Determinants of noninvasive ventilation success or failure in morbidly obese patients in acute respiratory failure.

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Malcolm Lemyze

Full Text Available Acute respiratory failure (ARF is a common life-threatening complication in morbidly obese patients with obesity hypoventilation syndrome (OHS. We aimed to identify the determinants of noninvasive ventilation (NIV success or failure for this indication.We prospectively included 76 consecutive patients with BMI>40 kg/m2 diagnosed with OHS and treated by NIV for ARF in a 15-bed ICU of a tertiary hospital.NIV failed to reverse ARF in only 13 patients. Factors associated with NIV failure included pneumonia (n = 12/13, 92% vs n = 9/63, 14%; p<0.0001, high SOFA (10 vs 5; p<0.0001 and SAPS2 score (63 vs 39; p<0.0001 at admission. These patients often experienced poor outcome despite early resort to endotracheal intubation (in-hospital mortality, 92.3% vs 17.5%; p<0.001. The only factor significantly associated with successful response to NIV was idiopathic decompensation of OHS (n = 30, 48% vs n = 0, 0%; p = 0.001. In the NIV success group (n = 63, 33 patients (53% experienced a delayed response to NIV (with persistent hypercapnic acidosis during the first 6 hours.Multiple organ failure and pneumonia were the main factors associated with NIV failure and death in morbidly obese patients in hypoxemic ARF. On the opposite, NIV was constantly successful and could be safely pushed further in case of severe hypercapnic acute respiratory decompensation of OHS.

French college students' sports practice and its relations with stress, coping strategies and academic success.

Science.gov (United States)

Décamps, Greg; Boujut, Emilie; Brisset, Camille

2012-01-01

College students at university have to face several stress factors. Although sports practice has been considered as having beneficial effects upon stress and general health, few studies have documented its influence on this specific population. The aim of this comparative study was to determine whether the intensity of the college students' sports practice (categorized into three groups: rare, regular, or intensive) would influence their levels of stress and self-efficacy, their coping strategies, and their academic success/failure. Three self-completion questionnaires were administered to 1071 French freshmen during their compulsory medical visit at the preventive medicine service of the university. Results indicated that students with intensive sport practice reported lower scores of general stress, academic stress, and emotion-focused coping strategies, and higher scores of self-efficacy than those with rare practice. However, the proportion of successful students did not differ significantly between the three groups of sports practice.

Factors contributing to migraine headache surgery failure and success.

Science.gov (United States)

Larson, Kelsey; Lee, Michelle; Davis, Janine; Guyuron, Bahman

2011-11-01

The purpose of this study was to identify factors that contribute to migraine headache surgery failure and success. A retrospective chart review was conducted of patients who underwent surgery for migraine headaches performed by the senior author (B.G.) and had at least 11 months of follow-up. The study population included three groups: migraine surgery success, improvement, and failure. Thirty-six unique data points were collected for each patient. A total of 169 patients met inclusion criteria. Of these, 66 patients comprised the migraine surgery success group (S, complete elimination of migraine headaches); 67 comprised the migraine surgery improvement group (I, >50 percent reduction in migraine frequency, intensity, or duration); and 36 comprised the migraine surgery failure group (F, I, p=0.02), migraine frequency (SI, p=0.003; S>F, p=0.04), history of head or neck injury (SI, p=0.02), increased intraoperative bleeding (SF, p=0.0006; I>F, p=0.0004), site II (S>F, p=0.015), single operative site (SI, p=0.05; S>F, p=0.04). Factors associated with migraine surgery failure include increased intraoperative bleeding and surgery on fewer trigger sites. Factors associated with migraine surgery success are older age of migraine onset, higher rate of visual symptoms versus improvement group, surgery at site I or II, and deactivating all four operative sites. Risk, III.

The embodiment of success and failure as forward versus backward movements.

Science.gov (United States)

Robinson, Michael D; Fetterman, Adam K

2015-01-01

People often speak of success (e.g., "advance") and failure (e.g., "setback") as if they were forward versus backward movements through space. Two experiments sought to examine whether grounded associations of this type influence motor behavior. In Experiment 1, participants categorized success versus failure words by moving a joystick forward or backward. Failure categorizations were faster when moving backward, whereas success categorizations were faster when moving forward. Experiment 2 removed the requirement to categorize stimuli and used a word rehearsal task instead. Even without Experiment 1's response procedures, a similar cross-over interaction was obtained (e.g., failure memorizations sped backward movements relative to forward ones). The findings are novel yet consistent with theories of embodied cognition and self-regulation.

The embodiment of success and failure as forward versus backward movements.

Directory of Open Access Journals (Sweden)

Michael D Robinson

Full Text Available People often speak of success (e.g., "advance" and failure (e.g., "setback" as if they were forward versus backward movements through space. Two experiments sought to examine whether grounded associations of this type influence motor behavior. In Experiment 1, participants categorized success versus failure words by moving a joystick forward or backward. Failure categorizations were faster when moving backward, whereas success categorizations were faster when moving forward. Experiment 2 removed the requirement to categorize stimuli and used a word rehearsal task instead. Even without Experiment 1's response procedures, a similar cross-over interaction was obtained (e.g., failure memorizations sped backward movements relative to forward ones. The findings are novel yet consistent with theories of embodied cognition and self-regulation.

Specific strain work as a failure criterion in plane stress state

International Nuclear Information System (INIS)

Zuchowski, R.; Zietkowski, L.

1985-01-01

An experimental verification of failure criterion based on specific strain work was performed. Thin-walled cylindrical specimens were examined by loading with constant force and constant torque moment, assuming different values for particular tests, at the same time keeping stress intensity constant, and by subjecting to thermal cycling. It was found that the critical value of failure did not depend on axial-to-shearing stresses ratio, i.e., on the type of state of stress. Thereby, the validity of the analysed failure criterion in plane stress was confirmed. Besides, a simple description of damage development in plane stress was suggested. (orig./RF)

Effect of Thermal Stresses on the Failure Criteria of Fiber Composites

DEFF Research Database (Denmark)

Leong, Martin Klitgaard; Sankar, Bhavani V.

2010-01-01

, the latter, called micro-thermal stresses, has not been given much attention. In this paper the Direct Micromechanics Method is used to investigate the effects of micro-thermal stresses on the failure envelope of composites. Using FEA the unit-cell of the composite is analyzed. Assuming the failure criteria...... for the fiber and matrix are known, the exact failure envelope is developed. Using the micromechanics results, the Tsai-Wu failure envelope is modified to account for the micro-thermal stresses. The approach is demonstrated using two example structures at cryogenic temperature....

Modes of failures: primary and secondary stresses

International Nuclear Information System (INIS)

Roche, R.L.

1987-07-01

The paper begins with a reminder that the purpose of stress classification is to ensure suitable margins with respect to failure modes. The distinction between primary stresses and secondary stresses is then examined and a method is given for assessing the degree of elastic follow up in the elastic plastic field. The importance of elastic follow up is then highlighted by an examination of the effect of primary and secondary stresses on crack behavior

Associations between psychological distress, workplace accidents, workplace failures and workplace successes.

Science.gov (United States)

Hilton, Michael F; Whiteford, Harvey A

2010-12-01

This study investigates associations between psychological distress and workplace accidents, workplace failures and workplace successes. The Health and Work Performance Questionnaire (HPQ) was distributed to employees of 58 large employers. A total of 60,556 full-time employees were eligible for analysis. The HPQ probed whether the respondent had, in the past 30-days, a workplace accident, success or failure ("yes" or "no"). Psychological distress was quantified using the Kessler 6 (K6) scale and categorised into low, moderate and high psychological distress. Three binomial logistic regressions were performed with the dependent variables being workplace accident, success or failure. Covariates in the models were K6 category, gender, age, marital status, education level, job category, physical health and employment sector. Accounting for all other variables, moderate and high psychological distress significantly (P work failures and decrease the OR of workplace successes at similar levels. As the prevalence of moderate psychological distress is approximately double that of high psychological distress moderate distress consequentially has a greater workplace impact.

French college students’ sports practice and its relations with stress, coping strategies and academic success

Directory of Open Access Journals (Sweden)

Greg eDécamps

2012-04-01

Full Text Available College students at university have to face several stress factors. Although sports practice has been considered as having beneficial effects upon stress and general health, few studies have documented its influence on this specific population. The aim of this comparative study was to determine whether the intensity of the college students’ sports practice (categorized into three groups: rare, regular or intensive would influence their levels of stress and self-efficacy, their coping strategies and their academic success/failure. Three self-completion questionnaires were administered to 1071 French freshmen during their compulsory medical visit at the preventive medicine service of the university. Results indicated that students with intensive sport practice reported lower scores of general stress, academic stress and emotion-focused coping strategies, and higher scores of self-efficacy than those with rare practice. However, the proportion of successful students did not differ significantly between the three groups of sports practice.

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

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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

Attributional Choices for Academic Success and Failure by Intellectually Gifted Students

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Assouline, Susan G.; Colangelo, Nicholas; Ihrig, Damien; Forstadt, Leslie

2006-01-01

This study emerges from the lack of empirical research on gifted students' attributions about academic success and failure in multiple subject areas and school in general. We explored differences in top attributional choices between boys and girls for success and failure in general academics, language arts, science, and mathematics. Gifted…

Urban freight transportation : challenges, failures and successes

NARCIS (Netherlands)

Kant, G.; Quak, H.; Peeters, R.; van Woensel, T.; Zijm, H.; Klumpp, M.; Clausen, U.; ten Hompel, M.

2016-01-01

In this paper, we present the challenges, failures and successes on urban freight transportation. We first identify the various involved stakeholders with their interests. Then we evaluate a large number of urban freight transport initiatives and identify lessons learned, which are distinguished in

Urban freight transportation : Challenges, failure, and successes

NARCIS (Netherlands)

Kant, Goos; Quak, H.; Peeters, Rene; Woensel van, T.; Zijm, H.; Klumpp, M.; Clausen, U.; Ten Hompel, M.

2016-01-01

In this paper, we present the challenges, failures and successes on urban freight transportation. We first identify the various involved stakeholders with their interests. Then we evaluate a large number of urban freight transport initiatives and identify lessons learned, which are distinguished in

Innovations in precision seed drilling technology: successes or failures?

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Johannes Benninger

2016-06-01

Full Text Available In view of the development of various technological alternatives in precision seed drilling, it has become a matter of research whether there are clear criteria for the success or failure of technological innovations. Around the turn to the 20th century, two very different precision seed drill methods were developed almost at the same time. Band seeding made it possible to achieve nearly perfect single grain sowing. For this purpose, individual, equally spaced seeds were embedded into bands of paper or cotton. In the field, these seed tapes were then unreeled from large drums. The pneumatic system proposed in 1897, by contrast, introduced grain singling using a vacuum for the first time. Although band seeding presented a satisfactory technological solution, it was never widely applied. Pneumatic systems, on the other hand, took long to catch on and only started to be successful in the late 1960s. Up to then, these innovative systems had to be considered as failures. Changing the period under review, however, may completely reverse the assessment of whether an innovation is a success or a failure.

actors of Success and Failure for International Retailers in Poland

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Florance Feldmann

2016-03-01

Full Text Available Purpose: This article provides an understanding of international retailers’ successes and failures when expanding in the Polish market. Accordingly, the objectives of this article were to define and identify what are the critical factors of success and failures of international retailers’ strategies while expanding in the Polish market according to the retailers themselves. Methodology: Adopting an interpretative research approach, this article elaborates a multiple explanatory case study design to discover how existing theory on internationalization compared to how internationalization is experienced and conceptualized by practitioners in their natural contexts. Findings: Twenty cases were studied among which were found four successful retailers and two who had failed. Coding of categories highlighted five critical success factors and five critical failure factors. Pricing strategy, necessity of adapting operations to local market, learning by doing, e-commerce and early entry timing appeared as factors of success or at least as “facilitating factors.” Choosing the inappropriate entry method, underestimating competition, developing the retail network and retail environment at a slow pace and not giving enough means of abnegation led to failures in Poland. Originality: This article contributes to filling two main gaps identified in the literature review. Many different theoretical approaches exist but no conclusive framework has emerged. Besides, most concepts were developed and tested on western European countries and nothing proved adequate to the specific retail landscape of eastern Europeans countries such as Poland.

Electromigration failures under bidirectional current stress

Science.gov (United States)

Tao, Jiang; Cheung, Nathan W.; Hu, Chenming

1998-01-01

Electromigration failure under DC stress has been studied for more than 30 years, and the methodologies for accelerated DC testing and design rules have been well established in the IC industry. However, the electromigration behavior and design rules under time-varying current stress are still unclear. In CMOS circuits, as many interconnects carry pulsed-DC (local VCC and VSS lines) and bidirectional AC current (clock and signal lines), it is essential to assess the reliability of metallization systems under these conditions. Failure mechanisms of different metallization systems (Al-Si, Al-Cu, Cu, TiN/Al-alloy/TiN, etc.) and different metallization structures (via, plug and interconnect) under AC current stress in a wide frequency range (from mHz to 500 MHz) has been study in this paper. Based on these experimental results, a damage healing model is developed, and electromigration design rules are proposed. It shows that in the circuit operating frequency range, the "design-rule current" is the time-average current. The pure AC component of the current only contributes to self-heating, while the average (DC component) current contributes to electromigration. To ensure longer thermal-migration lifetime under high frequency AC stress, an additional design rule is proposed to limit the temperature rise due to self-joule heating.

Endoscopic third ventriculostomy with choroid plexus cauterization outcome: distinguishing success from failure.

Science.gov (United States)

Dewan, Michael C; Lim, Jaims; Morgan, Clinton D; Gannon, Stephen R; Shannon, Chevis N; Wellons, John C; Naftel, Robert P

2016-12-01

OBJECTIVE Endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) offers an alternative to shunt treatment for infantile hydrocephalus. Diagnosing treatment failure is dependent on infantile hydrocephalus metrics, including head circumference, fontanel quality, and ventricle size. However, it is not clear to what degree these metrics should be expected to change after ETV/CPC. Using these clinical metrics, the authors present and analyze the decision making in cases of ETV/CPC failure. METHODS Infantile hydrocephalus metrics, including bulging fontanel, head circumference z-score, and frontal and occipital horn ratio (FOHR), were compared between ETV/CPC failures and successes. Treatment outcome predictive values of metrics individually and in combination were calculated. RESULTS Forty-four patients (57% males, median age 1.2 months) underwent ETV/CPC for hydrocephalus; of these patients, 25 (57%) experienced failure at a median time of 51 days postoperatively. Patients experiencing failure were younger than those experiencing successful treatment (0.8 vs 3.9 months, p = 0.01). During outpatient follow-up, bulging anterior fontanel, progressive macrocephaly, and enlarging ventricles each demonstrated a positive predictive value (PPV) of no less than 71%, but a bulging anterior fontanel remained the most predictive indicator of ETV/CPC failure, with a PPV of 100%, negative predictive value of 73%, and sensitivity of 72%. The highest PPVs and specificities existed when the clinical metrics were present in combination, although sensitivities decreased expectedly. Only 48% of failures were diagnosed on the basis all 3 hydrocephalus metrics, while only 37% of successes were negative for all 3 metrics. In the remaining 57% of patients, a diagnosis of success or failure was made in the presence of discordant data. CONCLUSIONS Successful ETV/CPC for infantile hydrocephalus was evaluated in relation to fontanel status, head growth, and change in

Success and failure factors for e-government projects: A case from Egypt

Directory of Open Access Journals (Sweden)

Hatem Elkadi

2013-07-01

Full Text Available E-government implementations in developing countries still face difficulties, leading to a large failure ratio. This is too high a cost for developing countries. Analysis of the reasons behind success and failure of e-government projects is still an interesting domain of investigation. Several approaches were advanced and success and failure factors have been stipulated, but factors pertinent to Public Administration have yet to be investigated and analyzed. This work builds on the results of earlier research, analyzing the factors behind the change in performance of the different sites of a specific project, reasons of their original success, and the relapse of one site. It reviews in detail the factors advanced by previous works and integrates for the first time the results obtained by 3 different research methodologies. It clarifies the causality between different factors presumed to individually affect the e-government implementations, thus enabling the disambiguation between the main and secondary less effective causes of failure. The success and failure factors significance and relative importance are identified, revealing the recommended track of action for the set-back remedy.

Stress Transmission and Failure in Disordered Porous Media

Science.gov (United States)

Laubie, Hadrien; Radjai, Farhang; Pellenq, Roland; Ulm, Franz-Josef

2017-08-01

By means of extensive lattice-element simulations, we investigate stress transmission and its relation with failure properties in increasingly disordered porous systems. We observe a non-Gaussian broadening of stress probability density functions under tensile loading with increasing porosity and disorder, revealing a gradual transition from a state governed by single-pore stress concentration to a state controlled by multipore interactions and metric disorder. This effect is captured by the excess kurtosis of stress distributions and shown to be nicely correlated with the second moment of local porosity fluctuations, which appears thus as a (dis)order parameter for the system. By generating statistical ensembles of porous textures with varying porosity and disorder, we derive a general expression for the fracture stress as a decreasing function of porosity and disorder. Focusing on critical sites where the local stress is above the global fracture threshold, we also analyze the transition to failure in terms of a coarse-graining length. These findings provide a general framework which can also be more generally applied to multiphase and structural heterogeneous materials.

In-situ observations of stress-induced thin film failures

Energy Technology Data Exchange (ETDEWEB)

Zhao, Z.B., E-mail: zzhao@firstsolar.co [Delphi Research Labs, 51786 Shelby Parkway, Shelby Twp., MI 48315 (United States); Hershberger, J. [Laird Technologies, 4707 Detroit Avenue, Cleveland, Ohio, 44102 (United States); Bilello, J.C. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109-2136 (United States)

2010-02-01

In this work, the failure modes of thin films under thermo-mechanical treatments were observed via in-situ white beam X-ray topography. The in-situ experiments were carried out using an experimental setup on Beamline 2-2 at the Stanford Synchrotron Radiation Laboratory. Magnetron sputtered polycrystalline thin films of Ta and CrN on Si substrates were selected for the present study due to their disparate states of intrinsic residual stresses: the Ta film was anisotropically compressive and the CrN film was isotropically tensile. Under a similar heating-cooling cycle in air, the two types of films exhibited distinct failure modes, which were observed in-situ and in a quasi-real-time fashion. The failures of the samples have been interpreted based on their distinctive growth stress states, superimposed on the additional stress development associated with different forms of thermal instabilities upon heating. These included the formation of oxide for the Ta/Si sample, which led to an increase in compressive stress, and a phase change for the CrN/Si sample, which caused the isotropic stress in the film to become increasingly tensile.

In-situ observations of stress-induced thin film failures

International Nuclear Information System (INIS)

Zhao, Z.B.; Hershberger, J.; Bilello, J.C.

2010-01-01

In this work, the failure modes of thin films under thermo-mechanical treatments were observed via in-situ white beam X-ray topography. The in-situ experiments were carried out using an experimental setup on Beamline 2-2 at the Stanford Synchrotron Radiation Laboratory. Magnetron sputtered polycrystalline thin films of Ta and CrN on Si substrates were selected for the present study due to their disparate states of intrinsic residual stresses: the Ta film was anisotropically compressive and the CrN film was isotropically tensile. Under a similar heating-cooling cycle in air, the two types of films exhibited distinct failure modes, which were observed in-situ and in a quasi-real-time fashion. The failures of the samples have been interpreted based on their distinctive growth stress states, superimposed on the additional stress development associated with different forms of thermal instabilities upon heating. These included the formation of oxide for the Ta/Si sample, which led to an increase in compressive stress, and a phase change for the CrN/Si sample, which caused the isotropic stress in the film to become increasingly tensile.

Reading Success and Failure among Chinese Children.

Science.gov (United States)

Hsu, Chen-chin

Drawing on a cross-national study of children's reading, a study examined the correlates of reading success and failure in Taiwan. Subjects, 240 randomly selected Taipei fifth graders, were administered a reading test, cognitive test, and mathematics achievement test. A structured interview with each child's mother and classroom behavior…

Albania’s Transformation since 1997: Successes and Failures

Directory of Open Access Journals (Sweden)

Jusufi Islam

2017-03-01

Full Text Available In 1997 Albania experienced a collapse of order and widespread violence, which resulted in a situation where the government was overthrown and some 2,000 people were killed. The 1997 disorder came as a result of the collapse of fraudulent financial pyramid schemes that had all the features of a war-like economic structure. During the 1997 events, large-scale confiscation and stealing of state assets occurred. Albania’s transitional period from communism to democracy, which began in 1990, led to the establishment of new structures for profiting from the country’s resources. Some of these political and economic structures, in the aftermath of the 1997 events, disappeared and others, including their structural effects, persist and have had an impact on the country’s political stability and economic progress. Today, both the successes and failures of the country are assessed based on the progress that the country has made since the 1997 events. The paper analyses the 1997 events and the transformation of Albania’s political and economic structures between 1997 and 2016, considering both achievements and failures. It looks at how the country has dealt with the post-1997 peace-building and development agenda from the perspective of it being a success. It looks at the factors that led to state failure in 1997 and at the factors that continue and have generated a path dependency to the current political context of the country. Although a lot has been written concerning the 1997 events, very little analysis has been conducted concerning what it means from the perspective of research on state failure. In this context, the proposed paper seeks to offer Albania as a case study example of a transformation process, from the uprising to the current situation, which is characterized as a mixture of successes and failures. The belief is that the proposed paper will point to some lessons learned for the strategies directed at the transformation processes.

Evaluation of possible prognostic factors for the success, survival, and failure of dental implants.

Science.gov (United States)

Geckili, Onur; Bilhan, Hakan; Geckili, Esma; Cilingir, Altug; Mumcu, Emre; Bural, Canan

2014-02-01

To analyze the prognostic factors that are associated with the success, survival, and failure rates of dental implants. Data including implant sizes, insertion time, implant location, and prosthetic treatment of 1656 implants have been collected, and the association of these factors with success, survival, and failure of implants was analyzed. The success rate was lower for short and maxillary implants. The failure rate of maxillary implants exceeded that of mandibular implants, and the failure rate of implants that were placed in the maxillary anterior region was significantly higher than other regions. The failure rates of implants that were placed 5 years ago or more were higher than those that were placed later. Anterior maxilla is more critical for implant loss than other sites. Implants in the anterior mandible show better success compared with other locations, and longer implants show better success rates. The learning curve of the clinician influences survival and success rates of dental implants.

Iridium: failures & successes

Science.gov (United States)

Christensen, CarissaBryce; Beard, Suzette

2001-03-01

This paper will provide an overview of the Iridium business venture in terms of the challenges faced, the successes achieved, and the causes of the ultimate failure of the venture — bankruptcy and system de-orbit. The paper will address technical, business, and policy issues. The intent of the paper is to provide a balanced and accurate overview of the Iridium experience, to aid future decision-making by policy makers, the business community, and technical experts. Key topics will include the history of the program, the objectives and decision-making of Motorola, the market research and analysis conducted, partnering strategies and their impact, consumer equipment availability, and technical issues — target performance, performance achieved, technical accomplishments, and expected and unexpected technical challenges. The paper will use as sources trade media and business articles on the Iridium program, technical papers and conference presentations, Wall Street analyst's reports, and, where possible, interviews with participants and close observers.

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats.

Science.gov (United States)

Chang, Xue-Ying; Cui, Lei; Wang, Xing-Zhi; Zhang, Lei; Zhu, Dan; Zhou, Xiao-Rong; Hao, Li-Rong

2017-01-01

This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta ( P chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

Science.gov (United States)

Chang, Xue-ying; Cui, Lei; Wang, Xing-zhi; Zhang, Lei; Zhu, Dan

2017-01-01

Background This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Results Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta (P chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway. PMID:28691026

People's Financial Choice Depends on their Previous Task Success or Failure.

Science.gov (United States)

Sekścińska, Katarzyna

2015-01-01

Existing knowledge about the impact of the experience prior to financial choices has been limited almost exclusively to single risky choices. Moreover, the results obtained in these studies have not been entirely consistent. For example, some studies suggested that the experience of success makes people more willing to take a risk, while other studies led to the opposite conclusions. The results of the two experimental studies presented in this paper provide evidence for the hypothesis that the experience of success or failure influences people's financial choices, but the effect of the success or failure depends on the type of task (financial and non-financial) preceding a financial decision. The experience of success in financial tasks increased participants' tendency to invest and make risky investment choices, while it also made them less prone to save. On the other hand, the experience of failure heightened the amount of money that participants decided to save, and lowered their tendency to invest and make risky investment choices. However, the effects of the experience of success or failure in non-financial tasks were exactly the opposite. The presented studies indicated the role of the specific circumstances in which the individual gains the experience as a possible way to explain the discrepancies in the results of studies on the relationship between the experience prior to financial choice with a tendency to take risks.

Failure of Sierra White granite under general states of stress

Science.gov (United States)

Ingraham, M. D.; Dewers, T. A.; Lee, M.; Holdman, O.; Cheung, C.; Haimson, B. C.

2017-12-01

The effect of the intermediate principal stress on the failure of Sierra White granite was investigated by performing tests under true triaxial states of stress. Tests were performed under constant Lode angle conditions with Lode angles ranging from 0 to 30°, pure shear to axisymmetric compression. Results show that the failure of Sierra White granite is heavily dependent on the intermediate principal stress which became more dramatic as the mean stress increased. An analysis of the shear bands formed at failure was performed using an associated flow rule and the Rudnicki and Rice (1975) localization criteria. The localization analysis showed excellent agreement with experimental results. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.

Failure of ETV in patients with the highest ETV success scores.

Science.gov (United States)

Gianaris, Thomas J; Nazar, Ryan; Middlebrook, Emily; Gonda, David D; Jea, Andrew; Fulkerson, Daniel H

2017-09-01

OBJECTIVE Endoscopic third ventriculostomy (ETV) is a surgical alternative to placing a CSF shunt in certain patients with hydrocephalus. The ETV Success Score (ETVSS) is a reliable, simple method to estimate the success of the procedure by 6 months of postoperative follow-up. The highest score is 90, estimating a 90% chance of the ETV effectively treating hydrocephalus without requiring a shunt. Treatment with ETV fails in certain patients, despite their being the theoretically best candidates for the procedure. In this study the authors attempted to identify factors that further predicted success in patients with the highest ETVSSs. METHODS A retrospective review was performed of all patients treated with ETV at 3 institutions. Demographic, radiological, and clinical data were recorded. All patients by definition were older than 1 year, had obstructive hydrocephalus, and did not have a prior shunt. Failure of ETV was defined as the need for a shunt by 1 year. The ETV was considered a success if the patient did not require another surgery (either shunt placement or a repeat endoscopic procedure) by 1 year. A statistical analysis was performed to identify factors associated with success or failure. RESULTS Fifty-nine patients met the entry criteria for the study. Eleven patients (18.6%) required further surgery by 1 year. All of these patients received a shunt. The presenting symptom of lethargy statistically correlated with success (p = 0.0126, odds ratio [OR] = 0.072). The preoperative radiological finding of transependymal flow (p = 0.0375, OR 0.158) correlated with success. A postoperative larger maximum width of the third ventricle correlated with failure (p = 0.0265). CONCLUSIONS The preoperative findings of lethargy and transependymal flow statistically correlated with success. This suggests that the best candidates for ETV are those with a relatively acute elevation of intracranial pressure. Cases without these findings may represent the failures in this

Interest, Enjoyment and Pride after Failure Experiences? Predictors of Students' State-Emotions after Success and Failure during Learning in Mathematics

Science.gov (United States)

Tulis, Maria; Ainley, Mary

2011-01-01

The current investigation was designed to identify emotion states students experience during mathematics activities, and in particular to distinguish emotions contingent on experiences of success and experiences of failure. Students' task-related emotional responses were recorded following experiences of success and failure while working with an…

Predictors of Success and Failure for ADN Students on the NCLEX-RN

Science.gov (United States)

Benefiel, Diane

2011-01-01

The purpose of this study was to: 1) analyze the relationship of preprogram and nursing program variables on National Council Licensure Examination for Registered Nurses (NCLEX-RN) success and failure, and 2) develop a model to predict success and failure on the NCLEX-RN. The convenience sample was comprised of 245 spring, summer, and fall midterm…

Political Economy: Success or Failure?

Directory of Open Access Journals (Sweden)

Bruno S. Frey

2012-09-01

Full Text Available The Political Economy and Public Choice approaches have promoted the study of interactions between the economy and the polity for over 60 years now. The present paper endeavours to provide a critical discussion of this literature and its achievements. In particular, it begins with the different approaches based on empirically tested or politometric models and it then proceeds to discuss different studies of the effects that particular rules of the game have on politico-economic outcomes. The third section of the paper will address studies that take institutions to be endogenous and aims to explain why particular institutions emerge. Finally, the question of whether Political Economy has been a success or a failure will be tackled. While the success in terms of the position it has gained in economic research and teaching is undeniable, a look at one of the most thriving recent areas of economics, happiness research, will reveal that some of its fundamental lessons are all too often disregarded.

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.

Biaxial failure criteria and stress-strain response for concrete of containment structure

International Nuclear Information System (INIS)

Lee, S. K.; Woo, S. K.; Song, Y. C.; Kweon, Y. K.; Cho, C. H.

2001-01-01

Biaxial failure criteria and stress-strain response for plain concrete of containment structure on nuclear power plants are studied under uniaxial and biaxial stress(compression-compression, compression-tension, and tension-tension combined stress). The concrete specimens of a square plate type are used for uniaxial and biaxial loading. The experimental data indicate that the strength of concrete under biaxial compression, f 2 /f 1 =-1/-1, is 17 percent larger than under uniaxial compression and the poisson's ratio of concrete is 0.1745. On the base of the results, a biaxial failure envelope for plain concrete that the uniaxial strength is 5660 psi are provided, and the biaxial failure behaviors for three biaxial loading areas are plotted respectively. And, various analytical equations having the reliability are proposed for representations of the biaxial failure criteria and stress-strain response curves of concrete

Perfectionism, achievement motives, and attribution of success and failure in female soccer players.

Science.gov (United States)

Stoeber, Joachim; Becker, Claudia

2008-12-01

While some researchers have identified adaptive perfectionism as a key characteristic to achieving elite performance in sport, others see perfectionism as a maladaptive characteristic that undermines, rather than helps, athletic performance. Arguing that perfectionism in sport contains both adaptive and maladaptive facets, the present article presents a study of N = 74 female soccer players investigating how two facets of perfectionism-perfectionistic strivings and negative reactions to imperfection (Stoeber, Otto, Pescheck, Becker, & Stoll, 2007 )-are related to achievement motives and attributions of success and failure. Results show that striving for perfection was related to hope of success and self-serving attributions (internal attribution of success). Moreover, once overlap between the two facets of perfectionism was controlled for, striving for perfection was inversely related to fear of failure and self-depreciating attributions (internal attribution of failure). In contrast, negative reactions to imperfection were positively related to fear of failure and self-depreciating attributions (external attribution of success) and inversely related to self-serving attributions (internal attribution of success and external attribution of failure). It is concluded that striving for perfection in sport is associated with an adaptive pattern of positive motivational orientations and self-serving attributions of success and failure, which may help athletic performance. In contrast, negative reactions to imperfection are associated with a maladaptive pattern of negative motivational orientations and self-depreciating attributions, which is likely to undermine athletic performance. Consequently, perfectionism in sport may be adaptive in those athletes who strive for perfection, but can control their negative reactions when performance is less than perfect.

Failure Forecasting in Triaxially Stressed Sandstones

Science.gov (United States)

Crippen, A.; Bell, A. F.; Curtis, A.; Main, I. G.

2017-12-01

Precursory signals to fracturing events have been observed to follow power-law accelerations in spatial, temporal, and size distributions leading up to catastrophic failure. In previous studies this behavior was modeled using Voight's relation of a geophysical precursor in order to perform `hindcasts' by solving for failure onset time. However, performing this analysis in retrospect creates a bias, as we know an event happened, when it happened, and we can search data for precursors accordingly. We aim to remove this retrospective bias, thereby allowing us to make failure forecasts in real-time in a rock deformation laboratory. We triaxially compressed water-saturated 100 mm sandstone cores (Pc= 25MPa, Pp = 5MPa, σ = 1.0E-5 s-1) to the point of failure while monitoring strain rate, differential stress, AEs, and continuous waveform data. Here we compare the current `hindcast` methods on synthetic and our real laboratory data. We then apply these techniques to increasing fractions of the data sets to observe the evolution of the failure forecast time with precursory data. We discuss these results as well as our plan to mitigate false positives and minimize errors for real-time application. Real-time failure forecasting could revolutionize the field of hazard mitigation of brittle failure processes by allowing non-invasive monitoring of civil structures, volcanoes, and possibly fault zones.

Staff and consumer perspectives on defining treatment success and failure in assertive community treatment.

Science.gov (United States)

Stull, Laura G; McGrew, John H; Salyers, Michelle P

2010-09-01

Although assertive community treatment (ACT) has been consistently recognized as effective, there has been little research as to what constitutes success in ACT. The purpose of this study was to understand how ACT consumers and staff define treatment success and failure and to examine whether definitions varied between staff and consumers. Investigators conducted semistructured interviews with 25 staff and 23 consumers from four ACT teams. Across perspectives, success and failure were most clearly related to consumer factors. Other themes included having basic needs met, being socially involved, and taking medications. Reduced hospitalizations were mentioned infrequently. Consumers were more likely than staff to identify the level or type of treatment as defining success and failure, whereas staff were more likely than consumers to discuss substance abuse when defining failure and improved symptoms when defining success. Success in ACT should be viewed more broadly than reduced hospitalizations and include domains such as social involvement.

Extubating Extremely Preterm Infants: Predictors of Success and Outcomes following Failure.

Science.gov (United States)

Manley, Brett J; Doyle, Lex W; Owen, Louise S; Davis, Peter G

2016-06-01

To identify variables that predict extubation success in extremely preterm infants born successful or failed extubation. A secondary analysis of data from a randomized trial of postextubation respiratory support that included 174 extremely preterm infants. "Extubation success" was defined as not requiring reintubation within 7 days, and "extubation failure" the converse. Predictive variables that were different between groups were included in a multivariable logistic regression model. Sixty-eight percent of infants were successfully extubated. Compared with those infants who had extubation failure, they had a higher GA and birth weight, were extubated earlier, were more often exposed to prolonged ruptured membranes, more often avoided intubation in the delivery room, had a higher pre-extubation pH, and had lower mean pre-extubation fraction of inspired oxygen and partial pressure of carbon dioxide (PCO2). Only GA and PCO2 remained significant in the multivariable analysis (area under a receiver operating characteristic curve = 0.81). Extubation failure was associated with death, bronchopulmonary dysplasia, severe retinopathy of prematurity, patent ductus arteriosus ligation, and longer durations of respiratory support, oxygen supplementation, and hospitalization. When adjusted for allocated treatment in the randomized trial, GA, and birth weight z-score, extubation failure remained associated with death before discharge and prolonged respiratory support and hospitalization. In extremely preterm infants, higher GA and lower pre-extubation PCO2 predicted extubation success. Infants in whom extubation failed were more likely to die and have prolonged respiratory support and hospitalization. Australian New Zealand Clinical Trials Network: ACTRN12610000166077. Copyright © 2016 Elsevier Inc. All rights reserved.

BILAM: a composite laminate failure-analysis code using bilinear stress-strain approximations

Energy Technology Data Exchange (ETDEWEB)

McLaughlin, P.V. Jr.; Dasgupta, A.; Chun, Y.W.

1980-10-01

The BILAM code which uses constant strain laminate analysis to generate in-plane load/deformation or stress/strain history of composite laminates to the point of laminate failure is described. The program uses bilinear stress-strain curves to model layer stress-strain behavior. Composite laminates are used for flywheels. The use of this computer code will help to develop data on the behavior of fiber composite materials which can be used by flywheel designers. In this program the stress-strain curves are modelled by assuming linear response in axial tension while using bilinear approximations (2 linear segments) for stress-strain response to axial compressive, transverse tensile, transverse compressive and axial shear loadings. It should be noted that the program attempts to empirically simulate the effects of the phenomena which cause nonlinear stress-strain behavior, instead of mathematically modelling the micromechanics involved. This code, therefore, performs a bilinear laminate analysis, and, in conjunction with several user-defined failure interaction criteria, is designed to provide sequential information on all layer failures up to and including the first fiber failure. The modus operandi is described. Code BILAM can be used to: predict the load-deformation/stress-strain behavior of a composite laminate subjected to a given combination of in-plane loads, and make analytical predictions of laminate strength.

Writing About Past Failures Attenuates Cortisol Responses and Sustained Attention Deficits Following Psychosocial Stress

Science.gov (United States)

DiMenichi, Brynne C.; Lempert, Karolina M.; Bejjani, Christina; Tricomi, Elizabeth

2018-01-01

Acute stress can harm performance. Paradoxically, writing about stressful events—such as past failures—has been shown to improve cognitive functioning and performance, especially in tasks that require sustained attention. Yet, there is little physiological evidence for whether writing about past failures or other negative events improves performance by reducing stress. In this experiment, we studied the effects of an acute psychosocial stressor, the Trier Social Stress Test, on attentional performance and salivary cortisol release in humans. Additionally, we investigated whether an expressive writing task could reduce the detrimental effects of stress, both on performance and physiological response. We found that when individuals were asked to write about a past failure before experiencing a stressor, they exhibited attenuated stress responses. Moreover, those who wrote about a past failure before being exposed to stress also exhibited better behavioral performance. Our results suggest that writing about a previous failure may allow an individual to experience a new stressor as less stressful, reducing its physiological and behavioral effects. PMID:29628878

What Is Better Than Coulomb Failure Stress? A Ranking of Scalar Static Stress Triggering Mechanisms from 105 Mainshock-Aftershock Pairs

Science.gov (United States)

Meade, Brendan J.; DeVries, Phoebe M. R.; Faller, Jeremy; Viegas, Fernanda; Wattenberg, Martin

2017-11-01

Aftershocks may be triggered by the stresses generated by preceding mainshocks. The temporal frequency and maximum size of aftershocks are well described by the empirical Omori and Bath laws, but spatial patterns are more difficult to forecast. Coulomb failure stress is perhaps the most common criterion invoked to explain spatial distributions of aftershocks. Here we consider the spatial relationship between patterns of aftershocks and a comprehensive list of 38 static elastic scalar metrics of stress (including stress tensor invariants, maximum shear stress, and Coulomb failure stress) from 213 coseismic slip distributions worldwide. The rates of true-positive and false-positive classification of regions with and without aftershocks are assessed with receiver operating characteristic analysis. We infer that the stress metrics that are most consistent with observed aftershock locations are maximum shear stress and the magnitude of the second and third invariants of the stress tensor. These metrics are significantly better than random assignment at a significance level of 0.005 in over 80% of the slip distributions. In contrast, the widely used Coulomb failure stress criterion is distinguishable from random assignment in only 51-64% of the slip distributions. These results suggest that a number of alternative scalar metrics are better predictors of aftershock locations than classic Coulomb failure stress change.

People’s financial choice depends on their previous task success or failure

Directory of Open Access Journals (Sweden)

Katarzyna eSekścińska

2015-11-01

Full Text Available Existing knowledge about the impact of the experience prior to financial choices has been limited almost exclusively to single risky choices. Moreover, the results obtained in these studies have not been entirely consistent. For example, some studies suggested that the experience of success makes people more willing to take a risk, while other studies led to the opposite conclusions. The results of the two experimental studies presented in this paper provide evidence for the hypothesis that the experience of success or failure influences people’s financial choices, but the effect of the success or failure depends on the type of task (financial and non-financial preceding a financial decision. The experience of success in financial tasks increased participants’ tendency to invest and make risky investment choices, while it also made them less prone to save. On the other hand, the experience of failure heightened the amount of money that participants decided to save, and lowered their tendency to invest and make risky investment choices. However, the effects of the experience of success or failure in non-financial tasks were exactly the opposite. The presented studies indicated the role of the specific circumstances in which the individual gains the experience as a possible way to explain the discrepancies in the results of studies on the relationship between the experience prior to financial choice with a tendency to take risks.

People’s Financial Choice Depends on their Previous Task Success or Failure

Science.gov (United States)

Sekścińska, Katarzyna

2015-01-01

Existing knowledge about the impact of the experience prior to financial choices has been limited almost exclusively to single risky choices. Moreover, the results obtained in these studies have not been entirely consistent. For example, some studies suggested that the experience of success makes people more willing to take a risk, while other studies led to the opposite conclusions. The results of the two experimental studies presented in this paper provide evidence for the hypothesis that the experience of success or failure influences people’s financial choices, but the effect of the success or failure depends on the type of task (financial and non-financial) preceding a financial decision. The experience of success in financial tasks increased participants’ tendency to invest and make risky investment choices, while it also made them less prone to save. On the other hand, the experience of failure heightened the amount of money that participants decided to save, and lowered their tendency to invest and make risky investment choices. However, the effects of the experience of success or failure in non-financial tasks were exactly the opposite. The presented studies indicated the role of the specific circumstances in which the individual gains the experience as a possible way to explain the discrepancies in the results of studies on the relationship between the experience prior to financial choice with a tendency to take risks. PMID:26635654

Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

Energy Technology Data Exchange (ETDEWEB)

Duffy, Stephen [Cleveland State Univ., Cleveland, OH (United States)

2013-09-09

This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

International Nuclear Information System (INIS)

Duffy, Stephen

2013-01-01

This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

Causal Attributions of Success and Failure and Mood States in Football Players

Directory of Open Access Journals (Sweden)

Szczepaniak Joanna

2016-12-01

Full Text Available Introduction. The aim of the study was to determine the causal attributions of success and failure in a football match in a group of football players, as well as to investigate the association of the players’ attributions with their level of achievement and the relationships between their causal attributions and affective states. Material and methods. The study involved 75 football players, including 44 players from the first league and 31 players from the third league. The research was carried out using the Profile of Mood States (POMS by D.M. McNair, M. Lorr, and L.F. Droppleman and a specially designed questionnaire concerning the causal attributions of success and failure. Results. It was found that the football players who participated in the study tended to attribute success to internal causes and failure to external causes. More frequent use of external attributions most likely had an adverse impact on the mood state of the players. Conclusion. Information concerning the attributions that a given player makes can be useful for coaches, as it can help them develop the athlete’s mental abilities more effectively. Beliefs related to attributions can be modified. It is worth considering the benefits of encouraging internal attributions in the case of success and external attributions in situations of failure.

Gravity-driven groundwater flow and slope failure potential: 1. Elastic effective-stress model

Science.gov (United States)

Iverson, Richard M.; Reid, Mark E.

1992-01-01

Hilly or mountainous topography influences gravity-driven groundwater flow and the consequent distribution of effective stress in shallow subsurface environments. Effective stress, in turn, influences the potential for slope failure. To evaluate these influences, we formulate a two-dimensional, steady state, poroelastic model. The governing equations incorporate groundwater effects as body forces, and they demonstrate that spatially uniform pore pressure changes do not influence effective stresses. We implement the model using two finite element codes. As an illustrative case, we calculate the groundwater flow field, total body force field, and effective stress field in a straight, homogeneous hillslope. The total body force and effective stress fields show that groundwater flow can influence shear stresses as well as effective normal stresses. In most parts of the hillslope, groundwater flow significantly increases the Coulomb failure potential Φ, which we define as the ratio of maximum shear stress to mean effective normal stress. Groundwater flow also shifts the locus of greatest failure potential toward the slope toe. However, the effects of groundwater flow on failure potential are less pronounced than might be anticipated on the basis of a simpler, one-dimensional, limit equilibrium analysis. This is a consequence of continuity, compatibility, and boundary constraints on the two-dimensional flow and stress fields, and it points to important differences between our elastic continuum model and limit equilibrium models commonly used to assess slope stability.

Thermomechanical Controls on the Success and Failure of Continental Rift Systems

Science.gov (United States)

Brune, S.

2017-12-01

Studies of long-term continental rift evolution are often biased towards rifts that succeed in breaking the continent like the North Atlantic, South China Sea, or South Atlantic rifts. However there are many prominent rift systems on Earth where activity stopped before the formation of a new ocean basin such as the North Sea, the West and Central African Rifts, or the West Antarctic Rift System. The factors controlling the success and failure of rifts can be divided in two groups: (1) Intrinsic processes - for instance frictional weakening, lithospheric thinning, shear heating or the strain-dependent growth of rift strength by replacing weak crust with strong mantle. (2) External processes - such as a change of plate divergence rate, the waning of a far-field driving force, or the arrival of a mantle plume. Here I use numerical and analytical modeling to investigate the role of these processes for the success and failure of rift systems. These models show that a change of plate divergence rate under constant force extension is controlled by the non-linearity of lithospheric materials. For successful rifts, a strong increase in divergence velocity can be expected to take place within few million years, a prediction that agrees with independent plate tectonic reconstructions of major Mesozoic and Cenozoic ocean-forming rift systems. Another model prediction is that oblique rifting is mechanically favored over orthogonal rifting, which means that simultaneous deformation within neighboring rift systems of different obliquity and otherwise identical properties will lead to success and failure of the more and less oblique rift, respectively. This can be exemplified by the Cretaceous activity within the Equatorial Atlantic and the West African Rifts that lead to the formation of a highly oblique oceanic spreading center and the failure of the West African Rift System. While in nature the circumstances of rift success or failure may be manifold, simplified numerical and

Writing About Past Failures Attenuates Cortisol Responses and Sustained Attention Deficits Following Psychosocial Stress

Directory of Open Access Journals (Sweden)

Brynne C. DiMenichi

2018-03-01

Full Text Available Acute stress can harm performance. Paradoxically, writing about stressful events—such as past failures—has been shown to improve cognitive functioning and performance, especially in tasks that require sustained attention. Yet, there is little physiological evidence for whether writing about past failures or other negative events improves performance by reducing stress. In this experiment, we studied the effects of an acute psychosocial stressor, the Trier Social Stress Test, on attentional performance and salivary cortisol release in humans. Additionally, we investigated whether an expressive writing task could reduce the detrimental effects of stress, both on performance and physiological response. We found that when individuals were asked to write about a past failure before experiencing a stressor, they exhibited attenuated stress responses. Moreover, those who wrote about a past failure before being exposed to stress also exhibited better behavioral performance. Our results suggest that writing about a previous failure may allow an individual to experience a new stressor as less stressful, reducing its physiological and behavioral effects.

Early predictors of success of non-invasive positive pressure ventilation in hypercapnic respiratory failure.

Science.gov (United States)

Bhattacharyya, D; Prasad, Bnbm; Tampi, P S; Ramprasad, R

2011-10-01

Non-invasive positive pressure ventilation (NIPPV) has emerged as a significant advancement in the management of acute hypercapnic respiratory failure. Patients with hypercapnic respiratory failure requiring ventilation therapy (respiratory rate [RR] of > 30 breaths per minutes, PaCO2 > 55 mmHg and arterial pH success group and these parameters continued to improve even after four and 24 hours of NIPPV treatment. Out of 24 (24%) patients who failed to respond, 13 (54%) needed endotracheal intubation within one hour. The failure group had higher baseline HR than the success group. Improvement in HR, RR, pH, and PCO2 one hour after putting the patient on NIPPV predicts success of non-invasive positive pressure ventilation in hypercapnic respiratory failure.

Turning Failure into Success: Trials of the Heart Failure Clinical Research Network.

Science.gov (United States)

Joyce, Emer; Givertz, Michael M

2016-12-01

The Heart Failure Clinical Research Network (HFN) was established in 2008 on behalf of the NIH National Heart, Lung and Blood Institute, with the primary goal of improving outcomes in heart failure (HF) by designing and conducting high-quality concurrent clinical trials testing interventions across the spectrum of HF. Completed HFN trials have answered several important and relevant clinical questions concerning the safety and efficacy of different decongestive and adjunctive vasodilator therapies in hospitalized acute HF, phosphodiesterase-5 inhibition and nitrate therapies in HF with preserved ejection fraction, and the role of xanthine oxidase inhibition in hyperuricemic HF. These successes, independent of the "positive" or "negative" result of each individual trial, have helped to shape the current clinical care of HF patients and serve as a platform to inform future research directions and trial designs.

Tutoring for Success: Empowering Graduate Nurses After Failure on the NCLEX-RN.

Science.gov (United States)

Lutter, Stacy L; Thompson, Cheryl W; Condon, Marian C

2017-12-01

Failure on the National Council Licensure Examination for Registered Nurses (NCLEX-RN) is a devastating experience. Most research related to NCLEX-RN is focused on predicting and preventing failure. Despite these efforts, more than 20,000 nursing school graduates experience failure on the NCLEX-RN each year, and there is a paucity of literature regarding remediation after failure. The aim of this article is to describe an individualized tutoring approach centered on establishing a trusting relationship and incorporating two core strategies for remediation: the nugget method, and a six-step strategy for question analysis. This individualized tutoring method has been used by three nursing faculty with a 95% success rate on an NCLEX retake attempt. Further research is needed to identify the elements of this tutoring method that influence success. [J Nurs Educ. 2017;56(12):758-761.]. Copyright 2017, SLACK Incorporated.

Probability of failure prediction for step-stress fatigue under sine or random stress

Science.gov (United States)

Lambert, R. G.

1979-01-01

A previously proposed cumulative fatigue damage law is extended to predict the probability of failure or fatigue life for structural materials with S-N fatigue curves represented as a scatterband of failure points. The proposed law applies to structures subjected to sinusoidal or random stresses and includes the effect of initial crack (i.e., flaw) sizes. The corrected cycle ratio damage function is shown to have physical significance.

Success by Failure

Science.gov (United States)

Andrews, Benjamin D.

2017-01-01

By taking the step to talk openly about his failure, the author stumbled upon one of several important lessons that he learned from this experience. The author recognized that he did not have to pretend anymore. In this article, the author shares his story of developing a "growth mindset" to overcome his own failure and support his…

Exploring success and failure in small firm business transfers

NARCIS (Netherlands)

Lex van Teeffelen

2010-01-01

The main purpose of this dissertation is to identify the factors that explain success and failure in SME business transfers. Three key concepts have been defined in the research framework: firm resources, capabilities (of predecessor and successor) and (successor’s) strategic renewal. Altogether

Driven by fear: the effect of success and failure information on passionate individuals' performance.

Science.gov (United States)

Bélanger, Jocelyn J; Lafrenière, Marc-André K; Vallerand, Robert J; Kruglanski, Arie W

2013-01-01

Four studies investigated the impact of success and failure information on passionate individuals' performance. Obsessive passion, characterized by a rigid and defensive mode of functioning, predicted greater performance in domains both related and unrelated to the passionate activity in response to exposure to failure information. Conversely, harmonious passion, characterized by a flexible, nondefensive mode of functioning, was found to be unaffected by success or failure information. These performance effects were deeply ingrained, did not require conscious thought, and were automatically activated after unconscious exposure to failure-related words. In addition, the present research evinced that following failure information, obsessive passion predicted increases of performance through its effect on fear of failure. However, performance augmented only when the performance task was framed in such a way that failure would entail important negative consequences for the self and not when framed as inconsequential.

Review on stress corrosion and corrosion fatigue failure of centrifugal compressor impeller

Science.gov (United States)

Sun, Jiao; Chen, Songying; Qu, Yanpeng; Li, Jianfeng

2015-03-01

Corrosion failure, especially stress corrosion cracking and corrosion fatigue, is the main cause of centrifugal compressor impeller failure. And it is concealed and destructive. This paper summarizes the main theories of stress corrosion cracking and corrosion fatigue and its latest developments, and it also points out that existing stress corrosion cracking theories can be reduced to the anodic dissolution (AD), the hydrogen-induced cracking (HIC), and the combined AD and HIC mechanisms. The corrosion behavior and the mechanism of corrosion fatigue in the crack propagation stage are similar to stress corrosion cracking. The effects of stress ratio, loading frequency, and corrosive medium on the corrosion fatigue crack propagation rate are analyzed and summarized. The corrosion behavior and the mechanism of stress corrosion cracking and corrosion fatigue in corrosive environments, which contain sulfide, chlorides, and carbonate, are analyzed. The working environments of the centrifugal compressor impeller show the behavior and the mechanism of stress corrosion cracking and corrosion fatigue in different corrosive environments. The current research methods for centrifugal compressor impeller corrosion failure are analyzed. Physical analysis, numerical simulation, and the fluid-structure interaction method play an increasingly important role in the research on impeller deformation and stress distribution caused by the joint action of aerodynamic load and centrifugal load.

Food Intake and Success or Failure of Dietary Restraint

NARCIS (Netherlands)

Anschutz, D.J.; Strien, T. van; Engels, R.C.M.E.

2006-01-01

Objectives: Determination of success and failure of dietary restraint in relation to food intake in 510 females. Methods: Food intake as measured with the Food Frequency Questionnaire (FFQ) was assessed in low vs. high restrained eaters and overeaters, as measured with the DEBQ (Dutch Eating

Exploring success and failure in small firm business transfers

NARCIS (Netherlands)

Teeffelen, van L.

2010-01-01

The main purpose of this dissertation is to identify the factors that explain success and failure in SME business transfers. Three key concepts have been defined in our research framework: firm resources, capabilities (of predecessor and successor) and (successor’s) strategic renewal. Firm resources

A methodology and success/failure criteria for determining emergency diesel generator reliability

International Nuclear Information System (INIS)

Wyckoff, H.L.

1986-01-01

In the U.S., comprehensive records of nationwide emergency diesel generator (EDG) reliability at nuclear power plants have not been consistently collected. Those surveys that have been undertaken have not always been complete and accurate. Moreover, they have been based On an extremely conservative methodology and success/failure criteria that are specified in U.S. Nuclear Regulatory Commission Reg. Guide 1.108. This Reg. Guide was one of the NRCs earlier efforts and does not yield the caliber of statistically defensible reliability values that are now needed. On behalf of the U.S. utilities, EPRI is taking the lead in organizing, investigating, and compiling a realistic database of EDG operating success/failure experience for the years 1983, 1984 and 1985. These data will be analyzed to provide an overall picture of EDG reliability. This paper describes the statistical methodology and start and run success/- failure criteria that EPRI is using. The survey is scheduled to be completed in March 1986. (author)

A methodology and success/failure criteria for determining emergency diesel generator reliability

Energy Technology Data Exchange (ETDEWEB)

Wyckoff, H. L. [Electric Power Research Institute, Palo Alto, California (United States)

1986-02-15

In the U.S., comprehensive records of nationwide emergency diesel generator (EDG) reliability at nuclear power plants have not been consistently collected. Those surveys that have been undertaken have not always been complete and accurate. Moreover, they have been based On an extremely conservative methodology and success/failure criteria that are specified in U.S. Nuclear Regulatory Commission Reg. Guide 1.108. This Reg. Guide was one of the NRCs earlier efforts and does not yield the caliber of statistically defensible reliability values that are now needed. On behalf of the U.S. utilities, EPRI is taking the lead in organizing, investigating, and compiling a realistic database of EDG operating success/failure experience for the years 1983, 1984 and 1985. These data will be analyzed to provide an overall picture of EDG reliability. This paper describes the statistical methodology and start and run success/- failure criteria that EPRI is using. The survey is scheduled to be completed in March 1986. (author)

ORCID @ CMU: Successes and Failures

Directory of Open Access Journals (Sweden)

Denise Troll Covey

2016-02-01

Full Text Available Setting and Objectives: Carnegie Mellon University (CMU recently planned and implemented a project to help CMU researchers get an Open Researcher and Contributor Identifier (ORCID and to enable administrators to integrate the ORCIDs into university systems. This article describes and assesses the planning, performance, and outcome of this initiative, branded ORCID @ CMU. Design and Methods: The article chronicles why and how ORCID was integrated at CMU, including the rationale for changes in strategic plans. It assesses researcher participation in the project using transaction log and content analyses, and the performance of the ORCID project team using recommendations in the Jisc ORCID project report, frankly reporting the team’s successes and failures. The article concludes with lessons learned that should inform ORCID integration projects and expectations at other institutions. Results: The ORCID @ CMU web application was a great success. However, the project team did not allow enough time to prepare or devote enough attention to advocacy. The marketing message was not sufficiently persuasive and the marketing channels were not particularly effective. The overall participation rate in ORCID @ CMU was far below the target of 40%, though participation in many demographics exceeded the goal. Conclusions: Strategic planning does not guarantee success. Secure more than lip service from senior administrators. Recruit champions from across the institution. Develop a message that resonates with researchers. Allow sufficient time to prepare. Empower the project manager. Start with the low hanging fruit. Develop special outreach to doctoral students and postdocs.

Attributions to Success and Failure in English Language Learning: The Effects of Gender, Age and Perceived Success

Science.gov (United States)

Genç, Gülten

2016-01-01

The main purpose of this study is to analyze Turkish tertiary level EFL learners' attributions to success and failure and the effects of gender, age, and perceived success on their attributions. The results indicated that EFL learners respectively attributed interest, ability, task difficulty, effort, luck and the influence of teacher and school…

Dynamic stresses, coulomb failure, and remote triggering: corrected

Science.gov (United States)

Hill, David P.

2012-01-01

Dynamic stresses associated with crustal surface waves with 15–30 s periods and peak amplitudes Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid‐onset triggered seismicity that develop during the surface‐wave peak dynamic stressing. Evaluation of the triggering potential of surface‐wave dynamic stresses acting on critically stressed faults using a Mohr’s circle representation together with the Coulomb failure criteria indicates that Love waves should have a higher triggering potential than Rayleigh waves for most fault orientations and wave incidence angles. That (1) the onset of triggered seismicity often appears to begin during the Rayleigh wave rather than the earlier arriving Love wave, and (2) Love‐wave amplitudes typically exceed those for Rayleigh waves suggests that the explanation for rapid‐onset dynamic triggering may not reside solely with a simple static‐threshold friction mode. The results also indicate that normal faults should be more susceptible to dynamic triggering by 20‐s Rayleigh‐wave stresses than thrust faults in the shallow seismogenic crust (<10  km) while the advantage tips in favor of reverse faults greater depths. This transition depth scales with wavelength and coincides roughly with the transition from retrograde‐to‐prograde particle motion. Locally elevated pore pressures may have a role in the observed prevalence of dynamic triggering in extensional regimes and geothermal/volcanic systems. The result is consistent with the apparent elevated susceptibility of extensional or transtensional tectonic regimes to remote triggering by Rayleigh‐wave dynamic stresses than compressional or transpressional regimes.

Numerical analysis oriented biaxial stress-strain relation and failure criterion of plain concrete

International Nuclear Information System (INIS)

Link, J.

1975-01-01

A biaxial stress-strain relation and failure criterion is proposed, which is applicable to structural analysis methods. The formulation of material behavior of plain concrete in biaxial stress-state was developed. A nonlinear elastic, anisotropic stress-strain relation was derived with two moduli of elasticity, E 1 , E 2 and Poisson's ratios, ν 1 , ν 2 , which depend on the prevailing biaxial stress state. The stress-strain relation is valid in the whole biaxial stress field, that means with a smooth transition between the domains of tension/tension, tension/compression and compression/compression. The stress-dependent moduli E 1 , E 2 and the Poisson's ratios ν 1 , ν 2 are approximated by polynomials, trigonometrical and exponential functions. A failure criterion was defined by approximating the test results of the biaxial ultimate concrete strength with a 7th degree polynomial, which is also valid in the whole biaxial stress domain. The definition of the state of failure is given as a function of stresses as well as strains. Initial parameters of the formulation of the biaxial material behavior are the uniaxial cylindrical strength of concrete and the initial values of Young's modulus and Poisson's ratio. A simple expansion of this formulation makes it applicable not only to normal but also to light-weight concrete. Comparison of numerically calculated stress-strain curves up to the ultimate biaxial stresses which indicate the failure criteria with those obtained from tests show a very good agreement. It is shown, that the biaxial stress-strain relation can be extended for use in cases of triaxial tension/tension/compression stress state. Numerical examples of analysis of concrete slabs show the importance of incorporation of a realistic material behavior for better safety estimations

Urodynamic changes associated with successful stress urinary incontinence surgery: is a little tension a good thing?

Science.gov (United States)

Kraus, Stephen R; Lemack, Gary E; Sirls, Larry T; Chai, Toby C; Brubaker, Linda; Albo, Michael; Leng, Wendy W; Lloyd, L Keith; Norton, Peggy; Litman, Heather J

2011-12-01

To identify urodynamic changes that correlate with successful outcomes after stress urinary incontinence (SUI) surgery. Six-hundred fifty-five women were randomized to Burch colposuspension or autologous fascial sling as part of the multicenter Stress Incontinence Surgical Treatment Efficacy Trial. Preoperatively and 24 months after surgery, participants underwent standardized urodynamic testing that included noninvasive uroflowmetry, cystometrogram, and pressure flow studies. Changes in urodynamic parameters were correlated to a successful outcome, defined a priori as (1) negative pad test; (2) no urinary incontinence on 3-day diary; (3) negative cough and Valsalva stress test; (4) no self-reported SUI symptoms on the Medical, Epidemiologic and Social Aspects of Aging Questionnaire; and (5) no re-treatment for SUI. Subjects who met criteria for surgical success showed a greater relative increase in mean Pdet@Qmax (baseline vs 24 months) than women who were considered surgical failures (P = .008). Although a trend suggested an association between greater increases in bladder outlet obstruction index and outcome success, this was not statistically significant. Other urodynamic variables, such as maximum uroflow, bladder compliance, and the presence of preoperative or de novo detrusor overactivity did not differ with respect to outcome status. Successful outcomes in both surgical groups (Burch and sling) were associated with higher voiding pressures relative to preoperative baseline values. However, concomitant changes in other urodynamic voiding parameters were not significantly associated with outcome. Copyright © 2011 Elsevier Inc. All rights reserved.

A case of multiple organ failure induced by postoperative radiation therapy probably evoking oxidative stress

International Nuclear Information System (INIS)

Soejima, Akinori; Ishizuka, Shynji; Suzuki, Michihiko; Minoshima, Shinobu; Nakabayashi, Kimimasa; Kitamoto, Kiyoshi; Nagasawa, Toshihiko

1995-01-01

In recent years, several laboratories have suggested that serum levels of antioxidant activity and redox balance are reduced in patients with chronic renal failure. Some clinical reports have also proposed that defective serum antioxidative enzymes may contribute to a certain uremic toxicity through peroxidative cell damage. A 48-year-old woman was referred to us from the surgical department of our hospital because of consciousness disturbance, panctytopenia and acute acceleration of chronic azotemia after postoperative radiation therapy. We diagnosed acute acceleration of chronic renal failure with severe acidemia and started hemodialysis therapy immediately. Two days after admission to our department, she developed upper abdominal sharp pain and bradyarrhythmia. Serum amylase activity was elevated markedly and the ECG finding showed myocardial ischemia. On the 24th hospital day these complications were treated successfully with conservative therapy and hemodialysis. We considered that radiation therapy in this patient with chronic renal failure evoked marked oxidative stress and that deficiency of transferrin played an important role in peroxidative cell damage. (author)

Personality Changes as a Function of Minimum Competency Test Success or Failure.

Science.gov (United States)

Richman, Charles L.; And Others

1987-01-01

The psychological effects of success and failure on the North Carolina Minimum Competency Test (MCT) were examined. Subjects were high school students, who were pre- and post-tested using the Rosenberg Self Esteem Scale and the High School Personality Questionnaire. Self-esteem decreased following knowledge of MCT failure. (LMO)

Assessment of obstructive sleep apnoea treatment success or failure after maxillomandibular advancement.

Science.gov (United States)

de Ruiter, M H T; Apperloo, R C; Milstein, D M J; de Lange, J

2017-11-01

Maxillomandibular advancement (MMA) is an alternative therapeutic option that is highly effective for treating obstructive sleep apnoea (OSA). MMA provides a solution for OSA patients that have difficulty accepting lifelong treatments with continuous positive airway pressure or mandibular advancement devices. The goal of this study was to investigate the different characteristics that determine OSA treatment success/failure after MMA. The apnoea-hypopnoea index (AHI) was used to determine the success or failure of OSA treatment after MMA. Sixty-two patients underwent MMA for moderate and severe OSA. A 71% success rate was observed with a mean AHI reduction of 69%. A statistically significant larger neck circumference was measured in patients with failed OSA treatments following MMA (P=0.008), and older patients had failed OSA treatments with MMA: 58 vs. 53 years respectively (P=0.037). Cephalometric analysis revealed no differences between successful and failed OSA treatment outcomes. There was no difference in maxillary and mandibular advancements between success and failed MMA-treated OSA patients. The complications most frequently reported following MMA were sensory disturbances in the inferior alveolar nerve (60%) and malocclusion (24%). The results suggest that age and neck girth may be important factors that could predict susceptibility to OSA treatment failures by MMA. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Construction of Academic Success and Failure in School Memories

Science.gov (United States)

Kaya, Gamze Inan

2018-01-01

The idea of "Apprenticeship of Observation", proposing that pre-service teachers' early academic experiences might have effects on their professional development, has been a concern in teacher education in the last forty years. Early success or failure experiences of pre-service teachers in school may have a role in their professional…

The dynamics of success and failure: how post-behaviour evaluations relate to subsequent exercise intentions and behaviour.

Science.gov (United States)

Kwan, Bethany M; Bryan, Angela D; Sheeran, Paschal

2018-01-25

Exercise behaviour change involves multiple experiences with success and failure. The Model of Action Phases (MAP) offers a dynamic account of how success and failure influence both immediate evaluations and future decisions and actions. However, predictions from the MAP have not been formally tested. A longitudinal daily diary study was used to examine how post-behaviour evaluations of exercise success and failure influence subsequent exercise intentions and behaviour. Participants (N = 104) set exercise goals, and then kept a daily online exercise diary for four weeks. Participants self-reported exercise behaviour, affective response to exercise, self-evaluations after success or failure at following through on intentions to exercise, and intentions to exercise in the next week. Multilevel modelling revealed significant within- and between-participant relationships among post-behaviour evaluations, intentions and subsequent behaviour. Findings supported MAP-derived predictions about how success and failure at exercise are associated with feelings about exercise and the self, and inform subsequent exercise intentions and behaviour. Positive post-behaviour evaluations of success or failure may stabilise positive intentions and aid maintenance of exercise behaviour. Implications of these MAP-based findings for intervention design are discussed.

Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

Directory of Open Access Journals (Sweden)

Xue-ying Chang

2017-01-01

Full Text Available Background. This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d, 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS/p38 mitogen activated protein kinase (p38MAPK pathway was determined to explore the potential mechanism. Results. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA and creatinine levels, malonaldehyde (MDA content, and superoxide dismutase (SOD activity in serum and the increases of calcium and alkaline phosphatase (ALP activity in the aorta (P<0.05 and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

Factors associated with nursing students' academic success or failure: a retrospective Italian multicenter study.

Science.gov (United States)

Dante, A; Valoppi, G; Saiani, L; Palese, A

2011-01-01

With the increasing standardization of nursing education in Europe under the Bologna Process Declaration (1999), there is a growing interest in defining a common concept of academic success and/or failure, measuring associated factors and comparing differences and similarities between different countries. While there is literature available on these issues from other countries, the phenomenon has not been studied in Italy. The aim of this study was to define the factors associated with academic success or failure in an Italian cohort of nursing students on a bachelor's degree course. A retrospective multicenter study design was adopted. All students enrolling in the academic year 2004-05 on two different bachelor's courses in the north of Italy were interviewed. Only 81 of the 117 students considered (69.2%) concluded their course in three years. Multivariate analysis identified two factors determining academic success/failure: good results in the entry examination for the bachelor's degree in nursing sciences were associated with academic success (OR 4.217, IC(95%) 1.501-11.84), while family commitments, e.g. caring for children or elderly people were associated with academic failure (OR 0.120, IC(95%) 0.03-0.471). Academic failure has a strong impact on students, their families, the teaching faculties and the community, and its prevention is a challenge in the countries with a shortage of nurses. Copyright © 2010 Elsevier Ltd. All rights reserved.

I act, therefore I err: EEG correlates of success and failure in a virtual throwing game.

Science.gov (United States)

Yazmir, Boris; Reiner, Miriam

2017-12-01

What are the neural responses to success and failure in a throwing task? To answer this question, we compared Event Related Potentials (ERPs) correlated with success and failure during a highly-ecological-virtual game. Participants played a tennis-like game in an immersive 3D virtual world, against a computer player, by controlling a virtual tennis racket with a force feedback robotic arm. Results showed that success, i.e. hitting the target, and failure, by missing the target, evoked ERP's that differ by peak, latencies, scalp signal distributions, sLORETA source estimation, and time-frequency patterns. The success related grand averaged ERP at the Cz electrode, had two peaks - a negative peak at 244ms and a positive peak at 12ms, prior to the actual successful hit, suggesting a possible process of prediction of success. The grand averaged ERP correlated with failure at Cz, had two peaks, a negative peak at about 107ms and a positive peak at about 311ms post failure. These results suggest different top-down and bottom-up loops for success and failure, which seem to be rooted in the spatial arrangement of the virtual game. Although the latency of the latter is consistent with the error related potentials reported in the literature, the characteristic is unique to this specific error, and differ significantly from other error related potentials in the same environment. These results further provide a basis for EEG based assessment and prediction of user's successful or erroneous movements, and design of the feedback loop in EEG based Brain-Computer Interfaces. Copyright © 2017 Elsevier B.V. All rights reserved.

Stress Voiding in IC Interconnects - Rules of Evidence for Failure Analysts

Energy Technology Data Exchange (ETDEWEB)

FILTER, WILLIAM F.

1999-09-17

Mention the words ''stress voiding'', and everyone from technology engineer to manager to customer is likely to cringe. This IC failure mechanism elicits fear because it is insidious, capricious, and difficult to identify and arrest. There are reasons to believe that a damascene-copper future might be void-free. Nevertheless, engineers who continue to produce ICs with Al-alloy interconnects, or who assess the reliability of legacy ICs with long service life, need up-to-date insights and techniques to deal with stress voiding problems. Stress voiding need not be fearful. Not always predictable, neither is it inevitable. On the contrary, stress voids are caused by specific, avoidable processing errors. Analytical work, though often painful, can identify these errors when stress voiding occurs, and vigilance in monitoring the improved process can keep it from recurring. In this article, they show that a methodical, forensics approach to failure analysis can solve suspected cases of stress voiding. This approach uses new techniques, and patiently applies familiar ones, to develop evidence meeting strict standards of proof.

Success and failure with phthalate buffers in capillary zone electrophoresis

NARCIS (Netherlands)

Bocek, P.; Gebauer, P.; Beckers, J.L.

2001-01-01

Phthalate buffers are currently used in capillary electrophoresis as robust electrolyte systems for indirect detection. This contribution demonstrates that these buffers show regularly not only successful regions of mobilities of analytes (sample window) but also regions of failure where the

[Endodontically treated teeth. Success--failure. Endorestorative treatment plan].

Science.gov (United States)

Zabalegui, B

1990-01-01

More and more often the general dentist is finding the presence of endodontically treated teeth during his treatment planning procedure. He has to ask himself if the endo-treated tooth functions and will continue to function function successfully, when deciding which final endo-restorative procedure to apply. For this reason the dentist or the endodontist with whom he works should clinically evaluate these teeth, establish a diagnostic criteria of their success or failure and a treatment plan according to the prognosis. The purpose of this article is to offer an organized clinical view of the steps to follow when evaluating an endodontically treated tooth and how to establish a final endo-restorative plan.

THE METHODOLOGICAL REVIEW OF THE STUDIES INVESTIGATING THE SUCCESS AND FAILURE FACTORS IN NEWPRODUCT DEVELOPMENT

Directory of Open Access Journals (Sweden)

Haluk Köksal

2013-05-01

Much has been written on the factors which can distinguish between successful and failure products. However, the methodologies in this area of research are almost as numerous as the articles which have been written. This article reviews the studies on new product success and failure factors from the methodological perspective.

Success/failure condition influences attribution of control, negative affect, and shame among patients with depression in Singapore.

Science.gov (United States)

Yeo, Si-Ning; Zainal, Hani; Tang, Catherine S; Tong, Eddie M; Ho, Cyrus S; Ho, Roger C

2017-08-02

There remains a paucity of research on control attribution and depression within Asian populations. This study examines: (1) Success/Failure condition as a moderator between depression and negative affect or shame, and (2) differences in control attribution between patients with depression and healthy controls in Singapore. Seventy one patients with depression and 71 healthy controls went through a digit-span memory task where they were randomized into either the Success or Failure condition. Participants in the Success condition had to memorize and recall 5-digit strings, while participants in the Failure condition did the same for 12-digit strings. They then completed self-report measures of negative affect, shame, and attribution of control. One-way ANCOVA was performed to examine task condition as a moderator of association between mental health status and post-task negative affect or shame. Test of simple effects was carried out on significant interactions. Sign test and Mann-Whitney U test were employed to investigate differences in attribution of control. Mental health status and Success/Failure condition had significant effects on reported negative affect and shame. Healthy controls reported less post-task negative affect and shame in the Success than in the Failure condition while patients with depression reported similar levels of post-task negative affect and shame in both conditions. However, these differences were not significant in the test of simple effects. In addition, healthy controls felt a stronger sense of personal control in success than in failure and were more likely to blame external factors in failure than in success. Conversely, patients with depression were more inclined to credit external factors in success than in failure and ascribed greater personal control in failure than in success. The results suggest that successful conditions may not necessitate the reduction of negative affect in Asians with depression, indicating possible

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

Science.gov (United States)

Miettinen, M; Millar, B J

2013-07-01

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

A Study of the Failure Wave Phenomenon in Glasses at Peak Stresses Exceeding the HEL

International Nuclear Information System (INIS)

Kanel, G. I.; Razorenov, S. V.; Savinykh, A. S.; Rajendran, A.; Chen Zhen

2006-01-01

Shock-wave experiments with two glasses of different hardness have been carried out at shock stress levels above the Hugoniot elastic limit. A comparison between the measured free surface velocity histories from two plate impact experiments performed at approximately the same shock stress level (one with a single thick target plate, and the other with several adjacent target plates of total thickness equal to that of the thick target plate) revealed: 1) at shock loading the failure wave is not formed at stress levels above the HEL, indicating suppression of the fracture process by plasticity, 2) at gradual compression the failure wave process occurs as the stress increases above the failure threshold up to the stress at which plastic deformation begins

Stress field sensitivity analysis within Mesozoic successions in the Swiss Alpine foreland using 3-D-geomechanical-numerical models

Science.gov (United States)

Reiter, Karsten; Hergert, Tobias; Heidbach, Oliver

2016-04-01

The in situ stress conditions are of key importance for the evaluation of radioactive waste repositories. In stage two of the Swiss site selection program, the three siting areas of high-level radioactive waste are located in the Alpine foreland in northern Switzerland. The sedimentary succession overlays the basement, consisting of variscan crystalline rocks as well as partly preserved Permo-Carboniferous deposits in graben structures. The Mesozoic sequence represents nearly the complete era and is covered by Cenozoic Molasse deposits as well as Quaternary sediments, mainly in the valleys. The target horizon (designated host rock) is an >100 m thick argillaceous Jurassic deposit (Opalinus Clay). To enlighten the impact of site-specific features on the state of stress within the sedimentary succession, 3-D-geomechanical-numerical models with elasto-plastic rock properties are set up for three potential siting areas. The lateral extent of the models ranges between 12 and 20 km, the vertical extent is up to a depth of 2.5 or 5 km below sea level. The sedimentary sequence plus the basement are separated into 10 to 14 rock mechanical units. The Mesozoic succession is intersected by regional fault zones; two or three of them are present in each model. The numerical problem is solved with the finite element method with a resolution of 100-150 m laterally and 10-30 m vertically. An initial stress state is established for all models taking into account the depth-dependent overconsolidation ratio in Opalinus Clay in northern Switzerland. The influence of topography, rock properties, friction on the faults as well as the impact of tectonic shortening on the state of stress is investigated. The tectonic stress is implemented with lateral displacement boundary conditions, calibrated on stress data that are compiled in Northern Switzerland. The model results indicate that the stress perturbation by the topography is significant to depths greater than the relief contrast. The

Influence of effective stress coefficient on mechanical failure of chalk

DEFF Research Database (Denmark)

Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Hjuler, M.L.

2012-01-01

The Effective stress coefficient is a measure of how chalk grains are connected with each other. The stiffness of chalk may decrease if the amount of contact cements between the grains decreases, which may lead to an increase of the effective stress coefficient. We performed CO2 injection in chal...... precise failure strength of chalk during changed stress state and under the influence of chemically reactive fluids during production of hydrocarbon and geological storage CO2....

The influence of daily stress and resilience on successful ageing.

Science.gov (United States)

Byun, J; Jung, D

2016-09-01

The aim of this study was to identify the effects of daily stress and resilience on successful ageing among community-dwelling older adults. Ageing can be a positive experience if there is good adaptation to ageing processes. Positive ageing needs to be a basis of nursing care, health promotion and education within community settings. Data were collected in March and April of 2014 from 262 older adults living in Seoul and Jeju, South Korea. We used a four-part survey consisting of demographic data, daily stress, resilience and successful ageing scales, in total 91 items. Data were analysed using descriptive statistics, t-test, one-way ANOVA, Tukey HSD test, Pearson's correlation coefficient and hierarchical multiple regression analysis to identify the influence of variables on successful ageing. Successful ageing had a significant negative correlation with daily stress and a positive correlation with resilience. Daily stress had a negative correlation with resilience. Findings of hierarchical multiple regression analysis indicated that resilience and subjective economic status had an effect on successful ageing. Furthermore, these variables accounted for 41.6% of the variance in successful ageing. Data were collected in only two cities of Korea based on convenience sampling. The findings of the study suggest that daily stress and resilience have a statistically significant relationship with successful ageing. Furthermore, resilience is an important influential factor and a much-needed personal characteristic for one's successful ageing. Nurses can advocate joining with health and social policy makers to implement policies on healthy ageing, including evaluation of stress, education programmes and implementation of self-help groups to enhance resilience in older people. © 2016 International Council of Nurses.

Three-dimensional analysis of stresses and the development of failure mechanism in prestressed thick-walled cylinders

International Nuclear Information System (INIS)

Bertrand, G.; Kotulla, B.

1984-01-01

The new design concept for a prestressed concrete reactor vessel which integrates the complete gas cycle into the pressure vessel demands knowledge of crack zone propagation even in zones where predominantly pressure stresses exist. Analytically, the state of stresses and strains, which is dependent on the loading history, can be computed by recording the triaxial stress-strain law for concrete up to the range of critical volumetric and shear deformations. The constitutive law is derived tensorially using invariant description in the stress space. It is demonstrated that near failure loads membrane stress states develop which increase failure resistance. Collapse loads can be defined through the observation of the principal stress vector with the aid of the triaxial failure law of concrete. (author)

Cognitive reactivity to success and failure relate uniquely to manic and depression tendencies and combine in bipolar tendencies.

Science.gov (United States)

Raes, Filip; Ghesquière, Ine; Van Gucht, Dinska

2012-01-01

The present study examined simultaneously the relations between cognitive reactivity to success and failure, on the one hand, and depression, manic, and bipolar tendencies, on the other hand. Participants (161 students) completed measures of success and failure reactivity, current manic and depressive symptoms, and tendencies towards depression, mania, and bipolarity. Results showed that respondents with a greater tendency towards depression evidenced greater (negative) reactivity to failure, whereas those with a greater tendency toward mania evidenced greater (positive) reactivity to success. Depression vulnerability was unrelated to success reactivity, and manic vulnerability was unrelated to failure reactivity. Tendencies toward bipolarity correlated significantly with both failure and success reactivity in a negative and positive manner, respectively. These findings add to the growing body of literature, suggesting that different features or cognitive tendencies are related to depression vulnerability versus manic vulnerability and imply that these "mirrored" cognitive features both form part of vulnerability to bipolar disorder.

Cognitive Reactivity to Success and Failure Relate Uniquely to Manic and Depression Tendencies and Combine in Bipolar Tendencies

Directory of Open Access Journals (Sweden)

Filip Raes

2012-01-01

Full Text Available The present study examined simultaneously the relations between cognitive reactivity to success and failure, on the one hand, and depression, manic, and bipolar tendencies, on the other hand. Participants (161 students completed measures of success and failure reactivity, current manic and depressive symptoms, and tendencies towards depression, mania, and bipolarity. Results showed that respondents with a greater tendency towards depression evidenced greater (negative reactivity to failure, whereas those with a greater tendency toward mania evidenced greater (positive reactivity to success. Depression vulnerability was unrelated to success reactivity, and manic vulnerability was unrelated to failure reactivity. Tendencies toward bipolarity correlated significantly with both failure and success reactivity in a negative and positive manner, respectively. These findings add to the growing body of literature, suggesting that different features or cognitive tendencies are related to depression vulnerability versus manic vulnerability and imply that these “mirrored” cognitive features both form part of vulnerability to bipolar disorder.

Heart Failure: Self-care to Success: Development and evaluation of a program toolkit.

Science.gov (United States)

Bryant, Rebecca

2017-08-17

The Heart Failure: Self-care to Success toolkit was developed to assist NPs in empowering patients with heart failure (HF) to improve individual self-care behaviors. This article details the evolution of this toolkit for NPs, its effectiveness with patients with HF, and recommendations for future research and dissemination strategies.

Interference fits and stress-corrosion failure. [aircraft parts fatigue life analysis

Science.gov (United States)

Hanagud, S.; Carter, A. E.

1976-01-01

It is pointed out that any proper design of interference fit fastener, interference fit bushings, or stress coining processes should consider both the stress-corrosion susceptibility and fatigue-life improvement together. Investigations leading to such a methodology are discussed. A service failure analysis of actual aircraft parts is considered along with the stress-corrosion susceptibility of cold-working interference fit bushings. The optimum design of the amount of interference is considered, giving attention to stress formulas and aspects of design methodology.

The Role of Requirements in the Success or Failure of Software Projects

OpenAIRE

Hussain, Azham; Mkpojiogu, Emmanuel O.C.; Kamal, Fazillah Mohmad

2016-01-01

Requirements engineering is pivotal and central to every successful software development project. There are several reasons why software projects fail; however, poorly elicited, documented, validated and managed requirements contribute grossly to software projects failure. Software project failures are normally very costly and risky and these could even a times be life threatening also. Projects that overlook requirements engineering processes often suffer or are most likely to suffer from fa...

Ductile failure analysis of defective API X65 pipes based on stress-modified fracture strain criterion

International Nuclear Information System (INIS)

Oh, Chang Kyun; Kim, Yun Jae; Baek, Jong Hyun; Kim, Young Pyo; Kim, Woo Sik

2006-01-01

A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure for API X65 pipes with gouge defects

STRESS AND FAILURE ANALYSIS OF RAPIDLY ROTATING ASTEROID (29075) 1950 DA

International Nuclear Information System (INIS)

Hirabayashi, Masatoshi; Scheeres, Daniel J.

2015-01-01

Rozitis et al. recently reported that near-Earth asteroid (29075) 1950 DA, whose bulk density ranges from 1.0 g cm –3 to 2.4 g cm –3 , is a rubble pile and requires a cohesive strength of at least 44-76 Pa to keep from failing due to its fast spin period. Since their technique for giving failure conditions required the averaged stress over the whole volume, it discarded information about the asteroid's failure mode and internal stress condition. This paper develops a finite element model and revisits the stress and failure analysis of 1950 DA. For the modeling, we do not consider material hardening and softening. Under the assumption of an associated flow rule and uniform material distribution, we identify the deformation process of 1950 DA when its constant cohesion reaches the lowest value that keeps its current shape. The results show that to avoid structural failure the internal core requires a cohesive strength of at least 75-85 Pa. It suggests that for the failure mode of this body, the internal core first fails structurally, followed by the surface region. This implies that if cohesion is constant over the whole volume, the equatorial ridge of 1950 DA results from a material flow going outward along the equatorial plane in the internal core, but not from a landslide as has been hypothesized. This has additional implications for the likely density of the interior of the body

Stress evaluation of baffle former bolt for IASCC failure prediction

International Nuclear Information System (INIS)

Matsubara, T.; Tsutsui, T.; Kamei, Y.; Kitsu, M.

2011-01-01

Baffle structure in PWRs Reactor is quite important assembly for the core safety, and Baffle Former Bolts (BFBs) are fastener members for maintaining Baffle structure. It has been reported worldwide that some of BFBs were cracked due to IASCC (Irradiation Assisted Stress Corrosion Cracking) because BFBs are located at core region under severe environments, high neutron flux, high temperature and high stress. According to the material studies of IASCC on austenitic stainless steel, a crack initiation of IASCC is strongly related with the stress and the neutron fluence. For this reason, it is very important for IASCC failure prediction to simulate the stress of BFBs. However, the stress of BFBs are considered to be influenced by several factors and to be changed complexly as operational time increases, by irradiation creep of Bolt itself, swelling of Baffle structure, and so on. Therefore, it is difficult to estimate the stress histories of BFBs (Bolt stress as a function of operational time) precisely. Then, the author has developed the calculation method of the stress histories of BFBs considering irradiation effects (swelling and irradiation creep). In this method, the stress histories of BFBs are calculated by combining two kinds of FE models, Global model (modeled whole Baffle structure which consists of Baffle plates, Former plates and Core Barrel) and Local model (modeled around BFB finely). The whole Baffle structure deformation changes as a function of heat, swelling and irradiated creep are calculated by Global model, and the stress histories of BFBs are calculated by Local model using the outputs (deformations on driving nodes) of Global model. In the FE analysis of Local model, the stress of BFBs are calculated considering irradiation effects and elastic-plastic characteristics depending on neutron fluence, so this method enables to calculate precisely the stress of extreme small area of BFBs surface. This paper shows the outline of the calculation method

Evolution of thermal stress and failure probability during reduction and re-oxidation of solid oxide fuel cell

Science.gov (United States)

Wang, Yu; Jiang, Wenchun; Luo, Yun; Zhang, Yucai; Tu, Shan-Tung

2017-12-01

The reduction and re-oxidation of anode have significant effects on the integrity of the solid oxide fuel cell (SOFC) sealed by the glass-ceramic (GC). The mechanical failure is mainly controlled by the stress distribution. Therefore, a three dimensional model of SOFC is established to investigate the stress evolution during the reduction and re-oxidation by finite element method (FEM) in this paper, and the failure probability is calculated using the Weibull method. The results demonstrate that the reduction of anode can decrease the thermal stresses and reduce the failure probability due to the volumetric contraction and porosity increasing. The re-oxidation can result in a remarkable increase of the thermal stresses, and the failure probabilities of anode, cathode, electrolyte and GC all increase to 1, which is mainly due to the large linear strain rather than the porosity decreasing. The cathode and electrolyte fail as soon as the linear strains are about 0.03% and 0.07%. Therefore, the re-oxidation should be controlled to ensure the integrity, and a lower re-oxidation temperature can decrease the stress and failure probability.

Effects of Stress Ratio and Microstructure on Fatigue Failure Behavior of Polycrystalline Nickel Superalloy

Science.gov (United States)

Zhang, H.; Guan, Z. W.; Wang, Q. Y.; Liu, Y. J.; Li, J. K.

2018-05-01

The effects of microstructure and stress ratio on high cycle fatigue of nickel superalloy Nimonic 80A were investigated. The stress ratios of 0.1, 0.5 and 0.8 were chosen to perform fatigue tests in a frequency of 110 Hz. Cleavage failure was observed, and three competing failure crack initiation modes were discovered by a scanning electron microscope, which were classified as surface without facets, surface with facets and subsurface with facets. With increasing the stress ratio from 0.1 to 0.8, the occurrence probability of surface and subsurface with facets also increased and reached the maximum value at R = 0.5, meanwhile the probability of surface initiation without facets decreased. The effect of microstructure on the fatigue fracture behavior at different stress ratios was also observed and discussed. Based on the Goodman diagram, it was concluded that the fatigue strength of 50% probability of failure at R = 0.1, 0.5 and 0.8 is lower than the modified Goodman line.

Tensile and compressive failure modes of laminated composites loaded by fatigue with different mean stress

Science.gov (United States)

Rotem, Assa

1990-01-01

Laminated composite materials tend to fail differently under tensile or compressive load. Under tension, the material accumulates cracks and fiber fractures, while under compression, the material delaminates and buckles. Tensile-compressive fatigue may cause either of these failure modes depending on the specific damage occurring in the laminate. This damage depends on the stress ratio of the fatigue loading. Analysis of the fatigue behavior of the composite laminate under tension-tension, compression-compression, and tension-compression had led to the development of a fatigue envelope presentation of the failure behavior. This envelope indicates the specific failure mode for any stress ratio and number of loading cycles. The construction of the fatigue envelope is based on the applied stress-cycles to failure (S-N) curves of both tensile-tensile and compressive-compressive fatigue. Test results are presented to verify the theoretical analysis.

Success and Failures of Acquisitions: A Case Study for a Chemical Company

Directory of Open Access Journals (Sweden)

Shainaaz MOOSA MUSTAFFA

2017-05-01

Full Text Available The purpose of this study was to perform a universal inspection of the processes adopted in acquisitions by concentrating on attributes which are speedily implemented in the industry. The approach to this research study was based on literature reviews to gain knowledge on the causes of failure and the factors attributed to the success of acquisitions in the case study concerning a chemical company. This method was applied to identify if the failures and successes researched are shown in the case study. The research study firstly looked at various approaches to acquisitions, namely, the pre-acquisition, post-acquisition and integration phases together with the motives for acquisitions. The study delves further into factors influencing the failures and successes of acquisitions. A notable body of research was consulted to focus on these factors. The research study highlights a framework incorporating the management of post-integration strategy concurrently with the people and the organisational goals. The key findings showed that the company lacked a formal integration plan, cultural integration, ad proper communication plans. This resulted in staff unrest and high attrition of staff from deal announcement date up to post integration, leading to high resistance from staff and poor people integration. The company did however achieve financial success through synergy realisation. This positive outcome could have been achieved quicker with the proper integration plans within the different phases of the acquisition. The knowledge attained from this study will hopefully add to the body of knowledge on acquisitions.

When Failure Means Success: Accepting Risk in Aerospace Development

Science.gov (United States)

Dumbacher, Daniel L.; Singer, Christopher E.

2009-01-01

Over the last three decades, NASA has been diligent in qualifying systems for human space flight. As the Agency transitions from operating the Space Shuttle, its employees must learn to accept higher risk levels to generate the data needed to certify its next human space flight system. The Marshall Center s Engineering workforce is developing the Ares I crew launch vehicle and designing the Ares V cargo launch vehicle for safety, reliability, and cost-effective operations. This presentation will provide a risk retrospective, using first-hand examples from the Delta Clipper-Experimental Advanced (DC-XA) and the X-33 single-stage-to-orbit flight demonstrators, while looking ahead to the upcoming Ares I-X uncrewed test flight. The DC-XA was successfully flown twice in 26 hours, setting a new turnaround-time record. Later, one of its 3 landing gears did not deploy, it tipped over, and was destroyed. During structural testing, the X-33 s advanced composite tanks were unable to withstand the forces to which it was subjected and the project was later cancelled. These are examples of successful failures, as the data generated are captured in databases used by vehicle designers today. More recently, the Ares I-X flight readiness review process was streamlined in keeping with the mission's objectives, since human lives are not at stake, which reflects the beginning of a cultural change. Failures are acceptable during testing, as they provide the lessons that actually lead to mission success. These and other examples will stimulate the discussion of when to accept risk in aerospace projects.

Establishing a Small Enterprise in Varkaus and Factors behind Success and Failure of Small Businesses

OpenAIRE

Rasheed, Shahzad

2014-01-01

Primary objectives of this thesis were to aid future entrepreneurs by describing the basic procedure of establishing an enterprise and the key issues to be considered during business establishment process. Second topic of this research was the key factors which lead a small business to its success or failure. These success and failure factors of small businesses were identified by conducting a qualitative research through participation of small business owners in Varkaus and neighbouring area...

Health IT success and failure: recommendations from literature and an AMIA workshop.

Science.gov (United States)

Kaplan, Bonnie; Harris-Salamone, Kimberly D

2009-01-01

With the United States joining other countries in national efforts to reap the many benefits that use of health information technology can bring for health care quality and savings, sobering reports recall the complexity and difficulties of implementing even smaller-scale systems. Despite best practice research that identified success factors for health information technology projects, a majority, in some sense, still fail. Similar problems plague a variety of different kinds of applications, and have done so for many years. Ten AMIA working groups sponsored a workshop at the AMIA Fall 2006 Symposium. It was entitled "Avoiding The F-Word: IT Project Morbidity, Mortality, and Immortality" and focused on this under-addressed problem. PARTICIPANTS discussed communication, workflow, and quality; the complexity of information technology undertakings; the need to integrate all aspects of projects, work environments, and regulatory and policy requirements; and the difficulty of getting all the parts and participants in harmony. While recognizing that there still are technical issues related to functionality and interoperability, discussion affirmed the emerging consensus that problems are due to sociological, cultural, and financial issues, and hence are more managerial than technical. Participants drew on lessons from experience and research in identifying important issues, action items, and recommendations to address the following: what "success" and "failure" mean, what contributes to making successful or unsuccessful systems, how to use failure as an enhanced learning opportunity for continued improvement, how system successes or failures should be studied, and what AMIA should do to enhance opportunities for successes. The workshop laid out a research agenda and recommended action items, reflecting the conviction that AMIA members and AMIA as an organization can take a leadership role to make projects more practical and likely to succeed in health care settings.

Deformation Failure Characteristics of Coal Body and Mining Induced Stress Evolution Law

Directory of Open Access Journals (Sweden)

Zhijie Wen

2014-01-01

Full Text Available The results of the interaction between coal failure and mining pressure field evolution during mining are presented. Not only the mechanical model of stope and its relative structure division, but also the failure and behavior characteristic of coal body under different mining stages are built and demonstrated. Namely, the breaking arch and stress arch which influence the mining area are quantified calculated. A systematic method of stress field distribution is worked out. All this indicates that the pore distribution of coal body with different compressed volume has fractal character; it appears to be the linear relationship between propagation range of internal stress field and compressed volume of coal body and nonlinear relationship between the range of outburst coal mass and the number of pores which is influenced by mining pressure. The results provide theory reference for the research on the range of mining-induced stress and broken coal wall.

Increased Dicarbonyl Stress as a Novel Mechanism of Multi-Organ Failure in Critical Illness

Directory of Open Access Journals (Sweden)

Bas C. T. van Bussel

2017-02-01

Full Text Available Molecular pathological pathways leading to multi-organ failure in critical illness are progressively being unravelled. However, attempts to modulate these pathways have not yet improved the clinical outcome. Therefore, new targetable mechanisms should be investigated. We hypothesize that increased dicarbonyl stress is such a mechanism. Dicarbonyl stress is the accumulation of dicarbonyl metabolites (i.e., methylglyoxal, glyoxal, and 3-deoxyglucosone that damages intracellular proteins, modifies extracellular matrix proteins, and alters plasma proteins. Increased dicarbonyl stress has been shown to impair the renal, cardiovascular, and central nervous system function, and possibly also the hepatic and respiratory function. In addition to hyperglycaemia, hypoxia and inflammation can cause increased dicarbonyl stress, and these conditions are prevalent in critical illness. Hypoxia and inflammation have been shown to drive the rapid intracellular accumulation of reactive dicarbonyls, i.e., through reduced glyoxalase-1 activity, which is the key enzyme in the dicarbonyl detoxification enzyme system. In critical illness, hypoxia and inflammation, with or without hyperglycaemia, could thus increase dicarbonyl stress in a way that might contribute to multi-organ failure. Thus, we hypothesize that increased dicarbonyl stress in critical illness, such as sepsis and major trauma, contributes to the development of multi-organ failure. This mechanism has the potential for new therapeutic intervention in critical care.

Characteristics of Male and Female Students Who Experienced Success or Failure in Their First College Science Course.

Science.gov (United States)

DeBoer, George E.

1985-01-01

Examined personality (persistence, future orientation, and the tendency toward reckless/rash behavior) and cognitive factors related to success or failure in college science courses. One finding noted is that both men and women were more apt to attribute their success to effort/ability, and their failure to the difficulty of a task. (JN)

European nursing students' academic success or failure: a post-Bologna Declaration systematic review.

Science.gov (United States)

Dante, Angelo; Petrucci, Cristina; Lancia, Loreto

2013-01-01

The aim of this systematic review is to synthesise the available evidence in the European scientific literature produced after the Bologna Declaration and to evaluate studies that quantify and examine the factors associated with the academic success or failure of nursing students. A systematic review of the literature was conducted. Major health literature databases were searched for studies published from 2000 to 2011. This review includes only European observational studies that were submitted to a quality assessment by two researchers before inclusion. Only five studies were included in this review. There are discordant results regarding the predictors of success or failure, which were common objects of study (gender, age, qualification on entry, ethnic group). other factors were studied individually (student personality, gendered view of nursing careers, intention to leave, family commitments, working while on course, student performance, clinical learning environment) need to be confirmed in additional studies. Although the predictors may be relevant at the local level, given their low external validity and the conflicting results, it is not possible to state with certainty that these factors are effectively predictive of success or failure in the context of post-Bologna Declaration Europe. This review showed that over the last ten years, in the European context, only a few high-quality observational studies have been performed. In this regard, given the small number and heterogeneity of the available studies, there is little useful evidence available for Higher Education Institutions (HEIs) to effectively address the problem. In the future, European researchers should focus not only on the documentation of the predictors but also on the documentation of the outcomes produced by the HEI strategies that have been implemented to prevent avoidable academic failure and contain physiological academic failure. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hope of Success and Fear of Failure Predicting Academic Procrastination Students Who Working on a Thesis

Directory of Open Access Journals (Sweden)

Sari Zakiah Akmal

2017-08-01

Full Text Available Students, who are working on the thesis, have some difficulties caused by internal and external factors. Those problems can disrupt the completion of their thesis, such as the tendency to do academic procrastination. Increasing achievement motivation can reduce academic procrastination. This study aims to look at the role of achievement motivation (hope of success and fear of failure in predicting academic procrastination. The study used a quantitative approach by distributing academic procrastination and achievement motivation questionnaires. The study involved 182 students who were working on a thesis as samples, which were obtained by using accidental sampling technique. Data were analyzed using multiple regressions. It showed that the hope of success and fear of failure have a significant role in predicting academic procrastination (R2 = 13.8%, F = 14,356, p <0.05. The hope of success can decrease academic procrastination, while fear of failure can improve it. Thus, interventions to reduce academic procrastination can be delivered by increasing students hope of success.

Underlying Reasons for Success and Failure of Terrorist Attacks: Selected Case Studies

National Research Council Canada - National Science Library

McCleskey, Edward; McCord, Diana; Leetz, Jennifer; Markey, John

2007-01-01

.... This is the second of a two-phased effort: Phase I focused on assessing the underlying reasons for the success and failure of terrorist attacks against targets within the United States and against U.S. interests abroad...

Software development project success and failure from the supplier's perspective: A systematic literature review

OpenAIRE

Savolainen, Paula; Ahonen, Jarmo J.; Richardson, Ita

2012-01-01

peer-reviewed In this paper, we consider software development project success and failure from the supplier's perspective. First we clarified concepts in order to be able to exclude review articles on in-house projects, continuous services, the customer's perspective, and software product development, with the aim of providing valid results for supplier firms. We divided success criteria into project success and project management (PM) success, and, in seven articles, identified thre...

Fear of failure, psychological stress, and burnout among adolescent athletes competing in high level sport.

Science.gov (United States)

Gustafsson, H; Sagar, S S; Stenling, A

2017-12-01

The purpose of this study was to investigate fear of failure in highly competitive junior athletes and the association with psychological stress and burnout. In total 258 athletes (152 males and 108 females) ranged in age from 15 to 19 years (M = 17.4 years, SD = 1.08) participated. Athletes competed in variety of sports including both team and individual sports. Results showed in a variable-oriented approach using regression analyses that one dimension, fear of experiencing shame and embarrassment had a statistically significant effect on perceived psychological stress and one dimension of burnout, reduced sense of accomplishment. However, adopting a person-oriented approach using latent class analysis, we found that athletes with high levels of fear failure on all dimensions scored high on burnout. We also found another class with high scores on burnout. These athletes had high scores on the individual-oriented dimensions of fear of failure and low scores on the other oriented fear of failure dimensions. The findings indicate that fear of failure is related to burnout and psychological stress in athletes and that this association is mainly associated with the individual-oriented dimensions of fear of failure. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of stress-based and strain-based creep failure criteria for severe accident analysis

International Nuclear Information System (INIS)

Chavez, S.A.; Kelly, D.L.; Witt, R.J.; Stirn, D.P.

1995-01-01

We conducted a parametic analysis of stress-based and strain-based creep failure criteria to determine if there is a significant difference between the two criteria for SA533B vessel steel under severe accident conditions. Parametric variables include debris composition, system pressure, and creep strain histories derived from different testing programs and mathematically fit, with and without tertiary creep. Results indicate significant differences between the two criteria. Stress gradient plays an important role in determining which criterion will predict failure first. Creep failure was not very sensitive to different creep strain histories, except near the transition temperature of the vessel steel (900K to 1000K). Statistical analyses of creep failure data of four independent sources indicate that these data may be pooled, with a spline point at 1000K. We found the Manson-Haferd parameter to have better failure predictive capability than the Larson-Miller parameter for the data studied. (orig.)

Systematically Identified Failure Is the Route to a Successful Health System.

Science.gov (United States)

Zwarenstein, Merrick

2015-01-01

Although we have a systematic approach to innovation and evaluation (and scale-up) for treatments, medical technologies and diagnostic tests in healthcare, we have no equivalent for service delivery innovations. Service delivery innovation is common but frequently goes unevaluated, leading to less systematic decisions about which innovations are scaled up and which ones are not. The absence of a formal evaluation system for service delivery innovation means that there is no objective standard for evaluating an innovation's success or failure, and thus no way to decide whether it should be scaled up, adapted and retested, or not scaled up at all. This results in "bad failure" - the scale-up of innovations that are untested, and the failure to scale-up other innovations that might have been effective but no one measured their effectiveness in a systematic way.

Situating Remediation: Accommodating Success and Failure in Medical Education Systems.

Science.gov (United States)

Ellaway, Rachel H; Chou, Calvin L; Kalet, Adina L

2018-03-01

There has been a widespread shift to competency-based medical education (CBME) in the United States and Canada. Much of the CBME discourse has focused on the successful learner, with relatively little attention paid to what happens in CBME systems when learners stumble or fail. Emerging issues, such as the well-documented problem of "failure to fail" and concerns about litigious learners, have highlighted a need for well-defined and integrated frameworks to support and guide strategic approaches to the remediation of struggling medical learners.This Perspective sets out a conceptual review of current practices and an argument for a holistic approach to remediation in the context of their parent medical education systems. The authors propose parameters for integrating remediation into CBME and describe a model based on five zones of practice along with the rules of engagement associated with each zone. The zones are "normal" curriculum, corrective action, remediation, probation, and exclusion.The authors argue that, by linking and integrating theory and practice in remediation with CBME, a more integrated systems-level response to differing degrees of learner difficulty and failure can be developed. The proposed model demonstrates how educational practice in different zones is based on different rules, roles, responsibilities, and thresholds for moving between zones. A model such as this can help medical educators and medical education leaders take a more integrated approach to learners' failures as well as their successes by being more explicit about the rules of engagement that apply in different circumstances across the competency continuum.

Stress Corrosion Cracking of Steel and Aluminum in Sodium Hydroxide: Field Failure and Laboratory Test

Directory of Open Access Journals (Sweden)

Y. Prawoto

2012-01-01

Full Text Available Through an investigation of the field failure analysis and laboratory experiment, a study on (stress corrosion cracking SCC behavior of steel and aluminum was performed. All samples were extracted from known operating conditions from the field failures. Similar but accelerated laboratory test was subsequently conducted in such a way as to mimic the field failures. The crack depth and behavior of the SCC were then analyzed after the laboratory test and the mechanism of stress corrosion cracking was studied. The results show that for the same given stress relative to ultimate tensile strength, the susceptibility to SCC is greatly influenced by heat treatment. Furthermore, it was also concluded that when expressed relative to the (ultimate tensile strength UTS, aluminum has similar level of SCC susceptibility to that of steel, although with respect to the same absolute value of applied stress, aluminum is more susceptible to SCC in sodium hydroxide environment than steel.

The conservatism of the net-section stress criterion for the failure of cracked stainless steel piping

International Nuclear Information System (INIS)

Smith, E.

1991-01-01

The failure of cracked stainless steel piping can be predicted by assuming that failure conforms to a net-section stress criterion, using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stresses at the cracked section are usually calculated via a purely elastic analysis based on the piping being uncracked. However because the piping is built-in at its ends into a larger component, this limits the amount of elastic follow-up and, consequently, use of the net-section stress approach in this manner can lead to conservative failure predictions. This paper quantifies the extent of this conservatism, and shows that it can be quite marked. There is an additional measure of conservatism due to the fact that unstable failure need not necessarily be associated with the onset of crack extension. A key parameter with regard to both these conservatisms is L EFF , a length parameter which is a measure of the degree of elastic follow-up in the system. (author)

Study of Stress Migration Failure in SiLKTM/SiO2 Hybrid Cu Interconnects

International Nuclear Information System (INIS)

Tsuchikawa, Haruo; Nakamura, Tomoji; Suzuki, Takashi; Mori, Hiroko; Shono, Ken

2004-01-01

Stress migration (SM) behavior is studied for a 130nm-node SiLK TM /SiO2 hybrid structure in which the interlevel dielectrics (ILD) consist of SiLK TM for trench levels and SiO2 for via levels. The failure rate dependence on the temperature, line width and circuit is examined in detail. Furthermore, an effect of dielectric deposition process on the reliability of the hybrid interconnects is investigated. It has been found that SM behavior is essentially similar to that reported in Cu/SiO2 systems. It has also been clarified that SiO2 PVD conditions at via level had a large impact on the failure rate. Therefore, the control of ILD deposition conditions is found to be one of the key factors in suppressing the SM failure. In order to examine the effect of the PVD conditions, the residual stress in vias were measured by using X-ray diffraction method. The results show that σx (the stress component parallel to the surface) in vias greatly depends on the PVD conditions. Then, the relationship between the PVD conditions and the SM failure rate is clarified

Psychological stress and short-term hospitalisations or death in patients with heart failure

NARCIS (Netherlands)

Endrighi, R.; Waters, A.J.; Gottlieb, S.S.; Harris, K.M.; Wawrzyniak, A.J.; Bekkouche, N.S.; Li, Y.; Kop, W.J.; Krantz, D.S.

2016-01-01

Objective Standard predictors do not fully explain variations in the frequency and timing of heart failure (HF) adverse events (AEs). Psychological stress can trigger acute cardiovascular (CV) events, but it is not known whether stress can precipitate AEs in patients with HF. We investigated

Factors Relating to the Success or Failure of College Algebra Internet Students: A Grounded Theory Study

OpenAIRE

Walker, Christine

2008-01-01

The purpose of this grounded theory study was to discover the factors that contribute to the success or failure of college algebra for students taking college algebra by distance education Internet, and then generate a theory of success or failure of the group of College Algebra Internet students at one Utah college. Qualitative data were collected and analyzed on students’ perceptions and perspectives of a College Algebra Internet course that they took during the spring or summer 2006 semest...

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.

Human Factors Predicting Failure and Success in Hospital Information System Implementations in Sub-Saharan Africa.

Science.gov (United States)

Verbeke, Frank; Karara, Gustave; Nyssen, Marc

2015-01-01

From 2007 through 2014, the authors participated in the implementation of open source hospital information systems (HIS) in 19 hospitals in Rwanda, Burundi, DR Congo, Congo-Brazzaville, Gabon, and Mali. Most of these implementations were successful, but some failed. At the end of a seven-year implementation effort, a number of risk factors, facilitators, and pragmatic approaches related to the deployment of HIS in Sub-Saharan health facilities have been identified. Many of the problems encountered during the HIS implementation process were not related to technical issues but human, cultural, and environmental factors. This study retrospectively evaluates the predictive value of 14 project failure factors and 15 success factors in HIS implementation in the Sub-Saharan region. Nine of the failure factors were strongly correlated with project failure, three were moderately correlated, and one weakly correlated. Regression analysis also confirms that eight factors were strongly correlated with project success, four moderately correlated, and two weakly correlated. The study results may help estimate the expedience of future HIS projects.

Success and failure with phthalate buffers in capillary zone electrophoresis.

Science.gov (United States)

Bocek, P; Gebauer, P; Beckers, J L

2001-04-01

Phthalate buffers are currently used in capillary electrophoresis as robust electrolyte systems for indirect detection. This contribution demonstrates that these buffers show regularly not only successful regions of mobilities of analytes (sample window) but also regions of failure where the migration of analytes is strongly deteriorated due to the presence of a system zone. System zones in phthalate buffers may be easily detected by UV detection and manifest themselves as peaks or dips. Peak shape diagrams are advantageously used for the prediction of the migration behavior of system zones in phthalate background electrolyte (BGE) systems at various pH. It is shown that the mobility of the system zone varies strongly with pH, is practically zero at pH values below 4 and above 7, and shows a maximum at pH 5. Thus, the system peak may coincide either with the peaks of various analytes or with the electroosmotic flow (EOF) peak. Experiments are given showing the effects of such coincidences as, e.g., zigzag detection patterns, double EOF peaks, and/or unusually broad peaks/dips. The message of this contribution is to show how to understand the electrophoretic properties of phthalate BGEs that, regardless of possible failure regions, may be successfully used in the analytical practice of capillary zone electrophoresis (CZE).

Exploring the success, failure and factors influencing M-government implementation in developing countries

CSIR Research Space (South Africa)

Ogunleye, OS

2014-05-01

Full Text Available and to provide better services to citizens, businesses, and government agencies through using mobile technology. This research reviews the success, failures and factors influencing m-Government development and implementation in developing countries...

The incorporation of displacement-controlled loadings within the net-section stress failure criterion

International Nuclear Information System (INIS)

Smith, E.

1985-01-01

A net-section stress failure criterion can be used to evaluate the critical flaw size for a material having a high fracture resistance. A simple analysis shows that the stress arising from displacement-controlled loadings should be taken into account fully if the applied tearing modulus exceeds a critical value. (author)

Numerical simulation of mechanisms of deformation,failure and energy dissipation in porous rock media subjected to wave stresses

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster

Constitutive modeling of void-growth-based tensile ductile failures with stress triaxiality effects

KAUST Repository

Mora Cordova, Angel

2014-07-01

In most metals and alloys, the evolution of voids has been generally recognized as the basic failure mechanism. Furthermore, stress triaxiality has been found to influence void growth dramatically. Besides strain intensity, it is understood to be the most important factor that controls the initiation of ductile fracture. We include sensitivity of stress triaxiality in a variational porous plasticity model, which was originally derived from hydrostatic expansion. Under loading conditions rather than hydrostatic deformation, we allow the critical pressure for voids to be exceeded so that the growth due to plasticity becomes dependent on the stress triaxiality. The limitations of the spherical void growth assumption are investigated. Our improved constitutive model is validated through good agreements with experimental data. Its capacity for reproducing realistic failure patterns is also indicated by a numerical simulation of a compact tensile (CT) test. © 2013 Elsevier Inc.

Rethinking infant knowledge: toward an adaptive process account of successes and failures in object permanence tasks.

Science.gov (United States)

Munakata, Y; McClelland, J L; Johnson, M H; Siegler, R S

1997-10-01

Infants seem sensitive to hidden objects in habituation tasks at 3.5 months but fail to retrieve hidden objects until 8 months. The authors first consider principle-based accounts of these successes and failures, in which early successes imply knowledge of principles and failures are attributed to ancillary deficits. One account is that infants younger than 8 months have the object permanence principle but lack means-ends abilities. To test this, 7-month-olds were trained on means-ends behaviors and were tested on retrieval of visible and occluded toys. Means-ends demands were the same, yet infants made more toy-guided retrievals in the visible case. The authors offer an adaptive process account in which knowledge is graded and embedded in specific behavioral processes. Simulation models that learn gradually to represent occluded objects show how this approach can account for success and failure in object permanence tasks without assuming principles and ancillary deficits.

Intervention for Nonorganic Failure To Thrive.

Science.gov (United States)

Wooster, Donna M.

2000-01-01

This article describes a variety of treatment options for infants and toddlers with nonorganic failure to thrive. Key elements of successful interventions are discussed and appropriate clinical applications are made. The need for a team approach to address the varied etiologically significant factors related to feeding difficulties is stressed.…

A generic approach for containment success criteria under severe accident loads

International Nuclear Information System (INIS)

Sammataro, R.F.; Solonick, W.R.; Edwards, N.W.

1992-01-01

The U.S. Department of Energy (DOE), Office of New Production Reactors (NP), has identified safety as the foremost design criterion for the Heavy Water New Production Reactor (NPR-HWR). The DOE-NP has issued the Deterministic Severe Accident Criteria (DSACs) to guide the design of the NPR-HWR containment for resistance to severe accidents. The DSAC concept provides for a generic approach for success criteria to predict the threshold of containment failure under severe accident loads. This concept consists of two parts: (1) Problem Statements that are qualitative and quantitative bases for calculating associated loadings and containment response to those loadings, and (2) Success Criteria that specify acceptable containment response measures and limits for each problem statement. This paper is limited to a discussion of a generic approach for containment success criteria. The main elements of these success criteria are expressed in terms of elastic stresses and inelastic strains. Containment performance is based on the best estimate of failure as predicted by either stress or strain, buckling, displacements, or ability to withstand missile perforation. Since these limits are best estimates of failure, no conservatism exists in these success criteria. Rather, conservatism is to be provided in the problem statements, i.e., the quantified severe accident loads. These success criteria are presented on a multi-tiered basis for static pressure and temperature loadings, dynamic loadings, and missiles. Within the static pressure and temperature loadings and the dynamic loadings, the criteria are separated into elastic analysis success criteria and inelastic analysis success criteria. Each of these areas, in turn, defines limits on either the stress or strain measures as well as on measures for buckling and displacements

Self-esteem regulation after success and failure to attain unconsciously activated goals

NARCIS (Netherlands)

Bongers, K.C.A.; Dijksterhuis, A.J.; Spears, R.

2009-01-01

People are motivated to establish and maintain a positive self-image. When people fail to attain their goals self-esteem is threatened, and this elicits the motivation to protect or repair self-esteem. We investigated whether success and failure to attain goals affects self-esteem if these goals

Self-esteem regulation after success and failure to attain unconsciously activated goals

NARCIS (Netherlands)

Bongers, Karin C. A.; Dijksterhuis, Ap; Spears, Russell

People are motivated to establish and maintain a positive self-image. When people fail to attain their goals self-esteem is threatened, and this elicits the motivation to protect or repair self-esteem. We investigated whether success and failure to attain goals affects self-esteem if these goals

Collective Success or Collective Failure?

DEFF Research Database (Denmark)

Fayyaz, Anjum

study of soccer village project to learn how various attempts at facilitating joint CSR action in the Pakistani football manufacturing have consistently failed in addressing international CSR compliance demands. I conclude that this form of collective failure – along with technological changes, lack...... of innovation, and government failure - can partly explain why Sialkot has been marginalized in terms of its overall share of world football manufacturing in the last decade....

ASSESSING THE NON-FINANCIAL PREDICTORS OF THE SUCCESS AND FAILURE OF YOUNG FIRMS IN THE NETHERLANDS

Directory of Open Access Journals (Sweden)

Philip VERGAUWEN

2005-01-01

Full Text Available In this study, the Lussier (1995 success and failure prediction model is improved and tested on asample of Dutch firms. Besides clearly defining a specific business plan, work experience is added asa variable, and contrary to previous researches, the discrete variables are dealt with appropriate thistime. The results of this improved model show that product/service timing, planning, managementexperience, knowledge of marketing, economic timing, professional advice, and having a businesspartner are predictors of success and failure for young firms in the Netherlands.

How Analysis Informs Regulation:Success and Failure of ...

Science.gov (United States)

How Analysis Informs Regulation:Success and Failure of Evolving Approaches to Polyfluoroalkyl Acid Contamination The National Exposure Research Laboratory (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA mission to protect human health and the environment. HEASD research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.

Factors Determining the Success and Failure of eHealth Interventions: Systematic Review of the Literature

Science.gov (United States)

Janssen, Wouter; Johansen, Monika Alise

2018-01-01

Background eHealth has an enormous potential to improve healthcare cost, effectiveness, and quality of care. However, there seems to be a gap between the foreseen benefits of research and clinical reality. Objective Our objective was to systematically review the factors influencing the outcome of eHealth interventions in terms of success and failure. Methods We searched the PubMed database for original peer-reviewed studies on implemented eHealth tools that reported on the factors for the success or failure, or both, of the intervention. We conducted the systematic review by following the patient, intervention, comparison, and outcome framework, with 2 of the authors independently reviewing the abstract and full text of the articles. We collected data using standardized forms that reflected the categorization model used in the qualitative analysis of the outcomes reported in the included articles. Results Among the 903 identified articles, a total of 221 studies complied with the inclusion criteria. The studies were heterogeneous by country, type of eHealth intervention, method of implementation, and reporting perspectives. The article frequency analysis did not show a significant discrepancy between the number of reports on failure (392/844, 46.5%) and on success (452/844, 53.6%). The qualitative analysis identified 27 categories that represented the factors for success or failure of eHealth interventions. A quantitative analysis of the results revealed the category quality of healthcare (n=55) as the most mentioned as contributing to the success of eHealth interventions, and the category costs (n=42) as the most mentioned as contributing to failure. For the category with the highest unique article frequency, workflow (n=51), we conducted a full-text review. The analysis of the 23 articles that met the inclusion criteria identified 6 barriers related to workflow: workload (n=12), role definition (n=7), undermining of face-to-face communication (n=6), workflow

Value of routine investigations to predict loop diuretic down-titration success in stable heart failure.

Science.gov (United States)

Martens, Pieter; Verbrugge, Frederik H; Boonen, Levinia; Nijst, Petra; Dupont, Matthias; Mullens, Wilfried

2018-01-01

Guidelines advocate down-titration of loop diuretics in chronic heart failure (CHF) when patients have no signs of volume overload. Limited data are available on the expected success rate of this practice or how routine diagnostic tests might help steering this process. Fifty ambulatory CHF-patients on stable neurohumoral blocker/diuretic therapy for at least 3months without any clinical sign of volume overload were prospectively included to undergo loop diuretic down-titration. All patients underwent a similar pre-down-titration evaluation consisting of a dyspnea scoring, physical examination, transthoracic echocardiography (diastolic function, right ventricular function, cardiac filling pressures and valvular disease), blood sample (serum creatinine, plasma NT-pro-BNP and neurohormones). Loop diuretic maintenance dose was subsequently reduced by 50% or stopped if dose was ≤40mg furosemide equivalents. Successful down-titration was defined as a persistent dose reduction after 30days without weight increase >1.5kg or new-onset symptoms of worsening heart failure. At 30-day follow-up, down-titration was successful in 62% (n=31). In 12/19 patients exhibiting down-titration failure, this occurred within the first week. Physical examination, transthoracic echocardiography and laboratory analysis had limited predictive capability to detect patients with down-titration success/failure (positive likelihood-ratios below 1.5, or area under the curve [AUC] non-statically different from AUC=0.5). Loop diuretic down-titration is feasible in a majority of stable CHF patients in which the treating clinician felt continuation of loops was unnecessary to sustain euvolemia. Importantly, routine diagnostics which suggest euvolemia, have limited diagnostic impact on the post-test probability. Copyright © 2017 Elsevier B.V. All rights reserved.

Self-handicapping status, claimed self-handicaps and reduced practice effort following success and failure feedback.

Science.gov (United States)

Thompson, T; Richardson, A

2001-03-01

Self-handicapping involves the strategic establishment of an impediment or obstacle to success prior to a performance situation which thereby provides a convenient excuse for poor performance. The study sought to establish that relative to low trait self-handicappers, high trait self-handicappers exposed to failure in an intellectually evaluative situation will (a) pre-emptively claim more handicaps, and (b) behaviourally self-handicap through reduced practice effort, and (c) report greater anxiety and negative affect relative to low trait self-handicappers. Participants were 72 undergraduate students, divided equally between high and low self-handicapping groups. This study utilised a 2 (self-handicapping status: high, low) x 3 (performance feedback: fail, low task importance; fail, high task importance; success) between-subjects factorial design to investigate claimed and behavioural self-handicapping through reduced practice effort. This was done by manipulating performance outcome and perceived task importance. Relative to low trait self-handicappers, high trait high self-handicappers claimed more handicaps and engaged in greater behavioural self-handicapping following failure when working on tasks that were described as potentially diagnostic of low ability. While low self-handicappers internalised their success more than their failure in the high task importance condition, high self-handicappers were undifferentiated in their attributions across performance conditions. Greater anxiety and greater negative affect were also characteristic of high self-handicappers. The study highlights the self-protective benefit of self-handicapping in sparing the individual from conclusions of low ability, and the failure of high self-handicappers to fully internalise their success. These elements and the role of uncertain estimates of ability are discussed in considering implications for intervention.

Social stress and reproductive success in the female Syrian hamster: endocrine and behavioral correlates.

Science.gov (United States)

Chelini, Marie Odile Monier; Palme, Rupert; Otta, Emma

2011-10-24

In many mammal species, reproduction is not shared equally among the members of a social unit. Even though reproductive skew seems unlikely in females of solitary species, this phenomenon could result from environmental factors. Although solitary in the wild, captive Syrian hamsters (Mesocricetus auratus) are generally housed in groups. We investigated whether social stress produces some degree of reproductive skew in this solitary species and whether female reproductive success varies as a function of social rank. To assess the physiological relationship between social stress and fertility, we monitored reproductive hormones and glucocorticoids of solitary and pair-housed females during pregnancy by means of recently established non-invasive methods for measuring hormone metabolites in the feces. The patterns of fecal progesterone, estrogen and glucocorticoid metabolites were similar to those found in blood and reported in the literature for pregnant hamsters. As expected, dominant females had higher breeding success than subordinate females. However the rate of reproductive failure was also very high among the singly housed females of our control group. The number of pups per litter, the average sex-ratio in each group, and the mean weight of pups did not differ significantly among groups. Glucocorticoid concentrations were unaffected by housing and social rank and the few differences between the endocrine profiles of singly- and pair-housed females are not sufficient to explain the observed difference in breeding success. It is likely that social isolation impairs reproduction in the same manner as subordination. Our findings suggest that social isolation of animals accustomed to group living was equally as disturbing as cohabitation with an unknown conspecific. Copyright © 2011 Elsevier Inc. All rights reserved.

The Motivational Effects of Success or Failure in Urban Elementary School Teaching

Science.gov (United States)

Waterman, Bradford H.

2012-01-01

This study describes teachers' experiences of success and failure in teaching through interviews. The analytical framework for this study was based on Activity Theory (Leon'tev, 1978), and the research methods were developed by Herzberg et al. (1959). The inclusion of factors identified by Seligman (2006) and Maslach (1982) allowed for…

Failure Characteristics of Granite Influenced by Sample Height-to-Width Ratios and Intermediate Principal Stress Under True-Triaxial Unloading Conditions

Science.gov (United States)

Li, Xibing; Feng, Fan; Li, Diyuan; Du, Kun; Ranjith, P. G.; Rostami, Jamal

2018-05-01

The failure modes and peak unloading strength of a typical hard rock, Miluo granite, with particular attention to the sample height-to-width ratio (between 2 and 0.5), and the intermediate principal stress was investigated using a true-triaxial test system. The experimental results indicate that both sample height-to-width ratios and intermediate principal stress have an impact on the failure modes, peak strength and severity of rockburst in hard rock under true-triaxial unloading conditions. For longer rectangular specimens, the transition of failure mode from shear to slabbing requires higher intermediate principal stress. With the decrease in sample height-to-width ratios, slabbing failure is more likely to occur under the condition of lower intermediate principal stress. For same intermediate principal stress, the peak unloading strength monotonically increases with the decrease in sample height-to-width. However, the peak unloading strength as functions of intermediate principal stress for different types of rock samples (with sample height-to-width ratio of 2, 1 and 0.5) all present the pattern of initial increase, followed by a subsequent decrease. The curves fitted to octahedral shear stress as a function of mean effective stress also validate the applicability of the Mogi-Coulomb failure criterion for all considered rock sizes under true-triaxial unloading conditions, and the corresponding cohesion C and internal friction angle φ are calculated. The severity of strainburst of granite depends on the sample height-to-width ratios and intermediate principal stress. Therefore, different supporting strategies are recommended in deep tunneling projects and mining activities. Moreover, the comparison of test results of different σ 2/ σ 3 also reveals the little influence of minimum principal stress on failure characteristics of granite during the true-triaxial unloading process.

Effect of failure/success feedback and the moderating influence of personality on reward motivation.

Science.gov (United States)

Anand, Deepika; Oehlberg, Katherine A; Treadway, Michael T; Nusslock, Robin

2016-01-01

While motivation to pursue goals is often assumed to be a trait-like characteristic, it is influenced by a variety of situational factors. In particular, recent experiences of success or failure, as well as cognitive responses to these outcomes, may shape subsequent willingness to expend effort for future rewards. To date, however, these effects have not been explicitly tested. In the present study, 131 healthy individuals received either failure or success feedback on a cognitive task. They were then instructed to either ruminate or distract themselves from their emotions. Finally, they completed the Effort Expenditure for Rewards Task, a laboratory measure of reward motivation. Results indicate that participants who received failure feedback relied more strongly on the reward magnitude when choosing whether to exert greater effort to obtain larger rewards, though this effect only held under conditions of significant uncertainty about whether the effort would be rewarded. Further, participants with high levels of trait inhibition were less responsive to reward value and probability when choosing whether to expend greater effort, results that echo past studies of effort-based decision-making in psychological disorders.

Multilinear stress-strain and failure calibrations for Ti-6Al-4V.

Energy Technology Data Exchange (ETDEWEB)

Corona, Edmundo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2018-02-01

This memo concerns calibration of an elastic-plastic J₂ material model for Ti-6Al-4V (grade 5) alloy based on tensile uniaxial stress-strain data obtained in the laboratory. In addition, tension tests on notched specimens provided data to calibrate two ductile failure models: Johnson-Cook and Wellman's tearing parameter. The tests were conducted by Kim Haulen- beek and Dave Johnson (1528) in the Structural Mechanics Laboratory (SML) during late March and early April, 2017. The SML EWP number was 4162. The stock material was a TIMETALR® 6-4 Titanium billet with 9 in. by 9 in. square section and length of 137 in. The product description indicates that it was a forging delivered in annealed condition (2 hours @ 1300oF, AC at the mill). The tensile mechanical properties reported in the material certi cation are given in Table 1, where σ_o represents the 0.2% strain offset yield stress, σ_u the ultimate stress, ε_f the elongation at failure and R.A. the reduction in area.

Perfectionism and self-conscious emotions in British and Japanese students: Predicting pride and embarrassment after success and failure

OpenAIRE

Stoeber, Joachim; Kobori, Osamu; Tanno, Yoshihiko

2013-01-01

Regarding self-conscious emotions, studies have shown that different forms of perfectionism show different relationships with pride, shame, and embarrassment depending on success and failure. What is unknown is whether these relationships also show cultural variations. Therefore, we conducted a study investigating how self-oriented and socially prescribed perfectionism predicted pride and embarrassment after success and failure comparing 363 British and 352 Japanese students. Students were as...

Predicting the success of noninvasive positive pressure ventilation in emergency room for patients with acute heart failure.

Science.gov (United States)

Shirakabe, Akihiro; Hata, Noritake; Yokoyama, Shinya; Shinada, Takuro; Kobayashi, Nobuaki; Tomita, Kazunori; Kitamura, Mitsunobu; Nozaki, Ayaka; Tokuyama, Hideo; Asai, Kuniya; Mizuno, Kyoichi

2011-01-01

Non-invasive positive pressure ventilation (NPPV) for acute heart failure (AHF) is increasingly used to avoid endotracheal intubation (ETI). We therefore reviewed our experience using respirator management in the emergency room for AHF, and evaluated the predictive factors in the success of NPPV in the emergency room. Three-hundred forty-three patients with AHF were analyzed. The AHF patients were assigned to either BiPAP-Synchrony (B-S; Respironics, Merrysville, PA, USA) period (2005-2007, n = 176) or BiPAP-Vision (B-V; Respironics) period (2008-2010, n = 167). The rate of carperitide use was significantly increased and dopamine use was significantly decreased in the B-V period. The total length of hospital stay was significantly shorter in the B-V period. AHF patients were also assigned to a failed trial of NPPV followed by ETI (NPPV failure group) or an NPPV success group in the emergency room for each period. NPPV was successfully used in 48 cases in the B-S period, and in 111 cases in the B-V period. Fifty-seven ETI patients included 45 direct ETI and 11 NPPV failure cases in the B-S period, and 16 ETI patients included 10 direct ETI and 6 NPPV failure cases in the B-V period. The pH values were significantly lower in the NPPV failure than in the NPPV success for both periods (7.19 ± 0.10 vs. 7.28 ± 0.11, B-S period, p successful estimates of NPPV with a high sensitivity and specificity, and the aortic blood gas level was above 7.03 pH when using the B-V system. Copyright © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

The Contribution of Counseling Providers to the Success or Failure of Marriages

Science.gov (United States)

Ansah-Hughes, Winifred

2015-01-01

This study is an investigation into the contribution of counseling providers to the success or failure of marriages. The purposive and the simple random sampling methods were used to select eight churches and 259 respondents (married people) in the Techiman Municipality. The instrument used to collect data was a 26-item questionnaire including a…

Bearing Stress at Failure of Double-Lap Hybrid Joints in Woven Fabric Kenaf Fiber Composite Plates under Quasi-static Loading

Directory of Open Access Journals (Sweden)

Lee Sim Yee

2017-01-01

Full Text Available The present paper is focused on the bearing stress at failure of double-lap woven fabric kenaf fiber reinforced polymer (KFRP hybrid bonded-bolted joints in experimental frameworks. The effects of different normalized plate width (plate width/hole diameter, W/d, lay-up types and bolt loads were incorporated in current study as specified in testing series. Generally, hybrid joint coupons separated within adhesive layer prior to net-tension failure or bearing/net-tension failure. The bearing stress at failure increased as W/d ratio increment, critical W/d is given as four and three in clamped and finger tight condition respectively. Lay-up types present insignificant effect to bearing stress at failure due to low volume fiber fraction in kenaf fiber composites. Combination of thicker and clamped conditions plate demonstrated greater bearing stress than equivalent finger-tight (FT conditions due to higher load transferred from friction, as expected.

Perceived success/failure and attributions associated with self-regulatory efficacy to meet physical activity recommendations for women with arthritis.

Science.gov (United States)

Spink, Kevin S; Brawley, Lawrence R; Gyurcsik, Nancy C

2016-10-01

The relationship between attributional dimensions women assign to the cause of their perceived success or failure at meeting the recommended physical activity dose and self-regulatory efficacy for future physical activity was examined among women with arthritis. Women (N = 117) aged 18-84 years, with self-reported medically-diagnosed arthritis, completed on-line questions in the fall of 2013 assessing endurance physical activity, perceived outcome for meeting the recommended levels of endurance activity, attributions for one's success or failure in meeting the recommendations, and self-regulatory efficacy to schedule/plan endurance activity over the next month. The main theoretically-driven finding revealed that the interaction of the stability dimension with perceived success/failure was significantly related to self-regulatory efficacy for scheduling and planning future physical activity (β = 0.35, p = .002). Outcomes attributed to more versus less stable factors accentuated differences in self-regulatory efficacy beliefs following perceived success and failure at being active. It appears that attributional dimensions were associated with self-regulatory efficacy in women with arthritis. This suggests that rather than objectively observed past mastery experience, women's subjective perceptions and explanations of their past experiences were related to efficacy beliefs, especially following a failure experience.

The failure of earthquake failure models

Science.gov (United States)

Gomberg, J.

2001-01-01

In this study I show that simple heuristic models and numerical calculations suggest that an entire class of commonly invoked models of earthquake failure processes cannot explain triggering of seismicity by transient or "dynamic" stress changes, such as stress changes associated with passing seismic waves. The models of this class have the common feature that the physical property characterizing failure increases at an accelerating rate when a fault is loaded (stressed) at a constant rate. Examples include models that invoke rate state friction or subcritical crack growth, in which the properties characterizing failure are slip or crack length, respectively. Failure occurs when the rate at which these grow accelerates to values exceeding some critical threshold. These accelerating failure models do not predict the finite durations of dynamically triggered earthquake sequences (e.g., at aftershock or remote distances). Some of the failure models belonging to this class have been used to explain static stress triggering of aftershocks. This may imply that the physical processes underlying dynamic triggering differs or that currently applied models of static triggering require modification. If the former is the case, we might appeal to physical mechanisms relying on oscillatory deformations such as compaction of saturated fault gouge leading to pore pressure increase, or cyclic fatigue. However, if dynamic and static triggering mechanisms differ, one still needs to ask why static triggering models that neglect these dynamic mechanisms appear to explain many observations. If the static and dynamic triggering mechanisms are the same, perhaps assumptions about accelerating failure and/or that triggering advances the failure times of a population of inevitable earthquakes are incorrect.

Residual stress measurements with barkhausen noise in power plant creep failure analysis

Energy Technology Data Exchange (ETDEWEB)

Karvonen, I. [CoMoTest Oy, Maentsaelae (Finland)] Suominen, L. [Stresstech Oy, Jyvaeskylae (Finland)

1998-12-31

Continuously developing power and process industry needs predictive maintenance inspection methods in order to prevent failures with correctly timed and properly specified measures. Materials` monitoring has traditionally been non-destructive inspection to detect growing cracks or other deficiencies. Recently, after the development of portable stress measurement systems, some advances has been reached. Based on stress anomalies due to creep, fatigue or corrosion, new applications have been found in the use of Barkhausen noise inspection. When the Barkhausen noise findings have been simultaneously confirmed with other stress measuring methods, a wider acceptance of the application of the method can be proposed. (orig.) 7 refs.

Residual stress measurements with barkhausen noise in power plant creep failure analysis

Energy Technology Data Exchange (ETDEWEB)

Karvonen, I. [CoMoTest Oy, Maentsaelae (Finland)] Suominen, L. [Stresstech Oy, Jyvaeskylae (Finland)

1997-12-31

Continuously developing power and process industry needs predictive maintenance inspection methods in order to prevent failures with correctly timed and properly specified measures. Materials` monitoring has traditionally been non-destructive inspection to detect growing cracks or other deficiencies. Recently, after the development of portable stress measurement systems, some advances has been reached. Based on stress anomalies due to creep, fatigue or corrosion, new applications have been found in the use of Barkhausen noise inspection. When the Barkhausen noise findings have been simultaneously confirmed with other stress measuring methods, a wider acceptance of the application of the method can be proposed. (orig.) 7 refs.

The effectiveness of telehealth care on caregiver burden, mastery of stress, and family function among family caregivers of heart failure patients: a quasi-experimental study.

Science.gov (United States)

Chiang, Li-Chi; Chen, Wan-Chou; Dai, Yu-Tzu; Ho, Yi-Lwun

2012-10-01

Telehealth care was developed to provide home-based monitoring and support for patients with chronic disease. The positive effects on physical outcome have been reported; however, more evidence is required concerning the effects on family caregivers and family function for heart failure patients transitioning from the hospital to home. To evaluate the effectiveness of nursing-led transitional care combining discharge plans and telehealth care on family caregiver burden, stress mastery and family function in family caregivers of heart failure patients compared to those receiving traditional discharge planning only. This is a quasi-experimental study design. Sixty-three patients with heart failure were assessed for eligibility and invited to participate in either telehealth care or standard care in a medical centre from May to October 2010. Three families refused to participate in data collection. Thirty families who chose telehealth care after discharge from the hospital to home comprised the experimental group; the others families receiving discharge planning only comprised the comparison group. Telenursing specialist provided the necessary family nursing interventions by 24-h remote monitoring of patients' health condition and counselling by telephone, helping the family caregivers successfully transition from hospital to home. Data on caregiver burden, stress mastery and family function were collected before discharge from the hospital and one month later at home. Effects of group, time, and group×time interaction were analysed using Mixed Model in SPSS (17.0). Family caregivers in both groups had significantly lower burden, higher stress mastery, and better family function at one-month follow-up compared to before discharge. The total score of caregiver burden, stress mastery and family function was significantly improved for the family caregivers in the experimental group compared to the comparison group at posttest. Two subscales of family function

Factors Determining the Success and Failure of eHealth Interventions: Systematic Review of the Literature.

Science.gov (United States)

Granja, Conceição; Janssen, Wouter; Johansen, Monika Alise

2018-05-01

eHealth has an enormous potential to improve healthcare cost, effectiveness, and quality of care. However, there seems to be a gap between the foreseen benefits of research and clinical reality. Our objective was to systematically review the factors influencing the outcome of eHealth interventions in terms of success and failure. We searched the PubMed database for original peer-reviewed studies on implemented eHealth tools that reported on the factors for the success or failure, or both, of the intervention. We conducted the systematic review by following the patient, intervention, comparison, and outcome framework, with 2 of the authors independently reviewing the abstract and full text of the articles. We collected data using standardized forms that reflected the categorization model used in the qualitative analysis of the outcomes reported in the included articles. Among the 903 identified articles, a total of 221 studies complied with the inclusion criteria. The studies were heterogeneous by country, type of eHealth intervention, method of implementation, and reporting perspectives. The article frequency analysis did not show a significant discrepancy between the number of reports on failure (392/844, 46.5%) and on success (452/844, 53.6%). The qualitative analysis identified 27 categories that represented the factors for success or failure of eHealth interventions. A quantitative analysis of the results revealed the category quality of healthcare (n=55) as the most mentioned as contributing to the success of eHealth interventions, and the category costs (n=42) as the most mentioned as contributing to failure. For the category with the highest unique article frequency, workflow (n=51), we conducted a full-text review. The analysis of the 23 articles that met the inclusion criteria identified 6 barriers related to workflow: workload (n=12), role definition (n=7), undermining of face-to-face communication (n=6), workflow disruption (n=6), alignment with clinical

Retrospective 25-year follow-up of treatment outcomes in Angle Class III patients : Success versus failure.

Science.gov (United States)

Wendl, Brigitte; Kamenica, A; Droschl, H; Jakse, N; Weiland, F; Wendl, T; Wendl, M

2017-03-01

Despite recommendations for early treatment of hereditary Angle Class III syndrome, late pubertal growth may cause a relapse requiring surgical intervention. This study was performed to identify predictors of successful Class III treatment. Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Data were collected from the data archive, cephalograms, and casts, including pretreatment (T0) and posttreatment (T1) data, as well as long-term follow-up data collected approximately 25 years after treatment (T2). Each patient was assigned to a success or a failure group. Data were analyzed based on time (T0, T1, T2), deviations from normal (Class I), and prognathism types (true mandibular prognathism, maxillary retrognathism, combined pro- and retrognathism). Compared to Class I normal values, the data obtained in both groups yielded 11 significant parameters. The success group showed values closer to normal at all times (T0, T1, T2) and vertical parameters decreased from T0 to T2. The failure group showed higher values for vertical and horizontal mandibular growth, as well as dentally more protrusion of the lower anterior teeth and more negative overjet at all times. In adittion, total gonial and upper gonial angle were higher at T0 and T1. A prognostic score-yet to be evaluated in clinical practice-was developed from the results. The failure group showed greater amounts of horizontal development during the years between T1 and T2. Treatment of true mandibular prognathism achieved better outcomes in female patients. Cases of maxillary retrognathism were treated very successfully without gender difference. Failure was clearly more prevalent, again without gender difference, among the patients with combined mandibular prognathism and maxillary retrognathism. Crossbite situations were observed in 44% of cases at T0. Even though this finding had been resolved by T1, it relapsed in 16% of the cases by T2. The failure rate increased in cases of

The Career Success/Personal Failure Phenomenon as Perceived in Others: Comparing Vignettes of Male and Female Managers.

Science.gov (United States)

Westman, Mina; Etzion, Dalia

1990-01-01

Reactions to 4 versions of a vignette describing a successful manager were obtained from 233 management students, including 50 executives in an extension course. Career success was perceived as a major cause of personal failure. The personal price paid by successful people was perceived differently depending on gender and marital status. (SK)

Device for detecting imminent failure of high-dielectric stress capacitors. [Patent application

Science.gov (United States)

McDuff, G.G.

1980-11-05

A device is described for detecting imminent failure of a high-dielectric stress capacitor utilizing circuitry for detecting pulse width variations and pulse magnitude variations. Inexpensive microprocessor circuitry is utilized to make numerical calculations of digital data supplied by detection circuitry for comparison of pulse width data and magnitude data to determine if preselected ranges have been exceeded, thereby indicating imminent failure of a capacitor. Detection circuitry may be incorporated in transmission lines, pulse power circuitry, including laser pulse circuitry or any circuitry where capacitors or capacitor banks are utilized.

On the failure analysis of bondlines: Stress or energy based fracture criteria?

DEFF Research Database (Denmark)

Anyfantis, Konstantinos

2014-01-01

that characterizes a given bondline, both its cohesive strength and fracture toughness material parameters must be experimentally defined. Based on these properties, failure analysis of the bondline can be done either through stress- or energy-based criteria. The aim of this work is to investigate the effectiveness...... to classify the wide range of bondlines with respect to the failure theory that best describes the debonding process. Cohesive length scale effects are first demonstrated by modeling end notch flexure geometries and later by modeling double strap joint geometries within the framework of a wide numerical...

Constitutive modeling of void-growth-based tensile ductile failures with stress triaxiality effects

KAUST Repository

Mora Cordova, Angel; Liu, Jinxing; El Sayed, Tamer S.

2014-01-01

In most metals and alloys, the evolution of voids has been generally recognized as the basic failure mechanism. Furthermore, stress triaxiality has been found to influence void growth dramatically. Besides strain intensity, it is understood

Microstructures, Forming Limit and Failure Analyses of Inconel 718 Sheets for Fabrication of Aerospace Components

Science.gov (United States)

Sajun Prasad, K.; Panda, Sushanta Kumar; Kar, Sujoy Kumar; Sen, Mainak; Murty, S. V. S. Naryana; Sharma, Sharad Chandra

2017-04-01

Recently, aerospace industries have shown increasing interest in forming limits of Inconel 718 sheet metals, which can be utilised in designing tools and selection of process parameters for successful fabrication of components. In the present work, stress-strain response with failure strains was evaluated by uniaxial tensile tests in different orientations, and two-stage work-hardening behavior was observed. In spite of highly preferred texture, tensile properties showed minor variations in different orientations due to the random distribution of nanoprecipitates. The forming limit strains were evaluated by deforming specimens in seven different strain paths using limiting dome height (LDH) test facility. Mostly, the specimens failed without prior indication of localized necking. Thus, fracture forming limit diagram (FFLD) was evaluated, and bending correction was imposed due to the use of sub-size hemispherical punch. The failure strains of FFLD were converted into major-minor stress space ( σ-FFLD) and effective plastic strain-stress triaxiality space ( ηEPS-FFLD) as failure criteria to avoid the strain path dependence. Moreover, FE model was developed, and the LDH, strain distribution and failure location were predicted successfully using above-mentioned failure criteria with two stages of work hardening. Fractographs were correlated with the fracture behavior and formability of sheet metal.

Mergers: Success versus failure

International Nuclear Information System (INIS)

Carley, G. R.

1997-01-01

Successful mergers in the context of long-term value creation, as measured by return realized on investor-provided capital, were discussed. In essence, a successful merger is characterized by being motivated by a sound business reason and strategy for the merger, a reasonable price and sound execution. The acquiror's pre-merger success in managing a company is a good indicator of future success. Poorly managed companies that acquire other companies generally continue to be poorly managed with no significant increase in shareholder value. Prior to the acquisition, identification of the potential target, assessment of the people involved on both sides of the transaction, thorough knowledge of the target's potential for value creation, financial implications (debt, equity, terms and demand, tax implications, the potential effect of the proposed acquisition on the acquiror's business plan) and finally the execution of the process itself, are the important determinants of successful mergers

Breakfast and Snacks: Associations with Cognitive Failures, Minor Injuries, Accidents and Stress

Directory of Open Access Journals (Sweden)

Katherine Chaplin

2011-05-01

Full Text Available One strategy for examining effects of nutrients on cognitive function is to initially investigate foods that contain many different nutrients. If effects are demonstrated with these foods then further studies can address the role of specific nutrients. Breakfast foods (e.g., cereals, dairy products and fruit provide many important nutrients and consumption of breakfast has been shown to be associated with beneficial effects on cognitive function. Isolating effects of specific constituents of breakfast has proved more difficult and it is still unclear what impact breakfast has on real-life performance. The present study provided initial information on associations between breakfast consumption and cognitive failures and accidents. A second aim was to examine associations between consumption of snacks which are often perceived as being unhealthy (chocolate, crisps and biscuits. A sample of over 800 nurses took part in the study. The results showed that frequency of breakfast consumption (varied breakfasts: 62% cereal was associated with lower stress, fewer cognitive failures, injuries and accidents at work. In contrast, snacking on crisps, chocolate and biscuits was associated with higher stress, more cognitive failures and more injuries outside of work. Further research requires intervention studies to provide a clearer profile of causality and underlying mechanisms.

Study on the main factors that contribute to the success or failure of strategic alliances

Institute of Scientific and Technical Information of China (English)

TANG Yu; WANG Hong-qi

2006-01-01

Strategic alliance is an effective way for enterprise to realize its development and to enhance its competitiveness; however, the success rate of strategic alliances is less than fifty percent. According to this problem, this paper makes systematic research on the factors that relevant to the failure or success of strategic alliance based on comprehensive analysis on internal and external motivation for the formation of strategic alliance,the purpose of which is to give some references and supports for successfully constructing the strategic alliance.

Temp-to-permanent employees: a longitudinal study of stress and selection success.

Science.gov (United States)

Bauer, T N; Truxillo, D M

2000-07-01

Temp-to-permanent employees are temporary workers who have the opportunity to become permanent employees after a specific amount of time (e.g., generally after a 3- to 12-month period of trial work). The authors predicted that temporary worker individual differences, self-monitoring, tolerance for ambiguity, and role adjustment are related to temporary worker physiological stress and to whether temporary employees are offered permanent employment. Longitudinal data collection (pre- and postentry) resulted in data from 136 temp-to-permanent employees. Tolerance for ambiguity and role adjustment were found to be related to temporary worker stress and selection success. Self-monitoring was related to selection success for workers in an extended probationary period. These results suggest the need for further exploration and application of models of stress in understanding factors related to temporary worker success.

Success/Failure Prediction of Noninvasive Mechanical Ventilation in Intensive Care Units. Using Multiclassifiers and Feature Selection Methods.

Science.gov (United States)

Martín-González, Félix; González-Robledo, Javier; Sánchez-Hernández, Fernando; Moreno-García, María N

2016-05-17

This paper addresses the problem of decision-making in relation to the administration of noninvasive mechanical ventilation (NIMV) in intensive care units. Data mining methods were employed to find out the factors influencing the success/failure of NIMV and to predict its results in future patients. These artificial intelligence-based methods have not been applied in this field in spite of the good results obtained in other medical areas. Feature selection methods provided the most influential variables in the success/failure of NIMV, such as NIMV hours, PaCO2 at the start, PaO2 / FiO2 ratio at the start, hematocrit at the start or PaO2 / FiO2 ratio after two hours. These methods were also used in the preprocessing step with the aim of improving the results of the classifiers. The algorithms provided the best results when the dataset used as input was the one containing the attributes selected with the CFS method. Data mining methods can be successfully applied to determine the most influential factors in the success/failure of NIMV and also to predict NIMV results in future patients. The results provided by classifiers can be improved by preprocessing the data with feature selection techniques.

Blocked learning in development aid? Reporting success rather than failure in Andhra Pradesh, India

DEFF Research Database (Denmark)

Saito, Moeko; Pasgaard, Maya

2014-01-01

This article aims to understand why development organizations tend to report project success rather than failure which blocks learning from project problems. Drawing on the case of a World Bank forestry project in Andhra Pradesh, India, the article analyses different interlinked sites of project...

Outcome and treatment of postoperative spine surgical site infections: predictors of treatment success and failure.

Science.gov (United States)

Maruo, Keishi; Berven, Sigurd H

2014-05-01

Surgical site infection (SSI) is an important complication after spine surgery. The management of SSI is characterized by significant variability, and there is little guidance regarding an evidence-based approach. The objective of this study was to identify risk factors associated with treatment failure of SSI after spine surgery. A total of 225 consecutive patients with SSI after spine surgery between July 2005 and July 2010 were studied retrospectively. Patients were treated with aggressive surgical debridement and prolonged antibiotic therapy. Outcome and risk factors were analyzed in 197 patients having 1 year of follow-up. Treatment success was defined as resolution within 90 days. A total of 126 (76 %) cases were treated with retention of implants. Forty-three (22 %) cases had treatment failure with five (2.5 %) cases resulting in death. Lower rates of treatment success were observed with late infection (38 %), fusion with fixation to the ilium (67 %), Propionibacterium acnes (43 %), poly microbial infection (68 %), >6 operated spinal levels (67 %), and instrumented cases (73 %). Higher rates of early resolution were observed with superficial infection (93 %), methicillin-sensitive Staphylococcus aureus (95 %), and failure. Superficial infection and methicillin-sensitive Staphylococcus aureus were predictors of early resolution. Postoperative spine infections were treated with aggressive surgical debridement and antibiotic therapy. High rates of treatment failure occurred in cases with late infection, long instrumented fusions, polymicrobial infections, and Propionibacterium acnes. Removal of implants and direct or staged re-implantation may be a useful strategy in cases with high risk of treatment failure.

High lung volume increases stress failure in pulmonary capillaries

Science.gov (United States)

Fu, Z.; Costello, M. L.; Tsukimoto, K.; Prediletto, R.; Elliott, A. R.; Mathieu-Costello, O.; West, J. B.

1992-01-01

We previously showed that when pulmonary capillaries in anesthetized rabbits are exposed to a transmural pressure (Ptm) of approximately 40 mmHg, stress failure of the walls occurs with disruption of the capillary endothelium, alveolar epithelium, or sometimes all layers. The present study was designed to test whether stress failure occurred more frequently at high than at low lung volumes for the same Ptm. Lungs of anesthetized rabbits were inflated to a transpulmonary pressure of 20 cmH2O, perfused with autologous blood at 32.5 or 2.5 cmH2O Ptm, and fixed by intravascular perfusion. Samples were examined by both transmission and scanning electron microscopy. The results were compared with those of a previous study in which the lung was inflated to a transpulmonary pressure of 5 cmH2O. There was a large increase in the frequency of stress failure of the capillary walls at the higher lung volume. For example, at 32.5 cmH2O Ptm, the number of endothelial breaks per millimeter cell lining was 7.1 +/- 2.2 at the high lung volume compared with 0.7 +/- 0.4 at the low lung volume. The corresponding values for epithelium were 8.5 +/- 1.6 and 0.9 +/- 0.6. Both differences were significant (P less than 0.05). At 52.5 cmH2O Ptm, the results for endothelium were 20.7 +/- 7.6 (high volume) and 7.1 +/- 2.1 (low volume), and the corresponding results for epithelium were 32.8 +/- 11.9 and 11.4 +/- 3.7. At 32.5 cmH2O Ptm, the thickness of the blood-gas barrier was greater at the higher lung volume, consistent with the development of more interstitial edema. Ballooning of the epithelium caused by accumulation of edema fluid between the epithelial cell and its basement membrane was seen at 32.5 and 52.5 cmH2O Ptm. At high lung volume, the breaks tended to be narrower and fewer were oriented perpendicular to the axis of the pulmonary capillaries than at low lung volumes. Transmission and scanning electron microscopy measurements agreed well. Our findings provide a physiological

Conditions for the clean slate effect after success or failure.

Science.gov (United States)

Körner, Anita; Strack, Fritz

2018-03-20

The act of physically cleaning one's hands may reduce the impact of past experiences, termed clean-slate effect. Cleaning was found to affect negative, neutral, and mildly positive states. We extend this influence to success, a self-serving state. We manipulated success vs. failure and measured changes in optimism (Experiment 1) or self-esteem (Experiment 2). Moreover, we examined boundary conditions for the clean-slate effect. Experiment 1 indicates that the influence of performance on optimism diminishes if participants knew (compared to did not know) they were cleaning their hands. Experiment 2 indicates that the influence of performance on self-esteem diminishes if participants cleaned themselves (compared to an object). These results suggest that the clean-slate effect requires both awareness and self-reference of the cleaning act. Thus, the clean-slate effect seems to depend on both conscious inferences and automatic processes. A meta-analysis across the experiments confirms a moderate-sized clean-slate effect.

A reference stress approach for the characterisation of the creep failure of dissimilar welds under isothermal conditions

International Nuclear Information System (INIS)

Nicholson, R.D.; Williams, J.A.

1988-11-01

In high temperature power plant, welds between austenitic and ferritic steels are required to operate under plant conditions for up to 250,000h. The experience and failure modes for such joints are briefly surveyed in this report. A semi-empirical reference stress approach is used to define the failure life of joints under isothermal conditions. The reference stress is based on a previously published form for multiaxial creep fracture of homogeneous materials but modified to include an additional factor to reflect the complex strains present close to the interface in a dissimilar weld. This reference stress can be modified to give approximate bounds characterised by the equivalent stress or the axial stress on the weld. The reference stress, when applied to the 21/4Cr1Mo:Type 316 welded component data base, gives conservative results for the test data available although conservatism is low for the 9Cr1Mo:Alloy 600 combination. The existing data base for welded components is limited. More data are needed covering a wider range of stress ratios and incorporating bending loads. (author)

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.

Objective Self Awareness, Self-Esteem and Causal Attributions for Success and Failure.

Science.gov (United States)

2 (high vs. low self - esteem subjects) design was employed. Objective self -awareness was manipulated by exposing subjects to their image on a wall...The investigation has applied the theory of objective self awareness (Duval and Wicklund, 1972) to the study of causal attributions that actors make...for their past performance. A 2 (male vs. female subject) by 2 (success vs. failure) by 3 (objective self -awareness vs. control vs. time control) by

Success rates and factors associated with failure of temporary anchorage devices: A prospective clinical trial.

Science.gov (United States)

Aly, Shehab A; Alyan, Doha; Fayed, Mona S; Alhammadi, Maged S; Mostafa, Yehya A

2018-03-06

The objective of the present study was to investigate success rates and associated factors affecting temporary anchorage device (TAD) failure in different biomechanical applications. A total of 180 TADs were used as a part of 82 patients' treatment plan (24 males and 58 females); their mean age was 21.41 years. Three types of TADs were used: 50 (3M ESPE, Neuss, Germany), 56 (Bone screw; Jeil Medical, Seoul, Korea), and 74 (Morelli, Sorocaba, Brazil). Eight maxillary and four mandibular sites were selected for insertion. Three different lengths (6, 8, and 10 mm) and three different diameters (1.5, 1.6, and 1.8 mm) were used. The force levels were set at 50, 100, 150, 200, and 250 g. Patient-, implant-, and operator-dependent factors were evaluated throughout the 266 days of function. Qualitative variables were described by proportions and percentages and analyzed using χ 2 test. The overall success rate was 82.2%. The higher age group showed a significantly higher success rate. Oral hygiene showed a statistically-significant (P ˂ .05) difference between both success and failure groups. All other patient-related factors showed no significant differences. Regarding force levels used, the highest success rate was in 250 g and the lowest was in 100 g. There were no significant differences between both groups regarding other implant- and operator-related factors. Temporary anchorage devices have a good success rate and are beneficial to be integrated in orthodontic treatment planning. Patient age, oral hygiene, and force level are the most significant factors affecting TAD success. © 2018 John Wiley & Sons Australia, Ltd.

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.

Framing African American Students' Success and Failure in Urban Settings: A Typology for Change

Science.gov (United States)

Lewis, Chance W.; James, Marlon; Hancock, Stephen; Hill-Jackson, Valerie

2008-01-01

Grounded in critical race theory, this article seeks to frame the ideological positions of success and failure for African American students in urban school settings. First, we revisit national data and research literature that illustrate the ongoing urban Black-White achievement gap. Second, the Matrix of Achievement Paradigms is shared in an…

Applying Cognitive Behavioural Methods to Retrain Children's Attributions for Success and Failure in Learning

Science.gov (United States)

Toland, John; Boyle, Christopher

2008-01-01

This study involves the use of methods derived from cognitive behavioral therapy (CBT) to change the attributions for success and failure of school children with regard to learning. Children with learning difficulties and/or motivational and self-esteem difficulties (n = 29) were identified by their schools. The children then took part in twelve…

Childrens' Sharing Behavior: Success and Failure, the "Norm of Deserving" and Reciprocity in Sharing.

Science.gov (United States)

Staub, Ervin

Three studies of children's sharing behavior were designed to discover the effects of success or failure on children's willingness to share material rewards with others. In two studies, age differences in willingness to share were noted. Extensive discussion of the results indicates how a child's self concept might influence a child's sharing. The…

An Investigation of the Relationship between Spiritual Health and Depression, Anxiety, and Stress in Patients with Heart Failure

Directory of Open Access Journals (Sweden)

Mahbobe Safavi

2016-06-01

Full Text Available Background and Objectives: Heart failure is a life-threatening illness in which panic disorder, anxiety, depression, and death expectation are constantly experienced. This study, thus, determined to examine the relationship between spiritual health and depression, anxiety, and stress in patients with heart failure. Methods: This study was a descriptive-correlational investigation that was performed on 150 patients with heart failure in selected Ardabil teaching hospitals in 2014. Data was collected using Demographic Questionnaire, Ellison-Paloutzian Spiritual Well-Being Scale, and Depression, Anxiety, and Stress Scale (DASS-21. They were, then, analyzed using SPSS, descriptive statistical method, Pearson’s correlation coefficient, and multivariable regression analysis. Results: The results of this study showed that the spiritual wellbeing level of most subjects (75.3% was in the range of medium. Mean scores of religious and existential aspects of spiritual well-being were obtained to be 33.26±1.247 and 45.76±1.328, respectively. In addition, depression, anxiety, and stress levels of most research units were in the medium range. Pearson’s correlation coefficient showed that there was a statistically significant relationship between depression, anxiety, and stress in all aspects of spiritual wellbeing (r=-0.592, P<0.01. Conclusion:  Results indicated that an increase in spiritual health would be a concomitant of a reduction in depression, anxiety, and stress levels in heart failure patients. Based on the results and importance of spiritual health, an improvement of proficiencies of medical and paramedical communities in offering spiritual healthcares appears to be mandatory.

Economic sustainability in franchising: a model to predict franchisor success or failure

OpenAIRE

Calderón Monge, Esther; Pastor Sanz, Ivan .; Huerta Zavala, Pilar Angélica

2017-01-01

As a business model, franchising makes a major contribution to gross domestic product (GDP). A model that predicts franchisor success or failure is therefore necessary to ensure economic sustainability. In this study, such a model was developed by applying Lasso regression to a sample of franchises operating between 2002 and 2013. For franchises with the highest likelihood of survival, the franchise fees and the ratio of company-owned to franchised outlets were suited to the age ...

The Food Industry and Self-Regulation: Standards to Promote Success and to Avoid Public Health Failures

Science.gov (United States)

Sharma, Lisa L.; Teret, Stephen P.

2010-01-01

Threatened by possible government regulation and critical public opinion, industries often undertake self-regulatory actions, issue statements of concern for public welfare, and assert that self-regulation is sufficient to protect the public. The food industry has made highly visible pledges to curtail children's food marketing, sell fewer unhealthy products in schools, and label foods in responsible ways. Ceding regulation to industry carries opportunities but is highly risky. In some industries (e.g., tobacco), self-regulation has been an abject failure, but in others (e.g., forestry and marine fisheries), it has been more successful. We examined food industry self-regulation in the context of other self-regulatory successes and failures and defined 8 standards that should be met if self-regulation is to be effective. PMID:20019306

Gender differences in implicit self-esteem following a romantic partner's success or failure.

Science.gov (United States)

Ratliff, Kate A; Oishi, Shigehiro

2013-10-01

This research examined the influence of a romantic partner's success or failure on one's own implicit and explicit self-esteem. In Experiment 1, men had lower implicit self-esteem when their partner did well at a "social intelligence" task than when their partner did poorly. Women's implicit self-esteem was unaffected by partner performance. Experiments 2 and 3 showed that Dutch men's implicit self-esteem was negatively affected by their romantic partner's success. In Experiment 4, we replicated Experiments 1-3 in both the academic and social domains, and in Experiment 5, we demonstrated that men's implicit self-esteem is negatively influenced by thinking about a romantic partner's success both when the success is relative and when it is not. In sum, men's implicit self-esteem is lower when a partner succeeds than when a partner fails, whereas women's implicit self-esteem is not. These gender differences have important implications for understanding social comparison in romantic relationships.

Organisational Role Climates: Success-Failure Configurations in Educational Leadership (or Are Educational Administrators Doomed to Succeed?)

Science.gov (United States)

Inbar, Dan E.

1980-01-01

Presents an analytical framework based on a threefold classification--unequivocal failure, "satisficing," and unequivocal success--and four basic role climates--apathetic, frustrating, tense, and tranquil--that is applied to the elementary school principalship. (Author/WD)

Academic Self-Concept and Causal Attributions for Success and Failure Amongst Elementary School Children

Science.gov (United States)

Lohbeck, Annette; Grube, Dietmar; Moschner, Barbara

2017-01-01

A great deal of research shows that the way in which children attribute causes to their successes and failures in school has implications for the development of their academic self-concept (ASC). The most common attributions are ability, effort, task difficulty, and luck. The present study asked 68 elementary school children aged seven to eight…

Are Success and Failure Experiences Equally Motivational? An Investigation of Regulatory Focus and Feedback

Science.gov (United States)

Shu, Tse-Mei; Lam, Shui-fong

2011-01-01

The present study extended regulatory focus theory (Idson & Higgins, 2000) to an educational setting and attempted to identify individuals with high motivation after both success and failure feedback. College students in Hong Kong (N = 180) participated in an experiment with a 2 promotion focus (high vs. low) x 2 prevention focus (high vs.…

Investigation of Turkish EFL Learners' Attributions on Success and Failure in Learning English

Science.gov (United States)

Yavuz, Aysun; Höl, Devrim

2017-01-01

The purpose of this study is to investigate the attributions of Turkish EFL learners on success and failure in learning English as a foreign language with different variables such as gender and level of English proficiency. To investigate the attributions of the participants and gather the relevant data, a questionnaire including 38 items and…

Successful management of acute respiratory failure with noninvasive mechanical ventilation after drowning, in an epileptic-patient

Directory of Open Access Journals (Sweden)

Paolo Ruggeri

2016-01-01

Full Text Available Sea drowning is a common cause of accidental death worldwide. Respiratory complications such as acute pulmonary oedema, which is often complicated by acute respiratory distress syndrome, is often seen. Noninvasive ventilation is already widely used as a first approach to treat acute respiratory failure resulting from multiple diseases. We report a case of a 45 year old man with a history of epilepsy, motor and mental handicap who developed acute respiratory failure secondary to sea water drowning after an epileptic crisis. We illustrate successful and rapid management of this case with noninvasive ventilation. We emphasize the advantages and limitations of using noninvasive ventilation to treat acute respiratory failure due to sea water drowning syndrome.

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

Science.gov (United States)

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

2014-04-01

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

Evaluation of Brace Treatment for Infant Hip Dislocation in a Prospective Cohort: Defining the Success Rate and Variables Associated with Failure.

Science.gov (United States)

Upasani, Vidyadhar V; Bomar, James D; Matheney, Travis H; Sankar, Wudbhav N; Mulpuri, Kishore; Price, Charles T; Moseley, Colin F; Kelley, Simon P; Narayanan, Unni; Clarke, Nicholas M P; Wedge, John H; Castañeda, Pablo; Kasser, James R; Foster, Bruce K; Herrera-Soto, Jose A; Cundy, Peter J; Williams, Nicole; Mubarak, Scott J

2016-07-20

The use of a brace has been shown to be an effective treatment for hip dislocation in infants; however, previous studies of such treatment have been single-center or retrospective. The purpose of the current study was to evaluate the success rate for brace use in the treatment of infant hip dislocation in an international, multicenter, prospective cohort, and to identify the variables associated with brace failure. All dislocations were verified with use of ultrasound or radiography prior to the initiation of treatment, and patients were followed prospectively for a minimum of 18 months. Successful treatment was defined as the use of a brace that resulted in a clinically and radiographically reduced hip, without surgical intervention. The Mann-Whitney test, chi-square analysis, and Fisher exact test were used to identify risk factors for brace failure. A multivariate logistic regression model was used to determine the probability of brace failure according to the risk factors identified. Brace treatment was successful in 162 (79%) of the 204 dislocated hips in this series. Six variables were found to be significant risk factors for failure: developing femoral nerve palsy during brace treatment (p = 0.001), treatment with a static brace (p failure, whereas hips with 4 or 5 risk factors had a 100% probability of failure. These data provide valuable information for patient families and their providers regarding the important variables that influence successful brace treatment for dislocated hips in infants. Prognostic Level I. See Instructions for Authors for a complete description of levels of evidence. Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Failures and suggestions in Earthquake forecasting and prediction

Science.gov (United States)

Sacks, S. I.

2013-12-01

Seismologists have had poor success in earthquake prediction. However, wide ranging observations from earlier great earthquakes show that precursory data can exist. In particular, two aspects seem promising. In agreement with simple physical modeling, b-values decrease in highly loaded fault zones for years before failure. Potentially more usefully, in high stress regions, breakdown of dilatant patches leading to failure can yield expelled water-related observations. The volume increase (dilatancy) caused by high shear stresses decreases the pore pressure. Eventually, water flows back in restoring the pore pressure, promoting failure and expelling the extra water. Of course, in a generally stressed region there may be many small patches that fail, such as observed before the 1975 Haicheng earthquake. Only a few days before the major event will most of the dilatancy breakdown occur in the fault zone itself such as for the Tangshan, 1976 destructive event. Observations of 'water release' effects have been observed before the 1923 great Kanto earthquake, the 1984 Yamasaki event, the 1975 Haicheng and the 1976 Tangshan earthquakes and also the 1995 Kobe earthquake. While there are obvious difficulties in water release observations, not least because there is currently no observational network anywhere, historical data does suggest some promise if we broaden our approach to this difficult subject.

Success and failure of reindeer herding in Greenland

Directory of Open Access Journals (Sweden)

Christine Cuyler

1999-04-01

Full Text Available Animal husbandry is a recent innovation in Greenland, specifically reindeer husbandry is less than 50 years old. Reindeer husbandry was first established in mid-west Greenland and later in southern Greenland. The Greenland hunter tradition and culture is, however, still dominant in many communities. During the 1980s and 1990s, the incompatibility of these two traditions resulted in the failure of reindeer husbandry in mid-west Greenland. There were neither herding nor seasonal herd movements. Animals remained year round on the winter range, which was destroyed as lichens were trampled every summer. Without seasonal herd movements both sustainable range use and control of the herd were lost. Today, there are just two semi-domestic reindeer herds left, and both are in southern Greenland. One herd is commercially successful, and the other is under development. In mid-west Greenland, semi-domestic reindeer husbandry officially ended in 1998, and a hunt was initiated to remove the remaining population. Possibly, by the year 2000 any animals left in this region will be considered wild caribou.

On the Quality of Failure

Directory of Open Access Journals (Sweden)

Bengt-Arne Vedin

2014-05-01

Full Text Available No innovation without failed experiments. No acquisition of competency without hard work, efforts to translate mistakes and insufficient – failed – attempts into mastery. The human condition is one defined by trial and error. Success equates with narrow escape from failure, whereas failure may be a success just missed. The purpose of management can be said to achieve success, so the management of failure is a key one, seeking to turn failure into profit. Almost no successful solutions remain eternally, so signals indicating that they have arrived in their twilight zone are important. Success may be too comforting and lulling, creating a dangerous success lock-in. Courting failure by acting against conventional wisdom and routine intuitions may, though risky, generate huge payoffs. A productive failure management should appreciate that failure is a way to uncertainty reduction, to better information and knowledge, new wisdom and new intuitions. Failure can and should be celebrated and harvested. The most successful mineral prospectors are those who drill more holes; while their percentage of dry ones is average, their number of lucky ones makes for success. The same holds for ideas, where there is the additional benefit that a larger number of ideas, diverse as they are, makes for improved idea handling proficiency.

Reading-Related Causal Attributions for Success and Failure: Dynamic Links With Reading Skill.

Science.gov (United States)

Frijters, Jan C; Tsujimoto, Kimberley C; Boada, Richard; Gottwald, Stephanie; Hill, Dina; Jacobson, Lisa A; Lovett, Maureen W; Mahone, E Mark; Willcutt, Erik G; Wolf, Maryanne; Bosson-Heenan, Joan; Gruen, Jeffrey R

2018-01-01

The present study investigated the relation among reading skills and attributions, naming speed, and phonological awareness across a wide range of reading skill. Participants were 1,105 school-age children and youths from two understudied populations: African Americans and Hispanic Americans. Individual assessments of children ranging in age from 8 to 15 years were conducted for reading outcomes, cognitive and linguistic predictors of reading, and attributions for success and failure in reading situations. Quantile regressions were formulated to estimate these relations across the full skill span of each outcome. Reading-related attributions predicted contextual word recognition, sight word and decoding fluency, and comprehension skills. Attributions to ability in success situations were positively related to each outcome across the full span. On three reading outcomes, this relation strengthened at higher skill levels. Attributions to effort in success situations were consistently and negatively related to all reading outcomes. The results provide evidence that the strength of the relation between reading and attributions varies according to reading skill levels, with the strongest evidence for ability-based attributions in situations of reading success.

Deformation and Failure Mechanism of Roadway Sensitive to Stress Disturbance and Its Zonal Support Technology

Directory of Open Access Journals (Sweden)

Qiangling Yao

2016-01-01

Full Text Available The 6163 haulage roadway in the Qidong coal mine passes through a fault zone, which causes severe deformation in the surrounding rock, requiring repeated roadway repairs. Based on geological features in the fault area, we analyze the factors affecting roadway deformation and failure and propose the concept of roadway sensitive to stress disturbance (RSSD. We investigate the deformation and failure mechanism of the surrounding rocks of RSSD using field monitoring, theoretical analysis, and numerical simulation. The deformation of the surrounding rocks involves dilatation of shallow rocks and separation of deep rocks. Horizontal and longitudinal fissures evolve to bed separation and fracture zones; alternatively, fissures can evolve into fracture zones with new fissures extending to deeper rock. The fault affects the stress field of the surrounding rock to ~27 m radius. Its maximum impact is on the vertical stress of the rib rock mass and its minimum impact is on the vertical stress of the floor rock mass. Based on our results, we propose a zonal support system for a roadway passing through a fault. Engineering practice shows that the deformation of the surrounding rocks of the roadway can be effectively controlled to ensure normal and safe production in the mine.

Influence of N-acetylcysteine on oxidative stress in slow-twitch soleus muscle of heart failure rats

OpenAIRE

Martinez, Paula Felippe [UNESP; Bonomo, Camila [UNESP; Guizoni, Daniele Mendes [UNESP; Oliveira Junior, Silvio Assis [UNESP; Damatto, Ricardo Luiz [UNESP; Cezar, Marcelo Diarcadia Mariano [UNESP; Lima, Aline Regina Ruiz [UNESP; Pagan, Luana Urbano [UNESP; Seiva, Fabio Rodrigues; Fernandes, Denise Castro; Laurindo, Francisco Rafael Martins; Novelli, Ethel Lourenzi Barbosa [UNESP; Matsubara, Luiz Shiguero [UNESP; Zornoff, Leonardo Antonio Mamede [UNESP; Okoshi, Katashi [UNESP

2015-01-01

Background: Chronic heart failure is characterized by decreased exercise capacity with early exacerbation of fatigue and dyspnea. Intrinsic skeletal muscle abnormalities can play a role in exercise intolerance. Causal or contributing factors responsible for muscle alterations have not been completely defined. This study evaluated skeletal muscle oxidative stress and NADPH oxidase activity in rats with myocardial infarction (MI) induced heart failure. Methods and Results: Four months after MI,...

Success and failure factors in the regional health information system design process--results from a constructive evaluation study.

Science.gov (United States)

Nykänen, P; Karimaa, E

2006-01-01

To identify success and failure factors in the design process of a regional health information system. A constructive evaluation study including interviews, observations, usability study and document analysis. Modelling was found to be a key element for the successful implementation of a health information system. The developed service chain model helped to define use cases and to implement seamless service chains. User participation in the design process was a success factor resulting in good user acceptance and signs of positive impacts on work practices. Evaluation study also helped system developers to guide the system's further development. An important failure factor identified was the lack of semantic interoperability of the system components. The results emphasize the socio-technical nature of health information systems. The starting point for development should be thorough insight into the health care work practices where the information systems are to be used. Successful system design should start from modelling of work processes, data and information flows and definition of concepts and their relations. Health informatics as a scientific discipline provides theories and models for the design and development process.

Paralysis and heart failure precede ion balance disruption in heat-stressed European green crabs.

Science.gov (United States)

Jørgensen, Lisa B; Overgaard, Johannes; MacMillan, Heath A

2017-08-01

Acute exposure of ectotherms to critically high temperatures causes injury and death, and this mortality has been associated with a number of physiological perturbations including impaired oxygen transport, loss of ion and water homeostasis, and neuronal failure. It is difficult to discern which of these factors, if any, is the proximate cause of heat injury because, for example, loss of ion homeostasis can impair neuromuscular function (including cardiac function), and conversely impaired oxygen transport reduces ATP supply and can thus reduce ion transport capacity. In this study we investigated if heat stress causes a loss of ion homeostasis in marine crabs and examined if such loss is related to heart failure. We held crabs (Carcinus maenas) at temperatures just below their critical thermal maximum and measured extracellular (hemolymph) and intracellular (muscle) ion concentrations over time. Analysis of Arrhenius plots for heart rates during heating ramps revealed a breakpoint temperature below which heart rate increased with temperature, and above which heart rate declined until complete cardiac failure. As hypothesised, heat stress reduced the Nernst equilibrium potentials of both K + and Na + , likely causing a depolarization of the membrane potential. To examine whether this loss of ion balance was likely to cause disruption of neuromuscular function, we exposed crabs to the same temperatures, but this time measured ion concentrations at the individual-specific times of complete paralysis (from which the crabs never recovered), and at the time of cardiac failure. Loss of ion balance was observed only after both paralysis and complete heart failure had occurred; indicating that the loss of neuromuscular function is not caused by a loss of ion homeostasis. Instead we suggest that the observed loss of ion balance may be linked to tissue damage related to heat death. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rising from failure and learning from success: The role of past experience in radical initiative taking

NARCIS (Netherlands)

D. Deichmann (Dirk); J.C.M. van den Ende (Jan)

2014-01-01

markdownabstract__Abstract__ We investigate how the successes and failures of people who initiate radical ideas influence (a) the inclination to take new personal initiatives and (b) the outcome of those initiatives. Using the data of 1,792 radical ideas suggested by 908 employees in a

Stress in telephone helpline nurses is associated with failures of concentration, attention and memory, and with more conservative referral decisions.

Science.gov (United States)

Allan, Julia L; Farquharson, Barbara; Johnston, Derek W; Jones, Martyn C; Choudhary, Carolyn J; Johnston, Marie

2014-05-01

Nurses working for telephone-based medical helplines must maintain attentional focus while quickly and accurately processing information given by callers to make safe and appropriate treatment decisions. In this study, both higher levels of general occupational stress and elevated stress levels on particular shifts were associated with more frequent failures of attention, memory, and concentration in telephone nurses. Exposure to a stressful shift was also associated with a measurable increase in objectively assessed information-processing errors. Nurses who experienced more frequent cognitive failures at work made more conservative decisions, tending to refer patients on to other health professionals more often than other nurses. As stress is associated with cognitive performance decrements in telephone nursing, stress-reduction interventions could improve the quality and safety of care that callers to medical helplines receive. © 2013 The British Psychological Society.

A Comparison of Success and Failure Rates between Computer-Assisted and Traditional College Algebra Sections

Science.gov (United States)

Herron, Sherry; Gandy, Rex; Ye, Ningjun; Syed, Nasser

2012-01-01

A unique aspect of the implementation of a computer algebra system (CAS) at a comprehensive university in the U.S. allowed us to compare the student success and failure rates to the traditional method of teaching college algebra. Due to space limitations, the university offered sections of both CAS and traditional simultaneously and, upon…

Leaking Containers: Success and Failure in Controlling the Mosquito Aedes aegypti in Brazil.

Science.gov (United States)

Löwy, Ilana

2017-04-01

In 1958, the Pan American Health Organization declared that Brazil had successfully eradicated the mosquito Aedes aegypti, responsible for the transmission of yellow fever, dengue fever, chikungunya, and Zika virus. Yet in 2016 the Brazilian minister of health described the situation of dengue fever as "catastrophic." Discussing the recent epidemic of Zika virus, which amplified the crisis produced by the persistence of dengue fever, Brazil's president declared in January 2016 that "we are in the process of losing the war against the mosquito Aedes aegypti." I discuss the reasons for the failure to contain Aedes in Brazil and the consequences of this failure. A longue durée perspective favors a view of the Zika epidemic that does not present it as a health crisis to be contained with a technical solution alone but as a pathology that has the persistence of deeply entrenched structural problems and vulnerabilities.

A Novel Risk Score in Predicting Failure or Success for Antegrade Approach to Percutaneous Coronary Intervention of Chronic Total Occlusion: Antegrade CTO Score.

Science.gov (United States)

Namazi, Mohammad Hasan; Serati, Ali Reza; Vakili, Hosein; Safi, Morteza; Parsa, Saeed Ali Pour; Saadat, Habibollah; Taherkhani, Maryam; Emami, Sepideh; Pedari, Shamseddin; Vatanparast, Masoomeh; Movahed, Mohammad Reza

2017-06-01

Total occlusion of a coronary artery for more than 3 months is defined as chronic total occlusion (CTO). The goal of this study was to develop a risk score in predicting failure or success during attempted percutaneous coronary intervention (PCI) of CTO lesions using antegrade approach. This study was based on retrospective analyses of clinical and angiographic characteristics of CTO lesions that were assessed between February 2012 and February 2014. Success rate was defined as passing through occlusion with successful stent deployment using an antegrade approach. A total of 188 patients were studied. Mean ± SD age was 59 ± 9 years. Failure rate was 33%. In a stepwise multivariate regression analysis, bridging collaterals (OR = 6.7, CI = 1.97-23.17, score = 2), absence of stump (OR = 5.8, CI = 1.95-17.9, score = 2), presence of calcification (OR = 3.21, CI = 1.46-7.07, score = 1), presence of bending (OR = 2.8, CI = 1.28-6.10, score = 1), presence of near side branch (OR = 2.7, CI = 1.08-6.57, score = 1), and absence of retrograde filling (OR = 2.5, CI = 1.03-6.17, score = 1) were independent predictors of PCI failure. A score of 7 or more was associated with 100% failure rate whereas a score of 2 or less was associated with over 80% success rate. Most factors associated with failure of CTO-PCI are related to lesion characteristics. A new risk score (range 0-8) is developed to predict CTO-PCI success or failure rate during antegrade approach as a guide before attempting PCI of CTO lesions.

Successful pregnancy after rituximab in a women with recurrent in vitro fertilisation failures and anti-phospholipid antibody positive.

LENUS (Irish Health Repository)

Ng, C T

2012-02-01

We report a case of successful pregnancy after rituximab in a patient with a history of in vitro fertilisation (IVF) failures and positive anti-cardiolipin antibody (ACA). Following a course of rituximab, her ACA became negative and she successfully conceived with IVF treatment. This is the first case in literature describing the use of rituximab therapy in this clinical scenario.

Rising from failure and learning from success: the role of past experience in radical initiative taking

NARCIS (Netherlands)

Deichmann, D.; van den Ende, J..

2014-01-01

We investigate how the successes and failures of people who initiate radical ideas influence (a) the inclination to take new personal initiatives and (b) the outcome of those initiatives. Using the data of 1,792 radical ideas suggested by 908 employees in a multinational firm's idea and innovation

Academic success or failure in nursing students: results of a retrospective observational study.

Science.gov (United States)

Lancia, Loreto; Petrucci, Cristina; Giorgi, Fabio; Dante, Angelo; Cifone, Maria Grazia

2013-12-01

Nursing student academic failure is a phenomenon of growing international interest, not only because of its economic impact but also because it negatively affects the availability of future nurses in different healthcare systems. To recruit the students with the highest probability of academic success, an open challenge for universities is to recruit students who have previously demonstrated superior scholastic aptitudes that appear to be associated with a greater likelihood of academic success. Documenting the relationship between the selection methods used when selecting nursing students and academic failure will contribute to the international debate concerning the optimisation of the selection strategies. The principal aim of this study was to investigate the role in predicting nursing student academic success of (1) the upper-secondary diploma grades and (2) the score obtained by students in the nursing degree program admission test. A retrospective observational study was conducted. Five cohorts of nursing students, matriculated in consecutive academic years from 2004 to 2008, in an Italian bachelor's degree program were observed retrospectively. Overall, 61.2% of the 1006 considered students concluded their degree within the legal duration allowed for the nursing degree. Students who failed were those who had lowest grades associated with their upper-secondary diploma coursework (p=0.000) and were male (p=0.000). The grades associated with the upper-secondary diploma coursework, unlike the admission test score, correlates positively with the final degree grade and the average value of degree program examination scores. No correlation was found between the upper-secondary diploma coursework grades and the scores obtained in the test for the nursing degree program admission test (r=-0.037). These results suggest that upper-secondary diploma coursework grades are a parameter that should receive great consideration, especially in cases where there are planned

A Large-scale Finite Element Model on Micromechanical Damage and Failure of Carbon Fiber/Epoxy Composites Including Thermal Residual Stress

Science.gov (United States)

Liu, P. F.; Li, X. K.

2018-06-01

The purpose of this paper is to study micromechanical progressive failure properties of carbon fiber/epoxy composites with thermal residual stress by finite element analysis (FEA). Composite microstructures with hexagonal fiber distribution are used for the representative volume element (RVE), where an initial fiber breakage is assumed. Fiber breakage with random fiber strength is predicted using Monte Carlo simulation, progressive matrix damage is predicted by proposing a continuum damage mechanics model and interface failure is simulated using Xu and Needleman's cohesive model. Temperature dependent thermal expansion coefficients for epoxy matrix are used. FEA by developing numerical codes using ANSYS finite element software is divided into two steps: 1. Thermal residual stresses due to mismatch between fiber and matrix are calculated; 2. Longitudinal tensile load is further exerted on the RVE to perform progressive failure analysis of carbon fiber/epoxy composites. Numerical convergence is solved by introducing the viscous damping effect properly. The extended Mori-Tanaka method that considers interface debonding is used to get homogenized mechanical responses of composites. Three main results by FEA are obtained: 1. the real-time matrix cracking, fiber breakage and interface debonding with increasing tensile strain is simulated. 2. the stress concentration coefficients on neighbouring fibers near the initial broken fiber and the axial fiber stress distribution along the broken fiber are predicted, compared with the results using the global and local load-sharing models based on the shear-lag theory. 3. the tensile strength of composite by FEA is compared with those by the shear-lag theory and experiments. Finally, the tensile stress-strain curve of composites by FEA is applied to the progressive failure analysis of composite pressure vessel.

Magnet failure workshop

Energy Technology Data Exchange (ETDEWEB)

Marston, P G [Massachusetts Institute of Technology, Cambridge (U.S.A.); Desportes, H [C.E.N.-Saclay, 91 - Gif-sur-Yvette (France); Morpurgo, M [C.E.R.N., Geneva (Switzerland); Komarek, P [Kernforschungszentrum, Karlsruhe (Germany, FR); Van Hulst, K [University of Nijmegen (The Netherlands); Hackley, D [General Dynamics Convair, San Diego, CA (U.S.A.); Young, J L [Westinghouse Electric Corporation, East Pittsburgh, PE (U.S.A.); Kibbe, K [Oak Ridge National Laboratory (U.S.A.)

1984-01-01

The dictionary defines failure as nonperformance or an unacceptable want of success. (The definition implies that the results should have been avoided). In an emerging technology such as ours, the boundaries of expectations and ''unacceptable success'' are often ill defined. Failures are often touted as hugh successes (occasionally rightfully so) and exceptional technological achievement can become dismal failure (if expectations are too high). We all, however, have experienced problems of one sort or another and the basic purpose of the workshop was simply to communicate these so that new or future workers don't make the same mistakes.

Magnet failure workshop

International Nuclear Information System (INIS)

Marston, P.G.; Desportes, H.; Morpurgo, M.; Komarek, P.; Van Hulst, K.; Hackley, D.; Young, J.L.; Kibbe, K.

1984-01-01

The dictionary defines failure as nonperformance or an unacceptable want of success. (The definition implies that the results should have been avoided). In an emerging technology such as ours, the boundaries of expectations and ''unacceptable success'' are often ill defined. Failures are often touted as hugh successes (occasionally rightfully so) and exceptional technological achievement can become dismal failure (if expectations are too high). We all, however, have experienced problems of one sort or another and the basic purpose of the workshop was simply to communicate these so that new or future workers don't make the same mistakes

A review of macroscopic ductile failure criteria.

Energy Technology Data Exchange (ETDEWEB)

Corona, Edmundo; Reedlunn, Benjamin

2013-09-01

The objective of this work was to describe several of the ductile failure criteria com- monly used to solve practical problems. The following failure models were considered: equivalent plastic strain, equivalent plastic strain in tension, maximum shear, Mohr- Coulomb, Wellman's tearing parameter, Johnson-Cook and BCJ MEM. The document presents the main characteristics of each failure model as well as sample failure predic- tions for simple proportional loading stress histories in three dimensions and in plane stress. Plasticity calculations prior to failure were conducted with a simple, linear hardening, J2 plasticity model. The resulting failure envelopes were plotted in prin- cipal stress space and plastic strain space, where the dependence on stress triaxiality and Lode angle are clearly visible. This information may help analysts select a ductile fracture model for a practical problem and help interpret analysis results.

Failure mechanism of coated biomaterials under high impact-sliding contact stresses

Science.gov (United States)

Chen, Ying

This study uses a newly developed testing method--- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose was accomplished in the three stages: First, impact-sliding test was carried out on TiN coated unhardened M2. It was found that soft substrate can cause early failure of coating due to the considerable plastic deformation in the substrate. In this case, stronger substrate is required to support coating better when tested under high contact stresses. Second, PEO coated Ti-6Al-4V was tested under pure sliding and impact-sliding wear conditions. PEO coating was found not strong enough to afford the high contact pressure under cyclic impact-sliding wear test due to its porous surface structure. However, the wear performance of PEO coating was enhanced due to the sub-stoichiometric oxide. To sum up, for load-bearing biomedical implants involved in high impacting movement, PEO coating may not be a promising surface protection. Third, the dense, smooth PVD/CVD bio-inert coatings were reconsidered. DLC and TiN coatings, combined by different substrates together with different interface materials were tested under the cyclic impact-sliding test using a set of proper loading. The results show that to choose a proper combination of coating, interface and substrate based on their mechanical properties is of great importance under the test condition. Hard substrates provide support

Theory-based psychosocial factors that discriminate between weight-loss success and failure over 6 months in women with morbid obesity receiving behavioral treatments.

Science.gov (United States)

Annesi, James J; Johnson, Ping H

2015-06-01

To improve success rates of behavioral weight-loss treatments, a better understanding of psychosocial factors that discriminate between weight-loss success and failure is required. The inclusion of cognitive-behavioral methods and manageable amounts of exercise might induce greater improvements than traditional methods of education in healthy eating practices. Women with morbid obesity [body mass index (BMI) ≥40 kg/m(2)] were recruited for a treatment of supported exercise paired with either a cognitive-behavioral or an educational approach to eating change over 6 months. They were classified as either successful with (i.e., at least 5 % loss; n = 40) or failed at (no loss, or weight gain; n = 43) weight loss. Discriminate function analysis incorporated theory-based models of 1 (self-efficacy), 5 (self-efficacy, self-regulation, mood, physical self-concept, body satisfaction), and 3 (self-efficacy, self-regulation, mood) psychosocial predictors at both month 6, and change from baseline-month 6. All three models significantly discriminated weight-loss success/failure (66, 88, and 87 % for success; and 81, 87, and 88 % for failure, respectively). Self-regulation had the strongest correlations within the multi-predictor models (0.90-0.96), and all variables entered were above the standard of 0.30 set for relevance. Participants in the cognitive-behavioral nutrition group demonstrated significantly greater improvements in all psychosocial variables and success with weight loss. Completing at least two sessions of exercise per week predicted success/failure with weight loss better than overall volume of exercise. New and relevant findings regarding treatment-induced psychosocial changes might be useful in the architecture of more successful behavioral weight-loss interventions.

Complex interplay between health and successful aging: Role of perceived stress, resilience, and social support

OpenAIRE

Moore, Raeanne C.; Eyler, Lisa T.; Mausbach, Brent T.; Zlatar, Zvinka Z.; Thompson, Wesley K.; Peavy, Guerry; Fazeli, Pariya L.; Jeste, Dilip V.

2014-01-01

Psychological and psychosocial resources, including resilience and social support, have traditionally been studied in the context of the stress paradigm and, more recently, in the context of successful aging. This study used moderated mediation analyses to examine the role of perceived stress in the relationships between physical and mental health functioning and self-rated successful aging (SRSA), and whether differences between people in level of resilience and social support changes the ro...

Theoretical Approach Regarding the Bases of Success and Reasons that May Lead to Failure in Project Management

OpenAIRE

Larisa Loredana Dragolea; Denisa Cotîrlea Denisa

2012-01-01

The present paper work deals with theoretical concepts regarding the reasons that may lead to a project’s failure or success. The primary aim of the work paper is to help readers to get a view of conceptualizations of project management and its phases, while providing an opportunity to see the interferences of factors that may determine project’s success. This work paper also contains some aspects regarding key-factors and elements that may assure a good management of projects. The present su...

A Failure Criterion for Concrete

DEFF Research Database (Denmark)

Ottosen, N. S.

1977-01-01

A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace in the devi......A four-parameter failure criterion containing all the three stress invariants explicitly is proposed for short-time loading of concrete. It corresponds to a smooth convex failure surface with curved meridians, which open in the negative direction of the hydrostatic axis, and the trace...

Failure Waves in Shock-Compressed Glasses

International Nuclear Information System (INIS)

Kanel, G. I.

2006-01-01

The failure wave is a network of cracks that are nucleated on the surface and propagate into the elastically stressed body. It is a mode of catastrophic fracture in an elastically stressed media whose relevance is not limited to impact events. In the paper, main properties of the failure waves are summarized and discussed. It has been shown that the failure wave is really a wave process which is characterized by small increase of the longitudinal stress and corresponding increments of the particle velocity and the density. The propagation velocity of the failure wave is less than the sound speed; it is not directly related to the compressibility but is determined by the crack growth speed. The failure wave is steady if the stress state ahead of it is supported unchanging. In some sense the process is similar to a subsonic combustion wave. Computer simulations based on the phenomenological combustion-like model reproduces well all kinematical aspects of the phenomenon

Fast Success and Slow Failure

DEFF Research Database (Denmark)

Mors, Louise; Waguespack, David

Full Abstract: Do the benefits of cross boundary collaborations outweigh the costs? We seek to answer this question by examining 5079 collaborations in the Internet Engineering Task Force (IETF). Our findings suggest that crossing formal boundaries is positively related to success and efficiency ...... of success, suggesting that firms are better off investing in nondiverse projects. This finding has important implications for how we think about the benefits of seeking novelty....

A Retrospective Study of Success, Failure, and Time Needed to Perform Awake Intubation.

Science.gov (United States)

Joseph, Thomas T; Gal, Jonathan S; DeMaria, Samuel; Lin, Hung-Mo; Levine, Adam I; Hyman, Jaime B

2016-07-01

Awake intubation is the standard of care for management of the anticipated difficult airway. The performance of awake intubation may be perceived as complex and time-consuming, potentially leading clinicians to avoid this technique of airway management. This retrospective review of awake intubations at a large academic medical center was performed to determine the average time taken to perform awake intubation, its effects on hemodynamics, and the incidence and characteristics of complications and failure. Anesthetic records from 2007 to 2014 were queried for the performance of an awake intubation. Of the 1,085 awake intubations included for analysis, 1,055 involved the use of a flexible bronchoscope. Each awake intubation case was propensity matched with two controls (1:2 ratio), with similar comorbidities and intubations performed after the induction of anesthesia (n = 2,170). The time from entry into the operating room until intubation was compared between groups. The anesthetic records of all patients undergoing awake intubation were also reviewed for failure and complications. The median time to intubation for patients intubated post induction was 16.0 min (interquartile range: 13 to 22) from entrance into the operating room. The median time to intubation for awake patients was 24.0 min (interquartile range: 19 to 31). The complication rate was 1.6% (17 of 1,085 cases). The most frequent complications observed were mucous plug, endotracheal tube cuff leak, and inadvertent extubation. The failure rate for attempted awake intubation was 1% (n = 10). Awake intubations have a high rate of success and low rate of serious complications and failure. Awake intubations can be performed safely and rapidly.

He's Skilled, She's Lucky: A Meta-analysis of Observers' Attributions for Women's and Men's Successes and Failures.

Science.gov (United States)

Swim, Janet K.; Sanna, Lawrence J.

1996-01-01

This meta-analysis builds on past qualitative reviews examining different attributions that observers give for other women's and men's successes and failures. Results suggest the greatest support for the argument that differences in expectations for women's and men's performances on masculine tasks influence the selection of stable or unstable…

A theoretical derivation of the Hoek–Brown failure criterion for rock materials

Directory of Open Access Journals (Sweden)

Jianping Zuo

2015-08-01

Full Text Available This study uses a three-dimensional crack model to theoretically derive the Hoek–Brown rock failure criterion based on the linear elastic fracture theory. Specifically, we argue that a failure characteristic factor needs to exceed a critical value when macro-failure occurs. This factor is a product of the micro-failure orientation angle (characterizing the density and orientation of damaged micro-cracks and the changing rate of the angle with respect to the major principal stress (characterizing the microscopic stability of damaged cracks. We further demonstrate that the factor mathematically leads to the empirical Hoek–Brown rock failure criterion. Thus, the proposed factor is able to successfully relate the evolution of microscopic damaged crack characteristics to macro-failure. Based on this theoretical development, we also propose a quantitative relationship between the brittle–ductile transition point and confining pressure, which is consistent with experimental observations.

A MIXED METHODS ANALYSIS OF THE EFFECT OF GOOGLE DOCS ENVIRONMENT ON EFL LEARNERS’ WRITING PERFORMANCE AND CAUSAL ATTRIBUTIONS FOR SUCCESS AND FAILURE

Directory of Open Access Journals (Sweden)

Zari Sadat SEYYEDREZAIE

2016-07-01

Full Text Available This study investigated the effect of writing process in Google Docs environment on Iranian EFL learners’ writing performance. It also examined students’ perceptions towards the effects of Google Docs and their perceived causes of success or failure in writing performance. In this regard, 48 EFL students were chosen based on their IELTs writing test scores. During the treatment, the students were taught how to write a formal five-paragraph essay in the class, but they were supposed to practice writing process and give feedback to their peers’ essays through Google Docs. At the end of the treatment phase, the participants received another sample of IELTs writing test (posttest. Moreover, 20 participants were interviewed for their perceptions regarding the causes for their success and failure and the influence of Google Docs on their writing performance. The analysis of a Paired-Sample t-test revealed that Google Docs played an effective role in improving students’ writing performance. In addition, the analysis of interview revealed that the students perceived both internal and external causes for their success and failure; but in case of failure, internal factors were cited more often than external ones. Also, it was revealed that students generally showed positive attitude towards the implication of Google Docs as a factor leading to success in their writing performance.

Influence of stress triaxiality and strain rate on the failure behavior of a dual-phase DP780 steel

International Nuclear Information System (INIS)

Anderson, D.; Winkler, S.; Bardelcik, A.; Worswick, M.J.

2014-01-01

Highlights: • DP780 steel sheet sensitive to strain rate and triaxiality. • Specimens failed due to ductile-shear mode. • Extent of transverse cracking due to martensitic islands increased with triaxiality. • Uniaxial stress decreased with strain rate then increased after 0.1 s −1 . • Predicted effective plastic strain, triaxiality at failure increased with strain rate. - Abstract: To better understand the in-service mechanical behavior of advanced high-strength steels, the influence of stress triaxiality and strain rate on the failure behavior of a dual-phase (DP) 780 steel sheet was investigated. Three flat, notched mini-tensile geometries with varying notch severities and initial stress triaxialities of 0.36, 0.45, and 0.74 were considered in the experiments. Miniature specimens were adopted to facilitate high strain rate testing in addition to quasi-static experiments. Tensile tests were conducted at strain rates of 0.001, 0.01, 0.1, 1, 10, and 100 s −1 for all three notched geometries and compared to mini-tensile uniaxial samples. Additional tests at a strain rate of 1500 s −1 were performed using a tensile split Hopkinson bar apparatus. The results showed that the stress–strain response of the DP780 steel exhibited mainly positive strain rate sensitivity for all geometries, with mild negative strain rate sensitivity up to 0.1 s −1 for the uniaxial specimens. The strain at failure was observed to decrease with strain rate at low strain rates of 0.001–0.1 s −1 ; however, it increased by 26% for an increase in strain rate from 0.1 to 1500 s −1 for the uniaxial condition. Initial triaxiality was found to have a significant negative impact on true failure strain with a decrease of 32% at the highest triaxiality compared to the uniaxial condition at a strain rate of 0.001 s −1 . High resolution scanning electron microscopy images of the failure surfaces revealed a dimpled surface while optical micrographs revealed shearing through the

Endoscopic Third Ventriculostomy: Success and Failure.

Science.gov (United States)

Deopujari, Chandrashekhar E; Karmarkar, Vikram S; Shaikh, Salman T

2017-05-01

Endoscopic third ventriculostomy (ETV) has now become an accepted mode of hydrocephalus treatment in children. Varying degrees of success for the procedure have been reported depending on the type and etiology of hydrocephalus, age of the patient and certain technical parameters. Review of these factors for predictability of success, complications and validation of success score is presented.

Evaluation of the onset of failure under mechanical and thermal stresses on luting agent for metal-ceramic and metal crowns by finite element analysis

Directory of Open Access Journals (Sweden)

Hema Agnihotri

2010-01-01

Full Text Available Long-term clinical failures of cemented prosthesis depend, to a large extent, on the integrity of the luting agent. The causative factors that lead to microfracture and, hence, failure of the luting agents are the stresses acting inside the oral cavity. Therefore, the present study was designed to develop an understanding of the relationship between stresses in the tooth and the failure potential of the luting agent. Two-dimensional finite element stress analysis was performed on the mandibular second premolar. The behavior of zinc-phosphate and glass-ionomer were studied under different crowns (metal-ceramic and metal crown and loading conditions (mechanical force of 450 N acting vertically over the occlusal surface, thermal loads of 60° and 0°C. It was observed from the study that failure threshold of the luting agent was influenced both by the elastic modulus of the luting agent and by the type of the crown.

Successful management of diastolic heart failure in a patient with restrictive cardiomyopathy following an anterior communicating artery aneurysm clipping

Directory of Open Access Journals (Sweden)

Rajasekar Arumugam

2017-01-01

Full Text Available Perioperative management of neurosurgical patients with an underlying myocardial dysfunction poses a unique challenge to the neuroanaesthesiologist and the neurointensivist. Sudden catecholamine surge during the aneurysmal subarachnoid haemorrhage (SAH can cause severe cardiac dysfunction such as myocardial ischaemia and cardiomyopathy. SAH in a patient with restrictive cardiomyopathy could be hazardous to the myocardium leading to severe cardiac morbidity. We report the successful management of an acute post-operative diastolic heart failure with a milrinone infusion in a patient with restrictive cardiomyopathy, following anterior communicating artery aneurysm clipping. We have discussed the 'dual beneficial' role of milrinone on the heart and the brain in this clinical setting. In addition, the importance of peri-operative utilisation of transoesophageal echocardiography and transthoracic echocardiography for the successful management of diastolic heart failure is highlighted.

Aerobic exercise training rescues cardiac protein quality control and blunts endoplasmic reticulum stress in heart failure rats.

Science.gov (United States)

Bozi, Luiz H M; Jannig, Paulo R; Rolim, Natale; Voltarelli, Vanessa A; Dourado, Paulo M M; Wisløff, Ulrik; Brum, Patricia C

2016-11-01

Cardiac endoplasmic reticulum (ER) stress through accumulation of misfolded proteins plays a pivotal role in cardiovascular diseases. In an attempt to reestablish ER homoeostasis, the unfolded protein response (UPR) is activated. However, if ER stress persists, sustained UPR activation leads to apoptosis. There is no available therapy for ER stress relief. Considering that aerobic exercise training (AET) attenuates oxidative stress, mitochondrial dysfunction and calcium imbalance, it may be a potential strategy to reestablish cardiac ER homoeostasis. We test the hypothesis that AET would attenuate impaired cardiac ER stress after myocardial infarction (MI). Wistar rats underwent to either MI or sham surgeries. Four weeks later, rats underwent to 8 weeks of moderate-intensity AET. Myocardial infarction rats displayed cardiac dysfunction and lung oedema, suggesting heart failure. Cardiac dysfunction in MI rats was paralleled by increased protein levels of UPR markers (GRP78, DERLIN-1 and CHOP), accumulation of misfolded and polyubiquitinated proteins, and reduced chymotrypsin-like proteasome activity. These results suggest an impaired cardiac protein quality control. Aerobic exercise training improved exercise capacity and cardiac function of MI animals. Interestingly, AET blunted MI-induced ER stress by reducing protein levels of UPR markers, and accumulation of both misfolded and polyubiquinated proteins, which was associated with restored proteasome activity. Taken together, our study provide evidence for AET attenuation of ER stress through the reestablishment of cardiac protein quality control, which contributes to better cardiac function in post-MI heart failure rats. These results reinforce the importance of AET as primary non-pharmacological therapy to cardiovascular disease. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Determining of factors influencing the success and failure of hospital information system and their evaluation methods: a systematic review.

Science.gov (United States)

Sadoughi, Farahnaz; Kimiafar, Khalil; Ahmadi, Maryam; Shakeri, Mohammad Taghi

2013-12-01

Nowadays, using new information technology (IT) has provided remarkable opportunities to decrease medical errors, support health care specialist, increase the efficiency and even the quality of patient's care and safety. The purpose of this study was the identification of Hospital Information System (HIS) success and failure factors and the evaluation methods of these factors. This research emphasizes the need to a comprehensive evaluation of HISs which considers a wide range of success and failure factors in these systems. We searched for relevant English language studies based on keywords in title and abstract, using PubMed, Ovid Medline (by applying MeSH terms), Scopus, ScienceDirect and Embase (earliest entry to march 17, 2012). Studies which considered success models and success or failure factors, or studied the evaluation models of HISs and the related ones were chosen. Since the studies used in this systematic review were heterogeneous, the combination of extracted data was carried out by using narrative synthesis method. We found 16 articles which required detailed analysis. Finally, the suggested framework includes 12 main factors (functional, organizational, behavioral, cultural, management, technical, strategy, economy, education, legal, ethical and political factors), 67 sub factors, and 33 suggested methods for the evaluation of these sub factors. The results of the present research indicates that the emphasis of the HIS evaluation moves from technical subjects to human and organizational subjects, and from objective to subjective issues. Therefore, this issue entails more familiarity with more qualitative evaluation methods. In most of the reviewed studies, the main focus has been laid on the necessity of using multi-method approaches and combining methods to obtain more comprehensive and useful results.

Hemiepiphysiodesis Implants for Late-onset Tibia Vara: A Comparison of Cost, Surgical Success, and Implant Failure.

Science.gov (United States)

Funk, Shawn S; Mignemi, Megan E; Schoenecker, Jonathan G; Lovejoy, Steven A; Mencio, Gregory A; Martus, Jeffrey E

2016-01-01

The purpose of this study was to compare hemiepiphysiodesis implants for late-onset tibia vara and to evaluate patient characteristics that may predict surgical failure. This is a retrospective review of late-onset tibia vara patients treated with temporary hemiepiphysiodesis from 1998 to 2012. Mechanical axis deviation (MAD), mechanical axis angle, mechanical lateral distal femoral angle, and medial proximal tibial angle were measured on standing bone length radiographs. Surgical failure was defined as residual deformity requiring osteotomy, revision surgery, or MAD exceeding 40 mm at the time of final follow-up. Implant failure was recorded. Costs included implants and disposables required for construct placement. Staple constructs included 2 or 3 staples. Plate constructs included the plate, screws, guide wires, and drill bits. A total of 25 patients with 38 temporary lateral proximal tibia hemiepiphysiodeses met the inclusion criteria. The average body mass index (BMI) was 39.1 kg/m with an average follow-up of 3.0 years (minimum 1 y). Surgical failure occurred in 57.9% of patients. Greater BMI (P=0.05) and more severe deformity (MAD, mechanical axis angle, and medial proximal tibial angle; Pfailure. Younger age predicted higher rates of implant failure (Pfailure between staple and plate systems. Hospital costs of plate constructs ($781 to $1244) were 1.5 to 3.5 times greater than the staple constructs ($332 to $498). Greater BMI, more severe deformity, and younger age were predictive of surgical or implant failure. There was no difference in success between implant types, whereas the cost of plate constructs was 1.5 to 3.5 times greater than staples. The rate of surgical failure was high (58%) and consideration should be given to reserving hemiepiphysiodesis for patients with lower BMI and less severe deformity. In our population, if hemiepiphysiodesis was not offered to patients with BMI>35 or MAD>80 mm varus, the surgical failure rate would diminish to 28

Factors Related to the Academic Success and Failure of College Football Players: The Case of the Mental Dropout.

Science.gov (United States)

Lang, Gale; And Others

1988-01-01

Examines variables used to predict the academic success or failure of college football players. Valid predictors include the following: (1) high school grades; (2) repeating a year in school; (3) feelings towards school; (4) discipline history; (5) mother's education; and (6) high school background. (FMW)

Repeated implantation failure versus repeated implantation success: discrimination at a metabolomic level.

Science.gov (United States)

RoyChoudhury, Sourav; Singh, Apoorva; Gupta, Nalini J; Srivastava, Sudha; Joshi, Mamata V; Chakravarty, Baidyanath; Chaudhury, Koel

2016-06-01

Is there any difference at the serum metabolic level between women with recurrent implantation failure (RIF) and women with recurrent implantation success (RIS) when undergoing in vitro fertilization (IVF)? Eight metabolites, including valine, adipic acid, l-lysine, creatine, ornithine, glycerol, d-glucose and urea, were found to be significantly up-regulated in women with RIF when compared with women with RIS. Despite transfer of three high-grade embryos per cycle, RIF following three or more consecutive IVF attempts occurs in a group of infertile women. Conversely, there is a group of women who undergo successful implantation each cycle, yet have a poor obstetric history. This study was conducted over a period of 10 years (January 2004-October 2014). Groups of 28 women with RIF (age ≤40 years and BMI ≤28) and 24 women with RIS (age and BMI matched) were selected from couples with primary infertility reporting at the Institute of Reproductive Medicine, Kolkata, India. Women recruited in the RIF group had history of implantation failure in at least three consecutive IVF attempts, in which three embryos of high-grade quality were transferred in each cycle. Blood samples were collected from both the groups during the implantation window following overnight fasting for at least 10 h (7-10 days post ovulation). Samples were analyzed using a 700 MHz NMR spectrometer and acquired spectra were subjected to chemometric and statistical analysis. Serum levels of endothelial nitric oxide synthase (eNOS) were measured using an enzyme immunoassay technique. Valine, adipic acid, l-lysine, creatine, ornithine, glycerol, d-glucose and urea were found to be significantly down-regulated in women with RIS when compared with those with RIF, with fold change values of 0.81, 0.82, 0.79, 0.80, 0.78, 0.68, 0.76 and 0.74, respectively. Further, serum eNOS was found to be significantly lower in women with RIF when compared with RIS (P failure. One of the authors, S.R.C. acknowledges the

Effective stresses and shear failure pressure from in situ Biot's coefficient, Hejre Field, North Sea

DEFF Research Database (Denmark)

Regel, Jeppe Bendix; Orozova-Bekkevold, Ivanka; Andreassen, Katrine Alling

2017-01-01

, is significantly different from 1. The log-derived Biot's coefficient is above 0.8 in the Shetland Chalk Group and in the Tyne Group, and 0.6-0.8 in the Heno Sandstone Formation. We show that the effective vertical and horizontal stresses obtained using the log-derived Biot's coefficient result in a drilling......We propose a combination of Biot's equations for effective stress and the expression for shear failure in a rock to obtain an expression for minimum pore pressure in a stable vertical well bore. We show that a Biot's coefficient calculated from logging data in the Hejre Field, North Sea...

Mitochondrial dysfunction in alveolar and white matter developmental failure in premature infants.

Science.gov (United States)

Ten, Vadim S

2017-02-01

At birth, some organs in premature infants are not developed enough to meet challenges of the extra-uterine life. Although growth and maturation continues after premature birth, postnatal organ development may become sluggish or even arrested, leading to organ dysfunction. There is no clear mechanistic concept of this postnatal organ developmental failure in premature neonates. This review introduces a concept-forming hypothesis: Mitochondrial bioenergetic dysfunction is a fundamental mechanism of organs maturation failure in premature infants. Data collected in support of this hypothesis are relevant to two major diseases of prematurity: white matter injury and broncho-pulmonary dysplasia. In these diseases, totally different clinical manifestations are defined by the same biological process, developmental failure of the main functional units-alveoli in the lungs and axonal myelination in the brain. Although molecular pathways regulating alveolar and white matter maturation differ, proper bioenergetic support of growth and maturation remains critical biological requirement for any actively developing organ. Literature analysis suggests that successful postnatal pulmonary and white matter development highly depends on mitochondrial function which can be inhibited by sublethal postnatal stress. In premature infants, sublethal stress results mostly in organ maturation failure without excessive cellular demise.

Stress-reducing preventive maintenance model for a unit under stressful environment

International Nuclear Information System (INIS)

Park, J.H.; Chang, Woojin; Lie, C.H.

2012-01-01

We develop a preventive maintenance (PM) model for a unit operated under stressful environment. The PM model in this paper consists of a failure rate model and two cost models to determine the optimal PM scheduling which minimizes a cost rate. The assumption for the proposed model is that stressful environment accelerates the failure of the unit and periodic maintenances reduce stress from outside. The failure rate model handles the maintenance effect of PM using improvement and stress factors. The cost models are categorized into two failure recognition cases: immediate failure recognition and periodic failure detection. The optimal PM scheduling is obtained by considering the trade-off between the related cost and the lifetime of a unit in our model setting. The practical usage of our proposed model is tested through a numerical example.

Creating E-Commerce Start-Ups with Information Systems Students: Lessons Learned from New Venture Successes and Failures

Science.gov (United States)

Abrahams, Alan

2010-01-01

In this paper, we review a variety of e-commerce startups created by senior information systems students, under the author's guidance, over a number of years at multiple universities. We compare the characteristics of the start-ups and comment on various factors which appear to have contributed to their success or failure. Our recommendations are…

Tracheostomy decannulation at the Royal Hospital for Sick Children in Glasgow: Predictors of success and failure.

Science.gov (United States)

Beaton, Fiona; Baird, Tracy-Anne; Clement, W Andrew; Kubba, Haytham

2016-11-01

Tracheostomy techniques, indications and care are extensively covered in the literature. However, little is written about the process of removing the tracheostomy tube. At the Royal Hospital for Sick Children in Glasgow we use a stepwise ward-based protocol for safe tracheostomy decannulation. Our aim therefore was to review all the paediatric tracheostomy decannulations that we attempted over the last 3 years to evaluate our protocol, to determine our success rate and to see whether any modifications to the protocol are required. We reviewed all patients who had undergone ward decannulation between January 2012 and May 2015. We extracted data from clinical records including patient characteristics, indications for tracheostomy, timing of decannulation and success or failure of the process. The 45 children in the study underwent 57 attempts at decannulation during the study period. 25 were male (56%) and 20 were female (44%), and they were aged between 1 day and 16 years 6 months at the time of the original tracheostomy operation. 33 attempts were successful (58%). 10 children had more than one attempt at decannulation. Children were found to fail at every stage of the protocol, with the commonest point of failure being day 2 when the tracheostomy tube was capped. We have demonstrated that our current protocol for ward decannulation is effective and safe, and that all five days of the protocol are required. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Failure of MPC overpack and inner container under corrosion and mechanical stresses in a backfilled drift

International Nuclear Information System (INIS)

Ladkany, S.G.; Rajagopalan, R.

1995-01-01

The thickness and time at failure of the 100mm thick overpack and the 9.5mm thick inner container of a Multi-purpose canister have been assessed due to loads resulting from temperature, overburden, backfill pressure and seismic loads. Critical stresses at various reduced thicknesses, resulting from pitting corrosion over the years of emplacement, have been evaluated using Finite element analysis. Both simple and continuous support conditions of the overpack have been considered in the analysis. The anticipated failure time due to corrosion of overpack and inner container is further reduced due to overburden, self and seismic loads

The evaluation of failure stress and released amount of fission product gas of power ramped rod by fuel behaviour analysis code 'FEMAXI-III'

International Nuclear Information System (INIS)

Yanagisawa, Kazuaki; Fujita, Misao

1984-01-01

Pellet-Cladding Interaction(PCI) related in-pile failure of Zircaloy sheathed fuel rod is in general considered to be caused by combination of pellet-cladding mechanical interaction(PCMI) with fuel-cladding chemical interaction(FCCI). An understanding of a basic mechanism of PCI-related fuel failure is therefore necessary to get actual cladding hoop stress from mechanical interaction and released amounts of fission product(FP) gas of aggressive environmental agency from chemical interaction. This paper describes results of code analysis performed on fuel failure to cladding hoop stress and amounts of FP gas released under the condition associated with power ramping. Data from Halden(HBWR) and from Studsvik(R2) are used for code analysis. The fuel behaviour analysis code ''FEMAXI-III'' is used as an analytical tool. The followings are revealed from the study: (1) PCI-related fuel failure is dependent upon cladding hoop stress and released amounts of FP gas at power ramping. (2) Preliminary calculated threshold values of hoop stress and of released amounts of FP gas to PCI failure are respectively 330MPa, 10% under the Halden condition, 190MPa, 5% under the Inter ramp(BWR) condition, and 270MPa, 14% under the Over ramp(PWR) condition. The values of hoop stress calculated are almost in the similar range of those obtained from ex-reactor PCI simulated tests searched from references published. (3) The FEMAXI-III code verification is made in mechanical manner by using in-pile deformation data(diametral strain) obtained from power ramping test undertaken by JAERI. While, the code verification is made in thermal manner by using punctured FP gas data obtained from post irradiation examination performed on non-defected power ramped fuel rods. The calculations are resulted in good agreements to both, mechanical and thermal experimental data suggesting the validity of the code evaluation. (J.P.N.)

Update on Simulating Ice-Cliff Failure

Science.gov (United States)

Parizek, B. R.; Christianson, K. A.; Alley, R. B.; Voytenko, D.; Vankova, I.; Dixon, T. H.; Walker, R. T.; Holland, D.

2017-12-01

Using a 2D full-Stokes diagnostic ice-flow model and engineering and glaciological failure criteria, we simulate the limiting physical conditions for rapid structural failure of subaerial ice cliffs. Previously, using a higher-order flowline model, we reported that the threshold height, in crevassed ice and/or under favorable conditions for hydrofracture or crack lubrication, may be only slightly above the 100-m maximum observed today and that under well-drained or low-melt conditions, mechanically-competent ice supports cliff heights up to 220 m (with a likely range of 180-275 m) before ultimately succumbing to tensional and compressive failure along a listric surface. However, proximal to calving fronts, bridging effects lead to variations in vertical normal stress from the background glaciostatic stress state that give rise to the along-flow gradients in vertical shear stress that are included within a full-Stokes momentum balance. When including all flowline stresses within the physics core, diagnostic solutions continue to support our earlier findings that slumping failure ultimately limits the upper bound for cliff heights. Shear failure still requires low cohesive strength, tensile failure leads to deeper dry-crevasse propagation (albeit, less than halfway through the cliff), and compressive failure drops the threshold height for triggering rapid ice-front retreat via slumping to 200 m (145-280 m).

Ductile shear failure or plug failure of spot welds modelled by modified Gurson model

DEFF Research Database (Denmark)

Nielsen, Kim Lau; Tvergaard, Viggo

2010-01-01

For resistance spot welded shear-lab specimens, interfacial failure under ductile shearing or ductile plug failure are analyzed numerically, using a shear modified Gurson model. The interfacial shear failure occurs under very low stress triaxiality, where the original Gurson model would predict...

A study of fuel failure behavior in high burnup HTGR fuel. Analysis by STRESS3 and STAPLE codes

International Nuclear Information System (INIS)

Martin, David G.; Sawa, Kazuhiro; Ueta, Shouhei; Sumita, Junya

2001-05-01

In current high temperature gas-cooled reactors (HTGRs), Tri-isotropic coated fuel particles are employed as fuel. In safety design of the HTGR fuels, it is important to retain fission products within particles so that their release to primary coolant does not exceed an acceptable level. From this point of view, the basic design criteria for the fuel are to minimize the failure fraction of as-fabricated fuel coating layers and to prevent significant additional fuel failures during operation. This report attempts to model fuel behavior in irradiation tests using the U.K. codes STRESS3 and STAPLE. Test results in 91F-1A and HRB-22 capsules irradiation tests, which were carried out at the Japan Materials Testing Reactor of JAERI and at the High Flux Isotope Reactor of Oak Ridge National Laboratory, respectively, were employed in the calculation. The maximum burnup and fast neutron fluence were about 10%FIMA and 3 x 10 25 m -2 , respectively. The fuel for the irradiation tests was called high burnup fuel, whose target burnup and fast neutron fluence were higher than those of the first-loading fuel of the High Temperature Engineering Test Reactor. The calculation results demonstrated that if only mean fracture stress values of PyC and SiC are used in the calculation it is not possible to predict any particle failures, by which is meant when all three load bearing layers have failed. By contrast, when statistical variations in the fracture stresses and particle specifications are taken into account, as is done in the STAPLE code, failures can be predicted. In the HRB-22 irradiation test, it was concluded that the first two particles which had failed were defective in some way, but that the third and fourth failures can be accounted for by the pressure vessel model. In the 91F-1A irradiation test, the result showed that 1 or 2 particles had failed towards the end of irradiation in the upper capsule and no particles failed in the lower capsule. (author)

Mesenchymal Stromal Cells Cultured in Serum from Heart Failure Patients Are More Resistant to Simulated Chronic and Acute Stress

Directory of Open Access Journals (Sweden)

Timo Z. Nazari-Shafti

2018-01-01

Full Text Available Despite regulatory issues surrounding the use of animal-derived cell culture supplements, most clinical cardiac cell therapy trials using mesenchymal stromal cells (MSCs still rely on fetal bovine serum (FBS for cell expansion before transplantation. We sought to investigate the effect of human serum from heart failure patients (HFS on cord blood MSCs (CB-MSCs during short-term culture under regular conditions and during simulated acute and chronic stress. Cell survival, proliferation, metabolic activity, and apoptosis were quantified, and gene expression profiles of selected apoptosis and cell cycle regulators were determined. Compared to FBS, HFS and serum from healthy donors (CS showed similar effects by substantially increasing cell survival during chronic and acute stress and by increasing cell yields 5 days after acute stress. Shortly after the termination of acute stress, both HFS and CS resulted in a marked decrease in apoptotic cells. Transcriptome analysis suggested a decrease in TNF-mediated induction of caspases and decreased activation of mitochondrial apoptosis. Our data confirm that human serum from both healthy donors and heart failure patients results in increased cell yields and increased resistance to cellular stress signals. Therefore, we consider autologous serum a valid alternative to FBS in cell-based therapies addressing severe heart disease.

Effectiveness and Factors Determining the Success of Management Programs for Patients With Heart Failure: A Systematic Review and Meta-analysis.

Science.gov (United States)

Oyanguren, Juana; Latorre García, Pedro María; Torcal Laguna, Jesús; Lekuona Goya, Iñaki; Rubio Martín, Susana; Maull Lafuente, Elena; Grandes, Gonzalo

2016-10-01

Heart failure management programs reduce hospitalizations. Some studies also show reduced mortality. The determinants of program success are unknown. The aim of the present study was to update our understanding of the reductions in mortality and readmissions produced by these programs, elucidate their components, and identify the factors determining program success. Systematic literature review (1990-2014; PubMed, EMBASE, CINAHL, Cochrane Library) and manual search of relevant journals. The studies were selected by 3 independent reviewers. Methodological quality was evaluated in a blinded manner by an external researcher (Jadad scale). These results were pooled using random effects models. Heterogeneity was evaluated with the I 2 statistic, and its explanatory factors were determined using metaregression analysis. Of the 3914 studies identified, 66 randomized controlled clinical trials were selected (18 countries, 13 535 patients). We determined the relative risks to be 0.88 for death (95% confidence interval [95%CI], 0.81-0.96; P < .002; I 2 , 6.1%), 0.92 for all-cause readmissions (95%CI, 0.86-0.98; P < .011; I 2 , 58.7%), and 0.80 for heart failure readmissions (95%CI, 0.71-0.90; P < .0001; I 2 , 52.7%). Factors associated with program success were implementation after 2001, program location outside the United States, greater baseline use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, a higher number of intervention team members and components, specialized heart failure cardiologists and nurses, protocol-driven education and its assessment, self-monitoring of signs and symptoms, detection of deterioration, flexible diuretic regimen, early care-seeking among patients and prompt health care response, psychosocial intervention, professional coordination, and program duration. We confirm the reductions in mortality and readmissions with heart failure management programs. Their success is associated with various structural and

The impact of the time interval on in-vitro fertilisation success after failure of the first attempt.

Science.gov (United States)

Bayoglu Tekin, Y; Ceyhan, S T; Kilic, S; Korkmaz, C

2015-05-01

The aim of this study was to identify the optimal time interval for in-vitro fertilisation that would increase treatment success after failure of the first attempt. This retrospective study evaluated 454 consecutive cycles of 227 infertile women who had two consecutive attempts within a 6-month period at an IVF centre. Data were collected on duration of stimulation, consumption of gonadotropin, numbers of retrieved oocytes, mature oocytes, fertilised eggs, good quality embryos on day 3/5 following oocyte retrieval and clinical and ongoing pregnancy. There were significant increases in clinical pregnancy rates at 2-, 3- and 4-month intervals. The maximum increase was after two menstrual cycles (p = 0.001). The highest rate of ongoing pregnancy was in women that had the second attempt after the next menstrual cycle following failure of IVF (27.2%). After IVF failure, initiating the next attempt within 2-4 months increases the clinical pregnancy rates.

Good alarm design plays a vital role in successful DCS implementation: Hard learned lessons from petrochemical applications

International Nuclear Information System (INIS)

Wilson, C.; Rothenberg, D.

2006-01-01

Nuclear operators are eager to update their automation infrastructure, but are apprehensive due to the consequences of failure. The process industries have learned that alarm design is critical to a successful Distributed Control System (DCS) implementation. This paper shares valuable insight into how alarms play a key role in successful management of upsets, help focus operator attention, and supply critical information during periods of high stress. (authors)

Oxidative Stress in Dog with Heart Failure: The Role of Dietary Fatty Acids and Antioxidants

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Emmanuelle Sagols

2011-01-01

Full Text Available In dogs with heart failure, cell oxygenation and cellular metabolism do not work properly, leading to the production of a large amount of free radicals. In the organism, these free radicals are responsible of major cellular damages: this is oxidative stress. However, a suitable food intake plays an important role in limiting this phenomenon: on the one hand, the presence of essential fatty acids in the composition of membranes decreases sensitivity of cells to free radicals and constitutes a first protection against the oxidative stress; on the other hand, coenzyme Q10, vitamin E, and polyphenols are antioxidant molecules which can help cells to neutralize these free radicals.

Visualising Three Dimensional Damage and Failure Envelopes: Implications for True Triaxial Deformation

Science.gov (United States)

Harland, S. R.; Browning, J.; Healy, D.; Meredith, P. G.; Mitchell, T. M.

2017-12-01

Ultimate failure in brittle rocks is commonly accepted to occur as a coalescence of micro-crack damage into a single failure plane. The geometry and evolution with stress of the cracks (damage) within the medium will play a role in dictating the geometry of the ultimate failure plane. Currently, the majority of experimental studies investigating damage evolution and rock failure use conventional triaxial stress states (σ1 > σ2 = σ3). Results from these tests can easily be represented on a Mohr-Coulomb plot (σn - τ), conveniently allowing the user to determine the geometry of the resultant failure plane. In reality however, stress in the subsurface is generally truly triaxial (σ1 > σ2 > σ3) and in this case, the Mohr-Coulomb failure criterion is inadequate as it incorporates no dependence on the intermediate stress (σ2), which has been shown to play an important role in controlling failure. It has recently been shown that differential stress is the key driver in initiating crack growth, regardless of the mean stress. Polyaxial failure criteria that incorporate the effect of the intermediate stress do exist and include the Modified Lade, Modified Wiebols and Cook, and the Drucker-Prager criteria. However, unlike the Mohr-Coulomb failure criterion, these polyaxial criteria do not offer any prediction of, or insight into, the geometry of the resultant failure plane. An additional downfall of all of the common conventional and polyaxial failure criteria is that they fail to describe the geometry of the damage (i.e. pre-failure microcracking) envelope with progressive stress; it is commonly assumed that the damage envelope is parallel to the ultimate brittle failure envelope. Here we use previously published polyaxial failure data for the Shirahama sandstone and Westerley granite to illustrate that the commonly used Mohr-Coulomb and polyaxial failure criteria do not sufficiently describe or capture failure or damage envelopes under true triaxial stress states

Biomarkers of myocardial stress and fibrosis as predictors of mode of death in patients with chronic heart failure.

Science.gov (United States)

Ahmad, Tariq; Fiuzat, Mona; Neely, Benjamin; Neely, Megan L; Pencina, Michael J; Kraus, William E; Zannad, Faiez; Whellan, David J; Donahue, Mark P; Piña, Ileana L; Adams, Kirkwood F; Kitzman, Dalane W; O'Connor, Christopher M; Felker, G Michael

2014-06-01

The aim of this study was to determine whether biomarkers of myocardial stress and fibrosis improve prediction of the mode of death in patients with chronic heart failure. The 2 most common modes of death in patients with chronic heart failure are pump failure and sudden cardiac death. Prediction of the mode of death may facilitate treatment decisions. The relationship between amino-terminal pro-brain natriuretic peptide (NT-proBNP), galectin-3, and ST2, biomarkers that reflect different pathogenic pathways in heart failure (myocardial stress and fibrosis), and mode of death is unknown. HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) was a randomized controlled trial of exercise training versus usual care in patients with chronic heart failure due to left ventricular systolic dysfunction (left ventricular ejection fraction ≤35%). An independent clinical events committee prospectively adjudicated mode of death. NT-proBNP, galectin-3, and ST2 levels were assessed at baseline in 813 subjects. Associations between biomarkers and mode of death were assessed using cause-specific Cox proportional hazards modeling, and interaction testing was used to measure differential associations between biomarkers and pump failure versus sudden cardiac death. Discrimination and risk reclassification metrics were used to assess the added value of galectin-3 and ST2 in predicting mode of death risk beyond a clinical model that included NT-proBNP. After a median follow-up period of 2.5 years, there were 155 deaths: 49 from pump failure, 42 from sudden cardiac death, and 64 from other causes. Elevations in all biomarkers were associated with increased risk for both pump failure and sudden cardiac death in both adjusted and unadjusted analyses. In each case, increases in the biomarker had a stronger association with pump failure than sudden cardiac death, but this relationship was attenuated after adjustment for clinical risk factors. Clinical

Technical Problem Identification for the Failures of the Liberty Ships

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Wei Zhang

2016-11-01

Full Text Available The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in half. This paper demonstrates and investigation of the Liberty Ships failure and problems, which reveals that the failures are caused by a combination of three factors. The welds produced by largely unskilled work force contain crack type flaws. Beyond these cracks, another important reason for failure associated with welding is the hydrogen embitterment; most of the fractures initiate at deck square hatch corners where there is a stress concentration; and the ship steel has fairly poor Charpy-Impact tested fracture toughness. It has been admitted that, although the numerous catastrophic failures were a painful experience, the failures of the Liberty Ships caused significant progress in the study of fracture mechanics. Considering their effect, the Liberty Ships are still a success.

'Luck, chance, and happenstance? Perceptions of success and failure amongst fixed-term academic staff in UK higher education'.

Science.gov (United States)

Loveday, Vik

2017-09-07

What does it mean to attribute success to 'luck', but failure to personal deficiency? In 2015/16, more than 34 per cent of academic employees in UK higher education institutions were employed on temporary contracts, and the sector itself has undergone a substantial transformation in recent years in terms of expansion, measurement, and marketization. Based on two waves of interviews conducted with fixed-term academic employees at different career stages, the article explores the narrativization of success and failure amongst staff working at the 'sharp end' of the so-called neoliberal academy. Arguing that precarious employment situations precipitate the feeling of being 'out of control', the majority of the participants' narratives were characterized by a distinct lack of agency. The paper explores the recourse to notions of chance and the consolidation of 'luck' as an explanatory factor in accounting for why good things happen; however, in tandem with this inclination is the tendency to individualize failure when expectations have been thwarted. While accounts of fixed-term work are suffused with notions of chance and fortune, 'luck' remains an under-researched concept within sociology. The article thus concludes by considering what the analysis of 'luck' might offer for a fuller, politicized understanding of processes at work in the contemporary academy. © London School of Economics and Political Science 2017.

True Triaxial Strength and Failure Modes of Cubic Rock Specimens with Unloading the Minor Principal Stress

Science.gov (United States)

Li, Xibing; Du, Kun; Li, Diyuan

2015-11-01

True triaxial tests have been carried out on granite, sandstone and cement mortar using cubic specimens with the process of unloading the minor principal stress. The strengths and failure modes of the three rock materials are studied in the processes of unloading σ 3 and loading σ 1 by the newly developed true triaxial test system under different σ 2, aiming to study the mechanical responses of the rock in underground excavation at depth. It shows that the rock strength increases with the raising of the intermediate principal stress σ 2 when σ 3 is unloaded to zero. The true triaxial strength criterion by the power-law relationship can be used to fit the testing data. The "best-fitting" material parameters A and n ( A > 1.4 and n plastic deformation. The maximum extension strain criterion Stacey (Int J Rock Mech Min Sci Geomech Abstr 651 18(6):469-474, 1981) can be used to explain the change of failure mode from shear to slabbing for strong and hard rocks under true triaxial unloading test condition.

The importance of scaling for detecting community patterns: success and failure in assemblages of introduced species

Science.gov (United States)

Allen, Craig R.; Angeler, David G.; Moulton, Michael P.; Holling, Crawford S.

2015-01-01

Community saturation can help to explain why biological invasions fail. However, previous research has documented inconsistent relationships between failed invasions (i.e., an invasive species colonizes but goes extinct) and the number of species present in the invaded community. We use data from bird communities of the Hawaiian island of Oahu, which supports a community of 38 successfully established introduced birds and where 37 species were introduced but went extinct (failed invasions). We develop a modified approach to evaluate the effects of community saturation on invasion failure. Our method accounts (1) for the number of species present (NSP) when the species goes extinct rather than during its introduction; and (2) scaling patterns in bird body mass distributions that accounts for the hierarchical organization of ecosystems and the fact that interaction strength amongst species varies with scale. We found that when using NSP at the time of extinction, NSP was higher for failed introductions as compared to successful introductions, supporting the idea that increasing species richness and putative community saturation mediate invasion resistance. Accounting for scale-specific patterns in body size distributions further improved the relationship between NSP and introduction failure. Results show that a better understanding of invasion outcomes can be obtained when scale-specific community structure is accounted for in the analysis.

Deconstructing national leadership: politicians' accounts of electoral success and failure in the Irish Lisbon Treaty referenda.

Science.gov (United States)

Burns, Michele; Stevenson, Clifford

2013-03-01

The Self Categorization approach to national leadership proposes that leaders rhetorically construct national identity as essentialized and inevitable in order to consensualize and mobilize the population. In contrast, discursive studies have demonstrated how national politicians flexibly construct the nation to manage their own accountability in local interactions, though this in turn has neglected broader leadership processes. The present paper brings both approaches together to examine how and when national politicians construct versions of national identity in order to account for their failure as well as success in mobilizing the electorate. Eight semi-structured conversational style interviews were conducted with a strategic sample of eight leading Irish politicians on the subject of the 2008/2009 Irish Lisbon Treaty referenda. Using a Critical Discourse Psychology approach, the hegemonic repertoire of the 'settled will' of the informed and consensualized Irish nation was identified across all interviews. Politicians either endorsed the 'settled will' repertoire as evidence of their successful leadership, or rejected the repertoire by denying the rationality or unity of the populace to account for their failure. Our results suggest national identity is only constructed as essentialized and inevitable to the extent that it serves a strategic political purpose. © 2011 The British Psychological Society.

Determination of Stress Profiles in Expanded Austenite by Combining Successive Layer Removal and GI-XRD

DEFF Research Database (Denmark)

Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin; Somers, Marcel A. J.

2014-01-01

The present work deals with the evaluation of the residual-stress profile in expanded-austenite by successive removal steps using GI-XRD. Preliminary results indicate stresses of several GPa's from 111 and 200 diffraction lines. These stresses appear largest for the 200 reflection. The strain......-free lattice parameter decayed smoothly with depth, while for the compressive stress a maximum value is observed at some depth below the surface. Additionally a good agreement was found between the nitrogen profile determined with GDOES analysis and the strain-free lattice parameter from XRD....

Changing the story the role of the narrative in the success or failure of terrorist groups

OpenAIRE

Mellen, Brian C.

2009-01-01

Approved for public release, distribution unlimited This thesis focuses on the nexus between a terrorist group's narrative and the group's success or failure in achieving its strategic goals. This work theorizes that the interaction of competing narratives exerts a systematic impact on the ability of the terrorist group to achieve its strategic goals through the influence that the narratives have over a group's members, the group's adversary, and the affected population. Although a te...

First-Ply-Failure Performance of Composite Clamped Spherical Shells

Science.gov (United States)

Ghosh, A.; Chakravorty, D.

2018-05-01

The failure aspects of composites are available for plates, but studies of the literature on shells unveils that similar reports on them are very limited in number. The aim of this work was to investigate the first-ply-failure of industrially and aesthetically important spherical shells under uniform loadings. Apart from solving benchmark problems, numerical experiments were carried out with different variations of their parameters to obtain the first-ply-failure stresses by using the finite-element method. The load was increased in steps, and the lamina strains and stresses were put into well-established failure criteria to evaluate their first-ply-failure stress, the failed ply, the point of initiation of failure, and failure modes and tendencies. The results obtained are analyzed to extract the points of engineering significance.

Successful treatment of severe sinusoidal obstruction syndrome despite multiple organ failure with defibrotide after allogeneic stem cell transplantation: a case report.

Science.gov (United States)

Behre, Gerhard; Theurich, Sebastian; Christopeit, Maximilian; Weber, Thomas

2009-03-10

We report a case of sinusoidal obstruction syndrome, a typical and life-threatening complication after allogeneic stem-cell transplantation, successfully treated with defibrotide despite massive multiple organ failure. A 64-year-old Caucasian woman underwent allogeneic peripheral blood stem-cell transplantation from her human leukocyte antigen-identical sister against aggressive lymphoplasmocytoid immunocytoma. Seven days later, the patient developed severe sinusoidal obstruction syndrome according to the modified Seattle criteria. We initiated treatment with defibrotide. Despite early treatment, multiple organ failure with kidney failure requiring dialysis and ventilator-dependent lung failure aggravated the clinical course. Furthermore, central nervous dysfunction occurred as well as transfusion refractory thrombocytopenia. As highlighted in our report, defibrotide is the most promising drug in the treatment of the formerly, almost lethal, severe sinusoidal obstruction syndrome to date. This is demonstrated very clearly in our patient. She improved completely, even after renal, cerebral and respiratory failure.

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

International Nuclear Information System (INIS)

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

1979-01-01

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

Success rate and risk factors of failure of the induced membrane technique in children: a systematic review.

Science.gov (United States)

Aurégan, Jean-Charles; Bégué, Thierry; Rigoulot, Guillaume; Glorion, Christophe; Pannier, Stéphanie

2016-12-01

The induced membrane technique was designed by Masquelet et al. to address segmental bone defects of critical size in adults. It has been used after bone defects of traumatic, infectious and tumoral origin with satisfactory results. Recently, it has been used in children but, after an initial enthusiasm, several cases of failure have been reported. The purpose of this study was to assess the success rate and the risk factors of failure of the induced membrane for children. We conducted a systematic review of all the studies reporting the results of the induced membrane technique to address bone defects of critical size in children. Our primary outcome was the success rate of the technique defined as a bone union before any iterative surgery. Our secondary outcomes were the complications and the risk factors of failure. We searched Medline via Pubmed, EMBASE and the Cochrane Library. Twelve studies, including 69 patients, met the inclusion criteria. There were 41 boys and 28 girls. Mean age at surgery was 10 years. Mean size of resection was 12.38 cm and the mean time between the two stages was 5.86 months. Mean rate of bone union after the two stages of the induced membrane technique was 58% (40/69) but this rate increased to 87% after revision surgeries (60/69). Main complications were non-unions (19/69), lysis of the graft (6/69) and fractures of the bone graft (6/69). Only 1/69 deep infection was reported. Other non specific complications were regularly reported such limb length discrepancies, joint stiffness and protruding wires. Risk factor of failure that could be suspected comprised the resection of a malignant tumour, a bone defect located at the femur, a wide resection, a long time between the two stages, an unstable osteosynthesis and a bone graft associating autograft to other graft materials. The induced membrane technique is suitable for bone defects of critical size in children. It is a reliable technique with no need of micro vascular surgery

Main factors for fatigue failure probability of pipes subjected to fluid thermal fluctuation

International Nuclear Information System (INIS)

Machida, Hideo; Suzuki, Masaaki; Kasahara, Naoto

2015-01-01

It is very important to grasp failure probability and failure mode appropriately to carry out risk reduction measures of nuclear power plants. To clarify the important factors for failure probability and failure mode of pipes subjected to fluid thermal fluctuation, failure probability analyses were performed by changing the values of a stress range, stress ratio, stress components and threshold of stress intensity factor range. The important factors for the failure probability are range, stress ratio (mean stress condition) and threshold of stress intensity factor range. The important factor for the failure mode is a circumferential angle range of fluid thermal fluctuation. When a large fluid thermal fluctuation acts on the entire circumferential surface of the pipe, the probability of pipe breakage increases, calling for measures to prevent such a failure and reduce the risk to the plant. When the circumferential angle subjected to fluid thermal fluctuation is small, the failure mode of piping is leakage and the corrective maintenance might be applicable from the viewpoint of risk to the plant. (author)

Micromechanical Failure Analyses for Finite Element Polymer Modeling

Energy Technology Data Exchange (ETDEWEB)

CHAMBERS,ROBERT S.; REEDY JR.,EARL DAVID; LO,CHI S.; ADOLF,DOUGLAS B.; GUESS,TOMMY R.

2000-11-01

Polymer stresses around sharp corners and in constrained geometries of encapsulated components can generate cracks leading to system failures. Often, analysts use maximum stresses as a qualitative indicator for evaluating the strength of encapsulated component designs. Although this approach has been useful for making relative comparisons screening prospective design changes, it has not been tied quantitatively to failure. Accurate failure models are needed for analyses to predict whether encapsulated components meet life cycle requirements. With Sandia's recently developed nonlinear viscoelastic polymer models, it has been possible to examine more accurately the local stress-strain distributions in zones of likely failure initiation looking for physically based failure mechanisms and continuum metrics that correlate with the cohesive failure event. This study has identified significant differences between rubbery and glassy failure mechanisms that suggest reasonable alternatives for cohesive failure criteria and metrics. Rubbery failure seems best characterized by the mechanisms of finite extensibility and appears to correlate with maximum strain predictions. Glassy failure, however, seems driven by cavitation and correlates with the maximum hydrostatic tension. Using these metrics, two three-point bending geometries were tested and analyzed under variable loading rates, different temperatures and comparable mesh resolution (i.e., accuracy) to make quantitative failure predictions. The resulting predictions and observations agreed well suggesting the need for additional research. In a separate, additional study, the asymptotically singular stress state found at the tip of a rigid, square inclusion embedded within a thin, linear elastic disk was determined for uniform cooling. The singular stress field is characterized by a single stress intensity factor K{sub a} and the applicable K{sub a} calibration relationship has been determined for both fully bonded and

Fear of Failure, Self-Handicapping, and Negative Emotions in Response to Failure

Science.gov (United States)

Bartels, Jared M.; Herman, William E.

2011-01-01

Research suggests that students who fear failure are likely to utilize cognitive strategies such as self-handicapping that serve to perpetuate failure. Such devastating motivational dispositions clearly limit academic success. The present study examined negative emotional responses to scenarios involving academic failure among a sample of…

Failure mechanism and coupled static-dynamic loading theory in deep hard rock mining: A review

Directory of Open Access Journals (Sweden)

Xibing Li

2017-08-01

Full Text Available Rock failure phenomena, such as rockburst, slabbing (or spalling and zonal disintegration, related to deep underground excavation of hard rocks are frequently reported and pose a great threat to deep mining. Currently, the explanation for these failure phenomena using existing dynamic or static rock mechanics theory is not straightforward. In this study, new theory and testing method for deep underground rock mass under coupled static-dynamic loading are introduced. Two types of coupled loading modes, i.e. “critical static stress + slight disturbance” and “elastic static stress + impact disturbance”, are proposed, and associated test devices are developed. Rockburst phenomena of hard rocks under coupled static-dynamic loading are successfully reproduced in the laboratory, and the rockburst mechanism and related criteria are demonstrated. The results of true triaxial unloading compression tests on granite and red sandstone indicate that the unloading can induce slabbing when the confining pressure exceeds a certain threshold, and the slabbing failure strength is lower than the shear failure strength according to the conventional Mohr-Column criterion. Numerical results indicate that the rock unloading failure response under different in situ stresses and unloading rates can be characterized by an equivalent strain energy density. In addition, we present a new microseismic source location method without premeasuring the sound wave velocity in rock mass, which can efficiently and accurately locate the rock failure in hard rock mines. Also, a new idea for deep hard rock mining using a non-explosive continuous mining method is briefly introduced.

Adherence and Extension of Adlerian Psychological Theory of "Beyond Success and Failure" by Beecher and Beecher.

OpenAIRE

Shibayama, Kenji; シバヤマ, ケンジ; 柴山, 謙二

1999-01-01

Individual-growth or self-help is one of the important tasks which Adlerian psychologist today should develop and cope with. Beecher and Beecher proposed his idea of self -reliance as a central concept. The purpose of this paper is to discuss adherence and extension of Adlerian psychological theory of "Beyond Success and Failure" by Beecher and Beecher from the author's experiences of practice for individual-growth. The author suggested following points: (1) Self-reliance is a very important ...

The effect of water stress on some morphological, physiological, and biochemical characteristics and bud success on apple and quince rootstocks.

Science.gov (United States)

Bolat, Ibrahim; Dikilitas, Murat; Ercisli, Sezai; Ikinci, Ali; Tonkaz, Tahsin

2014-01-01

The effects of different water stress (control, medium, and severe) on some morphological, physiological, and biochemical characteristics and bud success of M9 apple and MA quince rootstocks were determined. The results showed that water stress significantly affected most morphological, physiological, and biochemical characteristics as well as budding success on the both rootstocks. The increasing water stress decreased the relative shoot length, diameter, and plant total fresh and dry weights. Leaf relative water content and chlorophyll index decreased while electrolyte leakage increased with the increase of water stress in both rootstocks. An increase in water stress also resulted in reduction in budding success in Vista Bella/M9 (79.33% and 46.67%) and Santa Maria/MA (70.33% and 15.33%) combinations. However, the water stress in Santa Maria/MA was more prominent. The increase in water stress resulted in higher peroxidase activities as well as phenol contents in both rootstocks. Although catalase activity, anthocyanin, and proline contents increased with the impact of stress, this was not statistically significant. The results suggest that the impact of stress increased with the increase of water stress; therefore, growers should be careful when using M9 and MA rootstocks in both nursery and orchards where water scarcity is present.

The Effect of Water Stress on Some Morphological, Physiological, and Biochemical Characteristics and Bud Success on Apple and Quince Rootstocks

Directory of Open Access Journals (Sweden)

Ibrahim Bolat

2014-01-01

Full Text Available The effects of different water stress (control, medium, and severe on some morphological, physiological, and biochemical characteristics and bud success of M9 apple and MA quince rootstocks were determined. The results showed that water stress significantly affected most morphological, physiological, and biochemical characteristics as well as budding success on the both rootstocks. The increasing water stress decreased the relative shoot length, diameter, and plant total fresh and dry weights. Leaf relative water content and chlorophyll index decreased while electrolyte leakage increased with the increase of water stress in both rootstocks. An increase in water stress also resulted in reduction in budding success in Vista Bella/M9 (79.33% and 46.67% and Santa Maria/MA (70.33% and 15.33% combinations. However, the water stress in Santa Maria/MA was more prominent. The increase in water stress resulted in higher peroxidase activities as well as phenol contents in both rootstocks. Although catalase activity, anthocyanin, and proline contents increased with the impact of stress, this was not statistically significant. The results suggest that the impact of stress increased with the increase of water stress; therefore, growers should be careful when using M9 and MA rootstocks in both nursery and orchards where water scarcity is present.

Theories of TL systems: Failures, successes, conflicts, trends: Insights into possible future materials and techniques

International Nuclear Information System (INIS)

Horowitz, Y. S.; Belaish, Y.; Oster, L.

2006-01-01

In this paper some of the many theoretical models dealing with characteristics of TL materials are discussed. Special attention is given to some of the models dealing with the effects of ionisation density, that is Modified Track Structure Theory (MTST) and Micro-dosimetric Track Structure Theory (MTT) for the calculation of Heavy Charged Particle relative TL efficiencies, as well as solid-state models based on conduction band/valence band theory. Failures, successes, conflicts and trends are highlighted as well as a peek into future avenues of research for dosimetric TL materials. (authors)

Theory for Electromigration Failure in Cu Conductors

International Nuclear Information System (INIS)

Lloyd, J. R.; Murray, C. E.; Shaw, T. M.; Lane, M. W.; Liu, X.-H.; Liniger, E. G.

2006-01-01

A model for electromigration failure is proposed where the criterion for damage is not classical nucleation forming a void, but is a delamination at an interface. In addition, the anisotropy in the elastic constants of Cu metal is responsible for a bimodal failure distribution recognizing that the driving force for mass transport depends on the hydrostatic stress whereas the failure criterion depends on a normal stress. The agreement with published data is reasonably good

Successful treatment of severe sinusoidal obstruction syndrome despite multiple organ failure with defibrotide after allogeneic stem cell transplantation: a case report

Directory of Open Access Journals (Sweden)

Behre Gerhard

2009-03-01

Full Text Available Abstract Introduction We report a case of sinusoidal obstruction syndrome, a typical and life-threatening complication after allogeneic stem-cell transplantation, successfully treated with defibrotide despite massive multiple organ failure. Case presentation A 64-year-old Caucasian woman underwent allogeneic peripheral blood stem-cell transplantation from her human leukocyte antigen-identical sister against aggressive lymphoplasmocytoid immunocytoma. Seven days later, the patient developed severe sinusoidal obstruction syndrome according to the modified Seattle criteria. We initiated treatment with defibrotide. Despite early treatment, multiple organ failure with kidney failure requiring dialysis and ventilator-dependent lung failure aggravated the clinical course. Furthermore, central nervous dysfunction occurred as well as transfusion refractory thrombocytopenia. Conclusion As highlighted in our report, defibrotide is the most promising drug in the treatment of the formerly, almost lethal, severe sinusoidal obstruction syndrome to date. This is demonstrated very clearly in our patient. She improved completely, even after renal, cerebral and respiratory failure.

The hot (invisible?) hand: can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

Science.gov (United States)

Yaari, Gur; Eisenmann, Shmuel

2011-01-01

The long lasting debate initiated by Gilovich, Vallone and Tversky in [Formula: see text] is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons ([Formula: see text]) of the National Basketball Association (NBA). Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data.

Tidally Driven Failure Along Europa's Rhadamanthys Linea

Science.gov (United States)

Cameron, M.; Konter, B.; Pappalardo, R. T.

2013-12-01

The surface of Europa is crosscut by a dense network of fractures and there are many candidate faults for studying past tectonic activity. To better understand the role of tidal stress sources and implications for faulting on Europa, we investigate the relationship between shear and normal stresses at Rhadamanthys Linea, a northwest oriented fracture in the northern hemisphere. Previous work on Agenor Linea, a right-lateral strike-slip fracture in the southern hemisphere, suggests that both tidal diurnal and non-synchronous rotation (NSR) stresses play a critical role in the mechanics of Coulomb shear failure on Europa. At Agenor Linea, shear failure from diurnal tidal stress mechanisms is difficult to achieve because the relatively large over¬burden stress (ie., 1.2 MPa at 1 km depth) dominates the stress field; however, MPa order stresses from NSR permit right-lateral shear failure along the west side of the fault at shallow depths (Astypalea Linea and Conamara Chaos will also be investigated, offering a unique comparison of geologic activity of fractures residing in geographically diverse locations of Europa.

Failure criterion for graphene in biaxial loading—a molecular dynamics study

International Nuclear Information System (INIS)

Yazdani, Hessam; Hatami, Kianoosh

2015-01-01

Molecular dynamics simulations are carried out in order to develop a failure criterion for infinite/bulk graphene in biaxial tension. Stresses along the principal edge configurations of graphene (i.e. armchair and zigzag directions) are normalized to the corresponding uniaxial ultimate strength values. The combinations of normalized stresses resulting in the failure of graphene are used to define failure envelopes (limiting stress ratio surfaces). Results indicate that a bilinear failure envelope can be used to represent the tensile strength of graphene in biaxial loading at different temperatures with reasonable accuracy. A circular failure envelope is also introduced for practical applications. Both failure envelopes define temperature-independent upper limits for the feasible combinations of normalized stresses for a graphene sheet in biaxial loading. Predicted failure modes of graphene under biaxial loading are also shown and discussed. (paper)

Tell me who you are and I tell you how you feel: expected emotional reactions to success and failure are influenced by knowledge about a person's personality.

Science.gov (United States)

Hareli, Shlomo; Sharabi, Moshe; Hess, Ursula

2011-08-01

The present research investigated the influence of knowledge about a person's modesty or arrogance on people's expectations regarding that person's emotional reactions to success and failure. Arrogance and modesty reflect the extent to which someone is likely to publicize their ability. Accordingly, we predicted that observers' expectations regarding a person's tendency to publicize their ability should inform expectations about the person's emotional reactions to success and failure. In two vignette studies, observers predicted the emotional state of a protagonist, as well as the probability that s/he will actually express that emotion and share the experience with others. For success, participants predicted a protagonist's pride, happiness, schadenfreude, and embarrassment if praised for a positive outcome. For failure, participants predicted anger, shame, guilt, sadness, and fear reactions. Across studies, personality information explained more variance than did gender or status. Results showed that the expectations for an arrogant person matched modal expectations for success, whereas for failure the expectations for the modest individual were closest to the modal expectations. Specifically, both modest and arrogant individuals were expected to suppress emotions that do not fit their self-presentational styles rather than to exaggerate expressions that do. This paper adds to our understanding of the information that people use to predict others' emotional reactions.

Failure to achieve immunological recovery in HIV-infected patients with clinical and virological success after 10 years of combined ART: role of treatment course.

Science.gov (United States)

Raffi, François; Le Moing, Vincent; Assuied, Alex; Habak, Sofiane; Spire, Bruno; Cazanave, Charles; Billaud, Eric; Dellamonica, Pierre; Ferry, Tristan; Fagard, Catherine; Leport, Catherine

2017-01-01

We assessed factors, including treatment course, associated with failure to obtain a 10 year immunological response after starting first-generation PI-containing combined ART (cART). In the prospective COPILOTE cohort of HIV-infected patients started on a first-generation PI-containing regimen in 1997-99, the impact of cART history on the failure to achieve immunological response measured at 10 years was assessed by multivariate logistic regression models in the 399 patients with clinical and virological success of cART. Failure of CD4 response (CD4 >500/mm 3 ) was associated with age ≥40 years at baseline (P failure to achieve complete immunological response (CD4 >500/mm 3 and CD4:CD8 ratio >1) were CD4:CD8 ratio ≤0.8 at month 8 (P success. Lack of treatment interruption may improve long-term immunological outcome in HIV infection. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Review of constitutive models and failure criteria for concrete

Energy Technology Data Exchange (ETDEWEB)

Seo, Jeong Moon; Choun, Young Sun [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-03-01

The general behavior, constitutive models, and failure criteria of concrete are reviewed. The current constitutive models for concrete cannot satisfy all of mechanical behavior of concrete. Among several constitutive models, damage models are recommended to describe properly the structural behavior of concrete containment buildings, because failure modes and post-failure behavior are important in containment buildings. A constitutive model which can describe the concrete behavior in tension is required because the containment buildings will reach failure state due to ultimate internal pressure. Therefore, a thorough study on the behavior and models under tension stress state in concrete and reinforced concrete has to be performed. There are two types of failure criteria in containment buildings: structural failure criteria and leakage failure criteria. For reinforced or prestressed concrete containment buildings, concrete cracking does not mean the structural failure of containment building because the reinforcement or post-tensioning system is able to resist tensile stress up to yield stress. Therefore leakage failure criteria will be prior to structural failure criteria, and a strain failure criterion for concrete has to be established. 120 refs., 59 figs., 1 tabs. (Author)

Emotional reactions to success and failure of collective action as predictors of future action intentions: a longitudinal investigation in the context of student protests in Germany.

Science.gov (United States)

Tausch, Nicole; Becker, Julia C

2013-09-01

This research examined how emotional responses to success and failure of collective action relate to willingness to engage in collective action in the future. It was hypothesized that both pride (in relation to a success) and anger (in response to failure) would motivate future collective action. Findings are reported from a two-wave longitudinal study (N= 98) in the context of student protests against tuition fees in Germany, which was conducted before and after collective action had resulted in both a success and a failure. While anger positively predicted action intentions, over and above baseline action intentions, pride exerted a significant indirect effect on action intentions via increased efficacy perceptions, over and above baseline efficacy and action intentions. Politicized identification positively predicted the intensity of both pride and anger and baseline group efficacy positively predicted the intensity of anger. The theoretical and practical implications of these findings are discussed. © 2012 The British Psychological Society.

Complex interplay between health and successful aging: role of perceived stress, resilience, and social support.

Science.gov (United States)

Moore, Raeanne C; Eyler, Lisa T; Mausbach, Brent T; Zlatar, Zvinka Z; Thompson, Wesley K; Peavy, Guerry; Fazeli, Pariya L; Jeste, Dilip V

2015-06-01

Psychological and psychosocial resources, including resilience and social support, have traditionally been studied in the context of the stress paradigm and, more recently, in the context of successful aging. This study used moderated mediation analyses to examine the role of perceived stress in the relationships between physical and mental health functioning and self-rated successful aging (SRSA) and whether differences between people in level of resilience and social support changes the role of perceived stress in these relationships. A cross-sectional study of 1,006 older adults (mean age: 77 years) completed scales addressing SRSA, physical and mental health functioning, perceived stress, resilience, and social support. Results indicated that the strength of relationships between both physical and mental health functioning and SRSA were reduced after accounting for variation in level of perceived stress. The role of perceived stress in the association between mental health functioning and SRSA was found to be stronger among participants with the highest levels of resilience, and the influence of perceived stress on the degree of relationship between physical health functioning and SRSA was stronger among those with greatest social support. These findings suggest that interventions to reduce perceived stress may help break the link between disability and poor well-being in older adults. The findings further suggest that the impact of such interventions might differ depending on psychological resources (i.e., resilience) for mental health disabilities and external resources (i.e., social support) for those with physical health problems. The complex interplay of these factors should be taken into account in clinical settings. Copyright © 2015 American Association for Geriatric Psychiatry. All rights reserved.

[The degree of chronic renal failure is associated with the rate of pro-inflammatory cytokines, hyperhomocysteinemia and with oxidative stress].

Science.gov (United States)

Tbahriti, H F; Messaoudi, A; Kaddous, A; Bouchenak, M; Mekki, K

2014-06-01

To evaluate pro-inflammatory cytokines, homocysteinemia and markers of oxidative status in the course of chronic renal failure. One hundred and two patients (male/female: 38/64; age: 45±07 years) with chronic renal failure were divided into 4 groups according to the National Kidney Foundation classification. They included 28 primary stage renal failure patients, 28 moderate stage renal failure, 28 severe stage renal failure and 18 end stage renal failure. The inflammatory status was evaluated by the determination of pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6) and total homocysteine. Pro-oxidant status was assessed by assaying thiobarbituric acid reactive substances, hydroperoxides, and protein carbonyls. Antioxidant defence was performed by analysis of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase. Inflammatory markers were elevated in the end stage renal failure group compared to the other groups (Prenal failure group in comparison with the other groups (Prenal function is closely associated with the elevation of inflammatory markers leading to both increased markers of oxidative stress and decreased antioxidant defense. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Variations of fracture toughness and stress-strain curve of cold worked stainless steel and their influence on failure strength of cracked pipe

International Nuclear Information System (INIS)

Kamaya, Masayuki

2016-01-01

In order to assess failure probability of cracked components, it is important to know the variations of the material properties and their influence on the failure load assessment. In this study, variations of the fracture toughness and stress-strain curve were investigated for cold worked stainless steel. The variations of the 0.2% proof and ultimate strengths obtained using 8 specimens of 20% cold worked stainless steel (CW20) were 77 MPa and 81 MPa, respectively. The respective variations were decreased to 13 and 21 MPa for 40% cold worked material (CW40). Namely, the variation in the tensile strength was decreased by hardening. The COVs (coefficients of variation) of fracture toughness were 7.3% and 16.7% for CW20 and CW40, respectively. Namely, the variation in the fracture toughness was increased by hardening. Then, in order to investigate the influence of the variations in the material properties on failure load of a cracked pipe, flaw assessments were performed for a cracked pipe subjected to a global bending load. Using the obtained material properties led to variation in the failure load. The variation in the failure load of the cracked pipe caused by the variation in the stress-strain curve was less than 1.5% for the COV. The variation in the failure load caused by fracture toughness variation was relatively large for CW40, although it was less than 2.0% for the maximum case. It was concluded that the hardening induced by cold working does not cause significant variation in the failure load of cracked stainless steel pipe. (author)

Application Of Data Mining Techniques For Student Success And Failure Prediction The Case Of DebreMarkos University

OpenAIRE

Muluken Alemu Yehuala

2015-01-01

Abstract This research work has investigated the potential applicability of data mining technology to predict student success and failure cases on University students datasets. CRISP-DM Cross Industry Standard Process for Data mining is a data mining methodology to be used by the research. Classification and prediction data mining functionalities are used to extract hidden patterns from students data. These patterns can be seen in relation to different variables in the students records. The ...

Negotiating constructions of success and failure: women in mid-life and formations of subject, subjectivity and identity

OpenAIRE

McAvoy, Jean

2009-01-01

This thesis explores constructions of success and failure for women in mid-life in Britain in the early 21st century. It takes a discursive approach to social psychology, understanding language as social action constituting subjects and subjectivity. Data from 20 interviews, including 4 conducted with women in pairs, supported by loosely structured questionnaires and a collection of photographs of women including celebrities and unknown women, were used to generate talk of selves and others. ...

The hot (invisible? hand: can time sequence patterns of success/failure in sports be modeled as repeated random independent trials?

Directory of Open Access Journals (Sweden)

Gur Yaari

Full Text Available The long lasting debate initiated by Gilovich, Vallone and Tversky in [Formula: see text] is revisited: does a "hot hand" phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons ([Formula: see text] of the National Basketball Association (NBA. Evidence supporting the existence of the "hot hand" phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of "success breeds success" and "failure breeds failure" mechanisms or simply "better" and "worse" periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the "hot hand" phenomenon in the data.

Development of component failure data for seismic risk analysis

International Nuclear Information System (INIS)

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

1981-01-01

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

Mechanical characterization and modeling of the deformation and failure of the highly crosslinked RTM6 epoxy resin

Science.gov (United States)

Morelle, X. P.; Chevalier, J.; Bailly, C.; Pardoen, T.; Lani, F.

2017-08-01

The nonlinear deformation and fracture of RTM6 epoxy resin is characterized as a function of strain rate and temperature under various loading conditions involving uniaxial tension, notched tension, uniaxial compression, torsion, and shear. The parameters of the hardening law depend on the strain-rate and temperature. The pressure-dependency and hardening law, as well as four different phenomenological failure criteria, are identified using a subset of the experimental results. Detailed fractography analysis provides insight into the competition between shear yielding and maximum principal stress driven brittle failure. The constitutive model and a stress-triaxiality dependent effective plastic strain based failure criterion are readily introduced in the standard version of Abaqus, without the need for coding user subroutines, and can thus be directly used as an input in multi-scale modeling of fibre-reinforced composite material. The model is successfully validated against data not used for the identification and through the full simulation of the crack propagation process in the V-notched beam shear test.

Environmental stress-corrosion cracking of fiberglass: Lessons learned from failures in the chemical industry

International Nuclear Information System (INIS)

Myers, T.J.; Kytoemaa, H.K.; Smith, T.R.

2007-01-01

Fiberglass reinforced plastic (FRP) composite materials are often used to construct tanks, piping, scrubbers, beams, grating, and other components for use in corrosive environments. While FRP typically offers superior and cost effective corrosion resistance relative to other construction materials, the glass fibers traditionally used to provide the structural strength of the FRP can be susceptible to attack by the corrosive environment. The structural integrity of traditional FRP components in corrosive environments is usually dependent on the integrity of a corrosion-resistant barrier, such as a resin-rich layer containing corrosion resistant glass fibers. Without adequate protection, FRP components can fail under loads well below their design by an environmental stress-corrosion cracking (ESCC) mechanism when simultaneously exposed to mechanical stress and a corrosive chemical environment. Failure of these components can result in significant releases of hazardous substances into plants and the environment. In this paper, we present two case studies where fiberglass components failed due to ESCC at small chemical manufacturing facilities. As is often typical, the small chemical manufacturing facilities relied largely on FRP component suppliers to determine materials appropriate for the specific process environment and to repair damaged in-service components. We discuss the lessons learned from these incidents and precautions companies should take when interfacing with suppliers and other parties during the specification, design, construction, and repair of FRP components in order to prevent similar failures and chemical releases from occurring in the future

Renin-Angiotensin Activation and Oxidative Stress in Early Heart Failure with Preserved Ejection Fraction

Directory of Open Access Journals (Sweden)

Smita I. Negi

2015-01-01

Full Text Available Animal models have suggested a role of renin-angiotensin system (RAS activation and subsequent cardiac oxidation in heart failure with preserved ejection fraction (HFpEF. Nevertheless, RAS blockade has failed to show efficacy in treatment of HFpEF. We evaluated the role of RAS activation and subsequent systemic oxidation in HFpEF. Oxidative stress markers were compared in 50 subjects with and without early HFpEF. Derivatives of reactive oxidative metabolites (DROMs, F2-isoprostanes (IsoPs, and ratios of oxidized to reduced glutathione (Eh GSH and cysteine (Eh CyS were measured. Angiotensin converting enzyme (ACE levels and activity were measured. On univariate analysis, HFpEF was associated with male sex (p=0.04, higher body mass index (BMI (p=0.003, less oxidized Eh CyS (p=0.001, lower DROMs (p=0.02, and lower IsoP (p=0.03. Higher BMI (OR: 1.3; 95% CI: 1.1–1.6 and less oxidized Eh CyS (OR: 1.2; 95% CI: 1.1–1.4 maintained associations with HFpEF on multivariate analysis. Though ACE levels were higher in early HFpEF (OR: 1.09; 95% CI: 1.01–1.05, ACE activity was similar to that in controls. HFpEF is not associated with significant systemic RAS activation or oxidative stress. This may explain the failure of RAS inhibitors to alter outcomes in HFpEF.

Oxidative stress may be involved in distant organ failure in tourniquet shock model mice.

Science.gov (United States)

Nishikata, Rie; Kato, Naho; Hiraiwa, Kouichi

2014-03-01

Crush syndrome is characterized by prolonged shock resulting from extensive muscle damage and multiple organ failure. However, the pathogenesis of multiple organ failure has not yet been completely elucidated. Therefore, we investigated the molecular biological and histopathological aspects of distant organ injury in crush syndrome by using tourniquet shock model mice. DNA microarray analysis of the soleus muscle showed an increase in the mRNA levels of Cox-2, Hsp70, c-fos, and IL-6, at 3h after ischemia/reperfusion injury at the lower extremity. In vivo staining with hematoxylin and eosin (HE) showed edema and degeneration in the soleus muscle, but no change in the distant organs. Immunohistological staining of the HSP70 protein revealed nuclear translocation in the soleus muscle, kidney, liver, and lung. The c-fos mRNA levels were elevated in the soleus muscle, kidney, and liver, displaying nuclear translocation of c-FOS protein. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) analysis suggested the involvement of apoptosis in ischemia/reperfusion injury in the soleus muscle. Apoptotic cells were not found in greater quantities in the kidney. Oxidative stress, as determined using a free radical elective evaluator (d-ROM test), markedly increased after ischemia/reperfusion injury. Therefore, examination of immunohistological changes and determination of oxidative stress are proposed to be useful in evaluating the extent of tourniquet shock, even before changes are observed by HE staining. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Collective intelligence of the artificial life community on its own successes, failures, and future.

Science.gov (United States)

Rasmussen, Steen; Raven, Michael J; Keating, Gordon N; Bedau, Mark A

2003-01-01

We describe a novel Internet-based method for building consensus and clarifying conflicts in large stakeholder groups facing complex issues, and we use the method to survey and map the scientific and organizational perspectives of the artificial life community during the Seventh International Conference on Artificial Life (summer 2000). The issues addressed in this survey included artificial life's main successes, main failures, main open scientific questions, and main strategies for the future, as well as the benefits and pitfalls of creating a professional society for artificial life. By illuminating the artificial life community's collective perspective on these issues, this survey illustrates the value of such methods of harnessing the collective intelligence of large stakeholder groups.

The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: The effect of crack location on the degree of conservatism

International Nuclear Information System (INIS)

Smith, E.

1993-01-01

Interest in the integrity of cracked piping systems fabricated from ductile materials has been motivated, in large part, by the technological problem of intergranular stress corrosion cracking of Type 304 stainless steel piping in boiling water nuclear reactor piping systems. The failure of cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stresses at the cracked section are usually calculated via a purely elastic analysis based on the piping being uncracked. However because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. An earlier paper has quantified the extent of this conservatism, and has shown how it depends on the material ductility and the elastic flexibility of a piping system. Using the results of analyses for simple model systems, the present paper shows that, for the same cracked section geometry, the degree of conservatism is markedly influenced by the location of the cracked section within the system

Failure modes of composite sandwich beams

OpenAIRE

Gdoutos E.; Daniel I.M.

2008-01-01

A thorough investigation of failure behavior of composite sandwich beams under three-and four-point bending was undertaken. The beams were made of unidirectional carbon/epoxy facings and a PVC closed-cell foam core. The constituent materials were fully characterized and in the case of the foam core, failure envelopes were developed for general two-dimensional states of stress. Various failure modes including facing wrinkling, indentation failure and core failure were observed and compared wit...

Successful treatment of two cases of urorectal septum malformation sequence with oligohydramnios and severe respiratory failure

Directory of Open Access Journals (Sweden)

Sekiguchi K

2013-03-01

Full Text Available Kazuhito Sekiguchi, Daijiro Takahashi, Takehiko Hiroma, Tomohiko Nakamura Division of Neonatology, Nagano Children's Hospital, Nagano, Japan Abstract: Urorectal septum malformation sequence can be diagnosed prenatally. We report herein the successful treatment of severe respiratory failure in two patients with urorectal septum malformation sequence and prenatally diagnosed oligohydramnios. The patients showed significant hypoxic deterioration and persistent pulmonary artery hypertension soon after birth. We used high-frequency ventilation (HFO, nitric oxide (NO, and extracorporeal membrane oxygenation (ECMO. The patients were successfully weaned from ECMO and artificial ventilation and discharged to home. Although termination of the pregnancy has often been selected for fetuses with oligohydramnios-related urorectal septum malformation sequence, our results suggest the opportunity for these fetuses to be treated using respiratory supports including HFO, NO, and ECMO after birth. Keywords: urorectal septum malformation sequence, oligohydramnios, pulmonary hypoplasia

A pellet-clad interaction failure criterion

International Nuclear Information System (INIS)

Howl, D.A.; Coucill, D.N.; Marechal, A.J.C.

1983-01-01

A Pellet-Clad Interaction (PCI) failure criterion, enabling the number of fuel rod failures in a reactor core to be determined for a variety of normal and fault conditions, is required for safety analysis. The criterion currently being used for the safety analysis of the Pressurized Water Reactor planned for Sizewell in the UK is defined and justified in this paper. The criterion is based upon a threshold clad stress which diminishes with increasing fast neutron dose. This concept is consistent with the mechanism of clad failure being stress corrosion cracking (SCC); providing excess corrodant is always present, the dominant parameter determining the propagation of SCC defects is stress. In applying the criterion, the SLEUTH-SEER 77 fuel performance computer code is used to calculate the peak clad stress, allowing for concentrations due to pellet hourglassing and the effect of radial cracks in the fuel. The method has been validated by analysis of PCI failures in various in-reactor experiments, particularly in the well-characterised power ramp tests in the Steam Generating Heavy Water Reactor (SGHWR) at Winfrith. It is also in accord with out-of-reactor tests with iodine and irradiated Zircaloy clad, such as those carried out at Kjeller in Norway. (author)

Change in failure stress on the southern san andreas fault system caused by the 1992 magnitude = 7.4 landers earthquake.

Science.gov (United States)

Stein, R S; King, G C; Lin, J

1992-11-20

The 28 June Landers earthquake brought the San Andreas fault significantly closer to failure near San Bernardino, a site that has not sustained a large shock since 1812. Stress also increased on the San Jacinto fault near San Bernardino and on the San Andreas fault southeast of Palm Springs. Unless creep or moderate earthquakes relieve these stress changes, the next great earthquake on the southern San Andreas fault is likely to be advanced by one to two decades. In contrast, stress on the San Andreas north of Los Angeles dropped, potentially delaying the next great earthquake there by 2 to 10 years.

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

A comparative study of failure criteria in probabilistic fields and stochastic failure envelopes of composite materials

International Nuclear Information System (INIS)

Nakayasu, Hidetoshi; Maekawa, Zen'ichiro

1997-01-01

One of the major objectives of this paper is to offer a practical tool for materials design of unidirectional composite laminates under in-plane multiaxial load. Design-oriented failure criteria of composite materials are applied to construct the evaluation model of probabilistic safety based on the extended structural reliability theory. Typical failure criteria such as maximum stress, maximum strain and quadratic polynomial failure criteria are compared from the viewpoint of reliability-oriented materials design of composite materials. The new design diagram which shows the feasible region on in-plane strain space and corresponds to safety index or failure probability is also proposed. These stochastic failure envelope diagrams which are drawn in in-plane strain space enable one to evaluate the stochastic behavior of a composite laminate with any lamination angle under multi-axial stress or strain condition. Numerical analysis for a graphite/epoxy laminate of T300/5208 is shown for the comparative verification of failure criteria under the various combinations of multi-axial load conditions and lamination angles. The stochastic failure envelopes of T300/5208 were also described in in-plane strain space

Language-specific stress perception by 9-month-old French and Spanish infants.

Science.gov (United States)

Skoruppa, Katrin; Pons, Ferran; Christophe, Anne; Bosch, Laura; Dupoux, Emmanuel; Sebastián-Gallés, Núria; Limissuri, Rita Alves; Peperkamp, Sharon

2009-11-01

During the first year of life, infants begin to have difficulties perceiving non-native vowel and consonant contrasts, thus adapting their perception to the phonetic categories of the target language. In this paper, we examine the perception of a non-segmental feature, i.e. stress. Previous research with adults has shown that speakers of French (a language with fixed stress) have great difficulties in perceiving stress contrasts (Dupoux, Pallier, Sebastián & Mehler, 1997), whereas speakers of Spanish (a language with lexically contrastive stress) perceive these contrasts as accurately as segmental contrasts. We show that language-specific differences in the perception of stress likewise arise during the first year of life. Specifically, 9-month-old Spanish infants successfully distinguish between stress-initial and stress-final pseudo-words, while French infants of this age show no sign of discrimination. In a second experiment using multiple tokens of a single pseudo-word, French infants of the same age successfully discriminate between the two stress patterns, showing that they are able to perceive the acoustic correlates of stress. Their failure to discriminate stress patterns in the first experiment thus reflects an inability to process stress at an abstract, phonological level.

Failure analysis on a ruptured petrochemical pipe

Energy Technology Data Exchange (ETDEWEB)

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

2010-08-15

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

Failure of Elevating Calcium Induces Oxidative Stress Tolerance and Imparts Cisplatin Resistance in Ovarian Cancer Cells

OpenAIRE

Ma, Liwei; Wang, Hongjun; Wang, Chunyan; Su, Jing; Xie, Qi; Xu, Lu; Yu, Yang; Liu, Shibing; Li, Songyan; Xu, Ye; Li, Zhixin

2016-01-01

Cisplatin is a commonly used chemotherapeutic drug, used for the treatment of malignant ovarian cancer, but acquired resistance limits its application. There is therefore an overwhelming need to understand the mechanism of cisplatin resistance in ovarian cancer, that is, ovarian cancer cells are insensitive to cisplatin treatment. Here, we show that failure of elevating calcium and oxidative stress tolerance play key roles in cisplatin resistance in ovarian cancer cell lines. Cisplatin induce...

Biaxial Stress Tests of Plain Concrete

Energy Technology Data Exchange (ETDEWEB)

Lee, S.K.; Cho, M.S.; Song, Y.C. [Korea Electric Power Research Institute, Taejon (Korea)

2001-07-01

Containment concrete specimens(4000, 5000psi) were tested under biaxial stress and presented basic physical properties and biaxial failure envelops for the concrete specimens. Failure behaviors of concrete under biaxial stress were assessed with stress-strain responses and failure modes. Here provided real test data to develop nonlinear finite element concrete models. (author). 15 refs., 46 figs., 4 tabs.

The effects of stress exposure on prefrontal cortex: Translating basic research into successful treatments for post-traumatic stress disorder

Directory of Open Access Journals (Sweden)

Amy F.T. Arnsten

2015-01-01

Full Text Available Research on the neurobiology of the stress response in animals has led to successful new treatments for Post-Traumatic Stress Disorder (PTSD in humans. Basic research has found that high levels of catecholamine release during stress rapidly impair the top-down cognitive functions of the prefrontal cortex (PFC, while strengthening the emotional and habitual responses of the amygdala and basal ganglia. Chronic stress exposure leads to dendritic atrophy in PFC, dendritic extension in the amygdala, and strengthening of the noradrenergic (NE system. High levels of NE release during stress engage low affinity alpha-1 adrenoceptors, (and likely beta-1 adrenoceptors, which rapidly reduce the firing of PFC neurons, but strengthen amygdala function. In contrast, moderate levels of NE release during nonstress conditions engage higher affinity alpha-2A receptors, which strengthen PFC, weaken amygdala, and regulate NE cell firing. Thus, either alpha-1 receptor blockade or alpha-2A receptor stimulation can protect PFC function during stress. Patients with PTSD have signs of PFC dysfunction. Clinical studies have found that blocking alpha-1 receptors with prazosin, or stimulating alpha-2A receptors with guanfacine or clonidine can be useful in reducing the symptoms of PTSD. Placebo-controlled trials have shown that prazosin is helpful in veterans, active duty soldiers and civilians with PTSD, including improvement of PFC symptoms such as impaired concentration and impulse control. Open label studies suggest that guanfacine may be especially helpful in treating children and adolescents who have experienced trauma. Thus, understanding the neurobiology of the stress response has begun to help patients with stress disorders.

A STUDY OF THE RELATIONSHIP BETWEEN FEAR OF SUCCESS AND BURNOUT AMONG WORKING WOMEN IN IRANIAN PUBLIC SCHOOLS

Directory of Open Access Journals (Sweden)

Mohammad Hossein Motaghi-Pishe

2008-01-01

Full Text Available Fear of success is derived from lack of trust and confidence in one's own personality. To be in doubt of one's self and to be anxious about other's expectations, exists constantly in the thought and behavior of working women. This, on its own, is a great source of anxiety and sets the foundation of continuous job stress. Burnout is a response to chronic job stress. It is a gradual erosion and feeling of failure, and being worn out. This paper aims to investigate the relationship between fear of success and burnout among working women in Iranian public schools. Moreover, it examines whether fear of success and burnout are related to some demographic characteristics such as age, years of service, marital status, academic background and organizational rank. The results reveal that fear of success and burnout in women working in public schools are correlated; but there are no significant differences in levels of fear of success and/or burnout relative to demographic factors.

Case study of successful weld repair of a storage tank

International Nuclear Information System (INIS)

Sinha, S; Ambrose, S.

2012-01-01

Weld repairs or modifications may be required for existing welded structures or components as a result of service damage or failure, or as a result of wear, corrosion or changed service condition. A case study of a repair to a large oil storage tank which failed in Australia by brittle fracture during modification is described to demonstrate the application of basic principles and good practice needed to produce successful repairs/modifications. Prevention of brittle fracture in welded steel structures requires consideration of the toughness at minimum temperature of the weld, the HAZ and the base material itself, applied and residual stress and 'equivalent crack' size. This case shows the importance of residual stress, repair planning and the care needed with old steels.

How Successful is Non-Invasive Ventilation Treatment that is Initiated in the Emergency Department in Cases of COPD Exacerbations with Acute Hypercapnic Respiratory Failure? Can We Predict Treatment Failure?

Directory of Open Access Journals (Sweden)

Meltem Çoban Ağca

2017-04-01

Full Text Available Objective: We aimed to investigate the success rate of non-invasive ventilation (NIV in wards and the predictors of failure in cases of chronic obstructive pulmonary disease (COPD-related acute hypercapnic respiratory failure (AHRF. Methods: The was a retrospective study conducted in a tertiary teaching hospital between May 2011 and 2013. Patients who were admitted to the emergency department (ED because of COPD with AHRF were evaluated; 544 patients who initially received NIV in ED and were transferred to wards were included. Patient characteristics, baseline and follow-up pH values, and partial arterial carbon dioxide (PaCO2 values were recorded. Baseline pH values were categorized as severe (pH<7.26, moderate (pH≥7.26–7.30, and mild (pH≥7.30 acidosis. According to the in-hospital outcome, patients were classified in 2 groups: Group 1: home discharge, Group 2: death or intensive care unit transfer. Results: Treatment resulted in success in 477 (88% patients. Albumin levels were significantly low and the mean Charlson index (CI score was significantly high in Group 2. Admission pH and PaCO2 values did not affect the treatment outcome. Patients in Group 2 had higher PaCO2 and lower pH values as well as a lower level of decrease in PaCO2 values within 2 hours of treatment in ED. Similarly, higher PaCO2 and lower pH values at the end of the first day in wards were indicative of NIV failure (p<0.05. Conclusion: The success rate of NIV in wards in cases of AHRF is high. Patients with low albumin levels and higher CI scores have worse response to treatment. pH or PaCO2 values after a few hours of treatment and not the baseline pH or PaCO2 values are better predictors than the baseline pH and PaCO2 values.

THE ROLE OF DOMINANT MOTIVATION IN THE SUCCESS (FAILURE OF EDUCATIONAL ACTIVITY AND ITS RELATIONSHIP WITH PERSONAL AND SITUATIONAL ANXIETY

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Larisa Evgenievna Deryagina

2015-12-01

Full Text Available This article describes the structure of dominant motivation educational activity in student groups with good (I gr. and bad achievers (II gr., for example, learning a foreign language. Obtained results have revealed the fundamental differences of motivational profiles in two researched groups: there has been an active, adequate situation, aimed to successful achieving of motivational strategy in I group; and a passive, aimed to avoid failure, conflicting and therefore ineffective strategy in II group. There were analyzed levels of personal and situational anxiety among students with different structures of dominant motivation in a situation of test control and in normal conditions. It was revealed that subjects with leading motivation for success have demonstrated moderate levels of both personal and situational anxiety, which have not changed in testing situation practically. The students with motivation of avoiding failure have had a higher level of personal anxiety, especially. In situation of testing control the levels of personal and situational anxiety have increased significantly, which reduced the productivity of educational activity.

Using the 2011 Mw9.0 Tohoku earthquake to test the Coulomb stress triggering hypothesis and to calculate faults brought closer to failure

Science.gov (United States)

Toda, Shinji; Lin, Jian; Stein, Ross S.

2011-01-01

The 11 March 2011 Tohoku Earthquake provides an unprecedented test of the extent to which Coulomb stress transfer governs the triggering of aftershocks. During 11-31 March, there were 177 aftershocks with focal mechanisms, and so the Coulomb stress change imparted by the rupture can be resolved on the aftershock nodal planes to learn whether they were brought closer to failure. Numerous source models for the mainshock have been inverted from seismic, geodetic, and tsunami observations. Here, we show that, among six tested source models, there is a mean 47% gain in positively-stressed aftershock mechanisms over that for the background (1997-10 March 2011) earthquakes, which serve as the control group. An aftershock fault friction of 0.4 is found to fit the data better than 0.0 or 0.8, and among all the tested models, Wei and Sladen (2011) produced the largest gain, 63%. We also calculate that at least 5 of the seven large, exotic, or remote aftershocks were brought ≥0.3 bars closer to failure. With these tests as confirmation, we calculate that large sections of the Japan trench megathrust, the outer trench slope normal faults, the Kanto fragment beneath Tokyo, and the Itoigawa-Shizuoka Tectonic Line, were also brought ≥0.3 bars closer to failure.

Predictors of the success and failure of emergency pelvic artery embolisation for primary postpartum haemorrhage: a 12-year review.

Science.gov (United States)

Lai, Billy Ming Hei; Shum, John Sing Fai; Chu, Chi Yeung; Lo, Sherwin Shing Wai; Lau, Kam Ying

2017-05-01

This study aimed to identify predictors of the outcome and clinical efficacy of emergency pelvic artery embolisation (PAE) for primary postpartum haemorrhage (PPH) and to assess the post-embolisation fertility of PAE patients in a regional hospital setting. A 12-year retrospective study of patients undergoing emergency PAE was conducted at a regional acute general hospital. Clinical and procedural parameters, clinical outcomes and post-embolisation pregnancy success rates were analysed. There were 47,221 deliveries at the hospital during the study period, of which 33 patients required urgent PAE for primary PPH. The technical success rate of embolisation was 97.0% (n = 32). Clinically adequate haemostasis was achieved by a single embolisation procedure in 24 (72.7%) patients; the remaining eight eventually required surgery to achieve cessation of bleeding. Among the parameters studied, multivariate logistic regression analysis showed that pre-embolisation platelet count (p = 0.036) and maternal age (p = 0.019) were the only significant independent predictors of embolisation failure. Only two patients successfully conceived after PAE, although one of them had an ectopic pregnancy. Emergency PAE is an effective measure to arrest life-threatening bleeding in patients with primary PPH. As low pre-embolisation platelet count and advanced maternal age are associated with higher odds of embolisation failure, careful post-embolisation monitoring may be required for such patients. Embolisation also allows subsequent pregnancy. However, further studies are required to assess the outcomes of post-embolisation pregnancies. Copyright: © Singapore Medical Association

On rate-state and Coulomb failure models

Science.gov (United States)

Gomberg, J.; Beeler, N.; Blanpied, M.

2000-01-01

We examine the predictions of Coulomb failure stress and rate-state frictional models. We study the change in failure time (clock advance) Δt due to stress step perturbations (i.e., coseismic static stress increases) added to "background" stressing at a constant rate (i.e., tectonic loading) at time t0. The predictability of Δt implies a predictable change in seismicity rate r(t)/r0, testable using earthquake catalogs, where r0 is the constant rate resulting from tectonic stressing. Models of r(t)/r0, consistent with general properties of aftershock sequences, must predict an Omori law seismicity decay rate, a sequence duration that is less than a few percent of the mainshock cycle time and a return directly to the background rate. A Coulomb model requires that a fault remains locked during loading, that failure occur instantaneously, and that Δt is independent of t0. These characteristics imply an instantaneous infinite seismicity rate increase of zero duration. Numerical calculations of r(t)/r0 for different state evolution laws show that aftershocks occur on faults extremely close to failure at the mainshock origin time, that these faults must be "Coulomb-like," and that the slip evolution law can be precluded. Real aftershock population characteristics also may constrain rate-state constitutive parameters; a may be lower than laboratory values, the stiffness may be high, and/or normal stress may be lower than lithostatic. We also compare Coulomb and rate-state models theoretically. Rate-state model fault behavior becomes more Coulomb-like as constitutive parameter a decreases relative to parameter b. This is because the slip initially decelerates, representing an initial healing of fault contacts. The deceleration is more pronounced for smaller a, more closely simulating a locked fault. Even when the rate-state Δt has Coulomb characteristics, its magnitude may differ by some constant dependent on b. In this case, a rate-state model behaves like a modified

Definition of Success after Surgery for Female Stress Incontinence or Voiding Dysfunction: An Attempt at Standardization.

Science.gov (United States)

Carmel, Maude E; Deng, Donna Y; Greenwell, Tamsin J; Zimmern, Philippe E

2016-08-01

There is currently no standardized definition of success for surgery for stress urinary incontinence (SUI) and voiding dysfunction (VD) in women. To review the use of outcome measures (OMs) and definitions of success in the literature on SUI and VD surgery in women in an attempt to provide recommendations for future publications. A PubMed search of all English language full-text articles on SUI and VD surgery in women published between 2010 and 2015 was performed. A list of randomized trials and prospective and retrospective studies was obtained. Specific objective and subjective OMs used to define success were reviewed. Some 95 articles met the inclusion criteria for SUI surgery outcomes. Most trials reported outcomes at 12 mo after surgery. The majority (n=48) reported their primary outcomes using both objective and subjective success measures, 24 defined success using subjective OMs alone, and 23 using objective OMs alone. The OMs most frequently used for objective success were a negative cough stress test (CST), a negative pad test, and the absence of retreatment for SUI. The definition of subjective success most often involved questionnaires. The questionnaires most frequently used were Patient Global Impression of Improvement (PGI-I), Urinary Distress Inventory (UDI)/UDI-6, International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF) and Medical Epidemiologic and Social Aspects of Aging (MESA). Only 11 studies on OMs used for VD surgery were published between 2010 and 2015. The two most common criteria used for success were measurement of postvoid residual urine (PVR) and subjective resolution of VD symptoms. There is great heterogeneity in the definition of success used after surgery for SUI or VD in women. For SUI surgery, we recommend use of the CST and a 1-h pad test for the definition of objective success, and of the UDI/UDI-6, Incontinence Impact Questionnaire (IIQ), King's Health Questionnaire (KHQ), ICIQ-SF, or PGI-I questionnaire for

Young children's beliefs about self-disclosure of performance failure and success.

Science.gov (United States)

Hicks, Catherine M; Liu, David; Heyman, Gail D

2015-03-01

Self-disclosure of performance information involves the balancing of instrumental, learning benefits (e.g., obtaining help) against social costs (e.g., diminished reputation). Little is known about young children's beliefs about performance self-disclosure. The present research investigates preschool- and early school-age children's expectations of self-disclosure in different contexts. In two experiments, 3- to 7-year-old children (total N = 252) heard vignettes about characters who succeeded or failed at solving a puzzle. Both experiments showed that children across all ages reasoned that people are more likely to self-disclose positive than negative performances, and Experiment 2 showed that children across all ages reasoned that people are more likely to self-disclose both positive and negative performances in a supportive than an unsupportive peer environment. Additionally, both experiments revealed changes with age - Younger children were less likely to expect people to withhold their performance information (of both failures and successes) than older children. These findings point to the preschool ages as a crucial beginning to children's developing recognition of people's reluctance to share performance information. © 2014 The British Psychological Society.

An overview of the management consulting firms of the Spanish company in China: company profile and success and failure factors

Directory of Open Access Journals (Sweden)

A. Niñerola

2016-03-01

Full Text Available This article explores the vision of Management Consulting Firms (MCF specialized in internationalization processes of Spanish companies in China. The main objective is to shed light on a process full of uncertainty as is international expansion into emerging markets on the point of view of the advisors of that process. First, it is analyzed whether there is a Spanish company profile that is internationalized toward China in terms of sector of activity, size and experience in international business. And second, with their client’s experiences, success and failure factors in the internationalization process are studied. To achieve those objectives in depth interviews were held with partners and managers of six Management Consulting Firms with Spanish clients in their portfolio. As a result it is concluded that the sectors where the Spanish company has invested are several, the size of the company is important to undertake an implementation process in China and its international experience as well. Eight key factors were found relevant to invest in China successfully.  Five factors are related with their resources (humans and financials and the other three are related with their strategy. The main reasons of failure are also discussed. The article provides an outside perspective on the reasons why an internationalization process is successful and other fails.

Failures of austenitic stainless steel components during storage: Case studies

International Nuclear Information System (INIS)

Shah, B.K.; Rastogi, P.K.; Sinha, A.K.; Kulkarni, P.G.

1993-01-01

Three studies of failures of austenitic stainless steel components during storage are described. In all cases, stress corrosion cracking was the failure mode by the action of residual stress alone. However, the source of residual stress was different for each case. Case 1 was the failure of a sample tube header for a pressurized heavy water reactor (PHWR). In Case 2, a heat exchanger shell failed during a hydrotest in a fertilizer plant. Cases concerned the cracking of type 304L plates used for spent fuel pool lining of a nuclear power station

The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: the effect of crack shape complexity on the degree of conservatism

International Nuclear Information System (INIS)

Smith, E.

1996-01-01

The failure of circumferentially cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stress at the cracked section is usually calculated via a purely elastic analysis based on the piping being uncracked. however, because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. In earlier work, the author has quantified the extent of this conservatism, and has shown how it depends on the geometry of the cracked section, the material ductility and the elastic flexibility of a piping system. This paper quantifies the conservatism with regard to the case where a through-wall crack extends over a prescribed fraction of the pipe circumference, while there is also an internal circumferential crack extending around the remainder of the pipe section. This is an extreme form of circumferential cracking but nevertheless, simulates the well-known Duane Arnold safe-end crack. (Author)

Stress corrosion cracking in superheater and reheater austenitic tubing

Energy Technology Data Exchange (ETDEWEB)

Dooley, R. Barry [Structural Integrity Associates, Inc., Charlotte, NC (United States); Bursik, Albert [PowerPlant Chemistry GmbH, Neulussheim (Germany)

2011-02-15

University 101 courses are typically designed to help incoming first-year undergraduate students to adjust to the university, develop a better understanding of the college environment, and acquire essential academic success skills. Why are we offering a special Boiler and HRSG Tube Failures PPChem 101? The answer is simple, yet very conclusive: - There is a lack of knowledge on the identification of tube failure mechanisms and for the implementation of adequate counteractions in many power plants, particularly at industrial power and steam generators. - There is a lack of knowledge to prevent repeat tube failures. The vast majority of BTF/HTF have been, and continue to be, repeat failures. It is hoped that the information about the failure mechanisms of BTF supplied in this course will help to put plant engineers and chemists on the right track. The major goal of this course is the avoidance of repeat BTF. This eights lesson is focused on Stress Corrosion Cracking in Superheater and Reheater Austenitic Tubing. (orig.)

Overheating failure of superheater suspension tubes of a captive thermal power plant boiler

International Nuclear Information System (INIS)

Bhattacharya, Sova; Amir, Q.M.; Kannan, C.; Mahapatra, S.B.

2000-01-01

Failure of boiler tubes is the foremost cause of forced boiler outages. One of the predominant failure mechanism of boiler tubes is the stress rupture failure in the form of either short term overheating or long term overheating which are normally encountered in superheater and reheater sections working in the creep range. The strength of the boiler tube depends on the stress level as well on the temperature of exposure in the creep range. An increase in either can reduce the time to rupture. Time at the exposure temperature is an important factor based on which the failures are categorised as either short term or long term. Though there is no established time duration criteria demarcating the short or long term stress rupture failures, depending on the various manifestations on the failed samples, one can categorise the failure. This paper addresses one such stress rupture failure in the superheater section of a captive thermal power plant of a refinery. Multiple failures on the suspension coil of a superheater section was investigated for the cause of failure. Laboratory investigation of the failed sample involved visual inspection, dimensional measurements, chemical analysis of internal deposits and microstructural study. On the basis of these, the failure was attributed to deposition of trisodium phosphate carried over by the feed water into the superheater section resulting in chokage and increase in local operating hoop stresses of the tube. The ultimate failure was thus categorised as long term overheating failure. (author)

Performance success or failure is influenced by weeks lost to injury and illness in elite Australian track and field athletes: A 5-year prospective study.

Science.gov (United States)

Raysmith, Benjamin P; Drew, Michael K

2016-10-01

To investigate the impact of training modification on achieving performance goals. Previous research demonstrates an inverse relationship between injury burden and success in team sports. It is unknown whether this relationship exists within individual sport such as athletics. A prospective, cohort study (n=33 International Track and Field Athletes; 76 athlete seasons) across five international competition seasons. Athlete training status was recorded weekly over a 5-year period. Over the 6-month preparation season, relationships between training weeks completed, the number of injury/illness events and the success or failure of a performance goal at major championships was investigated. Two-by-two table were constructed and attributable risks in the exposed (AFE) calculated. A mixed-model, logistic regression was used to determine the relationship between failure and burden per injury/illness. Receiver Operator Curve (ROC) analysis was performed to ascertain the optimal threshold of training week completion to maximise the chance of success. Likelihood of achieving a performance goal increased by 7-times in those that completed >80% of planned training weeks (AUC, 0.72; 95%CI 0.64-0.81). Training availability accounted for 86% of successful seasons (AFE=0.86, 95%CI, 0.46 to 0.96). The majority of new injuries occurred within the first month of the preparation season (30%) and most illnesses occurred within 2-months of the event (50%). For every modified training week the chance of success significantly reduced (OR=0.74, 95%CI 0.58 to 0.94). Injuries and illnesses, and their influence on training availability, during preparation are major determinants of an athlete's chance of performance goal success or failure at the international level. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Standardizing Failure, Success, and Survival Decisions in Clinical Studies of Ceramic and Metal-Ceramic Fixed Dental Prostheses

Science.gov (United States)

Anusavice, Kenneth J.

2011-01-01

“Nothing worthwhile is ever without complications.”– Nora Roberts The recent increase in reports from clinical studies of ceramic chipping has raised the question of which criteria should constitute success or failure of total-ceramic prostheses. Terminology such as minor chipping[1], partial chipping, technical complications[2, 3], and biological complications have crept into the dental terminology and they have complicated our classification of success and failure of these crown and bridge restorations. Some journals have permitted the reporting of fractures as “complications” and they are not necessarily classified as failures in the study. One study has attempted to classify chipping fractures according to their severity and subsequent treatment.[4] This is a promising approach to resolve the challenges to the classification of chipping fracture. The term ‘chipping fracture’ is more descriptive than ‘chipping’ since the latter term tends to imply an event of minor consequence. Two types of statistics are reported routinely in these studies, i.e., percent success, which is a measure of restorations that survive without any adverse effects, and percent survival, which is a measure of all restorations that survive even though they may have exhibited chipping fracture or they may have been repaired. Why has this scenario occurred? One possible explanation is that many of these types of fractures are very small and do not affect function or esthetics. Another reason is that corporate sponsors prefer to use the term chipping since it does not connote failure in the sense that the term fracture does. In any event, we need to be more precise in our scientific observations of fracture and classifications of the various types of fracture including details on the location of fracture and the prosthesis design configuration. Because of the lack of standardized methods for describing chipping fractures, materials scientists are unable to properly analyze

Standardizing failure, success, and survival decisions in clinical studies of ceramic and metal-ceramic fixed dental prostheses.

Science.gov (United States)

Anusavice, Kenneth J

2012-01-01

The recent increase in reports from clinical studies of ceramic chipping has raised the question of which criteria should constitute success or failure of total-ceramic prostheses. Terminologies such as minor chipping [1], partial chipping, technical complications [2,3], and biological complications have crept into the dental terminology and they have complicated our classification of success and failure of these crown and bridge restorations. Some journals have permitted the reporting of fractures as "complications" and they are not necessarily classified as failures in the study. One study has attempted to classify chipping fractures according to their severity and subsequent treatment [4]. This is a promising approach to resolve the challenges to the classification of chipping fracture. The term 'chipping fracture' is more descriptive than 'chipping' since the latter term tends to imply an event of minor consequence. Two types of statistics are reported routinely in these studies, i.e., percent success, which is a measure of restorations that survive without any adverse effects, and percent survival, which is a measure of all restorations that survive even though they may have exhibited chipping fracture or they may have been repaired. Why has this scenario occurred? One possible explanation is that many of these types of fractures are very small and do not affect function or esthetics. Another reason is that corporate sponsors prefer to use the term chipping since it does not connote failure in the sense that the term fracture does. In any event, we need to be more precise in our scientific observations of fracture and classifications of the various types of fracture including details on the location of fracture and the prosthesis design configuration. Because of the lack of standardized methods for describing chipping fractures, materials scientists are unable to properly analyze the effect of material properties and design factors on the time

Failure modes of composite sandwich beams

Directory of Open Access Journals (Sweden)

Gdoutos E.

2008-01-01

Full Text Available A thorough investigation of failure behavior of composite sandwich beams under three-and four-point bending was undertaken. The beams were made of unidirectional carbon/epoxy facings and a PVC closed-cell foam core. The constituent materials were fully characterized and in the case of the foam core, failure envelopes were developed for general two-dimensional states of stress. Various failure modes including facing wrinkling, indentation failure and core failure were observed and compared with analytical predictions. The initiation, propagation and interaction of failure modes depend on the type of loading, constituent material properties and geometrical dimensions.

Examination stress at unified state examination: student destabilization or success factor?

Directory of Open Access Journals (Sweden)

Svetlana N. Kostromina

2017-01-01

Full Text Available The aim of the research is to clear up the influence of examination stress on the results of completing examination papers by students in the situation of trial General and Unified State Examinations, imitating the real-life environment of unified state certification of schoolchildren. The tasks of the research included determining the dynamics of psychophysiological stress indices at different examination stages, and evaluating additional factors (the subject in which the examination is held, the strategy of solving the variant, success of solving the task etc., influencing the quantity and quality of stress reactions at the examination.The novelty of the research is in the attempt to overcome the problem of confusing the notions of examination stress and examination anxiety, caused by metering the students’ state either before or after the examination. The technology of online monitoring the students’ psychophysiological state is used in the work, which makes it possible to eliminate a number of restrictions occurring during subjective evaluation of the state by the students themselves. Telemetric cardiorhythmography was chosen as the basic method. The method is based on a three-component model of extreme states with consequent domination of one of the three stress-reactive systems. A cardiointervalogramm was being registered in the research process in the online mode and underwent spectral analysis. The following indices of heart rate variability were recorded in order to determine stress reactions: the total power of the spectrum (TP, the spectrum power in low-frequency (LF and high-frequency (HF regions, and a vegetative balance index (relation of the spectrum powers in low-frequency and high-frequency regions (LF/HF. When the total power of the heart rate fell and, at the same time, the vegetative balance index rose, a conclusion was made of there being a stress reaction. Twenty-five students of an illustrious school were examined

Failure in imperfect anisotropic materials

DEFF Research Database (Denmark)

Legarth, Brian Nyvang

2005-01-01

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

Modeling combined tension-shear failure of ductile materials

International Nuclear Information System (INIS)

Partom, Y

2014-01-01

Failure of ductile materials is usually expressed in terms of effective plastic strain. Ductile materials can fail by two different failure modes, shear failure and tensile failure. Under dynamic loading shear failure has to do with shear localization and formation of adiabatic shear bands. In these bands plastic strain rate is very high, dissipative heating is extensive, and shear strength is lost. Shear localization starts at a certain value of effective plastic strain, when thermal softening overcomes strain hardening. Shear failure is therefore represented in terms of effective plastic strain. On the other hand, tensile failure comes about by void growth under tension. For voids in a tension field there is a threshold state of the remote field for which voids grow spontaneously (cavitation), and the material there fails. Cavitation depends on the remote field stress components and on the flow stress. In this way failure in tension is related to shear strength and to failure in shear. Here we first evaluate the cavitation threshold for different remote field situations, using 2D numerical simulations with a hydro code. We then use the results to compute examples of rate dependent tension-shear failure of a ductile material.

An analysis of policy success and failure in formal evaluations of Australia's national mental health strategy (1992-2012).

Science.gov (United States)

Grace, Francesca C; Meurk, Carla S; Head, Brian W; Hall, Wayne D; Harris, Meredith G; Whiteford, Harvey A

2017-05-30

Heightened fiscal constraints, increases in the chronic disease burden and in consumer expectations are among several factors contributing to the global interest in evidence-informed health policy. The present article builds on previous work that explored how the Australian Federal Government applied five instruments of policy, or policy levers, to implement a series of reforms under the Australian National Mental Health Strategy (NMHS). The present article draws on theoretical insights from political science to analyse the relative successes and failures of these levers, as portrayed in formal government evaluations of the NMHS. Documentary analysis of six evaluation documents corresponding to three National Mental Health Plans was undertaken. Both the content and approach of these government-funded, independently conducted evaluations were appraised. An overall improvement was apparent in the development and application of policy levers over time. However, this finding should be interpreted with caution due to variations in evaluation approach according to Plan and policy lever. Tabulated summaries of the success and failure of each policy initiative, ordered by lever type, are provided to establish a resource that could be consulted for future policy-making. This analysis highlights the complexities of health service reform and underscores the limitations of narrowly focused empirical approaches. A theoretical framework is provided that could inform the evaluation and targeted selection of appropriate policy levers in mental health.

Study of simple CFRP-metal joint failure

Science.gov (United States)

Cheng, Jingquan; Rodriguez, Antonio; Emerson, Nicolas; Symmes, Arthur

2008-07-01

In millimeter wavelength telescope design and construction, there have been a number of mysterious failures of simple CFRF-metal joints. Telescope designers have not had satisfactory interpretations of these failures. In this paper, factors which may influence the failure of joints are discussed. These include stress concentration, material creep, joint fatigue, reasons related to chemical process and manufacture process. Extrapolation formulas for material creep, joint fatigue, and differential thermal stresses are derived in this paper. Detailed chemical and manufacturing factors are also discussed. All these issues are the causes of a number of early failures under a loading which is significantly lower than the strength of adhesives used. For ensuring reliability of a precision instrument structure joint, the designer should have a thorough understanding of all these factors.

management of bilateral fracture femur with implant failure

African Journals Online (AJOL)

Keywords: Implant failure, nonunion, plating, intramedullary nailing, stress risers, stress shielding. CASE REPORT ... and the patient was thrust forwards, injuring both ... stress once weight bearing starts will be guided by .... J. Bone Joint Surg.

Dialysis Arteriovenous Fistula Failure and Angioplasty: Intimal Hyperplasia and Other Causes of Access Failure

Science.gov (United States)

Duque, Juan C.; Tabbara, Marwan; Martinez, Laisel; Cardona, Jose; Vazquez-Padron, Roberto I; Salman, Loay H

2016-01-01

Arteriovenous fistula (AVF) is the preferred hemodialysis access type because it has better patency rates and fewer complications than other access types. However, primary failure remains a common problem impeding AVF maturation and adding to patients’ morbidity and mortality. Juxta-anastomotic (or inflow) stenosis is the most common reason leading to primary failure, and percutaneous transluminal angioplasty (PTA) continues to be the gold standard treatment with excellent success rates. Intimal hyperplasia (IH) has been traditionally blamed as the main pathophysiologic culprit, but new evidence raises doubts regarding the contribution of IH alone to primary failure. We report a 64-year-old man with a two-stage brachio-basilic AVF that was complicated by failure four months after creation. Angiogram showed multiple juxta-anastomotic and mid-fistula stenotic lesions. PTA was successful in assisting maturation and subsequently cannulating AVF for hemodialysis treatment. We failed to identify the underlying cause of stenosis as biopsy specimens from fistula tissue obtained at the time of transposition revealed no occlusive IH. This case emphasizes the need for additional research on factors contributing to AVF failure besides IH, and highlights the need for more therapeutic options to reduce AVF failure rate. PMID:28084215

Failure Analysis of High-Power Piezoelectric Transducers

National Research Council Canada - National Science Library

Gabrielson, T. B

2005-01-01

... and stress in a piezoelectric material. For a transducer operated near resonance, there will be "hot spots" or regions of locally intense stress and electric field that precipitate premature failure...

Simulations of stress evolution and the current density scaling of electromigration-induced failure times in pure and alloyed interconnects

Science.gov (United States)

Park, Young-Joon; Andleigh, Vaibhav K.; Thompson, Carl V.

1999-04-01

An electromigration model is developed to simulate the reliability of Al and Al-Cu interconnects. A polynomial expression for the free energy of solution by Murray [Int. Met. Rev. 30, 211 (1985)] was used to calculate the chemical potential for Al and Cu while the diffusivities were defined based on a Cu-trapping model by Rosenberg [J. Vac. Sci. Technol. 9, 263 (1972)]. The effects of Cu on stress evolution and lifetime were investigated in all-bamboo and near-bamboo stud-to-stud structures. In addition, the significance of the effect of mechanical stress on the diffusivity of both Al and Cu was determined in all-bamboo and near-bamboo lines. The void nucleation and growth process was simulated in 200 μm, stud-to-stud lines. Current density scaling behavior for void-nucleation-limited failure and void-growth-limited failure modes was simulated in long, stud-to-stud lines. Current density exponents of both n=2 for void nucleation and n=1 for void growth failure modes were found in both pure Al and Al-Cu lines. Limitations of the most widely used current density scaling law (Black's equation) in the analysis of the reliability of stud-to-stud lines are discussed. By modifying the input materials properties used in this model (when they are known), this model can be adapted to predict the reliability of other interconnect materials such as pure Cu and Cu alloys.

Characterization of radioiodine therapy failures in Graves' disease

International Nuclear Information System (INIS)

Sabri, O.; Zimny, M.; Schreckenberger, M.; Reinartz, P.; Nowak, B.; Ostwald, E.; Schaefer, W.; Block, S.; Setani, K.; Buell, U.

2001-01-01

Aim of this study was a characterization of radioiodine therapy (RIT) failures in Graves' disease without simultaneous carbimazole. Method: 226 patients with a confirmed diagnosis of Graves' disease received 686.8 ± 376.4 MBq of iodine-131 orally for thyroid ablation. Target dose was 250 Gy. All patients were followed up for 6 months. Therapy failures were compared with successes regarding possible influencing variables initial thyroid volume, thyroid function, immune activity (TRAb), I-131 uptake, effective half-life, absorbed energy dose, age and gender. Results: 212 of 226 patients (93.8%) were treated successfully, 14 (6.2%) showed a hyperthyroidism relapse within 6 months which required a second radioiodine therapy. A success rate of 92.5% (62/67) could also be achieved with 67 patients who were hyperthyroid at the time of RIT. Compared to the therapy successes, the 14 failures achieved significantly lower absorbed doses (223.8 ± 76.6 Gy vs. 285.2 ± 82.1 Gy, p 0.2). Of the 14 failures, n = 8 reached an absorbed dose 250 Gy. Stepwise logistic regression revealed only absorbed energy dose as a variable significantly influencing therapy success (p 0.2) or gender (p = 0.13). Two-tailed Fisher's exact test showed no significant influence of gender on success rates (failures/successes: male 1/36, female 13/176, p = 0.48). Conclusions: Except for the absorbed energy dose, no other significant variable influencing the outcome of radioiodine therapy in Graves' disease without simultaneous carbimazole could be found. It should be noted, though, that 5 therapy failures (2.2%) reached an absorbed energy dose of >250 Gy. (orig.) [de

Progressive failure site generation in AlGaN/GaN high electron mobility transistors under OFF-state stress: Weibull statistics and temperature dependence

International Nuclear Information System (INIS)

Sun, Huarui; Bajo, Miguel Montes; Uren, Michael J.; Kuball, Martin

2015-01-01

Gate leakage degradation of AlGaN/GaN high electron mobility transistors under OFF-state stress is investigated using a combination of electrical, optical, and surface morphology characterizations. The generation of leakage “hot spots” at the edge of the gate is found to be strongly temperature accelerated. The time for the formation of each failure site follows a Weibull distribution with a shape parameter in the range of 0.7–0.9 from room temperature up to 120 °C. The average leakage per failure site is only weakly temperature dependent. The stress-induced structural degradation at the leakage sites exhibits a temperature dependence in the surface morphology, which is consistent with a surface defect generation process involving temperature-associated changes in the breakdown sites

Biofeedback in the treatment of heart failure.

Science.gov (United States)

McKee, Michael G; Moravec, Christine S

2010-07-01

Biofeedback training can be used to reduce activation of the sympathetic nervous system (SNS) and increase activation of the parasympathetic nervous system (PNS). It is well established that hyperactivation of the SNS contributes to disease progression in chronic heart failure. It has been postulated that underactivation of the PNS may also play a role in heart failure pathophysiology. In addition to autonomic imbalance, a chronic inflammatory process is now recognized as being involved in heart failure progression, and recent work has established that activation of the inflammatory process may be attenuated by vagal nerve stimulation. By interfering with both autonomic imbalance and the inflammatory process, biofeedback-assisted stress management may be an effective treatment for patients with heart failure by improving clinical status and quality of life. Recent studies have suggested that biofeedback and stress management have a positive impact in patients with chronic heart failure, and patients with higher perceived control over their disease have been shown to have better quality of life. Our ongoing study of biofeedback-assisted stress management in the treatment of end-stage heart failure will also examine biologic end points in treated patients at the time of heart transplant, in order to assess the effects of biofeedback training on the cellular and molecular components of the failing heart. We hypothesize that the effects of biofeedback training will extend to remodeling the failing human heart, in addition to improving quality of life.

Stress analysis of shear/compression test

International Nuclear Information System (INIS)

Nishijima, S.; Okada, T.; Ueno, S.

1997-01-01

Stress analysis has been made on the glass fiber reinforced plastics (GFRP) subjected to the combined shear and compression stresses by means of finite element method. The two types of experimental set up were analyzed, that is parallel and series method where the specimen were compressed by tilted jigs which enable to apply the combined stresses, to the specimen. Modified Tsai-Hill criterion was employed to judge the failure under the combined stresses that is the shear strength under the compressive stress. The different failure envelopes were obtained between the two set ups. In the parallel system the shear strength once increased with compressive stress then decreased. On the contrary in the series system the shear strength decreased monotonicly with compressive stress. The difference is caused by the different stress distribution due to the different constraint conditions. The basic parameters which control the failure under the combined stresses will be discussed

The Danish Rejsekortet (Smart Card for Public Transportation); Project Governance for Failure or Success?

DEFF Research Database (Denmark)

Harboe, Peter Georg; Riis, Eva

The authors examine a project regarded as a major failure in Danish public investments: The Smart Card for Public Transportation whose introduction was delayed for 9 years with an estimated cost overrun of 125 million EURO. After 3 years of operation, the Smart Card system only covers seven...... of the nine Danish regions and the discussion about giving up the system is continuing. The authors explore the overall conditions set up for these types of projects in the project governance - how project governance conditions a major public IT project and forms the success evaluation. The focus...... is on the whole cycle from project initiation to long-term use of the project results. Data collection is through documentation as governmental reports and evaluations, for example (Rigsrevisionen, 2011; The Comptroller and Auditor General, 2006; Transport Committee, 2011)and semi-structured interviews...

Anxiety, stress and depression in family members of patients with heart failure.

Science.gov (United States)

Lacerda, Marianna Sobral; Cirelli, Melissa Alves; Barros, Alba Lúcia Bottura Leite de; Lopes, Juliana de Lima

2017-03-20

Identifying the level of anxiety, stress and depression symptoms in family members of patients with heart failure; identifying the relationship between these feelings with sociodemographic and clinical variables. A cross-sectional study carried out with 100 family members. Depression, anxiety, and stress were evaluated by the Beck Depression and Anxiety Inventories and the Perceived Stress Scale - 10. The relationship between feelings and variables was performed through the t-test, Mann-Whitney or Kruskal-Wallis. Mean depression was 8.24, anxiety was 77.95, and stress was 17.43. The correlation coefficient between depression and anxiety and depression and stress was 0.53, and it was 0.66 between anxiety and stress. Females (p=0.002, p=0.031), smoking (p=0.05, p=0.011) and sedentary lifestyle (p=0.023, p=0.001) were related to anxiety and stress, respectively. Family income lower than five minimum wages (p=0.012) was related to depression, and regular/poor self-perceived health status related to the three feelings. Family members did not present high levels of these feelings. The scales were directly correlated with each one another and some variables were related to stress, anxiety and depression. Identificar o nível de ansiedade, estresse e sintomas de depressão de familiares de pacientes com insuficiência cardíaca; identificar a relação entre esses sentimentos com as variáveis sociodemográficas e clínicas. Estudo transversal composto por 100 familiares. A depressão, a ansiedade e o estresse foram avaliados pelos Inventários de Depressão e Ansiedade de Beck e pela Escala de Estresse Percebido ‒ 10. A relação dos sentimentos com as variáveis foi realizada pelo teste t, Mann-Whitney ou Kruskal-Wallis. A média de depressão foi de 8,24, ansiedade, 7,95 e estresse, 17,43. O coeficiente de correlação entre depressão e ansiedade e depressão e estresse foi de 0,53 e de 0,66 entre ansiedade e estresse. Sexo feminino (p=0,002; p=0,031), tabagismo (p=0

In-situ failure test in the research tunnel at Olkiluoto

Energy Technology Data Exchange (ETDEWEB)

Autio, J.; Johansson, E.; Kirkkomaeki, T. [Saanio and Riekkola Consulting Engineers, Helsinki (Finland); Hakala, M. [Gridpoint Finland Oy (Finland); Heikkilae, E. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Rock Engineering

2000-05-01

A failure test suitable for execution in the Research Tunnel at Olkiluoto has been planned to study the failure of rock in-situ. The objectives of the in-situ failure test is to assess the applicability of numerical modelling codes and methods to the study of rock failure and associated crack propagation and to develop a novel technique to be used to determine the strength of rock in-situ. The objective of this study was to make a preliminary design of the failure test, assess the technical feasibility of the test and to give input information for further numerical modelling of the test. The design of the failure test is reported and results of preliminary modelling are given. The input information for future modelling includes a study of rock properties, fracture propagation in rock, in-situ stresses and the development of techniques for using the expanding agent to produce artificial stress field. The study showed that mechanical properties such as strength of gneissic tonalite, the main rock type in the Research Tunnel, depends highly on the orientation of schistocity. The in-situ failure test was shown to be technically feasible and a state of stress high enough to cause failure can be created artificially by using a proper expansive agent and design. (orig.)

How is success or failure in river restoration projects evaluated? Feedback from French restoration projects.

Science.gov (United States)

Morandi, Bertrand; Piégay, Hervé; Lamouroux, Nicolas; Vaudor, Lise

2014-05-01

Since the 1990s, French operational managers and scientists have been involved in the environmental restoration of rivers. The European Water Framework Directive (2000) highlights the need for feedback from restoration projects and for evidence-based evaluation of success. Based on 44 French pilot projects that included such an evaluation, the present study includes: 1) an introduction to restoration projects based on their general characteristics 2) a description of evaluation strategies and authorities in charge of their implementation, and 3) a focus on the evaluation of results and the links between these results and evaluation strategies. The results show that: 1) the quality of an evaluation strategy often remains too poor to understand well the link between a restoration project and ecological changes; 2) in many cases, the conclusions drawn are contradictory, making it difficult to determine the success or failure of a restoration project; and 3) the projects with the poorest evaluation strategies generally have the most positive conclusions about the effects of restoration. Recommendations are that evaluation strategies should be designed early in the project planning process and be based on clearly-defined objectives. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stresses in Dolosse

DEFF Research Database (Denmark)

Burcharth, Hans F.; Liu, Zhou; Howell, Gary L.

1991-01-01

Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams for structu......Failures of rubble mound breakwaters armoured with complex types of unreinforced concrete armour units are often due to breakage. This happens when the stresses exceed the material strength. Sufficient parametric studies of the stresses are not yet available to produce design diagrams...... for structural integrity. The paper presents the results and the analyses of model tests with 200 kg and 200 g load-cell instrumented Dolosse. Static stresses and wave generated stresses were studied as well as model and scale effects. A preliminary design diagram for Dolosse is presented as well....

Mediterranean coastal dune vegetation: Are disturbance and stress the key selective forces that drive the psammophilous succession?

Science.gov (United States)

Ciccarelli, Daniela

2015-11-01

Plant communities of coastal dunes are distributed along a characteristic sea-inland gradient. Generally, there is a shift from annual and short height species with small leaves in the initial successional stages to perennial tall shrubs with tough leaves in later phases. Assessing the community-weighted mean (CWM) trait values is used in plant ecology to describe ecosystem properties especially during succession. In particular, CSR (Competitive, Stress-tolerant, and Ruderal strategy) classification allows us to explore community functional shifts in terms of disturbance, stress and competition selective forces. The functional basis of the psammophilous succession was studied based on the following questions: (1) Can we circumscribe different functional types among plant species of Mediterranean coastal dunes? (2) How do CWM trait values vary along the environmental sea-inland gradient? (3) What is the relative importance of competition, stress and disturbance in the processes of plant community assembling? (4) Can we postulate that along primary successions there is generally a shift from ruderality to stress-tolerance? An explorative analysis of functional groups was performed by Non-Metric Multidimensional Scaling (NMDS) analysing nine morpho-functional traits measured for 45 taxa from 880 dune plots localised in Tuscany (central Italy, Europe). NMDS ordination showed a scattered distribution of psammophytes that could not be delimited in precise plant functional types. The first NMDS axis has been interpreted as a leaf economics axis because it was correlated to leaf area (LA) and leaf dry matter content (LDMC), while the second one was a plant size axis because of its correlation with canopy height. Along the sea-inland gradient, pioneer plant communities of upper beach were dominated by ruderals (with the lowest values of LDMC and specific leaf area - SLA), well-adapted to the harsh environmental conditions of coastal dunes. More distant from the sea, where

Reliability analysis for the creep rupture mode of failure

International Nuclear Information System (INIS)

Vaidyanathan, S.

1975-01-01

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

On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

DEFF Research Database (Denmark)

Fernandes, Frederico Augusto Pires; Christiansen, Thomas L.; Winther, Grethe

2015-01-01

Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer...... removal. Several factors complicating the stress determination are analysed and discussed: (1) ghost stresses arising from a small variation in the shallow information depths probed with GI-XRD, (2) selection of the grain interaction model used to calculate the X-ray elastic constants for conversion...

On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

International Nuclear Information System (INIS)

Fernandes, Frederico A.P.; Christiansen, Thomas L.; Winther, Grethe; Somers, Marcel A.J.

2015-01-01

Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer removal. Several factors complicating the stress determination are analysed and discussed: (1) ghost stresses arising from a small variation in the shallow information depths probed with GI-XRD, (2) selection of the grain interaction model used to calculate the X-ray elastic constants for conversion of lattice strains into residual stress and (3) the composition dependence of these elastic constants

Bayesian estimation of source parameters and associated Coulomb failure stress changes for the 2005 Fukuoka (Japan) Earthquake

Science.gov (United States)

Dutta, Rishabh; Jónsson, Sigurjón; Wang, Teng; Vasyura-Bathke, Hannes

2018-04-01

Several researchers have studied the source parameters of the 2005 Fukuoka (northwestern Kyushu Island, Japan) earthquake (Mw 6.6) using teleseismic, strong motion and geodetic data. However, in all previous studies, errors of the estimated fault solutions have been neglected, making it impossible to assess the reliability of the reported solutions. We use Bayesian inference to estimate the location, geometry and slip parameters of the fault and their uncertainties using Interferometric Synthetic Aperture Radar and Global Positioning System data. The offshore location of the earthquake makes the fault parameter estimation challenging, with geodetic data coverage mostly to the southeast of the earthquake. To constrain the fault parameters, we use a priori constraints on the magnitude of the earthquake and the location of the fault with respect to the aftershock distribution and find that the estimated fault slip ranges from 1.5 to 2.5 m with decreasing probability. The marginal distributions of the source parameters show that the location of the western end of the fault is poorly constrained by the data whereas that of the eastern end, located closer to the shore, is better resolved. We propagate the uncertainties of the fault model and calculate the variability of Coulomb failure stress changes for the nearby Kego fault, located directly below Fukuoka city, showing that the main shock increased stress on the fault and brought it closer to failure.

Acute Respiratory Failure due to Neuromyelitis Optica Treated Successfully with Plasmapheresis

Directory of Open Access Journals (Sweden)

Massa Zantah

2016-01-01

Full Text Available Neuromyelitis Optica (NMO is a demyelinating autoimmune disease involving the central nervous system. Acute respiratory failure from cervical myelitis due to NMO is known to occur but is uncommon in monophasic disease and is treated with high dose steroids. We report a case of a patient with NMO who developed acute respiratory failure related to cervical spinal cord involvement, refractory to pulse dose steroid therapy, which resolved with plasmapheresis.

A PWR PCI failure criterion to burnups of 60 GW·d/t using the ENIGMA code

International Nuclear Information System (INIS)

Clarke, A.P.; Tempest, P.A.; Shea, J.H.

2000-01-01

A fuel performance modelling code (ENIGMA) has been used to analyse the empirical PCI failure criterion in terms of a clad failure stress as a function of burnup and fast neutron dose. The Studsvik database has been analysed. Results indicate a rising and then saturating failure stress with burnup and fast neutron dose. Using the PCI failure limits, equivalent to 95/95 confidence limits, an ENIGMA stress-based methodology is used to derive PWR PCI failure limits up to 60 GW·d/t U using a conservative assumption that the failure stress does not increase at high burnup and neutron dose. In addition experimental ramp data on gadolinia-doped fuel rods do not indicate any increased susceptibility to PCI failure implying that the UO 2 criterion can be used for gadolinia doped fuel. (author)

Stresses in Circular Plates with Rigid Elements

Science.gov (United States)

Velikanov, N. L.; Koryagin, S. I.; Sharkov, O. V.

2018-05-01

Calculations of residual stress fields are carried out by numerical and static methods, using the flat cross-section hypothesis. The failure of metal when exposed to residual stresses is, in most cases, brittle. The presence in the engineering structures of rigid elements often leads to the crack initiation and structure failure. This is due to the fact that rigid elements under the influence of external stresses are stress concentrators. In addition, if these elements are fixed by welding, the residual welding stresses can lead to an increase in stress concentration and, ultimately, to failure. The development of design schemes for such structures is a very urgent task for complex technical systems. To determine the stresses in a circular plate with a welded circular rigid insert under the influence of an external load, one can use the solution of the plane stress problem for annular plates in polar coordinates. The polar coordinates of the points are the polar radius and the polar angle, and the stress state is determined by normal radial stresses, tangential and shearing stresses. The use of the above mentioned design schemes, formulas, will allow more accurate determination of residual stresses in annular welded structures. This will help to establish the most likely directions of failure and take measures at the stages of designing, manufacturing and repairing engineering structures to prevent these failures. However, it must be taken into account that the external load, the presence of insulation can lead to a change in the residual stress field.

Elementary students' engagement in failure-prone engineering design tasks

Science.gov (United States)

Andrews, Chelsea Joy

Although engineering education has been practiced at the undergraduate level for over a century, only fairly recently has the field broadened to include the elementary level; the pre-college division of the American Society of Engineering Education was established in 2003. As a result, while recent education standards require engineering in elementary schools, current studies are still filling in basic research on how best to design and implement elementary engineering activities. One area in need of investigation is how students engage with physical failure in design tasks. In this dissertation, I explore how upper elementary students engage in failure-prone engineering design tasks in an out-of-school environment. In a series of three empirical case studies, I look closely at how students evaluate failed tests and decide on changes to their design constructions, how their reasoning evolves as they repeatedly encounter physical failure, and how students and facilitators co-construct testing norms where repetitive failure is manageable. I also briefly investigate how students' engagement differs in a task that features near-immediate success. By closely examining student groups' discourse and their interactions with their design constructions, I found that these students: are able to engage in iteration and see failure-as-feedback with minimal externally-imposed structure; seem to be designing in a more sophisticated manner, attending to multiple causal factors, after experiencing repetitive failure; and are able to manage the stress and frustration of repetitive failure, provided the co-constructed testing norms of the workshop environment are supportive of failure management. These results have both pedagogical implications, in terms of how to create and facilitate design tasks, and methodological implications--namely, I highlight the particular insights afforded by a case study approach for analyzing engagement in design tasks.

Stress for Success: How to Optimize Your Performance.

Science.gov (United States)

Gmelch, Walter H.

1983-01-01

This article explores linkages between stress and effective job performance: while too much stress can lead to burnout, too little stressful stimulation can result in boredom. Generating the proper amount of stress for optimal job performance is discussed. (PP)

A relation to describe rate-dependent material failure.

Science.gov (United States)

Voight, B

1989-01-13

The simple relation OmegaOmega-alpha = 0, where Omega is a measurable quantity such as strain and A and alpha are empirical constants, describes the behavior of materials in terminal stages of failure under conditions of approximately constant stress and temperature. Applicable to metals and alloys, ice, concrete, polymers, rock, and soil, the relation may be extended to conditions of variable and multiaxial stress and may be used to predict time to failure.

Successful treatment of acute renal failure secondary to complicated infective endocarditis by peritoneal dialysis: a case report.

Science.gov (United States)

Al-Osail, Aisha M; Al-Zahrani, Ibrahim M; Al-Abdulwahab, Abdullah A; Alhajri, Sarah M; Al-Osail, Emad M; Al-Hwiesh, Abdullah K; Al-Muhanna, Fahad A

2017-09-07

Infective endocarditis is one of the most common infections among intravenous drug addicts. Its complications can affect many systems, and these can include acute renal failure. There is a scarcity of cases in the literature related to acute renal failure secondary to infective endocarditis treated with peritoneal dialysis. In this paper, the case of a 48-year-old Saudi male is reported, who presented with features suggestive of infective endocarditis and who developed acute kidney injury that was treated successfully with high tidal volume automated peritoneal dialysis. To our knowledge, this is the second report of such an association in the literature. A 48-year-old Saudi gentleman diagnosed to have a glucose-6-phosphate dehydrogenase deficiency and hepatitis C infection for the last 9 years, presented to the emergency department with a history of fever of 2 days' duration. On examination: his temperature = 41 °C, there was clubbing of the fingers bilaterally and a pansystolic murmur in the left parasternal area. The results of the blood cultures and echocardiogram were supportive of the diagnosis of infective endocarditis, and the patient subsequently developed acute kidney injury, and his creatinine reached 5.2 mg/dl, a level for which dialysis is essential for the patient to survive. High tidal volume automated peritoneal dialysis is highly effective as a renal replacement therapy in acute renal failure secondary to infective endocarditis if no contraindication is present.

Failure modes of laminate structures

Energy Technology Data Exchange (ETDEWEB)

Gordon, L.B.; Druce, R.L.; Wilson, M.J.

1987-06-01

Laminate structures composed of alternating thin layers of conductor and dielectric material are commonly used in energy storage and transmission components. The failure of the dielectric layers in regions of high field stress, with applied 60 Hz ac, dc and impulse voltages, was studied. Several geometries were compared, including staggered and flush edges. Electrical trees developed between the laminated dielectric layers. The visual characteristics and growth rates of the electrical trees under ac, dc and impulse stresses were different. Partial discharge detection and analysis was used to measure the inception voltage and discharge activity at the conductor edge voids, to observe tree formation and growth, and to predict impending failure due to dielectric erosion. Electric field distributions were modeled and partial discharge inception levels were estimated from known void geometries. The staggered edge geometry appears to enhance the electric field stress at the recessed electrode.

Fuel-pin cladding transient failure strain criterion

International Nuclear Information System (INIS)

Bard, F.E.; Duncan, D.R.; Hunter, C.W.

1983-01-01

A criterion for cladding failure based on accumulated strain was developed for mixed uranium-plutonium oxide fuel pins and used to interpret the calculated strain results from failed transient fuel pin experiments conducted in the Transient Reactor Test (TREAT) facility. The new STRAIN criterion replaced a stress-based criterion that depends on the DORN parameter and that incorrectly predicted fuel pin failure for transient tested fuel pins. This paper describes the STRAIN criterion and compares its prediction with those of the stress-based criterion

Competing fatigue failure behaviors of Ni-based superalloy FGH96 at elevated temperature

Energy Technology Data Exchange (ETDEWEB)

Miao, Guolei [School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Yang, Xiaoguang [School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Collaborative Innovation Center of Advanced Aero-engine(CICAAE), Beihang University, Beijing 100191 (China); Shi, Duoqi, E-mail: shdq@buaa.edu.cn [School of Energy and Power Engineering, Beihang University, Beijing 100191 (China); Collaborative Innovation Center of Advanced Aero-engine(CICAAE), Beihang University, Beijing 100191 (China)

2016-06-21

Fatigue experiments were performed on a polycrystalline P/M processed nickel-based superalloy, FGH96 at 600 °C to investigate competing fatigue failure behaviors of the alloy. The experiments were performed at four levels of stress (from high cycle fatigue to low cycle fatigue) at stress ratio of 0.05. There was large variability in fatigue life at both high and low stresses. Scanning electron microscopy (SEM) was used to analyze the failure surfaces. Three types of competing failure modes were observed (surface, sub-surface and internal initiated failures). Crack initiation sites were gradually changed from the surface to the interior with the decreasing of stress level. Roles of microstructures in competing failure mechanism were analyzed. There were six kinds of fatigue crack initiation modes: (1) surface inclusion initiated; (2) surface facet initiated; (3) sub-surface inclusion initiated; (4) sub-surface facet initiated; (5) internal inclusion initiated; (6) internal facet initiated. Inclusions at surface were the life-limiting microstructures at higher stress levels. The probability of occurrence of inclusions initiated is gradually reduced with decreasing of stress level, simultaneously the probability of occurrence of facets initiated is increasing. The existence of the inclusions resulted in large life variability at higher stress levels, while heterogeneity of material caused by random combinations of grains was the main cause of fatigue variability at lower stress levels.

Competing fatigue failure behaviors of Ni-based superalloy FGH96 at elevated temperature

International Nuclear Information System (INIS)

Miao, Guolei; Yang, Xiaoguang; Shi, Duoqi

2016-01-01

Fatigue experiments were performed on a polycrystalline P/M processed nickel-based superalloy, FGH96 at 600 °C to investigate competing fatigue failure behaviors of the alloy. The experiments were performed at four levels of stress (from high cycle fatigue to low cycle fatigue) at stress ratio of 0.05. There was large variability in fatigue life at both high and low stresses. Scanning electron microscopy (SEM) was used to analyze the failure surfaces. Three types of competing failure modes were observed (surface, sub-surface and internal initiated failures). Crack initiation sites were gradually changed from the surface to the interior with the decreasing of stress level. Roles of microstructures in competing failure mechanism were analyzed. There were six kinds of fatigue crack initiation modes: (1) surface inclusion initiated; (2) surface facet initiated; (3) sub-surface inclusion initiated; (4) sub-surface facet initiated; (5) internal inclusion initiated; (6) internal facet initiated. Inclusions at surface were the life-limiting microstructures at higher stress levels. The probability of occurrence of inclusions initiated is gradually reduced with decreasing of stress level, simultaneously the probability of occurrence of facets initiated is increasing. The existence of the inclusions resulted in large life variability at higher stress levels, while heterogeneity of material caused by random combinations of grains was the main cause of fatigue variability at lower stress levels.

Conflict adaptation in positive and negative mood: Applying a success-failure manipulation.

Science.gov (United States)

Schuch, Stefanie; Zweerings, Jana; Hirsch, Patricia; Koch, Iring

2017-05-01

Conflict adaptation is a cognitive mechanism denoting increased cognitive control upon detection of conflict. This mechanism can be measured by the congruency sequence effect, indicating the reduction of congruency effects after incongruent trials (where response conflict occurs) relative to congruent trials (without response conflict). Several studies have reported increased conflict adaptation under negative, as compared to positive, mood. In these studies, sustained mood states were induced by film clips or music combined with imagination techniques; these kinds of mood manipulations are highly obvious, possibly distorting the actual mood states experienced by the participants. Here, we report two experiments where mood states were induced in a less obvious way, and with higher ecological validity. Participants received success or failure feedback on their performance in a bogus intelligence test, and this mood manipulation proved highly effective. We largely replicated previous findings of larger conflict adaptation under negative mood than under positive mood, both with a Flanker interference paradigm (Experiment 1) and a Stroop-like interference paradigm (Experiment 2). Results are discussed with respect to current theories on affective influences on cognitive control. Copyright © 2017 Elsevier B.V. All rights reserved.

Failure analysis of re-bars during bending operations

Directory of Open Access Journals (Sweden)

Souvik Das

2014-10-01

Full Text Available Thermo-mechanical treated (TMT rebar is suitable material for reinforcing concrete structures on accounts of similarity in thermal expansion, ability to bond well with concrete and, above all the ability to shoulder most of the tensile stress acting on the structure and also steel manufacturing industry has successfully developed a corrosion-resistant variety of rebar for the construction industry. As the TMT is the finish product thus proper control of rolling parameters and water box is needed to achieve adequate property. Water box plays an important role for achieving the final structure and property of the rebars. Water box is responsible for outer rim formation and which helps to achieve the yield strength of the material. The present paper highlights failure investigation of a failed rebar during bending operations. From fractography and microstructural analysis it is confirmed that the rebar sample failed in brittle manner due to through harden martensitic structure and which indicates that there is some anomaly in water box resulting in these premature failures.

Estimation of liver parameters and oxidative stress in chronic renal failure patients on hemodialysis in Erbil governorate

Science.gov (United States)

Kakey, Musher Ismail Salih; Abdoulrahman, Kamaran Kaiani

2017-09-01

The present study aims to evaluate iron related parameters in chronic renal failure (CRF) patients on hemodialysis (HD). The study was carried out in Kidney Dialysis Center of Hawler Teaching Hospital in Erbil governorate. This study comprised (76) patients with chronic renal failure on hemodialysis and 41 healthy subjects as a control group of same ages. All hemodialysis patients were taking erythropoietin. The blood samples were taken from the patients before and after the process of hemodialysis for liver parameters and oxidative stress estimations. The results of this study showed lower levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, total bilirubin, total protein and total antioxidant capacity (TAC), while higher levels of alkaline phosphatase (ALP), direct bilirubin and malondialdeyhde (MDA) before analysis was seen. Hemodialysis causes increasing in AST, ALT, albumin, total bilirubin, total protein and decreasing in ALP, direct bilirubin MDA and TAC.

Success and Failure in University-Based Startups

Science.gov (United States)

Dehn, J.; Webley, P.; Cunningham, K. W.

2014-12-01

Adapting from a traditional government-funded research program to supporting the work through a start-up company is a difficult (and often not successful) transition. This is made more challenging in that with the relative decline in federal funding for the sciences the transition is forced on many researchers as a matter of survival. The business model of traditional research is not that different from that of the private sector; the development of an idea, models or mock-ups of the product, pitching to sources of funding, creating and marketing the product. However they differ significantly in the environment in which they are applied, as well as in the life span of a project or product. The environments for pitching an idea and gaining investment are very different in academia from that of the private sector, and most academics are stymied by the new approach. In addition, many universities labor under the illusion that start-ups will be a windfall, when in reality they represent a long term investment that will not pay out for many years. This extended timeline is also something new to academics, though persistence pays and a project may take years to fund, after it is complete and the publications written, many in the geosciences go on to new ideas. If a business is to be successful it must continue with a product long term, and develop new ideas around it. A hopefully successful balance of these approaches is being tried at the University of Alaska Fairbanks, where start-ups can build upon university intellectual property and use university resources to build a successful business. In turn the business supports research and development, primarily through faculty, staff and students at the university.

Failure criteria for low-temperature irradiated organic composite insulation systems

International Nuclear Information System (INIS)

Schutz, J.B.; Fabian, P.E.

1997-01-01

Composite insulation systems in fusion magnet applications are often subjected to conditions of combined through thickness compression and shear at varying stress ratios. Characterization of insulation system strength under these conditions requires unidirectional shear and compression tests, as well as biaxial shear/compression testing to define the systems failure envelope. An appropriate failure criteria would reduce the number of tests required to define this envelope, and would give designers a better estimate of material strengths at intermediate stress ratios. Biaxial shear/compression testing requires the use of metallic sandwich specimens, which are susceptible to activation during irradiation. A reliable failure criteria which eliminates the need for biaxial characterization would also reduce the difficulty and expense involved in radiation effects characterization while still providing a complete failure envelope. Several generalized failure criteria, taken from classical composites analysis, were reformulated for application in the shear/compression quadrant. The maximum stress and Tsai-Hill criteria were found to be inadequate to represent the biaxial failure envelope. The generalized Tsai-Wu tensor quadratic failure criterion was also examined. Application of this criterion requires through thickness tensile strength data. Through thickness tensile strengths of insulation systems have not been routinely characterized, but limited data are available. Utilizing unidirectional through thickness tension, compression, and interlaminar shear strength data, the Tsai-Wu failure criteria was found to agree well with biaxial shear/compression test data

Compressive Failure of Fibre Reinforced Materials

DEFF Research Database (Denmark)

Jensen, Henrik Myhre

2003-01-01

Compressive failure of uni-directional fibre composites by the kink band mechanism is analysed taking into account effects of residual stresses. Two criteria for determining the strength of the composite material have been investigated: Kink band formation at a bifurcation stress in a composite...... with perfectly aligned fibres, and kink band formation at a peak stress in a composite with a band of imperfect material....

Shifting and Sharing: Academic Physicians' Strategies for Navigating Underperformance and Failure.

Science.gov (United States)

LaDonna, Kori A; Ginsburg, Shiphra; Watling, Christopher

2018-05-22

Medical practice is uncertain and complex. Consequently, even outstanding performers will inevitably experience moments of underperformance and failure. Coping relies on insight and resilience. However, how physicians develop and use these skills to navigate struggle remains underexplored. A better understanding may reveal strategies to support both struggling learners and stressed practitioners. In 2015, 28 academic physicians were interviewed about their experiences with underperformance or failure. Constructivist grounded theory informed data collection and analysis. Participants' experiences with struggle ranged from patient errors and academic failures to frequent, smaller moments of interpersonal conflict and work-life imbalance. To buffer impact, participants sometimes shifted their focus to an aspect of their identity where they felt successful. Additionally, while participants perceived that insight develops by acknowledging and reflecting on error, they sometimes deflected blame for performance gaps. More often, participants seemed to accept personal responsibility while simultaneously sharing accountability for underperformance or failure with external forces. Paradoxically, participants perceived learners who used these strategies as lacking in insight. Participants demonstrated the protective and functional value of distributing responsibility for underperformance and failure. Shifting and sharing may be an element of reflection and resilience; recognizing external factors may provide a way to gain perspective and to preserve the self. However, this strategy challenges educators' assumptions that learners who deflect are avoiding personal responsibility. The authors' findings raise questions about what it means to be resilient, and how assumptions about learners' responses to failure may affect strategies to support underperforming learners.

Success or failure of hospital information systems of public hospitals affiliated with Zahedan University of Medical Sciences: A cross sectional study in the Southeast of Iran.

Science.gov (United States)

Alipour, Jahanpour; Karimi, Afsaneh; Ebrahimi, Saeid; Ansari, Fatemeh; Mehdipour, Yousef

2017-12-01

After implementation, evaluation of hospital information systems (HISs) is critical to ensure the fulfillment of the system goals. This study aimed to assess the success or failure of HISs in public hospitals affiliated with Zahedan University of Medical Sciences. A cross-sectional descriptive and analytic study was performed in 2016. The study population comprised IT and HIS authorities and hospital information system users. The sample consisted of 468 participants. The data were collected using two questionnaires and analyzed with the SPSS software using descriptive and analytical statistics. The mean score of functional, behavioral, ethical, organizational, cultural and educational factors from the users' perspective was 3.14±0.66, 2.97± 0.60, 3.39±0.70, 2.96±0.642, 3.09±0.63, and 2.95±0.74, respectively. The mean score of organizational, behavioral, cultural, technological, educational and legal factors from IT and HIS authorities' perspective was 3.51±0.54, 3.35±0.45, 2.75±0.61, 3.58±0.32, and 3.96±0.59, respectively. The evaluated hospital information systems were considered relatively successful in terms of functional, ethical, and cultural factors but were considered as a relative failure in terms of behavioral, organizational, and educational factors form the users' perspective. Only the legal factor showed success, while organizational, behavioral, technical and educational factors showed relative success and the cultural factor showed relative failure from HIS and IT authorities' perspective. Therefore, assessing the users' needs before implementing the system, involving them in various stages of implementation, training them, and improving their computer skills seem to be necessary to achieve a better level of system success. Copyright © 2017 Elsevier B.V. All rights reserved.

Avoidance Behavior against Positive Allergens Detected with a Multiple Allergen Simultaneous Test Immunoblot Assay in Patients with Urticaria: Factors Associated with Avoidance Success/Failure.

Science.gov (United States)

Lee, Min Kyung; Kwon, In Ho; Kim, Han Su; Kim, Heung Yeol; Cho, Eun Byul; Bae, Youin; Park, Gyeong Hun; Park, Eun Joo; Kim, Kwang Ho; Kim, Kwang Joong

2016-02-01

Avoidance behavior against positive allergens detected by using multiple allergen simultaneous test (MAST)-immunoblot assay in patients with urticaria has been rarely reported. We aimed to assess the avoidance behavior of patients with urticaria against positive allergens detected with a MAST. One hundred and one urticaria patients who showed positivity to at least one allergen on a MAST completed a questionnaire regarding their test results. The avoidance behavior of the patients was evaluated, and relevant determining factors of avoidance success/failure were statistically assessed. We detected 144 different data (n=51, food allergens; n=17, pollen allergens; and n=76, aeroallergens) from 101 patients with urticaria. The avoidance failure rates were 33.3% for food allergens, 70.6% for pollen allergens, and 30.3% for aeroallergens. The pollen group showed a significantly higher avoidance failure rate than the food and aeroallergen groups (psuccessfully avoid allergens (psuccess or failure against allergens in patients with urticaria when clinicians conduct allergen-specific immunoglobulin E tests.

Ingredients for successful partnerships

NARCIS (Netherlands)

S.M. Pfisterer (Stella)

2011-01-01

textabstractFor the development of new cross-sector partnerships it is required to know what the essence of successful partnership projects is. Which factors influence success or failure of partnerships is highly related to the specific context where partnerships operate. The literature on critical

Deformation and failure mechanism of slope in three dimensions

Directory of Open Access Journals (Sweden)

Yingfa Lu

2015-04-01

Full Text Available Understanding three-dimensional (3D slope deformation and failure mechanism and corresponding stability analyses are crucially important issues in geotechnical engineering. In this paper, the mechanisms of progressive failure with thrust-type and pull-type landslides are described in detail. It is considered that the post-failure stress state and the pre-peak stress state may occur at different regions of a landslide body with deformation development, and a critical stress state element (or the soil slice block exists between the post-failure stress state and the pre-peak stress state regions. In this regard, two sorts of failure modes are suggested for the thrust-type and three sorts for pull-type landslides, based on the characteristics of shear stress and strain (or tensile stress and strain. Accordingly, a new joint constitutive model (JCM is proposed based on the current stability analytical theories, and it can be used to describe the mechanical behaviors of geo-materials with softening properties. Five methods, i.e. CSRM (comprehensive sliding resistance method, MTM (main thrust method, CDM (comprehensive displacement method, SDM (surplus displacement method, and MPM (main pull method, for slope stability calculation are proposed. The S-shaped curve of monitored displacement vs. time is presented for different points on the sliding surface during progressive failure process of landslide, and the relationship between the displacement of different points on the sliding surface and height of landslide body is regarded as the parabolic curve. The comparisons between the predicted and observed load–displacement and displacement–time relations of the points on the sliding surface are conducted. The classification of stable/unstable displacement–time curves is proposed. The definition of the main sliding direction of a landslide is also suggested in such a way that the failure body of landslide (simplified as “collapse body” is only

Successes and failures of sixty years of vector control in French Guiana: what is the next step?

Science.gov (United States)

Epelboin, Yanouk; Chaney, Sarah C; Guidez, Amandine; Habchi-Hanriot, Nausicaa; Talaga, Stanislas; Wang, Lanjiao; Dusfour, Isabelle

2018-03-12

Since the 1940s, French Guiana has implemented vector control to contain or eliminate malaria, yellow fever, and, recently, dengue, chikungunya, and Zika. Over time, strategies have evolved depending on the location, efficacy of the methods, development of insecticide resistance, and advances in vector control techniques. This review summarises the history of vector control in French Guiana by reporting the records found in the private archives of the Institute Pasteur in French Guiana and those accessible in libraries worldwide. This publication highlights successes and failures in vector control and identifies the constraints and expectations for vector control in this French overseas territory in the Americas.

Successes and failures of sixty years of vector control in French Guiana: what is the next step?

Directory of Open Access Journals (Sweden)

Yanouk Epelboin

2018-03-01

Full Text Available Since the 1940s, French Guiana has implemented vector control to contain or eliminate malaria, yellow fever, and, recently, dengue, chikungunya, and Zika. Over time, strategies have evolved depending on the location, efficacy of the methods, development of insecticide resistance, and advances in vector control techniques. This review summarises the history of vector control in French Guiana by reporting the records found in the private archives of the Institute Pasteur in French Guiana and those accessible in libraries worldwide. This publication highlights successes and failures in vector control and identifies the constraints and expectations for vector control in this French overseas territory in the Americas.

Efficacy and predictors of success of noninvasive ventilation for prevention of extubation failure in critically ill children with heart disease.

Science.gov (United States)

Gupta, Punkaj; Kuperstock, Jacob E; Hashmi, Sana; Arnolde, Vickie; Gossett, Jeffrey M; Prodhan, Parthak; Venkataraman, Shekhar; Roth, Stephen J

2013-04-01

The study aimed primarily to evaluate the efficacy of noninvasive ventilation (NIV) and to identify possible predictors for success of NIV therapy in preventing extubation failure in critically ill children with heart disease. The secondary objectives of this study were to assess the efficacy of prophylactic NIV therapy initiated immediately after tracheal extubation and to determine the characteristics, outcomes, and complications associated with NIV therapy in pediatric cardiac patients. A retrospective review examined the medical records of all children between the ages 1 day and 18 years who sustained acute respiratory failure (ARF) that required NIV in the cardiovascular intensive care unit (CVICU) at Lucile Packard Children's Hospital between January 2008 and June 2010. Patients were assigned to a prophylactic group if NIV was started directly after extubation and to a nonprophylactic group if NIV was started after signs and symptoms of ARF developed. Patients were designated as responders if they received NIV and did not require reintubation during their CVICU stay and nonresponders if they failed NIV and reintubation was performed. The data collected included demographic data, preexisting conditions, pre-event characteristics, event characteristics, and outcome data. The outcome data evaluated included success or failure of NIV, duration of NIV, CVICU length of stay (LOS), hospital LOS, and hospital mortality. The two complications of NIV assessed in the study included nasal bridge or forehead skin necrosis and pneumothorax. The 221 eligible events during the study period involved 172 responders (77.8 %) and 49 nonresponders (22.2 %). A total of 201 events experienced by the study cohort received continuous positive airway pressure (CPAP), with 156 responders (78 %), whereas 20 events received bilevel positive airway pressure (BiPAP), with 16 responders (80 %). In the study, 58 events (26.3 %) were assigned to the prophylactic group and 163 events (73

Reliability of mechanical components subjected to combined alternating and mean stresses with a nonconstant stress ratio

International Nuclear Information System (INIS)

Kececioglu, D.; Lamarre, G.B.

1979-01-01

The reliability of reactor mechanical components and structural members, submitted to external loads which induce alternating bending stresses and mean shear stresses at the critical section where failure has a high probability of occurring, is predicted assuming that the ratio of the distributed alternating stress to the mean stress is also distributed and yields a bivariate failure-governing, combined alternating and mean, stress distribution. A computer programmed methodology is developed to calculate the reliability under these conditions given the associated distributional Goodman diagram for a reactor component or structural member. (orig.)

Failure Criteria for Reinforced Materials

DEFF Research Database (Denmark)

Rathkjen, Arne

Failure of materials is often characterized as ductile yielding, brittle fracture, creep rupture, etc., and different criteria given in terms of different parameters have been used to describe different types of failure. Only criteria expressing failure in terms of stress are considered in what...... place until the matrix, the continuous component of the composite, fails. When an isotropic matrix is reinforced as described above, the result is an anisotropic composite material. Even if the material is anisotropic, it usually exhibits a rather high degree of symmetry and such symmetries place...... certain restrictions on the form of the failure criteria for anisotropic materials. In section 2, some failure criteria for homogenous materials are reviewed. Both isotropic and anisotropic materials are described, and in particular the constraints imposed on the criteria from the symmetries orthotropy...

Obstetrical and neonatal outcomes following unsuccessful external cephalic version: a stratified analysis amongst failures, successes, and controls.

Science.gov (United States)

Balayla, Jacques; Dahdouh, Elias M; Villeneuve, Sophie; Boucher, Marc; Gauthier, Robert J; Audibert, François; Fuchs, Florent

2015-03-01

Though on average one out of every two external cephalic versions (ECV) fails to rotate the breech fetus, little is known about the outcomes of pregnancies in which ECV is unsuccessful. The objective of the present study is to compare obstetrical and neonatal outcomes following failure of ECV, relative to cases of breech controls without an attempt at ECV. We conducted a retrospective, population-based, cohort study using the CDC's Birth Data files from the US for the year 2006. We stratified the cohort according to fetal presentation and ECV status: success, failure, and no ECV (controls). The effect of failure of ECV on the risk of several neonatal and obstetrical outcomes was estimated using logistic regression analysis, adjusting for relevant confounders. We analyzed a total of 4 273 225 births, out of which 183 323 (4.3%) met inclusion criteria. Relative to breech controls, failed ECV occurred more frequently amongst Caucasian, college-educated, married women bearing a female fetus. Compared to no ECV, failure of ECV was associated with increased odds of PROM (aOR, 1.75; 95% CI, 1.60-1.90), elective cesarean delivery (aOR, 1.53; 95% CI, 1.36-1.72), cesarean delivery in labor (aOR, 1.38; 95% CI, 1.21-1.57), abnormal fetal heart tracing (aOR, 1.78; 95% CI, 1.50-2.11), assisted ventilation at birth (aOR, 1.50; 95% CI, 1.27-1.78), 5-min APGAR scores <7 (aOR, 1.35; 95% CI, 1.20-1.51), and NICU admission (aOR, 1.48; 95% CI, 1.20-1.82). The delayed spontaneous fetal restitution rate was 13%. When stratifying controls with regards to trial of labor status, the increased risk of failed ECV persisted for cesarean delivery, NICU admission, assisted ventilation and abnormal fetal tracing, independently of whether a trial of labor took place. Relative to breech controls without attempt at ECV, failure of ECV to restitute cephalic presentation appears to be associated with an increased risk of adverse perinatal and obstetrical outcomes.

Return Migration as Failure or Success?: The Determinants of Return Migration Intentions Among Moroccan Migrants in Europe.

Science.gov (United States)

de Haas, Hein; Fokkema, Tineke; Fihri, Mohamed Fassi

Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after migrants have earned sufficient assets and knowledge and to invest in their origin countries. The projected return is then likely to be postponed for sustained or indefinite periods if integration is unsuccessful. So, from an indication or result of integration failure return is rather seen as a measure of success. Drawing on recent survey data ( N  = 2,832), this article tests these hypotheses by examining the main determinants of return intention among Moroccan migrants across Europe. The results indicate that structural integration through labour market participation, education and the maintenance of economic and social ties with receiving countries do not significantly affect return intentions. At the same time, investments and social ties to Morocco are positively related, and socio-cultural integration in receiving countries is negatively related to return migration intentions. The mixed results corroborate the idea that there is no uniform process of (return) migration and that competing theories might therefore be partly complementary.

Strain limit criteria to predict failure

International Nuclear Information System (INIS)

Flanders, H.E.

1995-01-01

In recent years extensive effort has been expended to qualify existing structures for conditions that are beyond the original design basis. Determination of the component failure load is useful for this type of evaluation. This paper presents criteria based upon strain limits to predict the load at failure. The failure modes addressed are excessive plastic deformations, localized plastic strains, and structural instability. The effects of analytical method sophistication, as built configurations, material properties degradation, and stress state are addressed by the criteria

A Mixed Methods Analysis of the Effect of Google Docs Environment on EFL Learners' Writing Performance and Causal Attributions for Success and Failure

Science.gov (United States)

Seyyedrezaie, Zari Sadat; Ghonsooly, Behzad; Shahriari, Hesamoddin; Fatemi, Hazar Hosseini

2016-01-01

This study investigated the effect of writing process in Google Docs environment on Iranian EFL learners' writing performance. It also examined students' perceptions towards the effects of Google Docs and their perceived causes of success or failure in writing performance. In this regard, 48 EFL students were chosen based on their IELTs writing…

Permeability Evolution and Rock Brittle Failure

OpenAIRE

Sun Qiang; Xue Lei; Zhu Shuyun

2015-01-01

This paper reports an experimental study of the evolution of permeability during rock brittle failure and a theoretical analysis of rock critical stress level. It is assumed that the rock is a strain-softening medium whose strength can be described by Weibull’s distribution. Based on the two-dimensional renormalization group theory, it is found that the stress level λ c (the ratio of the stress at the critical point to the peak stress) depends mainly on the homogeneity index or shape paramete...

Supersonic Localized Excitations Mediate Microscopic Dynamic Failure

Science.gov (United States)

Ghaffari, H. O.; Griffith, W. A.; Pec, M.

2017-12-01

A moving rupture front activates a fault patch by increasing stress above a threshold strength level. Subsequent failure yields fast slip which releases stored energy in the rock. A fraction of the released energy is radiated as seismic waves carrying information about the earthquake source. While this simplified model is widely accepted, the detailed evolution from the onset of dynamic failure to eventual re-equilibration is still poorly understood. To study dynamic failure of brittle solids we indented thin sheets of single mineral crystals and recorded the emitted ultrasound signals (high frequency analogues to seismic waves) using an array of 8 to 16 ultrasound probes. The simple geometry of the experiments allows us to unravel details of dynamic stress history of the laboratory earthquake sources. A universal pattern of failure is observed. First, stress increases over a short time period (1 - 2 µs), followed by rapid weakening (≈ 15 µs). Rapid weakening is followed by two distinct relaxation phases: a temporary quasi-steady state phase (10 µs) followed by a long-term relaxation phase (> 50 µs). We demonstrate that the dynamic stress history during failure is governed by formation and interaction of local non-dispersive excitations, or solitons. The formation and annihilation of solitons mediates the microscopic fast weakening phase, during which extreme acceleration and collision of solitons lead to non-Newtonian behavior and Lorentz contraction, i.e. shortening of solitons' characteristic length. Interestingly, a soliton can propagate as fast as 37 km/s, much faster than the p-wave velocity, implying that a fraction of the energy transmits through soliton excitations. The quasi-steady state phase delays the long-term ageing of the damaged crystal, implying a potentially weaker material. Our results open new horizons for understanding the complexity of earthquake sources, and, more generally, non-equilibrium relaxation of many body systems.

Explaining Success and Failure in Development

OpenAIRE

Szirmai, Adam

2008-01-01

Since 1950, there has been considerable diversity in developing country experiences. Some countries and some regions have experienced rapid growth and catch up, others have fallen behind. At a global level there is an increasing inequality of per capita incomes. However, within the framework of increasing inequality, some countries have experienced accelerated catch up. The speed of catch up in the successful countries is more rapid than in previous historical periods. This paper analyses the...

A Comparison of Teacher Stress and School Climate across Schools with Different Matric Success Rates

Science.gov (United States)

Milner, Karen; Khoza, Harriet

2008-01-01

Our aim was to investigate differences in teacher stress and perceptions of school climate among teachers from schools with differing matriculation success rates in the Limpopo province of South Africa. Two schools with matric pass rates of 100% and two schools with matric pass rates of less than 25% were selected from a list of schools provided…

Bayesian Estimation of Source Parameters and Associated Coulomb Failure Stress Changes for the 2005 Fukuoka (Japan) Earthquake

KAUST Repository

Dutta, Rishabh

2017-12-20

Several researchers have studied the source parameters of the 2005 Fukuoka (northwestern Kyushu Island, Japan) earthquake (MW 6.6) using teleseismic, strong motion and geodetic data. However, in all previous studies, errors of the estimated fault solutions have been neglected, making it impossible to assess the reliability of the reported solutions. We use Bayesian inference to estimate the location, geometry and slip parameters of the fault and their uncertainties using Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) data. The offshore location of the earthquake makes the fault parameter estimation challenging, with geodetic data coverage mostly to the southeast of the earthquake. To constrain the fault parameters, we use a priori constraints on the magnitude of the earthquake and the location of the fault with respect to the aftershock distribution and find that the estimated fault slip ranges from 1.5 m to 2.5 m with decreasing probability. The marginal distributions of the source parameters show that the location of the western end of the fault is poorly constrained by the data whereas that of the eastern end, located closer to the shore, is better resolved. We propagate the uncertainties of the fault model and calculate the variability of Coulomb failure stress changes for the nearby Kego fault, located directly below Fukuoka city, showing that the mainshock increased stress on the fault and brought it closer to failure.

The failure-tolerant leader.

Science.gov (United States)

Farson, Richard; Keyes, Ralph

2002-08-01

"The fastest way to succeed," IBM's Thomas Watson, Sr., once said, "is to double your failure rate." In recent years, more and more executives have embraced Watson's point of view, coming to understand what innovators have always known: Failure is a prerequisite to invention. But while companies may grasp the value of making mistakes at the level of corporate practices, they have a harder time accepting the idea at the personal level. People are afraid to fail, and corporate culture reinforces that fear. In this article, psychologist and former Harvard Business School professor Richard Farson and coauthor Ralph Keyes discuss how companies can reduce the fear of miscues. What's crucial is the presence of failure-tolerant leaders--executives who, through their words and actions, help employees overcome their anxieties about making mistakes and, in the process, create a culture of intelligent risk-taking that leads to sustained innovation. Such leaders don't just accept productive failure, they promote it. Drawing from their research in business, politics, sports, and science, the authors identify common practices among failure-tolerant leaders. These leaders break down the social and bureaucratic barriers that separate them from their followers. They engage at a personal level with the people they lead. They avoid giving either praise or criticism, preferring to take a nonjudgmental, analytical posture as they interact with staff. They openly admit their own mistakes rather than trying to cover them up or shifting the blame. And they try to root out the destructive competitiveness built into most organizations. Above all else, failure-tolerant leaders push people to see beyond traditional definitions of success and failure. They know that as long as a person views failure as the opposite of success, rather than its complement, he or she will never be able to take the risks necessary for innovation.

Stressors, stress and stress consequences during long-duration manned space missions: a descriptive model

Science.gov (United States)

Geuna, Stefano; Brunelli, Francesco; Perino, Maria A.

Keeping crew members in good health is a major factor in the success or failure of long-duration manned space missions. Among the many possible agents that can affect the crew's general well-being, stress is certainly one of the most critical because of its implications on human health and performance, both physical and mental. Nevertheless, very few studies have been performed on this fundamental issue and none of them has addressed it in its entirity, considering its diverse physical and psychological aspects. In this work, a descriptive model is proposed to expound the mechanism and sequence of events which mediate stress. A critical analysis of the information provided by past manned spaceflights and by dedicated research performed in analogous environments is presented, and an extrapolation of the available data on human stress in such extreme conditions is proposed. Both internal and external stressors have been identified, at physical and psychosocial levels, thus providing the basis for their early detection and preventive reduction. The possible negative consequences of stress that may lead to disease in crewmembers are described. Finally, the most effective instruments which may be of help in reducing space-related human stress and treating its negative consequences are suggested.

Oxidative Stress, Bone Marrow Failure, and Genome Instability in Hematopoietic Stem Cells

Directory of Open Access Journals (Sweden)

Christine Richardson

2015-01-01

Full Text Available Reactive oxygen species (ROS can be generated by defective endogenous reduction of oxygen by cellular enzymes or in the mitochondrial respiratory pathway, as well as by exogenous exposure to UV or environmental damaging agents. Regulation of intracellular ROS levels is critical since increases above normal concentrations lead to oxidative stress and DNA damage. A growing body of evidence indicates that the inability to regulate high levels of ROS leading to alteration of cellular homeostasis or defective repair of ROS-induced damage lies at the root of diseases characterized by both neurodegeneration and bone marrow failure as well as cancer. That these diseases may be reflective of the dynamic ability of cells to respond to ROS through developmental stages and aging lies in the similarities between phenotypes at the cellular level. This review summarizes work linking the ability to regulate intracellular ROS to the hematopoietic stem cell phenotype, aging, and disease.

Flexural fatigue failures and lives of Eco-Core sandwich beams

International Nuclear Information System (INIS)

Hossain, Mohammad Mynul; Shivakumar, Kunigal

2014-01-01

Highlights: • Eco-Core sandwich beam is flexural fatigue tested to study its fatigue response. • The core showed three failure types: damage onset, progression and final failure. • These failures were found to be represented by 1%, 5% and 7% change in compliance. • The fatigue stress-life (S–N) relationship follows a power low, σ max /σ ct = A o N α . • The fatigue failure was by multiple vertical cracks followed by 45° shear failure. - Abstract: Eco-Core is a class of syntactic foam made from small volume of high char yield binder and large volume of a class of flyash for fire resistance application. Very little or no flexural fatigue data of this class of core material is reported in the open literature. This paper presents a flexural fatigue response of Eco-Core in a glass/vinyl ester composite face sheet sandwich beam. A four-point loaded flexural test specimen was designed and tested in static and fatigue loadings to cause tension failure in the core. The fatigue test was conducted at maximum cyclic stress (σ max ) ranged from 0.7σ ct to 0.9σ ct , where σ ct is the static flexural strength of the core. The sinusoidal loading frequency of 2 Hz with the stress ratio of 0.1 was used. Flexural fatigue failure modes of Eco-Core sandwich beam were classified: damage onset (single tension crack), damage progression (multiple tension cracks) and ultimate failure (a combination of tension and shear). These failures were characterized by 1%, 5% and 7% changes in compliance that corresponds to N 1% , N 5% and N 7% lives. The fatigue stress-life (S–N) relationship was found to follow the well-known power law equation, σ max /σ ct = A o N α . The constants A o and α were established for all three types of failures. The endurance limit was established based on 1 million cycles limit and it was found to be 0.65σ ct , 0.70σ ct and 0.71σ ct , respectively for the three modes of failure. Flexural fatigue and static failure modes of Eco-Core sandwich

Successful treatment of thyroid storm presenting as recurrent cardiac arrest and subsequent multiorgan failure by continuous renal replacement therapy

Directory of Open Access Journals (Sweden)

Han Soo Park

2017-03-01

Full Text Available Thyroid storm is a rare and potentially life-threatening medical emergency. We experienced a case of thyroid storm associated with sepsis caused by pneumonia, which had a catastrophic course including recurrent cardiac arrest and subsequent multiple organ failure (MOF. A 22-year-old female patient with a 10-year history of Graves’ disease was transferred to our emergency department (ED. She had a cardiac arrest at her home and a second cardiac arrest at the ED. Her heart recovered after 20 min of cardiac resuscitation. She was diagnosed with thyroid storm associated with hyperthyroidism complicated by pneumonia and sepsis. Although full conventional medical treatment was given, she had progressive MOF and hemodynamic instability consisting of hyperthermia, tachycardia and hypotension. Because of hepatic and renal failure with refractory hypotension, we reduced the patient’s dose of beta-blocker and antithyroid drug, and she was started on continuous veno-venous renal replacement therapy (CRRT with intravenous albumin and plasma supplementation. Subsequently, her body temperature and pulse rate began to stabilize within 1 h, and her blood pressure reached 120/60 mmHg after 6 h. We discontinued antithyroid drug 3 days after admission because of aggravated hyperbilirubinemia. The patient exhibited progressive improvement in thyroid function even after cessation of antithyroid drug, and she successfully recovered from thyroid storm and MOF. This is the first case of thyroid storm successfully treated by CRRT in a patient considered unfit for antithyroid drug treatment.

Oxidative stress in primary glomerular diseases

DEFF Research Database (Denmark)

Markan, Suchita; Kohli, Harbir Singh; Sud, Kamal

2008-01-01

To evaluate the status of oxidative stress in patients with different primary glomerular diseases (PGD) which have differential predisposition to renal failure.......To evaluate the status of oxidative stress in patients with different primary glomerular diseases (PGD) which have differential predisposition to renal failure....

Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose.

Science.gov (United States)

Milner, Jos M; van Beest, Floris M; Solberg, Erling J; Storaas, Torstein

2013-08-01

A life history strategy that favours somatic growth over reproduction is well known for long-lived iteroparous species, especially in unpredictable environments. Risk-sensitive female reproductive allocation can be achieved by a reduced reproductive effort at conception, or the subsequent adjustment of investment during gestation or lactation in response to unexpected environmental conditions or resource availability. We investigated the relative importance of reduced investment at conception compared with later in the reproductive cycle (i.e. prenatal, perinatal or neonatal mortality) in explaining reproductive failure in two high-density moose (Alces alces) populations in southern Norway. We followed 65 multiparous, global positioning system (GPS)-collared females throughout the reproductive cycle and focused on the role of maternal nutrition during gestation in determining reproductive success using a quasi-experimental approach to manipulate winter forage availability. Pregnancy rates in early winter were normal (≥0.8) in all years while spring calving rates ranged from 0.4 to 0.83, with prenatal mortality accounting for most of the difference. Further losses over summer reduced autumn recruitment rates to 0.23-0.69, despite negligible predation. Over-winter mass loss explained variation in both spring calving and autumn recruitment success better than absolute body mass in early or late winter. Although pregnancy was related to body mass in early winter, overall reproductive success was unrelated to pre-winter body condition. We therefore concluded that reproductive success was limited by winter nutritional conditions. However, we could not determine whether the observed reproductive allocation adjustment was a bet-hedging strategy to maximise reproduction without compromising survival or whether females were simply unable to invest more resources in their offspring.

Instrument Failure, Stress, and Spatial Disorientation Leading to a Fatal Crash With a Large Aircraft.

Science.gov (United States)

Tribukait, Arne; Eiken, Ola

2017-11-01

An aircraft's orientation relative to the ground cannot be perceived via the sense of balance or the somatosensory system. When devoid of external visual references, the pilot must rely on instruments. A sudden unexpected instrument indication is a challenge to the pilot, who might have to question the instrument instead of responding with the controls. In this case report we analyze, from a human-factors perspective, how a limited instrument failure led to a fatal accident. During straight-ahead level flight in darkness, at 33,000 ft, the commander of a civil cargo airplane was suddenly confronted by an erroneous pitch-up indication on his primary flight display. He responded by pushing the control column forward, making a bunt maneuver with reduced/negative Gz during approximately 15 s. The pilots did not communicate rationally or cross-check instruments. Recordings of elevator and aileron positions suggest that the commander made intense efforts to correct for several extreme and erroneous roll and pitch indications. Gz displayed an increasing trend with rapid fluctuations and peaks of approximately 3 G. After 50 s the aircraft entered a turn with decreasing radius and finally hit the ground in an inverted attitude. A precipitate maneuvring response can, even if occurring in a large aircraft at high altitude, result in a seemingly inexorable course of events, ending with a crash. In the present case both pilots were probably incapacitated by acute psychological stress and spatial disorientation. Intense variations in Gz may have impaired the copilot's reading of the functioning primary flight display.Tribukait A, Eiken O. Instrument failure, stress, and spatial disorientation leading to a fatal crash with a large aircraft. Aerosp Med Hum Perform. 2017; 88(11):1043-1048.

Mathematical modeling of thermal stresses in basic oxygen furnace hood tubes

Science.gov (United States)

Samarasekera, I. V.

1985-06-01

The stress-strain history of Basic Oxygen Furnace hood tubes during thermal cycling has been computed using heat flow and stress analyses. The steady-state temperature distribution in a transverse section of the tube was computed at a location where gas temperature in the hood could be expected to be a maximum. Calculations were performed for peak gas temperatures in the range 1950 to 2480 °C (3500 to 4500 °F). The stress-strain history of an element of material located at the center of the tube hot face was traced for three consecutive cycles using elasto-plastic finite-element analysis. It has been shown that the state of stress in the element alternates between compression and tension as the tube successively heats and cools. Yielding and plastic flow occurs at the end of each half of a given cycle. It was postulated that owing to repctitive yielding, plastic strain energy accumulates causing failure of the tubes by fatigue in the low cycle region. Using fatigue theory a conservative estimate for tube life was arrived at. In-plant observations support this mechanism of failure, and the number of cycles within which tube cracking was observed compares reasonably with model predictions. Utilizing the heat flow and stress models it was recommended that tube life could be enhanced by changing the tube material to ARMCO 17-4 pH or AISI 405 steel or alternatively reconstructing hoods with AISI 316L tubes of reduced thickness. These recommendations were based on the criterion that low-cycle fatigue failure could be averted if the magnitude of the cyclic strain could be reduced or if macroscopic plastic flow could be prevented.

The Social Construction of Development Cooperation Success and Failure

DEFF Research Database (Denmark)

Fejerskov, Adam Moe

2016-01-01

Determining the success of development projects and programmes is often portrayed and understood as a question of measurable impact and effectiveness. More often than not however, success is a negotiated truth, socially constructed between the involved stakeholders that does not require measurable...... results of impact, and may very well hold the opposite circumstances. By examining the Intergovernmental Authority on Development in the Horn of Africa, the article investigates one such case of development project success despite no substantial impact on the ground. Success in development cooperation......, the article argues, is not a matter of attaining impact, but is rather constructed in the overlapping space between representation and interpretation of events, actions and discourses, made and sustained socially between recipient and donor....

Stress and strain field singularities, micro-cracks, and their role in failure initiation at the composite laminate free-edge

Science.gov (United States)

Dustin, Joshua S.

A state-of-the-art multi-scale analysis was performed to predict failure initiation at the free-edge of an angle-ply laminate using the Strain Invariant Failure Theory (SIFT), and multiple improvements to this analysis methodology were proposed and implemented. Application of this analysis and theory led to the conclusion that point-wise failure criteria which ignore the singular stress and strain fields from a homogenized analysis and the presence of free-edge damage in the form of micro-cracking, may do so at the expense of failure prediction capability. The main contributions of this work then are made in the study of the laminate free-edge singularity and in the effects of micro-cracking at the composite laminate free-edge. Study of both classical elasticity and finite element solutions of the laminate free-edge stress field based upon the assumption of homogenized lamina properties reveal that the order of the free-edge singularity is sufficiently small such that the domain of dominance of this term away from the laminate free-edge is much smaller than the relevant dimensions of the microstructure. In comparison to a crack-tip field, these free-edge singularities generate stress and strain fields which are half as intense as those at the crack-tip, leading to the conclusion that existing flaws at the free-edge in the form of micro-cracks would be more prone to the initiation of free-edge failure than the existence of a singularity in the free-edge elasticity solutions. A methodical experiment was performed on a family of [±25°/90°] s laminates made of IM7/8552 carbon/epoxy composite, to both characterize micro-cracks present at the laminate free-edge and to study their behavior under the application of a uniform extensional load. The majority of these micro-cracks were of length on the order of a few fiber diameters, though larger micro-cracks as long as 100 fiber diameters were observed in thicker laminates. A strong correlation between the application of

A Take Stock of Turbine Blades Failure Phenomenon

Science.gov (United States)

Roy, Abhijit

2018-02-01

Turbine Blade design and engineering is one of the most complicated and important aspects of turbine technology. Experiments with blades can be simple or very complicated, depending upon parameters of analysis. Turbine blades are subjected to vigorous environments, such as high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failures, which can destroy the turbine, and engine, so careful design is the prime consideration to resist those conditions. A high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery is common failure mode for turbine machine. Continuous study and investigation on failure of turbine blades are going on since last five decades. Some review papers published during these days aiming to present a review on recent studies and investigations done on failures of turbine blades. All the detailed literature related with the turbine blades has not been described but emphasized to provide all the methodologies of failures adopted by various researches to investigate turbine blade. This paper illustrate on various factors of failure.

Failure Waves in Cylindrical Glass Bars

Science.gov (United States)

Cazamias, James U.; Bless, Stephan J.; Marder, Michael P.

1997-07-01

Failure waves, a propagating front separating virgin and comminuted material, have been receiving a fair amount of attention the last couple of years. While most scientists have been looking at failure waves in plate impact geometries, we have conducted a series of experiments on Pyrex bars. In this paper, we present two types of photographic data from a series of tests. A streak camera was used to determine velocities of the failure front as a function of impact stress. A polaroid camera and a flash lamp provide detailed pictures of the actual event. Attempts were made to observe failure waves in amorphous quartz and acrylic.

[The advancement of robotic surgery--successes, failures, challenges].

Science.gov (United States)

Haidegger, Tamás

2010-10-10

Computer-integrated robotic surgery systems appeared more than twenty years ago and since then hundreds of different prototypes have been developed. Only a fraction of them have been commercialized, mostly to support neurosurgical and orthopaedic procedures.Unquestionably, the most successful one is the da Vinci surgical system, primarily deployed in urology and general laparoscopic surgery. It is developed and marketed by Intuitive Surgical Inc. (Sunnyvale, CA, USA), the only profitable company of the segment. The da Vinci made robotic surgery is known and acknowledged throughout the world, and the great results delivered convinced most of the former critics of the technology. Success derived from the well chosen business development strategy, proficiency of the developers, appropriate timing and a huge pot of luck. This article presents the most important features of the da Vinci system, the history of development along with its medical, economical and financial aspects, and seeks the answer why this particular system became successful.

Stress and food deprivation: linking physiological state to migration success in a teleost fish

DEFF Research Database (Denmark)

Midwood, J.D.; Larsen, Martin Hage; Aarestrup, Kim

2016-01-01

for the cortisol treatment. Food availability and individual energetic state appear to dictate the future life-history strategy (migrate or remain resident) of juvenile salmonids while experimental elevation of the stress hormone cortisol caused impaired growth and reduced survival of both resident and migratory......Food deprivation (FD) is a naturally occurring stressor that is thought to influence the ultimate life-history strategy of individuals. Little is known about how FD interacts with other stressors to influence migration success. European populations of brown trout (Salmo trutta) exhibit partial...... of the glucocorticoid stress response in determining life-history strategy and survival of a migratory species. Using an experimental approach, the relative influences of short-term FD and experimental cortisol elevation (i.e., intra-coelomic injection of cortisol suspended in cocoa butter) on migratory status...

Failure prediction of low-carbon steel pressure vessel and cylindrical models

International Nuclear Information System (INIS)

Zhang, K.D.; Wang, W.

1987-01-01

The failure loads predicted by failure assessment methods (namely the net-section stress criterion; the EPRI engineering approach for elastic-plastic analysis; the CEGB failure assessment route; the modified R6 curve by Milne for strain hardening; and the failure assessment curve based on J estimation by Ainsworth) have been compared with burst test results on externally, axially sharp notched pressure vessel and open-ended cylinder models made from typical low-carbon steel St45 seamless tube which has a transverse true stress-strain curve of straight-line and parabola type and a high value of ultimate strength to yield. It was concluded from the comparison that whilst the net-section stress criterion and the CEGB route did not give conservative predictions, Milne's modified curve did give a conservative and good prediction; Ainsworth's curve gave a fairly conservative prediction; and EPRI solutions also could conditionally give a good prediction but the conditions are still somewhat uncertain. It is suggested that Milne's modified R6 curve is used in failure assessment of low-carbon steel pressure vessels. (author)

Mechanistic considerations used in the development of the probability of failure in transient increases in power (PROFIT) pellet-zircaloy cladding (thermo-mechanical-chemical) interactions (pci) fuel failure model

International Nuclear Information System (INIS)

Pankaskie, P.J.

1980-05-01

A fuel Pellet-Zircaloy Cladding (thermo-mechanical-chemical) interactions (PCI) failure model for estimating the Probability of Failure in Transient Increases in Power (PROFIT) was developed. PROFIT is based on (1) standard statistical methods applied to available PCI fuel failure data and (2) a mechanistic analysis of the environmental and strain-rate-dependent stress versus strain characteristics of Zircaloy cladding. The statistical analysis of fuel failures attributable to PCI suggested that parameters in addition to power, transient increase in power, and burnup are needed to define PCI fuel failures in terms of probability estimates with known confidence limits. The PROFIT model, therefore, introduces an environmental and strain-rate dependent Strain Energy Absorption to Failure (SEAF) concept to account for the stress versus strain anomalies attributable to interstitial-dislocation interaction effects in the Zircaloy cladding

Personality dimensions and service failure severity

African Journals Online (AJOL)

kirstam

Dr L. Kruger is a senior lecturer in the Department of Marketing Management ... severity rather than possible individual consumer effects on service failure severity. ... When service failures occur, there is an imbalance in the relationship, because ... service recovery strategies may result in a successful recovery experience ( ...

Contact stresses by rounded punch subject to axial and transverse shear

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1999-05-01

Contact shear stresses by rounded punch were evaluated numerically. Numerical program was successfully implemented by using an influence function method. To simulate the physical fretting problem, a closed load path of shear was considered. The influence functions on surface displacements fo both axial and transverse direction were calculated using a triangular shear traction element. Behaviour of the contact surface, such as stick and slip region during the load path was investigated together with compliance change. Irreversibility of the shear stress was shown. The importance and the utilization of the present research were discussed for analyzing the material failure induced by contact such as fretting wear and fatigue.

Contact stresses by rounded punch subject to axial and transverse shear