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Sample records for failure analysis 8-11

  1. Failure to thrive as presentation in a patient with 22q11.2 microdeletion.

    Science.gov (United States)

    Bossi, Grazia; Gertosio, Chiara; Meazza, Cristina; Farello, Giovanni; Bozzola, Mauro

    2016-02-11

    Abnormalities of chromosome 22q11, including deletions and translocations, have been described in association with different birth defects and malformations occurring in many combinations and degrees of severity. We describe the case of an 8 month-old infant with no dysmorphic signs who showed progressive postnatal growth failure and no chronic systemic diseases. We found a 22q11.2 microdeletion, inherited from the mother, suggesting the diagnosis of DiGeorge syndrome. The patient had an isolated growth hormone (GH) deficiency and a significant increase in linear growth during the first and the second year of GH therapy, and a recovery of weight was shown. Sometimes, in infants with growth failure a genetic analysis is strongly suggested, since chromosomal abnormalities may be present.

  2. [Examination of safety improvement by failure record analysis that uses reliability engineering].

    Science.gov (United States)

    Kato, Kyoichi; Sato, Hisaya; Abe, Yoshihisa; Ishimori, Yoshiyuki; Hirano, Hiroshi; Higashimura, Kyoji; Amauchi, Hiroshi; Yanakita, Takashi; Kikuchi, Kei; Nakazawa, Yasuo

    2010-08-20

    How the maintenance checks of the medical treatment system, including start of work check and the ending check, was effective for preventive maintenance and the safety improvement was verified. In this research, date on the failure of devices in multiple facilities was collected, and the data of the trouble repair record was analyzed by the technique of reliability engineering. An analysis of data on the system (8 general systems, 6 Angio systems, 11 CT systems, 8 MRI systems, 8 RI systems, and the radiation therapy system 9) used in eight hospitals was performed. The data collection period assumed nine months from April to December 2008. Seven items were analyzed. (1) Mean time between failures (MTBF) (2) Mean time to repair (MTTR) (3) Mean down time (MDT) (4) Number found by check in morning (5) Failure generation time according to modality. The classification of the breakdowns per device, the incidence, and the tendency could be understood by introducing reliability engineering. Analysis, evaluation, and feedback on the failure generation history are useful to keep downtime to a minimum and to ensure safety.

  3. [11C]Choline PET/CT predicts survival in hormone-naive prostate cancer patients with biochemical failure after radical prostatectomy

    International Nuclear Information System (INIS)

    Giovacchini, Giampiero; Incerti, Elena; Mapelli, Paola; Gianolli, Luigi; Picchio, Maria; Kirienko, Margarita; Briganti, Alberto; Gandaglia, Giorgio; Montorsi, Francesco

    2015-01-01

    Over the last decade, PET/CT with radiolabelled choline has been shown to be useful for restaging patients with prostate cancer (PCa) who develop biochemical failure. The limitations of most clinical studies have been poor validation of [ 11 C]choline PET/CT-positive findings and lack of survival analysis. The aim of this study was to assess whether [ 11 C]choline PET/CT can predict survival in hormone-naive PCa patients with biochemical failure. This retrospective study included 302 hormone-naive PCa patients treated with radical prostatectomy who underwent [ 11 C]choline PET/CT from 1 December 2004 to 31 July 2007 because of biochemical failure (prostate-specific antigen, PSA, >0.2 ng/mL). Median PSA was 1.02 ng/mL. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathological variables and PCa-specific survival. The coefficients of the covariates included in the Cox regression analysis were used to develop a novel nomogram. Median follow-up was 7.2 years (1.4 - 18.9 years). [ 11 C]Choline PET/CT was positive in 101 of 302 patients (33 %). Median PCa-specific survival after prostatectomy was 14.9 years (95 % CI 9.7 - 20.1 years) in patients with positive [ 11 C]choline PET/CT. Median survival was not achieved in patients with negative [ 11 C]choline PET/CT. The 15-year PCa-specific survival probability was 42.4 % (95 % CI 31.7 - 53.1 %) in patients with positive [ 11 C]choline PET/CT and 95.5 % (95 % CI 93.5 - 97.5 %) in patients with negative [ 11 C]choline PET/CT. In multivariate analysis, [ 11 C]choline PET/CT (hazard ratio 6.36, 95 % CI 2.14 - 18.94, P < 0.001) and Gleason score >7 (hazard ratio 3.11, 95 % CI 1.11 - 8.66, P = 0.030) predicted PCa-specific survival. An internally validated nomogram predicted 15-year PCa-specific survival probability with an accuracy of 80 %. Positive [ 11 C]choline PET/CT after biochemical failure predicts PCa-specific survival in hormone

  4. [11C]-Acetoacetate PET imaging: a potential early marker for cardiac heart failure

    International Nuclear Information System (INIS)

    Croteau, Etienne; Tremblay, Sébastien; Gascon, Suzanne; Dumulon-Perreault, Véronique; Labbé, Sébastien M.; Rousseau, Jacques A.; Cunnane, Stephen C.; Carpentier, André C.; Bénard, François; Lecomte, Roger

    2014-01-01

    The ketone body acetoacetate could be used as an alternate nutrient for the heart, and it also has the potential to improve cardiac function in an ischemic–reperfusion model or reduce the mitochondrial production of oxidative stress involved in cardiotoxicity. In this study, [ 11 C]-acetoacetate was investigated as an early marker of intracellular damage in heart failure. Methods: A rat cardiotoxicity heart failure model was induced by doxorubicin, Dox(+). [ 14 C]-Acetoacetate, a non-positron (β −) emitting radiotracer, was used to characterize the arterial blood input function and myocardial mitochondrial uptake. Afterward, [ 11 C]-acetoacetate (β +) myocardial PET images were obtained for kinetic analysis and heart function assessment in control Dox(−) (n = 15) and treated Dox(+) (n = 6) rats. The uptake rate (K 1 ) and myocardial clearance rate (k 2 or k mono ) were extracted. Results: [ 14 C]-Acetoacetate in the blood was increased in Dox(+), from 2 min post-injection until the last withdrawal point when the heart was harvested, as well as the uptake in the heart and myocardial mitochondria (unpaired t-test, p < 0.05). PET kinetic analysis of [ 11 C]-acetoacetate showed that rate constants K 1 , k 2 and k mono were decreased in Dox(+) (p < 0.05) combined with a reduction of 24% of the left ventricular ejection fraction (p < 0.001). Conclusion: Radioactive acetoacetate ex vivo analysis [ 14 C], and in vivo kinetic [ 11 C] studies provided evidence that [ 11 C]-acetoacetate can assess heart failure Dox(+). Contrary to myocardial flow reserve (rest–stress protocol), [ 11 C]-acetoacetate can be used to assess reduced kinetic rate constants without requirement of hyperemic stress response. The proposed [ 11 C]-acetoacetate cardiac radiotracer in the investigation of heart disease is novel and paves the way to a potential role for [ 11 C]-acetoacetate in cardiac pathophysiology

  5. NuSTAR spectral analysis of two bright Seyfert 1 galaxies: MCG +8-11-11 and NGC 6814

    Science.gov (United States)

    Tortosa, A.; Bianchi, S.; Marinucci, A.; Matt, G.; Middei, R.; Piconcelli, E.; Brenneman, L. W.; Cappi, M.; Dadina, M.; De Rosa, A.; Petrucci, P. O.; Ursini, F.; Walton, D. J.

    2018-01-01

    We report on the NuSTAR observations of two bright Seyfert 1 galaxies, namely MCG +8-11-11 (100 ks) and NGC 6814 (150 ks). The main goal of these observations was to investigate the Comptonization mechanisms acting in the innermost regions of an active galactic nucleus (AGN) which are believed to be responsible for the UV/X-ray emission. The spectroscopic analysis of the NuSTAR spectra of these two sources revealed that although they had different properties overall (black hole masses, luminosity and Eddington ratios), they had very similar coronal properties. Both presented a power-law spectrum with a high-energy cut-off at ∼150-200 keV, a relativistically broadened Fe K α line and the associated disc reflection component, plus a narrow iron line likely emitted in Compton thin and distant matter. The intrinsic continuum was well described by Comptonization models that show for MCG +8-11-11 a temperature of the coronal plasma of kTe ∼ 60 keV and an extrapolated optical depth τ = 1.8; for NGC 6814, the coronal temperature was kTe ∼ 45 keV with an extrapolated optical depth of τ = 2.5. We compare and discuss these values to some most common Comptonization models that aim at explaining the energy production and stability of coronae in AGNs.

  6. Reduced myocardial carbon-11 hydroxyephedrine retention is associated with poor prognosis in chronic heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Pietilae, M.; Ukkonen, H. [Dept. of Medicine, Turku University Central Hospital (Finland); Turku PET Centre, Turku (Finland); Malminiemi, K. [Dept. of Clinical Chemistry, Tampere University Hospital (Finland); Saraste, M. [Dept. of Clinical Physiology, Turku University Central Hospital (Finland); Naagren, K.; Lehikoinen, P. [Turku PET Centre, Turku (Finland); Voipio-Pulkki, L.-M. [Dept. of Medicine, Turku University Central Hospital (Finland); Dept. of Medicine, Helsinki University Central Hospital (Finland)

    2001-03-01

    Abnormalities of the autonomic nervous system are known to be of prognostic significance in chronic heart failure (CHF). The prognostic value of positron emission tomography (PET) imaging of cardiac autonomic innervation in CHF has not been explored previously. We retrospectively studied the survival data of 46 NYHA class II-III CHF patients (mean LVEF 35%{+-}8%) who had undergone carbon-11 hydroxyephedrine ({sup 11}C-HED) studies at the Turku PET Centre between August 1992 and March 1996. The origin of CHF was dilated cardiomyopathy in 13 of the 46 patients and coronary artery disease with at least one prior myocardial infarction in the remaining 33. Data on causes of death and heart transplantation were collected, and the statistically significant predictors of prognosis were analysed using Cox's proportional hazards regression. During the mean follow-up period of 55{+-}19 months, 11 deaths occurred and two patients underwent heart transplantation successfully. Eleven end-points were classified as cardiac (nine sudden cardiac deaths and two deaths due to progressive heart failure) and two as non-cardiac. When divided into two groups based on the median of {sup 11}C-HED retention (mean 0.184{+-}0.061, median 0.183), eight end-points (death or cardiac transplantation) were reached in the group with {sup 11}C-HED retention below the median and three in the group with {sup 11}C-HED retention above the median (P<0.02). In proportional hazards regression analysis, only peak oxygen uptake (peak VO{sub 2}), left ventricular end-diastolic volume and HED retention were found to be statistically significant. It is concluded that {sup 11}C-HED PET provides independent prognostic information in patients with CHF. (orig.)

  7. Regulatory analysis for the resolution of generic issue C---8, main steam isolation valve leakage and LCS [leakage control system] failure

    International Nuclear Information System (INIS)

    Graves, C.C.

    1990-06-01

    Generic Issue C-8 deals with staff concerns about public risk because of the incidence of leak test failures reported for main steam isolation valves (MSIVs) at boiling water reactors and the limitations of the leakage control systems (LCSs) for mitigating the consequences of leakage from these valves. If the MSIV leakage is greatly in excess of the allowable value in the technical specifications, the LCS would be unavailable because of design limitations. The issue was initiated in 1983 to assess (1) the causes of MSIV leakage failures, (2) the effectiveness of the LCS and alternative mitigation paths, and (3) the need for additional regulatory action to reduce public risk. This report presents the regulatory analysis for Generic Issue C-8 and concludes that no new regulatory requirements are warranted

  8. 17 CFR 8.11 - Notice of charges.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Notice of charges. 8.11 Section 8.11 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION EXCHANGE PROCEDURES FOR DISCIPLINARY, SUMMARY, AND MEMBERSHIP DENIAL ACTIONS Disciplinary Procedure § 8.11 Notice of...

  9. A patient with familial bone marrow failure and an inversion of chromosome 8.

    Science.gov (United States)

    Buchbinder, David Kyle; Zadeh, Touran; Nugent, Diane

    2011-12-01

    Familial bone marrow failure has been associated with a variety of chromosomal aberrations. Chromosome 8 abnormalities have been described in association with neoplastic and hematologic disorders; however, to our knowledge, inversion of the long arm of chromosome 8 has not been described in the context of familial bone marrow failure. We describe a 9-year-old female with familial bone marrow failure and an inversion of chromosome 8 [inv (8) (q22, q24.3)]. Given the importance of considering the genetic determinants of familial bone marrow failure, the potential role of chromosome 8 abnormalities in the development of marrow failure is discussed.

  10. 11C-methionine PET/CT in 99mTc-sestamibi-negative hyperparathyroidism in patients with renal failure on chronic haemodialysis

    International Nuclear Information System (INIS)

    Rubello, Domenico; Fanti, Stefano; Nanni, Cristina; Farsad, Mohsen; Castellucci, Paolo; Boschi, Stefano; Franchi, Roberto; Mariani, Giuliano; Fig, Lorraine M.; Gross, Milton D.

    2006-01-01

    Scintigraphic localisation of parathyroid glands is often unsuccessful in patients with renal failure on chronic haemodialysis who have secondary hyperparathyroidism (HPT). The purpose of this study was to investigate the use of 11 C-methionine PET/CT to detect hyperfunctioning parathyroid glands in patients with renal failure on chronic haemodialysis who had 99m Tc-sestamibi-negative HPT. 11 C-methionine PET/CT was performed in 18 patients (11 women and 7 men, aged 42-79 years; mean age 57.8 years) on haemodialysis for renal failure (2-14 years' duration), with normo-, hypo- or hypercalcaemia and HPT not localised by either dual-tracer 99m Tc-pertechnetate/ 99m Tc-sestamibi subtraction scans or dual-phase 99m Tc-sestamibi scans. In three of ten patients with normo- or hypocalcaemic HPT there was increased 11 C-methionine accumulation in one gland. Seven of eight patients with hypercalcaemic HPT showed increased uptake: in five of these patients increased 11 C-methionine accumulation was present in one gland, while in two it was demonstrated in two glands. All patients also had high-resolution ultrasound of the neck and were treated with subtotal parathyroidectomy, leaving a remnant of the smallest of the four glands. Regardless of their size, all glands with abnormal 11 C-methionine parathyroid uptake were removed, and all demonstrated parathyroid hyperplasia. All patients developed post-parathyroidectomy hypoparathyroidism and one patient with normocalcaemic HPT relapsed 8 months after surgery. These data suggest that 11 C-methionine PET/CT may be used to identify hyperfunctioning parathyroid glands in non-primary HPT, and especially hypercalcaemic HPT, when conventional 99m Tc-sestamibi imaging is non-localising. (orig.)

  11. 15 CFR 8b.11 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Discrimination prohibited. 8b.11 Section 8b.11 Commerce and Foreign Trade Office of the Secretary of Commerce PROHIBITION OF DISCRIMINATION... Practices § 8b.11 Discrimination prohibited. (a) General. (1) No qualified handicapped individual shall, on...

  12. Reliability measurement for mixed mode failures of 33/11 kilovolt electric power distribution stations.

    Directory of Open Access Journals (Sweden)

    Faris M Alwan

    Full Text Available The reliability of the electrical distribution system is a contemporary research field due to diverse applications of electricity in everyday life and diverse industries. However a few research papers exist in literature. This paper proposes a methodology for assessing the reliability of 33/11 Kilovolt high-power stations based on average time between failures. The objective of this paper is to find the optimal fit for the failure data via time between failures. We determine the parameter estimation for all components of the station. We also estimate the reliability value of each component and the reliability value of the system as a whole. The best fitting distribution for the time between failures is a three parameter Dagum distribution with a scale parameter [Formula: see text] and shape parameters [Formula: see text] and [Formula: see text]. Our analysis reveals that the reliability value decreased by 38.2% in each 30 days. We believe that the current paper is the first to address this issue and its analysis. Thus, the results obtained in this research reflect its originality. We also suggest the practicality of using these results for power systems for both the maintenance of power systems models and preventive maintenance models.

  13. Risk factors of extubation failure in extremely low birth weight infants: a five year retrospective analysis.

    Science.gov (United States)

    Lee, Chao-Yi; Su, Bai-Horng; Lin, Tsung-Wen; Lin, Hung-Chih; Li, Tsai-Chung; Wang, Nai-Phon

    2002-01-01

    Extubation failure is one of the most serious complications in extremely low birth weight infants (ELBWI) on mechanical ventilation therapy. We performed a 5-year retrospective analysis to realize the status of extubation failure in ELBWI. Extubation failure was defined as requirements of re-intubation within 72 hours after extubation. The extubation failure rate was 21% (29/138). The mean birth body weight was 808.3 +/- 140.4 gm. The mean gestational age was 25.8 +/- 1.2 wks. The incidence of chronic lung disease (CLD) in infants with extubation failure was 100% (29/29). Apnea of prematurity 49% (14/29) and post-extubation atelectasis 39% (11/29) were the most common reasons for reintubation. The major microbiology findings which correlated with nosocomial pneumonia in infants with extubation failure were Acinetobacter baumanni (21%), Klebsiella pneumonia (21%), Pseudomonas aeroginosa (14%), and Methicillin resistant staphylococcus aureus (14%). In conclusion, post-extubation atelectasis and apnea were the most common reasons for reintubation. ELBWI with extubation failure had higher incidences of post-extubation atelectasis, CLD, and nosocomial pneumonia. Further prospective studies are needed in order to clarify the appropriate extubation program for ELBWI and to prevent post-extubation atelectasis and nosocomial pneumonia.

  14. Signal analysis for failure detection

    International Nuclear Information System (INIS)

    Parpaglione, M.C.; Perez, L.V.; Rubio, D.A.; Czibener, D.; D'Attellis, C.E.; Brudny, P.I.; Ruzzante, J.E.

    1994-01-01

    Several methods for analysis of acoustic emission signals are presented. They are mainly oriented to detection of changes in noisy signals and characterization of higher amplitude discrete pulses or bursts. The aim was to relate changes and events with failure, crack or wear in materials, being the final goal to obtain automatic means of detecting such changes and/or events. Performance evaluation was made using both simulated and laboratory test signals. The methods being presented are the following: 1. Application of the Hopfield Neural Network (NN) model for classifying faults in pipes and detecting wear of a bearing. 2. Application of the Kohonnen and Back Propagation Neural Network model for the same problem. 3. Application of Kalman filtering to determine time occurrence of bursts. 4. Application of a bank of Kalman filters (KF) for failure detection in pipes. 5. Study of amplitude distribution of signals for detecting changes in their shape. 6. Application of the entropy distance to measure differences between signals. (author). 10 refs, 11 figs

  15. Reduced myocardial carbon-11 hydroxyephedrine retention is associated with poor prognosis in chronic heart failure

    International Nuclear Information System (INIS)

    Pietilae, M.; Ukkonen, H.; Malminiemi, K.; Saraste, M.; Naagren, K.; Lehikoinen, P.; Voipio-Pulkki, L.-M.

    2001-01-01

    Abnormalities of the autonomic nervous system are known to be of prognostic significance in chronic heart failure (CHF). The prognostic value of positron emission tomography (PET) imaging of cardiac autonomic innervation in CHF has not been explored previously. We retrospectively studied the survival data of 46 NYHA class II-III CHF patients (mean LVEF 35%±8%) who had undergone carbon-11 hydroxyephedrine ( 11 C-HED) studies at the Turku PET Centre between August 1992 and March 1996. The origin of CHF was dilated cardiomyopathy in 13 of the 46 patients and coronary artery disease with at least one prior myocardial infarction in the remaining 33. Data on causes of death and heart transplantation were collected, and the statistically significant predictors of prognosis were analysed using Cox's proportional hazards regression. During the mean follow-up period of 55±19 months, 11 deaths occurred and two patients underwent heart transplantation successfully. Eleven end-points were classified as cardiac (nine sudden cardiac deaths and two deaths due to progressive heart failure) and two as non-cardiac. When divided into two groups based on the median of 11 C-HED retention (mean 0.184±0.061, median 0.183), eight end-points (death or cardiac transplantation) were reached in the group with 11 C-HED retention below the median and three in the group with 11 C-HED retention above the median (P 2 ), left ventricular end-diastolic volume and HED retention were found to be statistically significant. It is concluded that 11 C-HED PET provides independent prognostic information in patients with CHF. (orig.)

  16. HUC 8-11 Boundaries

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital hydrologic unit boundary that is at the 4-digit, 6-digit, 8-digit, and 11-digit level. The data set was developed by delineating the...

  17. Failure analysis: Status and future trends

    International Nuclear Information System (INIS)

    Anderson, R.E.; Soden, J.M.; Henderson, C.L.

    1995-01-01

    Failure analysis is a critical element in the integrated circuit manufacturing industry. This paper reviews the changing role of failure analysis and describes major techniques employed in the industry today. Several advanced failure analysis techniques that meet the challenges imposed by advancements in integrated circuit technology are described and their applications are discussed. Future trends in failure analysis needed to keep pace with the continuing advancements in integrated circuit technology are anticipated

  18. Effects of catheter-based renal denervation on heart failure with reduced ejection fraction: a systematic review and meta-analysis.

    Science.gov (United States)

    Fukuta, Hidekatsu; Goto, Toshihiko; Wakami, Kazuaki; Ohte, Nobuyuki

    2017-11-01

    Despite the recent advances in the management of heart failure, the mortality of heart failure patients remains high. It is of urgent need to develop new therapy for heart failure. Heart failure is characterized by increased sympathetic activity, and chronic sympathetic activation is involved in the maintenance of the pathological state. Catheter-based renal denervation (RDN) has emerged as an invasive but safe approach that can reduce sympathetic activation. Studies have reported inconsistent results regarding the effect of RDN in heart failure patients due to limited power with small sample sizes. We aimed to conduct a meta-analysis of the effect of RDN on heart failure patients with reduced left ventricular (LV) ejection fraction (EF). An electronic search for studies examining the effect of RDN on LV function in heart failure patients with reduced EF was conducted. Two controlled (80 patients) and 2 uncontrolled studies (21 patients) were included in this meta-analysis. In the pooled analysis, 6 months after RDN, there was a greater increase in EF (weighted mean difference [95% CI] = 8.63 [6.02, 11.24] %) and a greater decrease in LV end-diastolic diameter (-0.58 [-0.83, -0.34] cm) in RDN group than in control group. No serious adverse events such as acute renal artery stenosis and dissection occurred. Our meta-analysis of feasibility studies suggests that RDN may improve LV function in heart failure patients with reduced EF, providing the rationale to conduct next phase trials to confirm the observed potential benefits of RDN.

  19. Electrical failure analysis for root-cause determination

    International Nuclear Information System (INIS)

    Riddle, J.

    1990-01-01

    This paper outlines a practical failure analysis sequence. Several technical definitions are required. A failure is defined as a component that was operating in a system where the system malfunctioned and the replacement of the device restored system functionality. The failure mode is the malfunctioning behavior of the device. The failure mechanism is the underlying cause or source of the failure mode. The failure mechanism is the root cause of the failure mode. The failure analysis procedure needs to be adequately refined to result in the determination of the cause of failure to the degree that corrective action or design changes will prevent recurrence of the failure mode or mechanism. An example of a root-cause determination analysis performed for a nuclear power industry customer serves to illustrate the analysis methodology

  20. Economic impact of heart failure according to the effects of kidney failure.

    Science.gov (United States)

    Sicras Mainar, Antoni; Navarro Artieda, Ruth; Ibáñez Nolla, Jordi

    2015-01-01

    To evaluate the use of health care resources and their cost according to the effects of kidney failure in heart failure patients during 2-year follow-up in a population setting. Observational retrospective study based on a review of medical records. The study included patients ≥ 45 years treated for heart failure from 2008 to 2010. The patients were divided into 2 groups according to the presence/absence of KF. Main outcome variables were comorbidity, clinical status (functional class, etiology), metabolic syndrome, costs, and new cases of cardiovascular events and kidney failure. The cost model included direct and indirect health care costs. Statistical analysis included multiple regression models. The study recruited 1600 patients (prevalence, 4.0%; mean age 72.4 years; women, 59.7%). Of these patients, 70.1% had hypertension, 47.1% had dyslipidemia, and 36.2% had diabetes mellitus. We analyzed 433 patients (27.1%) with kidney failure and 1167 (72.9%) without kidney failure. Patients with kidney failure were associated with functional class III-IV (54.1% vs 40.8%) and metabolic syndrome (65.3% vs 51.9%, P<.01). The average unit cost was €10,711.40. The corrected cost in the presence of kidney failure was €14,868.20 vs €9,364.50 (P=.001). During follow-up, 11.7% patients developed ischemic heart disease, 18.8% developed kidney failure, and 36.1% developed heart failure exacerbation. Comorbidity associated with heart failure is high. The presence of kidney failure increases the use of health resources and leads to higher costs within the National Health System. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  1. 1,4,8,11-Tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes - synthesis, characterization, and x-ray crystallography of the first tetrakistriazenes to be reported

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, J.D.; Vaughan, K. [Dept. of Chemistry, Saint Mary' s Univ., Halifax, Nova Scotia (Canada)], E-mail: keith.vaughan@smu.ca; Bertolasi, V. [Dipartimento di Chimica and Centro di Strutturistica Diffrattometrica, Universita' di Ferrara, Ferrara (Italy)

    2006-10-15

    The reactions of a series of arene diazonium salts with 1,4,8,11-tetraazacyclotetradecane (cyclam) afford the novel compounds, the 1,4,8,11-tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes (1a-1f), which are the first examples of tetrakistriazenes to be reported. The tetrakistriazenes were characterized by IR spectroscopy, proton and carbon NMR, elemental analysis, high resolution electrospray mass spectrometry, and X-ray crystallography. The analogous reaction of a diazonium salt with 1,4,7-triazacyclononane or 1,5,9-triazacyclododecane yields the tristriazenes 2, 3a, and 3b. The structures of compounds 1c and 1e were solved by X-ray crystallography at low temperature (150 K). Both molecules display a conformation where the four phenyltriazenyl groups point alternately upwards and downwards with respect to the mean macrocyclic plane. (author)

  2. 1,4,8,11-Tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes - synthesis, characterization, and x-ray crystallography of the first tetrakistriazenes to be reported

    International Nuclear Information System (INIS)

    Clarke, J.D.; Vaughan, K.; Bertolasi, V.

    2006-01-01

    The reactions of a series of arene diazonium salts with 1,4,8,11-tetraazacyclotetradecane (cyclam) afford the novel compounds, the 1,4,8,11-tetra[2-aryl-1-diazenyl]-1,4,8,11-tetraazacyclotetradecanes (1a-1f), which are the first examples of tetrakistriazenes to be reported. The tetrakistriazenes were characterized by IR spectroscopy, proton and carbon NMR, elemental analysis, high resolution electrospray mass spectrometry, and X-ray crystallography. The analogous reaction of a diazonium salt with 1,4,7-triazacyclononane or 1,5,9-triazacyclododecane yields the tristriazenes 2, 3a, and 3b. The structures of compounds 1c and 1e were solved by X-ray crystallography at low temperature (150 K). Both molecules display a conformation where the four phenyltriazenyl groups point alternately upwards and downwards with respect to the mean macrocyclic plane. (author)

  3. The Advanced Glaucoma Intervention Study (AGIS): 11. Risk factors for failure of trabeculectomy and argon laser trabeculoplasty.

    Science.gov (United States)

    2002-10-01

    To investigate the association of pre-intervention and post-intervention patient and eye characteristics with failure of argon laser trabeculoplasty (ALT) and trabeculectomy. Cohort study of participants in the Advanced Glaucoma Intervention Study. This multicenter study took place between 1988 and 2001. Between 1988 and 1992, 789 eyes of 591 patients aged 35 to 80 years with advanced glaucoma were randomized into one of two surgical treatment sequences: argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy or trabeculectomy-ALT-trabeculectomy. Upon study-defined failure (based on maximum medications, sustained intraocular pressure (IOP) elevation, visual field defect, and disk rim deterioration) of each intervention, patients were offered the subsequent intervention. Potential follow-up was 8 to 13 years. This report is based on data from 779 eyes that had at least 3 months of follow-up. The main outcome measures are failure of ALT and trabeculectomy, whether as first or second interventions. Effect size is measured by the hazard ratio (HR) and its corresponding 95% confidence interval (CI) obtained from Cox multiple regression analysis, where HR corresponds to the coefficient of change in risk associated with a unit increase in a factor. For binary factors, this corresponds to the change in risk in eyes with the factor relative to the risk in eyes without the factor. Pre-intervention factors associated with failure of ALT are younger age (HR = 0.98, CI = 0.96-0.99, P =.009) and higher IOP (1.11, 1.08-1.15, P <.001). Pre-intervention factors associated with failure of trabeculectomy are younger age (HR = 0.97, CI = 0.95-0.99, P =.005) and higher IOP (1.04, 1.01-1.06, P =.002), as well as diabetes (2.86, 1.88-4.36, P <.001) and any postoperative complication (1.99, 1.35-2.93, P <.001). Individual postoperative complications significantly associated with increased risk of failure of trabeculectomy are elevated IOP (3.4, 1.9-6.1, P <.001) and marked

  4. Common cause failure analysis methodology for complex systems

    International Nuclear Information System (INIS)

    Wagner, D.P.; Cate, C.L.; Fussell, J.B.

    1977-01-01

    Common cause failure analysis, also called common mode failure analysis, is an integral part of a complex system reliability analysis. This paper extends existing methods of computer aided common cause failure analysis by allowing analysis of the complex systems often encountered in practice. The methods presented here aid in identifying potential common cause failures and also address quantitative common cause failure analysis

  5. Failure analysis of parameter-induced simulation crashes in climate models

    Science.gov (United States)

    Lucas, D. D.; Klein, R.; Tannahill, J.; Ivanova, D.; Brandon, S.; Domyancic, D.; Zhang, Y.

    2013-08-01

    Simulations using IPCC (Intergovernmental Panel on Climate Change)-class climate models are subject to fail or crash for a variety of reasons. Quantitative analysis of the failures can yield useful insights to better understand and improve the models. During the course of uncertainty quantification (UQ) ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation crashes within the Parallel Ocean Program (POP2) component of the Community Climate System Model (CCSM4). About 8.5% of our CCSM4 simulations failed for numerical reasons at combinations of POP2 parameter values. We applied support vector machine (SVM) classification from machine learning to quantify and predict the probability of failure as a function of the values of 18 POP2 parameters. A committee of SVM classifiers readily predicted model failures in an independent validation ensemble, as assessed by the area under the receiver operating characteristic (ROC) curve metric (AUC > 0.96). The causes of the simulation failures were determined through a global sensitivity analysis. Combinations of 8 parameters related to ocean mixing and viscosity from three different POP2 parameterizations were the major sources of the failures. This information can be used to improve POP2 and CCSM4 by incorporating correlations across the relevant parameters. Our method can also be used to quantify, predict, and understand simulation crashes in other complex geoscientific models.

  6. Isogeometric failure analysis

    NARCIS (Netherlands)

    Verhoosel, C.V.; Scott, M.A.; Borden, M.J.; Borst, de R.; Hughes, T.J.R.; Mueller-Hoeppe, D.; Loehnert, S.; Reese, S.

    2011-01-01

    Isogeometric analysis is a versatile tool for failure analysis. On the one hand, the excellent control over the inter-element continuity conditions enables a natural incorporation of continuum constitutive relations that incorporate higher-order strain gradients, as in gradient plasticity or damage.

  7. Failure Analysis

    International Nuclear Information System (INIS)

    Iorio, A.F.; Crespi, J.C.

    1987-01-01

    After ten years of operation at the Atucha I Nuclear Power Station a gear belonging to a pressurized heavy water reactor refuelling machine, failed. The gear box was used to operate the inlet-outlet heavy-water valve of the machine. Visual examination of the gear device showed an absence of lubricant and that several gear teeth were broken at the root. Motion was transmitted with a speed-reducing device with controlled adjustable times in order to produce a proper fitness of the valve closure. The aim of this paper is to discuss the results of the gear failure analysis in order to recommend the proper solution to prevent further failures. (Author)

  8. Standard guide for corrosion-related failure analysis

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide covers key issues to be considered when examining metallic failures when corrosion is suspected as either a major or minor causative factor. 1.2 Corrosion-related failures could include one or more of the following: change in surface appearance (for example, tarnish, rust, color change), pin hole leak, catastrophic structural failure (for example, collapse, explosive rupture, implosive rupture, cracking), weld failure, loss of electrical continuity, and loss of functionality (for example, seizure, galling, spalling, swelling). 1.3 Issues covered include overall failure site conditions, operating conditions at the time of failure, history of equipment and its operation, corrosion product sampling, environmental sampling, metallurgical and electrochemical factors, morphology (mode) or failure, and by considering the preceding, deducing the cause(s) of corrosion failure. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibili...

  9. The application of Petri nets to failure analysis

    International Nuclear Information System (INIS)

    Liu, T.S.; Chiou, S.B.

    1997-01-01

    Unlike the technique of fault tree analysis that has been widely applied to system failure analysis in reliability engineering, this study presents a Petri net approach to failure analysis. It is essentially a graphical method for describing relations between conditions and events. The use of Petri nets in failure analysis enables to replace logic gate functions in fault trees, efficiently obtain minimal cut sets, and absorb models. It is demonstrated that for failure analysis Petri nets are more efficient than fault trees. In addition, this study devises an alternative; namely, a trapezoidal graph method in order to account for failure scenarios. Examples validate this novel method in dealing with failure analysis

  10. Complete D =11 embedding of SO(8) supergravity

    Science.gov (United States)

    Varela, Oscar

    2018-02-01

    The truncation formulas of D =11 supergravity on S7 to D =4 N =8 SO(8)-gauged supergravity are completed to include the full nonlinear dependence of the D =11 three-form potential A^ (3 ) on the D =4 fields, and their consistency is shown. The full embedding into A^ (3 ) is naturally expressed in terms of a restricted version, still N =8 but only SL(8)-covariant, of the D =4 tensor hierarchy. The redundancies introduced by this approach are removed at the level of the field strength F^ (4 ) by exploiting D =4 duality relations. Finally, new expressions for the full consistent truncation formulas are given that are explicit in all D =11 and D =4 fields.

  11. Failure modes and effects analysis (FMEA) for Gamma Knife radiosurgery.

    Science.gov (United States)

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Flickinger, John; Arai, Yoshio; Vacsulka, Jonet; Feng, Wenzheng; Monaco, Edward; Niranjan, Ajay; Lunsford, L Dade; Huq, M Saiful

    2017-11-01

    Gamma Knife radiosurgery is a highly precise and accurate treatment technique for treating brain diseases with low risk of serious error that nevertheless could potentially be reduced. We applied the AAPM Task Group 100 recommended failure modes and effects analysis (FMEA) tool to develop a risk-based quality management program for Gamma Knife radiosurgery. A team consisting of medical physicists, radiation oncologists, neurosurgeons, radiation safety officers, nurses, operating room technologists, and schedulers at our institution and an external physicist expert on Gamma Knife was formed for the FMEA study. A process tree and a failure mode table were created for the Gamma Knife radiosurgery procedures using the Leksell Gamma Knife Perfexion and 4C units. Three scores for the probability of occurrence (O), the severity (S), and the probability of no detection for failure mode (D) were assigned to each failure mode by 8 professionals on a scale from 1 to 10. An overall risk priority number (RPN) for each failure mode was then calculated from the averaged O, S, and D scores. The coefficient of variation for each O, S, or D score was also calculated. The failure modes identified were prioritized in terms of both the RPN scores and the severity scores. The established process tree for Gamma Knife radiosurgery consists of 10 subprocesses and 53 steps, including a subprocess for frame placement and 11 steps that are directly related to the frame-based nature of the Gamma Knife radiosurgery. Out of the 86 failure modes identified, 40 Gamma Knife specific failure modes were caused by the potential for inappropriate use of the radiosurgery head frame, the imaging fiducial boxes, the Gamma Knife helmets and plugs, the skull definition tools as well as other features of the GammaPlan treatment planning system. The other 46 failure modes are associated with the registration, imaging, image transfer, contouring processes that are common for all external beam radiation therapy

  12. The interaction of NDE and failure analysis

    International Nuclear Information System (INIS)

    Nichols, R.W.

    1988-01-01

    This paper deals with the use of Non-Destructive Examination (NDE) and failure analysis for the assessment of the structural integrity. It appears that failure analysis enables to know whether NDE is required or not, and can help to direct NDE into the most useful directions by identifying the areas where it is most important that defects are absent. It also appears that failure analysis can help the operator to decide which NDE method is best suited to the component studied and provides detailed specifications for this NDE method. The interaction between failure analysis and NDE is then described. (TEC)

  13. The interaction of NDE and failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, R W

    1988-12-31

    This paper deals with the use of Non-Destructive Examination (NDE) and failure analysis for the assessment of the structural integrity. It appears that failure analysis enables to know whether NDE is required or not, and can help to direct NDE into the most useful directions by identifying the areas where it is most important that defects are absent. It also appears that failure analysis can help the operator to decide which NDE method is best suited to the component studied and provides detailed specifications for this NDE method. The interaction between failure analysis and NDE is then described. (TEC).

  14. Analysis of failures in concrete containments

    International Nuclear Information System (INIS)

    Moreno-Gonzalez, A.

    1989-09-01

    The function of Containment, in an accident event, is to avoid the release of radioactive substances into the surroundings. Containment failure, therefore, is defined as the appearance of leak paths to the external environment. These leak paths may appear either as a result of loss of leaktightness due to degradation of design conditions or structural failure with containment material break. This document is a survey of the state of the art of Containment Failure Analysis. It gives a detailed description of all failure mechanisms, indicating all the possible failure modes and their causes, right from failure resulting from degradation of the materials to structural failure and linear breake failure. Following the description of failure modes, possible failure criteria are identified, with special emphasis on structural failure criteria. These criteria have been obtained not only from existing codes but also from the latest experimental results. A chapter has been dedicated exclusively to failure criteria in conventional structures, for the purpose of evaluating the possibility of application to the case of containment. As the structural behaviour of the containment building is very complex, it is not possible to define failure through a single parameter. It is therefore advisable to define a methodology for containment failure analysis which could be applied to a particular containment. This methodology should include prevailing load and material conditions together with the behaviour of complex conditions such as the liner-anchorage-cracked concrete interaction

  15. FRAC (failure rate analysis code): a computer program for analysis of variance of failure rates. An application user's guide

    International Nuclear Information System (INIS)

    Martz, H.F.; Beckman, R.J.; McInteer, C.R.

    1982-03-01

    Probabilistic risk assessments (PRAs) require estimates of the failure rates of various components whose failure modes appear in the event and fault trees used to quantify accident sequences. Several reliability data bases have been designed for use in providing the necessary reliability data to be used in constructing these estimates. In the nuclear industry, the Nuclear Plant Reliability Data System (NPRDS) and the In-Plant Reliability Data System (IRPDS), among others, were designed for this purpose. An important characteristic of such data bases is the selection and identification of numerous factors used to classify each component that is reported and the subsequent failures of each component. However, the presence of such factors often complicates the analysis of reliability data in the sense that it is inappropriate to group (that is, pool) data for those combinations of factors that yield significantly different failure rate values. These types of data can be analyzed by analysis of variance. FRAC (Failure Rate Analysis Code) is a computer code that performs an analysis of variance of failure rates. In addition, FRAC provides failure rate estimates

  16. Importance of competing risks in the analysis of anti-epileptic drug failure

    Directory of Open Access Journals (Sweden)

    Sander Josemir W

    2007-03-01

    Full Text Available Abstract Background Retention time (time to treatment failure is a commonly used outcome in antiepileptic drug (AED studies. Methods Two datasets are used to demonstrate the issues in a competing risks analysis of AEDs. First, data collection and follow-up considerations are discussed with reference to information from 15 monotherapy trials. Recommendations for improved data collection and cumulative incidence analysis are then illustrated using the SANAD trial dataset. The results are compared to the more common approach using standard survival analysis methods. Results A non-significant difference in overall treatment failure time between gabapentin and topiramate (logrank test statistic = 0.01, 1 degree of freedom, p-value = 0.91 masked highly significant differences in opposite directions with gabapentin resulting in fewer withdrawals due to side effects (Gray's test statistic = 11.60, 1 degree of freedom, p = 0.0007 but more due to poor seizure control (Gray's test statistic = 14.47, 1 degree of freedom, p-value = 0.0001. The significant difference in overall treatment failure time between lamotrigine and carbamazepine (logrank test statistic = 5.6, 1 degree of freedom, p-value = 0.018 was due entirely to a significant benefit of lamotrigine in terms of side effects (Gray's test statistic = 10.27, 1 degree of freedom, p = 0.001. Conclusion Treatment failure time can be measured reliably but care is needed to collect sufficient information on reasons for drug withdrawal to allow a competing risks analysis. Important differences between the profiles of AEDs may be missed unless appropriate statistical methods are used to fully investigate treatment failure time. Cumulative incidence analysis allows comparison of the probability of failure between two AEDs and is likely to be a more powerful approach than logrank analysis for most comparisons of standard and new anti-epileptic drugs.

  17. Dependent failure analysis of NPP data bases

    International Nuclear Information System (INIS)

    Cooper, S.E.; Lofgren, E.V.; Samanta, P.K.; Wong Seemeng

    1993-01-01

    A technical approach for analyzing plant-specific data bases for vulnerabilities to dependent failures has been developed and applied. Since the focus of this work is to aid in the formulation of defenses to dependent failures, rather than to quantify dependent failure probabilities, the approach of this analysis is critically different. For instance, the determination of component failure dependencies has been based upon identical failure mechanisms related to component piecepart failures, rather than failure modes. Also, component failures involving all types of component function loss (e.g., catastrophic, degraded, incipient) are equally important to the predictive purposes of dependent failure defense development. Consequently, dependent component failures are identified with a different dependent failure definition which uses a component failure mechanism categorization scheme in this study. In this context, clusters of component failures which satisfy the revised dependent failure definition are termed common failure mechanism (CFM) events. Motor-operated valves (MOVs) in two nuclear power plant data bases have been analyzed with this approach. The analysis results include seven different failure mechanism categories; identified potential CFM events; an assessment of the risk-significance of the potential CFM events using existing probabilistic risk assessments (PRAs); and postulated defenses to the identified potential CFM events. (orig.)

  18. Studies on failure kind analysis of the radiologic medical equipment in general hospital

    International Nuclear Information System (INIS)

    Lee, Woo Cheul; Kim, Jeong Lae

    1999-01-01

    This paper included a data analysis of the unit of medical devices using maintenance recording card that had medical devices of unit failure mode, hospital of failure mode and MTBF. The results of the analysis were as follows : 1. Medical devices of unit failure mode was the highest in QC/PM such A hospital as 33.9%, B hospital 30.9%, C hospital 30.3%, second degree was the Electrical and Electronic failure such A hospital as 23.5%, B hospital 25.3%, C hospital 28%, third degree was mechanical failure such A hospital as 19.6%, B hospital 22.5%, C hospital 25.4%. 2. Hospital of failure mode was the highest in Mobile X-ray device(A hospital 62.5%, B hospital 69.5%, C hospital 37.4%), and was the lowest in Sono devices(A hospital 16.76%, B hospital 8.4%, C hospital 7%). 3. Mean time between failures(MTBT) was the highest in SONO devices and was the lowest in Mobile X-ray devices which have 200 - 400 failure hours. 4. Average failure ratio was the highest in Mobile X-ray devices(A hospital 31.3%, B hospital 34.8%, C hospital 18.7%), and was the lowest in Sono(Ultrasound) devices (A hospital 8.4%, B hospital 4.2%, C hospital 3.5%). 5. Failure ratio results of medical devices according to QC/PM part of unit failure mode were as follows ; A hospital was the highest part of QC/PM (50%) in Mamo X-ray device and was the lowest part of QC/PM(26.4%) in Gastro X-ray. B hospital was the highest part of QC/PM(56%) in Mobile X-ray device, and the lowest part of QC/PM(12%) in Gastro X-ray. C hospital was the highest part of QC/PM(60%) in R/F X-ray device, and the lowest a part of QC/PM(21%) in Universal X-ray. It was found that the units responsible for most failure decreased by systematic management. We made the preventive maintenance schedule focusing on adjustment of operating and dust removal

  19. An analysis of ‘non-Johannine’ vocabulary in John 7:53–8:11, Part 1

    Directory of Open Access Journals (Sweden)

    John D. Punch

    2013-08-01

    Full Text Available Although scholars usually use external evidence to argue against the inclusion of John 7:53–8:11 in the Gospel of John, they frequently suggest arguments of internal evidence, mostly based on the inclusion of non-Johannine vocabulary, to support these objections. However, in contrast to the textual evidence, arguments about non-Johannine vocabulary seldom receive the necessary amount of evaluation. This article is the first of a two-part series that evaluates explanations for the appearance of various ‘non-Johannine’ terms. Both articles rebut claims of ’non-Johannine’ vocabulary in John 7:53–8:11, thereby providing opportunities for discussing Johannine features in the passage. Hoewel navorsers eksterne bewyse gebruik om teen die insluiting van Johannes 7:53–8:11 in die Evangelie van Johannes te argumenteer, maak hulle dikwels voorstelle van interne bewyse, meestal gebaseer op die insluiting van nie-Johannese terme, ter ondersteuning van sodanige besware. In teenstelling met die tekstuele bewyse, ontvang die voorstelle vir nie-Johannese terme egter selde die nodige evaluering. Hierdie artikel is die eerste van ’n tweeledige reeks wat verklarings vir die verskynsel van verskeie ‘nie-Johannese’ terme evalueer. Albei artikels weerlê die bewerings wat gemaak word ten opsigte van ‘nie-Johannese’ terme in Johannes 7:53–8:11 en skep daardeur geleentheid vir ’n bespreking van Johannese eienskappe.

  20. 14 CFR 417.224 - Probability of failure analysis.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Probability of failure analysis. 417.224..., DEPARTMENT OF TRANSPORTATION LICENSING LAUNCH SAFETY Flight Safety Analysis § 417.224 Probability of failure..., must account for launch vehicle failure probability in a consistent manner. A launch vehicle failure...

  1. Tests and analysis on steam generator tube failure propagation

    International Nuclear Information System (INIS)

    Tanabe, Hiromi

    1990-01-01

    The understanding of leak enlargement and failure propagation behavior is essential to select a design basis leak (DBL) of LMFBR steam generators. Therefore, various series of experiments, such as self-enlargement tests, target wastage tests, failure propagation tests were conducted in a wide range of leak using test facilities of SWAT at PNC/OEC. Especially, in the large leak tests, potential of overheating failure was investigated under a prototypical steam cooling condition inside target tubes. In the small leak, the difference of wastage resistivity was clarified among several tube materials such as 9-chrome steels. In regard to an analytical approach, a computer code LEAP (Leak Enlargement and Propagation) was developed on the basis of all of these experimental results. The code was used to validate the previously selected DBL of the prototype reactor, Monju, steam generator. This approach proved to be successful in spite of somewhat over-conservatism in the analysis. Moreover, LEAP clarified the effectiveness of a rapid steam dump and an enhanced leak detection system. The code improvement toward a realistic analysis is desired, however, to lessen the DBL for a future large plant and then the re-evaluation of the experimental data such as the size of secondary failure is under way. (author). 4 refs, 8 figs, 1 tab

  2. Failure analysis of the cement mantle in total hip arthroplasty with an efficient probabilistic method.

    Science.gov (United States)

    Kaymaz, Irfan; Bayrak, Ozgu; Karsan, Orhan; Celik, Ayhan; Alsaran, Akgun

    2014-04-01

    Accurate prediction of long-term behaviour of cemented hip implants is very important not only for patient comfort but also for elimination of any revision operation due to failure of implants. Therefore, a more realistic computer model was generated and then used for both deterministic and probabilistic analyses of the hip implant in this study. The deterministic failure analysis was carried out for the most common failure states of the cement mantle. On the other hand, most of the design parameters of the cemented hip are inherently uncertain quantities. Therefore, the probabilistic failure analysis was also carried out considering the fatigue failure of the cement mantle since it is the most critical failure state. However, the probabilistic analysis generally requires large amount of time; thus, a response surface method proposed in this study was used to reduce the computation time for the analysis of the cemented hip implant. The results demonstrate that using an efficient probabilistic approach can significantly reduce the computation time for the failure probability of the cement from several hours to minutes. The results also show that even the deterministic failure analyses do not indicate any failure of the cement mantle with high safety factors, the probabilistic analysis predicts the failure probability of the cement mantle as 8%, which must be considered during the evaluation of the success of the cemented hip implants.

  3. Failure of Noninvasive Ventilation for De Novo Acute Hypoxemic Respiratory Failure: Role of Tidal Volume.

    Science.gov (United States)

    Carteaux, Guillaume; Millán-Guilarte, Teresa; De Prost, Nicolas; Razazi, Keyvan; Abid, Shariq; Thille, Arnaud W; Schortgen, Frédérique; Brochard, Laurent; Brun-Buisson, Christian; Mekontso Dessap, Armand

    2016-02-01

    A low or moderate expired tidal volume can be difficult to achieve during noninvasive ventilation for de novo acute hypoxemic respiratory failure (i.e., not due to exacerbation of chronic lung disease or cardiac failure). We assessed expired tidal volume and its association with noninvasive ventilation outcome. Prospective observational study. Twenty-four bed university medical ICU. Consecutive patients receiving noninvasive ventilation for acute hypoxemic respiratory failure between August 2010 and February 2013. Noninvasive ventilation was uniformly delivered using a simple algorithm targeting the expired tidal volume between 6 and 8 mL/kg of predicted body weight. Expired tidal volume was averaged and respiratory and hemodynamic variables were systematically recorded at each noninvasive ventilation session. Sixty-two patients were enrolled, including 47 meeting criteria for acute respiratory distress syndrome, and 32 failed noninvasive ventilation (51%). Pneumonia (n = 51, 82%) was the main etiology of acute hypoxemic respiratory failure. The median (interquartile range) expired tidal volume averaged over all noninvasive ventilation sessions (mean expired tidal volume) was 9.8 mL/kg predicted body weight (8.1-11.1 mL/kg predicted body weight). The mean expired tidal volume was significantly higher in patients who failed noninvasive ventilation as compared with those who succeeded (10.6 mL/kg predicted body weight [9.6-12.0] vs 8.5 mL/kg predicted body weight [7.6-10.2]; p = 0.001), and expired tidal volume was independently associated with noninvasive ventilation failure in multivariate analysis. This effect was mainly driven by patients with PaO2/FIO2 up to 200 mm Hg. In these patients, the expired tidal volume above 9.5 mL/kg predicted body weight predicted noninvasive ventilation failure with a sensitivity of 82% and a specificity of 87%. A low expired tidal volume is almost impossible to achieve in the majority of patients receiving noninvasive ventilation

  4. Dependency Defence and Dependency Analysis Guidance. Volume 2: Appendix 3-8. How to analyse and protect against dependent failures. Summary report of the Nordic Working Group on Common Cause Failure Analysis

    International Nuclear Information System (INIS)

    Johanson, Gunnar; Hellstroem, Per; Makamo, Tuomas; Bento, Jean-Pierre; Knochenhauer, Michael; Poern, Kurt

    2003-10-01

    The safety systems in Nordic nuclear power plants are characterised by substantial redundancy and/or diversification in safety critical functions, as well as by physical separation of critical safety systems, including their support functions. Viewed together with the evident additional fact, that the single failure criterion has been systematically applied in the design of safety systems, this means that the plant risk profile as calculated in existing PSA:s is usually strongly dominated by failures caused by dependencies resulting in the loss of more than one system sub. The overall objective with the working group is to support safety by studying potential and real CCF events, process statistical data and report conclusions and recommendations that can improve the understanding of these events eventually resulting in increased safety. The result is intended for application in NPP operation, maintenance, inspection and risk assessments. The NAFCS project is part of the activities of the Nordic PSA Group (NPSAG), and is financed jointly by the Nordic utilities and authorities. The work is divided into one quantitative and one qualitative part with the following specific objectives: Qualitative objectives-The goal with the qualitative analysis is to compile experience data and generate insights in terms of relevant failure mechanisms and effective CCF protection measures. The results shall be presented as a guide with checklists and recommendations on how to identify current CCF protection standard and improvement possibilities regarding CCF defences decreasing the CCF vulnerability. Quantitative objectives-The goal with the quantitative analysis is to prepare a Nordic C-book where quantitative insights as Impact Vectors and CCF parameters for different redundancy levels are presented. Uncertainties in CCF data shall be reduced as much as possible. The high redundancy systems sensitivity to CCF events demand a well structured quantitative analysis in support of

  5. Application of failure mode and effect analysis in an assisted reproduction technology laboratory.

    Science.gov (United States)

    Intra, Giulia; Alteri, Alessandra; Corti, Laura; Rabellotti, Elisa; Papaleo, Enrico; Restelli, Liliana; Biondo, Stefania; Garancini, Maria Paola; Candiani, Massimo; Viganò, Paola

    2016-08-01

    Assisted reproduction technology laboratories have a very high degree of complexity. Mismatches of gametes or embryos can occur, with catastrophic consequences for patients. To minimize the risk of error, a multi-institutional working group applied failure mode and effects analysis (FMEA) to each critical activity/step as a method of risk assessment. This analysis led to the identification of the potential failure modes, together with their causes and effects, using the risk priority number (RPN) scoring system. In total, 11 individual steps and 68 different potential failure modes were identified. The highest ranked failure modes, with an RPN score of 25, encompassed 17 failures and pertained to "patient mismatch" and "biological sample mismatch". The maximum reduction in risk, with RPN reduced from 25 to 5, was mostly related to the introduction of witnessing. The critical failure modes in sample processing were improved by 50% in the RPN by focusing on staff training. Three indicators of FMEA success, based on technical skill, competence and traceability, have been evaluated after FMEA implementation. Witnessing by a second human operator should be introduced in the laboratory to avoid sample mix-ups. These findings confirm that FMEA can effectively reduce errors in assisted reproduction technology laboratories. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  6. Failure Analysis Of Industrial Boiler Pipe

    International Nuclear Information System (INIS)

    Natsir, Muhammad; Soedardjo, B.; Arhatari, Dewi; Andryansyah; Haryanto, Mudi; Triyadi, Ari

    2000-01-01

    Failure analysis of industrial boiler pipe has been done. The tested pipe material is carbon steel SA 178 Grade A refer to specification data which taken from Fertilizer Company. Steps in analysis were ; collection of background operation and material specification, visual inspection, dye penetrant test, radiography test, chemical composition test, hardness test, metallography test. From the test and analysis result, it is shown that the pipe failure caused by erosion and welding was shown porosity and incomplete penetration. The main cause of failure pipe is erosion due to cavitation, which decreases the pipe thickness. Break in pipe thickness can be done due to decreasing in pipe thickness. To anticipate this problem, the ppe will be replaced with new pipe

  7. 75 FR 44992 - Review of Management Directive 8.11

    Science.gov (United States)

    2010-07-30

    ... NUCLEAR REGULATORY COMMISSION [NRC-2010-0242] Review of Management Directive 8.11 AGENCY: Nuclear... (NRC) is requesting public comment on Management Directive (MD) 8.11, ``Review Process for 10 CFR 2.206... members of the public and the NRC, the NRC is soliciting comments from the public, on what, if any...

  8. Failure probability analysis on mercury target vessel

    International Nuclear Information System (INIS)

    Ishikura, Syuichi; Futakawa, Masatoshi; Kogawa, Hiroyuki; Sato, Hiroshi; Haga, Katsuhiro; Ikeda, Yujiro

    2005-03-01

    Failure probability analysis was carried out to estimate the lifetime of the mercury target which will be installed into the JSNS (Japan spallation neutron source) in J-PARC (Japan Proton Accelerator Research Complex). The lifetime was estimated as taking loading condition and materials degradation into account. Considered loads imposed on the target vessel were the static stresses due to thermal expansion and static pre-pressure on He-gas and mercury and the dynamic stresses due to the thermally shocked pressure waves generated repeatedly at 25 Hz. Materials used in target vessel will be degraded by the fatigue, neutron and proton irradiation, mercury immersion and pitting damages, etc. The imposed stresses were evaluated through static and dynamic structural analyses. The material-degradations were deduced based on published experimental data. As a result, it was quantitatively confirmed that the failure probability for the lifetime expected in the design is very much lower, 10 -11 in the safety hull, meaning that it will be hardly failed during the design lifetime. On the other hand, the beam window of mercury vessel suffered with high-pressure waves exhibits the failure probability of 12%. It was concluded, therefore, that the leaked mercury from the failed area at the beam window is adequately kept in the space between the safety hull and the mercury vessel by using mercury-leakage sensors. (author)

  9. Combinatorial analysis of systems with competing failures subject to failure isolation and propagation effects

    International Nuclear Information System (INIS)

    Xing Liudong; Levitin, Gregory

    2010-01-01

    This paper considers the reliability analysis of binary-state systems, subject to propagated failures with global effect, and failure isolation phenomena. Propagated failures with global effect are common-cause failures originated from a component of a system/subsystem causing the failure of the entire system/subsystem. Failure isolation occurs when the failure of one component (referred to as a trigger component) causes other components (referred to as dependent components) within the same system to become isolated from the system. On the one hand, failure isolation makes the isolated dependent components unusable; on the other hand, it prevents the propagation of failures originated from those dependent components. However, the failure isolation effect does not exist if failures originated in the dependent components already propagate globally before the trigger component fails. In other words, there exists a competition in the time domain between the failure of the trigger component that causes failure isolation and propagated failures originated from the dependent components. This paper presents a combinatorial method for the reliability analysis of systems subject to such competing propagated failures and failure isolation effect. Based on the total probability theorem, the proposed method is analytical, exact, and has no limitation on the type of time-to-failure distributions for the system components. An illustrative example is given to demonstrate the basics and advantages of the proposed method.

  10. 8 CFR 208.10 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Failure to appear at an interview before an... WITHHOLDING OF REMOVAL Asylum and Withholding of Removal § 208.10 Failure to appear at an interview before an... scheduled interview without prior authorization may result in dismissal of the application or waiver of the...

  11. Clinical risk analysis with failure mode and effect analysis (FMEA) model in a dialysis unit.

    Science.gov (United States)

    Bonfant, Giovanna; Belfanti, Pietro; Paternoster, Giuseppe; Gabrielli, Danila; Gaiter, Alberto M; Manes, Massimo; Molino, Andrea; Pellu, Valentina; Ponzetti, Clemente; Farina, Massimo; Nebiolo, Pier E

    2010-01-01

    The aim of clinical risk management is to improve the quality of care provided by health care organizations and to assure patients' safety. Failure mode and effect analysis (FMEA) is a tool employed for clinical risk reduction. We applied FMEA to chronic hemodialysis outpatients. FMEA steps: (i) process study: we recorded phases and activities. (ii) Hazard analysis: we listed activity-related failure modes and their effects; described control measures; assigned severity, occurrence and detection scores for each failure mode and calculated the risk priority numbers (RPNs) by multiplying the 3 scores. Total RPN is calculated by adding single failure mode RPN. (iii) Planning: we performed a RPNs prioritization on a priority matrix taking into account the 3 scores, and we analyzed failure modes causes, made recommendations and planned new control measures. (iv) Monitoring: after failure mode elimination or reduction, we compared the resulting RPN with the previous one. Our failure modes with the highest RPN came from communication and organization problems. Two tools have been created to ameliorate information flow: "dialysis agenda" software and nursing datasheets. We scheduled nephrological examinations, and we changed both medical and nursing organization. Total RPN value decreased from 892 to 815 (8.6%) after reorganization. Employing FMEA, we worked on a few critical activities, and we reduced patients' clinical risk. A priority matrix also takes into account the weight of the control measures: we believe this evaluation is quick, because of simple priority selection, and that it decreases action times.

  12. Failure rate analysis using GLIMMIX

    International Nuclear Information System (INIS)

    Moore, L.M.; Hemphill, G.M.; Martz, H.F.

    1998-01-01

    This paper illustrates use of a recently developed SAS macro, GLIMMIX, for implementing an analysis suggested by Wolfinger and O'Connell (1993) in modeling failure count data with random as well as fixed factor effects. Interest in this software tool arose from consideration of modernizing the Failure Rate Analysis Code (FRAC), developed at Los Alamos National Laboratory in the early 1980's by Martz, Beckman and McInteer (1982). FRAC is a FORTRAN program developed to analyze Poisson distributed failure count data as a log-linear model, possibly with random as well as fixed effects. These statistical modeling assumptions are a special case of generalized linear mixed models, identified as GLMM in the current statistics literature. In the nearly 15 years since FRAC was developed, there have been considerable advances in computing capability, statistical methodology and available statistical software tools allowing worthwhile consideration of the tasks of modernizing FRAC. In this paper, the approaches to GLMM estimation implemented in GLIMMIX and in FRAC are described and a comparison of results for the two approaches is made with data on catastrophic time-dependent pump failures from a report by Martz and Whiteman (1984). Additionally, statistical and graphical model diagnostics are suggested and illustrated with the GLIMMIX analysis results

  13. Failure diagnosis and fault tree analysis

    International Nuclear Information System (INIS)

    Weber, G.

    1982-07-01

    In this report a methodology of failure diagnosis for complex systems is presented. Systems which can be represented by fault trees are considered. This methodology is based on switching algebra, failure diagnosis of digital circuits and fault tree analysis. Relations between these disciplines are shown. These relations are due to Boolean algebra and Boolean functions used throughout. It will be shown on this basis that techniques of failure diagnosis and fault tree analysis are useful to solve the following problems: 1. describe an efficient search of all failed components if the system is failed. 2. Describe an efficient search of all states which are close to a system failure if the system is still operating. The first technique will improve the availability, the second the reliability and safety. For these problems, the relation to methods of failure diagnosis for combinational circuits is required. Moreover, the techniques are demonstrated for a number of systems which can be represented by fault trees. (orig./RW) [de

  14. 8 CFR 240.68 - Failure to appear at an interview before an asylum officer or failure to follow requirements for...

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Failure to appear at an interview before an... Removal Under Section 203 of Pub. L. 105-100 § 240.68 Failure to appear at an interview before an asylum... interview without prior authorization may result in dismissal of the application or waiver of the right to...

  15. Failure and damage analysis of advanced materials

    CERN Document Server

    Sadowski, Tomasz

    2015-01-01

    The papers in this volume present basic concepts and new developments in failure and damage analysis with focus on advanced materials such as composites, laminates, sandwiches and foams, and also new metallic materials. Starting from some mathematical foundations (limit surfaces, symmetry considerations, invariants) new experimental results and their analysis are shown. Finally, new concepts for failure prediction and analysis will be introduced and discussed as well as new methods of failure and damage prediction for advanced metallic and non-metallic materials. Based on experimental results the traditional methods will be revised.

  16. Failure analysis of real-time systems

    International Nuclear Information System (INIS)

    Jalashgar, A.; Stoelen, K.

    1998-01-01

    This paper highlights essential aspects of real-time software systems that are strongly related to the failures and their course of propagation. The significant influence of means-oriented and goal-oriented system views in the description, understanding and analysing of those aspects is elaborated. The importance of performing failure analysis prior to reliability analysis of real-time systems is equally addressed. Problems of software reliability growth models taking the properties of such systems into account are discussed. Finally, the paper presents a preliminary study of a goal-oriented approach to model the static and dynamic characteristics of real-time systems, so that the corresponding analysis can be based on a more descriptive and informative picture of failures, their effects and the possibility of their occurrence. (author)

  17. [14C]-radiolabeling of {[trans-(8β)]-6-methyl-1-(1-methylethyl) ergoline-8-carboxylic acid, 4-methoxycyclohexyl ester (Z)-2-buteneidioate (1:1)}

    International Nuclear Information System (INIS)

    Marzoni, G.; Wheeler, W.J.; Garbrecht, W.L.

    1988-01-01

    The 5HT 2 -receptor antagonist, [ 14 C]-labeled brace[trans-(8β)]-6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid, 4-methoxycyclohexyl ester (Z)-2-butenedioate (1:1)brace (LY281067) was synthesized from unlabeled 6-methyl-1-(1-methylethyl)ergoline-8-carboxylic acid. The [ 14 C] label was introduced into the carboxyl group attached to the 8 position of the ergoline nucleus. This site is stable to metabolism. The synthesis involves removal of an unlabeled carboxyl group and subsequent reinsertion of a [ 14 C]-labeled carboxyl group into the same position. The radiolabel is not introduced until near the end of the synthesis which allows for ease of handling and scale-up of intermediates. (author)

  18. 8 CFR 1003.11 - Administrative control Immigration Courts.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Administrative control Immigration Courts. 1003.11 Section 1003.11 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE GENERAL PROVISIONS EXECUTIVE OFFICE FOR IMMIGRATION REVIEW Office of the Chief Immigration Judge...

  19. FEAT - FAILURE ENVIRONMENT ANALYSIS TOOL (UNIX VERSION)

    Science.gov (United States)

    Pack, G.

    1994-01-01

    saved as a library file which represents a generic digraph structure for a class of components. The Generate Model feature can then use library files to generate digraphs for every component listed in the modeling tables, and these individual digraph files can be used in a variety of ways to speed generation of complete digraph models. FEAT contains a preprocessor which performs transitive closure on the digraph. This multi-step algorithm builds a series of phantom bridges, or gates, that allow accurate bi-directional processing of digraphs. This preprocessing can be time-consuming, but once preprocessing is complete, queries can be answered and displayed within seconds. A UNIX X-Windows port of version 3.5 of FEAT, XFEAT, is also available to speed the processing of digraph models created on the Macintosh. FEAT v3.6, which is only available for the Macintosh, has some report generation capabilities which are not available in XFEAT. For very large integrated systems, FEAT can be a real cost saver in terms of design evaluation, training, and knowledge capture. The capability of loading multiple digraphs and schematics into FEAT allows modelers to build smaller, more focused digraphs. Typically, each digraph file will represent only a portion of a larger failure scenario. FEAT will combine these files and digraphs from other modelers to form a continuous mathematical model of the system's failure logic. Since multiple digraphs can be cumbersome to use, FEAT ties propagation results to schematic drawings produced using MacDraw II (v1.1v2 or later) or MacDraw Pro. This makes it easier to identify single and double point failures that may have to cross several system boundaries and multiple engineering disciplines before creating a hazardous condition. FEAT v3.6 for the Macintosh is written in C-language using Macintosh Programmer's Workshop C v3.2. It requires at least a Mac II series computer running System 7 or System 6.0.8 and 32 Bit QuickDraw. It also requires a math

  20. Constructing Ontology for Knowledge Sharing of Materials Failure Analysis

    Directory of Open Access Journals (Sweden)

    Peng Shi

    2014-01-01

    Full Text Available Materials failure indicates the fault with materials or components during their performance. To avoid the reoccurrence of similar failures, materials failure analysis is executed to investigate the reasons for the failure and to propose improved strategies. The whole procedure needs sufficient domain knowledge and also produces valuable new knowledge. However, the information about the materials failure analysis is usually retained by the domain expert, and its sharing is technically difficult. This phenomenon may seriously reduce the efficiency and decrease the veracity of the failure analysis. To solve this problem, this paper adopts ontology, a novel technology from the Semantic Web, as a tool for knowledge representation and sharing and describes the construction of the ontology to obtain information concerning the failure analysis, application area, materials, and failure cases. The ontology represented information is machine-understandable and can be easily shared through the Internet. At the same time, failure case intelligent retrieval, advanced statistics, and even automatic reasoning can be accomplished based on ontology represented knowledge. Obviously this can promote the knowledge sharing of materials service safety and improve the efficiency of failure analysis. The case of a nuclear power plant area is presented to show the details and benefits of this method.

  1. Failure Analysis of a Modern High Performance Diesel Engine Cylinder Head

    Directory of Open Access Journals (Sweden)

    Bingbin Guo

    2014-05-01

    Full Text Available This paper presents a failure analysis on a modern high performance diesel engine cylinder head made of gray cast iron. Cracks appeared intensively at the intersection of two exhaust passages in the cylinder head. The metallurgical examination was conducted in the crack origin zone and other zones. Meanwhile, the load state of the failure part of the cylinder head was determined through the Finite Element Analysis. The results showed that both the point of the maximum temperature and the point of the maximum thermal-mechanical coupling stress were not in the crack position. The excessive load was not the main cause of the failure. The large cooling rate in the casting process created an abnormal graphite zone that existed below the surface of the exhaust passage (about 1.1 mm depth, which led to the fracture of the cylinder head. In the fractured area, there were a large number of casting defects (dip sand, voids, etc. and inferior graphite structure (type D, type E which caused stress concentration. Moreover, high temperature gas entered the cracks, which caused material corrosion, material oxidization, and crack propagation. Finally, premature fracture of the cylinder head took place.

  2. Failures to further developing orphan medicinal products after designation granted in Europe: an analysis of marketing authorisation failures and abandoned drugs.

    Science.gov (United States)

    Giannuzzi, Viviana; Landi, Annalisa; Bosone, Enrico; Giannuzzi, Floriana; Nicotri, Stefano; Torrent-Farnell, Josep; Bonifazi, Fedele; Felisi, Mariagrazia; Bonifazi, Donato; Ceci, Adriana

    2017-09-11

    The research and development process in the field of rare diseases is characterised by many well-known difficulties, and a large percentage of orphan medicinal products do not reach the marketing approval.This work aims at identifying orphan medicinal products that failed the developmental process and investigating reasons for and possible factors influencing failures. Drugs designated in Europe under Regulation (European Commission) 141/2000 in the period 2000-2012 were investigated in terms of the following failures: (1) marketing authorisation failures (refused or withdrawn) and (2) drugs abandoned by sponsors during development.Possible risk factors for failure were analysed using statistically validated methods. This study points out that 437 out of 788 designations are still under development, while 219 failed the developmental process. Among the latter, 34 failed the marketing authorisation process and 185 were abandoned during the developmental process. In the first group of drugs (marketing authorisation failures), 50% reached phase II, 47% reached phase III and 3% reached phase I, while in the second group (abandoned drugs), the majority of orphan medicinal products apparently never started the development process, since no data on 48.1% of them were published and the 3.2% did not progress beyond the non-clinical stage.The reasons for failures of marketing authorisation were: efficacy/safety issues (26), insufficient data (12), quality issues (7), regulatory issues on trials (4) and commercial reasons (1). The main causes for abandoned drugs were efficacy/safety issues (reported in 54 cases), inactive companies (25.4%), change of company strategy (8.1%) and drug competition (10.8%). No information concerning reasons for failure was available for 23.2% of the analysed products. This analysis shows that failures occurred in 27.8% of all designations granted in Europe, the main reasons being safety and efficacy issues. Moreover, the stage of development

  3. Data needs for common cause failure analysis

    International Nuclear Information System (INIS)

    Parry, G.W.; Paula, H.M.; Rasmuson, D.; Whitehead, D.

    1990-01-01

    The procedures guide for common cause failure analysis published jointly by USNRC and EPRI requires a detailed historical event analysis. Recent work on the further development of the cause-defense picture of common cause failures introduced in that guide identified the information that is necessary to perform the detailed analysis in an objective manner. This paper summarizes these information needs

  4. 7 CFR 319.8-11 - From approved areas of Mexico.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false From approved areas of Mexico. 319.8-11 Section 319.8... Conditions for the Entry of Cotton and Covers from Mexico § 319.8-11 From approved areas of Mexico. (a) Entry... in, and which were produced and handled only in approved areas of Mexico 5 may be authorized through...

  5. Integrated failure probability estimation based on structural integrity analysis and failure data: Natural gas pipeline case

    International Nuclear Information System (INIS)

    Dundulis, Gintautas; Žutautaitė, Inga; Janulionis, Remigijus; Ušpuras, Eugenijus; Rimkevičius, Sigitas; Eid, Mohamed

    2016-01-01

    In this paper, the authors present an approach as an overall framework for the estimation of the failure probability of pipelines based on: the results of the deterministic-probabilistic structural integrity analysis (taking into account loads, material properties, geometry, boundary conditions, crack size, and defected zone thickness), the corrosion rate, the number of defects and failure data (involved into the model via application of Bayesian method). The proposed approach is applied to estimate the failure probability of a selected part of the Lithuanian natural gas transmission network. The presented approach for the estimation of integrated failure probability is a combination of several different analyses allowing us to obtain: the critical crack's length and depth, the failure probability of the defected zone thickness, dependency of the failure probability on the age of the natural gas transmission pipeline. A model's uncertainty analysis and uncertainty propagation analysis are performed, as well. - Highlights: • Degradation mechanisms of natural gas transmission pipelines. • Fracture mechanic analysis of the pipe with crack. • Stress evaluation of the pipe with critical crack. • Deterministic-probabilistic structural integrity analysis of gas pipeline. • Integrated estimation of pipeline failure probability by Bayesian method.

  6. Preliminary failure mode and effect analysis

    International Nuclear Information System (INIS)

    Addison, J.V.

    1972-01-01

    A preliminary Failure Mode and Effect Analysis (FMEA) was made on the overall 5 Kwe system. A general discussion of the system and failure effect is given in addition to the tabulated FMEA and a primary block diagram of the system. (U.S.)

  7. X-framework: Space system failure analysis framework

    Science.gov (United States)

    Newman, John Steven

    Space program and space systems failures result in financial losses in the multi-hundred million dollar range every year. In addition to financial loss, space system failures may also represent the loss of opportunity, loss of critical scientific, commercial and/or national defense capabilities, as well as loss of public confidence. The need exists to improve learning and expand the scope of lessons documented and offered to the space industry project team. One of the barriers to incorporating lessons learned include the way in which space system failures are documented. Multiple classes of space system failure information are identified, ranging from "sound bite" summaries in space insurance compendia, to articles in journals, lengthy data-oriented (what happened) reports, and in some rare cases, reports that treat not only the what, but also the why. In addition there are periodically published "corporate crisis" reports, typically issued after multiple or highly visible failures that explore management roles in the failure, often within a politically oriented context. Given the general lack of consistency, it is clear that a good multi-level space system/program failure framework with analytical and predictive capability is needed. This research effort set out to develop such a model. The X-Framework (x-fw) is proposed as an innovative forensic failure analysis approach, providing a multi-level understanding of the space system failure event beginning with the proximate cause, extending to the directly related work or operational processes and upward through successive management layers. The x-fw focus is on capability and control at the process level and examines: (1) management accountability and control, (2) resource and requirement allocation, and (3) planning, analysis, and risk management at each level of management. The x-fw model provides an innovative failure analysis approach for acquiring a multi-level perspective, direct and indirect causation of

  8. Importance analysis for the systems with common cause failures

    International Nuclear Information System (INIS)

    Pan Zhijie; Nonaka, Yasuo

    1995-01-01

    This paper extends the importance analysis technique to the research field of common cause failures to evaluate the structure importance, probability importance, and β-importance for the systems with common cause failures. These importance measures would help reliability analysts to limit the common cause failure analysis framework and find efficient defence strategies against common cause failures

  9. Goal-oriented failure analysis - a systems analysis approach to hazard identification

    International Nuclear Information System (INIS)

    Reeves, A.B.; Davies, J.; Foster, J.; Wells, G.L.

    1990-01-01

    Goal-Oriented Failure Analysis, GOFA, is a methodology which is being developed to identify and analyse the potential failure modes of a hazardous plant or process. The technique will adopt a structured top-down approach, with a particular failure goal being systematically analysed. A systems analysis approach is used, with the analysis being organised around a systems diagram of the plant or process under study. GOFA will also use checklists to supplement the analysis -these checklists will be prepared in advance of a group session and will help to guide the analysis and avoid unnecessary time being spent on identifying obvious failure modes or failing to identify certain hazards or failures. GOFA is being developed with the aim of providing a hazard identification methodology which is more efficient and stimulating than the conventional approach to HAZOP. The top-down approach should ensure that the analysis is more focused and the use of a systems diagram will help to pull the analysis together at an early stage whilst also helping to structure the sessions in a more stimulating way than the conventional techniques. GOFA will be, essentially, an extension of the HAZOP methodology. GOFA is currently being computerised using a knowledge-based systems approach for implementation. The Goldworks II expert systems development tool is being used. (author)

  10. Improved methods for dependent failure analysis in PSA

    International Nuclear Information System (INIS)

    Ballard, G.M.; Games, A.M.

    1988-01-01

    The basic design principle used in ensuring the safe operation of nuclear power plant is defence in depth. This normally takes the form of redundant equipment and systems which provide protection even if a number of equipment failures occur. Such redundancy is particularly effective in ensuring that multiple, independent equipment failures with the potential for jeopardising reactor safety will be rare events. However the achievement of high reliability has served to highlight the potentially dominant role of multiple, dependent failures of equipment and systems. Analysis of reactor operating experience has shown that dependent failure events are the major contributors to safety system failures and reactor incidents and accidents. In parallel PSA studies have shown that the results of a safety analysis are sensitive to assumptions made about the dependent failure (CCF) probability for safety systems. Thus a Westinghouse Analysis showed that increasing system dependent failure probabilities by a factor of 5 led to a factor 4 increase in core. This paper particularly refers to the engineering concepts underlying dependent failure assessment touching briefly on aspects of data. It is specifically not the intent of our work to develop a new mathematical model of CCF but to aid the use of existing models

  11. Patterns of Failure After MammoSite Brachytherapy Partial Breast Irradiation: A Detailed Analysis

    International Nuclear Information System (INIS)

    Chen, Sea; Dickler, Adam; Kirk, Michael; Shah, Anand; Jokich, Peter; Solmos, Gene; Strauss, Jonathan; Dowlatshahi, Kambiz; Nguyen, Cam; Griem, Katherine

    2007-01-01

    Purpose: To report the results of a detailed analysis of treatment failures after MammoSite breast brachytherapy for partial breast irradiation from our single-institution experience. Methods and Materials: Between October 14, 2002 and October 23, 2006, 78 patients with early-stage breast cancer were treated with breast-conserving surgery and accelerated partial breast irradiation using the MammoSite brachytherapy applicator. We identified five treatment failures in the 70 patients with >6 months' follow-up. Pathologic data, breast imaging, and radiation treatment plans were reviewed. For in-breast failures more than 2 cm away from the original surgical bed, the doses delivered to the areas of recurrence by partial breast irradiation were calculated. Results: At a median follow-up time of 26.1 months, five treatment failures were identified. There were three in-breast failures more than 2 cm away from the original surgical bed, one failure directly adjacent to the original surgical bed, and one failure in the axilla with synchronous distant metastases. The crude failure rate was 7.1% (5 of 70), and the crude local failure rate was 5.7% (4 of 70). Estimated progression-free survival at 48 months was 89.8% (standard error 4.5%). Conclusions: Our case series of 70 patients with >6 months' follow-up and a median follow-up of 26 months is the largest single-institution report to date with detailed failure analysis associated with MammoSite brachytherapy. Our failure data emphasize the importance of patient selection when offering partial breast irradiation

  12. Analysis of risk factors for cluster behavior of dental implant failures.

    Science.gov (United States)

    Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    2017-08-01

    Some studies indicated that implant failures are commonly concentrated in few patients. To identify and analyze cluster behavior of dental implant failures among subjects of a retrospective study. This retrospective study included patients receiving at least three implants only. Patients presenting at least three implant failures were classified as presenting a cluster behavior. Univariate and multivariate logistic regression models and generalized estimating equations analysis evaluated the effect of explanatory variables on the cluster behavior. There were 1406 patients with three or more implants (8337 implants, 592 failures). Sixty-seven (4.77%) patients presented cluster behavior, with 56.8% of all implant failures. The intake of antidepressants and bruxism were identified as potential negative factors exerting a statistically significant influence on a cluster behavior at the patient-level. The negative factors at the implant-level were turned implants, short implants, poor bone quality, age of the patient, the intake of medicaments to reduce the acid gastric production, smoking, and bruxism. A cluster pattern among patients with implant failure is highly probable. Factors of interest as predictors for implant failures could be a number of systemic and local factors, although a direct causal relationship cannot be ascertained. © 2017 Wiley Periodicals, Inc.

  13. Risk assessment of the emergency processes: Healthcare failure mode and effect analysis.

    Science.gov (United States)

    Taleghani, Yasamin Molavi; Rezaei, Fatemeh; Sheikhbardsiri, Hojat

    2016-01-01

    Ensuring about the patient's safety is the first vital step in improving the quality of care and the emergency ward is known as a high-risk area in treatment health care. The present study was conducted to evaluate the selected risk processes of emergency surgery department of a treatment-educational Qaem center in Mashhad by using analysis method of the conditions and failure effects in health care. In this study, in combination (qualitative action research and quantitative cross-sectional), failure modes and effects of 5 high-risk procedures of the emergency surgery department were identified and analyzed according to Healthcare Failure Mode and Effects Analysis (HFMEA). To classify the failure modes from the "nursing errors in clinical management model (NECM)", the classification of the effective causes of error from "Eindhoven model" and determination of the strategies to improve from the "theory of solving problem by an inventive method" were used. To analyze the quantitative data of descriptive statistics (total points) and to analyze the qualitative data, content analysis and agreement of comments of the members were used. In 5 selected processes by "voting method using rating", 23 steps, 61 sub-processes and 217 potential failure modes were identified by HFMEA. 25 (11.5%) failure modes as the high risk errors were detected and transferred to the decision tree. The most and the least failure modes were placed in the categories of care errors (54.7%) and knowledge and skill (9.5%), respectively. Also, 29.4% of preventive measures were in the category of human resource management strategy. "Revision and re-engineering of processes", "continuous monitoring of the works", "preparation and revision of operating procedures and policies", "developing the criteria for evaluating the performance of the personnel", "designing a suitable educational content for needs of employee", "training patients", "reducing the workload and power shortage", "improving team

  14. Comparative analysis of Nb and Ti addition in the Cu-11,8%wt.Al-0,5%wt.Be e Cu-11,8%wt.Al-3,0%wt.Ni shape memory alloy

    International Nuclear Information System (INIS)

    Silva Junior, M.Q. da; Oliveira, G.D. de

    2014-01-01

    The system of the Cu-Al alloys shape memory alloy have been the subject of many studies due to a wide range of possible applications and relatively low cost, and the chemical composition of the main factors that determine the properties of these properties. This work analyzed the influence of Nb and Ti elements in Cu-11,8Al-0,5Be and Cu-11,8Al-3,0Ni alloy. The alloys are obtained by melting and passed through homogenizing heat treatment followed by water quenching at 30°C. The samples were characterized by Microscopy Optical, X-ray Diffraction and Microhardness testing. The alloys showed fine precipitates of second phase homogeneously distributed in the matrix that provides improvement in the properties of these alloys. (author)

  15. Comparison of technical and physical activities between 8 vs. 8 and 11 vs. 11 games in young Korean soccer players.

    Science.gov (United States)

    Oh, Seong Hwan; Joo, Chang Hwa

    2018-04-01

    The aims of this study were to examine the differences in technical aspects and physical demands between small-size games (SSG; 8 vs. 8) and regular-size games (RSG; 11 vs. 11) in young Korean soccer players. Seventy-nine young soccer players from 6 teams (U-12) volunteered to participate in the study. The players completed 4 games (2 SSG, 62×51 m, and 2 RSG, 80×54 m) in 2 days. Each game was filmed to evaluate technical actions. Physical demand variables were measured using global positioning system technology. SSG showed significantly greater numbers of technical plays among 17 variables when compared to RSG ( P game format for Korean young soccer players, resulting in significantly greater exposure to technical plays without excessive physical demands.

  16. Lessons learned from failure analysis

    International Nuclear Information System (INIS)

    Le May, I.

    2006-01-01

    Failure analysis can be a very useful tool to designers and operators of plant and equipment. It is not simply something that is done for lawyers and insurance companies, but is a tool from which lessons can be learned and by means of which the 'breed' can be improved. In this presentation, several failure investigations that have contributed to understanding will be presented. Specifically, the following cases will be discussed: 1) A fire at a refinery that occurred in a desulphurization unit. 2) The failure of a pipeline before it was even put into operation. 3) Failures in locomotive axles that took place during winter operation. The refinery fire was initially blamed on defective Type 321 seamless stainless steel tubing, but there were conflicting views between 'experts' involved as to the mechanism of failure and the writer was called upon to make an in-depth study. This showed that there were a variety of failure mechanism involved, including high temperature fracture, environmentally-induced cracking and possible manufacturing defects. The unraveling of the failure sequence is described and illustrated. The failure of an oil transmission was discovered when the line was pressure tested some months after it had been installed and before it was put into service. Repairs were made and failure occurred in another place upon the next pressure test being conducted. After several more repairs had been made the line was abandoned and a lawsuit was commenced on the basis that the steel was defective. An investigation disclosed that the material was sensitive to embrittlement and the causes of this were determined. As a result, changes were made in the microstructural control of the product to avoid similar problems in future. A series of axle failures occurred in diesel electric locomotives during winter. An investigation was made to determine the nature of the failures which were not by classical fatigue, nor did they correspond to published illustrations of Cu

  17. Silicon-controlled rectifier failure investigation report, April 11 and May 7, 1986, Type A occurrence

    International Nuclear Information System (INIS)

    1986-01-01

    As a result of the April 11, 1986 failure and subsequent property damage of the silicon-controlled rectifier (SCR) device used to provide dc power to the motor driven construction and salt handling (CandSH) hoist at the Waste Isolation Pilot Plant (WIPP), the Project Manager, WIPP Project Office, appointed an Accident Investigation Board on April 14, 1986. The Board was tasked to investigate, to determine the cause or causes of the SCR failure, and to make appropriate recommendations to prevent a recurrence. Subsequently, the scope of the investigation was expanded on April 22, 1986, to include a series of failures that occurred after the initial failure. This occurrence came after the SCR had been released by the Board, repaired, modified, and returned to use. The investigation included a review of the engineering, procurement, operations, and maintenance programs of the Management and Operating Contractor (MOC), along with a detailed investigation of the hardware involved in the failure. Analytical techniques included use of the Management Oversight Risk Tree (MORT) and Events and Causal Factors Sequence Charting. 15 figs

  18. Failure analysis for WWER-fuel elements

    International Nuclear Information System (INIS)

    Boehmert, J.; Huettig, W.

    1986-10-01

    If the fuel defect rate proves significantly high, failure analysis has to be performed in order to trace down the defect causes, to implement corrective actions, and to take measures of failure prevention. Such analyses are work-consuming and very skill-demanding technical tasks, which require examination methods and devices excellently developed and a rich stock of experience in evaluation of features of damage. For that this work specifies the procedure of failure analyses in detail. Moreover prerequisites and experimental equipment for the investigation of WWER-type fuel elements are described. (author)

  19. failure analysis of a uav flight control system using markov analysis

    African Journals Online (AJOL)

    Failure analysis of a flight control system proposed for Air Force Institute of Technology (AFIT) Unmanned Aerial Vehicle (UAV) was studied using Markov Analysis (MA). It was perceived that understanding of the number of failure states and the probability of being in those state are of paramount importance in order to ...

  20. 4. Nuclear power plant component failures

    International Nuclear Information System (INIS)

    1990-01-01

    Nuclear power plant component failures are dealt with in relation to reliability in nuclear power engineering. The topics treated include classification of failures, analysis of their causes and impacts, nuclear power plant failure data acquisition and processing, interdependent failures, and human factor reliability in nuclear power engineering. (P.A.). 8 figs., 7 tabs., 23 refs

  1. Comparative analysis of Nb and Ti addition in the Cu-11,8%wt.Al-0,5%wt.Be e Cu-11,8%wt.Al-3,0%wt.Ni shape memory alloy; Analise comparativa da adicao de NB e TI nas ligas Cu-11,8Al-0,5Be e Cu-11,8Al-3,0Ni passiveis do efeito memoria de forma

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, M.Q. da; Oliveira, G.D. de, E-mail: manoel.quirino@ufersa.edu.br [Universidade Federal Rural do Semi-Arido (UFERSA), Mossoro, RN (Brazil)

    2014-07-01

    The system of the Cu-Al alloys shape memory alloy have been the subject of many studies due to a wide range of possible applications and relatively low cost, and the chemical composition of the main factors that determine the properties of these properties. This work analyzed the influence of Nb and Ti elements in Cu-11,8Al-0,5Be and Cu-11,8Al-3,0Ni alloy. The alloys are obtained by melting and passed through homogenizing heat treatment followed by water quenching at 30°C. The samples were characterized by Microscopy Optical, X-ray Diffraction and Microhardness testing. The alloys showed fine precipitates of second phase homogeneously distributed in the matrix that provides improvement in the properties of these alloys. (author)

  2. Failure analysis of prestressed concrete beam under impact loading

    International Nuclear Information System (INIS)

    Ishikawa, N.; Sonoda, Y.; Kobayashi, N.

    1993-01-01

    This paper presents a failure analysis of prestressed concrete (PC) beam under impact loading. At first, the failure analysis of PC beam section is performed by using the discrete section element method in order to obtain the dynamic bending moment-curvature relation. Secondary, the failure analysis of PC beam is performed by using the rigid panel-spring model. Finally, the numerical calculation is executed and is compared with the experimental results. It is found that this approach can simulate well the experiments at the local and overall failure of the PC beam as well as the impact load and the displacement-time relations. (author)

  3. Micromechanics Based Failure Analysis of Heterogeneous Materials

    Science.gov (United States)

    Sertse, Hamsasew M.

    are performed for both brittle failure/high cycle fatigue (HCF) for negligible plastic strain and ductile failure/low cycle fatigue (LCF) for large plastic strain. The proposed approach is incorporated in SwiftComp and used to predict the initial failure envelope, stress-strain curve for various loading conditions, and fatigue life of heterogeneous materials. The combined effects of strain hardening and progressive fatigue damage on the effective properties of heterogeneous materials are also studied. The capability of the current approach is validated using several representative examples of heterogeneous materials including binary composites, continuous fiber-reinforced composites, particle-reinforced composites, discontinuous fiber-reinforced composites, and woven composites. The predictions of MSG are also compared with the predictions obtained using various micromechanics approaches such as Generalized Methods of Cells (GMC), Mori-Tanaka (MT), and Double Inclusions (DI) and Representative Volume Element (RVE) Analysis (called as 3-dimensional finite element analysis (3D FEA) in this document). This study demonstrates that a micromechanics based failure analysis has a great potential to rigorously and more accurately analyze initiation and progression of damage in heterogeneous materials. However, this approach requires material properties specific to damage analysis, which are needed to be independently calibrated for each constituent.

  4. Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

    Science.gov (United States)

    Doherty, Ben; Lawlor, Denise; Gillet, Jean-Pierre; Gottesman, Michael; O'Leary, John J; Stordal, Britta

    2014-01-01

    KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer. A Taqman low-density array was used to characterize the expression of 380 genes previously associated with chemoresistance. Identified pathways were further analyzed using cytotoxicity assays, metabolomics and western blots. KB-8-5-11 cells were sensitive to CuSO4 and the glutathione inhibitor buthionine sulphoximine. Expression of ATPase, Cu(2+) transporting alpha (ATP7A) and ATP7B were decreased at the protein and gene levels respectively in KB-8-5-11. KB-8-5-11 had decreased gene expression of glutathione S-transferase pi 1 (GSTP1), GSTA4 and GSTK1. Cisplatin treatment significantly lowered total cellular glutathione in parental KB-3-1 cells. Glutathione also tended to be lower in KB-8-5-11 cells compared to KB-3-1 cells. KB-8-5-11 cells have alterations in their copper transporters and glutathione metabolism, contributing to their cisplatin-sensitive phenotype.

  5. Utility of the Seattle Heart Failure Model in patients with advanced heart failure.

    Science.gov (United States)

    Kalogeropoulos, Andreas P; Georgiopoulou, Vasiliki V; Giamouzis, Grigorios; Smith, Andrew L; Agha, Syed A; Waheed, Sana; Laskar, Sonjoy; Puskas, John; Dunbar, Sandra; Vega, David; Levy, Wayne C; Butler, Javed

    2009-01-27

    The aim of this study was to validate the Seattle Heart Failure Model (SHFM) in patients with advanced heart failure (HF). The SHFM was developed primarily from clinical trial databases and extrapolated the benefit of interventions from published data. We evaluated the discrimination and calibration of SHFM in 445 advanced HF patients (age 52 +/- 12 years, 68.5% male, 52.4% white, ejection fraction 18 +/- 8%) referred for cardiac transplantation. The primary end point was death (n = 92), urgent transplantation (n = 14), or left ventricular assist device (LVAD) implantation (n = 3); a secondary analysis was performed on mortality alone. Patients were receiving optimal therapy (angiotensin-II modulation 92.8%, beta-blockers 91.5%, aldosterone antagonists 46.3%), and 71.0% had an implantable device (defibrillator 30.4%, biventricular pacemaker 3.4%, combined 37.3%). During a median follow-up of 21 months, 109 patients (24.5%) had an event. Although discrimination was adequate (c-statistic >0.7), the SHFM overall underestimated absolute risk (observed vs. predicted event rate: 11.0% vs. 9.2%, 21.0% vs. 16.6%, and 27.9% vs. 22.8% at 1, 2, and 3 years, respectively). Risk underprediction was more prominent in patients with an implantable device. The SHFM had different calibration properties in white versus black patients, leading to net underestimation of absolute risk in blacks. Race-specific recalibration improved the accuracy of predictions. When analysis was restricted to mortality, the SHFM exhibited better performance. In patients with advanced HF, the SHFM offers adequate discrimination, but absolute risk is underestimated, especially in blacks and in patients with devices. This is more prominent when including transplantation and LVAD implantation as an end point.

  6. Debugging Nondeterministic Failures in Linux Programs through Replay Analysis

    Directory of Open Access Journals (Sweden)

    Shakaiba Majeed

    2018-01-01

    Full Text Available Reproducing a failure is the first and most important step in debugging because it enables us to understand the failure and track down its source. However, many programs are susceptible to nondeterministic failures that are hard to reproduce, which makes debugging extremely difficult. We first address the reproducibility problem by proposing an OS-level replay system for a uniprocessor environment that can capture and replay nondeterministic events needed to reproduce a failure in Linux interactive and event-based programs. We then present an analysis method, called replay analysis, based on the proposed record and replay system to diagnose concurrency bugs in such programs. The replay analysis method uses a combination of static analysis, dynamic tracing during replay, and delta debugging to identify failure-inducing memory access patterns that lead to concurrency failure. The experimental results show that the presented record and replay system has low-recording overhead and hence can be safely used in production systems to catch rarely occurring bugs. We also present few concurrency bug case studies from real-world applications to prove the effectiveness of the proposed bug diagnosis framework.

  7. Lecture notes: meantime to failure analysis

    International Nuclear Information System (INIS)

    Hanlen, R.C.

    1976-01-01

    A method is presented which affects the Quality Assurance Engineer's place in management decision making by giving him a working parameter to base sound engineering and management decisions. The theory used in Reliability Engineering to determine the mean-time-to-failure of a component or system is reviewed. The method presented derives the probability density function for the parameter of the exponential distribution. The exponential distribution is commonly used by industry to determine the reliability of a component or system when the failure rate is assumed to be constant. Some examples of N Reactor performance data are used. To be specific: The ball system data with 4.9 x 10 6 unit hours of service and 7 individual failures indicates a demonstrated 98.8 percent reliability at a 95 percent confidence level for a 12 month mission period, and the diesel starts data with 7.2 x 10 5 unit hours of service and 1 failure indicates a demonstrated 94.4 percent reliability at a 95 percent confidence level for a 12 month mission period

  8. Failure Modes and Effects Analysis (FMEA): A Bibliography

    Science.gov (United States)

    2000-01-01

    Failure modes and effects analysis (FMEA) is a bottom-up analytical process that identifies process hazards, which helps managers understand vulnerabilities of systems, as well as assess and mitigate risk. It is one of several engineering tools and techniques available to program and project managers aimed at increasing the likelihood of safe and successful NASA programs and missions. This bibliography references 465 documents in the NASA STI Database that contain the major concepts, failure modes or failure analysis, in either the basic index of the major subject terms.

  9. BACFIRE, Minimal Cut Sets Common Cause Failure Fault Tree Analysis

    International Nuclear Information System (INIS)

    Fussell, J.B.

    1983-01-01

    1 - Description of problem or function: BACFIRE, designed to aid in common cause failure analysis, searches among the basic events of a minimal cut set of the system logic model for common potential causes of failure. The potential cause of failure is called a qualitative failure characteristics. The algorithm searches qualitative failure characteristics (that are part of the program input) of the basic events contained in a set to find those characteristics common to all basic events. This search is repeated for all cut sets input to the program. Common cause failure analysis is thereby performed without inclusion of secondary failure in the system logic model. By using BACFIRE, a common cause failure analysis can be added to an existing system safety and reliability analysis. 2 - Method of solution: BACFIRE searches the qualitative failure characteristics of the basic events contained in the fault tree minimal cut set to find those characteristics common to all basic events by either of two criteria. The first criterion can be met if all the basic events in a minimal cut set are associated by a condition which alone may increase the probability of multiple component malfunction. The second criterion is met if all the basic events in a minimal cut set are susceptible to the same secondary failure cause and are located in the same domain for that cause of secondary failure. 3 - Restrictions on the complexity of the problem - Maxima of: 1001 secondary failure maps, 101 basic events, 10 cut sets

  10. Failure analysis of vise jaw holders for hacksaw machine

    Directory of Open Access Journals (Sweden)

    Essam Ali Al-Bahkali

    2018-01-01

    Full Text Available Failure analysis in mechanical components has been investigated in many studies in the last few years. Failure analysis and prevention are important functions in all engineering disciplines. Materials engineers are often the lead role in the analysis of failures, where a component or product fails in service or if a failure occurs during manufacturing or production processing. In any case, one must determine the cause of the failure to prevent future occurrences and/or to improve the performance of the device, component or structure. For example, the vise jaw holders of hacksaws can break due to accidental heavy loads or machine misuse. The parts that break are the stationary and movable vise jaw holders and the connecter power screw between the holders. To investigate the failure of these components, a three-dimensional finite element model for stress analysis was performed. First, the analysis identified the broken components of the hacksaw machine. In addition, the type of materials of the broken parts was identified, a CAD model was built, and the hacksaw mechanism was analyzed to determine the accurate applied loads on the broken parts. After analyzing the model using Abaqus CAE software, the results showed that the location of the high stresses was identical with the high-stress locations in the original, broken parts. Furthermore, the power screw was subjected to a high load, which deformed the power screw. Also, the stationary vise jaw holder was broken by impact because it was not touched by the power screw until the movable vise jaw holder broke. A conclusion is drawn from the failure analysis and a way to improve the design of the broken parts is suggested.

  11. Failure Propagation Modeling and Analysis via System Interfaces

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2016-01-01

    Full Text Available Safety-critical systems must be shown to be acceptably safe to deploy and use in their operational environment. One of the key concerns of developing safety-critical systems is to understand how the system behaves in the presence of failures, regardless of whether that failure is triggered by the external environment or caused by internal errors. Safety assessment at the early stages of system development involves analysis of potential failures and their consequences. Increasingly, for complex systems, model-based safety assessment is becoming more widely used. In this paper we propose an approach for safety analysis based on system interface models. By extending interaction models on the system interface level with failure modes as well as relevant portions of the physical system to be controlled, automated support could be provided for much of the failure analysis. We focus on fault modeling and on how to compute minimal cut sets. Particularly, we explore state space reconstruction strategy and bounded searching technique to reduce the number of states that need to be analyzed, which remarkably improves the efficiency of cut sets searching algorithm.

  12. Use of fuel failure correlations in accident analysis

    International Nuclear Information System (INIS)

    O'Dell, L.D.; Baars, R.E.; Waltar, A.E.

    1975-05-01

    The MELT-III code for analysis of a Transient Overpower (TOP) accident in an LMFBR is briefly described, including failure criteria currently applied in the code. Preliminary results of calculations exploring failure patterns in time and space in the reactor core are reported and compared for the two empirical fuel failure correlations employed in the code. (U.S.)

  13. Thermal stability of polyoxometalate compound of Keggin K8[2-SiW11O39]∙nH2O supported with SiO2

    Directory of Open Access Journals (Sweden)

    Yunita Sari M A

    2017-06-01

    Full Text Available Synthesis through sol-gel method and characterization of polyoxometalate compound of K8[b2-SiW11O39]∙nH2O supported with SiO2 have been done. The functional groups of polyoxometalate compound  was characterized by FT-IR spectrophotometer for the fungtional groups and the degree’s of crystalinity  using XRD. The acidity of K8[b2-SiW11O39]∙nH2O/SiO2 was determined qualitative analysis using ammonia and pyridine adsorption and the quantitative analysis using potentiometric titration method. The results of FT-IR spectrum of K8[b2-SiW11O39]∙nH2O appeared at  wavenumber 987.55 cm-1 (W=O, 864.11 cm-1 (W-Oe-W, 756.1 cm-1 (W-Oc-W, 3425.58 cm-1 (O-H, respectively and spectrum of  K8[b2-SiW11O39]SiO2 appeared at wavenumber  956.69 cm-1 (W=O, 864.11 cm-1 (W-Oe-W, 3448.72 cm-1 (O-H, respectively. The diffraction of XRD pattern of K8[b2-SiW11O39]∙nH2O and K8[b2-SiW11O39]∙nH2O/SiO2 compounds show high crystalinity. The acidic properties showed K8[b2-SiW11O39]∙nH2O/SiO2 more acidic compared to K8[b2-The SiW11O39]∙nH2O. The qualitative analysis showed pyridine compound adsorbed more of polyoxometalate compound of K8[b2-SiW11O39]∙nH2O/SiO2. Analysis of stability showed that the K8[b2-SiW11O39]∙nH2O/SiO2 at temperature 500°C has structural changes compare to 200-400oC which was indicated from vibration at wavenumber 800-1000 cm-1. Keywords : K8[b2-SiW11O39]∙nH2O, polyoxometalate, SiO2.

  14. Light water reactor lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L.

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response

  15. Light water reactor lower head failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

  16. FRESS pin failure model and its application to E-8 TREAT test

    International Nuclear Information System (INIS)

    Kalimullah.

    1979-01-01

    FRESS is a cladding rupture prediction model for an irradiated mixed-oxide LMFBR fuel pin during transient heating based only on the internal pressurization of the cladding by the fission gas released from fuel grains during the transient. The model is applied to the analysis of the hottest PNL-10-53 pin in the 7-pin E-8 TREAT test which simulates a $3/sec transient overpower. Although the uncertainties of the inputs to the temperature calculation done with the COBRA code have not been included, the uncertain input parameters to FRESS have been varied over their estimated uncertainties. The cladding rupture predictions are a few tens of milliseconds late compared to the most probable failure time detected in the test. However, these calculations seem to indicate that fisson gas pressure is a significant mechanism for causing clad rupture in this test

  17. The D543N polymorphism of the SLC11A1/NRAMP1 gene is associated with treatment failure in male patients with pulmonary tuberculosis.

    Science.gov (United States)

    Salinas-Delgado, Yvain; Galaviz-Hernández, Carlos; Toral, René García; Ávila Rejón, Carmen A; Reyes-Lopez, Miguel A; Martínez, Antonio Rojas; Martínez-Aguilar, Gerardo; Sosa-Macías, Martha

    2015-09-01

    Polymorphisms in SLC11A1/NRAMP1 have shown an important association with susceptibility to tuberculosis and progression to active disease. However, whether there is an association of these polymorphisms with treatment failure is unknown. The aim of this study was to determine the association of SLC11A1 polymorphisms with treatment failure in Mexican subjects with pulmonary tuberculosis. Thirty-three subjects with treatment failure were paired by age and body mass index with 33 patients who successfully completed treatment and were considered cured. We assessed the polymorphisms of SLC11A1 in the regions of D543N and INT4 via polymerase chain reaction real-time TaqMan® single nucleotide polymorphism (SNP) genotyping. We found that D543N (G/A genotype) was associated with treatment failure in patients with pulmonary tuberculosis [odds ratio (OR) 11.61, 95% confidence interval (CI) 3.66-36.78]. When adjusted by gender, this association remained significant in males (OR 11.09, 95% CI 3.46-35.51). In our male population, the presence of the D543N polymorphism of SLC11A1 is a risk factor for treatment failure. This finding should be confirmed in other populations.

  18. Replication of KCNJ11 (p.E23K and ABCC8 (p.S1369A Association in Russian Diabetes Mellitus 2 Type Cohort and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Ekaterina Alekseevna Sokolova

    Full Text Available The genes ABCC8 and KCNJ11 have received intense focus in type 2 diabetes mellitus (T2DM research over the past two decades. It has been hypothesized that the p.E23K (KCNJ11 mutation in the 11p15.1 region may play an important role in the development of T2DM. In 2009, Hamming et al. found that the p.1369A (ABCC8 variant may be a causal factor in the disease; therefore, in this study we performed a meta-analysis to evaluate the association between these single nucleotide polymorphisms (SNPs, including our original data on the Siberian population (1384 T2DM and 414 controls. We found rs5219 and rs757110 were not associated with T2DM in this population, and that there was linkage disequilibrium in Siberians (D'=0.766, r(2= 0.5633. In addition, the haplotype rs757110[T]-rs5219[C] (p.23K/p.S1369 was associated with T2DM (OR = 1.52, 95% CI: 1.04-2.24. We included 44 original studies published by June 2014 in a meta-analysis of the p.E23K association with T2DM. The total OR was 1.14 (95% CI: 1.11-1.17 for p.E23K for a total sample size of 137,298. For p.S1369A, a meta-analysis was conducted on a total of 10 studies with a total sample size of 14,136 and pooled OR of 1.14 [95% CI (1.08-1.19; p = 2 x 10-6]. Our calculations identified causal genetic variation within the ABCC8/KCNJ11 region for T2DM with an OR of approximately 1.15 in Caucasians and Asians. Moreover, the OR value was not dependent on the frequency of p.E23K or p.S1369A in the populations.

  19. A streamlined failure mode and effects analysis

    International Nuclear Information System (INIS)

    Ford, Eric C.; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg

    2014-01-01

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed

  20. A streamlined failure mode and effects analysis.

    Science.gov (United States)

    Ford, Eric C; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg

    2014-06-01

    Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes had RPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  1. A streamlined failure mode and effects analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric C., E-mail: eford@uw.edu; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21287 (United States)

    2014-06-15

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  2. Risk analysis of geothermal power plants using Failure Modes and Effects Analysis (FMEA) technique

    International Nuclear Information System (INIS)

    Feili, Hamid Reza; Akar, Navid; Lotfizadeh, Hossein; Bairampour, Mohammad; Nasiri, Sina

    2013-01-01

    Highlights: • Using Failure Modes and Effects Analysis (FMEA) to find potential failures in geothermal power plants. • We considered 5 major parts of geothermal power plants for risk analysis. • Risk Priority Number (RPN) is calculated for all failure modes. • Corrective actions are recommended to eliminate or decrease the risk of failure modes. - Abstract: Renewable energy plays a key role in the transition toward a low carbon economy and the provision of a secure supply of energy. Geothermal energy is a versatile source as a form of renewable energy that meets popular demand. Since some Geothermal Power Plants (GPPs) face various failures, the requirement of a technique for team engineering to eliminate or decrease potential failures is considerable. Because no specific published record of considering an FMEA applied to GPPs with common failure modes have been found already, in this paper, the utilization of Failure Modes and Effects Analysis (FMEA) as a convenient technique for determining, classifying and analyzing common failures in typical GPPs is considered. As a result, an appropriate risk scoring of occurrence, detection and severity of failure modes and computing the Risk Priority Number (RPN) for detecting high potential failures is achieved. In order to expedite accuracy and ability to analyze the process, XFMEA software is utilized. Moreover, 5 major parts of a GPP is studied to propose a suitable approach for developing GPPs and increasing reliability by recommending corrective actions for each failure mode

  3. Failure analysis of a helicopter's main rotor bearing

    International Nuclear Information System (INIS)

    Shahzad, M.; Qureshi, A.H.; Waqas, H.; Hussain, N.; Ali, N.

    2011-01-01

    Presented results report some of the findings of a detailed failure analysis carried out on a main rotor hub assembly, which had symptoms of burning and mechanical damage. The analysis suggests environmental degradation of the grease which causes pitting on bearing-balls. The consequent inefficient lubrication raises the temperature which leads to the smearing of cage material (brass) on the bearing-balls and ultimately causes the failure. The analysis has been supported by the microstructural studies, thermal analysis and micro-hardness testing performed on the affected main rotor bearing parts. (author)

  4. Failure probability analysis of optical grid

    Science.gov (United States)

    Zhong, Yaoquan; Guo, Wei; Sun, Weiqiang; Jin, Yaohui; Hu, Weisheng

    2008-11-01

    Optical grid, the integrated computing environment based on optical network, is expected to be an efficient infrastructure to support advanced data-intensive grid applications. In optical grid, the faults of both computational and network resources are inevitable due to the large scale and high complexity of the system. With the optical network based distributed computing systems extensive applied in the processing of data, the requirement of the application failure probability have been an important indicator of the quality of application and an important aspect the operators consider. This paper will present a task-based analysis method of the application failure probability in optical grid. Then the failure probability of the entire application can be quantified, and the performance of reducing application failure probability in different backup strategies can be compared, so that the different requirements of different clients can be satisfied according to the application failure probability respectively. In optical grid, when the application based DAG (directed acyclic graph) is executed in different backup strategies, the application failure probability and the application complete time is different. This paper will propose new multi-objective differentiated services algorithm (MDSA). New application scheduling algorithm can guarantee the requirement of the failure probability and improve the network resource utilization, realize a compromise between the network operator and the application submission. Then differentiated services can be achieved in optical grid.

  5. Launch Vehicle Failure Dynamics and Abort Triggering Analysis

    Science.gov (United States)

    Hanson, John M.; Hill, Ashely D.; Beard, Bernard B.

    2011-01-01

    Launch vehicle ascent is a time of high risk for an on-board crew. There are many types of failures that can kill the crew if the crew is still on-board when the failure becomes catastrophic. For some failure scenarios, there is plenty of time for the crew to be warned and to depart, whereas in some there is insufficient time for the crew to escape. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based primarily on data already available from the GN&C system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. Derivation of attitude and attitude rate abort triggers to ensure that abort occurs as quickly as possible when needed, but that false positives are avoided, forms a major portion of the paper. Some of the potential failure modes requiring use of these triggers are described, along with analysis used to determine the success rate of getting the crew off prior to vehicle demise.

  6. Failure analysis on a ruptured petrochemical pipe

    Energy Technology Data Exchange (ETDEWEB)

    Harun, Mohd [Industrial Technology Division, Malaysian Nuclear Agency, Ministry of Science, Technology and Innovation Malaysia, Bangi, Kajang, Selangor (Malaysia); Shamsudin, Shaiful Rizam; Kamardin, A. [Univ. Malaysia Perlis, Jejawi, Arau (Malaysia). School of Materials Engineering

    2010-08-15

    The failure took place on a welded elbow pipe which exhibited a catastrophic transverse rupture. The failure was located on the welding HAZ region, parallel to the welding path. Branching cracks were detected at the edge of the rupture area. Deposits of corrosion products were also spotted. The optical microscope analysis showed the presence of transgranular failures which were related to the stress corrosion cracking (SCC) and were predominantly caused by the welding residual stress. The significant difference in hardness between the welded area and the pipe confirmed the findings. Moreover, the failure was also caused by the low Mo content in the stainless steel pipe which was detected by means of spark emission spectrometer. (orig.)

  7. Corrosion induced failure analysis of subsea pipelines

    International Nuclear Information System (INIS)

    Yang, Yongsheng; Khan, Faisal; Thodi, Premkumar; Abbassi, Rouzbeh

    2017-01-01

    Pipeline corrosion is one of the main causes of subsea pipeline failure. It is necessary to monitor and analyze pipeline condition to effectively predict likely failure. This paper presents an approach to analyze the observed abnormal events to assess the condition of subsea pipelines. First, it focuses on establishing a systematic corrosion failure model by Bow-Tie (BT) analysis, and subsequently the BT model is mapped into a Bayesian Network (BN) model. The BN model facilitates the modelling of interdependency of identified corrosion causes, as well as the updating of failure probabilities depending on the arrival of new information. Furthermore, an Object-Oriented Bayesian Network (OOBN) has been developed to better structure the network and to provide an efficient updating algorithm. Based on this OOBN model, probability updating and probability adaptation are performed at regular intervals to estimate the failure probabilities due to corrosion and potential consequences. This results in an interval-based condition assessment of subsea pipeline subjected to corrosion. The estimated failure probabilities would help prioritize action to prevent and control failures. Practical application of the developed model is demonstrated using a case study. - Highlights: • A Bow-Tie (BT) based corrosion failure model linking causation with the potential losses. • A novel Object-Oriented Bayesian Network (OOBN) based corrosion failure risk model. • Probability of failure updating and adaptation with respect to time using OOBN model. • Application of the proposed model to develop and test strategies to minimize failure risk.

  8. Analysis Method of Common Cause Failure on Non-safety Digital Control System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Goo; Oh, Eun Gse [KHNP, Daejeon (Korea, Republic of)

    2014-08-15

    The effects of common cause failure on safety digital instrumentation and control system had been considered in defense in depth analysis with safety analysis method. However, the effects of common cause failure on non-safety digital instrumentation and control system also should be evaluated. The common cause failure can be included in credible failure on the non-safety system. In the I and C architecture of nuclear power plant, many design feature has been applied for the functional integrity of control system. One of that is segmentation. Segmentation defenses the propagation of faults in the I and C architecture. Some of effects from common cause failure also can be limited by segmentation. Therefore, in this paper there are two type of failure mode, one is failures in one control group which is segmented, and the other is failures in multiple control group because that the segmentation cannot defense all effects from common cause failure. For each type, the worst failure scenario is needed to be determined, so the analysis method has been proposed in this paper. The evaluation can be qualitative when there is sufficient justification that the effects are bounded in previous safety analysis. When it is not bounded in previous safety analysis, additional analysis should be done with conservative assumptions method of previous safety analysis or best estimation method with realistic assumptions.

  9. Management of long segment anterior urethral stricture (≥ 8cm using buccal mucosal (BM graft and penile skin (PS flap: outcome and predictors of failure

    Directory of Open Access Journals (Sweden)

    Gamal A. Alsagheer

    Full Text Available ABSTRACT Purpose To evaluate the surgical outcome and predictors of failure of substitution urethroplasty using either dorsal onlay buccal mucosal (BM graft or ventral onlay penile skin flap (PS for anterior urethral stricture ≥ 8cm. Patients and methods Between March 2010 and January 2016, 50 patients with anterior urethral stricture ≥ 8 cm were treated at our hospital. The surgical outcome and success rate were assessed. The predictors of failure were analyzed using multivariate analysis. Failure was considered when subsequent urethrotomy or urethroplasty were needed. Results Dorsal onlay BM graft was carried out in 24 patients, while PS urethroplasty in 26 patients. There was no significant difference between both groups regarding patients demographics, stricture characteristics or follow-up period. One case in the BM group was lost during follow-up. Stricture recurrence was detected in 7 (30.4% patients out of BM group while in 6 (23.1% patients out of PS group (p value= 0.5. No significant differences between both groups regarding overall early and late complications were observed. Occurrence of early complications and the stricture length were the only predictors of failure in univariate analysis, while in multivariate analysis the occurrence of early complications was only significant. Conclusion On short-term follow-up, both dorsal onlay BM graft and ventral onlay PS flap urethroplasty have similar success rates. However, BM graft has a potential advantage to reduce operative time and is also technically easier. The surgeon should avoid early local complications as they represent a higher risk for failure.

  10. 8 CFR 1245.11 - Adjustment of aliens in S nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of aliens in S nonimmigrant classification. 1245.11 Section 1245.11 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW... RESIDENCE § 1245.11 Adjustment of aliens in S nonimmigrant classification. (a) Eligibility. An application...

  11. Reliability analysis for the creep rupture mode of failure

    International Nuclear Information System (INIS)

    Vaidyanathan, S.

    1975-01-01

    An analytical study has been carried out to relate the factors of safety employed in the design of a component to the probability of failure in the thermal creep rupture mode. The analysis considers the statistical variations in the operating temperature, stress and rupture time, and applies the life fraction damage criterion as the indicator of failure. Typical results for solution annealed type 304-stainless steel material for the temperature and stress variations expected in an LMFBR environment have been obtained. The analytical problem was solved by considering the joint distribution of the independent variables and deriving the distribution for the function associated with the probability of failure by integrating over proper regions as dictated by the deterministic design rule. This leads to a triple integral for the final probability of failure where the coefficients of variation associated with the temperature, stress and rupture time distributions can be specified by the user. The derivation is general, and can be used for time varying stress histories and the case of irradiated material where the rupture time varies with accumulated fluence. Example calculations applied to solution annealed type 304 stainless steel material have been carried out for an assumed coefficient of variation of 2% for temperature and 6% for stress. The results show that the probability of failure associated with dependent stress intensity limits specified in the ASME Boiler and Pressure Vessel Section III Code Case 1592 is less than 5x10 -8 . Rupture under thermal creep conditions is a highly complicated phenomenon. It is believed that the present study will help in quantizing the reliability to be expected with deterministic design factors of safety

  12. 11 CFR 108.8 - Exemption for the District of Columbia.

    Science.gov (United States)

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Exemption for the District of Columbia. 108.8 Section 108.8 Federal Elections FEDERAL ELECTION COMMISSION GENERAL FILING COPIES OF REPORTS AND STATEMENTS WITH STATE OFFICERS (2 U.S.C. 439) § 108.8 Exemption for the District of Columbia. Any copy of a...

  13. Regional interaction between myocardial sympathetic denervation, contractile dysfunction, and fibrosis in heart failure with preserved ejection fraction: {sup 11}C-hydroxyephedrine PET study

    Energy Technology Data Exchange (ETDEWEB)

    Aikawa, Tadao; Naya, Masanao; Obara, Masahiko [Hokkaido University, Department of Cardiovascular Medicine, Faculty of Medicine and Graduate School of Medicine, Sapporo (Japan); Oyama-Manabe, Noriko [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, Sapporo (Japan); Manabe, Osamu [Hokkaido University, Department of Nuclear Medicine, Faculty of Medicine and Graduate School of Medicine, Sapporo (Japan); Magota, Keiichi [Hokkaido University Hospital, Division of Medical Imaging and Technology, Sapporo (Japan); Ito, Yoichi M. [Hokkaido University, Department of Biostatistics, Faculty of Medicine and Graduate School of Medicine, Sapporo (Japan); Katoh, Chietsugu [Hokkaido University, Department of Biomedical Science and Engineering, Faculty of Health Sciences, Sapporo (Japan); Tamaki, Nagara [Kyoto Prefectural University of Medicine, Department of Radiology, Kyoto (Japan)

    2017-10-15

    This investigation aimed to identify significant predictors of regional sympathetic denervation quantified by {sup 11}C-hydroxyephedrine (HED) positron emission tomography (PET) in patients with heart failure with preserved left ventricular ejection fraction (HFpEF). Included in the study were 34 patients (age 63 ± 15 years, 23 men) with HFpEF (left ventricular ejection fraction ≥40%) and 11 age-matched volunteers without heart failure. Cardiac magnetic resonance imaging was performed to measure left ventricular size and function, and the extent of myocardial late gadolinium enhancement (LGE). {sup 11}C-HED PET was performed to quantify myocardial sympathetic innervation that was expressed as a {sup 11}C-HED retention index (RI, %/min). To identify predictors of regional {sup 11}C-HED RI in HFpEF patients, we propose a multivariate mixed-effects model for repeated measures over segments with an unstructured covariance matrix. Global {sup 11}C-HED RI was significantly lower and more heterogeneous in HFpEF patients than in volunteers (P < 0.01 for all). Regional {sup 11}C-HED RI was correlated positively with systolic wall thickening (r = 0.42, P < 0.001) and negatively with the extent of LGE (r = -0.43, P < 0.001). Segments in HFpEF patients with a large extent of LGE had the lowest regional {sup 11}C-HED RI among all segments (P < 0.001 in post hoc tests). Multivariate analysis demonstrated that systolic wall thickening and the extent of LGE were significant predictors of regional {sup 11}C-HED RI in HFpEF patients (both P ≤ 0.001). Regional sympathetic denervation was associated with contractile dysfunction and fibrotic burden in HFpEF patients, suggesting that regional sympathetic denervation may provide an integrated measure of myocardial damage in HFpEF. (orig.)

  14. Computer aided approach to qualitative and quantitative common cause failure analysis for complex systems

    International Nuclear Information System (INIS)

    Cate, C.L.; Wagner, D.P.; Fussell, J.B.

    1977-01-01

    Common cause failure analysis, also called common mode failure analysis, is an integral part of a complete system reliability analysis. Existing methods of computer aided common cause failure analysis are extended by allowing analysis of the complex systems often encountered in practice. The methods aid in identifying potential common cause failures and also address quantitative common cause failure analysis

  15. Role of scanning electron microscope )SEM) in metal failure analysis

    International Nuclear Information System (INIS)

    Shaiful Rizam Shamsudin; Hafizal Yazid; Mohd Harun; Siti Selina Abd Hamid; Nadira Kamarudin; Zaiton Selamat; Mohd Shariff Sattar; Muhamad Jalil

    2005-01-01

    Scanning electron microscope (SEM) is a scientific instrument that uses a beam of highly energetic electrons to examine the surface and phase distribution of specimens on a micro scale through the live imaging of secondary electrons (SE) and back-scattered electrons (BSE) images. One of the main activities of SEM Laboratory at MINT is for failure analysis on metal part and components. The capability of SEM is excellent for determining the root cause of metal failures such as ductility or brittleness, stress corrosion, fatigue and other types of failures. Most of our customers that request for failure analysis are from local petrochemical plants, manufacturers of automotive components, pipeline maintenance personnel and engineers who involved in the development of metal parts and component. This paper intends to discuss some of the technical concepts in failure analysis associated with SEM. (Author)

  16. Anterior pituitary failure (panhypopituitarism) with balanced chromosome translocation 46,XY,t(11;22)(q24;q13).

    Science.gov (United States)

    Yang, C Y; Chou, C W; Chen, S Y; Cheng, H M

    2001-04-01

    Hypopituitarism is the clinical syndrome that results from failure of the anterior pituitary gland to produce its hormones. Hypopituitarism can result from: (1) intrinsic or primary pituitary disease; (2) intrinsic hypothalamic or secondary pituitary disease; or (3) extrinsic extrasellar or parasellar disease. The etiologies of primary hypopituitarism are miscellaneous. The dominant clinical picture of hypopituitarism in the adult is that of hypogonadism. Reports have associated hypopituitarism with anti-pituitary-antibodies, hereditary syndrome and chromosome defects, but hypopituitarism has rarely been associated with balanced chromosome translocation (11;22)(q24;q13). Here, we describe a case of anterior pituitary failure with balanced chromosome translocation. A 19-year-old Chinese teenager presented with failure of pubertal development and sexual infantilism. On examination, the patient had the classic appearance of hypogonadism. Endocrine studies and three combined pituitary function tests revealed panhypopituitarism. A chromosomal study revealed 46,XY,t(11;22)(q24;q13), a balanced translocation between 11q24 and 22q13. Chest films showed delayed fusion of bilateral humeral head epiphyses and bilateral acromions. Scrotal sonography revealed testes were small bilaterally. Magnetic resonance imaging (MRI) of the sella revealed pituitary dwarfism. The patient received 19 months replacement therapy, including steroids (prednisolone 5 mg each day), L-thyroxine (Eltroxin 100 ug each day), and testosterone enanthate 250 mg every two weeks. His height increased 4 cm with secondary sexual characteristics developed, and muscle power increased.

  17. Failure analysis of medical Linac (LMR-15)

    International Nuclear Information System (INIS)

    Kato, Kiyotaka; Nakamura, Katsumi; Ogihara, Kiyoshi; Takahashi, Katsuhiko; Sato, Kazuhisa.

    1994-01-01

    In August 1978, Linac (LMR-15, Z4 Toshiba) was installed at our hospital and in use for 12 years up to September 1990. Recently, we completed working and failure records on this apparatus during the 12-year period, for the purpose of their analysis in the basis of reliability engineering. The results revealed operation rate of 97.85% on the average, mean time between failures (MTBF) from 40-70 hours about the beginning of its working to 280 hours for 2 years before renewal and practically satisfactory values of mean life of parts of life such as magnetron, thyratron and electron gun; the above respective values proved to be above those reported by other literature. On the other hand, we classified, by occurring system, the contents of failures in the apparatus and determined the number of failures and the temperature and humidities in case of failures to examine the correlation between the working environment and failure. The results indicated a change in humidity to gain control of failures in the dosimetric system, especially the monitoring chamber and we could back up the strength of the above correlation from a coefficient of correlation value of 0.84. (author)

  18. Does Bruxism Contribute to Dental Implant Failure? A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Zhou, Yi; Gao, Jinxia; Luo, Le; Wang, Yining

    2016-04-01

    Bruxism was usually considered as a contraindication for oral implanting. The causal relationship between bruxism and dental implant failure was remained controversial in existing literatures. This meta-analysis was performed to investigate the relationship between them. This review conducted an electronic systematic literature search in MEDLINE (PubMed) and EmBase in November 2013 without time and language restrictions. Meanwhile, a hand searching for all the relevant references of included studies was also conducted. Study information extraction and methodological quality assessments were accomplished by two reviewers independently. A discussion ensued if any disagreement occurred, and unresolved issues were solved by consulting a third reviewer. Methodological quality was assessed by using the Newcastle-Ottawa Scale tool. Odds ratio (OR) with 95% confidence interval (CI) was pooled to estimate the relative effect of bruxism on dental implant failures. Fixed effects model was used initially; if the heterogeneity was high, random effects model was chosen for meta-analysis. Statistical analyses were carried out by using Review Manager 5.1. In this meta-analysis review, extracted data were classified into two groups based on different units. Units were based on the number of prostheses (group A) and the number of patients (group B). In group A, the total pooled OR of bruxers versus nonbruxers for all subgroups was 4.72 (95% CI: 2.66-8.36, p = .07). In group B, the total pooled OR of bruxers versus nonbruxers for all subgroups was 3.83 (95% CI: 2.12-6.94, p = .22). This meta-analysis was performed to evaluate the relationship between bruxism and dental implant failure. In contrast to nonbruxers, prostheses in bruxers had a higher failure rate. It suggests that bruxism is a contributing factor of causing the occurrence of dental implant technical/biological complications and plays a role in dental implant failure. © 2015 Wiley Periodicals, Inc.

  19. Failure analysis of the boiler water-wall tube

    Directory of Open Access Journals (Sweden)

    S.W. Liu

    2017-10-01

    Full Text Available Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tube meets the requirements of the relevant standards. Microscopic examinations showed that the spheroidization of pearlite is not very obvious. The failure mechanism is identified as a result of the significant localized wall thinning of the boiler water-wall tube due to oxidation.

  20. Failure analysis of the boiler water-wall tube

    OpenAIRE

    S.W. Liu; W.Z. Wang; C.J. Liu

    2017-01-01

    Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tu...

  1. Fuzzy logic prioritization of failures in a system failure mode, effects and criticality analysis

    International Nuclear Information System (INIS)

    Bowles, John B.; Pelaez, C.E.

    1995-01-01

    This paper describes a new technique, based on fuzzy logic, for prioritizing failures for corrective actions in a Failure Mode, Effects and Criticality Analysis (FMECA). As in a traditional criticality analysis, the assessment is based on the severity, frequency of occurrence, and detectability of an item failure. However, these parameters are here represented as members of a fuzzy set, combined by matching them against rules in a rule base, evaluated with min-max inferencing, and then defuzzified to assess the riskiness of the failure. This approach resolves some of the problems in traditional methods of evaluation and it has several advantages compared to strictly numerical methods: 1) it allows the analyst to evaluate the risk associated with item failure modes directly using the linguistic terms that are employed in making the criticality assessment; 2) ambiguous, qualitative, or imprecise information, as well as quantitative data, can be used in the assessment and they are handled in a consistent manner; and 3) it gives a more flexible structure for combining the severity, occurrence, and detectability parameters. Two fuzzy logic based approaches for assessing criticality are presented. The first is based on the numerical rankings used in a conventional Risk Priority Number (RPN) calculation and uses crisp inputs gathered from the user or extracted from a reliability analysis. The second, which can be used early in the design process when less detailed information is available, allows fuzzy inputs and also illustrates the direct use of the linguistic rankings defined for the RPN calculations

  2. Analysis of dependent failures in the ORNL precursor study

    International Nuclear Information System (INIS)

    Ballard, G.M.

    1985-01-01

    The study of dependent failures (or common cause/mode failures) in the safety assessment of potentially hazardous plant is one of the significant areas of uncertainty in performing probabilistic safety studies. One major reason for this uncertainty is that data on dependent failures is apparently not readily available in sufficient quantity to assist in the development and validation of models. The incident reports that were compiled for the ORNL study on Precursors to Severe Core Damage Accidents (NUREG/CR-2497) provide an opportunity to look at the importance of dependent failures in the most significant incidents of recent reactor operations, to look at the success of probabilistic risk assessment (PRA) methods in accounting for the contribution of dependent failures, and to look at the dependent failure incidents with the aim of identifying the most significant problem areas. In this paper an analysis has been made of the incidents compiled in NUREG/CR-2497 and events involving multiple failures which were not independent have been identified. From this analysis it is clear that dependent failures are a very significant contributor to the precursor incidents. The method of enumeration of accident frequency used in NUREG-2497 can be shown to take account of dependent failures and this may be a significant factor contributing to the apparent difference between the precursor accident frequency and typical PRA frequencies

  3. Operating personnel error analysis during operation failures in the Kozloduj NPP

    International Nuclear Information System (INIS)

    Jonkova, A.

    1990-01-01

    The failures due to personnel errors are analyzed for 10 years period (1977-1986). Most of the results are presented in absolute values and are considered in dynamics. The indices for relative shares are compared by alternative analysis. One of the most important causes is the fluctuation of manpower. The failures distribution by months within the year and by hours of the day is given. The biggest number of failures occurred in the period April-October (without August - the month of the leaves), when the refueling and repair were taken place, and in January-February, due to heavy meteorological conditions and some fatigue and disconcentration because of multiple holidays. The failures during the day shifts had the greatest relative share - 42%, during the afternoon shifts - 26% and during the night shifts - 32% The most 'dangerous' time periods happened to be 11-12 h and 13-14 h (deteriorated attention after lunch), 20-22 h (physiological drop of the psychological activity), 0-3 h (the lowest level of physiological and psychological activity) and in the first and last hours of every shift. Three groups of causes are pointed out as the most frequent: improper actions connected with orders; improper independent actions; uncoordinated teamwork. The following measures are proposed for reducing the effect of the human factor: setting up the training centre; preliminary evaluation of the professional qualification of the operators; current dynamic control of their neuro-psychological fitness and occupational reliability. 1 fig, 2 tabs, 5 refs

  4. Study on the Electrochemical Property of Microporous Cobalt Phosphite[Co_11(HPO_3)_8(OH)_6

    International Nuclear Information System (INIS)

    Lee, Dong Heon; Kang, Myunggoo; Jung, Hyun; Paek, Seung-Min

    2016-01-01

    Crystalline microporous cobalt phosphite, Co_11(HPO_3)_8(OH)_6, was prepared via facile hydrothermal route without the use of any templates or surfactants. The cobalt chloride hexahydrate (CoCl_2·6H_2O) and sodium hypophosphite monohydrate (NaH_2PO_2·H_2O) were employed as reactants, and sodium bicarbonate(NaHCO_3) was added to adjust the pH. The resultant Co_11(HPO_3)_8(OH)_6 shows dumbbell-like shape witha size of several micrometers. The obtained materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, thermal gravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), and energy dispersive spectrometry (EDS). The Co_11(HPO_3)_8(OH)_6 is applied as electrochemical energy storage electrode material because of its unique microporous nature. Different aqueous electrolytes (LiOH, NaOH, and KOH) have been tested in order to study the effect of electrolyte cations on electrochemical behavior. To investigate the capacity and stability of Co_11(HPO_3)_8(OH)_6 electrode, cyclic voltammetry (CV), galvanostatic charge-discharge (GC), and cycle stability were performed in aqueous electrolytes with different cations at room temperature. We found that the electrochemical behavior of these materials is strongly dependent on the species of electrolyte cations (Li"+,Na"+, and K"+).

  5. Failure modes and effects analysis of fusion magnet systems

    International Nuclear Information System (INIS)

    Zimmermann, M.; Kazimi, M.S.; Siu, N.O.; Thome, R.J.

    1988-12-01

    A failure modes and consequence analysis of fusion magnet system is an important contributor towards enhancing the design by improving the reliability and reducing the risk associated with the operation of magnet systems. In the first part of this study, a failure mode analysis of a superconducting magnet system is performed. Building on the functional breakdown and the fault tree analysis of the Toroidal Field (TF) coils of the Next European Torus (NET), several subsystem levels are added and an overview of potential sources of failures in a magnet system is provided. The failure analysis is extended to the Poloidal Field (PF) magnet system. Furthermore, an extensive analysis of interactions within the fusion device caused by the operation of the PF magnets is presented in the form of an Interaction Matrix. A number of these interactions may have significant consequences for the TF magnet system particularly interactions triggered by electrical failures in the PF magnet system. In the second part of this study, two basic categories of electrical failures in the PF magnet system are examined: short circuits between the terminals of external PF coils, and faults with a constant voltage applied at external PF coil terminals. An electromagnetic model of the Compact Ignition Tokamak (CIT) is used to examine the mechanical load conditions for the PF and the TF coils resulting from these fault scenarios. It is found that shorts do not pose large threats to the PF coils. Also, the type of plasma disruption has little impact on the net forces on the PF and the TF coils. 39 refs., 30 figs., 12 tabs

  6. Failure analysis of fractured dental zirconia implants.

    Science.gov (United States)

    Gahlert, M; Burtscher, D; Grunert, I; Kniha, H; Steinhauser, E

    2012-03-01

    The purpose of the present study was the macroscopic and microscopic failure analysis of fractured zirconia dental implants. Thirteen fractured one-piece zirconia implants (Z-Look3) out of 170 inserted implants with an average in situ period of 36.75±5.34 months (range from 20 to 56 months, median 38 months) were prepared for macroscopic and microscopic (scanning electron microscopy [SEM]) failure analysis. These 170 implants were inserted in 79 patients. The patient histories were compared with fracture incidences to identify the reasons for the failure of the implants. Twelve of these fractured implants had a diameter of 3.25 mm and one implant had a diameter of 4 mm. All fractured implants were located in the anterior side of the maxilla and mandibula. The patient with the fracture of the 4 mm diameter implant was adversely affected by strong bruxism. By failure analysis (SEM), it could be demonstrated that in all cases, mechanical overloading caused the fracture of the implants. Inhomogeneities and internal defects of the ceramic material could be excluded, but notches and scratches due to sandblasting of the surface led to local stress concentrations that led to the mentioned mechanical overloading by bending loads. The present study identified a fracture rate of nearly 10% within a follow-up period of 36.75 months after prosthetic loading. Ninety-two per cent of the fractured implants were so-called diameter reduced implants (diameter 3.25 mm). These diameter reduced implants cannot be recommended for further clinical use. Improvement of the ceramic material and modification of the implant geometry has to be carried out to reduce the failure rate of small-sized ceramic implants. Nevertheless, due to the lack of appropriate laboratory testing, only clinical studies will demonstrate clearly whether and how far the failure rate can be reduced. © 2011 John Wiley & Sons A/S.

  7. Failure mode and effects analysis: an empirical comparison of failure mode scoring procedures.

    Science.gov (United States)

    Ashley, Laura; Armitage, Gerry

    2010-12-01

    To empirically compare 2 different commonly used failure mode and effects analysis (FMEA) scoring procedures with respect to their resultant failure mode scores and prioritization: a mathematical procedure, where scores are assigned independently by FMEA team members and averaged, and a consensus procedure, where scores are agreed on by the FMEA team via discussion. A multidisciplinary team undertook a Healthcare FMEA of chemotherapy administration. This included mapping the chemotherapy process, identifying and scoring failure modes (potential errors) for each process step, and generating remedial strategies to counteract them. Failure modes were scored using both an independent mathematical procedure and a team consensus procedure. Almost three-fifths of the 30 failure modes generated were scored differently by the 2 procedures, and for just more than one-third of cases, the score discrepancy was substantial. Using the Healthcare FMEA prioritization cutoff score, almost twice as many failure modes were prioritized by the consensus procedure than by the mathematical procedure. This is the first study to empirically demonstrate that different FMEA scoring procedures can score and prioritize failure modes differently. It found considerable variability in individual team members' opinions on scores, which highlights the subjective and qualitative nature of failure mode scoring. A consensus scoring procedure may be most appropriate for FMEA as it allows variability in individuals' scores and rationales to become apparent and to be discussed and resolved by the team. It may also yield team learning and communication benefits unlikely to result from a mathematical procedure.

  8. Failure analysis of stainless steel femur fixation plate.

    Science.gov (United States)

    Hussain, P B; Mohammad, M

    2004-05-01

    Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed.

  9. failure analysis of a uav flight control system using markov analysis

    African Journals Online (AJOL)

    eobe

    2016-01-01

    Jan 1, 2016 ... Tree Analysis (FTA), Dependence Diagram Analysis. (DDA) and Markov Analysis (MA) are the most widely-used methods of probabilistic safety and reliability analysis for airborne system [1]. Fault trees analysis is a backward failure searching ..... [4] Christopher Dabrowski and Fern Hunt Markov Chain.

  10. Early failure analysis of machining centers: a case study

    International Nuclear Information System (INIS)

    Wang Yiqiang; Jia Yazhou; Jiang Weiwei

    2001-01-01

    To eliminate the early failures and improve the reliability, nine ex-factory machining centers are traced under field conditions in workshops. Their early failure information throughout the ex-factory run-in test is collected. The field early failure database is constructed based on the collection of field early failure data and the codification of data. Early failure mode and effects analysis is performed to indicate the weak subsystem of a machining center or the troublemaker. The distribution of the time between early failures is analyzed and the optimal ex-factory run-in test time for machining center that may expose sufficiently the early failures and cost minimum is discussed. Suggestions how to arrange ex-factory run-in test and how to take actions to reduce early failures for machining center is proposed

  11. Stereotactic core biopsy: Comparison of 11 gauge with 8 gauge vacuum assisted breast biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, Shambhavi, E-mail: svenkata@bidmc.harvard.edu [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Dialani, Vandana [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Gilmore, Hannah L. [Department of Pathology, UH Case Medical Center, 11100 Euclid Ave, Cleveland, OH 44106 (United States); Mehta, Tejas S. [Department of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States)

    2012-10-15

    Purpose: The compare the performance and ability to obtain a correct diagnosis on needle biopsy between 11 gauge and 8 gauge vacuum assisted biopsy devices. Materials and methods: Hospital records of all consecutive stereotactic core biopsies performed over five years were retrospectively reviewed in compliance Health Insurance Portability and Accountability Act (HIPPA) policy and with approval from the hospital institutional review board (IRB). Pathology from core biopsy was compared with surgical pathology and/or imaging follow-up. A histological underestimation was defined if the surgical excision yielded a higher grade on pathology which changed management. Results: 828 needle core biopsies (47.5%, 393/828 with 11 gauge and 52.5%, 435/828 with 8 gauge) yielded 471 benign, 153 high risk and 204 malignant lesions. 30/193 (15.5%) 11 gauge lesions and 16/185 (8.6%) 8 gauge lesions demonstrated higher grade pathology on surgical excision. The difference in the rates of the number of correct diagnoses on core needle biopsy between 11 gauge (363/393, 92.4%) and 8 gauge (419/435, 96.3%) based on either surgical or clinical/imaging follow up and the difference in the number of discordant benign core biopsies between 11 (17/217, 7.8%) and 8 gauge (4/254, 1.6%) necessitating a surgical biopsy was significant (P = 0.013; P = 0.001). Although there were more underestimations with the 11 gauge (25/193, 13.0%) than 8 gauge (15/185, 8.1%) needle, this was not significant. Conclusion: Our study demonstrates improved performance and increased diagnostic ability of 8 gauge needle over 11 gauge in obtaining a correct diagnosis on needle biopsy.

  12. Reliability analysis based on the losses from failures.

    Science.gov (United States)

    Todinov, M T

    2006-04-01

    The conventional reliability analysis is based on the premise that increasing the reliability of a system will decrease the losses from failures. On the basis of counterexamples, it is demonstrated that this is valid only if all failures are associated with the same losses. In case of failures associated with different losses, a system with larger reliability is not necessarily characterized by smaller losses from failures. Consequently, a theoretical framework and models are proposed for a reliability analysis, linking reliability and the losses from failures. Equations related to the distributions of the potential losses from failure have been derived. It is argued that the classical risk equation only estimates the average value of the potential losses from failure and does not provide insight into the variability associated with the potential losses. Equations have also been derived for determining the potential and the expected losses from failures for nonrepairable and repairable systems with components arranged in series, with arbitrary life distributions. The equations are also valid for systems/components with multiple mutually exclusive failure modes. The expected losses given failure is a linear combination of the expected losses from failure associated with the separate failure modes scaled by the conditional probabilities with which the failure modes initiate failure. On this basis, an efficient method for simplifying complex reliability block diagrams has been developed. Branches of components arranged in series whose failures are mutually exclusive can be reduced to single components with equivalent hazard rate, downtime, and expected costs associated with intervention and repair. A model for estimating the expected losses from early-life failures has also been developed. For a specified time interval, the expected losses from early-life failures are a sum of the products of the expected number of failures in the specified time intervals covering the

  13. Beyond reliability, multi-state failure analysis of satellite subsystems: A statistical approach

    International Nuclear Information System (INIS)

    Castet, Jean-Francois; Saleh, Joseph H.

    2010-01-01

    Reliability is widely recognized as a critical design attribute for space systems. In recent articles, we conducted nonparametric analyses and Weibull fits of satellite and satellite subsystems reliability for 1584 Earth-orbiting satellites launched between January 1990 and October 2008. In this paper, we extend our investigation of failures of satellites and satellite subsystems beyond the binary concept of reliability to the analysis of their anomalies and multi-state failures. In reliability analysis, the system or subsystem under study is considered to be either in an operational or failed state; multi-state failure analysis introduces 'degraded states' or partial failures, and thus provides more insights through finer resolution into the degradation behavior of an item and its progression towards complete failure. The database used for the statistical analysis in the present work identifies five states for each satellite subsystem: three degraded states, one fully operational state, and one failed state (complete failure). Because our dataset is right-censored, we calculate the nonparametric probability of transitioning between states for each satellite subsystem with the Kaplan-Meier estimator, and we derive confidence intervals for each probability of transitioning between states. We then conduct parametric Weibull fits of these probabilities using the Maximum Likelihood Estimation (MLE) approach. After validating the results, we compare the reliability versus multi-state failure analyses of three satellite subsystems: the thruster/fuel; the telemetry, tracking, and control (TTC); and the gyro/sensor/reaction wheel subsystems. The results are particularly revealing of the insights that can be gleaned from multi-state failure analysis and the deficiencies, or blind spots, of the traditional reliability analysis. In addition to the specific results provided here, which should prove particularly useful to the space industry, this work highlights the importance

  14. Proceedings of the specialists' meeting on steam generator failure and failure propagation experience, held in Aix-en Provence, France, 26-28 September 1990

    International Nuclear Information System (INIS)

    Maupre, J.P.

    1990-09-01

    The 35 participants, representing 7 Member States and one International Organization discussed recent investigations on leak development and propagation in LMFBR steam generators. The meeting was divided into three technical sessions: review of national status on studies of failure propagation (8 papers); propagation experience on reactor steam generators (4 papers); studies of failure propagation: codes, hydrogen detection, tests (11 papers). A separate abstract was prepared for each of these papers

  15. Extending Failure Modes and Effects Analysis Approach for Reliability Analysis at the Software Architecture Design Level

    NARCIS (Netherlands)

    Sözer, Hasan; Tekinerdogan, B.; Aksit, Mehmet; de Lemos, Rogerio; Gacek, Cristina

    2007-01-01

    Several reliability engineering approaches have been proposed to identify and recover from failures. A well-known and mature approach is the Failure Mode and Effect Analysis (FMEA) method that is usually utilized together with Fault Tree Analysis (FTA) to analyze and diagnose the causes of failures.

  16. Machinery failure analysis and troubleshooting practical machinery management for process plants

    CERN Document Server

    Bloch, Heinz P

    2012-01-01

    Solve the machinery failure problems costing you time and money with this classic, comprehensive guide to analysis and troubleshooting  Provides detailed, complete and accurate information on anticipating risk of component failure and avoiding equipment downtime Includes numerous photographs of failed parts to ensure you are familiar with the visual evidence you need to recognize Covers proven approaches to failure definition and offers failure identification and analysis methods that can be applied to virtually all problem situations Demonstr

  17. [Effect of benazepril on cardiac function in Chinese patients with chronic heart failure: a meta-analysis of randomized controlled trials].

    Science.gov (United States)

    Yan, Xiaowei; Xu, Dingli; Huang, Jun

    2014-10-14

    To evaluate the efficacy and tolerability of benazepril in Chinese patients with chronic systolic heart failure. We searched the databases of Cochrane, PubMed, EMbase, CBM and CNKI from January 1989 to November 2010 for the relevant studies. Two investigators identified randomized controlled trials (RCTs) independently according to the predefined inclusion and exclusion criteria. Statistical data analysis was performed with the Stata 11 software. A total of 15 studies with 1 355 Chinese patients of chronic systolic heart failure fulfilled the inclusion criteria. Among them, 546 received benazepril monotherapy. The dose range of benazepril was 5 to 40 mg daily. And it was similar to angiotensin II receptor blockers (ARBs) in improving left ventricular ejection fraction (LVEF)(P = 0.674), reducing LVEDD (P = 0.511) and improving cardiac output (P = 0.363). The combination therapy of benazepril and ARB was superior to ARB monotherapy in reducing left ventricular end-diastolic diameter (LVEDD) (P = 0.001). However, LVEF was comparable between patients with ACEI/ARB combination therapy and those with ARB monotherapy (P = 0.105). Compared with blank control, benazepril treatment was associated with a significant improvement in LVEF from baseline to follow-up (WMD = 6.5%; 95% CI: 0.9%, 12.0%; P = 0.022). Compared with baseline, benazepril treatment significantly increased LVEF (WMD = 10.4%; 95% confidence interval [CI]:7.1%, 13.8%; P benazepril group. As the most common side effect after benazepril treatment, cough had a prevalence of 11.6%. Other side effects were rare. Benazepril is both efficacious and safe in the management of Chinese patients with chronic heart failure.

  18. Root cause of failure analysis and the system engineer

    International Nuclear Information System (INIS)

    Coppock, M.S.; Hartwig, A.W.

    1990-01-01

    In an industry where ever-increasing emphasis is being placed on root cause of failure determination, it is imperative that a successful nuclear utility have an effective means of identifying failures and performing the necessary analyses. The current Institute of Nuclear Power Operations (INPO) good practice, OE-907, root-cause analysis, gives references to methodology that will help determine breakdowns in procedures, programs, or design but gives very little guidance on how or when to perform component root cause of failure analyses. The system engineers of nuclear utilities are considered the focal point for their respective systems and are required by most programs to investigate component failures. The problem that the system engineer faces in determining a component root cause of failures lies in acquisition of the necessary data to identify the need to perform the analysis and in having the techniques and equipment available to perform it. The system engineers at the Palo Verde nuclear generating station routinely perform detailed component root cause of failure analyses. The Palo Verde program provides the system engineers with the information necessary to identify when a component root cause of failure is required. Palo Verde also has the necessary equipment on-site to perform the analyses

  19. Modeling the recurrent failure to thrive in less than two-year children: recurrent events survival analysis.

    Science.gov (United States)

    Saki Malehi, Amal; Hajizadeh, Ebrahim; Ahmadi, Kambiz; Kholdi, Nahid

    2014-01-01

    This study aimes to evaluate the failure to thrive (FTT) recurrent event over time. This longitudinal study was conducted during February 2007 to July 2009. The primary outcome was growth failure. The analysis was done using 1283 children who had experienced FTT several times, based on recurrent events analysis. Fifty-nine percent of the children had experienced the FTT at least one time and 5.3% of them had experienced it up to four times. The Prentice-Williams-Peterson (PWP) model revealed significant relationship between diarrhea (HR=1.26), respiratory infections (HR=1.25), urinary tract infections (HR=1.51), discontinuation of breast-feeding (HR=1.96), teething (HR=1.18), initiation age of complementary feeding (HR=1.11) and hazard rate of the first FTT event. Recurrence nature of the FTT is a main problem, which taking it into account increases the accuracy in analysis of FTT event process and can lead to identify different risk factors for each FTT recurrences.

  20. 11 CFR 4.8 - Appeal of denial.

    Science.gov (United States)

    2010-01-01

    ... been received by the Commission, may appeal the adverse determination or the failure to respond by... writing, shall clearly and prominently state on the envelope or other cover and at the top of the first... will not entertain any appeal from an alleged denial or failure to comply with an oral request. Any...

  1. ChemSession'11 - 8. Warsaw Seminar of the PhD Students in Chemistry - Abstracts

    International Nuclear Information System (INIS)

    Madura, I.

    2011-01-01

    Book of Abstracts contains short descriptions of presentations: 4 lectures, 1 communication and 149 posters presented during ChemSession'11 - 8 th Warsaw Seminar of the PhD Students in Chemistry (Warsaw, 13.05.2011). Several posters were devoted to the radiochemistry, radiochemical analysis, radiation chemistry, application of the radionuclides and radiobiology. Some posters on the material science dealing with materials important to nuclear sciences can be also mentioned.

  2. Process Equipment Failure Mode Analysis in a Chemical Industry

    Directory of Open Access Journals (Sweden)

    J. Nasl Seraji

    2008-04-01

    Full Text Available Background and aims   Prevention of potential accidents and safety promotion in chemical processes requires systematic safety management in them. The main objective of this study was analysis of important process equipment components failure modes and effects in H2S and CO2  isolation from extracted natural gas process.   Methods   This study was done in sweetening unit of an Iranian gas refinery. Failure Mode and Effect Analysis (FMEA used for identification of process equipments failures.   Results   Totally 30 failures identified and evaluated using FMEA. P-1 blower's blade breaking and sour gas pressure control valve bearing tight moving had maximum risk Priority number (RPN, P-1 body corrosion and increasing plug lower side angle of reach DEAlevel control valve  in tower - 1 were minimum calculated RPN.   Conclusion   By providing a reliable documentation system for equipment failures and  incidents recording, maintaining of basic information for later safety assessments would be  possible. Also, the probability of failures and effects could be minimized by conducting preventive maintenance.

  3. Dissimilar weld failure analysis and development program

    International Nuclear Information System (INIS)

    Holko, K.H.; Li, C.C.

    1982-01-01

    The problem of dissimilar weld cracking and failure is examined. This problem occurs in boiler superheater and reheater sections as well as main steam piping. Typically, a dissimilar weld joins low-alloy steel tubing such as Fe-2-1/4 Cr-1Mo to stainless steel tubing such as 321H and 304H. Cracking and failure occur in the low-alloy steel heat-affected zone very close to the weld interface. The 309 stainless steel filler previously used has been replaced with nickel-base fillers such as Inconel 132, Inconel 182, and Incoweld A. This change has extended the time to cracking and failure, but has not solved the problem. To illustrate and define the problem, the metallography of damaged and failed dissimilar welds is described. Results of mechanical tests of dissimilar welds removed from service are presented, and factors believed to be influential in causing damage and failure are discussed. In addition, the importance of dissimilar weldment service history is demonstrated, and the Dissimilar Weld Failure Analysis and Development Program is described. 15 figures

  4. Analysis of reactor trips involving balance-of-plant failures

    International Nuclear Information System (INIS)

    Seth, S.; Skinner, L.; Ettlinger, L.; Lay, R.

    1986-01-01

    The relatively high frequency of plant transients leading to reactor trips at nuclear power plants in the US is of economic and safety concern to the industry. A majority of such transients is due to failures in the balance-of-plant (BOP) systems. As a part of a study conducted for the US Nuclear Regulatory Commission, Mitre has carried out a further analysis of the BOP failures associated with reactor trips. The major objectives of the analysis were to examine plant-to-plant variations in BOP-related trips, to understand the causes of failures, and to determine the extent of any associated safety system challenges. The analysis was based on the Licensee Event Reports submitted on all commercial light water reactors during the 2-yr period, 1984-1985

  5. Exchange nailing for nonunion of diaphyseal fractures of the tibia: our results and an analysis of the risk factors for failure.

    Science.gov (United States)

    Tsang, S T J; Mills, L A; Frantzias, J; Baren, J P; Keating, J F; Simpson, A H R W

    2016-04-01

    The aim of this study was to identify risk factors for the failure of exchange nailing in nonunion of tibial diaphyseal fractures. A cohort of 102 tibial diaphyseal nonunions in 101 patients with a mean age of 36.9 years (15 to 74) were treated between January 1992 and December 2012 by exchange nailing. Of which 33 (32%) were initially open injuries. The median time from primary fixation to exchange nailing was 6.5 months (interquartile range (IQR) 4.3 to 9.8 months). The main outcome measures were union, number of secondary fixation procedures required to achieve union and time to union. Univariate analysis and multiple regression were used to identify risk factors for failure to achieve union. Multiple causes for the primary nonunion were found for 28 (27%) tibiae, with infection present in 32 (31%). Six patients were lost to follow-up. Further surgical procedures were required in 35 (36%) nonunions. Other fixation modalities were required in five fractures. A single nail exchange procedure achieved union in 60/96 (63%) of all nonunions. Only 11 out of 31 infected nonunions (35.4%) healed after one exchange nail procedure. Up to five repeated exchange nailings, with or without bone grafting, ultimately achieved union in 89 (93%) fractures. The median time to union after exchange nailing was 8.7 months (IQR 5.7 to 14.0 months). Univariate analysis confirmed that an oligotrophic/atrophic pattern of nonunion (p = 0.002), a bone gap of 5 mm or more (p = 0.04) and infection (p exchange nailing Multiple regression analysis found that infection was the strongest predictor of failure (p Exchange nailing is an effective treatment for aseptic tibial diaphyseal nonunion. However, in the presence of severe infection with a highly resistant organism, or extensive sclerosis of the bone, other fixation modalities, such as Ilizarov treatment, should be considered. Exchange nailing is an effective treatment for aseptic tibial diaphyseal nonunion. ©2016 The British Editorial

  6. Study on shielded pump system failure analysis method based on Bayesian network

    International Nuclear Information System (INIS)

    Bao Yilan; Huang Gaofeng; Tong Lili; Cao Xuewu

    2012-01-01

    This paper applies Bayesian network to the system failure analysis, with an aim to improve knowledge representation of the uncertainty logic and multi-fault states in system failure analysis. A Bayesian network for shielded pump failure analysis is presented, conducting fault parameter learning, updating Bayesian network parameter based on new samples. Finally, through the Bayesian network inference, vulnerability in this system, the largest possible failure modes, and the fault probability are obtained. The powerful ability of Bayesian network to analyze system fault is illustrated by examples. (authors)

  7. 8 CFR 245.11 - Adjustment of aliens in S nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of aliens in S nonimmigrant classification. 245.11 Section 245.11 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... aliens in S nonimmigrant classification. (a) Eligibility. An application on Form I-854, requesting that...

  8. Comprehensive method of common-mode failure analysis for LMFBR safety systems

    International Nuclear Information System (INIS)

    Unione, A.J.; Ritzman, R.L.; Erdmann, R.C.

    1976-01-01

    A technique is demonstrated which allows the systematic treatment of common-mode failures of safety system performance. The technique uses log analysis in the form of fault and success trees to qualitatively assess the sources of common-mode failure and quantitatively estimate the contribution to the overall risk of system failure. The analysis is applied to the secondary control rod system of an early sized LMFBR

  9. Micromechanics of failure in brittle geomaterials. Final technical report (for 7/1/1994 - 8/31/2000)

    International Nuclear Information System (INIS)

    Wong, Teng-fong

    2000-01-01

    The overall objective was to provide a fundamental understanding of brittle failure processes in porous and compact geomaterials. This information is central to energy-related programs such as oil and gas exploration/production, reservoir engineering, drilling technology, geothermal energy recovery, nuclear waste isolation, and environmental remediation. The effects of key parameters such as grain boundary structure and cementation, damage state, and load path on the deformation and failure model of brittle geomaterials are still largely unknown. The research methodology emphasized the integration of experimental rock mechanical testing, quantitative microscopy, and detailed analysis using fracture mechanics, continuum plasticity theory, and numerical methods. Significant progress was made in elucidating the micromechanics of brittle failure in compact crystalline rocks, as well as high-porosity siliciclastic and carbonate rocks. Substantial effort was expended toward applying a new quantitative three-dimensional imaging technique to geomaterials and for developing enhanced image analysis capabilities. The research is presented under the following topics: technique for imaging the 3-D pore structure of geomaterials; mechanics of compressive failure in sandstone; effect of water on compressive failure of sandstone; micromechanics of compressive failure: observation and model; and the brittle-ductile transition in porous carbonate rocks

  10. Challenges in Resolution for IC Failure Analysis

    Science.gov (United States)

    Martinez, Nick

    1999-10-01

    Resolution is becoming more and more of a challenge in the world of Failure Analysis in integrated circuits. This is a result of the ongoing size reduction in microelectronics. Determining the cause of a failure depends upon being able to find the responsible defect. The time it takes to locate a given defect is extremely important so that proper corrective actions can be taken. The limits of current microscopy tools are being pushed. With sub-micron feature sizes and even smaller killing defects, optical microscopes are becoming obsolete. With scanning electron microscopy (SEM), the resolution is high but the voltage involved can make these small defects transparent due to the large mean-free path of incident electrons. In this presentation, I will give an overview of the use of inspection methods in Failure Analysis and show example studies of my work as an Intern student at Texas Instruments. 1. Work at Texas Instruments, Stafford, TX, was supported by TI. 2. Work at Texas Tech University, was supported by NSF Grant DMR9705498.

  11. Probabilistic analysis on the failure of reactivity control for the PWR

    Science.gov (United States)

    Sony Tjahyani, D. T.; Deswandri; Sunaryo, G. R.

    2018-02-01

    The fundamental safety function of the power reactor is to control reactivity, to remove heat from the reactor, and to confine radioactive material. The safety analysis is used to ensure that each parameter is fulfilled during the design and is done by deterministic and probabilistic method. The analysis of reactivity control is important to be done because it will affect the other of fundamental safety functions. The purpose of this research is to determine the failure probability of the reactivity control and its failure contribution on a PWR design. The analysis is carried out by determining intermediate events, which cause the failure of reactivity control. Furthermore, the basic event is determined by deductive method using the fault tree analysis. The AP1000 is used as the object of research. The probability data of component failure or human error, which is used in the analysis, is collected from IAEA, Westinghouse, NRC and other published documents. The results show that there are six intermediate events, which can cause the failure of the reactivity control. These intermediate events are uncontrolled rod bank withdrawal at low power or full power, malfunction of boron dilution, misalignment of control rod withdrawal, malfunction of improper position of fuel assembly and ejection of control rod. The failure probability of reactivity control is 1.49E-03 per year. The causes of failures which are affected by human factor are boron dilution, misalignment of control rod withdrawal and malfunction of improper position for fuel assembly. Based on the assessment, it is concluded that the failure probability of reactivity control on the PWR is still within the IAEA criteria.

  12. [Cross-sectional analysis of heart failure among patients in the Internal Medicine Service at a third-level hospital. Part I: epidemiologic analysis].

    Science.gov (United States)

    Cinza Sanjurjo, S; Cabarcos Ortiz de Barrón, A; Enrique Nieto Pol, E; Torre Carballada, J A

    2007-06-01

    To observe the epidemiologic characteristics of the patients intake during five years in a internal medicine department, with heart failure. A cross-sectional study of the intake patients in the Internal Medicine Service in the Hospital Clínico Universitario de Santiago de Compostela between 1999 to 2003. The variables analized were: sex, age, days of hospital stay, number of intake by failure cardiac, reason for admission (guide symptom), hypertension, diabetes mellitus, cardiac disease, fibrillation atrium, previous treatment with beta-blockers, blood pressure in the admission moment, to make echocardiography, disfunction systolic, etiology, deceased, treatment at the end. The statistical analysis was performed with qualitative and quantitative measures, chi-cuadrado and t-student, and multivariant analyses. 248 patients were accepted for the study. We observed more women than men (55.2%) and bigger median age (79 years old vs. 73 years old in men, p < 0.001). The mean income was 13.61 days and a median of 11 days. The 41,8% of the patients had hypertension, 30.9% diabetes mellitus and 81,9% had someone heart disease. The aetiologies of heart failure most frequent were ischemic cardiopathy (27.2%) and hypertension (24.2%). The most frequent symptom was the dyspnea (68.9%). It made echocardiography in 20.9% of patients and 45.1% showed systolic disfunction. The only factor related with this small percentage of echocardiographies was the incoming time. The most frequent etiology was respiratory infections (39.5%). The 8.6% of patients was deceased. The pharmacologic treatment more prescribed were the diuretics (86.9%) and transcutaneous nitrates (49.5%). It was indicated ECAI or AAR-II in the 86.9% of patients and beta-blockers in 0.9%. The number of echocardiograms practiced to the patients is smaller that the number advised by international associations and smaller to the cardiologist registers. The beta-blockers and ECAI use is smaller too.

  13. A quantitative method for Failure Mode and Effects Analysis

    NARCIS (Netherlands)

    Braaksma, Anne Johannes Jan; Meesters, A.J.; Klingenberg, W.; Hicks, C.

    2012-01-01

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

  14. Failure mode analysis of a PCRV. Influence of some hypothesis

    International Nuclear Information System (INIS)

    Zimmermann, T.; Saugy, B.; Rebora, B.

    1975-01-01

    This paper is concerned with the most recent developments and results obtained using a mathematical model for the non-linear analysis of massive reinforced and prestressed concrete strucures developed by the IPEN at the Swiss Federal Institute of Technology, in Lausanne. The method is based on three-dimensional isoparametric finite elements. A linear solution is adapted step by step to the idealized behavior laws of the materials up to the failure of the structure. The laws proposed here for the non-linear behavior of concrete and steel have been described elsewhere but a simple extension to the time-dependent behavior is presented. A numerical algorithm for the superposition of creep deformations is also proposed, the basic creep law being supposed to satisfy a power expression. Time-dependent failure is discussed. The calculus of a PCRV of a helium cooled fast reactor is then performed and the influence of the liner on the failure mode is analyzed. The failure analysis under increasing internal pressure is run at the present time and the influence of an eventual pressure in the cracks is being investigated. The paper aims mainly to demonstrate the accuracy of a failure analysis by three-dimensional finite-elements and to compare it with a model test, in particular when complete deformation and failure tests of the materials are available. The proposed model has already been extensively tested on simple structures and has proved to be useful for the analysis of different simplifying hypotheses

  15. Failure analysis of a Francis turbine runner

    Energy Technology Data Exchange (ETDEWEB)

    Frunzaverde, D; Campian, V [Research Center in Hydraulics, Automation and Heat Transfer, ' Eftimie Murgu' University of Resita P-ta Traian Vuia 1-4, RO-320085, Resita (Romania); Muntean, S [Centre of Advanced Research in Engineering Sciences, Romanian Academy - Timisoara Branch Bv. Mihai Viteazu 24, RO-300223, Timisoara (Romania); Marginean, G [University of Applied Sciences Gelsenkirchen, Neidenburger Str. 10, 45877 Gelsenkirchen (Germany); Marsavina, L [Department of Strength, ' Politehnica' University of Timisoara, Bv. Mihai Viteazu 1, RO-300222, Timisoara (Romania); Terzi, R; Serban, V, E-mail: gabriela.marginean@fh-gelsenkirchen.d, E-mail: d.frunzaverde@uem.r [Ramnicu Valcea Subsidiary, S.C. Hidroelectrica S.A., Str. Decebal 11, RO-240255, Ramnicu Valcea (Romania)

    2010-08-15

    The variable demand on the energy market requires great flexibility in operating hydraulic turbines. Therefore, turbines are frequently operated over an extended range of regimes. Francis turbines operating at partial load present pressure fluctuations due to the vortex rope in the draft tube cone. This phenomenon generates strong vibrations and noise that may produce failures on the mechanical elements of the machine. This paper presents the failure analysis of a broken Francis turbine runner blade. The failure appeared some months after the welding repair work realized in situ on fatigue cracks initiated near to the trailing edge at the junction with the crown, where stress concentration occurs. In order to determine the causes that led to the fracture of the runner blade, the metallographic investigations on a sample obtained from the blade is carried out. The metallographic investigations included macroscopic and microscopic examinations, both performed with light and scanning electron microscopy, as well as EDX - analyses. These investigations led to the conclusion, that the cracking of the blade was caused by fatigue, initiated by the surface unevenness of the welding seam. The failure was accelerated by the hydrogen embrittlement of the filling material, which appeared as a consequence of improper welding conditions. In addition to the metallographic investigations, numerical computations with finite element analysis are performed in order to evaluate the deformation and stress distribution on blade.

  16. Failure analysis of a Francis turbine runner

    International Nuclear Information System (INIS)

    Frunzaverde, D; Campian, V; Muntean, S; Marginean, G; Marsavina, L; Terzi, R; Serban, V

    2010-01-01

    The variable demand on the energy market requires great flexibility in operating hydraulic turbines. Therefore, turbines are frequently operated over an extended range of regimes. Francis turbines operating at partial load present pressure fluctuations due to the vortex rope in the draft tube cone. This phenomenon generates strong vibrations and noise that may produce failures on the mechanical elements of the machine. This paper presents the failure analysis of a broken Francis turbine runner blade. The failure appeared some months after the welding repair work realized in situ on fatigue cracks initiated near to the trailing edge at the junction with the crown, where stress concentration occurs. In order to determine the causes that led to the fracture of the runner blade, the metallographic investigations on a sample obtained from the blade is carried out. The metallographic investigations included macroscopic and microscopic examinations, both performed with light and scanning electron microscopy, as well as EDX - analyses. These investigations led to the conclusion, that the cracking of the blade was caused by fatigue, initiated by the surface unevenness of the welding seam. The failure was accelerated by the hydrogen embrittlement of the filling material, which appeared as a consequence of improper welding conditions. In addition to the metallographic investigations, numerical computations with finite element analysis are performed in order to evaluate the deformation and stress distribution on blade.

  17. Collateral sensitivity to cisplatin in KB-8-5-11 drug-resistant cancer cells.

    LENUS (Irish Health Repository)

    Doherty, Ben

    2014-01-01

    KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer.

  18. TU-AB-BRD-02: Failure Modes and Effects Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huq, M. [University of Pittsburgh Medical Center (United States)

    2015-06-15

    Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk-based quality management program for intensity-modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program. Learning Objectives: Learn how to design a process map for a radiotherapy process Learn how to

  19. TU-AB-BRD-02: Failure Modes and Effects Analysis

    International Nuclear Information System (INIS)

    Huq, M.

    2015-01-01

    Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk-based quality management program for intensity-modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program. Learning Objectives: Learn how to design a process map for a radiotherapy process Learn how to

  20. SU-E-T-627: Failure Modes and Effect Analysis for Monthly Quality Assurance of Linear Accelerator

    International Nuclear Information System (INIS)

    Xie, J; Xiao, Y; Wang, J; Peng, J; Lu, S; Hu, W

    2014-01-01

    Purpose: To develop and implement a failure mode and effect analysis (FMEA) on routine monthly Quality Assurance (QA) tests (physical tests part) of linear accelerator. Methods: A systematic failure mode and effect analysis method was performed for monthly QA procedures. A detailed process tree of monthly QA was created and potential failure modes were defined. Each failure mode may have many influencing factors. For each factor, a risk probability number (RPN) was calculated from the product of probability of occurrence (O), the severity of effect (S), and detectability of the failure (D). The RPN scores are in a range of 1 to 1000, with higher scores indicating stronger correlation to a given influencing factor of a failure mode. Five medical physicists in our institution were responsible to discuss and to define the O, S, D values. Results: 15 possible failure modes were identified and all RPN scores of all influencing factors of these 15 failue modes were from 8 to 150, and the checklist of FMEA in monthly QA was drawn. The system showed consistent and accurate response to erroneous conditions. Conclusion: The influencing factors of RPN greater than 50 were considered as highly-correlated factors of a certain out-oftolerance monthly QA test. FMEA is a fast and flexible tool to develop an implement a quality management (QM) frame work of monthly QA, which improved the QA efficiency of our QA team. The FMEA work may incorporate more quantification and monitoring fuctions in future

  1. Failure mode and effects analysis of software-based automation systems

    International Nuclear Information System (INIS)

    Haapanen, P.; Helminen, A.

    2002-08-01

    Failure mode and effects analysis (FMEA) is one of the well-known analysis methods having an established position in the traditional reliability analysis. The purpose of FMEA is to identify possible failure modes of the system components, evaluate their influences on system behaviour and propose proper countermeasures to suppress these effects. The generic nature of FMEA has enabled its wide use in various branches of industry reaching from business management to the design of spaceships. The popularity and diverse use of the analysis method has led to multiple interpretations, practices and standards presenting the same analysis method. FMEA is well understood at the systems and hardware levels, where the potential failure modes usually are known and the task is to analyse their effects on system behaviour. Nowadays, more and more system functions are realised on software level, which has aroused the urge to apply the FMEA methodology also on software based systems. Software failure modes generally are unknown - 'software modules do not fail, they only display incorrect behaviour' - and depend on dynamic behaviour of the application. These facts set special requirements on the FMEA of software based systems and make it difficult to realise. In this report the failure mode and effects analysis is studied for the use of reliability analysis of software-based systems. More precisely, the target system of FMEA is defined to be a safety-critical software-based automation application in a nuclear power plant, implemented on an industrial automation system platform. Through a literature study the report tries to clarify the intriguing questions related to the practical use of software failure mode and effects analysis. The study is a part of the research project 'Programmable Automation System Safety Integrity assessment (PASSI)', belonging to the Finnish Nuclear Safety Research Programme (FINNUS, 1999-2002). In the project various safety assessment methods and tools for

  2. Improving failure analysis efficiency by combining FTA and FMEA in a recursive manner

    NARCIS (Netherlands)

    Peeters, J.F.W.; Basten, R.J.I.; Tinga, Tiedo

    2018-01-01

    When designing a maintenance programme for a capital good, especially a new one, it is of key importance to accurately understand its failure behaviour. Failure mode and effects analysis (FMEA) and fault tree analysis (FTA) are two commonly used methods for failure analysis. FMEA is a bottom-up

  3. Improving failure analysis efficiency by combining FTA and FMEA in a recursive manner

    NARCIS (Netherlands)

    Peeters, J.F.W.; Basten, R.J.I.; Tinga, T.

    When designing a maintenance programme for a capital good, especially a new one, it is of key importance to accurately understand its failure behaviour. Failure mode and effects analysis (FMEA) and fault tree analysis (FTA) are two commonly used methods for failure analysis. FMEA is a bottom-up

  4. Association of sleep bruxism with ceramic restoration failure: A systematic review and meta-analysis.

    Science.gov (United States)

    de Souza Melo, Gilberto; Batistella, Elis Ângela; Bertazzo-Silveira, Eduardo; Simek Vega Gonçalves, Thais Marques; Mendes de Souza, Beatriz Dulcineia; Porporatti, André Luís; Flores-Mir, Carlos; De Luca Canto, Graziela

    2018-03-01

    Ceramic restorations are popular because of their excellent optical properties. However, failures are still a major concern, and dentists are confronted with the following question: is sleep bruxism (SB) associated with an increased frequency of ceramic restoration failures? The purpose of this systematic review and meta-analysis was to assess whether the presence of SB is associated with increased ceramic restoration failure. Observational studies and clinical trials that evaluated the short- and long-term survival rate of ceramic restorations in SB participants were selected. Sleep bruxism diagnostic criteria must have included at least 1 of the following: questionnaire, clinical evaluation, or polysomnography. Seven databases, in addition to 3 nonpeer-reviewed literature databases, were searched. The risk of bias was assessed by using the meta-analysis of statistics assessment and review instrument (MAStARI) checklist. Eight studies were included for qualitative synthesis, but only 5 for the meta-analysis. Three studies were categorized as moderate risk and 5 as high risk of bias. Clinical and methodological heterogeneity across studies were considered high. Increased hazard ratio (HR=7.74; 95% confidence interval [CI]=2.50 to 23.95) and odds ratio (OR=2.52; 95% CI=1.24 to 5.12) were observed considering only anterior ceramic veneers. Nevertheless, limited data from the meta-analysis and from the restricted number of included studies suggested that differences in the overall odds of failure concerning SB and other types of ceramic restorations did not favor or disfavor any association (OR=1.10; 95% CI=0.43 to 2.8). The overall quality of evidence was considered very low according to the GRADE criteria. Within the limitations of this systematic review, the overall result from the meta-analysis did not favor any association between SB and increased odds of failure for ceramic restorations. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry

  5. Reliability Evaluation of Machine Center Components Based on Cascading Failure Analysis

    Science.gov (United States)

    Zhang, Ying-Zhi; Liu, Jin-Tong; Shen, Gui-Xiang; Long, Zhe; Sun, Shu-Guang

    2017-07-01

    In order to rectify the problems that the component reliability model exhibits deviation, and the evaluation result is low due to the overlook of failure propagation in traditional reliability evaluation of machine center components, a new reliability evaluation method based on cascading failure analysis and the failure influenced degree assessment is proposed. A direct graph model of cascading failure among components is established according to cascading failure mechanism analysis and graph theory. The failure influenced degrees of the system components are assessed by the adjacency matrix and its transposition, combined with the Pagerank algorithm. Based on the comprehensive failure probability function and total probability formula, the inherent failure probability function is determined to realize the reliability evaluation of the system components. Finally, the method is applied to a machine center, it shows the following: 1) The reliability evaluation values of the proposed method are at least 2.5% higher than those of the traditional method; 2) The difference between the comprehensive and inherent reliability of the system component presents a positive correlation with the failure influenced degree of the system component, which provides a theoretical basis for reliability allocation of machine center system.

  6. Large-Scale Molecular Simulations on the Mechanical Response and Failure Behavior of a defective Graphene: Cases of 5-8-5 Defects

    Science.gov (United States)

    Wang, Shuaiwei; Yang, Baocheng; Yuan, Jinyun; Si, Yubing; Chen, Houyang

    2015-10-01

    Understanding the effect of defects on mechanical responses and failure behaviors of a graphene membrane is important for its applications. As examples, in this paper, a family of graphene with various 5-8-5 defects are designed and their mechanical responses are investigated by employing molecular dynamics simulations. The dependence of fracture strength and strain as well as Young’s moduli on the nearest neighbor distance and defect types is examined. By introducing the 5-8-5 defects into graphene, the fracture strength and strain become smaller. However, the Young’s moduli of DL (Linear arrangement of repeat unit 5-8-5 defect along zigzag-direction of graphene), DS (a Slope angle between repeat unit 5-8-5 defect and zigzag direction of graphene) and DZ (Zigzag-like 5-8-5 defects) defects in the zigzag direction become larger than those in the pristine graphene in the same direction. A maximum increase of 11.8% of Young’s modulus is obtained. Furthermore, the brittle cracking mechanism is proposed for the graphene with 5-8-5 defects. The present work may provide insights in controlling the mechanical properties by preparing defects in the graphene, and give a full picture for the applications of graphene with defects in flexible electronics and nanodevices.

  7. A human reliability analysis (HRA) method for identifying and assessing the error of commission (EOC) from a diagnosis failure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Whan; Jung, Won Dea; Park, Jin Yun; Kang, Dae Il

    2005-01-01

    The study deals with a method for systematically identifying and assessing the EOC events that might be caused from a diagnosis failure or misdiagnosis of the expected events in accident scenarios of nuclear power plants. The method for EOC identification and assessment consists of three steps: analysis of the potential for a diagnosis failure (or misdiagnosis), identification of the EOC events from the diagnosis failure, quantitative assessment of the identified EOC events. As a tool for analysing a diagnosis failure, the MisDiagnosis Tree Analysis (MDTA) technique is proposed with the taxonomy of misdiagnosis causes. Also, the guidance on the identification of EOC events and the classification system and data are given for quantitiative assessment. As an applicaton of the proposed method, the EOCs identification and assessment for Younggwang 3 and 4 plants and their impact on the plant risk were performed. As the result, six events or event sequences were considered for diagnosis failures and about 20 new Human Failure Events (HFEs) involving EOCs were identified. According to the assessment of the risk impact of the identified HFEs, they increase the CDF by 11.4 % of the current CDF value, which corresponds to 10.2 % of the new CDF. The small loss of coolant accident (SLOCA) turned out to be a major contributor to the increase of CDF resulting in 9.2 % increaseof the current CDF.

  8. Robustness Analysis of Real Network Topologies Under Multiple Failure Scenarios

    DEFF Research Database (Denmark)

    Manzano, M.; Marzo, J. L.; Calle, E.

    2012-01-01

    on topological characteristics. Recently approaches also consider the services supported by such networks. In this paper we carry out a robustness analysis of five real backbone telecommunication networks under defined multiple failure scenarios, taking into account the consequences of the loss of established......Nowadays the ubiquity of telecommunication networks, which underpin and fulfill key aspects of modern day living, is taken for granted. Significant large-scale failures have occurred in the last years affecting telecommunication networks. Traditionally, network robustness analysis has been focused...... connections. Results show which networks are more robust in response to a specific type of failure....

  9. Radiotherapy in desmoid tumors. Treatment response, local control, and analysis of local failures

    Energy Technology Data Exchange (ETDEWEB)

    Santti, Kirsi; Beule, Annette; Tuomikoski, Laura; Jaeaeskelaeinen, Anna-Stina; Saarilahti, Kauko; Tarkkanen, Maija; Blomqvist, Carl [Helsinki University Hospital and University of Helsinki, Comprehensive Cancer Center, Helsinki (Finland); Roenty, Mikko [HUSLAB and University of Helsinki, Department of Pathology, Helsinki (Finland); Ihalainen, Hanna [Helsinki University Hospital and University of Helsinki, Department of Plastic Surgery, Helsinki (Finland)

    2017-04-15

    Desmoid tumors (aggressive fibromatosis) are rare soft tissue tumors which frequently recur after surgery. Desmoid tumors arise from musculoaponeurotic tissue in the extremities, head and neck, abdominal wall, or intra-abdominally. Our aim was to examine the outcome of radiotherapy of desmoid tumors in a single institution series. We evaluated 41 patients with desmoid tumors treated with 49 radiotherapies between 1987 and 2012. Radiologic images for response evaluation were reassessed and responses to treatment registered according to RECIST criteria 1.1. For patients with local failures radiation dose distribution was determined in each local failure volume using image co-registration. Recurrences were classified as in-target, marginal, or out-of-target. Prognostic factors for radiotherapy treatment failure were evaluated. Radiotherapy doses varied from 20-63 Gy (median 50 Gy) with a median fraction size of 2 Gy. The objective response rate to definitive radiotherapy was 55% (12/22 patients). Median time to response was 14 months. A statistically significant dose-response relation for definitive and postoperative radiotherapy was observed both in univariate (p-value 0.002) and in multivariate analysis (p-value 0.02) adjusted for potential confounding factors. Surgery before radiotherapy or surgical margin had no significant effect on time to progression. Nine of 11 (82%) local failures were classified as marginal and two of 11 (18%) in-target. None of the recurrences occurred totally out-of-target. Radiotherapy is a valuable option for treating desmoid tumors. Radiotherapy dose appears to be significantly associated to local control. (orig.) [German] Desmoide (aggressive Fibromatosen) sind seltene Weichteiltumore der muskulaeren Membranen von Kopf, Hals, Extremitaeten und Bauchwand. Ziel war es, die Wirksamkeit der Strahlentherapie bei aggressiver Fibromatose an einer einzelnen Klinik zu untersuchen. Ausgewertet wurden 41 Patienten mit aggressiver Fibromatose, die

  10. Analysis of dependent failures in risk assessment and reliability evaluation

    International Nuclear Information System (INIS)

    Fleming, K.N.; Mosleh, A.; Kelley, A.P. Jr.; Gas-Cooled Reactors Associates, La Jolla, CA)

    1983-01-01

    The ability to estimate the risk of potential reactor accidents is largely determined by the ability to analyze statistically dependent multiple failures. The importance of dependent failures has been indicated in recent probabilistic risk assessment (PRA) studies as well as in reports of reactor operating experiences. This article highlights the importance of several different types of dependent failures from the perspective of the risk and reliability analyst and provides references to the methods and data available for their analysis. In addition to describing the current state of the art, some recent advances, pitfalls, misconceptions, and limitations of some approaches to dependent failure analysis are addressed. A summary is included of the discourse on this subject, which is presented in the Institute of Electrical and Electronics Engineers/American Nuclear Society PRA Procedures Guide

  11. Is age a factor in the success or failure of remote monitoring in heart failure? Telemonitoring and structured telephone support in elderly heart failure patients.

    Science.gov (United States)

    Inglis, Sally C; Conway, Aaron; Cleland, John Gf; Clark, Robyn A

    2015-06-01

    There are few data regarding the effectiveness of remote monitoring for older people with heart failure. We conducted a post-hoc sub-analysis of a previously published large Cochrane systematic review and meta-analysis of relevant randomized controlled trials to determine whether structured telephone support and telemonitoring were effective in this population. A post hoc sub-analysis of a systematic review and meta-analysis that applied the Cochrane methodology was conducted. Meta-analyses of all-cause mortality, all-cause hospitalizations and heart failure-related hospitalizations were performed for studies where the mean or median age of participants was 70 or more years. The mean or median age of participants was 70 or more years in eight of the 16 (n=2659/5613; 47%) structured telephone support studies and four of the 11 (n=894/2710; 33%) telemonitoring studies. Structured telephone support (RR 0.80; 95% CI=0.63-1.00) and telemonitoring (RR 0.56; 95% CI=0.41-0.76) interventions reduced mortality. Structured telephone support interventions reduced heart failure-related hospitalizations (RR 0.81; 95% CI=0.67-0.99). Despite a systematic bias towards recruitment of individuals younger than the epidemiological average into the randomized controlled trials, older people with heart failure did benefit from structured telephone support and telemonitoring. These post-hoc sub-analysis results were similar to overall effects observed in the main meta-analysis. While further research is required to confirm these observational findings, the evidence at hand indicates that discrimination by age alone may be not be appropriate when inviting participation in a remote monitoring service for heart failure. © The European Society of Cardiology 2014.

  12. Reliability analysis of multi-trigger binary systems subject to competing failures

    International Nuclear Information System (INIS)

    Wang, Chaonan; Xing, Liudong; Levitin, Gregory

    2013-01-01

    This paper suggests two combinatorial algorithms for the reliability analysis of multi-trigger binary systems subject to competing failure propagation and failure isolation effects. Propagated failure with global effect (PFGE) is referred to as a failure that not only causes outage to the component from which the failure originates, but also propagates through all other system components causing the entire system failure. However, the propagation effect from the PFGE can be isolated in systems with functional dependence (FDEP) behavior. This paper studies two distinct consequences of PFGE resulting from a competition in the time domain between the failure isolation and failure propagation effects. As compared to existing works on competing failures that are limited to systems with a single FDEP group, this paper considers more complicated cases where the systems have multiple dependent FDEP groups. Analysis of such systems is more challenging because both the occurrence order between the trigger failure event and PFGE from the dependent components and the occurrence order among the multiple trigger failure events have to be considered. Two combinatorial and analytical algorithms are proposed. Both of them have no limitation on the type of time-to-failure distributions for the system components. Their correctness is verified using a Markov-based method. An example of memory systems is analyzed to demonstrate and compare the applications and advantages of the two proposed algorithms. - Highlights: ► Reliability of binary systems with multiple dependent functional dependence groups is analyzed. ► Competing failure propagation and failure isolation effect is considered. ► The proposed algorithms are combinatorial and applicable to any arbitrary type of time-to-failure distributions for system components.

  13. 28 CFR 11.8 - Salary offset.

    Science.gov (United States)

    2010-07-01

    ... applicable. (7) Failure to appear. If, in the absence of good cause shown (e.g., illness), the employee or... changed circumstances, including but not limited to catastrophic illness, divorce, death, or disability...

  14. Recognition and Analysis of Corrosion Failure Mechanisms

    Directory of Open Access Journals (Sweden)

    Steven Suess

    2006-02-01

    Full Text Available Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, material evaluation, data review and conclusion procurement. In analyzing corrosion failures, one must recognize the wide range of common corrosion mechanisms. The features of any corrosion failure give strong clues as to the most likely cause of the corrosion. This article details a proven approach to properly determining the root cause of a failure, and includes pictographic illustrations of the most common corrosion mechanisms, including general corrosion, pitting, galvanic corrosion, dealloying, crevice corrosion, microbiologically-influenced corrosion (MIC, corrosion fatigue, stress corrosion cracking (SCC, intergranular corrosion, fretting, erosion corrosion and hydrogen damage.

  15. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    Directory of Open Access Journals (Sweden)

    Bloemer Wilhelm

    2010-01-01

    Full Text Available Abstract Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68 of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years and the average weight 102.3 kg (75 to 130 kg. The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck

  16. Uranyl-organic assemblies with the macrocyclic ligand 1, 4, 8, 11-tetra-aza-cyclo-tetradecane-1, 4, 8, 11-tetraacetate (TETA)

    International Nuclear Information System (INIS)

    Thuery, Pierre

    2010-01-01

    Three uranyl ion complexes obtained from the reaction of uranyl nitrate hexahydrate and 1, 4, 8, 11-tetra-aza-cyclo-tetradecane-1, 4, 8, 11-tetraacetic acid (H 4 TETA) were characterized by their crystal structure. The centrosymmetric macrocycle, in the [3434] conformation with either carbon or nitrogen atoms as corners, is zwitterionic, with four carboxylate groups and two or four protonated nitrogen atoms. The complexes [(UO 2 ) 2 (H 2 TETA)(C 2 O 4 )(H 2 O) 2 ] (1) and [UO 2 (H 4 TETA)(H 2 O)].NO 3 .Cl (2) were synthesized under hydrothermal conditions and 1 includes additional oxalate ligands generated in situ. Both compounds are two-dimensional polymers in which the four-fold monodentate macrocyclic ligand unites either four uranyl oxalate dinuclear species (1) or isolated uranyl ions (2). Complex 3, [UO 2 (H 2 TETA)(H 2 O)].6H 2 O, was obtained at room temperature and, although it displays the same stoichiometry as 2, it differs from it by being a three-dimensional framework. Both 2 and 3 present channels containing either counter-ions or water molecules. As often observed, the water content of the low-temperature species, 3, is higher than that of the high-temperature one, 2. (author)

  17. Propagated failure analysis for non-repairable systems considering both global and selective effects

    International Nuclear Information System (INIS)

    Wang Chaonan; Xing Liudong; Levitin, Gregory

    2012-01-01

    This paper proposes an algorithm for the reliability analysis of non-repairable binary systems subject to competing failure propagation and failure isolation events with both global and selective failure effects. A propagated failure that originates from a system component causes extensive damage to the rest of the system. Global effect happens when the propagated failure causes the entire system to fail; whereas selective effect happens when the propagated failure causes only failure of a subset of system components. In both cases, the failure propagation that originates from some system components (referred to as dependent components) can be isolated because of functional dependence between the dependent components and a component that prevents the failure propagation (trigger components) when the failure of the trigger component happens before the occurrence of the propagated failure. Most existing studies focus on the analysis of propagated failures with global effect. However, in many cases, propagated failures affect only a subset of system components not the entire system. Existing approaches for analyzing propagated failures with selective effect are limited to series-parallel systems. This paper proposes a combinatorial method for the propagated failure analysis considering both global and selective effects as well as the competition with the failure isolation in the time domain. The proposed method is not limited to series-parallel systems and has no limitation on the type of time-to-failure distributions for the system components. The method is verified using the Markov-based method. An example of computer memory systems is analyzed to demonstrate the application of the proposed method.

  18. System reliability analysis using dominant failure modes identified by selective searching technique

    International Nuclear Information System (INIS)

    Kim, Dong-Seok; Ok, Seung-Yong; Song, Junho; Koh, Hyun-Moo

    2013-01-01

    The failure of a redundant structural system is often described by innumerable system failure modes such as combinations or sequences of local failures. An efficient approach is proposed to identify dominant failure modes in the space of random variables, and then perform system reliability analysis to compute the system failure probability. To identify dominant failure modes in the decreasing order of their contributions to the system failure probability, a new simulation-based selective searching technique is developed using a genetic algorithm. The system failure probability is computed by a multi-scale matrix-based system reliability (MSR) method. Lower-scale MSR analyses evaluate the probabilities of the identified failure modes and their statistical dependence. A higher-scale MSR analysis evaluates the system failure probability based on the results of the lower-scale analyses. Three illustrative examples demonstrate the efficiency and accuracy of the approach through comparison with existing methods and Monte Carlo simulations. The results show that the proposed method skillfully identifies the dominant failure modes, including those neglected by existing approaches. The multi-scale MSR method accurately evaluates the system failure probability with statistical dependence fully considered. The decoupling between the failure mode identification and the system reliability evaluation allows for effective applications to larger structural systems

  19. Patterns of failure following treatment for medulloblastoma: is it necessary to treat the entire posterior fossa?

    International Nuclear Information System (INIS)

    Fukunaga-Johnson, Nina; Lee, Jason H.; Robertson, Patricia; Sandler, Howard M.; McNeil, Elizabeth; Goldwein, Joel W.

    1997-01-01

    as the solitary site of first failure in only (1(27)) failures. (11(14)) patients who failed in the tumor bed also failed in the spine, (8(14)) also failed within the PF but outside the tumor bed, and (7(14)) failed in the all three locations. Local failure within the PF but outside the tumor bed as any component of first failure occurred in 41% ((11(27))) of all failures but as the solitary site of first failure in only (1(27)) failures. Nine of 11 patients who failed in the PF but outside the tumor bed also failed in the spine, (8(11)) also failed within the tumor bed, and (7(11)) failed in the all three locations. Of the failures outside the tumor bed but still within the PF, (7(11)) failed in the leptomeninges, (1(11)) in the brainstem parenchyma, and (3(11)) in the PF parenchyma. (6(7)) who failed in the PF leptomeninges also failed within the spine. Failure within the spine as any component of first failure occurred in 70% ((19(27))) of all failures and as the only site of first failure in (5(27)) patients. (11(19)) patients who failed in the spine also failed in the tumor bed, (9(19)) also failed within the PF but outside the tumor bed, and (9(19)) failed in the all three locations. Conclusions: Leptomeningeal failure is a common component of failure and occurs in the leptomeninges of the PF as well as the spine. Isolated tumor bed failure is a rarely observed event and occurred in only (1(27)) failures here described. Similarly, parenchymal (non-leptomengingeal) failures in the PF but outside of the tumor bed were rare: 4 patients recurred in this manner, only 1 of which was an isolated event without other sites of recurrence. These data suggest that when the entire PF is treated, very few failures develop in the PF outside the tumor bed. Further studies will be necessary to determine whether RT the tumor bed alone will suffice as opposed to a boost to the entire PF. The former approach using 3D conformal therapy may minimize the ototoxicity and other

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

    Directory of Open Access Journals (Sweden)

    Iraj Alimohammadi

    2014-06-01

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

  1. Failure criterion of concrete type material and punching failure analysis of thick mortar plate

    International Nuclear Information System (INIS)

    Ohno, T.; Kuroiwa, M.; Irobe, M.

    1979-01-01

    In this paper falure surface of concrete type material is proposed and its validity to structural analysis is examined. The study is an introductory part of evaluation for ultimate strength of reinforced and prestressed concrete structures in reactor technology. The failure surface is expressed in a linear form in terms of octahedral normal and shear stresses. Coefficient of the latter stress is given by a trigonometric series in threefold angle of similarity. Hence, its meridians are multilinear and traces of its deviatoric sections are smooth curves having periodicity of 2π/3 around space diagonal in principal stress space. The mathematical expression of the surface has an arbitraty number of parameters so that material test results are well reflected. To confirm the effectiveness of proposed failure criterion, experiment and numerical analysis by the finite element method on punching failure of thick mortar plate in axial symmetry are compared. In the numerical procedure yield surface of the material is assumed to exist mainly in compression region, since a brittle cleavage or elastic fracture occurs in the concrete type material under stress state with tension, while a ductile or plastic fracture occurs under compressive stress state. (orig.)

  2. WE-G-BRA-08: Failure Modes and Effects Analysis (FMEA) for Gamma Knife Radiosurgery

    International Nuclear Information System (INIS)

    Xu, Y; Bhatnagar, J; Bednarz, G; Flickinger, J; Arai, Y; Huq, M Saiful; Vacsulka, J; Monaco, E; Niranjan, A; Lunsford, L Dade; Feng, W

    2015-01-01

    Purpose: To perform a failure modes and effects analysis (FMEA) study for Gamma Knife (GK) radiosurgery processes at our institution based on our experience with the treatment of more than 13,000 patients. Methods: A team consisting of medical physicists, nurses, radiation oncologists, neurosurgeons at the University of Pittsburgh Medical Center and an external physicist expert was formed for the FMEA study. A process tree and a failure mode table were created for the GK procedures using the Leksell GK Perfexion and 4C units. Three scores for the probability of occurrence (O), the severity (S), and the probability of no detection (D) for failure modes were assigned to each failure mode by each professional on a scale from 1 to 10. The risk priority number (RPN) for each failure mode was then calculated (RPN = OxSxD) as the average scores from all data sets collected. Results: The established process tree for GK radiosurgery consists of 10 sub-processes and 53 steps, including a sub-process for frame placement and 11 steps that are directly related to the frame-based nature of the GK radiosurgery. Out of the 86 failure modes identified, 40 failure modes are GK specific, caused by the potential for inappropriate use of the radiosurgery head frame, the imaging fiducial boxes, the GK helmets and plugs, and the GammaPlan treatment planning system. The other 46 failure modes are associated with the registration, imaging, image transfer, contouring processes that are common for all radiation therapy techniques. The failure modes with the highest hazard scores are related to imperfect frame adaptor attachment, bad fiducial box assembly, overlooked target areas, inaccurate previous treatment information and excessive patient movement during MRI scan. Conclusion: The implementation of the FMEA approach for Gamma Knife radiosurgery enabled deeper understanding of the overall process among all professionals involved in the care of the patient and helped identify potential

  3. Human oocyte calcium analysis predicts the response to assisted oocyte activation in patients experiencing fertilization failure after ICSI.

    Science.gov (United States)

    Ferrer-Buitrago, M; Dhaenens, L; Lu, Y; Bonte, D; Vanden Meerschaut, F; De Sutter, P; Leybaert, L; Heindryckx, B

    2018-01-10

    Can human oocyte calcium analysis predict fertilization success after assisted oocyte activation (AOA) in patients experiencing fertilization failure after ICSI? ICSI-AOA restores the fertilization rate only in patients displaying abnormal Ca2+ oscillations during human oocyte activation. Patients capable of activating mouse oocytes and who showed abnormal Ca2+ profiles after mouse oocyte Ca2+ analysis (M-OCA), have variable responses to ICSI-AOA. It remains unsettled whether human oocyte Ca2+ analysis (H-OCA) would yield an improved accuracy to predict fertilization success after ICSI-AOA. Sperm activation potential was first evaluated by MOAT. Subsequently, Ca2+ oscillatory patterns were determined with sperm from patients showing moderate to normal activation potential based on the capacity of human sperm to generate Ca2+ responses upon microinjection in mouse and human oocytes. Altogether, this study includes a total of 255 mouse and 122 human oocytes. M-OCA was performed with 16 different sperm samples before undergoing ICSI-AOA treatment. H-OCA was performed for 11 patients who finally underwent ICSI-AOA treatment. The diagnostic accuracy to predict fertilization success was calculated based on the response to ICSI-AOA. Patients experiencing low or total failed fertilization after conventional ICSI were included in the study. All participants showed moderate to high rates of activation after MOAT. Metaphase II (MII) oocytes from B6D2F1 mice were used for M-OCA. Control fertile sperm samples were used to obtain a reference Ca2+ oscillation profile elicited in human oocytes. Donated human oocytes, non-suitable for IVF treatments, were collected and vitrified at MII stage for further analysis by H-OCA. M-OCA and H-OCA predicted the response to ICSI-AOA in 8 out of 11 (73%) patients. Compared to M-OCA, H-OCA detected the presence of sperm activation deficiencies with greater sensitivity (75 vs 100%, respectively). ICSI-AOA never showed benefit to overcome

  4. The 8Li(α,n)11B reaction and primordial nucleosynthesis

    International Nuclear Information System (INIS)

    Boyd, R.N.

    1992-01-01

    The cross section for the 8 Li(α,n) 11 B reaction, of importance to synthesis of 11 B and heavier nuclides following the big bang, has been measured using the radioactive beam facility of The Institute of Physical and Chemical Reasearch (RIKEN). The reaction cross section was found to be about five times larger than that estimated from the time reversed reaction cross section. (author)

  5. Bruxism and dental implant failures: a multilevel mixed effects parametric survival analysis approach.

    Science.gov (United States)

    Chrcanovic, B R; Kisch, J; Albrektsson, T; Wennerberg, A

    2016-11-01

    Recent studies have suggested that the insertion of dental implants in patients being diagnosed with bruxism negatively affected the implant failure rates. The aim of the present study was to investigate the association between the bruxism and the risk of dental implant failure. This retrospective study is based on 2670 patients who received 10 096 implants at one specialist clinic. Implant- and patient-related data were collected. Descriptive statistics were used to describe the patients and implants. Multilevel mixed effects parametric survival analysis was used to test the association between bruxism and risk of implant failure adjusting for several potential confounders. Criteria from a recent international consensus (Lobbezoo et al., J Oral Rehabil, 40, 2013, 2) and from the International Classification of Sleep Disorders (International classification of sleep disorders, revised: diagnostic and coding manual, American Academy of Sleep Medicine, Chicago, 2014) were used to define and diagnose the condition. The number of implants with information available for all variables totalled 3549, placed in 994 patients, with 179 implants reported as failures. The implant failure rates were 13·0% (24/185) for bruxers and 4·6% (155/3364) for non-bruxers (P bruxism was a statistically significantly risk factor to implant failure (HR 3·396; 95% CI 1·314, 8·777; P = 0·012), as well as implant length, implant diameter, implant surface, bone quantity D in relation to quantity A, bone quality 4 in relation to quality 1 (Lekholm and Zarb classification), smoking and the intake of proton pump inhibitors. It is suggested that the bruxism may be associated with an increased risk of dental implant failure. © 2016 John Wiley & Sons Ltd.

  6. Common Cause Failure Analysis for the Digital Plant Protection System

    International Nuclear Information System (INIS)

    Kagn, Hyun Gook; Jang, Seung Cheol

    2005-01-01

    Safety-critical systems such as nuclear power plants adopt the multiple-redundancy design in order to reduce the risk from the single component failure. The digitalized safety-signal generation system is also designed based on the multiple-redundancy strategy which consists of more redundant components. The level of the redundant design of digital systems is usually higher than those of conventional mechanical systems. This higher redundancy would clearly reduce the risk from the single failure of components, but raise the importance of the common cause failure (CCF) analysis. This research aims to develop the practical and realistic method for modeling the CCF in digital safety-critical systems. We propose a simple and practical framework for assessing the CCF probability of digital equipment. Higher level of redundancy causes the difficulty of CCF analysis because it results in impractically large number of CCF events in the fault tree model when we use conventional CCF modeling methods. We apply the simplified alpha-factor (SAF) method to the digital system CCF analysis. The precedent study has shown that SAF method is quite realistic but simple when we consider carefully system success criteria. The first step for using the SAF method is the analysis of target system for determining the function failure cases. That is, the success criteria of the system could be derived from the target system's function and configuration. Based on this analysis, we can calculate the probability of single CCF event which represents the CCF events resulting in the system failure. In addition to the application of SAF method, in order to accommodate the other characteristics of digital technology, we develop a simple concept and several equations for practical use

  7. NDT in failure analysis - some case studies [Paper IIIA-g

    International Nuclear Information System (INIS)

    Raj, Baldev; Bhattacharya, D.K.; Lopez, E.C.; Jayakumar, T.

    1986-01-01

    The effective uses of several non-destructive techniques in failure analysis are discussed. The techniques considered are: dye penetrant testing, radiography, ultrasonic testing, hardness measurement and in-situ metallography. A few failure cases are discussed to highlight the usefulness of the techniques. (author)

  8. Renal failure in patients with multiple myeloma.

    Science.gov (United States)

    Almueilo, Samir H

    2015-01-01

    Renal dysfunction is encountered in 20-25% of patients with multiple myeloma (MM) at the time of diagnosis. There is often a precipitating event. Several biochemical and clinical correlations with renal failure in MM have been reported. Renal failure in MM is associated with worse outcome of the disease. We retrospectively analyzed the medical records of 64 patients with MM admitted to our institution during the period January 1992 to December 2012. Abnormal renal function was observed in 24 (37.5%) patients and 17 (26.6%) of them had renal failure; 14 of the 17 (82.4%) of patients with renal failure had Stage III MM. Urine Bence- Jones protein was positive in ten (58.8%) patients with renal failure versus ten (21.3%) patients without renal failure (P = 0.004). Potential precipitating factors of renal failure were determined in nine patients. Renal function normalized in 11 patients with simple measures, while six patients required hemodialysis; one remained dialysis dependent till time of death. Early mortality occurred in five (29.4%) patients with renal failure as compared with two (4.3%) patients in the group without renal failure (P = 0.005). In conclusion, renal failure is associated with a higher tumor burden and Bence-Jones proteinuria in patients with MM. It is reversible in the majority of patients; however, early mortality tends to be higher in patients with persistent renal failure.

  9. [Hazard function and life table: an introduction to the failure time analysis].

    Science.gov (United States)

    Matsushita, K; Inaba, H

    1987-04-01

    Failure time analysis has become popular in demographic studies. It can be viewed as a part of regression analysis with limited dependent variables as well as a special case of event history analysis and multistate demography. The idea of hazard function and failure time analysis, however, has not been properly introduced to nor commonly discussed by demographers in Japan. The concept of hazard function in comparison with life tables is briefly described, where the force of mortality is interchangeable with the hazard rate. The basic idea of failure time analysis is summarized for the cases of exponential distribution, normal distribution, and proportional hazard models. The multiple decrement life table is also introduced as an example of lifetime data analysis with cause-specific hazard rates.

  10. A Big Data Analysis Approach for Rail Failure Risk Assessment.

    Science.gov (United States)

    Jamshidi, Ali; Faghih-Roohi, Shahrzad; Hajizadeh, Siamak; Núñez, Alfredo; Babuska, Robert; Dollevoet, Rolf; Li, Zili; De Schutter, Bart

    2017-08-01

    Railway infrastructure monitoring is a vital task to ensure rail transportation safety. A rail failure could result in not only a considerable impact on train delays and maintenance costs, but also on safety of passengers. In this article, the aim is to assess the risk of a rail failure by analyzing a type of rail surface defect called squats that are detected automatically among the huge number of records from video cameras. We propose an image processing approach for automatic detection of squats, especially severe types that are prone to rail breaks. We measure the visual length of the squats and use them to model the failure risk. For the assessment of the rail failure risk, we estimate the probability of rail failure based on the growth of squats. Moreover, we perform severity and crack growth analyses to consider the impact of rail traffic loads on defects in three different growth scenarios. The failure risk estimations are provided for several samples of squats with different crack growth lengths on a busy rail track of the Dutch railway network. The results illustrate the practicality and efficiency of the proposed approach. © 2017 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  11. Reactor Core Failure Analysis for Feasibility Study of IVR-ERVC Strategy

    International Nuclear Information System (INIS)

    Lim, Kukhee; Cho, Yongjin; Hwang, Taesuk

    2014-01-01

    The complicated physical phenomena in a reactor vessel under severe accident environments should be evaluated by effective cooling methods at the same time to satisfy thermal failure margin of the strategy. The reactor integrity by this margin criterion is guaranteed if the heat flux obtained by the analysis of heat balance equations between heat structures in a reactor vessel does not exceed the critical-heat-flux (CHF) limit for nucleate boiling on the vessel outer surface. This method assumes the layer configuration of molten pools (number of layers, thickness of layers and heat generation rate of molten corium, etc.) and evaluates representative states by a 1-dimensional heat transfer analysis. Boundary conditions of model should be well defined to increase accuracy of assessed heat flux and these are dependent on accident scenarios. Therefore, conservative assumptions or results from the analysis using system codes for accident analyses should be considered to determine boundary conditions. In this paper, in-vessel molten corium behaviors during LBLOCA which is considered as the most conservative accident scenario in IVR-ERVC design concerns are examined using MELCOR 1.8.6 to check the feasibility of APR1400 IVR-ERVC strategy. The relocated debris mass in the lower head of APR1400 reactor is analyzed using MELCOR1.8.6. This analysis is to determine the boundary conditions of the heat balance equations consisting of the lumped parameter method in order to calculate heat flux at external vessel wall surface. As a result, lower head vessel failure has been occurred at the time of about 7e3 which is very short time comparing with total period of ERVC process. Even though the effect of external vessel cooling is well-modeled, however, the differences between debris mass are relatively small. Therefore, the physical feasibility of the creep rupture model in MELCOR COR package should be verified for an adequate debris mass assessment in a reactor lower head under the

  12. Hemithoracic Intensity Modulated Radiation Therapy After Pleurectomy/Decortication for Malignant Pleural Mesothelioma: Toxicity, Patterns of Failure, and a Matched Survival Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chance, William W. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rice, David C. [Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tsao, Anne S. [Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Fontanilla, Hiral P. [Princeton Radiation Oncology, Monroe Township, New Jersey (United States); Liao, Zhongxing; Chang, Joe Y.; Tang, Chad; Pan, Hubert Y.; Welsh, James W. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Mehran, Reza J. [Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gomez, Daniel R., E-mail: dgomez@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2015-01-01

    Purpose: To investigate safety, efficacy, and recurrence after hemithoracic intensity modulated radiation therapy after pleurectomy/decortication (PD-IMRT) and after extrapleural pneumonectomy (EPP-IMRT). Methods and Materials: In 2009-2013, 24 patients with mesothelioma underwent PD-IMRT to the involved hemithorax to a dose of 45 Gy, with an optional integrated boost; 22 also received chemotherapy. Toxicity was scored with the Common Terminology Criteria for Adverse Events v4.0. Pulmonary function was compared at baseline, after surgery, and after IMRT. Kaplan-Meier analysis was used to calculate overall survival (OS), progression-free survival (PFS), time to locoregional failure, and time to distant metastasis. Failures were in-field, marginal, or out of field. Outcomes were compared with those of 24 patients, matched for age, nodal status, performance status, and chemotherapy, who had received EPP-IMRT. Results: Median follow-up time was 12.2 months. Grade 3 toxicity rates were 8% skin and 8% pulmonary. Pulmonary function declined from baseline to after surgery (by 21% for forced vital capacity, 16% for forced expiratory volume in 1 second, and 19% for lung diffusion of carbon monoxide [P for all = .01]) and declined still further after IMRT (by 31% for forced vital capacity [P=.02], 25% for forced expiratory volume in 1 second [P=.01], and 30% for lung diffusion of carbon monoxide [P=.01]). The OS and PFS rates were 76% and 67%, respectively, at 1 year and 56% and 34% at 2 years. Median OS (28.4 vs 14.2 months, P=.04) and median PFS (16.4 vs 8.2 months, P=.01) favored PD-IMRT versus EPP-IMRT. No differences were found in grade 4-5 toxicity (0 of 24 vs 3 of 24, P=.23), median time to locoregional failure (18.7 months vs not reached, P not calculable), or median time to distant metastasis (18.8 vs 11.8 months, P=.12). Conclusions: Hemithoracic intensity modulated radiation therapy after pleurectomy/decortication produced little high-grade toxicity but

  13. Failure analysis of PB-1 (EBTS Be/Cu mockup)

    International Nuclear Information System (INIS)

    Odegard, B.C. Jr.; Cadden, C.H.

    1996-11-01

    Failure analysis was done on PB-1 (series of Be tiles joined to Cu alloy) following a tile failure during a high heat flux experiment in EBTS (electron beam test system). This heat flux load simulated ambient conditions inside ITER; the Be tiles were bonded to the Cu alloy using low-temperature diffusion bonding, which is being considered for fabricating plasma facing components in ITER. Results showed differences between the EBTS failure and a failure during a room temperature tensile test. The latter occurred at the Cu-Be interface in an intermetallic phase formed by reaction of the two metals at the bonding temperature. Fracture strengths measured by these tests were over 300 MPa. The high heat flux specimens failed at the Cu-Cu diffusion bond. Fracture morphology in both cases was a mixed mode of dimple rupture and transgranular cleavage. Several explanations for this difference in failure mechanism are suggested

  14. Sequentially linear analysis for simulating brittle failure

    NARCIS (Netherlands)

    van de Graaf, A.V.

    2017-01-01

    The numerical simulation of brittle failure at structural level with nonlinear finite
    element analysis (NLFEA) remains a challenge due to robustness issues. We attribute these problems to the dimensions of real-world structures combined with softening behavior and negative tangent stiffness at

  15. A review of the success and failure characteristics of resin-bonded bridges.

    Science.gov (United States)

    Miettinen, M; Millar, B J

    2013-07-01

    This literature review was designed to assess and compare the success rates and modes of failure of metal-framed, fibre-reinforced composite and all-ceramic resin-bonded bridges. A Medline search (Ovid), supplemented by hand searching, was conducted to identify prospective and retrospective cohort studies on different resin-bonded bridges within the last 16 years. A total of 49 studies met the pre-set inclusion criteria. Success rates of 25 studies on metal-framed, 17 studies on fibre-reinforced composite and 7 studies on all-ceramic resin-bonded bridges were analysed and characteristics of failures were identified. The analysis of the studies indicated an estimation of annual failure rates per year to be 4.6% (±1.3%, 95% CI) for metal-framed, 4.1% (±2.1%, 95% CI) for fibre-reinforced and 11.7% (±1.8%, 95% CI) for all-ceramic resin-bonded bridges. The most frequent complications were: debonding for metal-framed, resin-bonded bridges (93% of all failures); delamination of the composite veneering material for the fibre-reinforced bridges (41%) and fracture of the framework for the all-ceramic bridges (57%). All types of resin-bonded bridges provide an effective short- to medium-term option, with all-ceramic performing least well and having the least favourable mode of failure. The methods of failures were different for different bridges with metal frameworks performing the best over time.

  16. The extent of intestinal failure-associated liver disease in patients referred for intestinal rehabilitation is associated with increased mortality: an analysis of the pediatric intestinal failure consortium database.

    Science.gov (United States)

    Javid, Patrick J; Oron, Assaf P; Duggan, Christopher; Squires, Robert H; Horslen, Simon P

    2017-09-05

    The advent of regional multidisciplinary intestinal rehabilitation programs has been associated with improved survival in pediatric intestinal failure. Yet, the optimal timing of referral for intestinal rehabilitation remains unknown. We hypothesized that the degree of intestinal failure-associated liver disease (IFALD) at initiation of intestinal rehabilitation would be associated with overall outcome. The multicenter, retrospective Pediatric Intestinal Failure Consortium (PIFCon) database was used to identify all subjects with baseline bilirubin data. Conjugated bilirubin (CBili) was used as a marker for IFALD, and we stratified baseline bilirubin values as CBili4 mg/dL. The association between baseline CBili and mortality was examined using Cox proportional hazards regression. Of 272 subjects in the database, 191 (70%) children had baseline bilirubin data collected. 38% and 28% of patients had CBili >4 mg/dL and CBili 4 mg/dL, prematurity, race, and small bowel atresia. On regression analysis controlling for age, prematurity, and diagnosis, the risk of mortality was increased by 3-fold for baseline CBili 2-4 mg/dL (HR 3.25 [1.07-9.92], p=0.04) and 4-fold for baseline CBili >4 mg/dL (HR 4.24 [1.51-11.92], p=0.006). On secondary analysis, CBili >4 mg/dL at baseline was associated with a lower chance of attaining enteral autonomy. In children with intestinal failure treated at intestinal rehabilitation programs, more advanced IFALD at referral is associated with increased mortality and decreased prospect of attaining enteral autonomy. Early referral of children with intestinal failure to intestinal rehabilitation programs should be strongly encouraged. Treatment Study, Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Thinnes, G.L.; Allison, C.M.; Cronenberg, A.W.

    1991-01-01

    The US Nuclear Regulatory Commission is sponsoring a lower vessel head research program to investigate plausible modes of reactor vessel failure in order to determine (a) which modes have the greatest likelihood of occurrence during a severe accident and (b) the range of core debris and accident conditions that lead to these failures. This paper presents the methodology and preliminary results of an investigation of reactor designs and thermodynamic conditions using analytic closed-form approximations to assess the important governing parameters in non-dimensional form. Preliminary results illustrate the importance of vessel and tube geometrical parameters, material properties, and external boundary conditions on predicting vessel failure. Thermal analyses indicate that steady-state temperature distributions will occur in the vessel within several hours, although the exact time is dependent upon vessel thickness. In-vessel tube failure is governed by the tube-to-debris mass ratio within the lower head, where most penetrations are predicted to fail if surrounded by molten debris. Melt penetration distance is dependent upon the effective flow diameter of the tube. Molten debris is predicted to penetrate through tubes with a larger effective flow diameter, such as a boiling water reactor (BWR) drain nozzle. Ex-vessel tube failure for depressurized reactor vessels is predicted to be more likely for a BWR drain nozzle penetration because of its larger effective diameter. At high pressures (between ∼0.1 MPa and ∼12 MPa) ex-vessel tube rupture becomes a dominant failure mechanism, although tube ejection dominates control rod guide tube failure at lower temperatures. However, tube ejection and tube rupture predictions are sensitive to the vessel and tube radial gap size and material coefficients of thermal expansion

  18. Failure analysis of buried tanks

    International Nuclear Information System (INIS)

    Watkins, R.K.

    1994-01-01

    Failure of a buried tank can be hazardous. Failure may be a leak through which product is lost from the tank; but also through which contamination can occur. Failures are epidemic -- because buried tanks are out of sight, but also because designers of buried tanks have adopted analyses developed for pressure tanks. So why do pressure tanks fail when they are buried? Most failures of buried tanks are really soil failures. Soil compresses, or slips, or liquefies. Soil is not only a load, it is a support without which the tank deforms. A high water table adds to the load on the tank. It also reduces the strength of the soil. Based on tests, structural analyses are proposed for empty tanks buried in soils of various quality, with the water table at various levels, and with internal vacuum. Failure may be collapse tank. Such collapse is a sudden, audible inversion of the cylinder when the sidefill soil slips. Failure may be flotation. Failure may be a leak. Most leaks are fractures in the welds in overlap seams at flat spots. Flat spots are caused by a hard bedding or a heavy surface wheel load. Because the tank wall is double thick at the overlap, shearing stress in the weld is increased. Other weld failures occur when an end plate shears down past a cylinder; or when the tank is supported only at its ends like a beam. These, and other, failures can be analyzed with justifiable accuracy using basic principles of mechanics of materials. 10 figs

  19. Performance of immunological response in predicting virological failure.

    Science.gov (United States)

    Ingole, Nayana; Mehta, Preeti; Pazare, Amar; Paranjpe, Supriya; Sarkate, Purva

    2013-03-01

    In HIV-infected individuals on antiretroviral therapy (ART), the decision on when to switch from first-line to second-line therapy is dictated by treatment failure, and this can be measured in three ways: clinically, immunologically, and virologically. While viral load (VL) decreases and CD4 cell increases typically occur together after starting ART, discordant responses may be seen. Hence the current study was designed to determine the immunological and virological response to ART and to evaluate the utility of immunological response to predict virological failure. All treatment-naive HIV-positive individuals aged >18 years who were eligible for ART were enrolled and assessed at baseline, 6 months, and 12 months clinically and by CD4 cell count and viral load estimations. The patients were categorized as showing concordant favorable (CF), immunological only (IO), virological only (VO), and concordant unfavorable responses (CU). The efficiency of immunological failure to predict virological failure was analyzed across various levels of virological failure (VL>50, >500, and >5,000 copies/ml). At 6 months, 87(79.81%), 7(5.5%), 13 (11.92%), and 2 (1.83%) patients and at 12 months 61(69.3%), 9(10.2%), 16 (18.2%), and 2 (2.3%) patients had CF, IO, VO, and CU responses, respectively. Immunological failure criteria had a very low sensitivity (11.1-40%) and positive predictive value (8.3-25%) to predict virological failure. Immunological criteria do not accurately predict virological failure resulting in significant misclassification of therapeutic responses. There is an urgent need for inclusion of viral load testing in the initiation and monitoring of ART.

  20. Reliability test and failure analysis of high power LED packages

    International Nuclear Information System (INIS)

    Chen Zhaohui; Zhang Qin; Wang Kai; Luo Xiaobing; Liu Sheng

    2011-01-01

    A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 0 C/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h, showing no visible degradation in optical performance for our modules, with two other vendors showing significant degradation. Some failure analysis methods such as C-SAM, Nano X-ray CT and optical microscope are used for LED packages. Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing. The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging. One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing. (semiconductor devices)

  1. Application of failure mode and effects analysis in a clinical chemistry laboratory.

    Science.gov (United States)

    Jiang, Yuanyuan; Jiang, Hongmin; Ding, Siyi; Liu, Qin

    2015-08-25

    Timely delivery of correct results has long been considered as the goal of quality management in clinical laboratory. With increasing workload as well as complexities of laboratory testing and patient care, the traditional technical adopted like internal quality control (IQC) and external quality assessment (EQA) may not enough to cope with quality management problems for clinical laboratories. We applied failure mode and effects analysis (FMEA), a proactive tool, to reduce errors associated with the process beginning with sample collection and ending with a test report in a clinical chemistry laboratory. Our main objection was to investigate the feasibility of FMEA in a real-world situation, namely the working environment of hospital. A team of 8 people (3 laboratory workers, 2 couriers, 2 nurses, and 1 physician) from different departments who were involved in the testing process were recruited and trained. Their main responsibility was to analyze and score all possible clinical chemistry laboratory failures based on three aspects: the severity of the outcome (S), the likeliness of occurrence (O), and the probability of being detected (D). These three parameters were multiplied to calculate risk priority numbers (RPNs), which were used to prioritize remedial measures. Failure modes with RPN≥200 were deemed as high risk, meaning that they needed immediate corrective action. After modifications that were put, we compared the resulting RPN with the previous one. A total of 33 failure modes were identified. Many of the failure modes, including the one with the highest RPN (specimen hemolysis) appeared in the pre-analytic phase, whereas no high-risk failure modes (RPN≥200) were found during the analytic phase. High-priority risks were "sample hemolysis" (RPN, 336), "sample delivery delay" (RPN, 225), "sample volume error" (RPN, 210), "failure to release results in a timely manner" (RPN, 210), and "failure to identify or report critical results" (RPN, 200). The

  2. Statistical analysis of nuclear power plant pump failure rate variability: some preliminary results

    International Nuclear Information System (INIS)

    Martz, H.F.; Whiteman, D.E.

    1984-02-01

    In-Plant Reliability Data System (IPRDS) pump failure data on over 60 selected pumps in four nuclear power plants are statistically analyzed using the Failure Rate Analysis Code (FRAC). A major purpose of the analysis is to determine which environmental, system, and operating factors adequately explain the variability in the failure data. Catastrophic, degraded, and incipient failure severity categories are considered for both demand-related and time-dependent failures. For catastrophic demand-related pump failures, the variability is explained by the following factors listed in their order of importance: system application, pump driver, operating mode, reactor type, pump type, and unidentified plant-specific influences. Quantitative failure rate adjustments are provided for the effects of these factors. In the case of catastrophic time-dependent pump failures, the failure rate variability is explained by three factors: reactor type, pump driver, and unidentified plant-specific influences. Finally, point and confidence interval failure rate estimates are provided for each selected pump by considering the influential factors. Both types of estimates represent an improvement over the estimates computed exclusively from the data on each pump

  3. A Hybrid Approach to Composite Damage and Failure Analysis Combining Synergistic Damage Mechanics and Peridynamics

    Science.gov (United States)

    2017-12-31

    Composite Damage and Failure Analysis Combinin Synergistic Damage Mechanics and Peridynamics 6. AUTHOR(S) 5b. GRANT NUMBER N00014-16-1-2173 5c...NUMBER 8. PERFORMING ORGANIZATION REPORT NUMBER Texas A&M Engineering Experiment Station (TEES) 400 Harvey Mitchell Parkway, Suite 300 College...1.3 related to Synergistic Damage Mechanics and Tasks 2.2 and 2.4 related to Peridynamics, as described in the project proposal. The activities

  4. Heart Failure Care in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Callender, Thomas; Woodward, Mark; Roth, Gregory; Farzadfar, Farshad; Lemarie, Jean-Christophe; Gicquel, Stéphanie; Atherton, John; Rahimzadeh, Shadi; Ghaziani, Mehdi; Shaikh, Maaz; Bennett, Derrick; Patel, Anushka; Lam, Carolyn S. P.; Sliwa, Karen; Barretto, Antonio; Siswanto, Bambang Budi; Diaz, Alejandro; Herpin, Daniel; Krum, Henry; Eliasz, Thomas; Forbes, Anna; Kiszely, Alastair; Khosla, Rajit; Petrinic, Tatjana; Praveen, Devarsetty; Shrivastava, Roohi; Xin, Du; MacMahon, Stephen; McMurray, John; Rahimi, Kazem

    2014-01-01

    Background Heart failure places a significant burden on patients and health systems in high-income countries. However, information about its burden in low- and middle-income countries (LMICs) is scant. We thus set out to review both published and unpublished information on the presentation, causes, management, and outcomes of heart failure in LMICs. Methods and Findings Medline, Embase, Global Health Database, and World Health Organization regional databases were searched for studies from LMICs published between 1 January 1995 and 30 March 2014. Additional unpublished data were requested from investigators and international heart failure experts. We identified 42 studies that provided relevant information on acute hospital care (25 LMICs; 232,550 patients) and 11 studies on the management of chronic heart failure in primary care or outpatient settings (14 LMICs; 5,358 patients). The mean age of patients studied ranged from 42 y in Cameroon and Ghana to 75 y in Argentina, and mean age in studies largely correlated with the human development index of the country in which they were conducted (r = 0.71, pheart disease was the main reported cause of heart failure in all regions except Africa and the Americas, where hypertension was predominant. Taking both those managed acutely in hospital and those in non-acute outpatient or community settings together, 57% (95% confidence interval [CI]: 49%–64%) of patients were treated with angiotensin-converting enzyme inhibitors, 34% (95% CI: 28%–41%) with beta-blockers, and 32% (95% CI: 25%–39%) with mineralocorticoid receptor antagonists. Mean inpatient stay was 10 d, ranging from 3 d in India to 23 d in China. Acute heart failure accounted for 2.2% (range: 0.3%–7.7%) of total hospital admissions, and mean in-hospital mortality was 8% (95% CI: 6%–10%). There was substantial variation between studies (pheart failure was identified. Conclusions The presentation, underlying causes, management, and outcomes of heart

  5. Progressive Damage and Failure Analysis of Composite Laminates

    Science.gov (United States)

    Joseph, Ashith P. K.

    Composite materials are widely used in various industries for making structural parts due to higher strength to weight ratio, better fatigue life, corrosion resistance and material property tailorability. To fully exploit the capability of composites, it is required to know the load carrying capacity of the parts made of them. Unlike metals, composites are orthotropic in nature and fails in a complex manner under various loading conditions which makes it a hard problem to analyze. Lack of reliable and efficient failure analysis tools for composites have led industries to rely more on coupon and component level testing to estimate the design space. Due to the complex failure mechanisms, composite materials require a very large number of coupon level tests to fully characterize the behavior. This makes the entire testing process very time consuming and costly. The alternative is to use virtual testing tools which can predict the complex failure mechanisms accurately. This reduces the cost only to it's associated computational expenses making significant savings. Some of the most desired features in a virtual testing tool are - (1) Accurate representation of failure mechanism: Failure progression predicted by the virtual tool must be same as those observed in experiments. A tool has to be assessed based on the mechanisms it can capture. (2) Computational efficiency: The greatest advantages of a virtual tools are the savings in time and money and hence computational efficiency is one of the most needed features. (3) Applicability to a wide range of problems: Structural parts are subjected to a variety of loading conditions including static, dynamic and fatigue conditions. A good virtual testing tool should be able to make good predictions for all these different loading conditions. The aim of this PhD thesis is to develop a computational tool which can model the progressive failure of composite laminates under different quasi-static loading conditions. The analysis

  6. [Profile of heart failure according to the department of admission. Implications for multidisciplinary management].

    Science.gov (United States)

    Vicent, Lourdes; Ayesta, Ana; Vidán, María Teresa; Miguel-Yanes, José María de; García, Jorge; Tamargo, María; Gómez, Víctor; Véliz, Samuel; Fernández-Avilés, Francisco; Martínez-Sellés, Manuel

    Population aging has led to notable changes in heart failure admissions. The aim of this study was to analyse the characteristics, comorbidity, management, and outcomes of this patient population in three hospital departments. An analysis was made of a prospective register that included all patients admitted due to heart failure in Internal Medicine, Cardiology, and Geriatrics over a period of 45 days. Of a total of 235 patients, 124 (52.7%) were admitted to Internal Medicine, 83 (35.3%) to Cardiology, and 28 (11.9%) to Geriatrics. Mean age was 77.0±20.2 years (Cardiology 71.5±13.5; Internal Medicine 79.2±21.1; Geriatrics 89.9±5.1; prenal disease (89; 37.8%), and chronic obstructive pulmonary disease (65; 27.6%). Infections were the most common decompensating trigger in Internal Medicine (56; 45.2%), and there was often no trigger in Cardiology (45; 54.2%) and Geriatrics (14; 50.0%), p<.0001. The use of renin-angiotensin system inhibitors, beta-blockers, and spironolactone in patients with systolic dysfunction was higher in Cardiology. During the 45 days follow-up, 23 patients (9.9%) were readmitted, which was more frequent in Internal Medicine than in Cardiology (odds ratio 3.0 [95% confidence interval: 1.1 - 8.6], p=.03), with no other significant comparisons. Patients admitted due to decompensated heart failure are elderly and often have comorbidities. There are major differences between departments as regards age and clinical profile. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Analysis of Renal Artery Stenosis in Patients with Heart Failure: A RASHEF Study.

    Science.gov (United States)

    Zheng, Bin; Ma, Qin; Zheng, Li-Hong; Yong, Qiang; He, Yi-Hua; Liu, Jing-Hua

    2015-10-20

    Previous data are controversial about the association of renal artery stenosis (RAS) with clinical outcome in patients with heart failure. Definition of RAS in previous studies might not be appropriate. By definition of RAS with renal duplex sonography, we investigated the association of RAS with clinical outcome in patients with heart failure. In this retrospective study, we identified 164 patients with heart failure (New York Heart Association classification ≥II; left ventricular ejection fraction renal duplex sonography during hospital stay. RAS was defined as renal-aortic ratio ≥3.5 or a peak systolic velocity ≥200 cm/s (or both), or occlusion of the renal artery. Categorical data of patients were compared using the Chi-square test or Fisher's exact test. Cox proportional hazards regression modeling technique was used to investigate the prognostic significance of possible predictors. Finally, 143 patients were enrolled. Median follow-up time was 32 months (1-53 months). Twenty-two patients were diagnosed as RAS by renal duplex sonography, including 13 unilateral RAS (3 left RAS, 10 right RAS) and 9 bilateral RAS. There were more all-cause mortality and cardiovascular death in patients with RAS than patients without RAS. By multivariate analysis, RAS was a significant predictor for all-cause death and cardiovascular death (hazard ratio [HR] = 4.155, 95% confidence interval [CI]: 1.546-11.164, P = 0.005; and HR = 3.483, 95% CI: 1.200-10.104, P = 0.022, respectively). As for composite endpoint events, including death, nonfatal myocardial infarction, ischemic stroke or intracranial hemorrhage, rehospitalization for cardiac failure, and renal replacement therapy, only angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker was significant predictor. RAS was not a significant predictor for composite endpoint events. Our data suggested that RAS is associated with a poorer clinical outcome in patients with heart failure.

  8. Dependency Analysis Guidance Nordic/German Working Group on Common Cause Failure analysis. Phase 2, Development of Harmonized Approach and Applications for Common Cause Failure Quantification

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Guenter; Johanson, Gunnar; Lindberg, Sandra; Vaurio, Jussi

    2009-03-15

    The Regulatory Code SSMFS 2008:1 of Swedish Radiation Safety Authority (SSM) includes requirements regarding the performance of probabilistic safety assessments (PSA), as well as PSA activities in general. Therefore, the follow-up of these activities is part of the inspection tasks of SSM. According to the SSMFS 2008:1, the safety analyses shall be based on a systematic identification and evaluation of such events, event sequences and other conditions which may lead to a radiological accident. The research report Nordic/German Working Group on Common cause Failure analysis. Phase 2 project report: Development of Harmonized Approach and Applications for Common Cause Failure Quantification has been developed under a contract with the Nordic PSA Group (NPSAG) and its German counterpart VGB, with the aim to create a common experience base for defence and analysis of dependent failures i.e. Common Cause Failures CCF. Phase 2 in this project if a deepened data analyses of CCF events and a demonstration on how the so called impact vectors can be constructed and on how CCF parameters are estimated. The word Guidance in the report title is used in order to indicate a common methodological guidance accepted by the NPSAG, based on current state of the art concerning the analysis of dependent failures and adapted to conditions relevant for Nordic sites. This will make it possible for the utilities to perform cost effective improvements and analyses. The report presents a common attempt by the authorities and the utilities to create a methodology and experience base for defence and analysis of dependent failures. The performed benchmark application has shown how important the interpretation of base data is to obtain robust CCF data and data analyses results. Good features were found in all benchmark approaches. The obtained experiences and approaches should now be used in harmonised procedures. A next step could be to develop and agree on event and formula driven impact vector

  9. Dependency Analysis Guidance Nordic/German Working Group on Common Cause Failure analysis. Phase 2, Development of Harmonized Approach and Applications for Common Cause Failure Quantification

    International Nuclear Information System (INIS)

    Becker, Guenter; Johanson, Gunnar; Lindberg, Sandra; Vaurio, Jussi

    2009-03-01

    The Regulatory Code SSMFS 2008:1 of Swedish Radiation Safety Authority (SSM) includes requirements regarding the performance of probabilistic safety assessments (PSA), as well as PSA activities in general. Therefore, the follow-up of these activities is part of the inspection tasks of SSM. According to the SSMFS 2008:1, the safety analyses shall be based on a systematic identification and evaluation of such events, event sequences and other conditions which may lead to a radiological accident. The research report Nordic/German Working Group on Common cause Failure analysis. Phase 2 project report: Development of Harmonized Approach and Applications for Common Cause Failure Quantification has been developed under a contract with the Nordic PSA Group (NPSAG) and its German counterpart VGB, with the aim to create a common experience base for defence and analysis of dependent failures i.e. Common Cause Failures CCF. Phase 2 in this project if a deepened data analyses of CCF events and a demonstration on how the so called impact vectors can be constructed and on how CCF parameters are estimated. The word Guidance in the report title is used in order to indicate a common methodological guidance accepted by the NPSAG, based on current state of the art concerning the analysis of dependent failures and adapted to conditions relevant for Nordic sites. This will make it possible for the utilities to perform cost effective improvements and analyses. The report presents a common attempt by the authorities and the utilities to create a methodology and experience base for defence and analysis of dependent failures. The performed benchmark application has shown how important the interpretation of base data is to obtain robust CCF data and data analyses results. Good features were found in all benchmark approaches. The obtained experiences and approaches should now be used in harmonised procedures. A next step could be to develop and agree on event and formula driven impact vector

  10. Budget impact analysis of 8 hormonal contraceptive options.

    Science.gov (United States)

    Crespi, Simone; Kerrigan, Matthew; Sood, Vipan

    2013-07-01

    To develop a model comparing costs of 8 hormonal contraceptives and determine whether acquisition costs for implants and intrauterine devices (IUDs) were offset by decreased pregnancy-related costs over a 3-year time horizon from a managed care perspective. A model was developed to assess the budget impact of branded or generic oral contraceptives (OCs), quarterly intramuscular depot medroxyprogesterone, etonogestrel/ethinyl estradiol vaginal ring, etonogestrel implant, levonorgestrel IUD, norelgestromin/ethinyl estradiol transdermal contraceptive, and ethinyl estradiol/levonorgestrel extended-cycle OC. Major variables included drug costs, typical use failure rates, discontinuation rates, and pregnancy costs. The base case assessed costs for 1000 women initiating each of the hormonal contraceptives. The etonogestrel implant and levonorgestrel IUD resulted in the fewest pregnancies, 63 and 85, respectively, and the least cost, $1.75 million and $2.0 million, respectively. In comparison, generic OC users accounted for a total of 243 pregnancies and $3.4 million in costs. At the end of year 1, costs for the etonogestrel implant ($800,471) and levonorgestrel IUD ($949,721) were already lower than those for generic OCs ($1,146,890). Sensitivity analysis showed that the cost of pregnancies, not product acquisition cost, was the primary cost driver. Higher initial acquisition costs for the etonogestrel implant and levonorgestrel IUD were offset within 1 year by lower contraceptive failure rates and consequent pregnancy costs. Thus, after accounting for typical use failure rates of contraceptive products, the etonogestrel implant and levonorgestrel IUD emerged as the least expensive hormonal contraceptives.

  11. Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer’s disease

    Science.gov (United States)

    Lambert, Jean-Charles; Ibrahim-Verbaas, Carla A; Harold, Denise; Naj, Adam C; Sims, Rebecca; Bellenguez, Céline; Jun, Gyungah; DeStefano, Anita L; Bis, Joshua C; Beecham, Gary W; Grenier-Boley, Benjamin; Russo, Giancarlo; Thornton-Wells, Tricia A; Jones, Nicola; Smith, Albert V; Chouraki, Vincent; Thomas, Charlene; Ikram, M Arfan; Zelenika, Diana; Vardarajan, Badri N; Kamatani, Yoichiro; Lin, Chiao-Feng; Gerrish, Amy; Schmidt, Helena; Kunkle, Brian; Dunstan, Melanie L; Ruiz, Agustin; Bihoreau, Marie-Thérèse; Choi, Seung-Hoan; Reitz, Christiane; Pasquier, Florence; Hollingworth, Paul; Ramirez, Alfredo; Hanon, Olivier; Fitzpatrick, Annette L; Buxbaum, Joseph D; Campion, Dominique; Crane, Paul K; Baldwin, Clinton; Becker, Tim; Gudnason, Vilmundur; Cruchaga, Carlos; Craig, David; Amin, Najaf; Berr, Claudine; Lopez, Oscar L; De Jager, Philip L; Deramecourt, Vincent; Johnston, Janet A; Evans, Denis; Lovestone, Simon; Letenneur, Luc; Morón, Francisco J; Rubinsztein, David C; Eiriksdottir, Gudny; Sleegers, Kristel; Goate, Alison M; Fiévet, Nathalie; Huentelman, Matthew J; Gill, Michael; Brown, Kristelle; Kamboh, M Ilyas; Keller, Lina; Barberger-Gateau, Pascale; McGuinness, Bernadette; Larson, Eric B; Green, Robert; Myers, Amanda J; Dufouil, Carole; Todd, Stephen; Wallon, David; Love, Seth; Rogaeva, Ekaterina; Gallacher, John; St George-Hyslop, Peter; Clarimon, Jordi; Lleo, Alberto; Bayer, Anthony; Tsuang, Debby W; Yu, Lei; Tsolaki, Magda; Bossù, Paola; Spalletta, Gianfranco; Proitsi, Petroula; Collinge, John; Sorbi, Sandro; Sanchez-Garcia, Florentino; Fox, Nick C; Hardy, John; Deniz Naranjo, Maria Candida; Bosco, Paolo; Clarke, Robert; Brayne, Carol; Galimberti, Daniela; Mancuso, Michelangelo; Matthews, Fiona; Moebus, Susanne; Mecocci, Patrizia; Zompo, Maria Del; Maier, Wolfgang; Hampel, Harald; Pilotto, Alberto; Bullido, Maria; Panza, Francesco; Caffarra, Paolo; Nacmias, Benedetta; Gilbert, John R; Mayhaus, Manuel; Lannfelt, Lars; Hakonarson, Hakon; Pichler, Sabrina; Carrasquillo, Minerva M; Ingelsson, Martin; Beekly, Duane; Alvarez, Victoria; Zou, Fanggeng; Valladares, Otto; Younkin, Steven G; Coto, Eliecer; Hamilton-Nelson, Kara L; Gu, Wei; Razquin, Cristina; Pastor, Pau; Mateo, Ignacio; Owen, Michael J; Faber, Kelley M; Jonsson, Palmi V; Combarros, Onofre; O’Donovan, Michael C; Cantwell, Laura B; Soininen, Hilkka; Blacker, Deborah; Mead, Simon; Mosley, Thomas H; Bennett, David A; Harris, Tamara B; Fratiglioni, Laura; Holmes, Clive; de Bruijn, Renee F A G; Passmore, Peter; Montine, Thomas J; Bettens, Karolien; Rotter, Jerome I; Brice, Alexis; Morgan, Kevin; Foroud, Tatiana M; Kukull, Walter A; Hannequin, Didier; Powell, John F; Nalls, Michael A; Ritchie, Karen; Lunetta, Kathryn L; Kauwe, John S K; Boerwinkle, Eric; Riemenschneider, Matthias; Boada, Mercè; Hiltunen, Mikko; Martin, Eden R; Schmidt, Reinhold; Rujescu, Dan; Wang, Li-san; Dartigues, Jean-François; Mayeux, Richard; Tzourio, Christophe; Hofman, Albert; Nöthen, Markus M; Graff, Caroline; Psaty, Bruce M; Jones, Lesley; Haines, Jonathan L; Holmans, Peter A; Lathrop, Mark; Pericak-Vance, Margaret A; Launer, Lenore J; Farrer, Lindsay A; van Duijn, Cornelia M; Van Broeckhoven, Christine; Moskvina, Valentina; Seshadri, Sudha; Williams, Julie; Schellenberg, Gerard D; Amouyel, Philippe

    2013-01-01

    Eleven susceptibility loci for late-onset Alzheimer’s disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer’s disease cases and 37,154 controls. In stage 2,11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer’s disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10−8) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer’s disease. PMID:24162737

  12. Reliability analysis of the auxiliary feedwater system of Angra-1 including common cause failures using the multiple greek letter model

    International Nuclear Information System (INIS)

    Lapa, Celso Marcelo Franklin.

    1996-05-01

    The use of redundancy to increase the reliability of industrial systems make them subject to the occurrence of common cause events. The industrial experience and the results of safety analysis studies have indicated that common cause failures are the main contributors to the unreliability of plants that have redundant systems, specially in nuclear power plants. In this Thesis procedures are developed in order to include the impact of common cause failures in the calculation of the top event occurrence probability of the Auxiliary Feedwater System in a typical two-loop Nuclear Power Plant (PWR). For this purpose the Multiple Greek Letter Model is used. (author). 14 refs., 10 figs., 11 tabs

  13. A Study on the Abnormalities of the Various Endocrine Functions Associated with Chronic Renal Failure

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Chan Pyo; Kim, Man Woo; Rho, Bang Soo; Jang, Kyung Sik; Lee, Min Hyung; Oh, Hyun Kwan [Chosun University College of Medicine, Seoul (Korea, Republic of)

    1982-03-15

    In an attempt to evaluate the various serum hormonal changes in terminal renal failure, the fasting T{sub 4}, T{sub 3}, rT-3, gastrin, secretin prolactin, and aldosterone were measured by radioimmunoassay in 12 patients with chronic renal failure, who were admitted Chosun University Hospital from January to June, 1981. From the analysis the following results were obtained. 1. Mean values of serum hormonal concentration in 10 normal control were as follows: T{sub 4}, 12.93+-2.00 ug/ml; T{sub 3}, 113.0+-28.7 ng/ml; rT{sub 3}, 0.11+-0.10 ng/ml; gastrin, 100.0+-47.1 pg/ml; secretin, 32.46+-11.45 pg/ml; prolactin, 11.0+-3.6 ng/ml; aldosterone 137.0+-58.5 pg/ml. 2. Mean values of serum hormonal concentration in 12 chronic renal failure were as follows; T4, 7.34+-2.43 ug/ml; T3, 71.0+-19.1 ng/ml; reverse T3, 0.38+-0.19 ng/ml; gastrin, 162.5+-40.2 pg/ml; secretin, 107.50+-20.48 pg/ml; prolactin, 34.0+-17.2 ng/ml; aldosterone, 86.5+-19.8 pg/ml. 3. In chronic renal failure group, serum T4, T3, and adosterone level were significantly lower than those of the control group, but serum rT-3, gastrin, secretin and prolactin were significantly higher than those of the control group. 4. In the view of the correlation between serum hormonal concentrations and serum creatine levels in patients with chronic renal failure, rT{sub 3}, gastrin, secretin and prolactin showed increasing tendency (positive correlations), whereas T{sub 4}, T{sub 3} and aldosterone showed decreasing tendency (negative correlations) with increment of serum creatinine levels. And so, we observed the negative correlation between T{sub 3} and rT{sub 3}.

  14. Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

    Science.gov (United States)

    Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

    2013-09-30

    Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

  15. Acute liver failure caused by hepatitis E virus genotype 3 and 4: A systematic review and pooled analysis.

    Science.gov (United States)

    Haffar, Samir; Shalimar; Kaur, Ravinder J; Wang, Zhen; Prokop, Larry J; Murad, Mohammad H; Bazerbachi, Fateh

    2018-04-19

    Acute liver failure caused by hepatitis E virus genotype 3 and 4 has been rarely described. Because of the presence of a short golden therapeutic window in patients with viral acute liver failure from other causes, it is possible that early recognition and treatment might reduce the morbidity and mortality. We performed a systematic review and pooled analysis of acute liver failure caused by hepatitis E virus genotype 3 and 4. Two reviewers appraised studies after searching multiple databases on June 12th, 2017. Appropriate tests were used to compare hepatitis E virus genotype 3 vs 4, suspected vs confirmed genotypes, hepatitis E virus-RNA positive vs negative, and to discern important mortality risk factors. We identified 65 patients, with median age 58 years (range: 3-79), and a male to female ratio of 1.2:1. The median bilirubin, ALT, AST and alkaline phosphatase (expressed by multiplication of the upper limit of normal) levels were 14.8, 45.3, 34.8 and 1.63 respectively. Antihepatitis E virus IgG, antihepatitis E virus IgM and hepatitis E virus-RNA were positive in 84%, 91% and 86% of patients respectively. The median interval from symptoms onset to acute liver failure was 23 days, and 16 patients underwent liver transplantation. Final outcome was reported in 58 patients and mortality was 46%. Age was a predictor of poor prognosis in multivariate analysis. No important differences were found between patients infected with genotype 3 vs 4, patients with confirmed vs suspected genotypes, or patients with positive vs negative RNA. Acute liver failure caused by hepatitis E virus genotype 3 and 4 is rare, similar between genotypes, occurs commonly in middle-aged/elderly patients and has a very high mortality. Age is predictive of poor prognosis in multivariate analysis. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. SU-E-T-205: MLC Predictive Maintenance Using Statistical Process Control Analysis.

    Science.gov (United States)

    Able, C; Hampton, C; Baydush, A; Bright, M

    2012-06-01

    MLC failure increases accelerator downtime and negatively affects the clinic treatment delivery schedule. This study investigates the use of Statistical Process Control (SPC), a modern quality control methodology, to retrospectively evaluate MLC performance data thereby predicting the impending failure of individual MLC leaves. SPC, a methodology which detects exceptional variability in a process, was used to analyze MLC leaf velocity data. A MLC velocity test is performed weekly on all leaves during morning QA. The leaves sweep 15 cm across the radiation field with the gantry pointing down. The leaf speed is analyzed from the generated dynalog file using quality assurance software. MLC leaf speeds in which a known motor failure occurred (8) and those in which no motor replacement was performed (11) were retrospectively evaluated for a 71 week period. SPC individual and moving range (I/MR) charts were used in the analysis. The I/MR chart limits were calculated using the first twenty weeks of data and set at 3 standard deviations from the mean. The MLCs in which a motor failure occurred followed two general trends: (a) no data indicating a change in leaf speed prior to failure (5 of 8) and (b) a series of data points exceeding the limit prior to motor failure (3 of 8). I/MR charts for a high percentage (8 of 11) of the non-replaced MLC motors indicated that only a single point exceeded the limit. These single point excesses were deemed false positives. SPC analysis using MLC performance data may be helpful in detecting a significant percentage of impending failures of MLC motors. The ability to detect MLC failure may depend on the method of failure (i.e. gradual or catastrophic). Further study is needed to determine if increasing the sampling frequency could increase reliability. Project was support by a grant from Varian Medical Systems, Inc. © 2012 American Association of Physicists in Medicine.

  17. Failure analysis of high strength pipeline with single and multiple corrosions

    International Nuclear Information System (INIS)

    Chen, Yanfei; Zhang, Hong; Zhang, Juan; Li, Xin; Zhou, Jing

    2015-01-01

    Highlights: • We study failure of high strength pipelines with single corrosion. • We give regression equations for failure pressure prediction. • We propose assessment procedure for pipelines with multiple corrosions. - Abstract: Corrosion will compromise safety operation of oil and gas pipelines, accurate determination of failure pressure finds importance in residual strength assessment and corrosion allowance design of onshore and offshore pipelines. This paper investigates failure pressure of high strength pipeline with single and multiple corrosions using nonlinear finite element analysis. On the basis of developed regression equations for failure pressure prediction of high strength pipeline with single corrosion, the paper proposes an assessment procedure for predicting failure pressure of high strength pipeline with multiple corrosions. Furthermore, failure pressures predicted by proposed solutions are compared with experimental results and various assessment methods available in literature, where accuracy and versatility are demonstrated

  18. Acute renal failure: Nephrosonographic findings in asphyxiated neonates

    Directory of Open Access Journals (Sweden)

    Mohd. Ashraf

    2011-01-01

    Full Text Available To determine the incidence of acute renal failure (ARF and nephrosonographic findings among asphyxiated neonates, and to correlate this with uric acid levels and the severity of hypoxic encephalopathy, we studied 80 full-term appropriate-for-date singleton neonates with perinatal asphyxia, and 30 healthy full-term neonates as controls from March 2006 to February 2007. A detailed history, thorough clinical examination along with investigations, including urine examination, 24-h urine collection, ultrasonography of abdomen and cranium, serum electrolytes, blood urea nitrogen, serum creatinine, and serum uric acid were obtained. ARF developed in 45% (36/80 of the asphyxiated neonates. Forty-eight (60% neonates showed significant elevation of blood urea and 41 (51.3% neonates had significant elevation of serum creatinine than the control group (P < 0.001. Sixty-two (77.5% neonates developed significant elevation of serum uric acid levels, and nephrosonography revealed hyperechogenicity in all of them, while only two among the healthy neonates showed the raised uric acid levels (P < 0.001. Nonoliguric renal failure was seen 28/36 (77.8% of the neonates with ARF, whereas eight (22.2% neonates had oliguric renal failure. Eight (27.8% patients among ARF patients maintained abnormal biochemical parameters after 2 weeks, and of whom four patients died after variable lengths of time with a mortality rate of 11.11%. Kidneys are the most common organs involved in perinatal asphyxia, and uric acid might be a causative factor for failure in addition to hypoxic insult. Routine use of kidney function test, along with abdominal ultrasonography form an important screening tool to detect any additional morbidity in these patients.

  19. Failure analysis on a chemical waste pipe

    International Nuclear Information System (INIS)

    Ambler, J.R.

    1985-01-01

    A failure analysis of a chemical waste pipe illustrates how nuclear technology can spin off metallurgical consultant services. The pipe, made of zirconium alloy (Zr-2.5 wt percent Nb, UNS 60705), had cracked in several places, all at butt welds. A combination of fractography and metallography indicated delayed hydride cracking

  20. PACC information management code for common cause failures analysis

    International Nuclear Information System (INIS)

    Ortega Prieto, P.; Garcia Gay, J.; Mira McWilliams, J.

    1987-01-01

    The purpose of this paper is to present the PACC code, which, through an adequate data management, makes the task of computerized common-mode failure analysis easier. PACC processes and generates information in order to carry out the corresponding qualitative analysis, by means of the boolean technique of transformation of variables, and the quantitative analysis either using one of several parametric methods or a direct data-base. As far as the qualitative analysis is concerned, the code creates several functional forms for the transformation equations according to the user's choice. These equations are subsequently processed by boolean manipulation codes, such as SETS. The quantitative calculations of the code can be carried out in two different ways: either starting from a common cause data-base, or through parametric methods, such as the Binomial Failure Rate Method, the Basic Parameters Method or the Multiple Greek Letter Method, among others. (orig.)

  1. Trends, causes and timing of 30-day readmissions after hospitalization for heart failure: 11-year population-based analysis with linked data.

    Science.gov (United States)

    Fernandez-Gasso, Lucía; Hernando-Arizaleta, Lauro; Palomar-Rodríguez, Joaquín A; Abellán-Pérez, M Victoria; Pascual-Figal, Domingo A

    2017-12-01

    Reliable data are necessary if the burden of early readmissions following hospitalization for heart failure (HF) is to be addressed. We studied unplanned 30-day readmissions, their causes and timing over an 11-year period, using population-based linked data. All hospitalizations from 2003 to 2013 were analyzed by using administrative linked data based on the Minimum Basic Set discharge registry of the Department of Health (Region of Murcia, Spain). Index hospitalizations with HF as principal diagnosis (n=27,581) were identified. Transfers between centers were merged into one discharge. Readmissions were defined as unplanned admissions to any hospital within 30-days after discharge. In the 2003-2013 period, 30-day readmission rates had a relative mean annual growth of +1.36%, increasing from 17.6% to 22.1%, with similar trends for cardiovascular and non-cardiovascular causes. The figure of 22.1% decreased to 19.8% when only same-hospital readmissions were considered. Most readmissions were due to cardiovascular causes (60%), HF being the most common single cause (34%). The timing of readmission shows an early peak on the fourth day post discharge (+13.29%) due to causes other than HF, followed by a gradual decline (-3.32%); readmission for HF decreased steadily from the first day (-2.22%). Readmission for HF (12.7%) or non-cardiovascular causes (13.3%) had higher in-hospital mortality rates than the index hospitalization (9.2%, p<0.001). Age and comorbidity burden were the main predictors of any readmission, but the performance of a predictive model was poor. These findings support the need for population-based strategies to reduce the burden of early-unplanned readmissions. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The analysis of failure data in the presence of critical and degraded failures

    International Nuclear Information System (INIS)

    Haugen, Knut; Hokstad, Per; Sandtorv, Helge

    1997-01-01

    Reported failures are often classified into severityclasses, e.g., as critical or degraded. The critical failures correspond to loss of function(s) and are those of main concern. The rate of critical failures is usually estimated by the number of observed critical failures divided by the exposure time, thus ignoring the observed degraded failures. In the present paper failure data are analyzed, applying an alternative estimate for the critical failure rate, also taking the number of observed degraded failures into account. The model includes two alternative failure mechanisms, one being of the shock type, immediately leading to a critical failure, another resulting in a gradual deterioration, leading to a degraded failure before the critical failure occurs. Failure data on safety valves from the OREDA (Offshore REliability DAta) data base are analyzed using this model. The estimate for the critical failure rate is obtained and compared with the standard estimate

  3. Failure mode and effects analysis and fault tree analysis of surface image guided cranial radiosurgery.

    Science.gov (United States)

    Manger, Ryan P; Paxton, Adam B; Pawlicki, Todd; Kim, Gwe-Ya

    2015-05-01

    Surface image guided, Linac-based radiosurgery (SIG-RS) is a modern approach for delivering radiosurgery that utilizes optical stereoscopic imaging to monitor the surface of the patient during treatment in lieu of using a head frame for patient immobilization. Considering the novelty of the SIG-RS approach and the severity of errors associated with delivery of large doses per fraction, a risk assessment should be conducted to identify potential hazards, determine their causes, and formulate mitigation strategies. The purpose of this work is to investigate SIG-RS using the combined application of failure modes and effects analysis (FMEA) and fault tree analysis (FTA), report on the effort required to complete the analysis, and evaluate the use of FTA in conjunction with FMEA. A multidisciplinary team was assembled to conduct the FMEA on the SIG-RS process. A process map detailing the steps of the SIG-RS was created to guide the FMEA. Failure modes were determined for each step in the SIG-RS process, and risk priority numbers (RPNs) were estimated for each failure mode to facilitate risk stratification. The failure modes were ranked by RPN, and FTA was used to determine the root factors contributing to the riskiest failure modes. Using the FTA, mitigation strategies were formulated to address the root factors and reduce the risk of the process. The RPNs were re-estimated based on the mitigation strategies to determine the margin of risk reduction. The FMEA and FTAs for the top two failure modes required an effort of 36 person-hours (30 person-hours for the FMEA and 6 person-hours for two FTAs). The SIG-RS process consisted of 13 major subprocesses and 91 steps, which amounted to 167 failure modes. Of the 91 steps, 16 were directly related to surface imaging. Twenty-five failure modes resulted in a RPN of 100 or greater. Only one of these top 25 failure modes was specific to surface imaging. The riskiest surface imaging failure mode had an overall RPN-rank of eighth

  4. Application of failure mode and effect analysis in a radiology department.

    Science.gov (United States)

    Thornton, Eavan; Brook, Olga R; Mendiratta-Lala, Mishal; Hallett, Donna T; Kruskal, Jonathan B

    2011-01-01

    With increasing deployment, complexity, and sophistication of equipment and related processes within the clinical imaging environment, system failures are more likely to occur. These failures may have varying effects on the patient, ranging from no harm to devastating harm. Failure mode and effect analysis (FMEA) is a tool that permits the proactive identification of possible failures in complex processes and provides a basis for continuous improvement. This overview of the basic principles and methodology of FMEA provides an explanation of how FMEA can be applied to clinical operations in a radiology department to reduce, predict, or prevent errors. The six sequential steps in the FMEA process are explained, and clinical magnetic resonance imaging services are used as an example for which FMEA is particularly applicable. A modified version of traditional FMEA called Healthcare Failure Mode and Effect Analysis, which was introduced by the U.S. Department of Veterans Affairs National Center for Patient Safety, is briefly reviewed. In conclusion, FMEA is an effective and reliable method to proactively examine complex processes in the radiology department. FMEA can be used to highlight the high-risk subprocesses and allows these to be targeted to minimize the future occurrence of failures, thus improving patient safety and streamlining the efficiency of the radiology department. RSNA, 2010

  5. Exact combinatorial reliability analysis of dynamic systems with sequence-dependent failures

    International Nuclear Information System (INIS)

    Xing Liudong; Shrestha, Akhilesh; Dai Yuanshun

    2011-01-01

    Many real-life fault-tolerant systems are subjected to sequence-dependent failure behavior, in which the order in which the fault events occur is important to the system reliability. Such systems can be modeled by dynamic fault trees (DFT) with priority-AND (pAND) gates. Existing approaches for the reliability analysis of systems subjected to sequence-dependent failures are typically state-space-based, simulation-based or inclusion-exclusion-based methods. Those methods either suffer from the state-space explosion problem or require long computation time especially when results with high degree of accuracy are desired. In this paper, an analytical method based on sequential binary decision diagrams is proposed. The proposed approach can analyze the exact reliability of non-repairable dynamic systems subjected to the sequence-dependent failure behavior. Also, the proposed approach is combinatorial and is applicable for analyzing systems with any arbitrary component time-to-failure distributions. The application and advantages of the proposed approach are illustrated through analysis of several examples. - Highlights: → We analyze the sequence-dependent failure behavior using combinatorial models. → The method has no limitation on the type of time-to-failure distributions. → The method is analytical and based on sequential binary decision diagrams (SBDD). → The method is computationally more efficient than existing methods.

  6. Development of Compressive Failure Strength for Composite Laminate Using Regression Analysis Method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Keon [Agency for Defense Development, Daejeon (Korea, Republic of); Lee, Jeong Won; Yoon, Dong Hyun; Kim, Jae Hoon [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-10-15

    This paper provides the compressive failure strength value of composite laminate developed by using regression analysis method. Composite material in this document is a Carbon/Epoxy unidirection(UD) tape prepreg(Cycom G40-800/5276-1) cured at 350°F(177°C). The operating temperature is –60°F~+200°F(-55°C - +95°C). A total of 56 compression tests were conducted on specimens from eight (8) distinct laminates that were laid up by standard angle layers (0°, +45°, –45° and 90°). The ASTM-D-6484 standard was used for test method. The regression analysis was performed with the response variable being the laminate ultimate fracture strength and the regressor variables being two ply orientations (0° and ±45°)

  7. Development of Compressive Failure Strength for Composite Laminate Using Regression Analysis Method

    International Nuclear Information System (INIS)

    Lee, Myoung Keon; Lee, Jeong Won; Yoon, Dong Hyun; Kim, Jae Hoon

    2016-01-01

    This paper provides the compressive failure strength value of composite laminate developed by using regression analysis method. Composite material in this document is a Carbon/Epoxy unidirection(UD) tape prepreg(Cycom G40-800/5276-1) cured at 350°F(177°C). The operating temperature is –60°F~+200°F(-55°C - +95°C). A total of 56 compression tests were conducted on specimens from eight (8) distinct laminates that were laid up by standard angle layers (0°, +45°, –45° and 90°). The ASTM-D-6484 standard was used for test method. The regression analysis was performed with the response variable being the laminate ultimate fracture strength and the regressor variables being two ply orientations (0° and ±45°)

  8. Failure rate modeling using fault tree analysis and Bayesian network: DEMO pulsed operation turbine study case

    International Nuclear Information System (INIS)

    Dongiovanni, Danilo Nicola; Iesmantas, Tomas

    2016-01-01

    Highlights: • RAMI (Reliability, Availability, Maintainability and Inspectability) assessment of secondary heat transfer loop for a DEMO nuclear fusion plant. • Definition of a fault tree for a nuclear steam turbine operated in pulsed mode. • Turbine failure rate models update by mean of a Bayesian network reflecting the fault tree analysis in the considered scenario. • Sensitivity analysis on system availability performance. - Abstract: Availability will play an important role in the Demonstration Power Plant (DEMO) success from an economic and safety perspective. Availability performance is commonly assessed by Reliability Availability Maintainability Inspectability (RAMI) analysis, strongly relying on the accurate definition of system components failure modes (FM) and failure rates (FR). Little component experience is available in fusion application, therefore requiring the adaptation of literature FR to fusion plant operating conditions, which may differ in several aspects. As a possible solution to this problem, a new methodology to extrapolate/estimate components failure rate under different operating conditions is presented. The DEMO Balance of Plant nuclear steam turbine component operated in pulse mode is considered as study case. The methodology moves from the definition of a fault tree taking into account failure modes possibly enhanced by pulsed operation. The fault tree is then translated into a Bayesian network. A statistical model for the turbine system failure rate in terms of subcomponents’ FR is hence obtained, allowing for sensitivity analyses on the structured mixture of literature and unknown FR data for which plausible value intervals are investigated to assess their impact on the whole turbine system FR. Finally, the impact of resulting turbine system FR on plant availability is assessed exploiting a Reliability Block Diagram (RBD) model for a typical secondary cooling system implementing a Rankine cycle. Mean inherent availability

  9. Failure rate modeling using fault tree analysis and Bayesian network: DEMO pulsed operation turbine study case

    Energy Technology Data Exchange (ETDEWEB)

    Dongiovanni, Danilo Nicola, E-mail: danilo.dongiovanni@enea.it [ENEA, Nuclear Fusion and Safety Technologies Department, via Enrico Fermi 45, Frascati 00040 (Italy); Iesmantas, Tomas [LEI, Breslaujos str. 3 Kaunas (Lithuania)

    2016-11-01

    Highlights: • RAMI (Reliability, Availability, Maintainability and Inspectability) assessment of secondary heat transfer loop for a DEMO nuclear fusion plant. • Definition of a fault tree for a nuclear steam turbine operated in pulsed mode. • Turbine failure rate models update by mean of a Bayesian network reflecting the fault tree analysis in the considered scenario. • Sensitivity analysis on system availability performance. - Abstract: Availability will play an important role in the Demonstration Power Plant (DEMO) success from an economic and safety perspective. Availability performance is commonly assessed by Reliability Availability Maintainability Inspectability (RAMI) analysis, strongly relying on the accurate definition of system components failure modes (FM) and failure rates (FR). Little component experience is available in fusion application, therefore requiring the adaptation of literature FR to fusion plant operating conditions, which may differ in several aspects. As a possible solution to this problem, a new methodology to extrapolate/estimate components failure rate under different operating conditions is presented. The DEMO Balance of Plant nuclear steam turbine component operated in pulse mode is considered as study case. The methodology moves from the definition of a fault tree taking into account failure modes possibly enhanced by pulsed operation. The fault tree is then translated into a Bayesian network. A statistical model for the turbine system failure rate in terms of subcomponents’ FR is hence obtained, allowing for sensitivity analyses on the structured mixture of literature and unknown FR data for which plausible value intervals are investigated to assess their impact on the whole turbine system FR. Finally, the impact of resulting turbine system FR on plant availability is assessed exploiting a Reliability Block Diagram (RBD) model for a typical secondary cooling system implementing a Rankine cycle. Mean inherent availability

  10. Efficient surrogate models for reliability analysis of systems with multiple failure modes

    International Nuclear Information System (INIS)

    Bichon, Barron J.; McFarland, John M.; Mahadevan, Sankaran

    2011-01-01

    Despite many advances in the field of computational reliability analysis, the efficient estimation of the reliability of a system with multiple failure modes remains a persistent challenge. Various sampling and analytical methods are available, but they typically require accepting a tradeoff between accuracy and computational efficiency. In this work, a surrogate-based approach is presented that simultaneously addresses the issues of accuracy, efficiency, and unimportant failure modes. The method is based on the creation of Gaussian process surrogate models that are required to be locally accurate only in the regions of the component limit states that contribute to system failure. This approach to constructing surrogate models is demonstrated to be both an efficient and accurate method for system-level reliability analysis. - Highlights: → Extends efficient global reliability analysis to systems with multiple failure modes. → Constructs locally accurate Gaussian process models of each response. → Highly efficient and accurate method for assessing system reliability. → Effectiveness is demonstrated on several test problems from the literature.

  11. Development of component failure data for seismic risk analysis

    International Nuclear Information System (INIS)

    Fray, R.R.; Moulia, T.A.

    1981-01-01

    This paper describes the quantification and utilization of seismic failure data used in the Diablo Canyon Seismic Risk Study. A single variable representation of earthquake severity that uses peak horizontal ground acceleration to characterize earthquake severity was employed. The use of a multiple variable representation would allow direct consideration of vertical accelerations and the spectral nature of earthquakes but would have added such complexity that the study would not have been feasible. Vertical accelerations and spectral nature were indirectly considered because component failure data were derived from design analyses, qualification tests and engineering judgment that did include such considerations. Two types of functions were used to describe component failure probabilities. Ramp functions were used for components, such as piping and structures, qualified by stress analysis. 'Anchor points' for ramp functions were selected by assuming a zero probability of failure at code allowable stress levels and unity probability of failure at ultimate stress levels. The accelerations corresponding to allowable and ultimate stress levels were determined by conservatively assuming a linear relationship between seismic stress and ground acceleration. Step functions were used for components, such as mechanical and electrical equipment, qualified by testing. Anchor points for step functions were selected by assuming a unity probability of failure above the qualification acceleration. (orig./HP)

  12. Timing analysis of PWR fuel pin failures

    International Nuclear Information System (INIS)

    Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J.; Straka, M.

    1992-09-01

    Research has been conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B ampersand W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin bumup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PFL/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B ampersand W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B ampersand W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design bumup. Using peaking factors commensurate widi actual bumups would result in longer intervals for both reactor designs. This document also contains appendices A through J of this report

  13. Failure Mode and Effect Analysis for Wind Turbine Systems in China

    DEFF Research Database (Denmark)

    Zhu, Jiangsheng; Ma, Kuichao; N. Soltani, Mohsen

    2017-01-01

    This paper discusses a cost based Failure Mode and Effect Analysis (FMEA) approch for the Wind Turbine (WT) with condition monitoring system in China. Normally, the traditional FMEA uses the Risk Priority Number (RPN) to rank failure modes. But the RPN can be changed with the Condition Monitoring...... Systems (CMS) due to change of the score of detection. The cost of failure mode should also be considered because faults can be detected at an incipient level, and condition-based maintenance can be scheduled. The results show that the proposed failure mode priorities considering their cost consequences...

  14. The R-matrix investigation of 8Li(α, n)11B reaction below 6 MeV

    Science.gov (United States)

    Kilic, Ali Ihsan; Muecher, Dennis; Garret, Paul; Svensson, Carl

    2017-09-01

    The investigation of cross sections for the 8Li(α, n)11B reaction has important impact for both primordial nucleosynthesis in the inhomogeneous models as well as constraining the physical conditions characterizing the r-process. However, there are large discrepancies existing between inclusive and exclusive measurements of the cross section below 3 MeV. The R-Matrix technique is a powerful tool for the analysis of the nuclear data for the purpose of extracting level information of compound nucleus 12B and extrapolation of the astrophysical S-Factor to Gamow energies. We have applied the R-matrix calculations for the 8Li(α, n)11B reaction and will present results for both the reaction rates and the partial S-factor. Combining the direct reaction contribution with the results from our R-matrix calculations, we can well describe the experimental data from the inclusive measurements. However, new experiments are needed in order to understand the role of neutron detection close to the threshold, for which we describe our experimental plans at ISAC, TRIUMF, using the newly developed DESCANT array.

  15. Optimal tread design for agricultural lug tires determined through failure analysis

    Directory of Open Access Journals (Sweden)

    Hyun Seok Song

    2018-04-01

    Full Text Available Agricultural lug tires, commonly used in tractors, must provide safe and stable support for the body of the vehicle and bear any additional load while effectively traversing rough, poor-quality ground surfaces. Many agricultural lug tires fail unexpectedly. In this study, we optimised and validated a tread design for agricultural lug tires intended to increase their durability using failure analysis. Specifically, we identified tire failure modes using indoor driving tests and failure mode effects analysis. Next, we developed a threedimensional tire model using the Ogden material model and finite element method. Using sensitivity analysis and response surface methodology, we optimised the tread design. Finally, we evaluated the durability of the new design using a tire prototype and drum test equipment. Results indicated that the optimised tread design decreased the tire tread stress by 16% and increased its time until cracking by 38% compared to conventional agricultural lug tires.

  16. Software failure events derivation and analysis by frame-based technique

    International Nuclear Information System (INIS)

    Huang, H.-W.; Shih, C.; Yih, Swu; Chen, M.-H.

    2007-01-01

    A frame-based technique, including physical frame, logical frame, and cognitive frame, was adopted to perform digital I and C failure events derivation and analysis for generic ABWR. The physical frame was structured with a modified PCTran-ABWR plant simulation code, which was extended and enhanced on the feedwater system, recirculation system, and steam line system. The logical model is structured with MATLAB, which was incorporated into PCTran-ABWR to improve the pressure control system, feedwater control system, recirculation control system, and automated power regulation control system. As a result, the software failure of these digital control systems can be properly simulated and analyzed. The cognitive frame was simulated by the operator awareness status in the scenarios. Moreover, via an internal characteristics tuning technique, the modified PCTran-ABWR can precisely reflect the characteristics of the power-core flow. Hence, in addition to the transient plots, the analysis results can then be demonstrated on the power-core flow map. A number of postulated I and C system software failure events were derived to achieve the dynamic analyses. The basis for event derivation includes the published classification for software anomalies, the digital I and C design data for ABWR, chapter 15 accident analysis of generic SAR, and the reported NPP I and C software failure events. The case study of this research includes: (1) the software CMF analysis for the major digital control systems; and (2) postulated ABWR digital I and C software failure events derivation from the actual happening of non-ABWR digital I and C software failure events, which were reported to LER of USNRC or IRS of IAEA. These events were analyzed by PCTran-ABWR. Conflicts among plant status, computer status, and human cognitive status are successfully identified. The operator might not easily recognize the abnormal condition, because the computer status seems to progress normally. However, a well

  17. Failure mode, effect and criticality analysis (FMECA) on mechanical subsystems of diesel generator at NPP

    International Nuclear Information System (INIS)

    Kim, Tae Woon; Singh, Brijendra; Sung, Tae Yong; Park, Jin Hee; Lee, Yoon Hwan

    1996-06-01

    Largely, the RCM approach can be divided in three phases; (1) Functional failure analysis (FFA) on the selected system or subsystem, (2) Failure mode, effect and criticality analysis (FMECA) to identify the impact of failure to plant safety or economics, (3) Logical tree analysis (LTA) to select appropriate preventive maintenance and surveillance tasks. This report presents FMECA results for six mechanical subsystems of the diesel generators of nuclear power plants. The six mechanical subsystems are Starting air, Lub oil, Governor, Jacket water cooling, Fuel, and Engine subsystems. Generic and plant-specific failure and maintenance records are reviewed to identify critical components/failure modes. FMECA was performed for these critical component/failure modes. After reviewing current preventive maintenance activities of Wolsung unit 1, draft RCM recommendations are developed. 6 tabs., 16 refs. (Author)

  18. Failure mode, effect and criticality analysis (FMECA) on mechanical subsystems of diesel generator at NPP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Woon; Singh, Brijendra; Sung, Tae Yong; Park, Jin Hee; Lee, Yoon Hwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    Largely, the RCM approach can be divided in three phases; (1) Functional failure analysis (FFA) on the selected system or subsystem, (2) Failure mode, effect and criticality analysis (FMECA) to identify the impact of failure to plant safety or economics, (3) Logical tree analysis (LTA) to select appropriate preventive maintenance and surveillance tasks. This report presents FMECA results for six mechanical subsystems of the diesel generators of nuclear power plants. The six mechanical subsystems are Starting air, Lub oil, Governor, Jacket water cooling, Fuel, and Engine subsystems. Generic and plant-specific failure and maintenance records are reviewed to identify critical components/failure modes. FMECA was performed for these critical component/failure modes. After reviewing current preventive maintenance activities of Wolsung unit 1, draft RCM recommendations are developed. 6 tabs., 16 refs. (Author).

  19. The Statistical Analysis of Failure Time Data

    CERN Document Server

    Kalbfleisch, John D

    2011-01-01

    Contains additional discussion and examples on left truncation as well as material on more general censoring and truncation patterns.Introduces the martingale and counting process formulation swil lbe in a new chapter.Develops multivariate failure time data in a separate chapter and extends the material on Markov and semi Markov formulations.Presents new examples and applications of data analysis.

  20. Failure Modes and Effects Analysis (FMEA) Assistant Tool Feasibility Study

    Science.gov (United States)

    Flores, Melissa D.; Malin, Jane T.; Fleming, Land D.

    2013-09-01

    An effort to determine the feasibility of a software tool to assist in Failure Modes and Effects Analysis (FMEA) has been completed. This new and unique approach to FMEA uses model based systems engineering concepts to recommend failure modes, causes, and effects to the user after they have made several selections from pick lists about a component's functions and inputs/outputs. Recommendations are made based on a library using common failure modes identified over the course of several major human spaceflight programs. However, the tool could be adapted for use in a wide range of applications from NASA to the energy industry.

  1. Failure Modes and Effects Analysis (FMEA) Assistant Tool Feasibility Study

    Science.gov (United States)

    Flores, Melissa; Malin, Jane T.

    2013-01-01

    An effort to determine the feasibility of a software tool to assist in Failure Modes and Effects Analysis (FMEA) has been completed. This new and unique approach to FMEA uses model based systems engineering concepts to recommend failure modes, causes, and effects to the user after they have made several selections from pick lists about a component s functions and inputs/outputs. Recommendations are made based on a library using common failure modes identified over the course of several major human spaceflight programs. However, the tool could be adapted for use in a wide range of applications from NASA to the energy industry.

  2. Causes of liver failure and impact analysis of prognostic risk factors

    Directory of Open Access Journals (Sweden)

    WU Xiaoqing

    2013-04-01

    Full Text Available ObjectiveTo perform a retrospective analysis of patients with liver failure to investigate the causative factors and related risk factors that may affect patient prognosis. MethodsThe clinical, demographic, and laboratory data of 79 consecutive patients diagnosed with liver failure and treated at our hospital between January 2010 and January 2012 (58 males and 21 females; age range: 16-74 years old were collected from the medical records. To identify risk factors of liver failure, the patient variables were assessed by Student’s t-test (continuous variables or Chi-squared test (categorical variables. Multivariate logistic regression analysis was used to investigate the relation between patient outcome and independent risk factors. ResultsThe 79 cases of liver failure were grouped according to disease severity: acute liver failure (n=6; 5 died, subacute liver failure (n=35; 19 died, and chronic liver failure (n=38; 28 died. The overall rate of death was 66%. The majority of cases (81% were related to hepatitis B virus infection. While the three groups of liver failure severity did not show significant differences in sex, mean age, occupation, presence of potassium disorder, total bilirubin (TBil or total cholesterol (CHO at admission, or lowest recorded level of CHO during hospitalization, there were significant intergroup differences in highest recorded TBil level, prothrombin activity (PTA at admission, and highest and lowest recorded PTA, and highest recorded level of CHO. Five independent risk factors were identified: the highest recorded TBil level during hospitalization, presence of infection, hepatorenal syndrome, gastrointestinal bleeding, and hepatic encephalopathy. ConclusionThe major cause of liver failure in this cohort of patients was hepatitis infection, and common biomarkers of liver function, such as TBil, CHO and PTA, may indicate patients with poor prognosis despite clinical intervention. Complications should be addressed as

  3. Failure analysis a practical guide for manufacturers of electronic components and systems

    CERN Document Server

    Bâzu, Marius

    2011-01-01

    Failure analysis is the preferred method to investigate product or process reliability and to ensure optimum performance of electrical components and systems. The physics-of-failure approach is the only internationally accepted solution for continuously improving the reliability of materials, devices and processes. The models have been developed from the physical and chemical phenomena that are responsible for degradation or failure of electronic components and materials and now replace popular distribution models for failure mechanisms such as Weibull or lognormal. Reliability engineers nee

  4. Analysis of the failure of a vacuum spin-pit drive turbine spindle shaft

    OpenAIRE

    Pettitt, Jason M.

    2005-01-01

    The Naval Postgraduate School's Rotor Spin Research Facility experienced a failure in the Spring of 2005 in which the rotor dropped from the drive turbine and caused extensive damage. A failure analysis of the drive turbine spindle shaft was conducted in order to determine the cause of failure: whether due to a material or design flaw. Also, a dynamic analysis was conducted in order to determine the natural modes present in the system and the associated frequencies that could have contributed...

  5. Statistical analysis of events related to emergency diesel generators failures in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Kančev, Duško, E-mail: dusko.kancev@ec.europa.eu [European Commission, DG-JRC, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Duchac, Alexander; Zerger, Benoit [European Commission, DG-JRC, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Maqua, Michael [Gesellschaft für Anlagen-und-Reaktorsicherheit (GRS) mbH, Schwetnergasse 1, 50667 Köln (Germany); Wattrelos, Didier [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 17 - 92262 Fontenay-aux-Roses Cedex (France)

    2014-07-01

    Highlights: • Analysis of operating experience related to emergency diesel generators events at NPPs. • Four abundant operating experience databases screened. • Delineating important insights and conclusions based on the operating experience. - Abstract: This paper is aimed at studying the operating experience related to emergency diesel generators (EDGs) events at nuclear power plants collected from the past 20 years. Events related to EDGs failures and/or unavailability as well as all the supporting equipment are in the focus of the analysis. The selected operating experience was analyzed in detail in order to identify the type of failures, attributes that contributed to the failure, failure modes potential or real, discuss risk relevance, summarize important lessons learned, and provide recommendations. The study in this particular paper is tightly related to the performing of statistical analysis of the operating experience. For the purpose of this study EDG failure is defined as EDG failure to function on demand (i.e. fail to start, fail to run) or during testing, or an unavailability of an EDG, except of unavailability due to regular maintenance. The Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) and Institut de Radioprotection et de Sûreté Nucléaire (IRSN) databases as well as the operating experience contained in the IAEA/NEA International Reporting System for Operating Experience and the U.S. Licensee Event Reports were screened. The screening methodology applied for each of the four different databases is presented. Further on, analysis aimed at delineating the causes, root causes, contributing factors and consequences are performed. A statistical analysis was performed related to the chronology of events, types of failures, the operational circumstances of detection of the failure and the affected components/subsystems. The conclusions and results of the statistical analysis are discussed. The main findings concerning the testing

  6. Statistical analysis of events related to emergency diesel generators failures in the nuclear industry

    International Nuclear Information System (INIS)

    Kančev, Duško; Duchac, Alexander; Zerger, Benoit; Maqua, Michael; Wattrelos, Didier

    2014-01-01

    Highlights: • Analysis of operating experience related to emergency diesel generators events at NPPs. • Four abundant operating experience databases screened. • Delineating important insights and conclusions based on the operating experience. - Abstract: This paper is aimed at studying the operating experience related to emergency diesel generators (EDGs) events at nuclear power plants collected from the past 20 years. Events related to EDGs failures and/or unavailability as well as all the supporting equipment are in the focus of the analysis. The selected operating experience was analyzed in detail in order to identify the type of failures, attributes that contributed to the failure, failure modes potential or real, discuss risk relevance, summarize important lessons learned, and provide recommendations. The study in this particular paper is tightly related to the performing of statistical analysis of the operating experience. For the purpose of this study EDG failure is defined as EDG failure to function on demand (i.e. fail to start, fail to run) or during testing, or an unavailability of an EDG, except of unavailability due to regular maintenance. The Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) and Institut de Radioprotection et de Sûreté Nucléaire (IRSN) databases as well as the operating experience contained in the IAEA/NEA International Reporting System for Operating Experience and the U.S. Licensee Event Reports were screened. The screening methodology applied for each of the four different databases is presented. Further on, analysis aimed at delineating the causes, root causes, contributing factors and consequences are performed. A statistical analysis was performed related to the chronology of events, types of failures, the operational circumstances of detection of the failure and the affected components/subsystems. The conclusions and results of the statistical analysis are discussed. The main findings concerning the testing

  7. Analysis of arrhythmic events is useful to detect lead failure earlier in patients followed by remote monitoring.

    Science.gov (United States)

    Nishii, Nobuhiro; Miyoshi, Akihito; Kubo, Motoki; Miyamoto, Masakazu; Morimoto, Yoshimasa; Kawada, Satoshi; Nakagawa, Koji; Watanabe, Atsuyuki; Nakamura, Kazufumi; Morita, Hiroshi; Ito, Hiroshi

    2018-03-01

    Remote monitoring (RM) has been advocated as the new standard of care for patients with cardiovascular implantable electronic devices (CIEDs). RM has allowed the early detection of adverse clinical events, such as arrhythmia, lead failure, and battery depletion. However, lead failure was often identified only by arrhythmic events, but not impedance abnormalities. To compare the usefulness of arrhythmic events with conventional impedance abnormalities for identifying lead failure in CIED patients followed by RM. CIED patients in 12 hospitals have been followed by the RM center in Okayama University Hospital. All transmitted data have been analyzed and summarized. From April 2009 to March 2016, 1,873 patients have been followed by the RM center. During the mean follow-up period of 775 days, 42 lead failure events (atrial lead 22, right ventricular pacemaker lead 5, implantable cardioverter defibrillator [ICD] lead 15) were detected. The proportion of lead failures detected only by arrhythmic events, which were not detected by conventional impedance abnormalities, was significantly higher than that detected by impedance abnormalities (arrhythmic event 76.2%, 95% CI: 60.5-87.9%; impedance abnormalities 23.8%, 95% CI: 12.1-39.5%). Twenty-seven events (64.7%) were detected without any alert. Of 15 patients with ICD lead failure, none has experienced inappropriate therapy. RM can detect lead failure earlier, before clinical adverse events. However, CIEDs often diagnose lead failure as just arrhythmic events without any warning. Thus, to detect lead failure earlier, careful human analysis of arrhythmic events is useful. © 2017 Wiley Periodicals, Inc.

  8. 8.64-11.62 GHz CMOS VCO and divider in a zero-IF 802.11a/b/g WLAN and Bluetooth application

    International Nuclear Information System (INIS)

    Sun Yu; Mei Niansong; Lu Bo; Huang Yumei; Hong Zhiliang

    2010-01-01

    A fully integrated VCO and divider implemented in SMIC 0.13-μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.11a WLAN in 5.8 GHz band or for 802.11b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands. The testing results show that the VCO has a phase noise of-113 dBc - 1 MHz offset from the carrier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW. The figure-of-merit for the tuning-range (FOM T ) of the VCO is -192.6 dBc/Hz. (semiconductor integrated circuits)

  9. 8.64-11.62 GHz CMOS VCO and divider in a zero-IF 802.11a/b/g WLAN and Bluetooth application

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yu; Mei Niansong; Lu Bo; Huang Yumei; Hong Zhiliang, E-mail: yumeihuang@fudan.edu.c [ASIC and System State Key Laboratory, Fudan University, Shanghai 201203 (China)

    2010-10-15

    A fully integrated VCO and divider implemented in SMIC 0.13-{mu}m RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.11a WLAN in 5.8 GHz band or for 802.11b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands. The testing results show that the VCO has a phase noise of-113 dBc - 1 MHz offset from the carrier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW. The figure-of-merit for the tuning-range (FOM{sub T}) of the VCO is -192.6 dBc/Hz. (semiconductor integrated circuits)

  10. Failure analysis of motor bearing of sea water pump in nuclear power plant

    International Nuclear Information System (INIS)

    Bian Chunhua; Zhang Wei

    2015-01-01

    The motor bearing of sea water pump in Qinshan Phase II Nuclear Power plant broke after only one year's using. This paper introduces failure analysis process of the motor bearing. Chemical composition analysis, metallic phase analysis, micrographic examination, and hardness analysis, dimension analysis of each part of the bearing, as well as the high temperature and low temperature performance analysis of lubricating grease are performed. According to the analysis above mentioned, the failure mode of the bearing is wearing, and the reason of wearing is inappropriate installation of the bearing. (authors)

  11. Leishmania Antigenuria to Predict Initial Treatment Failure and Relapse in Visceral Leishmaniasis/HIV Coinfected Patients: An Exploratory Study Nested Within a Clinical Trial in Ethiopia.

    Science.gov (United States)

    van Griensven, Johan; Mengesha, Bewketu; Mekonnen, Tigist; Fikre, Helina; Takele, Yegnasew; Adem, Emebet; Mohammed, Rezika; Ritmeijer, Koert; Vogt, Florian; Adriaensen, Wim; Diro, Ermias

    2018-01-01

    Background: Biomarkers predicting the risk of VL treatment failure and relapse in VL/HIV coinfected patients are needed. Nested within a two-site clinical trial in Ethiopia (2011-2015), we conducted an exploratory study to assess whether (1) levels of Leishmania antigenuria measured at VL diagnosis were associated with initial treatment failure and (2) levels of Leishmania antigenuria at the end of treatment (parasitologically-confirmed cure) were associated with subsequent relapse. Methods: Leishmania antigenuria at VL diagnosis and cure was determined using KAtex urine antigen test and graded as negative (0), weak/moderate (grade 1+/2+) or strongly-positive (3+). Logistic regression and Kaplan-Meier methods were used to assess the association between antigenuria and (1) initial treatment failure, and (2) relapse over the 12 months after cure, respectively. Results: The analysis to predict initial treatment failure included sixty-three coinfected adults [median age: 30 years interquartile range (IQR) 27-35], median CD4 count: 56 cells/μL (IQR 38-113). KAtex results at VL diagnosis were negative in 11 (17%), weak/moderate in 17 (27%) and strongly-positive in 35 (36%). Twenty (32%) patients had parasitologically-confirmed treatment failure, with a risk of failure of 9% (1/11) with KAtex-negative results, 0% (0/17) for KAtex 1+/2+ and 54% (19/35) for KAtex 3+ results. Compared to KAtex-negative patients, KAtex 3+ patients were at increased risk of treatment failure [odds ratio 11.9 (95% CI 1.4-103.0); P : 0.025]. Forty-four patients were included in the analysis to predict relapse [median age: 31 years (IQR 28-35), median CD4 count: 116 cells/μL (IQR 95-181)]. When achieving VL cure, KAtex results were negative in 19 (43%), weak/moderate (1+/2+) in 10 (23%), and strongly positive (3+) in 15 patients (34%). Over the subsequent 12 months, eight out of 44 patients (18%) relapsed. The predicted 1-year relapse risk was 6% for KAtex-negative results, 14% for KAtex 1

  12. Skeleton polyhedral rearrangements of 8-alkyl-7,9-dicarba-nido-undecaborate(-1) anion to 11-alkyl-2,7-dicarba-nido-undecaborane(13) and to 9-alkyl-7,8-dicarba-nido-undecaborate(-1) anion. Molecular structure of 2,7-Me2-11-PhCH2-2,7-C2B9H10

    International Nuclear Information System (INIS)

    Zakharkin, K.I.; Zhigareva, G.G.; Antonovich, V.A.; Yanovskij, A.I.; Struchkov, Yu.T.

    1986-01-01

    Using the methods of 1 H and 11 B NMR-spectroscopy and X-ray diffraction analysis skeleton polyhedral rearrangements of carboranes are studied. During protonation of anion 8-R-7, 9-R' 2 -7, 9-C 2 B 9 H 9 - the skeleton polyhedral rearrangement in the series of nido-carboranes, resulting in 2,7-R' 2 -11-R-2, 7-C 2 B 9 H 10 (R=Me, PhCH 2 , R'=H, Me) is observed. The rearrangement is reversible. On the detachment of two protons from 2,7-Me 2 -11-PhCH 2 -2,7-C 2 B 9 H 10 and during subsequent protonation the skeleton polyhedral rearrangement with the formation of anion 9-PhCH 2 -7,8-Me 2 -7,8-C 2 B 9 H 9 - takes place

  13. 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

  14. FAILURE OF RADIOACTIVE IODINE IN TREATMENT OF HYPERTHYROIDISM

    Science.gov (United States)

    Schneider, David F.; Sonderman, Philip E.; Jones, Michaela F.; Ojomo, Kristin A.; Chen, Herbert; Jaume, Juan C.; Elson, Diane F.; Perlman, Scott B.; Sippel, Rebecca S.

    2015-01-01

    Introduction Persistent or recurrent hyperthyroidism after treatment with radioactive iodine (RAI) is common, and many patients require either additional doses or surgery before they are cured. The purpose of this study was to identify patterns and predictors of failure of RAI in patients with hyperthyroidism. Methods We conducted a retrospective review of patients treated with RAI from 2007–2010. Failure of RAI was defined as receipt of additional dose(s) and/or total thyroidectomy. Using a Cox proportional hazards model, we conducted univariate analysis to identify factors associated with failure of RAI. A final multivariate model was then constructed with significant (p treatment. 53 (71.6%) received additional RAI, 13 (17.6%) received additional RAI followed by surgery, and the remaining 8 (10.8%) were cured after thyroidectomy. The percentage of patients who failed decreased in a step-wise fashion as RAI dose increased. Similarly, the incidence of failure increased as the presenting T3 level increased. Sensitivity analysis revealed that RAI doses treatment (HR 2.55, 95% CI 1.22–5.33, p=0.01) were associated with failure. Conclusions Laboratory values at presentation can predict which patients with hyperthyroidism are at risk for failing RAI treatment. Higher doses of RAI or surgical referral may prevent the need for repeat RAI in selected patients. PMID:25001092

  15. "1"8F-FBPA as a tumor-specific probe of L-type amino acid transporter 1 (LAT1): a comparison study with "1"8F-FDG and "1"1C-Methionine PET

    International Nuclear Information System (INIS)

    Watabe, Tadashi; Ikeda, Hayato; Aoki, Masanao; Nagamori, Shushi; Wiriyasermkul, Pattama; Tanaka, Yoko; Hagiwara, Kohei; Kanai, Yoshikatsu; Naka, Sadahiro; Kanai, Yasukazu; Shimosegawa, Eku; Hatazawa, Jun

    2017-01-01

    The purpose of this study was to evaluate the usefulness of L-4-borono-2-"1"8F-fluoro-phenylalanine ("1"8F-FBPA) as a tumor-specific probe, in comparison to "1"8F-FDG and "1"1C-methionine (Met), focusing on its transport selectivity by L-type amino acid transporter 1 (LAT1), which is highly upregulated in cancers. Cellular analyses of FBPA were performed to evaluate the transportability and K_m value. PET studies were performed in rat xenograft models of C6 glioma (n = 12) and in rat models of turpentine oil-induced subcutaneous inflammation (n = 9). The kinetic parameters and uptake values on static PET images were compared using the one-tissue compartment model (K_1, k_2) and maximum standardized uptake value (SUVmax). The cellular analyses showed that FBPA had a lower affinity to a normal cell-type transporter LAT2 and induced less efflux through LAT2 among FBPA, Met, and BPA, while the efflux through LAT1 induced by FBPA was similar among the three compounds. The K_m value of "1"8F-FBPA for LAT1 (196.8 ± 11.4 μM) was dramatically lower than that for LAT2 (2813.8 ± 574.5 μM), suggesting the higher selectivity of "1"8F-FBPA for LAT1. K_1 and k_2 values were significantly smaller in "1"8F-FBPA PET (K_1 = 0.04 ± 0.01 ml/ccm/min and k_2 = 0.07 ± 0.01 /min) as compared to "1"1C-Met PET (0.22 ± 0.09 and 0.52 ± 0.10, respectively) in inflammatory lesions. Static PET analysis based on the SUVmax showed significantly higher accumulation of "1"8F-FDG in the tumor and inflammatory lesions (7.2 ± 2.1 and 4.6 ± 0.63, respectively) as compared to both "1"8F-FBPA (3.2 ± 0.40 and 1.9 ± 0.19) and "1"1C-Met (3.4 ± 0.43 and 1.6 ± 0.11). No significant difference was observed between "1"8F-FBPA and "1"1C-Met in the static PET images. This study shows the utility of "1"8F-FBPA as a tumor-specific probe of LAT1 with low accumulation in the inflammatory lesions. (orig.)

  16. Data book of the component failure rate stored in the RECORD

    International Nuclear Information System (INIS)

    Oikawa, Testukuni; Sasaki, Shinobu; Hikawa, Michihiro; Higuchi, Suminori.

    1989-04-01

    The Japan Atomic Energy Research Insitute (JAERI) has developed a computerized component reliability data base and its retrieval system, RECORD, on collected failure rates from published literatures in order to promote convenience and efficiency of systems reliability analysis in the PSA (Probabilistic Safety Assessment). In order to represent collected failure rates in a uniform format, codes are defined for component category, failure mode, data source, unit of failure rate and statistocal parameter. Up to now, approximately 11,500 pieces of component failure rate data from about 35 open literatures have been stored in the RECORD. This report provides the failure rate stored in the RECORD data base for the usage by systems analysts, as well as brief descriptions about the data base structure and how to use this data book. (author)

  17. Failure of radioactive iodine in the treatment of hyperthyroidism.

    Science.gov (United States)

    Schneider, David F; Sonderman, Philip E; Jones, Michaela F; Ojomo, Kristin A; Chen, Herbert; Jaume, Juan C; Elson, Diane F; Perlman, Scott B; Sippel, Rebecca S

    2014-12-01

    Persistent or recurrent hyperthyroidism after treatment with radioactive iodine (RAI) is common and many patients require either additional doses or surgery before they are cured. The purpose of this study was to identify patterns and predictors of failure of RAI in patients with hyperthyroidism. We conducted a retrospective review of patients treated with RAI from 2007 to 2010. Failure of RAI was defined as receipt of additional dose(s) and/or total thyroidectomy. Using a Cox proportional hazards model, we conducted univariate analysis to identify factors associated with failure of RAI. A final multivariate model was then constructed with significant (p treatment, 53 (71.6 %) received additional RAI, 13 (17.6 %) received additional RAI followed by surgery, and the remaining 8 (10.8 %) were cured after thyroidectomy. The percentage of patients who failed decreased in a stepwise fashion as RAI dose increased. Similarly, the incidence of failure increased as the presenting T3 level increased. Sensitivity analysis revealed that RAI doses treatment (HR 2.55; 95 % CI 1.22-5.33; p = 0.01) were associated with failure. Laboratory values at presentation can predict which patients with hyperthyroidism are at risk for failing RAI treatment. Higher doses of RAI or surgical referral may prevent the need for repeat RAI in selected patients.

  18. Individual Prediction of Heart Failure Among Childhood Cancer Survivors

    Science.gov (United States)

    Chow, Eric J.; Chen, Yan; Kremer, Leontien C.; Breslow, Norman E.; Hudson, Melissa M.; Armstrong, Gregory T.; Border, William L.; Feijen, Elizabeth A.M.; Green, Daniel M.; Meacham, Lillian R.; Meeske, Kathleen A.; Mulrooney, Daniel A.; Ness, Kirsten K.; Oeffinger, Kevin C.; Sklar, Charles A.; Stovall, Marilyn; van der Pal, Helena J.; Weathers, Rita E.; Robison, Leslie L.; Yasui, Yutaka

    2015-01-01

    Purpose To create clinically useful models that incorporate readily available demographic and cancer treatment characteristics to predict individual risk of heart failure among 5-year survivors of childhood cancer. Patients and Methods Survivors in the Childhood Cancer Survivor Study (CCSS) free of significant cardiovascular disease 5 years after cancer diagnosis (n = 13,060) were observed through age 40 years for the development of heart failure (ie, requiring medications or heart transplantation or leading to death). Siblings (n = 4,023) established the baseline population risk. An additional 3,421 survivors from Emma Children's Hospital (Amsterdam, the Netherlands), the National Wilms Tumor Study, and the St Jude Lifetime Cohort Study were used to validate the CCSS prediction models. Results Heart failure occurred in 285 CCSS participants. Risk scores based on selected exposures (sex, age at cancer diagnosis, and anthracycline and chest radiotherapy doses) achieved an area under the curve of 0.74 and concordance statistic of 0.76 at or through age 40 years. Validation cohort estimates ranged from 0.68 to 0.82. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups, corresponding to cumulative incidences of heart failure at age 40 years of 0.5% (95% CI, 0.2% to 0.8%), 2.4% (95% CI, 1.8% to 3.0%), and 11.7% (95% CI, 8.8% to 14.5%), respectively. In comparison, siblings had a cumulative incidence of 0.3% (95% CI, 0.1% to 0.5%). Conclusion Using information available to clinicians soon after completion of childhood cancer therapy, individual risk for subsequent heart failure can be predicted with reasonable accuracy and discrimination. These validated models provide a framework on which to base future screening strategies and interventions. PMID:25287823

  19. Laboratory and 3-D-distinct element analysis of failure mechanism of slope under external surcharge

    Science.gov (United States)

    Li, N.; Cheng, Y. M.

    2014-09-01

    Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient details. There are however increasing interest on the consequences after the initiation of failure which includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more details and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanism and the post-failure mechanism of slope will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure which can give additional information not available from the classical methods of analysis.

  20. The distributed failure probability approach to dependent failure analysis, and its application

    International Nuclear Information System (INIS)

    Hughes, R.P.

    1989-01-01

    The Distributed Failure Probability (DFP) approach to the problem of dependent failures in systems is presented. The basis of the approach is that the failure probability of a component is a variable. The source of this variability is the change in the 'environment' of the component, where the term 'environment' is used to mean not only obvious environmental factors such as temperature etc., but also such factors as the quality of maintenance and manufacture. The failure probability is distributed among these various 'environments' giving rise to the Distributed Failure Probability method. Within the framework which this method represents, modelling assumptions can be made, based both on engineering judgment and on the data directly. As such, this DFP approach provides a soundly based and scrutable technique by which dependent failures can be quantitatively assessed. (orig.)

  1. Failure analysis of multiple delaminated composite plates due

    Indian Academy of Sciences (India)

    The present work aims at the first ply failure analysis of laminated composite plates with arbitrarily located multiple delaminations subjected to transverse static load as well as impact. The theoretical formulation is based on a simple multiple delamination model. Conventional first order shear deformation is assumed using ...

  2. Effects of Sacubitril/Valsartan on Physical and Social Activity Limitations in Patients With Heart Failure: A Secondary Analysis of the PARADIGM-HF Trial.

    Science.gov (United States)

    Chandra, Alvin; Lewis, Eldrin F; Claggett, Brian L; Desai, Akshay S; Packer, Milton; Zile, Michael R; Swedberg, Karl; Rouleau, Jean L; Shi, Victor C; Lefkowitz, Martin P; Katova, Tzvetana; McMurray, John J V; Solomon, Scott D

    2018-04-04

    Health-related quality of life (HRQL) of patients with heart failure is markedly reduced compared with that in patients with other chronic diseases, demonstrating substantial limitations in physical and social activities. In the Prospective Comparison of ARNI With an ACE-Inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM-HF) trial, sacubitril/valsartan improved overall HRQL compared with enalapril, as determined by the Kansas City Cardiomyopathy Questionnaire (KCCQ). To examine the effects of sacubitril/valsartan on physical and social activities. The PARADIGM-HF trial was a randomized, double-blind, active treatment-controlled clinical trial performed from December 8, 2009, to March 31, 2014, in 8399 patients with New York Heart Association class II to IV disease and a left ventricular ejection fraction of 40% or less at 1043 centers in 38 countries. Data analysis was performed from August 1, 2017, to December 25, 2017. Sacubitril/valsartan, 200 mg twice daily, or enalapril, 10 mg twice daily. Patients completed HRQL assessments using the KCCQ at randomization, 4-month, 8-month, and annual visits. The effect of sacubitril/valsartan on components of the physical and social limitation sections of the KCCQ at 8 months and longitudinally and related biomarkers and clinical outcomes were studied. At baseline, 7618 of 8399 patients (90.7%) (mean [SD] age, 64 [11] years; 5987 [78.6%] male and 1631 [21.4%] female) completed the initial KCCQ assessment. Patients reported the greatest limitations at baseline in jogging and sexual relationships. Patients receiving sacubitril/valsartan had significantly better adjusted change scores in most physical and social activities at 8 months and during 36 months compared with those receiving enalapril. The largest improvement over enalapril was in household chores (adjusted change score difference, 2.35; 95% CI, 1.19-3.50; P sacubitril/valsartan significantly improved nearly all KCCQ physical

  3. Exploitation of a component event data bank for common cause failure analysis

    International Nuclear Information System (INIS)

    Games, A.M.; Amendola, A.; Martin, P.

    1985-01-01

    Investigations into using the European Reliability Data System Component Event Data Bank for common cause failure analysis have been carried out. Starting from early exercises where data were analyzed without computer aid, different types of linked multiple failures have been identified. A classification system is proposed based on this experience. It defines a multiple failure event space wherein each category defines causal, modal, temporal and structural links between failures. It is shown that a search algorithm which incorporates the specific interrogative procedures of the data bank can be developed in conjunction with this classification system. It is concluded that the classification scheme and the search algorithm are useful organizational tools in the field of common cause failures studies. However, it is also suggested that the use of the term common cause failure should be avoided since it embodies to many different types of linked multiple failures

  4. Sensor Failure Detection of FASSIP System using Principal Component Analysis

    Science.gov (United States)

    Sudarno; Juarsa, Mulya; Santosa, Kussigit; Deswandri; Sunaryo, Geni Rina

    2018-02-01

    In the nuclear reactor accident of Fukushima Daiichi in Japan, the damages of core and pressure vessel were caused by the failure of its active cooling system (diesel generator was inundated by tsunami). Thus researches on passive cooling system for Nuclear Power Plant are performed to improve the safety aspects of nuclear reactors. The FASSIP system (Passive System Simulation Facility) is an installation used to study the characteristics of passive cooling systems at nuclear power plants. The accuracy of sensor measurement of FASSIP system is essential, because as the basis for determining the characteristics of a passive cooling system. In this research, a sensor failure detection method for FASSIP system is developed, so the indication of sensor failures can be detected early. The method used is Principal Component Analysis (PCA) to reduce the dimension of the sensor, with the Squarred Prediction Error (SPE) and statistic Hotteling criteria for detecting sensor failure indication. The results shows that PCA method is capable to detect the occurrence of a failure at any sensor.

  5. Finite Element Creep-Fatigue Analysis of a Welded Furnace Roll for Identifying Failure Root Cause

    Science.gov (United States)

    Yang, Y. P.; Mohr, W. C.

    2015-11-01

    Creep-fatigue induced failures are often observed in engineering components operating under high temperature and cyclic loading. Understanding the creep-fatigue damage process and identifying failure root cause are very important for preventing such failures and improving the lifetime of engineering components. Finite element analyses including a heat transfer analysis and a creep-fatigue analysis were conducted to model the cyclic thermal and mechanical process of a furnace roll in a continuous hot-dip coating line. Typically, the roll has a short life, modeling heat convection from hot air inside the furnace. The creep-fatigue analysis was performed by inputting the predicted temperature history and applying mechanical loads. The analysis results showed that the failure was resulted from a creep-fatigue mechanism rather than a creep mechanism. The difference of material properties between the filler metal and the base metal is the root cause for the roll failure, which induces higher creep strain and stress in the interface between the weld and the HAZ.

  6. Risk of renal failure with the non-vitamin K antagonist oral anticoagulants: systematic review and meta-analysis.

    Science.gov (United States)

    Caldeira, Daniel; Gonçalves, Nilza; Pinto, Fausto J; Costa, João; Ferreira, Joaquim J

    2015-07-01

    Vitamin K antagonists (VKA)-related nephropathy is a novel entity characterized by acute kidney injury related to International Normalized Ratio supratherapeutic levels. Non-vitamin K antagonists oral anticoagulants (NOACs) have a predictable dose-response relationship and an improved safety profile. We hypothesized that these drugs do not have an increased risk of incident renal failure, which may be detrimental for the use of NOACs. Systematic review and meta-analysis of phase III randomized controlled trials (RCTs). Trials were searched through Medline, Cochrane Library and public assessment reports in August 2014. Primary outcome was renal failure. NOACs were evaluated against any comparator. Random-effects meta-analysis was performed by default, and pooled estimates were expressed as Risk Ratio (RR) and 95%CI. Heterogeneity was evaluated with I(2) test. Ten RCTs fulfilled inclusion criteria (one apixaban RCT, three dabigatran RCTs, and six rivaroxaban RCTs), enrolling 75 100 patients. Overall NOACs did not increase the risk of renal failure with an RR 0.96, 95%CI 0.88-1.05 compared with VKA or Low-molecular weight heparin (LMWH), without significant statistical heterogeneity (I(2)  = 3.5%). Compared with VKA, NOACs did not increase the risk of renal failure (RR 0.96, 95%CI 0.87-1.07; I(2)  = 17.8%; six RCTs). Rivaroxaban did not show differences in the incidence of renal failure compared with LMWH (RR 1.20, 95%CI 0.37-3.94; four trials), but there was an increased risk of creatinine elevation RR 1.25, 95%CI 1.08-1.45; I(2)  = 0%. NOACs had a similar risk of renal failure compared with VKA/LMWH in phase III RCTs. Post-marketing surveillance should be warranted. Copyright © 2015 John Wiley & Sons, Ltd.

  7. A pragmatic approach to estimate alpha factors for common cause failure analysis

    International Nuclear Information System (INIS)

    Hassija, Varun; Senthil Kumar, C.; Velusamy, K.

    2014-01-01

    Highlights: • Estimation of coefficients in alpha factor model for common cause analysis. • A derivation of plant specific alpha factors is demonstrated. • We examine sensitivity of common cause contribution to total system failure. • We compare beta factor and alpha factor models for various redundant configurations. • The use of alpha factors is preferable, especially for large redundant systems. - Abstract: Most of the modern technological systems are deployed with high redundancy but still they fail mainly on account of common cause failures (CCF). Various models such as Beta Factor, Multiple Greek Letter, Binomial Failure Rate and Alpha Factor exists for estimation of risk from common cause failures. Amongst all, alpha factor model is considered most suitable for high redundant systems as it arrives at common cause failure probabilities from a set of ratios of failures and the total component failure probability Q T . In the present study, alpha factor model is applied for the assessment of CCF of safety systems deployed at two nuclear power plants. A method to overcome the difficulties in estimation of the coefficients viz., alpha factors in the model, importance of deriving plant specific alpha factors and sensitivity of common cause contribution to the total system failure probability with respect to hazard imposed by various CCF events is highlighted. An approach described in NUREG/CR-5500 is extended in this study to provide more explicit guidance for a statistical approach to derive plant specific coefficients for CCF analysis especially for high redundant systems. The procedure is expected to aid regulators for independent safety assessment

  8. A statistical analysis of pellet-clad interaction failures in water reactor fuel

    International Nuclear Information System (INIS)

    McDonald, S.G.; Fardo, R.D.; Sipush, P.J.; Kaiser, R.S.

    1981-01-01

    The primary objective of the statistical analysis was to develop a mathematical function that would predict PCI fuel rod failures as a function of the imposed operating conditions. Linear discriminant analysis of data from both test and commercial reactors was performed. The initial data base used encompassed 713 data points (117 failures and 596 non-failures) representing a wide variety of water cooled reactor fuel (PWR, BWR, CANDU, and SGHWR). When applied on a best-estimate basis, the resulting function simultaneously predicts approximately 80 percent of both the failure and non-failure data correctly. One of the most significant predictions of the analysis is that relatively large changes in power can be tolerated when the pre-ramp irradiation power is low, but that only small changes in power can be tolerated when the pre-ramp irradiation power is high. However, it is also predicted that fuel rods irradiated at low power will fail at lower final powers than those irradiated at high powers. Other results of the analysis are that fuel rods with high clad operating temperatures can withstand larger power increases that fuel rods with low clad operating temperatures, and that burnup has only a minimal effect on PCI performance after levels of approximately 10000 MWD/MTU have been exceeded. These trends in PCI performance and the operating parameters selected are believed to be consistent with mechanistic considerations. Published PCI data indicate that BWR fuel usually operates at higher local powers and changes in power, lower clad temperatures, and higher local ramp rates than PWR fuel

  9. Direct analysis of viral-specific CD8+ T cells with soluble HLA-A2/Tax11-19 tetramer complexes in patients with human T cell lymphotropic virus-associated myelopathy.

    Science.gov (United States)

    Bieganowska, K; Höllsberg, P; Buckle, G J; Lim, D G; Greten, T F; Schneck, J; Altman, J D; Jacobson, S; Ledis, S L; Hanchard, B; Chin, J; Morgan, O; Roth, P A; Hafler, D A

    1999-02-01

    Human T cell lymphotropic virus-I (HTLV-I)-associated myelopathy is a slowly progressive neurologic disease characterized by inflammatory infiltrates in the central nervous system accompanied by clonal expansion of HTLV-I-reactive CD8+ T-cells. In patients carrying the HLA-A2 allele, the immune response is primarily directed to the Tax11-19 peptide. The frequency, activation state, and TCR usage of HLA-A2/Tax11-19 binding T cells in patients with HTLV-I-associated myelopathy was determined using MHC class I tetramers loaded with the Tax11-19 peptide. Circulating Tax11-19-reactive T cells were found at very high frequencies, approaching 1:10 circulating CD8+ T cells. T cells binding HLA-A2/Tax11-19 consisted of heterogeneous populations expressing different chemokine receptors and the IL-2R beta-chain but not the IL-2R alpha-chain. Additionally, Tax11-19-reactive CD8+ T cells used one predominant TCR Vbeta-chain for the recognition of the HLA-A2/Tax11-19 complex. These data provide direct evidence for high frequencies of circulating Tax11-19-reactive CD8+ T cells in patients with HTLV-I-associated myelopathy.

  10. Analysis of valve failures from the NUCLARR data base

    International Nuclear Information System (INIS)

    Moore, L.M.

    1997-11-01

    The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) contains data on component failures with categorical and qualifying information such as component design, normal operating state, system application and safety grade information which is important to the development of risk-based component surveillance testing requirements. This report presents descriptions and results of analyses of valve component failure data and covariate information available in the document Nuclear Computerized Library for Assessing Reactor Reliability Data Manual, Part 3: Hardware Component Failure Data (NUCLARR Data Manual). Although there are substantial records on valve performance, there are many categories of the corresponding descriptors and qualifying information for which specific values are missing. Consequently, this limits the data available for analysis of covariate effects. This report presents cross tabulations by different covariate categories and limited modeling of covariate effects for data subsets with substantive non-missing covariate information

  11. Quantitative Approach to Failure Mode and Effect Analysis for Linear Accelerator Quality Assurance

    Energy Technology Data Exchange (ETDEWEB)

    O' Daniel, Jennifer C., E-mail: jennifer.odaniel@duke.edu; Yin, Fang-Fang

    2017-05-01

    Purpose: To determine clinic-specific linear accelerator quality assurance (QA) TG-142 test frequencies, to maximize physicist time efficiency and patient treatment quality. Methods and Materials: A novel quantitative approach to failure mode and effect analysis is proposed. Nine linear accelerator-years of QA records provided data on failure occurrence rates. The severity of test failure was modeled by introducing corresponding errors into head and neck intensity modulated radiation therapy treatment plans. The relative risk of daily linear accelerator QA was calculated as a function of frequency of test performance. Results: Although the failure severity was greatest for daily imaging QA (imaging vs treatment isocenter and imaging positioning/repositioning), the failure occurrence rate was greatest for output and laser testing. The composite ranking results suggest that performing output and lasers tests daily, imaging versus treatment isocenter and imaging positioning/repositioning tests weekly, and optical distance indicator and jaws versus light field tests biweekly would be acceptable for non-stereotactic radiosurgery/stereotactic body radiation therapy linear accelerators. Conclusions: Failure mode and effect analysis is a useful tool to determine the relative importance of QA tests from TG-142. Because there are practical time limitations on how many QA tests can be performed, this analysis highlights which tests are the most important and suggests the frequency of testing based on each test's risk priority number.

  12. Quantitative Approach to Failure Mode and Effect Analysis for Linear Accelerator Quality Assurance.

    Science.gov (United States)

    O'Daniel, Jennifer C; Yin, Fang-Fang

    2017-05-01

    To determine clinic-specific linear accelerator quality assurance (QA) TG-142 test frequencies, to maximize physicist time efficiency and patient treatment quality. A novel quantitative approach to failure mode and effect analysis is proposed. Nine linear accelerator-years of QA records provided data on failure occurrence rates. The severity of test failure was modeled by introducing corresponding errors into head and neck intensity modulated radiation therapy treatment plans. The relative risk of daily linear accelerator QA was calculated as a function of frequency of test performance. Although the failure severity was greatest for daily imaging QA (imaging vs treatment isocenter and imaging positioning/repositioning), the failure occurrence rate was greatest for output and laser testing. The composite ranking results suggest that performing output and lasers tests daily, imaging versus treatment isocenter and imaging positioning/repositioning tests weekly, and optical distance indicator and jaws versus light field tests biweekly would be acceptable for non-stereotactic radiosurgery/stereotactic body radiation therapy linear accelerators. Failure mode and effect analysis is a useful tool to determine the relative importance of QA tests from TG-142. Because there are practical time limitations on how many QA tests can be performed, this analysis highlights which tests are the most important and suggests the frequency of testing based on each test's risk priority number. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Probabilistic analysis of ''common mode failures''

    International Nuclear Information System (INIS)

    Easterling, R.G.

    1978-01-01

    Common mode failure is a topic of considerable interest in reliability and safety analyses of nuclear reactors. Common mode failures are often discussed in terms of examples: two systems fail simultaneously due to an external event such as an earthquake; two components in redundant channels fail because of a common manufacturing defect; two systems fail because a component common to both fails; the failure of one system increases the stress on other systems and they fail. The common thread running through these is a dependence of some sort--statistical or physical--among multiple failure events. However, the nature of the dependence is not the same in all these examples. An attempt is made to model situations, such as the above examples, which have been termed ''common mode failures.'' In doing so, it is found that standard probability concepts and terms, such as statistically dependent and independent events, and conditional and unconditional probabilities, suffice. Thus, it is proposed that the term ''common mode failures'' be dropped, at least from technical discussions of these problems. A corollary is that the complementary term, ''random failures,'' should also be dropped. The mathematical model presented may not cover all situations which have been termed ''common mode failures,'' but provides insight into the difficulty of obtaining estimates of the probabilities of these events

  14. Statistical Analysis Of Failure Strength Of Material Using Weibull Distribution

    International Nuclear Information System (INIS)

    Entin Hartini; Mike Susmikanti; Antonius Sitompul

    2008-01-01

    In evaluation of ceramic and glass materials strength a statistical approach is necessary Strength of ceramic and glass depend on its measure and size distribution of flaws in these material. The distribution of strength for ductile material is narrow and close to a Gaussian distribution while strength of brittle materials as ceramic and glass following Weibull distribution. The Weibull distribution is an indicator of the failure of material strength resulting from a distribution of flaw size. In this paper, cumulative probability of material strength to failure probability, cumulative probability of failure versus fracture stress and cumulative probability of reliability of material were calculated. Statistical criteria calculation supporting strength analysis of Silicon Nitride material were done utilizing MATLAB. (author)

  15. Seismogenic ionospheric anomalies associated with the strong Indonesian earthquake occurred on 11 April 2012 (M = 8.5)

    Science.gov (United States)

    Pandey, Uma; Singh, Ashutosh K.; Kumar, Sanjay; Singh, A. K.

    2018-03-01

    Ionospheric perturbations in possible association with a major earthquake (EQ) (M = 8.5) which occurred in India-Oceania region are investigated by monitoring subionospheric propagation of VLF signals transmitted from the NWC transmitter (F = 19.8 kHz), Australia to a receiving station at Varanasi (geographic lat. 25.3°N, long 82.99°E), India. The EQ occurred on 11 April 2012 at 08:38:35 h UT (magnitude ≈ 8.5, depth = 10 km, and lat. = 2.3°N, long. = 93.0°E). A significant increase of few days before the EQ has been observed by using the VLF nighttime amplitude fluctuation method (fixed frequency transmitter signal). The analysis of total electron contents (TEC) derived from the global positioning system (GPS) at three different stations namely, Hyderabad (latitude 17.38°N, longitude 78.48°E), Singapore (latitude 1.37°N, longitude 103.84°E) and Port Blair (latitude 11.62°N, longitude 92.72°E) due to this EQ has also been presented. Significant perturbation in TEC data (enhancements and depletion) is noted before and after the main shock of the EQ. The possible mechanisms behind these perturbations due to EQ have also been discussed.

  16. Earthquake prediction analysis based on empirical seismic rate: the M8 algorithm

    Science.gov (United States)

    Molchan, G.; Romashkova, L.

    2010-12-01

    The quality of space-time earthquake prediction is usually characterized by a 2-D error diagram (n, τ), where n is the fraction of failures-to-predict and τ is the local rate of alarm averaged in space. The most reasonable averaging measure for analysis of a prediction strategy is the normalized rate of target events λ(dg) in a subarea dg. In that case the quantity H = 1 - (n + τ) determines the prediction capability of the strategy. The uncertainty of λ(dg) causes difficulties in estimating H and the statistical significance, α, of prediction results. We investigate this problem theoretically and show how the uncertainty of the measure can be taken into account in two situations, viz., the estimation of α and the construction of a confidence zone for the (n, τ)-parameters of the random strategies. We use our approach to analyse the results from prediction of M >= 8.0 events by the M8 method for the period 1985-2009 (the M8.0+ test). The model of λ(dg) based on the events Mw >= 5.5, 1977-2004, and the magnitude range of target events 8.0 <= M < 8.5 are considered as basic to this M8 analysis. We find the point and upper estimates of α and show that they are still unstable because the number of target events in the experiment is small. However, our results argue in favour of non-triviality of the M8 prediction algorithm.

  17. Failure frequencies and probabilities applicable to BWR and PWR piping

    International Nuclear Information System (INIS)

    Bush, S.H.; Chockie, A.D.

    1996-03-01

    This report deals with failure probabilities and failure frequencies of nuclear plant piping and the failure frequencies of flanges and bellows. Piping failure probabilities are derived from Piping Reliability Analysis Including Seismic Events (PRAISE) computer code calculations based on fatigue and intergranular stress corrosion as failure mechanisms. Values for both failure probabilities and failure frequencies are cited from several sources to yield a better evaluation of the spread in mean and median values as well as the widths of the uncertainty bands. A general conclusion is that the numbers from WASH-1400 often used in PRAs are unduly conservative. Failure frequencies for both leaks and large breaks tend to be higher than would be calculated using the failure probabilities, primarily because the frequencies are based on a relatively small number of operating years. Also, failure probabilities are substantially lower because of the probability distributions used in PRAISE calculations. A general conclusion is that large LOCA probability values calculated using PRAISE will be quite small, on the order of less than 1E-8 per year (<1E-8/year). The values in this report should be recognized as having inherent limitations and should be considered as estimates and not absolute values. 24 refs 24 refs

  18. Failure analysis and modeling of a multicomputer system. M.S. Thesis

    Science.gov (United States)

    Subramani, Sujatha Srinivasan

    1990-01-01

    This thesis describes the results of an extensive measurement-based analysis of real error data collected from a 7-machine DEC VaxCluster multicomputer system. In addition to evaluating basic system error and failure characteristics, we develop reward models to analyze the impact of failures and errors on the system. The results show that, although 98 percent of errors in the shared resources recover, they result in 48 percent of all system failures. The analysis of rewards shows that the expected reward rate for the VaxCluster decreases to 0.5 in 100 days for a 3 out of 7 model, which is well over a 100 times that for a 7-out-of-7 model. A comparison of the reward rates for a range of k-out-of-n models indicates that the maximum increase in reward rate (0.25) occurs in going from the 6-out-of-7 model to the 5-out-of-7 model. The analysis also shows that software errors have the lowest reward (0.2 vs. 0.91 for network errors). The large loss in reward rate for software errors is due to the fact that a large proportion (94 percent) of software errors lead to failure. In comparison, the high reward rate for network errors is due to fast recovery from a majority of these errors (median recovery duration is 0 seconds).

  19. Failure characteristics analysis and fault diagnosis for liquid rocket engines

    CERN Document Server

    Zhang, Wei

    2016-01-01

    This book concentrates on the subject of health monitoring technology of Liquid Rocket Engine (LRE), including its failure analysis, fault diagnosis and fault prediction. Since no similar issue has been published, the failure pattern and mechanism analysis of the LRE from the system stage are of particular interest to the readers. Furthermore, application cases used to validate the efficacy of the fault diagnosis and prediction methods of the LRE are different from the others. The readers can learn the system stage modeling, analyzing and testing methods of the LRE system as well as corresponding fault diagnosis and prediction methods. This book will benefit researchers and students who are pursuing aerospace technology, fault detection, diagnostics and corresponding applications.

  20. A Retrospective Cohort Analysis Shows that Coadministration of Minocycline with Colistin in Critically Ill Patients Is Associated with Reduced Frequency of Acute Renal Failure.

    Science.gov (United States)

    Lodise, Thomas P; Fan, Weihong; Griffith, David C; Dudley, Michael N; Sulham, Katherine A

    2018-01-01

    Nonclinical studies have suggested that oxidative damage, caspase-mediated apoptosis, and inducible nitric oxide synthase levels may be involved in the pathogenesis of colistin (CST)-associated acute renal failure. MIN inhibits caspase 1, caspase 3, and inducible nitric oxide synthase, leading to the hypothesis that coadministration of CST with MIN (CST-MIN) may reduce the incidence of acute renal failure as well as produce additive or synergistic antimicrobial effects. A multicenter retrospective cohort study was conducted using the Premier Research database to examine the impact of CST-MIN on acute renal failure. Inclusion criteria were as follows: age of ≥18 years, intensive care unit admission at CST initiation, primary International Classification of Diseases 9 (ICD-9) diagnosis of pneumonia or sepsis, nondialysis at hospital admission, and discharge between January 2010 and December 2015. ICD-9 code 584.XX or ICD-10 code N17 was used to define acute renal failure. Baseline comparisons, 1:8 propensity score matching, and confirmatory logistic regression analyses were conducted. In total, 4,817 patients received CST and met inclusion criteria; 93 received CST-MIN. Unadjusted frequency of acute renal failure was significantly lower in patients receiving CST-MIN than CST (11.8% versus 23.7%, P = 0.007). Similar results were seen in propensity score matching (12.0% versus 22.3%, P = 0.031) and logistic regression analyses (odds ratio of 0.403, P = 0.006). Mortalities and 30-day readmission rates were similar between groups. The acute renal failure rate was not impacted by prevalence of baseline renal disease. CST-MIN in critically ill patients may reduce CST-associated acute renal failure. Further evaluation of this combination in prospective clinical studies is warranted. Copyright © 2017 Lodise et al.

  1. A Study on the Abnormalities of the Various Endocrine Functions Associated with Chronic Renal Failure

    International Nuclear Information System (INIS)

    Hong, Chan Pyo; Kim, Man Woo; Rho, Bang Soo; Jang, Kyung Sik; Lee, Min Hyung; Oh, Hyun Kwan

    1982-01-01

    In an attempt to evaluate the various serum hormonal changes in terminal renal failure, the fasting T 4 , T 3 , rT-3, gastrin, secretin prolactin, and aldosterone were measured by radioimmunoassay in 12 patients with chronic renal failure, who were admitted Chosun University Hospital from January to June, 1981. From the analysis the following results were obtained. 1. Mean values of serum hormonal concentration in 10 normal control were as follows: T 4 , 12.93±2.00 ug/ml; T 3 , 113.0±28.7 ng/ml; rT 3 , 0.11±0.10 ng/ml; gastrin, 100.0±47.1 pg/ml; secretin, 32.46±11.45 pg/ml; prolactin, 11.0±3.6 ng/ml; aldosterone 137.0±58.5 pg/ml. 2. Mean values of serum hormonal concentration in 12 chronic renal failure were as follows; T4, 7.34±2.43 ug/ml; T3, 71.0±19.1 ng/ml; reverse T3, 0.38±0.19 ng/ml; gastrin, 162.5±40.2 pg/ml; secretin, 107.50±20.48 pg/ml; prolactin, 34.0±17.2 ng/ml; aldosterone, 86.5±19.8 pg/ml. 3. In chronic renal failure group, serum T4, T3, and adosterone level were significantly lower than those of the control group, but serum rT-3, gastrin, secretin and prolactin were significantly higher than those of the control group. 4. In the view of the correlation between serum hormonal concentrations and serum creatine levels in patients with chronic renal failure, rT 3 , gastrin, secretin and prolactin showed increasing tendency (positive correlations), whereas T 4 , T 3 and aldosterone showed decreasing tendency (negative correlations) with increment of serum creatinine levels. And so, we observed the negative correlation between T 3 and rT 3 .

  2. Advanced approaches to failure mode and effect analysis (FMEA applications

    Directory of Open Access Journals (Sweden)

    D. Vykydal

    2015-10-01

    Full Text Available The present paper explores advanced approaches to the FMEA method (Failure Mode and Effect Analysis which take into account the costs associated with occurrence of failures during the manufacture of a product. Different approaches are demonstrated using an example FMEA application to production of drawn wire. Their purpose is to determine risk levels, while taking account of the above-mentioned costs. Finally, the resulting priority levels are compared for developing actions mitigating the risks.

  3. Failure analysis of storage tank component in LNG regasification unit using fault tree analysis method (FTA)

    Science.gov (United States)

    Mulyana, Cukup; Muhammad, Fajar; Saad, Aswad H.; Mariah, Riveli, Nowo

    2017-03-01

    Storage tank component is the most critical component in LNG regasification terminal. It has the risk of failure and accident which impacts to human health and environment. Risk assessment is conducted to detect and reduce the risk of failure in storage tank. The aim of this research is determining and calculating the probability of failure in regasification unit of LNG. In this case, the failure is caused by Boiling Liquid Expanding Vapor Explosion (BLEVE) and jet fire in LNG storage tank component. The failure probability can be determined by using Fault Tree Analysis (FTA). Besides that, the impact of heat radiation which is generated is calculated. Fault tree for BLEVE and jet fire on storage tank component has been determined and obtained with the value of failure probability for BLEVE of 5.63 × 10-19 and for jet fire of 9.57 × 10-3. The value of failure probability for jet fire is high enough and need to be reduced by customizing PID scheme of regasification LNG unit in pipeline number 1312 and unit 1. The value of failure probability after customization has been obtained of 4.22 × 10-6.

  4. Etiology, clinical features and outcome of fulminant hepatic failure in pregnancy.

    Science.gov (United States)

    Brohi, Zahida Parveen; Sadaf, Aneela; Perveen, Uzma

    2013-09-01

    To determine the etiology, clinical features and outcome of fulminant hepatic failure in pregnancy. An observational hospital based study was conducted at Isra University hospital Hyderabad from 1st March 2009 to 28th February 2010. Total 1192 obstetric patients were admitted in obstetrics & gynaecology department during this period, of whom 52 were with Fulminant hepatic failure in pregnancy and were included in this study. A pre-designed structured proforma was used. All patients had clinical history and underwent a physical examination. Routine laboratory tests, liver function tests and viral serology were performed in all cases. All results were analyzed on statistical software SPSS version 11. Frequencies and percentages were calculated, the final outcome was recorded. Out of 52, 6 (11.5%) presented in the first trimester, 4 (7.6%) in the second trimester and 42 (80.7%) were in their 3rd trimester of pregnancy. Etiology of the disease was Hepatitis E in 28 (53.8%), Hepatitis B in 9 (17.3%), Hepatitis C in 7 (13.5%) HELLP syndrome in 7 (13.5%) and acute fatty liver of pregnancy in 1 (3.57%) case. Maternal mortality was 15 (28.8%) and foetal mortality was 40 (77%). Only 12 (23.1%) new born remained alive. Fulminant hepatic failure in pregnancy has very high foetal and maternal mortality which is mostly due to viral hepatitis E.

  5. Study of the excited levels of 11C and 12C by the analysis of protons induced reactions

    International Nuclear Information System (INIS)

    Rihet, Y.

    1984-07-01

    The present work is a study of 11 and 12 C excited states by reactions of non polarised protons on 10 B and 11 B. R-matrix analysis of the 10 B excitation curves in the range E p = 0 to 8 MeV was used to establish parameters of 41 levels in 11 C. Isobaric multiplets of T = 1/2 and T = 3/2 states in A = 11 nuclei are deduced. Analysis of 11 B excitation curves in the E p = 0.5 to 7.4 MeV range led to parameter values of 60 levels in 12 C. T = 1 states in A = 12 isobaric nuclei are discussed [fr

  6. 1988 failure rate screening data for fusion reliability and risk analysis

    International Nuclear Information System (INIS)

    Cadwallader, L.C.; Piet, S.J.

    1988-01-01

    This document contains failure rate screening data for application to fusion components. The screening values are generally fission or aerospace industry failure rate estimates that can be extrapolated for use by fusion system designers, reliability engineers and risk analysts. Failure rate estimates for tritium-bearing systems, liquid metal-cooled systems, gas-cooled systems, water-cooled systems and containment systems are given. Preliminary system availability estimates and selected initiating event frequency estimates are presented. This first edition document is valuable to design and safety analysis for the Compact Ignition Tokamak and the International Thermonuclear Experimental Reactor. 20 refs., 28 tabs

  7. Analysis approach for common cause failure on non-safety digital control system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Goo; Oh, Eungse [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

    2014-05-15

    The effects of common cause failure (CCF) on safety digital instrumentation and control (I and C) system had been considered in defense in depth and diversity coping analysis with safety analysis method. For the non-safety system, single failure had been considered for safety analysis. IEEE Std. 603-1991, Clause 5.6.3.1(2), 'Isolation' states that no credible failure on the non-safety side of an isolation device shall prevent any portion of a safety system from meeting its minimum performance requirements during and following any design basis event requiring that safety function. The software CCF is one of the credible failure on the non-safety side. In advanced digital I and C system, same hardware component is used for different control system and the defect in manufacture or common external event can generate CCF. Moreover, the non-safety I and C system uses complex software for its various function and software quality assurance for the development process is less severe than safety software for the cost effective design. Therefore the potential defects in software cannot be ignored and the effect of software CCF on non-safety I and C system is needed to be evaluated. This paper proposes the general process and considerations for the analysis of CCF on non-safety I and C system.

  8. Early dynamic imaging in "6"8Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions

    International Nuclear Information System (INIS)

    Uprimny, Christian; Kroiss, Alexander Stephan; Decristoforo, Clemens; Warwitz, Boris; Scarpa, Lorenza; Roig, Llanos Geraldo; Kendler, Dorota; Guggenberg, Elisabeth von; Virgolini, Irene Johanna; Fritz, Josef; Bektic, Jasmin; Horninger, Wolfgang

    2017-01-01

    PET/CT with "6"8Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic "6"8Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. Eighty consecutive PC patients referred to "6"8Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUV_m_a_x of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic "6"8Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suv_m_a_x was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. Early dynamic imaging in "6"8Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation

  9. Phenomenological uncertainty analysis of early containment failure at severe accident of nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Su Won

    2011-02-15

    The severe accident has inherently significant uncertainty due to wide range of conditions and performing experiments, validation and practical application are extremely difficult because of its high temperature and pressure. Although internal and external researches were put into practice, the reference used in Korean nuclear plants were foreign data of 1980s and safety analysis as the probabilistic safety assessment has not applied the newest methodology. Also, it is applied to containment pressure formed into point value as results of thermal hydraulic analysis to identify the probability of containment failure in level 2 PSA. In this paper, the uncertainty analysis methods for phenomena of severe accident influencing early containment failure were developed, the uncertainty analysis that apply Korean nuclear plants using the MELCOR code was performed and it is a point of view to present the distribution of containment pressure as a result of uncertainty analysis. Because early containment failure is important factor of Large Early Release Frequency(LERF) that is used as representative criteria of decision-making in nuclear power plants, it was selected in this paper among various modes of containment failure. Important phenomena of early containment failure at severe accident based on previous researches were comprehended and methodology of 7th steps to evaluate uncertainty was developed. The MELCOR input for analysis of the severe accident reflected natural circulation flow was developed and the accident scenario for station black out that was representative initial event of early containment failure was determined. By reviewing the internal model and correlation for MELCOR model relevant important phenomena of early containment failure, the uncertainty factors which could affect on the uncertainty were founded and the major factors were finally identified through the sensitivity analysis. In order to determine total number of MELCOR calculations which can

  10. Sensitivity analysis of fuel pin failure performance under slow-ramp type transient overpower condition by using a fuel performance analysis code FEMAXI-FBR

    International Nuclear Information System (INIS)

    Tsuboi, Yasushi; Ninokata, Hisashi; Endo, Hiroshi; Ishizu, Tomoko; Tatewaki, Isao; Saito, Hiroaki

    2012-01-01

    The FEMAXI-FBR is a fuel performance analysis code and has been developed as one module of core disruptive evaluation system, the ASTERIA-FBR. The FEMAXI-FBR has reproduced the failure pin behavior during slow transient overpower. The axial location of pin failure affects the power and reactivity behavior during core disruptive accident, and failure model of which pin failure occurs at upper part of pin is used by reflecting the results of the CABRI-2 test. By using the FEMAXI-FBR, sensitivity analysis of uncertainty of design parameters such as irradiation conditions and fuel fabrication tolerances was performed to clarify the effect on axial location of pin failure during slow transient overpower. The sensitivity analysis showed that the uncertainty of design parameters does not affect the failure location. It suggests that the failure model with which locations of failure occur at upper part of pin can be adopted for core disruptive calculation by taking into consideration of design uncertainties. (author)

  11. Competing failure analysis in phased-mission systems with functional dependence in one of phases

    International Nuclear Information System (INIS)

    Wang, Chaonan; Xing, Liudong; Levitin, Gregory

    2012-01-01

    This paper proposes an algorithm for the reliability analysis of non-repairable phased-mission systems (PMS) subject to competing failure propagation and isolation effects. A failure originating from a system component which causes extensive damage to other system components is a propagated failure. When the propagated failure affects all the system components, causing the entire system failure, a propagated failure with global effect (PFGE) is said to occur. However, the failure propagation can be isolated in systems subject to functional dependence (FDEP) behavior, where the failure of a component (referred to as trigger component) causes some other components (referred to as dependent components) to become inaccessible or unusable (isolated from the system), and thus further failures from these dependent components have no effect on the system failure behavior. On the other hand, if any PFGE from dependent components occurs before the trigger failure, the failure propagation effect takes place, causing the overall system failure. In summary, there are two distinct consequences of a PFGE due to the competition between the failure isolation and failure propagation effects in the time domain. Existing works on such competing failures focus only on single-phase systems. However, many real-world systems are phased-mission systems (PMS), which involve multiple, consecutive and non-overlapping phases of operations or tasks. Consideration of competing failures for PMS is a challenging and difficult task because PMS exhibit dynamics in the system configuration and component behavior as well as statistical dependencies across phases for a given component. This paper proposes a combinatorial method to address the competing failure effects in the reliability analysis of binary non-repairable PMS. The proposed method is verified using a Markov-based method through a numerical example. Different from the Markov-based approach that is limited to exponential distribution, the

  12. Preliminary failure modes and effects analysis on Korean HCCR TBS to be tested in ITER

    International Nuclear Information System (INIS)

    Ahn, Mu-Young; Cho, Seungyon; Jin, Hyung Gon; Lee, Dong Won; Park, Yi-Hyun; Lee, Youngmin

    2015-01-01

    Highlights: • Postulated initiating events are identified through failure modes and effects analysis on the current HCCR TBS design. • A set of postulated initiating events are selected for consideration of deterministic analysis. • Accident evolutions on the selected postualted initiating events are qualitatively described for deterministic analysis. - Abstract: Korean Helium cooled ceramic reflector (HCCR) Test blanket system (TBS), which comprises Test blanket module (TBM) and ancillary systems in various locations of ITER building, is operated at high temperature and pressure with decay heat. Therefore, safety is utmost concern in design process and it is required to demonstrate that the HCCR TBS is designed to comply with the safety requirements and guidelines of ITER. Due to complexity of the system with many interfaces with ITER, a systematic approach is necessary for safety analysis. This paper presents preliminary failure modes and effects analysis (FMEA) study performed for the HCCR TBS. FMEA is a systematic methodology in which failure modes for components in the system and their consequences are studied from the bottom-up. Over eighty failure modes have been investigated on the HCCR TBS. The failure modes that have similar consequences are grouped as postulated initiating events (PIEs) and total seven reference accident scenarios are derived from FMEA study for deterministic accident analysis. Failure modes not covered here due to evolving design of the HCCR TBS and uncertainty in maintenance procedures will be studied further in near future.

  13. Preliminary failure modes and effects analysis on Korean HCCR TBS to be tested in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Mu-Young, E-mail: myahn74@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); Cho, Seungyon [National Fusion Research Institute, Daejeon (Korea, Republic of); Jin, Hyung Gon; Lee, Dong Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi-Hyun; Lee, Youngmin [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Highlights: • Postulated initiating events are identified through failure modes and effects analysis on the current HCCR TBS design. • A set of postulated initiating events are selected for consideration of deterministic analysis. • Accident evolutions on the selected postualted initiating events are qualitatively described for deterministic analysis. - Abstract: Korean Helium cooled ceramic reflector (HCCR) Test blanket system (TBS), which comprises Test blanket module (TBM) and ancillary systems in various locations of ITER building, is operated at high temperature and pressure with decay heat. Therefore, safety is utmost concern in design process and it is required to demonstrate that the HCCR TBS is designed to comply with the safety requirements and guidelines of ITER. Due to complexity of the system with many interfaces with ITER, a systematic approach is necessary for safety analysis. This paper presents preliminary failure modes and effects analysis (FMEA) study performed for the HCCR TBS. FMEA is a systematic methodology in which failure modes for components in the system and their consequences are studied from the bottom-up. Over eighty failure modes have been investigated on the HCCR TBS. The failure modes that have similar consequences are grouped as postulated initiating events (PIEs) and total seven reference accident scenarios are derived from FMEA study for deterministic accident analysis. Failure modes not covered here due to evolving design of the HCCR TBS and uncertainty in maintenance procedures will be studied further in near future.

  14. High sensitivity boron quantification in bulk silicon using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moro, Marcos V.; Silva, Tiago F. da; Added, Nemitala; Rizutto, Marcia A.; Tabacniks, Manfredo H. [Instituto de Fisica da Universidade de Sao Paulo, C.P. 66318, 05315-970 Sao Paulo, SP (Brazil); Neira, John B.; Neto, Joao B. F. [Institute of Research Tecnology, Cidade Universitaria, SP, 05508-091 (Brazil)

    2013-05-06

    There is a great need to quantify sub-ppm levels of boron in bulk silicon. There are several methods to analyze B in Si: Nuclear Reaction Analysis using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be reaction exhibits a quantification limit of some hundreds ppm of B in Si. Heavy Ion Elastic Recoil Detection Analysis offers a detection limit of 5 to 10 at. ppm. Secondary Ion Mass Spectrometry is the method of choice of the semiconductor industry for the analysis of B in Si. This work verifies the use of NRA to quantify B in Si, and the corresponding detection limits. Proton beam with 1.6 up to 2.6 MeV was used to obtain the cross-section of the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction at 170 Degree-Sign scattering angle. The results show good agreementwith literature indicating that the quantification of boron in silicon can be achieved at 100 ppm level (high sensitivity) at LAMFI-IFUSP with about 16% uncertainty. Increasing the detection solid angle and the collected beam charge, can reduce the detection limit to less than 100 ppm meeting present technological needs.

  15. An analysis of human maintenance failures of a nuclear power plant

    International Nuclear Information System (INIS)

    Pyy, P.

    2000-01-01

    In the report, a study of faults caused by maintenance activities is presented. The objective of the study was to draw conclusions on the unplanned effects of maintenance on nuclear power plant safety and system availability. More than 4400 maintenance history reports from the years 1992-1994 of Olkiluoto BWR nuclear power plant (NPP) were analysed together with the maintenance personnel. The human action induced faults were classified, e.g., according to their multiplicity and effects. This paper presents and discusses the results of a statistical analysis of the data. Instrumentation and electrical components appeared to be especially prone to human failures. Many human failures were found in safety related systems. Several failures also remained latent from outages to power operation. However, the safety significance of failures was generally small. Modifications were an important source of multiple human failures. Plant maintenance data is a good source of human reliability data and it should be used more in the future. (orig.)

  16. Local buckling failure analysis of high-strength pipelines

    Institute of Scientific and Technical Information of China (English)

    Yan Li; Jian Shuai; Zhong-Li Jin; Ya-Tong Zhao; Kui Xu

    2017-01-01

    Pipelines in geological disaster regions typically suffer the risk of local buckling failure because of slender structure and complex load.This paper is meant to reveal the local buckling behavior of buried pipelines with a large diameter and high strength,which are under different conditions,including pure bending and bending combined with internal pressure.Finite element analysis was built according to previous data to study local buckling behavior of pressurized and unpressurized pipes under bending conditions and their differences in local buckling failure modes.In parametric analysis,a series of parameters,including pipe geometrical dimension,pipe material properties and internal pressure,were selected to study their influences on the critical bending moment,critical compressive stress and critical compressive strain of pipes.Especially the hardening exponent of pipe material was introduced to the parameter analysis by using the Ramberg-Osgood constitutive model.Results showed that geometrical dimensions,material and internal pressure can exert similar effects on the critical bending moment and critical compressive stress,which have different,even reverse effects on the critical compressive strain.Based on these analyses,more accurate design models of critical bending moment and critical compressive stress have been proposed for high-strength pipelines under bending conditions,which provide theoretical methods for highstrength pipeline engineering.

  17. Analysis of cause-specific failure endpoints using simple proportions: an example from a randomized controlled clinical trial in early breast cancer

    International Nuclear Information System (INIS)

    Panzarella, Tony; Meakin, J. William

    1998-01-01

    Purpose: To describe a statistically valid method for analyzing cause-specific failure data based on simple proportions, that is easy to understand and apply, and outline under what conditions its implementation is well-suited. Methods and Materials: In the comparison of treatment groups, time to first failure (in any site) was analyzed first, followed by an analysis of the pattern of first failure, preferably at the latest complete follow-up time common to each group. Results: A retrospective analysis of time to contralateral breast cancer in 777 early breast cancer patients was undertaken. Patients previously treated by mastectomy plus radiation therapy to the chest wall and regional nodal areas were randomized to receive further radiation and prednisone (R+P), radiation alone (R), or no further treatment (NT). Those randomized to R+P had a statistically significantly delayed time to first failure compared to the group randomized to NT (p = 0.0008). Patients randomized to R also experienced a delayed time to first failure compared to NT, but the difference was not statistically significant (p 0.14). At 14 years from the date of surgery (the latest common complete follow-up time) the distribution of first failures was statistically significantly different between R+P and NT (p = 0.005), but not between R and NT (p = 0.09). The contralateral breast cancer first failure rate at 14 years from surgery was 7.2% for NT, 4.6% for R, and 3.7% for R+P. The corresponding Kaplan-Meier estimates were 13.2%, 8.2%, and 5.4%, respectively. Conclusion: Analyzing cause-specific failure data using methods developed for survival endpoints is problematic. We encourage the use of the two-step analysis strategy described when, as in the example presented, competing causes of failure are not likely to be statistically independent, and when a treatment comparison at a single time-point is clinically relevant and feasible; that is, all patients have complete follow-up to this point

  18. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  19. A meta-analysis of the effects of β-adrenergic blockers in chronic heart failure.

    Science.gov (United States)

    Zhang, Xiaojian; Shen, Chengwu; Zhai, Shujun; Liu, Yukun; Yue, Wen-Wei; Han, Li

    2016-10-01

    Adrenergic β-blockers are drugs that bind to, but do not activate β-adrenergic receptors. Instead they block the actions of β-adrenergic agonists and are used for the treatment of various diseases such as cardiac arrhythmias, angina pectoris, myocardial infarction, hypertension, headache, migraines, stress, anxiety, prostate cancer, and heart failure. Several meta-analysis studies have shown that β-blockers improve the heart function and reduce the risks of cardiovascular events, rate of mortality, and sudden death through chronic heart failure (CHF) of patients. The present study identified results from recent meta-analyses of β-adrenergic blockers and their usefulness in CHF. Databases including Medline/Embase/Cochrane Central Register of Controlled Trials (CENTRAL), and PubMed were searched for the periods May, 1985 to March, 2011 and June, 2013 to August, 2015, and a number of studies identified. Results of those studies showed that use of β-blockers was associated with decreased sudden cardiac death in patients with heart failure. However, contradictory results have also been reported. The present meta-analysis aimed to determine the efficacy of β-blockers on mortality and morbidity in patients with heart failure. The results showed that mortality was significantly reduced by β-blocker treatment prior to the surgery of heart failure patients. The results from the meta-analysis studies showed that β-blocker treatment in heart failure patients correlated with a significant decrease in long-term mortality, even in patients that meet one or more exclusion criteria of the MERIT-HF study. In summary, the findings of the current meta-analysis revealed beneficial effects different β-blockers have on patients with heart failure or related heart disease.

  20. Azithromycin Treatment Failure for Chlamydia trachomatis Among Heterosexual Men With Nongonococcal Urethritis.

    Science.gov (United States)

    Kissinger, Patricia J; White, Scott; Manhart, Lisa E; Schwebke, Jane; Taylor, Stephanie N; Mena, Leandro; Khosropour, Christine M; Wilcox, Larissa; Schmidt, Norine; Martin, David H

    2016-10-01

    Three recent prospective studies have suggested that the 1-g dose of azithromycin for Chlamydia trachomatis (Ct) was less effective than expected, reporting a wide range of treatment failure rates (5.8%-22.6%). Reasons for the disparate results could be attributed to geographic or methodological differences. The purpose of this study was to reexamine the studies and attempt to harmonize methodologies to reduce misclassification as a result of false positives from early test-of-cure (TOC) or reinfection as a result of sexual exposure rather than treatment failure. Men who had sex with women, who received 1-g azithromycin under directly observed therapy for presumptive treatment of nongonococcal urethritis with confirmed Ct were included. Baseline screening was performed on urethral swabs or urine, and TOC screening was performed on urine using nucleic acid amplification tests. Posttreatment vaginal sexual exposure was elicited at TOC. Data from the 3 studies were obtained and reanalyzed. Rates of Ct retest positive were examined for all cases, and a sensitivity analysis was conducted to either reclassify potential false positives/reinfections as negative or remove them from the analysis. The crude treatment failure rate was 12.8% (31/242). The rate when potential false positives/reinfections were reclassified as negative was 6.2% (15/242) or when these were excluded from analysis was 10.9% (15/138). In these samples of men who have sex with women with Ct-related nongonococcal urethritis, azithromycin treatment failure was between 6.2% and 12.8%. This range of failure is lower than previously published but higher than the desired World Health Organization's target chlamydia treatment failure rate of < 5%.

  1. Corrosion failure analysis as related to prevention of corrosion failures

    International Nuclear Information System (INIS)

    Suss, H.

    1977-10-01

    The factors and conditions which have contributed to many of the corrosion related service failures are discussed based on a review of actual case histories. The anti-corrosion devices which developed as a result of these failure analyses are reviewed, and the method which must be adopted and used to take advantage of the available corrosion prevention techniques is discussed

  2. Acute Kidney Injury and Risk of Incident Heart Failure Among US Veterans.

    Science.gov (United States)

    Bansal, Nisha; Matheny, Michael E; Greevy, Robert A; Eden, Svetlana K; Perkins, Amy M; Parr, Sharidan K; Fly, James; Abdel-Kader, Khaled; Himmelfarb, Jonathan; Hung, Adriana M; Speroff, Theodore; Ikizler, T Alp; Siew, Edward D

    2018-02-01

    Acute kidney injury (AKI) is common and associated with poor outcomes. Heart failure is a leading cause of cardiovascular disease among patients with chronic kidney disease. The relationship between AKI and heart failure remains unknown and may identify a novel mechanistic link between kidney and cardiovascular disease. Observational study. We studied a national cohort of 300,868 hospitalized US veterans (2004-2011) without a history of heart failure. AKI was the predictor and was defined as a 0.3-mg/dL or 50% increase in serum creatinine concentration from baseline to the peak hospital value. Patients with and without AKI were matched (1:1) on 28 in- and outpatient covariates using optimal Mahalanobis distance matching. Incident heart failure was defined as 1 or more hospitalization or 2 or more outpatient visits with a diagnosis of heart failure within 2 years through 2013. There were 150,434 matched pairs in the study. Patients with and without AKI during the index hospitalization were well matched, with a median preadmission estimated glomerular filtration rate of 69mL/min/1.73m 2 . The overall incidence rate of heart failure was 27.8 (95% CI, 19.3-39.9) per 1,000 person-years. The incidence rate was higher in those with compared with those without AKI: 30.8 (95% CI, 21.8-43.5) and 24.9 (95% CI, 16.9-36.5) per 1,000 person-years, respectively. In multivariable models, AKI was associated with 23% increased risk for incident heart failure (HR, 1.23; 95% CI, 1.19-1.27). Study population was primarily men, reflecting patients seen at Veterans Affairs hospitals. AKI is an independent risk factor for incident heart failure. Future studies to identify underlying mechanisms and modifiable risk factors are needed. Copyright © 2017 National Kidney Foundation, Inc. All rights reserved.

  3. Dam failure analysis for the Lago El Guineo Dam, Orocovis, Puerto Rico

    Science.gov (United States)

    Gómez-Fragoso, Julieta; Heriberto Torres-Sierra,

    2016-08-09

    The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, completed hydrologic and hydraulic analyses to assess the potential hazard to human life and property associated with the hypothetical failure of the Lago El Guineo Dam. The Lago El Guineo Dam is within the headwaters of the Río Grande de Manatí and impounds a drainage area of about 4.25 square kilometers.The hydrologic assessment was designed to determine the outflow hydrographs and peak discharges for Lago El Guineo and other subbasins in the Río Grande de Manatí hydrographic basin for three extreme rainfall events: (1) a 6-hour probable maximum precipitation event, (2) a 24-hour probable maximum precipitation event, and (3) a 24-hour, 100-year recurrence rainfall event. The hydraulic study simulated a dam failure of Lago El Guineo Dam using flood hydrographs generated from the hydrologic study. The simulated dam failure generated a hydrograph that was routed downstream from Lago El Guineo Dam through the lower reaches of the Río Toro Negro and the Río Grande de Manatí to determine water-surface profiles developed from the event-based hydrologic scenarios and “sunny day” conditions. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC–HMS) and Hydrologic Engineering Center’s River Analysis System (HEC–RAS) computer programs, developed by the U.S. Army Corps of Engineers, were used for the hydrologic and hydraulic modeling, respectively. The flow routing in the hydraulic analyses was completed using the unsteady flow module available in the HEC–RAS model.Above the Lago El Guineo Dam, the simulated inflow peak discharges from HEC–HMS resulted in about 550 and 414 cubic meters per second for the 6- and 24-hour probable maximum precipitation events, respectively. The 24-hour, 100-year recurrence storm simulation resulted in a peak discharge of about 216 cubic meters per second. For the hydrologic analysis, no dam failure conditions are

  4. Development of severe accident analysis code - Development of a finite element code for lower head failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huh, Hoon; Lee, Choong Ho; Choi, Tae Hoon; Kim, Hyun Sup; Kim, Se Ho; Kang, Woo Jong; Seo, Chong Kwan [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-08-01

    The study concerns the development of analysis models and computer codes for lower head failure analysis when a severe accident occurs in a nuclear reactor system. Although the lower head failure modes consists of several failure modes, the study this year was focused on the global rupture with the collapse pressure and mode by limit analysis and elastic deformation. The behavior of molten core causes elevation of temperature in the reactor vessel wall and deterioration of load-carrying capacity of a reactor vessel. The behavior of molten core and the heat transfer modes were, therefore, postulated in several types and the temperature distributions according to the assumed heat flux modes were calculated. The collapse pressure of a nuclear reactor lower head decreases rapidly with elevation of temperature as time passes. The calculation shows the safety of a nuclear reactor is enhanced with the lager collapse pressure when the hot spot is located far from the pole. 42 refs., 2 tabs., 31 figs. (author)

  5. Cluster-to-cluster transformation among Au6, Au8 and Au11 nanoclusters.

    Science.gov (United States)

    Ren, Xiuqing; Fu, Junhong; Lin, Xinzhang; Fu, Xuemei; Yan, Jinghui; Wu, Ren'an; Liu, Chao; Huang, Jiahui

    2018-05-22

    We present the cluster-to-cluster transformations among three gold nanoclusters, [Au6(dppp)4]2+ (Au6), [Au8(dppp)4Cl2]2+ (Au8) and [Au11(dppp)5]3+ (Au11). The conversion process follows a rule that states that the transformation of a small cluster to a large cluster is achieved through an oxidation process with an oxidizing agent (H2O2) or with heating, while the conversion of a large cluster to a small one occurs through a reduction process with a reducing agent (NaBH4). All the reactions were monitored using UV-Vis spectroscopy and ESI-MS. This work may provide an alternative approach to the synthesis of novel gold nanoclusters and a further understanding of the structural transformation relationship of gold nanoclusters.

  6. Clinical indicators for success of misoprostol treatment after early pregnancy failure.

    Science.gov (United States)

    Robledo, C; Zhang, J; Troendle, J; Barnhart, K; Creinin, M D; Westhoff, C; Huang, X; Frederick, M

    2007-10-01

    To identify clinical indicators for success of misoprostol treatment after early pregnancy failure. A total of 473 women with early pregnancy failure received 800 microg of vaginal misoprostol on treatment day 1. At the follow-up visit on day 3, a second dose was given if expulsion was incomplete. On day 8, vacuum aspiration was offered if expulsion had not occurred. Ultrasonography was used as gold standard for success. A Classification and Regression Tree analysis was undertaken to derive two decision trees for the success of misoprostol treatment on study days 3 and 8. Heavy bleeding after the first dose and an open cervical os were identified as clinical indicators of treatment success on day 3. Treatment success occurred in 84% of women with either or both indicators. Reporting passage of tissue after a second misoprostol dose and old blood in the vagina were potential indicators of treatment success or failure on day 8. A woman with either of these indicators has a 65% chance of treatment success after the second dose. Conversely, a woman with neither indicator on day 8 has a 94% chance of treatment failure. Standard clinical findings may be useful as indicators for success or failure of medical management of early pregnancy failure in settings with limited or no access to ultrasonography. More research to identify even better indicators is warranted.

  7. Analysis of Failure Causes and the Criticality Degree of Elements of Motor Vehicle’s Drum Brakes

    Directory of Open Access Journals (Sweden)

    D. Ćatić

    2014-09-01

    Full Text Available The introduction of the paper gives the basic concepts, historical development of methods of Fault Tree Analysis - FTA and Failure Modes, Effects and Criticality Analysis - FMECA for analysis of the reliability and safety of technical systems and importance of applying this method is highlighted. Failure analysis is particularly important for systems whose failures lead to the endangerment of people safety, such as, for example, the braking system of motor vehicles. For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. By formation of the fault tree of drum brakes in braking systems of commercial vehicles, it was established a causal relation between the different events that lead to a reduction in performance or complete failure of the braking system. Based on data from exploitation, using FMECA methods, determination of the criticality degree of drum brake’s elements on the reliable and safe operation of the braking system is performed.

  8. Statistical trend analysis methodology for rare failures in changing technical systems

    International Nuclear Information System (INIS)

    Ott, K.O.; Hoffmann, H.J.

    1983-07-01

    A methodology for a statistical trend analysis (STA) in failure rates is presented. It applies primarily to relatively rare events in changing technologies or components. The formulation is more general and the assumptions are less restrictive than in a previously published version. Relations of the statistical analysis and probabilistic assessment (PRA) are discussed in terms of categorization of decisions for action following particular failure events. The significance of tentatively identified trends is explored. In addition to statistical tests for trend significance, a combination of STA and PRA results quantifying the trend complement is proposed. The STA approach is compared with other concepts for trend characterization. (orig.)

  9. Earthquake Prediction Analysis Based on Empirical Seismic Rate: The M8 Algorithm

    International Nuclear Information System (INIS)

    Molchan, G.; Romashkova, L.

    2010-07-01

    The quality of space-time earthquake prediction is usually characterized by a two-dimensional error diagram (n,τ), where n is the rate of failures-to-predict and τ is the normalized measure of space-time alarm. The most reasonable space measure for analysis of a prediction strategy is the rate of target events λ(dg) in a sub-area dg. In that case the quantity H = 1-(n +τ) determines the prediction capability of the strategy. The uncertainty of λ(dg) causes difficulties in estimating H and the statistical significance, α, of prediction results. We investigate this problem theoretically and show how the uncertainty of the measure can be taken into account in two situations, viz., the estimation of α and the construction of a confidence zone for the (n,τ)-parameters of the random strategies. We use our approach to analyse the results from prediction of M ≥ 8.0 events by the M8 method for the period 1985-2009 (the M8.0+ test). The model of λ(dg) based on the events Mw ≥ 5.5, 1977-2004, and the magnitude range of target events 8.0 ≤ M < 8.5 are considered as basic to this M8 analysis. We find the point and upper estimates of α and show that they are still unstable because the number of target events in the experiment is small. However, our results argue in favour of non-triviality of the M8 prediction algorithm. (author)

  10. Prediction of hospital failure: a post-PPS analysis.

    Science.gov (United States)

    Gardiner, L R; Oswald, S L; Jahera, J S

    1996-01-01

    This study investigates the ability of discriminant analysis to provide accurate predictions of hospital failure. Using data from the period following the introduction of the Prospective Payment System, we developed discriminant functions for each of two hospital ownership categories: not-for-profit and proprietary. The resulting discriminant models contain six and seven variables, respectively. For each ownership category, the variables represent four major aspects of financial health (liquidity, leverage, profitability, and efficiency) plus county marketshare and length of stay. The proportion of closed hospitals misclassified as open one year before closure does not exceed 0.05 for either ownership type. Our results show that discriminant functions based on a small set of financial and nonfinancial variables provide the capability to predict hospital failure reliably for both not-for-profit and proprietary hospitals.

  11. Success and failure rates of tumor genotyping techniques in routine pathological samples with non-small-cell lung cancer.

    Science.gov (United States)

    Vanderlaan, Paul A; Yamaguchi, Norihiro; Folch, Erik; Boucher, David H; Kent, Michael S; Gangadharan, Sidharta P; Majid, Adnan; Goldstein, Michael A; Huberman, Mark S; Kocher, Olivier N; Costa, Daniel B

    2014-04-01

    Identification of some somatic molecular alterations in non-small-cell lung cancer (NSCLC) has become evidence-based practice. The success and failure rate of using commercially available tumor genotyping techniques in routine day-to-day NSCLC pathology samples is not well described. We sought to evaluate the success and failure rate of EGFR mutation, KRAS mutation, and ALK FISH in a cohort of lung cancers subjected to routine clinical tumor genotype. Clinicopathologic data, tumor genotype success and failure rates were retrospectively compiled and analyzed from 381 patient-tumor samples. From these 381 patients with lung cancer, the mean age was 65 years, 61.2% were women, 75.9% were white, 27.8% were never smokers, 73.8% had advanced NSCLC and 86.1% had adenocarcinoma histology. The tumor tissue was obtained from surgical specimens in 48.8%, core needle biopsies in 17.9%, and as cell blocks from aspirates or fluid in 33.3% of cases. Anatomic sites for tissue collection included lung (49.3%), lymph nodes (22.3%), pleura (11.8%), bone (6.0%), brain (6.0%), among others. The overall success rate for EGFR mutation analysis was 94.2%, for KRAS mutation 91.6% and for ALK FISH 91.6%. The highest failure rates were observed when the tissue was obtained from image-guided percutaneous transthoracic core-needle biopsies (31.8%, 27.3%, and 35.3% for EGFR, KRAS, and ALK tests, respectively) and bone specimens (23.1%, 15.4%, and 23.1%, respectively). In specimens obtained from bone, the failure rates were significantly higher for biopsies than resection specimens (40% vs. 0%, p=0.024 for EGFR) and for decalcified compared to non-decalcified samples (60% vs. 5.5%, p=0.021 for EGFR). Tumor genotype techniques are feasible in most samples, outside small image-guided percutaneous transthoracic core-needle biopsies and bone samples from core biopsies with decalcification, and therefore expansion of routine tumor genotype into the care of patients with NSCLC may not require special

  12. Analysis of failure and maintenance experiences of motor operated valves in a Finnish nuclear power plant

    International Nuclear Information System (INIS)

    Simola, K.; Laakso, K.

    1992-01-01

    Operating experiences from 1981 up to 1989 of totally 104 motor operated closing valves (MOV) in different safety systems at TVO I and II nuclear power units were analysed in a systematic way. The qualitative methods used were failure mode and effects analysis (FMEA) and maintenance effects and criticality analysis (MECA). The failure descriptions were obtained from power plant's computerized failure reporting system. The reported 181 failure events were reanalysed and sorted according to specific classifications developed for the MOV function. Filled FMEA and MECA sheets on individual valves were stored in a microcomputer data base for further analyses. Analyses were performed for the failed mechanical and electrical valve parts, ways of detection of failure modes, failure effects, and repair and unavailability times

  13. Modeling of fast reactor cladding failure for hypothetical accident transient analysis

    International Nuclear Information System (INIS)

    Kramer, J.M.; DiMelfi, R.J.; Hughes, T.H.; Deitrich, L.W.

    1979-01-01

    An analysis is made of burst experiments performed on neutron irradiated cladding tubes. This is done by employing a generalized Voce equation to describe the mechanical deformation of type 316 stainless steel, combined with an empirical creep crack growth law, each modified to account for the effects of irradiation matrix hardening, and irradiation induced grain boundary embrittlement, respectively. The results of this analysis indicate that for large initial hoop stress, failure occurs at relatively low temperature and is controlled by the onset of plastic instability. The increase in failure temperature of irradiated material, in this low temperature region, is due to irradiation strengthening. Failure in the case of relatively small initial hoop stress occurs at high temperature where the Voce equation reduces to a power law creep formula. The ductility of irradiated material, in this high temperature region, is adequately described through the use of an empirical intergranular crack growth law used in conjunction with the creep law. The effect of neutron irradiation is to reduce the activation energy for crack propagation from the value for creep to some lower value correlated to independent Dorn rupture parameter measurements. The result is a predicted reduced ductility which translates into a reduction in failure temperature at a given hoop stress value for irradiated material. (orig.)

  14. Elastic-plastic failure analysis of pressure burst tests of thin toroidal shells

    International Nuclear Information System (INIS)

    Jones, D.P.; Holliday, J.E.; Larson, L.D.

    1998-07-01

    This paper provides a comparison between test and analysis results for bursting of thin toroidal shells. Testing was done by pressurizing two toroidal shells until failure by bursting. An analytical criterion for bursting is developed based on good agreement between structural instability predicted by large strain-large displacement elastic-plastic finite element analysis and observed burst pressure obtained from test. The failures were characterized by loss of local stability of the membrane section of the shells consistent with the predictions from the finite element analysis. Good agreement between measured and predicted burst pressure suggests that incipient structural instability as calculated by an elastic-plastic finite element analysis is a reasonable way to calculate the bursting pressure of thin membrane structures

  15. Use of failure mode effect analysis (FMEA) to improve medication management process.

    Science.gov (United States)

    Jain, Khushboo

    2017-03-13

    Purpose Medication management is a complex process, at high risk of error with life threatening consequences. The focus should be on devising strategies to avoid errors and make the process self-reliable by ensuring prevention of errors and/or error detection at subsequent stages. The purpose of this paper is to use failure mode effect analysis (FMEA), a systematic proactive tool, to identify the likelihood and the causes for the process to fail at various steps and prioritise them to devise risk reduction strategies to improve patient safety. Design/methodology/approach The study was designed as an observational analytical study of medication management process in the inpatient area of a multi-speciality hospital in Gurgaon, Haryana, India. A team was made to study the complex process of medication management in the hospital. FMEA tool was used. Corrective actions were developed based on the prioritised failure modes which were implemented and monitored. Findings The percentage distribution of medication errors as per the observation made by the team was found to be maximum of transcription errors (37 per cent) followed by administration errors (29 per cent) indicating the need to identify the causes and effects of their occurrence. In all, 11 failure modes were identified out of which major five were prioritised based on the risk priority number (RPN). The process was repeated after corrective actions were taken which resulted in about 40 per cent (average) and around 60 per cent reduction in the RPN of prioritised failure modes. Research limitations/implications FMEA is a time consuming process and requires a multidisciplinary team which has good understanding of the process being analysed. FMEA only helps in identifying the possibilities of a process to fail, it does not eliminate them, additional efforts are required to develop action plans and implement them. Frank discussion and agreement among the team members is required not only for successfully conducing

  16. Failure analysis of carbide fuels under transient overpower (TOP) conditions

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1980-06-01

    The failure of carbide fuels in the Fast Test Reactor (FTR) under Transient Overpower (TOP) conditions has been examined. The Beginning-of-Cycle Four (BOC-4) all-oxide base case, at $.50/sec ramp rate was selected as the reference case. A coupling between the advanced fuel performance code UNCLE-T and HCDA Code MELT-IIIA was necessary for the analysis. UNCLE-T was used to determine cladding failure and fuel preconditioning which served as initial conditions for MELT-III calculations. MELT-IIIA determined the time of molten fuel ejection from fuel pin

  17. Genome-wide occupancy profile of mediator and the Srb8-11 module reveals interactions with coding regions

    DEFF Research Database (Denmark)

    Zhu, Xuefeng; Wirén, Marianna; Sinha, Indranil

    2006-01-01

    Mediator exists in a free form containing the Med12, Med13, CDK8, and CycC subunits (the Srb8-11 module) and a smaller form, which lacks these four subunits and associates with RNA polymerase II (Pol II), forming a holoenzyme. We use chromatin immunoprecipitation (ChIP) and DNA microarrays...... to investigate genome-wide localization of Mediator and the Srb8-11 module in fission yeast. Mediator and the Srb8-11 module display similar binding patterns, and interactions with promoters and upstream activating sequences correlate with increased transcription activity. Unexpectedly, Mediator also interacts...... with the downstream coding region of many genes. These interactions display a negative bias for positions closer to the 5' ends of open reading frames (ORFs) and appear functionally important, because downregulation of transcription in a temperature-sensitive med17 mutant strain correlates with increased Mediator...

  18. Failure analysis of boiler tubes in lakhra coal power plant

    International Nuclear Information System (INIS)

    Shah, A.; Baluch, M.M.; Ali, A.

    2010-01-01

    Present work deals with the failure analysis of a boiler tube in Lakhra fluidized bed combustion power station. Initially, visual inspection technique was adopted to analyse the fractured surface. Detailed microstructural investigations of the busted boiler tube were carried out using light optical microscope and scanning electron microscope. The hardness tests were also performed. A 50 percent decrease in hardness of intact portion of the tube material and from area adjacent to failure was measured, which was found to be in good agreement with the wall thicknesses measured of the busted boiler tube i.e. 4 mm and 2 mm from unaffected portion and ruptured area respectively. It was concluded that the major cause of failure of boiler tube is erosion of material which occurs due the coal particles strike at the surface of the tube material. Since the temperature of boiler is not maintained uniformly. The variations in boiler temperature can also affect the material and could be another reason for the failure of the tube. (author)

  19. [Retrieval and failure analysis of surgical implants in Brazil: the need for proper regulation].

    Science.gov (United States)

    Azevedo, Cesar R de Farias; Hippert, Eduardo

    2002-01-01

    This paper summarizes several cases of metallurgical failure analysis of surgical implants conducted at the Laboratory of Failure Analysis, Instituto de Pesquisas Tecnológicas (IPT), in Brazil. Failures with two stainless steel femoral compression plates, one stainless steel femoral nail plate, one Ti-6Al-4V alloy maxillary reconstruction plate, and five Nitinol wires were investigated. The results showed that the implants were not in accordance with ISO standards and presented evidence of corrosion-assisted fracture. Furthermore, some of the implants presented manufacturing/processing defects which also contributed to their premature failure. Implantation of materials that are not biocompatible may cause several types of adverse effects in the human body and lead to premature implant failure. A review of prevailing health legislation is needed in Brazil, along with the adoption of regulatory mechanisms to assure the quality of surgical implants on the market, providing for compulsory procedures in the reporting and investigation of surgical implants which have failed in service.

  20. Pharmacophore modeling and in silico / in vitro screening for human cytochrome P450 11B1 & cytochrome P450 11B2 inhibitors

    Science.gov (United States)

    Akram, Muhammad; Waratchareeyakul, Watcharee; Haupenthal, Joerg; Hartmann, Rolf W.; Schuster, Daniela

    2017-12-01

    Cortisol synthase (CYP11B1) is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing’s syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2) is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8-10), one selective CYP11B1 inhibitor (Compound 11, IC50 = 2.5 µM), and one selective CYP11B2 inhibitor (compound 12, IC50 = 1.1 µM), respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

  1. Etiology, clinical features and outcome of fulminant hepatic failure in pregnancy

    International Nuclear Information System (INIS)

    Brohi, Z.P.; Sadaf, A.

    2013-01-01

    Objective: To determine the etiology, clinical features and outcome of fulminant hepatic failure in pregnancy. Methods: An observational hospital based study was conducted at Isra University hospital Hyderabad from 1st March 2009 to 28th February 2010. Total 1192 obstetric patients were admitted in obstetrics and gynaecology department during this period, of whom 52 were with Fulminant hepatic failure in pregnancy and were included in this study. A pre-designed structured proforma was used. All patients had clinical history and underwent a physical examination. Routine laboratory tests, liver function tests and viral serology were performed in all cases. All results were analyzed on statistical software SPSS version 11. Frequencies and percentages were calculated, the final outcome was recorded. Results: Out of 52, 6(11.5%) presented in the first trimester, 4 (7.6%) in the second trimester and 42 (80.7%) were in their 3rd trimester of pregnancy. Etiology of the disease was Hepatitis E in 28(53.8%), Hepatitis B in 9 (17.3%), Hepatitis C in 7 (13.5%) HELLP syndrome in 7 (13.5%) and acute fatty liver of pregnancy in 1 (3.57%) case. Maternal mortality was 15(28.8%) and foetal mortality was 40 (77%). Only 12 (23.1%) new born remained alive. Conclusion: Fulminant hepatic failure in pregnancy has very high foetal and maternal mortality which is mostly due to viral hepatitis E. (author)

  2. Nonacetaminophen Drug-Induced Acute Liver Failure.

    Science.gov (United States)

    Thomas, Arul M; Lewis, James H

    2018-05-01

    Acute liver failure of all causes is diagnosed in between 2000 and 2500 patients annually in the United States. Drug-induced acute liver failure is the leading cause of acute liver failure, accounting for more than 50% of cases. Nonacetaminophen drug injury represents 11% of all cases in the latest registry from the US Acute Liver Failure Study Group. Although rare, acute liver failure is clinically dramatic when it occurs, and requires a multidisciplinary approach to management. In contrast with acetaminophen-induced acute liver failure, non-acetaminophen-induced acute liver failure has a more ominous prognosis with a lower liver transplant-free survival. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Predicting Bank Financial Failures Using Discriminant Analysis And Support Vector Machines Methods A Comparative Analysis In Commercial Banks In Sudan 2006-2014

    Directory of Open Access Journals (Sweden)

    Mohammed A. SirElkhatim

    2017-04-01

    Full Text Available Bank failures threaten the economic system as a whole. Therefore predicting bank financial failures is crucial to prevent andor lessen its negative effects on the economic system. Financial crises affecting both emerging markets and advanced countries over the centuries have severe economic consequences but they can be hard to prevent and predict identifying financial crises causes remains both science and art said Stijn Claessens assistant director of the International Monetary Fund. While it would be better to mitigate risks financial crises will recur often in waves and better crisis management is therefore important. Analyses of recurrent causes suggest that to prevent crises governments should consider reforms in many underlying areas. That includes developing prudent fiscal and monetary policies better regulating the financial sector including reducing the problem of too-big-to-fail banks and developing effective macro-prudential policies. Despite new regulations and better supervision crises are likely to recur in part because they can reflect deeper problems related to income inequality the political economy and common human behavior. As such improvements in crisis management are also needed. This is originally a classification problem to categorize banks as healthy or non-healthy ones. This study aims to apply Discriminant analysis and Support Vector Machines methods to the bank failure prediction problem in a Sudanese case and to present a comprehensive computational comparison of the classification performances of the techniques tested. Eleven financial and non-financial ratios with six feature groups including capital adequacy asset quality Earning and liquidity CAMELS are selected as predictor variables in the study. Credit risk also been evaluated using logistic analysis to study the effect of Islamic finance modes sectors and payment types used by Sudanese banks with regard to their possibilities of failure. Experimental results

  4. Failure mode and effects analysis outputs: are they valid?

    Science.gov (United States)

    Shebl, Nada Atef; Franklin, Bryony Dean; Barber, Nick

    2012-06-10

    Failure Mode and Effects Analysis (FMEA) is a prospective risk assessment tool that has been widely used within the aerospace and automotive industries and has been utilised within healthcare since the early 1990s. The aim of this study was to explore the validity of FMEA outputs within a hospital setting in the United Kingdom. Two multidisciplinary teams each conducted an FMEA for the use of vancomycin and gentamicin. Four different validity tests were conducted: Face validity: by comparing the FMEA participants' mapped processes with observational work. Content validity: by presenting the FMEA findings to other healthcare professionals. Criterion validity: by comparing the FMEA findings with data reported on the trust's incident report database. Construct validity: by exploring the relevant mathematical theories involved in calculating the FMEA risk priority number. Face validity was positive as the researcher documented the same processes of care as mapped by the FMEA participants. However, other healthcare professionals identified potential failures missed by the FMEA teams. Furthermore, the FMEA groups failed to include failures related to omitted doses; yet these were the failures most commonly reported in the trust's incident database. Calculating the RPN by multiplying severity, probability and detectability scores was deemed invalid because it is based on calculations that breach the mathematical properties of the scales used. There are significant methodological challenges in validating FMEA. It is a useful tool to aid multidisciplinary groups in mapping and understanding a process of care; however, the results of our study cast doubt on its validity. FMEA teams are likely to need different sources of information, besides their personal experience and knowledge, to identify potential failures. As for FMEA's methodology for scoring failures, there were discrepancies between the teams' estimates and similar incidents reported on the trust's incident

  5. Structures for common-cause failure analysis

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1981-01-01

    Common-cause failure methodology and terminology have been reviewed and structured to provide a systematical basis for addressing and developing models and methods for quantification. The structure is based on (1) a specific set of definitions, (2) categories based on the way faults are attributable to a common cause, and (3) classes based on the time of entry and the time of elimination of the faults. The failure events are then characterized by their likelihood or frequency and the average residence time. The structure provides a basis for selecting computational models, collecting and evaluating data and assessing the importance of various failure types, and for developing effective defences against common-cause failure. The relationships of this and several other structures are described

  6. Seasonal variations in growth and body composition of 8-11-year-old Danish children

    DEFF Research Database (Denmark)

    Dalskov, Stine-Mathilde; Ritz, Christian; Larnkjær, Anni

    2016-01-01

    BACKGROUND: Earlier studies on seasonality in growth reported the largest height gains during spring and largest body weight gains during autumn. We examined seasonality in height, body weight, BMI, fat mass index (FMI) and fat-free mass index (FFMI) among contemporary Danish 8-11-year......-olds. METHODS: 760 children from the OPUS School Meal Study provided >2200 measurements on height, body weight and composition between September-June. Average velocities were calculated using change-score analyses based on three-month intervals. As a complementary analysis, point velocities derived from...... suggest seasonality in growth and body composition of Danish children. We recovered the well-known height velocity peak during spring time, but unlike earlier studies we found coincident peaks in body weight, BMI, and FFMI velocities.Pediatric Research (2015); doi:10.1038/pr.2015.206....

  7. ANALYSIS OF RELIABILITY OF NONRECTORABLE REDUNDANT POWER SYSTEMS TAKING INTO ACCOUNT COMMON FAILURES

    Directory of Open Access Journals (Sweden)

    V. A. Anischenko

    2014-01-01

    Full Text Available Reliability Analysis of nonrestorable redundant power Systems of industrial plants and other consumers of electric energy was carried out. The main attention was paid to numbers failures influence, caused by failures of all elements of System due to one general reason. Noted the main possible reasons of common failures formation. Two main indicators of reliability of non-restorable systems are considered: average time of no-failure operation and mean probability of no-failure operation. Modeling of failures were carried out by mean of division of investigated system into two in-series connected subsystems, one of them indicated independent failures, but the other indicated common failures. Due to joined modeling of single and common failures resulting intensity of failures is the amount incompatible components: intensity statistically independent failures and intensity of common failures of elements and system in total.It is shown the influence of common failures of elements on average time of no-failure operation of system. There is built the scale of preference of systems according to criterion of  average time maximum of no-failure operation, depending on portion of common failures. It is noticed that such common failures don’t influence on the scale of preference, but  change intervals of time, determining the moments of systems failures and excepting them from the number of comparators. There were discussed two problems  of conditionally optimization of  systems’  reservation choice, taking into account their reliability and cost. The first problem is solved due to criterion of minimum cost of system providing mean probability of no-failure operation, the second problem is solved due to criterion of maximum of mean probability of no-failure operation with cost limitation of system.

  8. Quantification of a decision-making failure probability of the accident management using cognitive analysis model

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Yoshitaka; Ohtani, Masanori [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Fujita, Yushi [TECNOVA Corp., Tokyo (Japan)

    2002-09-01

    In the nuclear power plant, much knowledge is acquired through probabilistic safety assessment (PSA) of a severe accident, and accident management (AM) is prepared. It is necessary to evaluate the effectiveness of AM using the decision-making failure probability of an emergency organization, operation failure probability of operators, success criteria of AM and reliability of AM equipments in PSA. However, there has been no suitable qualification method for PSA so far to obtain the decision-making failure probability, because the decision-making failure of an emergency organization treats the knowledge based error. In this work, we developed a new method for quantification of the decision-making failure probability of an emergency organization using cognitive analysis model, which decided an AM strategy, in a nuclear power plant at the severe accident, and tried to apply it to a typical pressurized water reactor (PWR) plant. As a result: (1) It could quantify the decision-making failure probability adjusted to PSA for general analysts, who do not necessarily possess professional human factors knowledge, by choosing the suitable value of a basic failure probability and an error-factor. (2) The decision-making failure probabilities of six AMs were in the range of 0.23 to 0.41 using the screening evaluation method and in the range of 0.10 to 0.19 using the detailed evaluation method as the result of trial evaluation based on severe accident analysis of a typical PWR plant, and a result of sensitivity analysis of the conservative assumption, failure probability decreased about 50%. (3) The failure probability using the screening evaluation method exceeded that using detailed evaluation method by 99% of probability theoretically, and the failure probability of AM in this study exceeded 100%. From this result, it was shown that the decision-making failure probability was more conservative than the detailed evaluation method, and the screening evaluation method satisfied

  9. Quantification of a decision-making failure probability of the accident management using cognitive analysis model

    International Nuclear Information System (INIS)

    Yoshida, Yoshitaka; Ohtani, Masanori; Fujita, Yushi

    2002-01-01

    In the nuclear power plant, much knowledge is acquired through probabilistic safety assessment (PSA) of a severe accident, and accident management (AM) is prepared. It is necessary to evaluate the effectiveness of AM using the decision-making failure probability of an emergency organization, operation failure probability of operators, success criteria of AM and reliability of AM equipments in PSA. However, there has been no suitable qualification method for PSA so far to obtain the decision-making failure probability, because the decision-making failure of an emergency organization treats the knowledge based error. In this work, we developed a new method for quantification of the decision-making failure probability of an emergency organization using cognitive analysis model, which decided an AM strategy, in a nuclear power plant at the severe accident, and tried to apply it to a typical pressurized water reactor (PWR) plant. As a result: (1) It could quantify the decision-making failure probability adjusted to PSA for general analysts, who do not necessarily possess professional human factors knowledge, by choosing the suitable value of a basic failure probability and an error-factor. (2) The decision-making failure probabilities of six AMs were in the range of 0.23 to 0.41 using the screening evaluation method and in the range of 0.10 to 0.19 using the detailed evaluation method as the result of trial evaluation based on severe accident analysis of a typical PWR plant, and a result of sensitivity analysis of the conservative assumption, failure probability decreased about 50%. (3) The failure probability using the screening evaluation method exceeded that using detailed evaluation method by 99% of probability theoretically, and the failure probability of AM in this study exceeded 100%. From this result, it was shown that the decision-making failure probability was more conservative than the detailed evaluation method, and the screening evaluation method satisfied

  10. Safety Management in an Oil Company through Failure Mode Effects and Critical Analysis

    Directory of Open Access Journals (Sweden)

    Benedictus Rahardjo

    2016-06-01

    Full Text Available This study attempts to apply Failure Mode Effects and Criticality Analysis (FMECA to improve the safety of a production system, specifically the production process of an oil company. Since food processing is a worldwide issue and self-management of a food company is more important than relying on government regulations, therefore this study focused on that matter. The initial step of this study is to identify and analyze the criticality of the potential failure modes of the production process. Furthermore, take corrective action to minimize the probability of repeating the same failure mode, followed by a re-analysis of its criticality. The results of corrective actions were compared with those before improvement conditions by testing the significance of the difference using two sample t-test. The final measured result is the Criticality Priority Number (CPN, which refers to the severity category of the failure mode and the probability of occurrence of the same failure mode. The recommended actions proposed by the FMECA significantly reduce the CPN compared with the value before improvement, with increases of 38.46% for the palm olein case study.

  11. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    Energy Technology Data Exchange (ETDEWEB)

    Lee C. Cadwallader

    2010-06-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with “generic” component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance.

  12. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    Energy Technology Data Exchange (ETDEWEB)

    Lee C. Cadwallader

    2007-08-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with “generic” component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance.

  13. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    International Nuclear Information System (INIS)

    Lee C. Cadwallader

    2007-01-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with 'generic' component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance

  14. Patterns of Failure in Pediatric Rhabdomyosarcoma After Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Vern-Gross, Tamara Z.; Indelicato, Daniel J., E-mail: dindelicato@floridaproton.org; Bradley, Julie A.; Rotondo, Ronny L.

    2016-12-01

    Purpose: To report on the patterns of failure in children with rhabdomyosarcoma treated with proton therapy. Patients and Methods: Between February 2007 and November 2013, 66 children with a median age of 4.1 years (range, 0.6-15.3 years) diagnosed with nonmetastatic rhabdomyosarcoma were treated with proton therapy. Clinical target volume 1 was defined as the prechemotherapy tumor plus a 1-cm anatomically constrained margin. Clinical target volume 2 was defined as the postchemotherapy tumor (or tumor bed) plus a 0.5-cm anatomically constrained margin, further expanded to encompass potential pathways of spread, including soft tissue infiltrated with tumor at diagnosis. Results: Of the 66 children, 11 developed locally progressive disease at a median of 16 months (range, 14-32 months), for an actuarial 2-year local control rate of 88%. Among the children who progressed, median age and tumor size at diagnosis were 6.7 years (range, 0.6-16 years) and 6 cm (range, 2-8 cm), respectively. Of the recurrences, 64% and 36% were embryonal and alveolar, respectively. Disease progression was observed in 7 (64%) parameningeal, 2 (18%) head and neck (other), and 2 (18%) bladder/prostate subsites. At diagnosis, 8 of 11 patients who developed a recurrence were Intergroup Rhabdomyosarcoma Study stage 3, and all 11 were group III. Of the relapses, 100% (11 of 11) were confirmed as in-field within the composite 95% isodose line. One of the 11 patients (9%) developed a new simultaneous regional nodal recurrence outside of the previously treated radiation field. Conclusion: Early data suggest that the sharp dosimetric gradient associated with proton therapy is not associated with an increased risk of marginal failure. Routine use of a 0.5- to 1-cm clinical target volume 1/2 margin with highly conformal proton therapy does not compromise local control in children diagnosed with rhabdomyosarcoma with unfavorable risk features.

  15. Mutational Analysis of PTPN11 Gene in Taiwanese Children with Noonan Syndrome

    Directory of Open Access Journals (Sweden)

    Chia-Sui Hung

    2007-01-01

    Full Text Available Noonan syndrome (NS is an autosomal dominant disorder presenting with characteristic facies, short stature, skeletal anomalies, and congenital heart defects. Mutations in protein-tyrosine phosphatase, nonreceptor-type 11 (PTPN11, encoding SHP-2, account for 33-50% of NS. This study screened for mutations in the PTPN11 gene in 34 Taiwanese patients with NS. Mutation analysis of the 15 coding exons and exon/intron boundaries was performed by polymerase chain reaction and direct sequencing of the PTPN11 gene. We identified 10 different missense mutations in 13 (38% patients, including a novel missense mutation (855T > G, F285L. These mutations were clustered in exon 3 (n = 6 encoding the N-SH2 domain, exon 4 (n = 2 encoding the C-SH2 domain, and in exons 8 (n = 2 and 13 (n = 3 encoding the PTP domain. In conclusion, this study provides further support that PTPN11 mutations are responsible for Noonan syndrome in Taiwanese patients. [J Formos Med Assoc 2007;106(2:169-172

  16. New Complex Chromosomal Translocation in Chronic Myeloid Leukaemia: t(9;18;22(q34;p11;q11

    Directory of Open Access Journals (Sweden)

    Abdeljabar El Andaloussi

    2007-01-01

    Full Text Available A Chronic myeloid leukaemia (CML case with a new complex t(9;18;22(q34;p11;q11 of a 29-year-old man is being reported. For the first time, this translocation has been characterized by karyotype complemented with fluorescence in situ hybridization (FISH. In CML, the complex and standard translocations have the same prognosis. The patient was treated with standard initial therapy based on hydroxyurea before he died due to heart failure four months later. Our finding indicates the importance of combined cytogenetic analysis for diagnosis and guidance of treatment in clinical diagnosis of CML.

  17. Association between vitamin D deficiency and heart failure risk in the elderly.

    Science.gov (United States)

    Porto, Catarina Magalhães; Silva, Vanessa De Lima; da Luz, João Soares Brito; Filho, Brivaldo Markman; da Silveira, Vera Magalhães

    2018-02-01

    The aim of this study was to evaluate the association between vitamin D deficiency and risk of heart failure in elderly patients of cardiology outpatient clinics. A cross-sectional study with an analytical approach was employed. Clinical data were collected from the elderly from August 2015 to February 2016. The dependent variable was the risk of heart failure; the independent variable was vitamin D deficiency; and intervening factors were age, gender, education, ethnicity, hypertension, diabetes mellitus, hypothyroidism, renal failure, dementia, stroke, dyslipidaemia, depression, smoking, alcoholism, obesity, andropause, and cardiac arrhythmia. To analyse the association between vitamin D deficiency and risk of heart failure, we used the bivariate logistic analysis, followed by analysis through the multivariate logistic regression model. Of the 137 elderly, the study found the following: women (75.9%); overweight (48.2%); obese (30.6%); increase in the index waist/hip (88.3%); dyslipidaemia (94.2%) and hypertension (91.2%); coronary artery disease (35.0%); and 27.7% with cardiac arrhythmia or left ventricular hypertrophy. Sixty-five per cent of the elderly were deficient in vitamin D. The risk of heart failure was significantly associated with vitamin D deficiency [odds ratio (OR): 12.19; 95% confidence interval (CI) = 4.23-35.16; P = 0.000], male gender (OR: 15.32; 95% CI = 3.39-69.20, P = 0.000), obesity (OR: 4.17; 95% CI = 1.36-12.81; P = 0.012), and cardiac arrhythmia (OR: 3.69; 95% CI = 1.23-11.11; P = 0.020). There was a high prevalence of vitamin D deficiency in the elderly, and the evidence shows a strong association between vitamin D deficiency and increased risk of heart failure in this population. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  18. Relation of Renal Function with Left Ventricular Systolic Function and NT-proBNP Level and Its Prognostic Implication in Heart Failure with Preserved versus Reduced Ejection Fraction: an analysis from the Korean Heart Failure (KorHF) Registry.

    Science.gov (United States)

    Park, Chan Soon; Park, Jin Joo; Oh, Il-Young; Yoon, Chang-Hwan; Choi, Dong-Ju; Park, Hyun-Ah; Kang, Seok-Min; Yoo, Byung-Su; Jeon, Eun-Seok; Kim, Jae-Joong; Cho, Myeong-Chan; Chae, Shung Chull; Ryu, Kyu-Hyung; Oh, Byung-Hee

    2017-09-01

    The relationship between ejection fraction (EF), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and renal function is unknown as stratified by heart failure (HF) type. We investigated their relation and the prognostic value of renal function in heart failure with preserved ejection fraction (HFpEF) vs. reduced ejection fraction (HFrEF). NT-proBNP, glomerular filtration rate (GFR), and EF were obtained in 1,932 acute heart failure (AHF) patients. HFrEF was defined as EFrenal dysfunction as GFRrenal dysfunction: 30≤GFRrenal dysfunction: GFRrenal dysfunction did not differ between HFpEF and HFrEF (49% vs. 52%, p=0.210). Patients with renal dysfunction had higher 12-month mortality in both HFpEF (7.9% vs. 15.2%, log-rank p=0.008) and HFrEF (8.6% vs. 16.8%, log-rank prenal dysfunction was an independent predictor of 12-month mortality (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.40-3.11). When stratified according to EF: the prognostic value of severe renal dysfunction was attenuated in HFpEF patients (HR, 1.46; 95% CI, 0.66-3.21) contrary to HFrEF patients (HR, 2.43; 95% CI, 1.52-3.89). In AHF patients, the prevalence of renal dysfunction did not differ between HFpEF and HFrEF patients. However, the prognostic value of renal dysfunction was attenuated in HFpEF patients.

  19. Preliminary Analysis of the Common Cause Failure Events for Domestic Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kang, Daeil; Han, Sanghoon

    2007-01-01

    It is known that the common cause failure (CCF) events have a great effect on the safety and probabilistic safety assessment (PSA) results of nuclear power plants (NPPs). However, the domestic studies have been mainly focused on the analysis method and modeling of CCF events. Thus, the analysis of the CCF events for domestic NPPs were performed to establish a domestic database for the CCF events and to deliver them to the operation office of the international common cause failure data exchange (ICDE) project. This paper presents the analysis results of the CCF events for domestic nuclear power plants

  20. Predictors of Failure in Infant Mandibular Distraction Osteogenesis.

    Science.gov (United States)

    Hammoudeh, Jeffrey A; Fahradyan, Artur; Brady, Colin; Tsuha, Michaela; Azadgoli, Beina; Ward, Sally; Urata, Mark M

    2018-03-15

    Mandibular distraction osteogenesis (MDO) has been shown to be successful in treating upper airway obstruction caused by micrognathia in pediatric patients. The purpose of this study was to assess the success rate of MDO and possible predictors of failure. The records of all neonates and infants who underwent MDO from 2008 to 2015 were retrospectively reviewed. Procedural failure was defined as patient death or the need for tracheostomy postoperatively. Details of distraction, length of stay, and failures were captured and elucidated. Of the 82 patients, 47 (57.3%) were male; 46 (56.1%) had sporadic Pierre Robin sequence; 33 (40.3%) had syndromic Pierre Robin sequence; and 3 (3.7%) had micrognathia, not otherwise specified. The average distraction length was 27.5 mm (range, 15 to 30 mm; SD, 4.4 mm), the average age at operation was 63.3 days (range, 3 to 342 days; SD, 71.4 days), and the average length of post-MDO hospital stay was 43 days (range, 9 to 219 days; SD, 35 days) with an average follow-up period of 4.3 years (range, 1.1 to 9.6 years; SD, 2.6 years). There were 7 failures (8.5%) (5 tracheostomies and 2 deaths) resulting in a 91.5% success rate. Regression analysis showed that the predicted probability of the need for tracheostomy was 45% (P = .02) when the patient had a central nervous system (CNS) anomaly. The predicted probability of the need for tracheostomy and death combined was 99.6% when the patient had laryngomalacia and a CNS anomaly and was preoperatively intubated (P < .05). This review confirms that MDO is an effective method of treating the upper airway obstruction caused by micrognathia with a high success rate. In our sample the presence of CNS abnormalities, laryngomalacia, and preoperative intubation had a significant impact on the failure rate. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  1. High-power parametric amplification of 11.8-fs laser pulses with carrier-envelope phase control

    NARCIS (Netherlands)

    Zinkstok, R.T.; Witte, S.; Hogervorst, W.; Eikema, K.S.E.

    2005-01-01

    Phase-stable parametric chirped-pulse amplification of ultrashort pulses from a carrier-envelope phase-stabilized mode-locked Ti:sapphire oscillator (11.0 fs) to 0.25 mJ/pulse at 1 kHz is demonstrated. Compression with a grating compressor and a LCD shaper yields near-Fourier-limited 11.8-fs pulses

  2. A model-based prognostic approach to predict interconnect failure using impedance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Dae Il; Yoon, Jeong Ah [Dept. of System Design and Control Engineering. Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2016-10-15

    The reliability of electronic assemblies is largely affected by the health of interconnects, such as solder joints, which provide mechanical, electrical and thermal connections between circuit components. During field lifecycle conditions, interconnects are often subjected to a DC open circuit, one of the most common interconnect failure modes, due to cracking. An interconnect damaged by cracking is sometimes extremely hard to detect when it is a part of a daisy-chain structure, neighboring with other healthy interconnects that have not yet cracked. This cracked interconnect may seem to provide a good electrical contact due to the compressive load applied by the neighboring healthy interconnects, but it can cause the occasional loss of electrical continuity under operational and environmental loading conditions in field applications. Thus, cracked interconnects can lead to the intermittent failure of electronic assemblies and eventually to permanent failure of the product or the system. This paper introduces a model-based prognostic approach to quantitatively detect and predict interconnect failure using impedance analysis and particle filtering. Impedance analysis was previously reported as a sensitive means of detecting incipient changes at the surface of interconnects, such as cracking, based on the continuous monitoring of RF impedance. To predict the time to failure, particle filtering was used as a prognostic approach using the Paris model to address the fatigue crack growth. To validate this approach, mechanical fatigue tests were conducted with continuous monitoring of RF impedance while degrading the solder joints under test due to fatigue cracking. The test results showed the RF impedance consistently increased as the solder joints were degraded due to the growth of cracks, and particle filtering predicted the time to failure of the interconnects similarly to their actual timesto- failure based on the early sensitivity of RF impedance.

  3. Structure of 12B from measurement and R-matrix analysis of sigma(theta) for 11B(n,n)11B and 11B(n,n')11Bsup(*)(2.12 MeV), and shell-model calculations

    International Nuclear Information System (INIS)

    Koehler, P.E.; Knox, H.D.; Resler, D.A.; Lane, R.O.

    1983-01-01

    Differential cross sections for neutrons, elastically scattered from 11 B and inelastically scattered to the first excited state 11 B*(2.12 MeV) have been measured at 13 incident energies for 4.8 12 B of 7.8 to 10.3 MeV. The cross sections were measured at nine laboratory angles per energy from 20 0 to 160 0 and show considerable resonance structure. Differential inelastic cross sections were also measured for the 4.45 and 5.02 MeV levels of 11 B for 2 to 9 angles at several incident energies. These new elastic and inelastic 2.12 MeV level data have been analyzed together with previously publsihed cross sections for 2 12 B. The shell model was used to calculate states in 12 B as well as spectroscopic amplitudes for reactions leading to these states. The results of this model calculation are compared to those of the R-matrix analysis. Much of the structure observed in the experimental work is predicted by the model for Esub(x) < or approx. 7 MeV. For levels of higher excitation the agreement is not as good. The experimental data are also compared to continuum shell-model calculations. (orig.)

  4. Failure mode analysis in adrenal vein sampling: a single-center experience.

    Science.gov (United States)

    Trerotola, Scott O; Asmar, Melissa; Yan, Yan; Fraker, Douglas L; Cohen, Debbie L

    2014-10-01

    To analyze failure modes in a high-volume adrenal vein sampling (AVS) practice in an effort to identify preventable causes of nondiagnostic sampling. A retrospective database was constructed containing 343 AVS procedures performed over a 10-year period. Each nondiagnostic AVS procedure was reviewed for failure mode and correlated with results of any repeat AVS. Data collected included selectivity index, lateralization index, adrenalectomy outcomes if performed, and details of AVS procedure. All AVS procedures were performed after cosyntropin stimulation, using sequential technique. AVS was nondiagnostic in 12 of 343 (3.5%) primary procedures and 2 secondary procedures. Failure was right-sided in 8 (57%) procedures, left-sided in 4 (29%) procedures, bilateral in 1 procedure, and neither in 1 procedure (laboratory error). Failure modes included diluted sample from correctly identified vein (n = 7 [50%]; 3 right and 4 left), vessel misidentified as adrenal vein (n = 3 [21%]; all right), failure to locate an adrenal vein (n = 2 [14%]; both right), cosyntropin stimulation failure (n = 1 [7%]; diagnostic by nonstimulated criteria), and laboratory error (n = 1 [7%]; specimen loss). A second AVS procedure was diagnostic in three of five cases (60%), and a third AVS procedure was diagnostic in one of one case (100%). Among the eight patients in whom AVS ultimately was not diagnostic, four underwent adrenalectomy based on diluted AVS samples, and one underwent adrenalectomy based on imaging; all five experienced improvement in aldosteronism. A substantial percentage of AVS failures occur on the left, all related to dilution. Even when technically nondiagnostic per strict criteria, some "failed" AVS procedures may be sufficient to guide therapy. Repeat AVS has a good yield. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  5. Advanced composites structural concepts and materials technologies for primary aircraft structures: Structural response and failure analysis

    Science.gov (United States)

    Dorris, William J.; Hairr, John W.; Huang, Jui-Tien; Ingram, J. Edward; Shah, Bharat M.

    1992-01-01

    Non-linear analysis methods were adapted and incorporated in a finite element based DIAL code. These methods are necessary to evaluate the global response of a stiffened structure under combined in-plane and out-of-plane loading. These methods include the Arc Length method and target point analysis procedure. A new interface material model was implemented that can model elastic-plastic behavior of the bond adhesive. Direct application of this method is in skin/stiffener interface failure assessment. Addition of the AML (angle minus longitudinal or load) failure procedure and Hasin's failure criteria provides added capability in the failure predictions. Interactive Stiffened Panel Analysis modules were developed as interactive pre-and post-processors. Each module provides the means of performing self-initiated finite elements based analysis of primary structures such as a flat or curved stiffened panel; a corrugated flat sandwich panel; and a curved geodesic fuselage panel. This module brings finite element analysis into the design of composite structures without the requirement for the user to know much about the techniques and procedures needed to actually perform a finite element analysis from scratch. An interactive finite element code was developed to predict bolted joint strength considering material and geometrical non-linearity. The developed method conducts an ultimate strength failure analysis using a set of material degradation models.

  6. Pharmacophore Modeling and in Silico/in Vitro Screening for Human Cytochrome P450 11B1 and Cytochrome P450 11B2 Inhibitors.

    Science.gov (United States)

    Akram, Muhammad; Waratchareeyakul, Watcharee; Haupenthal, Joerg; Hartmann, Rolf W; Schuster, Daniela

    2017-01-01

    Cortisol synthase (CYP11B1) is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing's syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2) is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8 - 10 ), one selective CYP11B1 inhibitor (Compound 11 , IC 50 = 2.5 μM), and one selective CYP11B2 inhibitor (compound 12 , IC 50 = 1.1 μM), respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

  7. Pharmacophore Modeling and in Silico/in Vitro Screening for Human Cytochrome P450 11B1 and Cytochrome P450 11B2 Inhibitors

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2017-12-01

    Full Text Available Cortisol synthase (CYP11B1 is the main enzyme for the endogenous synthesis of cortisol and its inhibition is a potential way for the treatment of diseases associated with increased cortisol levels, such as Cushing's syndrome, metabolic diseases, and delayed wound healing. Aldosterone synthase (CYP11B2 is the key enzyme for aldosterone biosynthesis and its inhibition is a promising approach for the treatment of congestive heart failure, cardiac fibrosis, and certain forms of hypertension. Both CYP11B1 and CYP11B2 are structurally very similar and expressed in the adrenal cortex. To facilitate the identification of novel inhibitors of these enzymes, ligand-based pharmacophore models of CYP11B1 and CYP11B2 inhibition were developed. A virtual screening of the SPECS database was performed with our pharmacophore queries. Biological evaluation of the selected hits lead to the discovery of three potent novel inhibitors of both CYP11B1 and CYP11B2 in the submicromolar range (compounds 8–10, one selective CYP11B1 inhibitor (Compound 11, IC50 = 2.5 μM, and one selective CYP11B2 inhibitor (compound 12, IC50 = 1.1 μM, respectively. The overall success rate of this prospective virtual screening experiment is 20.8% indicating good predictive power of the pharmacophore models.

  8. Laboratory and 3-D distinct element analysis of the failure mechanism of a slope under external surcharge

    Science.gov (United States)

    Li, N.; Cheng, Y. M.

    2015-01-01

    Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient detail. There is however increasing interest in the consequences after the initiation of failure that includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more detail and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and a laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanisms and the post-failure mechanisms of slopes will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure, which can give additional information not available from the classical methods of analysis.

  9. SYNTHESIS AND APPLICATION OF THE 11-BISHOMODRIMANE-8α-OL -12-ONE

    Directory of Open Access Journals (Sweden)

    Aculina Aricu

    2008-12-01

    Full Text Available This review deals the methods of preparation of the 11-bishomodrimane-8α-ol-12-one, a convenient synton for the synthesis of drimanic and bishomodrimanic compounds, including the biologically active ones. The triterpenic tetracyclic derivatives of the onoceranic range and the fragrance compounds with ambergris odour can be also obtained from this compound.

  10. Comprehensive Deployment Method for Technical Characteristics Base on Multi-failure Modes Correlation Analysis

    Science.gov (United States)

    Zheng, W.; Gao, J. M.; Wang, R. X.; Chen, K.; Jiang, Y.

    2017-12-01

    This paper put forward a new method of technical characteristics deployment based on Reliability Function Deployment (RFD) by analysing the advantages and shortages of related research works on mechanical reliability design. The matrix decomposition structure of RFD was used to describe the correlative relation between failure mechanisms, soft failures and hard failures. By considering the correlation of multiple failure modes, the reliability loss of one failure mode to the whole part was defined, and a calculation and analysis model for reliability loss was presented. According to the reliability loss, the reliability index value of the whole part was allocated to each failure mode. On the basis of the deployment of reliability index value, the inverse reliability method was employed to acquire the values of technology characteristics. The feasibility and validity of proposed method were illustrated by a development case of machining centre’s transmission system.

  11. SEMICONDUCTOR INTEGRATED CIRCUITS 8.64-11.62 GHz CMOS VCO and divider in a zero-IF 802.11a/b/g WLAN and Bluetooth application

    Science.gov (United States)

    Yu, Sun; Niansong, Mei; Bo, Lu; Yumei, Huang; Zhiliang, Hong

    2010-10-01

    A fully integrated VCO and divider implemented in SMIC 0.13-μm RFCMOS 1P8M technology with a 1.2 V supply voltage is presented. The frequency of the VCO is tuning from 8.64 to 11.62 GHz while the quadrature LO signals for 802.11a WLAN in 5.8 GHz band or for 802.11b/g WLAN and Bluetooth in 2.4 GHz band can be obtained by a frequency division by 2 or 4, respectively. A 6 bit switched capacitor array is applied for precise tuning of all necessary frequency bands. The testing results show that the VCO has a phase noise of—113 dBc @ 1 MHz offset from the carrier of 5.5 GHz by dividing VCO output by two and the VCO core consumes 3.72 mW. The figure-of-merit for the tuning-range (FOMT) of the VCO is -192.6 dBc/Hz.

  12. Test OPTRAN 1-1 results

    International Nuclear Information System (INIS)

    Martinson, Z.R.

    1982-01-01

    The objective of the OPT 1-1 Test Series was to evaluate the extent of damage and the threshold for failure during simulated BWR anticipated transients. Four power transient tests with progressively higher power levels were performed with preirradiated fuel rods at power ramp rates as high as 550 kW/m per second. Six separately shrouded fuel rods fabricated by the General Electric Co., and preirradiated in the Monticello BWR to burnups of about 5000 to 23,000 MWd/t were tested, four at a time. Four of the fuel rods were of typical GE 8 x 8 design, except for fuel length (0.75 m). Two of the rods included design modifications to improve their PCI-resistant characteristics. A lengthy fuel conditioning preceded the transient testing of the fuel rods

  13. Statistical analysis of human maintenance failures of a nuclear power plant

    International Nuclear Information System (INIS)

    Pyy, P.

    2000-01-01

    In this paper, a statistical study of faults caused by maintenance activities is presented. The objective of the study was to draw conclusions on the unplanned effects of maintenance on nuclear power plant safety and system availability. More than 4400 maintenance history reports from the years 1992-1994 of Olkiluoto BWR nuclear power plant (NPP) were analysed together with the maintenance personnel. The human action induced faults were classified, e.g., according to their multiplicity and effects. This paper presents and discusses the results of a statistical analysis of the data. Instrumentation and electrical components are especially prone to human failures. Many human failures were found in safety related systems. Similarly, several failures remained latent from outages to power operation. The safety significance was generally small. Modifications are an important source of multiple human failures. Plant maintenance data is a good source of human reliability data and it should be used more, in future. (orig.)

  14. Failure propagation tests and analysis at PNC

    International Nuclear Information System (INIS)

    Tanabe, H.; Miyake, O.; Daigo, Y.; Sato, M.

    1984-01-01

    Failure propagation tests have been conducted using the Large Leak Sodium Water Reaction Test Rig (SWAT-1) and the Steam Generator Safety Test Facility (SWAT-3) at PNC in order to establish the safety design of the LMFBR prototype Monju steam generators. Test objectives are to provide data for selecting a design basis leak (DBL), data on the time history of failure propagations, data on the mechanism of the failures, and data on re-use of tubes in the steam generators that have suffered leaks. Eighteen fundamental tests have been performed in an intermediate leak region using the SWAT-1 test rig, and ten failure propagation tests have been conducted in the region from a small leak to a large leak using the SWAT-3 test facility. From the test results it was concluded that a dominant mechanism was tube wastage, and it took more than one minute until each failure propagation occurred. Also, the total leak rate in full sequence simulation tests including a water dump was far less than that of one double-ended-guillotine (DEG) failure. Using such experimental data, a computer code, LEAP (Leak Enlargement and Propagation), has been developed for the purpose of estimating the possible maximum leak rate due to failure propagation. This paper describes the results of the failure propagation tests and the model structure and validation studies of the LEAP code. (author)

  15. Heart failure etiology impacts survival of patients with heart failure

    DEFF Research Database (Denmark)

    Pecini, Redi; Møller, Daniel Vega; Torp-Pedersen, Christian

    2010-01-01

    .4%), valvular disease (VHD, 9.5%), dilated cardiomyopathy (DCM, 7.9%), other (11.5%), and unknown etiology (14.8%). Patients with normal left ventricular ejection fraction (LVEF) were also included. Follow-up was up to 5years. RESULTS: In multivariable analysis, with HTN as the reference, VHD showed the highest...

  16. Failure analysis of radioisotopic heat source capsules tested under multi-axial conditions

    International Nuclear Information System (INIS)

    Zielinski, R.E.; Stacy, E.; Burgan, C.E.

    In order to qualify small radioisotopic heat sources for a 25-yr design life, multi-axial mechanical tests were performed on the structural components of the heat source. The results of these tests indicated that failure predominantly occurred in the middle of the weld ramp-down zone. Examination of the failure zone by standard metallographic techniques failed to indicate the true cause of failure. A modified technique utilizing chemical etching, scanning electron microscopy, and energy dispersive x-ray analysis was employed and dramatically indicated the true cause of failure, impurity concentration in the ramp-down zone. As a result of the initial investigation, weld parameters for the heat sources were altered. Example welds made with a pulse arc technique did not have this impurity buildup in the ramp-down zone

  17. Efficacy and safety of regorafenib for advanced gastrointestinal stromal tumor after failure with imatinib and sunitinib treatment: A meta-analysis.

    Science.gov (United States)

    Zhang, Zhenan; Jiang, Tao; Wang, Wensheng; Piao, Daxun

    2017-12-01

    This meta-analysis aimed to evaluate the safety and efficacy of regorafenib as a treatment for patients with advanced (metastatic and/or unresectable) gastrointestinal stromal tumor (AGIST) after developing resistance to imatinib and sunitinib. A literature search of databases such as PubMed, Embase, and Cochrane library was conducted up to February 2017. The pooled percentages and the corresponding 95% confidence intervals (CIs) were calculated using the Stata 11.0 software. Four studies involving 243 patients with AGIST were included. Results revealed that approximately 49% (95% CI 30-67), 14% (95% CI 5-23), and 41% (95% CI 21-61) of patients with AGIST showed clinical benefit (including complete response), partial response, and stable disease, respectively, after regorafenib treatment, which was given after failure with imatinib and sunitinib treatments. No complete response was found in the included studies. Pooled progression-free survival was 6.58 months (95% CI 4.62-8.54). Hypertension (20%; 95% CI 7-33), hand-foot skin reaction (22%; 95% CI 17-27), and hypophosphatemia (18%; 95% CI 5-41) were common grade ≥3 regorafenib-related adverse events in patients treated with regorafenib after failure with imatinib and sunitinib treatments. Forty-nine per cent of patients with AGIST benefited after regorafenib treatment after the development of resistance to imatinib and sunitinib. More studies should be performed to improve the clinical survival of patients with AGIST. Close monitoring and appropriate management of grade ≥3 regorafenib-related adverse events should be considered during treatment.

  18. Uncertainty analysis with statistically correlated failure data

    International Nuclear Information System (INIS)

    Modarres, M.; Dezfuli, H.; Roush, M.L.

    1987-01-01

    Likelihood of occurrence of the top event of a fault tree or sequences of an event tree is estimated from the failure probability of components that constitute the events of the fault/event tree. Component failure probabilities are subject to statistical uncertainties. In addition, there are cases where the failure data are statistically correlated. At present most fault tree calculations are based on uncorrelated component failure data. This chapter describes a methodology for assessing the probability intervals for the top event failure probability of fault trees or frequency of occurrence of event tree sequences when event failure data are statistically correlated. To estimate mean and variance of the top event, a second-order system moment method is presented through Taylor series expansion, which provides an alternative to the normally used Monte Carlo method. For cases where component failure probabilities are statistically correlated, the Taylor expansion terms are treated properly. Moment matching technique is used to obtain the probability distribution function of the top event through fitting the Johnson Ssub(B) distribution. The computer program, CORRELATE, was developed to perform the calculations necessary for the implementation of the method developed. (author)

  19. Photovoltaic module reliability improvement through application testing and failure analysis

    Science.gov (United States)

    Dumas, L. N.; Shumka, A.

    1982-01-01

    During the first four years of the U.S. Department of Energy (DOE) National Photovoltatic Program, the Jet Propulsion Laboratory Low-Cost Solar Array (LSA) Project purchased about 400 kW of photovoltaic modules for test and experiments. In order to identify, report, and analyze test and operational problems with the Block Procurement modules, a problem/failure reporting and analysis system was implemented by the LSA Project with the main purpose of providing manufacturers with feedback from test and field experience needed for the improvement of product performance and reliability. A description of the more significant types of failures is presented, taking into account interconnects, cracked cells, dielectric breakdown, delamination, and corrosion. Current design practices and reliability evaluations are also discussed. The conducted evaluation indicates that current module designs incorporate damage-resistant and fault-tolerant features which address field failure mechanisms observed to date.

  20. Failure trend analysis for safety related components of Korean standard NPPs

    International Nuclear Information System (INIS)

    Choi, Sun Yeong; Han, Sang Hoon

    2005-01-01

    The component reliability data of Korean NPP that reflects the plant specific characteristics is required necessarily for PSA of Korean nuclear power plants. We have performed a project to develop the component reliability database (KIND, Korea Integrated Nuclear Reliability Database) and S/W for database management and component reliability analysis. Based on the system, we have collected the component operation data and failure/repair data during from plant operation date to 2002 for YGN 3, 4 and UCN 3, 4 plants. Recently, we provided the component failure rate data for UCN 3, 4 standard PSA model from the KIND. We evaluated the components that have high-ranking failure rates with the component reliability data from plant operation date to 1998 and 2000 for YGN 3,4 and UCN 3, 4 respectively. We also identified their failure mode that occurred frequently. In this study, we analyze the component failure trend and perform site comparison based on the generic data by using the component reliability data which is extended to 2002 for UCN 3, 4 and YGN 3, 4 respectively. We focus on the major safety related rotating components such as pump, EDG etc

  1. SU-G-TeP4-05: An Evaluation of a Low Dose Rate (LDR) Prostate Brachytherapy Procedure Using a Failure Modes and Effects Analysis (FMEA)

    International Nuclear Information System (INIS)

    Cheong, S-K; Kim, J

    2016-01-01

    Purpose: The aim of the study is the application of a Failure Modes and Effects Analysis (FMEA) to access the risks for patients undergoing a Low Dose Rate (LDR) Prostate Brachytherapy Treatment. Methods: FMEA was applied to identify all the sub processes involved in the stages of identifying patient, source handling, treatment preparation, treatment delivery, and post treatment. These processes characterize the radiation treatment associated with LDR Prostate Brachytherapy. The potential failure modes together with their causes and effects were identified and ranked in order of their importance. Three indexes were assigned for each failure mode: the occurrence rating (O), the severity rating (S), and the detection rating (D). A ten-point scale was used to score each category, ten being the number indicating most severe, most frequent, and least detectable failure mode, respectively. The risk probability number (RPN) was calculated as a product of the three attributes: RPN = O X S x D. The analysis was carried out by a working group (WG) at UPMC. Results: The total of 56 failure modes were identified including 32 modes before the treatment, 13 modes during the treatment, and 11 modes after the treatment. In addition to the protocols already adopted in the clinical practice, the prioritized risk management will be implanted to the high risk procedures on the basis of RPN score. Conclusion: The effectiveness of the FMEA method was established. The FMEA methodology provides a structured and detailed assessment method for the risk analysis of the LDR Prostate Brachytherapy Procedure and can be applied to other radiation treatment modes.

  2. SU-G-TeP4-05: An Evaluation of a Low Dose Rate (LDR) Prostate Brachytherapy Procedure Using a Failure Modes and Effects Analysis (FMEA)

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, S-K; Kim, J [University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2016-06-15

    Purpose: The aim of the study is the application of a Failure Modes and Effects Analysis (FMEA) to access the risks for patients undergoing a Low Dose Rate (LDR) Prostate Brachytherapy Treatment. Methods: FMEA was applied to identify all the sub processes involved in the stages of identifying patient, source handling, treatment preparation, treatment delivery, and post treatment. These processes characterize the radiation treatment associated with LDR Prostate Brachytherapy. The potential failure modes together with their causes and effects were identified and ranked in order of their importance. Three indexes were assigned for each failure mode: the occurrence rating (O), the severity rating (S), and the detection rating (D). A ten-point scale was used to score each category, ten being the number indicating most severe, most frequent, and least detectable failure mode, respectively. The risk probability number (RPN) was calculated as a product of the three attributes: RPN = O X S x D. The analysis was carried out by a working group (WG) at UPMC. Results: The total of 56 failure modes were identified including 32 modes before the treatment, 13 modes during the treatment, and 11 modes after the treatment. In addition to the protocols already adopted in the clinical practice, the prioritized risk management will be implanted to the high risk procedures on the basis of RPN score. Conclusion: The effectiveness of the FMEA method was established. The FMEA methodology provides a structured and detailed assessment method for the risk analysis of the LDR Prostate Brachytherapy Procedure and can be applied to other radiation treatment modes.

  3. Non-invasive ventilation in acute respiratory failure in children.

    Science.gov (United States)

    Abadesso, Clara; Nunes, Pedro; Silvestre, Catarina; Matias, Ester; Loureiro, Helena; Almeida, Helena

    2012-04-02

    The aim of this paper is to assess the clinical efficacy of non-invasive ventilation (NIV) in avoiding endotracheal intubation (ETI), to demonstrate clinical and gasometric improvement and to identify predictive risk factors associated with NIV failure. An observational prospective clinical study was carried out. Included Patients with acute respiratory disease (ARD) treated with NIV, from November 2006 to January 2010 in a Pediatric Intensive Care Unit (PICU). NIV was used in 151 patients with acute respiratory failure (ARF). Patients were divided in two groups: NIV success and NIV failure, if ETI was required. Mean age was 7.2±20.3 months (median: 1 min: 0,3 max.: 156). Main diagnoses were bronchiolitis in 102 (67.5%), and pneumonia in 44 (29%) patients. There was a significant improvement in respiratory rate (RR), heart rate (HR), pH, and pCO(2) at 2, 6, 12 and 24 hours after NIV onset (Papneia (P<0.001; odds ratio 15.8; 95% confidence interval: 3.42-71.4) and pneumonia (P<0.001, odds ratio 31.25; 95% confidence interval: 8.33-111.11). There were no major complications related with NIV. In conclusion this study demonstrates the efficacy of NIV as a form of respiratory support for children and infants with ARF, preventing clinical deterioration and avoiding ETI in most of the patients. Risk factors for failure were related with immaturity and severe infection.

  4. A biomechanical analysis of point of failure during lateral-row tensioning in transosseous-equivalent rotator cuff repair.

    Science.gov (United States)

    Dierckman, Brian D; Goldstein, Jordan L; Hammond, Kyle E; Karas, Spero G

    2012-01-01

    The purpose of this study was to determine the maximum load and point of failure of the construct during tensioning of the lateral row of a transosseous-equivalent (TOE) rotator cuff repair. In 6 fresh-frozen human shoulders, a TOE rotator cuff repair was performed, with 1 suture from each medial anchor passed through the tendon and tied in a horizontal mattress pattern. One of 2 limbs from each of 2 medial anchors was pulled laterally over the tendon. After preparation of the lateral bone for anchor placement, the 2 limbs were passed through the polyether ether ketone (PEEK) eyelet of a knotless anchor and tied to a tensiometer. The lateral anchor was placed into the prepared bone tunnel but not fully seated. Tensioning of the lateral-row repair was simulated by pulling the tensiometer to tighten the suture limbs as they passed through the eyelet of the knotless anchor. The mode of failure and maximum tension were recorded. The procedure was then repeated for the second lateral-row anchor. The mean load to failure during lateral-row placement in the TOE model was 80.8 ± 21.0 N (median, 83 N; range, 27.2 to 115.8 N). There was no statistically significant difference between load to failure during lateral-row tensioning for the anterior and posterior anchors (P = .84). Each of the 12 constructs failed at the eyelet of the lateral anchor. Retrieval analysis showed no failure of the medial anchors, no medial suture cutout through the rotator cuff tendon, and no signs of gapping at the repair site. Our results suggest that the medial-row repair does not appear vulnerable during tensioning of the lateral row of a TOE rotator cuff repair with the implants tested. However, surgeons should exercise caution when tensioning the lateral row, especially when lateral-row anchors with PEEK eyelets are implemented. For this repair construct, the findings suggest that although the medial row is not vulnerable during lateral-row tensioning of a TOE rotator cuff repair, lateral

  5. Failure Analysis of PRDS Pipe in a Thermal Power Plant Boiler

    Science.gov (United States)

    Ghosh, Debashis; Ray, Subrata; Mandal, Jiten; Mandal, Nilrudra; Shukla, Awdhesh Kumar

    2018-04-01

    The pressure reducer desuperheater (PRDS) pipeline is used for reducing the pressure and desuperheating of the steam in different auxiliary pipeline. When the PRDS pipeline is failed, the reliability of the boiler is affected. This paper investigates the probable cause/causes of failure of the PRDS tapping line. In that context, visual inspection, outside diameter and wall thickness measurement, chemical analysis, metallographic examination and hardness measurement are conducted as part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it has been concluded that the PRDS pipeline has mainly failed due to graphitization due to prolonged exposure of the pipe at higher temperature. The improper material used is mainly responsible for premature failure of the pipe.

  6. A quantitative impact analysis of sensor failures on human operator's decision making in nuclear power plants

    International Nuclear Information System (INIS)

    Seong, Poong Hyun

    2004-01-01

    In emergency or accident situations in nuclear power plants, human operators take important roles in generating appropriate control signals to mitigate accident situation. In human reliability analysis (HRA) in the framework of probabilistic safety assessment (PSA), the failure probabilities of such appropriate actions are estimated and used for the safety analysis of nuclear power plants. Even though understanding the status of the plant is basically the process of information seeking and processing by human operators, it seems that conventional HRA methods such as THERP, HCR, and ASEP does not pay a lot of attention to the possibilities of providing wrong information to human operators. In this paper, a quantitative impact analysis of providing wrong information to human operators due to instrument faults or sensor failures is performed. The quantitative impact analysis is performed based on a quantitative situation assessment model. By comparing the situation in which there are sensor failures and the situation in which there are not sensor failures, the impact of sensor failures can be evaluated quantitatively. It is concluded that the impact of sensor failures are quite significant at the initial stages, but the impact is gradually reduced as human operators make more and more observations. Even though the impact analysis is highly dependent on the situation assessment model, it is expected that the conclusions made based on other situation assessment models with be consistent with the conclusion made in this paper. (author)

  7. Impact of cognitive function on compliance with treatment in heart failure

    Directory of Open Access Journals (Sweden)

    Beata Jankowska-Polańska

    2017-02-01

    Full Text Available In heart failure (HF patients frailty syndrome and cognitive impairment (CI affect outcome by decreasing the capability for performing self-care, adhering to the prescribed treatment regimen, monitoring symptoms. The aim was to investigate whether CI affects the compliance to therapeutic regimens. Methods: 170 with HF were included. We employed the Mini Mental State Examination (MMSE, for dementia and the Revised Heart Failure Compliance Scale to assess compliance. Results: CI patients showed lower compliance in all domains: 2.8±1.0 vs 3.3±1.0 (keeping appointments, 2.8±0.9 vs. 3.4±0.9 (pharmaceutical compliance, 0.4±0.8 vs. 1.4±1.2 (regular body weight monitoring, 2.0±1.3 vs. 2.7±1.0 (reduced salt intake, 1.9±1.2vs. 2.9±1.0 (fluid intake restriction, and 0.5±0.8 vs. 1.7±1.1 (regular exercise. Multiple regression analysis showed cognitive function to be an independent predictor for regular body weight monitoring (β=1.223;p<0.001, fluid intake restriction (β=1.081;p<0.001, and regular exercise (β=1.237;p<0.001. In multivariate analysis, the stimulant variables for compliance with HF treatment were: education (β=1.124, being in a relationship (β=2.231, and lack of cognitive impairment (β=0.320; the number of hospitalizations due to HF was identified as a destimulant (β=-0.495. Conclusion: Non-compliance is a major problem in elderly with HF. The cognitive function is an independent contributor to total compliance and to compliance with non-pharmaceutical recommendations. Being in a relationship and education are independent predictors of better compliance, while the number of rehospitalizations due to HF exacerbations is an independent predictor of worse compliance. Early detection of CI may offer an opportunity for intervention and a key strategy for improving clinical outcomes in older adults with HF.

  8. Patterns of initial treatment failure of esophageal cancer following radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sugahara, Shinji; Nakajima, Kotaro [Hitachi General Hospital, Ibaraki (Japan); Ohara, Kiyoshi; Okumura, Toshiyuki; Irie, Toshiyuki; Itai, Yuji

    1999-11-01

    Sixty patients with stage I-III esophageal squamous cell cancer treated by definitive radiotherapy (RT) were analyzed for patterns of treatment failure. Patients were treated by external RT alone (n=45) or in combination with intraluminal RT (N=15) when suitable, with prescribed total doses ranging from 59.4 to 104.4 Gy. Concurrent chemotherapy consisting of cisplatin and/or 5-fluorouracil was administered to 19 patients. The two-year actuarial survival rate and two year disease-free survival rate were 29.5% and 18.3%, respectively. Two-year failure rates were 66.5%, 36.9%, and 3.8%, for the esophagus, lymph nodes, and other sites, respectively. Two-year esophageal failure rates for patients with T1-2 (n=8), T3 (n=30), and T4 disease (n=22) were 14.3%, 64.7%, and 87.9%, respectively (p<0.05). A multivariate analysis of esophageal failure with descriptive variables of T classification, tumor length, and performance of intraluminal RT revealed that only T classification was an independent factor (p=0.021). Two-year lymph node failure rates were 24.8% and 33.6% for patients with N0 (n=36) and N1 disease (n=24), respectively (p=0.0035). Lymph node failure in N0 patients was found exclusively outside the treatment field. These results suggest that inclusion of potential lymph node metastases in the radiation field could lessen the lymph node failure rate in T1-3N0M0 patients. (author)

  9. Chest wall thickness and decompression failure: A systematic review and meta-analysis comparing anatomic locations in needle thoracostomy.

    Science.gov (United States)

    Laan, Danuel V; Vu, Trang Diem N; Thiels, Cornelius A; Pandian, T K; Schiller, Henry J; Murad, M Hassan; Aho, Johnathon M

    2016-04-01

    Current Advanced Trauma Life Support guidelines recommend decompression for thoracic tension physiology using a 5-cm angiocatheter at the second intercostal space (ICS) on the midclavicular line (MCL). High failure rates occur. Through systematic review and meta-analysis, we aimed to determine the chest wall thickness (CWT) of the 2nd ICS-MCL, the 4th/5th ICS at the anterior axillary line (AAL), the 4th/5th ICS mid axillary line (MAL) and needle thoracostomy failure rates using the currently recommended 5-cm angiocatheter. A comprehensive search of several databases from their inception to July 24, 2014 was conducted. The search was limited to the English language, and all study populations were included. Studies were appraised by two independent reviewers according to a priori defined PRISMA inclusion and exclusion criteria. Continuous outcomes (CWT) were evaluated using weighted mean difference and binary outcomes (failure with 5-cm needle) were assessed using incidence rate. Outcomes were pooled using the random-effects model. The search resulted in 34,652 studies of which 15 were included for CWT analysis, 13 for NT effectiveness. Mean CWT was 42.79 mm (95% CI, 38.78-46.81) at 2nd ICS-MCL, 39.85 mm (95% CI, 28.70-51.00) at MAL, and 34.33 mm (95% CI, 28.20-40.47) at AAL (P=.08). Mean failure rate was 38% (95% CI, 24-54) at 2nd ICS-MCL, 31% (95% CI, 10-64) at MAL, and 13% (95% CI, 8-22) at AAL (P=.01). Evidence from observational studies suggests that the 4th/5th ICS-AAL has the lowest predicted failure rate of needle decompression in multiple populations. Level 3 SR/MA with up to two negative criteria. Therapeutic. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Gearbox Reliability Collaborative Gearbox 1 Failure Analysis Report: December 2010 - January 2011

    Energy Technology Data Exchange (ETDEWEB)

    Errichello, R.; Muller, J.

    2012-02-01

    Unintended gearbox failures have a significant impact on the cost of wind farm operations. In 2007, NREL initiated the Gearbox Reliability Collaborative (GRC). The project combines analysis, field testing, dynamometer testing, condition monitoring, and the development and population of a gearbox failure database in a multi-pronged approach to determine why wind turbine gearboxes do not achieve their expected design life. The collaborative of manufacturers, owners, researchers, and consultants focuses on gearbox testing and modeling and the development of a gearbox failure database. Collaborative members also investigate gearbox condition monitoring techniques. Data gained from the GRC will enable designers, developers, and manufacturers to improve gearbox designs and testing standards and create more robust modeling tools. GRC project essentials include the development of two identical, heavily instrumented representative gearbox designs. Knowledge gained from the field and dynamometer tests conducted on these gearboxes builds an understanding of how the selected loads and events translate into bearing and gear response. This report contains the analysis of the first gearbox design.

  11. Advances on the Failure Analysis of the Dam—Foundation Interface of Concrete Dams

    Directory of Open Access Journals (Sweden)

    Luis Altarejos-García

    2015-12-01

    Full Text Available Failure analysis of the dam-foundation interface in concrete dams is characterized by complexity, uncertainties on models and parameters, and a strong non-linear softening behavior. In practice, these uncertainties are dealt with a well-structured mixture of experience, best practices and prudent, conservative design approaches based on the safety factor concept. Yet, a sound, deep knowledge of some aspects of this failure mode remain unveiled, as they have been offset in practical applications by the use of this conservative approach. In this paper we show a strategy to analyse this failure mode under a reliability-based approach. The proposed methodology of analysis integrates epistemic uncertainty on spatial variability of strength parameters and data from dam monitoring. The purpose is to produce meaningful and useful information regarding the probability of occurrence of this failure mode that can be incorporated in risk-informed dam safety reviews. In addition, relationships between probability of failure and factors of safety are obtained. This research is supported by a more than a decade of intensive professional practice on real world cases and its final purpose is to bring some clarity, guidance and to contribute to the improvement of current knowledge and best practices on such an important dam safety concern.

  12. Failure mode and effects analysis of witnessing protocols for ensuring traceability during IVF.

    Science.gov (United States)

    Rienzi, Laura; Bariani, Fiorenza; Dalla Zorza, Michela; Romano, Stefania; Scarica, Catello; Maggiulli, Roberta; Nanni Costa, Alessandro; Ubaldi, Filippo Maria

    2015-10-01

    Traceability of cells during IVF is a fundamental aspect of treatment, and involves witnessing protocols. Failure mode and effects analysis (FMEA) is a method of identifying real or potential breakdowns in processes, and allows strategies to mitigate risks to be developed. To examine the risks associated with witnessing protocols, an FMEA was carried out in a busy IVF centre, before and after implementation of an electronic witnessing system (EWS). A multidisciplinary team was formed and moderated by human factors specialists. Possible causes of failures, and their potential effects, were identified and risk priority number (RPN) for each failure calculated. A second FMEA analysis was carried out after implementation of an EWS. The IVF team identified seven main process phases, 19 associated process steps and 32 possible failure modes. The highest RPN was 30, confirming the relatively low risk that mismatches may occur in IVF when a manual witnessing system is used. The introduction of the EWS allowed a reduction in the moderate-risk failure mode by two-thirds (highest RPN = 10). In our experience, FMEA is effective in supporting multidisciplinary IVF groups to understand the witnessing process, identifying critical steps and planning changes in practice to enable safety to be enhanced. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Common-Cause Failure Analysis in Event Assessment

    International Nuclear Information System (INIS)

    Rasmuson, D.M.; Kelly, D.L.

    2008-01-01

    This paper reviews the basic concepts of modeling common-cause failures (CCFs) in reliability and risk studies and then applies these concepts to the treatment of CCF in event assessment. The cases of a failed component (with and without shared CCF potential) and a component being unavailable due to preventive maintenance or testing are addressed. The treatment of two related failure modes (e.g. failure to start and failure to run) is a new feature of this paper, as is the treatment of asymmetry within a common-cause component group

  14. SU-F-T-246: Evaluation of Healthcare Failure Mode And Effect Analysis For Risk Assessment

    International Nuclear Information System (INIS)

    Harry, T; Manger, R; Cervino, L; Pawlicki, T

    2016-01-01

    Purpose: To evaluate the differences between the Veteran Affairs Healthcare Failure Modes and Effect Analysis (HFMEA) and the AAPM Task Group 100 Failure and Effect Analysis (FMEA) risk assessment techniques in the setting of a stereotactic radiosurgery (SRS) procedure were compared respectively. Understanding the differences in the techniques methodologies and outcomes will provide further insight into the applicability and utility of risk assessments exercises in radiation therapy. Methods: HFMEA risk assessment analysis was performed on a stereotactic radiosurgery procedure. A previous study from our institution completed a FMEA of our SRS procedure and the process map generated from this work was used for the HFMEA. The process of performing the HFMEA scoring was analyzed, and the results from both analyses were compared. Results: The key differences between the two risk assessments are the scoring criteria for failure modes and identifying critical failure modes for potential hazards. The general consensus among the team performing the analyses was that scoring for the HFMEA was simpler and more intuitive then the FMEA. The FMEA identified 25 critical failure modes while the HFMEA identified 39. Seven of the FMEA critical failure modes were not identified by the HFMEA and 21 of the HFMEA critical failure modes were not identified by the FMEA. HFMEA as described by the Veteran Affairs provides guidelines on which failure modes to address first. Conclusion: HFMEA is a more efficient model for identifying gross risks in a process than FMEA. Clinics with minimal staff, time and resources can benefit from this type of risk assessment to eliminate or mitigate high risk hazards with nominal effort. FMEA can provide more in depth details but at the cost of elevated effort.

  15. SU-F-T-246: Evaluation of Healthcare Failure Mode And Effect Analysis For Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Harry, T [Oregon State University, Corvallis, OR (United States); University of California, San Diego, La Jolla, CA (United States); Manger, R; Cervino, L; Pawlicki, T [University of California, San Diego, La Jolla, CA (United States)

    2016-06-15

    Purpose: To evaluate the differences between the Veteran Affairs Healthcare Failure Modes and Effect Analysis (HFMEA) and the AAPM Task Group 100 Failure and Effect Analysis (FMEA) risk assessment techniques in the setting of a stereotactic radiosurgery (SRS) procedure were compared respectively. Understanding the differences in the techniques methodologies and outcomes will provide further insight into the applicability and utility of risk assessments exercises in radiation therapy. Methods: HFMEA risk assessment analysis was performed on a stereotactic radiosurgery procedure. A previous study from our institution completed a FMEA of our SRS procedure and the process map generated from this work was used for the HFMEA. The process of performing the HFMEA scoring was analyzed, and the results from both analyses were compared. Results: The key differences between the two risk assessments are the scoring criteria for failure modes and identifying critical failure modes for potential hazards. The general consensus among the team performing the analyses was that scoring for the HFMEA was simpler and more intuitive then the FMEA. The FMEA identified 25 critical failure modes while the HFMEA identified 39. Seven of the FMEA critical failure modes were not identified by the HFMEA and 21 of the HFMEA critical failure modes were not identified by the FMEA. HFMEA as described by the Veteran Affairs provides guidelines on which failure modes to address first. Conclusion: HFMEA is a more efficient model for identifying gross risks in a process than FMEA. Clinics with minimal staff, time and resources can benefit from this type of risk assessment to eliminate or mitigate high risk hazards with nominal effort. FMEA can provide more in depth details but at the cost of elevated effort.

  16. Failure analysis and failure prevention in electric power systems

    International Nuclear Information System (INIS)

    Rau, C.A. Jr.; Becker, D.G.; Besuner, P.M.; Cipolla, R.C.; Egan, G.R.; Gupta, P.; Johnson, D.P.; Omry, U.; Tetelman, A.S.; Rettig, T.W.; Peters, D.C.

    1977-01-01

    New methods have been developed and applied to better quantify and increase the reliability, safety, and availability of electric power plants. Present and potential problem areas have been identified both by development of an improved computerized data base of malfunctions in nuclear power plants and by detailed metallurgical and mechanical failure analyses of selected problems. Significant advances in the accuracy and speed of structural analyses have been made through development and application of the boundary integral equation and influence function methods of stress and fracture mechanics analyses. The currently specified flaw evaluation procedures of the ASME Boiler and Pressure Vessel Code have been computerized. Results obtained from these procedures for evaluation of specific in-service inspection indications have been compared with results obtained utilizing the improved analytical methods. Mathematical methods have also been developed to describe and analyze the statistical variations in materials properties and in component loading, and uncertainties in the flaw size that might be passed by quality assurance systems. These new methods have been combined to develop accurate failure rate predictions based upon probabilistic fracture mechanics. Improved failure prevention strategies have been formulated by combining probabilistic fracture mechanics and cost optimization techniques. The approach has been demonstrated by optimizing the nondestructive inspection level with regard to both reliability and cost. (Auth.)

  17. Vacuum-assisted breast biopsy: A comparison of 11-gauge and 8-gauge needles in benign breast disease

    Directory of Open Access Journals (Sweden)

    Kraemer Bernhard

    2008-05-01

    Full Text Available Abstract Background Minimal invasive breast biopsy is standard care for the diagnosis of suspicious breast lesions. There are different vacuum biopsy (VB systems in use. The aim of the study was to determine the differences between the 8-gauge and the 11-gauge needle with respect to a diagnostic reliability, b complication rate and c subjective perception of pain when used for vacuum-assisted breast biopsy. Methods Between 01/2000 and 09/2004, 923 patients at St. Josefs-Hospital Wiesbaden underwent VB using the Mammotome® (Ethicon Endosurgery, Hamburg. Depending on preoperative detection, the procedure was performed under sonographic or mammographic guidance under local anaesthesia. All patients included in the study were followed up both clinically and using imaging techniques one week after the VB and a second time after a median of 41 months. Excisional biopsy on the ipsilateral breast was an exclusion criteria. Subjective pain scores were recorded on a scale of 0 – 10 (0 = no pain, 10 = unbearable pain. The mean age of the patients was 53 years (30 – 88. Results 123 patients were included in the study in total. 48 patients were biopsied with the 8-gauge needle and 75 with the 11-gauge needle. The use of the 8-gauge needle did not show any significant differences to the 11-gauge needle with regard to diagnostic reliability, complication rate and subjective perception of pain. Conclusion Our data show that there are no relevant differences between the 8-gauge and 11-gauge needle when used for VB. Under sonographic guidance, the use of the 8-gauge needle is recommended for firm breast tissue due to its sharp scalpel point and especially for complete removal of benign lesions. We did not find any advantages in the use of the larger 8-gauge needle compared to the 11-gauge needle in the mammography setting. The utilisation costs of the 8-gauge needle are somewhat higher.

  18. Failure mode analysis using state variables derived from fault trees with application

    International Nuclear Information System (INIS)

    Bartholomew, R.J.

    1982-01-01

    Fault Tree Analysis (FTA) is used extensively to assess both the qualitative and quantitative reliability of engineered nuclear power systems employing many subsystems and components. FTA is very useful, but the method is limited by its inability to account for failure mode rate-of-change interdependencies (coupling) of statistically independent failure modes. The state variable approach (using FTA-derived failure modes as states) overcomes these difficulties and is applied to the determination of the lifetime distribution function for a heat pipe-thermoelectric nuclear power subsystem. Analyses are made using both Monte Carlo and deterministic methods and compared with a Markov model of the same subsystem

  19. Clinical effectiveness, toxicity, and failure patterns of helical tomotherapy for postoperative oral cavity cancer patients

    Directory of Open Access Journals (Sweden)

    Hsieh CH

    2014-03-01

    Full Text Available Chen-Hsi Hsieh,1–3 Pei-Wei Shueng,1,4 Li-Ying Wang,5 Li-Jen Liao,6 Yu-Chin Lin,7 Ying-Shiung Kuo,8 Wu-Chia Lo,6 Chien-Fu Tseng,8 Hui-Ju Tien,1 Hsiu-Ling Chou,9,10 Yen-Ping Hsieh,11 Le-Jung Wu,1 Yu-Jen Chen3,12–14 1Department of Radiation Oncology, Far Eastern Memorial Hospital, 2Department of Medicine, 3Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 4Department of Radiation Oncology, National Defense Medical Center, 5School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, 6Department of Otolaryngology, 7Division of Medical Oncology and Hematology, Department of Internal Medicine, 8Department of Dentistry and Oral Surgery, 9Department of Nursing, Far Eastern Memorial Hospital, 10Department of Nursing, Oriental Institute of Technology, Taipei, 11Department of Senior Citizen Service Management, National Taichung University of Science and Technology, Taichung, 12Department of Radiation Oncology, 13Department of Medical Research, Mackay Memorial Hospital, 14Graduate Institute of Sport Coaching Science, Chinese Culture University, Taipei, Taiwan Background: The outcome of postoperative high- and intermediate-risk oral cavity cancer (OCC patients receiving helical tomotherapy (HT remains limited. Materials and methods: Between November 2006 and November 2012, 53 postoperative high- and intermediate-risk OCC patients treated with HT were enrolled. Results: The 4-year locoregional, local, and regional control rates were 66%, 76.4%, and 94.3%, respectively. The 4-year locoregional control rates of oral tongue and buccal mucosa cancer were 88.3% and 37.1%, respectively (P=0.012. Eleven (20.8% patients experienced locoregional failure. In-field failure occurred in six of 53 (11.3% in the primary area and three of 53 (5.7% in the regional lymph-node area. No marginal failure was noted. Two of 53 (3.8% experienced out-of-field failure. The rates of grade 3 dermatitis

  20. Both in- and out-hospital worsening of renal function predict outcome in patients with heart failure: results from the Coordinating Study Evaluating Outcome of Advising and Counseling in Heart Failure (COACH).

    Science.gov (United States)

    Damman, Kevin; Jaarsma, Tiny; Voors, Adriaan A; Navis, Gerjan; Hillege, Hans L; van Veldhuisen, Dirk J

    2009-09-01

    The effect of worsening renal function (WRF) after discharge on outcome in patients with heart failure is unknown. We assessed estimated glomerular filtration rate (eGFR) and serum creatinine at admission, discharge, and 6 and 12 months after discharge, in 1023 heart failure patients. Worsening renal function was defined as an increase in serum creatinine of >26.5 micromol/L and >25%. The primary endpoint was a composite of all-cause mortality and heart failure admissions. The mean age of patients was 71 +/- 11 years, and 62% was male. Mean eGFR at admission was 55 +/- 21 mL/min/1.73 m(2). In-hospital WRF occurred in 11% of patients, while 16 and 9% experienced WRF from 0 to 6, and 6 to 12 months after discharge, respectively. In multivariate landmark analysis, WRF at any point in time was associated with a higher incidence of the primary endpoint: hazard ratio (HR) 1.63 (1.10-2.40), P = 0.014 for in-hospital WRF, HR 2.06 (1.13-3.74), P = 0.018 for WRF between 0-6 months, and HR 5.03 (2.13-11.88), P < 0.001 for WRF between 6-12 months. Both in- and out-hospital worsening of renal function are independently related to poor prognosis in patients with heart failure, suggesting that renal function in heart failure patients should be monitored long after discharge.

  1. Random safety auditing, root cause analysis, failure mode and effects analysis.

    Science.gov (United States)

    Ursprung, Robert; Gray, James

    2010-03-01

    Improving quality and safety in health care is a major concern for health care providers, the general public, and policy makers. Errors and quality issues are leading causes of morbidity and mortality across the health care industry. There is evidence that patients in the neonatal intensive care unit (NICU) are at high risk for serious medical errors. To facilitate compliance with safe practices, many institutions have established quality-assurance monitoring procedures. Three techniques that have been found useful in the health care setting are failure mode and effects analysis, root cause analysis, and random safety auditing. When used together, these techniques are effective tools for system analysis and redesign focused on providing safe delivery of care in the complex NICU system. Copyright 2010 Elsevier Inc. All rights reserved.

  2. Failure mode and effects analysis outputs: are they valid?

    Directory of Open Access Journals (Sweden)

    Shebl Nada

    2012-06-01

    Full Text Available Abstract Background Failure Mode and Effects Analysis (FMEA is a prospective risk assessment tool that has been widely used within the aerospace and automotive industries and has been utilised within healthcare since the early 1990s. The aim of this study was to explore the validity of FMEA outputs within a hospital setting in the United Kingdom. Methods Two multidisciplinary teams each conducted an FMEA for the use of vancomycin and gentamicin. Four different validity tests were conducted: · Face validity: by comparing the FMEA participants’ mapped processes with observational work. · Content validity: by presenting the FMEA findings to other healthcare professionals. · Criterion validity: by comparing the FMEA findings with data reported on the trust’s incident report database. · Construct validity: by exploring the relevant mathematical theories involved in calculating the FMEA risk priority number. Results Face validity was positive as the researcher documented the same processes of care as mapped by the FMEA participants. However, other healthcare professionals identified potential failures missed by the FMEA teams. Furthermore, the FMEA groups failed to include failures related to omitted doses; yet these were the failures most commonly reported in the trust’s incident database. Calculating the RPN by multiplying severity, probability and detectability scores was deemed invalid because it is based on calculations that breach the mathematical properties of the scales used. Conclusion There are significant methodological challenges in validating FMEA. It is a useful tool to aid multidisciplinary groups in mapping and understanding a process of care; however, the results of our study cast doubt on its validity. FMEA teams are likely to need different sources of information, besides their personal experience and knowledge, to identify potential failures. As for FMEA’s methodology for scoring failures, there were discrepancies

  3. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

    Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

  4. 11 CFR 9405.8 - Appeals of denials of requests for records.

    Science.gov (United States)

    2010-01-01

    ... received by the Commission, may appeal the adverse determination or the failure to respond by requesting... occur. (b) The appeal request shall be in writing, shall clearly and prominently state on the envelope... not entertain any appeal from an alleged denial or failure to comply with an oral request. Any person...

  5. Somatic mutation analysis of MYH11 in breast and prostate cancer

    International Nuclear Information System (INIS)

    Alhopuro, Pia; Karhu, Auli; Winqvist, Robert; Waltering, Kati; Visakorpi, Tapio; Aaltonen, Lauri A

    2008-01-01

    MYH11 (also known as SMMHC) encodes the smooth-muscle myosin heavy chain, which has a key role in smooth muscle contraction. Inversion at the MYH11 locus is one of the most frequent chromosomal aberrations found in acute myeloid leukemia. We have previously shown that MYH11 mutations occur in human colorectal cancer, and may also be associated with Peutz-Jeghers syndrome. The mutations found in human intestinal neoplasia result in unregulated proteins with constitutive motor activity, similar to the mutant myh11 underlying the zebrafish meltdown phenotype characterized by disrupted intestinal architecture. Recently, MYH1 and MYH9 have been identified as candidate breast cancer genes in a systematic analysis of the breast cancer genome. The aim of this study was to investigate the role of somatic MYH11 mutations in two common tumor types; breast and prostate cancers. A total of 155 breast cancer and 71 prostate cancer samples were analyzed for those regions in MYH11 (altogether 8 exons out of 42 coding exons) that harboured mutations in colorectal cancer in our previous study. In breast cancer samples only germline alterations were observed. One prostate cancer sample harbored a frameshift mutation c.5798delC, which we have previously shown to result in a protein with unregulated motor activity. Little evidence for a role of somatic MYH11 mutations in the formation of breast or prostate cancers was obtained in this study

  6. Synthesis and hydrogen storage of La23Nd7.8Ti1.1Ni33.9Co32.9Al0.65 alloys

    Directory of Open Access Journals (Sweden)

    Priyanka Meena

    2018-04-01

    Full Text Available The present work investigates structural and hydrogen storage properties of first time synthesized La23Nd7.8Ti1.1Ni33.9Co32.9Al0.65 alloy by arc melting process and ball milled to get it in nano structure form. XRD analysis of as-prepared alloy showed single phased hexagonal LaNi5-type structure with 52 nm average particle size, which reduces to about 31 nm after hydrogenations. Morphological studies by SEM were undertaken to investigate the effect of hydrogenation of nanostructured alloy. EDX analysis confirmed elemental composition of the as-prepared alloy. Activation energy for hydrogen desorption was studied using TGA analysis and found to be −76.86 kJ/mol. Hydrogenation/dehydrogenation reactions and absorption kinetics were measured at temperature 100 °C. The equilibrium plateau pressure was determined to be 2 bar at 100 °C giving hydrogen storage capacity of about 2.1 wt%. Keywords: Hydrogen storage, La23Nd7.8Ti1.1Ni33.9Co32.9Al0.65 alloy, SEM, EDS, TGA, Hydrogenation/dehydrogenation

  7. Statistical Analysis of the Random Telegraph Noise in a 1.1 μm Pixel, 8.3 MP CMOS Image Sensor Using On-Chip Time Constant Extraction Method.

    Science.gov (United States)

    Chao, Calvin Yi-Ping; Tu, Honyih; Wu, Thomas Meng-Hsiu; Chou, Kuo-Yu; Yeh, Shang-Fu; Yin, Chin; Lee, Chih-Lin

    2017-11-23

    A study of the random telegraph noise (RTN) of a 1.1 μm pitch, 8.3 Mpixel CMOS image sensor (CIS) fabricated in a 45 nm backside-illumination (BSI) technology is presented in this paper. A noise decomposition scheme is used to pinpoint the noise source. The long tail of the random noise (RN) distribution is directly linked to the RTN from the pixel source follower (SF). The full 8.3 Mpixels are classified into four categories according to the observed RTN histogram peaks. A theoretical formula describing the RTN as a function of the time difference between the two phases of the correlated double sampling (CDS) is derived and validated by measured data. An on-chip time constant extraction method is developed and applied to the RTN analysis. The effects of readout circuit bandwidth on the settling ratios of the RTN histograms are investigated and successfully accounted for in a simulation using a RTN behavior model.

  8. BILAM: a composite laminate failure-analysis code using bilinear stress-strain approximations

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, P.V. Jr.; Dasgupta, A.; Chun, Y.W.

    1980-10-01

    The BILAM code which uses constant strain laminate analysis to generate in-plane load/deformation or stress/strain history of composite laminates to the point of laminate failure is described. The program uses bilinear stress-strain curves to model layer stress-strain behavior. Composite laminates are used for flywheels. The use of this computer code will help to develop data on the behavior of fiber composite materials which can be used by flywheel designers. In this program the stress-strain curves are modelled by assuming linear response in axial tension while using bilinear approximations (2 linear segments) for stress-strain response to axial compressive, transverse tensile, transverse compressive and axial shear loadings. It should be noted that the program attempts to empirically simulate the effects of the phenomena which cause nonlinear stress-strain behavior, instead of mathematically modelling the micromechanics involved. This code, therefore, performs a bilinear laminate analysis, and, in conjunction with several user-defined failure interaction criteria, is designed to provide sequential information on all layer failures up to and including the first fiber failure. The modus operandi is described. Code BILAM can be used to: predict the load-deformation/stress-strain behavior of a composite laminate subjected to a given combination of in-plane loads, and make analytical predictions of laminate strength.

  9. Analysis of Service Recovery Failure: From Minority Perspective

    OpenAIRE

    Yasemin Öcal Atınç

    2016-01-01

    We investigate the service failures towards diverse customer groups for the purpose to bring insightful proposals to the managers to recover from these failures. Previous literature provided insights regarding the perception of service failures by minorities and the challenge of recovery due to racial implications driven from the failure, however lacked to propose suggestions for the managers so that they can take either corrective steps toward service failure recovery or prevent service fail...

  10. [Predictive factors for failure of non-invasive positive pressure ventilation in immunosuppressed patients with acute respiratory failure].

    Science.gov (United States)

    Jia, Xiangli; Yan, Ci; Xu, Sicheng; Gu, Xingli; Wan, Qiufeng; Hu, Xinying; Li, Jingwen; Liu, Guangming; Caikai, Shareli; Guo, Zhijin

    2018-02-01

    To evaluate the predictive factors for failure of non-invasive positive pressure ventilation (NIPPV) in immunosuppressed patients with acute respiratory failure (ARF). The clinical data of 118 immuno-deficient patients treated with NIPPV in the respiratory and intensive care unit (RICU) of the First Affiliated Hospital of Xinjiang Medical University from January 2012 to August 2017 were retrospectively analyzed. The patients were divided into a non-endotracheal intubation (ETI) group (n = 62) and ETI group (n = 56) according to whether ETI was performed during the hospitalization period or not. Each observed indicator was analyzed by univariate analysis, and factors leading to failure of NIPPV were further analyzed by Logistic regression. Receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of risk factors for failure of NIPPV in immunosuppressed patients with ARF. The non-intubation rate for NIPPV in immunosuppressed patients was 50.8% (60/118). Compared with the non-ETI group, the body temperature, pH value in the ETI group were significantly increased, the partial pressure of arterial carbon dioxide (PaCO 2 ) was significantly decreased, the ratio of oxygenation index (PaO 2 /FiO 2 ) failure of NIPPV. ROC curve analysis showed that the APACHE II score ≥ 20 and PaO 2 /FiO 2 failure of NIPPV, the area under ROC curve (AUC) of the APACHE II score ≥ 20 was 0.787, the sensitivity was 83.93%, the specificity was 69.35%, the positive predict value (PPV) was 71.21%, the negative predict value (NPV) was 82.69%, the positive likelihood ratio (PLR) was 2.74, the negative likelihood ratio (NLR) was 0.23, and Youden index was 0.53; the AUC of PaO 2 /FiO 2 failure of NIPPV in immunocompromised patients.

  11. [Failure mode and effects analysis (FMEA) of insulin in a mother-child university-affiliated health center].

    Science.gov (United States)

    Berruyer, M; Atkinson, S; Lebel, D; Bussières, J-F

    2016-01-01

    Insulin is a high-alert drug. The main objective of this descriptive cross-sectional study was to evaluate the risks associated with insulin use in healthcare centers. The secondary objective was to propose corrective measures to reduce the main risks associated with the most critical failure modes in the analysis. We conducted a failure mode and effects analysis (FMEA) in obstetrics-gynecology, neonatology and pediatrics. Five multidisciplinary meetings occurred in August 2013. A total of 44 out of 49 failure modes were analyzed. Nine out of 44 (20%) failure modes were deemed critical, with a criticality score ranging from 540 to 720. Following the multidisciplinary meetings, everybody agreed that an FMEA was a useful tool to identify failure modes and their relative importance. This approach identified many corrective measures. This shared experience increased awareness of safety issues with insulin in our mother-child center. This study identified the main failure modes and associated corrective measures. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Root cause analysis of SI line-seated thermal sleeve separation failures

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Jhung, Myung Jo; Kim, Hho Jung

    2004-01-01

    At conventional pressurized water reactors, a thermal sleeve (named simply 'sleeve' hereafter) is seated inside the nozzle part of each Safety Injection (SI) branch pipe to prevent and relieve potential excessive transient thermal stress in the nozzle wall when a cold water is injected during the safety injection mode Recently, mechanical failures that the sleeves are separated from the SI branch pipe and fall into the connected cold leg main pipe were occurred in sequence at Yonggwang units 5 and 6 and Ulchin unit 5. There were many activities and efforts to figure out the causes of those failures with experts' reasoning, but the proposed causes were derived from superficial views rather than physically concrete grounds or analysis results. The prerequisites to find out the root causes of failure mechanism will be to identify the flow situation in the pipe junction area connecting the cold leg with the SI pipe and to know the vibration characteristics of sleeves. This paper investigates the flow field in the pipe junction thru a numerical simulation and vibration characteristics of thermal sleeves thru a modal analysis, from which the root causes of sleeve separation mechanism are analyzed

  13. Failure analysis of top nozzle holddown spring screw for nuclear fuel assembly

    International Nuclear Information System (INIS)

    Koh, S. K.; Ryu, C. H.; Na, E. G.; Baek, T. H.; Jeon, K. L.

    2003-01-01

    A failure analysis of holddown spring screw was performed using fracture mechanics approach. The spring screw was designed such that it was capable of sustaining the loads imposed by the initial tensile preload and operational loads. In order to investigate the cause of failure, a stress analysis of the top nozzle spring assembly was done using finite element analysis and a life prediction of the screw was made using a fracture mechanics approach. The elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Primary water stress corrosion cracking life of the Inconel 600 screw was predicted by using integration of the Scott model and resulted in 1.42 years, which was fairly close to the actual service life of the holddown spring screw

  14. FAILURE MODE AND EFFECT ANALYSIS (FMEA OF BUTTERFLY VALVE IN OIL AND GAS INDUSTRY

    Directory of Open Access Journals (Sweden)

    MUHAMMAD AMIRUL BIN YUSOF

    2016-04-01

    Full Text Available Butterfly valves are mostly used in various industries such as oil and gas plant. This valve operates with rotating motion using pneumatic system. Rotating actuator turns the disc either parallel or perpendicular to the flow. When the valve is fully open, the disc is rotated a quarter turn so that it allows free passage of the fluid and when fully closed, the disc rotated a quarter turns to block the fluid. The primary failure modes for valves are the valve leaks to environment through flanges, seals on the valve body, valve stem packing not properly protected, over tightened packing nuts, the valve cracks and leaks over the seat. To identify the failure of valve Failure Mode and Effects Analysis has been chosen. FMEA is the one of technique to perform failure analysis. It involves reviewing as many components to identify failure modes, and their causes and effects. For each component, the failure modes and their resulting effects on the rest of the system are recorded in a specific FMEA form. Risk priority number, severity, detection, occurrence are the factor determined in this studies. Risk priority number helps to find out the highest hazardous activities which need more attention than the other activity. The highest score of risk priority number in this research is seat. Action plan was proposed to reduce the risk priority number and so that potential failures also will be reduced.

  15. Investigation of a Rise in Obstetric Acute Renal Failure in the United States, 1999-2011.

    Science.gov (United States)

    Mehrabadi, Azar; Dahhou, Mourad; Joseph, K S; Kramer, Michael S

    2016-05-01

    To estimate whether the reported increase in obstetric acute renal failure in the United States was attributable to a concurrent rise in postpartum hemorrhage, a change in other risk factors, or changes in the diagnosis of acute renal failure. We conducted a retrospective cohort study to quantify temporal trends in acute renal failure among 10,969,263 hospital deliveries in the United States from 1999 to 2011 using data from the Nationwide Inpatient Sample. Dialysis and maternal death were used as markers of severe acute renal failure. Logistic regression was used to determine whether changes in risk factors explained the temporal rise in acute renal failure. Obstetric acute renal failure rose from 2.4 to 6.3 per 10,000 deliveries between 1999-2001 and 2010-2011, a 10% yearly increase (95% confidence interval [CI] 8-11%) and adjustment for risk factors only partially explained the rise (adjusted yearly increase 6%, 95% CI 5-8%). The overall severity of acute renal failure decreased, although acute renal failure with dialysis rose from 0.27 to 0.36 per 10,000 deliveries (P for trend=.01), and acute renal failure associated with maternal death increased from 0.13 to 0.23 per 10,000 deliveries (P for trend=.01). The temporal increase in acute renal failure with dialysis was abolished by adjustment for chronic kidney disease and chronic hypertension. Changes in diagnosis or ascertainment have led to substantial increases in obstetric acute renal failure, whereas increases in chronic kidney disease and chronic hypertension among pregnant women have resulted in modest but significant increases in acute renal failure with dialysis.

  16. Performance Demonstration Initiative U.S. implementation of ASME B and PV code section 11 Appendix 8

    International Nuclear Information System (INIS)

    Becker, F.L.; Ammirato, F.; Huffman, K.

    1994-01-01

    New requirements have now been added to Section 11 as mandatory Appendix 8, ''Performance Demonstration Requirements for Ultrasonic Examination systems''. The appendix was recently published and incorporates performance demonstration requirements for ultrasonic examination equipment, procedures, and personnel. These new requirements will have far reaching and significant impact on the conduct of ISI at all nuclear power plants. For the first time since Section 11 was issued in 1970, the effectiveness of ultrasonic examination procedures and the proficiency of examiners must be demonstrated on reactor pressure vessel (RPV), piping, and bolting markups containing real flaws, Recognizing the importance and complexity of Appendix 8 implementation, representatives from all US nuclear utilities have formed the Performance Demonstration Initiative (PDI) to implement Appendix 8 to provide for uniform implementation

  17. 8 to 11 keV x-ray sources for imaging and absorption experiments

    International Nuclear Information System (INIS)

    Molitoris, J.D.; Phillion, D.W.; Osterheld, A.L.; Stewart, R.E.; Rothman, S.D.

    1992-01-01

    We have measured the 8 to 11 keV emission spectra from plasmas produced by impinging 0.53 μm 100 and 200 ps FWHM Gaussian laser pulses on targets of different materials. The experimental spectra from W and Zn are identified by comparison with local thermodynamic equilibrium plasma emission calculations

  18. Definition of the locus responsible for systemic carnitine deficiency within a 1.6-cM region of mouse chromosome 11 by detailed linkage analysis

    Energy Technology Data Exchange (ETDEWEB)

    Okita, Kohei; Tokino, Takashi; Nishimori, Hiroyuki [Univ. of Tokyo (Japan)] [and others

    1996-04-15

    Carnitine is an essential cofactor for oxidation of mitochondrial fatty acids. Carnitine deficiency results in failure of energy production by mitochondria and leads to metabolic encephalopathy, lipid-storage myopathy, and cardiomyopathy. The juvenile visceral steatosis (JVS) mouse, an animal model of systemic carnitine deficiency, inherits the JVS phenotype in autosomal recessive fashion, through a mutant allele mapped to mouse chromosome 11. As a step toward identifying the gene responsible for JVS by positional cloning, we attempted to refine the jvs locus in the mouse by detailed linkage analysis with 13 microsatellite markers, using 190 backcross progeny. Among the 13 loci tested, 5 (defined by markers D11Mit24, D11Mit111,D11Nds9, D11Mit86, and D11Mit23) showed no recombination, with a maximum lod score of 52.38. Our results implied that the jvs gene can be sought on mouse chromosome 11 within a genetic distance no greater than about 1.6 cM. 21 refs., 2 figs.

  19. Reliability Analysis of Fatigue Failure of Cast Components for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Hesam Mirzaei Rafsanjani

    2015-04-01

    Full Text Available Fatigue failure is one of the main failure modes for wind turbine drivetrain components made of cast iron. The wind turbine drivetrain consists of a variety of heavily loaded components, like the main shaft, the main bearings, the gearbox and the generator. The failure of each component will lead to substantial economic losses such as cost of lost energy production and cost of repairs. During the design lifetime, the drivetrain components are exposed to variable loads from winds and waves and other sources of loads that are uncertain and have to be modeled as stochastic variables. The types of loads are different for offshore and onshore wind turbines. Moreover, uncertainties about the fatigue strength play an important role in modeling and assessment of the reliability of the components. In this paper, a generic stochastic model for fatigue failure of cast iron components based on fatigue test data and a limit state equation for fatigue failure based on the SN-curve approach and Miner’s rule is presented. The statistical analysis of the fatigue data is performed using the Maximum Likelihood Method which also gives an estimate of the statistical uncertainties. Finally, illustrative examples are presented with reliability analyses depending on various stochastic models and partial safety factors.

  20. Geotechnical Failure of a Concrete Crown Wall on a Rubble Mound Breakwater Considering Sliding Failure and Rupture Failure of Foundation

    DEFF Research Database (Denmark)

    Christiani, E.; Burcharth, H. F.; Sørensen, John Dalsgaard

    1995-01-01

    Sliding and rupture failure in the rubble mound are considered in this paper. In order to describe these failure modes the wave breaking forces have to be accounted for. Wave breaking forces on a crown wall are determined from Burcharth's wave force formula Burcharth (1992). Overtopping rates...... are calculated for a given design by Bradbury et al. (1988a,b) and compared to acceptable overtopping rates, prior to a determininstic design. The method of foundation stability analysis is presented by the example of a translation slip failure involving kinematically correct slip surfaces and failure zones...... in friction based soil. Rupture failure modes for a crown wall with a plane base and a crown wall with an extended leg on the seaward side will be formulated. The failure modes are described by limit state functions. This allows a deterministic analysis to be performed....

  1. Patterns of Failure for Rhabdomyosarcoma of the Perineal and Perianal Region

    International Nuclear Information System (INIS)

    Casey, Dana L.; Wexler, Leonard H.; LaQuaglia, Michael P.; Meyers, Paul A.; Wolden, Suzanne L.

    2014-01-01

    Purpose: To analyze prognostic factors and patterns of failure for rhabdomyosarcoma of the perineal and perianal region (PRMS), with an emphasis on radiation therapy for locoregional control. Methods and Materials: Detailed records of all 14 patients treated for PRMS at Memorial Sloan-Kettering Cancer Center between 1998 and 2012 were reviewed. The Kaplan-Meier method was used to assess the event-free survival (EFS) and overall survival (OS), and a competing-risks analysis was used to assess the cumulative incidence of local, regional, and distant failures. Results: Median age was 15.8 years (range, 1.1-31.9 years). High-risk features were identified: 9 of 14 patients (64%) had group 3 disease and 3 of 14 (21%) had group 4; 11 of 14 tumors (78%) were alveolar; 12 of 14 tumors (86%) were ≥5 cm; and 9 of 14 patients (64%) had involved lymph nodes (N1). Of those aged ≥10 years at diagnosis, 9 of 10 (90%) had alveolar histology, all had tumors ≥5 cm, and 8 of 10 (80%) presented with N1 disease. The rates of local, regional, and distant failure at 5 years were 17%, 31%, and 52%, respectively. Although 3 of the 4 patients with regional failure received nodal irradiation, only one of the nodal failures occurred in the radiation therapy field. The 5-year EFS was 33%, and OS was 39%. Age ≥10 years was associated with poor outcomes: EFS was 13% in patients aged ≥10 years, compared with 75% in those aged <10 years (P=.04); the OS was 13% in patients aged ≥10 years, compared with 100% in those aged <10 years (P=.04). Conclusions: Patients with PRMS, especially those aged ≥10 years, present with poor prognostic features and continue to have poor outcomes. Given the high incidence of regional node recurrence, we recommend prophylactic ilioinguinal lymph node irradiation for all patients aged ≥10 years. For children aged <10 years, nodal evaluation is essential to determine the role for lymph node irradiation

  2. Failure Mode and Effect Analysis of Subsea Multiphase Pump Equipment

    Directory of Open Access Journals (Sweden)

    Oluwatoyin Shobowale Kafayat

    2014-07-01

    Full Text Available Finding oil and gas reserves in deep/harsh environment with challenging reservoir and field conditions, subsea multiphase pumping benefits has found its way to provide solutions to these issues. Challenges such as failure issues that are still surging the industry and with the current practice of information hiding, this issues becomes even more difficult to tackle. Although, there are some joint industry projects which are only accessible to its members, still there is a need to have a clear understanding of these equipment groups so as to know which issues to focus attention on. A failure mode and effect analysis (FMEA is a potential first aid in understanding this equipment groups. A survey questionnaire/interview was conducted with the oil and gas operating company and equipment manufacturer based on the literature review. The results indicates that these equipment’s group are similar with its onshore counterpart, but the difference is the robustness built into the equipment internal subsystems for subsea applications. The results from the manufacturer perspectives indicates that Helico-axial multiphase pump have a mean time to failure of more than 10 years, twin-screw and electrical submersible pumps are still struggling with a mean time to failure of less than 5 years.

  3. Reliability analysis of Markov history-dependent repairable systems with neglected failures

    International Nuclear Information System (INIS)

    Du, Shijia; Zeng, Zhiguo; Cui, Lirong; Kang, Rui

    2017-01-01

    Markov history-dependent repairable systems refer to the Markov repairable systems in which some states are changeable and dependent on recent evolutional history of the system. In practice, many Markov history-dependent repairable systems are subjected to neglected failures, i.e., some failures do not affect system performances if they can be repaired promptly. In this paper, we develop a model based on the theory of aggregated stochastic processes to describe the history-dependent behavior and the effect of neglected failures on the Markov history-dependent repairable systems. Based on the developed model, instantaneous and steady-state availabilities are derived to characterize the reliability of the system. Four reliability-related time distributions, i.e., distribution for the k th working period, distribution for the k th failure period, distribution for the real working time in an effective working period, distribution for the neglected failure time in an effective working period, are also derived to provide a more comprehensive description of the system's reliability. Thanks to the power of the theory of aggregated stochastic processes, closed-form expressions are obtained for all the reliability indexes and time distributions. Finally, the developed indexes and analysis methods are demonstrated by a numerical example. - Highlights: • Markovian history-dependent repairable systems with neglected failures is modeled. • Aggregated stochastic processes are used to derive reliability indexes and time distributions. • Closed-form expressions are derived for the considered indexes and distributions.

  4. Rooting out causes in failure analysis; Risk analysis

    Energy Technology Data Exchange (ETDEWEB)

    Keith, Graeme

    2010-07-01

    The Deepwater Horizon disaster was a terrible reminder of the consequences of equipment failure on facilities operating in challenging environments. Thankfully catastrophes on the scale of the Deepwater Horizon are rare, but equipment failure is a daily occurrence on installations around the globe. The consequences range from short unexpected downtime, to a total stop on production. from a brief burst of flaring to lasting environmental damage and from the momentary discomfiture of a worker to incapability or death. (Author)

  5. WE-H-BRC-02: Failure Mode and Effect Analysis of Liver Stereotactic Body Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Rusu, I; Thomas, T; Roeske, J; Price, J; Perino, C; Surucu, M [Loyola University Chicago, Maywood, IL (United States); Mescioglu, I [Lewis University, Romeoville, IL (United States)

    2016-06-15

    Purpose: To identify areas of improvement in our liver stereotactic body radiation therapy (SBRT) program, using failure mode and effect analysis (FMEA). Methods: A multidisciplinary group consisting of one physician, three physicists, one dosimetrist and two therapists was formed. A process map covering 10 major stages of the liver SBRT program from the initial diagnosis to post treatment follow-up was generated. A total of 102 failure modes, together with their causes and effects, were identified. The occurrence (O), severity (S) and lack of detectability (D) were independently scored. The ranking was done using the risk probability number (RPN) defined as the product of average O, S and D numbers for each mode. The scores were normalized to remove inter-observer variability, while preserving individual ranking order. Further, a correlation analysis on the overall agreement on rank order of all failure modes resulted in positive values for successive pairs of evaluators. The failure modes with the highest RPN value were considered for further investigation. Results: The average normalized RPN values for all modes were 39 with a range of 9 to 103. The FMEA analysis resulted in the identification of the top 10 critical failures modes as: Incorrect CT-MR registration, MR scan not performed in treatment position, patient movement between CBCT acquisition and treatment, daily IGRT QA not verified, incorrect or incomplete ITV delineation, OAR contours not verified, inaccurate normal liver effective dose (Veff) calculation, failure of bolus tracking for 4D CT scan, setup instructions not followed for treatment and plan evaluation metrics missed. Conclusion: The application of FMEA to our liver SBRT program led to the identification and possible improvement of areas affecting patient safety.

  6. WE-H-BRC-02: Failure Mode and Effect Analysis of Liver Stereotactic Body Radiotherapy

    International Nuclear Information System (INIS)

    Rusu, I; Thomas, T; Roeske, J; Price, J; Perino, C; Surucu, M; Mescioglu, I

    2016-01-01

    Purpose: To identify areas of improvement in our liver stereotactic body radiation therapy (SBRT) program, using failure mode and effect analysis (FMEA). Methods: A multidisciplinary group consisting of one physician, three physicists, one dosimetrist and two therapists was formed. A process map covering 10 major stages of the liver SBRT program from the initial diagnosis to post treatment follow-up was generated. A total of 102 failure modes, together with their causes and effects, were identified. The occurrence (O), severity (S) and lack of detectability (D) were independently scored. The ranking was done using the risk probability number (RPN) defined as the product of average O, S and D numbers for each mode. The scores were normalized to remove inter-observer variability, while preserving individual ranking order. Further, a correlation analysis on the overall agreement on rank order of all failure modes resulted in positive values for successive pairs of evaluators. The failure modes with the highest RPN value were considered for further investigation. Results: The average normalized RPN values for all modes were 39 with a range of 9 to 103. The FMEA analysis resulted in the identification of the top 10 critical failures modes as: Incorrect CT-MR registration, MR scan not performed in treatment position, patient movement between CBCT acquisition and treatment, daily IGRT QA not verified, incorrect or incomplete ITV delineation, OAR contours not verified, inaccurate normal liver effective dose (Veff) calculation, failure of bolus tracking for 4D CT scan, setup instructions not followed for treatment and plan evaluation metrics missed. Conclusion: The application of FMEA to our liver SBRT program led to the identification and possible improvement of areas affecting patient safety.

  7. Association of adiposity measures with blood lipids and blood pressure in children aged 8-11 years.

    Science.gov (United States)

    Vizcaíno, Vicente Martínez; Aguilar, Fernando Salcedo; Martínez, Montserrat Solera; López, Mairena Sánchez; Gutiérrez, Ricardo Franquelo; Rodríguez-Artalejo, Fernando

    2007-09-01

    To examine the association of body mass index (BMI), triceps skinfold thickness (TST) and percentage body fat (%BF) from bioelectrical impedance analysis (BIA) with blood lipids, systolic blood pressure (SBP) and diastolic blood pressure (DBP) in children. Cross-sectional study was conducted on 1280 schoolchildren aged 8-11 years from the Cuenca province (Spain). Data collection was conducted under standardized conditions, taking several measurements of each variable to enhance accuracy. Analyses were performed using age-adjusted correlation coefficients, and multiple linear regression adjusted for age, BMI, TST and %BF. Correlations between %BF and apolipoprotein (apo) B, total cholesterol, low-density lipoprotein cholesterol (LDL-c), total cholesterol/HDL-c ratio and DBP were higher than those for BMI and TST. In contrast, the correlations between BMI, and apo A-I and SBP were higher than those for %BF and TST. The results were similar across the sexes. The correlations between each of the three measures of body fatness, and blood lipids and blood pressure were highest in children with greatest BMI and %BF. When analyses were adjusted for the three body fatness measures, %BF showed stronger associations than did BMI or TST with blood lipids and blood pressure, with the exception of apo A-I and SBP, which were more closely associated with BMI. %BF from BIA is more strongly associated than either BMI or TST with most of the blood lipid fractions in schoolchildren aged 8-11 years.

  8. Electronic spectroscopy and ligand-field analysis of cis-carbonato (rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) chromium(III) chloride

    International Nuclear Information System (INIS)

    Choi, Jong-Ha; Oh, In-Gyung; Linder, Rolf; Schoenherr, Thomas

    2004-01-01

    The absorption spectra of microcrystalline salts of cis-[Cr(cycb)(O 2 CO)] + (cycb=rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) have been measured between 13,000 and 50,000 cm -1 at temperatures down to 2 K. The vibrational intervals of the electronic ground state were extracted by recording emission and far-IR spectra. The zero-phonon line in the sharp-line absorption spectrum splits into two components by 144 cm -1 . The nine electronic bands due to spin-allowed and spin-forbidden transitions were assigned. Using the observed transitions, a ligand-field analysis has been performed to probe the ligand-field properties of carbonato group in the chromium(III) complex. It is found that the carbonato oxygen has moderately strong σ- and π-donor properties toward chromium(III) ion

  9. Failure probabilistic model of CNC lathes

    International Nuclear Information System (INIS)

    Wang Yiqiang; Jia Yazhou; Yu Junyi; Zheng Yuhua; Yi Shangfeng

    1999-01-01

    A field failure analysis of computerized numerical control (CNC) lathes is described. Field failure data was collected over a period of two years on approximately 80 CNC lathes. A coding system to code failure data was devised and a failure analysis data bank of CNC lathes was established. The failure position and subsystem, failure mode and cause were analyzed to indicate the weak subsystem of a CNC lathe. Also, failure probabilistic model of CNC lathes was analyzed by fuzzy multicriteria comprehensive evaluation

  10. ATLAS tunes of PYTHIA 6 and Pythia 8 for MC11

    CERN Document Server

    The ATLAS collaboration

    2011-01-01

    We present the latest developments of the ATLAS MC generator tuning project for the Pythia family of event generators, including the C++ Pythia 8 code for the first time. The PYTHIA 6 tunes presented here, titled AMBT2B and AUET2B and constructed for a variety of PDFs, constitute alternatives to the AMBT2/AUET2 tunes previously presented as a candidate for MC11 event simulation. They systematically differ from the AMBT2/AUET2 PYTHIA 6 tunes in the treatment of alpha_S, to address concerns with those tunes. Systematic tune variations are also presented. The Pythia 8 tunes have been constructed for two different PDFs, and are aimed at an optimal description of minimum bias, for use in pile-up simulation. PDF-sensitive effects are observed and discussed in the MPI tunings of both generators.

  11. The revolving door syndrome in internal medicine: a study on 11,846 subjects discharged from all Internal Medicine Departments of Tuscany with diagnosis of heart failure and pneumonia

    Directory of Open Access Journals (Sweden)

    Matteo Tellini

    2015-05-01

    Full Text Available Rehospitalization is the return of a patient to a surgical or medical department within 30 days from discharge. We have limited information on the frequency and patterns of rehospitalization in Italy. Our purpose is to describe this phenomenon in Tuscany. We analyzed regional hospital discharge abstract data in Tuscany 2012, to describe 30-day all cause readmissions. We studied patients aged 18 or more (11,846 discharged with diagnoses of heart failure and pneumonia from Internal Medicine Departments. Relationships between 30-day readmission rates, demographic and clinical characteristics have been analyzed. 18% and 15% of subjects respectively discharged with diagnosis of heart failure and pneumonia were readmitted within 30 days. Risk factors significantly related to readmissions were longer length of stay, increasing number of different medications taken during the year preceding hospitalization and greater number of hospitalizations during the semester preceding admission. From the analysis of risk factors we found that frailty and complexity of patients (identified by long hospitalization stays, high number of drugs and previous admissions are the most important factors for unplanned readmissions.

  12. Failure mode and effect analysis: improving intensive care unit risk management processes.

    Science.gov (United States)

    Askari, Roohollah; Shafii, Milad; Rafiei, Sima; Abolhassani, Mohammad Sadegh; Salarikhah, Elaheh

    2017-04-18

    Purpose Failure modes and effects analysis (FMEA) is a practical tool to evaluate risks, discover failures in a proactive manner and propose corrective actions to reduce or eliminate potential risks. The purpose of this paper is to apply FMEA technique to examine the hazards associated with the process of service delivery in intensive care unit (ICU) of a tertiary hospital in Yazd, Iran. Design/methodology/approach This was a before-after study conducted between March 2013 and December 2014. By forming a FMEA team, all potential hazards associated with ICU services - their frequency and severity - were identified. Then risk priority number was calculated for each activity as an indicator representing high priority areas that need special attention and resource allocation. Findings Eight failure modes with highest priority scores including endotracheal tube defect, wrong placement of endotracheal tube, EVD interface, aspiration failure during suctioning, chest tube failure, tissue injury and deep vein thrombosis were selected for improvement. Findings affirmed that improvement strategies were generally satisfying and significantly decreased total failures. Practical implications Application of FMEA in ICUs proved to be effective in proactively decreasing the risk of failures and corrected the control measures up to acceptable levels in all eight areas of function. Originality/value Using a prospective risk assessment approach, such as FMEA, could be beneficial in dealing with potential failures through proposing preventive actions in a proactive manner. The method could be used as a tool for healthcare continuous quality improvement so that the method identifies both systemic and human errors, and offers practical advice to deal effectively with them.

  13. Competing failure analysis in phased-mission systems with multiple functional dependence groups

    International Nuclear Information System (INIS)

    Wang, Chaonan; Xing, Liudong; Peng, Rui; Pan, Zhusheng

    2017-01-01

    A phased-mission system (PMS) involves multiple, consecutive, non-overlapping phases of operation. The system structure function and component failure behavior in a PMS can change from phase to phase, posing big challenges to the system reliability analysis. Further complicating the problem is the functional dependence (FDEP) behavior where the failure of certain component(s) causes other component(s) to become unusable or inaccessible or isolated. Previous studies have shown that FDEP can cause competitions between failure propagation and failure isolation in the time domain. While such competing failure effects have been well addressed in single-phase systems, only little work has focused on PMSs with a restrictive assumption that a single FDEP group exists in one phase of the mission. Many practical systems (e.g., computer systems and networks), however may involve multiple FDEP groups during the mission. Moreover, different FDEP groups can be dependent due to sharing some common components; they may appear in a single phase or multiple phases. This paper makes new contributions by modeling and analyzing reliability of PMSs subject to multiple FDEP groups through a Markov chain-based methodology. Propagated failures with both global and selective effects are considered. Four case studies are presented to demonstrate application of the proposed method. - Highlights: • Reliability of phased-mission systems subject to competing failure propagation and isolation effects is modeled. • Multiple independent or dependent functional dependence groups are considered. • Propagated failures with global effects and selective effects are studied. • Four case studies demonstrate generality and application of the proposed Markov-based method.

  14. Construct validity of the Heart Failure Screening Tool (Heart-FaST) to identify heart failure patients at risk of poor self-care: Rasch analysis.

    Science.gov (United States)

    Reynolds, Nicholas A; Ski, Chantal F; McEvedy, Samantha M; Thompson, David R; Cameron, Jan

    2018-02-14

    The aim of this study was to psychometrically evaluate the Heart Failure Screening Tool (Heart-FaST) via: (1) examination of internal construct validity; (2) testing of scale function in accordance with design; and (3) recommendation for change/s, if items are not well adjusted, to improve psychometric credential. Self-care is vital to the management of heart failure. The Heart-FaST may provide a prospective assessment of risk, regarding the likelihood that patients with heart failure will engage in self-care. Psychometric validation of the Heart-FaST using Rasch analysis. The Heart-FaST was administered to 135 patients (median age = 68, IQR = 59-78 years; 105 males) enrolled in a multidisciplinary heart failure management program. The Heart-FaST is a nurse-administered tool for screening patients with HF at risk of poor self-care. A Rasch analysis of responses was conducted which tested data against Rasch model expectations, including whether items serve as unbiased, non-redundant indicators of risk and measure a single construct and that rating scales operate as intended. The results showed that data met Rasch model expectations after rescoring or deleting items due to poor discrimination, disordered thresholds, differential item functioning, or response dependence. There was no evidence of multidimensionality which supports the use of total scores from Heart-FaST as indicators of risk. Aggregate scores from this modified screening tool rank heart failure patients according to their "risk of poor self-care" demonstrating that the Heart-FaST items constitute a meaningful scale to identify heart failure patients at risk of poor engagement in heart failure self-care. © 2018 John Wiley & Sons Ltd.

  15. Metabolic connectivity analysis in Alzheimer’s disease (AD) by interregional correlation combining [11C] PIB and [18F] FDG PET

    NARCIS (Netherlands)

    2015-01-01

    Objectives: to determine whether [18F] FDG PET brain pattern correlates with [11C] PIB uptake in AD specific brain region using a SPM (Statistical Parametric Mapping) based network analysis. Methods: Combined [11C] PIB and [18F] FDG PET patterns data of 15 patients: 3 controls (CP), 8 probable

  16. Anal Carcinoma: Impact of TN Category of Disease on Survival, Disease Relapse, and Colostomy Failure in US Gastrointestinal Intergroup RTOG 98-11 Phase 3 Trial

    Science.gov (United States)

    Gunderson, Leonard L.; Moughan, Jennifer; Ajani, Jaffer A.; Pedersen, John E.; Winter, Kathryn A.; Benson, Al B.; Thomas, Charles R.; Mayer, Robert J.; Haddock, Michael G.; Rich, Tyvin A.; Willett, Christopher G.

    2013-01-01

    Purpose The long-term update of US GI Intergroup RTOG 98-11 anal cancer trial found that concurrent chemoradiation (CCRT) with fluorouracil (5-FU) plus mitomycin had a significant impact on disease-free survival (DFS) and overall survival (OS) compared with induction plus concurrent 5-FU plus cisplatin. The intent of the current analysis was to determine the impact of tumor node (TN) category of disease on survival (DFS and OS), colostomy failure (CF), and relapse (local-regional failure [LRF] and distant metastases [DM]) in this patient group. Methods and Materials DFS and OS were estimated univariately by using the Kaplan-Meier method, and 6 TN categories were compared by the log–rank test (T2N0, T3N0, T4N0, T2N1-3, T3N1-3, and T4N1-3). Time to relapse and colostomy were estimated by the cumulative incidence method, and TN categories were compared using Gray’s test. Results Of 682 patients, 620 were analyzable for outcomes by TN category. All endpoints showed statistically significant differences among the TN categories of disease (OS, P<.0001; DFS, P<.0001; LRF, P<.0001; DM, P=.0011; CF, P=.01). Patients with the poorest OS, DFS, and LRF outcomes were those with T3-4N-positive (+) disease. CF was lowest for T2N0 and T2N+ (11%, 11%, respectively) and worst for the T4N0, T3N+, and T4N+ categories (26%, 27%, 24%, respectively). Conclusions TN category of disease has a statistically significant impact on OS, DFS, LRF, DM, and CF in patients treated with CCRT and provides excellent prognostic information for outcomes in patients with anal carcinoma. Significant challenges remain for patients with T4N0 and T3-4N+ categories of disease with regard to survival, relapse, and CF and lesser challenges for T2-3N0/T2N+ categories. PMID:24035327

  17. Anal Carcinoma: Impact of TN Category of Disease on Survival, Disease Relapse, and Colostomy Failure in US Gastrointestinal Intergroup RTOG 98-11 Phase 3 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Leonard L., E-mail: gunderson.leonard@mayo.edu [Mayo Clinic Cancer Center, Scottsdale, Arizona (United States); Moughan, Jennifer [Radiation Therapy Oncology Group, Philadelphia, Pennsylvania (United States); Ajani, Jaffer A. [The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Pedersen, John E. [Cross Cancer Institute, Edmonton, Alberta (Canada); Winter, Kathryn A. [Radiation Therapy Oncology Group, Philadelphia, Pennsylvania (United States); Benson, Al B. [Northwestern University, Chicago, Illinois (United States); Thomas, Charles R. [Knight Cancer Institute/Oregon Health and Science University, Portland, Oregon (United States); Mayer, Robert J. [Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Haddock, Michael G. [Mayo Clinic Cancer Center, Rochester, Minnesota (United States); Rich, Tyvin A. [University of Virginia, Charlottesville, Virginia (United States); Willett, Christopher G. [Duke University, Durham, North Carolina (United States)

    2013-11-15

    Purpose: The long-term update of US GI Intergroup RTOG 98-11 anal cancer trial found that concurrent chemoradiation (CCRT) with fluorouracil (5-FU) plus mitomycin had a significant impact on disease-free survival (DFS) and overall survival (OS) compared with induction plus concurrent 5-FU plus cisplatin. The intent of the current analysis was to determine the impact of tumor node (TN) category of disease on survival (DFS and OS), colostomy failure (CF), and relapse (local-regional failure [LRF] and distant metastases [DM]) in this patient group. Methods and Materials: DFS and OS were estimated univariately by using the Kaplan-Meier method, and 6 TN categories were compared by the log–rank test (T2N0, T3N0, T4N0, T2N1-3, T3N1-3, and T4N1-3). Time to relapse and colostomy were estimated by the cumulative incidence method, and TN categories were compared using Gray's test. Results: Of 682 patients, 620 were analyzable for outcomes by TN category. All endpoints showed statistically significant differences among the TN categories of disease (OS, P<.0001; DFS, P<.0001; LRF, P<.0001; DM, P=.0011; CF, P=.01). Patients with the poorest OS, DFS, and LRF outcomes were those with T3-4N-positive (+) disease. CF was lowest for T2N0 and T2N+ (11%, 11%, respectively) and worst for the T4N0, T3N+, and T4N+ categories (26%, 27%, 24%, respectively). Conclusions: TN category of disease has a statistically significant impact on OS, DFS, LRF, DM, and CF in patients treated with CCRT and provides excellent prognostic information for outcomes in patients with anal carcinoma. Significant challenges remain for patients with T4N0 and T3-4N+ categories of disease with regard to survival, relapse, and CF and lesser challenges for T2-3N0/T2N+ categories.

  18. Anal Carcinoma: Impact of TN Category of Disease on Survival, Disease Relapse, and Colostomy Failure in US Gastrointestinal Intergroup RTOG 98-11 Phase 3 Trial

    International Nuclear Information System (INIS)

    Gunderson, Leonard L.; Moughan, Jennifer; Ajani, Jaffer A.; Pedersen, John E.; Winter, Kathryn A.; Benson, Al B.; Thomas, Charles R.; Mayer, Robert J.; Haddock, Michael G.; Rich, Tyvin A.; Willett, Christopher G.

    2013-01-01

    Purpose: The long-term update of US GI Intergroup RTOG 98-11 anal cancer trial found that concurrent chemoradiation (CCRT) with fluorouracil (5-FU) plus mitomycin had a significant impact on disease-free survival (DFS) and overall survival (OS) compared with induction plus concurrent 5-FU plus cisplatin. The intent of the current analysis was to determine the impact of tumor node (TN) category of disease on survival (DFS and OS), colostomy failure (CF), and relapse (local-regional failure [LRF] and distant metastases [DM]) in this patient group. Methods and Materials: DFS and OS were estimated univariately by using the Kaplan-Meier method, and 6 TN categories were compared by the log–rank test (T2N0, T3N0, T4N0, T2N1-3, T3N1-3, and T4N1-3). Time to relapse and colostomy were estimated by the cumulative incidence method, and TN categories were compared using Gray's test. Results: Of 682 patients, 620 were analyzable for outcomes by TN category. All endpoints showed statistically significant differences among the TN categories of disease (OS, P<.0001; DFS, P<.0001; LRF, P<.0001; DM, P=.0011; CF, P=.01). Patients with the poorest OS, DFS, and LRF outcomes were those with T3-4N-positive (+) disease. CF was lowest for T2N0 and T2N+ (11%, 11%, respectively) and worst for the T4N0, T3N+, and T4N+ categories (26%, 27%, 24%, respectively). Conclusions: TN category of disease has a statistically significant impact on OS, DFS, LRF, DM, and CF in patients treated with CCRT and provides excellent prognostic information for outcomes in patients with anal carcinoma. Significant challenges remain for patients with T4N0 and T3-4N+ categories of disease with regard to survival, relapse, and CF and lesser challenges for T2-3N0/T2N+ categories

  19. Failure modes and effects criticality analysis and accelerated life testing of LEDs for medical applications

    Science.gov (United States)

    Sawant, M.; Christou, A.

    2012-12-01

    While use of LEDs in Fiber Optics and lighting applications is common, their use in medical diagnostic applications is not very extensive. Since the precise value of light intensity will be used to interpret patient results, understanding failure modes [1-4] is very important. We used the Failure Modes and Effects Criticality Analysis (FMECA) tool to identify the critical failure modes of the LEDs. FMECA involves identification of various failure modes, their effects on the system (LED optical output in this context), their frequency of occurrence, severity and the criticality of the failure modes. The competing failure modes/mechanisms were degradation of: active layer (where electron-hole recombination occurs to emit light), electrodes (provides electrical contact to the semiconductor chip), Indium Tin Oxide (ITO) surface layer (used to improve current spreading and light extraction), plastic encapsulation (protective polymer layer) and packaging failures (bond wires, heat sink separation). A FMECA table is constructed and the criticality is calculated by estimating the failure effect probability (β), failure mode ratio (α), failure rate (λ) and the operating time. Once the critical failure modes were identified, the next steps were generation of prior time to failure distribution and comparing with our accelerated life test data. To generate the prior distributions, data and results from previous investigations were utilized [5-33] where reliability test results of similar LEDs were reported. From the graphs or tabular data, we extracted the time required for the optical power output to reach 80% of its initial value. This is our failure criterion for the medical diagnostic application. Analysis of published data for different LED materials (AlGaInP, GaN, AlGaAs), the Semiconductor Structures (DH, MQW) and the mode of testing (DC, Pulsed) was carried out. The data was categorized according to the materials system and LED structure such as AlGaInP-DH-DC, Al

  20. A Novel Mutation in the CYP11B1 Gene Causes Steroid 11β-Hydroxylase Deficient Congenital Adrenal Hyperplasia with Reversible Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Mohammad A. Alqahtani

    2015-01-01

    Full Text Available Congenital adrenal hyperplasia (CAH due to steroid 11β-hydroxylase deficiency is the second most common form of CAH, resulting from a mutation in the CYP11B1 gene. Steroid 11β-hydroxylase deficiency results in excessive mineralcorticoids and androgen production leading to hypertension, precocious puberty with acne, enlarged penis, and hyperpigmentation of scrotum of genetically male infants. In the present study, we reported 3 male cases from a Saudi family who presented with penile enlargement, progressive darkness of skin, hypertension, and cardiomyopathy. The elder patient died due to heart failure and his younger brothers were treated with hydrocortisone and antihypertensive medications. Six months following treatment, cardiomyopathy disappeared with normal blood pressure and improvement in the skin pigmentation. The underlying molecular defect was investigated by PCR-sequencing analysis of all coding exons and intron-exon boundary of the CYP11B1 gene. A novel biallelic mutation c.780 G>A in exon 4 of the CYP11B1 gene was found in the patients. The mutation created a premature stop codon at amino acid 260 (p.W260∗, resulting in a truncated protein devoid of 11β-hydroxylase activity. Interestingly, a somatic mutation at the same codon (c.779 G>A, p.W260∗ was reported in a patient with papillary thyroid cancer (COSMIC database. In conclusion, we have identified a novel nonsense mutation in the CYP11B1 gene that causes classic steroid 11β-hydroxylase deficient CAH. Cardiomyopathy and cardiac failure can be reversed by early diagnosis and treatment.

  1. Failure mode and effect analysis-based quality assurance for dynamic MLC tracking systems

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, Amit; Dieterich, Sonja; Svatos, Michelle; Keall, Paul [Stanford University, Stanford, California 94394 (United States); Varian Medical Systems, Palo Alto, California 94304 (United States); Stanford University, Stanford, California 94394 (United States)

    2010-12-15

    Purpose: To develop and implement a failure mode and effect analysis (FMEA)-based commissioning and quality assurance framework for dynamic multileaf collimator (DMLC) tumor tracking systems. Methods: A systematic failure mode and effect analysis was performed for a prototype real-time tumor tracking system that uses implanted electromagnetic transponders for tumor position monitoring and a DMLC for real-time beam adaptation. A detailed process tree of DMLC tracking delivery was created and potential tracking-specific failure modes were identified. For each failure mode, a risk probability number (RPN) was calculated from the product of the probability of occurrence, the severity of effect, and the detectibility of the failure. Based on the insights obtained from the FMEA, commissioning and QA procedures were developed to check (i) the accuracy of coordinate system transformation, (ii) system latency, (iii) spatial and dosimetric delivery accuracy, (iv) delivery efficiency, and (v) accuracy and consistency of system response to error conditions. The frequency of testing for each failure mode was determined from the RPN value. Results: Failures modes with RPN{>=}125 were recommended to be tested monthly. Failure modes with RPN<125 were assigned to be tested during comprehensive evaluations, e.g., during commissioning, annual quality assurance, and after major software/hardware upgrades. System latency was determined to be {approx}193 ms. The system showed consistent and accurate response to erroneous conditions. Tracking accuracy was within 3%-3 mm gamma (100% pass rate) for sinusoidal as well as a wide variety of patient-derived respiratory motions. The total time taken for monthly QA was {approx}35 min, while that taken for comprehensive testing was {approx}3.5 h. Conclusions: FMEA proved to be a powerful and flexible tool to develop and implement a quality management (QM) framework for DMLC tracking. The authors conclude that the use of FMEA-based QM ensures

  2. Failure mode and effect analysis-based quality assurance for dynamic MLC tracking systems.

    Science.gov (United States)

    Sawant, Amit; Dieterich, Sonja; Svatos, Michelle; Keall, Paul

    2010-12-01

    To develop and implement a failure mode and effect analysis (FMEA)-based commissioning and quality assurance framework for dynamic multileaf collimator (DMLC) tumor tracking systems. A systematic failure mode and effect analysis was performed for a prototype real-time tumor tracking system that uses implanted electromagnetic transponders for tumor position monitoring and a DMLC for real-time beam adaptation. A detailed process tree of DMLC tracking delivery was created and potential tracking-specific failure modes were identified. For each failure mode, a risk probability number (RPN) was calculated from the product of the probability of occurrence, the severity of effect, and the detectibility of the failure. Based on the insights obtained from the FMEA, commissioning and QA procedures were developed to check (i) the accuracy of coordinate system transformation, (ii) system latency, (iii) spatial and dosimetric delivery accuracy, (iv) delivery efficiency, and (v) accuracy and consistency of system response to error conditions. The frequency of testing for each failure mode was determined from the RPN value. Failures modes with RPN > or = 125 were recommended to be tested monthly. Failure modes with RPN < 125 were assigned to be tested during comprehensive evaluations, e.g., during commissioning, annual quality assurance, and after major software/hardware upgrades. System latency was determined to be approximately 193 ms. The system showed consistent and accurate response to erroneous conditions. Tracking accuracy was within 3%-3 mm gamma (100% pass rate) for sinusoidal as well as a wide variety of patient-derived respiratory motions. The total time taken for monthly QA was approximately 35 min, while that taken for comprehensive testing was approximately 3.5 h. FMEA proved to be a powerful and flexible tool to develop and implement a quality management (QM) framework for DMLC tracking. The authors conclude that the use of FMEA-based QM ensures efficient allocation

  3. Failure mode and effect analysis-based quality assurance for dynamic MLC tracking systems

    International Nuclear Information System (INIS)

    Sawant, Amit; Dieterich, Sonja; Svatos, Michelle; Keall, Paul

    2010-01-01

    Purpose: To develop and implement a failure mode and effect analysis (FMEA)-based commissioning and quality assurance framework for dynamic multileaf collimator (DMLC) tumor tracking systems. Methods: A systematic failure mode and effect analysis was performed for a prototype real-time tumor tracking system that uses implanted electromagnetic transponders for tumor position monitoring and a DMLC for real-time beam adaptation. A detailed process tree of DMLC tracking delivery was created and potential tracking-specific failure modes were identified. For each failure mode, a risk probability number (RPN) was calculated from the product of the probability of occurrence, the severity of effect, and the detectibility of the failure. Based on the insights obtained from the FMEA, commissioning and QA procedures were developed to check (i) the accuracy of coordinate system transformation, (ii) system latency, (iii) spatial and dosimetric delivery accuracy, (iv) delivery efficiency, and (v) accuracy and consistency of system response to error conditions. The frequency of testing for each failure mode was determined from the RPN value. Results: Failures modes with RPN≥125 were recommended to be tested monthly. Failure modes with RPN<125 were assigned to be tested during comprehensive evaluations, e.g., during commissioning, annual quality assurance, and after major software/hardware upgrades. System latency was determined to be ∼193 ms. The system showed consistent and accurate response to erroneous conditions. Tracking accuracy was within 3%-3 mm gamma (100% pass rate) for sinusoidal as well as a wide variety of patient-derived respiratory motions. The total time taken for monthly QA was ∼35 min, while that taken for comprehensive testing was ∼3.5 h. Conclusions: FMEA proved to be a powerful and flexible tool to develop and implement a quality management (QM) framework for DMLC tracking. The authors conclude that the use of FMEA-based QM ensures efficient allocation

  4. Analysis of Moderator System Failure Accidents by Using New Method for Wolsong-1 CANDU 6 Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Dongsik; Kim, Jonghyun; Cho, Cheonhwey [Atomic Creative Technology Co., Ltd., Daejeon (Korea, Republic of); Kim, Sungmin [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of)

    2013-05-15

    To reconfirm the safety of moderator system failure accidents, the safety analysis by using the reactor physics code, RFSP-IST, coupled with the thermal hydraulics code, CATHENA is performed additionally. In the present paper, the newly developed analysis method is briefly described and the results obtained from the moderator system failure accident simulations for Wolsong-1 CANDU 6 reactor by using the new method are summarized. The safety analysis of the moderator system failure accidents for Wolsong-1 CANDU 6 reactor was carried out by using the new code system, i. e., CATHENA and RFSP-IST, instead of the non-IST old codes, namely, SMOKIN G-2 and MODSTBOIL. The analysis results by using the new method revealed as same with the results by using the old method that the fuel integrity is warranted because the localized power peak remained well below the limits and, most importantly, the reactor operation enters into the self-shutdown mode due to the substantial loss of moderator D{sub 2}O inventory from the moderator system. In the analysis results obtained by using the old method, it was predicted that the ROP trip conditions occurred for the transient cases which are also studied in the present paper. But, in the new method, it was found that the ROP trip conditions did not occur. Consequently, in the safety analysis performed additionally by using the new method, the safety of moderator system failure accidents was reassured. In the future, the new analysis method by using the IST codes instead of the non-IST old codes for the moderator system failure accidents is strongly recommended.

  5. Potential failure mode and effects analysis for the ITER NB injector

    International Nuclear Information System (INIS)

    Boldrin, M.; De Lorenzi, A.; Fiorentin, A.; Grando, L.; Marcuzzi, D.; Peruzzo, S.; Pomaro, N.; Rigato, W.; Serianni, G.

    2009-01-01

    The failure mode and effects analysis (FMEA) is a widely used analytical technique that helps in identifying and reducing the risks of failure in a system, component or process. The application of a systematic method like the FMEA was deemed necessary and adequate to support the design process of the ITER NBI (neutral beam injector). The approach adopted was to develop a FMEA at a general 'system level', focusing the study on the main functions of the system and ensuring that all the interfaces and interactions are covered among the various subsystems. The FMEA was extended to the whole NBI system taking into account the present design status. The FMEA procedure will be then applied to the detailed design phase at the component level, in particular to identify (or define) the ITER Class of Risk. Several important failure modes were evidenced, and estimates of subsystems and components reliability are now available. FMEA procedure resulted essential to identify and confirm the diagnostic systems required for protection and control, and the outcome of this analysis will represent the baseline document for the design of the NBI and NBTF integrated protection system. In the paper, rationale and background of the FMEA for ITER NBI are presented, methods employed are described and most interesting results are reported and discussed.

  6. Hyperinsulinaemic hypoglycaemia and diabetes mellitus due to dominant ABCC8/KCNJ11 mutations.

    LENUS (Irish Health Repository)

    Kapoor, R R

    2011-10-01

    Dominantly acting loss-of-function mutations in the ABCC8\\/KCNJ11 genes can cause mild medically responsive hyperinsulinaemic hypoglycaemia (HH). As controversy exists over whether these mutations predispose to diabetes in adulthood we investigated the prevalence of diabetes in families with dominantly inherited ATP-sensitive potassium (K(ATP)) channel mutations causing HH in the proband.

  7. Failure Mode and Effect Analysis using Soft Set Theory and COPRAS Method

    Directory of Open Access Journals (Sweden)

    Ze-Ling Wang

    2017-01-01

    Full Text Available Failure mode and effect analysis (FMEA is a risk management technique frequently applied to enhance the system performance and safety. In recent years, many researchers have shown an intense interest in improving FMEA due to inherent weaknesses associated with the classical risk priority number (RPN method. In this study, we develop a new risk ranking model for FMEA based on soft set theory and COPRAS method, which can deal with the limitations and enhance the performance of the conventional FMEA. First, trapezoidal fuzzy soft set is adopted to manage FMEA team membersr linguistic assessments on failure modes. Then, a modified COPRAS method is utilized for determining the ranking order of the failure modes recognized in FMEA. Especially, we treat the risk factors as interdependent and employ the Choquet integral to obtain the aggregate risk of failures in the new FMEA approach. Finally, a practical FMEA problem is analyzed via the proposed approach to demonstrate its applicability and effectiveness. The result shows that the FMEA model developed in this study outperforms the traditional RPN method and provides a more reasonable risk assessment of failure modes.

  8. Coupled Mechanical-Electrochemical-Thermal Analysis of Failure Propagation in Lithium-ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao; Santhanagopalan, Shriram; Pesaran, Ahmad

    2016-07-28

    This is a presentation given at the 12th World Congress for Computational Mechanics on coupled mechanical-electrochemical-thermal analysis of failure propagation in lithium-ion batteries for electric vehicles.

  9. Environmental Tobacco Smoke Exposure and Children’s Intelligence at 811 Years of Age

    Science.gov (United States)

    Park, Subin; Cho, Soo-Churl; Hong, Yun-Chul; Shin, Min-Sup; Yoo, Hee Jeong; Han, Doug Hyun; Cheong, Jae Hoon

    2014-01-01

    Background: Evidence supporting a link between postnatal environmental tobacco smoke (ETS) exposure and cognitive problems among children is mounting, but inconsistent. Objectives: We examined the relationship between ETS exposure, measured using urine cotinine, and IQ scores in Korean school-aged children. Methods: The participants were 996 children 811 years of age recruited from five administrative regions in South Korea. We performed a cross-sectional analysis of urinary cotinine concentrations and IQ scores obtained using the abbreviated form of a Korean version of the Wechsler Intelligence Scales for Children. Associations were adjusted for potential confounders, and estimates were derived with and without adjustment for mother’s Full-Scale IQ (FSIQ) score. Results: After adjusting for sociodemographic and developmental covariates, urinary cotinine concentrations were inversely associated with FSIQ, Verbal IQ (VIQ), Performance IQ (PIQ), vocabulary, math, and block design scores. Following further adjustment for maternal IQ, only the VIQ scores remained significantly associated with urinary cotinine concentration (B = –0.31; 95% CI: –0.60, –0.03 for a 1-unit increase in natural log-transformed urine cotinine concentration; p = 0.03). Conclusion: Urine cotinine concentrations were inversely associated with children’s VIQ scores before and after adjusting for maternal IQ. Further prospective studies with serial measurements of cotinine are needed to confirm our findings. Citation: Park S, Cho SC, Hong YC, Kim JW, Shin MS, Yoo HJ, Han DH, Cheong JH, Kim BN. 2014. Environmental tobacco smoke exposure and children’s intelligence at 811 years of age. Environ Health Perspect 122:1123–1128; http://dx.doi.org/10.1289/ehp.1307088 PMID:24911003

  10. The failure trace archive : enabling comparative analysis of failures in diverse distributed systems

    NARCIS (Netherlands)

    Kondo, D.; Javadi, B.; Iosup, A.; Epema, D.H.J.

    2010-01-01

    With the increasing functionality and complexity of distributed systems, resource failures are inevitable. While numerous models and algorithms for dealing with failures exist, the lack of public trace data sets and tools has prevented meaningful comparisons. To facilitate the design, validation,

  11. Failure Mode and Effect Analysis in Increasing the Revenue of Emergency Department

    Directory of Open Access Journals (Sweden)

    Farhad Rahmati

    2015-02-01

    Full Text Available Introduction: Successful performance of emergency department(ED is one of the important indications of increasing the satisfaction among referees. The insurance of such successful performance is fiscal discipline and avoiding from non-beneficial activities in this department. Therefore, the increasing revenue of emergency department is one of the interested goals of hospital management system. According to above-mentioned, the researchers assessed problems lead to loss the revenue of ED and eliminate them by using failure mode and effects analysis (FMEA.Methods: This was the prospective cohort study performed during 18 months, set in 6 phases. In the first phase, the failures were determined and some solutions suggested to eliminate them. During 2-5 phases, based on the prioritizing the problems, solutions were performed. In the sixth phase, final assessment of the study was done. Finally, the feedback of system’s revenue was evaluated and data analyzed using repeated measure ANOVA.Results: Lack of recording the consuming instrument and attribution of separate codes for emergency services of hospitalized patients were the most important failures that lead to decrease the revenue of ED. Such elimination caused to 75.9% increase in revenue within a month (df = 1.6; F = 84.0; p<0.0001.  Totally, 18 months following the eliminating of failures caused to 328.2% increase in the revenue of ED (df = 15.9; F = 215; p<0.0001.Conclusion: The findings of the present study shows that failure mode and effect analysis, can be used as a safe and effected method to reduce the expenses of ED and increase its revenue.

  12. Sensitivity analysis of repairable redundant system with switching failure and geometric reneging

    Directory of Open Access Journals (Sweden)

    Chandra Shekhar

    2017-09-01

    Full Text Available This study deals with the performance modeling and reliability analysis of a redundant machining system composed of several functional machines. To analyze the more realistic scenarios, the concepts of switching failure and geometric reneging are included. The time-to-breakdown and repair time of operating and standby machines are assumed to follow the exponential distribution. For the quantitative assessment of the machine interference problem, various performance measures such as mean-time-to-failure, reliability, reneging rate, etc. have been formulated. To show the practicability of the developed model, a numerical illustration has been presented. For the practical justification and validity of the results established, the sensitivity analysis of reliability indices has been presented by varying different system descriptors.

  13. Adaptive Failure Identification for Healthcare Risk Analysis and Its Application on E-Healthcare

    Directory of Open Access Journals (Sweden)

    Kuo-Chung Chu

    2014-01-01

    Full Text Available To satisfy the requirement for diverse risk preferences, we propose a generic risk priority number (GRPN function that assigns a risk weight to each parameter such that they represent individual organization/department/process preferences for the parameters. This research applies GRPN function-based model to differentiate the types of risk, and primary data are generated through simulation. We also conduct sensitivity analysis on correlation and regression to compare it with the traditional RPN (TRPN. The proposed model outperforms the TRPN model and provides a practical, effective, and adaptive method for risk evaluation. In particular, the defined GRPN function offers a new method to prioritize failure modes in failure mode and effect analysis (FMEA. The different risk preferences considered in the healthcare example show that the modified FMEA model can take into account the various risk factors and prioritize failure modes more accurately. In addition, the model also can apply to a generic e-healthcare service environment with a hierarchical architecture.

  14. Using the failure mode and effects analysis model to improve parathyroid hormone and adrenocorticotropic hormone testing

    Directory of Open Access Journals (Sweden)

    Magnezi R

    2016-12-01

    Full Text Available Racheli Magnezi,1 Asaf Hemi,1 Rina Hemi2 1Department of Management, Public Health and Health Systems Management Program, Bar Ilan University, Ramat Gan, 2Endocrine Service Unit, Sheba Medical Center, Tel Aviv, Israel Background: Risk management in health care systems applies to all hospital employees and directors as they deal with human life and emergency routines. There is a constant need to decrease risk and increase patient safety in the hospital environment. The purpose of this article is to review the laboratory testing procedures for parathyroid hormone and adrenocorticotropic hormone (which are characterized by short half-lives and to track failure modes and risks, and offer solutions to prevent them. During a routine quality improvement review at the Endocrine Laboratory in Tel Hashomer Hospital, we discovered these tests are frequently repeated unnecessarily due to multiple failures. The repetition of the tests inconveniences patients and leads to extra work for the laboratory and logistics personnel as well as the nurses and doctors who have to perform many tasks with limited resources.Methods: A team of eight staff members accompanied by the Head of the Endocrine Laboratory formed the team for analysis. The failure mode and effects analysis model (FMEA was used to analyze the laboratory testing procedure and was designed to simplify the process steps and indicate and rank possible failures.Results: A total of 23 failure modes were found within the process, 19 of which were ranked by level of severity. The FMEA model prioritizes failures by their risk priority number (RPN. For example, the most serious failure was the delay after the samples were collected from the department (RPN =226.1.Conclusion: This model helped us to visualize the process in a simple way. After analyzing the information, solutions were proposed to prevent failures, and a method to completely avoid the top four problems was also developed. Keywords: failure mode

  15. Interventional bleeding, hematoma and scar-formation after vacuum-biopsy under stereotactic guidance: Mammotome®-system 11g/8g vs. ATEC®-system 12g/9g

    International Nuclear Information System (INIS)

    Schaefer, F.K.W.; Order, B.M.; Eckmann-Scholz, C.; Strauss, A.; Hilpert, F.; Kroj, K.; Biernath-Wüpping, J.; Heller, M.; Jonat, W.; Schaefer, P.J.

    2012-01-01

    Purpose: To evaluate prospectively the correlation of scar-formations after vacuum-assisted biopsy with different systems and needle-sizes and interventional bleeding/post-interventional hematoma. Methods and materials: Between 01/2008 and 12/2009, 479 patients underwent vacuum-assisted biopsy under stereotactic-guidance, using the Mammotome ® -system with 11/8-gauge and ATEC ® -system with 12/9-gauge, whereas in 178 cases with representative benign histology no surgical-biopsy after vacuum-assisted biopsy was performed and at least a 2-plane-follow-up-mammogram after 6 month post-vacuum-assisted biopsy was available. Bleeding during intervention, hematoma post-intervention and scar-tissue was scored as minimal and moderate/severe. Statistical analysis included Chi-Square-trend-test, p-value ® -system vs. 11-gauge-Mammotome ® -system (41.9% vs. 8.4%, p ® -systems 9-gauge vs. 12-gauge (26.9% vs. 29.7%, p = 0.799/42.3% vs. 43.2%, p = 0.596). 11-gauge-Mammotome ® -system vs. ATEC ® -12-gauge-system revealed significantly less bleedings/hematomas (8.4% vs. 29.7%, p = 0.015/16.7% vs. 43.2%, p = 0.001), no significant differences for the large-systems (p = 0.135/p = 0.352). Follow-up of Mammotome ® -11/8-gauge-system system has shown 13.1/16.1% minimal scar-formation and 1.2/3.2% moderate/severe scars, whereas ATEC ® -12/9-gauge-system has shown 10.8/3.8% minimal scar-formation and 0/11.5% moderate/severe scars, no significant differences. No significant difference was found when comparing Mammotome ® -11/8-g-systems vs. ATEC ® -12/9-g-systems (p = 0.609/p = 0.823). There was also no correlation between risk of scar-formation after occurrence of bleeding or hematoma with any examined VAB-system or any needle size in this study (p = 0.800). Conclusion: Using larger needle-sizes significantly (Mammotome ®) /not significant for ATEC ® ) more interventional bleedings and post-interventional hematomas were detected, only a tendency concerning scar-formation.

  16. WWER expert system for fuel failure analysis using the RTOP-CA code

    International Nuclear Information System (INIS)

    Likhanskii, V.; Evdokimov, I.; Sorokin, A.; Khromov, A.; Kanukova, V.; Apollonova, O.; Ugryumov, A.

    2008-01-01

    The computer expert system for fuel failure analysis of WWER during operation is presented. The diagnostics is based on the measurement of specific activity of reference nuclides in reactor primary coolant and application of a computer code for the data interpretation. The data analysis includes an evaluation of tramp uranium mass in reactor core, detection of failures by iodine and caesium spikes, evaluation of burnup of defective fuel. Evaluation of defective fuel burnup was carried out by applying the relation of caesium nuclides activity in spikes and relations of activities of gaseous fission products for steady state operational conditions. The method of burnup evaluation of defective fuel by use of fission gas activity is presented in details. The neural-network analysis is performed for determination of failed fuel rod number and defect size. Results of the expert system application are illustrated for several fuel campaigns on operating WWER NPPs. (authors)

  17. Evaluation of Safety in a Radiation Oncology Setting Using Failure Mode and Effects Analysis

    International Nuclear Information System (INIS)

    Ford, Eric C.; Gaudette, Ray; Myers, Lee; Vanderver, Bruce; Engineer, Lilly; Zellars, Richard; Song, Danny Y.; Wong, John; DeWeese, Theodore L.

    2009-01-01

    Purpose: Failure mode and effects analysis (FMEA) is a widely used tool for prospectively evaluating safety and reliability. We report our experiences in applying FMEA in the setting of radiation oncology. Methods and Materials: We performed an FMEA analysis for our external beam radiation therapy service, which consisted of the following tasks: (1) create a visual map of the process, (2) identify possible failure modes; assign risk probability numbers (RPN) to each failure mode based on tabulated scores for the severity, frequency of occurrence, and detectability, each on a scale of 1 to 10; and (3) identify improvements that are both feasible and effective. The RPN scores can span a range of 1 to 1000, with higher scores indicating the relative importance of a given failure mode. Results: Our process map consisted of 269 different nodes. We identified 127 possible failure modes with RPN scores ranging from 2 to 160. Fifteen of the top-ranked failure modes were considered for process improvements, representing RPN scores of 75 and more. These specific improvement suggestions were incorporated into our practice with a review and implementation by each department team responsible for the process. Conclusions: The FMEA technique provides a systematic method for finding vulnerabilities in a process before they result in an error. The FMEA framework can naturally incorporate further quantification and monitoring. A general-use system for incident and near miss reporting would be useful in this regard.

  18. Epidemiology of acute decompensated heart failure in India : The AFAR study (Acute failure registry study

    Directory of Open Access Journals (Sweden)

    Sandeep Seth

    2015-01-01

    Full Text Available Objectives: There is a paucity of data on acute decompensated heart failure (ADHF in Indian patients. We herein report the in-hospital and 6-month outcome of Indian patients admitted with ADHF. Methods: We prospectively enrolled consecutive patients with ADHF due to systolic dysfunction in the acute failure registry and followed them up for at least 6 months. We analyzed the data on death and hospitalization of the first 90 patients on death and hospitalization over 6-months. Results: A total of 90 patients were enrolled with a mean age of 53.5 ± 17. 7 years and the majority were male (63%. The mean left ventricular ejection fraction was 29.2± 11.9%. The in hospital mortality was 30.8%. Postdischarge 6-month major adverse event (re-hospitalization/mortality combined and mortality rates were 39.5% and 26.3%, respectively. Conclusions: These data from a single referral center provide insights into the current status of acute HF care in India. We report a higher in-hospital and follow-up mortality rates in ADHF patients who present at younger ages than reported in Western literature.

  19. Changing things around: Dramatic aspect in the Pericope Adulterae (Jn 7:53–8:11

    Directory of Open Access Journals (Sweden)

    Piet van Staden

    2015-09-01

    Full Text Available In this article the transactional model of narrative as expounded by Louise Rosenblatt, supported by an analysis in terms of dramatic aspect, is employed to show how the interpolated scene in John 7:53–8:11 (known as the Pericope Adulterae and hereafter referred to as PA functions as a pivot of power in the gospel. The content of the scene, as well as its placement within the gospel, serves to promote an aesthetic reading that focusses attention on the experience during the reading event. Awareness of sensations, images, feelings and ideas from past experiences, as well as the sounds and rhythms of the words become important. The reader responds to the aesthetic transaction, the various elements of total experience, rather than simply to the text, during and after the reading event.

  20. Probability of Failure Analysis Standards and Guidelines for Expendable Launch Vehicles

    Science.gov (United States)

    Wilde, Paul D.; Morse, Elisabeth L.; Rosati, Paul; Cather, Corey

    2013-09-01

    Recognizing the central importance of probability of failure estimates to ensuring public safety for launches, the Federal Aviation Administration (FAA), Office of Commercial Space Transportation (AST), the National Aeronautics and Space Administration (NASA), and U.S. Air Force (USAF), through the Common Standards Working Group (CSWG), developed a guide for conducting valid probability of failure (POF) analyses for expendable launch vehicles (ELV), with an emphasis on POF analysis for new ELVs. A probability of failure analysis for an ELV produces estimates of the likelihood of occurrence of potentially hazardous events, which are critical inputs to launch risk analysis of debris, toxic, or explosive hazards. This guide is intended to document a framework for POF analyses commonly accepted in the US, and should be useful to anyone who performs or evaluates launch risk analyses for new ELVs. The CSWG guidelines provide performance standards and definitions of key terms, and are being revised to address allocation to flight times and vehicle response modes. The POF performance standard allows a launch operator to employ alternative, potentially innovative methodologies so long as the results satisfy the performance standard. Current POF analysis practice at US ranges includes multiple methodologies described in the guidelines as accepted methods, but not necessarily the only methods available to demonstrate compliance with the performance standard. The guidelines include illustrative examples for each POF analysis method, which are intended to illustrate an acceptable level of fidelity for ELV POF analyses used to ensure public safety. The focus is on providing guiding principles rather than "recipe lists." Independent reviews of these guidelines were performed to assess their logic, completeness, accuracy, self- consistency, consistency with risk analysis practices, use of available information, and ease of applicability. The independent reviews confirmed the

  1. Home inotropic therapy in advanced heart failure: cost analysis and clinical outcomes.

    Science.gov (United States)

    Harjai, K J; Mehra, M R; Ventura, H O; Lapeyre, Y M; Murgo, J P; Stapleton, D D; Smart, F W

    1997-11-05

    This study was conducted to assess cost savings and clinical outcomes associated with the use of home i.v. inotropic therapy in patients with advanced (New York Heart Association [NYHA] class IV) heart failure. Retrospective analysis. Tertiary care referral center. Twenty-four patients (13 men, 11 women; age, 61+/-12 years) with left ventricular ejection fraction home i.v. inotropic therapy for at least 4 consecutive weeks between May 1994 and April 1996. Inotropic agents used included dobutamine (n=20; dose, 5.0+/-2.2 microg/kg/min) or milrinone (n=7; dose, 0.53+/-0.05 microg/kg/min). Cost of care and clinical outcomes (hospital admissions, length of hospital stay, NYHA functional class) were compared during the period of inotropic therapy (study period) and the immediate preceding period of equal duration (control period). In comparison to the control period, the study period (3.9+/-2.7 months) was associated with a 16% reduction in cost, amounting to a calculated savings of $5,700 per patient or $1,465 per patient per month. Concomitantly, a decrease in the number of hospital admissions from 2.7+/-2.6 to 1.3+/-1.3 (p=0.056) and length of hospital stay from 20.9+/-12.7 to 5.5+/-5.4 days (p=0.0004) was observed with improvement in NYHA functional class from 4.0+/-0.0 to 2.7+/-0.9 (phome i.v. inotropic therapy. Home i.v. inotropic therapy reduces hospital admissions, length of stay, and cost of care and improves functional class in patients with advanced (NYHA class IV) heart failure.

  2. Failure analysis of re-bars during bending operations

    Directory of Open Access Journals (Sweden)

    Souvik Das

    2014-10-01

    Full Text Available Thermo-mechanical treated (TMT rebar is suitable material for reinforcing concrete structures on accounts of similarity in thermal expansion, ability to bond well with concrete and, above all the ability to shoulder most of the tensile stress acting on the structure and also steel manufacturing industry has successfully developed a corrosion-resistant variety of rebar for the construction industry. As the TMT is the finish product thus proper control of rolling parameters and water box is needed to achieve adequate property. Water box plays an important role for achieving the final structure and property of the rebars. Water box is responsible for outer rim formation and which helps to achieve the yield strength of the material. The present paper highlights failure investigation of a failed rebar during bending operations. From fractography and microstructural analysis it is confirmed that the rebar sample failed in brittle manner due to through harden martensitic structure and which indicates that there is some anomaly in water box resulting in these premature failures.

  3. Determination of 11 trace elements in U3O8 CRMs by ICP-AES

    International Nuclear Information System (INIS)

    Liu Husheng

    1994-01-01

    The TBP extractant-containing resin and extraction chromatography technique were used to separate 11 trace elements in U 3 O 8 CRMs. The sample was separated at a flow rate of 0.5 mL/min with 3 mol/L HNO 3 as medium. A model 975 ICP direct reading spectrometer was used to determine the trace elements of Ca, Cd, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb and Sn in U 3 O 8 CRMs. The lowest quantitatively determinable concentration of impurities in U 3 O 8 CRMs are 0.02-1.6 μg/g. The RSD is less than 10%. The proposed method provides excellent and accurate analytical data for the U 3 O 8 samples prepared as certified reference materials (CRMs)

  4. Failure and Reliability Analysis for the Master Pump Shutdown System

    International Nuclear Information System (INIS)

    BEVINS, R.R.

    2000-01-01

    The Master Pump Shutdown System (MPSS) will be installed in the 200 Areas of the Hanford Site to monitor and control the transfer of liquid waste between tank farms and between the 200 West and 200 East areas through the Cross-Site Transfer Line. The Safety Function provided by the MPSS is to shutdown any waste transfer process within or between tank farms if a waste leak should occur along the selected transfer route. The MPSS, which provides this Safety Class Function, is composed of Programmable Logic Controllers (PLCs), interconnecting wires, relays, Human to Machine Interfaces (HMI), and software. These components are defined as providing a Safety Class Function and will be designated in this report as MPSS/PLC. Input signals to the MPSS/PLC are provided by leak detection systems from each of the tank farm leak detector locations along the waste transfer route. The combination of the MPSS/PLC, leak detection system, and transfer pump controller system will be referred to as MPSS/SYS. The components addressed in this analysis are associated with the MPSS/SYS. The purpose of this failure and reliability analysis is to address the following design issues of the Project Development Specification (PDS) for the MPSS/SYS (HNF 2000a): (1) Single Component Failure Criterion, (2) System Status Upon Loss of Electrical Power, (3) Physical Separation of Safety Class cables, (4) Physical Isolation of Safety Class Wiring from General Service Wiring, and (5) Meeting the MPSS/PLC Option 1b (RPP 1999) Reliability estimate. The failure and reliability analysis examined the system on a component level basis and identified any hardware or software elements that could fail and/or prevent the system from performing its intended safety function

  5. Investigation of tautomeric transformations of adducts of 7,8-dicarba-nido-undecaborana(11) with derivatives of pyridine by 11B NMR spectroscopy method

    International Nuclear Information System (INIS)

    Volkov, O.V.; Il'inchik, E.A.; Volkov, V.V.

    1999-01-01

    Tautomeric transformations are investigated in solutions of o-carborane(12) derivatives 7,8-C 2 B 9 H 11 ·Py(X), where Py(X)=4-picoline (4-CH 3 -C 5 H 4 N), 3-picoline (3-CH 3 -C 5 H 4 N), 4-stilbazol (4-C 6 H 5 -C 2 H 2 -C 5 H 4 N), 3-bromopyridine (3-Br-C 5 H 4 N) and 7,8-C 2 B 9 H 10 I·C 5 H 5 N. Uncovered tautomeric transformations are bound with migration of bridge hydrogen of C 2 B 9 H 11 cluster assisting in structure of these compounds. Signal of boron nuclei in 11 B NMR spectra is observed in the region of high field of spectrum if the nearest two atoms of boron are bounded by bridge hydrogen additionally. That permits to fix happening dynamic structural transformations of adducts investigated. The dependence of tautomeric equilibrium on nature of substituents introduced in heterocyclic ligand and carborane cluster. Increase of electron-acceptor properties of substituent induces displacement of equilibrium in the direction of tautomer bridge hydrogen in which is removed from boron atom bounded with substituent [ru

  6. Continuum Damage Mechanics Models for the Analysis of Progressive Failure in Open-Hole Tension Laminates

    Science.gov (United States)

    Song, Kyonchan; Li, Yingyong; Rose, Cheryl A.

    2011-01-01

    The performance of a state-of-the-art continuum damage mechanics model for interlaminar damage, coupled with a cohesive zone model for delamination is examined for failure prediction of quasi-isotropic open-hole tension laminates. Limitations of continuum representations of intra-ply damage and the effect of mesh orientation on the analysis predictions are discussed. It is shown that accurate prediction of matrix crack paths and stress redistribution after cracking requires a mesh aligned with the fiber orientation. Based on these results, an aligned mesh is proposed for analysis of the open-hole tension specimens consisting of different meshes within the individual plies, such that the element edges are aligned with the ply fiber direction. The modeling approach is assessed by comparison of analysis predictions to experimental data for specimen configurations in which failure is dominated by complex interactions between matrix cracks and delaminations. It is shown that the different failure mechanisms observed in the tests are well predicted. In addition, the modeling approach is demonstrated to predict proper trends in the effect of scaling on strength and failure mechanisms of quasi-isotropic open-hole tension laminates.

  7. Insulin resistance and hyperinsulinaemia in mild to moderate progressive chronic renal failure and its association with aerobic work capacity

    DEFF Research Database (Denmark)

    Eidemak, I; Feldt-Rasmussen, B; Kanstrup, I L

    1995-01-01

    Tissue sensitivity to insulin and aerobic work capacity was measured in patients with mild to moderate progressive chronic renal failure. Twenty-nine non-diabetic patients with a glomerular filtration rate of 25 ml.min-1.1.73 m-2 (11-43) (median, range) and 15 sex, age, and body mass index matched.......02) (M/I ratio 1.77 +/- 0.71 vs 2.57 +/- 0.70 (mg/(kgBW.min) per pmol/l.100, p aerobic work capacity was significantly lower in the patients than in the control subjects (24 +/- 8 vs 32 +/- 11 ml O2/(kg body weight.min), p .../I ratio in both groups. In conclusion, not only patients with end-stage chronic renal failure but also those with mild to moderate progressive chronic renal failure are insulin resistant and hyperinsulinaemic. The tissue sensitivity to insulin is correlated to the maximal aerobic work capacity suggesting...

  8. An estimation method of system failure frequency using both structure and component failure data

    International Nuclear Information System (INIS)

    Takaragi, Kazuo; Sasaki, Ryoichi; Shingai, Sadanori; Tominaga, Kenji

    1981-01-01

    In recent years, the importance of reliability analysis is appreciated for large systems such as nuclear power plants. A reliability analysis method is described for a whole system, using structure failure data for its main working subsystem and component failure data for its safety protection subsystem. The subsystem named main working system operates normally, and the subsystem named safety protection system acts as standby or protection. Thus the main and the protection systems are given mutually different failure data; then, between the subsystems, there exists common mode failure, i.e. the component failure affecting the reliability of both two. A calculation formula for sytem failure frequency is first derived. Then, a calculation method with digraphs is proposed for conditional system failure probability. Finally the results of numerical calculation are given for the purpose of explanation. (J.P.N.)

  9. Growth and Characterization of Organic Marine Dye Compound: 6-Amino-8α-methoxy-5-methyl-4,7-dioxo-1,1a, 2,4,7,8,8a,8b-octahydroazireno[2',3':3,4] pyrrolo[1,2-α]indol- 8-yl]methyl Carbamate

    OpenAIRE

    Jayandran, M.; Balasubramanian, V.

    2011-01-01

    Single crystals of 6-amino-8α-methoxy-5-methyl-4,7-dioxo-1,1a, 2,4,7,8,8a,8b-octahydroazireno[2',3':3,4]pyrrolo[1,2-α]indol-8-yl]methyl carbamate (Mitomycin), an organic marine dye material has been grown from solution by slow evaporation at ambient temperature. The growth of crystals has been carried out at various pH values and the growth was confirmed at pH 6. The chemical composition of the grown crystals was determined by the FTIR spectra. The crystalline nature and its various planes of...

  10. Uncertainty Analysis via Failure Domain Characterization: Unrestricted Requirement Functions

    Science.gov (United States)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2011-01-01

    This paper proposes an uncertainty analysis framework based on the characterization of the uncertain parameter space. This characterization enables the identification of worst-case uncertainty combinations and the approximation of the failure and safe domains with a high level of accuracy. Because these approximations are comprised of subsets of readily computable probability, they enable the calculation of arbitrarily tight upper and lower bounds to the failure probability. The methods developed herein, which are based on nonlinear constrained optimization, are applicable to requirement functions whose functional dependency on the uncertainty is arbitrary and whose explicit form may even be unknown. Some of the most prominent features of the methodology are the substantial desensitization of the calculations from the assumed uncertainty model (i.e., the probability distribution describing the uncertainty) as well as the accommodation for changes in such a model with a practically insignificant amount of computational effort.

  11. Failure of Emperion modular femoral stem with implant analysis

    Directory of Open Access Journals (Sweden)

    Benjamin M. Stronach, MD, MS

    2016-03-01

    Full Text Available Modularity in total hip arthroplasty provides multiple benefits to the surgeon in restoring the appropriate alignment and position to a previously damaged hip joint. The vast majority of modern implants incorporate modularity into their design with some implants having multiple modular interfaces. There is the potential for failure at modular junctions because of fretting and crevice corrosion in combination with mechanical loading. This case report details the failure of an Emperion (Smith and Nephew, Memphis, TN femoral stem in a 67-year-old male patient 6 years after total hip replacement. Analysis of the implant revealed mechanically assisted crevice corrosion that likely accelerated fatigue crack initiation in the hip stem. The benefits of modularity come with the potential drawback of a combination of fretting and crevice corrosion at the modular junction, which may accelerate fatigue, crack initiation and ultimately reduce the hip longevity.

  12. [Clinical analysis of 41 children's urinary calculus and acute renal failure].

    Science.gov (United States)

    Li, Lu-Ping; Fan, Ying-Zhong; Zhang, Qian; Zhang, Sheng-Li

    2013-04-01

    To analyze the treatment of acute renal failure caused by irrational drug use. Data of 41 cases of acute renal failure seen from July 2008 to June 2012 in our hospital were reviewed. Bilateral renal parenchymas diffuse echo was found enhanced by ultrasound in all cases. Calculus image was not found by X-ray. All children had medical history of using cephalosporins or others. Alkalinization of urine and antispasmodic treatment were given to all children immediately, 17 children were treated with hemodialysis and 4 children accepted intraureteral cannula placement. In 24 children who accepted alkalinization of urine and antispasmodic treatment micturition could be restored within 24 hours, in 11 children micturition recovered after only one hemodialysis treatment and 2 children gradually restored micturition after hemodialysis twice, 4 children who accepted intraureteral cannula immediately restored micturition. In all children micturition recovered gradually after a week of treatment. Ultrasound examination showed that 39 children's calculus disappeared totally and renal parenchymas echo recovered to normal. The residual calculi with diameter less than 5 mm were found in 2 children, but they had no symptoms. The children received potassium sodium hydrogen citrate granules per os and were discharged from hospital. Ultrasound showed calculus disappeared totally one month later. Irrational drug use can cause children urolithiasis combined with acute renal failure, while renal dysfunction can reverse by drug withdrawal and early alkalinization of urine, antispasmodic treatment, intraureteral cannula or hemodialysis when necessary, most calculus can be expelled after micturition recovered to normal.

  13. 46 CFR 54.25-8 - Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). 54.25-8 Section 54.25-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Radiography (modifies UW-11(a), UCS-57, UNF-57, UHA-33, and UHT-57). (a) Full radiography is required for all...

  14. Failure analysis of axle shaft of a fork lift

    Directory of Open Access Journals (Sweden)

    Souvik Das

    2015-04-01

    Full Text Available An axle shaft of fork lift failed at operation within 296 h of service. The shaft transmits torque from discrepancy to wheel through planetary gear arrangement. A section of fractured axle shaft made of induction-hardened steel was analyzed to determine the root cause of the failure. Optical microscopies as well as field emission gun scanning electron microscopy (FEG-SEM along with energy dispersive spectroscopy (EDS were carried out to characterize the microstructure. Hardness profile throughout the cross-section was evaluated by micro-hardness measurements. Chemical analysis indicated that the shaft was made of 42CrMo4 steel grade as per specification. Microstructural analysis and micro-hardness profile revealed that the shaft was improperly heat treated resulting in a brittle case, where crack was found to initiate from the case in a brittle mode in contrast to ductile mode within the core. This behaviour was related to differences in microstructure, which was observed to be martensitic within the case with a micro-hardness equivalent to 735 HV, and a mixture of non-homogeneous structure of pearlite and ferrite within the core with a hardness of 210 HV. The analysis suggests that the fracture initiated from the martensitic case as brittle mode due to improper heat treatment process (high hardness. Moreover the inclusions along the hot working direction i.e. in the longitudinal axis made the component more susceptible to failure.

  15. Carcinoma of Uterine Cervix Treated with High Dose Rate Intracavitary Irradiation : 1. Patterns of Failure

    International Nuclear Information System (INIS)

    Kim, Ok Bae; Choi, Tae Jin; Kim, Jin Hee

    1993-01-01

    226 patients with carcinoma of the uterine cervix treated with curative radiation therapy at the Department of Therapeutic Radiology, Dongsan hospital, Keimyung university, School of medicine, from July, 1988 to May, 1991 were evaluated. The patients with all stages of the disease were included in this study. The maximum and mean follow up durations were 60 and 43 months. The radiation therapy consisted of external irradiation to the whole pelvis (2700 - 4500 cGy) and boost parametrial doses(for a total of 4500 - 6300 cGy) with midline shill(4x10 cm), and combined with intracavitary irradiation irradiation(5700 - 7500 cGy to point A). The distribution of patients according to the stage was as follows: stage IB 37(16.4%), stage IIA 91 (40.3%), Stage IIB 58(25.7%), stage III 32(13.8%), stage IV 8 (3.5%). The overall failure rate was 23.9%(54 patients). The failure rate increased as a function of stage from 13.5% in stage 1B to 15.4% in stage IIA, 25.9% in stage IIB, 46.9% in stage III, and 62.5% in stage IV. The pelvic failure alone were 32 patients and 11 patients were as a components of other failure, and remaining 11 patients had distant metastasis only. Among the 43 patients of locoregional failure, 28 patients were not controlled initially and in other words nearly half of total failures were due to residual tumor. The mean medial paracervical(point A) doses were 6700 cGy in stage IIB, 7200 cGy in stage IIA, 7450 cGy in stage IIB, 7600 cGy in stage III and 8100 cGy in stage IV. The medial paracevical doses showed some correlation with tumor control rate in early stage of disease (stage Ib, IIA), but there were higher central failure rate in advanced stage in spite of higher paracervical doses. In advanced stage, failure were not reduced by simple Increment of paracervical doses. To improve a locoregional control rate in advanced stages, it is necessary to give additional treatment such as concomitant chemoradiation

  16. A statistical analysis on failure-to open/close probability of pneumatic valve in sodium cooling systems

    International Nuclear Information System (INIS)

    Kurisaka, Kenichi

    1999-11-01

    The objective of this study is to develop fundamental data for examination on efficiency of preventive maintenance and surveillance test from the standpoint of failure probability. In this study, as a major standby component, a pneumatic valve in sodium cooling systems was selected. A statistical analysis was made about a trend of valve in sodium cooling systems was selected. A statistical analysis was made about a trend of valve failure-to-open/close (FTOC) probability depending on number of demands ('n'), time since installation ('t') and standby time since last open/close action ('T'). The analysis is based on the field data of operating- and failure-experiences stored in the Component Reliability Database and Statistical Analysis System for LMFBR's (CORDS). In the analysis, the FTOC probability ('P') was expressed as follows: P=1-exp{-C-En-F/n-λT-aT(t-T/2)-AT 2 /2}. The functional parameters, 'C', 'E', 'F', 'λ', 'a' and 'A', were estimated with the maximum likelihood estimation method. As a result, the FTOC probability is almost expressed with the failure probability being derived from the failure rate under assumption of the Poisson distribution only when valve cycle (i.e. open-close-open cycle) exceeds about 100 days. When the valve cycle is shorter than about 100 days, the FTOC probability can be adequately estimated with the parameter model proposed in this study. The results obtained from this study may make it possible to derive an adequate frequency of surveillance test for a given target of the FTOC probability. (author)

  17. A mid-layer model for human reliability analysis: understanding the cognitive causes of human failure events

    International Nuclear Information System (INIS)

    Shen, Song-Hua; Chang, James Y.H.; Boring, Ronald L.; Whaley, April M.; Lois, Erasmia; Langfitt Hendrickson, Stacey M.; Oxstrand, Johanna H.; Forester, John Alan; Kelly, Dana L.; Mosleh, Ali

    2010-01-01

    The Office of Nuclear Regulatory Research (RES) at the US Nuclear Regulatory Commission (USNRC) is sponsoring work in response to a Staff Requirements Memorandum (SRM) directing an effort to establish a single human reliability analysis (HRA) method for the agency or guidance for the use of multiple methods. As part of this effort an attempt to develop a comprehensive HRA qualitative approach is being pursued. This paper presents a draft of the method's middle layer, a part of the qualitative analysis phase that links failure mechanisms to performance shaping factors. Starting with a Crew Response Tree (CRT) that has identified human failure events, analysts identify potential failure mechanisms using the mid-layer model. The mid-layer model presented in this paper traces the identification of the failure mechanisms using the Information-Diagnosis/Decision-Action (IDA) model and cognitive models from the psychological literature. Each failure mechanism is grouped according to a phase of IDA. Under each phase of IDA, the cognitive models help identify the relevant performance shaping factors for the failure mechanism. The use of IDA and cognitive models can be traced through fault trees, which provide a detailed complement to the CRT.

  18. A Mid-Layer Model for Human Reliability Analysis: Understanding the Cognitive Causes of Human Failure Events

    Energy Technology Data Exchange (ETDEWEB)

    Stacey M. L. Hendrickson; April M. Whaley; Ronald L. Boring; James Y. H. Chang; Song-Hua Shen; Ali Mosleh; Johanna H. Oxstrand; John A. Forester; Dana L. Kelly; Erasmia L. Lois

    2010-06-01

    The Office of Nuclear Regulatory Research (RES) is sponsoring work in response to a Staff Requirements Memorandum (SRM) directing an effort to establish a single human reliability analysis (HRA) method for the agency or guidance for the use of multiple methods. As part of this effort an attempt to develop a comprehensive HRA qualitative approach is being pursued. This paper presents a draft of the method’s middle layer, a part of the qualitative analysis phase that links failure mechanisms to performance shaping factors. Starting with a Crew Response Tree (CRT) that has identified human failure events, analysts identify potential failure mechanisms using the mid-layer model. The mid-layer model presented in this paper traces the identification of the failure mechanisms using the Information-Diagnosis/Decision-Action (IDA) model and cognitive models from the psychological literature. Each failure mechanism is grouped according to a phase of IDA. Under each phase of IDA, the cognitive models help identify the relevant performance shaping factors for the failure mechanism. The use of IDA and cognitive models can be traced through fault trees, which provide a detailed complement to the CRT.

  19. Evaluating wood failure in plywood shear by optical image analysis

    Science.gov (United States)

    Charles W. McMillin

    1984-01-01

    This exploratory study evaulates the potential of using an automatic image analysis method to measure percent wood failure in plywood shear specimens. The results suggest that this method my be as accurate as the visual method in tracking long-term gluebond quality. With further refinement, the method could lead to automated equipment replacing the subjective visual...

  20. An analysis of pretreatment characteristics and the risk of PSA failure by race and ethnicity in prostate cancer patients treated with definitive radiotherapy

    International Nuclear Information System (INIS)

    Coleman, Cardella W.; Lewis, Pamalar P.; Kroll, Stewart M.; Roach, Mack

    1997-01-01

    Purpose/Objective: This study was performed to: (1) determine the pretreatment characteristics of racially and ethnically diverse men who were treated with definitive radiotherapy for prostate cancer and; (2) to assess whether race or ethnicity is an independent prognostic factor for biochemical failure using the serum PSA (prostate specific antigen) as a marker of disease free status. Materials and Methods: Between 1987 and 1995, 505 men, (including 487 with pretreatment PSA determined), were treated with radiotherapy for adenocarcinoma of the prostate in the Department of Radiation Oncology at the UCSF or its affiliated hospitals and form the basis of this analysis. These patients were referred from local VA, County, HMO and private facilities in the Northern California Bay Area and represent a diverse group by race, ethnicity and social economic status. PSA failure was defined as a PSA >1.0 ng/ml or rises of ≥ 0.5 ng/ml in 1 year. Results: The median PSA for all patients was 11.5 ng/ml and the mean was 20.8 ng/ml. The mean Gleason score was 5.95, and was similar among treatment groups. Twenty percent of the patients were T1, 56% were T2 and 24% were T3/4. The maximum dose at depth (Dmax) was 71.5 in 42% of the patients. Seventy two men (14%) received neoadjuvant +/- adjuvant hormonal therapy combined with radiotherapy. With a median follow-up exceeding 2 years, 47% of the patients are disease free at 4 years. Major pretreatment characteristics by race or ethnicity are summarized below: On univariate analysis, the relative risk of PSA failure in Blacks compared to Whites was 1.04 (95% confidence interval, 0.72- 1.52, p = 0.82) and in others compared to Whites was 1.12 (95% confidence interval, 0.55 - 2.28, p = 0.77). On multivariate analysis, neither race nor ethnicity were independently significant predictors of outcome. For example, the relative risk of PSA failure in Blacks was 0.88 (95% confidence interval, 0.59 - 1.32, p = 0.53). Factors that influenced

  1. Hepatic blood flow and splanchnic oxygen consumption in patients with liver failure. Effect of high-volume plasmapheresis.

    Science.gov (United States)

    Clemmesen, J O; Gerbes, A L; Gülberg, V; Hansen, B A; Larsen, F S; Skak, C; Tygstrup, N; Ott, P

    1999-02-01

    Liver failure represents a major therapeutic challenge, and yet basic pathophysiological questions about hepatic perfusion and oxygenation in this condition have been poorly investigated. In this study, hepatic blood flow (HBF) and splanchnic oxygen delivery (DO2, sp) and oxygen consumption (VO2,sp) were assessed in patients with liver failure defined as hepatic encephalopathy grade II or more. Measurements were repeated after high-volume plasmapheresis (HVP) with exchange of 8 to 10 L of plasma. HBF was estimated by use of constant infusion of D-sorbitol and calculated according to Fick's principle from peripheral artery and hepatic vein concentrations. In 14 patients with acute liver failure (ALF), HBF (1.78 +/- 0.78 L/min) and VO2,sp (3.9 +/- 0.9 mmol/min) were higher than in 11 patients without liver disease (1.07 +/- 0.19 L/min, P HVP, HBF increased from 1.67 +/- 0.72 to 2.07 +/- 1.11 L/min (n=11) in ALF, and from 1.89 +/- 1.32 to 2.34 +/- 1.54 L/min (n=7) in AOCLD, P HVP. Blood flow was redirected to the liver as the systemic vascular resistance index increased (1,587 +/- 650 vs. 2, 020 +/- 806 Dyne. s. cm-5. m2, P HVP, but as cardiac output increased from 9.1 +/- 2.8 to 10.1 +/- 2.9 L/min (P HVP (n=18), DO2,sp increased by 15% (P HVP. Changes of ET-1 were positively correlated with changes in HBF (P HVP (P HVP did not correlate. Our data suggest that liver failure is associated with increased HBF and VO2, sp. HVP further increased HBF and DO2,sp but VO2,sp was unchanged, indicating that splanchnic hypoxia was not present.

  2. Mutational analysis of the PTPN11 gene in Egyptian patients with Noonan syndrome.

    Science.gov (United States)

    Essawi, Mona L; Ismail, Manal F; Afifi, Hanan H; Kobesiy, Maha M; El Kotoury, Ahmed; Barakat, Maged M

    2013-11-01

    Noonan syndrome (NS) is inherited as an autosomal dominant disorder with dysmorphic facies, short stature, and cardiac defects, which can be caused by missense mutations in the protein tyrosine phosphatase nonreceptor type 11 (PTPN11) gene, which encodes src homology region 2 domain containing tyrosine phosphatase-2 (SHP-2), a protein tyrosine phosphatase that acts in signal transduction downstream to growth factors and cytokines. The current study aimed to study the molecular characterization of the PTPN11 gene among Egyptian patients with Noonan syndrome. Eleven exons of the PTPN11 gene were amplified and screened by single stranded conformational polymorphism (SSCP). DNA samples showing band shift in SSCP were subjected to sequencing. Mutational analysis of the PTPN11 gene revealed T→C transition at position 854 in exon 8, predicting Phe285Ser substitution within PTP domain of SHP-2 protein, in one NS patient and -21C→T polymorphism in intron 7 in four other cases. Knowing that NS is phenotypically heterogeneous, molecular characterization of the PTPN11 gene should serve to establish NS diagnosis in patients with atypical features, although lack of a mutation does not exclude the possibility of NS. Copyright © 2012. Published by Elsevier B.V.

  3. Detailed analysis of the Valdes slide: a landward facing slope failure off Chile

    Science.gov (United States)

    Anasetti, Andrea; Krastel, Sebastian; Weinrebe, Willy; Klaucke, Ingo; Bialas, Jorge

    2010-05-01

    The Chilean continental margin is a very active area interested by important tectonic movements and characterized by a fast morphological evolution. Geophysical data acquired during cruise JC 23, aboard RV JAMES COOK in March/April 2008 and previous cruises cover most of the active Chilean continental margin between 33° and 37° S. Integrated interpretation of multi-beam bathymetric, sub-bottom profiles, side-scan sonar and seismic data allowed the identification of a number of slope failures. The main topic of this project is the morphological and sedimentological analysis of the Valdes slide, a medium-sized submarine landslide offshore the city of Talcahuano (300 km south of Santiago). In contrast to most other slides along continental margins, the Valdes slide is located on the landward facing eastern slope of a submarine ridge. This setting has important implications for the associated tsunami wave field (first arrival of positive amplitude). We measured geometrical parameters of the failure and adjacent slope. The slide affected an area of 19 km2 between ~1060 m and >1700 m water depths. Its is ~ 6 km long, up to 3 km wide and involved a total sedimentary volume of about 0,8 km3. The failure process was characterized by a multiple-event and we assume its tsunami potential to be high. Using the high resolution bathymetric data and the seismic profiles along the slide deposit it was possible to reconstruct the original morphology of the area in order to understand the relation between the slide event and the structural evolution of the ridge. Through the analysis of the data and bibliographic information about the Chilean margin, we analyzed potential trigger mechanisms for the landslide. The Valdes slide is situated on a steep ridge flank. The ridge follows an elongated fault zone running app. parallel to the margin. This fault zone has a dextral component which in combination with the faults elongation results in a compressional regime that is superimposed on

  4. Failure analysis – basic step of applying Reliability Centered Maintenance in general aviation

    Directory of Open Access Journals (Sweden)

    Martin BUGAJ

    2012-01-01

    Full Text Available Performing a reliability analysis on a product or system can actually include a number of different analyses to determine how reliable the product or system is. A reliability centered maintenance program consists of a set of scheduled tasks generated on the basis of specific reliability characteristics of the equipment they are designed to protect. Complex equipment is composed of a vast number of parts and assemblies. All these items can be expected to fail at one time or another, but some of the failures have more serious consequences than others. Certain kinds of failures have a direct effect on operating safety, and others affect the operational capability of the equipment. The consequences of a particular failure depend on the design of the item and the equipment in which it is installed. Although the environment in which the equipment is operated is sometimes an additional factor, the impact of failures on the equipment, and hence their consequences for the operating organization, are established primarily by the equipment designer. Failure consequences are therefore a primary inherent reliability characteristic.

  5. A COCAP program for the statistical analysis of common cause failure parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Baehyeuk; Jae, Moosung [Hanyang Univ., Seoul (Korea, Republic of). Dept. of Nuclear Engineering

    2016-03-15

    Probabilistic Safety Assessment (PSA) based applications and regulations are becoming more important in the field of nuclear energy. According to the results of a PSA in Korea, the common cause failure evaluates CDF (Core Damage Frequency) as one of the significant factors affecting redundancy of NPPs. The purpose of the study is to develop a COCAP (Common Cause Failure parameter Analysis for PSA) program for the accurate use of the alpha factor model parameter data provided by other countries and for obtaining the indigenous CCF data of NPPs in Korea through Bayesian updating.

  6. On the failure analysis of bondlines: Stress or energy based fracture criteria?

    DEFF Research Database (Denmark)

    Anyfantis, Konstantinos

    2014-01-01

    that characterizes a given bondline, both its cohesive strength and fracture toughness material parameters must be experimentally defined. Based on these properties, failure analysis of the bondline can be done either through stress- or energy-based criteria. The aim of this work is to investigate the effectiveness...... to classify the wide range of bondlines with respect to the failure theory that best describes the debonding process. Cohesive length scale effects are first demonstrated by modeling end notch flexure geometries and later by modeling double strap joint geometries within the framework of a wide numerical...

  7. Statistical analysis on failure-to-open/close probability of motor-operated valve in sodium system

    International Nuclear Information System (INIS)

    Kurisaka, Kenichi

    1998-08-01

    The objective of this work is to develop basic data for examination on efficiency of preventive maintenance and actuation test from the standpoint of failure probability. This work consists of a statistical trend analysis of valve failure probability in a failure-to-open/close mode on time since installation and time since last open/close action, based on the field data of operating- and failure-experience. In this work, the terms both dependent and independent on time were considered in the failure probability. The linear aging model was modified and applied to the first term. In this model there are two terms with both failure rates in proportion to time since installation and to time since last open/close-demand. Because of sufficient statistical population, motor-operated valves (MOV's) in sodium system were selected to be analyzed from the CORDS database which contains operating data and failure data of components in the fast reactors and sodium test facilities. According to these data, the functional parameters were statistically estimated to quantify the valve failure probability in a failure-to-open/close mode, with consideration of uncertainty. (J.P.N.)

  8. Identifying novel phenotypes of acute heart failure using cluster analysis of clinical variables.

    Science.gov (United States)

    Horiuchi, Yu; Tanimoto, Shuzou; Latif, A H M Mahbub; Urayama, Kevin Y; Aoki, Jiro; Yahagi, Kazuyuki; Okuno, Taishi; Sato, Yu; Tanaka, Tetsu; Koseki, Keita; Komiyama, Kota; Nakajima, Hiroyoshi; Hara, Kazuhiro; Tanabe, Kengo

    2018-07-01

    Acute heart failure (AHF) is a heterogeneous disease caused by various cardiovascular (CV) pathophysiology and multiple non-CV comorbidities. We aimed to identify clinically important subgroups to improve our understanding of the pathophysiology of AHF and inform clinical decision-making. We evaluated detailed clinical data of 345 consecutive AHF patients using non-hierarchical cluster analysis of 77 variables, including age, sex, HF etiology, comorbidities, physical findings, laboratory data, electrocardiogram, echocardiogram and treatment during hospitalization. Cox proportional hazards regression analysis was performed to estimate the association between the clusters and clinical outcomes. Three clusters were identified. Cluster 1 (n=108) represented "vascular failure". This cluster had the highest average systolic blood pressure at admission and lung congestion with type 2 respiratory failure. Cluster 2 (n=89) represented "cardiac and renal failure". They had the lowest ejection fraction (EF) and worst renal function. Cluster 3 (n=148) comprised mostly older patients and had the highest prevalence of atrial fibrillation and preserved EF. Death or HF hospitalization within 12-month occurred in 23% of Cluster 1, 36% of Cluster 2 and 36% of Cluster 3 (p=0.034). Compared with Cluster 1, risk of death or HF hospitalization was 1.74 (95% CI, 1.03-2.95, p=0.037) for Cluster 2 and 1.82 (95% CI, 1.13-2.93, p=0.014) for Cluster 3. Cluster analysis may be effective in producing clinically relevant categories of AHF, and may suggest underlying pathophysiology and potential utility in predicting clinical outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Identification of Modeling Approaches To Support Common-Cause Failure Analysis

    International Nuclear Information System (INIS)

    Korsah, Kofi; Wood, Richard Thomas

    2015-01-01

    Experience with applying current guidance and practices for common-cause failure (CCF) mitigation to digital instrumentation and control (I&C) systems has proven problematic, and the regulatory environment has been unpredictable. The impact of CCF vulnerability is to inhibit I&C modernization and, thereby, challenge the long-term sustainability of existing plants. For new plants and advanced reactor concepts, the issue of CCF vulnerability for highly integrated digital I&C systems imposes a design burden resulting in higher costs and increased complexity. The regulatory uncertainty regarding which mitigation strategies are acceptable (e.g., what diversity is needed and how much is sufficient) drives designers to adopt complicated, costly solutions devised for existing plants. The conditions that constrain the transition to digital I&C technology by the U.S. nuclear industry require crosscutting research to resolve uncertainty, demonstrate necessary characteristics, and establish an objective basis for qualification of digital technology for usage in Nuclear Power Plant (NPP) I&C applications. To fulfill this research need, Oak Ridge National Laboratory is conducting an investigation into mitigation of CCF vulnerability for nuclear-qualified applications. The outcome of this research is expected to contribute to a fundamentally sound, comprehensive technical basis for establishing the qualification of digital technology for nuclear power applications. This report documents the investigation of modeling approaches for representing failure of I&C systems. Failure models are used when there is a need to analyze how the probability of success (or failure) of a system depends on the success (or failure) of individual elements. If these failure models are extensible to represent CCF, then they can be employed to support analysis of CCF vulnerabilities and mitigation strategies. Specifically, the research findings documented in this report identify modeling approaches that

  10. Identification of Modeling Approaches To Support Common-Cause Failure Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Korsah, Kofi [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wood, Richard Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-06-01

    Experience with applying current guidance and practices for common-cause failure (CCF) mitigation to digital instrumentation and control (I&C) systems has proven problematic, and the regulatory environment has been unpredictable. The impact of CCF vulnerability is to inhibit I&C modernization and, thereby, challenge the long-term sustainability of existing plants. For new plants and advanced reactor concepts, the issue of CCF vulnerability for highly integrated digital I&C systems imposes a design burden resulting in higher costs and increased complexity. The regulatory uncertainty regarding which mitigation strategies are acceptable (e.g., what diversity is needed and how much is sufficient) drives designers to adopt complicated, costly solutions devised for existing plants. The conditions that constrain the transition to digital I&C technology by the U.S. nuclear industry require crosscutting research to resolve uncertainty, demonstrate necessary characteristics, and establish an objective basis for qualification of digital technology for usage in Nuclear Power Plant (NPP) I&C applications. To fulfill this research need, Oak Ridge National Laboratory is conducting an investigation into mitigation of CCF vulnerability for nuclear-qualified applications. The outcome of this research is expected to contribute to a fundamentally sound, comprehensive technical basis for establishing the qualification of digital technology for nuclear power applications. This report documents the investigation of modeling approaches for representing failure of I&C systems. Failure models are used when there is a need to analyze how the probability of success (or failure) of a system depends on the success (or failure) of individual elements. If these failure models are extensible to represent CCF, then they can be employed to support analysis of CCF vulnerabilities and mitigation strategies. Specifically, the research findings documented in this report identify modeling approaches that

  11. Reprioritization of failures in a system failure mode and effects analysis by decision making trial and evaluation laboratory technique

    International Nuclear Information System (INIS)

    Seyed-Hosseini, S.M.; Safaei, N.; Asgharpour, M.J.

    2006-01-01

    In this paper an effective methodology related to decision making field has been developed for reprioritization of failure modes in a system Failure Mode and Effects Analysis (FMEA) for corrective actions. The proposed methodology can cover some of inherently shortcomings of conventional Risk Priority Number (RPN) method and like. The current prioritization methods have two main deficiencies as: they have not considered indirect relations between components and are deficient for systems with many subsystems or components. The proposed method called Decision Making Trial and Evaluation Laboratory (DEMATEL) is an effective approach for analyzing relation between components of a system in respect to its type (direct/indirect) and severity. The main advantages of DEMATEL are involving indirect relations in analyze, allocating as possible as unique ranks to alternatives and clustering alternatives in large systems. The demonstrated results have shown that DEMATEL method can be an efficient, complementary and confident approach for reprioritization of failure modes in a FMEA. For verification of proposed methodology, two illustrative practical examples are solved and obtained outcomes are reported

  12. Fast neutron reactor noise analysis: beginning failure detection and physical parameter estimation

    International Nuclear Information System (INIS)

    Le Guillou, G.

    1975-01-01

    The analysis of the signals fluctuations coming from a power nuclear reactor (a breeder), by correlation methods and spectral analysis has two principal applications: on line estimation of physical parameters (reactivity coefficients); beginning failures (little boiling, abnormal mechanic vibrations). These two applications give important informations to the reactor core control and permit a good diagnosis [fr

  13. Radiographic failure and rates of re-operation after acromioclavicular joint reconstruction: a comparison of surgical techniques.

    Science.gov (United States)

    Spencer, H T; Hsu, L; Sodl, J; Arianjam, A; Yian, E H

    2016-04-01

    To compare radiographic failure and re-operation rates of anatomical coracoclavicular (CC) ligament reconstructional techniques with non-anatomical techniques after chronic high grade acromioclavicular (AC) joint injuries. We reviewed chronic AC joint reconstructions within a region-wide healthcare system to identify surgical technique, complications, radiographic failure and re-operations. Procedures fell into four categories: (1) modified Weaver-Dunn, (2) allograft fixed through coracoid and clavicular tunnels, (3) allograft loop coracoclavicular fixation, and (4) combined allograft loop and synthetic cortical button fixation. Among 167 patients (mean age 38.1 years, (standard deviation (sd) 14.7) treated at least a four week interval after injury, 154 had post-operative radiographs available for analysis. Radiographic failure occurred in 33/154 cases (21.4%), with the lowest rate in Technique 4 (2/42 4.8%, p = 0.001). Half the failures occurred by six weeks, and the Kaplan-Meier survivorship at 24 months was 94.4% (95% confidence interval (CI) 79.6 to 98.6) for Technique 4 and 69.9% (95% CI 59.4 to 78.3) for the other techniques when combined. In multivariable survival analysis, Technique 4 had better survival than other techniques (Hazard Ratio 0.162, 95% CI 0.039 to 0.068, p = 0.013). Among 155 patients with a minimum of six months post-operative insurance coverage, re-operation occurred in 9.7% (15 patients). However, in multivariable logistic regression, Technique 4 did not reach a statistically significant lower risk for re-operation (odds ratio 0.254, 95% CI 0.05 to 1.3, p = 0.11). In this retrospective series, anatomical CC ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure. Anatomical coracoclavicular ligament reconstruction using combined synthetic cortical button and allograft loop fixation had the lowest rate of radiographic failure. ©2016 The British Editorial

  14. Obesity-related decrease in intraoperative blood flow is associated with maturation failure of radiocephalic arteriovenous fistula.

    Science.gov (United States)

    Kim, Jwa-Kyung; Jeong, Jae Han; Song, Young Rim; Kim, Hyung Jik; Lee, Won Yong; Kim, Kun Il; Kim, Sung Gyun

    2015-10-01

    Successful arteriovenous fistula (AVF) maturation is often challenging in obese patients. Optimal initial intraoperative blood flow (IOBF) is essential for adequate AVF maturation. This study was conducted to elucidate the effect of obesity on IOBF and radiocephalic AVF maturation. Patients with a newly created radiocephalic AVF were included (N = 252). Obesity was defined as a baseline body mass index (BMI) ≥25 kg/m(2), and primary maturation failure was defined as failure to use the AVF successfully by 3 months after its creation. IOBF was measured immediately after construction of the AVF with a VeriQ system (MediStim, Oslo, Norway). The mean BMI was 24.1 ± 3.9 kg/m(2), and the prevalence of obesity was 31.3%. Particularly, 8.3% (21 patients) had a BMI ≥30 kg/m(2). Primary maturation failure occurred in 100 patients (39.7%), and an IOBF <190 mL/min was closely associated with the risk of maturation failure (relative risk, 3.05; 95% confidence interval, 1.52-6.11). Compared with nonobese patients, obese subjects had a significantly higher prevalence of diabetes and elevated high-sensitivity C-reactive protein levels, whereas diameters of vessels were similar. When the patients were further divided into three groups as BMI <25, 25 to 29.9, and ≥30 kg/m(2), patients in the higher BMI group showed significantly lower IOBF and higher maturation failure rate. According to multivariate analysis, the statistically significant variables that determined maturation failure were obesity, previous vascular disease, increased high-sensitivity C-reactive protein levels, and IOBF <190 mL/min. Obese patients had a significantly lower IOBF, and both obesity and low IOBF contributed to the primary maturation failure of AVF. Obesity-associated inflammation and atherosclerosis might play roles in this association. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  15. Numerical Analysis on Failure Modes and Mechanisms of Mine Pillars under Shear Loading

    Directory of Open Access Journals (Sweden)

    Tianhui Ma

    2016-01-01

    Full Text Available Severe damage occurs frequently in mine pillars subjected to shear stresses. The empirical design charts or formulas for mine pillars are not applicable to orebodies under shear. In this paper, the failure process of pillars under shear stresses was investigated by numerical simulations using the rock failure process analysis (RFPA 2D software. The numerical simulation results indicate that the strength of mine pillars and the corresponding failure mode vary with different width-to-height ratios and dip angles. With increasing dip angle, stress concentration first occurs at the intersection between the pillar and the roof, leading to formation of microcracks. Damage gradually develops from the surface to the core of the pillar. The damage process is tracked with acoustic emission monitoring. The study in this paper can provide an effective means for understanding the failure mechanism, planning, and design of mine pillars.

  16. Skin Effect Simulation for Area 11 Dense Plasma Focus Hot Plate

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, B. Timothy [National Security Technologies, LLC. (NSTec), Mercury, NV (United States)

    2017-07-27

    Two arc flashover events occurred at the DPF Area 11 facility. These flashover events happened in the same location on the bank current delivery plates. The damage from one of these events can be seen on the left-hand side of Figure 1. Since the flashovers occurred in the same area of the bank, and the reliability of the bank is important for future DPF experiments, a failure analysis effort was initiated. Part of this failure analysis effort was an effort to understand the physical reasons behind why the flashover happened, and why it happened in the same place twice. This paper summarizes an effort to simulate the current flow in the bank in order to understand the reasons for the flashover.

  17. OD (order-disorder) character of the crystal structure of maucherite Ni8As11

    DEFF Research Database (Denmark)

    Makovicky, Emil; Merlino, Stefano

    2009-01-01

    Maucherite Ni11As8 has been found to be an OD (order-disorder) structure consisting of unit layers, which display stacking orientation disorder. Maucherite is composed of OD layers of one kind, with layer symmetry P( )m2 (the bracketed element is perpendicular to the layer), the simplest, uniform...

  18. Common cause failure analysis of the rodded scram system of the Arkansas Nuclear One-Unit 1 Plant

    International Nuclear Information System (INIS)

    Montague, D.F.; Campbell, D.J.; Flanagan, G.F.

    1986-10-01

    This study demonstrates the use of a formal method for common cause failure analysis in a reliability analysis of the Arkansas Nuclear One - Unit 1 rodded scram system. The scram system failure of interest is loss of capability of the system to shut the reactor down when required. The results of this analysis support the ATWS program sponsored by the US Nuclear Regulatory Commission. The methods used in this analysis support the NRC's Risk Methods Integration and Evaluation Program (RMIEP)

  19. Computer-tomography and its use in failure analysis; Computertomographie und deren Anwendung in der Schadensanalytik

    Energy Technology Data Exchange (ETDEWEB)

    Panzenboeck, Michael; Freitag, Caroline [Montanuniv. Leoben (Austria). Dept. Metallkunde und Werkstoffpruefung; Borchert, Marlies [Materials Center Leoben (Austria)

    2017-04-15

    In the last fifteen years computer-tomography has proven to be a valuable aid in the fields of medicine, materials technology and forensics. Nowadays it is hard to image non-destructive testing being carried out without its use. This article serves to demonstrate the power of the technique within the field of failure analysis with reference to two chosen case studies. The first case concerns the failure of magnetic valves, the second case focusses on the failure of corrosion resistant screws.

  20. An engineering approach to common mode failure analysis

    International Nuclear Information System (INIS)

    Gangloff, W.C.; Franke, T.H.

    1975-01-01

    Safety systems for nuclear reactors can be designed using standard reliability engineering techniques such that system failure due to random component faults is extremely unlikely. However, the common-mode failure where several components fail together from a common cause is not susceptible to prevention by the usual tactics. In systems where a high degree of redundancy has been employed, the actual reliability of the system in service may be limited by common-mode failures. A methodical and thorough procedure for evaluation of system vulnerability to common-mode failures is presented. This procedure was developed for use in nuclear reactor safety systems and has been applied specifically to reactor protection. The method offers a qualitative assessment of a system whereby weak points can be identified and the resistance to common-mode failure can be judged. It takes into account all factors influencing system performance including design, manufacturing, installation, operation, testing, and maintenance. It is not a guarantee or sure solution, but rather a practical tool which can provide good assurance that the probability of common-mode protection failure has been made acceptably low. (author)

  1. Impact of Renal Failure on Survival of African Patients with Cirrhosis

    Directory of Open Access Journals (Sweden)

    Attia K

    2008-01-01

    Full Text Available To assess the effect of renal failure on the survival of black African patients with cirrhosis, we studied 132 (82 males, 50 females cirrhotic black African patients with mean age of 47.5 ±14.4 years and mean follow-up period of 373 ± 194 days. The edema and ascitis were the main reasons for admission to hospital. Renal failure was present in 30 (22.7% patients, and it was positively correlated to the severity of the stage of the liver disease, and associated with severe hyponatremia. Survival at 1 year was 60.1% and 37.6% in the absence or presence of renal failure, respectively (p< 0.001. The stage of the liver disease was significantly inversely corre-lated with survival, which was further diminished in the presence of renal failure:23.7% versus 12.5% for Child-Pugh-Turcote (CPT A-B in the absence or presence of renal failure, respectively (p= 0.67, 30.2% versus 81.8% for CPT C in the absence or the presence of renal failure respectively (p< 0.001. Hyponatremia has also appeared detrimental to survival, since mortality was 38.4% versus 81.8% in the absence or the presence of hyponatremia respectively (p< 0.001. By multivariate analysis, renal failure, CPT stage C, and hyponatremia independently significantly correlated to mortality in patients with cirrhosis. We conclude that renal failure is frequently associated with decompensated cirrhosis. The presence of renal failure in this setting often results in high mortality. Renal failure that occurs in the setting of a severe liver disease and hyponatremia may be part of hepatorenal syndrome.

  2. Failure mode and effects analysis: too little for too much?

    Science.gov (United States)

    Dean Franklin, Bryony; Shebl, Nada Atef; Barber, Nick

    2012-07-01

    Failure mode and effects analysis (FMEA) is a structured prospective risk assessment method that is widely used within healthcare. FMEA involves a multidisciplinary team mapping out a high-risk process of care, identifying the failures that can occur, and then characterising each of these in terms of probability of occurrence, severity of effects and detectability, to give a risk priority number used to identify failures most in need of attention. One might assume that such a widely used tool would have an established evidence base. This paper considers whether or not this is the case, examining the evidence for the reliability and validity of its outputs, the mathematical principles behind the calculation of a risk prioirty number, and variation in how it is used in practice. We also consider the likely advantages of this approach, together with the disadvantages in terms of the healthcare professionals' time involved. We conclude that although FMEA is popular and many published studies have reported its use within healthcare, there is little evidence to support its use for the quantitative prioritisation of process failures. It lacks both reliability and validity, and is very time consuming. We would not recommend its use as a quantitative technique to prioritise, promote or study patient safety interventions. However, the stage of FMEA involving multidisciplinary mapping process seems valuable and work is now needed to identify the best way of converting this into plans for action.

  3. Projectile fragmentation of a weakly-bound 11Be nucleus at 0.8 GeV/nucleon

    International Nuclear Information System (INIS)

    Kobayashi, T.

    1990-01-01

    The projectile fragmentation of a weakly-bound 11 Be projectile has been measured on a carbon target at 0.8 GeV/nucleon. The transverse momentum distribution of 10 Be fragments showed a two-Gaussian structure: a narrow component with σ ∼ 25 MeV/c on top of a wide component with σ ∼ 110 MeV/c. As in the case of 11 Li fragmentation, the narrow momentum distribution indicates a long tail in the neutron density distribution which is consistent with the large nuclear matter radius of the 11 Be nucleus. Neutrons were also measured in coincidence with 10 Be fragments. In contrast to 10 Be fragments, no narrow momentum distribution was observed for coincident neutrons

  4. Defining Business decline, failure and turnaround: A content analysis

    Directory of Open Access Journals (Sweden)

    Marius Pretorius

    2009-12-01

    Full Text Available In the past, researchers have often defined failure to suit their data. This has led to a lack of comparability in research outputs. The overriding objective of this paper is to propose a universal definition for the failure phenomenon. Clear definitions are a prerequisite for exploring major constructs, their relationship to failure and the context and processes involved. The study reports on the core definitions of the failure phenomenon and identifies core criteria for distinguishing between them. It places decline, failure and turnaround in perspective and highlights level of distress and turnaround as key moderating elements. It distinguishes the failure phenomenon from controversial synonyms such as closure, accidental bankruptcy and closure for alternative motives. Key words and phrases: business decline, failure, turnaround, level of distress

  5. Failure mode and effects analysis on typical reactor trip system

    International Nuclear Information System (INIS)

    Eisawy, E.A.

    2010-01-01

    An updated failure mode and effects analysis, FMEA , has been performed on a typical reactor trip system. This upgrade helps to avoid system damage and ,as a result, extends the system service life. It also provides for simplified maintenance and surveillance testing. The operating conditions under which the system is to carry out its function and the operational profile expected for the system have been determined. The results of the FMEA have been given in terms of operating states of the subsystem.The results are given in form of table which is set up such that for a given failure one can read across it and determine which items remain operating in the system. From this data one can identify the number of components operating in the system for monitors pressure exceeds the setpoint pressure.

  6. Why an entrepreneur needs three failures before success:entrepreneurial learning after failure

    OpenAIRE

    Haapala, S. (Sami)

    2016-01-01

    Abstract This thesis aims to give an understanding of what is behind a failure in a startup industry. To understand why failures are needed for a success, the serial entrepreneur process has to be clarified at an individual level. In the failure process, under analysis are the main phases of turning a failure into a success and the outcomes which should be used as the next venture foundations. This study also aims to give b...

  7. A Hybrid Approach to Composite Damage and Failure Analysis Combining Synergistic Damage Mechanics and Peridynamics

    Science.gov (United States)

    2017-03-30

    manufacturing defects in the intermediately -homogenized model of fiber-reinforced composites. 15. SUBJECT TERMS Computational micromechanics; Cavitation...defects in the intermediately -homogenized model of fiber-reinforced composites. Task 1.1 Micro-level crack initiation Background and motivation In...new Intermediate Homogenization Peridynamic approach (IH-PD model) for failure in multiphase materials. We plan to apply this IH-PD model for the

  8. Synthesis and physicochemical properties of 7,8-dicarba-nido-undecarborane(11) adducts with pyridine bases

    International Nuclear Information System (INIS)

    Volkov, O.V.; Il'inchik, E.A.; Volkov, V.V.; Voronina, G.S.; Yur'eva, O.P.; Polyanskaya, T.M.

    1993-01-01

    Synthesis of some 7,8-C 2 B 9 H 11 adducts in conducted via 7.8-C 2 B 9 H 12 ion interaction with iron (3) chloride at presence of pyridine derivatives and their study is carried out using IR, NMR 12 B, PMR, X-ray phase, UV spectroscopy techniques. Character of bond between heterocycle and carborane holyhedron is discussed. Luminescent properties of the prepared compounds under UV radiation are detected

  9. Risk factors for treatment failure and recurrence of anisometropic amblyopia.

    Science.gov (United States)

    Kirandi, Ece Uzun; Akar, Serpil; Gokyigit, Birsen; Onmez, Funda Ebru Aksoy; Oto, Sibel

    2017-08-01

    The aim of this study was to identify factors associated with failed vision improvement and recurrence following occlusion therapy for anisometropic amblyopia in children aged 7-9 years. We retrospectively reviewed the medical records of 64 children aged 7-9 years who had been diagnosed as having anisometropic amblyopia and were treated with patching. Functional treatment failure was defined as final visual acuity in the amblyopic eye of worse than 20/32. Improvement of fewer than two logMAR lines was considered relative treatment failure. Recurrence was defined as the reduction of at least two logMAR levels of visual acuity after decreased or discontinued patching. Functional and relative success rates were 51.6 and 62.5 %, respectively. The most important factor for functional treatment failure [adjusted odds ratio (OR) (95 % confidence interval, CI) 11.57 (1.4-95.74)] and the only risk factor for recurrence [adjusted OR (95 % CI) 3.04 (1.13-8.12)] were the same: high spherical equivalent (SE) of the amblyopic eye. A large interocular difference in the best-corrected visual acuity was found to be a risk factor for both functional and relative failure. High SE of the amblyopic eye was the most influential risk factor for treatment failure and recurrence in compliant children aged 7-9 years.

  10. Non-destructive failure analysis and measurement for molded devices and complex assemblies with X-ray CT and 3D image processing techniques

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Liew, Seaw Jia; Jiang, Ting Ying; Xu, Jian; Kakarala, Ramakrishna

    2013-01-01

    In both automotive and healthcare sectors, reliable failure analysis and accurate measurement of molded devices and complex assemblies are important. Current methods of failure analysis and measurement require these molded parts to be cross-sectioned so that internal features or dimensions can be accessible. As a result, the parts are deemed unusable and additional failure introduced by sectioning may cause misinterpretation of the results. X-ray CT and 3D image processing techniques provide a new nondestructive solution for failure analysis and measurement of molded devices and complex assemblies. These techniques simplify failure analysis and measurement of molded devices and assemblies, and improve the productivity of molding manufacturing significantly.

  11. Uncertainty Analysis via Failure Domain Characterization: Polynomial Requirement Functions

    Science.gov (United States)

    Crespo, Luis G.; Munoz, Cesar A.; Narkawicz, Anthony J.; Kenny, Sean P.; Giesy, Daniel P.

    2011-01-01

    This paper proposes an uncertainty analysis framework based on the characterization of the uncertain parameter space. This characterization enables the identification of worst-case uncertainty combinations and the approximation of the failure and safe domains with a high level of accuracy. Because these approximations are comprised of subsets of readily computable probability, they enable the calculation of arbitrarily tight upper and lower bounds to the failure probability. A Bernstein expansion approach is used to size hyper-rectangular subsets while a sum of squares programming approach is used to size quasi-ellipsoidal subsets. These methods are applicable to requirement functions whose functional dependency on the uncertainty is a known polynomial. Some of the most prominent features of the methodology are the substantial desensitization of the calculations from the uncertainty model assumed (i.e., the probability distribution describing the uncertainty) as well as the accommodation for changes in such a model with a practically insignificant amount of computational effort.

  12. Survival analysis of heart failure patients: A case study.

    Science.gov (United States)

    Ahmad, Tanvir; Munir, Assia; Bhatti, Sajjad Haider; Aftab, Muhammad; Raza, Muhammad Ali

    2017-01-01

    This study was focused on survival analysis of heart failure patients who were admitted to Institute of Cardiology and Allied hospital Faisalabad-Pakistan during April-December (2015). All the patients were aged 40 years or above, having left ventricular systolic dysfunction, belonging to NYHA class III and IV. Cox regression was used to model mortality considering age, ejection fraction, serum creatinine, serum sodium, anemia, platelets, creatinine phosphokinase, blood pressure, gender, diabetes and smoking status as potentially contributing for mortality. Kaplan Meier plot was used to study the general pattern of survival which showed high intensity of mortality in the initial days and then a gradual increase up to the end of study. Martingale residuals were used to assess functional form of variables. Results were validated computing calibration slope and discrimination ability of model via bootstrapping. For graphical prediction of survival probability, a nomogram was constructed. Age, renal dysfunction, blood pressure, ejection fraction and anemia were found as significant risk factors for mortality among heart failure patients.

  13. Failure analysis of electrolyte-supported solid oxide fuel cells

    Science.gov (United States)

    Fleischhauer, Felix; Tiefenauer, Andreas; Graule, Thomas; Danzer, Robert; Mai, Andreas; Kuebler, Jakob

    2014-07-01

    For solid oxide fuel cells (SOFCs) one key aspect is the structural integrity of the cell and hence its thermo mechanical long term behaviour. The present study investigates the failure mechanisms and the actual causes for fracture of electrolyte supported SOFCs which were run using the current μ-CHP system of Hexis AG, Winterthur - Switzerland under lab conditions or at customer sites for up to 40,000 h. In a first step several operated stacks were demounted for post-mortem inspection, followed by a fractographic evaluation of the failed cells. The respective findings are then set into a larger picture including an analysis of the present stresses acting on the cell like thermal and residual stresses and the measurements regarding the temperature dependent electrolyte strength. For all investigated stacks, the mechanical failure of individual cells can be attributed to locally acting bending loads, which rise due to an inhomogeneous and uneven contact between the metallic interconnect and the cell.

  14. Decreased DGCR8 expression and miRNA dysregulation in individuals with 22q11.2 deletion syndrome.

    Directory of Open Access Journals (Sweden)

    Chantal Sellier

    Full Text Available Deletion of the 1.5-3 Mb region of chromosome 22 at locus 11.2 gives rise to the chromosome 22q11.2 deletion syndrome (22q11DS, also known as DiGeorge and Velocardiofacial Syndromes. It is the most common micro-deletion disorder in humans and one of the most common multiple malformation syndromes. The syndrome is characterized by a broad phenotype, whose characterization has expanded considerably within the last decade and includes many associated findings such as craniofacial anomalies (40%, conotruncal defects of the heart (CHD; 70-80%, hypocalcemia (20-60%, and a range of neurocognitive anomalies with high risk of schizophrenia, all with a broad phenotypic variability. These phenotypic features are believed to be the result of a change in the copy number or dosage of the genes located in the deleted region. Despite this relatively clear genetic etiology, very little is known about which genes modulate phenotypic variations in humans or if they are due to combinatorial effects of reduced dosage of multiple genes acting in concert. Here, we report on decreased expression levels of genes within the deletion region of chromosome 22, including DGCR8, in peripheral leukocytes derived from individuals with 22q11DS compared to healthy controls. Furthermore, we found dysregulated miRNA expression in individuals with 22q11DS, including miR-150, miR-194 and miR-185. We postulate this to be related to DGCR8 haploinsufficiency as DGCR8 regulates miRNA biogenesis. Importantly we demonstrate that the level of some miRNAs correlates with brain measures, CHD and thyroid abnormalities, suggesting that the dysregulated miRNAs may contribute to these phenotypes and/or represent relevant blood biomarkers of the disease in individuals with 22q11DS.

  15. Comparison of stress-based and strain-based creep failure criteria for severe accident analysis

    International Nuclear Information System (INIS)

    Chavez, S.A.; Kelly, D.L.; Witt, R.J.; Stirn, D.P.

    1995-01-01

    We conducted a parametic analysis of stress-based and strain-based creep failure criteria to determine if there is a significant difference between the two criteria for SA533B vessel steel under severe accident conditions. Parametric variables include debris composition, system pressure, and creep strain histories derived from different testing programs and mathematically fit, with and without tertiary creep. Results indicate significant differences between the two criteria. Stress gradient plays an important role in determining which criterion will predict failure first. Creep failure was not very sensitive to different creep strain histories, except near the transition temperature of the vessel steel (900K to 1000K). Statistical analyses of creep failure data of four independent sources indicate that these data may be pooled, with a spline point at 1000K. We found the Manson-Haferd parameter to have better failure predictive capability than the Larson-Miller parameter for the data studied. (orig.)

  16. Association of cardiac cachexia and atrial fibrillation in heart failure patients.

    Science.gov (United States)

    Arámbula-Garza, Estefanía; Castillo-Martínez, Lilia; González-Islas, Dulce; Orea-Tejeda, Arturo; Santellano-Juárez, Brenda; Keirns-Davies, Candace; Peláez-Hernández, Viridiana; Sánchez-Santillán, Rocío; Pineda-Juárez, Juan; Cintora-Martínez, Carlos; Pablo-Santiago, Ruth

    2016-11-15

    Cachexia is a common complication in patients with advanced heart failure (HF) associated with inflammatory response activation. Atrial fibrillation (AF) is the most frequent arrhythmia (26%), probably both exacerbate the cardiac cachexia (CC). Evaluate the association of cardiac cachexia and atrial fibrillation in heart failure patients. In a case control study, CC was diagnosed by electrical bioimpedance with vectorial analysis (BIVA). Subjects with congenital heart disease, cancer, HIV, drug use and other causes than HF were excluded. Of the 359 subjects analyzed (men: 52.9%) median age 65years (55-74). Those with CC were older [72 (61-67)] vs. without [62 (52-70) years old, p<0.01]. During follow-up 47.8% of subjects developed CC and 17.27% AF, this was significantly more frequent in cachectic patients CC (23% vs 12.11%, OR: 2.17, 95% CI: 1.19-4.01, p=0.006). Subjects, with AF had lower left ventricular ejection fraction (25.49±12.96 vs. 32.01±15.02, p=0.08), lower posterior wall thickness (10.03±2.12 vs. 11.00±2.47, p=0.007), larger diameter of the left atrium (49.87±9.84 vs. 42.66±7.56, p<0.001), and a higher prevalence of CC (85.42% vs. 69.77%, p=0.028). The 50.58% of was in NYHA class I. In NYHA III, 22.95% were in AF vs. 12.10% with not AF (p=0.027). The frequent coexistence of CC and AF as HF complications indicate greater severity of HF, regardless of its type of HF. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. Targets downstream of Cdk8 in Dictyostelium development

    Directory of Open Access Journals (Sweden)

    Skelton Jason

    2011-01-01

    Full Text Available Abstract Background Cdk8 is a component of the mediator complex which facilitates transcription by RNA polymerase II and has been shown to play an important role in development of Dictyostelium discoideum. This eukaryote feeds as single cells but starvation triggers the formation of a multicellular organism in response to extracellular pulses of cAMP and the eventual generation of spores. Strains in which the gene encoding Cdk8 have been disrupted fail to form multicellular aggregates unless supplied with exogenous pulses of cAMP and later in development, cdk8- cells show a defect in spore production. Results Microarray analysis revealed that the cdk8- strain previously described (cdk8-HL contained genome duplications. Regeneration of the strain in a background lacking detectable gene duplication generated strains (cdk8-2 with identical defects in growth and early development, but a milder defect in spore generation, suggesting that the severity of this defect depends on the genetic background. The failure of cdk8- cells to aggregate unless rescued by exogenous pulses of cAMP is consistent with a failure to express the catalytic subunit of protein kinase A. However, overexpression of the gene encoding this protein was not sufficient to rescue the defect, suggesting that this is not the only important target for Cdk8 at this stage of development. Proteomic analysis revealed two potential targets for Cdk8 regulation, one regulated post-transcriptionally (4-hydroxyphenylpyruvate dioxygenase (HPD and one transcriptionally (short chain dehydrogenase/reductase (SDR1. Conclusions This analysis has confirmed the importance of Cdk8 at multiple stages of Dictyostelium development, although the severity of the defect in spore production depends on the genetic background. Potential targets of Cdk8-mediated gene regulation have been identified in Dictyostelium which will allow the mechanism of Cdk8 action and its role in development to be determined.

  18. Effects of cardiac energy efficiency in diastolic heart failure. Assessment with positron emission tomography with 11C-acetate

    International Nuclear Information System (INIS)

    Hasegawa, Shinji; Yamamoto, Kazuhiro; Sakata, Yasushi; Takeda, Yasuharu; Kajimoto, Katsufumi; Kanai, Yasukazu; Hori, Masatsugu; Hatazawa, Jun

    2008-01-01

    Diastolic heart failure (DHF) has become a high social burden, and its major underlying cardiovascular disease is hypertensive heart disease. However, the pathogenesis of DHF remains to be clarified. This study aimed to assess the effects of cardiac energy efficiency in DHF patients. 11 C-Acetate positron emission tomography and echocardiography were conducted in 11 DHF Japanese patients and 10 normal volunteers. The myocardial clearance rate of radiolabeled 11 C-acetate was measured to calculate the work metabolic index (WMI), an index of cardiac efficiency. The ratio of peak mitral E wave velocity to peak early diastolic septal myocardial velocity (E/e') was calculated to assess left ventricular (LV) filling pressure. The LV mass index was greater and the mean age was higher in the DHF patients than in the normal volunteers. There was no difference in WMI between the two groups. However, WMI varied widely among the DHF patients and was inversely correlated with E/e' (r=-0.699, p=0.017). In contrast, there was no correlation in the normal volunteers. In conclusion, the inefficiency of energy utilization is not a primary cause of diastolic dysfunction or DHF, and cardiac efficiency may not affect diastolic function in normal hearts. However, the energy-wasting state may induce the elevation of LV filling pressure in DHF patients, which was considered to principally result from the progressive diastolic dysfunction. (author)

  19. Launch Vehicle Abort Analysis for Failures Leading to Loss of Control

    Science.gov (United States)

    Hanson, John M.; Hill, Ashley D.; Beard, Bernard B.

    2013-01-01

    Launch vehicle ascent is a time of high risk for an onboard crew. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based on data already available from the Guidance, Navigation, and Control system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. The two primary areas of focus are the derivation of abort triggers to ensure that abort occurs as quickly as possible when needed, but that false aborts are avoided, and evaluation of success in aborting off the failing launch vehicle.

  20. PV System Component Fault and Failure Compilation and Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Klise, Geoffrey Taylor; Lavrova, Olga; Gooding, Renee Lynne

    2018-02-01

    This report describes data collection and analysis of solar photovoltaic (PV) equipment events, which consist of faults and fa ilures that occur during the normal operation of a distributed PV system or PV power plant. We present summary statistics from locations w here maintenance data is being collected at various intervals, as well as reliability statistics gathered from that da ta, consisting of fault/failure distributions and repair distributions for a wide range of PV equipment types.