SU-F-T-250: What Does It Take to Correctly Assess the High Failure Modes of an Advanced Radiotherapy Procedure Such as Stereotactic Body Radiation Therapy?

Energy Technology Data Exchange (ETDEWEB)

Han, D; Vile, D; Rosu, M; Palta, J [Virginia Commonwealth University, Richmond, VA (United States)

2016-06-15

Purpose: Assess the correct implementation of risk-based methodology of TG 100 to optimize quality management and patient safety procedures for Stereotactic Body Radiation Therapy. Methods: A detailed process map of SBRT treatment procedure was generated by a team of three physicists with varying clinical experience at our institution to assess the potential high-risk failure modes. The probabilities of occurrence (O), severity (S) and detectability (D) for potential failure mode in each step of the process map were assigned by these individuals independently on the scale from1 to 10. The risk priority numbers (RPN) were computed and analyzed. The highest 30 potential modes from each physicist’s analysis were then compared. Results: The RPN values assessed by the three physicists ranged from 30 to 300. The magnitudes of the RPN values from each physicist were different, and there was no concordance in the highest RPN values recorded by three physicists independently. The 10 highest RPN values belonged to sub steps of CT simulation, contouring and delivery in the SBRT process map. For these 10 highest RPN values, at least two physicists, irrespective of their length of experience had concordance but no general conclusions emerged. Conclusion: This study clearly shows that the risk-based assessment of a clinical process map requires great deal of preparation, group discussions, and participation by all stakeholders. One group albeit physicists cannot effectively implement risk-based methodology proposed by TG100. It should be a team effort in which the physicists can certainly play the leading role. This also corroborates TG100 recommendation that risk-based assessment of clinical processes is a multidisciplinary team effort.

SU-F-T-250: What Does It Take to Correctly Assess the High Failure Modes of an Advanced Radiotherapy Procedure Such as Stereotactic Body Radiation Therapy?

International Nuclear Information System (INIS)

Han, D; Vile, D; Rosu, M; Palta, J

2016-01-01

Purpose: Assess the correct implementation of risk-based methodology of TG 100 to optimize quality management and patient safety procedures for Stereotactic Body Radiation Therapy. Methods: A detailed process map of SBRT treatment procedure was generated by a team of three physicists with varying clinical experience at our institution to assess the potential high-risk failure modes. The probabilities of occurrence (O), severity (S) and detectability (D) for potential failure mode in each step of the process map were assigned by these individuals independently on the scale from1 to 10. The risk priority numbers (RPN) were computed and analyzed. The highest 30 potential modes from each physicist’s analysis were then compared. Results: The RPN values assessed by the three physicists ranged from 30 to 300. The magnitudes of the RPN values from each physicist were different, and there was no concordance in the highest RPN values recorded by three physicists independently. The 10 highest RPN values belonged to sub steps of CT simulation, contouring and delivery in the SBRT process map. For these 10 highest RPN values, at least two physicists, irrespective of their length of experience had concordance but no general conclusions emerged. Conclusion: This study clearly shows that the risk-based assessment of a clinical process map requires great deal of preparation, group discussions, and participation by all stakeholders. One group albeit physicists cannot effectively implement risk-based methodology proposed by TG100. It should be a team effort in which the physicists can certainly play the leading role. This also corroborates TG100 recommendation that risk-based assessment of clinical processes is a multidisciplinary team effort.

High-temperature flaw assessment procedure: A state-of-the-art survey

International Nuclear Information System (INIS)

Ruggles, M.B.; Takahashi, Y.

1989-05-01

High-temperature crack growth under cyclic, static, and combined loading is received with an emphasis on fracture mechanics aspects. Experimental studies of the effects of loading history, microstructure, temperature, and environment on crack growth behavior are described and interpreted. The experimental evidence is used to examine crack growth parameters and theoretical models for fatigue, creep, and creep-fatigue crack propagation at elevated temperatures. The limitations of both elastic and elastic-plastic fracture mechanics for high-temperature subcritical crack growth are assessed. Existing techniques for modeling critical crack growth/ligament instability failure are also presented. Related topics of defect modeling and engineering flaw assessment procedures, nondestructive evaluation methods, and probabilistic failure analysis are briefly discussed. 142 refs., 33 figs

Assessment selection in human-automation interaction studies: The Failure-GAM2E and review of assessment methods for highly automated driving.

Science.gov (United States)

Grane, Camilla

2018-01-01

Highly automated driving will change driver's behavioural patterns. Traditional methods used for assessing manual driving will only be applicable for the parts of human-automation interaction where the driver intervenes such as in hand-over and take-over situations. Therefore, driver behaviour assessment will need to adapt to the new driving scenarios. This paper aims at simplifying the process of selecting appropriate assessment methods. Thirty-five papers were reviewed to examine potential and relevant methods. The review showed that many studies still relies on traditional driving assessment methods. A new method, the Failure-GAM 2 E model, with purpose to aid assessment selection when planning a study, is proposed and exemplified in the paper. Failure-GAM 2 E includes a systematic step-by-step procedure defining the situation, failures (Failure), goals (G), actions (A), subjective methods (M), objective methods (M) and equipment (E). The use of Failure-GAM 2 E in a study example resulted in a well-reasoned assessment plan, a new way of measuring trust through feet movements and a proposed Optimal Risk Management Model. Failure-GAM 2 E and the Optimal Risk Management Model are believed to support the planning process for research studies in the field of human-automation interaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sepsis and multiorgan failure following TVT procedure.

Science.gov (United States)

Stec, Piotr; Connell, Rowan

2014-04-01

Tension-free vaginal tape (TVT), is a commonly performed, low risk procedure for treatment of stress urinary incontinence (SUI). Severe complications are rare, but can be potentially life threatening. We present a case of 66 year old patient who sustained bladder perforation at the time of TVT procedure and subsequently developed sepsis rapidly leading to multi-organ failure and triggering sequence of serious complications. During her inpatient stay she required ITU admission, emergency laparotomy, TVT mesh removal, bowel resection due to ischemic colitis and anticoagulation for pulmonary embolism. Despite of clinical picture of sepsis her microbiology tests were almost consistently negative. This case emphasise importance of awareness and quick recognition of TVT related complications. Patient ultimately survived and recovered thanks to timely and coordinated management by the multidisciplinary team of doctors.

High-temperature flaw assessment procedure

International Nuclear Information System (INIS)

Ruggles, M.B.; Takahashi, Y.; Ainsworth, R.A.

1989-08-01

The current program represents a joint effort between the Electric Power Research Institute (EPRI) in the USA, the Central Research Institute of Electric Power Industry (CRIEPI) in Japan, and the Central Electricity Generating Board (CEGB) in the UK. The goal is to develop an interim high-temperature flaw assessment procedure for high-temperature reactor components. This is to be accomplished through exploratory experimental and analytical studies of high-temperature crack growth. The state-of-the-art assessment and the fracture mechanics database for both types 304 and 316 stainless steels, completed in 1988, serve as a foundation for the present work. Work in the three participating organizations is progressing roughly on schedule. Results to-date are presented in this document. Fundamental tests results are discussed in Section 2. Section 3 focuses on results of exploratory subcritical crack growth tests. Progress in subcritical crack growth modeling is reported in Section 4. Exploratory failure tests are outlined in Section 5. 21 refs., 70 figs., 7 tabs

An engineering assessment methodology for non-sharp defects in steel structures – Part I: Procedure development

International Nuclear Information System (INIS)

Horn, A.J.; Sherry, A.H.

2012-01-01

This Part I paper describes a new engineering assessment methodology for ferritic steel structures containing non-sharp defects within the context of a Failure Assessment Diagram (FAD) approach. Although the modification of the FAD for non-sharp defects can be applied whether the initiating failure mechanism is cleavage or ductile tearing, this paper focuses on cleavage fracture. The parameters describing the sensitivity of the material toughness to the notch effect can either be measured by testing notched specimens of the same thickness as the structure, or for cleavage fracture they can be obtained using look-up tables generated using the Weibull stress toughness scaling model. The other parameters in the procedure can either be conservatively estimated using simple equations or they can be determined more accurately using finite element analysis. Validation of the new method is presented in the companion Part II paper: this shows that assessments of U-notched SE(B) specimens have significantly reduced conservatism when using the new assessment methodology compared to the standard FAD approach for sharp cracks. - Highlights: ► Development of a new procedure for predicting failure from non-sharp defects. ► Based on a modification of the Failure Assessment Diagram (FAD) approach. ► Applicable to cleavage and ductile tearing initiation although paper focuses on cleavage. ► Validation provided in a companion Part II paper.

Thermocouple module halt failure acceptance test procedure for Tank 241-SY-101 DACS-1

International Nuclear Information System (INIS)

Ermi, A.M.

1997-01-01

The readiness of the Tank 241-SY-101 Data Acquisition and Control System (DACS-1) to provide monitoring and alarms for a halt failure of any thermocouple module will be tested during the performance of this procedure. Updated DACS-1 ''1/0 MODULE HEALTH STATUS'', ''MININ1'', and ''MININ2'' screens, which now provide indication of thermocouple module failure, will also be tested as part of this procedure

Failure probability assessment of wall-thinned nuclear pipes using probabilistic fracture mechanics

International Nuclear Information System (INIS)

Lee, Sang-Min; Chang, Yoon-Suk; Choi, Jae-Boong; Kim, Young-Jin

2006-01-01

The integrity of nuclear piping system has to be maintained during operation. In order to maintain the integrity, reliable assessment procedures including fracture mechanics analysis, etc., are required. Up to now, this has been performed using conventional deterministic approaches even though there are many uncertainties to hinder a rational evaluation. In this respect, probabilistic approaches are considered as an appropriate method for piping system evaluation. The objectives of this paper are to estimate the failure probabilities of wall-thinned pipes in nuclear secondary systems and to propose limited operating conditions under different types of loadings. To do this, a probabilistic assessment program using reliability index and simulation techniques was developed and applied to evaluate failure probabilities of wall-thinned pipes subjected to internal pressure, bending moment and combined loading of them. The sensitivity analysis results as well as prototypal integrity assessment results showed a promising applicability of the probabilistic assessment program, necessity of practical evaluation reflecting combined loading condition and operation considering limited condition

Procedures for treating common cause failures in safety and reliability studies: Volume 2, Analytic background and techniques: Final report

International Nuclear Information System (INIS)

Mosleh, A.; Fleming, K.N.; Parry, G.W.; Paula, H.M.; Worledge, D.H.; Rasmuson, D.M.

1988-12-01

This report presents a framework for the inclusion of the impact of common cause failures in risk and reliability evaluations. Common cause failures are defined as that subset of dependent failures for which causes are not explicitly included in the logic model as basic events. The emphasis here is on providing procedures for a practical, systematic approach that can be used to perform and clearly document the analysis. The framework and the methods discussed for performing the different stages of the analysis integrate insights obtained from engineering assessments of the system and the historical evidence from multiple failure events into a systematic, reproducible, and defensible analysis. This document, Volume 2, contains a series of appendices that provide additional background and methodological detail on several important topics discussed in Volume 1

A formal language to describe a wide class of failure detection and signal validation procedures

Energy Technology Data Exchange (ETDEWEB)

Racz, A. [Hungarian Academy of Sciences, Budapest (Hungary). Atomic Energy Research Inst.

1996-01-01

In the present article we make the first step towards the implementation of a user-friendly, object-oriented system devoted to failure detection and signal validation purposes. After overviewing different signal modelling, residual making and hypothesis testing procedures, a mathematical tool is suggested to describe a general failure detection problem. Three different levels of the abstraction are distinguished; direct examination, preliminary decision support mechanism and indirect examination. Possible scenarios are introduced depending both on the objective properties of the investigated signal and the particular requirements prescribed by the expert himself. Finally it is showed how to build up systematically a complete, general failure detection procedure. (author).

Reliability assessment of a manual-based procedure towards learning curve modeling and fmea analysis

Directory of Open Access Journals (Sweden)

Gustavo Rech

2013-03-01

Full Text Available Separation procedures in drug Distribution Centers (DC are manual-based activities prone to failures such as shipping exchanged, expired or broken drugs to the customer. Two interventions seem as promising in improving the reliability in the separation procedure: (i selection and allocation of appropriate operators to the procedure, and (ii analysis of potential failure modes incurred by selected operators. This article integrates Learning Curves (LC and FMEA (Failure Mode and Effect Analysis aimed at reducing the occurrence of failures in the manual separation of a drug DC. LCs parameters enable generating an index to identify the recommended operators to perform the procedures. The FMEA is then applied to the separation procedure carried out by the selected operators in order to identify failure modes. It also deployed the traditional FMEA severity index into two sub-indexes related to financial issues and damage to company´s image in order to characterize failures severity. When applied to a drug DC, the proposed method significantly reduced the frequency and severity of failures in the separation procedure.

Structural assessment procedure of corroding submarine gas pipelines using on-line inspection data

International Nuclear Information System (INIS)

Nordin Yahaya

2000-01-01

This paper presents 'the alternative approach of overall procedure in the assessment of corroded pipelines using data gathered by the on-line inspection device. The methodology adopts a generalised approach of analysing pipeline inspection data and a prediction of the structural reliability due to the deteriorating corrosion environment. The whole assessment methodology is divided into four separate stages; 1 to IV. Stages 1 and 11 are the initial procedure prior to the actual analysis of the inspection data. The scope of this paper is concerted into the procedure to be taken in Stage 111 where the stage is sub-divided into 3 major steps; Part A, B and C. These procedures are Part A (statistical and probabilistic analysis of the inspection data) and Part B (the application of extreme value statistics) and C (reliability assessment). Stage IV (risk assessment) is the final step in the procedure where the consequences of failure are evaluated. The proposed risk-based assessment procedure is more systematic and reliable to account for a huge amount of collected data usually obtained in an on-line inspection using the intelligent devices. The outcomes of this risk-based methodology can be very useful in the decision-making process by the operation management. This in turn will produce an efficient inspection, repair and maintenance program and enhanced the optimised return in investment. (author)

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Guide to data processing and revision: Part 3, Hardware component failure data entry and revision procedures

International Nuclear Information System (INIS)

Gilmore, W.E.; Gertman, D.I.; Gilbert, B.G.; Reece, W.J.

1988-11-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability (HEP) and hardware component failure data (HCFD). The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. Users can perform data base searches to furnish HEP estimates and HCFD rates. In this manner, the NUCLARR system can be used to support a variety of risk assessment activities. This volume, Volume 3 of a 5-volume series, presents the procedures used to process HEP and HCFD for entry in NUCLARR and describes how to modify the existing NUCLARR taxonomy in order to add equipment types of action verbs. Volume 3 also specifies the various roles of the administrative staff on assignment to the NUCLARR Clearinghouse who are tasked with maintaining the data base, dealing with user requests, and processing NUCLARR data

Failure Impact Assessment for Large-Scale Landslides Located Near Human Settlement: Case Study in Southern Taiwan

Directory of Open Access Journals (Sweden)

Ming-Chien Chung

2018-05-01

Full Text Available In 2009, Typhoon Morakot caused over 680 deaths and more than 20,000 landslides in Taiwan. From 2010 to 2015, the Central Geological Survey of the Ministry of Economic Affairs identified 1047 potential large-scale landslides in Taiwan, of which 103 may have affected human settlements. This paper presents an analytical procedure that can be applied to assess the possible impact of a landslide collapse on nearby settlements. In this paper, existing technologies, including interpretation of remote sensing images, hydrogeological investigation, and numerical analysis, are integrated to evaluate potential failure scenarios and the landslide scale of a specific case: the Xinzhuang landslide. GeoStudio and RAMMS analysis modes and hazard classification produced the following results: (1 evaluation of the failure mechanisms and the influence zones of large-scale landslides; (2 assessment of the migration and accumulation of the landslide mass after failure; and (3 a landslide hazard and evacuation map. The results of the case study show that this analytical procedure can quantitatively estimate potential threats to human settlements. Furthermore, it can be applied to other villages and used as a reference in disaster prevention and evacuation planning.

The elastic-plastic failure assessment diagram of surface cracked structure

International Nuclear Information System (INIS)

Ning, J.; Gao, Q.

1987-01-01

The simplified NLSM is able to calculate the EPFM parameters and failure assessment curve for the surface cracked structure correctly and conveniently. The elastic-plastic failure assessment curve of surface crack is relevant to crack geometry, loading form and material deformation behaviour. It is necessary to construct the EPFM failure assessment curve of the surface crack for the failure assessment of surface cracked structure. (orig./HP)

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

Intra-procedural continuous dialysis to facilitate interventional catheterization in pediatric patients with severe renal failure.

Science.gov (United States)

Opina, Angeline D; Qureshi, Athar M; Brewer, Eileen; Elenberg, Ewa; Swartz, Sarah; Michael, Mini; Justino, Henri

2017-11-01

Interventional catheterization procedures may be needed for patients with severe renal failure who are dependent on dialysis. To avoid the risk of fluid overload and electrolyte derangement during complex procedures in this oliguric/anuric patient population, we performed intra-procedural dialysis, either continuous renal replacement therapy (CRRT) or continous cycling peritoneal dialysis (CCPD). We performed a retrospective review of a cohort of pediatric patients, ages 0-18 years, with dialysis-dependent renal failure who received CRRT or CCPD during catheterization procedures from January 2013 to March 2016. Eight patients underwent a total of nine interventional catheterization procedures while receiving intra-procedural dialysis. Median age was 4.5 years (range 8 months to 17 years) and weight, 11.6 kg (11.2-62.6 kg). Six patients had end-stage renal disease (ESRD) and two patients had acute kidney injury (AKI), one due to hepatorenal syndrome and one due to multifactorial causes associated with congenital heart disease. The most common reason for catheterization was occlusive venous thrombosis requiring recanalization. CRRT was used during five cases and CCPD during four cases. Median procedure time was 337 min (95-651 min) and median contrast dose 4.2 mL kg -1 (1.2-8.2 mL kg -1 ). Euvolemia was maintained based on pre- and post-catheterizations weights, and no significant electrolyte abnormalities occurred based on lab monitoring during and post-procedure. Intra-procedural dialysis using CRRT or CCPD enables even small pediatric patients with severe renal failure to undergo long and complex interventional catheterizations by reducing the risk of fluid overload and electrolyte abnormalities. Collaboration between nephrology, cardiology, and dialysis teams is necessary for successful management of this challenging patient population. © 2017 Wiley Periodicals, Inc.

Improving FMEA risk assessment through reprioritization of failures

Science.gov (United States)

Ungureanu, A. L.; Stan, G.

2016-08-01

Most of the current methods used to assess the failure and to identify the industrial equipment defects are based on the determination of Risk Priority Number (RPN). Although conventional RPN calculation is easy to understand and use, the methodology presents some limitations, such as the large number of duplicates and the difficulty of assessing the RPN indices. In order to eliminate the afore-mentioned shortcomings, this paper puts forward an easy and efficient computing method, called Failure Developing Mode and Criticality Analysis (FDMCA), which takes into account the failures and the defect evolution in time, from failure appearance to a breakdown.

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

SINTAP: draft of a unified European failure assessment procedure. An introduction; SINTAP: Entwurf einer vereinheitlichten europaeischen Fehlerbewertungsprozedur. Eine Einfuehrung

Energy Technology Data Exchange (ETDEWEB)

Zerbst, U.; Kocak, M. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung; Wiesner, C. [The Welding Institute (TWI), Cambridge (United Kingdom). Structural Integrity Dept.; Hodulak, L. [Fraunhofer-Institut fuer Werkstoffmechanik (IWM), Freiburg im Breisgau (Germany)

1999-07-01

Fracture mechanics based flaw assessment concepts are increasingly used in industrial regulations and standards. A considerable number of different guidelines and procedures are available which are partly based on each other but also exhibit significant differences. At this background, the EU sponsored SINTAP, an interdisciplinary Brite Euram project. SINTAP stands for 'Structural Integrity Assessment Procedures for European Industry'. From 1996 to 1999 seventeen organisations from nine European countries participated in the project the aim of which was to unify the available procedures. The present report is an introduction into the content, the structure and the scientific background of the procedure which was generated within SINTAP. (orig.) [German] Bruchmechanische Bewertungskonzepte werden international in zunehmendem Masse Bestandteil industrieller Regelwerke und Fachbereichsstandards. Bereits heute existiert eine Vielzahl derartiger Vorschriften und Rechnerprogramme, die teilweise aufeinander aufbauen, teilweise aber auch signifikante Unterschiede aufweisen. Vor diesem Hintergrund wurde durch die EU von 1996 bis 1999 SINTAP, ein interdisziplinaeres Brite-Euram-Projekt gefoerdert, dessen Ziel in einer Vereinheitlichung der vorhandenen Ansaetze bestand, und an dem siebzehn Institutionen aus neun europaeischen Laendern beteiligt waren. SINTAP steht fuer 'Structural Integrity Assessment Procedures for European Industry'. Der vorliegende Bericht ist eine Einfuehrung in Inhalt, Struktur und wissenschaftlichen Hintergrund der im Ergebnis des Projektes entstandenen SINTAP-Prozedur. (orig.)

Evaluation of flaws in ferritic piping: ASME Code Appendix J, Deformation Plasticity Failure Assessment Diagram (DPFAD)

International Nuclear Information System (INIS)

Bloom, J.M.

1991-08-01

This report summarizes the methods and bases used by an ASME Code procedure for the evaluation of flaws in ferritic piping. The procedure is currently under consideration by the ASME Boiler and Pressure Vessel Code Committee of Section 11. The procedure was initially proposed in 1985 for the evaluation of the acceptability of flaws detected in piping during in-service inspection for certain materials, identified in Article IWB-3640 of the ASME Boiler and Pressure Vessel Code Section 11 ''Rules for In-service Inspection of Nuclear Power Plant Components.'' for which the fracture toughness is not sufficiently high to justify acceptance based solely on the plastic limit load evaluation methodology of Appendix C and IWB-3641. The procedure, referred to as Appendix J, originally included two approaches: a J-integral based tearing instability (J-T) analysis and the deformation plasticity failure assessment diagram (DPFAD) methodology. In Appendix J, a general DPFAD approach was simplified for application to part-through wall flows in ferritic piping through the use of a single DPFAD curve for circumferential flaws. Axial flaws are handled using two DPFAD curves where the ratio of flaw depth to wall thickness is used to determine the appropriate DPFAD curve. Flaws are evaluated in Appendix J by comparing the actual pipe applied stress with the allowable stress with the appropriate safety factors for the flaw size at the end of the evaluation period. Assessment points for circumferential and axial flaws are plotted on the appropriate failure assessment diagram. In addition, this report summarizes the experimental test predictions of the results of the Battelle Columbus Laboratory experiments, the Eiber experiments, and the JAERI tests using the Appendix J DPFAD methodology. Lastly, this report also provides guidelines for handling residual stresses in the evaluation procedure. 22 refs., 13 figs., 5 tabs

Predicting device failure after percutaneous repair of functional mitral regurgitation in advanced heart failure: Implications for patient selection.

Science.gov (United States)

Stolfo, Davide; De Luca, Antonio; Morea, Gaetano; Merlo, Marco; Vitrella, Giancarlo; Caiffa, Thomas; Barbati, Giulia; Rakar, Serena; Korcova, Renata; Perkan, Andrea; Pinamonti, Bruno; Pappalardo, Aniello; Berardini, Alessandra; Biagini, Elena; Saia, Francesco; Grigioni, Francesco; Rapezzi, Claudio; Sinagra, Gianfranco

2018-04-15

Patients with heart failure (HF) and severe symptomatic functional mitral regurgitation (FMR) may benefit from MitraClip implantation. With increasing numbers of patients being treated the success of procedure becomes a key issue. We sought to investigate the pre-procedural predictors of device failure in patients with advanced HF treated with MitraClip. From April 2012 to November 2016, 76 patients with poor functional class (NYHA class III-IV) and severe left ventricular (LV) remodeling underwent MitraClip implantation at University Hospitals of Trieste and Bologna (Italy). Device failure was assessed according to MVARC criteria. Patients were subsequently followed to additionally assess the patient success after 12months. Mean age was 67±12years, the mean Log-EuroSCORE was 23.4±16.5%, and the mean LV end-diastolic volume index and ejection fraction (EF) were 112±33ml/m 2 and 30.6±8.9%, respectively. At short-term evaluation, device failure was observed in 22 (29%) patients. Univariate predictors of device failure were LVEF, LV and left atrial volumes and anteroposterior mitral annulus diameter. Annulus dimension (OR 1.153, 95% CI 1.002-1.327, p=0.043) and LV end-diastolic volume (OR 1.024, 95% CI 1.000-1.049, p=0.049) were the only variables independently associated with the risk of device failure at the multivariate model. Pre-procedural anteroposterior mitral annulus diameter accurately predicted the risk of device failure after MitraClip in the setting of advanced HF. Its assessment might aid the selection of the best candidates to percutaneous correction of FMR. Copyright © 2018 Elsevier B.V. All rights reserved.

Laparoscopy is safe among patients with congestive heart failure undergoing general surgery procedures.

Science.gov (United States)

Speicher, Paul J; Ganapathi, Asvin M; Englum, Brian R; Vaslef, Steven N

2014-08-01

Over the past 2 decades, laparoscopy has been established as a superior technique in many general surgery procedures. Few studies, however, have examined the impact of the use of a laparoscopic approach in patients with symptomatic congestive heart failure (CHF). Because pneumoperitoneum has known effects on cardiopulmonary physiology, patients with CHF may be at increased risk. This study examines current trends in approaches to patients with CHF and effects on perioperative outcomes. The 2005-2011 National Surgical Quality Improvement Program Participant User File was used to identify patients who underwent the following general surgery procedures: Appendectomy, segmental colectomy, small bowel resection, ventral hernia repair, and splenectomy. Included for analysis were those with newly diagnosed CHF or chronic CHF with new signs or symptoms. Trends of use of laparoscopy were assessed across procedure types. The primary endpoint was 30-day mortality. The independent effect of laparoscopy in CHF was estimated with a multiple logistic regression model. A total of 265,198 patients were included for analysis, of whom 2,219 were identified as having new or recently worsened CHF. Of these patients, there were 1,300 (58.6%) colectomies, 486 (21.9%) small bowel resections, 216 (9.7%) ventral hernia repairs, 141 (6.4%) appendectomies, and 76 (3.4%) splenectomies. Laparoscopy was used less frequently in patients with CHF compared with their non-CHF counterparts, particularly for nonelective procedures. Baseline characteristics were similar for laparoscopy versus open procedures with the notable exception of urgent/emergent case status (36.4% vs 71.3%; P surgery procedures, particularly in urgent/emergent cases. Despite these patterns and apparent preferences, laparoscopy seems to offer a safe alternative in appropriately selected patients. Because morbidity and mortality were considerable regardless of approach, further understanding of appropriate management in this

Pollutant Assessments Group procedures manual: Volume 2, Technical procedures

Energy Technology Data Exchange (ETDEWEB)

1992-03-01

This is volume 2 of the manuals that describes the technical procedures currently in use by the Pollution Assessments Group. This manual incorporates new developments in hazardous waste assessment technology and administrative policy. Descriptions of the equipment, procedures and operations of such things as radiation detection, soil sampling, radionuclide monitoring, and equipment decontamination are included in this manual. (MB)

Example of an application of an assessment procedure for defects in plant operating in the creep range

International Nuclear Information System (INIS)

Ainsworth, R.; Coleman, M.C.

1986-10-01

A worked example is presented to illustrate the application of a CEGB procedure for the assessment of defects in plant that operates within the creep range. The example chosen is a large cylindrical pressure vessel with a fully circumferential crack for which experimental results are available. The example demonstrates that it is straightforward to perform the calculations required in the procedure for the time for structural failure by continuum damage mechanisms, the time for crack incubation and the time for crack growth. It is predicted that crack incubation in the pressure vessel occurs at about one-third of life with the remaining life being taken up by crack growth. The predictions are in close agreement with the experimentally observed incubation, growth and final failure times. (UK)

Frailty Assessment in Heart Failure: an Overview of the Multi-domain Approach.

Science.gov (United States)

McDonagh, Julee; Ferguson, Caleb; Newton, Phillip J

2018-02-01

The study aims (1) to provide a contemporary description of frailty assessment in heart failure and (2) to provide an overview of multi-domain frailty assessment in heart failure. Frailty assessment is an important predictive measure for mortality and hospitalisation in individuals with heart failure. To date, there are no frailty assessment instruments validated for use in heart failure. This has resulted in significant heterogeneity between studies regarding the assessment of frailty. The most common frailty assessment instrument used in heart failure is the Frailty Phenotype which focuses on five physical domains of frailty; the appropriateness a purely physical measure of frailty in individuals with heart failure who frequently experience decreased exercise tolerance and shortness of breath is yet to be determined. A limited number of studies have approached frailty assessment using a multi-domain view which may be more clinically relevant in heart failure. There remains a lack of consensus regarding frailty assessment and an absence of a validated instrument in heart failure. Despite this, frailty continues to be assessed frequently, primarily for research purposes, using predominantly physical frailty measures. A more multidimensional view of frailty assessment using a multi-domain approach will likely be more sensitive to identifying at risk patients.

Failure assessment diagrams for circular hollow section X- and K-joints

International Nuclear Information System (INIS)

Qian, Xudong

2013-01-01

This paper reports the failure assessment curves for semi-elliptical surface cracks located at hot-spot positions in the circular hollow section X- and K-joints. The failure assessment curves derive from the square root of the ratio between the linear–elastic and the elastic–plastic energy release rates, computed from the domain-integral approach. This study examines both the material and geometric dependence of the failure assessment curves. The area reduction factor, used in defining the strength of the cracked joints, imposes a significant effect on the computed failure assessment curve. The failure assessment curves indicate negligible variations with respect to the crack-front locations and the material yield strength. The crack depth ratio exerts a stronger effect on the computed failure assessment curve than does the crack aspect ratio. This study proposes a parametric expression for the failure assessment curves based on the geometric parameters for surface cracks in circular hollow section X- and K-joints. -- Highlights: ► This study proposes geometric dependent expressions of FADs for tubular joints. ► We examine the geometric and material dependence of the FADs for X- and K-joints. ► The proposed FAD is independent of yield strength and is a lower-bound for typical hardening

Sedation for pediatric radiological procedures: analysis of potential causes of sedation failure and paradoxical reactions

International Nuclear Information System (INIS)

Karian, V.E.; Burrows, P.E.; Connor, L.; Zurakowski, D.; Mason, K.P.

1999-01-01

Background. Sedation for diagnostic imaging and interventional radiologic procedures in pediatrics has greatly increased over the past decade. With appropriate patient selection and monitoring, serious adverse effects are infrequent, but failure to sedate and paradoxical reactions do occur. Objective. The purpose of this study was to determine, among patients undergoing sedation for radiologic procedures, the incidence of sedation failure and paradoxical reaction to pentobarbital and to identify potentially correctable causes. Materials and methods. Records of 1665 patients who were sedated in the radiology department from 1 November 1997 to 1 July 1998 were reviewed. Patients failing sedation or experiencing paradoxical reaction were compared with respect to sex, age group, diagnosis, scan type, time of day, NPO status, use of IV contrast and type of sedation agent using the Fisher exact test, Pearson chi-square, analysis of variance (ANOVA), the Student t-test, and logistic regression. Results. Data analysis revealed a sedation failure rate of 1 % and paradoxical reaction rate of 1.2 %. Stepwise multiple logistic regression revealed that the only significant independent multivariate predictor of failure was the need for the administration of a combination of pentobarbital, fentanyl, and midazolam IV. Conclusion. The low rate of sedation failure and paradoxical reactions to pentobarbital was near optimal and probably cannot be improved with the currently available sedatives. (orig.)

Sedation for pediatric radiological procedures: analysis of potential causes of sedation failure and paradoxical reactions

Energy Technology Data Exchange (ETDEWEB)

Karian, V.E.; Burrows, P.E.; Connor, L. [Dept. of Radiology, Children' s Hospital, Boston, MA (United States); Zurakowski, D. [Dept. of Biostatistics, Children' s Hospital, Boston, MA (United States); Mason, K.P. [Dept. of Anesthesiology, Children' s Hospital, Boston, MA (United States)

1999-11-01

Background. Sedation for diagnostic imaging and interventional radiologic procedures in pediatrics has greatly increased over the past decade. With appropriate patient selection and monitoring, serious adverse effects are infrequent, but failure to sedate and paradoxical reactions do occur. Objective. The purpose of this study was to determine, among patients undergoing sedation for radiologic procedures, the incidence of sedation failure and paradoxical reaction to pentobarbital and to identify potentially correctable causes. Materials and methods. Records of 1665 patients who were sedated in the radiology department from 1 November 1997 to 1 July 1998 were reviewed. Patients failing sedation or experiencing paradoxical reaction were compared with respect to sex, age group, diagnosis, scan type, time of day, NPO status, use of IV contrast and type of sedation agent using the Fisher exact test, Pearson chi-square, analysis of variance (ANOVA), the Student t-test, and logistic regression. Results. Data analysis revealed a sedation failure rate of 1 % and paradoxical reaction rate of 1.2 %. Stepwise multiple logistic regression revealed that the only significant independent multivariate predictor of failure was the need for the administration of a combination of pentobarbital, fentanyl, and midazolam IV. Conclusion. The low rate of sedation failure and paradoxical reactions to pentobarbital was near optimal and probably cannot be improved with the currently available sedatives. (orig.)

How and why of orthodontic bond failures: An in vivo study

Directory of Open Access Journals (Sweden)

R K Vijayakumar

2014-01-01

Full Text Available Introduction: The bonding of orthodontic brackets and their failure rates by both direct and in-direct procedures are well-documented in orthodontic literature. Over the years different adhesive materials and various indirect bonding transfer procedures have been compared and evaluated for bond failure rates. The aim of our study is to highlight the use of a simple, inexpensive and ease of manipulation of a single thermo-plastic transfer tray and the use the of a single light cure adhesive to evaluate the bond failure rates in clinical situations. Materials and Methods: A total of 30 patients were randomly divided into two groups (Group A and Group B. A split-mouth study design was used, for, both the groups so that they were distributed equally with-out bias. After initial prophylaxis, both the procedures were done as per manufactures instructions. All patients were initially motivated and reviewed for bond failures rates for 6 months. Results: Bond failure rates were assessed for over-all direct and indirect procedures, anterior and posterior arches, and for individual tooth. Z-test was used for statistically analyzing, the normal distribution of the sample in a spilt mouth study. The results of the two groups were compared and P value was calculated using Z-proportion test to assess the significance of the bond failure. Conclusion: Over-all bond failure was more for direct bonding. Anterior bracket failure was more in-direct bonding than indirect procedure, which showed more posterior bracket failures. In individual tooth bond failure, mandibular incisor, and premolar brackets showed more failure, followed by maxillary premolars and canines.

A procedure for safety assessment of components with cracks - Handbook. 3rd revised edition

Energy Technology Data Exchange (ETDEWEB)

Andersson, P.; Bergman, M.; Brickstad, B.; Dahlberg, L.; Nilsson, F.; Sattari-Far, I. [SAQ Kontroll AB, Stockholm (Sweden)

1999-12-01

In this handbook a procedure is described which can be used both for assessment of detected cracks or crack-like defects and for defect tolerance analysis. The procedure can be used to calculate possible crack growth due to fatigue or stress corrosion and to calculate the reserve margin for failure due to fracture and plastic collapse. For ductile materials, the procedure gives the reserve margin for initiation of stable crack growth. Thus, an extra reserve margin, unknown to size, exists for failure in components made of ductile materials. The procedure was developed for operative use with the following objectives in mind: a) The procedure should be able to handle both linear and non-linear problems without any a priori division. b) The procedure shall ensure uniqueness of the safety assessment. c) The procedure should be well defined and easy to use. d) The conservatism of the procedure should be well validated. e) The handbook, that documents the procedure, should be so complete that for most assessments, access to any other fracture mechanics literature should not be necessary. The method utilized in the procedure is based on the R6-method developed at Nuclear Electric plc. The basic assumption is that fracture initiated by a crack can be described by the variables K{sub r} and L{sub r}. K{sub r} is the ratio between the stress intensity factor and the fracture toughness of the material. L{sub r} is the ratio between applied load and the plastic limit load of the structure. The pair of calculated values of these variables is plotted in a diagram. If the point is situated within the noncritical region, fracture is assumed not to occur. If the point is situated outside the region, crack growth and fracture may occur. The method can in principal be used for all metallic materials. It is, however, more extensively verified for steel alloys only. The method is not intended for use in temperature regions where creep deformation is of importance. To fulfil the above

A procedure for safety assessment of components with cracks - Handbook. 3rd revised edition

International Nuclear Information System (INIS)

Andersson, P.; Bergman, M.; Brickstad, B.; Dahlberg, L.; Nilsson, F.; Sattari-Far, I.

1999-12-01

In this handbook a procedure is described which can be used both for assessment of detected cracks or crack-like defects and for defect tolerance analysis. The procedure can be used to calculate possible crack growth due to fatigue or stress corrosion and to calculate the reserve margin for failure due to fracture and plastic collapse. For ductile materials, the procedure gives the reserve margin for initiation of stable crack growth. Thus, an extra reserve margin, unknown to size, exists for failure in components made of ductile materials. The procedure was developed for operative use with the following objectives in mind: a) The procedure should be able to handle both linear and non-linear problems without any a priori division. b) The procedure shall ensure uniqueness of the safety assessment. c) The procedure should be well defined and easy to use. d) The conservatism of the procedure should be well validated. e) The handbook, that documents the procedure, should be so complete that for most assessments, access to any other fracture mechanics literature should not be necessary. The method utilized in the procedure is based on the R6-method developed at Nuclear Electric plc. The basic assumption is that fracture initiated by a crack can be described by the variables K r and L r . K r is the ratio between the stress intensity factor and the fracture toughness of the material. L r is the ratio between applied load and the plastic limit load of the structure. The pair of calculated values of these variables is plotted in a diagram. If the point is situated within the noncritical region, fracture is assumed not to occur. If the point is situated outside the region, crack growth and fracture may occur. The method can in principal be used for all metallic materials. It is, however, more extensively verified for steel alloys only. The method is not intended for use in temperature regions where creep deformation is of importance. To fulfil the above given objectives

A Zebrafish Heart Failure Model for Assessing Therapeutic Agents.

Science.gov (United States)

Zhu, Xiao-Yu; Wu, Si-Qi; Guo, Sheng-Ya; Yang, Hua; Xia, Bo; Li, Ping; Li, Chun-Qi

2018-03-20

Heart failure is a leading cause of death and the development of effective and safe therapeutic agents for heart failure has been proven challenging. In this study, taking advantage of larval zebrafish, we developed a zebrafish heart failure model for drug screening and efficacy assessment. Zebrafish at 2 dpf (days postfertilization) were treated with verapamil at a concentration of 200 μM for 30 min, which were determined as optimum conditions for model development. Tested drugs were administered into zebrafish either by direct soaking or circulation microinjection. After treatment, zebrafish were randomly selected and subjected to either visual observation and image acquisition or record videos under a Zebralab Blood Flow System. The therapeutic effects of drugs on zebrafish heart failure were quantified by calculating the efficiency of heart dilatation, venous congestion, cardiac output, and blood flow dynamics. All 8 human heart failure therapeutic drugs (LCZ696, digoxin, irbesartan, metoprolol, qiliqiangxin capsule, enalapril, shenmai injection, and hydrochlorothiazide) showed significant preventive and therapeutic effects on zebrafish heart failure (p failure model developed and validated in this study could be used for in vivo heart failure studies and for rapid screening and efficacy assessment of preventive and therapeutic drugs.

Failure assessment of pressure vessels under yielding conditions

International Nuclear Information System (INIS)

Harrison, R.P.; Darlaston, B.J.L.; Townley, C.H.A.

1977-01-01

The paper summarizes the work carried out to establish the behavior of structures containing defects and outlines a failure assessment route which can be used to assess the integrity of a structure containing a defect. The basis for this failure assessment route is the two-criteria approach of Dowling and Townley, which can be applied to structures containing defects irrespective of whether they are in the linear elastic fracture mechanics regime, the fully plastic regime, or in an intermediate regime. The extension of this concept to include crack growth by stable tearing is dealt with in the paper

Dynamic loads during failure risk assessment of bridge crane structures

Science.gov (United States)

Gorynin, A. D.; Antsev, V. Yu; Shaforost, A. N.

2018-03-01

The paper presents the method of failure risk assessment associated with a bridge crane metal structure at the design stage. It also justifies the necessity of taking into account dynamic loads with regard to the operational cycle of a bridge crane during failure risk assessment of its metal structure.

Renal function assessment in heart failure.

Science.gov (United States)

Pérez Calvo, J I; Josa Laorden, C; Giménez López, I

Renal function is one of the most consistent prognostic determinants in heart failure. The prognostic information it provides is independent of the ejection fraction and functional status. This article reviews the various renal function assessment measures, with special emphasis on the fact that the patient's clinical situation and response to the heart failure treatment should be considered for the correct interpretation of the results. Finally, we review the literature on the performance of tubular damage biomarkers. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Assessment of Nonorganic Failure To Thrive.

Science.gov (United States)

Wooster, Donna M.

1999-01-01

This article describes basic assessment considerations for infants and toddlers exhibiting nonorganic failure to thrive. The evaluation process must examine feeding, maternal-child interactions, child temperament, and environmental risks and behaviors. Early identification and intervention are necessary to minimize the long-term developmental…

Clinical use of nuclear cardiology in the assessment of heart failure

International Nuclear Information System (INIS)

Han Lei; Shi Hongcheng

2011-01-01

Nuclear cardiology is the most commonly performed non-invasive cardiac imaging test in patients with heart failure, and it plays an important role in their assessment and management. Quantitative gated single positron emission computed tomography is used to assess quantitatively cardiac volume, left ventricular ejection fraction, stroke volume, and cardiac diastolic function. Resting and stress myocardial perfusion imaging can not only identify nonischemic heart failure and ischemic heart failure, but also demonstrate myocardial viability. Diastolic heart failure also termed as heart failure with a preserved left ventricular ejection fraction is readily identified by nuclear cardiology techniques and can accurately be estimated by peak filling rate and time to peak filling rate. With newer techniques such as three-dimensional, quantitative gated single positron emission computed tomography can assess movement of the left ventricle, and wall thickening evaluation aids its assessment. Myocardial perfusion imaging is also commonly used to identify candidates for implantable cardiac defibrillator and cardiac resynchronization therapies. Neurotransmitter imaging using 123 I-metaiodobenzylguanidine offers prognostic information in patients with heart failure. Metabolism and function in the heart are closely related, and energy substrate metabolism is a potential target of medical therapies to improve cardiac function in patients with heart failure. Cardiac metabolic imaging using 123 I-15-(p-iodophenyl) 3-R, S-methylpentadecacoic acid is a commonly used tracer in clinical studies to diagnose metabolic heart failure. Nuclear cardiology tests, including neurotransmitter imaging and metabolic imaging, are now easily preformed with new tracers to improve heart failure diagnosis. Nuclear cardiology techniques contribute significantly to identifying patients with heart failure and to guiding their management decisions. (authors)

A method for risk informing procedures at operating nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Nelson, P. F.; Martin del Campo, C., E-mail: pnelson_007@yahoo.com [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac No. 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico)

2012-10-15

The technical approach presented establishes a framework intended to provide the necessary elements for a deployable human performance monitoring program that incorporates insights from plant specific probabilistic risk assessments, human reliability analysis, as well as the development of plant specific human failure data. A human performance monitoring program of this structure would be used to provide the ability to risk inform procedures (e.g., operations or maintenance) to determine the operational risk significance of procedural performance (i.e., precautions, prerequisites, procedure steps), the likelihood of consequential human error dur the performance of the procedure, and the identification of procedure specific barriers to reduce or eliminate consequential human errors. The program would provide the means to assess procedures prior to execution and the means to record and trend human failure events leading to a plant specific human failure database for human activities characterized as pre-initiator. The technical methods and data processing for each of these areas are developed and presented, as well as an example application of an operational procedure error leading to a plant level event (i.e, plant trip). (Author)

Reliability-based failure cause assessment of collapsed bridge during construction

International Nuclear Information System (INIS)

Choi, Hyun-Ho; Lee, Sang-Yoon; Choi, Il-Yoon; Cho, Hyo-Nam; Mahadevan, Sankaran

2006-01-01

Until now, in many forensic reports, the failure cause assessments are usually carried out by a deterministic approach so far. However, it may be possible for the forensic investigation to lead to unreasonable results far from the real collapse scenario, because the deterministic approach does not systematically take into account any information on the uncertainties involved in the failures of structures. Reliability-based failure cause assessment (reliability-based forensic engineering) methodology is developed which can incorporate the uncertainties involved in structural failures and structures, and to apply them to the collapsed bridge in order to identify the most critical failure scenario and find the cause that triggered the bridge collapse. Moreover, to save the time and cost of evaluation, an algorithm of automated event tree analysis (ETA) is proposed and possible to automatically calculate the failure probabilities of the failure events and the occurrence probabilities of failure scenarios. Also, for reliability analysis, uncertainties are estimated more reasonably by using the Bayesian approach based on the experimental laboratory testing data in the forensic report. For the applicability, the proposed approach is applied to the Hang-ju Grand Bridge, which collapsed during construction, and compared with deterministic approach

Failure of acute procedural success predicts adverse outcome after percutaneous edge-to-edge mitral valve repair with MitraClip.

Science.gov (United States)

Puls, Miriam; Tichelbäcker, Tobias; Bleckmann, Annalen; Hünlich, Mark; von der Ehe, Katrin; Beuthner, Bo Eric; Rüter, Karin; Beißbarth, Tim; Seipelt, Ralf; Schöndube, Friedrich; Hasenfuß, Gerd; Schillinger, Wolfgang

2014-01-01

MitraClip implantation is evolving as a potential alternative treatment to conventional surgery in high-risk patients with significant mitral regurgitation (MR). However, outcome predictors are under-investigated. The aim of this study was to identify predictors of midterm mortality and heart failure rehospitalisation after percutaneous mitral valve repair with MitraClip. A total of 150 consecutive patients were followed for a median of 463 days. Survival analyses were performed for baseline characteristics, risk scores and failure of acute procedural success (APS) defined as persisting MR grade 3+ or 4+. Univariate significant risk stratifiers were tested in multivariate analyses using a Cox proportional hazards model. Overall survival was 96% at 30 days, 79.5% at 12 months, and 62% at two years. Multivariate analysis identified APS failure (HR 2.13, p=0.02), NYHA Class IV at baseline (HR 2.11, p=0.01) and STS score ≥12 (HR 2.20, pfailure (HR 2.31, p=0.01) and NYHA Class IV at baseline (HR 1.89, p=0.03) as significant independent predictors of heart failure rehospitalisation. Furthermore, a post-procedural significant decrease in hospitalisation rate could only be observed after successful interventions (0.89±1.07 per year before vs. 0.54±0.96 after implantation, p=0.01). Patients with severely dilated and overloaded ventricles who did not meet EVEREST II eligibility criteria were at higher risk of APS failure. The failure of acute procedural success proved to have the most important impact on outcome after MitraClip implantation.

Assessment of Competence in EVAR Procedures

DEFF Research Database (Denmark)

Strøm, M; Lönn, L; Bech, B

2017-01-01

OBJECTIVE/BACKGROUND: To develop a procedure specific global rating scale for assessment of operator competence in endovascular aortic repair (EVAR). METHODS: A Delphi approach was used to achieve expert consensus. A panel of 32 international experts (median 300 EVAR procedures, range 200...... suggested by the panel and reduced to seven pivotal assessment items that reached consensus, Cronbach's alpha = 0.82. The seven item rating scale covers key elements of competence in EVAR stent placement and deployment. Each item has well defined grades with explicit anchors at unacceptable, acceptable......, and superior performance on a 5 point Likert scale. CONCLUSION: The Delphi methodology allowed for international consensus on a new procedure specific global rating scale for assessment of competence in EVAR. The resulting scale, EndoVascular Aortic Repair Assessment of Technical Expertise (EVARATE...

System analysis procedures for conducting PSA of nuclear power plants

International Nuclear Information System (INIS)

Lee, Yoon Hwan; Jeong, Won Dae; Kim, Tae Un; Kim, Kil You; Han, Sang Hoon; Chang, Seung Chul; Sung, Tae Yong; Yang, Jun Eon; Kang, Dae Il; Park, Jin Hee; Hwang, Mi Jeong; Jin, Young Ho.

1997-03-01

This document, the Probabilistic Safety Assessment(PSA) procedures guide for system analysis, is intended to provide the guidelines to analyze the target of system consistently and technically in the performance of PSA for nuclear power plants(NPPs). The guide has been prepared in accordance with the procedures and techniques for fault tree analysis(FTA) used in system analysis. Normally the main objective of system analysis is to assess the reliability of system modeled by Event Tree Analysis(ETA). A variety of analytical techniques can be used for the system analysis, however, FTA method is used in this procedures guide. FTA is the method used for representing the failure logic of plant systems deductively using AND, OR or NOT gates. The fault tree should reflect all possible failure modes that may contribute to the system unavailability. This should include contributions due to the mechanical failures of the components, Common Cause Failures (CCFs), human errors and outages for testing and maintenance. After the construction of fault tree is completed, system unavailability is calculated with the CUT module of KIRAP, and the qualitative and quantitative analysis is performed through the process as above stated. As above mentioned, the procedures for system analysis is based on PSA procedures and methods which has been applied to the safety assessments of constructing NPPs in the country. Accordingly, the method of FTA stated in this procedures guide will be applicable to PSA for the NPPs to be constructed in the future. (author). 6 tabs., 11 figs., 7 refs

System analysis procedures for conducting PSA of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Hwan; Jeong, Won Dae; Kim, Tae Un; Kim, Kil You; Han, Sang Hoon; Chang, Seung Chul; Sung, Tae Yong; Yang, Jun Eon; Kang, Dae Il; Park, Jin Hee; Hwang, Mi Jeong; Jin, Young Ho

1997-03-01

This document, the Probabilistic Safety Assessment(PSA) procedures guide for system analysis, is intended to provide the guidelines to analyze the target of system consistently and technically in the performance of PSA for nuclear power plants(NPPs). The guide has been prepared in accordance with the procedures and techniques for fault tree analysis(FTA) used in system analysis. Normally the main objective of system analysis is to assess the reliability of system modeled by Event Tree Analysis(ETA). A variety of analytical techniques can be used for the system analysis, however, FTA method is used in this procedures guide. FTA is the method used for representing the failure logic of plant systems deductively using AND, OR or NOT gates. The fault tree should reflect all possible failure modes that may contribute to the system unavailability. This should include contributions due to the mechanical failures of the components, Common Cause Failures (CCFs), human errors and outages for testing and maintenance. After the construction of fault tree is completed, system unavailability is calculated with the CUT module of KIRAP, and the qualitative and quantitative analysis is performed through the process as above stated. As above mentioned, the procedures for system analysis is based on PSA procedures and methods which has been applied to the safety assessments of constructing NPPs in the country. Accordingly, the method of FTA stated in this procedures guide will be applicable to PSA for the NPPs to be constructed in the future. (author). 6 tabs., 11 figs., 7 refs.

Failure assessments of corroded pipelines with axial defects using stress-based criteria: Numerical studies and verification analyses

International Nuclear Information System (INIS)

Chiodo, Mario S.G.; Ruggieri, Claudio

2009-01-01

Conventional procedures used to assess the integrity of corroded piping systems with axial defects generally employ simplified failure criteria based upon a plastic collapse failure mechanism incorporating the tensile properties of the pipe material. These methods establish acceptance criteria for defects based on limited experimental data for low strength structural steels which do not necessarily address specific requirements for the high grade steels currently used. For these cases, failure assessments may be overly conservative or provide significant scatter in their predictions, which lead to unnecessary repair or replacement of in-service pipelines. Motivated by these observations, this study examines the applicability of a stress-based criterion based upon plastic instability analysis to predict the failure pressure of corroded pipelines with axial defects. A central focus is to gain additional insight into effects of defect geometry and material properties on the attainment of a local limit load to support the development of stress-based burst strength criteria. The work provides an extensive body of results which lend further support to adopt failure criteria for corroded pipelines based upon ligament instability analyses. A verification study conducted on burst testing of large-diameter pipe specimens with different defect length shows the effectiveness of a stress-based criterion using local ligament instability in burst pressure predictions, even though the adopted burst criterion exhibits a potential dependence on defect geometry and possibly on material's strain hardening capacity. Overall, the results presented here suggests that use of stress-based criteria based upon plastic instability analysis of the defect ligament is a valid engineering tool for integrity assessments of pipelines with axial corroded defects

Failure assessments of corroded pipelines with axial defects using stress-based criteria: Numerical studies and verification analyses

Energy Technology Data Exchange (ETDEWEB)

Chiodo, Mario S.G. [Department of Naval Architecture and Ocean Engineering, University of Sao Paulo, Av. Prof. Mello Moraes, 2231 (PNV-EPUSP), Sao Paulo, SP 05508-030 (Brazil); Ruggieri, Claudio [Department of Naval Architecture and Ocean Engineering, University of Sao Paulo, Av. Prof. Mello Moraes, 2231 (PNV-EPUSP), Sao Paulo, SP 05508-030 (Brazil)], E-mail: claudio.ruggieri@poli.usp.br

2009-02-15

Conventional procedures used to assess the integrity of corroded piping systems with axial defects generally employ simplified failure criteria based upon a plastic collapse failure mechanism incorporating the tensile properties of the pipe material. These methods establish acceptance criteria for defects based on limited experimental data for low strength structural steels which do not necessarily address specific requirements for the high grade steels currently used. For these cases, failure assessments may be overly conservative or provide significant scatter in their predictions, which lead to unnecessary repair or replacement of in-service pipelines. Motivated by these observations, this study examines the applicability of a stress-based criterion based upon plastic instability analysis to predict the failure pressure of corroded pipelines with axial defects. A central focus is to gain additional insight into effects of defect geometry and material properties on the attainment of a local limit load to support the development of stress-based burst strength criteria. The work provides an extensive body of results which lend further support to adopt failure criteria for corroded pipelines based upon ligament instability analyses. A verification study conducted on burst testing of large-diameter pipe specimens with different defect length shows the effectiveness of a stress-based criterion using local ligament instability in burst pressure predictions, even though the adopted burst criterion exhibits a potential dependence on defect geometry and possibly on material's strain hardening capacity. Overall, the results presented here suggests that use of stress-based criteria based upon plastic instability analysis of the defect ligament is a valid engineering tool for integrity assessments of pipelines with axial corroded defects.

Semiconductor failure threshold estimation problem in electromagnetic assessment

International Nuclear Information System (INIS)

Enlow, E.W.; Wunsch, D.C.

1984-01-01

Present semiconductor failure models to predict the one-microsecond square-wave power failure level for use with system electromagnetic (EM) assessments and hardening design are incomplete. This is because for a majority of device types there is insufficient data readily available in a composite data source to quantify the model parameters and the inaccuracy of the models cause complications in definition of adequate hardness margins and quantification of EM performance. This paper presents new semiconductor failure models which use a generic approach that are an integration and simplification of many present models. This generic approach uses two categorical models: one for diodes and transistors, and one for integrated circuits. The models were constructed from a large database of semiconductor failure data. The approach used for constructing diode and transistor failure level models is based on device rated power and are simple to use and universally applicable. The model predicts the value of the 1 μ second failure power to be used in the power failure models P = Kt /SUP -1/2/ or P = K 1 t -1 + K 2 t /SUP -1/2/ + K 3

Controller recovery from equipment failures in air traffic control: A framework for the quantitative assessment of the recovery context

International Nuclear Information System (INIS)

Subotic, Branka; Schuster, Wolfgang; Majumdar, Arnab; Ochieng, Washington

2014-01-01

Air Traffic Control (ATC) involves a complex interaction of human operators (primarily air traffic controllers), equipment and procedures. On the rare occasions when equipment malfunctions, controllers play a crucial role in the recovery process of the ATC system for continued safe operation. Research on human performance in other safety critical industries using human reliability assessment techniques has shown that the context in which recovery from failures takes place has a significant influence on the outcome of the process. This paper investigates the importance of context in which air traffic controller recovery from equipment failures takes place, defining it in terms of 20 Recovery Influencing Factors (RIFs). The RIFs are used to develop a novel approach for the quantitative assessment of the recovery context based on a metric referred to as the Recovery Context Indicator (RCI). The method is validated by a series of simulation exercises conducted at a specific ATC Centre. The proposed method is useful to assess recovery enhancement approaches within ATC centres

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)

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.

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.

Failure Monitoring and Condition Assessment of Steel-Concrete Adhesive Connection Using Ultrasonic Waves

Directory of Open Access Journals (Sweden)

Magdalena Rucka

2018-02-01

Full Text Available Adhesive bonding is increasingly being incorporated into civil engineering applications. Recently, the use of structural adhesives in steel-concrete composite systems is of particular interest. The aim of the study is an experimental investigation of the damage assessment of the connection between steel and concrete during mechanical degradation. Nine specimens consisted of a concrete cube and two adhesively bonded steel plates were examined. The inspection was based on the ultrasound monitoring during push-out tests. Ultrasonic waves were excited and registered by means of piezoelectric transducers every two seconds until the specimen failure. To determine the slip between the steel and concrete a photogrammetric method was applied. The procedure of damage evaluation is based on the monitoring of the changes in the amplitude and phase shift of signals measured during subsequent phases of degradation. To quantify discrepancies between the reference signal and other registered signals, the Sprague and Gears metric was applied. The results showed the possibilities and limitations of the proposed approach in diagnostics of adhesive connections between steel and concrete depending on the failure modes.

Environmental Impact Assessment: A Procedure.

Science.gov (United States)

Stover, Lloyd V.

Prepared by a firm of consulting engineers, this booklet outlines the procedural "whys and hows" of assessing environmental impact, particularly for the construction industry. Section I explores the need for environmental assessment and evaluation to determine environmental impact. It utilizes a review of the National Environmental Policy Act and…

Failure rate data for fusion safety and risk assessment

International Nuclear Information System (INIS)

Cadwallader, L.C.

1993-01-01

The Fusion Safety Program (FSP) at the Idaho National Engineering Laboratory (INEL) conducts safety research in materials, chemical reactions, safety analysis, risk assessment, and in component research and development to support existing magnetic fusion experiments and also to promote safety in the design of future experiments. One of the areas of safety research is applying probabilistic risk assessment (PRA) methods to fusion experiments. To apply PRA, we need a fusion-relevant radiological dose code and a component failure rate data base. This paper describes the FSP effort to develop a failure rate data base for fusion-specific components

Assessing Risks of Mine Tailing Dam Failures

Science.gov (United States)

Concha Larrauri, P.; Lall, U.

2017-12-01

The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

15 CFR 990.27 - Use of assessment procedures.

Science.gov (United States)

2010-01-01

...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OIL POLLUTION ACT REGULATIONS NATURAL RESOURCE DAMAGE ASSESSMENTS Authorities § 990.27 Use of assessment procedures. (a) Standards for... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Use of assessment procedures. 990.27...

Defect assessment procedures at high temperature

International Nuclear Information System (INIS)

Ainsworth, R.A.

1991-01-01

A comprehensive assessment procedure for the high-temperature response of structures is being produced. The procedure is referred to as R5 and is written as a series of step-by-step instructions in a number of volumes. This paper considers in detail those parts of R5 which address the behaviour of defects. The defect assessment procedures may be applied to defects found in service, postulated defects, or defects formed during operation as a result of creep-fatigue loading. In the last case, a method is described for deducing from endurance data the number of cycles to initiate a crack of a specified size. Under steady loading, the creep crack tip parameter C * is used to assess crack growth. Under cyclic loading, the creep crack growth during dwell periods is stiell governed by C * but crack growth due to cyclic excursions must also be included. This cyclic crack growth is described by an effective stress intensity factor range. A feature of the R5 defect assessment procedures in that they are based on simplified methods and approximate reference stress methods are described which enable C * in a component to be evaluated. It is shown by comparison with theoretical calculations and experimental data that reliable estimates of C * and the associated crack growth are obtained provided realistic creep strain rate date are used in the reference stress approximation. (orig./HP)

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.

Validation of BS7910:2005 failure assessment diagrams for cracked square hollow section T-, Y- and K-joints

International Nuclear Information System (INIS)

Lie, S.T.; Yang, Z.M.; Gho, W.M.

2009-01-01

This paper describes the usage of finite element (FE) analyses results to validate the standard BS7910 assessment procedure for the safe design of cracked square hollow section (SHS) T-, Y- and K-joints. In the study, the actual 3D surface cracks obtained from previous fatigue tests have been included in the FE models. An automatic mesh generation program is then developed and used to produce the failure assessment diagram (FAD) through the J-integral method. The ultimate strength of uncracked SHS joints with reduced load bearing areas have been referenced to derive the plastic collapse loads of cracked SHS joints for the development of FAD. These loads have been validated against the previous experimental results. In comparison with the existing standard BS7910 Level 2A/3A FAD curve and the proposed assessment procedure for circular hollow section joints, it is found that a plastic collapse load with a penalty factor of 1.05 will be sufficient for the safe assessment of cracked SHS T, Y, and K-joints under brace end axial loading

Types of Heart Failure

Science.gov (United States)

... Introduction Types of Heart Failure Classes of Heart Failure Heart Failure in Children Advanced Heart Failure • Causes and ... and procedures related to heart disease and stroke. Heart Failure Questions to Ask Your Doctor Use these questions ...

A limited assessment of the ASEP human reliability analysis procedure using simulator examination results

International Nuclear Information System (INIS)

Gore, B.R.; Dukelow, J.S. Jr.; Mitts, T.M.; Nicholson, W.L.

1995-10-01

This report presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR-4772. In particular, the, ASEP post-accident, post-diagnosis, nominal HRA procedure is assessed within the context of an individual's performance of critical tasks on the simulator portion of requalification examinations administered to nuclear power plant operators. An assessment of the degree to which operator perforn:Lance during simulator examinations is an accurate reflection of operator performance during actual accident conditions was outside the scope of work for this project; therefore, no direct inference can be made from this report about such performance. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle. A total of 4071 critical tasks were identified, of which 45 had been failed. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. ASEP analyses were performed for a sample of 162 critical tasks selected randomly from the 4071, and the results were used to characterize the entire population. ASEP analyses were also performed for all of the 45 failed critical tasks. Two tests were performed to assess the bias of the ASEP HEPs compared with the data from the requalification examinations. The first compared the average of the ASEP HEP values with the fraction of the population actually failed and it found a statistically significant factor of two bias on the average

A big data analysis approach for rail failure risk assessment

NARCIS (Netherlands)

Jamshidi, A.; Faghih Roohi, S.; Hajizadeh, S.; Nunez Vicencio, Alfredo; Babuska, R.; Dollevoet, R.P.B.J.; Li, Z.; De Schutter, B.H.K.

2017-01-01

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

Risk assessment of component failure modes and human errors using a new FMECA approach: application in the safety analysis of HDR brachytherapy

International Nuclear Information System (INIS)

Giardina, M; Castiglia, F; Tomarchio, E

2014-01-01

Failure mode, effects and criticality analysis (FMECA) is a safety technique extensively used in many different industrial fields to identify and prevent potential failures. In the application of traditional FMECA, the risk priority number (RPN) is determined to rank the failure modes; however, the method has been criticised for having several weaknesses. Moreover, it is unable to adequately deal with human errors or negligence. In this paper, a new versatile fuzzy rule-based assessment model is proposed to evaluate the RPN index to rank both component failure and human error. The proposed methodology is applied to potential radiological over-exposure of patients during high-dose-rate brachytherapy treatments. The critical analysis of the results can provide recommendations and suggestions regarding safety provisions for the equipment and procedures required to reduce the occurrence of accidental events. (paper)

Preventing blood transfusion failures: FMEA, an effective assessment method.

Science.gov (United States)

Najafpour, Zhila; Hasoumi, Mojtaba; Behzadi, Faranak; Mohamadi, Efat; Jafary, Mohamadreza; Saeedi, Morteza

2017-06-30

Failure Mode and Effect Analysis (FMEA) is a method used to assess the risk of failures and harms to patients during the medical process and to identify the associated clinical issues. The aim of this study was to conduct an assessment of blood transfusion process in a teaching general hospital, using FMEA as the method. A structured FMEA was recruited in our study performed in 2014, and corrective actions were implemented and re-evaluated after 6 months. Sixteen 2-h sessions were held to perform FMEA in the blood transfusion process, including five steps: establishing the context, selecting team members, analysis of the processes, hazard analysis, and developing a risk reduction protocol for blood transfusion. Failure modes with the highest risk priority numbers (RPNs) were identified. The overall RPN scores ranged from 5 to 100 among which, four failure modes were associated with RPNs over 75. The data analysis indicated that failures with the highest RPNs were: labelling (RPN: 100), transfusion of blood or the component (RPN: 100), patient identification (RPN: 80) and sampling (RPN: 75). The results demonstrated that mis-transfusion of blood or blood component is the most important error, which can lead to serious morbidity or mortality. Provision of training to the personnel on blood transfusion, knowledge raising on hazards and appropriate preventative measures, as well as developing standard safety guidelines are essential, and must be implemented during all steps of blood and blood component transfusion.

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

Dependent failure analysis research for the US NRC Risk Methods Integration and Evaluation Program

International Nuclear Information System (INIS)

Bohn, M.P.; Stack, D.W.; Campbell, D.J.; Rooney, J.J.; Rasmuson, D.M.

1985-01-01

The Risk Methods Integration and Evaluation Program (RMIEP), which is being performed for the Nuclear Regulatory Commission by Sandia National Laboratories, has the goals of developing new risk assessment methods and integrating the new and existing methods in a uniform procedure for performing an in-depth probabilistic risk assessment (PRA) with consistent levels of analysis for internal, external, and dependent failure scenarios. An important part of RMIEP is the recognition of the crucial importance of dependent common cause failures (CCFs) and the pressing need to develop effective methods for analyzing CCFs as part of a PRA. The NRC-sponsored Integrated Dependent Failure Methodology Program at Sandia is addressing this need. This paper presents a preliminary approach for analyzing CCFs as part of a PRA. A nine-step procedure for efficiently screening and analyzing dependent failure scenarios is presented, and each step is discussed

Simple estimation procedures for regression analysis of interval-censored failure time data under the proportional hazards model.

Science.gov (United States)

Sun, Jianguo; Feng, Yanqin; Zhao, Hui

2015-01-01

Interval-censored failure time data occur in many fields including epidemiological and medical studies as well as financial and sociological studies, and many authors have investigated their analysis (Sun, The statistical analysis of interval-censored failure time data, 2006; Zhang, Stat Modeling 9:321-343, 2009). In particular, a number of procedures have been developed for regression analysis of interval-censored data arising from the proportional hazards model (Finkelstein, Biometrics 42:845-854, 1986; Huang, Ann Stat 24:540-568, 1996; Pan, Biometrics 56:199-203, 2000). For most of these procedures, however, one drawback is that they involve estimation of both regression parameters and baseline cumulative hazard function. In this paper, we propose two simple estimation approaches that do not need estimation of the baseline cumulative hazard function. The asymptotic properties of the resulting estimates are given, and an extensive simulation study is conducted and indicates that they work well for practical situations.

Validation of self assessment patient knowledge questionnaire for heart failure patients.

Science.gov (United States)

Lainscak, Mitja; Keber, Irena

2005-12-01

Several studies showed insufficient knowledge and poor compliance to non-pharmacological management in heart failure patients. Only a limited number of validated tools are available to assess their knowledge. The aim of the study was to test our 10-item Patient knowledge questionnaire. The Patient knowledge questionnaire was administered to 42 heart failure patients from Heart failure clinic and to 40 heart failure patients receiving usual care. Construct validity (Pearson correlation coefficient), internal consistency (Cronbach alpha), reproducibility (Wilcoxon signed rank test), and reliability (chi-square test and Student's t-test for independent samples) were assessed. Overall score of the Patient knowledge questionnaire had the strongest correlation to the question about regular weighing (r=0.69) and the weakest to the question about presence of heart disease (r=0.33). There was a strong correlation between question about fluid retention and questions assessing regular weighing, (r=0.86), weight of one litre of water (r=0.86), and salt restriction (r=0.57). The Cronbach alpha was 0.74 and could be improved by exclusion of questions about clear explanation (Chronbach alpha 0.75), importance of fruit, soup, and vegetables (Chronbach alpha 0.75), and self adjustment of diuretic (Chronbach alpha 0.81). During reproducibility testing 91% to 98% of questions were answered equally. Patients from Heart failure clinic scored significantly better than patients receiving usual care (7.9 (1.3) vs. 5.7 (2.2), p<0.001). Patient knowledge questionnaire is a valid and reliable tool to measure knowledge of heart failure patients.

Assessment of the coronary venous system in heart failure patients by blood pool agent enhanced whole-heart MRI

Energy Technology Data Exchange (ETDEWEB)

Manzke, Robert [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Philips Research Europe, Clinical Sites Research, Hamburg (Germany); Binner, Ludwig; Bornstedt, Axel; Merkle, Nico; Lutz, Anja; Gradinger, Robert [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Rasche, Volker [University Hospital of Ulm, Department of Internal Medicine II, Ulm (Germany); Experimental Cardiovascular Imaging, Internal Medicine II, Ulm (Germany)

2011-04-15

To investigate the feasibility of MRI for non-invasive assessment of the coronary sinus (CS) and the number and course of its major tributaries in heart failure patients. Fourteen non-ischaemic heart failure patients scheduled for cardiac resynchronisation therapy (CRT) underwent additional whole-heart coronary venography. MRI was performed 1 day before device implantation. The visibility, location and dimensions of the CS and its major tributaries were assessed and the number of potential implantation sites identified. The MRI results were validated by X-ray venography conventionally acquired during the device implantation procedure. The right atrium (RA), CS and mid-cardiac vein (MCV) could be visualised in all patients. 36% of the identified candidate branches were located posterolaterally, 48% laterally and 16% anterolaterally. The average diameter of the CS was quantified as 9.8 mm, the posterior interventricular vein (PIV) 4.6 mm, posterolateral segments 3.3 mm, lateral 2.9 mm and anterolateral 2.9 mm. Concordance with X-ray in terms of number and location of candidate branches was given in most cases. Contrast-enhanced MRI venography appears feasible for non-invasive pre-interventional assessment of the course of the CS and its major tributaries. (orig.)

Assessment of the coronary venous system in heart failure patients by blood pool agent enhanced whole-heart MRI

International Nuclear Information System (INIS)

Manzke, Robert; Binner, Ludwig; Bornstedt, Axel; Merkle, Nico; Lutz, Anja; Gradinger, Robert; Rasche, Volker

2011-01-01

To investigate the feasibility of MRI for non-invasive assessment of the coronary sinus (CS) and the number and course of its major tributaries in heart failure patients. Fourteen non-ischaemic heart failure patients scheduled for cardiac resynchronisation therapy (CRT) underwent additional whole-heart coronary venography. MRI was performed 1 day before device implantation. The visibility, location and dimensions of the CS and its major tributaries were assessed and the number of potential implantation sites identified. The MRI results were validated by X-ray venography conventionally acquired during the device implantation procedure. The right atrium (RA), CS and mid-cardiac vein (MCV) could be visualised in all patients. 36% of the identified candidate branches were located posterolaterally, 48% laterally and 16% anterolaterally. The average diameter of the CS was quantified as 9.8 mm, the posterior interventricular vein (PIV) 4.6 mm, posterolateral segments 3.3 mm, lateral 2.9 mm and anterolateral 2.9 mm. Concordance with X-ray in terms of number and location of candidate branches was given in most cases. Contrast-enhanced MRI venography appears feasible for non-invasive pre-interventional assessment of the course of the CS and its major tributaries. (orig.)

Consequences assessment for fuel channel failure with consequential moderator drain

International Nuclear Information System (INIS)

Wahba, N.N.; Bayoumi, M.H.

2002-01-01

This paper documents the consequences of spontaneous pressure tube/consequential calandria tube rupture followed by the ejection of end fittings (as a result of guillotine failure of pressure tube) leading to the drain of the moderator. The event is postulated to occur in conjunction with an independent failure of Emergency Coolant Injection System (ECIS). The results of the detailed consequence assessments are used to propose a course of action to mitigate the consequences of such an event. A methodology based on a lumped-parameter model was developed to assess the consequences of the postulated event. (author)

Using impedance cardiography to assess left ventricular systolic function via postural change in patients with heart failure.

Science.gov (United States)

DeMarzo, Arthur P; Calvin, James E; Kelly, Russell F; Stamos, Thomas D

2005-01-01

For the diagnosis and management of heart failure, it would be useful to have a simple point-of-care test for assessing ventricular function that could be performed by a nurse. An impedance cardiography (ICG) parameter called systolic amplitude (SA) can serve as an indicator of left ventricular systolic function (LVSF). This study tested the hypothesis that patients with normal LVSF should have a significant increase in SA in response to an increase in end-diastolic volume caused by postural change from sitting upright to supine, while patients with depressed LVSF associated with heart failure should have a minimal increase or a decrease in SA from upright to supine. ICG data were obtained in 12 patients without heart disease and with normal LVSF and 18 patients with clinically diagnosed heart failure. Consistent with the hypothesis, patients with normal LVSF had a significant increase in SA from upright to supine, whereas heart failure patients had a minimal increase or a decrease in SA from upright to supine. This ICG procedure may be useful for monitoring the trend of patient response to titration of beta blockers and other medications. ICG potentially could be used to detect worsening LVSF and provide a means of measurement for adjusting treatment.

Analysis of leak and break behavior in a failure assessment diagram for carbon steel pipes

International Nuclear Information System (INIS)

Kanno, Satoshi; Hasegawa, Kunio; Shimizu, Tasuku; Saitoh, Takashi; Gotoh, Nobuho

1992-01-01

The leak and break behavior of a cracked coolant pipe subjected to an internal pressure and a bending moment was analyzed with a failure assessment diagram using the R6 approach. This paper examines the conditions of the detectable coolant leakage without breakage. A leakage assessment curve, a locus of assessment point for detectable coolant leakage, was defined in the failure assessment diagram. The region between the leak assessment and failure assessment curves satisfies the condition of detectable leakage without breakage. In this region, a crack can be safely inspected by a coolant leak detector. (orig.)

Failure detection system risk reduction assessment

Science.gov (United States)

Aguilar, Robert B. (Inventor); Huang, Zhaofeng (Inventor)

2012-01-01

A process includes determining a probability of a failure mode of a system being analyzed reaching a failure limit as a function of time to failure limit, determining a probability of a mitigation of the failure mode as a function of a time to failure limit, and quantifying a risk reduction based on the probability of the failure mode reaching the failure limit and the probability of the mitigation.

VALIDATING A COMPUTER-BASED TECHNIQUE FOR ASSESSING STABILITY TO FAILURE STRESS

Directory of Open Access Journals (Sweden)

I. F. Arshava

2013-03-01

Full Text Available An upsurge of interest in the implicit personality assessment, currently observed both in personality psycho-diagnostics and in experimental studies of social attitudes and prejudices, signals the shifting of researchers’ attention from de?ning between-person personality taxonomy to specifying comprehensive within-person processes, the dynamics of which can be captured at the level of an individual case. This research examines the possibility of the implicit assessment of the individual’s stability vs. susceptibility to failure stress by comparing the degrees of ef?cacy in the voluntary self-regulation of a computer-simulated information-processing activity under different conditions (patent of Ukraine № 91842, issued in 2010. By exposing two groups of participants (university undergraduates to processing the information, the scope of which exceeds the human short-term memory capacity at one of the stages of the modeled activity an unexpected and unavoidable failure is elicited. The participants who retain stability of their self-regulation behavior after having been exposed to failure, i.e. who keep processing information as effectively as they did prior to failure, are claimed to retain homeostasis and thus possess emotional stability. Those, who loose homeostasis after failure and display lower standards of self-regulation behavior, are considered to be susceptible to stress. The validity of the suggested type of the implicit diagnostics was empirically tested by clustering (K-means algorithm two samples of the participants on the  properties of their self-regulation behavior and testing between-cluster differences by a set of the explicitly assessed variables: Action control ef?cacy (Kuhl, 2001, preferred strategies of Coping with Stressful Situations (Endler, Parker, 1990,  Purpose-in-Life orientation (a Russian version of the test by Crumbaugh and Maholick, modi?ed by D.Leontiev, 1992, Psychological Well-being (Ryff, 1989

Risk assessment of tailings facility dam failure

OpenAIRE

Hadzi-Nikolova, Marija; Mirakovski, Dejan; Stefanova, Violeta

2011-01-01

This paper presents the consequences of tailings facility dam failure and therefore the needs for its risk assessment. Tailings are fine-grained wastes of the mining industry, output as slurries, due to mixing with water during mineral processing. Tailings dams vary a lot as it is affected by: tailings characteristics and mill output, site characteristics as: topography, hydrology, geology, groundwater, seismicity and available material and disposal methods. The talings which accumulat...

Patients exposure assessment for radiographic procedures in diagnostic radiology

International Nuclear Information System (INIS)

Arandjic, D.; Ciraj-Bjelac, O.; Stankovic, K.; Lazarevic, Dj.; Ciraj-Bjelac, O.)

2007-01-01

In this work the results of dose assessment for the most frequent radiographic procedures in diagnostic radiology are shown. Entrance surface doses were assessed for 7 radiographic procedures. Three hospitals, six x-ray units in total, were enrolled in investigation. Patient doses were estimated based on results of x-ray tube output measurements. Finally, doses were compared with Diagnostic reference level. Higher dose values were observed for chest examinations. In comparison with results from other countries, doses from this procedure in Serbia are significantly higher. Estimated doses for other procedures were well below Diagnostic reference levels [sr

Flood risk analysis procedure for nuclear power plants

International Nuclear Information System (INIS)

Wagner, D.P.

1982-01-01

This paper describes a methodology and procedure for determining the impact of floods on nuclear power plant risk. The procedures are based on techniques of fault tree and event tree analysis and use the logic of these techniques to determine the effects of a flood on system failure probability and accident sequence occurrence frequency. The methodology can be applied independently or as an add-on analysis for an existing risk assessment. Each stage of the analysis yields useful results such as the critical flood level, failure flood level, and the flood's contribution to accident sequence occurrence frequency. The results of applications show the effects of floods on the risk from nuclear power plants analyzed in the Reactor Safety Study

Software quality assurance procedures for radioactive waste risk assessment codes

International Nuclear Information System (INIS)

Hill, I.; Mayer, J.

1990-01-01

This support study for the evaluation of the safety of geological disposal systems is aimed at identifying the requirements for software quality assurance procedures for radioactive waste risk assessment codes, and to recommend appropriate procedures. The research covers: (i) the analysis of existing procedures and definition of requirements; (ii) a case study of the use of some existing procedures; (iii) the definition and the implementation of procedures. The report is supported by appendices that give more detail on the procedures recommended. It is intended to provide ideas on the steps that should be taken to ensure the quality of the programs used for assessment of the safety case for radioactive waste repositories, and does not represent the introduction of wholly new ideas or techniques. The emphasis throughout is on procedures that will be easily implemented, rather than on the fully rigorous procedures that are required for some application areas. The study has concentrated on measures that will increase the confidence in repository performance assessments among the wider scientific/engineering community, and the lay public

Tubal risk markers for failure to place transcervical sterilization coils

Science.gov (United States)

Leyser-Whalen, Ophra; Rouhani, Mahta; Rahman, Mahbubur; Berenson, Abbey B

2011-01-01

Background There is a growing body of literature on placement rates of the Essure® procedure, yet prior studies have not attempted to identify tubal-associated risk factors for placement failures. The current study examines risk markers associated with the inability to deploy the Essure® coils into the tubal lumen using the new ESS305 design. Study Design We used electronic medical record data to assess risk markers associated with the inability to place the Essure coils in the tubal lumen using the new ESS305 design. A total of 310 attempted procedures between June 14, 2007, and April 29, 2011 were analyzed. Results There were 18 tubal failures (5.8%) out of the 310 attempted procedures. A history of a prior sexually transmitted infection (STI) was associated with tubal failure (OR 2.64, 95% confidence interval (CI) 1.01–6.90; p=.048). Conclusions We speculate that the observed association between a prior STI and an inability to place the coil was due to a past history of pelvic inflammatory disease. PMID:22036044

Assessment in Counseling: A Guide to the Use of Psychological Assessment Procedures. Third Edition.

Science.gov (United States)

Hood, Albert B.; Johnson, Richard W.

This book presents information about various psychological assessment procedures that are specifically relevant for practicing counselors. It deals with the use of assessment procedures in the counseling process and emphasizes the selection, interpretation, and communication of psychological test results. The importance of integrating test results…

Improving L2 Reading Comprehension through Emotionalized Dynamic Assessment Procedures.

Science.gov (United States)

Abdolrezapour, Parisa

2017-06-01

The paper reports a study on an emotionally-loaded dynamic assessment procedure used with Iranian EFL learners. It focuses on the effect of using emotional intelligence characteristics (based on Goleman's framework) as a tool for motivating learners while performing reading tasks. The study with 50 intermediate learners aged 12-15 used three modalities: a control group, which was taught under institute's normal procedures; a comparison group, which received dynamic assessment (DA); and an experimental group, which received emotionalized dynamic assessment (EDA) procedures, in the form of an intervention focusing on characteristics of Goleman's emotional intelligence framework with the express purpose of inducing them to work with their emotions. Results showed that applying EDA procedures to reading assessment tasks made a difference in learners' level of performance in comparison to those who went through pure DA procedures who in turn performed significantly better than those who did not received DA in any form.

A procedure for the assessment of low frequency noise complaints.

Science.gov (United States)

Moorhouse, Andy T; Waddington, David C; Adams, Mags D

2009-09-01

The development and application of a procedure for the assessment of low frequency noise (LFN) complaints are described. The development of the assessment method included laboratory tests addressing low frequency hearing threshold and the effect on acceptability of fluctuation, and field measurements complemented with interview-based questionnaires. Environmental health departments then conducted a series of six trials with genuine "live" LFN complaints to test the workability and usefulness of the procedure. The procedure includes guidance notes and a pro-forma report with step-by-step instructions. It does not provide a prescriptive indicator of nuisance but rather gives a systematic procedure to help environmental health practitioners to form their own opinion. Examples of field measurements and application of the procedure are presented. The procedure and examples are likely to be of particular interest to environmental health practitioners involved in the assessment of LFN complaints.

TU-FG-201-12: Designing a Risk-Based Quality Assurance Program for a Newly Implemented Y-90 Microspheres Procedure

Energy Technology Data Exchange (ETDEWEB)

Vile, D; Zhang, L; Cuttino, L; Kim, S; Palta, J [Virginia Commonwealth University, Richmond, VA (United States)

2016-06-15

Purpose: To create a quality assurance program based upon a risk-based assessment of a newly implemented SirSpheres Y-90 procedure. Methods: A process map was created for a newly implemented SirSpheres procedure at a community hospital. The process map documented each step of this collaborative procedure, as well as the roles and responsibilities of each member. From the process map, different potential failure modes were determined as well as any current controls in place. From this list, a full failure mode and effects analysis (FMEA) was performed by grading each failure mode’s likelihood of occurrence, likelihood of detection, and potential severity. These numbers were then multiplied to compute the risk priority number (RPN) for each potential failure mode. Failure modes were then ranked based on their RPN. Additional controls were then added, with failure modes corresponding to the highest RPNs taking priority. Results: A process map was created that succinctly outlined each step in the SirSpheres procedure in its current implementation. From this, 72 potential failure modes were identified and ranked according to their associated RPN. Quality assurance controls and safety barriers were then added for failure modes associated with the highest risk being addressed first. Conclusion: A quality assurance program was created from a risk-based assessment of the SirSpheres process. Process mapping and FMEA were effective in identifying potential high-risk failure modes for this new procedure, which were prioritized for new quality assurance controls. TG 100 recommends the fault tree analysis methodology to design a comprehensive and effective QC/QM program, yet we found that by simply introducing additional safety barriers to address high RPN failure modes makes the whole process simpler and safer.

TU-FG-201-12: Designing a Risk-Based Quality Assurance Program for a Newly Implemented Y-90 Microspheres Procedure

International Nuclear Information System (INIS)

Vile, D; Zhang, L; Cuttino, L; Kim, S; Palta, J

2016-01-01

Purpose: To create a quality assurance program based upon a risk-based assessment of a newly implemented SirSpheres Y-90 procedure. Methods: A process map was created for a newly implemented SirSpheres procedure at a community hospital. The process map documented each step of this collaborative procedure, as well as the roles and responsibilities of each member. From the process map, different potential failure modes were determined as well as any current controls in place. From this list, a full failure mode and effects analysis (FMEA) was performed by grading each failure mode’s likelihood of occurrence, likelihood of detection, and potential severity. These numbers were then multiplied to compute the risk priority number (RPN) for each potential failure mode. Failure modes were then ranked based on their RPN. Additional controls were then added, with failure modes corresponding to the highest RPNs taking priority. Results: A process map was created that succinctly outlined each step in the SirSpheres procedure in its current implementation. From this, 72 potential failure modes were identified and ranked according to their associated RPN. Quality assurance controls and safety barriers were then added for failure modes associated with the highest risk being addressed first. Conclusion: A quality assurance program was created from a risk-based assessment of the SirSpheres process. Process mapping and FMEA were effective in identifying potential high-risk failure modes for this new procedure, which were prioritized for new quality assurance controls. TG 100 recommends the fault tree analysis methodology to design a comprehensive and effective QC/QM program, yet we found that by simply introducing additional safety barriers to address high RPN failure modes makes the whole process simpler and safer.

Failure Modes Taxonomy for Reliability Assessment of Digital Instrumentation and Control Systems for Probabilistic Risk Analysis - Failure modes taxonomy for reliability assessment of digital I and C systems for PRA

International Nuclear Information System (INIS)

Amri, A.; Blundell, N.; ); Authen, S.; Betancourt, L.; Coyne, K.; Halverson, D.; Li, M.; Taylor, G.; Bjoerkman, K.; Brinkman, H.; Postma, W.; Bruneliere, H.; Chirila, M.; Gheorge, R.; Chu, L.; Yue, M.; Delache, J.; Georgescu, G.; Deleuze, G.; Quatrain, R.; Thuy, N.; Holmberg, J.-E.; Kim, M.C.; Kondo, K.; Mancini, F.; Piljugin, E.; Stiller, J.; Sedlak, J.; Smidts, C.; Sopira, V.

2015-01-01

Digital protection and control systems appear as upgrades in older nuclear power plants (NPP), and are commonplace in new NPPs. To assess the risk of NPP operation and to determine the risk impact of digital systems, there is a need to quantitatively assess the reliability of the digital systems in a justifiable manner. Due to the many unique attributes of digital systems (e.g., functions are implemented by software, units of the system interact in a communication network, faults can be identified and handled online), a number of modelling and data collection challenges exist, and international consensus on the reliability modelling has not yet been reached. The objective of the task group called DIGREL has been to develop a taxonomy of failure modes of digital components for the purposes of probabilistic risk analysis (PRA). An activity focused on the development of a common taxonomy of failure modes is seen as an important step towards standardised digital instrumentation and control (I and C) reliability assessment techniques for PRA. Needs from PRA has guided the work, meaning, e.g., that the I and C system and its failures are studied from the point of view of their functional significance point of view. The taxonomy will be the basis of future modelling and quantification efforts. It will also help to define a structure for data collection and to review PRA studies. The proposed failure modes taxonomy has been developed by first collecting examples of taxonomies provided by the task group organisations. This material showed some variety in the handling of I and C hardware failure modes, depending on the context where the failure modes have been defined. Regarding the software part of I and C, failure modes defined in NPP PRAs have been simple - typically a software CCF failing identical processing units. The DIGREL task group has defined a new failure modes taxonomy based on a hierarchical definition of five levels of abstraction: 1. system level (complete

How to interpret safety critical failures in risk and reliability assessments

International Nuclear Information System (INIS)

Selvik, Jon Tømmerås; Signoret, Jean-Pierre

2017-01-01

Management of safety systems often receives high attention due to the potential for industrial accidents. In risk and reliability literature concerning such systems, and particularly concerning safety-instrumented systems, one frequently comes across the term ‘safety critical failure’. It is a term associated with the term ‘critical failure’, and it is often deduced that a safety critical failure refers to a failure occurring in a safety critical system. Although this is correct in some situations, it is not matching with for example the mathematical definition given in ISO/TR 12489:2013 on reliability modeling, where a clear distinction is made between ‘safe failures’ and ‘dangerous failures’. In this article, we show that different interpretations of the term ‘safety critical failure’ exist, and there is room for misinterpretations and misunderstandings regarding risk and reliability assessments where failure information linked to safety systems are used, and which could influence decision-making. The article gives some examples from the oil and gas industry, showing different possible interpretations of the term. In particular we discuss the link between criticality and failure. The article points in general to the importance of adequate risk communication when using the term, and gives some clarification on interpretation in risk and reliability assessments.

Damage Control Orthopedics Management as Vital Procedure in Elderly Patients with Femoral Neck Fractures Complicated with Chronic Renal Failure: A Retrospective Cohort Study

Science.gov (United States)

Dong, Chenhui; Wang, Yunjiao; Wang, Ziming; Wang, Yu; Wu, Siyu; Du, Quanyin; Wang, Aimin

2016-01-01

Background Chronic renal failure (CRF) predisposes to hip fractures in elderly patients, with high subsequent mortality. Selection and timing of the surgical procedure of such patients is a serious challenge. Many clinicians believe in earlier surgery as preferable and providing better outcomes. Damage control orthopedics (DCO) aids to adjust and optimize the overall condition of patients. Methods In 32 patients with femoral neck fractures complicated with CRF, we evaluated how the timing of the surgery determines the mortality rates if the DCO approach is applied. Preoperative ASA grading, POSSUM score, P-POSSUM score and DCO were carried out. Based on the assessment, timing of the surgery was ascertained. Results Of a total of 32 patients, twenty-nine patients were accepted for either early (failures and acute respiratory distress syndrome. There was no significant difference in complication rates and Harris hip score between both groups. Conclusion In patients with femoral neck fracture complicated with CRF, delaying the surgery for several days does not increase the incidence of postoperative adverse events. PMID:27149117

A new approach for estimation of component failure rate

International Nuclear Information System (INIS)

Jordan Cizelj, R.; Kljenak, I.

1999-01-01

In the paper, a formal method for component failure rate estimation is described, which is proposed to be used for components, for which no specific numerical data necessary for probabilistic estimation exist. The framework of the method is the Bayesian updating procedure. A prior distribution is selected from a generic database, whereas the likelihood distribution is assessed from specific data on component state using principles of fuzzy logic theory. With the proposed method the component failure rate estimation is based on a much larger quantity of information compared to presently used classical methods.(author)

Structured Assessment Approach: a procedure for the assessment of fuel cycle safeguard systems

International Nuclear Information System (INIS)

Parziale, A.A.; Patenaude, C.J.; Renard, P.A.; Sacks, I.J.

1980-01-01

Lawrence Livermore National Laboratory has developed and tested for the United States Nuclear Regulatory Commission a procedure for the evaluation of Material Control and Accounting (MC and A) Systems at Nuclear Fuel Facilities. This procedure, called the Structured Assessment Approach, SAA, subjects the MC and A system at a facility to a series of increasingly sophisticated adversaries and strategies. A fully integrated version of the computer codes which assist the analyst in this assessment was made available in October, 1979. The concepts of the SAA and the results of the assessment of a hypothetical but typical facility are presented

Correlation of radiological assessment of congestive heart failure with left ventricular end-diastolic pressure

International Nuclear Information System (INIS)

Herman, P.G.; Kahn, A.; Kallman, C.E.; Rojas, K.A.; Bodenheimer, M.M.

1988-01-01

Left ventricular end-diastolic pressure (LVEDP) has been considered a reliable indicator of left ventricular function. The purpose of this study was to correlate the radiologic assessment of congestive heart failure with LVEDP. The population of the study consisted of 85 consecutive cases in four ranges of LVEDP ( 24). The PA chest radiographs obtained 1 day prior to cardiac catherization were assessed for radiological evidence of congestive heart failure and were graded from normal to abnormal (0-3). The results will be summarized in the authors' presentation. The discordance of radiological assessment of congestive heart failure in patients with elevated LVEDP will be discussed in light of recent advances in pathophysiologic understanding of left ventricular function and the impact of new classes of drugs in the management of these patients

Assessment of congestive heart failure in chest radiographs

International Nuclear Information System (INIS)

Henriksson, L.; Sundin, A.; Smedby, Oe.; Albrektsson, P.

1990-01-01

The effect of observer variations and film-screen quality on the diagnosis of congestive heart failure based on chest radiographs was studied in 27 patients. For each patient, two films were exposed, one with the Kodak Lanex Medium system and one with the Agfa MR 400 system. The films were presented to three observers who assessed the presence of congestive heart failure on a three-graded scale. The results showed no significant difference between the two systems but large systematic differences between the observers. There were also differences between the two ratings by the same observer that could not be explained by the film-screen factor. It is concluded that the choice between these two systems is of little importance in view of the interobserver and intraobserver variability that can exist within the same department. (orig.)

Reasons for failure to identify positive sentinel nodes in breast cancer patients with significant nodal involvement

NARCIS (Netherlands)

de Kanter, A. Y.; Menke-Pluijmers, M. B. E.; Henzen-Logmans, S. C.; van Geel, A. N.; van Eijck, C. J. H.; Wiggers, T.; Eggermont, A. M. M.

Aim: To analyse causes of failure of sentinel node (SN) procedures in breast cancer patients and assess the role of pre-operative ultrasound examination of the axilla. Methods: In 138 consecutive clinically node negative breast cancer patients with the primary turnout in situ a SN procedure with

Validity, reliability and support for implementation of independence-scaled procedural assessment in laparoscopic surgery.

Science.gov (United States)

Kramp, Kelvin H; van Det, Marc J; Veeger, Nic J G M; Pierie, Jean-Pierre E N

2016-06-01

There is no widely used method to evaluate procedure-specific laparoscopic skills. The first aim of this study was to develop a procedure-based assessment method. The second aim was to compare its validity, reliability and feasibility with currently available global rating scales (GRSs). An independence-scaled procedural assessment was created by linking the procedural key steps of the laparoscopic cholecystectomy to an independence scale. Subtitled and blinded videos of a novice, an intermediate and an almost competent trainee, were evaluated with GRSs (OSATS and GOALS) and the independence-scaled procedural assessment by seven surgeons, three senior trainees and six scrub nurses. Participants received a short introduction to the GRSs and independence-scaled procedural assessment before assessment. The validity was estimated with the Friedman and Wilcoxon test and the reliability with the intra-class correlation coefficient (ICC). A questionnaire was used to evaluate user opinion. Independence-scaled procedural assessment and GRS scores improved significantly with surgical experience (OSATS p = 0.001, GOALS p < 0.001, independence-scaled procedural assessment p < 0.001). The ICCs of the OSATS, GOALS and independence-scaled procedural assessment were 0.78, 0.74 and 0.84, respectively, among surgeons. The ICCs increased when the ratings of scrub nurses were added to those of the surgeons. The independence-scaled procedural assessment was not considered more of an administrative burden than the GRSs (p = 0.692). A procedural assessment created by combining procedural key steps to an independence scale is a valid, reliable and acceptable assessment instrument in surgery. In contrast to the GRSs, the reliability of the independence-scaled procedural assessment exceeded the threshold of 0.8, indicating that it can also be used for summative assessment. It furthermore seems that scrub nurses can assess the operative competence of surgical trainees.

Application of failure assessment diagram methods to cracked straight pipes and elbows

International Nuclear Information System (INIS)

Ainsworth, R.A.; Gintalas, M.; Sahu, M.K.; Chattopadhyay, J.; Dutta, B.K.

2016-01-01

This paper reports fracture assessments of large-scale straight pipes and elbows of various pipe diameters and crack sizes. The assessments estimate the load for ductile fracture initiation using the failure assessment diagram method. Recent solutions in the literature for stress intensity factor and limit load provide the analysis inputs. An assessment of constraint effects is also performed using recent solutions for elastic T-stress. It is found that predictions of initiation load are close to the experimental values for straight pipes under pure bending. For elbows, there is generally increased conservatism in the sense that the experimental loads are greater than those predicted. The effects of constraint are found not to be a major contributor to the initiation fracture assessments but may have some influence on the ductile crack extension. - Highlights: • This paper presents assessments of the loads for ductile fracture initiation in 21 large-scale piping tests. • Modern stress intensity factor and limit load solutions were used for standard failure assessment diagram methods. • This leads to generally accurate assessments of the loads for ductile crack initiation. • The effects of constraint are found not to be a major contributor to the initiation fracture assessments.

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

International Nuclear Information System (INIS)

Louit, D.M.; Pascual, R.; Jardine, A.K.S.

2009-01-01

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

Development of assessment procedures at the CEGB's nuclear power training centre

International Nuclear Information System (INIS)

Chapman, C.R.; Harris, N.D.C.

1986-01-01

The work of a power station engineer can be considered under four aspects: technology, diagnosis action and communication. The development, validation and use of assessment procedures can successfully incorporate the same aspects. The purposes of assessment are reporting training achievement and giving feedback to course members and tutorial staff. The development of standardized procedures to produce, evaluate and mark assessments and to optimize feedback ensures objectivity and uniformity. This has been achieved at the Central Electricity Generating Board's Nuclear Power Training Centre by enlisting an educational consultant to provide guidance and assist in training the resident tutors in assessment procedures. (author)

Crowd-sourced assessment of surgical skills in cricothyrotomy procedure.

Science.gov (United States)

Aghdasi, Nava; Bly, Randall; White, Lee W; Hannaford, Blake; Moe, Kris; Lendvay, Thomas S

2015-06-15

Objective assessment of surgical skills is resource intensive and requires valuable time of expert surgeons. The goal of this study was to assess the ability of a large group of laypersons using a crowd-sourcing tool to grade a surgical procedure (cricothyrotomy) performed on a simulator. The grading included an assessment of the entire procedure by completing an objective assessment of technical skills survey. Two groups of graders were recruited as follows: (1) Amazon Mechanical Turk users and (2) three expert surgeons from University of Washington Department of Otolaryngology. Graders were presented with a video of participants performing the procedure on the simulator and were asked to grade the video using the objective assessment of technical skills questions. Mechanical Turk users were paid $0.50 for each completed survey. It took 10 h to obtain all responses from 30 Mechanical Turk users for 26 training participants (26 videos/tasks), whereas it took 60 d for three expert surgeons to complete the same 26 tasks. The assessment of surgical performance by a group (n = 30) of laypersons matched the assessment by a group (n = 3) of expert surgeons with a good level of agreement determined by Cronbach alpha coefficient = 0.83. We found crowd sourcing was an efficient, accurate, and inexpensive method for skills assessment with a good level of agreement to experts' grading. Copyright © 2015 Elsevier Inc. All rights reserved.

Assessing changes in failure probability of dams in a changing climate

Science.gov (United States)

Mallakpour, I.; AghaKouchak, A.; Moftakhari, H.; Ragno, E.

2017-12-01

Dams are crucial infrastructures and provide resilience against hydrometeorological extremes (e.g., droughts and floods). In 2017, California experienced series of flooding events terminating a 5-year drought, and leading to incidents such as structural failure of Oroville Dam's spillway. Because of large socioeconomic repercussions of such incidents, it is of paramount importance to evaluate dam failure risks associated with projected shifts in the streamflow regime. This becomes even more important as the current procedures for design of hydraulic structures (e.g., dams, bridges, spillways) are based on the so-called stationary assumption. Yet, changes in climate are anticipated to result in changes in statistics of river flow (e.g., more extreme floods) and possibly increasing the failure probability of already aging dams. Here, we examine changes in discharge under two representative concentration pathways (RCPs): RCP4.5 and RCP8.5. In this study, we used routed daily streamflow data from ten global climate models (GCMs) in order to investigate possible climate-induced changes in streamflow in northern California. Our results show that while the average flow does not show a significant change, extreme floods are projected to increase in the future. Using the extreme value theory, we estimate changes in the return periods of 50-year and 100-year floods in the current and future climates. Finally, we use the historical and future return periods to quantify changes in failure probability of dams in a warming climate.

Anterior cruciate ligament reconstruction failure after tibial shaft malunion.

Science.gov (United States)

LaFrance, Russell M; Gorczyca, John T; Maloney, Michael D

2012-02-17

Anterior cruciate ligament (ACL) reconstruction is common, with >100,000 procedures performed each year in the United States. Several factors are associated with failure, including poor surgical technique, graft incorporation failure, overly aggressive rehabilitation, and trauma. Tibial shaft fracture is also common and frequently requires operative intervention. Failure to reestablish the anatomic alignment of the tibia may cause abnormal forces across adjacent joints, which can cause degenerative joint disease or attritional failure of the surrounding soft tissues. This article describes a case of ACL reconstruction failure after a tibial fracture that resulted in malunion. Excessive force across the graft from lower-extremity malalignment and improper tunnel placement likely contributed to the attritional failure of the graft. This patient required a staged procedure for corrective tibial osteotomy followed by revision ACL reconstruction. This article describes ACL reconstruction failure, tibial shaft malunions, their respective treatments, the technical details of each procedure, and the technical aspects that must be considered when these procedures are done in a staged manner by 2 surgeons. Copyright 2012, SLACK Incorporated.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-10-15

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

Optimization of rock-bit life based on bearing failure criteria

International Nuclear Information System (INIS)

Feav, M.J.; Thorogood, J.L.; Whelehan, O.P.; Williamson, H.S.

1992-01-01

This paper reports that recent advances in rock-bit seal technology have allowed greater predictability of bearing life. Cone loss following bearing failure incurs costs related to remedial activities. A risk analysis approach, incorporating bearing-life relationships and the inter-dependence of drilling events, is used to formulate a bit-run cost-optimization method. The procedure enables a choice to be made between elastomeric and metal seals on a lowest-replacement-cost basis. The technique also provides a formal method for assessing the opportunity cost for using a device to detect bit-bearing failures downhole

Failure Assessment for the High-Strength Pipelines with Constant-Depth Circumferential Surface Cracks

Directory of Open Access Journals (Sweden)

X. Liu

2018-01-01

Full Text Available In the oil and gas transportation system over long distance, application of high-strength pipeline steels can efficiently reduce construction and operation cost by increasing operational pressure and reducing the pipe wall thickness. Failure assessment is an important issue in the design, construction, and maintenance of the pipelines. The small circumferential surface cracks with constant depth in the welded pipelines are of practical interest. This work provides an engineering estimation procedure based upon the GE/EPRI method to determine the J-integral for the thin-walled pipelines with small constant-depth circumferential surface cracks subject to tension and bending loads. The values of elastic influence functions for stress intensity factor and plastic influence functions for fully plastic J-integral estimation are derived in tabulated forms through a series of three-dimensional finite element calculations for different crack geometries and material properties. To check confidence of the J-estimation solution in practical application, J-integral values obtained from detailed finite element (FE analyses are compared with those estimated from the new influence functions. Excellent agreement of FE results with the proposed J-estimation solutions for both tension and bending loads indicates that the new solutions can be applied for accurate structural integrity assessment of high-strength pipelines with constant-depth circumferential surface cracks.

Assessment of the MPACT Resonance Data Generation Procedure

Energy Technology Data Exchange (ETDEWEB)

Kim, Kang Seog [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Mark L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-12-26

Currently, heterogeneous models are being used to generate resonance self-shielded cross-section tables as a function of background cross sections for important nuclides such as ²³⁵U and ²³⁸U by performing the CENTRM (Continuous Energy Transport Model) slowing down calculation with the MOC (Method of Characteristics) spatial discretization and ESSM (Embedded Self-Shielding Method) calculations to obtain background cross sections. And then the resonance self-shielded cross section tables are converted into subgroup data which are to be used in estimating problem-dependent self-shielded cross sections in MPACT (Michigan Parallel Characteristics Transport Code). Although this procedure has been developed and thus resonance data have been generated and validated by benchmark calculations, assessment has never been performed to review if the resonance data are properly generated by the procedure and utilized in MPACT. This study focuses on assessing the procedure and a proper use in MPACT.

Procedures for health risk assessment in Europe

NARCIS (Netherlands)

Seeley, M.R.; Tonner-Navarro, L.E.; Beck, B.D.; Deskin, R.; Feron, V.J.; Johanson, G.; Bolt, H.M.

2001-01-01

This report compares cancer classification systems, health risk assessment approaches, and procedures used for establishing occupational exposure limits (OELs), in various European countries and scientific organizations. The objectives were to highlight and compare key aspects of these processes and

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.

Using the Entrustable Professional Activities Framework in the Assessment of Procedural Skills.

Science.gov (United States)

Pugh, Debra; Cavalcanti, Rodrigo B; Halman, Samantha; Ma, Irene W Y; Mylopoulos, Maria; Shanks, David; Stroud, Lynfa

2017-04-01

The entrustable professional activity (EPA) framework has been identified as a useful approach to assessment in competency-based education. To apply an EPA framework for assessment, essential skills necessary for entrustment to occur must first be identified. Using an EPA framework, our study sought to (1) define the essential skills required for entrustment for 7 bedside procedures expected of graduates of Canadian internal medicine (IM) residency programs, and (2) develop rubrics for the assessment of these procedural skills. An initial list of essential skills was defined for each procedural EPA by focus groups of experts at 4 academic centers using the nominal group technique. These lists were subsequently vetted by representatives from all Canadian IM training programs through a web-based survey. Consensus (more than 80% agreement) about inclusion of each item was sought using a modified Delphi exercise. Qualitative survey data were analyzed using a framework approach to inform final assessment rubrics for each procedure. Initial lists of essential skills for procedural EPAs ranged from 10 to 24 items. A total of 111 experts completed the national survey. After 2 iterations, consensus was reached on all items. Following qualitative analysis, final rubrics were created, which included 6 to 10 items per procedure. These EPA-based assessment rubrics represent a national consensus by Canadian IM clinician educators. They provide a practical guide for the assessment of procedural skills in a competency-based education model, and a robust foundation for future research on their implementation and evaluation.

Seismically induced common cause failures in PSA of nuclear power plants

International Nuclear Information System (INIS)

Ravindra, M.K.; Johnson, J.J.

1991-01-01

In this paper, a research project on the seismically induced common cause failures in nuclear power plants performed for Toshiba Corp. is described. The objective of this research was to develop the procedure for estimating the common cause failure probabilities of different nuclear power plant components using the combination of seismic experience data, the review of sources of dependency, sensitivity studies and engineering judgement. The research project consisted of three tasks: the investigation of damage instances in past earthquakes, the analysis of multiple failures and their root causes, and the development of the methodology for assessing seismically induced common cause failures. The details of these tasks are explained. In this paper, the works carried out in the third task are described. A methodology for treating common cause failures and the correlation between component failures is formulated; it highlights the modeling of event trees taking into account common cause failures and the development of fault trees considering the correlation between component failures. The overview of seismic PSA, the quantification methods for dependent failures and Latin Hypercube sampling method are described. (K.I.)

A procedure for NEPA assessment of selenium hazards associated with mining.

Science.gov (United States)

Lemly, A Dennis

2007-02-01

This paper gives step-by-step instructions for assessing aquatic selenium hazards associated with mining. The procedure was developed to provide the U.S. Forest Service with a proactive capability for determining the risk of selenium pollution when it reviews mine permit applications in accordance with the National Environmental Policy Act (NEPA). The procedural framework is constructed in a decision-tree format in order to guide users through the various steps, provide a logical sequence for completing individual tasks, and identify key decision points. There are five major components designed to gather information on operational parameters of the proposed mine as well as key aspects of the physical, chemical, and biological environment surrounding it--geological assessment, mine operation assessment, hydrological assessment, biological assessment, and hazard assessment. Validation tests conducted at three mines where selenium pollution has occurred confirmed that the procedure will accurately predict ecological risks. In each case, it correctly identified and quantified selenium hazard, and indicated the steps needed to reduce this hazard to an acceptable level. By utilizing the procedure, NEPA workers can be confident in their ability to understand the risk of aquatic selenium pollution and take appropriate action. Although the procedure was developed for the Forest Service it should also be useful to other federal land management agencies that conduct NEPA assessments, as well as regulatory agencies responsible for issuing coal mining permits under the authority of the Surface Mining Control and Reclamation Act (SMCRA) and associated Section 401 water quality certification under the Clean Water Act. Mining companies will also benefit from the application of this procedure because priority selenium sources can be identified in relation to specific mine operating parameters. The procedure will reveal the point(s) at which there is a need to modify operating

Impact assessment procedures for sustainable development: A complexity theory perspective

International Nuclear Information System (INIS)

Nooteboom, Sibout

2007-01-01

The author assumes that effective Impact Assessment procedures should somehow contribute to sustainable development. There is no widely agreed framework for evaluating such effectiveness. The author suggests that complexity theories may offer criteria. The relevant question is 'do Impact Assessment Procedures contribute to the 'requisite variety' of a social system for it to deal with changing circumstances?' Requisite variety theoretically relates to the capability of a system to deal with changes in its environment. The author reconstructs how thinking about achieving sustainable development has developed in a sequence of discourses in The Netherlands since the 1970s. Each new discourse built on the previous ones, and is supposed to have added to 'requisite variety'. The author asserts that Impact Assessment procedures may be a necessary component in such sequences and derives possible criteria for effectiveness

Determining procedures for simulation-based training in radiology: a nationwide needs assessment.

Science.gov (United States)

Nayahangan, Leizl Joy; Nielsen, Kristina Rue; Albrecht-Beste, Elisabeth; Bachmann Nielsen, Michael; Paltved, Charlotte; Lindorff-Larsen, Karen Gilboe; Nielsen, Bjørn Ulrik; Konge, Lars

2018-01-09

New training modalities such as simulation are widely accepted in radiology; however, development of effective simulation-based training programs is challenging. They are often unstructured and based on convenience or coincidence. The study objective was to perform a nationwide needs assessment to identify and prioritize technical procedures that should be included in a simulation-based curriculum. A needs assessment using the Delphi method was completed among 91 key leaders in radiology. Round 1 identified technical procedures that radiologists should learn. Round 2 explored frequency of procedure, number of radiologists performing the procedure, risk and/or discomfort for patients, and feasibility for simulation. Round 3 was elimination and prioritization of procedures. Response rates were 67 %, 70 % and 66 %, respectively. In Round 1, 22 technical procedures were included. Round 2 resulted in pre-prioritization of procedures. In round 3, 13 procedures were included in the final prioritized list. The three highly prioritized procedures were ultrasound-guided (US) histological biopsy and fine-needle aspiration, US-guided needle puncture and catheter drainage, and basic abdominal ultrasound. A needs assessment identified and prioritized 13 technical procedures to include in a simulation-based curriculum. The list may be used as guide for development of training programs. • Simulation-based training can supplement training on patients in radiology. • Development of simulation-based training should follow a structured approach. • The CAMES Needs Assessment Formula explores needs for simulation training. • A national Delphi study identified and prioritized procedures suitable for simulation training. • The prioritized list serves as guide for development of courses in radiology.

DMM assessments of attachment and adaptation: Procedures, validity and utility.

Science.gov (United States)

Farnfield, Steve; Hautamäki, Airi; Nørbech, Peder; Sahhar, Nicola

2010-07-01

This article gives a brief over view of the Dynamic-Maturational Model of attachment and adaptation (DMM; Crittenden, 2008) together with the various DMM assessments of attachment that have been developed for specific stages of development. Each assessment is discussed in terms of procedure, outcomes, validity, advantages and limitations, comparable procedures and areas for further research and validation. The aims are twofold: to provide an introduction to DMM theory and its application that underlie the articles in this issue of CCPP; and to provide researchers and clinicians with a guide to DMM assessments.

Procedure for the assessment of material control and accounting systems

International Nuclear Information System (INIS)

Parziale, A.A.; Sacks, I.J.

1979-01-01

For the United States Nuclear Regulatory Commission, a procedure was developed and tested for the evaluation of Material Control and Accounting (MC and A) Systems at nuclear fuel facilities. This procedure, called the Structured Assessment Approach, SAA, subjects the MC and A system at a facility to a series of increasingly sophisticated adversaries and strategies. A fully integrated version of the computer codes which assist the analyst in this assessment will become available in October 1979. The concepts of the SAA and the results of the assessment of a hypothetical but typical facility are presented

Assessment of radiological properties of wastes from urban decontamination procedures

International Nuclear Information System (INIS)

Da Silva, D.N.G.; Guimarães, J.R.D.; Rochedo, E.R.R.; Rochedo, P.R.R.; De Luca, C.

2015-01-01

One important activity associated to urban areas contaminated from accidental releases to the atmosphere of nuclear power plants is the management of radioactive wastes generated from decontamination procedures. This include the collection, conditioning, packing, transport and temporary/final disposition. The final destination is defined usually through a political decision. Thus, transport of packed radioactive wastes shall depend on decisions not just under the scope of radiological protection issues. However, the simulations performed to assess doses for the public and decontamination workers allows the estimate of radiological aspects related to the waste generated and these characteristics may be included in a multi-criteria decision tool aiming to support, under the radiological protection point of view, the decision-making process on post-emergency procedures. Important information to decision makers are the type, amount and activity concentration of wastes. This work describes the procedures to be included in the urban area model to account for the assessment of qualitative and quantitative description of wastes. The results will allow the classification of different procedures according to predefined criteria that shall then feed the multi-criteria assessment tool, currently under development, considering basic radiological protection aspects of wastes generated by the different available cleanup procedures on typical tropical urban environments. (authors)

Physics of Failure as a Basis for Solder Elements Reliability Assessment in Wind Turbines

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2012-01-01

description of the reliability. A physics of failure approach is applied. A SnAg solder component used in power electronics is used as an example. Crack propagation in the SnAg solder is modeled and a model to assess the accumulated plastic strain is proposed based on a physics of failure approach. Based...... on the proposed model it is described how to find the accumulated linear damage and reliability levels for a given temperature loading profile. Using structural reliability methods the reliability levels of the electrical components are assessed by introducing scale factors for stresses....

Bayesian analysis of repairable systems showing a bounded failure intensity

International Nuclear Information System (INIS)

Guida, Maurizio; Pulcini, Gianpaolo

2006-01-01

The failure pattern of repairable mechanical equipment subject to deterioration phenomena sometimes shows a finite bound for the increasing failure intensity. A non-homogeneous Poisson process with bounded increasing failure intensity is then illustrated and its characteristics are discussed. A Bayesian procedure, based on prior information on model-free quantities, is developed in order to allow technical information on the failure process to be incorporated into the inferential procedure and to improve the inference accuracy. Posterior estimation of the model-free quantities and of other quantities of interest (such as the optimal replacement interval) is provided, as well as prediction on the waiting time to the next failure and on the number of failures in a future time interval is given. Finally, numerical examples are given to illustrate the proposed inferential procedure

Contemporary statistical procedures (Parametric Empirical Bayes) and nuclear plant event rates

International Nuclear Information System (INIS)

Gaver, D.P.; Worledge, D.H.

1985-01-01

The conduct of a nuclear power plant probabilistic risk assessment (PRA) recognizes that each of a great many vital components and systems is subject to failure. One aspect of the PRA procedure is to quantify individual item failure propensity, often in terms of the failure rate parameter of an exponential distribution or Poisson process, and then to combine rates so as to effectively infer the probability of plant failure, e.g., core damage. The formal method of combination of such rates involves use of fault-tree analysis. The defensibility of the final fault-tree result depends both upon the adequacy of the failure representations of its components, and upon the correctness and inclusiveness of the fault tree logic. This paper focuses upon the first issue, in particular, upon contemporary proposals for deriving estimates of individual rates. The purpose of the paper is to present, in basically non-mathematical terms, the essential nature of some of these proposals, and an assessment of how they might fit into, and contribute positively to, a more defensible or trustworthy PRA process

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.

Total fertilization failure and idiopathic subfertility

Directory of Open Access Journals (Sweden)

Goverde Angelique J

2009-01-01

Full Text Available Abstract Background To gain more insight in whether failure of intrauterine insemination (IUI treatment in patients with idiopathic subfertility could be related to diminished fertilization, the aim of this study is to compare the fertilization of an initial IVF procedure after six cycles of IUI and the fertilization of an initial IVF procedure without preceding IUI cycles in couples with idiopathic subfertility. Methods We performed a complimentary analysis of a randomized controlled trial, in which the number of total fertilization failure (TFF in the first IVF procedure after unsuccessful IUI was compared to those of IVF without preceding IUI in patients with idiopathic subfertility. These patients participated in a previous study that assessed the cost effectiveness of IUI versus IVF in idiopathic subfertility and were randomized to either IUI or IVF treatment. Results 45 patients underwent IVF after 6 cycles of unsuccessful IUI and 58 patients underwent IVF immediately without preceding IUI. In 7 patients the IVF treatment was cancelled before ovum pick. In the IVF after unsuccessful IUI group TFF was seen in 2 of the 39 patients (5% versus 7 of the 56 patients (13% in the immediate IVF group. After correction for confounding factors the TFF rate was not significantly different between the two groups (p = 0.08, OR 7.4; 95% CI: 0.5–14.9. Conclusion Our data showed that TFF and the fertilization rate in the first IVF treatment were not significantly different between couples with idiopathic subfertility undergoing IVF after failure of IUI versus those couples undergoing IVF immediately without prior IUI treatment. Apparently, impaired fertilization does not play a significant role in the success rate of IUI in patients with idiopathic subfertility.

Pipework failures - a review of historical incidents

International Nuclear Information System (INIS)

Blything, K.W.; Parry, S.T.

1988-01-01

A description is presented of the gathering of historical pipework incident data and its analysis to determine the causes and underlying reasons for failure. The following terms of reference were agreed: (a) To review data on failures associated with pipework to establish the principal causes of failure. This should include not only rupture of the pipe itself, but also pipework induced failures, such as severe flange leaks and excessive strains resulting in failure of connected equipment. (b) To suggest an incident classification for pipework systems which will alert design, construction, maintenance, and operating personnel to the need for special care. (c) To advise non-piping specialists of the type of situation which could result in failure if not allowed for in the design, e.g. dynamic and transient conditions. (d) To recommend, possibly as the result of (a) above, areas where present procedures and codes of practice may require amplification. Brief descriptions are given of selected incidents where the consequences are considered to be serious in terms of damage and financial loss. For consequence analysis, the release rate is an important parameter and, where possible, the proportion of incidents in the failure mode categories, leaks, ''ruptures/severances'' are given. Although not one of the agreed objectives, the determination of failure rates was recognised as an important requirement in the risk assessment of pipework systems. The quality of data gathered however was found to be inadequate for any statistical analysis and no failure rate values are given in this report. (author)

A Procedure to Address the Fuel Rod Failures during LB-LOCA Transient in Atucha-2 NPP

Directory of Open Access Journals (Sweden)

Martina Adorni

2011-01-01

Full Text Available Depending on the specific event scenario and on the purpose of the analysis, the availability of calculation methods that are not implemented in the standard system thermal hydraulic codes might be required. This may imply the use of a dedicated fuel rod thermomechanical computer code. This paper provides an outline of the methodology for the analysis of the 2A LB-LOCA accident in Atucha-2 NPP and describes the procedure adopted for the use of the fuel rod thermomechanical code. The methodology implies the application of best estimate thermalhydraulics, neutron physics, and fuel pin performance computer codes, with the objective to verify the compliance with the specific acceptance criteria. The fuel pin performance code is applied with the main objective to evaluate the extent of cladding failures during the transient. The procedure consists of a deterministic calculation by the fuel performance code of each individual fuel rod during its lifetime and in the subsequent LB-LOCA transient calculations. The boundary and initial conditions are provided by core physics and three-dimensional neutron kinetic coupled thermal-hydraulic system codes calculations. The procedure is completed by the sensitivity calculations and the application of the probabilistic method, which are outside the scope of the current paper.

Development of KSC program for investigating and generating field failure rates. Reliability handbook for ground support equipment

Science.gov (United States)

Bloomquist, C. E.; Kallmeyer, R. H.

1972-01-01

Field failure rates and confidence factors are presented for 88 identifiable components of the ground support equipment at the John F. Kennedy Space Center. For most of these, supplementary information regarding failure mode and cause is tabulated. Complete reliability assessments are included for three systems, eight subsystems, and nine generic piece-part classifications. Procedures for updating or augmenting the reliability results are also included.

Construct validation of teacher portfolio assessment : Procedures for improving teacher competence assessment illustrated by teaching students research skills

NARCIS (Netherlands)

Schaaf, M.F. van der

2005-01-01

The study aims to design and test procedures for teacher portfolio assessments. What are suitable procedures to assess teachers' competencies in developing students' research skills? We first searched into the tasks teachers have in teaching students research skills and the competencies needed to

CT fluoroscopy-guided renal tumour cutting needle biopsy. Retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure

International Nuclear Information System (INIS)

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

2018-01-01

To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. (orig.)

CT fluoroscopy-guided renal tumour cutting needle biopsy. Retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure

Energy Technology Data Exchange (ETDEWEB)

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu [Okayama University Medical School, Department of Radiology, Okayama (Japan)

2018-01-15

To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. (orig.)

Nonorganic Failure to Thrive: Developmental Outcomes and Psychosocial Assessment and Intervention Issues.

Science.gov (United States)

Heffer, Robert W.; Kelley, Mary L.

1994-01-01

This review describes Nonorganic Failure to Thrive, presents developmental outcomes, and discusses psychosocial assessment and intervention issues relevant to this developmental disability of early childhood, focusing on child-specific variables, situational and family variables, parent-child interaction variables, and biopsychosocial formulation…

Quantitative relationships between aging failure data and risk

International Nuclear Information System (INIS)

Vesely, W.E.; Vora, J.P.

1988-01-01

As part of the United States Nuclear Regulatory Commission's Nuclear Plant Aging Research program, a project is being carried out to quantify the risk effects of aging. The project is called the Risk Evaluation of Aging Phenomena (REAP) Project. With the REAP Project, a procedure has been developed to quantify nuclear power plant risks from aging failure data. The procedure utilizes the linear aging model and its extensions in order to relate component aging failure rates to aging mechanism parameters which are estimable from failure and maintenance data. The aging failure rates can then be used to quantify the age dependent plant risks, such as system unavailabilities, core melt frequency and public health risks. The REAP procedure is different from standard time dependent approaches in that the failure rates are phenomenologically based, allowing engineering information to be utilized. Furthermore, gross data and incomplete data can be utilized. A software package has been developed which systematically analyzes data for aging effects and interfaces with a time dependent risk analysis module to determine the risk implications of the aging effects. (author). 10 refs, 10 figs

Measuring variability of procedure progression in proceduralized scenarios

International Nuclear Information System (INIS)

Kim, Yochan; Park, Jinkyun; Jung, Wondea

2012-01-01

Highlights: ► The VPP measure was developed to quantify how differently operators follow the procedures. ► Sources that cause variability of ways to follow a given procedure were identified. ► The VPP values for the scenarios are positively related to the scenario performance time. ► The VPP measure is meaningful for explaining characteristics of several PSFs. -- Abstract: Various performance shaping factors (PSFs) have been presented to explain the contributors to unsafe acts in a human failure event or predict a human error probability of new human performance. However, because most of these parameters of an HRA depend on the subjective knowledge and experience of HRA analyzers, the results of an HRA insufficiently provide unbiased standards to explain human performance variations or compare collected data with other data from different analyzers. To secure the validity of the HRA results, we propose a quantitative measure, which represents the variability of procedure progression (VPP) in proceduralized scenarios. A VPP measure shows how differently the operators follow the steps of the procedures. This paper introduces the sources of the VPP measure and relevance to PSFs. The assessment method of the VPP measure is also proposed, and the application examples are shown with a comparison of the performance time. Although more empirical studies should be conducted to reveal the relationship between the VPP measure and other PSFs, it is believed that the VPP measure provides evidence to quantitatively evaluate human performance variations and to cross-culturally compare the collected data.

Contextualized personality: traditional and new assessment procedures.

Science.gov (United States)

Heller, Daniel; Watson, David; Komar, Jennifer; Min, Ji-A; Perunovic, Wei Qi Elaine

2007-12-01

We describe our ongoing program of research related to the assessment of contextualized personality, focusing on social roles and cultural cues as contextual factors. First, we present our research employing the traditional assessment approach, wherein participants are asked to rate explicitly their personality across several different roles. We argue that this hypothetical approach is potentially susceptible to the influence of stereotypes, social desirability, and demand characteristics. We therefore describe the development of three novel and subtle assessment procedures that are based on obtaining online self-representations that are activated while occupying a specific context. Finally, the strengths and limitations of all four approaches, as well as directions for future research in the study of contextualized personality, are discussed.

Visual assessment of brain magnetic resonance imaging detects injury to cognitive regulatory sites in patients with heart failure.

Science.gov (United States)

Pan, Alan; Kumar, Rajesh; Macey, Paul M; Fonarow, Gregg C; Harper, Ronald M; Woo, Mary A

2013-02-01

Heart failure (HF) patients exhibit depression and executive function impairments that contribute to HF mortality. Using specialized magnetic resonance imaging (MRI) analysis procedures, brain changes appear in areas regulating these functions (mammillary bodies, hippocampi, and frontal cortex). However, specialized MRI procedures are not part of standard clinical assessment for HF (which is usually a visual evaluation), and it is unclear whether visual MRI examination can detect changes in these structures. Using brain MRI, we visually examined the mammillary bodies and frontal cortex for global and hippocampi for global and regional tissue changes in 17 HF and 50 control subjects. Significantly global changes emerged in the right mammillary body (HF 1.18 ± 1.13 vs control 0.52 ± 0.74; P = .024), right hippocampus (HF 1.53 ± 0.94 vs control 0.80 ± 0.86; P = .005), and left frontal cortex (HF 1.76 ± 1.03 vs control 1.24 ± 0.77; P = .034). Comparison of the visual method with specialized MRI techniques corroborates right hippocampal and left frontal cortical, but not mammillary body, tissue changes. Visual examination of brain MRI can detect damage in HF in areas regulating depression and executive function, including the right hippocampus and left frontal cortex. Visual MRI assessment in HF may facilitate evaluation of injury to these structures and the assessment of the impact of potential treatments for this damage. Copyright © 2013 Elsevier Inc. All rights reserved.

The results of questionnaire on quantitative assessment of 123I-metaiodobenzylguanidine myocardial scintigraphy in heart failure

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Sugishita, Yasurou; Sasaki, Yasuhito.

1997-01-01

This study was done by working group under the cooperation between Japanese Society of Nuclear Medicine and Japanese Circulation Society. We evaluated the usefulness of quantitative assessment of 123 I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in heart failure by the results of questionnaire. Forty-nine (72.1%) of 68 selected institutions participated in this study. The incidence of MIBG myocardial scintigraphy used in heart failure was 41.1%. The imaging protocol was mostly done by both planar and SPECT at 15 min and 3.6 hr after intravenous injection of 111 MBq of MIBG. The quantitative assessment was mostly done by heart/mediastinum (H/M) ratio and washout rate analysis based on planar imaging. The mean normal value of H/M ratio were 2.34±0.36, and 2.49±0.40, at early and delayed images, respectively. The normal value of washout rate was 27.74±5.34%. On the other hand, those of H/M ratio in heart failure were 1.87±0.27, and 1.75±0.24, at early and delayed images, respectively. That of washout rate was 42.30±6.75%. These parameters were very useful for the evaluation of heart failure. In conclusion, MIBG myocardial scintigraphy was widely used for not only early detection and severity assessment, but also indication for therapy and prognosis evaluation in heart failure patients. (author)

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.)

On the major ductile fracture methodologies for failure assessment of nuclear reactor components

International Nuclear Information System (INIS)

Cruz, Julio R.B.; Andrade, Arnaldo H.P. de; Landes, John D.

1996-01-01

In structures like nuclear reactor components there is a special concern with the loads that may occur under postulated accident conditions. These loads can cause the stresses to go well beyond the linear elastic limits, requiring the use of ductile fracture mechanics methods to the prediction of the structure behavior. Since the use of numerical methods to apply EPFM concepts is expensive and time consuming, the existence of analytical engineering procedures are of great relevance. The lack of precision in detail, as compared with numerical nonlinear analyses, is compensated by the possibility of quick failure assessments. This is a determinant factor in situations where a systematic evaluation of a large range of geometries and loading conditions is necessary, like in thr application of the Leak-Before-Break (LBB) concept on nuclear piping. This paper outlines four ductile fracture analytical methods, pointing out positive and negative aspects of each one. The objective is to take advantage of this critical review to conceive a new methodology, one that would gather strong points of the major existent methods and would try to eliminate some of their drawbacks. (author)

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.

A study of graphite-epoxy laminate failures due to high transverse shear strains using the multi-span-beam shear test procedure

Science.gov (United States)

Jegley, Dawn C.

1989-01-01

The multi-span-beam shear test procedure is used to study failure mechanisms in graphite-epoxy laminates due to high transverse shear strains induced by severe local bending deformations in test specimens. Results of a series of tests on specimens with a variety of stacking sequences, including some with adhesive interleaving, are presented. These results indicate that laminates with stacking sequences with several + or - 45 and 90 deg plies next to each other are more susceptible to failures due to high transverse shear strains than laminates with + or - 45 and 0 deg plies next to each other or with + or - 45 deg plies next to layers of adhesive interleaving. Results of these tests are compared with analytical results based on finite elements.

[Implantable sensors for outpatient assessment of ventricular filling pressure in advanced heart failure : Which telemonitoring design is optimal?

Science.gov (United States)

Herrmann, E; Fichtlscherer, S; Hohnloser, S H; Zeiher, A M; Aßmus, B

2016-12-01

Patients with advanced heart failure suffer from frequent hospitalizations. Non-invasive hemodynamic telemonitoring for assessment of ventricular filling pressure has been shown to reduce hospitalizations. We report on the right ventricular (RVP), the pulmonary artery (PAP) and the left atrial pressure (LAP) sensor for non-invasive assessment of the ventricular filling pressure. A literature search concerning the available implantable pressure sensors for noninvasive haemodynamic telemonitoring in patients with advanced heart failure was performed. Until now, only implantation of the PAP-sensor was able to reduce hospitalizations for cardiac decompensation and to improve quality of life. The right ventricular pressure sensor missed the primary endpoint of a significant reduction of hospitalizations, clinical data using the left atrial pressure sensor are still pending. The implantation of a pressure sensor for assessment of pulmonary artery filling pressure is suitable for reducing hospitalizations for heart failure and for improving quality of life in patients with advanced heart failure.

[Assessment of medical management of heart failure at National Hospital Blaise COMPAORE].

Science.gov (United States)

Kambiré, Y; Konaté, L; Diallo, I; Millogo, G R C; Kologo, K J; Tougouma, J B; Samadoulougou, A K; Zabsonré, P

2018-05-09

The aim of this study was to assess the quality of medical management of heart failure at the National Hospital Blaise Compaoré according to the international guidelines. A retrospective study was performed including consecutive patients admitted for heart failure documented sonographically from October 2012 to March 2015 in the Medicine and Medical Specialties Department of National Hospital Blaise Compaore with a minimum follow-up of six weeks. Data analysis was made by the SPSS 20.0 software. Eighty-four patients, mean age of 57.61±18.24 years, were included. It was an acute heart failure in 84.5% of patients with systolic left ventricular function impaired (77.4%). The rate of prescription of different drugs in heart failure any type was 88.1% for loop diuretics; 77.1% for angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and 65.5% for betablockers. In patients with systolic dysfunction, 84.62% of patients were received the combination of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and 75.38% for betablockers. Exercise rehabilitation was undergoing in 10.7% of patients. The death rate was 16.7% and hospital readmission rate of 16.7%. The prescription rate of major heart failure drugs is satisfactory. Cardiac rehabilitation should be developed. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Development of a tool to support holistic generic assessment of clinical procedure skills.

Science.gov (United States)

McKinley, Robert K; Strand, Janice; Gray, Tracey; Schuwirth, Lambert; Alun-Jones, Tom; Miller, Helen

2008-06-01

The challenges of maintaining comprehensive banks of valid checklists make context-specific checklists for assessment of clinical procedural skills problematic. This paper reports the development of a tool which supports generic holistic assessment of clinical procedural skills. We carried out a literature review, focus groups and non-participant observation of assessments with interview of participants, participant evaluation of a pilot objective structured clinical examination (OSCE), a national modified Delphi study with prior definitions of consensus and an OSCE. Participants were volunteers from a large acute teaching trust, a teaching primary care trust and a national sample of National Health Service staff. Results In total, 86 students, trainees and staff took part in the focus groups, observation of assessments and pilot OSCE, 252 in the Delphi study and 46 candidates and 50 assessors in the final OSCE. We developed a prototype tool with 5 broad categories amongst which were distributed 38 component competencies. There was > 70% agreement (our prior definition of consensus) at the first round of the Delphi study for inclusion of all categories and themes and no consensus for inclusion of additional categories or themes. Generalisability was 0.76. An OSCE based on the instrument has a predicted reliability of 0.79 with 12 stations and 1 assessor per station or 10 stations and 2 assessors per station. This clinical procedural skills assessment tool enables reliable assessment and has content and face validity for the assessment of clinical procedural skills. We have designated it the Leicester Clinical Procedure Assessment Tool (LCAT).

Sequential decision reliability concept and failure rate assessment

International Nuclear Information System (INIS)

Ciftcioglu, O.

1990-11-01

Conventionally, a reliability concept is considered together with both each basic unit and their integration in a complicated large scale system such as a nuclear power plant (NPP). Basically, as the plant's operational status is determined by the information obtained from various sensors, the plant's reliability and the risk assessment is closely related to the reliability of the sensory information and hence the sensor components. However, considering the relevant information-processing systems, e.g. fault detection processors, there exists a further question about the reliability of such systems, specifically the reliability of the systems' decision-based outcomes by means of which the further actions are performed. To this end, a general sequential decision reliability concept and the failure rate assessment methodology is introduced. The implications of the methodology are investigated and the importance of the decision reliability concept in system operation is demonstrated by means of sensory signals in real-time from the Borssele NPP in the Netherlands. (author). 21 refs.; 8 figs

Pediatric cardiac catheterization procedure with dexmedetomidine sedation: Radiographic airway patency assessment

Directory of Open Access Journals (Sweden)

Ashwini Thimmarayappa

2015-01-01

Full Text Available Aims: The aim of the study was to measure airway patency objectively during dexmedetomidine sedation under radiographic guidance in spontaneously breathing pediatric patients scheduled for cardiac catheterization procedures. Subjects and Methods: Thirty-five patients in the age group 5-10 years scheduled for cardiac catheterization procedures were enrolled. All study patients were given loading dose of dexmedetomidine at 1 mg/kg/min for 10 min and then maintenance dose of 1.5 mg/kg/h. Radiographic airway patency was assessed at the start of infusion (0 min and after 30 min. Antero-posterior (AP diameters were measured manually at the nasopharyngeal and retroglossal levels. Dynamic change in airway between inspiration and expiration was considered a measure of airway collapsibility. Patients were monitored for hemodynamics, recovery time and complications. Statistical Analysis: Student paired t-test was used for data analysis. P < 0.05 was considered significant. Results: Minimum and maximum AP diameters were compared at 0 and 30 min. Nasopharyngeal level showed significant reduction in the minimum (6.27 ± 1.09 vs. 4.26 ± 1.03, P < 0.0001 and maximum (6.51 ± 1.14 vs. 5.99 ± 1.03, P < 0.0001 diameters. Similarly retroglossal level showed significant reduction in the minimum (6.98 ± 1.09 vs. 5.27 ± 1.15, P < 0.0001 and maximum (7.49 ± 1.22 vs. 6.92 ± 1.12, P < 0.0003 diameters. The degree of collapsibility was greater at 30 min than baseline ( P < 0.0001. There was a significant decrease in heart rate ( P < 0.0001, and the average recovery time was 39.86 ± 12.22 min. Conclusion: Even though airway patency was maintained in all children sedated with dexmedetomidine, there were significant reductions in the upper airway dimensions measured, so all precautions to manage the airway failure should be taken.

Youth Reactions to Participation in Psychological Assessment Procedures

Science.gov (United States)

Saldana, Lisa; DuBois, David L.

2006-01-01

This study investigates self-reported positive and negative reactions of youth to psychological assessment procedures. A community sample (COM) reported reactions to completing a self-report questionnaire of negative emotional states. A clinical sample (CL) reported reactions both to completion of the questionnaire and to a clinical intake.…

The costs of heart failure in Poland from the public payer's perspective. Polish programme assessing diagnostic procedures, treatment and costs in patients with heart failure in randomly selected outpatient clinics and hospitals at different levels of care: POLKARD.

Science.gov (United States)

Czech, Marcin; Opolski, Grzegorz; Zdrojewski, Tomasz; Dubiel, Jacek S; Wizner, Barbara; Bolisęga, Dorota; Fedyk-Łukasik, Małgorzata; Grodzicki, Tomasz

2013-01-01

Heart failure (HF) is a chronic disease of great clinical and economic significance for both the healthcare system and patients themselves. To determine the consumption of medical resources for treatment and care of HF patients and to estimate the related costs. The study involved 400 primary care practices and 396 specialist outpatient clinics, as well as 259 hospitals at all reference levels. The sample was representative and supplemented with patient interview data. Based on the consumption of particular resources and the unit costs of services in 2011, costs of care for HF patients in Poland were estimated. Separate analyses were conducted depending on the stage of the disease (according to NYHA classification I-IV). The public payer's perspective and a one year time horizon were adopted. Direct annual costs of an HF patient's treatment in Poland may range between PLN 3,373.23 and 7,739.49 (2011), the main cost item being hospitalisation. The total costs for the healthcare system could be as high as PLN 1,703 million, which is 3.16% of the National Health Fund's budget (Ex. rate from 05.03.2012: 1 EUR = 4.14 PLN). The costs of treating heart failure in Poland are high; proper allocation of resources to diagnostic procedures and treatment may contribute to rationalisation of the relevant expenditure.

The results of questionnaire on quantitative assessment of {sup 123}I-metaiodobenzylguanidine myocardial scintigraphy in heart failure

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tsunehiko [Osaka Univ., Suita (Japan). Medical school; Sugishita, Yasurou; Sasaki, Yasuhito

1997-12-01

This study was done by working group under the cooperation between Japanese Society of Nuclear Medicine and Japanese Circulation Society. We evaluated the usefulness of quantitative assessment of {sup 123}I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in heart failure by the results of questionnaire. Forty-nine (72.1%) of 68 selected institutions participated in this study. The incidence of MIBG myocardial scintigraphy used in heart failure was 41.1%. The imaging protocol was mostly done by both planar and SPECT at 15 min and 3.6 hr after intravenous injection of 111 MBq of MIBG. The quantitative assessment was mostly done by heart/mediastinum (H/M) ratio and washout rate analysis based on planar imaging. The mean normal value of H/M ratio were 2.34{+-}0.36, and 2.49{+-}0.40, at early and delayed images, respectively. The normal value of washout rate was 27.74{+-}5.34%. On the other hand, those of H/M ratio in heart failure were 1.87{+-}0.27, and 1.75{+-}0.24, at early and delayed images, respectively. That of washout rate was 42.30{+-}6.75%. These parameters were very useful for the evaluation of heart failure. In conclusion, MIBG myocardial scintigraphy was widely used for not only early detection and severity assessment, but also indication for therapy and prognosis evaluation in heart failure patients. (author)

Assessment of current structural design methodology for high-temperature reactors based on failure tests

International Nuclear Information System (INIS)

Corum, J.M.; Sartory, W.K.

1985-01-01

A mature design methodology, consisting of inelastic analysis methods, provided in Department of Energy guidelines, and failure criteria, contained in ASME Code Case N-47, exists in the United States for high-temperature reactor components. The objective of this paper is to assess the adequacy of this overall methodology by comparing predicted inelastic deformations and lifetimes with observed results from structural failure tests and from an actual service failure. Comparisons are presented for three types of structural situations: (1) nozzle-to-spherical shell specimens, where stresses at structural discontinuities lead to cracking, (2) welded structures, where metallurgical discontinuities play a key role in failures, and (3) thermal shock loadings of cylinders and pipes, where thermal discontinuities can lead to failure. The comparison between predicted and measured inelastic responses are generally reasonalbly good; quantities are sometimes overpredicted somewhat, and, sometimes underpredicted. However, even seemingly small discrepancies can have a significant effect on structural life, and lifetimes are not always as closely predicted. For a few cases, the lifetimes are substantially overpredicted, which raises questions regarding the adequacy of existing design margins

Fracture analysis procedure for cast austenitic stainless steel pipe with an axial crack

International Nuclear Information System (INIS)

Kamaya, Masayuki

2012-01-01

Since the ductility of cast austenitic stainless steel pipes decreases due to thermal aging embrittlement after long term operation, not only plastic collapse failure but also unstable ductile crack propagation (elastic-plastic failure) should be taken into account for the structural integrity assessment of cracked pipes. In the fitness-for-service code of the Japan Society of Mechanical Engineers (JSME), Z-factor is used to incorporate the reduction in failure load due to elastic-plastic failure. However, the JSME code does not provide the Z-factor for axial cracks. In this study, Z-factor for axial cracks in aged cast austenitic stainless steel pipes was derived. Then, a comparison was made for the elastic-plastic failure load obtained from different analysis procedures. It was shown that the obtained Z-factor could derive reasonable elastic-plastic failure loads, although the failure loads were more conservative than those obtained by the two-parameter method. (author)

Guidelines and procedures for the International Code Assessment and Applications Program

International Nuclear Information System (INIS)

1987-04-01

This document presents the guidelines and procedures by which the International Code Assessment and Applications Program (ICAP) will be conducted. The document summarizes the management structure of the program and the relationships between and responsibilities of the United States Nuclear Regulatory Commission (USNRC) and the international participants. The procedures for code maintenance and necessary documentation are described. Guidelines for the performance and documentation of code assessment studies are presented. An overview of an effort to quantify code uncertainty, which the ICAP supports, is included

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

Ultrasonography in chronic renal failure

International Nuclear Information System (INIS)

Buturovic-Ponikvar, Jadranka; Visnar-Perovic, Alenka

2003-01-01

Many chronic renal diseases lead to the final common state of decrease in renal size, parenchymal atrophy, sclerosis and fibrosis. The ultrasound image show a smaller kidney, thinning of the parenchyma and its hyperechogenicity (reflecting sclerosis and fibrosis). The frequency of renal cysts increases with the progression of the disease. Ultrasound generally does not allow for the exact diagnosis of an underlying chronic disease (renal biopsy is usually required), but it can help to determine an irreversible disease, assess prognosis and avoid unnecessary diagnostic or therapeutic procedures. The main exception in which the ultrasound image does not show a smaller kidney with parenchymal atrophy is diabetic nephropathy, the leading cause of chronic and end-stage renal failure in developed countries in recent years. In this case, both renal size and parenchymal thickness are preserved until end-stage renal failure. Doppler study of intrarenal vessels can provide additional information about microvascular and parenchymal lesions, which is helpful in deciding for or against therapeutic intervention and timely planning for optimal renal replacement therapy option

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-15

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

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

International Nuclear Information System (INIS)

Ebisawa, K.; Teragaki, T.; Nomura, S.; Abe, H.; Shigemori, M.; Shimomoto, M.

2015-01-01

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

Disease assessment and prognosis of liver failure

Directory of Open Access Journals (Sweden)

ZHANG Jing

2016-09-01

Full Text Available Liver failure has a high fatality rate and greatly threatens human health. Liver transplantation can effectively reduce the fatality rate. However, the problems such as donor shortage and allograft rejection limit the wide application of liver transplantation. An accurate early assessment helps to evaluate patients′ condition and optimize therapeutic strategies. At present, commonly used systems for prognostic evaluation include the King′s College Hospital, MELD, integrated MELD, Child-Pugh score, CLIF-SOFA, CLIF-C ACLFS, and D-MELD, and each system has its own advantages and disadvantages. Among these systems, the MELD scoring system is the most commonly used one, and the D-MELD scoring system is the most innovative one, which can be used for patients on the waiting list for liver transplantation. This article elaborates on the characteristics and predictive value of each scoring system in clinical practice.

Generic component failure data base

International Nuclear Information System (INIS)

Eide, S.A.; Calley, M.B.

1992-01-01

This report discusses comprehensive component generic failure data base which has been developed for light water reactor probabilistic risk assessments. The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) was used to generate component failure rates. Using this approach, most of the failure rates are based on actual plant data rather then existing estimates

Evaluation of the effect of corrosion defects on the structural integrity of X52 gas pipelines using the SINTAP procedure and notch theory

International Nuclear Information System (INIS)

Adib, H.; Jallouf, S.; Schmitt, C.; Carmasol, A.; Pluvinage, G.

2007-01-01

The notch stress intensity factor concept and the structural integrity assessment procedure for European industry (SINTAP) structural integrity procedure are used to assess gas pipeline integrity using deterministic and probabilistic methods. These pipes have external longitudinal semi-elliptical corrosion defects. Stress concentration at a defect tip is investigated via elastic-plastic finite element method analysis. The notch stress intensity concept is implemented into the SINTAP procedure and a notch-based failure assessment diagram is proposed. The safety factor and security factor are calculated through the SINTAP basic level

Evaluation of the effect of corrosion defects on the structural integrity of X52 gas pipelines using the SINTAP procedure and notch theory

Energy Technology Data Exchange (ETDEWEB)

Adib, H. [ENIM, Laboratoire de Fiabilite Mecanique (LFM) Ile du Saulcy, 57045 Metz Cedex (France); Jallouf, S. [ENIM, Laboratoire de Fiabilite Mecanique (LFM) Ile du Saulcy, 57045 Metz Cedex (France); Schmitt, C. [ENIM, Laboratoire de Fiabilite Mecanique (LFM) Ile du Saulcy, 57045 Metz Cedex (France)]. E-mail: schmitt@enim.fr; Carmasol, A. [ENIM, Laboratoire de Fiabilite Mecanique (LFM) Ile du Saulcy, 57045 Metz Cedex (France); Pluvinage, G. [ENIM, Laboratoire de Fiabilite Mecanique (LFM) Ile du Saulcy, 57045 Metz Cedex (France)

2007-03-15

The notch stress intensity factor concept and the structural integrity assessment procedure for European industry (SINTAP) structural integrity procedure are used to assess gas pipeline integrity using deterministic and probabilistic methods. These pipes have external longitudinal semi-elliptical corrosion defects. Stress concentration at a defect tip is investigated via elastic-plastic finite element method analysis. The notch stress intensity concept is implemented into the SINTAP procedure and a notch-based failure assessment diagram is proposed. The safety factor and security factor are calculated through the SINTAP basic level.

A probabilistic seismic risk assessment procedure for nuclear power plants: (I) Methodology

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

A new procedure for probabilistic seismic risk assessment of nuclear power plants (NPPs) is proposed. This procedure modifies the current procedures using tools developed recently for performance-based earthquake engineering of buildings. The proposed procedure uses (a) response-based fragility curves to represent the capacity of structural and nonstructural components of NPPs, (b) nonlinear response-history analysis to characterize the demands on those components, and (c) Monte Carlo simulations to determine the damage state of the components. The use of response-rather than ground-motion-based fragility curves enables the curves to be independent of seismic hazard and closely related to component capacity. The use of Monte Carlo procedure enables the correlation in the responses of components to be directly included in the risk assessment. An example of the methodology is presented in a companion paper to demonstrate its use and provide the technical basis for aspects of the methodology. ?? 2011 Published by Elsevier B.V.

Probabilistic fracture failure analysis of nuclear piping containing defects using R6 method

International Nuclear Information System (INIS)

Lin, Y.C.; Xie, Y.J.; Wang, X.H.

2004-01-01

Failure analysis of in-service nuclear piping containing defects is an important subject in the nuclear power plants. Considering the uncertainties in various internal operating loadings and external forces, including earthquake and wind, flaw sizes, material fracture toughness and flow stress, this paper presents a probabilistic assessment methodology for in-service nuclear piping containing defects, which is especially designed for programming. A general sampling computation method of the stress intensity factor (SIF), in the form of the relationship between the SIF and the axial force, bending moment and torsion, is adopted in the probabilistic assessment methodology. This relationship has been successfully used in developing the software, Safety Assessment System of In-service Pressure Piping Containing Flaws (SAPP-2003), based on a well-known engineering safety assessment procedure R6. A numerical example is given to show the application of the SAPP-2003 software. The failure probabilities of each defect and the whole piping can be obtained by this software

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

Chronic renal failure and sexual functioning: clinical status versus objectively assessed sexual response

NARCIS (Netherlands)

Toorians, A. W.; Janssen, E.; Laan, E.; Gooren, L. J.; Giltay, E. J.; Oe, P. L.; Donker, A. J.; Everaerd, W.

1997-01-01

BACKGROUND: Sexual dysfunctions are common among patients with chronic renal failure. The prevalence was assessed in a population of 281 patients (20-60 years), and it was attempted to determine whether their mode of treatment (haemodialysis, peritoneal dialysis, or kidney transplantation), or

Assessment of ALWR passive safety system reliability. Phase 1: Methodology development and component failure quantification

International Nuclear Information System (INIS)

Hake, T.M.; Heger, A.S.

1995-04-01

Many advanced light water reactor (ALWR) concepts proposed for the next generation of nuclear power plants rely on passive systems to perform safety functions, rather than active systems as in current reactor designs. These passive systems depend to a great extent on physical processes such as natural circulation for their driving force, and not on active components, such as pumps. An NRC-sponsored study was begun at Sandia National Laboratories to develop and implement a methodology for evaluating ALWR passive system reliability in the context of probabilistic risk assessment (PRA). This report documents the first of three phases of this study, including methodology development, system-level qualitative analysis, and sequence-level component failure quantification. The methodology developed addresses both the component (e.g. valve) failure aspect of passive system failure, and uncertainties in system success criteria arising from uncertainties in the system's underlying physical processes. Traditional PRA methods, such as fault and event tree modeling, are applied to the component failure aspect. Thermal-hydraulic calculations are incorporated into a formal expert judgment process to address uncertainties in selected natural processes and success criteria. The first phase of the program has emphasized the component failure element of passive system reliability, rather than the natural process uncertainties. Although cursory evaluation of the natural processes has been performed as part of Phase 1, detailed assessment of these processes will take place during Phases 2 and 3 of the program

CT fluoroscopy-guided renal tumour cutting needle biopsy: retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure.

Science.gov (United States)

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

2018-01-01

To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. • CT fluoroscopy-guided renal tumour biopsy has a high diagnostic yield. • CT fluoroscopy-guided renal tumour biopsy is safe. • Small tumour size (≤1.5 cm) is a risk factor for diagnostic failure.

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

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

Pouch failures following ileal pouch-anal anastomosis for ulcerative colitis

DEFF Research Database (Denmark)

Mark-Christensen, A; Erichsen, R; Brandsborg, S

2018-01-01

BACKGROUND: The ileal pouch-anal anastomosis is a procedure offered to patients with ulcerative colitis who opt for restoration of bowel continuity. The aim of this study was to determine the risk of pouch failure and ascertain risk factors associated with failure. METHOD: 1,991 patients with ulc......BACKGROUND: The ileal pouch-anal anastomosis is a procedure offered to patients with ulcerative colitis who opt for restoration of bowel continuity. The aim of this study was to determine the risk of pouch failure and ascertain risk factors associated with failure. METHOD: 1,991 patients......-anal anastomosis from Denmark, where pouch surgery is centralized, females had a higher risk of pouch failure. Of modifiable factors, low hospital volume and non-diversion were associated with a higher risk of pouch failure. This article is protected by copyright. All rights reserved....

Selected component failure rate values from fusion safety assessment tasks

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, L.C.

1998-09-01

This report is a compilation of component failure rate and repair rate values that can be used in magnetic fusion safety assessment tasks. Several safety systems are examined, such as gas cleanup systems and plasma shutdown systems. Vacuum system component reliability values, including large vacuum chambers, have been reviewed. Values for water cooling system components have also been reported here. The report concludes with the examination of some equipment important to personnel safety, atmospheres, combustible gases, and airborne releases of radioactivity. These data should be useful to system designers to calculate scoping values for the availability and repair intervals for their systems, and for probabilistic safety or risk analysts to assess fusion systems for safety of the public and the workers.

Selected Component Failure Rate Values from Fusion Safety Assessment Tasks

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, Lee Charles

1998-09-01

This report is a compilation of component failure rate and repair rate values that can be used in magnetic fusion safety assessment tasks. Several safety systems are examined, such as gas cleanup systems and plasma shutdown systems. Vacuum system component reliability values, including large vacuum chambers, have been reviewed. Values for water cooling system components have also been reported here. The report concludes with the examination of some equipment important to personnel safety, atmospheres, combustible gases, and airborne releases of radioactivity. These data should be useful to system designers to calculate scoping values for the availability and repair intervals for their systems, and for probabilistic safety or risk analysts to assess fusion systems for safety of the public and the workers.

Selected component failure rate values from fusion safety assessment tasks

International Nuclear Information System (INIS)

Cadwallader, L.C.

1998-01-01

This report is a compilation of component failure rate and repair rate values that can be used in magnetic fusion safety assessment tasks. Several safety systems are examined, such as gas cleanup systems and plasma shutdown systems. Vacuum system component reliability values, including large vacuum chambers, have been reviewed. Values for water cooling system components have also been reported here. The report concludes with the examination of some equipment important to personnel safety, atmospheres, combustible gases, and airborne releases of radioactivity. These data should be useful to system designers to calculate scoping values for the availability and repair intervals for their systems, and for probabilistic safety or risk analysts to assess fusion systems for safety of the public and the workers

Knowing the operative game plan: a novel tool for the assessment of surgical procedural knowledge.

Science.gov (United States)

Balayla, Jacques; Bergman, Simon; Ghitulescu, Gabriela; Feldman, Liane S; Fraser, Shannon A

2012-08-01

What is the source of inadequate performance in the operating room? Is it a lack of technical skills, poor judgment or a lack of procedural knowledge? We created a surgical procedural knowledge (SPK) assessment tool and evaluated its use. We interviewed medical students, residents and training program staff on SPK assessment tools developed for 3 different common general surgery procedures: inguinal hernia repair with mesh in men, laparoscopic cholecystectomy and right hemicolectomy. The tools were developed as a step-wise assessment of specific surgical procedures based on techniques described in a current surgical text. We compared novice (medical student to postgraduate year [PGY]-2) and expert group (PGY-3 to program staff) scores using the Mann-Whitney U test. We calculated the total SPK score and defined a cut-off score using receiver operating characteristic analysis. In all, 5 participants in 7 different training groups (n = 35) underwent an interview. Median scores for each procedure and overall SPK scores increased with experience. The median SPK for novices was 54.9 (95% confidence interval [CI] 21.6-58.8) compared with 98.05 (95% CP 94.1-100.0) for experts (p = 0.012). The SPK cut-off score of 93.1 discriminates between novice and expert surgeons. Surgical procedural knowledge can reliably be assessed using our SPK assessment tool. It can discriminate between novice and expert surgeons for common general surgical procedures. Future studies are planned to evaluate its use for more complex procedures.

Risk assessment for pipelines with active defects based on artificial intelligence methods

Energy Technology Data Exchange (ETDEWEB)

Anghel, Calin I. [Department of Chemical Engineering, Faculty of Chemistry and Chemical Engineering, University ' Babes-Bolyai' , Cluj-Napoca (Romania)], E-mail: canghel@chem.ubbcluj.ro

2009-07-15

The paper provides another insight into the pipeline risk assessment for in-service pressure piping containing defects. Beside of the traditional analytical approximation methods or sampling-based methods safety index and failure probability of pressure piping containing defects will be obtained based on a novel type of support vector machine developed in a minimax manner. The safety index or failure probability is carried out based on a binary classification approach. The procedure named classification reliability procedure, involving a link between artificial intelligence and reliability methods was developed as a user-friendly computer program in MATLAB language. To reveal the capacity of the proposed procedure two comparative numerical examples replicating a previous related work and predicting the failure probabilities of pressured pipeline with defects were presented.

Risk assessment for pipelines with active defects based on artificial intelligence methods

International Nuclear Information System (INIS)

Anghel, Calin I.

2009-01-01

The paper provides another insight into the pipeline risk assessment for in-service pressure piping containing defects. Beside of the traditional analytical approximation methods or sampling-based methods safety index and failure probability of pressure piping containing defects will be obtained based on a novel type of support vector machine developed in a minimax manner. The safety index or failure probability is carried out based on a binary classification approach. The procedure named classification reliability procedure, involving a link between artificial intelligence and reliability methods was developed as a user-friendly computer program in MATLAB language. To reveal the capacity of the proposed procedure two comparative numerical examples replicating a previous related work and predicting the failure probabilities of pressured pipeline with defects were presented.

Delusions as performance failures.

Science.gov (United States)

Gerrans, P

2001-08-01

Delusions are explanations of anomalous experiences. A theory of delusion requires an explanation of both the anomalous experience and the apparently irrational explanation generated by the delusional subject. Hence, we require a model of rational belief formation against which the belief formation of delusional subjects can be evaluated. I first describe such a model, distinguishing procedural from pragmatic rationality. Procedural rationality is the use of rules or procedures, deductive or inductive, that produce an inferentially coherent set of propositions. Pragmatic rationality is the use of procedural rationality in context. I then apply the distinction to the explanation of the Capgras and the Cotard delusions. I then argue that delusions are failures of pragmatic rationality. I examine the nature of these failures employing the distinction between performance and competence familiar from Chomskian linguistics. This approach to the irrationality of delusions reconciles accounts in which the explanation of the anomalous experience exhausts the explanation of delusion, accounts that appeal to further deficits within the reasoning processes of delusional subjects, and accounts that argue that delusions are not beliefs at all. (Respectively, one-stage, two-stage, and expressive accounts.) In paradigm cases that concern cognitive neuropsychiatry the irrationality of delusional subjects should be thought of as a performance deficit in pragmatic rationality.

Assessment of creep-fatigue damage using the UK strain based procedure

International Nuclear Information System (INIS)

Bate, S.K.

1997-01-01

The UK strain based procedures have been developed for the evaluation of damage in structures, arising from fatigue cycles and creep processes. The fatigue damage is assessed on the basis of modelling crack growth from about one grain depth to an allowable limit which represents an engineering definition of crack formation. Creep damage is based up on the exhaustion of available ductility by creep strain accumulation. The procedures are applicable only when level A and B service conditions apply, as defined in RCC-MR or ASME Code Case N47. The procedures require the components of strain to be evaluated separately, thus they may be used with either full inelastic analysis or simplified methods. To support the development of the UK strain based creep-fatigue procedures an experimental program was undertaken by NNC to study creep-fatigue interaction of structures operating at high temperature. These tests, collectively known as the SALTBATH tests considered solid cylinder and tube-plate specimens, manufactured from Type 316 stainless steel. These specimens were subjected to thermal cycles between 250 deg. C and 600 deg. C. In all the cases the thermal cycle produces tensile residual stresses during dwells at 600 deg. C. One of the tube-plate specimens was used as a benchmark for validating the strain based creep fatigue procedures and subsequently as part of a CEC co-operative study. This benchmark work is described in this paper. A thermal and inelastic stress analysis was carried out using the finite element code ABAQUS. The inelastic behaviour of the material was described using the ORNL constitutive equations. A creep fatigue assessment using the strain based procedures has been compared with an assessment using the RCC-MR inelastic rules. The analyses indicated that both the UK strain based procedures and the RCC-MR rules were conservative, but the conservatism was greater for the RCC-MR rules. (author). 8 refs, 8 figs, 4 tabs

Sequential Organ Failure Assessment Score for Evaluating Organ Failure and Outcome of Severe Maternal Morbidity in Obstetric Intensive Care

Directory of Open Access Journals (Sweden)

Antonio Oliveira-Neto

2012-01-01

Full Text Available Objective. To evaluate the performance of Sequential Organ Failure Assessment (SOFA score in cases of severe maternal morbidity (SMM. Design. Retrospective study of diagnostic validation. Setting. An obstetric intensive care unit (ICU in Brazil. Population. 673 women with SMM. Main Outcome Measures. mortality and SOFA score. Methods. Organ failure was evaluated according to maximum score for each one of its six components. The total maximum SOFA score was calculated using the poorest result of each component, reflecting the maximum degree of alteration in systemic organ function. Results. highest total maximum SOFA score was associated with mortality, 12.06 ± 5.47 for women who died and 1.87 ± 2.56 for survivors. There was also a significant correlation between the number of failing organs and maternal mortality, ranging from 0.2% (no failure to 85.7% (≥3 organs. Analysis of the area under the receiver operating characteristic (ROC curve (AUC confirmed the excellent performance of total maximum SOFA score for cases of SMM (AUC = 0.958. Conclusions. Total maximum SOFA score proved to be an effective tool for evaluating severity and estimating prognosis in cases of SMM. Maximum SOFA score may be used to conceptually define and stratify the degree of severity in cases of SMM.

FFTF fuel pin design procedure verification for transient operation

International Nuclear Information System (INIS)

Baars, R.E.

1975-05-01

The FFTF design procedures for evaluating fuel pin transient performance are briefly reviewed, and data where available are compared with design procedure predictions. Specifically, burst conditions derived from Fuel Cladding Transient Tester (FCTT) tests and from ANL loss-of-flow tests are compared with burst pressures computed using the design procedure upon which the cladding integrity limit was based. Failure times are predicted using the design procedure for evaluation of rapid reactivity insertion accidents, for five unterminated TREAT experiments in which well characterized fuel failures were deliberately incurred. (U.S.)

Critical Emergency Medicine Procedural Skills: A Comparative Study of Methods for Teaching and Assessment.

Science.gov (United States)

Chapman, Dane M.; And Others

Three critical procedural skills in emergency medicine were evaluated using three assessment modalities--written, computer, and animal model. The effects of computer practice and previous procedure experience on skill competence were also examined in an experimental sequential assessment design. Subjects were six medical students, six residents,…

Assessment of characteristic failure envelopes for intact rock using results from triaxial tests

OpenAIRE

Muralha, J.; Lamas, L.

2014-01-01

The paper presents contributions to the statistical study of the parameters of the Mohr-Coulomb and Hoek-Brown strength criteria, in order to assess the characteristic failure envelopes for intact rock, based on the results of several sets of triaxial tests performed by LNEC. 10p DBB/NMMR

Assessing the impact of heart failure specialist services on patient populations

Directory of Open Access Journals (Sweden)

Lyratzopoulos Georgios

2004-05-01

Full Text Available Abstract Background The assessment of the impact of healthcare interventions may help commissioners of healthcare services to make optimal decisions. This can be particularly the case if the impact assessment relates to specific patient populations and uses timely local data. We examined the potential impact on readmissions and mortality of specialist heart failure services capable of delivering treatments such as b-blockers and Nurse-Led Educational Intervention (N-LEI. Methods Statistical modelling of prevented or postponed events among previously hospitalised patients, using estimates of: treatment uptake and contraindications (based on local audit data; treatment effectiveness and intolerance (based on literature; and annual number of hospitalization per patient and annual risk of death (based on routine data. Results Optimal treatment uptake among eligible but untreated patients would over one year prevent or postpone 11% of all expected readmissions and 18% of all expected deaths for spironolactone, 13% of all expected readmisisons and 22% of all expected deaths for b-blockers (carvedilol and 20% of all expected readmissions and an uncertain number of deaths for N-LEI. Optimal combined treatment uptake for all three interventions during one year among all eligible but untreated patients would prevent or postpone 37% of all expected readmissions and a minimum of 36% of all expected deaths. Conclusion In a population of previously hospitalised patients with low previous uptake of b-blockers and no uptake of N-LEI, optimal combined uptake of interventions through specialist heart failure services can potentially help prevent or postpone approximately four times as many readmissions and a minimum of twice as many deaths compared with simply optimising uptake of spironolactone (not necessarily requiring specialist services. Examination of the impact of different heart failure interventions can inform rational planning of relevant healthcare

Assessing the impact of heart failure specialist services on patient populations.

Science.gov (United States)

Lyratzopoulos, Georgios; Cook, Gary A; McElduff, Patrick; Havely, Daniel; Edwards, Richard; Heller, Richard F

2004-05-24

The assessment of the impact of healthcare interventions may help commissioners of healthcare services to make optimal decisions. This can be particularly the case if the impact assessment relates to specific patient populations and uses timely local data. We examined the potential impact on readmissions and mortality of specialist heart failure services capable of delivering treatments such as b-blockers and Nurse-Led Educational Intervention (N-LEI). Statistical modelling of prevented or postponed events among previously hospitalised patients, using estimates of: treatment uptake and contraindications (based on local audit data); treatment effectiveness and intolerance (based on literature); and annual number of hospitalization per patient and annual risk of death (based on routine data). Optimal treatment uptake among eligible but untreated patients would over one year prevent or postpone 11% of all expected readmissions and 18% of all expected deaths for spironolactone, 13% of all expected readmisisons and 22% of all expected deaths for b-blockers (carvedilol) and 20% of all expected readmissions and an uncertain number of deaths for N-LEI. Optimal combined treatment uptake for all three interventions during one year among all eligible but untreated patients would prevent or postpone 37% of all expected readmissions and a minimum of 36% of all expected deaths. In a population of previously hospitalised patients with low previous uptake of b-blockers and no uptake of N-LEI, optimal combined uptake of interventions through specialist heart failure services can potentially help prevent or postpone approximately four times as many readmissions and a minimum of twice as many deaths compared with simply optimising uptake of spironolactone (not necessarily requiring specialist services). Examination of the impact of different heart failure interventions can inform rational planning of relevant healthcare services.

Probabilistic assessment of SGTR management

International Nuclear Information System (INIS)

Champ, M.; Cornille, Y.; Lanore, J.M.

1989-04-01

In case of steam generator tube rupture (SGTR) event, in France, the mitigation of accident relies on operator intervention, by applying a specific accidental procedure. A detailed probabilistic analysis has been conducted which required the assessment of the failure probability of the operator actions, and for that purpose it was necessary to estimate the time available for the operator to apply the adequate procedure for various sequences. The results indicate that by taking into account the delays and the existence of adequate accidental procedures, the risk is reduced to a reasonably low level

A combined deterministic and probabilistic procedure for safety assessment of components with cracks - Handbook.

Energy Technology Data Exchange (ETDEWEB)

Dillstroem, Peter; Bergman, Mats; Brickstad, Bjoern; Weilin Zang; Sattari-Far, Iradj; Andersson, Peder; Sund, Goeran; Dahlberg, Lars; Nilsson, Fred (Inspecta Technology AB, Stockholm (Sweden))

2008-07-01

SSM has supported research work for the further development of a previously developed procedure/handbook (SKI Report 99:49) for assessment of detected cracks and tolerance for defect analysis. During the operative use of the handbook it was identified needs to update the deterministic part of the procedure and to introduce a new probabilistic flaw evaluation procedure. Another identified need was a better description of the theoretical basis to the computer program. The principal aim of the project has been to update the deterministic part of the recently developed procedure and to introduce a new probabilistic flaw evaluation procedure. Other objectives of the project have been to validate the conservatism of the procedure, make the procedure well defined and easy to use and make the handbook that documents the procedure as complete as possible. The procedure/handbook and computer program ProSACC, Probabilistic Safety Assessment of Components with Cracks, has been extensively revised within this project. The major differences compared to the last revision are within the following areas: It is now possible to deal with a combination of deterministic and probabilistic data. It is possible to include J-controlled stable crack growth. The appendices on material data to be used for nuclear applications and on residual stresses are revised. A new deterministic safety evaluation system is included. The conservatism in the method for evaluation of the secondary stresses for ductile materials is reduced. A new geometry, a circular bar with a circumferential surface crack has been introduced. The results of this project will be of use to SSM in safety assessments of components with cracks and in assessments of the interval between the inspections of components in nuclear power plants

Flaw assessment procedure for high temperature reactor components

International Nuclear Information System (INIS)

Ainsworth, R.A.; Takahashi, Y.

1990-01-01

An interim high-temperature flaw assessment procedure is described. This is a result of a collaborative effort between Electric Power Research Institute in the USA, Central Research Institute of Electric Power Industry in Japan, and Nuclear Electric plc in the UK. The procedure addresses preexisting defects subject to creep-fatigue loading conditions. Laws employed to calculate the crack growth per cycle are defined in terms of fracture mechanics parameters and constants related to the component material. The crack growth laws may be integrated to calculate the remaining life of a component or to predict the amount of crack extension in a given period. Fatigue and creep crack growth per cycle are calculated separately, and the total crack extension is taken as the simple sum of the two contributions. An interaction between the two propagation modes is accounted for in the material properties in the separate calculations. In producing the procedure, limitations of the approach have been identified. Some of these limitations are to be addressed in an extension of the current collaborative program. 20 refs

Optimized in vitro procedure for assessing the cytocompatibility of magnesium-based biomaterials.

Science.gov (United States)

Jung, Ole; Smeets, Ralf; Porchetta, Dario; Kopp, Alexander; Ptock, Christoph; Müller, Ute; Heiland, Max; Schwade, Max; Behr, Björn; Kröger, Nadja; Kluwe, Lan; Hanken, Henning; Hartjen, Philip

2015-09-01

Magnesium (Mg) is a promising biomaterial for degradable implant applications that has been extensively studied in vitro and in vivo in recent years. In this study, we developed a procedure that allows an optimized and uniform in vitro assessment of the cytocompatibility of Mg-based materials while respecting the standard protocol DIN EN ISO 10993-5:2009. The mouse fibroblast line L-929 was chosen as the preferred assay cell line and MEM supplemented with 10% FCS, penicillin/streptomycin and 4mM l-glutamine as the favored assay medium. The procedure consists of (1) an indirect assessment of effects of soluble Mg corrosion products in material extracts and (2) a direct assessment of the surface compatibility in terms of cell attachment and cytotoxicity originating from active corrosion processes. The indirect assessment allows the quantification of cell-proliferation (BrdU-assay), viability (XTT-assay) as well as cytotoxicity (LDH-assay) of the mouse fibroblasts incubated with material extracts. Direct assessment visualizes cells attached to the test materials by means of live-dead staining. The colorimetric assays and the visual evaluation complement each other and the combination of both provides an optimized and simple procedure for assessing the cytocompatibility of Mg-based biomaterials in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Assessment of importance of elements for systems that condition depends on the sequence of elements failures

International Nuclear Information System (INIS)

Povyakalo, A.A.

1996-01-01

This paper proposes new general formulas for calculation of indices of elements importance for systems whose condition depends on sequence of elements failures. These systems have been called as systems with memory of failures (M-systems). Techniques existing for assessment of importance of elements are based on the Bool's models of system reliability, for which it is significant to suggest, that in every period of time system state depends only on a combination of states of elements at that very moment of time. These systems have been called as combinational systems (C-systems). Reliability of M-systems at any moment of operating time is a functional having distributions of elements time before failure as its arguments. Bool's models and methods of assessment of element importance, based on these models, are not appropriate for these systems. Pereguda and Povyakalo proposed the new techniques for assessment of elements importance for PO-SS systems that includes Protection Object (PO) and Safety System (PO). PO-SS system is an example of M-system. That technique is used at this paper as a basis for more general consideration. It has been shown that technique proposed for assessment of elements importance for M-systems has well-known Birnbaum's method as its particular case. Also the system with double protection is considered as an example

Acceptability of Functional Behavioral Assessment Procedures to Special Educators and School Psychologists

Science.gov (United States)

O'Neill, Robert E.; Bundock, Kaitlin; Kladis, Kristin; Hawken, Leanne S.

2015-01-01

This survey study assessed the acceptability of a variety of functional behavioral assessment (FBA) procedures (i.e., functional assessment interviews, rating scales/questionnaires, systematic direct observations, functional analysis manipulations) to a national sample of 123 special educators and a state sample of 140 school psychologists.…

Uncertainties and quantification of common cause failure rates and probabilities for system analyses

International Nuclear Information System (INIS)

Vaurio, Jussi K.

2005-01-01

Simultaneous failures of multiple components due to common causes at random times are modelled by constant multiple-failure rates. A procedure is described for quantification of common cause failure (CCF) basic event probabilities for system models using plant-specific and multiple-plant failure-event data. Methodology is presented for estimating CCF-rates from event data contaminated with assessment uncertainties. Generalised impact vectors determine the moments for the rates of individual systems or plants. These moments determine the effective numbers of events and observation times to be input to a Bayesian formalism to obtain plant-specific posterior CCF-rates. The rates are used to determine plant-specific common cause event probabilities for the basic events of explicit fault tree models depending on test intervals, test schedules and repair policies. Three methods are presented to determine these probabilities such that the correct time-average system unavailability can be obtained with single fault tree quantification. Recommended numerical values are given and examples illustrate different aspects of the methodology

Verification of failure avoidance concepts in R6 Rev3

International Nuclear Information System (INIS)

Milne, I.; Knee, N.

1988-09-01

The first part of this Report outlines how recent developments in fracture mechanics have led to a more accurate interpretation of the two-criteria approach to defect assessment. The implementation of these developments into Revision 3 of the Central Electricity Generating Board code of practice for the assessment of the defect tolerance of structures (R6) is described. One of the key elements of the revised version is the recommendation that the failure assessment line should be derived from the actual tensile stress/strain properties of the material. The second part of the Report addresses the validation of the method, which is a crucial step on the way to obtaining acceptance of R6 by, in particular, the regulatory bodies. The range of structures used to validate the procedure is illustrated by two examples. The use of conservative data and assumptions is fundamental to the R6 philosophy, which means that the procedure should not be used as a predictive tool. In the second example the importance of making these conservative assumptions is clearly illustrated. (author)

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)

Space Stirling Cryocooler Contamination Lessons Learned and Recommended Control Procedures

Science.gov (United States)

Glaister, D. S.; Price, K.; Gully, W.; Castles, S.; Reilly, J.

The most important characteristic of a space cryocooler is its reliability over a lifetime typically in excess of 7 years. While design improvements have reduced the probability of mechanical failure, the risk of internal contamination is still significant and has not been addressed in a consistent approach across the industry. A significant fraction of the endurance test and flight units have experienced some performance degradation related to internal contamination. The purpose of this paper is to describe and assess the contamination issues inside long life, space cryocoolers and to recommend procedures to minimize the probability of encountering contamination related failures and degradation. The paper covers the sources of contamination, the degradation and failure mechanisms, the theoretical and observed cryocooler sensitivity, and the recommended prevention procedures and their impact. We begin with a discussion of the contamination sources, both artificial and intrinsic. Next, the degradation and failure mechanisms are discussed in an attempt to arrive at a contaminant susceptibility, from which we can derive a contamination budget for the machine. This theoretical sensitivity is then compared with the observed sensitivity to illustrate the conservative nature of the assumed scenarios. A number of lessons learned on Raytheon, Ball, Air Force Research Laboratory, and NASA GSFC programs are shared to convey the practical aspects of the contamination problem. Then, the materials and processes required to meet the proposed budget are outlined. An attempt is made to present a survey of processes across industry.

Developments in UK defect assessment procedures R6 revision 4 and BS7910

International Nuclear Information System (INIS)

Sharples, J.K.; Ainsworth, R.A.; Budden, P.J.

2003-01-01

The R6 defect assessment procedures have been developed over many years by the UK nuclear power generation industry. The procedures are updated on a regular basis, taking into account the information resulting from the R6 development programme and other available information worldwide. A major revision, Revision 4, of the R6 procedures was released in 2000. Just prior to that release, in 1999, the British Standards flaw assessment procedure BS7910 was issued and combined and updated the previous published documents PD6493 and PD6539, for components operating at temperatures where creep was negligible and important, respectively. BS79l0 is also under constant development. This paper provides a brief overview of the BS7910 and R6 Revision 4 procedures and describes updates to the respective documents since they were first issued. Some ongoing developments which will lead to future revisions to the documents are also described. (author)

A National Needs Assessment to Identify Technical Procedures in Vascular Surgery for Simulation Based Training

DEFF Research Database (Denmark)

Nayahangan, L J; Konge, L; Schroeder, T V

2017-01-01

to identify technical procedures that vascular surgeons should learn. Round 2 was a survey that used a needs assessment formula to explore the frequency of procedures, the number of surgeons performing each procedure, risk and/or discomfort, and feasibility for simulation based training. Round 3 involved...... eliminated, resulting in a final prioritised list of 19 technical procedures. Conclusion A national needs assessment using a standardised Delphi method identified a list of procedures that are highly suitable and may provide the basis for future simulation based training programs for vascular surgeons......Objectives and background Practical skills training in vascular surgery is facing challenges because of an increased number of endovascular procedures and fewer open procedures, as well as a move away from the traditional principle of “learning by doing.” This change has established simulation...

[Orthognathic surgery: surgical failures and complications].

Science.gov (United States)

Guyot, Laurent

2016-03-01

Orthognathic surgery procedures mark the endpoint of lengthy orthodontic-surgical preparations and herald the completion of treatment for patients and their families. The main types of procedure are full maxillary Le Fort I osteotomies, mandibular osteotomies and chin surgery. To ensure a successful outcome, all require a favorable environment and extreme technical skill. But, like all surgical operations, they are also subject to peri- and post-operative complications resulting from treatment hazards or errors. Whatever the cause, surgical complications can entail failures in the management of the malformation. By seeking to understand and analyzing these complications, we can already help to prevent and reduce the contingent risks of failure. © EDP Sciences, SFODF, 2016.

A National Needs Assessment to Identify Technical Procedures in Vascular Surgery for Simulation Based Training.

Science.gov (United States)

Nayahangan, L J; Konge, L; Schroeder, T V; Paltved, C; Lindorff-Larsen, K G; Nielsen, B U; Eiberg, J P

2017-04-01

Practical skills training in vascular surgery is facing challenges because of an increased number of endovascular procedures and fewer open procedures, as well as a move away from the traditional principle of "learning by doing." This change has established simulation as a cornerstone in providing trainees with the necessary skills and competences. However, the development of simulation based programs often evolves based on available resources and equipment, reflecting convenience rather than a systematic educational plan. The objective of the present study was to perform a national needs assessment to identify the technical procedures that should be integrated in a simulation based curriculum. A national needs assessment using a Delphi process was initiated by engaging 33 predefined key persons in vascular surgery. Round 1 was a brainstorming phase to identify technical procedures that vascular surgeons should learn. Round 2 was a survey that used a needs assessment formula to explore the frequency of procedures, the number of surgeons performing each procedure, risk and/or discomfort, and feasibility for simulation based training. Round 3 involved elimination and ranking of procedures. The response rate for round 1 was 70%, with 36 procedures identified. Round 2 had a 76% response rate and resulted in a preliminary prioritised list after exploring the need for simulation based training. Round 3 had an 85% response rate; 17 procedures were eliminated, resulting in a final prioritised list of 19 technical procedures. A national needs assessment using a standardised Delphi method identified a list of procedures that are highly suitable and may provide the basis for future simulation based training programs for vascular surgeons in training. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

A discussion about simplified methodologies for failure assessment of nuclear reactor components

International Nuclear Information System (INIS)

Cruz, J.R.B.; Andrade, A.H.P. de; Landes, J.D.

1996-01-01

Failure of nuclear reactor components like pressure vessels and piping must be avoided for all phases of reactor operation. Especially severe loading conditions come from postulated accident scenarios during which the integrity of the component is required. The use of Fracture Mechanics concepts to investigate the mechanical behavior of flawed structures in the non-linear regime is a complex subject due to the fact that the crack driving force (expressed in terms of J or CTOD) is not /only a function of the cracked geometry, but depends also on the plastic flow properties of the material. Since the numerical solutions by the finite element method are expensive and time consuming, the existence of simplified engineering procedures is of great relevance. These allow a ready identification of the main parameters affecting the crack driving force, and permit a fast and simple evaluation of the structural integrity of the cracked component. This paper presents an overview of the major simplified ductile fracture methodologies that have been proposed in the literature trying to point out their similarities, strong points and negative aspects. Once the best characteristics of each method are identified, they could then be combined to develop a single methodology, one that would be both easy to use and capable of making accurate failure predictions

Provisional crown failures in dental school predoctoral clinics.

Science.gov (United States)

Hyde, Jeffrey D; Bader, James A; Shugars, Daniel A

2007-11-01

Following a preliminary study indicating that at least 10 percent of single-unit crown temporary restorations failed in patients who received treatment by predoctoral students, a comprehensive examination of provisional crown failure was initiated to identify strategies to reduce the failure rate. For all provisionalized, natural tooth, single-unit crown preparations in University of North Carolina School of Dentistry predoctoral clinics for one year (N=1008), we noted tooth type, type of crown, student level, faculty coverage experience, treatment clinic, temporary material and luting agent, and retreatment (failure) of the provisional restoration. For failures, we also noted the stage of crown preparation at failure and the time since initial placement of the temporary. We analyzed these data using simple cross-tabs and logistic regression on need for retreatment (alpha =0.05). The failure rate was 18.75 percent (N=189). The median time to failure was twelve days; the 25(th) and 75(th) percentiles were six and twenty-six days. Significant risk factors, in order of odds ratio estimates, were molar tooth, second- or third-year student, and inexperienced faculty. Most provisional failures occurred during the final preparation phase of treatment. Provisional restoration failure is more frequent than was initially suspected from preliminary studies. Strategies for institutional intervention to reduce provisional restoration failure include greater attention to evaluating provisional crowns placed by inexperienced students (sophomores and juniors) and placing more emphasis on the retentiveness of provisional restorations reused following the final impression. Review of provisional evaluation procedures is also indicated for faculty who do not routinely supervise these procedures.

Development of KSC program for investigating and generating field failure rates. Volume 2: Recommended format for reliability handbook for ground support equipment

Science.gov (United States)

Bloomquist, C. E.; Kallmeyer, R. H.

1972-01-01

Field failure rates and confidence factors are presented for 88 identifiable components of the ground support equipment at the John F. Kennedy Space Center. For most of these, supplementary information regarding failure mode and cause is tabulated. Complete reliability assessments are included for three systems, eight subsystems, and nine generic piece-part classifications. Procedures for updating or augmenting the reliability results presented in this handbook are also included.

Assessing patient preferences in heart failure using conjoint methodology

Directory of Open Access Journals (Sweden)

Pisa G

2015-08-01

Full Text Available Giovanni Pisa,1 Florian Eichmann,1 Stephan Hupfer21Kantar Health GmbH, Munich, Germany; 2Novartis Pharma GmbH, Nuernberg, GermanyAim: The course of heart failure (HF is characterized by frequent hospitalizations, a high mortality rate, as well as a severely impaired health-related quality of life (HRQoL. To optimize disease management, understanding of patient preferences is crucial. We aimed to assess patient preferences using conjoint methodology and HRQoL in patients with HF.Methods: Two modules were applied: an initial qualitative module, consisting of in-depth interviews with 12 HF patients, and the main quantitative module in 300 HF patients from across Germany. Patients were stratified according to the time of their last HF hospitalization. Each patient was presented with ten different scenarios during the conjoint exercise. Additionally, patients completed the generic HRQoL instrument, EuroQol health questionnaire (EQ-5D™.Results: The attribute with the highest relative importance was dyspnea (44%, followed by physical capacity (18%. Of similar importance were exhaustion during mental activities (13%, fear due to HF (13%, and autonomy (12%. The most affected HRQoL dimensions according to the EQ-5D questionnaire were anxiety/depression (23% with severe problems, pain/discomfort (19%, and usual activities (15%. Overall average EQ-5D score was 0.39 with stable, chronic patients (never hospitalized having a significantly better health state vs the rest of the cohort.Conclusion: This paper analyzed patient preference in HF using a conjoint methodology. The preference weights resulting from the conjoint analysis could be used in future to design HRQoL questionnaires which could better assess patient preferences in HF care.Keywords: heart failure, quality of life, conjoint analysis, utility, patient preference

The Implicit Relational Assessment Procedure as a Measure of Self-Esteem

Science.gov (United States)

Timko, C. Alix; England, Erica L.; Herbert, James D.; Forman, Evan M.

2010-01-01

Two studies were conducted to pilot the Implicit Relational Assessment Procedure (IRAP) in measuring attitudes toward the self: one related to body image specifically and another assessing the broader construct of self-esteem. Study 1 utilized the IRAP with female college students to examine self-referential beliefs regarding body image. Results…

Towards a whole-network risk assessment for railway bridge failures caused by scour during flood events

Directory of Open Access Journals (Sweden)

Lamb Rob

2016-01-01

Full Text Available Localised erosion (scour during flood flow conditions can lead to costly damage or catastrophic failure of bridges, and in some cases loss of life or significant disruption to transport networks. Here, we take a broad scale view to assess risk associated with bridge scour during flood events over an entire infrastructure network, illustrating the analysis with data from the British railways. There have been 54 recorded events since 1846 in which scour led to the failure of railway bridges in Britain. These events tended to occur during periods of extremely high river flow, although there is uncertainty about the precise conditions under which failures occur, which motivates a probabilistic analysis of the failure events. We show how data from the historical bridge failures, combined with hydrological analysis, have been used to construct fragility curves that quantify the conditional probability of bridge failure as a function of river flow, accompanied by estimates of the associated uncertainty. The new fragility analysis is tested using flood events simulated from a national, spatial joint probability model for extremes in river flows. The combined models appear robust in comparison with historical observations of the expected number of bridge failures in a flood event, and provide an empirical basis for further broad-scale network risk analysis.

Variation in Cognitive Failures: An Individual Differences Investigation of Everyday Attention and Memory Failures

Science.gov (United States)

Unsworth, Nash; Brewer, Gene A.; Spillers, Gregory J.

2012-01-01

The present study examined individual differences in everyday cognitive failures assessed by diaries. A large sample of participants completed various cognitive ability measures in the laboratory. Furthermore, a subset of these participants also recorded everyday cognitive failures (attention, retrospective memory, and prospective memory failures)…

A procedure for estimation of pipe break probabilities due to IGSCC

International Nuclear Information System (INIS)

Bergman, M.; Brickstad, B.; Nilsson, F.

1998-06-01

A procedure has been developed for estimation of the failure probability of welds joints in nuclear piping susceptible to intergranular stress corrosion cracking. The procedure aims at a robust and rapid estimate of the failure probability for a specific weld with known stress state. Random properties are taken into account of the crack initiation rate, the initial crack length, the in-service inspection efficiency and the leak rate. A computer realization of the procedure has been developed for user friendly applications by design engineers. Some examples are considered to investigate the sensitivity of the failure probability to different input quantities. (au)

An operational procedure for rapid flood risk assessment in Europe

Science.gov (United States)

Dottori, Francesco; Kalas, Milan; Salamon, Peter; Bianchi, Alessandra; Alfieri, Lorenzo; Feyen, Luc

2017-07-01

The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real-time components to assess potential impacts generated by forecasted flood events. To overcome this limitation, this study describes the benchmarking of an operational procedure for rapid flood risk assessment based on predictions issued by the European Flood Awareness System (EFAS). Daily streamflow forecasts produced for major European river networks are translated into event-based flood hazard maps using a large map catalogue derived from high-resolution hydrodynamic simulations. Flood hazard maps are then combined with exposure and vulnerability information, and the impacts of the forecasted flood events are evaluated in terms of flood-prone areas, economic damage and affected population, infrastructures and cities.An extensive testing of the operational procedure has been carried out by analysing the catastrophic floods of May 2014 in Bosnia-Herzegovina, Croatia and Serbia. The reliability of the flood mapping methodology is tested against satellite-based and report-based flood extent data, while modelled estimates of economic damage and affected population are compared against ground-based estimations. Finally, we evaluate the skill of risk estimates derived from EFAS flood forecasts with different lead times and combinations of probabilistic forecasts. Results highlight the potential of the real-time operational procedure in helping emergency response and management.

Modeling the failure data of a repairable equipment with bathtub type failure intensity

International Nuclear Information System (INIS)

Pulcini, G.

2001-01-01

The paper deals with the reliability modeling of the failure process of large and complex repairable equipment whose failure intensity shows a bathtub type non-monotonic behavior. A non-homogeneous Poisson process arising from the superposition of two power law processes is proposed, and the characteristics and mathematical details of the proposed model are illustrated. A graphical approach is also presented, which allows to determine whether the proposed model can adequately describe a given failure data. A graphical method for obtaining crude but easy estimates of the model parameters is then illustrated, as well as more accurate estimates based on the maximum likelihood method are provided. Finally, two numerical applications are given to illustrate the proposed model and the estimation procedures

Evaluation and treatment of failed shoulder instability procedures.

Science.gov (United States)

Ho, Anthony G; Gowda, Ashok L; Michael Wiater, J

2016-09-01

Management of the unstable shoulder after a failed stabilization procedure can be difficult and challenging. Detailed understanding of the native shoulder anatomy, including its static and dynamic restraints, is necessary for determining the patient's primary pathology. In addition, evaluation of the patient's history, physical exam, and imaging is important for identifying the cause for failure after the initial procedure. Common mistakes include under-appreciation of bony defects, failure to recognize capsular laxity, technical errors, and missed associated pathology. Many potential treatment options exist for revision surgery, including open or arthroscopic Bankart repair, bony augmentation procedures, and management of Hill Sachs defects. The aim of this narrative review is to discuss in-depth the common risk factors for post-surgical failure, components for appropriate evaluation, and the different surgical options available for revision stabilization. Level of evidence Level V.

Assessment of Conventional Teaching Procedures: Implications for Gifted Learners

Science.gov (United States)

Alenizi, Mogbel Aid K.

2016-01-01

The present research aims to assess the conventional teaching procedures in the development of mathematical skills of the students with learning difficulties. The study group was made up of all the children with academic learning disorders in KSA. The research questions have been scrutinized from the averages and the standard deviation of the…

Innovative Approaches to Increasing the Student Assessment Procedures Effectiveness

Science.gov (United States)

Dorozhkin, Evgenij M.; Chelyshkova, Marina B.; Malygin, Alexey A.; Toymentseva, Irina A.; Anopchenko, Tatiana Y.

2016-01-01

The relevance of the investigated problem is determined by the need to improving the evaluation procedures in education and the student assessment in the age of the context of education widening, new modes of study developing (such as blending learning, e-learning, massive open online courses), immediate feedback necessity, reliable and valid…

Spacecraft electrical power subsystem: Failure behavior, reliability, and multi-state failure analyses

International Nuclear Information System (INIS)

Kim, So Young; Castet, Jean-Francois; Saleh, Joseph H.

2012-01-01

This article investigates the degradation and failure behavior of spacecraft electrical power subsystem (EPS) on orbit. First, this work provides updated statistical reliability and multi-state failure analyses of spacecraft EPS and its different constituents, namely the batteries, the power distribution, and the solar arrays. The EPS is shown to suffer from infant mortality and to be a major driver of spacecraft unreliability. Over 25% of all spacecraft failures are the result of EPS failures. As a result, satellite manufacturers may wish to pursue targeted improvement to this subsystem, either through better testing or burn-in procedures, better design or parts selection, or additional redundancy. Second, this work investigates potential differences in the EPS degradation and failure behavior for spacecraft in low earth orbits (LEO) and geosynchronous orbits (GEO). This analysis was motivated by the recognition that the power/load cycles and the space environment are significantly different in LEO and GEO, and as such, they may result in different failure behavior for the EPS in these two types of orbits. The results indicate, and quantify the extent to which, the EPS fails differently in LEO and GEO, both in terms of frequency and severity of failure events. A casual summary of the findings can be stated as follows: the EPS fails less frequently but harder (with fatal consequences to the spacecraft) in LEO than in GEO.

Assessing rockfall susceptibility in steep and overhanging slopes using three-dimensional analysis of failure mechanisms

Science.gov (United States)

Matasci, Battista; Stock, Greg M.; Jaboyedoff, Michael; Carrea, Dario; Collins, Brian D.; Guérin, Antoine; Matasci, G.; Ravanel, L.

2018-01-01

Rockfalls strongly influence the evolution of steep rocky landscapes and represent a significant hazard in mountainous areas. Defining the most probable future rockfall source areas is of primary importance for both geomorphological investigations and hazard assessment. Thus, a need exists to understand which areas of a steep cliff are more likely to be affected by a rockfall. An important analytical gap exists between regional rockfall susceptibility studies and block-specific geomechanical calculations. Here we present methods for quantifying rockfall susceptibility at the cliff scale, which is suitable for sub-regional hazard assessment (hundreds to thousands of square meters). Our methods use three-dimensional point clouds acquired by terrestrial laser scanning to quantify the fracture patterns and compute failure mechanisms for planar, wedge, and toppling failures on vertical and overhanging rock walls. As a part of this work, we developed a rockfall susceptibility index for each type of failure mechanism according to the interaction between the discontinuities and the local cliff orientation. The susceptibility for slope parallel exfoliation-type failures, which are generally hard to identify, is partly captured by planar and toppling susceptibility indexes. We tested the methods for detecting the most susceptible rockfall source areas on two famously steep landscapes, Yosemite Valley (California, USA) and the Drus in the Mont-Blanc massif (France). Our rockfall susceptibility models show good correspondence with active rockfall sources. The methods offer new tools for investigating rockfall hazard and improving our understanding of rockfall processes.

Fuel failure assessments based on radiochemistry. Experience feedback and challenges

International Nuclear Information System (INIS)

Petit, C.; Ziabletsev, D.; Zeh, P.

2015-01-01

Significant improvements have been observed in LWR nuclear fuel reliability over the past years. As a result, the number of fuel failures in PWRs and BWRs has recently dramatically decreased. Nevertheless, a few remaining challenges still exist. One of them is that the industry has recently started seeing a relatively new type of fuel failure, so-called 'weak leak failures', which could be characterized by a very small release of gaseous fission products and essentially almost zero release of iodines or any other soluble fission products in the reactor coolant. Correspondingly, the behavior of these weak leakers does not follow typical behavior of a conventional leaker characterized by a proportionality of the amount of released Xe 133 related to the failed rod power. Instead, for a weak leaker, the activity of Xe 133 is directly correlated to the size of the cladding defects of the leaker. The presence of undetected weak leaker in the core may lead to carryover of a leaker into the subsequent cycle. Even if the presence of weak leaker in the core is suspected, it typically requires more effort to identify the leaker which could result in extended duration of the outage and ultimately to economic losses to the utility operating the reactor. To effectively deal with this issue the industry has been facing, several changes have been recently realized, which are different from the methodology of dealing with conventional leaker. These changes include new assessment methods, the need for improved sipping techniques to better identify low release leakers, and correspondingly better equipment to be able to locate small clad defects associated with weak leaker, such as sensitive localization device of failed rods, sensitive eddy current coil for the failed rod, ultra high definition cameras for the failed rod examination and experienced fuel reliability engineers performing cause of failure and rood cause research and analyses. Ultimately, the destructive

Experimental models of hepatotoxicity related to acute liver failure

Energy Technology Data Exchange (ETDEWEB)

Maes, Michaël [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Vinken, Mathieu, E-mail: mvinken@vub.ac.be [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Jaeschke, Hartmut [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City (United States)

2016-01-01

Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposure or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure. - Highlights: • The murine APAP model is very close to what is observed in patients. • The Gal/ET model is useful to study TNFα-mediated apoptotic signaling mechanisms. • Fas receptor activation is an effective model of apoptosis and secondary necrosis. • The ConA model is a relevant model of auto-immune hepatitis and viral hepatitis. • Multiple time point evaluation needed in experimental models of acute liver injury.

Reframing Success and Failure of Information Systems

DEFF Research Database (Denmark)

Cecez-Kecmanovic, Dubravka; Kautz, Karlheinz; Abrahall, Rebecca

2014-01-01

-networks of developers, managers, technologies, project documents, methodologies, and other actors. Drawing from a controversial case of a highly innovative information system in an insurance company-considered a success and failure at the same time- the paper reveals the inherent indeterminacy of IS success and failure......he paper questions common assumptions in the dominant representational framings of information systems success and failure and proposes a performative perspective that conceives IS success and failure as relational effects performed by sociomaterial practices of IS project actor...... that performed both different IS realities and competing IS assessments. The analysis shows that the IS project and the implemented system as objects of assessment are not given and fixed, but are performed by the agencies of assessment together with the assessment outcomes of success and failure. The paper...

A comparative assessment of alternative waste management procedures for selected reprocessing wastes

International Nuclear Information System (INIS)

Hickford, G.E.; Plews, M.J.

1983-07-01

This report, which has been prepared by Associated Nuclear Services for the Department of the Environment, presents the results of a study and comparative assessment of management procedures for low and intermediate level solid waste streams arising from current and future fuel reprocessing operations on the Sellafield site. The characteristics and origins of the wastes under study are discussed and a reference waste inventory is presented, based on published information. Waste management strategy in the UK and its implications for waste conditioning, packaging and disposal are discussed. Wastes currently arising which are not suitable for Drigg burial or sea dumping are stored in an untreated form. Work is in hand to provide additional and improved disposal facilities which will accommodate all the waste streams under study. For each waste stream viable procedures are identified for further assessment. The procedures comprise a series of on-site operations-recovery from storage, pre-treatment, treatment, encapsulation, and packaging, prior to storage or disposal of the conditioned waste form. Assessments and comparisons of each procedure for each waste are presented. These address various process, operational, economic, radiological and general safety factors. The results are presented in a series of tables with supporting text. For the majority of wastes direct encapsulation with minimal treatment appears to be a viable procedure. Occupational exposure and general safety are not identified as significant factors governing the choice of procedures. The conditioned wastes meet the general requirements for safe handling during storage and transportation. The less active wastes suitable for disposal by currently available routes meet the appropriate disposal criteria. It is not possible to consider in detail the suitability for disposal of the more active wastes for which disposal facilities are not yet available. (Author)

Control of Risks Through the Use of Procedures: A Method for Evaluating the Change in Risk

Science.gov (United States)

Praino, Gregory T.; Sharit, Joseph

2010-01-01

This paper considers how procedures can be used to control risks faced by an organization and proposes a means of recognizing if a particular procedure reduces risk or contributes to the organization's exposure. The proposed method was developed out of the review of work documents and the governing procedures performed in the wake of the Columbia accident by NASA and the Space Shuttle prime contractor, United Space Alliance, LLC. A technique was needed to understand the rules, or procedural controls, in place at the time in the context of how important the role of each rule was. The proposed method assesses procedural risks, the residual risk associated with a hazard after a procedure's influence is accounted for, by considering each clause of a procedure as a unique procedural control that may be beneficial or harmful. For procedural risks with consequences severe enough to threaten the survival of the organization, the method measures the characteristics of each risk on a scale that is an alternative to the traditional consequence/likelihood couple. The dual benefits of the substitute scales are that they eliminate both the need to quantify a relationship between different consequence types and the need for the extensive history a probabilistic risk assessment would require. Control Value is used as an analog for the consequence, where the value of a rule is based on how well the control reduces the severity of the consequence when operating successfully. This value is composed of two parts: the inevitability of the consequence in the absence of the control, and the opportunity to intervene before the consequence is realized. High value controls will be ones where there is minimal need for intervention but maximum opportunity to actively prevent the outcome. Failure Likelihood is used as the substitute for the conventional likelihood of the outcome. For procedural controls, a failure is considered to be any non-malicious violation of the rule, whether intended or

Psychomotor skills assessment in practicing surgeons experienced in performing advanced laparoscopic procedures.

Science.gov (United States)

Gallagher, Anthony G; Smith, C Daniel; Bowers, Steven P; Seymour, Neal E; Pearson, Adam; McNatt, Steven; Hananel, David; Satava, Richard M

2003-09-01

Minimally invasive surgery (MIS) has introduced a new and unique set of psychomotor skills for a surgeon to acquire and master. Although assessment technologies have been proposed, precise and objective psychomotor skills assessment of surgeons performing laparoscopic procedures has not been detailed. Two hundred ten surgeons attending the 2001 annual meeting of the American College of Surgeons in New Orleans who reported having completed more than 50 laparoscopic procedures participated. Subjects were required to complete one box-trainer laparoscopic cutting task and a similar virtual reality task. These tasks were specifically designed to test only psychomotor and not cognitive skills. Both tasks were completed twice. Performance of tasks was assessed and analyzed. Demographic and laparoscopic experience data were also collected. Complete data were available on 195 surgeons. In this group, surgeons performed the box-trainer task better with their dominant hand (p psychomotor skills is now possible. Surgeons who had performed more than 50 laparoscopic procedures showed considerable variability in their performance on a simple laparoscopic and virtual reality task. Approximately 10% of surgeons tested performed the task significantly worse than the group's average performance. Studies such as this may form the methodology for establishing criteria levels and performance objectives in objective assessment of the technical skills component of determining surgical competence.

Vitamin D and Heart Failure.

Science.gov (United States)

Marshall Brinkley, D; Ali, Omair M; Zalawadiya, Sandip K; Wang, Thomas J

2017-10-01

Vitamin D is principally known for its role in calcium homeostasis, but preclinical studies implicate multiple pathways through which vitamin D may affect cardiovascular function and influence risk for heart failure. Many adults with cardiovascular disease have low vitamin D status, making it a potential therapeutic target. We review the rationale and potential role of vitamin D supplementation in the prevention and treatment of chronic heart failure. Substantial observational evidence has associated low vitamin D status with the risk of heart failure, ventricular remodeling, and clinical outcomes in heart failure, including mortality. However, trials assessing the influence of vitamin D supplementation on surrogate markers and clinical outcomes in heart failure have generally been small and inconclusive. There are insufficient data to recommend routine assessment or supplementation of vitamin D for the prevention or treatment of chronic heart failure. Prospective trials powered for clinical outcomes are warranted.

Peer-assisted learning model enhances clinical clerk's procedural skills.

Science.gov (United States)

Huang, Chia-Chang; Hsu, Hui-Chi; Yang, Ling-Yu; Chen, Chen-Huan; Yang, Ying-Ying; Chang, Ching-Chih; Chuang, Chiao-Lin; Lee, Wei-Shin; Lee, Fa-Yauh; Hwang, Shinn-Jang

2018-05-17

Failure to transfer procedural skills learned in a laboratory to the bedside is commonly due to a lack of peer support/stimulation. A digital platform (Facebook) allows new clinical clerks to share experiences and tips that help augment their procedural skills in a peer-assisted learning/teaching method. This study aims to investigate the effectiveness of the innovation of using the digital platform to support the transfer of laboratory-trained procedural skills in the clinical units. Volunteer clinical clerks (n = 44) were enrolled into the peer-assisted learning (PAL) group, which was characterized by the peer-assisted learning of procedural skills during their final 3-month clinical clerkship block. Other clerks (n = 51) did not join the procedural skills-specific Facebook group and served as the self-directed learning regular group. The participants in both the PAL and regular groups completed pre- and post-intervention self-assessments for general self-assessed efficiency ratings (GSER) and skills specific self-assessed efficiency ratings (SSSER) for performing vein puncture, intravenous (IV) catheter and nasogastric (NG) tube insertion. Finally, all clerks received the post-intervention 3-station Objective Structured Clinical Skills Examination (OSCE) to test their proficiency for the abovementioned three procedural skills. Higher cumulative numbers of vein punctures, IV catheter insertions and NG tube insertions at the bedside were carried out by the PAL group than the regular group. A greater improvement in GSERs and SSSERs for medical procedures was found in the PAL group than in the regular group. The PAL group obtained higher procedural skills scores in the post-intervention OSCEs than the regular group. Our study suggested that the implementation of a procedural skill-specific digital platform effectively helps clerks to transfer laboratory-trained procedural skills into the clinical units. In comparison with the regular self-directed learning

Impaired cardiac uptake of meta-[123I]iodobenzylguanidine in Parkinson's disease with autonomic failure

International Nuclear Information System (INIS)

Braune, S.; Luecking, C.H.; Reinhardt, M.; Bathmann, J.; Krause, T.; Lehmann, M.

1998-01-01

Objective - To selectively investigate postganglionic sympathetic cardiac neurons in patients with Parkinson's disease and autonomic failure. Material and methods - Metaiodobenzylguanidine (MIBG) is a pharmacologically inactive analogue of noradrenaline, which is similarly metabolized in noradrenergic neurons. Therefore the uptake of radiolabelled MIBG represents not only the localization of postganglionic sympathetic neurons but also their functional integrity. Ten patients with Parkinson's disease and autonomic failure underwent standardized autonomic testing, assessment of catecholamine plasma levels and scintigraphy with [ 123 I]MIGB. Results - The cardiac uptake of MIBG, as demonstrated by the heart/mediastinum ratio, was significantly lower in patients in comparison with controls. Scintigraphy with MIBG allowed the selective in-vivo investigation of postganglionic sympathetic cardiac efferent in patients with autonomic failure, a procedure which was previously confined to post-mortem examination. Conclusion - These findings point to a relevant postganglionic pattern of involvement of the autonomic nervous system (ANS) in Parkinson's disease and autonomic failure. (au)

Application of a few orthogonal polynomials to the assessment of the fracture failure probability of a spherical tank

International Nuclear Information System (INIS)

Cao Tianjie; Zhou Zegong

1993-01-01

This paper presents some methods to assess the fracture failure probability of a spherical tank. These methods convert the assessment of the fracture failure probability into the calculation of the moment of cracks and a one-dimensional integral. In the paper, we first derive series' formulae to calculation the moments of cracks on the occasion of the crack fatigue growth and the moments of crack opening displacements according to JWES-2805 code. We then use the first n moments of crack opening displacements and a few orthogonal polynomials to compose the probability density function of the crack opening displacement. Lastly, the fracture failure probability is obtained according to the interference theory. An example proves that these methods are simpler, quicker, and more accurate. At the same time, these methods avoid the disadvantage of Edgeworth's series method. (author)

Trial application of the candidate root cause categorization scheme and preliminary assessment of selected data bases for the root causes of component failures program

International Nuclear Information System (INIS)

Bruske, S.Z.; Cadwallader, L.C.; Stepina, P.L.

1985-04-01

The objective of the Nuclear Regulatory Commission's (NRC) Root Causes of Component Failures Program is to develop and apply a categorization scheme for identifying root causes of failures for components that comprise safety and safety support systems of nuclear power plants. Results from this program will provide valuable input in the areas of probabilistic risk assessment, reliability assurance, and application of risk assessments in the inspection program. This report presents the trial application and assessment of the candidate root cause categorization scheme to three failure data bases: the In-Plant Reliability Data System (IPRDS), the Licensee Event Report (LER) data base, and the Nuclear Plant Reliability Data System (NPRDS). Results of the trial application/assessment show that significant root cause information can be obtained from these failure data bases

Generic procedures for assessment and response during a radiological emergency

International Nuclear Information System (INIS)

2000-08-01

One of the most important aspects of managing a radiological emergency is the ability to promptly and adequately determine and take actions to protect members of the public and emergency workers. Radiological accident assessment must take account of all critical information available at any time and must be an iterative and dynamic process aimed at reviewing the response as more detailed and complete information becomes available. This manual provides the tools, generic procedures and data needed for an initial response to a non-reactor radiological accident. This manual is one out of a set of IAEA publications on emergency preparedness and response, including Method for the Development of Emergency Response Preparedness for Nuclear or Radiological Accidents (IAEA-TECDOC-953), Generic Assessment Procedures for Determining Protective Actions During a Reactor Accident (IAEA-TECDOC-955) and Intervention Criteria in a Nuclear or Radiation Emergency (Safety Series No. 109)

Procedures and methods of benefit assessments for medicines in Germany.

Science.gov (United States)

Bekkering, Geertruida E; Kleijnen, Jos

2008-11-01

The Federal Joint Committee (FJC; Gemeinsamer Bundesausschuss, G-BA) defines the health-care elements that are to be reimbursed by sickness funds. To define a directive, the FJC can commission benefit assessments, which provide an overview of the scientific evidence regarding the efficacy and benefits of an intervention. This paper describes the operational implementation of the legal requirements with regard to the benefit assessments of medicines. Such benefit assessments are sometimes referred to as "isolated benefit assessments," to distinguish them from benefit assessments as part of a full economic evaluation.The FJC has the freedom to commission these assessments from any agency; however, to date the majority have commissioned the Institute for Quality and Efficiency in Health Care (IQWiG). Nevertheless, the content of this paper applies integrally to any institute commissioned for such assessments. In this report, 'the institute' is used when the text refers to any of these institutes.The legal framework for benefit assessments is laid out in the German Social Code Book version V ( http://www.sozialgesetzbuch.de ), Sects. 35b ( section 1), 139a ( section 4-6) and Sect. 139b ( section 3). It is specified that: The institute must guarantee high transparency. The institute must provide appropriate participation of relevant parties for the commission-related development of assessments, and opportunity for comment on all important segments of the assessment procedure. The institute has to report on the progress and results of the work at regular intervals. The institute is held to giving the commission to external experts. Based on the legal framework, the institute must guarantee a high procedural transparency. Transparency of the whole process should be achieved, which is evidenced by clear reporting of procedures and criteria in all phases undertaken in the benefit assessment. The most important means of enhancing transparency are: 1. To implement a scoping

[Procedures and methods of benefit assessments for medicines in Germany].

Science.gov (United States)

Bekkering, G E; Kleijnen, J

2008-12-01

The Federal Joint Committee (FJC; Gemeinsamer Bundesausschuss, G-BA) defines the health-care elements that are to be reimbursed by sickness funds. To define a directive, the FJC can commission benefit assessments, which provide an overview of the scientific evidence regarding the efficacy and benefits of an intervention. This paper describes the operational implementation of the legal requirements with regard to the benefit assessments of medicines. Such benefit assessments are sometimes referred to as "isolated benefit assessments," to distinguish them from benefit assessments as part of a full economic evaluation. The FJC has the freedom to commission these assessments from any agency; however, to date the majority have commissioned the Institute for Quality and Efficiency in Health Care (IQWiG). Nevertheless, the content of this paper applies integrally to any institute commissioned for such assessments. In this report, "the institute"' is used when the text refers to any of these institutes. The legal framework for benefit assessments is laid out in the German Social Code Book version V (http://www. sozialgesetzbuch.de), Sects. 35b ( section sign 1), 139a ( section sign 4-6) and Sect. 139b ( section sign 3). It is specified that: The institute must guarantee high transparency. The institute must provide appropriate participation of relevant parties for the commission-related development of assessments, and opportunity for comment on all important segments of the assessment procedure. The institute has to report on the progress and results of the work at regular intervals. The institute is held to giving the commission to external experts. Based on the legal framework, the institute must guarantee a high procedural transparency. Transparency of the whole process should be achieved, which is evidenced by clear reporting of procedures and criteria in all phases undertaken in the benefit assessment. The most important means of enhancing transparency are: 1. To

Comparing risk of failure models in water supply networks using ROC curves

International Nuclear Information System (INIS)

Debon, A.; Carrion, A.; Cabrera, E.; Solano, H.

2010-01-01

The problem of predicting the failure of water mains has been considered from different perspectives and using several methodologies in engineering literature. Nowadays, it is important to be able to accurately calculate the failure probabilities of pipes over time, since water company profits and service quality for citizens depend on pipe survival; forecasting pipe failures could have important economic and social implications. Quantitative tools (such as managerial or statistical indicators and reliable databases) are required in order to assess the current and future state of networks. Companies managing these networks are trying to establish models for evaluating the risk of failure in order to develop a proactive approach to the renewal process, instead of using traditional reactive pipe substitution schemes. The main objective of this paper is to compare models for evaluating the risk of failure in water supply networks. Using real data from a water supply company, this study has identified which network characteristics affect the risk of failure and which models better fit data to predict service breakdown. The comparison using the receiver operating characteristics (ROC) graph leads us to the conclusion that the best model is a generalized linear model. Also, we propose a procedure that can be applied to a pipe failure database, allowing the most appropriate decision rule to be chosen.

Comparing risk of failure models in water supply networks using ROC curves

Energy Technology Data Exchange (ETDEWEB)

Debon, A., E-mail: andeau@eio.upv.e [Centro de Gestion de la Calidad y del Cambio, Dpt. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Carrion, A. [Centro de Gestion de la Calidad y del Cambio, Dpt. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Cabrera, E. [Dpto. De Ingenieria Hidraulica Y Medio Ambiente, Instituto Tecnologico del Agua, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Solano, H. [Universidad Diego Portales, Santiago (Chile)

2010-01-15

The problem of predicting the failure of water mains has been considered from different perspectives and using several methodologies in engineering literature. Nowadays, it is important to be able to accurately calculate the failure probabilities of pipes over time, since water company profits and service quality for citizens depend on pipe survival; forecasting pipe failures could have important economic and social implications. Quantitative tools (such as managerial or statistical indicators and reliable databases) are required in order to assess the current and future state of networks. Companies managing these networks are trying to establish models for evaluating the risk of failure in order to develop a proactive approach to the renewal process, instead of using traditional reactive pipe substitution schemes. The main objective of this paper is to compare models for evaluating the risk of failure in water supply networks. Using real data from a water supply company, this study has identified which network characteristics affect the risk of failure and which models better fit data to predict service breakdown. The comparison using the receiver operating characteristics (ROC) graph leads us to the conclusion that the best model is a generalized linear model. Also, we propose a procedure that can be applied to a pipe failure database, allowing the most appropriate decision rule to be chosen.

Generic assessment procedures for determining protective actions during a reactor accident

International Nuclear Information System (INIS)

1997-08-01

This manual provides the tools, procedures and data needed to evaluate the consequences of a nuclear accident occurring at a nuclear power plant throughout all phases of the emergency before, during and after a release of radioactive material. It is intended for use by on-site and off-site groups responsible for evaluating the accident consequences and making recommendations for the protection of the plant personnel, the emergency workers and the public. The scope of this manual is restricted to the technical assessment of radiological consequences. It does not address the emergency response infrastructure requirements, nor does it cover the emergency management aspects of accident assessment (e.g. reporting, staff qualification, shift replacement, and procedure implementation). The procedures and methods in this manual were developed based on a number of assumptions concerning the design and operation of the nuclear power plant and national practices. Therefore, this manual must be reviewed as part of the planning process to match the potential accidents, local conditions, national criteria and other unique characteristics of an area or nuclear reactor where it may be used. Refs, figs, tabs

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

Assessment of eye lens doses for workers during interventional radiology procedures

International Nuclear Information System (INIS)

Urboniene, A.; Sadzeviciene, E.; Ziliukas, J.

2015-01-01

The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using H p (3) measured at the level of the eyes and were compared with H p (10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. (authors)

Electrical impedance tomography in the assessment of extravascular lung water in noncardiogenic acute respiratory failure

NARCIS (Netherlands)

Kunst, P. W.; Vonk Noordegraaf, A.; Raaijmakers, E.; Bakker, J.; Groeneveld, A. B.; Postmus, P. E.; de Vries, P. M.

1999-01-01

STUDY OBJECTIVES: To establish the value of electrical impedance tomography (EIT) in assessing pulmonary edema in noncardiogenic acute respiratory failure (ARF), as compared to the thermal dye double indicator dilution technique (TDD). DESIGN: Prospective clinical study. SETTING: ICU of a general

Asymptotic failure rate of a continuously monitored system

International Nuclear Information System (INIS)

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

2006-01-01

This paper deals with a perfectly continuously monitored system which gradually and stochastically deteriorates. The system is renewed by a delayed maintenance operation, which is triggered when the measured deterioration level exceeds an alarm threshold. A mathematical model is developed to study the asymptotic behavior of the reliability function. A procedure is proposed which allows us to identify the asymptotic failure rate of the maintained system. Numerical experiments illustrate the efficiency of the proposed procedure and emphasize the relevance of the asymptotic failure rate as an interesting indicator for the evaluation of the control-limit preventive replacement policy

Asymptotic failure rate of a continuously monitored system

Energy Technology Data Exchange (ETDEWEB)

Grall, A. [Institut des Sciences et Technologies de l' Information de Troyes (CNRS-FRE 2732), Equipe de Modelisation et de Surete des Systemes, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France)]. E-mail: antoine.grall@utt.fr; Dieulle, L. [Institut des Sciences et Technologies de l' Information de Troyes (CNRS-FRE 2732), Equipe de Modelisation et de Surete des Systemes, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France)]. E-mail: laurence.dieulle@utt.fr; Berenguer, C. [Institut des Sciences et Technologies de l' Information de Troyes (CNRS-FRE 2732), Equipe de Modelisation et de Surete des Systemes, Universite de Technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France)]. E-mail: christophe.berenguer@utt.fr; Roussignol, M. [Laboratoire d' Analyse et de Mathematiques Appliquees, Universite de Marne la Vallee, 5 bd Descartes, Champs sur Marne, 77454 Marne la Vallee, Cedex 2 (France)]. E-mail: michel.roussignol@univ-mlv.fr

2006-02-01

This paper deals with a perfectly continuously monitored system which gradually and stochastically deteriorates. The system is renewed by a delayed maintenance operation, which is triggered when the measured deterioration level exceeds an alarm threshold. A mathematical model is developed to study the asymptotic behavior of the reliability function. A procedure is proposed which allows us to identify the asymptotic failure rate of the maintained system. Numerical experiments illustrate the efficiency of the proposed procedure and emphasize the relevance of the asymptotic failure rate as an interesting indicator for the evaluation of the control-limit preventive replacement policy.

Noninvasive radiographic assessment of cardiovascular function in acute and chronic respiratory failure

International Nuclear Information System (INIS)

Berger, H.J.; Matthay, R.A.

1981-01-01

Noninvasive radiographic techniques have provided a means of studying the natural history and pathogenesis of cardiovascular performance in acute and chronic respiratory failure. Chest radiography, radionuclide angiocardiography and thallium-201 imaging, and M mode and cross-sectional echocardiography have been employed. Each of these techniques has specific uses, attributes and limitations. For example, measurement of descending pulmonary arterial diameters on the plain chest radiograph allows determination of the presence or absence of pulmonary arterial hypertension. Right and left ventricular performance can be evaluated at rest and during exercise using radionuclide angiocardiography. The biventricular response to exercise and to therapeutic interventions also can be assessed with this approach. Evaluation of the pulmonary valve echogram and echocardiographic right ventricular dimensions have been shown to reflect right ventricular hemodynamics and size. Each of these noninvasive techniques has been applied to the study of patients with respiratory failure and has provided important physiologic data

Advanced structural integrity assessment procedures. Working material

International Nuclear Information System (INIS)

1994-01-01

The purpose of the meeting was to provide an international forum for discussion on recent results in research and utility practice in the field of methodology for the structural integrity assessment of components including relevant non-codified procedures. The scope of the meeting included deterministic and probabilistic approaches. The papers covered the following topics: Leak-before-break concepts; non-destructive examination (NDE) and surveillance results; statistical evaluation of non-destructive examination data; pressurized thermal shock evaluation; fatigue effects (including vibration); and verification qualification. The meeting was attended by 32 specialists from 8 countries. Refs, figs and tabs

Two viewpoints for software failures and their relation in probabilistic safety assessment of digital instrumentation and control systems

International Nuclear Information System (INIS)

Kim, Man Cheol

2015-01-01

As the use of digital systems in nuclear power plants increases, the reliability of the software becomes one of the important issues in probabilistic safety assessment. In this paper, two viewpoints for a software failure during the operation of a digital system or a statistical software test are identified, and the relation between them is provided. In conventional software reliability analysis, a failure is mainly viewed with respect to the system operation. A new viewpoint with respect to the system input is suggested. The failure probability density functions for the two viewpoints are defined, and the relation between the two failure probability density functions is derived. Each failure probability density function can be derived from the other failure probability density function by applying the derived relation between the two failure probability density functions. The usefulness of the derived relation is demonstrated by applying it to the failure data obtained from the software testing of a real system. The two viewpoints and their relation, as identified in this paper, are expected to help us extend our understanding of the reliability of safety-critical software. (author)

Omnibus risk assessment via accelerated failure time kernel machine modeling.

Science.gov (United States)

Sinnott, Jennifer A; Cai, Tianxi

2013-12-01

Integrating genomic information with traditional clinical risk factors to improve the prediction of disease outcomes could profoundly change the practice of medicine. However, the large number of potential markers and possible complexity of the relationship between markers and disease make it difficult to construct accurate risk prediction models. Standard approaches for identifying important markers often rely on marginal associations or linearity assumptions and may not capture non-linear or interactive effects. In recent years, much work has been done to group genes into pathways and networks. Integrating such biological knowledge into statistical learning could potentially improve model interpretability and reliability. One effective approach is to employ a kernel machine (KM) framework, which can capture nonlinear effects if nonlinear kernels are used (Scholkopf and Smola, 2002; Liu et al., 2007, 2008). For survival outcomes, KM regression modeling and testing procedures have been derived under a proportional hazards (PH) assumption (Li and Luan, 2003; Cai, Tonini, and Lin, 2011). In this article, we derive testing and prediction methods for KM regression under the accelerated failure time (AFT) model, a useful alternative to the PH model. We approximate the null distribution of our test statistic using resampling procedures. When multiple kernels are of potential interest, it may be unclear in advance which kernel to use for testing and estimation. We propose a robust Omnibus Test that combines information across kernels, and an approach for selecting the best kernel for estimation. The methods are illustrated with an application in breast cancer. © 2013, The International Biometric Society.

Reaction Times to Consecutive Automation Failures: A Function of Working Memory and Sustained Attention.

Science.gov (United States)

Jipp, Meike

2016-12-01

This study explored whether working memory and sustained attention influence cognitive lock-up, which is a delay in the response to consecutive automation failures. Previous research has demonstrated that the information that automation provides about failures and the time pressure that is associated with a task influence cognitive lock-up. Previous research has also demonstrated considerable variability in cognitive lock-up between participants. This is why individual differences might influence cognitive lock-up. The present study tested whether working memory-including flexibility in executive functioning-and sustained attention might be crucial in this regard. Eighty-five participants were asked to monitor automated aircraft functions. The experimental manipulation consisted of whether or not an initial automation failure was followed by a consecutive failure. Reaction times to the failures were recorded. Participants' working-memory and sustained-attention abilities were assessed with standardized tests. As expected, participants' reactions to consecutive failures were slower than their reactions to initial failures. In addition, working-memory and sustained-attention abilities enhanced the speed with which participants reacted to failures, more so with regard to consecutive than to initial failures. The findings highlight that operators with better working memory and sustained attention have small advantages when initial failures occur, but their advantages increase across consecutive failures. The results stress the need to consider personnel selection strategies to mitigate cognitive lock-up in general and training procedures to enhance the performance of low ability operators. © 2016, Human Factors and Ergonomics Society.

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.)

Clinical skills assessment of procedural and advanced communication skills: performance expectations of residency program directors

Science.gov (United States)

Langenau, Erik E.; Zhang, Xiuyuan; Roberts, William L.; DeChamplain, Andre F.; Boulet, John R.

2012-01-01

Background High stakes medical licensing programs are planning to augment and adapt current examinations to be relevant for a two-decision point model for licensure: entry into supervised practice and entry into unsupervised practice. Therefore, identifying which skills should be assessed at each decision point is critical for informing examination development, and gathering input from residency program directors is important. Methods Using data from previously developed surveys and expert panels, a web-delivered survey was distributed to 3,443 residency program directors. For each of the 28 procedural and 18 advanced communication skills, program directors were asked which clinical skills should be assessed, by whom, when, and how. Descriptive statistics were collected, and Intraclass Correlations (ICC) were conducted to determine consistency across different specialties. Results Among 347 respondents, program directors reported that all advanced communication and some procedural tasks are important to assess. The following procedures were considered ‘important’ or ‘extremely important’ to assess: sterile technique (93.8%), advanced cardiovascular life support (ACLS) (91.1%), basic life support (BLS) (90.0%), interpretation of electrocardiogram (89.4%) and blood gas (88.7%). Program directors reported that most clinical skills should be assessed at the end of the first year of residency (or later) and not before graduation from medical school. A minority were considered important to assess prior to the start of residency training: demonstration of respectfulness (64%), sterile technique (67.2%), BLS (68.9%), ACLS (65.9%) and phlebotomy (63.5%). Discussion Results from this study support that assessing procedural skills such as cardiac resuscitation, sterile technique, and phlebotomy would be amenable to assessment at the end of medical school, but most procedural and advanced communications skills would be amenable to assessment at the end of the first

[Conversional and endoscopic procedures following bariatric surgery].

Science.gov (United States)

Zorron, R; Bothe, C; Junghans, T; Pratschke, J; Benzing, C; Krenzien, F

2016-10-01

The Roux-en-Y gastric bypass (RYGB) is the therapy of choice in bariatric surgery. Sleeve gastrectomy and gastric banding are showing higher rates of treatment failure, reducing obesity-associated morbidity and body weight insufficiently. Moreover, gastroesophageal reflux disease (GERD) can occur refractory to medication. Therefore, a laparoscopic conversion to RYGB can be reasonable as long as specific conditions are fulfilled.Endoscopic procedures are currently being applied to revise bariatric procedures. Therapy failure following RYGB occurs in up to 20 % of cases. Transoral outlet reduction is the minimally invasive method of choice to reduce gastrojejunal anastomosis of the alimentary limb. The diameter of a gastric sleeve can be unwantedly enlarged as well; that can be reduced by placement of a longitudinal full-thickness suture.Severe hypoglycemic episodes can be present in patients following RYGB. Hypoglycemic episodes have to be diagnosed first and can be treated conventionally. Alternatively, a laparoscopic approach according to Branco-Zorron can be used for non-responders. Hypoglycemic episodes can thus be prevented and body weight reduction can be assured.Conversional and endoscopic procedures can be used in patients with treatment failure following bariatric surgery. Note that non-invasive approaches should have been applied intensively before a revisional procedure is performed.

Estimation Procedure of Common Cause Failure Parameters for CAFE-PSA

International Nuclear Information System (INIS)

Kang, Dae Il; Hwang, M. J.; Han, S. H.

2009-03-01

Detailed common cause failure (CCF) analysis generally needs the data for CCF events from other nuclear power plants because the CCF events rarely occur. Since 2002, KAERI has participated in the international common cause failure data exchange (ICDE) project to get data for CCF events. The operation office of the ICDE project sent about 400 CCF event data for emergency diesel generators, motor operated valves, check valves, pumps, and breakers to KAERI in 2009. However, there was no program available to analyze the ICDE CCF event data. Therefore, we developed the CAFE-PSA (common CAuse Failure Event analysis program for PSA) to estimate CCF parameters by using the ICDE CCF event data. With CAFE-PSA, the CCF events in the ICDE database can be qualitatively and quantitatively analyzed. The qualitative analysis results of the ICDE CCF data, by using the CAFE-PSA, showed that the major root cause of CCF events, for motor operated valves, check valves, and pumps, was the fault of their internal parts, and that for emergency diesel generators and breakers was the inadequacy of design/manufacture or construction. The quantitative analysis results of the ICDE CCF data, by using the CAFE-PSA, showed that the estimated Alpha Factors of components, mentioned above, were lower than those previously used in the PSA for domestic nuclear power plants, but were higher than those in USNRC 2007 CCF data. Through performing qualitative and quantitative analysis of the ICDE CCF data, by using the CAFE-PSA, a plan for coping with CCF events for design and operation of nuclear power plants can be produced and reasonable values for CCF parameters can be estimated. In addition, it is expected that the technical adequacy of PSA can be improved

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

Definition of containment failure

International Nuclear Information System (INIS)

Cybulskis, P.

1982-01-01

Core meltdown accidents of the types considered in probabilistic risk assessments (PRA's) have been predicted to lead to pressures that will challenge the integrity of containment structures. Review of a number of PRA's indicates considerable variation in the predicted probability of containment failure as a function of pressure. Since the results of PRA's are sensitive to the prediction of the occurrence and the timing of containment failure, better understanding of realistic containment capabilities and a more consistent approach to the definition of containment failure pressures are required. Additionally, since the size and location of the failure can also significantly influence the prediction of reactor accident risk, further understanding of likely failure modes is required. The thresholds and modes of containment failure may not be independent

Assessment of compressive failure process of cortical bone materials using damage-based model.

Science.gov (United States)

Ng, Theng Pin; R Koloor, S S; Djuansjah, J R P; Abdul Kadir, M R

2017-02-01

The main failure factors of cortical bone are aging or osteoporosis, accident and high energy trauma or physiological activities. However, the mechanism of damage evolution coupled with yield criterion is considered as one of the unclear subjects in failure analysis of cortical bone materials. Therefore, this study attempts to assess the structural response and progressive failure process of cortical bone using a brittle damaged plasticity model. For this reason, several compressive tests are performed on cortical bone specimens made of bovine femur, in order to obtain the structural response and mechanical properties of the material. Complementary finite element (FE) model of the sample and test is prepared to simulate the elastic-to-damage behavior of the cortical bone using the brittle damaged plasticity model. The FE model is validated in a comparative method using the predicted and measured structural response as load-compressive displacement through simulation and experiment. FE results indicated that the compressive damage initiated and propagated at central region where maximum equivalent plastic strain is computed, which coincided with the degradation of structural compressive stiffness followed by a vast amount of strain energy dissipation. The parameter of compressive damage rate, which is a function dependent on damage parameter and the plastic strain is examined for different rates. Results show that considering a similar rate to the initial slope of the damage parameter in the experiment would give a better sense for prediction of compressive failure. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.)

Probabilistic assessment of flaw evaluation procedures for pressure vessel integrity

International Nuclear Information System (INIS)

Shaffer, D.H.; Bamford, W.H.; Jouris, G.M.

1980-01-01

Prudent design procedures, in order to err in the direction of conservative over-strength rather than risky under-strength, have taken bounding values rather than best estimates for material parameters, and wherever possible, used conservative input for the calculations. The growing data base for this work is now beginning to allow an assessment of the conservatism that has been incorporated into the design procedure. Quantitative estimates of the variability associated with crack growth rates and fracture toughness have been generated in connection with other studies, and it would be useful to incorporate such information into an overall assessment of the design margins that are prescribed. In addition to getting an estimate of the conservatism in the current procedure, this study should provide a useful insight into the relative degree of margin that is introduced at each stage of the flaw evaluation process. Identification of the step by step margins should lead to more effective data collection programs from which information for adequately controlling the design conservatism can be obtained. The study will also provide valuable guidance in fixing revised design reference curves and safety factors so that adequate overall margins can be maintained without excess conservatism. This study is limited to vessel rupture in a brittle mode, and examples for illustration are particularly related to the beltline region of a reactor pressure vessel. The methodology, however, is applicable to all regions for which the required stress analyses, operating history, and material parameters are available. The work being carried out here is in consonance with ASME Section XI on Flaw Evaluation Procedures. It is concerned both with flaws under normal operating conditions and flaws under faulted conditions. (author)

Analysis of field usage failure rate data for plastic encapsulated solid state devices

Science.gov (United States)

1981-01-01

Survey and questionnaire techniques were used to gather data from users and manufacturers on the failure rates in the field of plastic encapsulated semiconductors. It was found that such solid state devices are being successfully used by commercial companies which impose certain screening and qualification procedures. The reliability of these semiconductors is now adequate to support their consideration in NASA systems, particularly in low cost systems. The cost of performing necessary screening for NASA applications was assessed.

Preoperative short hookwire placement for small pulmonary lesions: evaluation of technical success and risk factors for initial placement failure.

Science.gov (United States)

Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Masaoka, Yoshihisa; Tanaka, Takashi; Sato, Takuya; Gobara, Hideo; Toyooka, Shinichi; Kanazawa, Susumu

2018-05-01

To retrospectively evaluate the technical success of computed tomography fluoroscopy-guided short hookwire placement before video-assisted thoracoscopic surgery and to identify the risk factors for initial placement failure. In total, 401 short hookwire placements for 401 lesions (mean diameter 9.3 mm) were reviewed. Technical success was defined as correct positioning of the hookwire. Possible risk factors for initial placement failure (i.e., requirement for placement of an additional hookwire or to abort the attempt) were evaluated using logistic regression analysis for all procedures, and for procedures performed via the conventional route separately. Of the 401 initial placements, 383 were successful and 18 failed. Short hookwires were finally placed for 399 of 401 lesions (99.5%). Univariate logistic regression analyses revealed that in all 401 procedures only the transfissural approach was a significant independent predictor of initial placement failure (odds ratio, OR, 15.326; 95% confidence interval, CI, 5.429-43.267; p < 0.001) and for the 374 procedures performed via the conventional route only lesion size was a significant independent predictor of failure (OR 0.793, 95% CI 0.631-0.996; p = 0.046). The technical success of preoperative short hookwire placement was extremely high. The transfissural approach was a predictor initial placement failure for all procedures and small lesion size was a predictor of initial placement failure for procedures performed via the conventional route. • Technical success of preoperative short hookwire placement was extremely high. • The transfissural approach was a significant independent predictor of initial placement failure for all procedures. • Small lesion size was a significant independent predictor of initial placement failure for procedures performed via the conventional route.

Developing best practices teaching procedures for skinfold assessment: observational examination using the Think Aloud method.

Science.gov (United States)

Holmstrup, Michael E; Verba, Steven D; Lynn, Jeffrey S

2015-12-01

Skinfold assessment is valid and economical; however, it has a steep learning curve, and many programs only include one exposure to the technique. Increasing the number of exposures to skinfold assessment within an undergraduate curriculum would likely increase skill proficiency. The present study combined observational and Think Aloud methodologies to quantify procedural and cognitive characteristics of skinfold assessment. It was hypothesized that 1) increased curricular exposure to skinfold assessment would improve proficiency and 2) the combination of an observational and Think Aloud analysis would provide quantifiable areas of emphasis for instructing skinfold assessment. Seventy-five undergraduates with varied curricular exposure performed a seven-site skinfold assessment on a test subject while expressing their thoughts aloud. A trained practitioner recorded procedural observations, with transcripts generated from audio recordings to capture cognitive information. Skinfold measurements were compared with a criterion value, and bias scores were generated. Participants whose total bias fell within ±3.5% of the criterion value were proficient, with the remainder nonproficient. An independent-samples t-test was used to compare procedural and cognitive observations across experience and proficiency groups. Additional curricular exposure improved performance of skinfold assessment in areas such as the measurement of specific sites (e.g., chest, abdomen, and thigh) and procedural (e.g., landmark identification) and cognitive skills (e.g., complete site explanation). Furthermore, the Think Aloud method is a valuable tool for determining curricular strengths and weaknesses with skinfold assessment and as a pedagogical tool for individual instruction and feedback in the classroom. Copyright © 2015 The American Physiological Society.

An analytical model for interactive failures

International Nuclear Information System (INIS)

Sun Yong; Ma Lin; Mathew, Joseph; Zhang Sheng

2006-01-01

In some systems, failures of certain components can interact with each other, and accelerate the failure rates of these components. These failures are defined as interactive failure. Interactive failure is a prevalent cause of failure associated with complex systems, particularly in mechanical systems. The failure risk of an asset will be underestimated if the interactive effect is ignored. When failure risk is assessed, interactive failures of an asset need to be considered. However, the literature is silent on previous research work in this field. This paper introduces the concepts of interactive failure, develops an analytical model to analyse this type of failure quantitatively, and verifies the model using case studies and experiments

PROCRU: A model for analyzing crew procedures in approach to landing

Science.gov (United States)

Baron, S.; Muralidharan, R.; Lancraft, R.; Zacharias, G.

1980-01-01

A model for analyzing crew procedures in approach to landing is developed. The model employs the information processing structure used in the optimal control model and in recent models for monitoring and failure detection. Mechanisms are added to this basic structure to model crew decision making in this multi task environment. Decisions are based on probability assessments and potential mission impact (or gain). Sub models for procedural activities are included. The model distinguishes among external visual, instrument visual, and auditory sources of information. The external visual scene perception models incorporate limitations in obtaining information. The auditory information channel contains a buffer to allow for storage in memory until that information can be processed.

Predisposing factors for peripheral intravenous puncture failure in children

OpenAIRE

Negri,Daniela Cavalcante de; Avelar,Ariane Ferreira Machado; Andreoni,Solange; Pedreira,Mavilde da Luz Gonçalvez

2012-01-01

OBJECTIVE: To identify predisposing factors for peripheral intravenous puncture failure in children. METHODS: Cross-sectional cohort study conducted with 335 children in a pediatric ward of a university hospital after approval of the ethics committee. The Wald Chi-squared, Prevalence Ratio (PR) and backward procedure (p≤0.05) tests were applied. RESULTS: Success of peripheral intravenous puncture was obtained in 300 (89.5%) children and failure in 35 (10.4%). The failure rates were sign...

European project for developing general guidelines for harmonising internal dose assessment procedures (IDEAS)

International Nuclear Information System (INIS)

Andrasi, A.; Bailey, M.; Puncher, M.; Berkovski, V.; Eric Blanchardon, E.; Jourdain, J.-R.; Carlo-Maria Castellani, C.-M.; Doerfel, H.; Christian Hurtgen, Ch.; Le Guen, B.

2003-01-01

Several international intercomparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly mainly because of the wide variety of methods and assumptions applied in the assessment procedure. Based on these experiences the need for harmonisation of the procedures has been formulated as an EU research project under the 5 th Framework Programme (2001-2005), with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project eight institutions from seven European countries are participating using inputs also from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. The IDEAS project is explained

Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

International Nuclear Information System (INIS)

Burton, Kirsteen R.; Guo, Lancia L. Q.; Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K.

2012-01-01

Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

Failure Assessment for the High-Strength Pipelines with Constant-Depth Circumferential Surface Cracks

OpenAIRE

X. Liu; Z. X. Lu; Y. Chen; Y. L. Sui; L. H. Dai

2018-01-01

In the oil and gas transportation system over long distance, application of high-strength pipeline steels can efficiently reduce construction and operation cost by increasing operational pressure and reducing the pipe wall thickness. Failure assessment is an important issue in the design, construction, and maintenance of the pipelines. The small circumferential surface cracks with constant depth in the welded pipelines are of practical interest. This work provides an engineering estimation pr...

Epistemic uncertainties when estimating component failure rate

International Nuclear Information System (INIS)

Jordan Cizelj, R.; Mavko, B.; Kljenak, I.

2000-01-01

A method for specific estimation of a component failure rate, based on specific quantitative and qualitative data other than component failures, was developed and is described in the proposed paper. The basis of the method is the Bayesian updating procedure. A prior distribution is selected from a generic database, whereas likelihood is built using fuzzy logic theory. With the proposed method, the component failure rate estimation is based on a much larger quantity of information compared to the presently used classical methods. Consequently, epistemic uncertainties, which are caused by lack of knowledge about a component or phenomenon are reduced. (author)

Proactive restoration of slow-failures in optical networks

DEFF Research Database (Denmark)

Siracusa, Domenico; Pederzolli, Federico; Salvadori, Elio

2014-01-01

Current optical networks, while offering outstanding reliability, still suffer from occasional failures. A resource-efficient procedure to handle these failures in un-protected scenarios is to perform restoration, i.e., to dynamically setup a backup lightpath after the primary one stops working......, which leads to traffic losses while such operation completes. In this paper we propose a technique, applicable to optical networks with centralized control, to better handle failures with slow transients. The idea is to proactively perform the backup lightpath's setup, triggered by either a fixed...

Readability Assessment of Online Patient Education Material on Congestive Heart Failure

Science.gov (United States)

2017-01-01

Background Online health information is being used more ubiquitously by the general population. However, this information typically favors only a small percentage of readers, which can result in suboptimal medical outcomes for patients. Objective The readability of online patient education materials regarding the topic of congestive heart failure was assessed through six readability assessment tools. Methods The search phrase “congestive heart failure” was employed into the search engine Google. Out of the first 100 websites, only 70 were included attending to compliance with selection and exclusion criteria. These were then assessed through six readability assessment tools. Results Only 5 out of 70 websites were within the limits of the recommended sixth-grade readability level. The mean readability scores were as follows: the Flesch-Kincaid Grade Level (9.79), Gunning-Fog Score (11.95), Coleman-Liau Index (15.17), Simple Measure of Gobbledygook (SMOG) index (11.39), and the Flesch Reading Ease (48.87). Conclusion Most of the analyzed websites were found to be above the sixth-grade readability level recommendations. Efforts need to be made to better tailor online patient education materials to the general population. PMID:28656111

Fibre failure assessment in carbon fibre reinforced polymers under fatigue loading by synchrotron X-ray computed tomography

OpenAIRE

Garcea, Serafina; Sinclair, Ian; Spearing, Simon

2016-01-01

In situ fatigue experiments using synchrotron X-ray computed tomography (SRCT) are used to assess the underpinning micromechanisms of fibre failure in double notch carbon/epoxy coupons. Observations showed fibre breaks along the 0º ply splits, associated with the presence and failure of bridging fibres, as well as fibres failed in the bulk composite within the 0º plies. A tendency for cluster formation, with multiple adjacent breaks in the bulk composite was observed when higher peak loads we...

Phantoms for quality control procedures in digital breast tomosynthesis: dose assessment

NARCIS (Netherlands)

Bouwman, R. W.; Diaz, O.; van Engen, R. E.; Young, K. C.; den Heeten, G. J.; Broeders, M. J. M.; Veldkamp, W. J. H.; Dance, D. R.

2013-01-01

The recent introduction of digital breast tomosynthesis into clinical practice requires quality control procedures. In this study we have investigated whether the assessment of the average glandular dose for modelled standard breasts can be performed using a combination of polymethyl methacrylate

Incorporating mesh-insensitive structural stress into the fatigue assessment procedure of common structural rules for bulk carriers

Directory of Open Access Journals (Sweden)

Seong-Min Kim

2015-01-01

Full Text Available This study introduces a fatigue assessment procedure using mesh-insensitive structural stress method based on the Common Structural Rules for Bulk Carriers by considering important factors, such as mean stress and thickness effects. The fatigue assessment result of mesh-insensitive structural stress method have been compared with CSR procedure based on equivalent notch stress at major hot spot points in the area near the ballast hold for a 180 K bulk carrier. The possibility of implementing mesh-insensitive structural stress method in the fatigue assessment procedure for ship structures is discussed.

Health and environmental impacts of electricity generation systems: procedures for comparative assessments

International Nuclear Information System (INIS)

Demin, V.F.

2002-01-01

The IAEA technical report involving description of the Manual for procedure of comparison risk assessment (CRA) and external cost (ECA) of environmental and public health effect from nuclear energetics and other power generation is treated. CRA and ECA results depend on national and regional social-economic, geographic, medical and demographic, and other features. When using CRA and ECA procedures developed in concrete countries their adaptation is necessary for conditions of other countries [ru

Assessment of the causes of failures of roto-dynamic equipment in Cirus

International Nuclear Information System (INIS)

Rao, K.N.; Singh, S.; Ganeshan, P.

1994-01-01

As a part of Cirus reactor life extension program study, a service life evaluation of critical roto-dynamic equipment in Cirus such as primary coolant pumps, and their concrete foundation structures, pressurised water loop pumps, main air compressors and supply and exhaust fans, was performed. An assessment of the causes of failures of roto-dynamic equipment in Cirus was done. Based on assessment of the degradation mitigating features and comparison to similar roto-dynamic equipment and their concrete foundation structures, it was concluded that life extension of these roto-dynamic equipment and their structures is feasible. To support this conclusion a program involving: a) non-destructive testing, b) surveillance and monitoring and, c) preventive maintenance is recommended. (author). 4 refs

The role of minimum supply and social vulnerability assessment for governing critical infrastructure failure: current gaps and future agenda

Directory of Open Access Journals (Sweden)

M. Garschagen

2018-04-01

Full Text Available Increased attention has lately been given to the resilience of critical infrastructure in the context of natural hazards and disasters. The major focus therein is on the sensitivity of critical infrastructure technologies and their management contingencies. However, strikingly little attention has been given to assessing and mitigating social vulnerabilities towards the failure of critical infrastructure and to the development, design and implementation of minimum supply standards in situations of major infrastructure failure. Addressing this gap and contributing to a more integrative perspective on critical infrastructure resilience is the objective of this paper. It asks which role social vulnerability assessments and minimum supply considerations can, should and do – or do not – play for the management and governance of critical infrastructure failure. In its first part, the paper provides a structured review on achievements and remaining gaps in the management of critical infrastructure and the understanding of social vulnerabilities towards disaster-related infrastructure failures. Special attention is given to the current state of minimum supply concepts with a regional focus on policies in Germany and the EU. In its second part, the paper then responds to the identified gaps by developing a heuristic model on the linkages of critical infrastructure management, social vulnerability and minimum supply. This framework helps to inform a vision of a future research agenda, which is presented in the paper's third part. Overall, the analysis suggests that the assessment of socially differentiated vulnerabilities towards critical infrastructure failure needs to be undertaken more stringently to inform the scientifically and politically difficult debate about minimum supply standards and the shared responsibilities for securing them.

The role of minimum supply and social vulnerability assessment for governing critical infrastructure failure: current gaps and future agenda

Science.gov (United States)

Garschagen, Matthias; Sandholz, Simone

2018-04-01

Increased attention has lately been given to the resilience of critical infrastructure in the context of natural hazards and disasters. The major focus therein is on the sensitivity of critical infrastructure technologies and their management contingencies. However, strikingly little attention has been given to assessing and mitigating social vulnerabilities towards the failure of critical infrastructure and to the development, design and implementation of minimum supply standards in situations of major infrastructure failure. Addressing this gap and contributing to a more integrative perspective on critical infrastructure resilience is the objective of this paper. It asks which role social vulnerability assessments and minimum supply considerations can, should and do - or do not - play for the management and governance of critical infrastructure failure. In its first part, the paper provides a structured review on achievements and remaining gaps in the management of critical infrastructure and the understanding of social vulnerabilities towards disaster-related infrastructure failures. Special attention is given to the current state of minimum supply concepts with a regional focus on policies in Germany and the EU. In its second part, the paper then responds to the identified gaps by developing a heuristic model on the linkages of critical infrastructure management, social vulnerability and minimum supply. This framework helps to inform a vision of a future research agenda, which is presented in the paper's third part. Overall, the analysis suggests that the assessment of socially differentiated vulnerabilities towards critical infrastructure failure needs to be undertaken more stringently to inform the scientifically and politically difficult debate about minimum supply standards and the shared responsibilities for securing them.

The constant failure rate model for fault tree evaluation as a tool for unit protection reliability assessment

International Nuclear Information System (INIS)

Vichev, S.; Bogdanov, D.

2000-01-01

The purpose of this paper is to introduce the fault tree analysis method as a tool for unit protection reliability estimation. The constant failure rate model applies for making reliability assessment, and especially availability assessment. For that purpose an example for unit primary equipment structure and fault tree example for simplified unit protection system is presented (author)

Development of a screening procedure for vibrational fatigue in small bore piping

International Nuclear Information System (INIS)

Smith, J.K.; Riccardella, P.C.; Gosselin, S.R.

1995-01-01

Approximately 80% of the documented fatigue failures in nuclear power plants are caused by high cycle vibrational fatigue. These failures typically occur in socket welded pipe fittings in small bore piping (2 in. nominal diameter and smaller). These failures have been unexpected, and have caused costly, unscheduled outages in some cases. In order to reduce the number of vibrational fatigue failures in operating nuclear power plants, a vibrational fatigue screening procedure has been developed under Electric Power Research Institute (EPRI) sponsorship. The purpose of this paper is to describe this procedure, and to discuss topics related to vibrational fatigue failures. These topics include sources of vibration in nuclear power plants, the effect of socket welds on vibrational fatigue failures, vibrational fatigue screening criteria for small bore piping systems, and good design practices for reducing the number of vibrational fatigue failures in small bore piping

IRS/TUEV activities during the licensing procedure. Safety assessment and preexamination

International Nuclear Information System (INIS)

Fendler, H.

1976-01-01

Short summary about the IRS/TUEV activities in the licensing procedure for a nuclear power plant: work for assessments, for pre-examination and approval specifications and drawings and for the quality control, time and the manpower necessary for this work. (orig./HP) [de

Development of internal dose assessment procedure for workers in industries using raw materials containing naturally occurring radioactive materials

International Nuclear Information System (INIS)

Choi, Cheol Kyu; KIm, Yong Geon; Ji, Seung Woo; Kim, Kwang Pyo; Koo, Bon Cheol; Chang, Byung Uck

2016-01-01

It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are 10 Bq·g-1 for 40K and 1 Bq·g-1 for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups (<0.1 mSv, 0.1-0.3 mSv, and >0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels (<0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and >1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries

Development of internal dose assessment procedure for workers in industries using raw materials containing naturally occurring radioactive materials

Energy Technology Data Exchange (ETDEWEB)

Choi, Cheol Kyu; KIm, Yong Geon; Ji, Seung Woo; Kim, Kwang Pyo [College of Engineering, Kyung Hee University, Yongin (Korea, Republic of); Koo, Bon Cheol; Chang, Byung Uck [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2016-09-15

It is necessary to assess radiation dose to workers due to inhalation of airborne particulates containing naturally occurring radioactive materials (NORM) to ensure radiological safety required by the Natural Radiation Safety Management Act. The objective of this study is to develop an internal dose assessment procedure for workers at industries using raw materials containing natural radionuclides. The dose assessment procedure was developed based on harmonization, accuracy, and proportionality. The procedure includes determination of dose assessment necessity, preliminary dose estimation, airborne particulate sampling and characterization, and detailed assessment of radiation dose. The developed dose assessment procedure is as follows. Radioactivity concentration criteria to determine dose assessment necessity are 10 Bq·g-1 for 40K and 1 Bq·g-1 for the other natural radionuclides. The preliminary dose estimation is performed using annual limit on intake (ALI). The estimated doses are classified into 3 groups (<0.1 mSv, 0.1-0.3 mSv, and >0.3 mSv). Air sampling methods are determined based on the dose estimates. Detailed dose assessment is performed using air sampling and particulate characterization. The final dose results are classified into 4 different levels (<0.1 mSv, 0.1-0.3 mSv, 0.3-1 mSv, and >1 mSv). Proper radiation protection measures are suggested according to the dose level. The developed dose assessment procedure was applied for NORM industries in Korea, including coal combustion, phosphate processing, and monazite handing facilities. The developed procedure provides consistent dose assessment results and contributes to the establishment of optimization of radiological protection in NORM industries.

Methodology for probability of failure assessment of offshore pipelines; Metodologia qualitativa de avaliacao da probabilidade de falha de dutos rigidos submarinos estaticos

Energy Technology Data Exchange (ETDEWEB)

Pezzi Filho, Mario [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2005-07-01

In this study it is presented a methodology for assessing the likelihood of failure for every failure mechanism defined for carbon steel static offshore pipelines. This methodology is aimed to comply with the Integrity Management policy established by the Company. Decision trees are used for the development of the methodology and the evaluation of the extent and the significance of these failure mechanisms. Decision trees enable also the visualization of the logical structure of algorithms which eventually will be used in risk assessment software. The benefits of the proposed methodology are presented and it is recommended that it be tested on static offshore pipelines installed in different assets for validation. (author)

Assessment of Conventional Teaching Procedures: Implications for Gifted Learners

Directory of Open Access Journals (Sweden)

Mogbel Aid K Alenizi

2016-07-01

Full Text Available The present research aims to assess the conventional teaching procedures in the development of mathematical skills of the students with learning difficulties. The study group was made up of all the children with academic learning disorders in KSA. The research questions have been scrutinized from the averages and the standard deviation of the marks scored by the participants in the test and control group. The outcomes of the study show that the conventional teaching procedures have effects on mathematical skill development of the female pupils with learning disorders. The results of the study show that the test group outperformed the control group. Based on the data and the evidences, various recommendations have been proposed for the stakeholders in the area of teaching the gifted children so as to ascertain better training for them. Keywords: Maths skills, Learning difficulties, Saudi Arabia

A cadaveric procedural anatomy simulation course improves video-based assessment of operative performance.

Science.gov (United States)

Sharma, Gaurav; Aycart, Mario A; O'Mara, Lynne; Havens, Joaquim; Nehs, Matthew; Shimizu, Naomi; Smink, Douglas S; Gravereaux, Edwin; Gates, Jonathan D; Askari, Reza

2018-03-01

Inadequate anatomic knowledge has been cited as a major contributor to declining surgical resident operative competence. We analyzed the impact of a comprehensive, procedurally oriented cadaveric procedural anatomy dissection laboratory on the operative performance of surgery residents, hypothesizing that trainees' performance of surgical procedures would improve after such a dissection course. Midlevel general surgery residents (n = 9) participated in an 8 wk, 16-h surgery faculty-led procedurally oriented cadaver simulation course. Both before and after completion of the course, residents participated in a practical examination, in which they were randomized to perform one of nine Surgical Council on Resident Education-designated "essential" procedures. The procedures were recorded using wearable video technology. Videos were deidentified before evaluation by six faculty raters blinded to examinee and whether performances occurred before or after an examinee had taken the course. Raters used the validated Operative Performance Rating System and Objective Structured Assessment of Technical Skill scales. After the course residents had higher procedure-specific scores (median, 4.0 versus 2.4, P 4.0 versus 3.0, P = 0.006), respect for tissue (4.0 versus 3.0, P = 0.0004), time and motion (3.0 versus 2.0, P = 0.0007), operation flow (3.0 versus 2.0, P = 0.0005), procedural knowledge (4.0 versus 2.0, P = 0.0001), and overall performance scores (4.0 versus 2.0, P < 0.0001). Operative Performance Rating System and Objective Structured Assessment of Technical Skill scales averaged by number of items in each were also higher (3.2 versus 2.0, P = 0.0002 and 3.1 versus 2.2, P = 0.002, respectively). A cadaveric procedural anatomy simulation course covering a broad range of open general surgery procedures was associated with significant improvements in trainees' operative performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of support system failure limitations on probabilistic safety assessment and in regulatory decision making

International Nuclear Information System (INIS)

Bickel, J.H.

1990-01-01

When used as a tool for safety decision making, Probabilistic Safety Assessment (PSA) is as effective as it realistically characterizes the overall frequency and consequences of various types of system and component failures. If significant support system failure events are omitted from consideration, the PSA process omits the characterization of possible unique contributors to core damage risk, possibly underestimates the frequency of core damage, and reduces the future utility of the PSA as a decision making tool for the omitted support system. This paper is based on a review of several recent US PSA studies and the author's participation in several International Atomic Energy Agency (IAEA) sponsored peer reviews. 21 refs., 2 figs., 1 tab

NEESROCK: A Physical and Numerical Modeling Investigation of Seismically Induced Rock-Slope Failure

Science.gov (United States)

Applegate, K. N.; Wartman, J.; Keefer, D. K.; Maclaughlin, M.; Adams, S.; Arnold, L.; Gibson, M.; Smith, S.

2013-12-01

Worldwide, seismically induced rock-slope failures have been responsible for approximately 30% of the most significant landslide catastrophes of the past century. They are among the most common, dangerous, and still today, least understood of all seismic hazards. Seismically Induced Rock-Slope Failure: Mechanisms and Prediction (NEESROCK) is a major research initiative that fully integrates physical modeling (geotechnical centrifuge) and advanced numerical simulations (discrete element modeling) to investigate the fundamental mechanisms governing the stability of rock slopes during earthquakes. The research is part of the National Science Foundation-supported Network for Earthquake Engineering Simulation Research (NEES) program. With its focus on fractures and rock materials, the project represents a significant departure from the traditional use of the geotechnical centrifuge for studying soil, and pushes the boundaries of physical modeling in new directions. In addition to advancing the fundamental understanding of the rock-slope failure process under seismic conditions, the project is developing improved rock-slope failure assessment guidelines, analysis procedures, and predictive tools. Here, we provide an overview of the project, present experimental and numerical modeling results, discuss special considerations for the use of synthetic rock materials in physical modeling, and address the suitability of discrete element modeling for simulating the dynamic rock-slope failure process.

Financial and testamentary capacity evaluations: procedures and assessment instruments underneath a functional approach.

Science.gov (United States)

Sousa, Liliana B; Simões, Mário R; Firmino, Horácio; Peisah, Carmelle

2014-02-01

Mental health professionals are frequently involved in mental capacity determinations. However, there is a lack of specific measures and well-defined procedures for these evaluations. The main purpose of this paper is to provide a review of financial and testamentary capacity evaluation procedures, including not only the traditional neuropsychological and functional assessment but also the more recently developed forensic assessment instruments (FAIs), which have been developed to provide a specialized answer to legal systems regarding civil competencies. Here the main guidelines, papers, and other references are reviewed in order to achieve a complete and comprehensive selection of instruments used in the assessment of financial and testamentary capacity. Although some specific measures for financial abilities have been developed recently, the same is not true for testamentary capacity. Here are presented several instruments or methodologies for assessing financial and testamentary capacity, including neuropsychological assessment, functional assessment scales, performance based functional assessment instruments, and specific FAIs. FAIs are the only specific instruments intended to provide a specific and direct answer to the assessment of financial capacity based on legal systems. Considering the need to move from a diagnostic to a functional approach in financial and testamentary capacity evaluations, it is essential to consider both general functional examination as well as cognitive functioning.

Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR): Guide to data processing and revision: Part 2, Human error probability data entry and revision procedures

International Nuclear Information System (INIS)

Gilmore, W.E.; Gertman, D.I.; Gilbert, B.G.; Reece, W.J.

1988-11-01

The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) is an automated data base management system for processing and storing human error probability (HEP) and hardware component failure data (HCFD). The NUCLARR system software resides on an IBM (or compatible) personal micro-computer. Users can perform data base searches to furnish HEP estimates and HCFD rates. In this manner, the NUCLARR system can be used to support a variety of risk assessment activities. This volume, Volume 3 of a 5-volume series, presents the procedures used to process HEP and HCFD for entry in NUCLARR and describes how to modify the existing NUCLARR taxonomy in order to add either equipment types or action verbs. Volume 3 also specifies the various roles of the administrative staff on assignment to the NUCLARR Clearinghouse who are tasked with maintaining the data base, dealing with user requests, and processing NUCLARR data. 5 refs., 34 figs., 3 tabs

Analytical Study of different types Of network failure detection and possible remedies

Science.gov (United States)

Saxena, Shikha; Chandra, Somnath

2012-07-01

Faults in a network have various causes,such as the failure of one or more routers, fiber-cuts, failure of physical elements at the optical layer, or extraneous causes like power outages. These faults are usually detected as failures of a set of dependent logical entities and the links affected by the failed components. A reliable control plane plays a crucial role in creating high-level services in the next-generation transport network based on the Generalized Multiprotocol Label Switching (GMPLS) or Automatically Switched Optical Networks (ASON) model. In this paper, approaches to control-plane survivability, based on protection and restoration mechanisms, are examined. Procedures for the control plane state recovery are also discussed, including link and node failure recovery and the concepts of monitoring paths (MPs) and monitoring cycles (MCs) for unique localization of shared risk linked group (SRLG) failures in all-optical networks. An SRLG failure is a failure of multiple links due to a failure of a common resource. MCs (MPs) start and end at same (distinct) monitoring location(s). They are constructed such that any SRLG failure results in the failure of a unique combination of paths and cycles. We derive necessary and sufficient conditions on the set of MCs and MPs needed for localizing an SRLG failure in an arbitrary graph. Procedure of Protection and Restoration of the SRLG failure by backup re-provisioning algorithm have also been discussed.

Video observation of procedural skills for assessment of trabeculectomy performed by residents.

Science.gov (United States)

Hassanpour, Narges; Chen, Rebecca; Baikpour, Masoud; Moghimi, Sasan

2016-06-01

The efficacy and sufficiency of a healthcare system is directly related to the knowledge and skills of graduates working in the system. In this regard, many different assessment methods have been proposed to evaluate various skills of the learners. Video Observation of Procedural Skills (VOPS) is one newly-proposed method. In this study we aimed to compare the results of the VOPS method with the more commonly used Direct Observation of Procedural Skills (DOPS). In this prospective study conducted in 2012, all 10 ophthalmology residents of post graduate year 4 were selected for participation. Three months into training in the glaucoma ward, these residents performed trabeculectomy surgery on patients, and their procedural skills were assessed in real time by an expert via the DOPS method. All surgeries were also recorded and later evaluated via the VOPS method by an expert. Bland-Altman plot also was used to compare the two methods and calculating the mean and 95% limit of agreement. Residents have been done a mean of 14.9 ± 3.5 (range 10-20) independent trabeculectomy before the assessments. DOPS grade was positively associated with number of independent trabeculectomy during glaucoma rotation (β=0.227, p = 0.004). The intra-observer reproducibility of VOPS measurements was 0.847 (95% CI: 0.634, 0.961). The mean VOPS grade was significantly lower than the mean DOPS grade (8.4 vs. 8.9, p = 0.02). However, a good correlation was observed between the grades of VOPS and DOPS (r = 0.89, p = 0.001). Bland-Altman analysis demonstrated that all data points fell within the 95% limits of agreement (-1.46, 0.46). The present study showed that VOPS might be considered a feasible, valid, and reliable assessment method for procedural skills of medical students and residents that can be used as an alternative to the DOPS method. However, VOPS might underestimate DOPS in evaluating surgical skills of residents.

A probabilistic assessment procedure for evaluating and comparing various NDT methods

International Nuclear Information System (INIS)

Kauer, R.; Guo, W.F.; Schall, M.

2005-01-01

By applying NDT methodologies to assess the integrity of a certain structure, it is strictly recommended to have knowledge about the advantages and disadvantages of the various methods. Especially when new technologies shall be applied, the final question always will be: What is the influence on the overall integrity of the structure? Here, different Probability of Detection (PoD) capacities in combination with different accuracies in sizing a flaw and in combination with different initial crack distributions e.g. resulting from various fabrication methods yield to different values regarding false call rate, rejection rate, and failure rate. So the final goal must be to select the most appropriate and efficient methodology as well as a suitable acceptance criteria addressing the specific advantages and disadvantages of each method. Usually these acceptance criteria are given in the relevant codes. However, often there are various levels of acceptance given, depending on the criticality of the service conditions. In other cases, more information is needed about the consequences of those acceptance criteria to a specific structure. Another application might be the evaluation of a 'new' NDT technology in comparison to an established one. For this purpose, we present a probabilistic evaluation method starting with the initial failure distribution and taking into account PoD and sizing capacities of certain NDT-methods. Finally, Failure Rate, False Call Rate, and Rejection Rate can be presented with respect to the acceptance criteria chosen. (authors)

14 CFR 25.1585 - Operating procedures.

Science.gov (United States)

2010-01-01

...) Non-normal procedures for malfunction cases and failure conditions involving the use of special... envelopes, determined under § 25.251 must be furnished. The buffet onset envelopes presented may reflect the...

Human Reliability Analysis For Computerized Procedures

International Nuclear Information System (INIS)

Boring, Ronald L.; Gertman, David I.; Le Blanc, Katya

2011-01-01

This paper provides a characterization of human reliability analysis (HRA) issues for computerized procedures in nuclear power plant control rooms. It is beyond the scope of this paper to propose a new HRA approach or to recommend specific methods or refinements to those methods. Rather, this paper provides a review of HRA as applied to traditional paper-based procedures, followed by a discussion of what specific factors should additionally be considered in HRAs for computerized procedures. Performance shaping factors and failure modes unique to computerized procedures are highlighted. Since there is no definitive guide to HRA for paper-based procedures, this paper also serves to clarify the existing guidance on paper-based procedures before delving into the unique aspects of computerized procedures.

The costs of failure: A preliminary assessment of major energy accidents, 1907-2007

International Nuclear Information System (INIS)

Sovacool, Benjamin K.

2008-01-01

A combination of technical complexity, tight coupling, speed, and human fallibility contribute to the unexpected failure of large-scale energy technologies. This study offers a preliminary assessment of the social and economic costs of major energy accidents from 1907 to 2007. It documents 279 incidents that have been responsible for $41 billion in property damage and 182,156 deaths. Such disasters highlight an often-ignored negative externality to energy production and use, and emphasize the need for further research

Usage of Failure Mode & EffectAnalysis Method (FMEA forsafety assessment in a drug manufacture

Directory of Open Access Journals (Sweden)

Y Nazari

2006-04-01

Full Text Available Background and Aims: This study was hold in purpose of recognizing and controlling workplacehazards in production units of a drag ManufactureMethod:So for recognition and assessment of hazards, FMEA Method was used. FMEASystematically investigates the effects of equipment and system failures leading often toequipment design improvements. At first the level of the study defined as system. Then accordingto observations, accident statistic, and interview with managers, supervisory, and workers highrisk system were determiner. So the boundaries of the system established and informationregarding the relevant Components, their function and interactions gathered. To preventConfusion between Similar pieces of equipment, a unique system identifier developed. After thatall failure modes and their causes for each equipment or system listed, the immediate effects ofeach failure mode and interactive effect on other equipment or system was described too. Riskpriority number was determined according to global and local criteriaResults: After all some actions and solution proposed to reduce the likelihood and severity offailures and raise their delectability.Conclusion :This study illustrated that although of the first step drug manufacture may seem safe,but there are still many hazardous condition that could cause serious accidents, The result proposedit is necessary: (1 to develop comprehensive manual for periodical and regular inspection ofinstruments of workplaces in purpose of recognize unknown failures and their causes, (2 developa comprehensive program for systems maintenance and repair, and (3 conduct worker training.

Valvular Heart Disease in Heart Failure

Directory of Open Access Journals (Sweden)

Giuseppe MC Rosano

2017-01-01

Full Text Available Structural valvular heart disease may be the cause of heart failure or may worsen the clinical status of patients with heart failure. Heart failure may also develop in patients treated with valve surgery. Patients with heart failure with valvular heart disease are at increased risk of events including sudden cardiac death. Before considering intervention (surgical or percutaneous all patients should receive appropriate medical and device therapy taking into account that vasodilators must be used with caution in patients with severe aortic stenosis. Numerous percutaneous and/or hybrid procedures have been introduced in the past few years and they are changing the management of valvular heart disease. In patients with heart failure and valvular heart disease, either primary or functional, the whole process of decision-making should be staged through a comprehensive evaluation of the risk– benefit ratio of different treatment strategies and should be made by a multidisciplinary ‘heart team’ with a particular expertise in valvular heart disease. The heart team should include heart failure cardiologists, cardiac surgeons/structural valve interventionists, imaging specialists, anaesthetists, geriatricians and intensive care specialists. This article will review recent developments and distill practical guidance in the management of this important heart failure co-morbidity.

Updating of adventitious fuel pin failure frequency in sodium-cooled fast reactors and probabilistic risk assessment on consequent severe accident in Monju

International Nuclear Information System (INIS)

Fukano, Yoshitaka; Kurisaka, Kenichi; Nishimura, Masahiro; Naruto, Kenichi

2015-01-01

Experimental studies, deterministic approaches and probabilistic risk assessments (PRAs) on local fault (LF) propagation in sodium-cooled fast reactors (SFRs) have been performed in many countries because LFs have been historically considered as one of the possible causes of severe accidents. Adventitious-fuel-pin-failures (AFPFs) have been considered to be the most dominant initiators of LFs in these PRAs because of their high frequency of occurrence during reactor operation and possibility of fuel-element-failure-propagation (FEFP). A PRA on FEFP from AFPF (FEFPA) in the Japanese prototype SFR (Monju) was performed in this study based on the state-of-the-art knowledge, reflecting the most recent operation procedures under off-normal conditions. Frequency of occurrence of AFPF in SFRs which was the initiating event of the event tree in this PRA was updated using a variety of methods based on the above-mentioned latest review on experiences of this phenomenon. As a result, the frequency of occurrence of, and the core damage frequency (CDF) from, AFPF in Monju was significantly reduced to a negligible magnitude compared with those in the existing PRAs. It was, therefore concluded that the CDF of FEFPA in Monju could be comprised in that of anticipated transient without scram or protected loss of heat sink events from both the viewpoint of occurrence probability and consequences. (author)

A Procedural Skills OSCE: Assessing Technical and Non-Technical Skills of Internal Medicine Residents

Science.gov (United States)

Pugh, Debra; Hamstra, Stanley J.; Wood, Timothy J.; Humphrey-Murto, Susan; Touchie, Claire; Yudkowsky, Rachel; Bordage, Georges

2015-01-01

Internists are required to perform a number of procedures that require mastery of technical and non-technical skills, however, formal assessment of these skills is often lacking. The purpose of this study was to develop, implement, and gather validity evidence for a procedural skills objective structured clinical examination (PS-OSCE) for internal…

FRP-RC Beam in Shear: Mechanical Model and Assessment Procedure for Pseudo-Ductile Behavior

Directory of Open Access Journals (Sweden)

Floriana Petrone

2014-07-01

Full Text Available This work deals with the development of a mechanics-based shear model for reinforced concrete (RC elements strengthened in shear with fiber-reinforced polymer (FRP and a design/assessment procedure capable of predicting the failure sequence of resisting elements: the yielding of existing transverse steel ties and the debonding of FRP sheets/strips, while checking the corresponding compressive stress in concrete. The research aims at the definition of an accurate capacity equation, consistent with the requirement of the pseudo-ductile shear behavior of structural elements, that is, transverse steel ties yield before FRP debonding and concrete crushing. For the purpose of validating the proposed model, an extended parametric study and a comparison against experimental results have been conducted: it is proven that the common accepted rule of assuming the shear capacity of RC members strengthened in shear with FRP as the sum of the maximum contribution of both FRP and stirrups can lead to an unsafe overestimation of the shear capacity. This issue has been pointed out by some authors, when comparing experimental shear capacity values with the theoretical ones, but without giving a convincing explanation of that. In this sense, the proposed model represents also a valid instrument to better understand the mechanical behavior of FRP-RC beams in shear and to calculate their actual shear capacity.

The prehospital intravenous access assessment: a prospective study on intravenous access failure and access delay in prehospital emergency medicine.

Science.gov (United States)

Prottengeier, Johannes; Albermann, Matthias; Heinrich, Sebastian; Birkholz, Torsten; Gall, Christine; Schmidt, Joachim

2016-12-01

Intravenous access in prehospital emergency care allows for early administration of medication and extended measures such as anaesthesia. Cannulation may, however, be difficult, and failure and resulting delay in treatment and transport may have negative effects on the patient. Therefore, our study aims to perform a concise assessment of the difficulties of prehospital venous cannulation. We analysed 23 candidate predictor variables on peripheral venous cannulations in terms of cannulation failure and exceedance of a 2 min time threshold. Multivariate logistic regression models were fitted for variables of predictive value (P0.6) of their respective receiver operating characteristic curve. A total of 762 intravenous cannulations were enroled. In all, 22% of punctures failed on the first attempt and 13% of punctures exceeded 2 min. Model selection yielded a three-factor model (vein visibility without tourniquet, vein palpability with tourniquet and insufficient ambient lighting) of fair accuracy for the prediction of puncture failure (AUC=0.76) and a structurally congruent model of four factors (failure model factors plus vein visibility with tourniquet) for the exceedance of the 2 min threshold (AUC=0.80). Our study offers a simple assessment to identify cases of difficult intravenous access in prehospital emergency care. Of the numerous factors subjectively perceived as possibly exerting influences on cannulation, only the universal - not exclusive to emergency care - factors of lighting, vein visibility and palpability proved to be valid predictors of cannulation failure and exceedance of a 2 min threshold.

Endovascular retrieval of a CardioMEMS heart failure system

Directory of Open Access Journals (Sweden)

Arun Reghunathan, MD

2018-04-01

Full Text Available As the creation and utilization of new implantable devices increases, so does the need for interventionalists to devise unique retrieval mechanisms. This report describes the first endovascular retrieval of a CardioMEMS heart failure monitoring device. A 20-mm gooseneck snare was utilized in conjunction with a 9-French sheath and Envoy catheter for retrieval. The patient suffered no immediate postprocedural complications but died 5 days after the procedure from multiorgan failure secondary to sepsis. Keywords: CardioMEMS heart failure system, Endovascular retrieval

Development of residual stress analysis procedure for fitness-for-service assessment of welded structure

International Nuclear Information System (INIS)

Kim, Jong Sung; Jin, Tae Eun; Dong, P.; Prager, M.

2003-01-01

In this study, a state of art review of existing residual stress analysis techniques and representative solutions is presented in order to develop the residual stress analysis procedure for Fitness-For-Service(FFS) assessment of welded structure. Critical issues associated with existing residual stress solutions and their treatments in performing FFS are discussed. It should be recognized that detailed residual stress evolution is an extremely complicated phenomenon that typically involves material-specific thermomechanical/metallurgical response, welding process physics, and structural interactions within a component being welded. As a result, computational procedures can vary significantly from highly complicated numerical techniques intended only to elucidate a small part of the process physics to cost-effective procedures that are deemed adequate for capturing some of the important features in a final residual stress distribution. Residual stress analysis procedure for FFS purposes belongs to the latter category. With this in mind, both residual stress analysis techniques and their adequacy for FFS are assessed based on both literature data and analyses performed in this investigation

A new method for explicit modelling of single failure event within different common cause failure groups

International Nuclear Information System (INIS)

Kančev, Duško; Čepin, Marko

2012-01-01

Redundancy and diversity are the main principles of the safety systems in the nuclear industry. Implementation of safety components redundancy has been acknowledged as an effective approach for assuring high levels of system reliability. The existence of redundant components, identical in most of the cases, implicates a probability of their simultaneous failure due to a shared cause—a common cause failure. This paper presents a new method for explicit modelling of single component failure event within multiple common cause failure groups simultaneously. The method is based on a modification of the frequently utilised Beta Factor parametric model. The motivation for development of this method lays in the fact that one of the most widespread softwares for fault tree and event tree modelling as part of the probabilistic safety assessment does not comprise the option for simultaneous assignment of single failure event to multiple common cause failure groups. In that sense, the proposed method can be seen as an advantage of the explicit modelling of common cause failures. A standard standby safety system is selected as a case study for application and study of the proposed methodology. The results and insights implicate improved, more transparent and more comprehensive models within probabilistic safety assessment.

A method to assign failure rates for piping reliability assessments

International Nuclear Information System (INIS)

Gamble, R.M.; Tagart, S.W. Jr.

1991-01-01

This paper reports on a simplified method that has been developed to assign failure rates that can be used in reliability and risk studies of piping. The method can be applied on a line-by-line basis by identifying line and location specific attributes that can lead to piping unreliability from in-service degradation mechanisms and random events. A survey of service experience for nuclear piping reliability also was performed. The data from this survey provides a basis for identifying in-service failure attributes and assigning failure rates for risk and reliability studies

[THE FAILURE MODES AND EFFECTS ANALYSIS FACILITATES A SAFE, TIME AND MONEY SAVING OPEN ACCESS COLONOSCOPY SERVICE].

Science.gov (United States)

Gingold-Belfer, Rachel; Niv, Yaron; Horev, Nehama; Gross, Shuli; Sahar, Nadav; Dickman, Ram

2017-04-01

Failure modes and effects analysis (FMEA) is used for the identification of potential risks in health care processes. We used a specific FMEA - based form for direct referral for colonoscopy and assessed it for procedurerelated perforations. Ten experts in endoscopy evaluated and computed the entire referral process, modes of preparation for the endoscopic procedure, the endoscopic procedure itself and the discharge process. We used FMEA assessing for likelihood of occurrence, detection and severity and calculated the risk profile number (RPN) for each of the above points. According to the highest RPN results we designed a specific open access referral form and then compared the occurrence of colonic perforations (between 2010 and 2013) in patients who were referred through the open access arm (Group 1) to those who had a prior clinical consultation (non-open access, Group 2). Our experts in endoscopy (5 physicians and 5 nurses) identified 3 categories of failure modes that, on average, reached the highest RPNs. We identified 9,558 colonoscopies in group 1, and 12,567 in group 2. Perforations were identified in three patients from the open access group (1:3186, 0.03%) and in 10 from group 2 (1:1256, 0.07%) (p = 0.024). Direct referral for colonoscopy saved 9,558 pre-procedure consultations and the sum of $850,000. The FMEA tool-based specific referral form facilitates a safe, time and money saving open access colonoscopy service. Our form may be adopted by other gastroenterological clinics in Israel.

Uncertainty analysis on probabilistic fracture mechanics assessment methodology

International Nuclear Information System (INIS)

Rastogi, Rohit; Vinod, Gopika; Chandra, Vikas; Bhasin, Vivek; Babar, A.K.; Rao, V.V.S.S.; Vaze, K.K.; Kushwaha, H.S.; Venkat-Raj, V.

1999-01-01

Fracture Mechanics has found a profound usage in the area of design of components and assessing fitness for purpose/residual life estimation of an operating component. Since defect size and material properties are statistically distributed, various probabilistic approaches have been employed for the computation of fracture probability. Monte Carlo Simulation is one such procedure towards the analysis of fracture probability. This paper deals with uncertainty analysis using the Monte Carlo Simulation methods. These methods were developed based on the R6 failure assessment procedure, which has been widely used in analysing the integrity of structures. The application of this method is illustrated with a case study. (author)

Failure mode and effects analysis based risk profile assessment for stereotactic radiosurgery programs at three cancer centers in Brazil

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Flavia C., E-mail: flavitiz@gmail.com [CNEN—Comissao Nacional de Energia Nuclear, Rio de Janeiro, RJ 22290-901, Brazil and LCR/UERJ—Laboratorio de Ciencias Radiologicas/Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ 20550-013 (Brazil); Almeida, Carlos E. de [LCR/UERJ—Laboratorio de Ciencias Radiologicas/Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ 20550-013 (Brazil); Saiful Huq, M. [Department of Radiation Oncology, University of Pittsburgh Cancer Institute and UPMC Cancer Center, Pittsburgh, Pennsylvania 15232 (United States)

2016-01-15

Purpose: The goal of this study was to evaluate the safety and quality management program for stereotactic radiosurgery (SRS) treatment processes at three radiotherapy centers in Brazil by using three industrial engineering tools (1) process mapping, (2) failure modes and effects analysis (FMEA), and (3) fault tree analysis. Methods: The recommendations of Task Group 100 of American Association of Physicists in Medicine were followed to apply the three tools described above to create a process tree for SRS procedure for each radiotherapy center and then FMEA was performed. Failure modes were identified for all process steps and values of risk priority number (RPN) were calculated from O, S, and D (RPN = O × S × D) values assigned by a professional team responsible for patient care. Results: The subprocess treatment planning was presented with the highest number of failure modes for all centers. The total number of failure modes were 135, 104, and 131 for centers I, II, and III, respectively. The highest RPN value for each center is as follows: center I (204), center II (372), and center III (370). Failure modes with RPN ≥ 100: center I (22), center II (115), and center III (110). Failure modes characterized by S ≥ 7, represented 68% of the failure modes for center III, 62% for center II, and 45% for center I. Failure modes with RPNs values ≥100 and S ≥ 7, D ≥ 5, and O ≥ 5 were considered as high priority in this study. Conclusions: The results of the present study show that the safety risk profiles for the same stereotactic radiotherapy process are different at three radiotherapy centers in Brazil. Although this is the same treatment process, this present study showed that the risk priority is different and it will lead to implementation of different safety interventions among the centers. Therefore, the current practice of applying universal device-centric QA is not adequate to address all possible failures in clinical processes at different

Failure mode and effects analysis based risk profile assessment for stereotactic radiosurgery programs at three cancer centers in Brazil

International Nuclear Information System (INIS)

Teixeira, Flavia C.; Almeida, Carlos E. de; Saiful Huq, M.

2016-01-01

Purpose: The goal of this study was to evaluate the safety and quality management program for stereotactic radiosurgery (SRS) treatment processes at three radiotherapy centers in Brazil by using three industrial engineering tools (1) process mapping, (2) failure modes and effects analysis (FMEA), and (3) fault tree analysis. Methods: The recommendations of Task Group 100 of American Association of Physicists in Medicine were followed to apply the three tools described above to create a process tree for SRS procedure for each radiotherapy center and then FMEA was performed. Failure modes were identified for all process steps and values of risk priority number (RPN) were calculated from O, S, and D (RPN = O × S × D) values assigned by a professional team responsible for patient care. Results: The subprocess treatment planning was presented with the highest number of failure modes for all centers. The total number of failure modes were 135, 104, and 131 for centers I, II, and III, respectively. The highest RPN value for each center is as follows: center I (204), center II (372), and center III (370). Failure modes with RPN ≥ 100: center I (22), center II (115), and center III (110). Failure modes characterized by S ≥ 7, represented 68% of the failure modes for center III, 62% for center II, and 45% for center I. Failure modes with RPNs values ≥100 and S ≥ 7, D ≥ 5, and O ≥ 5 were considered as high priority in this study. Conclusions: The results of the present study show that the safety risk profiles for the same stereotactic radiotherapy process are different at three radiotherapy centers in Brazil. Although this is the same treatment process, this present study showed that the risk priority is different and it will lead to implementation of different safety interventions among the centers. Therefore, the current practice of applying universal device-centric QA is not adequate to address all possible failures in clinical processes at different

NASA Safety Standard: Guidelines and Assessment Procedures for Limiting Orbital Debris

Science.gov (United States)

1995-01-01

Collision with orbital debris is a hazard of growing concern as historically accepted practices and procedures have allowed man-made objects to accumulate in orbit. To limit future debris generation, NASA Management Instruction (NMI) 1700.8, 'Policy to Limit Orbital Debris Generation,' was issued in April of 1993. The NMI requires each program to conduct a formal assessment of the potential to generate orbital debris. This document serves as a companion to NMI 1700.08 and provides each NASA program with specific guidelines and assessment methods to assure compliance with the NMI. Each main debris assessment issue (e.g., Post Mission Disposal) is developed in a separate chapter.

Procedural advice on self-assessment and task selection in learner-controlled education

NARCIS (Netherlands)

Taminiau, Bettine; Corbalan, Gemma; Kester, Liesbeth; Van Merriënboer, Jeroen; Kirschner, Paul A.

2011-01-01

Taminiau, E. M. C., Corbalan, G., Kester, L., Van Merriënboer, J. J. G., & Kirschner, P. A. (2010, March). Procedural advice on self-assessment and task selection in learner-controlled education. Presentation at the ICO Springschool, Niederalteich, Germany.

Analysis of non simultaneous common mode failures. Application to the reliability assessment of the decay heat removal of the RNR 1500 project

International Nuclear Information System (INIS)

Natta, M.; Bloch, M.

1991-01-01

The experience with the LMFBR PHENIX has shown many cases of failures on identical and redundant components, which were close in time but not simultaneous and due to the same causes such as a design error, an unappropriate material, corrosion, ... Since the decay heat removal (DHR) must be assured for a long period after shutdown of the reactor, the overall reliability of the DHR system depends much on this type of successive failures by common mode causes, for which the usual β factor methods are not appropriate since they imply that the several failures are simultaneous. In this communication, two methods will be presented. The first one was used to assess the reliability of the DHR system of the RNR 1500 project. In this method, one modelize the occurrence of successive failures on n identical files by a sudden jump of the failure rate from the value λ attributed to the first failure to the value λ' attributed to the (n-1) still available files. This method leads to a quite natural quantification of the interest of diversity for highly redundant systems. For the RNR 1500 project where, in case of the loss of normal DHR path through the steam generators, the decay heat is removed by four separated sodium loops of 26 MW unit capacity in forced convection, the probabilistic assessment shows that it is necessary to diversify the sodium-sodium heat exchanger in order to fullfil the upper limit of 10 -7 /year for the probability of failure of DHR. A separate assessment for the main sequence leading to DHR loss was performed using a different method in which the successive failures are interpreted as a premature end of life, the lifetimes being directly used as random variables. This Monte-Carlo type method, which can be applied to any type of lifetime distribution, leads to results consistent to those obtained with the first one

Survey Procedures Manual for the Environmental Survey and Site Assessment Program (ESSAP). Revision 10

International Nuclear Information System (INIS)

2000-01-01

The Environmental Survey and Site Assessment Program (ESSAP) of the Oak Ridge Institute for Science and Education (ORISE) conducts radiological survey activities under a contract with the U. S. Department of Energy (DOE) and for the U.S. Nuclear Regulatory Commission (NRC). ORISE and its programs are operated by Oak Ridge Associated Universities (ORAU) through a contract with DOE. The purpose of this Procedures Manual is to provide a standardized set of procedures that document activities of the program in an auditable manner. These procedures are applicable to both DOE and NRC operations. Procedures presented in this manual are limited to those associated with site survey activities

Canagliflozin and Heart Failure in Type 2 Diabetes Mellitus: Results From the CANVAS Program (Canagliflozin Cardiovascular Assessment Study).

Science.gov (United States)

Rådholm, Karin; Figtree, Gemma; Perkovic, Vlado; Solomon, Scott D; Mahaffey, Kenneth W; de Zeeuw, Dick; Fulcher, Greg; Barrett, Terrance D; Shaw, Wayne; Desai, Mehul; Matthews, David R; Neal, Bruce

2018-03-11

BACKGROUND : Canagliflozin is a sodium glucose cotransporter 2 inhibitor that reduces the risk of cardiovascular events. We report the effects on heart failure and cardiovascular death overall, in those with and without a baseline history of heart failure, and in other participant subgroups. METHODS : The CANVAS Program (Canagliflozin Cardiovascular Assessment Study) enrolled 10 142 participants with type 2 diabetes mellitus and high cardiovascular risk. Participants were randomly assigned to canagliflozin or placebo and followed for a mean of 188 weeks. The primary end point for these analyses was adjudicated cardiovascular death or hospitalized heart failure. RESULTS : Participants with a history of heart failure at baseline (14.4%) were more frequently women, white, and hypertensive and had a history of prior cardiovascular disease (all P failure was reduced in those treated with canagliflozin compared with placebo (16.3 versus 20.8 per 1000 patient-years; hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.67-0.91), as was fatal or hospitalized heart failure (HR, 0.70; 95% CI, 0.55-0.89) and hospitalized heart failure alone (HR, 0.67; 95% CI, 0.52-0.87). The benefit on cardiovascular death or hospitalized heart failure may be greater in patients with a prior history of heart failure (HR, 0.61; 95% CI, 0.46-0.80) compared with those without heart failure at baseline (HR, 0.87; 95% CI, 0.72-1.06; P interaction =0.021). The effects of canagliflozin compared with placebo on other cardiovascular outcomes and key safety outcomes were similar in participants with and without heart failure at baseline (all interaction P values >0.130), except for a possibly reduced absolute rate of events attributable to osmotic diuresis among those with a prior history of heart failure ( P =0.03). CONCLUSIONS : In patients with type 2 diabetes mellitus and an elevated risk of cardiovascular disease, canagliflozin reduced the risk of cardiovascular death or hospitalized heart

Weibull Parameters Estimation Based on Physics of Failure Model

DEFF Research Database (Denmark)

Kostandyan, Erik; Sørensen, John Dalsgaard

2012-01-01

Reliability estimation procedures are discussed for the example of fatigue development in solder joints using a physics of failure model. The accumulated damage is estimated based on a physics of failure model, the Rainflow counting algorithm and the Miner’s rule. A threshold model is used...... for degradation modeling and failure criteria determination. The time dependent accumulated damage is assumed linearly proportional to the time dependent degradation level. It is observed that the deterministic accumulated damage at the level of unity closely estimates the characteristic fatigue life of Weibull...

Arterial embolization for treating post-transplanted renal failure

International Nuclear Information System (INIS)

Yang Xizhang; Yang Li; Chen Ziqian; Yang Yongyan

2008-01-01

Objective: To investigate the significance of renal arterial embolization nephrectomy for treating post-transplanted renal failure. Methods: 15 cases of post-transplanted renal failure received renal arterial embolization. The post-procedural efficacies were followed up for about 6 months to 4 years. Results: Among the 15 cases, 11 showed blood pressure decreasing to normal level, 3 with reduction of the drug dose for anti-hypertension and 1 of no response. In addition, 12 suffered from postprocedural anuria, and 3 with obvious hypourocrinia associated with significant decrease of proteinuia; 5 with positive lymphcytic population response antigen (PRA > 20%), but turning negative with 3 of them after 3 weeks. All the transplanted kidneys revealed different degrees of atrophy but 4 of them obtained chances of successful retransplantation 3- 6 months after the procedure, 3 of them with follow up of 1-3 years were being well. Conclusions: Renal arterial embolization is a safe, efficient measure for treating post-transplanted renal failure with obvious decrease of correlative clinical symptoms and providing conditions for renal retransplantation. (authors)

Aging assessment of essential HVAC chillers used in nuclear power plants

International Nuclear Information System (INIS)

Blahnik, D.E.; Camp, T.W.

1996-09-01

The Pacific Northwest Laboratory conducted a comprehensive aging assessment of chillers used in the essential safety air-conditioning systems in nuclear power plants (NPPs). The chillers used, and air-conditioning systems served, vary in design from plant to plant. The review of operating experience indicated that chillers experience aging degradation and failures. The primary aging factors of concern for chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. The evaluation of Licensee Event Reports (LERs) indicated that about 38% of the failures were primarily related to aging, 55% were partially aging related, and 7% of the failures were unassignable. About 25% of the failures were primarily caused by human, design, procedure, and other errors. The large number of errors is probably directly related to the complexity of chillers and their interfacing systems. Nearly all of the LERs were the result of entering plant Technical Specification Limiting Condition for Operation (LCO) that initiated remedial actions like plant shutdown procedures. The trend for chiller-related LERs has stabilized at about 0.13 LERs per plant year since 1988. Carefully following the vendor procedures and monitoring the equipment can help to minimize and/or eliminate most of the premature failures. Recording equipment performance can be useful for trending analysis. Periodic operation for a few hours on a weekly or monthly basis is useful to remove moisture and non-condensable gases that gradually build up inside the chiller. Chiller pressurization kits are available that will help minimize the amount of moisture and air ingress to low-pressure chillers during standby periods. The assessment of service life condition monitoring of chillers indicated there are many simple to sophisticated methods available that can help in chiller surveillance and monitoring

Aging assessment of essential HVAC chillers used in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Blahnik, D.E.; Camp, T.W.

1996-09-01

The Pacific Northwest Laboratory conducted a comprehensive aging assessment of chillers used in the essential safety air-conditioning systems in nuclear power plants (NPPs). The chillers used, and air-conditioning systems served, vary in design from plant to plant. The review of operating experience indicated that chillers experience aging degradation and failures. The primary aging factors of concern for chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. The evaluation of Licensee Event Reports (LERs) indicated that about 38% of the failures were primarily related to aging, 55% were partially aging related, and 7% of the failures were unassignable. About 25% of the failures were primarily caused by human, design, procedure, and other errors. The large number of errors is probably directly related to the complexity of chillers and their interfacing systems. Nearly all of the LERs were the result of entering plant Technical Specification Limiting Condition for Operation (LCO) that initiated remedial actions like plant shutdown procedures. The trend for chiller-related LERs has stabilized at about 0.13 LERs per plant year since 1988. Carefully following the vendor procedures and monitoring the equipment can help to minimize and/or eliminate most of the premature failures. Recording equipment performance can be useful for trending analysis. Periodic operation for a few hours on a weekly or monthly basis is useful to remove moisture and non-condensable gases that gradually build up inside the chiller. Chiller pressurization kits are available that will help minimize the amount of moisture and air ingress to low-pressure chillers during standby periods. The assessment of service life condition monitoring of chillers indicated there are many simple to sophisticated methods available that can help in chiller surveillance and monitoring.

Study of the Atucha I nuclear power plant's residual heat removal system unavailability through the fault tree analysis and common cause failures

International Nuclear Information System (INIS)

Terrado, C.A.

1991-06-01

The present essay offers a comprehensive research of the Atucha I nuclear power plant's residual heat removal system unavailability, including Fault Tree Analysis and Common Cause Failures (CCF) treatment. The study is developed within the Event Tree perspective that considers the loss of external electrical power of the initiating event. The event was constructed by the Safety Evaluations Division of the Ezeiza Atomic Center in Argentina. According to the Event Tree, the research includes system demand during plant operation with 132 KV and emergency generation (Diesel motor generators). The system unavailability assessment is approached in two different ways: a) Considering independent failures only. b) Taking into account the existence of Common Cause Events, and modeling dependent failures. The Fault Tree quantification is played using the AIEA PSAPACK Code. The assessment data base is compiled from plant specific records and generic data bases like TECDOC 478. After Fault Tree model logic development, some general procedures used in common cause failures treating are applied to pick up another set of solutions. The results of the study are: a) Four Fault Trees have been developed to model the abovementioned system: 132 KV and emergency generation, both including and excluding CCF. b) The following unavailability values were obtained: 132 KV independent failures only: 7 10 -4 . Emergency generation independent failures only: 1.53 10 -2 . 132 KV dependent and independent failures: 3.6 10 -3 . Emergency generation dependent and independent failures: 1.74 10 -2 . The major conclusions obtained from the precedent results are: a) When using 132 KV system configuration, minimal cut sets involving common cause failures represents 81%from total system unavailability. b) The dependent failures treatment is an important task to be considered in safety assessments in order to reach more realistic values. (Author) [es

Acute kidney failure

Science.gov (United States)

... Renal failure - acute; ARF; Kidney injury - acute Images Kidney anatomy References Devarajan P. Biomarkers for assessment of renal function during acute kidney injury. In: Alpern RJ, Moe OW, Caplan M, ...

An analysis of marketing authorisation applications via the mutual recognition and decentralised procedures in Europe

DEFF Research Database (Denmark)

Ebbers, Hans C; Langedijk, Joris; Bouvy, Jacoline C

2015-01-01

the frequency of licensing failure prior to CMDh referrals. RESULTS: During the study period, 10392 MRP/DCP procedures were finalized. Three hundred seventy-seven (3.6%) resulted in a referral procedure, of which 70 (19%) resulted in licensing failure, defined as refusal or withdrawal of the application...

On the assessment of extremely low breakdown probabilities by an inverse sampling procedure [gaseous insulation

DEFF Research Database (Denmark)

Thyregod, Poul; Vibholm, Svend

1991-01-01

the flashover probability function and the corresponding distribution of first breakdown voltages under the inverse sampling procedure, and show how this relation may be utilized to assess the single-shot flashover probability corresponding to the observed average first breakdown voltage. Since the procedure......First breakdown voltages obtained under the inverse sampling procedure assuming a double exponential flashover probability function are discussed. An inverse sampling procedure commences the voltage application at a very low level, followed by applications at stepwise increased levels until...... is based on voltage applications in the neighbourhood of the quantile under investigation, the procedure is found to be insensitive to the underlying distributional assumptions...

Weight Loss Failure and Reoperation After Laparoscopic Adjustable Gastric Banding and Gastric Bypass: a Case-Matched Cohort Study.

Science.gov (United States)

Bittner, James G; Clingempeel, Natasha L; Wolf, Luke G

2017-11-01

Not long ago, laparoscopic adjustable gastric banding (LAGB) was considered a safe and effective treatment of morbid obesity; however, long-term outcomes revealed significant complication and failure rates. We hypothesized that LAGB has higher rates of weight loss failure, reoperation, and overall failure compared to laparoscopic gastric bypass (LRYGB) at long-term follow-up. A matched case-control study was performed. Patients who underwent primary LAGB or LRYGB at a university hospital between 2004 and 2011 were propensity matched for age, gender, race, body mass index (BMI), and weight-related co-morbidities. Outcomes included demographics, percent excess weight loss (% EWL) and reoperation, weight loss failure (failure (procedure-related reoperation and/or failure at 3 years (75 vs. 10.5%, P failure rates were higher after LAGB. The most common complication after LAGB was pouch/esophageal enlargement (9.7%) and after LRYGB was internal hernia (4.8%). LAGB patients had higher morbidity (19 vs. 12.7%, P = 0.04) but similar procedure-related mortality (0 vs. 0.4%). LAGB has significantly higher rates of weight loss failure compared to LRYGB with similar rates of procedure-related reoperation. Overall failure rates are higher after LAGB. These data suggest the long-term effectiveness of LAGB might be limited.

Analysis of emergency operating procedures effectiveness for core damage prevention using computer code RELAP for nuclear power plants with VVER-1000/B-320 in reference to primary to secondary circuit leak with external power loss and BRU-A stuck open failure

International Nuclear Information System (INIS)

Arkhangelski, L.; Sheveliov, D. V.

1999-01-01

This report presents analysis of development emergency operating procedures effectiveness for possible accident on nuclear power plant with WWER-1000 reactor type. Accident initiating event is the primary to secondary circuit leak caused by steam generator primary cover lift-up. In according to conservative assumptions the following additional failures were considered: dump valve BRU-A stuck open failure; loss of external power. The results of this work are represented as a comparative analysis of two possible ways of accident evolution: according to functioning automatic safety systems responses; according to accident management based on development emergency operating procedures with operator intervention. Developed emergency operating procedures assure the following significant goals to mitigate accident sequences: optimal use of ECCS water inventory; severe core damage prevention; mitigation of environment radioactive contamination. (authors)

Modeling of Electrical Cable Failure in a Dynamic Assessment of Fire Risk

Science.gov (United States)

Bucknor, Matthew D.

complexity to existing cable failure techniques and tuned to empirical data can better approximate the temperature response of a cables located in tightly packed cable bundles. The new models also provide a way to determine the conditions insides a cable bundle which allows for separate treatment of cables on the interior of the bundle from cables on the exterior of the bundle. The results from the DET analysis show that the overall assessed probability of cable failure can be significantly reduced by more realistically accounting for the influence that the fire brigade has on a fire progression scenario. The shielding analysis results demonstrate a significant reduction in the temperature response of a shielded versus a non-shielded cable bundle; however the computational cost of using a fire progression model that can capture these effects may be prohibitive for performing DET analyses with currently available computational fluid dynamics models and computational resources.

Development of Procedures to Assess Problem-Solving Competence in Computing Engineering

Science.gov (United States)

Pérez, Jorge; Vizcarro, Carmen; García, Javier; Bermúdez, Aurelio; Cobos, Ruth

2017-01-01

In the context of higher education, a competence may be understood as the combination of skills, knowledge, attitudes, values, and abilities that underpin effective and/or superior performance in a professional area. The aim of the work reported here was to design a set of procedures to assess a transferable competence, i.e., problem solving, that…

Critical crack path assessments in failure investigations

Directory of Open Access Journals (Sweden)

Robert D. Caligiuri

2015-10-01

Full Text Available This paper presents a case study in which identification of the controlling crack path was critical to identifying the root cause of the failure. The case involves the rupture of a 30-inch (0.76 m natural gas pipeline in 2010 that tragically led to the destruction of a number of homes and the loss of life. The segment of the pipeline that ruptured was installed in 1956. The longitudinal seam of the segment that ruptured was supposed to have been fabricated by double submerged arc welding. Unfortunately, portions of the segment only received a single submerged arc weld on the outside, leaving unwelded areas on the inside diameter. Post-failure examination of the segment revealed that the rupture originated at one of these unwelded areas. Examination also revealed three additional crack paths or zones emanating from the unwelded area: a zone of ductile tearing, a zone of fatigue, and a zone of cleavage fracture, in that sequence. Initial investigators ignored the ductile tear, assumed the critical crack path was the fatigue component, and (incorrectly concluded that the root cause of the incident was the failure of the operator to hydrotest the segment after it was installed in 1956. However, as discussed in this paper, the critical path or mechanism was the ductile tear. Furthermore, it was determined that the ductile tear was created during the hydrotest at installation by a mechanism known as pressure reversal. Thus the correct root cause of the rupture was the hydrotest the operator subjected the segment to at installation, helping to increase the awareness of operators and regulators about the potential problems associated with hydrotesting.

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.

Nonspecialist Raters Can Provide Reliable Assessments of Procedural Skills

DEFF Research Database (Denmark)

Mahmood, Oria; Dagnæs, Julia; Bube, Sarah

2018-01-01

was significant (p Pearson's correlation of 0.77 for the nonspecialists and 0.75 for the specialists. The test-retest reliability showed the biggest difference between the 2 groups, 0.59 and 0.38 for the nonspecialist raters and the specialist raters, respectively (p ... was chosen as it is a simple procedural skill that is crucial to master in a resident urology program. RESULTS: The internal consistency of assessments was high, Cronbach's α = 0.93 and 0.95 for nonspecialist and specialist raters, respectively (p correlations). The interrater reliability...

Procedural advice on self-assessment and task selection in learner-controlled education

NARCIS (Netherlands)

Taminiau, Bettine; Kester, Liesbeth; Corbalan, Gemma; Van Merriënboer, Jeroen; Kirschner, Paul A.

2010-01-01

Taminiau, E. M. C., Kester, L., Corbalan, G., Van Merriënboer, J. J. G., & Kirschner, P. A. (2010, July). Procedural advice on self-assessment and task selection in learner-controlled education. Paper presented at the Junior Researchers of EARLI Conference 2010, Frankfurt, Germany.

[Comorbidities of heart failure: sleep apnea].

Science.gov (United States)

Woehrle, H; Oldenburg, O; Stadler, S; Arzt, M

2018-05-01

Since sleep apnea often occurs in heart failure, physicians regularly need to decide whether further diagnostic procedures and/or treatment are required. Which types of sleep apnea occur in heart failure patients? When is treatment needed? Which treatments and treatment goals are appropriate? Clinical trials and guidelines as well as their implementation in clinical practice are discussed. At least 40% of patients with heart failure, both with reduced and preserved left ventricular ejection fraction (HFrEF and HFpEF, respectively), suffer from relevant sleep apnea. In heart failure patients both obstructive and central sleep apnea are associated with increased mortality. In HFrEF as well as in HFpEF patients with obstructive sleep apnea, treatment with continuous positive airway pressure (CPAP) achieves symptomatic and functional improvements. In patients with HFpEF, positive airway pressure treatment of central sleep apnea may be beneficial. In patients with HFrEF and left ventricular ejection fraction ≤45%, adaptive servoventilation is contraindicated. Sleep apnea is highly prevalent in heart failure patients and its treatment in specific patient groups can improve symptoms and functional outcomes. Thus, testing for sleep apnea is recommended.

Lessons learned from failure analysis

International Nuclear Information System (INIS)

Le May, I.

2006-01-01

-induced embrittlement from inadequate lubrication in bearings. After the mechanisms responsible for failure were determined, changes were made in operating procedures to minimize such failures in future. (author)

The multi-class binomial failure rate model for the treatment of common-cause failures

International Nuclear Information System (INIS)

Hauptmanns, U.

1995-01-01

The impact of common cause failures (CCF) on PSA results for NPPs is in sharp contrast with the limited quality which can be achieved in their assessment. This is due to the dearth of observations and cannot be remedied in the short run. Therefore the methods employed for calculating failure rates should be devised such as to make the best use of the few available observations on CCF. The Multi-Class Binomial Failure Rate (MCBFR) Model achieves this by assigning observed failures to different classes according to their technical characteristics and applying the BFR formalism to each of these. The results are hence determined by a superposition of BFR type expressions for each class, each of them with its own coupling factor. The model thus obtained flexibly reproduces the dependence of CCF rates on failure multiplicity insinuated by the observed failure multiplicities. This is demonstrated by evaluating CCFs observed for combined impulse pilot valves in German NPPs. (orig.) [de

Effects of intravenous home dobutamine in palliative end-stage heart failure on quality of life, heart failure hospitalization, and cost expenditure.

Science.gov (United States)

Martens, Pieter; Vercammen, Jan; Ceyssens, Wendy; Jacobs, Linda; Luwel, Evert; Van Aerde, Herwig; Potargent, Peter; Renaers, Monique; Dupont, Matthias; Mullens, Wilfried

2018-01-17

In patients with palliative end-stage heart failure, interventions that could provide symptomatic relief and prevent hospital admissions are important. Ambulatory continuous intravenous inotropes have been advocated by guidelines for such a purpose. We sought to determine the effect of intravenous dobutamine on symptomatic status, hospital stay, mortality, and cost expenditure. All consecutive end-stage heart failure patients not amenable for advanced therapies and discharged with continuous intravenous home dobutamine from a single tertiary centre between April 2011 and January 2017 were retrospectively analysed. Dobutamine (fixed dose) was infused through a single-lumen central venous catheter with a small pump that was refilled by a nurse on a daily basis. Symptomatic status was longitudinally assessed as the change in New York Heart Association class and patient global assessment scale. Antecedent and incident heart failure hospitalizations were determined in a paired fashion, and cost impact was assessed. A total of 21 patients (age 77 ± 9 years) were followed up for 869 ± 647 days. At first follow-up (6 ± 1 weeks) after the initiation of dobutamine, patients had a significant improvement in New York Heart Association class (-1.29 ± 0.64; P heart failure hospitalizations assessed at 3, 6, and 12 months were significantly reduced (P heart failure hospitalizations over the same time period. Cost expenditure was significantly lower at 3 (P heart failure is feasible and associated with improved symptomatic status, heart failure hospitalizations, and health-care-related costs. Nevertheless, results should be interpreted in the context of the small and retrospective design. Larger studies are necessary to evaluate the effect of dobutamine in palliative end-stage heart failure. © 2018 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Failure diagnosis using discrete event models

International Nuclear Information System (INIS)

Sampath, M.; Sengupta, R.; Lafortune, S.; Teneketzis, D.; Sinnamohideen, K.

1994-01-01

We propose a Discrete Event Systems (DES) approach to the failure diagnosis problem. We present a methodology for modeling physical systems in a DES framework. We discuss the notion of diagnosability and present the construction procedure of the diagnoser. Finally, we illustrate our approach using a Heating, Ventilation and Air Conditioning (HVAC) system

32 CFR 504.2 - Procedures.

Science.gov (United States)

2010-07-01

... transferred only where an official need-to-know exists. Failure to do so, however, does not render the... information is from a Federal agency authorized to conduct foreign intelligence or foreign counterintelligence... according to existing procedures, to include applicable Privacy Act System Notices published in AR 340-21...

Does autoimmunity play a role in the risk of implantation failures?

Science.gov (United States)

Motak-Pochrzest, Hanna; Malinowski, Andrzej

2018-02-01

158 non-pregnant women with recurrent implantation failures after IVF/ET procedures were tested for peripheral blood autoimmune profile. The control group consisted of 76 patients after first successful IVF procedure and pregnancy outcome. The objective of this study was to investigate different autoantibodies peripheral blood profile after excluding anatomical, endocrinological, endometrial and genetic disorders and to estimate the risk of implantation failures. The study's including criteria were 1.indications for IVF/ET determined by male factor and unexplained infertility 2. absence of implantation after two consecutive cycles of IVF, ICSI or frozen embryo replacement cycles. The presence of ANA in the sera increased the risk of RIF after ET/IVF procedures, especially in older patients. Patients with RIF have a higher frequency of the presence of autoantibodies ACA IgG, IgM and anti-β2GP I IgG in the sera than in patients with successful pregnancies after IVF/ET procedures.

Framework and operational procedure for implementing Strategic Environmental Assessment in China

International Nuclear Information System (INIS)

Bao Cunkuan; Lu Yongsen; Shang Jincheng

2004-01-01

Over the last 20 years, Environmental Impact Assessment (EIA) has been implemented and become an important instrument for decision-making in development projects in China. The Environmental Impact Assessment Law of the P.R. China was promulgated on 28 October 2002 and will be put into effect on 1 September of 2003. The law provides that Strategic Environmental Assessment (SEA) is required in regional and sector plans and programs. This paper introduces the research achievements and practice of SEA in China, discusses the relationship of SEA and 'integrating of environment and development in decision-making (IEDD)', and relevant political and legal basis of SEA. The framework and operational procedures of SEA administration and enforcement are presented. Nine cases are analyzed and some proposals are given

The Hitchcock procedure. A cause for failure: a case report.

Science.gov (United States)

Kumar, V P; Satku, K

1992-02-01

A 40-year-old man with a tenodesis of the long head of the biceps brachii in the bicipital groove (Hitchcock's operation) for bicipital tendinitis had recurrence of pain seven months after the operation. Roentgenograms of the acromiohumeral interval, taken when the patient tensed the biceps brachii, showed significant upward migration of the humeral head with a decrease in the acromio-humeral interval on the operated side. The authors postulate that resection of the stabilizing, intraarticular segment of the long head of the biceps in the Hitchcock's procedure allowed the short head to draw the humeral head proximally, resulting in a decrease in the acromiohumeral interval and recurrence of impingement. This is one possible explanation for the poor long-term results of the Hitchcock procedure.

A probabilistic seismic risk assessment procedure for nuclear power plants: (II) Application

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

This paper presents the procedures and results of intensity- and time-based seismic risk assessments of a sample nuclear power plant (NPP) to demonstrate the risk-assessment methodology proposed in its companion paper. The intensity-based assessments include three sets of sensitivity studies to identify the impact of the following factors on the seismic vulnerability of the sample NPP, namely: (1) the description of fragility curves for primary and secondary components of NPPs, (2) the number of simulations of NPP response required for risk assessment, and (3) the correlation in responses between NPP components. The time-based assessment is performed as a series of intensity-based assessments. The studies illustrate the utility of the response-based fragility curves and the inclusion of the correlation in the responses of NPP components directly in the risk computation. ?? 2011 Published by Elsevier B.V.

Teachers' use of a self-assessment procedure : the role of criteria, standards, feedback and reflection

NARCIS (Netherlands)

Diggelen, van M.R.; Brok, den P.J.; Beijaard, D.

2013-01-01

This article reports on the way teachers assess their own coaching competencies regarding the development of vocational education students’ reflection skills. The participating teachers used a self-assessment procedure in which they had to judge themselves with the help of criteria and standards,

Are minimally invasive procedures harder to acquire than conventional surgical procedures?

Science.gov (United States)

Hiemstra, Ellen; Kolkman, Wendela; le Cessie, Saskia; Jansen, Frank Willem

2011-01-01

It is frequently suggested that minimally invasive surgery (MIS) is harder to acquire than conventional surgery. To test this hypothesis, residents' learning curves of both surgical skills are compared. Residents had to be assessed using a general global rating scale of the OSATS (Objective Structured Assessment of Technical Skills) for every procedure they performed as primary surgeon during a 3-month clinical rotation in gynecological surgery. Nine postgraduate-year-4 residents collected a total of 319 OSATS during the 2 years and 3 months investigation period. These assessments concerned 129 MIS (laparoscopic and hysteroscopic) and 190 conventional (open abdominal and vaginal) procedures. Learning curves (in this study defined as OSATS score plotted against procedure-specific caseload) for MIS and conventional surgery were compared using a linear mixed model. The MIS curve revealed to be steeper than the conventional curve (1.77 vs. 0.75 OSATS points per assessed procedure; 95% CI 1.19-2.35 vs. 0.15-1.35, p < 0.01). Basic MIS procedures do not seem harder to acquire during residency than conventional surgical procedures. This may have resulted from the incorporation of structured MIS training programs in residency. Hopefully, this will lead to a more successful implementation of the advanced MIS procedures. Copyright © 2010 S. Karger AG, Basel.

Failure diagnostics of rotational machines and machine groups in the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Nagy, I.; Kiss, G.

1997-01-01

Machine failure diagnostic system based on vibration analysis is described. The design of the measurements, the measurement procedure, and the evaluation of the results are presented. The common diagnostic technology for groups of rotation machinery has several advantages. The rules used for the evaluation of three-directional vibration measurements are shown, and the identification criteria of some specific failures are demonstrated. The steps of expert decision making and the diagnosis procedure are discussed through practical examples. (R.P.)

Steam-generator tube failures: world experience in water-cooled nuclear power reactors in 1974

International Nuclear Information System (INIS)

Hare, M.G.

1976-01-01

Steam-generator tube failures were reported at 25 of 59 water-cooled nuclear power reactors surveyed in 1974, compared to 11 of 49 in 1973. A summary is presented of these failures, most of which, where the cause is known, were the result of corrosion. Water chemistry control, inspection and repair procedures, and failure rates are discussed

Serviceability Assessment for Cascading Failures in Water Distribution Network under Seismic Scenario

Directory of Open Access Journals (Sweden)

Qing Shuang

2016-01-01

Full Text Available The stability of water service is a hot point in industrial production, public safety, and academic research. The paper establishes a service evaluation model for the water distribution network (WDN. The serviceability is measured in three aspects: (1 the functionality of structural components under disaster environment; (2 the recognition of cascading failure process; and (3 the calculation of system reliability. The node and edge failures in WDN are interrelated under seismic excitations. The cascading failure process is provided with the balance of water supply and demand. The matrix-based system reliability (MSR method is used to represent the system events and calculate the nonfailure probability. An example is used to illustrate the proposed method. The cascading failure processes with different node failures are simulated. The serviceability is analyzed. The critical node can be identified. The result shows that the aged network has a greater influence on the system service under seismic scenario. The maintenance could improve the antidisaster ability of WDN. Priority should be given to controlling the time between the initial failure and the first secondary failure, for taking postdisaster emergency measures within this time period can largely cut down the spread of cascade effect in the whole WDN.

Correlation model to analyze dependent failures for probabilistic risk assessment

International Nuclear Information System (INIS)

Dezfuli, H.

1985-01-01

A methodology is formulated to study the dependent (correlated) failures of various abnormal events in nuclear power plants. This methodology uses correlation analysis is a means for predicting and quantifying the dependent failures. Appropriate techniques are also developed to incorporate the dependent failure in quantifying fault trees and accident sequences. The uncertainty associated with each estimation in all of the developed techniques is addressed and quantified. To identify the relative importance of the degree of dependency (correlation) among events and to incorporate these dependencies in the quantification phase of PRA, the interdependency between a pair of events in expressed with the aid of the correlation coefficient. For the purpose of demonstrating the methodology, the data base used in the Accident Sequence Precursor Study (ASP) was adopted and simulated to obtain distributions for the correlation coefficients. A computer program entitled Correlation Coefficient Generator (CCG) was developed to generate a distribution for each correlation coefficient. The method of bootstrap technique was employed in the CCG computer code to determine confidence limits of the estimated correlation coefficients. A second computer program designated CORRELATE was also developed to obtain probability intervals for both fault trees and accident sequences with statistically correlated failure data

The Implicit Relational Assessment Procedure (IRAP) as a Measure of Spider Fear

Science.gov (United States)

Nicholson, Emma; Barnes-Holmes, Dermot

2012-01-01

A greater understanding of implicit cognition can provide important information regarding the etiology and maintenance of psychological disorders. The current study sought to determine the utility of the Implicit Relational Assessment Procedure (IRAP) as a measure of implicit aversive bias toward spiders in two groups of known variation, high fear…

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.

Margins in high temperature leak-before-break assessments

Energy Technology Data Exchange (ETDEWEB)

Budden, P.J.; Hooton, D.G.

1997-04-01

Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep.

Margins in high temperature leak-before-break assessments

International Nuclear Information System (INIS)

Budden, P.J.; Hooton, D.G.

1997-01-01

Developments in the defect assessment procedure R6 to include high-temperature mechanisms in Leak-before-Break arguments are described. In particular, the effect of creep on the time available to detect a leak and on the crack opening area, and hence leak rate, is discussed. The competing influence of these two effects is emphasized by an example. The application to Leak-before-Break of the time-dependent failure assessment diagram approach for high temperature defect assessment is then outlined. The approach is shown to be of use in assessing the erosion of margins by creep

Development of critical digital review procedure

International Nuclear Information System (INIS)

Huang Huiwen; Liao Benching; Tseng Maosheng; Chung Hsianghan; Cheng Tsungchieh; Chen Minghuei

2011-01-01

This paper describes the critical digital review (CDR) procedure, which was developed by Institute of Nuclear Energy Research (INER), and sponsored by Taiwan Power Company (TPC). A preliminary CDR application experience which was performed by INER, is also described in this paper. Currently, CDR becomes one of the policies for digital Instrumentation and Control (I and C) system replacement in TPC. The contents of this CDR procedure include: Scope, Responsibility, Operation Procedure, Operation Flow Chart, CDR review items. The 'CDR Review Items' chapter proposes optional review items, including the comparison of the design change, Software Verification and Validation (SV and V), Failure Mode and Effects Analysis (FMEA), Evaluation of Watchdog Timer, Evaluation of Electromagnetic Compatibility (EMC), Evaluation of Grounding for System/Component, Seismic Evaluation, HFE Evaluation, Witness and Inspection, Lessons Learnt from the Digital I and C Failure Events. Since CDR has become a TPC policy, Chin Shan Nuclear Power Plant (NPP) performed the CDR practice of Automatic Voltage Regulator (AVR) digital I and C replacement, even though the project had been on the half way. The major review items of this CDR were: the comparison of the design change, SV and V, FMEA, Evaluation of Watchdog Timer, Evaluation of Electromagnetic Compatibility (EMC), Evaluation of Grounding for System/ Component, Witness and Inspection, Lessons Learnt from the Digital I and C Failure Events. The experience of the CDR showed the importance of preparation of the documents by the vendor. This means the communication with the vendors for the bid preparation is crucial. (author)

Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

Energy Technology Data Exchange (ETDEWEB)

Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke [Nihon Univ., Tokyo (Japan). School of Medicine

2000-12-01

Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5{+-}6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33{+-}0.22 in chronic heart failure class I, 2.50{+-}0.34 in class II, 1.95{+-}0.61 in class III, and 1.39{+-}0.29 in class IV (p<0.05). %WR was 24.8{+-}12.8% in chronic heart failure class I, 23.3{+-}10.2% in class II, 49.2{+-}24.5% in class III, and 66.3{+-}26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

Pertussis toxin treatment of whole blood. A novel approach to assess G protein function in congestive heart failure

NARCIS (Netherlands)

Maisel, A. S.; Michel, M. C.; Insel, P. A.; Ennis, C.; Ziegler, M. G.; Phillips, C.

1990-01-01

This study was designed to assess G protein function in mononuclear leukocytes (MNL) of patients with congestive heart failure (CHF). MNL membranes were ADP-ribosylated in vitro in the presence of pertussis or cholera toxin. The amount of pertussis toxin substrates did not differ significantly

Failure of sheathed thermocouples due to thermal cycling

International Nuclear Information System (INIS)

Anderson, R.L.; Ludwig, R.L.

1982-03-01

Open circuit failures (up to 100%) in small-diameter thermocouples used in electrically heated nuclear fuel rod simulator prototypes during thermal cycling tests were investigated to determine the cause(s) of the failures. The experiments conducted to determine the relative effects of differential thermal expansion, wire size, grain size, and manufacturing technology are described. It was concluded that the large grain size and embrittlement which result from certain common manufacturing annealing and drawing procedures were a major contributing factor in the breakage of the thermocouple wires

Coracoid process x-ray investigation before Latarjet procedure: a radioanatomic study.

Science.gov (United States)

Bachy, Manon; Lapner, Peter L C; Goutallier, Daniel; Allain, Jérôme; Hernigou, Phillipe; Bénichou, Jacques; Zilber, Sébastien

2013-12-01

The purpose of this study was to determine whether a preoperative radiologic assessment of the coracoid process is predictive of the amount of bone available for coracoid transfer by the Latarjet procedure. Thirty-five patients with anterior instability undergoing a Latarjet procedure were included. A preoperative radiologic assessment was performed with the Bernageau and true anteroposterior (true AP) views. The length of the coracoid process was measured on both radiographic views and the values were compared with the length of the bone block during surgery. Statistical analysis was carried out by ANOVA and Wilcoxon tests (P process length was 29 ± 4 and 33 ± 4 mm on the Bernageau and true AP views, respectively. The mean bone block length during surgery was 21.6 ± 2.7 mm. A significant correlation was found (P = .032) between the coracoid process length on the true AP view and the intraoperative bone block length. Preoperative planning for the Latarjet procedure, including graft orientation and screw placement, requires knowledge of the length of coracoid bone available for transfer. This can be facilitated with the use of preoperative standard radiographs, thus avoiding computed tomography. This planning allows the detection of coracoid process anatomic variations or the analysis of the remaining part of the coracoid process after failure of a first Latarjet procedure to avoid an iliac bone graft. Radiologic preoperative coracoid process measurement is an easy, reliable method to aid preoperative planning of the Latarjet procedure in primary surgery and reoperations. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Procedure to select test organisms for environmental risk assessment of genetically modified crops in aquatic systems.

Science.gov (United States)

Hilbeck, Angelika; Bundschuh, Rebecca; Bundschuh, Mirco; Hofmann, Frieder; Oehen, Bernadette; Otto, Mathias; Schulz, Ralf; Trtikova, Miluse

2017-11-01

For a long time, the environmental risk assessment (ERA) of genetically modified (GM) crops focused mainly on terrestrial ecosystems. This changed when it was scientifically established that aquatic ecosystems are exposed to GM crop residues that may negatively affect aquatic species. To assist the risk assessment process, we present a tool to identify ecologically relevant species usable in tiered testing prior to authorization or for biological monitoring in the field. The tool is derived from a selection procedure for terrestrial ecosystems with substantial but necessary changes to adequately consider the differences in the type of ecosystems. By using available information from the Water Framework Directive (2000/60/EC), the procedure can draw upon existing biological data on aquatic systems. The proposed procedure for aquatic ecosystems was tested for the first time during an expert workshop in 2013, using the cultivation of Bacillus thuringiensis (Bt) maize as the GM crop and 1 stream type as the receiving environment in the model system. During this workshop, species executing important ecological functions in aquatic environments were identified in a stepwise procedure according to predefined ecological criteria. By doing so, we demonstrated that the procedure is practicable with regard to its goal: From the initial long list of 141 potentially exposed aquatic species, 7 species and 1 genus were identified as the most suitable candidates for nontarget testing programs. Integr Environ Assess Manag 2017;13:974-979. © 2017 SETAC. © 2017 SETAC.

Field failure mechanisms for photovoltaic modules

Science.gov (United States)

Dumas, L. N.; Shumka, A.

1981-01-01

Beginning in 1976, Department of Energy field centers have installed and monitored a number of field tests and application experiments using current state-of-the-art photovoltaic modules. On-site observations of module physical and electrical degradation, together with in-depth laboratory analysis of failed modules, permits an overall assessment of the nature and causes of early field failures. Data on failure rates are presented, and key failure mechanisms are analyzed with respect to origin, effect, and prospects for correction. It is concluded that all failure modes identified to date are avoidable or controllable through sound design and production practices.

Screening Criteria for Loss of Room Cooling Failure

Energy Technology Data Exchange (ETDEWEB)

Hwang, Mee Jeong; Yang, Joon Eon; Yoon, Churl

2007-01-15

In this report, we estimated the temperature of the pump rooms and reviewed the operability of the components under the loss of the HVAC (Heating, Ventilation, and Air Condition) system. The issues relevant to the HVAC system in the PSA (Probabilistic Safety Assessment) FT (Fault Tree) model are as follows: (1) Does the loss of the HVAC system bring about a function failure of other components? (2) Can the operator take action to reduce the temperature of the room in case of a HVAC function failure? At present, we do not know whether a component will lose its function or not under the loss of the HVAC. ASME Standard describes that a recovery action can be credited if the related recovery action is included in the procedure or there are similar recovery experiences in the plant. However, there is no description about the recovery action of the HVAC in the EOP (Emergency Operation Procedure) of the UCN3, 4 under the situation of a loss of the HVAC. Even though we consider this assumption positively, it would be limited to the rooms such as the Switchgear Room, Inverter Room, and Main Control Room etc. where a real recovery action can be performed easily. However, if we consider the HVAC failure in the PSA FT model according to the above background, the problem is that the unavailability induced from the loss of a HVAC is highly unrealistically. From a viewpoint of the PSA, it is not true that the related system always fails even though the HVAC system fails. Therefore, we reviewed the necessity of the HVAC model through the identification of the operable temperature of the components' within the pump room and the change of the temperature of the pump room under the situation of a loss of the HVAC system. In this paper, we performed a heat up calculation for the Auxiliary Feedwater Motor Operated Pump (AFW MDP) room, PAB-077-11A with CFX 10 and RATT when the HVAC system is failed. We also reviewed the operability of the components under a loss of the HVAC. Room

Screening Criteria for Loss of Room Cooling Failure

International Nuclear Information System (INIS)

Hwang, Mee Jeong; Yang, Joon Eon; Yoon, Churl

2007-01-01

In this report, we estimated the temperature of the pump rooms and reviewed the operability of the components under the loss of the HVAC (Heating, Ventilation, and Air Condition) system. The issues relevant to the HVAC system in the PSA (Probabilistic Safety Assessment) FT (Fault Tree) model are as follows: (1) Does the loss of the HVAC system bring about a function failure of other components? (2) Can the operator take action to reduce the temperature of the room in case of a HVAC function failure? At present, we do not know whether a component will lose its function or not under the loss of the HVAC. ASME Standard describes that a recovery action can be credited if the related recovery action is included in the procedure or there are similar recovery experiences in the plant. However, there is no description about the recovery action of the HVAC in the EOP (Emergency Operation Procedure) of the UCN3, 4 under the situation of a loss of the HVAC. Even though we consider this assumption positively, it would be limited to the rooms such as the Switchgear Room, Inverter Room, and Main Control Room etc. where a real recovery action can be performed easily. However, if we consider the HVAC failure in the PSA FT model according to the above background, the problem is that the unavailability induced from the loss of a HVAC is highly unrealistically. From a viewpoint of the PSA, it is not true that the related system always fails even though the HVAC system fails. Therefore, we reviewed the necessity of the HVAC model through the identification of the operable temperature of the components' within the pump room and the change of the temperature of the pump room under the situation of a loss of the HVAC system. In this paper, we performed a heat up calculation for the Auxiliary Feedwater Motor Operated Pump (AFW MDP) room, PAB-077-11A with CFX 10 and RATT when the HVAC system is failed. We also reviewed the operability of the components under a loss of the HVAC. Room

Strategic environmental assessment and national development plans in Turkey: Towards legal framework and operational procedure

International Nuclear Information System (INIS)

Say, Nuriye Peker; Yuecel, Muzaffer

2006-01-01

National development plans were started to be prepared in Turkey in 1963. These plans are mandatory for public investments and guiding principles for private investments. They have a quality which guides and sets objectives for other plans in the country. Therefore, they can be evaluated as the main reason of successes and failures of sectoral investments or the problems that they cause directly or indirectly. Turkey is undergoing rapid industrialization, urbanization and population growth, thus environmental problems are on the increase. Although Environmental Impact Assessment (EIA) has been applied to individual investments in Turkey since 1993, natural environment has continued to be affected because of human activities. Today, parallel to the developments in the world, it has been discussed that it is necessary to strengthen project-level Environmental Assessment (EA) and to practice Strategic Environmental Assessment (SEA). The interest in SEA, that is, EA at the level of proposed policies, plans and programs has grown significantly since 2000 in the country. Discussions and preparations have started about regulation which provides the legal and institutional framework for SEA in The Ministry of Environment and Forestry. However, since the scientific approach into the subject is very new in Turkey, it will take time to answer the questions about how and in what fields to practice. This research project aims at analyzing the possible practice opportunities of SEA in Turkey and the practicability of SEA into the National Five-Year Development Plan (FYDP) which is assumed at the highest level of planning hierarchy in the country. The research is conducted on two sections. In the first section, procedural approaches to SEA on national development plans are investigated and a framework for these approaches is adapted at the institutional level. In the second section, SEA form for energy sector in the development plans is developed. In this article, the findings

Safety assessment of a lithium target

International Nuclear Information System (INIS)

Burgazzi, Luciano; Roberta, Ferri; Barbara, Giannone

2006-01-01

This paper addresses the safety assessment of the lithium target of the International Fusion Materials Irradiation Facility (IFMIF) through evaluating the most important risk factors related to system operation and verifying the fulfillment of the safety criteria. The hazard assessment is based on using a well-structured Failure Mode and Effect Analysis (FMEA) procedure by detailing on a component-by-component basis all the possible failure modes and identifying their effects on the plant. Additionally, a systems analysis, applying the fault tree technique, is performed in order to evaluate, from a probabilistic standpoint, all the relevant and possible failures of each component required for safe system operation and assessing the unavailability of the lithium target system. The last task includes the thermal-hydraulic transient analysis of the target lithium loop, including operational and accident transients. A lithium target loop model is developed, using the RELAP5/Mod3.2 thermal-hydraulic code, which has been modified to include specific features of IFMIF itself. The main conclusions are that target safety is fulfilled, the hazards associated with lithium operation are confined within the IFMIF security boundaries, the environmental impact is negligible, and the plant responds to the simulated transients by being able to reach steady conditions in a safety situation

Failure to Fail

Directory of Open Access Journals (Sweden)

Samuel Vriezen

2013-07-01

Full Text Available Between pessimism and optimism, Samuel Vriezen attempts to intuit a third way through an assessment of failure and negativity in the consonances and tensions between the prosody of Irish playwright Samuel Becekett and American poet Gertrude Stein.

High mortality among heart failure patients treated with antidepressants

DEFF Research Database (Denmark)

Veien, Karsten Tang; Videbæk, Lars; Schou, Morten

2011-01-01

This study was designed to assess whether pharmacologically treated depression was associated with increased mortality risk in systolic heart failure (SHF) patients.......This study was designed to assess whether pharmacologically treated depression was associated with increased mortality risk in systolic heart failure (SHF) patients....

Prognostic importance of pulmonary hypertension in patients with heart failure

DEFF Research Database (Denmark)

Kjaergaard, Jesper; Akkan, Dilek; Iversen, Kasper Karmark

2007-01-01

Pulmonary hypertension is a well-known complication in heart failure, but its prognostic importance is less well established. This study assessed the risk associated with pulmonary hypertension in patients with heart failure with preserved or reduced left ventricular (LV) ejection fractions. Pati...... obstructive lung disease, heart failure, and impaired renal function. In conclusion, pulmonary hypertension is associated with increased short- and long-term mortality in patients with reduced LV ejection fractions and also in patients with preserved LV ejection fractions.......Pulmonary hypertension is a well-known complication in heart failure, but its prognostic importance is less well established. This study assessed the risk associated with pulmonary hypertension in patients with heart failure with preserved or reduced left ventricular (LV) ejection fractions....... Patients with known or presumed heart failure (n = 388) underwent the echocardiographic assessment of pulmonary systolic pressure and LV ejection fraction. Patients were followed for up to 5.5 years. Increased pulmonary pressure was associated with increased short- and long-term mortality (p

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.

A methodological approach to assessing alveolar ridge preservation procedures in humans: soft tissue profile.

Science.gov (United States)

Vanhoutte, Vanessa; Rompen, Eric; Lecloux, Geoffrey; Rues, Stefan; Schmitter, Marc; Lambert, France

2014-03-01

The aesthetic results of implant restoration in the anterior maxilla are particularly related to the soft tissue profile. Although socket preservation techniques appear to reduce bone remodelling after tooth extraction, there is still few investigations assessing the external soft tissue profile after such procedures. The goal of this study was to describe an accurate technique to evaluate soft tissue contour changes after performing socket preservation procedures. The secondary objective was to apply the newly developed measuring method to a specific socket preservation using a "saddled" connective tissue graft combined with the insertion of slowly resorbable biomaterials into the socket. A total of 14 patients needing tooth replacement in the aesthetic region were included to receive a socket preservation procedure using a connective tissue graft. Impressions were taken before the tooth extraction (baseline) and at 2, 4, and 12 weeks after the procedure. The corresponding plaster casts were scanned, and the evolution of the soft tissue profile in relation to the baseline situation was assessed using imaging software. The measuring technique allowed assessing the soft tissue profiles accurately at different levels of the alveolar process. The insertion of a saddled connective tissue appeared to compensate for the horizontal and vertical bone remodelling after a socket preservation procedure in most regions of the alveolar crest. After 12 weeks, the only significant change was located in the more cervical and central region of the alveolar process and reached a median drop of 0.62 mm from baseline. Within the limitations of this study, we found that a saddled connective tissue graft combined with a socket preservation procedure could almost completely counteract the bone remodelling in terms of the external soft tissue profile. The minor changes found in the cervical region might disappear with the emergence profile of the prosthodontic components. The described

Consistency of FMEA used in the validation of analytical procedures.

Science.gov (United States)

Oldenhof, M T; van Leeuwen, J F; Nauta, M J; de Kaste, D; Odekerken-Rombouts, Y M C F; Vredenbregt, M J; Weda, M; Barends, D M

2011-02-20

In order to explore the consistency of the outcome of a Failure Mode and Effects Analysis (FMEA) in the validation of analytical procedures, an FMEA was carried out by two different teams. The two teams applied two separate FMEAs to a High Performance Liquid Chromatography-Diode Array Detection-Mass Spectrometry (HPLC-DAD-MS) analytical procedure used in the quality control of medicines. Each team was free to define their own ranking scales for the probability of severity (S), occurrence (O), and detection (D) of failure modes. We calculated Risk Priority Numbers (RPNs) and we identified the failure modes above the 90th percentile of RPN values as failure modes needing urgent corrective action; failure modes falling between the 75th and 90th percentile of RPN values were identified as failure modes needing necessary corrective action, respectively. Team 1 and Team 2 identified five and six failure modes needing urgent corrective action respectively, with two being commonly identified. Of the failure modes needing necessary corrective actions, about a third were commonly identified by both teams. These results show inconsistency in the outcome of the FMEA. To improve consistency, we recommend that FMEA is always carried out under the supervision of an experienced FMEA-facilitator and that the FMEA team has at least two members with competence in the analytical method to be validated. However, the FMEAs of both teams contained valuable information that was not identified by the other team, indicating that this inconsistency is not always a drawback. Copyright © 2010 Elsevier B.V. All rights reserved.

Considering the normative, systemic and procedural dimensions in indicator-based sustainability assessments in agriculture

International Nuclear Information System (INIS)

Binder, Claudia R.; Feola, Giuseppe; Steinberger, Julia K.

2010-01-01

This paper develops a framework for evaluating sustainability assessment methods by separately analyzing their normative, systemic and procedural dimensions as suggested by Wiek and Binder [Wiek, A, Binder, C. Solution spaces for decision-making - a sustainability assessment tool for city-regions. Environ Impact Asses Rev 2005, 25: 589-608.]. The framework is then used to characterize indicator-based sustainability assessment methods in agriculture. For a long time, sustainability assessment in agriculture has focused mostly on environmental and technical issues, thus neglecting the economic and, above all, the social aspects of sustainability, the multi-functionality of agriculture and the applicability of the results. In response to these shortcomings, several integrative sustainability assessment methods have been developed for the agricultural sector. This paper reviews seven of these that represent the diversity of tools developed in this area. The reviewed assessment methods can be categorized into three types: (i) top-down farm assessment methods; (ii) top-down regional assessment methods with some stakeholder participation; (iii) bottom-up, integrated participatory or transdisciplinary methods with stakeholder participation throughout the process. The results readily show the trade-offs encountered when selecting an assessment method. A clear, standardized, top-down procedure allows for potentially benchmarking and comparing results across regions and sites. However, this comes at the cost of system specificity. As the top-down methods often have low stakeholder involvement, the application and implementation of the results might be difficult. Our analysis suggests that to include the aspects mentioned above in agricultural sustainability assessment, the bottom-up, integrated participatory or transdisciplinary methods are the most suitable ones.

The quality of procedures to assess and credit prior learning: Implications for design.

NARCIS (Netherlands)

Joosten-ten Brinke, Desirée; Sluijsmans, Dominique; Brand-Gruwel, Saskia; Jochems, Wim

2008-01-01

Joosten-ten Brinke, D., Sluijsmans, D. M. A., Brand-Gruwel, S., & Jochems, W. M. G. (2008). The quality of procedures to assess and credit prior learning: Implications for design. Educational Research Review, 3, 51-65. doi:10.1016/j.edurev.2007.08.001.

Clinical evaluation of new methods for the assessment of heart failure

NARCIS (Netherlands)

J.A.M. Wijbenga (Anke)

1999-01-01

textabstractAlthough every physician seems to know the term "heart failure", there is no general agreement on its definition. Due to the complex nature of heart failure and the changing Insights into its pathophysiology over time, many different definitions exist. l.' Some focus on clinical

Assessment of a Business-to-Consumer (B2C) model for Telemonitoring patients with Chronic Heart Failure (CHF)

NARCIS (Netherlands)

A.S. Grustam (Andrija); Vrijhoef, H.J.M. (Hubertus J. M.); R. Koymans (Ron); Hukal, P. (Philipp); J.L. Severens (Hans)

2017-01-01

textabstractBackground: The purpose of this study is to assess the Business-to-Consumer (B2C) model for telemonitoring patients with Chronic Heart Failure (CHF) by analysing the value it creates, both for organizations or ventures that provide telemonitoring services based on it, and for society.

Assessing the Value-Added by the Environmental Testing Process with the Aide of Physics/Engineering of Failure Evaluations

Science.gov (United States)

Cornford, S.; Gibbel, M.

1997-01-01

NASA's Code QT Test Effectiveness Program is funding a series of applied research activities focused on utilizing the principles of physics and engineering of failure and those of engineering economics to assess and improve the value-added by the various validation and verification activities to organizations.

Traditional and new composite endpoints in heart failure clinical trials : facilitating comprehensive efficacy assessments and improving trial efficiency

NARCIS (Netherlands)

Anker, Stefan D. t; Schroeder, Stefan; Atar, Dan; Bax, Jeroen J.; Ceconi, Claudio; Cowie, Martin R.; AdamCrisp,; Dominjon, Fabienne; Ford, Ian; Ghofrani, Hossein-Ardeschir; Gropper, Savion; Hindricks, Gerhard; Hlatky, Mark A.; Holcomb, Richard; Honarpour, Narimon; Jukema, J. Wouter; Kim, Albert M.; Kunz, Michael; Lefkowitz, Martin; Le Floch, Chantal; Landmesser, Ulf; McDonagh, Theresa A.; McMurray, John J.; Merkely, Bela; Packer, Milton; Prasad, Krishna; Revkin, James; Rosano, Giuseppe M. C.; Somaratne, Ransi; Stough, Wendy Gattis; Voors, Adriaan A.; Ruschitzka, Frank

Composite endpoints are commonly used as the primary measure of efficacy in heart failure clinical trials to assess the overall treatment effect and to increase the efficiency of trials. Clinical trials still must enrol large numbers of patients to accrue a sufficient number of outcome events and

Assessment of bleeding during minor oral surgical procedures and extraction in patients on anticoagulant therapy

Directory of Open Access Journals (Sweden)

S Jimson

2015-01-01

Full Text Available Introduction: The risk of postoperative hemorrhage from oral surgical procedures has been a concern in the treatment of patients who are receiving long-term anticoagulation therapy. A study undertaken in our institution to address questions about the amount and severity of bleeding associated with minor outpatient oral surgery procedures by assessing bleeding in patients who did not alter their anticoagulant regimen. Subjects and Methods: Eighty-three patients receiving long-term anticoagulant therapy visited Department of Oral and Maxillofacial Surgery from May 2010 to October 2011 for extractions and minor oral surgical procedures. Each patient was required to undergo preoperative assessment of prothrombin time (PT and measurement of the international normalized ratio. Fifty-six patients with preoperative PT values within the therapeutic range 3-4 were included in the study. The patients′ age ranged between 30 and 75 years. Application of surgispon was done following the procedure. Extraction of teeth performed with minimal trauma to the surrounding tissues, the socket margins sutured, and sutures removed after 5 days. Results: There was no significant incidence of prolonged or excessive hemorrhage and wound infection and the healing process was normal.

A standardized model for predicting flap failure using indocyanine green dye

Science.gov (United States)

Zimmermann, Terence M.; Moore, Lindsay S.; Warram, Jason M.; Greene, Benjamin J.; Nakhmani, Arie; Korb, Melissa L.; Rosenthal, Eben L.

2016-03-01

Techniques that provide a non-invasive method for evaluation of intraoperative skin flap perfusion are currently available but underutilized. We hypothesize that intraoperative vascular imaging can be used to reliably assess skin flap perfusion and elucidate areas of future necrosis by means of a standardized critical perfusion threshold. Five animal groups (negative controls, n=4; positive controls, n=5; chemotherapy group, n=5; radiation group, n=5; chemoradiation group, n=5) underwent pre-flap treatments two weeks prior to undergoing random pattern dorsal fasciocutaneous flaps with a length to width ratio of 2:1 (3 x 1.5 cm). Flap perfusion was assessed via laser-assisted indocyanine green dye angiography and compared to standard clinical assessment for predictive accuracy of flap necrosis. For estimating flap-failure, clinical prediction achieved a sensitivity of 79.3% and a specificity of 90.5%. When average flap perfusion was more than three standard deviations below the average flap perfusion for the negative control group at the time of the flap procedure (144.3+/-17.05 absolute perfusion units), laser-assisted indocyanine green dye angiography achieved a sensitivity of 81.1% and a specificity of 97.3%. When absolute perfusion units were seven standard deviations below the average flap perfusion for the negative control group, specificity of necrosis prediction was 100%. Quantitative absolute perfusion units can improve specificity for intraoperative prediction of viable tissue. Using this strategy, a positive predictive threshold of flap failure can be standardized for clinical use.

Prospective randomized assessment of single versus double-gloving for general surgical procedures.

Science.gov (United States)

Na'aya, H U; Madziga, A G; Eni, U E

2009-01-01

There is increased tendency towards double-gloving by general surgeons in our practice, due probably to awareness of the risk of contamination with blood or other body fluids during surgery. The aim of the study was to compare the relative frequency of glove puncture in single-glove versus double glove sets in general surgical procedures, and to determine if duration of surgery affects perforation rate. Surgeons at random do single or double gloves at their discretion, for general surgical procedures. All the gloves used by the surgeons were assessed immediately after surgery for perforation. A total of 1120 gloves were tested, of which 880 were double-glove sets and 240 single-glove sets. There was no significant difference in the overall perforation rate between single and double glove sets (18.3% versus 20%). However, only 2.3% had perforations in both the outer and inner gloves in the double glove group. Therefore, there was significantly greater risk for blood-skin exposure in the single glove sets (p < 0.01). The perforation rate was also significantly greater during procedures lasting an hour or more compared to those lasting less than an hour (p < 0.01). Double-gloving reduces the risk of blood-skin contamination in all general surgical procedures, and especially so in procedures lasting an hour or more.

Can failure carefully observed become a springboard to success?

Science.gov (United States)

Adrian, Manuella

2012-01-01

Since its inception, the addictions field has had a history of failure: failures in conceptualizations, in treatment, in interventions, in policies, in process as well as outcome assessment. Certain actions and activities have had a less than stellar effect which may lead to feelings of personal failure among practitioners, the tagging of processes and programs as being failures when they are not so, as well as an identification of the person being intervened with, by self and others, as being a failure or loser. This paper discusses how to define success and failure and the need to identify both the short(er) and long(er) term, as well as temporary and permanent effects, including the implications of using binary (success or failure; success and failure) and nonbinary (and in addition) categories of assessment. The need to clarify expectations and to establish goals and measurable effects are noted. Being open to accepting results which may be personally disappointing, initially, but which offer opportunities for needed changes may lead to new developments in the field and the establishment of better interventions.

Assessment of SPACE code for multiple failure accident: 1% Cold Leg Break LOCA with HPSI failure at ATLAS Test Facility

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Hyuk; Lee, Seung Wook; Kim, Kyung-Doo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Design extension conditions (DECs) is a popular key issue after the Fukushima accident. In a viewpoint of the reinforcement of the defense in depth concept, a high-risk multiple failure accident should be reconsidered. The target scenario of ATLAS A5.1 test was LSTF (Large Scale Test Facility) SB-CL-32 test, a 1% SBLOCA with total failure of high pressure safety injection (HPSI) system of emergency core cooling system (ECCS) and secondary side depressurization as the accident management (AM) action, as a counterpart test. As the needs to prepare the DEC accident because of a multiple failure of the present NPPs are emphasized, the capability of SPACE code, just like other system analysis code, is required to expand the DEC area. The objectives of this study is to validate the capability of SPACE code for a DEC scenario, which represents multiple failure accident like as a SBLOCA with HPSI fail. Therefore, the ATLAS A5.1 test scenario was chosen. As the needs to prepare the DEC accident because of a multiple failure of operating NPPs are emphasized, the capability of SPACE code is needed to expand the DEC area. So the capability of SPACE code was validated for one of a DEC scenario. The target scenario was selected as the ATLAS A5.1 test, which is a 1% SBLOCA with total failure of HPSI system of ECCS and secondary side depressurization. Through the sensitivity study on discharge coefficient of break flow, the best fit of integrated mass was found. Using the coefficient, the ATLAS A5.1 test was analyzed using the SPACE code. The major thermal hydraulic parameters such as the system pressure, temperatures were compared with the test and have a good agreement. Through the simulation, it was concluded that the SPACE code can effectively simulate one of multiple failure accidents like as SBLOCA with HPSI failure accident.

Evaluating strategic environmental assessment in the Netherlands: Content, process and procedure as indissoluble criteria for effectiveness

NARCIS (Netherlands)

M.W. van Buuren (Arwin); S.G. Nooteboom (Sibout)

2009-01-01

textabstractTo assess the effectiveness of strategic environmental assessment (SEA) we distinguish between its contribution to the quality of the ultimate policy choice (usefulness, applicability), the procedural quality of the planning process (transparency, timeliness) and the quality of

Cellular cardiomyoplasty for a patient with heart failure

International Nuclear Information System (INIS)

Zhang Fumin; Chen Yijiang; Yang Zhijian; Gao Xiang; Ma Wenzhu; Li Chuanfu; Kao, Race L.

2003-01-01

Background: A 73-year-old man with a history of myocardial infarction and hypertension for 5 years suffered heart failure (NYHA III-IV). Methods: 2D echo indicated hypokinesia at septal, left ventricular anterior wall and apical regions. Coronary angiograms demonstrated 60% stenosis in distal left main and 99% stenosis in proximal and distal left anterior descending coronary arteries (LAD). Both proximal artery and middle left circumflex coronary artery (LC) had 90% stenosis, and diffuse stenosis of right coronary artery (RC) was found. Myocardial perfusion imaging using 99m Tc-MIBI indicated defective perfusion of left ventricular apex, anterior wall and septal region and severe reduced perfusion of posterior inferior wall. Myocardial metabolic activities ( 18 F-deoxyglucose) also showed comparable reductions. After exposing the heart, LAD, LC, and RC were all completely occluded and bypass procedure could not be completed. Autologous satellite cells were implanted without any complication and the patient had an uneventful recovery. Results: During the first 2 months, he remained in heart failure, and by the third month, he gradually improved and reached NYHA II. At fifth month after the procedure, significant increased ejection fraction (37.1-48.6%) and wall movement with modest reduction of left ventricular systolic diameter (48-45 mm) were observed. Imaging with 18 F-deoxyglucose showed dramatic improvement in myocardial metabolic activity with similar improvement in myocardial perfusion ( 99m Tc-MIBI). Conclusion: This is the first successful case of cellular cardiomyoplasty without any conjunctional procedure for patient with severe coronary heart disease and heart failure

Preliminary Guideline for the High Temperature Structure Integrity Assessment Procedure Part II. High Temperature Structural Integrity Assessment

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Han; Kim, J. B.; Lee, H. Y.; Park, C. G.; Joo, Y. S.; Koo, G. H.; Kim, S. H

2007-02-15

A high temperature structural integrity assessment belongs to the Part II of a whole preliminary guideline for the high temperature structure. The main contents of this guideline are the evaluation procedures of the creep-fatigue crack initiation and growth in high temperature condition, the high temperature LBB evaluation procedure, and the inelastic evaluations of the welded joints in SFR structures. The methodologies for the proper inelastic analysis of an SFR structures in high temperatures are explained and the guidelines of inelastic analysis options using ANSYS and ABAQUS are suggested. In addition, user guidelines for the developed NONSTA code are included. This guidelines need to be continuously revised to improve the applicability to the design and analysis of the SFR structures.

Independent predictors of retrograde failure in CTO-PCI after successful collateral channel crossing.

Science.gov (United States)

Suzuki, Yoriyasu; Muto, Makoto; Yamane, Masahisa; Muramatsu, Toshiya; Okamura, Atsunori; Igarashi, Yasumi; Fujita, Tsutomu; Nakamura, Shigeru; Oida, Akitsugu; Tsuchikane, Etsuo

2017-07-01

To evaluate factors for predicting retrograde CTO-PCI failure after successful collateral channel crossing. Successful guidewire/catheter collateral channel crossing is important for the retrograde approach in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). A total of 5984 CTO-PCI procedures performed in 45 centers in Japan from 2009 to 2012 were studied. The retrograde approach was used in 1656 CTO-PCIs (27.7%). We investigated these retrograde procedures to evaluate factors for predicting retrograde CTO-PCI failure even after successful collateral channel crossing. Successful guidewire/catheter collateral crossing was achieved in 77.1% (n = 1,276) of 1656 retrograde CTO-PCI procedures. Retrograde procedural success after successful collateral crossing was achieved in 89.4% (n = 1,141). Univariate analysis showed that the predictors for retrograde CTO-PCI failure were in-stent occlusion (OR = 1.9829, 95%CI = 1.1783 - 3.3370 P = 0.0088), calcified lesions (OR = 1.9233, 95%CI = 1.2463 - 2.9679, P = 0.0027), and lesion tortuosity (OR = 1.5244, 95%CI = 1.0618 - 2.1883, P = 0.0216). On multivariate analysis, lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing (OR = 1.3472, 95%CI = 1.0614 - 1.7169, P = 0.0141). The success rate of retrograde CTO-PCI following successful guidewire/catheter collateral channel crossing was high in this registry. Lesion calcification was an independent predictor of retrograde CTO-PCI failure after successful collateral channel crossing. Devices and techniques to overcome complex CTO lesion morphology, such as lesion calcification, are required to further improve the retrograde CTO-PCI success rate. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Generic nuclear power plant component failure data bank

International Nuclear Information System (INIS)

Araujo Goes, A.G. de; Gibelli, S.M.O.

1988-11-01

This report consist in the development of a generic nuclear power plant component failure data bank. This data bank was implemented in a PC-XT microcomputer, IBM compatible, using the Open Access II program. Generic failure data tables for Westinghouse nuclear power plants and for general PWR power plants are presented. They are the final product of a research which included a preselection and a selection of data collected from the available sources in the library of CNEN (National Nuclear Energy Commission) and from the CIN/CNEN (Neclear Information Center). Futhermore, a proposal of evaluating models of average failure rates of pumps and valves are also presented. Through the electronic data bank one can easily have a generic view of failure rate ranges as well as failure models foe a certain component. It is very importante to develop procedures to collect and store generic failure data that can be quickly accessed, in order to update the Probabilistic Safety Study of Angra-1 and to used in studies which may have component failures of nuclear power plant safety systems. In the future, data specialization can be achieved by means of statistical calculations involving specific data collected from the operational experience of Angra-1 nuclear power plant and the generic data bank. (author) [pt

A systematic review with procedural assessments and meta-analysis of low level laser therapy in lateral elbow tendinopathy (tennis elbow).

Science.gov (United States)

Bjordal, Jan M; Lopes-Martins, Rodrigo Ab; Joensen, Jon; Couppe, Christian; Ljunggren, Anne E; Stergioulas, Apostolos; Johnson, Mark I

2008-05-29

Recent reviews have indicated that low level level laser therapy (LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing validity of treatment procedures and doses or the influence of prior steroid injections. Systematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures. 18 randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730 patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Egger's graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p elbow tendon insertions, seem to offer short-term pain relief and less disability in LET, both alone and in conjunction with an exercise regimen. This finding contradicts the conclusions of

A systematic review with procedural assessments and meta-analysis of Low Level Laser Therapy in lateral elbow tendinopathy (tennis elbow

Directory of Open Access Journals (Sweden)

Couppe Christian

2008-05-01

Full Text Available Abstract Background Recent reviews have indicated that low level level laser therapy (LLLT is ineffective in lateral elbow tendinopathy (LET without assessing validity of treatment procedures and doses or the influence of prior steroid injections. Methods Systematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures. Results 18 randomised placebo-controlled trials (RCTs were identified with 13 RCTs (730 patients meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Egger's graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p Conclusion LLLT administered with optimal doses of 904 nm and possibly 632 nm wavelengths directly to the lateral elbow tendon insertions

Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

International Nuclear Information System (INIS)

Karasawa, Kensuke; Ayusawa, Mamoru; Noto, Nobutaka; Sumitomo, Naokata; Okada, Tomoo; Harada, Kensuke

2000-01-01

Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

Philosophy, policies, and procedures - The three P's of flight-deck operations

Science.gov (United States)

Degani, Asaf; Wiener, Earl L.

1991-01-01

Standard operating procedures are drafted and provided to flightcrews to dictate the manner in which tasks are carried out. Failure to conform to Standard Operating Procedures (SOP) is frequently listed as the cause of violations, incidents, and accidents. However, procedures are often designed piecemeal, rather than being based on a sound philosophy of operations and policies that follow from such a philosophy. A framework of philosophy, policies, and procedures is proposed.

Productive failure in learning math.

Science.gov (United States)

Kapur, Manu

2014-06-01

When learning a new math concept, should learners be first taught the concept and its associated procedures and then solve problems, or solve problems first even if it leads to failure and then be taught the concept and the procedures? Two randomized-controlled studies found that both methods lead to high levels of procedural knowledge. However, students who engaged in problem solving before being taught demonstrated significantly greater conceptual understanding and ability to transfer to novel problems than those who were taught first. The second study further showed that when given an opportunity to learn from the failed problem-solving attempts of their peers, students outperformed those who were taught first, but not those who engaged in problem solving first. Process findings showed that the number of student-generated solutions significantly predicted learning outcomes. These results challenge the conventional practice of direct instruction to teach new math concepts and procedures, and propose the possibility of learning from one's own failed problem-solving attempts or those of others before receiving instruction as alternatives for better math learning. © 2014 Cognitive Science Society, Inc.

Teachers' Use of a Self-Assessment Procedure: The Role of Criteria, Standards, Feedback and Reflection

Science.gov (United States)

van Diggelen, Migchiel; den Brok, Perry; Beijaard, Douwe

2013-01-01

This article reports on the way teachers assess their own coaching competencies regarding the development of vocational education students' reflection skills. The participating teachers used a self-assessment procedure in which they had to judge themselves with the help of criteria and standards, received feedback from a colleague based on the…

A Multimode Adaptive Pushover Procedure for Seismic Assessment of Integral Bridges

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Ehsan Mohtashami

2013-01-01

Full Text Available This paper presents a new adaptive pushover procedure to account for the effect of higher modes in order to accurately estimate the seismic response of bridges. The effect of higher modes is considered by introducing a minimum value for the total effective modal mass. The proposed method employs enough number of modes to ensure that the defined total effective modal mass participates in all increments of the pushover loading. An adaptive demand curve is also developed for assessment of the seismic demand. The efficiency and robustness of the proposed method are demonstrated by conducting a parametric study. The analysis includes 18 four-span integral bridges with various heights of piers. The inelastic response history analysis is employed as reference solution in this study. Numerical results indicate excellent accuracy of the proposed method in assessment of the seismic response. For most bridges investigated in this study, the difference between the estimated response of the proposed method and the inelastic response history analysis is less than 25% for displacements and 10% for internal forces. This indicates a very good accuracy compared to available pushover procedures in the literature. The proposed method is therefore recommended to be applied to the seismic performance evaluation of integral bridges for engineering applications.

ASSESSMENT OF BUILDING FAILURES IN NIGERIA: LAGOS AND ...

African Journals Online (AJOL)

Common failures seen on buildings were wall cracking, wall spalling, foundation settlement, column buckling, etc. Proper assurance of competent professionals and strict enforcement of ethical standards by the Nigerian Society of Engineers, the Nigerian Institute of Building, and the Nigerian Institute of Architects would ...

Steam generator tube failures: world experience in water-cooled nuclear power reactors in 1975

International Nuclear Information System (INIS)

Hare, M.G.

1976-11-01

Steam generator tube failures were reported in 22 out of 62 water-cooled nuclear power plants surveyed in 1975. This was less than in 1974, and the number of the tubes affected was noticeably less. This report summarizes these failures, most of which were due to corrosion. Secondary-water chemistry control, procedures for inspection and repair, tube materials, and failure rates are discussed. (author)

Common cause failure investigations using the European Reliability Data System

International Nuclear Information System (INIS)

Games, A.M.; Breewood, M.; Amendola, A.; Keller, A.Z.

1984-01-01

The European Reliability Data System (ERDS) has provided data for use in investigations into common cause failures (CCFs) in nuclear power plants. These investigations have been made on two levels, at a system and inter-system level. Data have been used from the Component Event Data Bank and from the Licensee Event Report Files, both part of the ERDS. The two studies required different methodologies although both commenced with a temporal sorting procedure for the failure events. The studies demonstrated that different types of common cause failure necessitate different search algorithms, and thus a data search must be closely related to an appropriate CCF classification system, which in the first instance would not be based on causes of failure. (author)

Failure of operative treatment for glenohumeral instability: etiology and management.

Science.gov (United States)

Shah, Apurva S; Karadsheh, Mark S; Sekiya, Jon K

2011-05-01

Failure of primary shoulder stabilization procedures is often related to uncorrected anatomic pathology. Orthopaedic surgeons must recognize excessive capsular laxity or large glenohumeral bone defects preoperatively to avoid recurrence of instability. When history, physical examination, and radiographic evaluation are used in conjunction, patients at risk for failure can be identified. The instability severity index score permits precise identification of patients at risk. When treating patients in whom prior surgical intervention has failed, the success of revision procedures correlates to the surgeon's ability to identify the essential pathology and use lesion-specific treatment strategies. Revision procedures remain technically demanding. Keen preoperative and intraoperative judgment is required to avoid additional recurrence of instability after revision procedures, particularly because results deteriorate with each successive operation. Glenoid or humeral defects with greater than 25% bone loss compromise stability provided through the mechanism of concavity compression. These defects must be specifically addressed to avoid recurrence of instability. We prefer anatomic reconstruction techniques combined with capsulolabral repair and, if bone defects are present, anatomic reconstruction with osteochondral allograft. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

A self-controlled case series to assess the effectiveness of beta blockers for heart failure in reducing hospitalisations in the elderly

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Pratt Nicole L

2011-07-01

Full Text Available Abstract Background To determine the suitability of using the self-controlled case series design to assess improvements in health outcomes using the effectiveness of beta blockers for heart failure in reducing hospitalisations as the example. Methods The Australian Government Department of Veterans' Affairs administrative claims database was used to undertake a self-controlled case-series in elderly patients aged 65 years or over to compare the risk of a heart failure hospitalisation during periods of being exposed and unexposed to a beta blocker. Two studies, the first using a one year period and the second using a four year period were undertaken to determine if the estimates varied due to changes in severity of heart failure over time. Results In the one year period, 3,450 patients and in the four year period, 12, 682 patients had at least one hospitalisation for heart failure. The one year period showed a non-significant decrease in hospitalisations for heart failure 4-8 months after starting beta-blockers, (RR, 0.76; 95% CI (0.57-1.02 and a significant decrease in the 8-12 months post-initiation of a beta blocker for heart failure (RR, 0.62; 95% CI (0.39, 0.99. For the four year study there was an increased risk of hospitalisation less than eight months post-initiation and significant but smaller decrease in the 8-12 month window (RR, 0.90; 95% CI (0.82, 0.98. Conclusions The results of the one year observation period are similar to those observed in randomised clinical trials indicating that the self-controlled case-series method can be successfully applied to assess health outcomes. However, the result appears sensitive to the study periods used and further research to understand the appropriate applications of this method in pharmacoepidemiology is still required. The results also illustrate the benefits of extending beta blocker utilisation to the older age group of heart failure patients in which their use is common but the evidence is

A REVIEW OF SOFTWARE-INDUCED FAILURE EXPERIENCE.

Energy Technology Data Exchange (ETDEWEB)

CHU, T.L.; MARTINEZ-GURIDI, G.; YUE, M.; LEHNER, J.

2006-09-01

We present a review of software-induced failures in commercial nuclear power plants (NPPs) and in several non-nuclear industries. We discuss the approach used for connecting operational events related to these failures and the insights gained from this review. In particular, we elaborate on insights that can be used to model this kind of failure in a probabilistic risk assessment (PRA) model. We present the conclusions reached in these areas.

Definition, development, and demonstration of analytical procedures for the structured assessment approach. Final report

International Nuclear Information System (INIS)

1979-01-01

Analytical procedures were refined for the Structural Assessment Approach for assessing the Material Control and Accounting systems at facilities that contain special nuclear material. Requirements were established for an efficient, feasible algorithm to be used in evaluating system performance measures that involve the probability of detection. Algorithm requirements to calculate the probability of detection for a given type of adversary and the target set are described

Failure mode effects and criticality analysis: innovative risk assessment to identify critical areas for improvement in emergency department sepsis resuscitation.

Science.gov (United States)

Powell, Emilie S; O'Connor, Lanty M; Nannicelli, Anna P; Barker, Lisa T; Khare, Rahul K; Seivert, Nicholas P; Holl, Jane L; Vozenilek, John A

2014-06-01

Sepsis is an increasing problem in the practice of emergency medicine as the prevalence is increasing and optimal care to reduce mortality requires significant resources and time. Evidence-based septic shock resuscitation strategies exist, and rely on appropriate recognition and diagnosis, but variation in adherence to the recommendations and therefore outcomes remains. Our objective was to perform a multi-institutional prospective risk-assessment, using failure mode effects and criticality analysis (FMECA), to identify high-risk failures in ED sepsis resuscitation. We conducted a FMECA, which prospectively identifies critical areas for improvement in systems and processes of care, across three diverse hospitals. A multidisciplinary group of participants described the process of emergency department (ED) sepsis resuscitation to then create a comprehensive map and table listing all process steps and identified process failures. High-risk failures in sepsis resuscitation from each of the institutions were compiled to identify common high-risk failures. Common high-risk failures included limited availability of equipment to place the central venous catheter and conduct invasive monitoring, and cognitive overload leading to errors in decision-making. Additionally, we identified great variability in care processes across institutions. Several common high-risk failures in sepsis care exist: a disparity in resources available across hospitals, a lack of adherence to the invasive components of care, and cognitive barriers that affect expert clinicians' decision-making capabilities. Future work may concentrate on dissemination of non-invasive alternatives and overcoming cognitive barriers in diagnosis and knowledge translation.

Diuretics for heart failure.

Science.gov (United States)

Faris, Rajaa F; Flather, Marcus; Purcell, Henry; Poole-Wilson, Philip A; Coats, Andrew J S

2012-02-15

Chronic heart failure is a major cause of morbidity and mortality worldwide. Diuretics are regarded as the first-line treatment for patients with congestive heart failure since they provide symptomatic relief. The effects of diuretics on disease progression and survival remain unclear. To assess the harms and benefits of diuretics for chronic heart failure Updated searches were run in the Cochrane Central Register of Controlled Trials in The Cochrane Library (CENTRAL Issue 1 of 4, 2011), MEDLINE (1966 to 22 February 2011), EMBASE (1980 to 2011 Week 07) and HERDIN database (1990 to February 2011). We hand searched pertinent journals and reference lists of papers were inspected. We also contacted manufacturers and researchers in the field. No language restrictions were applied. Double-blinded randomised controlled trials of diuretic therapy comparing one diuretic with placebo, or one diuretic with another active agent (e.g. ACE inhibitors, digoxin) in patients with chronic heart failure. Two authors independently abstracted the data and assessed the eligibility and methodological quality of each trial. Extracted data were analysed by determining the odds ratio for dichotomous data, and difference in means for continuous data, of the treated group compared with controls. The likelihood of heterogeneity of the study population was assessed by the Chi-square test. If there was no evidence of statistical heterogeneity and pooling of results was clinically appropriate, a combined estimate was obtained using the fixed-effects model. This update has not identified any new studies for inclusion. The review includes 14 trials (525 participants), 7 were placebo-controlled, and 7 compared diuretics against other agents such as ACE inhibitors or digoxin. We analysed the data for mortality and for worsening heart failure. Mortality data were available in 3 of the placebo-controlled trials (202 participants). Mortality was lower for participants treated with diuretics than for

An assessment of consumers’ subconscious responses to frontline employees’ attractiveness in a service failure and recovery situation

Directory of Open Access Journals (Sweden)

Christo Boshoff

2017-06-01

Full Text Available Background: Initial analyses of the impact of physical attractiveness in a business context have supported the ‘what is beautiful is good’ contention. However, in circumstances characterised by negative emotions, duress and stress, very little is known about how human beings respond at the subconscious level to the attractiveness of frontline service providers. Aim: The purpose of this study was to assess whether consumers who complain to a frontline service provider about a service failure respond differently at the subconscious level when the service provider involved in the service encounter is attractive compared with one who is less attractive. Method: Forty respondents were exposed to a video clip of a service failure and service recovery situation. While viewing the hypothetical scenario, two neuro-physiological measurements were used to collect data at the subconscious level, namely galvanic skin response (GSR and electroencephalography (EEG. Results: The results suggest that, at the subconscious level, customers respond differently to the service recovery efforts depending on the attractiveness of the frontline service provider who attempts to rectify the service failure. Conclusion: The results seem to suggest that the physical attractiveness of a frontline service provider moderates (or softens the negative emotions that a complaining customer might experience during a service failure and complaint situation – consistent with the ‘what is beautiful is good’ contention.

A comparison of Google Glass and traditional video vantage points for bedside procedural skill assessment.

Science.gov (United States)

Evans, Heather L; O'Shea, Dylan J; Morris, Amy E; Keys, Kari A; Wright, Andrew S; Schaad, Douglas C; Ilgen, Jonathan S

2016-02-01

This pilot study assessed the feasibility of using first person (1P) video recording with Google Glass (GG) to assess procedural skills, as compared with traditional third person (3P) video. We hypothesized that raters reviewing 1P videos would visualize more procedural steps with greater inter-rater reliability than 3P rating vantages. Seven subjects performed simulated internal jugular catheter insertions. Procedures were recorded by both Google Glass and an observer's head-mounted camera. Videos were assessed by 3 expert raters using a task-specific checklist (CL) and both an additive- and summative-global rating scale (GRS). Mean scores were compared by t-tests. Inter-rater reliabilities were calculated using intraclass correlation coefficients. The 1P vantage was associated with a significantly higher mean CL score than the 3P vantage (7.9 vs 6.9, P = .02). Mean GRS scores were not significantly different. Mean inter-rater reliabilities for the CL, additive-GRS, and summative-GRS were similar between vantages. 1P vantage recordings may improve visualization of tasks for behaviorally anchored instruments (eg, CLs), whereas maintaining similar global ratings and inter-rater reliability when compared with conventional 3P vantage recordings. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic flexible pharyngo-laryngoscopy: development of a procedure specific assessment tool using a Delphi methodology.

Science.gov (United States)

Melchiors, Jacob; Henriksen, Mikael Johannes Vuokko; Dikkers, Frederik G; Gavilán, Javier; Noordzij, J Pieter; Fried, Marvin P; Novakovic, Daniel; Fagan, Johannes; Charabi, Birgitte W; Konge, Lars; von Buchwald, Christian

2018-05-01

Proper training and assessment of skill in flexible pharyngo-laryngoscopy are central in the education of otorhinolaryngologists. To facilitate an evidence-based approach to curriculum development in this field, a structured analysis of what constitutes flexible pharyngo-laryngoscopy is necessary. Our aim was to develop an assessment tool based on this analysis. We conducted an international Delphi study involving experts from twelve countries in five continents. Utilizing reiterative assessment, the panel defined the procedure and reached consensus (defined as 80% agreement) on the phrasing of an assessment tool. FIFTY PANELISTS COMPLETED THE DELPHI PROCESS. THE MEDIAN AGE OF THE PANELISTS WAS 44 YEARS (RANGE 33-64 YEARS). MEDIAN EXPERIENCE IN OTORHINOLARYNGOLOGY WAS 15 YEARS (RANGE 6-35 YEARS). TWENTY-FIVE WERE SPECIALIZED IN LARYNGOLOGY, 16 WERE HEAD AND NECK SURGEONS, AND NINE WERE GENERAL OTORHINOLARYNGOLOGISTS. AN ASSESSMENT TOOL WAS CREATED CONSISTING OF TWELVE DISTINCT ITEMS.: Conclusion The gathering of validity evidence for assessment of core procedural skills within Otorhinolaryngology is central to the development of a competence-based education. The use of an international Delphi panel allows for the creation of an assessment tool which is widely applicable and valid. This work allows for an informed approach to technical skills training for flexible pharyngo-laryngoscopy and as further validity evidence is gathered allows for a valid assessment of clinical performance within this important skillset.

Assessment procedures results of training in biology