 kg BW, and they were housed in balance cages for 12 d from 60 to 66 kg BW. Supplementation of BA and/or CaCl2 had only minor effect on accumulation of digesta organic acids (acetate...

A Novel Short-Term Maintenance Strategy for Power Transmission and Transformation Equipment Based on Risk-Cost-Analysis

Directory of Open Access Journals (Sweden)

Hang Yang

2017-11-01

Full Text Available Current studies on preventive condition-based maintenance of power transmission and transformation equipment mainly focus on mid-term or long-term maintenance, and cannot meet the requirements of short-term especially temporary maintenance. In order to solve the defects of the present preventive maintenance strategies, according to the engineering application and based on risk-cost analysis, a short-term maintenance strategy is proposed in this manuscript. For the equipment working in bad health condition, its active maintenance costs and operation risk costs are evaluated, respectively. Then the latest maintenance time is calculated in accordance with the principle that its operation risk costs are no higher than active maintenance costs. Utilizing the latest maintenance time, the best maintenance time is calculated by setting the maximum relative earnings of postponing maintenance as the target, which provides the operation staffs with comprehensive maintenance-decision support. In the end, different cases on the IEEE 24-bus system are simulated. The effectiveness and advantages of the proposed strategy are demonstrated by the simulation results.

Insulin receptor-related receptor as an extracellular pH sensor involved in the regulation of acid-base balance.

Science.gov (United States)

Petrenko, Alexander G; Zozulya, Sergey A; Deyev, Igor E; Eladari, Dominique

2013-10-01

Recent studies of insulin receptor-related receptor (IRR) revealed its unusual property to activate upon extracellular application of mildly alkaline media, pH>7.9. The activation of IRR with hydroxyl anion has typical features of ligand-receptor interaction; it is specific, dose-dependent, involves the IRR extracellular domain and is accompanied by a major conformational change. IRR is a member of the insulin receptor minifamily and has been long viewed as an orphan receptor tyrosine kinase since no peptide or protein agonist of IRR was found. In the evolution, IRR is highly conserved since its divergence from the insulin and insulin-like growth factor receptors in amphibia. The latter two cannot be activated by alkali. Another major difference between them is that unlike ubiquitously expressed insulin and insulin-like growth factor receptors, IRR is found in specific sets of cells of only some tissues, most of them being exposed to extracorporeal liquids of extreme pH. In particular, largest concentrations of IRR are in beta-intercalated cells of the kidneys. The primary physiological function of these cells is to excrete excessive alkali as bicarbonate into urine. When IRR is removed genetically, animals loose the property to excrete bicarbonate upon experimentally induced alkalosis. In this review, we will discuss the available in vitro and in vivo data that support the hypothesis of IRR role as a physiological alkali sensor that regulates acid-base balance. This article is part of a Special Issue entitled: Emerging recognition and activation mechanisms of receptor tyrosine kinases. Copyright © 2012 Elsevier B.V. All rights reserved.

The Issues of Track Maintenance Management in Indonesia (Based on Study of the British Railways

Directory of Open Access Journals (Sweden)

Tetria Yunik Dewi Pamungkas

2017-01-01

Full Text Available It is believed that there is merit in researching how the management of track maintenance is organized in the United Kingdom, in particular by Network Rail, and then evaluating how this can be applied to the benefit of Indonesian Railways. The purpose of this research was expected to provide recommendations for management improvement of track maintenance by researching the track maintenance management system in Network Rail. This research study is based on secondary data. The analysis was conducted by using comparison method which compares the British Railways management and Indonesia railway management related to track maintenance management. The track maintenance management system was studied by using Network Rail. The results were compared with track maintenance management system in Indonesia. The comparison will provide the data differences that evaluated so the problem can be identified. The final result of this analysis was the identification of problems and improvisation that can be done for the development of track maintenance management in Indonesia. Several management issues have been mapped to several groups: finance management, structure organization, and asset management. From the problems that have been mapped, some improvements are recommended as monopolist authority restriction, maintenance system contract extension, re-structuring organization hierarchy, business plan consideration, track monitoring strategy arrangement, and condition based maintenance strategy adoption.

Structural health monitoring methodology for aircraft condition-based maintenance

Science.gov (United States)

Saniger, Jordi; Reithler, Livier; Guedra-Degeorges, Didier; Takeda, Nobuo; Dupuis, Jean Pierre

2001-06-01

Reducing maintenance costs while keeping a constant level of safety is a major issue for Air Forces and airlines. The long term perspective is to implement condition based maintenance to guarantee a constant safety level while decreasing maintenance costs. On this purpose, the development of a generalized Structural Health Monitoring System (SHMS) is needed. The objective of such a system is to localize the damages and to assess their severity, with enough accuracy to allow low cost corrective actions. The present paper describes a SHMS based on acoustic emission technology. This choice was driven by its reliability and wide use in the aerospace industry. The described SHMS uses a new learning methodology which relies on the generation of artificial acoustic emission events on the structure and an acoustic emission sensor network. The calibrated acoustic emission events picked up by the sensors constitute the knowledge set that the system relies on. With this methodology, the anisotropy of composite structures is taken into account, thus avoiding the major cause of errors of classical localization methods. Moreover, it is adaptive to different structures as it does not rely on any particular model but on measured data. The acquired data is processed and the event's location and corrected amplitude are computed. The methodology has been demonstrated and experimental tests on elementary samples presented a degree of accuracy of 1cm.

Bayesian Based Diagnostic Model for Condition Based Maintenance of Offshore Wind Farms

Directory of Open Access Journals (Sweden)

Masoud Asgarpour

2018-01-01

Full Text Available Operation and maintenance costs are a major contributor to the Levelized Cost of Energy for electricity produced by offshore wind and can be significantly reduced if existing corrective actions are performed as efficiently as possible and if future corrective actions are avoided by performing sufficient preventive actions. This paper presents an applied and generic diagnostic model for fault detection and condition based maintenance of offshore wind components. The diagnostic model is based on two probabilistic matrices; first, a confidence matrix, representing the probability of detection using each fault detection method, and second, a diagnosis matrix, representing the individual outcome of each fault detection method. Once the confidence and diagnosis matrices of a component are defined, the individual diagnoses of each fault detection method are combined into a final verdict on the fault state of that component. Furthermore, this paper introduces a Bayesian updating model based on observations collected by inspections to decrease the uncertainty of initial confidence matrix. The framework and implementation of the presented diagnostic model are further explained within a case study for a wind turbine component based on vibration, temperature, and oil particle fault detection methods. The last part of the paper will have a discussion of the case study results and present conclusions.

Facile and Benign Conversion of Sucrose to Fructose Using Zeolites With Balanced Brønsted and Lewis Acidity

DEFF Research Database (Denmark)

Shunmugavel, Saravanamurugan; Tosi, Irene; Rasmussen, Kristoffer Hauberg

2017-01-01

Sucrose is by far the industrially most abundant simple carbohydrate with a production volume of more than 160 million metric tons from sugar cane and sugar beet per year. Many promising pathways towards bio-based organic compounds use, however, fructose as the pathway substrate. Hence, a chemoca......Sucrose is by far the industrially most abundant simple carbohydrate with a production volume of more than 160 million metric tons from sugar cane and sugar beet per year. Many promising pathways towards bio-based organic compounds use, however, fructose as the pathway substrate. Hence......, a chemocatalytic approach to convert sucrose into fructose would provide a means to channel sucrose into pathways for sugar valorization. Here, we show that a variety of heterogeneous zeolite catalysts with balanced Brønsted and Lewis acidity enable a simple route for the conversion of sucrose to more than 80......% fructosides or fructose at 100 °C. The catalysts can encompass aluminum or tin Lewis acidic sites in various zeolite frameworks. The reaction proceeds in volatile alcohol solvents and broadly enables the channelling of sucrose into processes that use fructose as the pathway substrate....

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

University of Tennessee - Industry collaborative research and development in preventive maintenance technology

International Nuclear Information System (INIS)

Upadhyaya, B.R.

1992-01-01

The Preventive Maintenance Engineering Laboratory (PMEL) was inaugurated at the University of Tennessee Nuclear Engineering Department in September 1989. The startup funding was provided by Gilbert/Commonwealth, Inc. The purpose of PMEL is to identify maintenance-related problems in the power and process industries and to find their solutions through the development and application of emerging technologies. These include advanced digital signal processing, applied artificial intelligence (AI), artificial neural networks, and reliability based methods. The Laboratory activities are being expanded by the formation of an industrial consortium within the Measurement and Control Engineering Center at the University of Tennessee. Several research and development projects in preventive maintenance are being carried out. These include condition monitoring of air operated valves, automated diagnostics of motor operated valves, instrument calibration, verification, and estimation of expected residual life of electric motors using applied AI technology and reliability-based methods. The new methodology will be applied to other industrial subsystems. A long-term research and development project is being sponsored by the T.V.A. Nuclear Maintenance Department. The overall objective of the research program is to develop and apply advanced artificial intelligence and information processing methods to the problems of plant performance monitoring and preventive maintenance. The program includes the development of a workstation/PC-based, networking of plant information for easy access to operational and management personnel, implementation of a sensor verification system, monitoring of feedwater flow venturi fouling and heat rate balance, and integration of signal validation, command validation, and fault-tolerant control strategies

Earnings with Condition Based Maintenance; Ganhos com manutencao preditiva baseada em dados de processo em tempo real

Energy Technology Data Exchange (ETDEWEB)

Barabas, Elizabeth [Softbrasil Automacao, Sao Paulo, SP (Brazil)

2008-07-01

Keeping active in perfect functioning is essential for any company. Today, the maintenance has been performed in most of the stops for maintenance. In a modern industrial environment, where the systems provide data and process information in real time, it is possible bring the performance of the plant to a optimized level, through the maintenance based on condition of equipment. This work described the earnings with CBM (Condition Based Maintenance)

[Acid-base equilibrium and the brain].

Science.gov (United States)

Rabary, O; Boussofara, M; Grimaud, D

1994-01-01

In physiological conditions, the regulation of acid-base balance in brain maintains a noteworthy stability of cerebral pH. During systemic metabolic acid-base imbalances cerebral pH is well controlled as the blood/brain barrier is slowly and poorly permeable to electrolytes (HCO3- and H+). Cerebral pH is regulated by a modulation of the respiratory drive, triggered by the early alterations of interstitial fluid pH, close to medullary chemoreceptors. As blood/brain barrier is highly permeable to Co2, CSF pH is corrected in a few hours, even in case of severe metabolic acidosis and alkalosis. Conversely, during ventilatory acidosis and alkalosis the cerebral pH varies in the same direction and in the same range than blood pH. Therefore, the brain is better protected against metabolic than ventilatory acid-base imbalances. Ventilatory acidosis and alkalosis are able to impair cerebral blood flow and brain activity through interstitial pH alterations. During respiratory acidosis, [HCO3-] increases in extracellular fluids to control cerebral pH by two main ways: a carbonic anhydrase activation at the blood/brain and blood/CSF barriers level and an increase in chloride shift in glial cells (HCO3- exchanged for Cl-). During respiratory alkalosis, [HCO3-] decreases in extracellular fluids by the opposite changes in HCO3- transport and by an increase in lactic acid synthesis by cerebral cells. The treatment of metabolic acidosis with bicarbonates may induce a cerebral acidosis and worsen a cerebral oedema during ketoacidosis. Moderate hypocapnia carried out to treat intracranial hypertension is mainly effective when cerebral blood flow is high and vascular CO2 reactivity maintained. Hypocapnia may restore an altered cerebral blood flow autoregulation. Instrumental hypocapnia requires a control of cerebral perfusion pressure and cerebral arteriovenous difference for oxygen, to select patients for whom this kind of treatment may be of benefit, to choose the optimal level of

Concept design of CFETR superconducting magnet system based on different maintenance ports

International Nuclear Information System (INIS)

Zheng, Jinxing; Liu, Xufeng; Song, Yuntao; Wan, Yuanxi; Li, Jiangang; Wu, Sontao; Wan, Baonian; Ye, Minyou; Wei, Jianghua; Xu, Weiwei; Liu, Sumei; Weng, Peide; Lu, Kun; Luo, Zhengping

2013-01-01

Highlights: • This article discussed the concept design of the magnet system of CFETR based on different maintenance port cases. • The major and minor radius of plasma is 5.7 m and 1.6 m, and the central magnetic field was designed as 4.5/5.0 T. • The different maintenance ports design have little impact on the design of TF and CS coils’ design, but have certain impact on the PF coils’ design. -- Abstract: CFETR which stands for “China Fusion Engineering Test Reactor” is a new tokamak device. Its magnet system includes the Toroidal Field (TF) winding, Center solenoid winding (CS) and Poloidal Field (PF) winding. The main goal of the project is to build a fusion engineering Tokamak reactor with its fusion power is 50–200 MW and should be self-sufficiency by blanket. In order to ensure the maintenance ports design and maintenance method, this article discussed the concept design of the magnet system based on different maintenance port cases. The paper detailed studied the magnet system of CFETR including the electromagnetic analysis and parameters for TF (CS)PF. Besides, the volt-seconds of ohmic field are presented as detailed as possible in this paper. In addition, the calculations and optimizations of equilibrium field which should guarantee the plasma discharge of single null shape is carried out. The design work reported here illustrates that the present maintenance ports will not have a great impact on the design of the magnet system. The concept design of the magnet system can meet the requirement of the physical target

An overview of the recent advances in delay-time-based maintenance modelling

International Nuclear Information System (INIS)

Wang, Wenbin

2012-01-01

Industrial plant maintenance is an area which has enormous potential to be improved. It is also an area attracted significant attention from mathematical modellers because of the random phenomenon of plant failures. This paper reviews the recent advances in delay-time-based maintenance modelling, which is one of the mathematical techniques for optimising inspection planning and related problems. The delay-time is a concept that divides a plant failure process into two stages: from new until the point of an identifiable defect, and then from this point to failure. The first stage is called the normal working stage and the second stage is called the failure delay-time stage. If the distributions of the two stages can be quantified, the relationship between the number of failures and the inspection interval can be readily established. This can then be used for optimizing the inspection interval and other related decision variables. In this review, we pay particular attention to new methodological developments and industrial applications of the delay-time-based models over the last few decades. The use of the delay-time concept and modeling techniques in other areas rather than in maintenance is also reviewed. Future research directions are also highlighted. - Highlights: ► Reviewed the recent advances in delay-time-based maintenance models and applications. ► Compared the delay-time-based models with other models. ► Focused on methodologies and applications. ► Pointed out future research directions.

Risk-based and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, K.; Nagai, S.; Akikuni, Y.; Fujiwara, T.; Furuya, K.; Matsumoto, S.; Takagi, K.; Kawabata, T.

2003-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants. (orig.)

Efficient graph-based dynamic load-balancing for parallel large-scale agent-based traffic simulation

NARCIS (Netherlands)

Xu, Y.; Cai, W.; Aydt, H.; Lees, M.; Tolk, A.; Diallo, S.Y.; Ryzhov, I.O.; Yilmaz, L.; Buckley, S.; Miller, J.A.

2014-01-01

One of the issues of parallelizing large-scale agent-based traffic simulations is partitioning and load-balancing. Traffic simulations are dynamic applications where the distribution of workload in the spatial domain constantly changes. Dynamic load-balancing at run-time has shown better efficiency

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

International Nuclear Information System (INIS)

Benvenuto, F.; Ferrari, L.

2005-01-01

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

An evaluation of the Browns Ferry Nuclear Plant preventive maintenance program based on reliability centered maintenance analysis

International Nuclear Information System (INIS)

McCullough, C.L.; McCullough, C.A.

1989-01-01

Reliability centered maintenance (RCM) techniques were used to support a preventative maintenance (PM) upgrade program (PMUP) performed at TVA Browns Ferry Nuclear Plant (BFNP). The purpose of the RCM analysis was to identify critical equipment based on risk and economic importance and to evaluate the PM activities applicable to that equipment. The analysis may be conveniently divided into three steps, which will be outlined in the Approach section of this paper. The net benefit of the RCM approach was a prioritization of the focus of the PM upgrade program so that plant components receive attention proportional to their importance, and assurance that PM activities properly address the most likely component failure causes

Sex differences in amino acids lost via sweating could lead to differential susceptibilities to disturbances in nitrogen balance and collagen turnover.

Science.gov (United States)

Dunstan, R H; Sparkes, D L; Dascombe, B J; Stevens, C J; Murphy, G R; Macdonald, M M; Gottfries, J; Gottfries, C-G; Roberts, T K

2017-08-01

Fluid collected during sweating is enriched with amino acids derived from the skin's natural moisturising factors and has been termed "faux" sweat. Little is known about sex differences in sweat amino acid composition or whether faux sweat amino acid losses affect nitrogen balance. Faux sweat collected by healthy adults (n = 47) after exercise, and at rest by chronic fatigue patients, was analysed for amino acid composition. Healthy females had higher total amino acid concentrations in sweat (10.5 ± 1.2 mM) compared with healthy males (6.9 ± 0.9 mM). Females had higher levels of 13 amino acids in sweat including serine, alanine and glycine. Higher hydroxyproline and proline levels suggested greater collagen turnover in females. Modelling indicated that with conservative levels of exercise, amino acid losses in females via faux sweat were triple than those predicted for urine, whereas in males they were double. It was concluded that females were more susceptible to key amino acid loss during exercise and/or hot conditions. Females reporting chronic fatigue had higher levels of methionine in faux sweat than healthy females. Males reporting chronic fatigue had higher levels of numerous amino acids in faux sweat compared to healthy males. Higher amino acid loss in faux sweat associated with chronic fatigue could contribute to a hypometabolic state. Depending on activity levels, climatic conditions and gender, amino acid losses in sweat and skin leachate could influence daily protein turnover where periods of continuously high turnover could lead to a negative net nitrogen balance.

GENETIC ALGORITHM BASED CONCEPT DESIGN TO OPTIMIZE NETWORK LOAD BALANCE

Directory of Open Access Journals (Sweden)

Ashish Jain

2012-07-01

Full Text Available Multiconstraints optimal network load balancing is an NP-hard problem and it is an important part of traffic engineering. In this research we balance the network load using classical method (brute force approach and dynamic programming is used but result shows the limitation of this method but at a certain level we recognized that the optimization of balanced network load with increased number of nodes and demands is intractable using the classical method because the solution set increases exponentially. In such case the optimization techniques like evolutionary techniques can employ for optimizing network load balance. In this paper we analyzed proposed classical algorithm and evolutionary based genetic approach is devise as well as proposed in this paper for optimizing the balance network load.

Impact of telephone reinforcement and negotiated contracts on behavioral predictors of exercise maintenance in older adults with osteoarthritis.

Science.gov (United States)

Desai, Pakaja M; Hughes, Susan L; Peters, Karen E; Mermelstein, Robin J

2014-05-01

To examine the impact of telephone reinforcement (TR) on predictors of physical activity (PA) maintenance in older adults with osteoarthritis. Mixed effects modeling was conducted of data from a randomized PA trial that used negotiated maintenance contracts, supplemented by TR, to test impact of TR on barriers, decisional balance, and stage of change at multiple points in time. Participants who were referred to a PA program and received TR improved the most in barriers and decisional balance. Participants who negotiated a tailored maintenance contract but did not receive TR improved the most in stage. TR appears to positively affect perceptions around engagement, whereas negotiation positively impacts PA behavior. Further research should examine the effectiveness of specific PA maintenance strategies.

An open-source automated continuous condition-based maintenance platform for commercial buildings

Energy Technology Data Exchange (ETDEWEB)

Katipamula, Srinivas; Gowri, Krishnan; Hernandez, George

2016-09-09

This paper describes one such reference process that can be deployed to provide continuous automated conditioned-based maintenance management for buildings that have BIM, a building automation system (BAS) and a computerized maintenance management software (CMMS) systems. The process can be deployed using an open source transactional network platform, VOLTTRON™, designed for distributed sensing and controls and supports both energy efficiency and grid services.

Fluid, electrolyte, and acid-base balances in three-day, combined-training horses.

Science.gov (United States)

White, S L

1998-04-01

Horses competing in 3-day, combined-training events develop a metabolic acidosis that is partially compensated for by a respiratory alkalosis immediately after phases B and D. By the end of phase C and 30 minutes to 2 hours after phase D, the acidosis is resolved by the oxidation of lactate, and a metabolic alkalosis prevails. A reduction in TBW and cation content occurs, which often is not replenished 12 to 24 hours after the event, even though the serum or plasma concentration of various constituents may be within normal limits. Hypochloremia and hypocalcemia, however, may persist 12 or more hours after the speed and endurance test. All of the data cited in this article are from horses that successfully completed their respective tests. Nevertheless, some horses developed substantial fluid and cation losses. In horses that are not well conditioned or in competitions in which terrain, footing, or hot environments increase the thermal load or decrease heat loss, greater losses of fluids and electrolytes can be expected. Body weight losses exceeding 5% and cation losses exceeding 4000 mEq/L occur in endurance horses suffering from exhaustion and synchronous diaphragmatic flutter. In one study, two thirds of the Na+ lost during exercise-induced sweating in cool, dry conditions was replenished from salt supplements added to a balanced forage and concentrated diet. Consequently, horses in regular training and competition may benefit from salt supplementation. The composition of the salt supplement and the amount fed should be based on the composition of the horse's diet, degree of work, and environmental conditions. Horses competing in a 3-day, combined-training event may be expected to have persistent losses of weight and cations, particularly if conditions result in heavy sweating. Many horses in the field studies had minimal changes in weight and cation balance compared with pre-event values. The diet and electrolyte supplementation of the horses in the majority of

Effects of chronic acetazolamide administration on gas exchange and acid-base control in pulmonary circulation in exercising horses.

Science.gov (United States)

Vengust, M; Stämpfli, H; De Moraes, A N; Teixeiro-Neto, F; Viel, L; Heigenhauser, G

2010-11-01

Carbonic anhydrase (CA) catalyses the hydration/dehydration reaction of CO(2) and increases the rate of Cl(-) and HCO(3)(-) exchange between the erythrocytes and plasma. Therefore, chronic inhibition of CA has a potential to attenuate CO(2) output and induce greater metabolic and respiratory acidosis in exercising horses. To determine the effects of Carbonic anhydrase inhibition on CO(2) output and ionic exchange between erythrocytes and plasma and their influence on acid-base balance in the pulmonary circulation (across the lung) in exercising horses with and without CA inhibition. Six horses were exercised to exhaustion on a treadmill without (Con) and with CA inhibition (AczTr). CA inhibition was achieved with administration of acetazolamide (10 mg/kg bwt t.i.d. for 3 days and 30 mg/kg bwt before exercise). Arterial, mixed venous blood and CO(2) output were sampled at rest and during exercise. An integrated physicochemical systems approach was used to describe acid base changes. AczTr decreased the duration of exercise by 45% (P changes across the lung with exception of lactate. CO(2) and chloride changes in erythrocytes across the lung seem to be the major contributors to acid-base and ions balance in pulmonary circulation in exercising horses. © 2010 EVJ Ltd.

Risk based maintenance to increase safety and decrease costs

International Nuclear Information System (INIS)

Phillips, J.H.

2000-01-01

Risk-Based techniques have been developed for commercial nuclear power plants for the last eight years by a team working through the ASME Center for Research and Technology Development (CRTD). System boundaries and success criteria is defined using the Probabilistic Risk Analysis or Probabilistic Safety Analysis developed to meet the Individual Plant Evaluation. Final ranking of components is by a plant expert panel similar to the one developed for the Maintenance Rule. Components are identified as being high risk-significant or low risk-significant. Maintenance and resources are focused on those components that have the highest risk-significance. The techniques have been developed and applied at a number of plants. Results from the first risk-based inspection pilot plant indicates safety due to pipe failure can be doubled while the inspection reduced to about 80% when compared with current inspection programs. Pilot studies on risk-based testing indicate that about 60% of pumps and 25 to 30% of valves in plants are high safety-significant The reduction in inspection and testing reduces the person-rem exposure and resulting in further increases in safety. These techniques have been documented in publications by the ASME CRTD which are referenced. (author)

Impact of a multifaceted community-based falls prevention program on balance-related psychologic factors.

Science.gov (United States)

Filiatrault, Johanne; Gauvin, Lise; Richard, Lucie; Robitaille, Yvonne; Laforest, Sophie; Fournier, Michel; Corriveau, Hélène

2008-10-01

To assess the impact of a multifaceted falls prevention program including exercise and educational components on perceived balance and balance confidence among community-dwelling seniors. Quasi-experimental design. Community-based organizations. Two hundred community-dwelling adults aged 60 years and over recruited by community-based organizations. A 12-week multifaceted falls prevention program including 3 components (a 1-hour group exercise class held twice a week, a 30-minute home exercise module to be performed at least once a week, a 30-minute educational class held once a week). Perceived balance and balance confidence. Multivariate analysis showed that the program was successful in increasing perceived balance in experimental participants. However, balance confidence was not improved by program participation. A multifaceted community-based falls prevention program that was successful in improving balance performance among community-dwelling seniors also had a positive impact on perceived balance. However, the program did not improve participants' balance confidence. These results suggest that balance confidence has determinants other than balance and that new components and/or modifications of existing components of the program are required to achieve maximal benefits for seniors in terms of physical and psychologic outcomes.

Virtual Reality-Based Center of Mass-Assisted Personalized Balance Training System

Directory of Open Access Journals (Sweden)

Deepesh Kumar

2018-01-01

Full Text Available Poststroke hemiplegic patients often show altered weight distribution with balance disorders, increasing their risk of fall. Conventional balance training, though powerful, suffers from scarcity of trained therapists, frequent visits to clinics to get therapy, one-on-one therapy sessions, and monotony of repetitive exercise tasks. Thus, technology-assisted balance rehabilitation can be an alternative solution. Here, we chose virtual reality as a technology-based platform to develop motivating balance tasks. This platform was augmented with off-the-shelf available sensors such as Nintendo Wii balance board and Kinect to estimate one’s center of mass (CoM. The virtual reality-based CoM-assisted balance tasks (Virtual CoMBaT was designed to be adaptive to one’s individualized weight-shifting capability quantified through CoM displacement. Participants were asked to interact with Virtual CoMBaT that offered tasks of varying challenge levels while adhering to ankle strategy for weight shifting. To facilitate the patients to use ankle strategy during weight-shifting, we designed a heel lift detection module. A usability study was carried out with 12 hemiplegic patients. Results indicate the potential of our system to contribute to improving one’s overall performance in balance-related tasks belonging to different difficulty levels.

EFFECTS OF HEAT STRESS ON BLOOD ACID-BASE BALANCE AND MINERAL CONTENT IN GUINEA FOWLS WHEN DRINKING WATER TREATED WITH MAGNETIC FIELD WAS USED

Directory of Open Access Journals (Sweden)

Beata GŁOWIŃSKA

2011-01-01

Full Text Available The purpose of the study was to examine the effect of 24-hour heat stress on blood acid-base balance parameters and mineral content in guinea fowls when drinking water treated with magnetic field was used. The maximum environmental temperature at the end of the present experiment was 32oC. The relative humidity was maintained at 55% (±2. Blood samples were collected from birds three times: in the 1st, 12th and 24th hour of stress. Exposure to heat stress significantly increased blood bicarbonate ion concentration (HCO3 -, content of buffer alkali (BB and decreased shortage of alkali (BE but only in the 12th hour of stress. In the level of oxygen pressure (pO2 and percentage of oxygen content (O2sat in the 12th and 24th hour of the experiment statistically high significant decrease occurred. In consequence of high environmental temperature the statistically significant decrease of sodium was found. No changes in the level of potassium and chlorine ions in guinea fowls watered magnetized water occurred.

Balancing risk and benefit: maintenance of a thawed Group A plasma inventory for trauma patients requiring massive transfusion.

Science.gov (United States)

Mehr, Chelsea R; Gupta, Rajan; von Recklinghausen, Friedrich M; Szczepiorkowski, Zbigniew M; Dunbar, Nancy M

2013-06-01

Transfusion of plasma and red blood cell (RBC) units in a balanced ratio approximating 1:1 has been shown in retrospective studies to be associated with improved outcomes for trauma patients. Our low-volume rural trauma center uses a trauma-activated transfusion algorithm. Plasma is thawed upon activation to avoid wastage. However, the time required for plasma thawing has made achievement of a 1:1 ratio early in resuscitation challenging. In this study, the time required for plasma thawing is characterized, and a potential solution is proposed. A retrospective chart study of 38 moderately and massively transfused (≥6 U in the first 24 hours) trauma patients admitted from January 2008 to March 2012 was performed. We evaluated the time required to dispense plasma and the number of RBCs dispensed before plasma in these patients. The average time between the dispense of RBCs and plasma was 26 minutes (median, 28; range, 0-48 minutes). The average number of RBCs dispensed before plasma was 8 U (median, 7 U; range, 0-24 U). Nearly one third of massively transfused patients had 10 RBCs or greater dispensed before plasma was available. There exists the potential for delayed plasma availability owing to time required for thawing, which may compromise the ability to provide balanced plasma to RBC transfusion to trauma patients. Maintenance of a thawed Group AB plasma inventory may not be operationally feasible for rural centers with low trauma volumes. Use of a thawed Group A plasma inventory is a potential alternative to ensure rapid plasma availability. Therapeutic study, level V.

Home-based balance training using the Wii balance board: a randomized, crossover pilot study in multiple sclerosis.

Science.gov (United States)

Prosperini, Luca; Fortuna, Deborah; Giannì, Costanza; Leonardi, Laura; Marchetti, Maria Rita; Pozzilli, Carlo

2013-01-01

To evaluate the effectiveness of a home-based rehabilitation of balance using the Nintendo Wii Balance Board System (WBBS) in patients affected by multiple sclerosis (MS). In this 24-week, randomized, 2-period crossover pilot study, 36 patients having an objective balance disorder were randomly assigned in a 1:1 ratio to 2 counterbalanced arms. Group A started a 12-week period of home-based WBBS training followed by a 12-week period without any intervention; group B received the treatment in reverse order. As endpoints, we considered the mean difference (compared with baseline) in force platform measures (i.e., the displacement of body center of pressure in 30 seconds), 4-step square test (FSST), 25-foot timed walking test (25-FWT), and 29-item MS Impact Scale (MSIS-29), as evaluated after 12 weeks and at the end of the 24-week study period. The 2 groups did not differ in baseline characteristics. Repeated-measures analyses of variance showed significant time × treatment effects, indicating that WBBS was effective in ameliorating force platform measures (F = 4.608, P = .016), FSST (F = 3.745, P = .034), 25-FWT (F = 3.339, P = .048), and MSIS-29 (F = 4.282, P = .023). Five adverse events attributable to the WBSS training (knee or low back pain) were recorded, but only 1 patient had to retire from the study. A home-based WBBS training might potentially provide an effective, engaging, balance rehabilitation solution for people with MS. However, the risk of WBBS training-related injuries should be carefully balanced with benefits. Further studies, including cost-effectiveness analyses, are warranted to establish whether WBBS may be useful in the home setting.

Nucleic Acid-Based Therapy Approaches for Huntington's Disease

Directory of Open Access Journals (Sweden)

Tatyana Vagner

2012-01-01

Full Text Available Huntington's disease (HD is caused by a dominant mutation that results in an unstable expansion of a CAG repeat in the huntingtin gene leading to a toxic gain of function in huntingtin protein which causes massive neurodegeneration mainly in the striatum and clinical symptoms associated with the disease. Since the mutation has multiple effects in the cell and the precise mechanism of the disease remains to be elucidated, gene therapy approaches have been developed that intervene in different aspects of the condition. These approaches include increasing expression of growth factors, decreasing levels of mutant huntingtin, and restoring cell metabolism and transcriptional balance. The aim of this paper is to outline the nucleic acid-based therapeutic strategies that have been tested to date.

The first proton sponge-based amino acids: synthesis, acid-base properties and some reactivity.

Science.gov (United States)

Ozeryanskii, Valery A; Gorbacheva, Anastasia Yu; Pozharskii, Alexander F; Vlasenko, Marina P; Tereznikov, Alexander Yu; Chernov'yants, Margarita S

2015-08-21

The first hybrid base constructed from 1,8-bis(dimethylamino)naphthalene (proton sponge or DMAN) and glycine, N-methyl-N-(8-dimethylamino-1-naphthyl)aminoacetic acid, was synthesised in high yield and its hydrobromide was structurally characterised and used to determine the acid-base properties via potentiometric titration. It was found that the basic strength of the DMAN-glycine base (pKa = 11.57, H2O) is on the level of amidine amino acids like arginine and creatine and its structure, zwitterionic vs. neutral, based on the spectroscopic (IR, NMR, mass) and theoretical (DFT) approaches has a strong preference to the zwitterionic form. Unlike glycine, the DMAN-glycine zwitterion is N-chiral and is hydrolytically cleaved with the loss of glycolic acid on heating in DMSO. This reaction together with the mild decarboxylative conversion of proton sponge-based amino acids into 2,3-dihydroperimidinium salts under air-oxygen was monitored with the help of the DMAN-alanine amino acid. The newly devised amino acids are unique as they combine fluorescence, strongly basic and redox-active properties.

Design and evaluation of augmented reality for nuclear power plant maintenance based on Cognitive activity analysis

International Nuclear Information System (INIS)

Koo, Jwa Jin

2008-02-01

The goals of maintenance in nuclear power plants (NPPs) are to reduce the number of plant shutdowns, to decrease the shutdown time, to minimize the maintenance costs, and to improve nuclear safety. Furthermore, it is difficult for maintenance personnel to conduct work in NPPs due to the complexity of NPPs, safety issues and time constraints. Human errors should be prevented to achieve maintenance goals in NPPs. Therefore, it is necessary to improve working conditions by introducing support systems. Augmented Reality (AR) has the potential to assist with maintenance tasks and make maintenance personnel concentrate on the tasks, which will then the reduced human error and improve human performance. The working procedure for AR systems was designed based on the characteristics of cognitive activity, and an experiment was conducted to estimate the effectiveness of AR. The results indicated that a well-designed working procedure for AR systems was more effective than a conventional paper-based working procedure. In addition, participants made fewer errors using the designed working procedure. AR systems as maintenance support systems are beneficial technology that can improve maintenance performance by reducing cognitive loads and unnecessary movements. An AR application can be attractive and effective at supporting maintenance task

Simulation based comparison of predictive maintenance policies

NARCIS (Netherlands)

Tinga, Tiedo; Janssen, R.H.P.; Steenbergen, R.; van Gelder, P.

2013-01-01

When an asset is operated in variable conditions, its operational efficiency can be improved significantly when the maintenance is performed in a dynamic manner. This means that variations in usage and operating environment are taken into account when deciding on the length of the maintenance

The safety monitor and RCM workstation as complementary tools in risk based maintenance optimization

International Nuclear Information System (INIS)

Rawson, P.D.

2000-01-01

Reliability Centred Maintenance (RCM) represents a proven technique for rendering maintenance activities safer, more effective, and less expensive, in terms of systems unavailability and resource management. However, it is believed that RCM can be enhanced by the additional consideration of operational plant risk. This paper discusses how two computer-based tools, i.e., the RCM Workstation and the Safety Monitor, can complement each other in helping to create a living preventive maintenance strategy. (author)

Primer on lead-acid storage batteries

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

This handbook was developed to help DOE facility contractors prevent accidents caused during operation and maintenance of lead-acid storage batteries. Major types of lead-acid storage batteries are discussed as well as their operation, application, selection, maintenance, and disposal (storage, transportation, as well). Safety hazards and precautions are discussed in the section on battery maintenance. References to industry standards are included for selection, maintenance, and disposal.

An Optimization Method for Condition Based Maintenance of Aircraft Fleet Considering Prognostics Uncertainty

Directory of Open Access Journals (Sweden)

Qiang Feng

2014-01-01

Full Text Available An optimization method for condition based maintenance (CBM of aircraft fleet considering prognostics uncertainty is proposed. The CBM and dispatch process of aircraft fleet is analyzed first, and the alternative strategy sets for single aircraft are given. Then, the optimization problem of fleet CBM with lower maintenance cost and dispatch risk is translated to the combinatorial optimization problem of single aircraft strategy. Remain useful life (RUL distribution of the key line replaceable Module (LRM has been transformed into the failure probability of the aircraft and the fleet health status matrix is established. And the calculation method of the costs and risks for mission based on health status matrix and maintenance matrix is given. Further, an optimization method for fleet dispatch and CBM under acceptable risk is proposed based on an improved genetic algorithm. Finally, a fleet of 10 aircrafts is studied to verify the proposed method. The results shows that it could realize optimization and control of the aircraft fleet oriented to mission success.

A screw-based dynamic balancing approach, applied to a 5-bar mechanism

NARCIS (Netherlands)

de Jong, Jan Johannes; van Dijk, Johannes; Herder, Justus Laurens; Lenarcic, Jadran; Merlet, Jean-Pierre

2016-01-01

Dynamic balancing aims to reduce or eliminate the shaking base reaction forces and moments of mechanisms, in order to minimize vibration and wear. The derivation of the dynamic balance conditions requires significant algebraic effort, even for simple mechanisms. In this study, a screw-based

The μ3 model of acids and bases: extending the Lewis theory to intermetallics.

Science.gov (United States)

Stacey, Timothy E; Fredrickson, Daniel C

2012-04-02

A central challenge in the design of new metallic materials is the elucidation of the chemical factors underlying the structures of intermetallic compounds. Analogies to molecular bonding phenomena, such as the Zintl concept, have proven very productive in approaching this goal. In this Article, we extend a foundational concept of molecular chemistry to intermetallics: the Lewis theory of acids and bases. The connection is developed through the method of moments, as applied to DFT-calibrated Hückel calculations. We begin by illustrating that the third and fourth moments (μ(3) and μ(4)) of the electronic density of states (DOS) distribution tune the properties of a pseudogap. μ(3) controls the balance of states above and below the DOS minimum, with μ(4) then determining the minimum's depth. In this way, μ(3) predicts an ideal occupancy for the DOS distribution. The μ(3)-ideal electron count is used to forge a link between the reactivity of transition metals toward intermetallic phase formation, and that of Lewis acids and bases toward adduct formation. This is accomplished through a moments-based definition of acidity which classifies systems that are electron-poor relative to the μ(3)-ideal as μ(3)-acidic, and those that are electron-rich as μ(3)-basic. The reaction of μ(3) acids and bases, whether in the formation of a Lewis acid/base adduct or an intermetallic phase, tends to neutralize the μ(3) acidity or basicity of the reactants. This μ(3)-neutralization is traced to the influence of electronegativity differences at heteroatomic contacts on the projected DOS curves of the atoms involved. The role of μ(3)-acid/base interactions in intermetallic phases is demonstrated through the examination of 23 binary phases forming between 3d metals, the stability range of the CsCl type, and structural trends within the Ti-Ni system.

Optimization of maintenance programme at Daya Bay Nuclear Power Station based on RCM analysis results

International Nuclear Information System (INIS)

Liu Min

2003-01-01

This paper begins with an introduction to Guangdong Daya Bay Nuclear Power Station (GNPS) and gives a simple introduction to the operations and maintenance documentation system at GNPS. It then will review the maintenance program guidelines base and the associated problems prior to the application of reliability centered maintenance (RCM). How RCM was implemented at GNPS, how the results of RCM analysis were used to optimize the maintenance program and test program, and what is the interface between RCM and the existing maintenance program will be shown. Next, it will show the successful implementation of RCM at GNPS resulted in the following changes: A new understanding of equipment failure challenges operations and maintenance beliefs, maintenance concepts undergo a large change, maintenance program and periodic testing program are continuously modified and optimized, new on-condition maintenance technologies are introduced, non-productive scheduled overhauls are discarded, maintenance costs are effectively controlled, maintenance appropriateness has improved, management of hidden failures is more effective and timely. It will show the benefit of greater equipment reliability brought about by all of these changes, which in turn increases the reliability and safety of the entire power station. (author)

Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

International Nuclear Information System (INIS)

Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

2015-01-01

Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

Cognitive Artificial Intelligence Method for Interpreting Transformer Condition Based on Maintenance Data

Directory of Open Access Journals (Sweden)

Karel Octavianus Bachri

2017-07-01

Full Text Available A3S(Arwin-Adang-Aciek-Sembiring is a method of information fusion at a single observation and OMA3S(Observation Multi-time A3S is a method of information fusion for time-series data. This paper proposes OMA3S-based Cognitive Artificial-Intelligence method for interpreting Transformer Condition, which is calculated based on maintenance data from Indonesia National Electric Company (PLN. First, the proposed method is tested using the previously published data, and then followed by implementation on maintenance data. Maintenance data are fused to obtain part condition, and part conditions are fused to obtain transformer condition. Result shows proposed method is valid for DGA fault identification with the average accuracy of 91.1%. The proposed method not only can interpret the major fault, it can also identify the minor fault occurring along with the major fault, allowing early warning feature. Result also shows part conditions can be interpreted using information fusion on maintenance data, and the transformer condition can be interpreted using information fusion on part conditions. The future works on this research is to gather more data, to elaborate more factors to be fused, and to design a cognitive processor that can be used to implement this concept of intelligent instrumentation.

Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

Science.gov (United States)

Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

2011-01-01

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

Present state of condition based maintenance (CBM) and its future problem

International Nuclear Information System (INIS)

Hashimoto, Satoshi; Nogami, Takeki; Sugiyama, Naoki

2008-01-01

New inspection system of the nuclear power plant will be introduced from 2008. In this feature, eleven experts from electric utilities, venders and academia described their views or activities about Condition Based Maintenance (CBM) with a new inspection system attracting attention. These are titled as 'Electric utilities view on CBM and its technology', Deployment results of developed CBM technologies', 'Valve diagnostic analysis support system with wireless technology applied', 'Portable vibration checker', 'Tribology diagnosis with no overhaul', 'Infrared thermograph diagnosis', 'Pipewall thinning inspection and management' and, in addition, the US trend and also the development trend of the CBM advancement technology in the vender and university. CBM technology will be introduced step-by-step and contribute to establish reliability based maintenance. (T. Tanaka)

Maintenance Production Demand and Capacity Analysis of Third Maintenance Battalion

Science.gov (United States)

2017-12-01

Delivery T/E Table of Equipment TFSMS Total Force Structure Management System TFSP Total Force Structure Process TM Technical Manual T/O Table of...exercises each year, both on Okinawa and throughout the Pacific theater. When equipment requires maintenance beyond the organizational -level...demand was analyzed based on customer cycle time (i.e., time that equipment was in Third Maintenance Battalion custody), maintenance cycle time during

Work-Life Balance among academic staff of the University of Lagos ...

African Journals Online (AJOL)

Work-Life Balance among academic staff of the University of Lagos. ... Abstract. Work-life balance is associated with the maintenance of stability in both one's professional and personal life. It is key to the welfare and, subsequently, job satisfaction and productivity of employees. It is against this understanding that this study ...

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

DEFF Research Database (Denmark)

Nielsen, Jannie Jessen; Sørensen, John Dalsgaard

2011-01-01

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

Use of mass and toxicity balances in risk-based corrective action decisions at contaminated sites

International Nuclear Information System (INIS)

Sevigny, J.H.; Lintott, D.; Wrubleski, R.M.; Drury, C.R.

1997-01-01

The contaminated groundwater at a sour gas plant facility was studied to identify the chemicals of environmental concern. Simple mass balance principles were used to determine the proportion of organic carbon, organic nitrogen and Microtox R toxicity that can be attributed to two process chemicals that have contaminated several sour gas plants in western Canada. The two process chemicals are sulfolane and diisopropanolamine (DIPA). The organic carbon balance was calculated by determining the molar contribution of sulfolane and DIPA relative to the mass of carboxylic acid-corrected dissolved organic carbon. Organic carbon balances ranged from 44 to 96 per cent. The organic nitrogen balance was calculated by determining the molar contribution of DIPA relative to the mass of ammonium ion-corrected dissolved Kjeldahl nitrogen. The nitrogen balances were highly variable between 8 to 48 per cent for samples with organic nitrogen concentrations between 10 and 32 mg/L. The Microtox R toxicity balance was calculated by determining the proportions of toxicity that could be accounted for by pure phase sulfolane and DIPA. The Microtox R toxicity balance for samples that showed significant toxicity ranged from 71 to 122 per cent

Use of mass and toxicity balances in risk-based corrective action decisions at contaminated sites

Energy Technology Data Exchange (ETDEWEB)

Sevigny, J.H. [Komex Consultants Ltd., Calgary, AB (Canada); Lintott, D. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wrubleski, R.M.; Drury, C.R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

1997-12-31

The contaminated groundwater at a sour gas plant facility was studied to identify the chemicals of environmental concern. Simple mass balance principles were used to determine the proportion of organic carbon, organic nitrogen and Microtox{sup R} toxicity that can be attributed to two process chemicals that have contaminated several sour gas plants in western Canada. The two process chemicals are sulfolane and diisopropanolamine (DIPA). The organic carbon balance was calculated by determining the molar contribution of sulfolane and DIPA relative to the mass of carboxylic acid-corrected dissolved organic carbon. Organic carbon balances ranged from 44 to 96 per cent. The organic nitrogen balance was calculated by determining the molar contribution of DIPA relative to the mass of ammonium ion-corrected dissolved Kjeldahl nitrogen. The nitrogen balances were highly variable between 8 to 48 per cent for samples with organic nitrogen concentrations between 10 and 32 mg/L. The Microtox{sup R} toxicity balance was calculated by determining the proportions of toxicity that could be accounted for by pure phase sulfolane and DIPA. The Microtox{sup R} toxicity balance for samples that showed significant toxicity ranged from 71 to 122 per cent.

A comparison of traditional and quantitative analysis of acid-base imbalances in hypoalbuminemic dogs.

Science.gov (United States)

Torrente, Carlos; Manzanilla, Edgar G; de Gopegui, Rafael Ruiz

2014-01-01

To compare the traditional (HH) and quantitative approaches used for the evaluation of the acid-base balance in hypoalbuminemic dogs. Prospective observational study. ICU of a veterinary teaching hospital. One hundred and five client-owned dogs. Jugular venous blood samples were collected from each patient on admission to determine: total plasma protein (TP), albumin (Alb), blood urea nitrogen (BUN), glucose (Glu), hematocrit (HCT), Na(+) , Cl(-) , K(+) , phosphate (Pi ), pH, PvCO2, bicarbonate (HCO3 (-) ), anion gap (AG), adjusted anion gap for albumin (AGalb ) or phosphate (AGalb-phos ), standardized base excess (SBE), strong ion difference (SID), concentration of nonvolatile weak buffers (Atot ), and strong ion gap (SIG). Patients were divided in 2 groups according to the severity of the hypoalbuminemia: mild (Alb = 21-25 g/L) and severe (Alb ≤20 g/L). All parameters were compared among groups. Patients with severe hypoalbuminemia showed significant decrease in TP (P = 0.011), Atot (P = 0.050), and a significant increase in adjusted AG (P = 0.048) and the magnitude of SIG (P = 0.011) compared to animals with mild hypoalbuminemia. According to the HH approach, the most frequent imbalances were simple disorders (51.4%), primarily metabolic acidosis (84.7%) associated with a high AG acidosis. However, when using the quantitative method, 58.1% of patients had complex disorders, with SIG acidosis (74.3%) and Atot alkalosis (33.3%) as the most frequent acid-base imbalances. Agreement between methods only matched in 32 cases (kappa acid-base balance was poor and many imbalances detected using the quantitative approach were missed using the HH approach. Further studies are necessary to confirm the clinical utility of using the quantitative approach in the decision-making process of the severely ill hypoalbuminemic patients. © Veterinary Emergency and Critical Care Society 2014.

Knowledge-based machine indexing from natural language text: Knowledge base design, development, and maintenance

Science.gov (United States)

Genuardi, Michael T.

1993-01-01

One strategy for machine-aided indexing (MAI) is to provide a concept-level analysis of the textual elements of documents or document abstracts. In such systems, natural-language phrases are analyzed in order to identify and classify concepts related to a particular subject domain. The overall performance of these MAI systems is largely dependent on the quality and comprehensiveness of their knowledge bases. These knowledge bases function to (1) define the relations between a controlled indexing vocabulary and natural language expressions; (2) provide a simple mechanism for disambiguation and the determination of relevancy; and (3) allow the extension of concept-hierarchical structure to all elements of the knowledge file. After a brief description of the NASA Machine-Aided Indexing system, concerns related to the development and maintenance of MAI knowledge bases are discussed. Particular emphasis is given to statistically-based text analysis tools designed to aid the knowledge base developer. One such tool, the Knowledge Base Building (KBB) program, presents the domain expert with a well-filtered list of synonyms and conceptually-related phrases for each thesaurus concept. Another tool, the Knowledge Base Maintenance (KBM) program, functions to identify areas of the knowledge base affected by changes in the conceptual domain (for example, the addition of a new thesaurus term). An alternate use of the KBM as an aid in thesaurus construction is also discussed.

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.

Geometric Process-Based Maintenance and Optimization Strategy for the Energy Storage Batteries

Directory of Open Access Journals (Sweden)

Yan Li

2016-01-01

Full Text Available Renewable energy is critical for improving energy structure and reducing environment pollution. But its strong fluctuation and randomness have a serious effect on the stability of the microgrid without the coordination of the energy storage batteries. The main factors that influence the development of the energy storage system are the lack of valid operation and maintenance management as well as the cost control. By analyzing the typical characteristics of the energy storage batteries in their life cycle, the geometric process-based model including the deteriorating system and the improving system is firstly built for describing the operation process, the preventive maintenance process, and the corrective maintenance process. In addition, this paper proposes an optimized management strategy, which aims to minimize the long-run average cost of the energy storage batteries by defining the time interval of the detection and preventive maintenance process as well as the optimal corrective maintenance times, subjected to the state of health and the reliability conditions. The simulation is taken under the built model by applying the proposed energy storage batteries’ optimized management strategy, which verifies the effectiveness and applicability of the management strategy, denoting its obvious practicality on the current application.

Unified Balance Scale: an activity-based, bed to community, and aetiology-independent measure of balance calibrated with Rasch analysis.

Science.gov (United States)

La Porta, Fabio; Franceschini, Marco; Caselli, Serena; Cavallini, Paola; Susassi, Sonia; Tennant, Alan

2011-04-01

To build a new activity-based, "bed to community", aetiology-independent measure of balance within the neurological rehabilitation setting by merging some existing scales. Balance scales were selected using a conceptual framework and subsequently administered to a convenience sample of adult patients with balance problems due to different neurological aetiologies. Data were then processed using classical psychometric analyses and Rasch analysis in order to construct a new balance measurement tool. The Berg Balance Scale, the Tinetti Scales and the Fullerton Advanced Balance Scale were selected and administered to a sample of patients, giving 302 observations. Classical psychometric analyses (item and scale analysis; confirmatory factor analysis) were undertaken on the pooled 40-item set with confirmation of unidimensionality. The subsequent Rasch analysis allowed the identification of a 27-item set satisfying the Rasch Model's requirements for fundamental measurement, with further confirmation of unidimensionality by post-hoc confirmatory factor analysis. The new scale (Unified Balance Scale) holds proven measurement properties and may be a candidate tool for "bed to community" balance measurement for patients with balance problems within the neuro-rehabilitation setting. Future studies are warranted to explore further its external validity and other clinical properties, as well as to improve its usability.

Scalable Coverage Maintenance for Dense Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Jun Lu

2007-06-01

Full Text Available Owing to numerous potential applications, wireless sensor networks have been attracting significant research effort recently. The critical challenge that wireless sensor networks often face is to sustain long-term operation on limited battery energy. Coverage maintenance schemes can effectively prolong network lifetime by selecting and employing a subset of sensors in the network to provide sufficient sensing coverage over a target region. We envision future wireless sensor networks composed of a vast number of miniaturized sensors in exceedingly high density. Therefore, the key issue of coverage maintenance for future sensor networks is the scalability to sensor deployment density. In this paper, we propose a novel coverage maintenance scheme, scalable coverage maintenance (SCOM, which is scalable to sensor deployment density in terms of communication overhead (i.e., number of transmitted and received beacons and computational complexity (i.e., time and space complexity. In addition, SCOM achieves high energy efficiency and load balancing over different sensors. We have validated our claims through both analysis and simulations.

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.

Eco-Balance analysis of the disused lead-acid-batteries recycling technology

Science.gov (United States)

Kamińska, Ewa; Kamiński, Tomasz

2017-10-01

The article presents the results of the eco-balance analysis of the disused lead-acid batteries recycling process. Test-dedicated technology offers the possibility to recover other elements, for example, polypropylene of the battery case or to obtain crystalline sodium sulphate. The life cycle assessment was made using ReCiPe and IMPACT2002 + methods. The results are shown as environmental points [Pt]. The results are shown in the environmental categories, specific for each of the methods grouped in the impact categories. 1 Mg of the processed srap was a dopted as the functional unit. The results of the analyses indicate that recycling processes may provide the environmental impact of recycling technology less harmful. Repeated use of lead causes that its original sources are not explored. Similarly, the use of granule production-dedicated polypropylene extracted from battery casings that are used in the plastics industry, has environmental benefits. Due to the widespread use of lead-acid batteries, the attention should be paid to their proper utilization, especially in terms of heavy metals, especially lead. According to the calculations, the highest level of environmental benefits from the use of lead from secondary sources in the production of new products, was observed in the refining process.

Eco-Balance analysis of the disused lead-acid-batteries recycling technology

Directory of Open Access Journals (Sweden)

Kamińska Ewa

2017-01-01

Full Text Available The article presents the results of the eco-balance analysis of the disused lead-acid batteries recycling process. Test-dedicated technology offers the possibility to recover other elements, for example, polypropylene of the battery case or to obtain crystalline sodium sulphate. The life cycle assessment was made using ReCiPe and IMPACT2002 + methods. The results are shown as environmental points [Pt]. The results are shown in the environmental categories, specific for each of the methods grouped in the impact categories. 1 Mg of the processed srap was a dopted as the functional unit. The results of the analyses indicate that recycling processes may provide the environmental impact of recycling technology less harmful. Repeated use of lead causes that its original sources are not explored. Similarly, the use of granule production-dedicated polypropylene extracted from battery casings that are used in the plastics industry, has environmental benefits. Due to the widespread use of lead-acid batteries, the attention should be paid to their proper utilization, especially in terms of heavy metals, especially lead. According to the calculations, the highest level of environmental benefits from the use of lead from secondary sources in the production of new products, was observed in the refining process.

A prospective randomized trial of two solutions for intrapartum amnioinfusion: effects on fetal electrolytes, osmolality, and acid-base status.

Science.gov (United States)

Pressman, E K; Blakemore, K J

1996-10-01

Our purpose was to compare the effects of intrapartum amnioinfusion with normal saline solution versus lactated Ringer's solution plus physiologic glucose on neonatal electrolytes and acid-base balance. Patients undergoing amnioinfusion for obstetric indications were randomized to receive normal saline solution or lactated Ringer's solution plus physiologic glucose at standardized amnioinfusion rates. Data were collected prospectively on maternal demographics, course of labor, and maternal and neonatal outcome. Arterial cord blood was obtained for analysis of electrolytes, glucose, osmolality, lactic acid, and blood gases. Control subjects with normal fetal heart rate patterns, and clear amniotic fluid not receiving amnioinfusion were studied concurrently. Data were collected on 59 patients (21 normal saline solution, 18 lactated Ringer's solution plus physiologic glucose, and 20 controls). Maternal demographics, course of labor, and neonatal outcome were similar in all three groups. Cesarean sections were performed more often in the amnioinfusion groups (33.3% for normal saline solution, 38.9% for lactated Ringer's solution plus physiologic glucose) than in the control group (5.0%), p amnioinfusion with either solution. Intrapartum amnioinfusion with normal saline solution or lactated Ringer's solution plus physiologic glucose has no effect on neonatal electrolytes or acid-base balance.

Feature-based and object-based attention orientation during short-term memory maintenance.

Science.gov (United States)

Ku, Yixuan

2015-12-01

Top-down attention biases the short-term memory (STM) processing at multiple stages. Orienting attention during the maintenance period of STM by a retrospective cue (retro-cue) strengthens the representation of the cued item and improves the subsequent STM performance. In a recent article, Backer et al. (Backer KC, Binns MA, Alain C. J Neurosci 35: 1307-1318, 2015) extended these findings from the visual to the auditory domain and combined electroencephalography to dissociate neural mechanisms underlying feature-based and object-based attention orientation. Both event-related potentials and neural oscillations explained the behavioral benefits of retro-cues and favored the theory that feature-based and object-based attention orientation were independent. Copyright © 2015 the American Physiological Society.

Using the system maintenance datastore to characterize lifetime maintenance for PLiM

International Nuclear Information System (INIS)

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

2004-01-01

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

Planning of operation & maintenance using risk and reliability based methods

DEFF Research Database (Denmark)

Florian, Mihai; Sørensen, John Dalsgaard

2015-01-01

Operation and maintenance (OM) of offshore wind turbines contributes with a substantial part of the total levelized cost of energy (LCOE). The objective of this paper is to present an application of risk- and reliability-based methods for planning of OM. The theoretical basis is presented...

Cernavoda NPP risk - Based test and maintenance planning - Methodology development

International Nuclear Information System (INIS)

Georgescu, G.; Popa, P.; Petrescu, A.; Naum, M.; Gutu, M.

1997-01-01

The Cernavoda Power Plant starts the commercial operation in November 1996. During operation of the nuclear power plant, several mandatory tests and maintenance are performed on stand-by safety system components to ensure their availability in case of accident. The basic purpose of such activities is the early detection of any failure and degradation, and timely correction of deteriorations. Because of the large number of such activities, emphasis on plant safety and allocation of resources becomes difficult. The probabilistic model and methodology can be effectively used to obtain the risk significance of these activities so that the resources are directed to the most important areas. The proposed Research Contract activity is strongly connected with other safety related areas under development. Since, the Cernavoda Probabilistic Safety Evaluation Level 1 PSA Study (CPSE) was performed and now the study is revised taking into account the as-built information, it is recommended to implement into the model the necessary modeling features to support further PSA application, especially related to Test and Maintenance optimization. Methods need to be developed in order to apply the PSA model including risk information together with other needed information for Test and Maintenance optimization. Also, in parallel with the CPSE study updating, the software interface for the PSA model is under development (Risk Monitor Software class), methods and models needing to be developed for the purpose of using it for qualified monitoring of Test and Maintenance Strategy efficiency. Similar, the Data Collection System need to be appropriate for the purpose of an ongoing implementation of a risk - based Test and Maintenance Strategy. (author). 4 refs, 1 fig

Complexity in Acid-Base Titrations: Multimer Formation Between Phosphoric Acids and Imines.

Science.gov (United States)

Malm, Christian; Kim, Heejae; Wagner, Manfred; Hunger, Johannes

2017-08-10

Solutions of Brønsted acids with bases in aprotic solvents are not only common model systems to study the fundamentals of proton transfer pathways but are also highly relevant to Brønsted acid catalysis. Despite their importance the light nature of the proton makes characterization of acid-base aggregates challenging. Here, we track such acid-base interactions over a broad range of relative compositions between diphenyl phosphoric acid and the base quinaldine in dichloromethane, by using a combination of dielectric relaxation and NMR spectroscopy. In contrast to what one would expect for an acid-base titration, we find strong deviations from quantitative proton transfer from the acid to the base. Even for an excess of the base, multimers consisting of one base and at least two acid molecules are formed, in addition to the occurrence of proton transfer from the acid to the base and simultaneous formation of ion pairs. For equimolar mixtures such multimers constitute about one third of all intermolecular aggregates. Quantitative analysis of our results shows that the acid-base association constant is only around six times larger than that for the acid binding to an acid-base dimer, that is, to an already protonated base. Our findings have implications for the interpretation of previous studies of reactive intermediates in organocatalysis and provide a rationale for previously observed nonlinear effects in phosphoric acid catalysis. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Risk-based inspection and maintenance systems for steam turbines

International Nuclear Information System (INIS)

Fujiyama, Kazunari; Nagai, Satoshi; Akikuni, Yasunari; Fujiwara, Toshihiro; Furuya, Kenichiro; Matsumoto, Shigeru; Takagi, Kentaro; Kawabata, Taro

2004-01-01

The risk-based maintenance (RBM) system has been developed for steam turbine plants coupled with the quick inspection systems. The RBM system utilizes the field failure and inspection database accumulated over 30 years. The failure modes are determined for each component of steam turbines and the failure scenarios are described as event trees. The probability of failure is expressed in the form of unreliability functions of operation hours or start-up cycles through the cumulative hazard function method. The posterior unreliability is derived from the field data analysis according to the inspection information. Quick inspection can be conducted using air-cooled borescope and heat resistant ultrasonic sensors even if the turbine is not cooled down sufficiently. Another inspection information comes from degradation and damage measurement. The probabilistic life assessment using structural analysis and statistical material properties, the latter is estimated from hardness measurement, replica observation and embrittlement measurement. The risk function is calculated as the sum product of unreliability functions and expected monetary loss as the consequence of failure along event trees. The optimum maintenance plan is determined among simulated scenarios described through component breakdown trees, life cycle event trees and risk functions. Those methods are effective for total condition assessment and economical maintenance for operating plants

The balancing act of GABAergic synapse organizers.

Science.gov (United States)

Ko, Jaewon; Choii, Gayoung; Um, Ji Won

2015-04-01

GABA (γ-aminobutyric acid) is the main neurotransmitter at inhibitory synapses in the mammalian brain. It is essential for maintaining the excitation and inhibition (E/I) ratio, whose imbalance underlies various brain diseases. Emerging information about inhibitory synapse organizers provides a novel molecular framework for understanding E/I balance at the synapse, circuit, and systems levels. This review highlights recent advances in deciphering these components of the inhibitory synapse and their roles in the development, transmission, and circuit properties of inhibitory synapses. We also discuss how their dysfunction may lead to a variety of brain disorders, suggesting new therapeutic strategies based on balancing the E/I ratio.

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

In the last years, EIE GROUP has been more and more involved in large optical telescopes and radio antennas array projects. In this frame, the paper describes a fundamental aspect of the Logistic Support Analysis (LSA) process, that is the application of the Reliability-Centered Maintenance (RCM) methodology for the generation of maintenance plans for ground-based large optical telescopes and radio antennas arrays. This helps maintenance engineers to make sure that the telescopes continue to work properly, doing what their users require them to do in their present operating conditions. The main objective of the RCM process is to establish the complete maintenance regime, with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems. At the same time, a correct application of the RCM allows to increase the cost effectiveness, telescope uptime and items availability, and to provide greater understanding of the level of risk that the organization is managing. At the same time, engineers shall make a great effort since the initial phase of the project to obtain a telescope requiring easy maintenance activities and simple replacement of the major assemblies, taking special care on the accesses design and items location, implementation and design of special lifting equipment and handling devices for the heavy items. This maintenance engineering framework is based on seven points, which lead to the main steps of the RCM program. The initial steps of the RCM process consist of: system selection and data collection (MTBF, MTTR, etc.), definition of system boundaries and operating context, telescope description with the use of functional block diagrams, and the running of a FMECA to address the dominant causes of equipment failure and to lay down the Critical Items List. In the second part of the process the RCM logic is applied, which helps to determine the appropriate maintenance tasks for each identified failure mode. Once

Comparison of the effects of virtual reality-based balance exercises and conventional exercises on balance and fall risk in older adults living in nursing homes in Turkey.

Science.gov (United States)

Yeşilyaprak, Sevgi Sevi; Yıldırım, Meriç Şenduran; Tomruk, Murat; Ertekin, Özge; Algun, Z Candan

2016-01-01

There is limited information on effective balance training techniques including virtual reality (VR)-based balance exercises in residential settings and no studies have been designed to compare the effects of VR-based balance exercises with conventional balance exercises in older adults living in nursing homes in Turkey. The objective of our study was to investigate the effects of VR-based balance exercises on balance and fall risk in comparison to conventional balance exercises in older adults living in nursing homes. A total sample of 18 subjects (65-82 years of age) with fall history who were randomly assigned to either the VR group (Group 1, n = 7) or the conventional exercise group (Group 2, n = 11) completed the exercise training. In both groups, Berg balance score (BBS), timed up & go duration, and left leg stance and tandem stance duration with eyes closed significantly improved with time (p 0.05) after training, indicating that neither the exercise method was superior. Similar improvements were found in balance and fall risk with VR-based balance training and conventional balance training in older adults living in the nursing home. Both exercise trainings can be preferable by health care professionals considering fall prevention. Appropriate patient selection is essential.

Review of key Belotero Balance safety and efficacy trials.

Science.gov (United States)

Lorenc, Z Paul; Fagien, Steven; Flynn, Timothy C; Waldorf, Heidi A

2013-10-01

Belotero Balance is a novel highly cross-linked hyaluronic acid that uses cohesive polydensified matrix technology to achieve cohesive gel; improved adaptation by the dermis; and a soft, smooth fill. Several studies have now compared Belotero Balance to bovine collagen and other hyaluronic acids. Two pivotal studies demonstrated the noninferiority and superiority of Belotero Balance to bovine collagen. In the first study, more than half of the patients maintained optimal correction at 6 months on the Belotero-treated side of the face. The second of those two studies followed patients to week 96 and demonstrated that the effects of Belotero Balance in this long-term, open-label study persisted in the majority of subjects without repeated treatment for at least one interval of 48 weeks. The filler was well tolerated, with only one of 34 total adverse events (injection-site bruising) considered to be related to the study device. A third study compared the safety and efficacy of other hyaluronic acids (i.e., Juvéderm and Restylane) with Belotero Balance. In this study, the safety profiles of all three hyaluronic acids were generally favorable, with site-specific adverse events mild to moderate and comparable across each hyaluronic acid. Aesthetic results were also similar, although Belotero Balance resulted in greater evenness than Restylane at 4 weeks by one indicator used in the study. Finally, a 5-year retrospective safety review of 317 patients treated with Belotero Balance over a 5-year period revealed no severe adverse events in any patients, including the absence of persistent nodules or granulomas.

Balancing omega-6 and omega-3 fatty acids in ready-to-use therapeutic foods (RUTF)

OpenAIRE

Brenna, Thomas; Akomo, Peter; Bahwere, Paluku; Berkley, James; Calder, Phillip; Jones, Kelsey; Liu, Lei; Manary, Mark; Trehan, Indi; Briend, André

2015-01-01

Ready-to-use therapeutic foods (RUTFs) are a key component of a life-saving treatment for young children who present with uncomplicated severe acute malnutrition in resource limited settings. Increasing recognition of the role of balanced dietary omega-6 and omega-3 polyunsaturated fatty acids (PUFA) in neurocognitive and immune development led two independent groups to evaluate RUTFs. Jones et al. (BMC Med 13:93, 2015), in a study in BMC Medicine, and Hsieh et al. (J Pediatr Gastroenterol Nu...

Knowledge maintenance in myCBR

OpenAIRE

Aul, Vani; Sauer, Christian; Roth-Berghofer, Thomas

2014-01-01

CBR systems, being knowledge based systems, process knowledge. Due to changes in the environment a CBR system’s knowledge model can become outdated, thus creating a need for constant maintenance of said knowledge model. In this paper, we describe an implementation of (semi-)automatic knowledge maintenance of two of the four knowledge containers of CBR systems, specifically case base maintenance and maintenance of similarity measures within the CBR system development SDK myCBR. We describe our...

Amino Acid Signatures to Evaluate the Beneficial Effects of Weight Loss

DEFF Research Database (Denmark)

Geidenstam, Nina; Magnusson, Martin; Danielsson, Anders P H

2017-01-01

-associated amino acids from the MDC-CC, alanine, isoleucine, tyrosine, phenylalanine, and glutamate decreased after weight loss, while asparagine increased after weight maintenance. These changes were validated in the replication cohort. Scores that were constructed based on obesity-associated amino acids...

Maintenance cost optimization in condition based maintenance: a case study for critical facilities

OpenAIRE

Filippo De Carlo; Maria Antonietta Arleo

2013-01-01

The increasing availability required to industrial plants and the limited budget often existing to assure it, require a careful formulation of maintenance optimization models. This need is primary for process plants, for which minimization of stops and maximization of their availability, are essential for ensuring targeted production and, therefore, profitability. In this context, the choice of the maintenance strategy is hence fundamental, depending on the system features and then on the eff...

Computer-Based Simulations for Maintenance Training: Current ARI Research. Technical Report 544.

Science.gov (United States)

Knerr, Bruce W.; And Others

Three research efforts that used computer-based simulations for maintenance training were in progress when this report was written: Game-Based Learning, which investigated the use of computer-based games to train electronics diagnostic skills; Human Performance in Fault Diagnosis Tasks, which evaluated the use of context-free tasks to train…

Improving the TRIGA facility maintenance by predictive maintenance techniques

International Nuclear Information System (INIS)

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

1997-01-01

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

Embracing Safe Ground Test Facility Operations and Maintenance

Science.gov (United States)

Dunn, Steven C.; Green, Donald R.

2010-01-01

Conducting integrated operations and maintenance in wind tunnel ground test facilities requires a balance of meeting due dates, efficient operation, responsiveness to the test customer, data quality, effective maintenance (relating to readiness and reliability), and personnel and facility safety. Safety is non-negotiable, so the balance must be an "and" with other requirements and needs. Pressure to deliver services faster at increasing levels of quality in under-maintained facilities is typical. A challenge for management is to balance the "need for speed" with safety and quality. It s especially important to communicate this balance across the organization - workers, with a desire to perform, can be tempted to cut corners on defined processes to increase speed. Having a lean staff can extend the time required for pre-test preparations, so providing a safe work environment for facility personnel and providing good stewardship for expensive National capabilities can be put at risk by one well-intending person using at-risk behavior. This paper documents a specific, though typical, operational environment and cites management and worker safety initiatives and tools used to provide a safe work environment. Results are presented and clearly show that the work environment is a relatively safe one, though still not good enough to keep from preventing injury. So, the journey to a zero injury work environment - both in measured reality and in the minds of each employee - continues. The intent of this paper is to provide a benchmark for others with operational environments and stimulate additional sharing and discussion on having and keeping a safe work environment.

Home-Based Computer Gaming in Vestibular Rehabilitation of Gaze and Balance Impairment.

Science.gov (United States)

Szturm, Tony; Reimer, Karen M; Hochman, Jordan

2015-06-01

Disease or damage of the vestibular sense organs cause a range of distressing symptoms and functional problems that could include loss of balance, gaze instability, disorientation, and dizziness. A novel computer-based rehabilitation system with therapeutic gaming application has been developed. This method allows different gaze and head movement exercises to be coupled to a wide range of inexpensive, commercial computer games. It can be used in standing, and thus graded balance demands using a sponge pad can be incorporated into the program. A case series pre- and postintervention study was conducted of nine adults diagnosed with peripheral vestibular dysfunction who received a 12-week home rehabilitation program. The feasibility and usability of the home computer-based therapeutic program were established. Study findings revealed that using head rotation to interact with computer games, when coupled to demanding balance conditions, resulted in significant improvements in standing balance, dynamic visual acuity, gaze control, and walking performance. Perception of dizziness as measured by the Dizziness Handicap Inventory also decreased significantly. These preliminary findings provide support that a low-cost home game-based exercise program is well suited to train standing balance and gaze control (with active and passive head motion).

Ethylenediamine-functionalized graphene oxide incorporated acid-base ion exchange membranes for vanadium redox flow battery

International Nuclear Information System (INIS)

Liu, Shuai; Li, Dan; Wang, Lihua; Yang, Haijun; Han, Xutong; Liu, Biqian

2017-01-01

Highlights: • Ethylenediamine functionalized graphene oxide. • Layered structure of functionalized graphene oxide block vanadium ions crossover. • Protonated N-containing groups suppress vanadium ions permeation. • Ion transport channels are narrowed by electrostatic interactions. • Vanadium crossover decreased due to enhanced Donnan effect and special structure. - Abstract: As a promising large-scale energy storage battery, vanadium redox flow battery (VRFB) is urgently needed to develop cost-effective membranes with excellent performance. Novel acid-base ion exchange membranes (IEMs) are fabricated based on sulfonated poly(ether ether ketone) (SPEEK) matrix and modified graphene oxide (GO) by solution blending. N-based functionalized graphene oxide (GO-NH 2 ) is fabricated by grafting ethylenediamine onto the edge of GO via a facile method. On one hand, the impermeable layered structures effectively block ion transport pathway to restrain vanadium ions crossover. On the other hand, acid-base pairs form between −SO 3 − groups and N-based groups on the edge of GO nanosheets, which not only suppress vanadium ions contamination but also provide a narrow pathway for proton migration. The structure is beneficial for achieving an intrinsic balance between conductivity and permeability. By altering amounts of GO-NH 2 , a sequence of acid-base IEMs are characterized in detail. The single cells assembled with acid-base IEMs show self-discharge time for 160 h, capacity retention 92% after 100 cycle, coulombic efficiency 97.2% and energy efficiency 89.5%. All data indicate that acid-base IEMs have promising prospects for VRFB applications.

Research on gesture recognition of augmented reality maintenance guiding system based on improved SVM

Science.gov (United States)

Zhao, Shouwei; Zhang, Yong; Zhou, Bin; Ma, Dongxi

2014-09-01

Interaction is one of the key techniques of augmented reality (AR) maintenance guiding system. Because of the complexity of the maintenance guiding system's image background and the high dimensionality of gesture characteristics, the whole process of gesture recognition can be divided into three stages which are gesture segmentation, gesture characteristic feature modeling and trick recognition. In segmentation stage, for solving the misrecognition of skin-like region, a segmentation algorithm combing background mode and skin color to preclude some skin-like regions is adopted. In gesture characteristic feature modeling of image attributes stage, plenty of characteristic features are analyzed and acquired, such as structure characteristics, Hu invariant moments features and Fourier descriptor. In trick recognition stage, a classifier based on Support Vector Machine (SVM) is introduced into the augmented reality maintenance guiding process. SVM is a novel learning method based on statistical learning theory, processing academic foundation and excellent learning ability, having a lot of issues in machine learning area and special advantages in dealing with small samples, non-linear pattern recognition at high dimension. The gesture recognition of augmented reality maintenance guiding system is realized by SVM after the granulation of all the characteristic features. The experimental results of the simulation of number gesture recognition and its application in augmented reality maintenance guiding system show that the real-time performance and robustness of gesture recognition of AR maintenance guiding system can be greatly enhanced by improved SVM.

Advanced maintenance strategies for power plant operators - introducing inter-plant life cycle management. ZES research focus 'condition-based maintenance in power engineering'

International Nuclear Information System (INIS)

Graeber, U.

2003-01-01

The optimisation of maintenance activities observed in recent years can be attributed above all to the use and continuing development of testing and diagnostic techniques, to the increased level of system and component automation and to more efficient work organisation. Despite the considerable success of these efforts, the potential for further cost reductions is still far from exhausted. The risks connected to reliability, availability and safety need to be analysed in greater detail in order to ensure the sustainability of the savings already achieved as well as those yet to be realised. The systematic application of condition-based maintenance and the introduction of structured life cycle management are essential prerequisites. Within the framework of its ''Condition-Based Maintenance in Power Engineering'' research focus, the Energy Research Centre (ZES) has set up a specialist network in which experts from various institutes belonging to the Faculty of Mechanical Engineering and the Faculty of Informatic, Electrical Engineering and Information Technology can develop interdisciplinary solutions for advanced maintenance strategies. The ZES offers the industry a platform for cooperating on current issues relating to the supply of energy and supports the movement towards sustainable improvements to competitiveness through research and consulting activities. It applies professional project and quality management procedures to ensure that contracts covering interdisciplinary topics and projects are handled in a coherent manner. (orig.)

Effect of short-term low-protein diet supplemented with keto acids on hyperphosphatemia in maintenance hemodialysis patients.

Science.gov (United States)

Li, Haiming; Long, Quan; Shao, Chunhai; Fan, Hong; Yuan, Li; Huang, Bihong; Gu, Yong; Lin, Shanyan; Hao, Chuanming; Chen, Jing

2011-01-01

To evaluate the effects of short-term restriction of dietary protein intake (DPI) supplemented with keto acids on hyperphosphatemia in maintenance hemodialysis (MHD) patients. Forty MHD patients with uncontrolled hyperphosphatemia were randomized to either low DPI with keto acid-supplemented (sLP) or normal DPI (NP) group for 8 weeks. After 8 weeks, the sLP group was shifted to NP for another 8 weeks. Low-protein diet (LPD) was individualized with total caloric intake 30-35 kcal/kg/day, protein intake of 0.8 g/kg/day and phosphate intake of 500 mg/day. Keto acids were supplied in a dosage of 12 pills per day. Calcium phosphorous metabolism index and nutritional index (serum albumin, total protein, somatometric measurements, 3-day diaries and Mini-Nutritional Assessment score) were recorded. C-reactive protein, CO(2) combining power and Kt/V were measured to evaluate the inflammation, metabolic acidosis and dialysis adequacy, respectively. Serum phosphorus level and calcium-phosphate product were significantly decreased at the end of the first 8 weeks in the sLP group compared to the basal value and the NP group (p keto acids could decrease hyperphosphatemia and calcium-phosphate product, while keeping stable nutritional status among MHD patients. Copyright © 2010 S. Karger AG, Basel.

A maintenance optimization model for mission-oriented systems based on Wiener degradation

International Nuclear Information System (INIS)

Guo, Chiming; Wang, Wenbin; Guo, Bo; Si, Xiaosheng

2013-01-01

Over the past few decades, condition-based maintenance (CBM) has attracted many researchers because of its effectiveness and practical significance. This paper deals with mission-oriented systems subject to gradual degradation modeled by a Wiener stochastic process within the context of CBM. For a mission-oriented system, the mission usually has constraints on availability/reliability, the opportunity for maintenance actions, and the monitoring type (continuous or discrete). Furthermore, in practice, a mission-oriented system may undertake some preventive maintenance (PM) and after such PM, the system may return to an intermediate state between an as-good-as new state and an as-bad-as old state, i.e., the PM is not perfect and only partially restores the system. However, very few CBM models integrated these mission constraints together with an imperfect nature of the PM into the course of optimizing the PM policy. This paper develops a model to optimize the PM policy in terms of the maintenance related cost jointly considering the mission constraints and the imperfect PM nature. A numerical example is presented to demonstrate the proposed model. The comparison with the simulated results and the sensitivity analysis show the usefulness of the optimization model for mission-oriented system maintenance presented in this paper.

A cost effective degradation-based maintenance strategy under imperfect repair

International Nuclear Information System (INIS)

Wu, Fan; Niknam, Seyed A.; Kobza, John E.

2015-01-01

An optimization model is developed to minimize the total cost of imperfect degradation-based maintenance by determining an optimal interval of condition monitoring and the degradation level after imperfect preventive repairs. The decision model is based on a novel cost model that considers functional relationship between the expected degradation reduction and the cost of preventive repairs. The decision model is applied to simulated vibration signals with a variety of specifications of cost values and degradation model parameters. This study has initiated a new area for the research of cost effective maintenance strategies. The results clearly indicate the significance of the proposed model and the decision variables under the objective of minimal cost. For instance, the results indicate direct relationship between the optimal length of monitoring interval and the monitoring cost. However, longer monitoring interval increases the risk of failure, and therefore, more degradation reduction is needed. By increasing the slope of cumulative degradation, the cost effective strategy advocates taking more frequent monitoring. The optimal degradation level after each preventive repair is not so sensitive to the change in the degradation slope due to the uncertainty associated with degradation patterns. - Highlights: • Discuss the relationship of degradation reduction and maintenance cost. • Determine the optimal interval of condition monitoring with minimal cost. • Identify the optimal degradation level after imperfect preventive repairs. • Discuss the effects of change in the slope of cumulative degradation.

Routine maintenance: safety term based work selection; Selecao de trabalho baseado no prazo seguro

Energy Technology Data Exchange (ETDEWEB)

Camargo, Albair de; Filho, Antnio S.; Brendler, Fabiano E.; Adamatti, Gilberto A.; Naruto, Itiro; Araujo, Luiz C.F.; Puerari, Roberto [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2004-07-01

This work has objective to present the experience of improvement of routine maintenance system in some refineries of the PETROBRAS system, with the purpose to increase the efficiency in the Industrial Maintenance Management (cost), Utilization and HSE (Health, Safety and Environment), key of success of a petroleum company. The new system is based on the implantation of the culture of work selection in the safe period, through elaboration of new maintenance procedure, with emphasis in decisions shared between Operation and Maintenance Team, resulting in reduction of emergencies, making possible contract of services of maintenance for packages and improved allocation of resources. This work treat about improvement of the system in use, in view of that it has already taken in consideration the consequence of fail in the maintenance with participation of the operators. Besides of these challenge, this modification was made without causing riots in the process of implantation of SAP. As main result, financial profits had got better of resources with increase of safety, considering that they are analyzed in a way it that systematized potential risks. (author)

Optimal in-feed amino acid ratio for broiler breeder hens based on deletion studies.

Science.gov (United States)

Dorigam, J C P; Sakomura, N K; Sarcinelli, M F; Gonçalves, C A; de Lima, M B; Peruzzi, N J

2017-12-01

An ideal amino acid ratio (IAAR) for breeder hens is needed for maximum nitrogen retention (NR) taking into account nitrogen deposition in body (ND B ), feathers (ND F ) and egg mass (NEM) to improve dietary protein efficiency. Thus, the aim of this study was to apply the deletion method to derive the IAAR for broiler breeder hens. The nitrogen balance trials were performed from 31 to 35 weeks and from 46 to 50 weeks. Twelve treatments with eight replicates and one hen per cage were used. A balanced diet (BD) was formulated to meet the requirement of all nutrients. The other diets were formulated diluting 55% of BD with corn starch and refilled with amino acids (AAs) and other ingredients, except the AA tested. Each trial lasted 25 days. Feather losses, egg production and egg weight were recorded daily, and the samples were stored to further determine NEM and nitrogen in feather losses (ND FL ). At the start and the end of each period, a group of birds were slaughtered to further determine ND B and ND F . The NR was calculated as the sum of ND B , ND F , ND FL , NEM and the nitrogen maintenance requirement (NMR). The deletion of valine greatly depressed the NR in peak production (31 to 35 weeks) while the deletion of the isoleucine greatly depressed the NR of the hens from 46 to 50 weeks of age. The percentual reduction in NR and the per cent of the AA to delete from the BD were used to calculate the AA requirement. The average IAAR was Lys 100, Met+Cys 86, Trp 23, Thr 80, Arg 113, Val 90, Ile 91, Leu 133, Phe+Tyr 108, Gly+Ser 94 and His 35. The IAAR was in line with the recommendation from the literature, validating deletion method with the advantages from a rapid and low-cost procedure. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

A reliability-based preventive maintenance methodology for the projection spot welding machine

Directory of Open Access Journals (Sweden)

Fayzimatov Ulugbek

2018-06-01

Full Text Available An effective operations of a projection spot welding (PSW machine is closely related to the effec-tiveness of the maintenance. Timely maintenance can prevent failures and improve reliability and maintainability of the machine. Therefore, establishing the maintenance frequency for the welding machine is one of the most important tasks for plant engineers. In this regard, reliability analysis of the welding machine can be used to establish preventive maintenance intervals (PMI and to identify the critical parts of the system. In this reliability and maintainability study, analysis of the PSW machine was carried out. The failure and repair data for analysis were obtained from automobile manufacturing company located in Uzbekistan. The machine was divided into three main sub-systems: electrical, pneumatic and hydraulic. Different distributions functions for all sub-systems was tested and their parameters tabulated. Based on estimated parameters of the analyzed distribu-tions, PMI for the PSW machines sub-systems at different reliability levels was calculated. Finally, preventive measures for enhancing the reliability of the PSW machine sub-systems are suggested.

Imperfect Preventive Maintenance Model Study Based On Reliability Limitation

Directory of Open Access Journals (Sweden)

Zhou Qian

2016-01-01

Full Text Available Effective maintenance is crucial for equipment performance in industry. Imperfect maintenance conform to actual failure process. Taking the dynamic preventive maintenance cost into account, the preventive maintenance model was constructed by using age reduction factor. The model regards the minimization of repair cost rate as final target. It use allowed smallest reliability as the replacement condition. Equipment life was assumed to follow two parameters Weibull distribution since it was one of the most commonly adopted distributions to fit cumulative failure problems. Eventually the example verifies the rationality and benefits of the model.

Threonine and lysine requirements for maintenance in chickens ...

African Journals Online (AJOL)

The maintenance requirement for threonine and lysine were estimated in two different experiments by measuring the nitrogen balance of adult male cockerels. Measured amounts of a diet first-limiting in threonine or lysine were fed by intubation each day for 4 d to give a range of intakes (unbalanced series) of from 0 to 239 ...

Balanced Civilization Map Generation based on Open Data

DEFF Research Database (Denmark)

Barros, Gabriella; Togelius, Julian

2015-01-01

This work investigates how to incorporate real-world data into game content so that the content is playable and enjoyable while not misrepresenting the data. We propose a method for generating balanced Civilization maps based on Open Data, describing how to acquire, transform and integrate...

Maternal and fetal Acid-base chemistry: a major determinant of perinatal outcome.

Science.gov (United States)

Omo-Aghoja, L

2014-01-01

Very small changes in pH may significantly affect the function of various fetal organ systems, such as the central nervous system, and the cardiovascular system with associated fetal distress and poor Apgar score. Review of existing data on maternal-fetal acid-base balance in pregnancy highlight the factors that are associated with derangements of the acid-base status and the impact of the derangements on fetal outcome. Extensive search of electronic databases and manual search of journals for relevant literature on maternal and fetal acid chemistry, clinical studies and case studies were undertaken. There is a substantial reduction in the partial pressure of carbon dioxide (pCO2) in pregnancy. Adequate buffering prevents significant changes in maternal arterial pH. Normal fetal metabolism results in the production of acids which are buffered to maintain extracellular pH within a critical range. Fetal hypoxia can occur when maternal oxygenation is compromised, maternal perfusion of the placenta is reduced, or delivery of oxygenated blood from the placenta to the fetus is impeded. When adequate fetal oxygenation does not occur, metabolisms proceed along with an anaerobic pathway with production of organic acids, such as lactic acid. Accumulation of lactic acid can deplete the buffer system and result in metabolic acidosis with associated low fetal pH, fetal distress and poor Apgar score. There is a significant reduction in pCO2 in pregnancy. This change, however, does not result in a corresponding significant reduction in maternal arterial pH, because of adequate buffering. Very small changes in pH may cause significant derangement in fetal function and outcome.

Lean Maintenance Applied to Improve Maintenance Efficiency in Thermoelectric Power Plants

Directory of Open Access Journals (Sweden)

Orlando Duran

2017-10-01

Full Text Available Thermoelectric power plants consist of a set of critical equipment that require high levels of availability and reliability. Due to this, maintenance of these physical assets is gaining momentum in industry. Maintenance is considered as an activity that contributes to improving the availability, efficiency and productivity of each piece of equipment. Several techniques have been used to achieve greater efficiencies in maintenance, among which we can find the lean maintenance philosophy. Despite the wide diffusion of lean maintenance, there is no structured method that supports the prescription of lean tools applied to the maintenance function. This paper presents the experience gathered in two lean maintenance projects in thermoelectric power plants. The application of lean techniques was based on using a previously developed multicriterial decision making process that uses the Fuzzy Analytic Hierarchy Process (AHP methodology to carry out a diagnosis and prescription tasks. That methodology allowed the prescription of the appropriated lean techniques to resolve the main deficiencies in maintenance function. The results of applying such lean tools show that important results can be obtained, making the maintenance function in thermoelectric power plants more efficient and lean.

MOVES: A knowledge-based system for maintenance planning for motor-operated valves

International Nuclear Information System (INIS)

Winter, M.

1987-01-01

Over the past several years, knowledge-based expert systems have emerged as an important part of the general research area known as artificial intelligence. This paper describes a cooperative effort between faculty members at Iowa State University and engineers at the Duane Arnold Energy Center [a 545-MW(electric) boiling water reactor operated by Iowa Electric Light and Power Company] to explore the development of an advisory system for valve maintenance planning. This knowledge-based program, known as Motor-Operated Valves Expert System (MOVES), has a data base that currently includes safety-related motor-operated valves (∼117 valves). Valve maintenance was selected as the subject for the expert system because of the importance of valves in nuclear plant and their impact of plant availability. MOVES is being developed using the microcomputer-(IBM compatible) based expert system tool INSIGHT2+. The authors have found that the project benefits both the university and the utility

A probabilistic maintenance model for diesel engines

Science.gov (United States)

Pathirana, Shan; Abeygunawardane, Saranga Kumudu

2018-02-01

In this paper, a probabilistic maintenance model is developed for inspection based preventive maintenance of diesel engines based on the practical model concepts discussed in the literature. Developed model is solved using real data obtained from inspection and maintenance histories of diesel engines and experts' views. Reliability indices and costs were calculated for the present maintenance policy of diesel engines. A sensitivity analysis is conducted to observe the effect of inspection based preventive maintenance on the life cycle cost of diesel engines.

Genetic algorithm-based optimization of testing and maintenance under uncertain unavailability and cost estimation: A survey of strategies for harmonizing evolution and accuracy

International Nuclear Information System (INIS)

Villanueva, J.F.; Sanchez, A.I.; Carlos, S.; Martorell, S.

2008-01-01

This paper presents the results of a survey to show the applicability of an approach based on a combination of distribution-free tolerance interval and genetic algorithms for testing and maintenance optimization of safety-related systems based on unavailability and cost estimation acting as uncertain decision criteria. Several strategies have been checked using a combination of Monte Carlo (simulation)--genetic algorithm (search-evolution). Tolerance intervals for the unavailability and cost estimation are obtained to be used by the genetic algorithms. Both single- and multiple-objective genetic algorithms are used. In general, it is shown that the approach is a robust, fast and powerful tool that performs very favorably in the face of noise in the output (i.e. uncertainty) and it is able to find the optimum over a complicated, high-dimensional nonlinear space in a tiny fraction of the time required for enumeration of the decision space. This approach reduces the computational effort by means of providing appropriate balance between accuracy of simulation and evolution; however, negative effects are also shown when a not well-balanced accuracy-evolution couple is used, which can be avoided or mitigated with the use of a single-objective genetic algorithm or the use of a multiple-objective genetic algorithm with additional statistical information

Effect of Wii-based balance training on corticomotor excitability post stroke.

Science.gov (United States)

Omiyale, Oluwabunmi; Crowell, Charles R; Madhavan, Sangeetha

2015-01-01

The objective was to examine the effectiveness of a 3-week balance training program using the Nintendo Wii Fit gaming system (Nintendo Wii Sports, Nintendo, Redmond, WA) on lower limb corticomotor excitability and other clinical measures in chronic stroke survivors. Ten individuals diagnosed with ischemic stroke with residual hemiparesis received balance training using the Wii Fit for 60 min/day, three times/week, for three weeks. At the end of training, an increase in interhemispheric symmetry of corticomotor excitability of the tibialis anterior muscle representations was noted (n = 9). Participants also showed improvements in reaction time, time to perform the Dual Timed-Up-and-Go test, and balance confidence. The training-induced balance in corticomotor excitability suggests that this Wii-based balance training paradigm has the potential to influence neural plasticity and thereby functional recovery.

Experimental study on the plant state estimation for the condition-based maintenance

International Nuclear Information System (INIS)

Harada, J. I.; Takahashi, M.; Kitamura, M.; Wakabayashi, T.

2006-01-01

A framework of maintenance support system based on the plant state estimation using diverse methods has been proposed and the validity of the plant state estimation methods has been experimentally evaluated. The focus has been set on the construction of the BN for the objective system with the scale and complexity as same as real world systems. Another focus has been set on the other functions for maintenance support system such as signal processing tool and similarity matching. The validity of the proposed inference method has been confirmed through numerical experiments. (authors)

Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

Energy Technology Data Exchange (ETDEWEB)

Najjar, B [ER Konsult Utveckling AB, Vaexjoe (Sweden)

1999-12-31

The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

Integrated vibration-based maintenance: an approach for continuous reduction in LCC. A case study

Energy Technology Data Exchange (ETDEWEB)

Najjar, B. [ER Konsult Utveckling AB, Vaexjoe (Sweden)

1998-12-31

The biggest thread in achieving and maintaining high equipment effectiveness can be stated as: whether the improved manufacturing processes capable of producing quality products at a competitive cost. The effect of a new vibration-based maintenance concept, called Total Quality Maintenance (TQMain), is introduced. It aims to make intensive use of the real-time data acquisition and analysis to detect causes behind product quality deviation and failures in machinery, and following defect development at an early stage to increase machine mean effective life and improve company`s economics. The effect of TQMain on LCC of machinery and company`s economics is discussed. A case study to reveal savings in maintenance cost when a vibration-based policy involved, is presented. Using TQMain, company`s economics can be improved effectively through continuous improvement of the technical and economic effectiveness of production processes. (orig.) 14 refs.

The effect of a supervised community-based exercise program on balance, balance confidence, and gait in individuals with lower limb amputation.

Science.gov (United States)

Miller, Carol A; Williams, Jennifer E; Durham, Katey L; Hom, Selena C; Smith, Julie L

2017-10-01

Many individuals with lower limb loss report concern with walking ability after completing structured traditional rehabilitation. The purpose of this study was to explore the impact of a supervised community-based exercise program on balance, balance confidence, and gait in individuals with lower limb amputation. Repeated measures. The supervised exercise program was offered biweekly for 6 weeks. The GAITRite System by CIR Systems, Inc., the Figure-of-8 Walk Test, and Activity-specific Balance Confidence Scale were used to measure clinical outcomes pre- and post-intervention. In total, 16 participants with lower limb amputation (mean age: 50.8 years) completed the study. A multivariate, repeated measures analysis of variance indicated a statistically significant effect of training across six clinical outcome measures ( F(6, 10) = 4.514, p = .018). Moderate effect sizes were found for the Figure-of-8 Walk Test ( η 2 = .586), Activity-specific Balance Confidence Scale ( η 2 = .504), and gait velocity at comfortable walking speed ( η 2 = .574). The average increase in gait speed was clinically meaningful at .14 m/s. The supervised community-based exercise program implemented in this study was designed to address specific functional needs for individuals with lower limb loss. Each participant experienced clinically meaningful improvements in balance, balance confidence, and walking ability. Clinical relevance The provision of a supervised community-based exercise program, after traditional rehabilitation, provides opportunity to offer a continuum of care that may enhance prosthetic functional ability and active participation in the community for individuals with lower limb amputation.

The influence of Pilates exercises on body balance in the standing position of hearing impaired people.

Science.gov (United States)

Walowska, Jagoda; Bolach, Bartosz; Bolach, Eugeniusz

2017-11-13

Hearing impairment may affect the body posture maintenance. The aim of the study was to evaluate the effect of modified Pilates exercise program on the body posture maintenance in hearing impaired people. Eighty students (aged 13-24) were enrolled and randomly allocated into two groups: test group (n = 41) which attended an original program based on modified Pilates exercises and control group (n = 39) which attended standard physical education classes. Stabilographic tests were conducted at baseline and after 6-week training program. Both groups showed improved control of body balance in a standing position manifested in reductions of the length of path, surface area, and speed of deflection. Modified Pilates program was significantly more effective in improving body balance control in relaxed posture and with feet together than standard physical education classes. The greater efficiency of the modified Pilates program was expressed in a significant improvement in balance control parameters, i.e., path length, surface area, and speed of deflection. The modified Pilates program was more effective in improving body balance control in the hearing impaired people than standard physical education classes. Modification of physical activity recommendations for hearing impaired students may be considered; however, further research is required. Implications for Rehabilitation Hearing impairment impacts the mental, social and, physical spheres of life as well as deteriorates equivalent reactions and the way body posture is maintained. In hearing impaired people, control of body balance and muscle coordination is often disturbed, thus more attention should be paid to exercises associated with balance which may improve the ability to learn and develop motor skills. Modified Pilates program was significantly more effective in improving body balance control than standard physical education classes in hearing impaired people.

Systematic maintenance analysis with decision support method and tool for optimizing maintenance programme

International Nuclear Information System (INIS)

Laakso, K.; Simola, K.; Dorrepaal, J.; Skogberg, P.

1999-01-01

This report describes an approach to evaluate the effectiveness of test and maintenance programs of technical systems used during several years. The method combines an analysis of the historical data on faults and repairs with an analysis of the history of periodic testing and preventive maintenance action programs. The application of the maintenance analysis from the methodological point of view in the reliability centered maintenance (RCM) project for Barsebaeck nuclear power plant is described. In order to limit the analysis resources, a method for ranking of objects for maintenance analysis is needed. Preliminary suggestions for changes in maintenance action programs are based on signals from simple maintenance indicators and qualitative analysis of underlying data on failures and maintenance. To facilitate generation of maintenance indicators, and make the maintenance analysis more efficient, a powerful and suitable data treatment tool is needed for analysis of the work order history. In the final maintenance decisions, additional decision criteria must be taken into account, and thus a more formal decision analysis is often needed for decision support. (au)

Good practices for effective maintenance to manage aging at NPPs

International Nuclear Information System (INIS)

Scott, W.B.; Enderlin, W.I.; Levy, I.S.

1989-01-01

The Nuclear Regulatory Commission's Office of Nuclear Regulatory Research is sponsoring this effort to study maintenance as it relates to aging, under the Nuclear Plant Aging Research (NPAR). Maintenance is the primary means of combating and correcting the effects of aging degradation at nuclear power plants. Maintenance effectiveness directly affects the safety of nuclear power plants. Several recent plant events have shown that improper maintenance or a lack of maintenance can be a significant contributory cause of plant incidents (e.g., transients at Rancho Seco and Davis Besse, and the Salem anticipated transient without scram event). In these, and other events, safety related plant equipment functions have been impaired by poor maintenance practices or a lack of maintenance on the specific equipment or in ancillary equipment that affects the ability of the safety related equipment to function. In some cases, the ancillary equipment has been nonsafety-related equipment, or balance-of-plant equipment that has not received adequate maintenance attention. In addition to the potential for causing safety significant plant transients, poor or lacking maintenance may allow the licensing basis of the plant to be eroded without detection. In some cases, time-related aging degradation of equipment that has not been detected, corrected or managed by the maintenance program has been a significant contributory factor. The NPAR program has developed significant information on aging degradation, detection, mitigation, and correction practices for safety-significant structures, systems and components that can be factored into maintenance programs and their effectiveness

The serum anion gap in the evaluation of acid-base disorders: what are its limitations and can its effectiveness be improved?

Science.gov (United States)

Kraut, Jeffrey A; Nagami, Glenn T

2013-11-01

The serum anion gap has been utilized to identify errors in the measurement of electrolytes, to detect paraproteins, and, most relevant to the nephrologist, to evaluate patients with suspected acid-base disorders. In regard to the latter purpose, traditionally an increased anion gap is identified when it exceeds the upper limit of normal for a particular clinical laboratory measurement. However, because there is a wide range of normal values (often 8-10 mEq/L), an increase in anion concentration can be present in the absence of an increased anion gap. In addition, the type of retained anion can affect the magnitude of the increase in anion gap relative to change in serum [HCO3(-)] being greater with lactic acidosis compared with ketoacidosis. This review examines the methods of calculation of the serum anion gap in textbooks and published literature, the effect of perturbations other than changes in acid-base balance, and its effectiveness in identifying mild and more severe disturbances in acid-base balance. Limitations of the present methods of determining the normal anion gap and change in the anion gap are highlighted. The possibility of identifying the baseline value for individuals to optimize the use of the calculation in the detection of metabolic acidosis is suggested.

The correct use and maintenance of electronic balance%电子天平的正确使用与维护保养探究

Institute of Scientific and Technical Information of China (English)

姜润洲

2015-01-01

电子天平在日常生活中的使用愈发频繁，它是根据电磁力平衡原理制作而成。因此，可以直接进行称量，不需要像传统称一样添加砝码，这也是其受到欢迎的重要原因之一。将物体放置在称上之后，几秒钟之内便可以得出称量结果。本文主要是分析电子天平的正确使用方法，对当中需要注意的事项进行阐述，同时为了能够更好地发挥电子天平的效用，本文也对其日常地维护与保养工作进行了探究。%The electronic balance in daily life use more frequently,it is according to the electromagnetic force balance principle manufacture and become.Therefore,it can be directly weighed,without the need to add weight as the traditional,which is one of the important reasons for the important.After the object is placed in a number of seconds,the results can be obtained within seconds..The main purpose of this paper is analysis of the right to use the electronic balance,to need to pay attention to matters is expounded, also in order to better develop the effect of electronic balance,this paper also on the daily maintenance work of inquiry.

Complexity in Acid?Base Titrations: Multimer Formation Between Phosphoric Acids and Imines

OpenAIRE

Malm, Christian; Kim, Heejae; Wagner, Manfred; Hunger, Johannes

2017-01-01

Abstract Solutions of Br?nsted acids with bases in aprotic solvents are not only common model systems to study the fundamentals of proton transfer pathways but are also highly relevant to Br?nsted acid catalysis. Despite their importance the light nature of the proton makes characterization of acid?base aggregates challenging. Here, we track such acid?base interactions over a broad range of relative compositions between diphenyl phosphoric acid and the base quinaldine in dichloromethane, by u...

Maintenance-based prognostics of nuclear plant equipment for long-term operation

Energy Technology Data Exchange (ETDEWEB)

Welz, Zachary; Coble, Jamie; Upadhyaya, Belle; Hines, Wes [University of Tennessee, Knoxville (United States)

2017-08-15

While industry understands the importance of keeping equipment operational and well maintained, the importance of tracking maintenance information in reliability models is often overlooked. Prognostic models can be used to predict the failure times of critical equipment, but more often than not, these models assume that all maintenance actions are the same or do not consider maintenance at all. This study investigates the influence of integrating maintenance information on prognostic model prediction accuracy. By incorporating maintenance information to develop maintenance-dependent prognostic models, prediction accuracy was improved by more than 40% compared with traditional maintenance-independent models. This study acts as a proof of concept, showing the importance of utilizing maintenance information in modern prognostics for industrial equipment.

Basic Concept and Theoretical Study of Condition-based Maintenance for Power Transmission System

Institute of Scientific and Technical Information of China (English)

LIMing; HAN Xueshan; YANG Ming; GUO Zhihong

2011-01-01

The appropriate maintenance time for the single equipment can be found easily and efficiently under the background of condition-based maintenance. However, from the perspective of the whole power system, discrepancy between equipment individual and the whole power system would appear. Once this discrepancy can not be coordinated, it will certainly cause contradiction and conflict between individual equipment and the whole system, and lose the integral efficiency. To solve this contradiction and conflicts is of significant meaning.

Automotive Maintenance Data Base for Model Years 1976-1979. Part I

Science.gov (United States)

1980-12-01

An update of the existing data base was developed to include life cycle maintenance costs of representative vehicles for the model years 1976-1979. Repair costs as a function of time are also developed for a passenger car in each of the compact, subc...

Maintenance strategies and safety on a deregulated market. Mapping of changes in maintenance strategies and their possible consequences

International Nuclear Information System (INIS)

Kecklund, Lena

2004-11-01

, computer based methods. The difficulties of risk based methods are several: they might not correspond with reality, they might not measure what they are intended to measure and it might be that the probabilistic risk assessment approach is allowed to dominate over the deterministic at the expense of a good balance between them. There is also a risk that the methods are not enough developed, that the knowledge of how the results should be interpreted is limited and that this might lead to the wrong conclusions. With tighter priorities there is an increasing risk that the wrong things are left out. The feeling of 'ownership' towards a certain production unit as well as the team feeling might disappear when the employees work on several units. Deficiencies in the maintenance instructions become evident when the staff are transferred. If the work routines have not been thoroughly documented there is a risk that the staff make mistakes or that the measures are forgotten. A number of conditions have been identified that might influenced the reactor safety negatively in the long term if they are not taken care of. Such conditions are an increased pressure on the staff, high work load and too much overtime, uncertainties as to responsibility and roles, lack of job satisfaction and motivation and deficient maintenance instructions. Economic pressure and a high rate of change might also give negative influence. It is, however, important to stress that the results indicate that the changes are not carried out with a one-sided focus on cost reductions but with a focus on both individual and organisational learning and development. Safety culture has also been an important part of the change operations. It seems, though, as if it has been more difficult to balance the economy and safety messages to the staff

Reliability-Based Planning of Inspection, Operation and Maintenance for Offshore Oil & Gas Structures and Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2011-01-01

Reliability-based cost-optimal planning of inspection, maintenance and operation has many applications. In this paper applications for planning of inspections for oil & gas jacket structures and of operation and maintenance of offshore wind turbines are described and illustrated by examples....

Optimizing preventive maintenance

International Nuclear Information System (INIS)

DiCola, F.E.

1988-01-01

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

Effect of acute acid loading on acid-base and calcium metabolism

DEFF Research Database (Denmark)

Osther, Palle J

2006-01-01

OBJECTIVE: To investigate the acid-base and calcium metabolic responses to acute non-carbonic acid loading in idiopathic calcium stone-formers and healthy males using a quantitative organ physiological approach. MATERIAL AND METHODS: Five-h ammonium chloride loading studies were performed in 12...... male recurrent idiopathic calcium stone-formers and 12 matched healthy men using a randomized, placebo-controlled, cross-over design. Arterialized capillary blood, serum and urine were collected hourly for measurement of electrolytes, ionized calcium, magnesium, phosphate, parathyroid hormone and acid-base...... status. Concentrations of non-metabolizable base (NB) and acid (NA) were calculated from measured concentrations of non-metabolizable ions. RESULTS: The extracellular acid-base status in the stone-formers during basal conditions and acid loading was comparable to the levels in the healthy controls...

CANDU plant maintenance: Recent developments

International Nuclear Information System (INIS)

Charlebois, P.

2000-01-01

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

Utility based maintenance analysis using a Random Sign censoring model

International Nuclear Information System (INIS)

Andres Christen, J.; Ruggeri, Fabrizio; Villa, Enrique

2011-01-01

Industrial systems subject to failures are usually inspected when there are evident signs of an imminent failure. Maintenance is therefore performed at a random time, somehow dependent on the failure mechanism. A competing risk model, namely a Random Sign model, is considered to relate failure and maintenance times. We propose a novel Bayesian analysis of the model and apply it to actual data from a water pump in an oil refinery. The design of an optimal maintenance policy is then discussed under a formal decision theoretic approach, analyzing the goodness of the current maintenance policy and making decisions about the optimal maintenance time.

Condition-based maintenance effectiveness for series–parallel power generation system—A combined Markovian simulation model

International Nuclear Information System (INIS)

Azadeh, A.; Asadzadeh, S.M.; Salehi, N.; Firoozi, M.

2015-01-01

Condition-based maintenance (CBM) is an increasingly applicable policy in the competitive marketplace as a means of improving equipment reliability and efficiency. Not only has maintenance a close relationship with safety but its costs also make it even more attractive issue for researchers. This study proposes a model to evaluate the effectiveness of CBM policy compared to two other maintenance policies: Corrective Maintenance (CM) and Preventive Maintenance (PM). Maintenance policies are compared through two system performance indicators: reliability and cost. To estimate the reliability and costs of the system, the proposed Markovian discrete-event simulation model is developed under each of these policies. The applicability and usefulness of the proposed Markovian simulation model is illustrated for a series–parallel power generation system. The simulated characteristics of CBM system include its prognostics efficiency to estimate remaining useful life of the equipment. Results show that with an efficient prognostics, CBM policy is an effective strategy compared to other maintenance strategies. - Highlights: • A model is developed to evaluate the effectiveness of CBM policy. • Maintenance policies are compared through reliability and cost. • A Markovian simulation model is developed. • A series–parallel power generation system is considered. • CBM is an effective strategy compared to others

Optimization of surface maintenance

International Nuclear Information System (INIS)

Oeverland, E.

1990-01-01

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

Framework for Risk-based Planning of Operation and Maintenance for Offshore Wind Turbines

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

2009-01-01

, and to sequential optimal decision making on planning of OM taking into account new information. Deterioration mechanisms such as fatigue, corrosion, wear and erosion are associated with significant uncertainty. Observations of the degree of damage can increase the reliability of predictions, especially......For offshore wind turbines, costs to operation and maintenance (OM) are substantial. This paper describes a risk-based life cycle approach for optimal planning of OM. The approach is based on pre-posterior Bayesian decision theory, and can be used both to overall, initial planning of OM...... in connection with condition-based maintenance. The approach can be used for gearboxes, generators, fatigue cracks, corrosion, etc. This paper also describes how probabilistic indicators can be used to quantify indirect information about the damage state for critical components, e.g. gearboxes....

BIM authoring for an image-based bridge maintenance system of existing cable-supported bridges

Science.gov (United States)

Dang, N. S.; Shim, C. S.

2018-04-01

Infrastructure nowadays is increasingly become the main backbone for the metropolitan development in general. Along with the rise of new facilities, the demand in term of maintenance for the existing bridges is indispensable. Recently, the terminology of “preventive maintenance” is not unfamiliar with the engineer, literally is the use of a bridge maintenance system (BMS) based on a BIM-oriented model. In this paper, the process of generating a BMS based on BIM model is introduced in detail. Data management for this BMS is separated into two modules: site inspection system and information management system. The noteworthy aspect of this model lays on the closed and automatic process of “capture image, generate the technical damage report, and upload/feedback to the BMS” in real-time. A pilot BMS system for a cable-supported bridge is presented which showed a good performance and potential to further development of preventive maintenance.

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

International Nuclear Information System (INIS)

Jessen Nielsen, Jannie; Dalsgaard Sorensen, John

2011-01-01

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

Incidence of Postoperative Acid-Base Disturbances in Abdominal Surgery

Directory of Open Access Journals (Sweden)

Taghavi Gilani M

2014-04-01

Full Text Available Introduction: Respiratory and blood pressure changes as well as fluid administration alter the acid-base balance during the perioperative period which may cause consciousness disturbance and additional hemodynamic disorders. The aim of this study was to identify frequent postoperative acid-base disturbances in order to control postoperative complications. Materials and Methods:This prospective, observational study design was used on patients who underwent abdominal surgery during a six-month period. Gasometry was performed immediately after the patients’ admittion to ICU and six and 12 hours postoperatively. SPSS v13 software was used, and PResults: 213 patients (123 male and 90 female aged 14-85 years (51.7± 22.4 were evaluated. During admission, PH and PaCO2 were (7.29±0.13 and (38.3±11.9, respectively; however, although PH increased gradually (P=0.001, PaCO2 was reduced (P=0.03. Bicarbonate and base excess had opposite effects; bicarbonate initially decreased but increased after 12 hours (P=0.001, whereas base excess initially increased (-6.3±11.6 and then decreased gradually (P=0.003. The arterial oxygen pressure was reduced for 22.5% of the patients throughout the admission period, and this did not significantly change (P=0.57. Conclusion: According to the results, in admission, 65.7% had metabolic acidosis, but metabolic alkalosis was the least. Gradually, metabolic acidosis was modified, but metabolic alkalosis increased. Intraoperative hypotension and fluid infusion may be the main factors of early metabolic acidosis and control of hypotension, or correction of acidosis may increase metabolic alkalosis.