The Tonian Beck Spring Dolomite: Marine dolomitization in a shallow, anoxic sea

Science.gov (United States)

Shuster, Alice Mary; Wallace, Malcolm William; van Smeerdijk Hood, Ashleigh; Jiang, Ganqing

2018-06-01

The reason for the abundance of dolomite lithologies in Earth's early geological record compared to modern environments remains contentious. This study provides new insight into this Precambrian "dolomite problem" by revisiting one of the most controversial dolomite localities, the Beck Spring Dolomite, of Death Valley, USA. Consistent with some previous studies, petrographic evidence indicates that although the Beck Spring Dolomite now consists almost entirely of dolomite, it was originally precipitated largely as aragonite and high-Mg calcite. Depositional constituents (microbialites and ooids) were likely originally aragonitic, and early marine length-fast cements (now dolomite) are suggested to have precipitated as high-Mg calcite then replaced syntaxially by dolomite. Based on petrographic and geochemical evidence, we suggest that marine dolomitization was the dominant synsedimentary diagenetic process in the unit, and for the most part, involved syntaxial and mimetic replacement. Further, a length-slow fibrous dolomite generation was precipitated during the later stages of marine diagenesis as a primary marine dolomite cement. This is indicated by the length-slow crystallographic structure of the cement and from its preserved geochemical and cathodoluminescence growth zonation. This new evidence for Tonian marine dolomite precipitation reinforces the idea of Precambrian marine environmental conditions, including the chemical composition of seawater, promoting dolomite formation at this time. The trace metal geochemical composition of well-preserved marine components, especially dolomite marine cements, reveals information about redox conditions in this Tonian shallow seawater. In terms of rare earth element geochemistry, the Beck Spring Dolomite has no significant Ce anomaly, and a ubiquitous positive Eu anomaly, consistent with widespread oceanic anoxia during deposition. Furthermore, the relatively low levels of iron and chalcophile elements Co, Cu, Pb and

Exploratory Factor Analysis of the Beck Anxiety Inventory and the Beck Depression Inventory-II in a Psychiatric Outpatient Population

Science.gov (United States)

2018-01-01

Background To further understand the relationship between anxiety and depression, this study examined the factor structure of the combined items from two validated measures for anxiety and depression. Methods The participants were 406 patients with mixed psychiatric diagnoses including anxiety and depressive disorders from a psychiatric outpatient unit at a university-affiliated medical center. Responses of the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI)-II, and Symptom Checklist-90-Revised (SCL-90-R) were analyzed. We conducted an exploratory factor analysis of 42 items from the BAI and BDI-II. Correlational analyses were performed between subscale scores of the SCL-90-R and factors derived from the factor analysis. Scores of individual items of the BAI and BDI-II were also compared between groups of anxiety disorder (n = 185) and depressive disorder (n = 123). Results Exploratory factor analysis revealed the following five factors explaining 56.2% of the total variance: somatic anxiety (factor 1), cognitive depression (factor 2), somatic depression (factor 3), subjective anxiety (factor 4), and autonomic anxiety (factor 5). The depression group had significantly higher scores for 12 items on the BDI while the anxiety group demonstrated higher scores for six items on the BAI. Conclusion Our results suggest that anxiety and depressive symptoms as measured by the BAI and BDI-II can be empirically differentiated and that particularly items of the cognitive domain in depression and those of physical domain in anxiety are noteworthy. PMID:29651821

Juvenile osteoarthritis as consequence of enchondral injuries.. Frostbite, Kashin-Beck disease, rat bites and other causes; Kindliche Arthrosen als Folge enchondraler Schaedigungen. Am Beispiel von Erfrierungen, der Kashin-Beck-Erkrankung, Rattenbissen und anderen Ursachen

Energy Technology Data Exchange (ETDEWEB)

Oestreich, A.E. [Children' s Hospital Medical Center, Cincinnati, OH (United States)

2000-12-01

Purpose. To review the similarities of the radiographic changes in frostbite, the Asian disease of Kashin-Beck, and long term growth damage from injury such as rate bite. Materials and Methods. Radiographs and literature from subjects with these diagnoses were analyzed for the common features and differences. Included was an infant with hand changes 8 months after unwitnessed rat bites. Results. Each condition revealed findings consistent with the hypothesis of localized damage to sites of enchondral ossification, including at acrophyses - the growth plates that are not between epiphysis and metaphysis, but instead lie at the margins of growth centers, including carpal and tarsal bones, and the non-epiphyseal ends of small tubular bones. Discussion. The patterns observed support a final common pathway of damage in frostbite due to cold injury, Kashin-Beck disease (endemic in China) of unknown etiology, and damage from toxines associated, for example, with rat bite. In frostbite, the distribution is acral because of the site of exposure, while the distribution in Kashin-Beck is more diffuse and often less contiguous. In each condition, arthrotic sequelae may be expected in the natural course of follow-up. MRI may play a role in acute diagnosis that might modify the course of each disease. (orig.) [German] Ziel dieser Arbeit ist es, die radiologische Gleichartigkeit enchondraler Wachstumsschaedigungen im Rahmen von Erfrierungen, der asiatischen Kashin-Beck-Erkrankung und (Ratten-)Bissverletzungen darzustellen. Alle 3 Krankheitsbilder zeigen Veraenderungen, die mit einer lokalen Schaedigung enchondraler Ossifikationszonen in Verbindung zu bringen sind. Zu diesen Ossifikationszonen zaehlen auch die sog. 'Akrophysen'. Das sind Wachstumszonen, die nicht zwischen Epi- und Metaphyse liegen, sondern am Rande der Wachstumszentren bzw. in den nichtepiphysialen Enden der kleinen Roehrenknochen. Das radiologisch aehnliche Erscheinungsbild deutet darauf hin, dass

Escala de Desesperanza BHS (A. Beck, 1974: estudio de las propiedades psicométricas y baremización de la Adaptación Argentina Beck Hopelessness Scale BHS (A. Beck, 1974: psychometric study and standardization of Argentinian Adaptation

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Isabel María Mikulic

2009-12-01

Full Text Available El presente estudio se propone presentar los resultados obtenidos en la adaptación, validación y estandarización de la Escala de Desesperanza-BHS (A. Beck, 1974; Adaptación Argentina: I.M. Mikulic, 1998. La adaptación se realizó mediante la técnica de "back translation" y en el proceso de validación participaron 377 participantes de Capital Federal y Gran Buenos Aires, entre las edades de 18 y 50 años (M: 28; SD: 7,9. Se analizó la consistencia interna de la escala, así como su validez concurrente, predictiva, diferencial y factorial. El coeficiente alpha de confiabilidad del instrumento fue aceptable. Los coeficientes de correlación de la BHS con la adaptación argentina del Inventario de Depresión de Beck (BDI-II demuestran ser significativos, sobre todo con aquellos ítems del BDI que evalúan pesimismo. El análisis de regresión realizado advierte que el 16% de la variabilidad en los puntajes de la prueba BDI pueden ser atribuidos a la variable desesperanza. El análisis factorial realizado con la técnica de Componentes Principales y rotación Varimax identificó tres factores que explican el 54,8 % de la varianza. Al considerar la validez diferencial de la BHS, se evidencia que no existe asociación entre desesperanza y género, y que las correlaciones con nivel educativo y edad son muy bajas. Con el fin de disponer de normas locales, se han elaborado las tablas de equivalencia para Capital Federal y Gran Buenos Aires. Los resultados obtenidos en el presente estudio permiten concluir que la Escala BHS adaptada evalúa un constructo psicológicamente significativo en nuestro medio y puede ser usada con propósitos de "screening" en diversos contextos.Present study aims to show adaptation process, validation procedures and standardization norms for Beck Hopelessness Scale BHS (A. Beck, 1974; Argentinian Version: I.M. Mikulic, 1998. Argentinian Adaptation underwent a "back translation" process and it has been validated in an

Inventários Beck para crianças e adolescentes: revisão sistemática da literatura

OpenAIRE

Morais, Résia Silva de

2014-01-01

A teoria/terapia cognitiva (TC) promoveu profundas mudanças na psiquiatria e psicologia colaborando, assim, para o tratamento de uma ampla variedade de transtornos. Em termos diagnósticos, a TC faz uso de escalas psicométricas e de outros instrumentos. Por exemplo, em 1961, Beck desenvolveu as Escalas de Depressão de Beck (BDI) revisadas em 1978 (BDI-1A) e em 1996 a BDI-II foi publicada. Em 2001, elaborou o Beck Youth Inventory - (BYI-II) para crianças e adolescentes com idades entre 7 a 18 a...

Brief Report Reliability of the Beck Depression Inventory and the ...

African Journals Online (AJOL)

Objective — This study aimed to assess the reliability of the Beck Depression Inventory (BDI) and the Self-Rating Anxiety Scale for epidemiological investigations of adolescents' symptoms. Method — Self-report questionnaires were administered on two occasions to 104 students in four private high schools in Cape Town ...

Validation of the Beck Hopelessness Scale in patients with suicide risk.

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Rueda-Jaimes, German Eduardo; Castro-Rueda, Vanessa Alexandra; Rangel-Martínez-Villalba, Andrés Mauricio; Moreno-Quijano, Catalina; Martinez-Salazar, Gustavo Adolfo; Camacho, Paul Anthony

Only a few scales have been validated in Spanish for the assessment of suicide risk, and none of them have achieved predictive validity. To determine the validity and reliability of the Beck Hopelessness Scale in patients with suicide risk attending the specialist clinic. The Beck Hopelessness Scale, reasons for living inventory, and the suicide behaviour questionnaire were applied in patients with suicide risk attending the psychiatric clinic and the emergency department. A new assessment was made 30 days later to determine the predictive validity of suicide or suicide attempt. The evaluation included a total of 244 patients, with a mean age of 30.7±13.2 years, and the majority were women. The internal consistency was .9 (Kuder-Richardson formula 20). Four dimensions were found which accounted for 50% of the variance. It was positively correlated with the suicidal behaviour questionnaire (Spearman .48, P<.001), number of suicide attempts (Spearman .25, P<.001), severity of suicide risk (Spearman .23, P<.001). The correlation with the reasons for living inventory was negative (Spearman -.52, P<.001). With a cut-off ≥12, the negative predictive value was 98.4% (95% CI: 94.2-99.8), and the positive predictive value was 14.8% (95% CI: 6.6-27.1). The Beck Hopelessness Scale in Colombian patients with suicidality shows results similar to the original version, with adequate reliability and moderate concurrent and predictive validity. Copyright © 2016 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Application of the Beck model to stock markets: Value-at-Risk and portfolio risk assessment

Science.gov (United States)

Kozaki, M.; Sato, A.-H.

2008-02-01

We apply the Beck model, developed for turbulent systems that exhibit scaling properties, to stock markets. Our study reveals that the Beck model elucidates the properties of stock market returns and is applicable to practical use such as the Value-at-Risk estimation and the portfolio analysis. We perform empirical analysis with daily/intraday data of the S&P500 index return and find that the volatility fluctuation of real markets is well-consistent with the assumptions of the Beck model: The volatility fluctuates at a much larger time scale than the return itself and the inverse of variance, or “inverse temperature”, β obeys Γ-distribution. As predicted by the Beck model, the distribution of returns is well-fitted by q-Gaussian distribution of Tsallis statistics. The evaluation method of Value-at-Risk (VaR), one of the most significant indicators in risk management, is studied for q-Gaussian distribution. Our proposed method enables the VaR evaluation in consideration of tail risk, which is underestimated by the variance-covariance method. A framework of portfolio risk assessment under the existence of tail risk is considered. We propose a multi-asset model with a single volatility fluctuation shared by all assets, named the single β model, and empirically examine the agreement between the model and an imaginary portfolio with Dow Jones indices. It turns out that the single β model gives good approximation to portfolios composed of the assets with non-Gaussian and correlated returns.

Aaron Temkin BECK: After Cricitical Thinking to A Creative Psychotherapy Theory

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Mehmet DÝNÇ

2012-08-01

Full Text Available There is growing interest in the cognitive psychotherapy all around the world including Turkey. According to American Institute of cognitive Therapy; cognitive psychotherapy is the fastest growing and most rigorously studied kind of talk therapy and it is practiced around the world, taking hold in places from the Middle East to Japan. Cognitive psychotherapy was designed first by Aaron Temkin Beck in 1950’s. He has published over 450 articles and authored or co-authored seventeen books and he has been listed as one of the “10 individuals who shaped the face of American Psychiatry” and one of the 5 most influential psychotherapists of all time since then. Beck’s groundbreaking systematic research established for the first time the efficacy of any psychotherapy for the treatment of depression. Moreover he not only developed and tested an effective short-term treatment (cognitive therapy for depression, but he and his former students have successfully adapted cognitive therapy to a wide range of other psychiatric disorders as well. Numerous controlled clinical trials have now demonstrated that cognitive therapy is effective in a variety of psychiatric conditions including depression, bulimia nervosa, hypochondriasis, social phobia, obsessive-compulsive disorder, substance abuse, body dysmorphic disorder, and post-traumatic stress disorder. Therefore knowing the father of cognitive therapy and his journey from 1950’s to 2010’s will help to understand cognitive therapy and its development during these years. This article aims to give an overview of the historical background to contemporary cognitive and cognitive-behavioral approaches to psychotherapy by focusing on Beck’s life, characteristics and works. [JCBPR 2012; 1(2.000: 70-76

Psychometric Properties of the Beck Scale for Depression (Beck Depression Inventory BDI-II)--A Study on a Sample of Students in the State of Kuwait Universities

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Dahem, Ahmed Mohammed Faleh

2016-01-01

The study aimed to identify the psychometric properties of the Beck Depression Inventory (BDI-II) the Arabized version by Gharib (2000); the study sample consisted of 500 male and female students from the Kuwaiti universities by 250 males and 250 females on whom the BDI-II scale was applied twice; the psychometric characteristics such as the…

Self-statements, self-esteem, and locus of control in discriminating college students' scores on the Beck Depression Inventory.

Science.gov (United States)

Madonna, S; Philpot, V D

1996-04-01

To study the use of the ratio of positive to negative self-statements, locus of control, and self-esteem in discriminating between scores on the Beck Depression Inventory 145 undergraduate college students were administered the Beck Depression Inventory, Automatic Thoughts Questionnaire-Revised, Coopersmith Self-esteem Inventory-Adult Form, and the Rotter Locus of Control scale in their classrooms. A stepwise discriminant analysis indicated that five variables combined to yield a statistically significant discrimination among low, middle, and high scores on the Beck Depression Inventory. The classification analysis indicated that 77.1% (n = 111) of the undergraduate students were correctly classified; 93.2% (82 of 88) were correctly classified as low scorers and 73.3% (18 of 46) were correctly classified as high scorers.

[Change on the rate of children's finger metaphysics in the non-Kaschin-Beck disease areas of China].

Science.gov (United States)

Gao, Mei; Liu, Yunqi; Zhou, Lingwang; Liu, Hui; Deng, Qing; Song, Jiucheng; Yu, Jun

2014-11-01

36 non-Kaschin-Beck disease villages in five provinces including Jilin, Liaoning, Shaanxi, Shanxi and Inner Mongolia in the severe endemic areas of Kaschin-Beck disease (KBD) were selected. The aim of this project was to provide the basis showing these KBD villages had already eliminated the KBD. Fully digital versatile X-ray radiography systems(DR) was used to shoot children's right hand X-ray, in accordance with the "Kashin-Beck Disease Diagnosis Standard" (WS/T 207-2010) for diagnosis. Results indicated that children showing metaphyseal changes only appeared in 13 of the 36 villages, where the rate of change on metaphyseal was less than or equal to three percent. When KBD had been eliminated in a village, the rate of change on aged 7 to 12 children's metaphyseal would have been less than three percent.

Reliability and validity of the Beck depression inventory in patients with Parkinson's disease

NARCIS (Netherlands)

Visser, Martine; Leentjens, Albert F. G.; Marinus, Johan; Stiggelbout, Anne M.; van Hilten, Jacobus J.

2006-01-01

We evaluated the validity, reliability, and potential responsiveness of the Beck Depression Inventory (BDI) in patients with Parkinson's disease (PD). In part 1 of the study, 92 patients with PD underwent a structured clinical interview for DSM major depression and based on this patients were

El legado psicoanalítico en la terapia cognitiva de Aaron Beck

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Guido Pablo Korman

2013-01-01

Full Text Available El psicoanálisis en el que Beck se formó tenía como objetivo incluir al psicoanálisis dentro del modelo científico. Esto era consistente con los intereses de un gran número de investigadores clínicos en los Estados Unidos durante las décadas de 1950 y 1960. Este trayecto intelectual lo llevará, años después, a desarrollar la terapia cognitiva. En este trabajo nos enfocaremos en el entrenamiento psicoanalítico de Beck así como en las primeras publicaciones de éste como especialista en psiquiatría durante su práctica hospitalaria en la Clínica de Austen Riggs y en el Hospital Valley Forge Army. Analizaremos sus primeras hipótesis, intentando rastrear los indicios de su modo de actuar como psicoanalista. Esta misma formación posteriormente lo llevará a un replanteo del modelo psicoanalítico, hecho que será clave para explicar las características que adoptará la terapia cognitiva.

Sex Differences in the Expression of Depressive Responses on the Beck Depression Inventory

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Hammen, Constance L.; Padesky, Christine A.

1977-01-01

Although epidemiological data have documented sex differences in depression, the nature and origins of the differences are unclear. Depression in a large sample of young, unmarried college students was measured and described by the Beck Depression Inventory. Considers the consequences of sex differences in depressive responses, including…

Review: Gerald Beck (2013. Sichtbare Soziologie. Visualisierung und soziologische Wissenschaftskommunikation in der Zweiten Moderne

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Axel Philipps

2014-01-01

Full Text Available Visualisierungen von Wissen hatten und haben im Kern des Faches Soziologie einen schweren Stand. Gerald BECK nimmt sich daher in seinem Buch "Sichtbare Soziologie" der Thematik an, um die Stellung von Visualisierungen in der Soziologie zu verstehen, damit verbundene Problemfelder zu identifizieren und für visuelle Umsetzungen zu sensibilisieren. Er setzt dazu beim Übergang zur Zweiten Moderne an und betrachtet anhand von neun Fallbeispielen gelungene und weniger gelungene Visualisierungen. Durch die verkürzte Aufarbeitung des Verhältnisses der Soziologie zum Bild bleiben jedoch wichtige Einsichten unberücksichtigt, sodass BECKs Empfehlungen, die Zahl der Visualisierungen und die visuelle Kompetenz zu erhöhen, kaum geeignet sind, die Skepsis in der Soziologie gegenüber Visualisierungen zu überwinden. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1401228

Association of Beck Depression Inventory score and Temperament and Character Inventory-125 in patients with eating disorders and severe malnutrition

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Tanaka, Satoshi; Yoshida, Keizo; Katayama, Hiroto; Kohmura, Kunihiro; Kawano, Naoko; Imaeda, Miho; Kato, Saki; Ando, Masahiko; Aleksic, Branko; Nishioka, Kazuo; Ozaki, Norio

2015-01-01

The authors investigated the association between personality and physical/mental status in malnourished patients with eating disorders. A total of 45 patients with anorexia nervosa, avoidant/restrictive food intake disorder, and other specified feeding or eating disorders were included and compared with 39 healthy controls. Personality characteristics and severity of depression were assessed using the Temperament and Character Inventory-125 and Beck?s Depression Inventory. Depression correlat...

Meta-Analysis of the English Version of the Beck Depression Inventory-Second Edition

Science.gov (United States)

Erford, Bradley T.; Johnson, Erin; Bardoshi, Gerta

2016-01-01

This meta-analysis reviewed 144 studies from 1996 to 2013 using the Beck Depression Inventory-Second Edition. Internal consistency was 0.89 and test-retest reliability 0.75. Convergent comparisons were robust across 43 depression instruments. Structural validity supported both one- and two-factor solutions and diagnostic accuracy varied according…

Juvenile osteoarthritis as consequence of enchondral injuries.. Frostbite, Kashin-Beck disease, rat bites and other causes

International Nuclear Information System (INIS)

Oestreich, A.E.

2000-01-01

Purpose. To review the similarities of the radiographic changes in frostbite, the Asian disease of Kashin-Beck, and long term growth damage from injury such as rate bite. Materials and Methods. Radiographs and literature from subjects with these diagnoses were analyzed for the common features and differences. Included was an infant with hand changes 8 months after unwitnessed rat bites. Results. Each condition revealed findings consistent with the hypothesis of localized damage to sites of enchondral ossification, including at acrophyses - the growth plates that are not between epiphysis and metaphysis, but instead lie at the margins of growth centers, including carpal and tarsal bones, and the non-epiphyseal ends of small tubular bones. Discussion. The patterns observed support a final common pathway of damage in frostbite due to cold injury, Kashin-Beck disease (endemic in China) of unknown etiology, and damage from toxines associated, for example, with rat bite. In frostbite, the distribution is acral because of the site of exposure, while the distribution in Kashin-Beck is more diffuse and often less contiguous. In each condition, arthrotic sequelae may be expected in the natural course of follow-up. MRI may play a role in acute diagnosis that might modify the course of each disease. (orig.) [de

Confirmatory Factor Analysis of the Beck Depression Inventory-II in Bariatric Surgery Candidates

Science.gov (United States)

Hall, Brian J.; Hood, Megan M.; Nackers, Lisa M.; Azarbad, Leila; Ivan, Iulia; Corsica, Joyce

2013-01-01

Screening for depression is an integral part of psychological evaluations conducted prior to bariatric surgery. The Beck Depression Inventory-II (BDI-II) is the most commonly used measure of depression in these treatment evaluations. The reliability and validity of the BDI-II has not yet been evaluated within bariatric surgery-seeking samples,…

Depressive symptoms in breast cancer: Beck Depression Inventory - Short Form

OpenAIRE

Cangussu, Renata de Oliveira; Soares, Thiago Barbabela de Castro; Barra, Alexandre de Almeida; Nicolato, Rodrigo

2010-01-01

Objetivos: Verificar a prevalência de sintomas depressivos em mulheres com câncer de mama e identificar os fatores de risco associados à sua ocorrência. Métodos: Foi realizado um estudo transversal, em que foram entrevistadas 71 mulheres com câncer de mama. Foram empregados dois instrumentos: um questionário para verificar os dados sociodemográficos e clínicos e o Inventário de Depressão de Beck – Short Form (BDI-SF), para avaliação dos sintomas depressivos. Para análise dos da...

Norms for the Beck Depression Inventory (BDI-II) in a Large Dutch Community Sample.

NARCIS (Netherlands)

Roelofs, J.; van Breukelen, G.; de Graaf, L.E.; Beck, A.T.; Arntz, A.; Huibers, M.J.H.

2013-01-01

The Beck Depression Inventory (BDI-II) is a widely used instrument that provides information about the presence and severity of depressive symptoms. Although the BDI-II is a psychometrically sound instrument, relatively little is known about norm scores. This study aimed to develop reliable norms

Prevalence of hand osteoarthritis and knee osteoarthritis in Kashin-Beck disease endemic areas and non Kashin-Beck disease endemic areas: A status survey

Science.gov (United States)

Song, QuanQuan; Liu, Yun Qi; Sun, Li Yan; Deng, Qing; Wang, Shao Ping; Cao, Yan Hong; Zhang, Xue Ying; Jiang, Yuan Yuan; Lv, Hong Yan; Duan, Li Bin; Yu, Jun

2018-01-01

Osteoarthritis (OA) is a considerable health problem worldwide, and the prevalence of OA varies in different regions. In this study, the prevalence of OA in Kashin-Beck disease (KBD) and non-KBD endemic areas was examined, respectively. According to monitoring data, 4 types of regions (including none, mild, moderate and high KBD endemic areas) in Heilongjiang and Jilin provinces were selected. All local residents were eligible for inclusion criteria have undergone X-ray images of hands and anteroposterior image of knees. A total of 1673 cases were collected, 1446 cases were analyzed after removing the KBD patients (227). The overall hand OA and knee OA detection rates were 33.3% (481/1446) and 56.6% (818/1446), respectively. After being standardized by age, the detection rate of hand OA in the KBD endemic areas was significantly higher than that in the non-endemic endemic areas. Differently, there was no significant difference in the detection rates of knee OA between the KBD endemic areas and the non-endemic area. The correlation coefficient between the severity of OA and the severity of knee OA was 0.358 and 0.197 in the KBD and non-KBD endemic areas, respectively. Where the KBD historical prevalence level was higher, the severity of the residents’ hand OA was more serious. The detection rates of hand OA and knee OA increased with age. The detection rate of knee OA increased with the increase in body mass index. The prevalence of hand OA was closely related to the pathogenic factors of Kashin-Beck disease, and the prevalence of knee OA had no significant correlation with KBD pathogenic factors. PMID:29320581

The "Self-Interested" Woman Academic: A Consideration of Beck's Model of the "Individualised Individual"

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Skelton, Christine

2005-01-01

The work of Ulrich Beck, particularly his concept of the "individualised individual", is increasingly cited by educational social scientists. As yet, there have been few empirical investigations that consider how applicable and relevant is the notion of the "individualised individual" in understanding how people make sense of…

A meta-analytic comparison of the Beck Depression Inventory and the Hamilton Rating Scale for Depression as measures of treatment outcome.

Science.gov (United States)

Edwards, B C; Lambert, M J; Moran, P W; McCully, T; Smith, K C; Ellingson, A G

1984-05-01

Some clinicians have considered the Beck Depression Inventory, a self-rating scale, too reactive to patient halo effects and, therefore, a liberal measure of treatment outcome. On the other hand, interviewer-rating scales, like the Hamilton Rating Scale for Depression have been viewed as more conservative measures of treatment gain. Studies which compared the Beck Depression Inventory to the Hamilton Rating Scale, as dependent measures, were reviewed for the purpose of determining if the scales provided comparable data for assessing treatment effects. The use of meta-analysis techniques resulted in a comparison of effect sizes which indicated that the Beck Depression Inventory was significantly less liberal than the Hamilton Rating Scale for Depression. The implications of these results for selecting outcome measures and the application of meta-analysis techniques for comparing dependent measures are discussed.

A generalized Grubbs-Beck test statistic for detecting multiple potentially influential low outliers in flood series

Science.gov (United States)

Cohn, T.A.; England, J.F.; Berenbrock, C.E.; Mason, R.R.; Stedinger, J.R.; Lamontagne, J.R.

2013-01-01

he Grubbs-Beck test is recommended by the federal guidelines for detection of low outliers in flood flow frequency computation in the United States. This paper presents a generalization of the Grubbs-Beck test for normal data (similar to the Rosner (1983) test; see also Spencer and McCuen (1996)) that can provide a consistent standard for identifying multiple potentially influential low flows. In cases where low outliers have been identified, they can be represented as “less-than” values, and a frequency distribution can be developed using censored-data statistical techniques, such as the Expected Moments Algorithm. This approach can improve the fit of the right-hand tail of a frequency distribution and provide protection from lack-of-fit due to unimportant but potentially influential low flows (PILFs) in a flood series, thus making the flood frequency analysis procedure more robust.

Validating the Beck Depression Inventory-II in Indonesia's general population and coronary heart disease patients

NARCIS (Netherlands)

Ginting, H.; Näring, G.W.B.; Veld, W.M. van der; Srisayekti, W.; Becker, E.S.

2013-01-01

This study assesses the validity and determines the cut-off point for the Beck Depression Inventory-II (the BDI-II) among Indonesians. The Indonesian version of the BDI-II (the Indo BDI-II) was administered to 720 healthy individuals from the general population, 215 Coronary Heart Disease (CHD)

The Beck depression inventory as a measure of subjective well-being : A cross-national study

NARCIS (Netherlands)

van Hemert, D.A.; van de Vijver, F.J.R.; Poortinga, Y.H.

2002-01-01

The present study examined the question whether the Beck Depression Inventory (BDI), which is one of the most widely used instruments to assess depression, can be used to measure differences in subjective well-being at national level. In order to establish the meaning of depression scores at country

Cross-cultural examination of measurement invariance of the Beck Depression Inventory-II.

Science.gov (United States)

Dere, Jessica; Watters, Carolyn A; Yu, Stephanie Chee-Min; Bagby, R Michael; Ryder, Andrew G; Harkness, Kate L

2015-03-01

Given substantial rates of major depressive disorder among college and university students, as well as the growing cultural diversity on many campuses, establishing the cross-cultural validity of relevant assessment tools is important. In the current investigation, we examined the Beck Depression Inventory-Second Edition (BDI-II; Beck, Steer, & Brown, 1996) among Chinese-heritage (n = 933) and European-heritage (n = 933) undergraduates in North America. The investigation integrated 3 distinct lines of inquiry: (a) the literature on cultural variation in depressive symptom reporting between people of Chinese and Western heritage; (b) recent developments regarding the factor structure of the BDI-II; and (c) the application of advanced statistical techniques to the issue of cross-cultural measurement invariance. A bifactor model was found to represent the optimal factor structure of the BDI-II. Multigroup confirmatory factor analysis showed that the BDI-II had strong measurement invariance across both culture and gender. In group comparisons with latent and observed variables, Chinese-heritage students scored higher than European-heritage students on cognitive symptoms of depression. This finding deviates from the commonly held view that those of Chinese heritage somatize depression. These findings hold implications for the study and use of the BDI-II, highlight the value of advanced statistical techniques such as multigroup confirmatory factor analysis, and offer methodological lessons for cross-cultural psychopathology research more broadly. 2015 APA, all rights reserved

The Latent Symptom Structure of the Beck Depression Inventory-II in Outpatients with Major Depression

Science.gov (United States)

Quilty, Lena C.; Zhang, K. Anne; Bagby, R. Michael

2010-01-01

The Beck Depression Inventory-II (BDI-II) is a self-report instrument frequently used in clinical and research settings to assess depression severity. Although investigators have examined the factor structure of the BDI-II, a clear consensus on the best fitting model has not yet emerged, resulting in different recommendations regarding how to best…

Adaptación y propiedades psicométricas del inventario de depresión de Beck II en estudiantes de la Universidad Pública de Huánuco

OpenAIRE

Rivera Mansilla, Yessica María

2014-01-01

El presente estudio tuvo como objetivo adaptar y evaluar las propiedades psicométricas del Inventario de Depresión de Beck II (Beck, Steer y Brown, 1996) en una muestra probabilística estratificada de 869 estudiantes de pregrado de la Universidad Nacional Hermilio Valdizán de Huánuco, matriculados en el semestre 2013-I. Se realizó la adaptación lingüística a partir del análisis de contenido con criterio de jueces; el nuevo Inventario de Depresión de Beck II Adaptación Huanuqueña alcanzó una a...

Effects of chondroitin sulfate and glucosamine in adult patients with Kaschin-Beck disease

DEFF Research Database (Denmark)

Zhang, Ya-xu; Dong, Wei; Liu, Hui

2010-01-01

The purpose is to investigate the effects of chondroitin sulfate and glucosamine on adult patients with Kaschin-Beck disease (KBD). A total of 80 patients, aged over 40 years, were randomized into two groups receiving either 1,600 mg oral mixture of chondroitin sulfate and glucosamine or placebo......). But the overall mean change in joint space was significant between the two groups (P chondroitin sulfate and glucosamine might play a protective role in preserving articular cartilage and provide...

Self-Concepts and Psychological Well-Being Assessed by Beck Youth Inventory among Pupils with Reading Difficulties

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Lindeblad, Emma; Svensson, Idor; Gustafson, Stefan

2016-01-01

This study investigated the self-image and psychological well-being in 67 children and adolescents age 10-16 years with severe reading difficulties and/or dyslexia. The participants were assessed with Beck Youth Inventory regarding symptoms of depression, anxiety, and negative self-image. The results showed that the participants do not depict…

Guido Beck and the night of the long police batons: some observations about the relationship between physics and politics in the Argentinean context

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Antonio Augusto Passos Videira

2009-12-01

Full Text Available The objective of this paper consists in presenting the reaction of the physicist Guido Beck (1903-1988 towards the political events that occurred in the University of Buenos Aires (UBA, during the second term of 1966. It is not our intention to write a deep treatise on the problem, but to outline some of the ideas that Guido Beck had on the relation between science, State and society in South-American context. That will be done by describing his reaction to the well-known ‘night of the long police batons’. Beck had always been sensitive to the political instability in Argentinean academic system, once that political and ideological disputes could jeopardize the work towards the establishment of a scientific community in that country. As a conclusion, I defend the thesis that in Beck’s point of view the physicists at UBA had misunderstood the importance they had to Argentinean government and to part of the population in that same country.

Psychometric properties of the Persian version of Beck Anxiety Inventory (BAI

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Hossein Kaviani H

2008-06-01

Full Text Available Background: Measuring anxiety level in clinical and non-clinical population needs valid and reliable tool. This research examined the validity and reliability of Beck Anxiety Inventory in Iranian normal population as well as clinically anxious patients.Methods: First, a two-session course was run to train research workers. After they were sufficiently prepared, they were dispatched to different regions of the city, Tehran, referring to residential places for men and women volunteer to take part in the research. At the end, 1513 respondents were randomly recruited and tested using Beck Anxiety Inventory (BAI. Of this population, 112 respondents were randomly selected and re-tested in order to measure test-retest reliability with a one-month interval time between first and second tests. Meanwhile, 261 clinically anxious patients (from clinics and mental health centers were tested. In order to measure validity, 150 patients were interviewed by two parallel clinicians and the anxiety level was rated based on a 10-point scale from 0 (the least to 10 (the most. The two raters were blind to the BAI scores of the patients.    Results: For data reduction and analysis, the SPSS for Windows-edition 14, was conducted. Findings showed that the Persian version of BAI proved a good reliability (r=0.72, p<0.001, a very good validity (r=0.83, p<0.001, and an excellent internal consistency (Alpha=0.92. Conclusions: The results support the applicability of BAI in Iranian population and suggest the use of this inventory for clinical and research aims. Persian version of BAI not only can help clinicians in assessment and diagnosis, but also assist researchers to evaluate anxiety level when needed.

Evaluation of the Beck Depression Inventory in a nonclinical student sample.

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Ignjatović-Ristić, D; Hinić, D; Jović, J

2012-08-01

Depression is one of the most common psychological disorders in individuals seeking psychiatric treatment, and a frequent psychological disorder among patients who seek primary healthcare. Therefore, it is vitally important to employ reliable and valid diagnostic instruments and norms, both in clinical and research work to investigate this problem. This article is part of a larger study which has been conducted for ten years now with the aim to create a clearer picture about the level of depression which may be expected in the nonclinical population in Serbia, and in that way provide a basis for comparisons when diagnosing the clinical population. The subsidiary aims were to monitor potential changes in level of depressive reactions within the set time and to examine the psychometric properties and factor structure of the Beck Depression Inventory (BDI) scale. The sample consisted of 782 students (40% male, 60% female), mean age = 23.10 years, SD = 1.782. Mean score on the BDI-IA scale was 6.69; SD = 6.412. The study showed no significant relationships between the BDI scores and sociodemographic variables such as age, economic status, and educational profile, but showed significant differences within gender (t (780) = 3.222, p = 0.001). There was also a relatively stable level of depressive reactions in this population over the previous ten years. The Cronbach's coefficient of the BDI scale was alpha = 0.860, with the majority of item-total correlations above 0.37. The three-factor structure represents cognitive aspect, affective component of depression, and somatic problems attached to depression. The cognitive factor prevails in the entire sample, which is in accordance with the Beck theory about dysfunctional attitudes, ie cognitive vulnerability is a psychological predisposition to depression.

Electronic structure engineering of ZnO with the modified Becke-Johnson exchange versus the classical correlation potential approaches

KAUST Repository

Ul Haq, Bakhtiar; Ahmed, Rashid; Goumri-Said, Souraya; Shaari, Amiruddin; Afaq, Ahmad

2013-01-01

applied. Where for electronic properties in addition to these, Tran-Blaha modified Becke-Johnson (mBJ) potential has been used. Our computed band gap values of ZnO in WZ and ZB phases with mBJ potential are significantly improved compared to those with LDA

The structure of negative emotional states: comparison of the Depression Anxiety Stress Scales (DASS) with the Beck Depression and Anxiety Inventories.

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Lovibond, P F; Lovibond, S H

1995-03-01

The psychometric properties of the Depression Anxiety Stress Scales (DASS) were evaluated in a normal sample of N = 717 who were also administered the Beck Depression Inventory (BDI) and the Beck Anxiety Inventory (BAI). The DASS was shown to possess satisfactory psychometric properties, and the factor structure was substantiated both by exploratory and confirmatory factor analysis. In comparison to the BDI and BAI, the DASS scales showed greater separation in factor loadings. The DASS Anxiety scale correlated 0.81 with the BAI, and the DASS Depression scale correlated 0.74 with the BDI. Factor analyses suggested that the BDI differs from the DASS Depression scale primarily in that the BDI includes items such as weight loss, insomnia, somatic preoccupation and irritability, which fail to discriminate between depression and other affective states. The factor structure of the combined BDI and BAI items was virtually identical to that reported by Beck for a sample of diagnosed depressed and anxious patients, supporting the view that these clinical states are more severe expressions of the same states that may be discerned in normals. Implications of the results for the conceptualisation of depression, anxiety and tension/stress are considered, and the utility of the DASS scales in discriminating between these constructs is discussed.

Construct validity of the Beck Hopelessness Scale (BHS) among university students: A multitrait-multimethod approach.

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Boduszek, Daniel; Dhingra, Katie

2016-10-01

There is considerable debate about the underlying factor structure of the Beck Hopelessness Scale (BHS) in the literature. An established view is that it reflects a unitary or bidimensional construct in nonclinical samples. There are, however, reasons to reconsider this conceptualization. Based on previous factor analytic findings from both clinical and nonclinical studies, the aim of the present study was to compare 16 competing models of the BHS in a large university student sample (N = 1, 733). Sixteen distinct factor models were specified and tested using conventional confirmatory factor analytic techniques, along with confirmatory bifactor modeling. A 3-factor solution with 2 method effects (i.e., a multitrait-multimethod model) provided the best fit to the data. The reliability of this conceptualization was supported by McDonald's coefficient omega and the differential relationships exhibited between the 3 hopelessness factors ("feelings about the future," "loss of motivation," and "future expectations") and measures of goal disengagement, brooding rumination, suicide ideation, and suicide attempt history. The results provide statistical support for a 3-trait and 2-method factor model, and hence the 3 dimensions of hopelessness theorized by Beck. The theoretical and methodological implications of these findings are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Specificity and sensitivity of the Beck Hopelessness Scale for suicidal ideation among adolescents entering early intervention service.

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Granö, Niklas; Oksanen, Jorma; Kallionpää, Santeri; Roine, Mikko

2017-01-01

Previous studies have shown an association between hopelessness and suicidal behaviour in clinical populations. The aim of the study was to investigate sensitivity, specificity, and predictive validity of the Beck Hopelessness Scale (BHS) for suicidal ideation in adolescents who show early risk signs on the psychiatric disorder continuum. Three-hundred and two help-seeking adolescents (mean age = 15.5 years) who were entering an early intervention team at Helsinki University Central Hospital, Finland, completed questionnaires of BHS and suicidal ideation, derived from Beck Depression Inventory (BDI-II). Results suggest that a BHS cut-off score ≥8 (sensitivity = 0.70, specificity = 0.76) or cut-off score ≥9 (sensitivity = 0.63, specificity = 0.80) may be useful to detect suicidal ideation with BHS in help-seeking adolescents population. Results remain mainly the same in a separate analysis with adolescents at risk for psychosis. The results support previous cut-off points for BHS in identification of suicidal ideation. The results suggest also that lower cut-off scores may be useful in sense of sensitivity, especially in clinical settings.

Beck's cognitive theory and the response style theory of depression in adolescents with and without mild to borderline intellectual disability

NARCIS (Netherlands)

Weeland, M.M.; Nijhof, K.S.; Otten, R.; Vermaes, I.P.R.; Buitelaar, J.K.

2017-01-01

Aim: This study tests the validity of Beck’s cognitive theory and Nolen-Hoeksema's response style theory of depression in adolescents with and without MBID. Methods: The relationship between negative cognitive errors (Beck), response styles (Nolen-Hoeksema) and depressive symptoms was examined in

[Association between polymorphism in DVWA and IL-1beta and Kashin-Beck disease].

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Y U, Min; Guo, Xiong; Gao, Xiao-Yun; Lai, Jiang-Hua; Tu, Qian-Qian

2010-07-01

To investigate the association between IL-1beta and DVWA gene and Kashin-Beck disease (KBD). Peripheral genomic DNA were extracted from 105 patients with KBD and 98 healthy controls. PCR-RFLP were performed to detect SNP loci of IL-1beta gene and DVWA gene. The patients with KBD had significantly higher frequency of rs16944 (IL-1beta) locus (chi2 = 24.28, P rs16944 (chi2 = 5.683, P = 0.0171) than the healthy controls. There were no significant differences in genotype frequencies,single allele frequencies and haplotypes in rs4685241 and rs1143627 between the patients with KBD and the healthy controls. rs16944 (IL-1beta) is associated with KBD.

Arthroscopic Ankle Arthrodesis for Treating Osteoarthritis in a Patient with Kashin-Beck Disease

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Kenjiro Iwasa

2014-01-01

Full Text Available Kashin-Beck disease (KBD is an endemic degenerative osteoarthritis. Death of cartilage and growth plate is the pathologic feature; therefore, KBD involves skeletal deformity and often results in osteoarthritis. Deficiency of selenium, high humic acid levels in water, and fungi on storage gains are considered the cause of KBD. The most frequently involved joints are ankles, knees, wrists, and elbows and symptoms are pain and limited motions of those joints. The main treatments for KBD are rehabilitation and osteotomy to correct the deformities because preventive treatment has not been established. In this report, we present a case of ankle osteoarthritis due to KBD and first describe arthroscopic ankle arthrodesis for treating osteoarthritis of KBD.

Comparison of Reliability and Validity of the Breast Cancer depression anxiety stress scales (DASS- 21) with the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS)

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Bener A; Alsulaiman R; Doodson LG; El Ayoubi HR

2016-01-01

Background: No study has been conducted to determine the reliability and validity of the Depression, Anxiety and Stress Scale (DASS-21), Hospital Anxiety and Depression [HADS] and Beck Depression Inventory (BDI-II) among the Arab Breast Cancer population. Aim: The aim of this study was to compare the reliability and validity of the Depression, Anxiety, and Stress scale (DASS-21), the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS) among Breast Cancer women ...

[Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe]/ Dennis Hortmuth

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Hormuth, Dennis

2012-01-01

Arvustus: Antjekathrin Grassmann. Zu den wirtschaftlichen und persönlichen Beziehungen Lübecks ins Baltikum im Lichte einer unbeachteten mittelalterlichen Quellegruppe. In: Leder ist Brot. Beiträge zur norddeutschen Landes- und Archivgeseten. Schwerin 2011. S. 125-135

Validity of the Hospital Anxiety and Depression Scale and the Beck Depression Inventory for use in end-stage renal disease patients

NARCIS (Netherlands)

Loosman, W.L.; Siegert, C.E.H.; Korzec, A.; Honig, A.

2010-01-01

Objective. To validate the Hospital Anxiety and Depression Scale (HADS) and the Beck Depression Inventory (BDI) for use in patients with end-stage renal disease (ESRD) and to compare the outcome of both screening measures with each other. Design. Cross-sectional and between-subjects design. The

The Yoruba version of the Beck Hopelessness Scale: psychometric characteristics and correlates of hopelessness in a sample of Nigerian psychiatric outpatients.

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Aloba, Olutayo; Akinsulore, Adesanmi; Mapayi, Boladale; Oloniniyi, Ibiduniyi; Mosaku, Kolawole; Alimi, Taiwo; Esan, Olufemi

2015-01-01

Previous studies from the developed western countries have repeatedly demonstrated that hopelessness positively correlates with an increased risk of suicide in the context of chronic mental disorders such as schizophrenia and affective disorders. Despite this persistently strong association, the construct of hopelessness in terms of its factorial structure and correlates has not been explored among Nigerian psychiatric outpatients. The aim of this present study is to examine the psychometric characteristics of the Yoruba language culturally adapted version of the Beck Hopelessness Scale in a cross-sectional sample of psychiatric outpatients in South-western Nigeria. The participants were 327 Nigerian adult outpatients receiving treatment for schizophrenia, bipolar and depressive disorders, consecutively recruited from the outpatient psychiatric clinics of a university teaching hospital in South-western Nigeria. The outpatients were recruited over a one year period. They completed the Yoruba translated version of the Beck Hopelessness Scale (BHS-Y), a sociodemographic and illness-related questionnaire, the Beck Depression Inventory-II (BDI-II). Their level of functioning was assessed with the Global Assessment of Functioning Scale (GAF), psychopathology was evaluated with the Positive and Negative Syndrome Scale (PANSS) and the level of disability measured with the World Health Organization Disability Assessment Schedule (WHODAS-II). Suicidality and confirmation of the diagnoses of schizophrenia, bipolar and depressive disorders were evaluated with the Mini International Neuropsychiatric Interview (MINI). The construct of hopelessness in terms of factorial structure, reliability, validity and correlates was explored. Exploratory Factor Analysis using Principal Component Analysis with Varimax rotation was used to examine the factorial structure of the BHS-Y. Internal consistency was examined with Cronbach's alpha, and the construct validity of the scale was assessed

The Beck Initiative: A Partnership to Implement Cognitive Therapy in a Community Behavioral Health System

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Stirman, Shannon Wiltsey; Buchhofer, Regina; McLaulin, J. Bryce; Evans, Arthur C.; Beck, Aaron T.

2010-01-01

The Beck Initiative is a partnership between researchers and clinicians at a large university and an urban behavioral health managed care system. Both partners share a commitment to ensuring that consumers in the community have access to competently delivered, individualized, evidence-based mental health care and that the providers who serve them have the support they need to deliver high-quality evidence-based treatments. Central features of the program are individualized training and consultation in cognitive therapy for each provider agency and policies to promote the sustainability of the initiative and its continuing evolution to meet the needs of providers and consumers. PMID:19797367

Prevalence of depression and its associated factors using Beck Depression Inventory among students of a medical college in Karnataka

OpenAIRE

Kumar, Ganesh S.; Jain, Animesh; Hegde, Supriya

2012-01-01

Background and Objective: Depression among medical students is an area of increasing concern worldwide. This study aimed to assess the prevalence of depression and its associated factors among medical students. Materials and Methods: A stratified random sample of 400 students was assessed using Beck Depression Inventory by investigators. Associations between depression and class of studying, social factors like alcohol use, drug addiction, family problems, family history of depression, and st...

The end of the Strecknitz asylum at Lübeck - a contribution to the social history of psychiatry during National Socialism.

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Delius, P; Dilling, H

1995-09-01

At a first place the NS-policy of psychiatry is outlined -its global planning as well as its excecution. The picture is supplemented by and contrasted with its local implementation exemplified by the Strecknitz asylum at Lübeck. It becomes clear how much the global concept of the extermination of patients was interwoven with pragmatic plans of local authorities. At Lübeck only the partial identity of these interests led to the deportation of more than 600 patients. They were distributed to several transit camps in Hesse where more than 80% had died by the end of the Second World War. The main causes of death were hunger and infectious diseases - consequences of a deliberate and well-organized neglect. The behaviour and the reactions on the part of the relatives were shaped by supply shortages during the war, by internalized propaganda and by fear. The long-term effects beyond the end of the NS-regime vary a lot. Some of the relatives' coping strategies are portrayed. In some cases the murder of close family members continues to have its effects in the form of family secrets.

Factorial Structure of Depressive Symptoms in Anglophone Caribbean University Students: Psychometric Properties of the Beck Depression Inventory-II

OpenAIRE

Michael H. Campbell; Jonathan W. Roberti; Donna-Maria Maynard; Maisha K. Emmanuel

2009-01-01

Este estudio buscó establecer propiedades psicométricas del Inventario de Depresión de Beck-Segunda Edición (BDI-II) con estudiantes de una universidad del Caribe (n=400, 76% mujeres, edad media=25.2). Además, administramos la Escala de Elasticidad de Ego-89, La Escala de Tensión Percibida, La Escala de Ansiedad Estado-Rasgo (Versión de Rasgo) y La Escala de Depresión de Zung. El análisis factorial confirmativo comparó la estructura observada con las estructuras oblicuas propuestas en los mod...

[Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410] / Dennis Hortmuth

Index Scriptorium Estoniae

Hortmuth, Dennis

2011-01-01

Arvustus:Manfred Schneider. Lübeck im 12. und 13. Jahrhundert. Archäologische Befunde zur entstehung einer mittelalterlichen Grossstadt. In : Expansion - integration? Danish-Baltic Contacts 1147-1410 AD. (Vordingborg, 2009).

Beck's cognitive theory and the response style theory of depression in adolescents with and without mild to borderline intellectual disability.

Science.gov (United States)

Weeland, Martine M; Nijhof, Karin S; Otten, R; Vermaes, Ignace P R; Buitelaar, Jan K

2017-10-01

This study tests the validity of Beck's cognitive theory and Nolen-Hoeksema's response style theory of depression in adolescents with and without MBID. The relationship between negative cognitive errors (Beck), response styles (Nolen-Hoeksema) and depressive symptoms was examined in 135 adolescents using linear regression. The cognitive error 'underestimation of the ability to cope' was more prevalent among adolescents with MBID than among adolescents with average intelligence. This was the only negative cognitive error that predicted depressive symptoms. There were no differences between groups in the prevalence of the three response styles. In line with the theory, ruminating was positively and problem-solving was negatively related to depressive symptoms. Distractive response styles were not related to depressive symptoms. The relationship between response styles, cognitive errors and depressive symptoms were similar for both groups. The main premises of both theories of depression are equally applicable to adolescents with and without MBID. The cognitive error 'Underestimation of the ability to cope' poses a specific risk factor for developing a depression for adolescents with MBID and requires special attention in treatment and prevention of depression. WHAT THIS PAPER ADDS?: Despite the high prevalence of depression among adolescents with MBID, little is known about the etiology and cognitive processes that play a role in the development of depression in this group. The current paper fills this gap in research by examining the core tenets of two important theories on the etiology of depression (Beck's cognitive theory and Nolen-Hoeksema's response style theory) in a clinical sample of adolescents with and without MBID. This paper demonstrated that the theories are equally applicable to adolescents with MBID, as to adolescents with average intellectual ability. However, the cognitive bias 'underestimation of the ability to cope' was the only cognitive error

Sintomas depressivos no câncer de mama: Inventário de Depressão de Beck - Short Form Depressive symptoms in breast cancer: Beck Depression Inventory - Short Form

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Renata de Oliveira Cangussu

2010-01-01

Full Text Available OBJETIVOS: Verificar a prevalência de sintomas depressivos em mulheres com câncer de mama e identificar os fatores de risco associados à sua ocorrência. MÉTODOS: Foi realizado um estudo transversal, em que foram entrevistadas 71 mulheres com câncer de mama. Foram empregados dois instrumentos: um questionário para verificar os dados sociodemográficos e clínicos e o Inventário de Depressão de Beck - Short Form (BDI-SF, para avaliação dos sintomas depressivos. Para análise dos dados, utilizaram-se medidas descritivas e o teste de qui-quadrado, que avaliou a associação entre variáveis sociodemográficas e clínicas e os sintomas depressivos. O nível de significância considerado foi de 5%. RESULTADOS: A prevalência de sintomas depressivos foi de 29,6%. Os fatores associados à presença desses sintomas foram o tratamento quimioterápico (p = 0,021, presença de dor (p = 0,018 e limitação do movimento do membro superior (p = 0,010 e pior percepção da saúde (p = 0,018. CONCLUSÃO: Sintomas depressivos são frequentes no câncer de mama, assim a saúde mental das mulheres com esse tipo de câncer deve ser investigada e tratada quando necessário, reduzindo o impacto desses sintomas na vida da mulher.OBJECTIVES: To verify the prevalence of depressive symptoms in women with breast cancer and identify risk factors associated to its occurrence. METHODS: It was a transversal study where 71 women with breast cancer were interviewed. Two instruments were applied, being one questionnaire used to verify sociodemographic and clinical data, and the Beck Depression Inventory - Short Form to evaluate depressive symptoms. Descriptive methods and chi-square test were utilized to analyze data, evaluating association between depressive symptoms, sociodemographic and clinical data. Significance level was considered of 5%. RESULTS: Depressive symptoms prevalence was 29,6%. Factors associated to the presence of this kind of symptoms were

Electronic and Transport Properties of LaNi4Sb12 Skutterudite: Modified Becke-Johnson Approach

Science.gov (United States)

Bhat, Tahir Mohiuddin; Singh, Srishti; Gupta, Dinesh C.

2018-05-01

We carried out an ab initio study of structural, electronic, thermodynamic, and thermoelectric properties of the lanthanum-filled skutterudite, LaNi4Sb12. Generalized gradient approximation and modified Becke-Johnson potentials were employed for the exchange-correlation potential. The electronic structure calculations display the metallic behavior of the compound. The alloy offers low lattice thermal conductivity along with a high Seebeck coefficient with a value of - 158 (μVK-1) at room temperature. The effect of high pressure and temperature on thermal properties like thermal expansion coefficient, heat capacity, and Grüneisen parameter are also investigated by means of a quasi-harmonic Debye model. The large Seebeck coefficient and high power factor exhibited by LaNi4Sb12 make it an attractive candidate for thermoelectric materials.

Beck x Roberts: Comparativos do Diagrama do Metrô de Londres

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Joaquim Redig

2015-06-01

Full Text Available Este artigo foi originalmente dirigido à disciplina Design e Visualização da Informação, ministrada pelo Prof. André Monat no curso de Doutorado em Design da ESDI-UERJ, Escola Superior de Desenho Industrial da Universidade do Estado do Rio de Janeiro, em 2013, a partir da proposta do professor de se examinar a pertinência da estrutura radial proposta por Maxwell J. Roberts para o design de mapas de redes de transporte. No artigo, procuro demonstrar que, por ser uma forma padrão pré-convencionada e abstrata, não valorizando a relação visual analógica com o objeto representado – a rede geo-espacial do sistema de transporte, variável para cada cidade – a estrutura radial não facilita a compreensão e o uso da rede, relativamente ao sistema ortogonal/diagonal projetado por Harry Beck para o assim chamado Diagrama do metrô londrino, que, partindo do código mais universal e ancestral de orientação que é a Rosa dos Ventos, se baseia nos eixos dos percursos. Por isso, este sistema se tornou um paradigma mundial no campo do Design de Informação, ainda não superado.

A terapia cognitiva de Aaron Beck como reflexividade na alta modernidade: uma sociologia do conhecimento

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Cláudio Ivan de Oliveira

Full Text Available Uma sociologia do conhecimento interpreta a produção do conhecimento como vinculada a situações sociais. Partindo dessa premissa epistemológica, nosso artigo objetivou interpretar a terapia cognitiva de Aaron Beck como conhecimento construído e construtor do fenômeno de reflexividade da alta modernidade, conforme interpretada por Anthony Giddens. Nossa hipótese é que a reorientação do sistema de crenças do cliente, proposta pela terapia cognitiva, é uma forma de reconstrução reflexiva da autoidentidade, visando superar conflitos típicos da instabilidade da alta modernidade. Assinalamos aspectos na terapia cognitiva que a identificam com a reflexividade, sobretudo a ideia de que a construção da autoidentidade é uma tarefa na qual o indivíduo se engaja reflexivamente.

Efektifitas Skala Edinburgh dan Skala Beck dalam Mendeteksi Risiko Depresi Post Partum di Rumah Sakit Umum Prof. DR. Margono Soekarjo Purwokerto

OpenAIRE

Latifah, Lutfatul; Hartati

2006-01-01

The aim of this study is to evaluate the effectiveness of Edinburgh post partum depression scale (EPDS) and Beck Depression Inventory (BDI) scale to detect risk of post partum depression. This study utilized survey with quantitative approach. Of 25 patients were chosen with purposive sampling method. The criteria of sample was post partum mother who admitted at Margono Soekardjo hospital in the sixth days. The assessment of post partum mother was evaluated directly to the target population ...

Modified Becke-Johnson exchange potential: improved modeling of lead halides for solar cell applications

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Radi A. Jishi

2016-01-01

Full Text Available We report first-principles calculations, within density functional theory, on the lead halide compounds PbCl2, PbBr2, and CH3NH3PbBr3−xClx, taking into account spin-orbit coupling. We show that, when the modified Becke-Johnson exchange potential is used with a suitable choice of defining parameters, excellent agreement between calculations and experiment is obtained. The computational model is then used to study the effect of replacing the methylammonium cation in CH3NH3PbI3 and CH3NH3PbBr3 with either N2H5+or N2H3+, which have slightly smaller ionic radii than methylammonium. We predict that a considerable downshift in the values of the band gaps occurs with this replacement. The resulting compounds would extend optical absorption down to the near-infrared region, creating excellent light harvesters for solar cells.

THE CONCEPT OF INDIVIDUAL AND INDIVIDUALIZATION IN THE THEORY OF Z. BAUMAN AND U. BECK

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A. A. Batsenkova

2018-01-01

Full Text Available One of the major trends of the modern world is a process of individualization. Despite the fact that the term “individualization” has existed since the XVII century, it is often confused, mixing with the concept of “individualism”, “individuation” and “individuality”. But individualization is not a political or moral worldview, it is not a process of identity formation, and it is the natural multi-level complex social process associated with defined design conditions of life of the individual and the conditions of its existence.The purpose of this paper is to, based on the works of U. Beck and Z. Bauman, to define the process of individualization, to consider the process of occurrence and development of individualization in the modern society. To reveal features of this process at the present stage of development of society, where the process of individualization acquires new features.According to sociologists, the process of individualization affects all aspects of society and has two levels of its manifestation. The first level the author calls structural or objective level, because it is independent on the actions of individuals and the inertia phenomenon associated with the spreading of social space, social differentiation, division of labor, with the processes of globalization and modernization.The second level is the sphere of individual action. At this level the meaning of individualization is the expansion of individual rights and opportunities and the liberation of the individual from traditional social forms and relationships that defined his model of behavior in the modern society. Due to the change in “life situations”, there is an increase of opportunities of the individual for independent decision-making, self-selection and successful action. The change in “life situations” (under U. Beck due to detraditionalization life spheres and emergence of new “spaces of freedom”, which create new challenges for

In-plant demonstration of energy optimization in beck dyeing of carpet. Final report, June 1, 1979-January 1, 1980

Energy Technology Data Exchange (ETDEWEB)

Tincher, W.C.

1980-01-01

Several energy-conservative technologies have been successfully combined and transferred to a commercial carpet finishing plant to optimize beck dyeing. The technology of bump-and-run, in which the dyebath temperature was allowed to drift for the last 85% of the hold time instead of being maintained by active steam sparging, reduced the energy consumption by 38% with negligible capital investment required. Merging of dyebath reuse with bump-and-run only marginally increased the energy consumption (to 39%), but substantially lowered the plant's finishing costs further by directly recycling dyes, auxiliary chemicals, and water. Final optimization, which merged a technique whereby the carpet was pulled directly from the hot bath with bump-and-run and dyebath reuse, further improved the economics by drastically reducing water/sewer requirements by 90% and eliminating the holding tank/pumping assembly as a reuse requirement. From a carpet industry viewpoint, the demonstrated modifications have a direct energy conservation potential of 2.4 x 10/sup 5/ barrels of oil equivalent per year assuming the technology is directly transferable to similar atmospheric dyeing processes, e.g., beck dyeing of nylon and polyester fabrics, the potential to the entire textile industry is 2.6 x 10/sup 6/ BOE/year. Economically, total potential savings for the carpet industry on reuse incorporation was $1.2 x 10/sup 7//year, based on a 2.3 cents/lb. savings figure. When the allied fabric industry was included, the national potential was raised to $1.0 x 10/sup 8//year. These figures include cost savings due to materials recycled (water, auxiliary chemicals and dyes) as well as energy conservation.

Does the Beck Cognitive Insight Scale Predict Response to Cognitive Remediation in Schizophrenia?

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Audrey Benoit

2016-01-01

Full Text Available Cognitive remediation therapy (CRT has emerged as a viable treatment option for people diagnosed with schizophrenia presenting disabling cognitive deficits. However, it is important to determine which variables can influence response to CRT in order to provide cost-effective treatment. This study’s aim was to explore cognitive insight as a potential predictor of cognitive improvement after CRT. Twenty patients with schizophrenia completed a 24-session CRT program involving 18 hours of computer exercises and 6 hours of group discussion to encourage generalization of cognitive training to everyday activities. Pre- and posttest assessments included the CogState Research Battery and the Beck Cognitive Insight Scale (BCIS. Lower self-certainty on the BCIS at baseline was associated with greater improvement in speed of processing (rs=-0.48; p<0.05 and visual memory (rs=-0.46; p<0.05. The results of this study point out potential associations between self-certainty and cognitive improvement after CRT, a variable that can easily be measured in clinical settings to help evaluate which patients may benefit most from the intervention. They also underline the need to keep investigating the predictors of good CRT outcomes, which can vary widely between patients.

The role of psychological inflexibility in Beck's cognitive model of depression in a sample of undergraduates

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Francisco J. Ruiz

Full Text Available Beck's cognitive model of depression proposes that depressogenic schemas have an effect on depressive symptoms by increasing the frequency of negative automatic thoughts in response to negative life events. We aimed to test a moderated, serial mediation model where psychological inflexibility, a core concept of the Acceptance and Commitment Therapy (ACT model of psychopathology, both mediates and moderates the relationship between depressogenic schemas and the frequency of negative automatic thoughts. A cross-sectional design was used in which 210 undergraduates responded to questionnaires assessing the constructs of interest. Results supported the proposed moderated mediation model. Both psychological inflexibility and negative automatic thoughts were significant mediators of the relationship between depressogenic schemas and depressive symptoms, and psychological inflexibility also moderated the effect of depressogenic schemas on negative automatic thoughts. We conclude that the role of psychological inflexibility in the cognitive model of depression deserves more attention.

Beck Depression Inventory-II: Factor Analyses with Three Groups of Midlife Women of African Descent in the Midwest, the South, and the U.S. Virgin Islands.

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Gary, Faye A; Yarandi, Hossein; Evans, Edris; Still, Carolyn; Mickels, Prince; Hassan, Mona; Campbell, Doris; Conic, Ruzica

2018-03-01

This research encompasses a factor analysis of the Beck Depression Inventory-II (BDI-II), which involves three groups of midlife women of African descent who reside in the Midwest, the South, and the U.S. Virgin Islands. The purpose of the study was to determine the factor structure of the BDI-II when administered to a sample of women aged 40-65 of African descent who reside in the three distinct geographical regions of the United States. A correlational, descriptive design was used, and 536 women of African descent were invited to participate in face-to-face interviews that transpired in community settings. Results of the factor analysis revealed a two-factor explanation. Factor one included symptoms such as punishment feelings and pessimism (cognitive), and the second factor included symptoms such as tiredness and loss of energy (somatic-affective). The application of the Beck Depression Inventory-II among the three groups of women generated specific information about each group and common findings across the groups. Knowledge gained from the research could help to guide specific intervention programs for the three groups of women, and explicate the common approaches that could be used for the three groups.

Optical response of mixed molybdenum dichalcogenides for solar cell applications using the modified Becke-Johnson potential

Energy Technology Data Exchange (ETDEWEB)

Ahuja, Ushma [Sardar Patel College of Engineering, Mumbai (India). Dept. of Electrical Engineering; Joshi, Ritu; Venugopalan, K. [M.L. Sukhadia Univ., Udaipur (India). Dept. of Physics; Kothari, D.C. [Mumbai Univ. (India). National Center for Nanosciences and Nanotechnology; Tiwari, Harpal [Malaviya National Institute of Technology, Jaipur (India). Dept. of Electrical Engineering

2016-07-01

Energy bands and density of states (DOS) of mixed molybdenum dichalcogenides like MoS{sub 2}, MoSeS, MoSe{sub 2}, MoTe{sub 2}, MoTeS, and MoTe{sub 0.5}S{sub 1.5} are reported for the first time using the Tran-Blaha modified Becke-Johnson potential within full potential-linearised augmented plane wave technique. From the partial DOS, a strong hybridisation between the Mo-d and chalcogen-p states is observed below the Fermi energy E{sub F}. In addition, the dielectric constants, absorption coefficients, and refractivity spectra of these compounds have also been deduced. The integrated absorption coefficients derived from the frequency-dependent absorption spectra within the energy range of 0-4.5 eV show a possibility of using molybdenum dichalcogenides, particularly MoTe{sub 0.5}S{sub 1.5}, in solar cell applications. Birefringence and degree of anisotropy are also discussed using the data on refractivity and imaginary components of the dielectric constant.

[Concurrent validation of the suicidal risk assessment scale (R.S.D.) with the Beck's suicidal ideation scale].

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Ducher, J-L; Daléry, J

2004-01-01

The prevention of suicide is a top priority in mental health. The determination of high risk suicidal groups is not sufficient. The expressing suicidal ideas is not a protective factor, but in contrary a risk factor to take into account, or even to search and to quantify: 80% of the subjects who attempt to commit suicide or commit suicide express such ideas months before. Several evaluation instruments try to help the practitioners or the research workers in this reasoning. The suicidal risk assessment scale RSD can be cited in particular. It is composed of eleven sections. The 0 level corresponds to the absence of particular ideas of death or suicide. Levels 1 and 2, the presence of ideas of death. Levels 3-4-5, the presence of suicidal ideas. The difference compared to the majority of the other scales consecrated to the same subject, the passif desire of death, occupies a place totally particular in the RSD (level 6). From the level 7, the risk of acting out seems to become more important. It stops being a simple idea of suicide, but becomes a real will of dying, firstly retained by something or someone (level 7), the fear of causing suffering to dear ones or a religious belief., then determined (level 8). Finally, the patient has elaborated a concrete plan (level 9) or he has already started the preparation of acting out (level 10). It is just necessary to evaluate and to note the highest level of the scale. The inclusion of the suicidal risk assessment scale RSD and of the Suicidal Ideation Scale by Beck in an international multicenters, phase IV, double-blind study, according to two parallel groups, with a fixed dose of fluoxétine or fluvoxamine for six weeks, allowed to search correlations which could exist between the two scales. The ana-lysis before the beginning of the treatment was done on 108 outpatients depressive, male and female, aged 18 or over. It finds a satisfactory concurrent validity between the suicidal risk assessment scale RSD and the

Half-metallicity and electronic structures for carbon-doped group III-nitrides: Calculated with a modified Becke-Johnson potential

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Fan, Shuai-wei; Wang, Ri-gao; Xu, Pemg

2016-09-01

The electronic structures and magnetism for carbon-doped group III-nitrides are investigated by utilizing the first principle method with the modified Becke-Johnson potential. Calculations show that carbon substituting cations (anions) would induce the group III-nitrides to be paramagnetic metals (half-metallic ferromagnets). Single carbon substituting nitrogen could produce 1.00μB magnetic moment. Electronic structures indicate that the carriers-mediated double-exchange interaction plays a crucial role in forming the ferromagnetism. Based on the mean-field theory, the Curie temperature for carbon-doped group III-nitrides would be above the room temperature. Negative chemical pair interactions imply that carbon dopants tend to form clustering distribution in group III-nitrides. The nitrogen vacancy would make the carbon-doped group III-nitrides lose the half-metallic ferromagnetism.

'Extra-regional' strike-slip fault systems in Chile and Alaska: the North Pacific Rim orogenic Stream vs. Beck's Buttress

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Redfield, T. F.; Scholl, D. W.; Fitzgerald, P. G.

2010-12-01

us to speculate towards the role of obliquity of plate tectonic convergence for the along-strike evolution of extra-regional strike-slip systems. Highly-oblique initiation of the DFS encourages detachment of fault-bounded terranes and provides a driver that encourages a westward-fanning pattern of extrusion towards the free face of the Beringian margin. Plausibly, its less-oblique central segment promotes vertical pathway exhumation observed at (for example) Denali itself. A more orthogonal regime drives the entire LOFZ, precluding slivering at its initiation and promoting upstream buttressing (Beck et al., 1993). The convergent plate boundary setting opens a window through time and space on the evolution of large-magnitude fault-systems. Escape, or not to escape ~ what best answers the question ? Citations Redfield, T. F., Scholl, D. W., Fitzgerald, P. G., and Beck, M. E., & 2007. Escape tectonics and the extrusion of Alaska: past, present, and future. Geology. 35, 11, 1039-1042 Beck, M.E., Rojas, C. and Cembrano, J. (1993). “On the nature of buttressing in margin-parallel strike-fault systems.” Geology, Vol. 21, pp. 755-758.

Aaron Temkin BECK: After Cricitical Thinking to A Creative Psychotherapy Theory

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Mehmet DİNÇ

2012-07-01

Full Text Available There is growing interest in the cognitive psychotherapy all around the world including Turkey. According to American Institute of Cognitive Therapy; cognitive psychotherapy is the fastest growing and most rigorously studied kind of talk therapy and it is practiced around the world, taking hold in places from the Middle East to Japan. Cognitive psychotherapy was designed first by Aaron Temkin Beck in 1950’s. He has published over 450 articles and authored or co-authored seventeen books and he has been listed as one of the “10 individuals who shaped the face of American Psychiatry” and one of the 5 most influential psychotherapists of all time since then. Beck’s groundbreaking systematic research established for the first time the efficacy of any psychotherapy for the treatment of depression. Moreover he not only developed and tested an effective short-term treatment (cognitive therapy for depression, but he and his former students have successfully adapted cognitive therapy to a wide range of other psychiatric disorders as well. Numerous controlled clinical trials have now demonstrated that cognitive therapy is effective in a variety of psychiatric conditions including depression, bulimia nervosa, hypochondriasis, social phobia, obsessive-compulsive disorder, substance abuse, body dysmorphic disorder, and post-traumatic stress disorder. Therefore knowing the father of cognitive therapy and his journey from 1950’s to 2010’s will help to understand cognitive therapy and its development during these years. This article aims to give an overview of the historical background to contemporary cognitive and cognitive-behavioral approaches to psychotherapy by focusing on Beck’s life, characteristics and works.

Electronic properties of III-nitride semiconductors: A first-principles investigation using the Tran-Blaha modified Becke-Johnson potential

International Nuclear Information System (INIS)

Araujo, Rafael B.; Almeida, J. S. de; Ferreira da Silva, A.

2013-01-01

In this work, we use density functional theory to investigate the influence of semilocal exchange and correlation effects on the electronic properties of III-nitride semiconductors considering zinc-blende and wurtzite crystal structures. We find that the inclusion of such effects through the use of the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structures of these materials giving energy band gaps which are systematically larger than the ones obtained with standard functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced with semilocal exchange and correlation effects. However, the effective masses are overestimated in the zinc-blende nitrides, but no systematic trend is found in the wurtzite compounds. New results for energy band gaps and effective masses of zinc-blende and wurtzite indium nitrides are presented

[Rolf Hammel-Kiesow. Der Lübecker Katasterplan des 19. Jahrhunderts als historische Quelle. Überlegungen zur Stadtentwicklung Lübecks aus archäologischer, historischer und bauhistorischen Zicht] / Dennis Hormuth

Index Scriptorium Estoniae

Hormuth, Dennis

2013-01-01

Arvustus : Rolf Hammel-Kiesow. Der LÜbecker Katasterplan des 19. Jahrhunderts als historische Quelle. Überlegungen zur Stadtentwicklung Lübecks aus archäologischer, historischer und bauhistorischen Sicht. In: Stadtgründung und Stadterweiterung. Beiträge von Archäologie und Stadtgeschichtsforschung (=Beiträge zur Geschichte der Städte Mitteleuropas XXII). Linz, 2011. S. 75-104

Béatrix Beck: The “Barny Cycle”: Writing to Inform and Heal the Self

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Myrna Bell Rochester

2012-01-01

Full Text Available To cope with the traumatic reality of World War II, French society repressed its memories, resulting in a false collective memory. Today, a more truthful history can be restored with the study of wartime and post-war texts. We examine the first six books (1948-67 of Belgian-French writer Béatrix Beck (1914-2008, alongside the theories of psychiatrist Judith Lewis Herman, who wrote that “traumatic reactions occur when action is of no avail.” Beck’s semi-autobiographical protagonist, Barny, goes through Herman’s stages of forgetting and remembering, healing and recovery. Her emergence as a writer also follows that trajectory: Barny, like Occupied France, was isolated. Helpless to act or react, she was traumatized—by her father’s death, a dysfunctional childhood, her mother’s suicide, and, in Occupied France, her husband’s death, single motherhood, poverty, menial jobs, and fear of arrest. In the first stage of recovery, Barny reaches safety. In the second, she begins to remember, to probe the issues and articulate them, in their painful ambiguity. For Herman, the ultimate goal is to put the story, with its imagery, into words. In the third stage, Barny, against fierce odds, becomes a writer.

Sleep disorders and depressive feelings: a global survey with the Beck depression scale.

Science.gov (United States)

Vandeputte, Melissa; de Weerd, Al

2003-07-01

Patients with (chronic) sleep disorders are prone to depression. Until now studies on the prevalence of depression in the various sleep disorders focused mainly on obstructive sleep apnea patients and narcolepsy. Studies in other common sleep disorders are scarce. The aim of our study was to estimate the prevalence of depressive feelings in the various sleep disorders diagnosed in a Center for Sleep and Wake Disorders. We included 917 consecutive patients (age between 14 and 84 years, median age: 49, 396 male and 521 female), seen in our center for sleep and wake disorders during 2001 and first half of 2002. The diagnosis was based on the history taken at the outpatient-clinic and two consecutive 24-h polysomnographic recordings at home (APSG). The final decisions on the diagnosis were made according to the ASDA international classification of sleep disorders. The severity of depressive feelings was based on the Beck depression scale. Overall, the prevalence of depressive feelings was high. There were no significant differences in age and gender. In psychophysiological insomnia, inadequate sleep- and wake hygiene, sleep state misperception and periodic limb movement disorder/restless legs syndrome some form of depression occurred in more than half of the patients. Moderate to severe depression was found in 3.5% of the patients. The study suggests that the use of a depression scale in the daily routine of diagnosing and treating sleep disorders should be encouraged in order to optimise diagnosis and therapy in these patients.

Factorial Structure of Depressive Symptoms in Anglophone Caribbean University Students: Psychometric Properties of the Beck Depression Inventory-II

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Michael H. Campbell

2009-01-01

Full Text Available Este estudio buscó establecer propiedades psicométricas del Inventario de Depresión de Beck-Segunda Edición (BDI-II con estudiantes de una universidad del Caribe (n=400, 76% mujeres, edad media=25.2. Además, administramos la Escala de Elasticidad de Ego-89, La Escala de Tensión Percibida, La Escala de Ansiedad Estado-Rasgo (Versión de Rasgo y La Escala de Depresión de Zung. El análisis factorial confirmativo comparó la estructura observada con las estructuras oblicuas propuestas en los modelos de dos factores. Las estimaciones factoriales y los índices de calidad de ajuste sugirieron adecuado ajuste para modelos de dos factores. La consistencia interna (=.86 y la fiabilidad test-retest (n=57, r=.78 eran fuertes. Las correlaciones de validez eran significativas en las direcciones teóricamente esperadas. Los resultados apoyan el uso del BDI-II con estudiantes del Caribe.

Biological reduction of iron to the elemental state from ochre deposits of Skelton Beck in Northeast England

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Pattanathu K S M Rahman

2014-06-01

Full Text Available Ochre, consequence of acid mine drainage, is iron oxides-rich soil pigments that can be found in the water drainage from historic base metal and coal mines. The anaerobic strains of Geobacter sulfurreducens and Shewanella denitrificans were used for the microbial reduction of iron from samples of ochre collected from Skelton Beck (Saltburn Orange River, NZ 66738 21588 in Northeast England. The aim of the research was to determine the ability of the two anaerobic bacteria to reduce the iron present in ochre and to determine the rate of the reduction process. The physico-chemical changes in the ochre sample after the microbial reduction process were observed by the production of zero-valent iron which was later confirmed by the detection of elemental Fe in XRD spectrum. The XRF results revealed that 69.16% and 84.82% of iron oxide can be reduced using G. sulfurreducens and S. denitrificans respectively after 8 days of incubation. These results could provide the basis for the development of a biohydrometallurgical process for the production of elemental iron from ochre sediments.

Ab-initio study of electronic, magnetic and thermoelectric behaviors of LiV2O4 and LiCr2O4 using modified Becke-Johson (mBJ) potential

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Ali, Saima; Rashid, Muhammad; Hassan, M.; Noor, N. A.; Mahmood, Q.; Laref, A.; Haq, Bakhtiar Ul

2018-05-01

Owing to the large energy storage capacity and higher working voltage, the spinel oxides LiV2O4 and LiCr2O4, have remained under intense research attention for utilization as electrode materials in lithium-ion batteries. In this study, we explore the half-metallic nature and thermoelectric response in both LiV2O4 and LiCr2O4 spinel oxides using ab-initio density functional theory (DFT) based computations. The ground-state energies of these compounds have been studied at the optimized structural parameters in the ferromagnetic phase. In order to obtain a correct picture of the electronic structure and magnetic properties, the modified Becke-Johnson (mBJ) potential is applied to compute the electronic structures. The half-metallic behavior is confirmed by the spin-polarized electronic band structures and density of state plots. The magnetic nature is elucidated by computing the John-Teller energy, direct and indirect exchange and crystal field splitting energies. Our computations indicate strong hybridization decreasing the V/Cr site magnetic moments and increasing magnetic momenta at the nonmagnetic atomic sites. We also present the computed parameters significant for expressing the thermoelectric response, which are electrical conductivity, thermal conductivity, See-beck coefficient and power factor. The computed properties are of immense interest owing to the potential spintronics and Li-ion battery applications of the studied spinel materials.

Band gaps from the Tran-Blaha modified Becke-Johnson approach: A systematic investigation

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Jiang, Hong

2013-04-01

The semi-local Becke-Johnson (BJ) exchange-correlation potential and its modified form proposed by Tran and Blaha (TB-mBJ) have attracted a lot of interest recently because of the surprisingly accurate band gaps they can deliver for many semiconductors and insulators. In this work, we have investigated the performance of the TB-mBJ potential for the description of electronic band structures in a comprehensive set of semiconductors and insulators. We point out that a perturbative use of the TB-mBJ potential can give overall better results. By investigating a set of IIB-VI and III-V semiconductors, we point out that although the TB-mBJ approach can describe the band gap of these materials quite well, the binding energies of semi-core d-states in these materials deviate strongly from experiment. The difficulty of the TB-mBJ potential to describe the localized states is likely the cause for the fact that the electronic band structures of Cu2O and La2O3 are still poorly described. Based on these observations, we propose to combine the TB-mBJ approach with the Hubbard U correction for localized d/f states, which is able to provide overall good descriptions for both the band gaps and semi-core states binding energies. We further apply the approach to calculate the band gaps of a set of Ti(IV)-oxides, many of which have complicated structures so that the more advanced methods like GW are expensive to treat directly. An overall good agreement with experiment is obtained, which is remarkable considering its little computational efforts compared to GW.

Electronic structure engineering of ZnO with the modified Becke-Johnson exchange versus the classical correlation potential approaches

KAUST Repository

Ul Haq, Bakhtiar

2013-12-01

In this study, we report investigations of structural and electronic properties of ZnO in wurtzite (WZ), rock salt (RS) and zinc-blende (ZB) phases. Calculations have been done with full-potential linearized augmented plane wave plus local orbital method developed within the frame work of Density Functional Theory (DFT). For structural properties investigations, Perdew and Wang proposed local density approximations (LDA) and Perdew et al. proposed generalized gradient approximations (GGA) have been applied. Where for electronic properties in addition to these, Tran-Blaha modified Becke-Johnson (mBJ) potential has been used. Our computed band gap values of ZnO in WZ and ZB phases with mBJ potential are significantly improved compared to those with LDA and GGA; however, in RS phase, energy gap is significantly overestimated compared to experimental measurements. The Zn-d band was found to be more narrower with mBJ potential than that of LDA and GGA. On the other hand, our evaluated crystal field splitting energy values overestimate the experimental values. © 2013 Taylor and Francis.

Validating the Beck Depression Inventory-II in Indonesia’s general population and coronary heart disease patients

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Henndy Ginting

2013-01-01

Full Text Available Este estudio evalúa la validez y determina los puntos de corte del Inventario de Depresión de Beck -II (BDI-II en Indonesia. La versión indonesia del BDI-II (BDI-II Indo se administró a 720 personas sanas de la población general, a 215 pacientes con Enfermedad Coronaria (EC y a 102 pacientes con depresión. El análisis factorial confirmatorio mostró similitud factorial de las tres muestras. Las correlaciones entre el Indo BDI-II y otras medidas de auto-percepción relacionadas con la depresión fueron significativas, mostrando la validez de constructo del Indo BDI-II. Además, la diferencia de puntuación del Indo BDI-II entre los participantes deprimidos y no deprimidos fue altamente significativa. La consistencia interna y la fiabilidad re- test fueron suficientemente altas. La curva ROC (receiver operating characteristic indicó que el punto de corte de la BDI-II para el nivel de gravedad leve de depresión la población de Indonesia es igual a 17. En conclusión, el Indo BDI-II es una medida válida de depresión, tanto para la población general indonesia como en pacientes con EC.

Validação da bateria "Beck" de testes de habilidades para atletas brasileiros de "rugby" em cadeira de rodas Validation of beck battery of skills tests to Brazilian players of wheelchair rugby

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José Irineu Gorla

2011-09-01

Full Text Available O "Rugby" em Cadeira de Rodas é uma modalidade praticada por sujeitos com tetraplegia ou tetra-equivalência, desde 2005 no Brasil, onde existem aproximadamente 10 equipes em atividade. A avaliação motora é um dos meios de controle do treinamento que possibilita conquistar avanços no planejamento. A bateria "Beck" de testes de habilidades (manejo de bola, precisão de passes, bloqueio, velocidade e passes de longa distância para atletas da modalidade foi desenvolvida nos EUA por Yilla e Sherrill (1998. O objetivo deste estudo foi analisar os critérios de autenticidade científica da bateria para a população de atletas brasileiros. Os resultados de duas avaliações com a bateria (teste e re-teste realizadas com 11 atletas (média de idade 27,59 ± 5,37 anos, tempo de lesão 8,19 ± 3,83 anos, foram registrados por três avaliadores, o que possibilitou a análise de objetividade, fidedignidade e consistência interna. Foram utilizadas as ferramentas ANOVA para análise de objetividade e, coeficiente de correlação intraclasse e teste t para análise de fidedignidade e consistência. Não foram encontradas diferenças entre os resultados dos diferentes avaliadores (valores de p variando de 0,45 a 1,00 e os valores de correlação intraclasse encontrados (variação de r de 0,78 a 0,99 permitem concluir que a bateria é consistente e fidedigna. Os resultados encontrados neste estudo são evidências de que os critérios de autenticidade científica para a bateria são satisfeitos e a bateria pode ser considerada um instrumento válido para avaliação motora de atletas brasileiros de "rugby" em cadeira de rodas.The Wheelchair Rugby is a sport practiced by subjects with tetraplegia or tetra-equivalence, since 2005 in Brazil, where there are approximately 10 teams in business. The motricity evaluation is a means of training control that allows achieve real progress in planning. The BECK battery of skills tests (ball handling, precision

Pain, depression and sleep disorders in patients with diabetic and nondiabetic carpal tunnel syndrome: a vicious cycle

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Nermin Tanik

2016-03-01

Full Text Available ABSTRACT Carpal tunnel syndrome (CTS is a condition involving nerve entrapment that often leads to chronic neuropathic pain. We aimed to evaluate sleep quality and related parameters in diabetic and non-diabetic CTS patients. Method This study included a total of 366 patients with chronic CTS. These patients’ sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI and depression using the Beck Depression Inventory (BDI. The severity of neuropathic pain was evaluated using the Douleur Neuropathique-4 (DN4 questionnaire and a visual analogue scale (VAS. Results In the non-diabetic patient group, the total PSQI score was found to affect BDI and VAS, while in the diabetic patient group, the duration of symptoms affected VAS, BDI and fasting glucose levels. Conclusion For diabetic patients, hyperglycemia depression and chronification of neuropathic pain may lead to deterioration of sleep quality. Therefore, consideration of these parameters in the treatment may break a vicious cycle.

German Beck Scale for Suicide Ideation (BSS): psychometric properties from a representative population survey.

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Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

2017-12-04

Suicidal ideation has been identified as one of the major predictors of attempted or actual suicide. Routinely screening individuals for endorsing suicidal thoughts could save lives and protect many from severe psychological consequences following the suicide of loved ones. The aim of this study was to validate the German version of the Beck Scale for Suicide Ideation (BSS) in a sample representative for the Federal Republic of Germany. All 2450 participants completed the first part of the Scale, the BSS-Screen. A risk group of n = 112 individuals (4.6%) with active or passive suicidal ideation was identified and subsequently completed the entire BSS. Satisfactory internal reliability (α = .97 for the BSS-Screen; α = .94 for the entire BSS) and excellent model fit indices for the one-dimensional factorial structure of the BSS-Screen (CFI = .998; TLI = .995; RMSEA = .045 [95%-CI: .030-.061]) were confirmed. Measurement invariance analyses supported strict invariance across gender, age, and depression status. We found correlations with related self-report measures in expected directions comparable to previous studies, indicating satisfactory construct validity. Our study involved cross sectional data, hence neither predictive validity nor retest-reliability were examined. As only the risk group of n = 112 individuals completed the entire measure, confirmatory factor analyses could not be conducted for the full BSS. The German translation of the BSS is a reliable and valid instrument for assessing suicidal ideation in the general population. Using it as a screening device in general and specialized medical care could substantially advance suicide prevention.

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease, an endemic osteoarthritis in China

International Nuclear Information System (INIS)

Wu, Cuiyan; Lei, Ronghui; Tiainen, Mika; Wu, Shixun; Zhang, Qiang; Pei, Fuxing; Guo, Xiong

2014-01-01

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance ( 1 H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD. - Highlights: • Disordered glycometabolism in KBD was demonstrated by combining serum metabolomics and chondrocyte studies. • Glucose and TNF-α were key molecules linked to altered metabolism and inflammation in the pathophysiology of KBD. • The glycometabolism disorder was linked to expression of type II collagen and aggrecan, ROS and apoptosis of KBD chondrocytes

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease, an endemic osteoarthritis in China

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Wu, Cuiyan, E-mail: xj.cy.69@stu.xjtu.edu.cn [School of Public Health, Health Science Centre of Xi' an Jiaotong University, No. 76 Yanta West Road, Xi' an, Shaanxi 710061 (China); Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education (China); Key Laboratory of Trace elements and Endemic Diseases, Ministry of Health, Xi' an, Shaanxi 710061 (China); Lei, Ronghui, E-mail: leirh@mail.xjtu.edu.cn [School of Public Health, Health Science Centre of Xi' an Jiaotong University, No. 76 Yanta West Road, Xi' an, Shaanxi 710061 (China); Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education (China); Key Laboratory of Trace elements and Endemic Diseases, Ministry of Health, Xi' an, Shaanxi 710061 (China); Tiainen, Mika, E-mail: mika.tiainen@uef.fi [School of Pharmacy, University of Eastern Finland, Kuopio (Finland); Wu, Shixun, E-mail: wushixun313@stu.xjtu.edu.cn [School of Public Health, Health Science Centre of Xi' an Jiaotong University, No. 76 Yanta West Road, Xi' an, Shaanxi 710061 (China); Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education (China); Key Laboratory of Trace elements and Endemic Diseases, Ministry of Health, Xi' an, Shaanxi 710061 (China); Zhang, Qiang, E-mail: wdrr@163.com [Department of Kashin–Beck Disease, Qinghai Institute for Endemic Disease Control and Prevention, Xining, Qinghai 811602 (China); Pei, Fuxing, E-mail: peifuxing@vip.163.com [Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Guo, Xiong, E-mail: guox@mail.xjtu.edu.cn [School of Public Health, Health Science Centre of Xi' an Jiaotong University, No. 76 Yanta West Road, Xi' an, Shaanxi 710061 (China); Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education (China); Key Laboratory of Trace elements and Endemic Diseases, Ministry of Health, Xi' an, Shaanxi 710061 (China)

2014-08-15

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance ({sup 1}H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD. - Highlights: • Disordered glycometabolism in KBD was demonstrated by combining serum metabolomics and chondrocyte studies. • Glucose and TNF-α were key molecules linked to altered metabolism and inflammation in the pathophysiology of KBD. • The glycometabolism disorder was linked to expression of type II collagen and aggrecan, ROS and apoptosis of KBD chondrocytes.

Prevalence of depression in patients with β-thalassemia as assessed by the Beck's Depression Inventory.

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Shafiee, Akbar; Nazari, Shiva; Jorjani, Soudeh; Bahraminia, Emad; Sadeghi-Koupaei, Mohammadtaghi

2014-01-01

β-Thalassemia (β-thal) is a frequent, chronic hereditary disease, and a plausible cause for psychological disorders. In this cross-sectional study, we aimed to identify the rate and severity of depression among Iranian patients with β-thal using the Beck's Depression Inventory (BDI). β-Thalassemic patients aged 13-20 years [median age 17.2 years; 27 males (48.2%), 29 females (51.8%)], who presented to the Mofid Children Hospital, Tehran, Iran, for blood transfusions within a 1-year period, were asked to complete the BDI questionnaire. Based on the BDI score, patients were classified as normal or mild-to-severe depression groups, and the collected data were then analyzed according to age and sex. A total of 56 subjects completed the BDI form. Mean score for BDI was 14.27 ± 12.79. Based on the BDI results, 35 (62.5%) had a BDI score below 16 and were therefore not classified as being depressed, while seven (12.5%) patients suffered from severe depression (BDI > 47). Age and gender did not have any significant association with the BDI results (p = 0.52 and p = 0.67, respectively). The total prevalence of various degrees of depression was 30.8% in this study. We concluded that the noticeable rate of depression in thalassemic patients signifies the necessity for improving psychosocial care in this specific group of patients.

Measuring Depression in a Non-Western War-Affected Displaced Population: Measurement Equivalence of the Beck Depression Inventory

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Nuwan Jayawickreme

2017-09-01

Full Text Available Depression is commonly seen in survivors of conflict and disaster across the world. There is a dearth of research on the validity of commonly used measures of depression in these populations. Measurements of depression that are used in multiple contexts need to meet measurement equivalence, i.e., the instrument measures the same construct in the same manner across different groups. The Beck Depression Inventory (BDI was administered to female trauma survivors in the United States (n = 268 and female survivors of war in Sri Lanka (n = 149. Three metrics of measurement equivalence—structural, metric, and scalar—were examined. Two- and three-factor structures of the BDI that have been identified in other populations did not provide a good fit for our data. However, a bifactor model revealed a similar general distress dimension across populations, but dissimilar secondary dimensions or subfactors. The Sri Lankan subfactor comprised of predominantly somatic symptoms and the United States subfactor comprised of cognitive and somatic symptoms. While intercepts of individual BDI items differed, their differences seem to be offsetting. Total BDI scores across these two populations are roughly comparable, although caution is recommended when interpreting them. Making comparisons on subscales is not recommended.

The Level of Anxiety and Depression Among Iranian Infertile Couples Undergoing In Vitro Fertilization or Intra Cytoplasmic Sperm Injection Cycles

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M Yassini

2005-11-01

Full Text Available Background: Approximately 10% of Iranian couples wishing to have a child experience some types of infertility which may impose a considerable psychological burden on them. The main objective of this cross-sectional study was to examine the level of anxiety and depression among infertile couples undergoing IVF or ICSI treatment cycles in Iran. Methods: Fifty infertile couples that who undergoing IVF (n=25 or ICSI (n=25 cycles were considered for this descriptive cross-sectional study. Also, 25 married couples (18-40 years old with history of fertility served as control subjects. All husbands and wives were examined by means of Beck Depression and Spielberger Anxiety Inventories. Results: Comparing with controls, the highest rates of moderate and severe anxiety, were observed in women undergoing IVF (76% and 12%, respectively; P<0.05. However, the rate of depression among women in IVF group was comparable to women undergoing ICSI. Also, the highest rates of severe depression and anxiety were demonstrated among housewives (23.9% and 11%, respectively. The lowest rates of severe anxiety and depression were observed in husbands participated in either IVF or ICSI cycles. In addition, illiterates, compared with educated couples, undergoing IVF or ICSI program were shown to have the highest rates of both depression and anxiety. Conclusion: The results showed that the levels of anxiety and depression were higher in women, especially housewives, undergoing IVF or ICSI cycles than control subjects. Also, men showed lower rates of anxiety and depression than women undergoing IVF or ICSI. Therefore, this can provide useful information and guidance for health professionals working with infertile patients. KeyWords: anxiety, depression, infertility, IVF, ICSI, Iran

Adaptación española del Inventario para la Depresión de Beck-II (BDI-II: 3. Propiedades psicométricas en pacientes con trastornos psicológicos

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JESÚS SANZ

2005-01-01

Full Text Available Se presentan datos sobre la fiabilidad y validez de la adaptación española del Inventario para la Depresión de Beck-II (BDI-II; Beck, Steer y Brown, 1996, obtenidos con una muestra de 305 pacientes ambulatorios con diversos diagnósticos psicopatológicos según el DSM-IV. El coeficiente alfa de fiabilidad fue alto (alfa = 0,89. Las correlaciones con otras medidas autoaplicadas y heteroaplicadas de depresión fueron elevadas y significativamente mayores que la correlación con una medida de ansiedad, lo que avala la validez convergente y discriminante del BDI-II, respectivamente. Respecto a la validez de criterio, los resultados demostraron que los pacientes diagnosticados con un trastorno depresivo mayor tenían niveles de depresión más elevados, medidos con el BDI-II, que los pacientes de otros grupos diagnósticos, aunque no hubo diferencias con los pacientes con trastornos de personalidad. Finalmente, la validación factorial del BDI-II proporcionó una solución bifactorial (factor somático- motivacional y factor cognitivo que coincide con la hallada en estudios previos. Se concluye que el BDI es un instrumento válido de detección y cuantificación de síntomas depresivos en pacientes, si bien su utilidad como herramienta para el diagnóstico diferencial de la depresión es una cuestión pendiente de investigación.

Recomendaciones para la utilización de la adaptación española del Inventario de Ansiedad de Beck (BAI) en la práctica clínica

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Jesús Sanz

2014-01-01

En sus 25 años de existencia, el Inventario de Ansiedad de Beck (BAI) se ha convertido en el cuestionario autoaplicado para evaluar la gravedad de la ansiedad más utilizado en los países con mayor producción científica en psicología, aunque en España dicho instrumento sigue siendo el Cuestionario de Ansiedad Estado-Rasgo (STAI). En este trabajo se presentan las características básicas del BAI en comparación con la escala de Ansiedad Rasgo del STAI, se describe el proceso de adapta...

Reliability and validity of the 12-item WHODAS 2.0 in patients with Kashin-Beck disease.

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Younus, Mohammad Imran; Wang, Di-Miao; Yu, Fang-Fang; Fang, Hua; Guo, Xiong

2017-09-01

The purpose of this study was to check the reliability and validity of the 12-item Chinese version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) for the assessment of disability in patients with Kashin-Beck disease (KBD). We recruited 219 patients with KBD from the high-risk KBD area in the Shaanxi province, using stratified multistage random sampling. We assessed each patient using the Chinese version of the 12-item WHODAS 2.0 and the Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC). Statistical evaluations of the instruments consisted of Cronbach's alpha, intraclass correlation coefficient (ICC), confirmatory factor analysis (CFA), and Pearson's correlation coefficient. Cronbach's alpha and ICC for the six domains ranged from 0.704 to 0.906 and 0.690 to 0.852, respectively. A six-factor structure fits the data well (CFI = 0.967, TLI = 0.944, RMSEA = 0.08). Regarding convergent validity, the four domains of the 12-item WHODAS 2.0 (getting around, self-care, life activity, and participation) showed moderate-to-strong correlation for all three domains of the WOMAC (0.428 < |r| < 0.804). Regarding divergent validity, the two domains of the 12-item WHODAS 2.0 (understanding and communication, and getting along with people) showed weak correlation for the three domains of WOMAC (0.182 < |r| < 0.295). The Chinese version of 12-item WHODAS 2.0 questionnaire is a reliable and valid instrument when administered to KBD patients.

Bipolar mood cycles and lunar tidal cycles.

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Wehr, T A

2018-04-01

In 17 patients with rapid cycling bipolar disorder, time-series analyses detected synchronies between mood cycles and three lunar cycles that modulate the amplitude of the moon's semi-diurnal gravimetric tides: the 14.8-day spring-neap cycle, the 13.7-day declination cycle and the 206-day cycle of perigee-syzygies ('supermoons'). The analyses also revealed shifts among 1:2, 1:3, 2:3 and other modes of coupling of mood cycles to the two bi-weekly lunar cycles. These shifts appear to be responses to the conflicting demands of the mood cycles' being entrained simultaneously to two different bi-weekly lunar cycles with slightly different periods. Measurements of circadian rhythms in body temperature suggest a biological mechanism through which transits of one of the moon's semi-diurnal gravimetric tides might have driven the patients' bipolar cycles, by periodically entraining the circadian pacemaker to its 24.84-h rhythm and altering the pacemaker's phase-relationship to sleep in a manner that is known to cause switches from depression to mania.

Beck Self-Esteem Scale-Short Form: Development and psychometric evaluation of a scale for the assessment of self-concept in schizophrenia.

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Thomas, Elizabeth C; Murakami-Brundage, Jessica; Bertolami, Nina; Beck, Aaron T; Grant, Paul M

2018-05-01

A requisite step for testing cognitive theories regarding the role of self-concept in schizophrenia is the development of measures that follow a cognitive conceptualization and better capture the multifaceted nature of this construct. The purpose of this study was to examine the psychometric properties a new self-concept measure, the Beck Self-Esteem Scale-Short Form (BSES-SF), based on a sample of 204 individuals with schizophrenia or schizoaffective disorder. We evaluated the BSES-SF's dimensionality, internal consistency reliability, and construct and divergent validity using confirmatory factor analysis, Cronbach's alpha, Pearson correlations, independent samples t-tests, and one-way analysis of variance. Findings indicate that the 10-item BSES-SF is a reliable and valid measure of self-concept that is appropriate for a broad group of individuals with schizophrenia spectrum disorders. Following cognitive theory, the scale demonstrated significant relationships with delusion severity, motivation, and depression, further signifying its utility for research and practice efforts that are designed to address psychopathology in schizophrenia. Copyright © 2018 Elsevier B.V. All rights reserved.

Prediction of Beck Depression Inventory (BDI-II) Score Using Acoustic Measurements in a Sample of Iium Engineering Students

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Fikri Zanil, Muhamad; Nur Wahidah Nik Hashim, Nik; Azam, Huda

2017-11-01

Psychiatrist currently relies on questionnaires and interviews for psychological assessment. These conservative methods often miss true positives and might lead to death, especially in cases where a patient might be experiencing suicidal predisposition but was only diagnosed as major depressive disorder (MDD). With modern technology, an assessment tool might aid psychiatrist with a more accurate diagnosis and thus hope to reduce casualty. This project will explore on the relationship between speech features of spoken audio signal (reading) in Bahasa Malaysia with the Beck Depression Inventory scores. The speech features used in this project were Power Spectral Density (PSD), Mel-frequency Ceptral Coefficients (MFCC), Transition Parameter, formant and pitch. According to analysis, the optimum combination of speech features to predict BDI-II scores include PSD, MFCC and Transition Parameters. The linear regression approach with sequential forward/backward method was used to predict the BDI-II scores using reading speech. The result showed 0.4096 mean absolute error (MAE) for female reading speech. For male, the BDI-II scores successfully predicted 100% less than 1 scores difference with MAE of 0.098437. A prediction system called Depression Severity Evaluator (DSE) was developed. The DSE managed to predict one out of five subjects. Although the prediction rate was low, the system precisely predict the score within the maximum difference of 4.93 for each person. This demonstrates that the scores are not random numbers.

Psychometric Adaptation of the Beck Hopelessness Scale as a Self-Rated Suicide Risk Screening Instrument Among Nigerian University Students.

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Aloba, Olutayo; Awe, Oluwatosin; Adelola, Aderopo; Olatunji, Philemon; Aloba, Tolulope

2018-03-01

Globally, suicide is the most important cause of mortality among adolescents and young adults. The factor that correlates most significantly with suicide is hopelessness. The aim is to explore the psychometric adaptation of the Beck Hopelessness Scale (BHS) as a suicide risk evaluation tool among Nigerian university students. A total of 554 Nigerian students completed the BHS and the Depression Anxiety Stress Scale (DASS). Suicide risk level among them was determined by interviewing them with the Mini International Neuropsychiatric Interview Suicidality module. Cronbach's alpha for the 16-item BHS was 0.87. It exhibited satisfactory concurrent validity with the Mini International Neuropsychiatric Interview (MINI) Suicidality module and the subscales of the DASS among the students. The 2-factor model of the BHS-16 exhibited satisfactory indices of fitness (goodness of fit index = 0.930; parsimonious goodness of fit index = 0.601; comparative fit index = 0.934; incremental fit index = 0.936; Tucker-Lewis index = 0.910; root mean square error of approximation = 0.059; χ 2 / df = 1.9). Receiver operating characteristics curve indicated that the best cutoff score for those categorized as high suicide risk was 7 (sensitivity 0.700, specificity 0.908, AUC = 0.897). The BHS has satisfactory psychometric properties as a suicide risk screening tool among Nigerian university students.

Evaluation of the relationship and genetic overlap between Kashin-Beck disease and body mass index.

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Wen, Y; Hao, J; Xiao, X; Guo, X; Wang, W; Yang, T; Shen, H; Tian, Q; Tan, L; Deng, H-W; Zhang, F

2016-11-01

Body mass index (BMI) is one of the major factors affecting the development of osteoarthritis (OA) but there is currently no information available regarding the relationship between BMI and Kashin-Beck disease (KBD). Our aim in this study was to investigate the relationship and genetic overlap between BMI and KBD. A total of 2050 Han Chinese subjects participated in this study. Using a cohort of 333 grade I KBD patients, logistic regression analysis was conducted to evaluate the correlation between BMI and KBD. Another independent sample of 1717 subjects was genotyped for a genome-wide association study (GWAS) using Affymetrix Human SNP 6.0 Arrays. Single nucleotide polymorphism (SNP) effect concordance analysis (SECA) was applied to the GWAS summaries of KBD and BMI for pleiotropy analysis. Genome-wide bivariate association analysis (GWBAA) of KBD and BMI was carried out to identify the genes with pleiotropic effects on KBD and BMI. The relevance of identified genes with KBD was validated by gene expression profiling and immunohistochemistry. BMI correlated positively with knee movement disorder in KBD (coefficient β = 0.068, p = 0.045). SECA identified a significant pleiotropic effect (empirical p = 0.021) between KBD and BMI. In the GWBAA, the rs1893577 of the ADAMTS1 gene achieved the most significant association signal (p = 7.38 × 10 -9 ). ADAMTS1 was also up-regulated in KBD vs. normal (ratio = 2.64 ± 2.80) and KBD vs. OA (ratio = 2.31 ± 2.01). The rate of ADAMTS1-positive chondrocytes in KBD was significantly higher than that in OA (p < 0.05) and healthy controls (p < 0.05). Our results suggest that ADAMTS1 is a novel susceptibility gene for KBD.

The Krebs Uric Acid Cycle: A Forgotten Krebs Cycle.

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Salway, Jack G

2018-05-25

Hans Kornberg wrote a paper entitled 'Krebs and his trinity of cycles' commenting that every school biology student knows of the Krebs cycle, but few know that Krebs discovered two other cycles. These are (i) the ornithine cycle (urea cycle), (ii) the citric acid cycle (tricarboxylic acid or TCA cycle), and (iii) the glyoxylate cycle that was described by Krebs and Kornberg. Ironically, Kornberg, codiscoverer of the 'glyoxylate cycle', overlooked a fourth Krebs cycle - (iv) the uric acid cycle. Copyright © 2018 Elsevier Ltd. All rights reserved.

Alternative ORC bottoming cycles FOR combined cycle power plants

International Nuclear Information System (INIS)

Chacartegui, R.; Sanchez, D.; Munoz, J.M.; Sanchez, T.

2009-01-01

In this work, low temperature Organic Rankine Cycles are studied as bottoming cycle in medium and large scale combined cycle power plants. The analysis aims to show the interest of using these alternative cycles with high efficiency heavy duty gas turbines, for example recuperative gas turbines with lower gas turbine exhaust temperatures than in conventional combined cycle gas turbines. The following organic fluids have been considered: R113, R245, isobutene, toluene, cyclohexane and isopentane. Competitive results have been obtained for toluene and cyclohexane ORC combined cycles, with reasonably high global efficiencies. The paper is structured in four main parts. A review of combined cycle and ORC cycle technologies is presented, followed by a thermodynamic analysis of combined cycles with commercial gas turbines and ORC low temperature bottoming cycles. Then, a parametric optimization of an ORC combined cycle plant is performed in order to achieve a better integration between these two technologies. Finally, some economic considerations related to the use of ORC in combined cycles are discussed.

Cycling infrastructure for reducing cycling injuries in cyclists.

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Mulvaney, Caroline A; Smith, Sherie; Watson, Michael C; Parkin, John; Coupland, Carol; Miller, Philip; Kendrick, Denise; McClintock, Hugh

2015-12-10

Cycling is an attractive form of transport. It is beneficial to the individual as a form of physical activity that may fit more readily into an individual's daily routine, such as for cycling to work and to the shops, than other physical activities such as visiting a gym. Cycling is also beneficial to the wider community and the environment as a result of fewer motorised journeys. Cyclists are seen as vulnerable road users who are frequently in close proximity to larger and faster motorised vehicles. Cycling infrastructure aims to make cycling both more convenient and safer for cyclists. This review is needed to guide transport planning. To:1. evaluate the effects of different types of cycling infrastructure on reducing cycling injuries in cyclists, by type of infrastructure;2. evaluate the effects of cycling infrastructure on reducing the severity of cycling injuries in cyclists;3. evaluate the effects of cycling infrastructure on reducing cycling injuries in cyclists with respect to age, sex and social group. We ran the most recent search on 2nd March 2015. We searched the Cochrane Injuries Group Specialised Register, CENTRAL (The Cochrane Library), MEDLINE (OvidSP), Embase Classic + Embase(OvidSP), PubMed and 10 other databases. We searched websites, handsearched conference proceedings, screened reference lists of included studies and previously published reviews and contacted relevant organisations. We included randomised controlled trials, cluster randomised controlled trials, controlled before-after studies, and interrupted time series studies which evaluated the effect of cycling infrastructure (such as cycle lanes, tracks or paths, speed management, roundabout design) on cyclist injury or collision rates. Studies had to include a comparator, that is, either no infrastructure or a different type of infrastructure. We excluded studies that assessed collisions that occurred as a result of competitive cycling. Two review authors examined the titles and

Optimum gas turbine cycle for combined cycle power plant

International Nuclear Information System (INIS)

Polyzakis, A.L.; Koroneos, C.; Xydis, G.

2008-01-01

The gas turbine based power plant is characterized by its relatively low capital cost compared with the steam power plant. It has environmental advantages and short construction lead time. However, conventional industrial engines have lower efficiencies, especially at part load. One of the technologies adopted nowadays for efficiency improvement is the 'combined cycle'. The combined cycle technology is now well established and offers superior efficiency to any of the competing gas turbine based systems that are likely to be available in the medium term for large scale power generation applications. This paper has as objective the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, intercooled cycle, reheated cycle and intercooled and reheated cycle. The proposed combined cycle plant would produce 300 MW of power (200 MW from the gas turbine and 100 MW from the steam turbine). The results showed that the reheated gas turbine is the most desirable overall, mainly because of its high turbine exhaust gas temperature and resulting high thermal efficiency of the bottoming steam cycle. The optimal gas turbine (GT) cycle will lead to a more efficient combined cycle power plant (CCPP), and this will result in great savings. The initial approach adopted is to investigate independently the four theoretically possible configurations of the gas plant. On the basis of combining these with a single pressure Rankine cycle, the optimum gas scheme is found. Once the gas turbine is selected, the next step is to investigate the impact of the steam cycle design and parameters on the overall performance of the plant, in order to choose the combined cycle offering the best fit with the objectives of the work as depicted above. Each alterative cycle was studied, aiming to find the best option from the standpoint of overall efficiency, installation and operational costs, maintainability and reliability for a combined power

Βιβλιοκρισία:P. SCHREINER-E. VOGT(eds., Karl Krumbacher. Leben und Werk, München, Verlag der Bayerischen Akademie der Wissenschaften in Kommission beim Verlag C. H. Beck, München 2011

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Walter PUCHNER

2013-04-01

Full Text Available Βιβλιοκρισία: P. Schreiner-E. Vogt (eds., Karl Krumbacher. Leben und Werk, München, Verlag der Bayerischen Akademie der Wissenschaften in Kommission beim Verlag C. H. Beck, München 2011 (Bayerische Akademie der Wissenschaften, Philosophisch-historische Klasse, Sitzungsberichte, Jahrgang 2011, Heft 4, σελ. 147, 5 εικ., ΙSBN 978 3 7696 1569 0.

Cycles and Common Cycles in Property and Related Sectors

OpenAIRE

Peijie Wang

2003-01-01

This paper examines cycles and common cycles in the property market and the economy. While focusing on common cycles, the study also incorporates common trends in the meantime, so it covers the whole spectrum of dynamic analysis. It has been found that property shares common cycles, particularly with those sectors that are the user markets of property. The mechanisms of common cycles and the relative magnitudes of cycles of the sectors related to property are discussed to shed light on proper...

HCl removal using cycled carbide slag from calcium looping cycles

International Nuclear Information System (INIS)

Xie, Xin; Li, Yingjie; Wang, Wenjing; Shi, Lei

2014-01-01

Highlights: • Cycled carbide slag from calcium looping cycles is used to remove HCl. • The optimum temperature for HCl removal of cycled carbide slag is 700 °C. • The presence of CO 2 restrains HCl removal of cycled carbide slag. • CO 2 capture conditions have important effects on HCl removal of cycled carbide slag. • HCl removal capacity of carbide slag drops with cycle number rising from 1 to 50. - Abstract: The carbide slag is an industrial waste from chlor-alkali plants, which can be used to capture CO 2 in the calcium looping cycles, i.e. carbonation/calcination cycles. In this work, the cycled carbide slag from the calcium looping cycles for CO 2 capture was proposed to remove HCl in the flue gas from the biomass-fired and RDFs-fired boilers. The effects of chlorination temperature, HCl concentration, particle size, presence of CO 2 , presence of O 2 , cycle number and CO 2 capture conditions in calcium looping cycles on the HCl removal behavior of the carbide slag experienced carbonation/calcination cycles were investigated in a triple fixed-bed reactor. The chlorination product of the cycled carbide slag from the calcium looping after absorbing HCl is not CaCl 2 but CaClOH. The optimum temperature for HCl removal of the cycled carbide slag from the carbonation/calcination cycles is 700 °C. The chlorination conversion of the cycled carbide slag increases with increasing the HCl concentration. The cycled carbide slag with larger particle size exhibits a lower chlorination conversion. The presence of CO 2 decreases the chlorination conversions of the cycled carbide slag and the presence of O 2 has a trifling impact. The chlorination conversion of the carbide slag experienced 1 carbonation/calcination cycle is higher than that of the uncycled calcined sorbent. As the number of carbonation/calcination cycles increases from 1 to 50, the chlorination conversion of carbide slag drops gradually. The high calcination temperature and high CO 2

50 AÑOS DE LOS INVENTARIOS DE DEPRESIÓN DE BECK: CONSEJOS PARA LA UTILIZACIÓN DE LA ADAPTACIÓN ESPAÑOLA DEL BDI-II EN LA PRÁCTICA CLÍNICA

OpenAIRE

Jesús Sanz

2013-01-01

En 2011 se publicó la primera adaptación española del Inventario de Depresión de Beck-II (BDI-II), justo cuando se cumplía el 50º aniversario de la publicación de su primera edición. En este tiempo, el BDI se ha convertido en el cuestionario autoaplicado más utilizado en España y en el mundo para evaluar la gravedad de la depresión. En este trabajo se presentan las características básicas del BDI-II en relación con sus versiones anteriores (BDI-I y BDI-IA) y el proceso de su adaptación a l...

Will Solar Cycles 25 and 26 Be Weaker than Cycle 24?

Science.gov (United States)

Javaraiah, J.

2017-11-01

The study of variations in solar activity is important for understanding the underlying mechanism of solar activity and for predicting the level of activity in view of the activity impact on space weather and global climate. Here we have used the amplitudes (the peak values of the 13-month smoothed international sunspot number) of Solar Cycles 1 - 24 to predict the relative amplitudes of the solar cycles during the rising phase of the upcoming Gleissberg cycle. We fitted a cosine function to the amplitudes and times of the solar cycles after subtracting a linear fit of the amplitudes. The best cosine fit shows overall properties (periods, maxima, minima, etc.) of Gleissberg cycles, but with large uncertainties. We obtain a pattern of the rising phase of the upcoming Gleissberg cycle, but there is considerable ambiguity. Using the epochs of violations of the Gnevyshev-Ohl rule (G-O rule) and the `tentative inverse G-O rule' of solar cycles during the period 1610 - 2015, and also using the epochs where the orbital angular momentum of the Sun is steeply decreased during the period 1600 - 2099, we infer that Solar Cycle 25 will be weaker than Cycle 24. Cycles 25 and 26 will have almost same strength, and their epochs are at the minimum between the current and upcoming Gleissberg cycles. In addition, Cycle 27 is expected to be stronger than Cycle 26 and weaker than Cycle 28, and Cycle 29 is expected to be stronger than both Cycles 28 and 30. The maximum of Cycle 29 is expected to represent the next Gleissberg maximum. Our analysis also suggests a much lower value (30 - 40) for the maximum amplitude of the upcoming Cycle 25.

Culture in cycles: considering H.T. Odum's 'information cycle'

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Abel, Thomas

2014-01-01

'Culture' remains a conundrum in anthropology. When recast in the mold of 'information cycles,' culture is transformed. New fault lines appear. Information is splintered into parallel or nested forms. Dynamics becomes cycling. Energy is essential. And culture has function in a directional universe. The 'information cycle' is the crowning component of H.T. Odum's theory of general systems. What follows is an application of the information cycle to the cultural domains of discourse, social media, ritual, education, journalism, technology, academia, and law, which were never attempted by Odum. In information cycles, cultural information is perpetuated - maintained against Second Law depreciation. Conclusions are that culture is in fact a nested hierarchy of cultural forms. Each scale of information production is semi-autonomous, with its own evolutionary dynamics of production and selection in an information cycle. Simultaneously, each information cycle is channeled or entrained by its larger scale of information and ultimately human-ecosystem structuring.

Factor structure and clinical utility of the Beck depression inventory in patients with binge eating disorder and obesity.

Science.gov (United States)

Udo, Tomoko; McKee, Sherry A; Grilo, Carlos M

2015-01-01

The Beck Depression Inventory (BDI) is often used to assess depression symptoms, but its factor structure and its clinical utility have not been evaluated in patients with binge eating disorder (BED) and obesity. A total of 882 treatment-seeking obese patients with BED were administered structured interviews (Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I Disorders) and completed self-report questionnaires. Exploratory and confirmatory factor analyses supported a brief 16-item BDI version with a three-factor structure (affective, attitudinal and somatic). Both 21- and 16-item versions showed excellent internal consistency (both α=0.89) and had significant correlation patterns with different aspects of eating disorder psychopathology; three factors showed significant but variable associations with eating disorder psychopathology. Area under the curves (AUC) for both BDI versions were significant in predicting major depressive disorder (MDD; AUC=0.773 [16-item], 73.5% sensitivity/70.2% specificity, AUC=0.769 [21-item], 79.5% sensitivity/64.1% specificity) and mood disorders (AUC=0.763 [16-item], 67.1% sensitivity/71.5% specificity, AUC=0.769 [21-item], 84.2% sensitivity/55.7% specificity). The 21-item BDI (cutoff score ≥16) showed higher negative predictive values (94.0% vs. 93.0% [MDD]; 92.4% vs. 88.3% [mood disorders]) than the brief 16-item BDI (cutoff score ≥13). Both BDI versions demonstrated moderate performance as a screening instrument for MDD/mood disorders in obese patients with BED. Advantages and disadvantages for both versions are discussed. A three-factor structure has potential to inform the conceptualization of depression features. Copyright © 2015 Elsevier Inc. All rights reserved.

Response pattern of depressive symptoms among college students: What lies behind items of the Beck Depression Inventory-II?

Science.gov (United States)

de Sá Junior, Antonio Reis; de Andrade, Arthur Guerra; Andrade, Laura Helena; Gorenstein, Clarice; Wang, Yuan-Pang

2018-07-01

This study examines the response pattern of depressive symptoms in a nationwide student sample, through item analyses of a rating scale by both classical test theory (CTT) and item response theory (IRT). The 21-item Beck Depression Inventory-II (BDI-II) was administered to 12,711 college students. First, the psychometric properties of the scale were described. Thereafter, the endorsement probability of depressive symptom in each scale item was analyzed through CTT and IRT. Graphical plots depicted the endorsement probability of scale items and intensity of depression. Three items of different difficulty level were compared through CTT and IRT approach. Four in five students reported the presence of depressive symptoms. The BDI-II items presented good reliability and were distributed along the symptomatic continuum of depression. Similarly, in both CTT and IRT approaches, the item 'changes in sleep' was easily endorsed, 'loss of interest' moderately and 'suicidal thoughts' hardly. Graphical representation of BDI-II of both methods showed much equivalence in terms of item discrimination and item difficulty. The item characteristic curve of the IRT method provided informative evaluation of item performance. The inventory was applied only in college students. Depressive symptoms were frequent psychopathological manifestations among college students. The performance of the BDI-II items indicated convergent results from both methods of analysis. While the CTT was easy to understand and to apply, the IRT was more complex to understand and to implement. Comprehensive assessment of the functioning of each BDI-II item might be helpful in efficient detection of depressive conditions in college students. Copyright © 2018 Elsevier B.V. All rights reserved.

Proliferation in cycle

Energy Technology Data Exchange (ETDEWEB)

Piao Yunsong [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: yspiao@gucas.ac.cn

2009-06-15

In the contracting phase with w{approx_equal}0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w{approx_equal}0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

Proliferation in cycle

International Nuclear Information System (INIS)

Piao Yunsong

2009-01-01

In the contracting phase with w≅0, the scale invariant spectrum of curvature perturbation is given by the increasing mode of metric perturbation. In this Letter, it is found that if the contracting phase with w≅0 is included in each cycle of a cycle universe, since the metric perturbation is amplified on super horizon scale cycle by cycle, after each cycle the universe will be inevitably separated into many parts independent of one another, each of which corresponds to a new universe and evolves up to next cycle, and then is separated again. In this sense, a cyclic multiverse scenario is actually presented, in which the universe proliferates cycle by cycle. We estimate the number of new universes proliferated in each cycle, and discuss the implications of this result.

Substance Use and Depression Symptomatology: Measurement Invariance of the Beck Depression Inventory (BDI-II among Non-Users and Frequent-Users of Alcohol, Nicotine and Cannabis.

Directory of Open Access Journals (Sweden)

Ashlee A Moore

Full Text Available Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.

Substance Use and Depression Symptomatology: Measurement Invariance of the Beck Depression Inventory (BDI-II) among Non-Users and Frequent-Users of Alcohol, Nicotine and Cannabis.

Science.gov (United States)

Moore, Ashlee A; Neale, Michael C; Silberg, Judy L; Verhulst, Brad

2016-01-01

Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II) in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.

High Beck Depression Inventory 21 scores in adolescents without depression are associated with negative self-image and immature defense style.

Science.gov (United States)

Savilahti, Emma M; Haravuori, Henna; Rytilä-Manninen, Minna; Lindberg, Nina; Kettunen, Kirsi; Marttunen, Mauri

2018-05-01

Beck Depression Inventory (BDI) is widely used in assessing adolescents' psychological wellbeing, but occasionally the result diverges from diagnostics. Our aim was to identify factors associated with discrepancies between BDI scores and diagnostic assessment in adolescent psychiatric patients and general population. The study comprised 206 inpatients (13-17 years old) and 203 age and gender matched non-referred adolescents. Study subjects filled self-reports on depression symptoms (BDI-21), alcohol use (AUDIT), defense styles (DSQ-40) and self-image (OSIQ-R), and on background information and adverse life events. Diagnostics was based on K-SADS-PL interview, and/or clinical interview and clinical records when available. We compared subjects who scored in BDI-21 either 0-15 points or 16-63 points firstly among subjects without current unipolar depression (n = 284), secondly among those with unipolar depression (n = 105). High BDI-21 scores in subjects without depression diagnosis (n = 48) were associated with female sex, adverse life events, parents' psychiatric problems, higher comorbidity, higher AUDIT scores, worse self-image and more immature defense styles. Low BDI-21 scores among subjects with depression diagnosis (n = 23) were associated with male sex, more positive self-image and less immature defense style. In conclusion, high BDI-21 scores in the absence of depression may reflect a broad range of challenges in an adolescent's psychological development. Copyright © 2018 Elsevier B.V. All rights reserved.

Your Menstrual Cycle

Science.gov (United States)

... your menstrual cycle What happens during your menstrual cycle The menstrual cycle includes not just your period, but the rise ... that take place over the weeks in your cycle. Want to know what happens on each day ...

Fuel cycle cost uncertainty from nuclear fuel cycle comparison

International Nuclear Information System (INIS)

Li, J.; McNelis, D.; Yim, M.S.

2013-01-01

This paper examined the uncertainty in fuel cycle cost (FCC) calculation by considering both model and parameter uncertainty. Four different fuel cycle options were compared in the analysis including the once-through cycle (OT), the DUPIC cycle, the MOX cycle and a closed fuel cycle with fast reactors (FR). The model uncertainty was addressed by using three different FCC modeling approaches with and without the time value of money consideration. The relative ratios of FCC in comparison to OT did not change much by using different modeling approaches. This observation was consistent with the results of the sensitivity study for the discount rate. Two different sets of data with uncertainty range of unit costs were used to address the parameter uncertainty of the FCC calculation. The sensitivity study showed that the dominating contributor to the total variance of FCC is the uranium price. In general, the FCC of OT was found to be the lowest followed by FR, MOX, and DUPIC. But depending on the uranium price, the FR cycle was found to have lower FCC over OT. The reprocessing cost was also found to have a major impact on FCC

Near-edge band structures and band gaps of Cu-based semiconductors predicted by the modified Becke-Johnson potential plus an on-site Coulomb U

International Nuclear Information System (INIS)

Zhang, Yubo; Zhang, Jiawei; Wang, Youwei; Gao, Weiwei; Abtew, Tesfaye A.; Zhang, Peihong; Zhang, Wenqing

2013-01-01

Diamond-like Cu-based multinary semiconductors are a rich family of materials that hold promise in a wide range of applications. Unfortunately, accurate theoretical understanding of the electronic properties of these materials is hindered by the involvement of Cu d electrons. Density functional theory (DFT) based calculations using the local density approximation or generalized gradient approximation often give qualitative wrong electronic properties of these materials, especially for narrow-gap systems. The modified Becke-Johnson (mBJ) method has been shown to be a promising alternative to more elaborate theory such as the GW approximation for fast materials screening and predictions. However, straightforward applications of the mBJ method to these materials still encounter significant difficulties because of the insufficient treatment of the localized d electrons. We show that combining the promise of mBJ potential and the spirit of the well-established DFT + U method leads to a much improved description of the electronic structures, including the most challenging narrow-gap systems. A survey of the band gaps of about 20 Cu-based semiconductors calculated using the mBJ + U method shows that the results agree with reliable values to within ±0.2 eV

DETECTING ALIEN LIMIT CYCLES NEAR A HAMILTONIAN 2-SADDLE CYCLE

OpenAIRE

LUCA, Stijn; DUMORTIER, Freddy; Caubergh, M.; Roussarie, R.

2009-01-01

This paper aims at providing and example of a cubic Hamiltonian 2-saddle cycle that after bifurcation can give rise to an alien limit cycle; this is a limit cycle that is not controlled by a zero of the related Abelian integral. To guarantee the existence of an alien limit cycle one can verify generic conditions on the Abelian integral and on the transition map associated to the connections of the 2-saddle cycle. In this paper, a general method is developed to compute the first and second der...

Proposal of a nuclear cycle research and development plan in Tokai works. The roadmap from LWR cycle to FBR cycle

International Nuclear Information System (INIS)

Nakamura, Hirofumi; Abe, Tomoyuki; Kashimura, Takuo; Nagai, Toshihisa; Maeda, Seichiro; Yamaguchi, Toshiya; Kuroki, Ryoichiro

2003-07-01

The Generation-II Project Task Force Team has investigated a research and development plan of a future nuclear fuel cycle in Tokai works for about three months from December 19, 2002. First we have discussed about the present condition of Japanese nuclear fuel cycle and have recognized it as the following. The relation of the technology between the LWR-cycle and the FBR-cycle is not clear. MOX Fuel Use in Light Water Reactors is important to establish technology of the FBR fuel cycle. Radioactive waste disposal issue is urgent. Next we have proposed the three basic policies on R and D plan of nuclear fuel cycle in consideration of the F.S. on FBR-cycle. Establishment and advancement of 'the tough nuclear fuel cycle'. Early establishment of the FBR cycle technology to be able to supply energy stably for long-term. Establishment of the radioactive waste treatment and disposal technology, and optimization of nuclear fuel cycle technology from the viewpoint of radioactive waste. And we have proposed the Japanese technical holder system to integrate all LWR and FBR cycle technology. (author)

Psychometric properties and measurement invariance of the Beck hopelessness scale (BHS): results from a German representative population sample.

Science.gov (United States)

Kliem, Sören; Lohmann, Anna; Mößle, Thomas; Brähler, Elmar

2018-04-25

The Beck Hopelessness Scale (BHS) has been the most frequently used instrument for the measurement of hopelessness in the past 40 years. Only recently has it officially been translated into German. The psychometric properties and factor structure of the BHS have been cause for intensive debate in the past. Based on a representative sample of the German population (N = 2450) item analysis including item sensitivity, item-total correlation and item difficulty was performed. Confirmatory factor analyses (CFA) for several factor solutions from the literature were performed. Multiple group factor analysis was performed to assess measurement invariance. Construct validity was assessed via the replication of well-established correlations with concurrently assessed measures. Most items exhibited adequate properties. Items #4, #8 and #13 exhibited poor item characteristics- each of these items had previously received negative evaluations in international studies. A one-dimensional factor solution, favorable for the calculation and interpretation of a sum score, was regarded as adequate. A bi-factor model with one content factor and two method factors (defined by positive/negative item coding) resulted in an excellent model fit. Cronbach's alpha in the current sample was .87. Hopelessness, as measured by the BHS, significantly correlated in the expected direction with suicidal ideation (r = .36), depression (r = .53) and life satisfaction (r = -.53). Strict measurement invariance could be established regarding gender and depression status. Due to limited research regarding the interpretation of fit indices with dichotomous data, interpretation of CFA results needs to remain tentative. The BHS is a valid measure of hopelessness in various subgroups of the general population. Future research could aim at replicating these findings using item response theory and cross-cultural samples. A one-dimensional bi-factor model seems appropriate even in a non

Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

KAUST Repository

Jaasim, Mohammed

2017-03-13

Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities, such as the indicated mean effective pressure (IMEP) are observed at different levels. Accurate prediction of CCV in IC engines is an important but challenging task. Computational fluid dynamics (CFD) simulations using high performance computing (HPC) can be used effectively to visualize such 3D spatial distributions. In the present study, a dual fuel large engine is considered, with natural gas injected into the manifold accompanied with direct injection of diesel pilot fuel to trigger ignition. Multiple engine cycles in 3D are simulated in series as in the experiments to investigate the potential of HPC based high fidelity simulations to accurately capture the cycle to cycle variation in dual fuel engines. Open cycle simulations are conducted to predict the combined effect of the stratification of fuel-air mixture, temperature and turbulence on the CCV of pressure. The predicted coefficient of variation (COV) of pressure compared to the results from closed cycle simulations and the experiments.

Post-critical behavior of Beck`s column with a tip mass

DEFF Research Database (Denmark)

Andersen, S. B.; Thomsen, Jon Juel

2002-01-01

This study examines how a tip mass with rotary inertia affects the stability of a follower-loaded cantilevered column. Using nonlinear modeling and perturbation analysis, expressions are set up for determining the stability of the straight column and the amplitude of post-critical flutter...... oscillations. Bifurcation diagrams are given, showing how the vibration amplitude changes with follower load and other parameters. These results agree closely with numerical simulation. It is found that sufficiently large values of tip mass rotary inertia can change the primary bifurcation from supercritical...

Simulation of Cycle-to-Cycle Variation in Dual-Fuel Engines

KAUST Repository

Jaasim, Mohammed; Pasunurthi, Shyamsundar; Jupudi, Ravichandra S.; Gubba, Sreenivasa Rao; Primus, Roy; Klingbeil, Adam; Wijeyakulasuriya, Sameera; Im, Hong G.

2017-01-01

Standard practices of internal combustion (IC) engine experiments are to conduct the measurements of quantities averaged over a large number of cycles. Depending on the operating conditions, the cycle-to-cycle variation (CCV) of quantities

Life-cycle cost analysis of adsorption cycles for desalination

KAUST Repository

Thu, Kyaw

2010-08-01

This paper presents the thermo-economic analysis of the adsorption desalination (AD) cycle that is driven by low-temperature waste heat from exhaust of industrial processes or renewable sources. The AD cycle uses an adsorbent such as the silica gel to desalt the sea or brackish water. Based on an experimental prototype AD plant, the life-cycle cost analysis of AD plants of assorted water production capacities has been simulated and these predictions are translated into unit cost of water production. Our results show that the specific energy consumption of the AD cycle is 1.38 kWh/m3 which is the lowest ever reported. For a plant capacity of 1000 m3/d, the AD cycle offers a unit cost of $0.457/m3 as compared to more than $0.9 for the average RO plants. Besides being cost-effective, the AD cycle is also environment-friendly as it emits less CO2 emission per m3 generated, typically 85% less, by comparison to an RO process. © 2010 Desalination Publications.

How well can business cycle accounting account for business cycles?

OpenAIRE

Keisuke Otsu

2012-01-01

The business cycle accounting method introduced by Chari, Kehoe and McGrattan (2007) is a useful tool to decompose business cycle fluctuations into their contributing factors. However, the model estimated by the maximum likelihood method cannot replicate business cycle moments computed from data. Moment-based estimation might be an attractive alternative if the purpose of the research is to study business cycle properties such as volatility, persistence and cross-correlation of variables inst...

Beck Depression Inventory (BDI) in patients with breast disease and breast cancer: a prospective case-control study.

Science.gov (United States)

Eskelinen, Matti; Ollonen, Paula

2011-01-01

In 1972, Beck introduced an inventory (BDI) for rapid screening of depression. The associations between the BDI and the risk of breast cancer (BC) are rarely considered together in prospective studies. In an extension of the Kuopio Breast Cancer Study, 115 women with breast cancer symptoms were semi-structurally interviewed in-depth as well as asked to complete standardised questionnaires (Forsen, Spielberger, MADRS), and all study variables were obtained before any diagnostic procedures were carried out. BDI was used to evaluate the depression of the study participants. The clinical examinations and biopsies showed BC in 34 patients, benign breast disease (BBD) in 53 patients, and 28 individuals were shown to be healthy (HSS). There was a trend for the women with HSS to have less sadness (BDI mean score, 0.27) than those of the BC (BDI mean score, 0.56) and BBD groups (BDI mean score, 0.49). The HSS group tended to be less pessimistic (BDI mean score, 0.15) than the patients in the BC group (BDI mean score, 0.44) and in the BBD group (BDI mean score, 0.42). The HSS group also had less self-accusation (BDI mean score, 0.19) than the patients in the BC group (BDI mean score, 0.50) and the patients in the BBD group (BDI mean score, 0.62). The HSS group also reported less work inhibition and weight loss than the patients in the BC group and in the BBD group. The mean sum of the scores of BDI variables was significantly lower in the HSS group (BDI mean score, 7.1) than in the BC (BDI mean score, 8.4) or BBD groups (BDI mean score, 8.8). The results of this study do not support a specific link between BDI and breast cancer risk. However, the patients with BC and BBD tended to have an increased risk for depressive symptoms.

The effect of measurement quality on targeted structural model fit indices: A comment on Lance, Beck, Fan, and Carter (2016).

Science.gov (United States)

McNeish, Daniel; Hancock, Gregory R

2018-03-01

Lance, Beck, Fan, and Carter (2016) recently advanced 6 new fit indices and associated cutoff values for assessing data-model fit in the structural portion of traditional latent variable path models. The authors appropriately argued that, although most researchers' theoretical interest rests with the latent structure, they still rely on indices of global model fit that simultaneously assess both the measurement and structural portions of the model. As such, Lance et al. proposed indices intended to assess the structural portion of the model in isolation of the measurement model. Unfortunately, although these strategies separate the assessment of the structure from the fit of the measurement model, they do not isolate the structure's assessment from the quality of the measurement model. That is, even with a perfectly fitting measurement model, poorer quality (i.e., less reliable) measurements will yield a more favorable verdict regarding structural fit, whereas better quality (i.e., more reliable) measurements will yield a less favorable structural assessment. This phenomenon, referred to by Hancock and Mueller (2011) as the reliability paradox, affects not only traditional global fit indices but also those structural indices proposed by Lance et al. as well. Fortunately, as this comment will clarify, indices proposed by Hancock and Mueller help to mitigate this problem and allow the structural portion of the model to be assessed independently of both the fit of the measurement model as well as the quality of indicator variables contained therein. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Cycling in Sydney, Australia

Directory of Open Access Journals (Sweden)

Alexis Zander

2013-01-01

Full Text Available Introduction. Cycling can be an enjoyable way to meet physical activity recommendations and is suitable for older people; however cycling participation by older Australians is low. This qualitative study explored motivators, enablers, and barriers to cycling among older people through an age-targeted cycling promotion program. Methods. Seventeen adults who aged 50–75 years participated in a 12-week cycling promotion program which included a cycling skills course, mentor, and resource pack. Semistructured interviews at the beginning and end of the program explored motivators, enablers, and barriers to cycling. Results. Fitness and recreation were the primary motivators for cycling. The biggest barrier was fear of cars and traffic, and the cycling skills course was the most important enabler for improving participants’ confidence. Reported outcomes from cycling included improved quality of life (better mental health, social benefit, and empowerment and improved physical health. Conclusions. A simple cycling program increased cycling participation among older people. This work confirms the importance of improving confidence in this age group through a skills course, mentors, and maps and highlights additional strategies for promoting cycling, such as ongoing improvement to infrastructure and advertising.

Marine nitrogen cycle

Digital Repository Service at National Institute of Oceanography (India)

Naqvi, S.W.A.

) such as the Marine nitrogen cycle The marine nitrogen cycle. ‘X’ and ‘Y’ are intra-cellular intermediates that do not accumulate in water column. (Source: Codispoti et al., 2001) Page 1 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

Reproductive cycles in tropical intertidal gastropods are timed around tidal amplitude cycles.

Science.gov (United States)

Collin, Rachel; Kerr, Kecia; Contolini, Gina; Ochoa, Isis

2017-08-01

Reproduction in iteroparous marine organisms is often timed with abiotic cycles and may follow lunar, tidal amplitude, or daily cycles. Among intertidal marine invertebrates, decapods are well known to time larval release to coincide with large amplitude nighttime tides, which minimizes the risk of predation. Such bimonthly cycles have been reported for few other intertidal invertebrates. We documented the reproduction of 6 gastropod species from Panama to determine whether they demonstrate reproductive cycles, whether these cycles follow a 2-week cycle, and whether cycles are timed so that larval release occurs during large amplitude tides. Two of the species ( Crepidula cf. marginalis and Nerita scabricosta ) showed nonuniform reproduction, but without clear peaks in timing relative to tidal or lunar cycles. The other 4 species show clear peaks in reproduction occurring every 2 weeks. In 3 of these species ( Cerithideopsis carlifornica var. valida, Littoraria variegata , and Natica chemnitzi ), hatching occurred within 4 days of the maximum amplitude tides. Siphonaria palmata exhibit strong cycles, but reproduction occurred during the neap tides. Strong differences in the intensity of reproduction of Cerithideopsis carlifornica , and in particular, Littoraria variegata , between the larger and smaller spring tides of a lunar month indicate that these species time reproduction with the tidal amplitude cycle rather than the lunar cycle. For those species that reproduce during both the wet and dry seasons, we found that reproductive timing did not differ between seasons despite strong differences in temperature and precipitation. Overall, we found that most (4/6) species have strong reproductive cycles synchronized with the tidal amplitude cycle and that seasonal differences in abiotic factors do not alter these cycles.

Creeping of hysteresis cycles; Reptation des cycles d'hysteresis

Energy Technology Data Exchange (ETDEWEB)

Neel, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Faculte des Sciences de Grenoble, 38 (France)

1959-07-01

Creeping consists of a kind of progressive translation of dissymmetric ferromagnetic hysteresis cycles as a function of the order number of the cycle. It is interpreted here by means of a probable coupling field, the existence of which is connected to a statistical conception of the distribution of the elementary regions. (author) [French] La reptation consiste en une sorte de translation progressive des cycles d'hysteresis ferromagnetiques dissymetriques en fonction du numero d'ordre du cycle. L'auteur l'interprete au moyen d'un champ aleatoire de couplage dont l'existence est liee a une conception statistique de la distribution des domaines elementaires. (auteur)

Glacial cycles

DEFF Research Database (Denmark)

Kaufmann, R. K.; Juselius, Katarina

We use a statistical model, the cointegrated vector autoregressive model, to assess the degree to which variations in Earth's orbit and endogenous climate dynamics can be used to simulate glacial cycles during the late Quaternary (390 kyr-present). To do so, we estimate models of varying complexity...... and compare the accuracy of their in-sample simulations. Results indicate that strong statistical associations between endogenous climate variables are not enough for statistical models to reproduce glacial cycles. Rather, changes in solar insolation associated with changes in Earth's orbit are needed...... to simulate glacial cycles accurately. Also, results suggest that non-linear 10 dynamics, threshold effects, and/or free oscillations may not play an overriding role in glacial cycles....

The glutathione cycle: Glutathione metabolism beyond the γ-glutamyl cycle.

Science.gov (United States)

Bachhawat, Anand Kumar; Yadav, Shambhu

2018-04-17

Glutathione was discovered in 1888, over 125 years ago. Since then, our understanding of various functions and metabolism of this important molecule has grown over these years. But it is only now, in the last decade, that a somewhat complete picture of its metabolism has emerged. Glutathione metabolism has till now been largely depicted and understood by the γ-glutamyl cycle that was proposed in 1970. However, new findings and knowledge particularly on the transport and degradation of glutathione have revealed that many aspects of the γ-glutamyl cycle are incorrect. Despite this, an integrated critical analysis of the cycle has never been undertaken and this has led to the cycle and its errors perpetuating in the literature. This review takes a careful look at the γ-glutamyl cycle and its shortcomings and presents a "glutathione cycle" that captures the current understanding of glutathione metabolism. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Single generation cycles and delayed feedback cycles are not separate phenomena.

Science.gov (United States)

Pfaff, T; Brechtel, A; Drossel, B; Guill, C

2014-12-01

We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations. Copyright © 2014 Elsevier Inc. All rights reserved.

[Cycling in Zagreb].

Science.gov (United States)

Matos, Stipan; Krapac, Ladislav; Krapac, Josip

2007-01-01

Cycling in Zagreb, as means of urban transport inside and outside the city, has a bright past, hazy presence but a promising future. Every day, aggressive citizens who lack urban traffic culture mistreat many cyclists but also many pedestrians. Sedentary way of living, unhealthy eating habits and inadequate recreation would surely be reduced if Zagreb had a network of cycling tracks (190 cm) or lanes (80 cm). Main city roads were constructed at the beginning of the 20th century. Today, the lack of cycling tracks is particularly evident in terms of missing connections between northern and southern parts of the city. Transportation of bikes in public vehicles, parking of bikes as well as cycling along the foot of the mountains Medvednica and Zumberacko gorje is not adequately organized. Better organization is necessary not only because of the present young generation but also because of the young who will shortly become citizens of the EU, where cycling is enormously popular. Cycling tourism is not known in Zagreb, partly due to inadequate roads. The surroundings of Zagreb are more suitable for cycling tourism and attractive brochures and tourist guides offer information to tourists on bikes. Professional, acrobatic and sports cycling do not have a tradition in Zagreb and in Croatia. The same holds true for recreational cycling and indoor exercise cycling. The authors discuss the impact of popularization of cycling using print and electronic media. The role of district and local self-government in the construction and improvement of traffic roads in Zagreb is very important. It is also significant for the implementation of legal regulations that must be obeyed by all traffic participants in order to protect cyclists, the most vulnerable group of traffic participants besides passengers. Multidisciplinary action of all benevolent experts would surely increase safety and pleasure of cycling in the city and its surroundings. This would also help reduce daily stress and

Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

KAUST Repository

Pasunurthi, Shyamsundar

2017-03-28

The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP) is captured from many consecutive combustion cycles for each test condition. However, obtaining 3D spatial distribution of all the relevant quantities such as fuel-air mixing, temperature, turbulence levels and emissions from such experiments is a challenging task. Computational Fluid Dynamics (CFD) simulations of engine flow and combustion can be used effectively to visualize such 3D spatial distributions. A dual fuel engine is considered in the current study, with manifold injected natural gas (NG) and direct injected diesel pilot for ignition. Multiple engine cycles in 3D are simulated in series like in the experiments to investigate the potential of high fidelity RANS simulations coupled with detailed chemistry, to accurately predict the CCV. Cycle to cycle variation (CCV) is expected to be due to variabilities in operating and boundary conditions, in-cylinder stratification of diesel and natural gas fuels, variation in in-cylinder turbulence levels and velocity flow-fields. In a previous publication by the authors [1], variabilities in operating and boundary conditions are incorporated into several closed cycle simulations performed in parallel. Stochastic variations/stratifications of fuel-air mixture, turbulence levels, temperature and internal combustion residuals cannot be considered in such closed cycle simulations. In this study, open cycle simulations with port injection of natural gas predicted the combined effect of the stratifications on the CCV of in-cylinder pressure. The predicted Coefficient of Variation (COV) of cylinder pressure is improved compared to the one captured by closed cycle simulations in parallel.

Internal cycle modeling and environmental assessment of multiple cycle consumer products

International Nuclear Information System (INIS)

Tsiliyannis, C.A.

2012-01-01

Highlights: ► Dynamic flow models are presented for remanufactured, reused or recycled products. ► Early loss and stochastic return are included for fast and slow cycling products. ► The reuse-to-input flow ratio (Internal Cycle Factor, ICF) is determined. ► The cycle rate, which is increasing with the ICF, monitors eco-performance. ► Early internal cycle losses diminish the ICF, the cycle rate and performance. - Abstract: Dynamic annual flow models incorporating consumer discard and usage loss and featuring deterministic and stochastic end-of-cycle (EOC) return by the consumer are developed for reused or remanufactured products (multiple cycle products, MCPs), including fast and slow cycling, short and long-lived products. It is shown that internal flows (reuse and overall consumption) increase proportionally to the dimensionless internal cycle factor (ICF) which is related to environmental impact reduction factors. The combined reuse/recycle (or cycle) rate is shown capable for shortcut, albeit effective, monitoring of environmental performance in terms of waste production, virgin material extraction and manufacturing impacts of all MCPs, a task, which physical variables (lifetime, cycling frequency, mean or total number of return trips) and conventional rates, via which environmental policy has been officially implemented (e.g. recycling rate) cannot accomplish. The cycle rate is shown to be an increasing (hyperbolic) function of ICF. The impact of the stochastic EOC return characteristics on total reuse and consumption flows, as well as on eco-performance, is assessed: symmetric EOC return has a small, positive effect on performance compared to deterministic, while early shifted EOC return is more beneficial. In order to be efficient, environmental policy should set higher minimum reuse targets for higher trippage MCPs. The results may serve for monitoring, flow accounting and comparative eco-assessment of MCPs. They may be useful in identifying

Cycle to Cycle Variation Study in a Dual Fuel Operated Engine

KAUST Repository

Pasunurthi, Shyamsundar; Jupudi, Ravichandra; Wijeyakulasuriya, Sameera; Gubba, Sreenivasa Rao; Im, Hong G.; Jaasim, Mohammed; Primus, Roy; Klingbeil, Adam; Finney, Charles

2017-01-01

The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP

The Hamburg oceanic carbon cycle circulation model. Cycle 1

International Nuclear Information System (INIS)

Maier-Reimer, E.; Heinze, C.

1992-02-01

The carbon cycle model calculates the prognostic fields of oceanic geochemical carbon cycle tracers making use of a 'frozen' velocity field provided by a run of the LSG oceanic circulation model (see the corresponding manual, LSG=Large Scale Geostrophic). The carbon cycle model includes a crude approximation of interactions between sediment and bottom layer water. A simple (meridionally diffusive) one layer atmosphere model allows to calculate the CO 2 airborne fraction resulting from the oceanic biogeochemical interactions. (orig.)

Future fuel cycles

International Nuclear Information System (INIS)

Archinoff, G.H.

1980-01-01

A fuel cycle must offer both financial and resource savings if it is to be considered for introduction into Ontario's nuclear system. The most promising alternative CANDU fuel cycles are examined in the context of both of these factors over a wide range of installed capacity growth rates and economic assumptions, in order to determine which fuel cycle, or cycles, should be introduced, and when. It is concluded that the optimum path for the long term begins with the prompt introduction of the low-enriched-uranium fuel cycle. For a wide range of conditions, this cycle remains the optimum throughout the very long term. Conditions of rapid nuclear growth and very high uranium price escalation rates warrant the supersedure of the low-enriched-uranium cycle by either a plutonium-topped thorium cycle or plutonium recycle, beginning between 2010 and 2025. It is also found that the uranium resource position is sound in terms of both known resources and production capability. Moreover, introduction of the low-enriched-uranium fuel cycle and 1250 MWe reactor units will assure the economic viability of nuclear power until at least 2020, even if uranium prices increase at a rate of 3.5% above inflation. The interrelationship between these two conclusions lies in the tremendous incentive for exploration which will occur if the real uranium price escalation rate is high. From a competitive viewpoint, nuclear power can withstand increases in the price of uranium. However, such increases will likely further expand the resource base, making nuclear an even more reliable energy source. (auth)

Life Cycle Management

DEFF Research Database (Denmark)

Bey, Niki

2018-01-01

This chapter gives an overview of Life Cycle Management (LCM)—a discipline that deals with the managerial tasks related to practicing sustainable development in an organisation . Just as Life Cycle Assessment, LCM advocates the life cycle perspective , and it applies this perspective in decision...

BWROPT: A multi-cycle BWR fuel cycle optimization code

Energy Technology Data Exchange (ETDEWEB)

Ottinger, Keith E.; Maldonado, G. Ivan, E-mail: Ivan.Maldonado@utk.edu

2015-09-15

Highlights: • A multi-cycle BWR fuel cycle optimization algorithm is presented. • New fuel inventory and core loading pattern determination. • The parallel simulated annealing algorithm was used for the optimization. • Variable sampling probabilities were compared to constant sampling probabilities. - Abstract: A new computer code for performing BWR in-core and out-of-core fuel cycle optimization for multiple cycles simultaneously has been developed. Parallel simulated annealing (PSA) is used to optimize the new fuel inventory and placement of new and reload fuel for each cycle considered. Several algorithm improvements were implemented and evaluated. The most significant of these are variable sampling probabilities and sampling new fuel types from an ordered array. A heuristic control rod pattern (CRP) search algorithm was also implemented, which is useful for single CRP determinations, however, this feature requires significant computational resources and is currently not practical for use in a full multi-cycle optimization. The PSA algorithm was demonstrated to be capable of significant objective function reduction and finding candidate loading patterns without constraint violations. The use of variable sampling probabilities was shown to reduce runtime while producing better results compared to using constant sampling probabilities. Sampling new fuel types from an ordered array was shown to have a mixed effect compared to random new fuel type sampling, whereby using both random and ordered sampling produced better results but required longer runtimes.

Sulfur cycle

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.

Microbes, especially bacteria, play an important role in oxidative and reductive cycle of sulfur. The oxidative part of the cycle is mediated by photosynthetic bacteria in the presence of light energy and chemosynthetic forms in the absence of light...

Fast Reactor Fuel Cycle Cost Estimates for Advanced Fuel Cycle Studies

International Nuclear Information System (INIS)

Harrison, Thomas

2013-01-01

Presentation Outline: • Why Do I Need a Cost Basis?; • History of the Advanced Fuel Cycle Cost Basis; • Description of the Cost Basis; • Current Work; • Fast Reactor Fuel Cycle Applications; • Sample Fuel Cycle Cost Estimate Analysis; • Future Work

Essays on economic cycles

NARCIS (Netherlands)

Groot, de E.A. (Bert)

2006-01-01

Schumpeter’s line of thought of multiple economic cycles is further investigated. The existence of multiple cycles in economic variables is demonstrated. In basic innovations five different cycles are found. Multiple cycle structures are shown in various macro-economic variables from the United

Nuclear-fuel-cycle education: Module 1. Nuclear fuel cycle overview

International Nuclear Information System (INIS)

Eckhoff, N.D.

1981-07-01

This educational module is an overview of the nuclear-fule-cycle. The overview covers nuclear energy resources, the present and future US nuclear industry, the industry view of nuclear power, the International Nuclear Fuel Cycle Evaluation program, the Union of Concerned Scientists view of the nuclear-fuel-cycle, an analysis of this viewpoint, resource requirements for a model light water reactor, and world nuclear power considerations

Thorium cycles and proliferation

International Nuclear Information System (INIS)

Lovins, A.B.

1979-01-01

This paper analyzes several prevalent misconceptions about nuclear fuel cycles that breed fissile uranium-233 from thorium. Its main conclusions are: U-233, despite the gamma radioactivity of associated isotopes, is a rather attractive material for making fission bombs, and is a credible material for subnational as well as national groups to use for this purpose; (2) pure thorium cycles, which in effect merely substitute U-233 for Pu, would take many decades and much U to establish, and offer no significant safeguards advantage over Pu, cycles; (3) denatured Th-U cycles, which dilute the U-233 with inert U-238 to a level not directly usable in bombs, are not an effective safeguard even against subnational bomb-making; (4) several other features of mixed Th-U cycles are rather unattractive from a safeguards point of view; (5) thus, Th cycles of any kind are not a technical fix for proliferation (national or subnational) and, though probably more safeguardable than Pu cycles, are less so than once-through U cycles that entail no reprocessing; (6) while thorium cycles have some potential technical advantages, including flexibility, they cannot provide major savings in nuclear fuel resources compared to simpler ways of saving neutrons and U; and (7) while advocates of nuclear power may find Th cycles worth exploring, such cycles do not differ fundamentally from U cycles in any of the respects--including safeguards and fuel resources--that are relevant to the broader nuclear debate, and should not be euphorically embraced as if they did

Drivers of cycling demand and cycling futures in the Danish context

DEFF Research Database (Denmark)

Analysis of the time trend in cycling mode share based on longest possible time series. Logistic regression model of cycling as mode choice as basis for studying ‘driver variables’ contribution to time trend. Describing important vectors of change behind the time trend.......Analysis of the time trend in cycling mode share based on longest possible time series. Logistic regression model of cycling as mode choice as basis for studying ‘driver variables’ contribution to time trend. Describing important vectors of change behind the time trend....

Assessing Cycling Participation in Australia

Directory of Open Access Journals (Sweden)

Chris Rissel

2013-01-01

Full Text Available Planning and evaluating cycling programs at a national or state level requires accurate measures of cycling participation. However, recent reports of cycling participation have produced very different estimates. This paper examines the reported rates of cycling in five recent population surveys of cycling. Three surveys (one national and two from Sydney asking respondents when they last rode a bicycle generated cycling participation (cycled in the past year estimates of 29.7%, 34.1% and 28.9%. Two other national surveys which asked participants to recall (unprompted any physical activity done for exercise, recreation or sport in the previous 12 months, estimated cycling in the past year as 11.1% and 6.5%. While unprompted recall of cycling as a type of physical activity generates lower estimates of cycling participation than specific recall questions, both assessment approaches produced similar patterns of cycling by age and sex with both approaches indicating fewer women and older adults cycling. The different question styles most likely explain the substantial discrepancies between the estimates of cycling participation. Some differences are to be expected due to sampling variability, question differences, and regional variation in cycling.

Life-cycle cost analysis of adsorption cycles for desalination

KAUST Repository

Thu, Kyaw; Chakraborty, A.; Saha, B.B.; Chun, Won Gee; Ng, K.C.

2010-01-01

This paper presents the thermo-economic analysis of the adsorption desalination (AD) cycle that is driven by low-temperature waste heat from exhaust of industrial processes or renewable sources. The AD cycle uses an adsorbent such as the silica gel

On approximating restricted cycle covers

NARCIS (Netherlands)

Manthey, Bodo

2008-01-01

A cycle cover of a graph is a set of cycles such that every vertex is part of exactly one cycle. An $L$-cycle cover is a cycle cover in which the length of every cycle is in the set $L$. The weight of a cycle cover of an edge-weighted graph is the sum of the weights of its edges. We come close to

Nuclear power fuel cycle

International Nuclear Information System (INIS)

Havelka, S.; Jakesova, L.

1982-01-01

Economic problems are discussed of the fuel cycle (cost of the individual parts of the fuel cycle and the share of the fuel cycle in the price of 1 kWh), the technological problems of the fuel cycle (uranium ore mining and processing, uranium isotope enrichment, the manufacture of fuel elements, the building of long-term storage sites for spent fuel, spent fuel reprocessing, liquid and gaseous waste processing), and the ecologic aspects of the fuel cycle. (H.S.)

40 CFR 1065.514 - Cycle-validation criteria for operation over specified duty cycles.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Cycle-validation criteria for operation over specified duty cycles. 1065.514 Section 1065.514 Protection of Environment ENVIRONMENTAL... Over Specified Duty Cycles § 1065.514 Cycle-validation criteria for operation over specified duty...

Benefits of cycle stretchout in pressurized water reactor extended-burnup fuel cycles

International Nuclear Information System (INIS)

Matzie, R.A.; Leung, D.C.; Liu, Y.; Beekmann, R.W.

1981-01-01

Nuclear reactors are inherently capable of operating for a substantial period beyond their nominal end of cycle (EOC) as a result of negative moderator and fuel temperature coefficients and the decrease in xenon poisoning with lower core power levels. This inherent capability can be used to advantage to reduce annual uranium makeup requirements and cycle energy costs by the use of planned EOC stretchout. This paper discusses the fuel utilization efficiency and economics of both the five-batch, extended-burnup cycle and the three-batch, standard-burnup cycle, which can be improved by employing planned EOC (end of cycle) stretchout. 11 refs

Denatured fuel cycles

International Nuclear Information System (INIS)

Till, C.E.

1979-01-01

This paper traces the history of the denatured fuel concept and discusses the characteristics of fuel cycles based on the concept. The proliferation resistance of denatured fuel cycles, the reactor types they involve, and the limitations they place on energy generation potential are discussed. The paper concludes with some remarks on the outlook for such cycles

Edgeworth cycles revisited

International Nuclear Information System (INIS)

Doyle, Joseph; Muehlegger, Erich; Samphantharak, Krislert

2010-01-01

Some gasoline markets exhibit remarkable price cycles, where price spikes are followed by a series of small price declines: a pattern consistent with a model of Edgeworth cycles described by Maskin and Tirole. We extend the model and empirically test its predictions with a new dataset of daily station-level prices in 115 US cities. Consistent with the theory, and often in contrast with previous empirical work, we find the least and most concentrated markets are much less likely to exhibit cycling behavior both within and across cities; areas with more independent convenience-store gas stations are also more likely to cycle. (author)

Reliability and validity of the EQ-5D-3L for Kashin-Beck disease in China.

Science.gov (United States)

Fang, Hua; Farooq, Umer; Wang, Dimiao; Yu, Fangfang; Younus, Mohammad Imran; Guo, Xiong

2016-01-01

Kashin-Beck Disease (KBD) is an endemic osteoarthropathy in areas which extend from the North-East to the South-West of China. Most of the patients with KBD suffer multiple dysfunctions in major joints causing decreased health status. However because of their low education level and unique living habits, it is hard to find tools to measure the health-related quality of life (HRQOL). European quality of life (EQ-5D-3L) patient-reported instrument is widely used to measure HRQOL. This study aimed to establish the validity and reliability of the Chinese version of the EQ-5D-3L for evaluating HRQOL of KBD individuals in rural area. 368 individuals who were suffering from KBD were recruited through stratified multistage random sampling from Shaanxi province, China. The EQ-5D-3L and the WHOQOL-BREF were administrated in each individual by face to face interview. Test-retest reliability was assessed at 10-14 days intervals. The test-retest reliability was measured by calculating the Kappa coefficients for EQ-5D-3L five dimensions. For the EQ VAS, the intraclass correlation coefficient (ICC) was computed. Convergent and divergent analysis, construct validity was established using Spearman's rank correlation between the EQ-5D-3L and the WHOQOL-BREF. Known groups' validity was examined by comparing groups with a priori expected differences in health-related quality of life (HRQOL). For 362 individuals (98%), comprehensive data of all the EQ-5D-3L dimensions were available. Kappa values of the EQ-5D-3L five items ranged from 0.324 to 0.554. ICC of the EQ VAS was 0.497. For convergent validity, the three items (self-care, usual activity, and mobility) of EQ-5D-3L, index scores, and VAS showed moderate correlations with the physical health domain of the WHOQOL-BREF (r absolute value ranged from 0.339 to 0.475). For divergent validity, the 5 items of EQ-5D-3L showed weak or no correlations with environment and social relationship domains of WHOQOL-BREF. The Chinese EQ-5D-3L

Fuel cycle management

International Nuclear Information System (INIS)

Herbin, H.C.

1977-01-01

The fuel cycle management is more and more dependent on the management of the generation means among the power plants tied to the grid. This is due mainly because of the importance taken by the nuclear power plants within the power system. The main task of the fuel cycle management is to define the refuelling pattern of the new and irradiated fuel assemblies to load in the core as a function of: 1) the differences which exist between the actual conditions of the core and what was expected for the present cycle, 2) the operating constraints and the reactor availability, 3) the technical requirements in safety and the technological limits of the fuel, 4) the economics. Three levels of fuel cycle management can be considered: 1) a long term management: determination of enrichments and expected cycle lengths, 2) a mid term management whose aim corresponds to the evaluation of the batch to load within the core as a function of both: the next cycle length to achieve and the integrated power history of all the cycles up to the present one, 3) a short term management which deals with the updating of the loaded fuel utilisations to take into account the operation perturbations, or with the alteration of the loading pattern of the next batch to respect unexpected conditions. (orig.) [de

Insights in the electronic structure and redox reaction energy in LiFePO4 battery material from an accurate Tran-Blaha modified Becke Johnson potential

International Nuclear Information System (INIS)

Araujo, Rafael B.; Almeida, J. de S; Ferreira da Silva, A.; Ahuja, Rajeev

2015-01-01

The main goals of this paper are to investigate the accuracy of the Tran-Blaha modified Becke Johnson (TB-mBJ) potential to predict the electronic structure of lithium iron phosphate and the related redox reaction energy with the lithium deintercalation process. The computed electronic structures show that the TB-mBJ method is able to partially localize Fe-3d electrons in LiFePO 4 and FePO 4 which usually is a problem for the generalized gradient approximation (GGA) due to the self interaction error. The energy band gap is also improved by the TB-mBJ calculations in comparison with the GGA results. It turned out, however, that the redox reaction energy evaluated by the TB-mBJ technique is not in good agreement with the measured one. It is speculated that this disagreement in the computed redox energy and the experimental value is due to the lack of a formal expression to evaluate the exchange and correlation energy. Therefore, the TB-mBJ is an efficient method to improve the prediction of the electronic structures coming form the standard GGA functional in LiFePO 4 and FePO 4 . However, it does not appear to have the same efficiency for evaluating the redox reaction energies for the investigated system

Chondrocytes damage induced by T-2 toxin via Wnt/β-catenin signaling pathway is involved in the pathogenesis of an endemic osteochondropathy, Kashin-Beck disease.

Science.gov (United States)

Wang, Xi; Ning, Yujie; Zhang, Pan; Yang, Lei; Wang, Yingting; Guo, Xiong

2017-12-01

Kashin-Beck disease (KBD), an endemic osteochondropathy, is characterized by cartilage degeneration which is caused by abnormal catabolism in the extracellular matrix (ECM). In this study, we investigated the expression of the Wnt/β-catenin signaling pathway in KBD pathogenesis. Among the proteins involved in the Wnt/β-catenin signaling pathway, WNT-3A, FZD1, SOX9, and β-catenin were up-regulated, while FRZB was down-regulated in KBD cartilage. C28/I2 cells were evaluated for cell viability using the MTT assay after exposure to T-2 toxin, a suspicious environmental pathogenic factors of KBD. C28/I2 cells were treated with different intervening concentrations (0.001μg/mL,0.005μg/mL and 0.01μg/mL) of T-2 toxin for 24h. The expression of FZD1 and CTNNB1 (i.e.,β-catenin) was significantly reduced and SOX9 expression was significantly increased in chondrocytes after treatment with different intervening concentrations of T-2 toxin. Our results indicate that alterations in the Wnt/β-catenin signaling pathway in articular cartilage play an important role in the onset and pathogenesis of KBD. Copyright © 2017 Elsevier Inc. All rights reserved.

Exergoeconomic comparison of TLC (trilateral Rankine cycle), ORC (organic Rankine cycle) and Kalina cycle using a low grade heat source

International Nuclear Information System (INIS)

Yari, M.; Mehr, A.S.; Zare, V.; Mahmoudi, S.M.S.; Rosen, M.A.

2015-01-01

Recently, the TLC (trilateral power cycle) has attracted significant interest as it provides better matching between the temperature profiles in the evaporator compared to conventional power cycles. This article investigates the performance of this cycle and compares it with those for the ORC (organic Rankine cycle) and the Kalina cycle, from the viewpoints of thermodynamics and thermoeconomics. A low-grade heat source with a temperature of 120 °C is considered for all the three systems. Parametric studies are performed for the systems for several working fluids in the ORC and TLC. The systems are then optimized for either maximum net output power or minimum product cost, using the EES (engineering equation solver) software. The results for the TLC indicate that an increase in the expander inlet temperature leads to an increase in net output power and a decrease in product cost for this power plant, whereas this is not the case for the ORC system. It is found that, although the TLC can achieve a higher net output power compared with the ORC and Kalina (KCS11 (Kalina cycle system 11)) systems, its product cost is greatly affected by the expander isentropic efficiency. It is also revealed that using n-butane as the working fluid can result in the lowest product cost in the ORC and the TLC. In addition, it is observed that, for both the ORC and Kalina systems, the optimum operating condition for maximum net output power differs from that for minimum product cost. - Highlights: • Exergoeconomic analysis of trilateral Rankine cycle is performed. • The system performance is compared with Organic Rankine and Kalina cycles. • Net power from trilateral Rankine cycle is higher than the other power systems. • Superiority of trilateral cycle depends on its expander isentropic efficiency

Out-of-core fuel cycle optimization for nonequilibrium cycles

International Nuclear Information System (INIS)

Comes, S.A.; Turinsky, P.J.

1988-01-01

A methodology has been developed for determining the family of near-optimum fuel management schemes that minimize the levelized fuel cycle costs of a light water reactor over a multicycle planning horizon. Feed batch enrichments and sizes, burned batches to reinsert, and burnable poison loadings are determined for each cycle in the planning horizon. Flexibility in the methodology includes the capability to assess the economic benefits of various partially burned bath reload strategies as well as the effects of using split feed enrichments and enrichment palettes. Constraint limitations are imposed on feed enrichments, discharge burnups, moderator temperature coefficient, and cycle energy requirements

Air bottoming cycle, an alternative to combined cycles. Final report

Energy Technology Data Exchange (ETDEWEB)

Kaikko, J. [Royal Inst. of Techn., Stockholm (Sweden). Dept. of Energy Technology

2001-10-01

In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

Assessing cognitive insight in nonpsychiatric individuals and outpatients with schizophrenia in Taiwan: an investigation using the Beck Cognitive Insight Scale

Directory of Open Access Journals (Sweden)

Lu Chien-Wen

2011-10-01

Full Text Available Abstract Background The Beck Cognitive Insight Scale (BCIS was designed for the assessment of the cognitive processes involved in self-reflection and the ability to modify erroneous beliefs and misinterpretations. Studies investigating the factor structure of the BCIS have indicated a two-factor model in the psychotic population. The factor structure of the BCIS, however, has not received much consideration in the nonpsychiatric population. The present study examined the factor structure and validity of the BCIS and compared its scores between nonpsychiatric individuals and outpatients with psychosis. Method The Taiwanese version of the BCIS was administered to 507 nonpsychiatric individuals and 118 outpatients with schizophrenia. The psychometric properties of the BCIS were examined through the following analyses: exploratory and confirmatory factor analyses, reliability, correlation analyses, and discriminative validity. Results The BCIS showed adequate internal consistency and stability over time. Exploratory and confirmatory factor analyses on the 15-item measure indicated a two-factor solution that supported the two dimensions of the Taiwanese BCIS, which was also observed with the original BCIS. Following the construct validation, we obtained a composite index (self-reflectiveness minus self-certainty of the Taiwanese BCIS that reflected cognitive insight. Consistent with previous studies, our results indicated that psychosis is associated with low self-reflectiveness and high self-certainty, which possibly reflect lower cognitive insight. Our results also showed that better cognitive insight is related to worse depression in patients with schizophrenia spectrum disorders, but not in nonpsychiatric individuals. The receiver operating characteristic (ROC analyses revealed that the area under the curve (AUC was 0.731. A composite index of 3 was a good limit, with a sensitivity of 87% and a specificity of 51%. Conclusion The BCIS proved to be

'Benefits cycle' replacing premium cycle as consumerism takes hold.

Science.gov (United States)

2002-05-01

The traditional premium cycle of ups and downs in rates is giving way to a new phenomenon--driven by the advent of consumerism in health care--termed the "benefits cycle" by one consultant. Rather than shifts in rates, he argues, the future will see shifts in benefits packages.

Natural cycle IVF with and without terminal HCG: learning from failed cycles.

Science.gov (United States)

Lenton, Elizabeth A

2007-08-01

Natural cycle IVF, without the use of LH down-regulation, is difficult because women start spontaneous LH surges at any time of the day and on any day of the week. This is not readily compatible with delivery of a routine IVF service and so historically the natural cycle has been modified by the use of human chorionic gonadotrophin (HCG) to make the natural cycle fit convenient clinical practice. This report re-evaluates data collected some years ago and seeks to determine whether the use of HCG is ultimately beneficial. Two large series of natural cycle IVF where only LH monitoring was performed (534 cycles) or where this was combined with HCG as necessary (241 cycles) were analysed. In essence, the use of HCG introduced as many problems as it overcame: there was no net benefit with respect to the number of eggs collected or clinical pregnancies generated. In fact there was an overall deterioration in all indices. The principle difficulties with natural cycle IVF are those associated with the prediction of follicle maturity and hence timing egg collection, and the conflict between costly and intrusively frequent monitoring with simpler but far less effective approaches.

Dual Expander Cycle Rocket Engine with an Intermediate, Closed-cycle Heat Exchanger

Science.gov (United States)

Greene, William D. (Inventor)

2008-01-01

A dual expander cycle (DEC) rocket engine with an intermediate closed-cycle heat exchanger is provided. A conventional DEC rocket engine has a closed-cycle heat exchanger thermally coupled thereto. The heat exchanger utilizes heat extracted from the engine's fuel circuit to drive the engine's oxidizer turbomachinery.

Ammonia-water Rankine cycle

International Nuclear Information System (INIS)

Bo Hanliang; Ma Changwen; Wu Shaorong

1997-01-01

On characteristics of heating source and cooling source in nuclear heating reactor cooperation, the authors advance a new kind of power cycle in which a multicomponent mixture as the work fluid, ammonia-water Rankine cycle, describe its running principle, and compare it with steam Rankine cycle in the same situation. The result is that: the new kind of power cycle, ammonia-water Rankine cycle has higher electricity efficiency; it suits for the situation of heating source and cooling source which offered by nuclear heating reactor cooperation. For low temperature heating source, it maybe has a widely application

Prevalence of depression and its associated factors using Beck Depression Inventory among students of School of Health and Nutrition, Tabriz, Iran in 2009

Directory of Open Access Journals (Sweden)

Saeid Safiri

2013-12-01

Full Text Available BACKGROUND: Depression is a debilitating disease which is caused by social and environmental factors in additionto genetic factors. University students are among the young and vulnerable population to depression and theirpopulation is increasing with increase in universities and higher education institutions. Therefore, any disturbance instudent's mental and physical health is a serious threat for the next generation. In this study, we aimed to estimate theprevalence of depression and its related factors in students of School of Health and Nutrition at Tabriz University ofMedical Sciences, Iran. METHODS: This was a cross-sectional survey on 175 students selected by stratified random sampling, educating indifferent fields at School of Health and Nutrition in 2009. The data collection tool was the short form of the standardBeck Depression Inventory (BDI which is used for screening depression. The collected data were analyzed by softwareStata Statistical Software, Release 10.0 (Stata Corporation, College Station, TX, USA. RESULTS: The results showed that 62.7% of the students had depression and from these 10.9% suffered from severedepression. Significantly higher depression rates were seen in students with worrisome about the future. Marriedstudents, those interested in their field of study, those performing prayers and regularly reading the Quran hadsignificantly lower rates of depression. CONCLUSIONS: Due to the high prevalence of depression, screening strategies should be implemented to identifydepressed students. Counseling services should be available and accessible to students at risk.

Study on the supercritical CO2 power cycles for landfill gas firing gas turbine bottoming cycle

International Nuclear Information System (INIS)

Kim, Min Seok; Ahn, Yoonhan; Kim, Beomjoo; Lee, Jeong Ik

2016-01-01

In this paper, a comparison of nine supercritical carbon dioxide (S-CO 2 ) bottoming power cycles in conjunction with a topping cycle of landfill gas (LFG) fired 5MWe gas turbine is presented. For the comparison purpose, a sensitivity study of the cycle design parameters for nine different cycles was conducted and each cycle thermodynamic performance is evaluated. In addition, the cycle performance evaluation dependency on the compressor inlet temperature variation is performed to investigate how S-CO 2 cycles sensitive to the heat sink temperature variation. Furthermore, the development of new S-CO 2 cycle layouts is reported and the suggested cycles' performances are compared to the existing cycle layouts. It was found that a recompression cycle is not suitable for the bottoming cycle application, but a partial heating cycle has relatively higher net produced work with a simple layout and small number of components. Although a dual heated and flow split cycle has the highest net produced work, it has disadvantages of having numerous components and complex process which requires more sophisticated operational strategies. This study identified that the recuperation process is much more important than the intercooling process to the S-CO 2 cycle design for increasing the thermal efficiency and the net produced work point of view. - Highlights: • Study of nine S-CO 2 power cycle layouts for a small scale landfill gas power generation application. • Development of new S-CO 2 cycle layouts. • Sensitivity analysis of S-CO 2 cycles to evaluate and compare nine cycles' performances.

A comparison of advanced heat recovery power cycles in a combined cycle for large ships

International Nuclear Information System (INIS)

Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

2014-01-01

Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus in the literature. In the present work we compare these cycles in a combined cycle application with a large marine two-stroke diesel engine. We present an evaluation of the efficiency and the environmental impact, safety concerns and practical aspects of each of the cycles. A previously validated numerical engine model is combined with a turbocharger model and bottoming cycle models written in Matlab. Genetic algorithm optimisation results suggest that the Kalina cycle possess no significant advantages compared to the ORC or the steam cycle. While contributing to very high efficiencies, the organic working fluids possess high global warming potentials and hazard levels. It is concluded that the ORC has the greatest potential for increasing the fuel efficiency, and the combined cycle offers very high thermal efficiency. While being less efficient, the steam cycle has the advantages of being well proven, harmless to the environment as well as being less hazardous in comparison. - Highlights: • We compare steam, ORC (organic Rankine cycle) and Kalina cycles for waste heat recovery in marine engines. • We evaluate the efficiency and important qualitative differences. • The Kalina cycle presents no apparent advantages. • The steam cycle is well known, harmless and has a high efficiency. • The ORC has the highest efficiency but also important drawbacks

Effect of cycle coupling-configuration on energy cascade utilization for a new power and cooling cogeneration cycle

International Nuclear Information System (INIS)

Jing, Xuye; Zheng, Danxing

2014-01-01

Highlights: • A new power and cooling cogeneration cycle was proposed. • The thermophysical properties and the performance of the new cycle were calculated. • Different cycle coupling-configurations were analyzed. • The energy efficiency boosting mechanism of the new cycle was elucidated. - Abstract: To recover mid-low grade heat, a new power/cooling cogeneration cycle was proposed by combining the Kalina cycle and the double-effect ammonia–water absorption refrigeration (DAAR) cycle together, and the equivalent heat-to-power and exergy efficiencies of the cogeneration cycle reached 41.18% and 58.00%, respectively. To determine the effect of cycle coupling-configuration on energy cascade utilization for the new cycle, the cycle coupling-configuration of the Kalina and DAAR cycles were first analyzed, after which the cycle coupling-configuration of the new cycle was analyzed. Analysis results showed that the cycle coupling-configuration of the new cycle enhanced the energy cascade utilization. Furthermore, the energy efficiency boosting mechanism of the new cycle was elucidated

50 años de los Inventarios de Depresión de Beck: consejos para la utilización de la adaptación española del BDI-II en la práctica clínica

OpenAIRE

Sanz Fernández, Jesús

2013-01-01

En 2011 se publicó la primera adaptación española del Inventario de Depresión de Beck-II (BDI-II), justo cuando se cumplía el 50º aniversario de la publicación de su primera edición. En este tiempo, el BDI se ha convertido en el cuestionario autoaplicado más utilizado en España y en el mundo para evaluar la gravedad de la depresión. En este trabajo se presentan las características básicas del BDI-II en relación con sus versiones anteriores (BDI-I y BDI-IA) y el proceso de su adaptación a la p...

Air bottoming cycle, an alternative to combined cycles. Final report

Energy Technology Data Exchange (ETDEWEB)

Kaikko, J. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

2002-02-01

In this work, the idea of Air Bottoming Cycle (ABC) has been studied. The objectives for the work have been to establish an understanding of the concept for power and heat generation as well as to find - if possible - feasible concepts for future use in the Swedish energy system. Combined cycle in power generation is an established technology. In the conventional combined cycle, a gas turbine works as a topping cycle together with the steam (Rankine) bottoming cycle. In the ABC the steam bottoming cycle is replaced with a gas turbine (Brayton) bottoming cycle having air as a working fluid. The two gas turbines are thermally connected over a gas-to-gas heat exchanger. This concept promises savings in weight and cost, as well as operating benefits, compared to the Rankine bottoming technology. The ABC has been modelled using a heat balance program, and a parametric study for the concept optimisation as well as for off-design analysis has been performed. Performance of the ABC has been compared to other, established technologies. A preliminary economic evaluation has been made. As a result of the study, it is clarified that the Rankine bottoming cycle with steam remains superior to the ABC as regards electrical efficiency in the medium and large power scale. For small-scale applications (<10 MW{sub e}) where the thermodynamic advantage of the Rankine cycle is not dominating any longer and its economy is burdened by the heavy investment structure, the ABC becomes the better alternative for energy utilisation. A preliminary economic evaluation shows that (at energy prices autumn 2000) the ABC is at the same level as the comparable small-scale cogeneration installations. Due to high power-to-heat ratio however, higher electricity prices will favour the ABC. One interesting feature of the ABC is that about 50% of the dissipated low-value heat from the cycle is carried by clean (sterile) air at the temperature around 200 deg C. This air can be utilised for space heating or

Very high cycle fatigue testing of concrete using ultrasonic cycling

Energy Technology Data Exchange (ETDEWEB)

Karr, Ulrike; Schuller, Reinhard; Fitzka, Michael; Mayer, Herwig [Univ. of Natural Resources and Life Sciences, Vienna (Austria). Inst. of Physics and Materials Science; Denk, Andreas; Strauss, Alfred [Univ. of Natural Resources and Life Sciences, Vienna (Austria)

2017-06-01

The ultrasonic fatigue testing method has been further developed to perform cyclic compression tests with concrete. Cylindrical specimens vibrate in resonance at a frequency of approximately 20 kHz with superimposed compressive static loads. The high testing frequency allows time-saving investigations in the very high cycle fatigue regime. Fatigue tests were carried out on ''Concrete 1'' (compressive strength f{sub c} = 80 MPa) and ''Concrete 2'' (f{sub c} = 107 MPa) under purely compressive loading conditions. Experiments at maximum compressive stresses of 0.44 f{sub c} (Concrete 1) and 0.38 f{sub c} (Concrete 2) delivered specimen failures above 109 cycles, indicating that no fatigue limit exists for concrete below one billion load cycles. Resonance frequency, power required to resonate the specimen and second order harmonics of the vibration are used to monitor fatigue damage in situ. Specimens were scanned by X-ray computed tomography prior to and after testing. Fatigue cracks were produced by ultrasonic cycling in the very high cycle fatigue regime at interfaces of grains as well as in cement. The possibilities as well as limitations of ultrasonic fatigue testing of concrete are discussed.

International Business Cycle

OpenAIRE

Marek Lubiński

2007-01-01

Prime stylized facts of international business cycle theory refer to positive correlation in the cyclical components of important macroeconomic variables across countries. However a number of indicators of business cycle synchronization do not point to clear trends. It can be ascribed to the fact that different forces influence level of business cycle correlation. When investigating into the forces behind the commonness in aggregate fluctuations economic research seems to have pointed in two ...

Nuclear fuel cycle system analysis

International Nuclear Information System (INIS)

Ko, W. I.; Kwon, E. H.; Kim, S. G.; Park, B. H.; Song, K. C.; Song, D. Y.; Lee, H. H.; Chang, H. L.; Jeong, C. J.

2012-04-01

The nuclear fuel cycle system analysis method has been designed and established for an integrated nuclear fuel cycle system assessment by analyzing various methodologies. The economics, PR(Proliferation Resistance) and environmental impact evaluation of the fuel cycle system were performed using improved DB, and finally the best fuel cycle option which is applicable in Korea was derived. In addition, this research is helped to increase the national credibility and transparency for PR with developing and fulfilling PR enhancement program. The detailed contents of the work are as follows: 1)Establish and improve the DB for nuclear fuel cycle system analysis 2)Development of the analysis model for nuclear fuel cycle 3)Preliminary study for nuclear fuel cycle analysis 4)Development of overall evaluation model of nuclear fuel cycle system 5)Overall evaluation of nuclear fuel cycle system 6)Evaluate the PR for nuclear fuel cycle system and derive the enhancement method 7)Derive and fulfill of nuclear transparency enhancement method The optimum fuel cycle option which is economical and applicable to domestic situation was derived in this research. It would be a basis for establishment of the long-term strategy for nuclear fuel cycle. This work contributes for guaranteeing the technical, economical validity of the optimal fuel cycle option. Deriving and fulfillment of the method for enhancing nuclear transparency will also contribute to renewing the ROK-U.S Atomic Energy Agreement in 2014

KOH concentration effect on cycle life of nickel-hydrogen cells. III - Cycle life test

Science.gov (United States)

Lim, H. S.; Verzwyvelt, S. A.

1988-01-01

A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

Driving and engine cycles

CERN Document Server

Giakoumis, Evangelos G

2017-01-01

This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

The heat engine cycle, the heat removal cycle, and ergonomics of the control room displays

International Nuclear Information System (INIS)

Beltracchi, L.

1986-01-01

This paper discusses and illustrates the ergonomics of an integrated display, which will allow operators to monitor the heat engine cycle during normal operation of the plant, and the heat removal cycle during emergency operation of the plant. A computer-based iconic display is discussed as an overview to monitor these cycles. Specific emphasis is placed upon the process variables and process functions within each cycle, and the action of control systems and engineered safeguard systems within each cycle. This paper contains examples of display formats for the heat engine cycle and the heat removal cycle in a pressurized water reactor

Novel combined cycle configurations for propane pre-cooled mixed refrigerant (APCI) natural gas liquefaction cycle

International Nuclear Information System (INIS)

Mortazavi, Amir; Alabdulkarem, Abdullah; Hwang, Yunho; Radermacher, Reinhard

2014-01-01

Highlights: • 10 New LNG plants driver cycle enhancement configurations were developed. • All the 14 enhancement options design variables were optimized to demonstrate their energy saving potentials. • The best driver cycle enhancement option improved the driver cycle energy efficiency by 38%. • The effects of technological advancements on the performances of the enhancement options were studied. - Abstract: A significant amount of energy is required for natural gas liquefaction. Due to the production scale of LNG plants, they consume an intensive amount of energy. Consequently, any enhancement to the energy efficiency of LNG plants will result in a considerable reduction in natural gas consumption and CO 2 emission. Compressor drivers are the main energy consumer in the LNG plants. In this paper, 14 different driver cycle enhancement options were considered. A number of these options have not been proposed for the LNG plants. The new driver cycle development was performed by analyzing and optimizing the design variables of four conventional driver cycle enhancement options. The optimization results were used to develop more efficient cycles through mitigating the active constrains and driver cycle innovations. Based on the current available technologies five of our newly developed driver cycle configurations have higher efficiency than the most efficient existing conventional driver cycle. The best developed driver cycle enhancement option improved the base driver cycle energy efficiency by 38%. The effects of technological advancement on the performances of the all driver cycle enhancement options were also considered

Chords in longest cycles

DEFF Research Database (Denmark)

Thomassen, Carsten

2017-01-01

If a graph G is 3-connected and has minimum degree at least 4, then some longest cycle in G has a chord. If G is 2-connected and cubic, then every longest cycle in G has a chord.......If a graph G is 3-connected and has minimum degree at least 4, then some longest cycle in G has a chord. If G is 2-connected and cubic, then every longest cycle in G has a chord....

Temporal fluxomics reveals oscillations in TCA cycle flux throughout the mammalian cell cycle.

Science.gov (United States)

Ahn, Eunyong; Kumar, Praveen; Mukha, Dzmitry; Tzur, Amit; Shlomi, Tomer

2017-11-06

Cellular metabolic demands change throughout the cell cycle. Nevertheless, a characterization of how metabolic fluxes adapt to the changing demands throughout the cell cycle is lacking. Here, we developed a temporal-fluxomics approach to derive a comprehensive and quantitative view of alterations in metabolic fluxes throughout the mammalian cell cycle. This is achieved by combining pulse-chase LC-MS-based isotope tracing in synchronized cell populations with computational deconvolution and metabolic flux modeling. We find that TCA cycle fluxes are rewired as cells progress through the cell cycle with complementary oscillations of glucose versus glutamine-derived fluxes: Oxidation of glucose-derived flux peaks in late G1 phase, while oxidative and reductive glutamine metabolism dominates S phase. These complementary flux oscillations maintain a constant production rate of reducing equivalents and oxidative phosphorylation flux throughout the cell cycle. The shift from glucose to glutamine oxidation in S phase plays an important role in cell cycle progression and cell proliferation. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Alternative fuel cycles

International Nuclear Information System (INIS)

Penn, W.J.

1979-05-01

Uranium resource utilization and economic considerations provide incentives to study alternative fuel cycles as future options to the PHWR natural uranium cycle. Preliminary studies to define the most favourable alternatives and their possible introduction dates are discussed. The important and uncertain components which influence option selection are reviewed, including nuclear capacity growth, uranium availability and demand, economic potential, and required technological developments. Finally, a summary of Ontario Hydro's program to further assess cycle selection and define development needs is given. (auth)

Educational Business Cycles

DEFF Research Database (Denmark)

Tepe, Markus; Vanhuysse, Pieter

Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...... teacher employment patterns at the state level in Germany and find strong evidence of cycling mechanisms, in the form of electioneering and honeymooning. Against a backdrop of a continuously shrinking total teachers' pool, German state-level incumbents accelerate the hiring of new teachers during election...... periods and partly reverse this during politically safer points in the electoral cycle. Cycles are mediated by issue salience: heightened attention to German public schooling after the notorious PISA-2000 tests further strengthens the manipulation of new teacher hiring for electoral purposes....

Educational Business Cycles

DEFF Research Database (Denmark)

Tepe, Markus; Vanhuysse, Pieter

2009-01-01

Strong institutional constraints and better-informed voters may lead re-election seeking incumbents to shift the use of political business cycle mechanisms away from monetary and fiscal policy towards other policy domains that are more easily manipulable, targetable, and timeable. We investigate...... teacher employment patterns at the state level in Germany and find strong evidence of cycling mechanisms, in the form of electioneering and honeymooning. Against a backdrop of a continuously shrinking total teachers' pool, German state-level incumbents accelerate the hiring of new teachers during election...... periods and partly reverse this during politically safer points in the electoral cycle. Cycles are mediated by issue salience: heightened attention to German public schooling after the notorious PISA-2000 tests further strengthens the manipulation of new teacher hiring for electoral purposes....

Termination of cycle rewriting

NARCIS (Netherlands)

Zantema, H.; König, B.; Bruggink, H.J.S.; Dowek, G.

2014-01-01

String rewriting can not only be applied on strings, but also on cycles and even on general graphs. In this paper we investigate termination of string rewriting applied on cycles, shortly denoted as cycle rewriting, which is a strictly stronger requirement than termination on strings. Most

The Nuclear Fuel Cycle

International Nuclear Information System (INIS)

2011-08-01

This brochure describes the nuclear fuel cycle, which is an industrial process involving various activities to produce electricity from uranium in nuclear power reactors. The cycle starts with the mining of uranium and ends with the disposal of nuclear waste. The raw material for today's nuclear fuel is uranium. It must be processed through a series of steps to produce an efficient fuel for generating electricity. Used fuel also needs to be taken care of for reuse and disposal. The nuclear fuel cycle includes the 'front end', i.e. preparation of the fuel, the 'service period' in which fuel is used during reactor operation to generate electricity, and the 'back end', i.e. the safe management of spent nuclear fuel including reprocessing and reuse and disposal. If spent fuel is not reprocessed, the fuel cycle is referred to as an 'open' or 'once-through' fuel cycle; if spent fuel is reprocessed, and partly reused, it is referred to as a 'closed' nuclear fuel cycle.

Can cycling safety be improved by opening all unidirectional cycle paths for cycle traffic in both directions? A theoretical examination of available literature and data.

Science.gov (United States)

Methorst, Rob; Schepers, Paul; Kamminga, Jaap; Zeegers, Theo; Fishman, Elliot

2017-08-01

Many studies have found bicycle-motor vehicle crashes to be more likely on bidirectional cycle paths than on unidirectional cycle paths because drivers do not expect cyclists riding at the right side of the road. In this paper we discuss the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions prevent this lack of expectancy and accordingly improves cycling safety. A new national standard requires careful consideration because a reversal is difficult once cyclists are used to their new freedom of route choice. We therefore explored the hypothesis using available data, research, and theories. The results show that of the length of cycle paths along distributor roads in the Netherlands, 72% is bidirectional. If drivers would become used to cyclists riding at the left side of the road, this result raises the question of why bidirectional cycle paths in the Netherlands still have a poor safety record compared to unidirectional cycle paths. Moreover, our exploration suggested that bidirectional cycle paths have additional safety problems. It increases the complexity of unsignalized intersections because drivers have to scan more directions in a short period of time. Moreover, there are some indications that the likelihood of frontal crashes between cyclists increases. We reject the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions will improve cycle safety. We recommend more attention for mitigating measures given the widespread application of bidirectional cycle paths in the Netherlands. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nuclear Fuel Cycle Information System. A directory of nuclear fuel cycle facilities. 2009 ed

International Nuclear Information System (INIS)

2009-04-01

The Nuclear Fuel Cycle Information System (NFCIS) is an international directory of civilian nuclear fuel cycle facilities, published online as part of the Integrated Nuclear Fuel Cycle Information System (iNFCIS: http://www-nfcis.iaea.org/). This is the fourth hardcopy publication in almost 30 years and it represents a snapshot of the NFCIS database as of the end of 2008. Together with the attached CD-ROM, it provides information on 650 civilian nuclear fuel cycle facilities in 53 countries, thus helping to improve the transparency of global nuclear fuel cycle activities

Ulrich Beck : riskiühiskond / Ulrich Beck ; tõlk. Külli-Riin Tigasson

Index Scriptorium Estoniae

Beck, Ulrich

2004-01-01

Katkend raamatust "Risikogesellschaft". Autori hinnangul on tänapäeval poliitikute roll ühiskonna arengu otsustamisel kahanenud, sest võtmelise tähtsusega otsuseid teevad teadlased ja äriühingute juhid. Poliitika ja mittepoliitika vahetavad kohad

Entrepreneurship and the business cycle

NARCIS (Netherlands)

Koellinger, Philipp D.; Thurik, A. Roy

2012-01-01

We find new empirical regularities in the business cycle in a cross-country panel of 22 OECD countries for the period 1972 to 2007; entrepreneurship Granger-causes the cycles of the world economy. Furthermore, the entrepreneurial cycle is positively affected by the national unemployment cycle. We

Continuation of connecting orbits in 3d-ODEs. (ii) cycle-to-cycle connections.

NARCIS (Netherlands)

Doedel, E.J.; Kooi, B.W.; van Voorn, G.A.K.; Kuznetzov, Y.A.

2009-01-01

In Part I of this paper we have discussed new methods for the numerical continuation of point-to-cycle connecting orbits in three-dimensional autonomous ODE's using projection boundary conditions. In this second part we extend the method to the numerical continuation of cycle-to-cycle connecting

LIFE CYCLE OF INFORMATION SYSTEMS

Directory of Open Access Journals (Sweden)

Y. S. Sennik

2015-01-01

Full Text Available This work is a generalization of the theoretical propositions related to the life cycle of information systems. There was given the definition of the life cycle, specify which items you should include every step of the cycle. Describes the methodology division of the life cycle on the main stage, including methodology Rational Unified Process. The description of the fundamental standards in this area. Special attention was paid to the work of the basic life cycle models. It was carried out their comparative characteristics. On the basis of the theoretical propositions, it was concluded that the preferred model of the life cycle for the corporate network is a spiral model and the use of international standards in the life cycle saves a lot of effort, time and material resources.

Two Quantum Polytropic Cycles

Science.gov (United States)

Arias-Hernández, L. A.; Morales-Serrano, A. F.

2002-11-01

In this work we follow the Bender et al paper [1] to study the quantum analogues of the Stirling and Ericsson polytropic cycles. In the context of the classical thermodynamics, the Stirling and Ericsson cycles correspond to reversible heat engines with two isothermal processes joined by two polytropic branches which occur in a device called regenerator. If this device is an ideal one, the efficiency of these cycles is the Carnot efficiency. Here, we introduce the quantum analogues of the Stirling and Ericsson cycles, the first one based on a double square potential well with a finite potential barrier, since in this system the tunnel effect could be the analogue to the regeneration classical process, therefore the isochoric quantum branches would really correspond to an internal energy storage, and the last one with an unknown system where the isobaric quantum processes don't induce changes in its quantum state. With these systems the quantum engines have cycles consisting of polytropic and isothermal quantum processes analogues to the corresponding classical processes. We show that in both cases the quantum cycles have an efficiency given by ηCQM = 1 - EC/EH, which is the same expression for the quantum analogue of the Carnot cycle studied by Bender.

Increasing thermal efficiency of Rankine cycles by using refrigeration cycles: A theoretical analysis

International Nuclear Information System (INIS)

Sarr, Joachim-André Raymond; Mathieu-Potvin, François

2016-01-01

Highlights: • A new stratagem is proposed to improve thermal efficiency of Rankine cycles. • Three new configurations are optimized by means of numerical simulations. • The Rankine-1SCR design is advantageous for 1338 different fluid combinations. • The Rankine-2SCR design is advantageous for 772 different fluid combinations. • The Rankine-3SCR design is advantageous for 768 different fluid combinations. - Abstract: In this paper, three different modifications of the basic Rankine thermodynamic cycle are proposed. The objective is to increase the thermal efficiency of power systems based on Rankine cycles. The three new systems are named “Rankine-1SCR”, “Rankine-2SCR”, and “Rankine-3SCR” cycles, and they consist of linking a refrigeration cycle to the basic Rankine cycle. The idea is to use the refrigeration cycle to create a low temperature heat sink for the Rankine cycle. These three new power plant configurations are modeled and optimized with numerical tools, and then they are compared with the basic Rankine cycle. The objective function is the thermal efficiency of the systems (i.e., net power output (kW) divided by heat rate (kW) entering the system), and the design variables are the operating temperatures within the systems. Among the 84 × 84 (i.e., 7056) possible combinations of working and cooling fluids investigated in this paper, it is shown that: (i) the Rankine-1SCR system is advantageous for 1338 different fluid combinations, (ii) the Rankine-2SCR system is advantageous for 772 different fluid combinations, and (iii) the Rankine-3SCR system is advantageous for 768 different fluid combinations.

Hybrid Combined Cycles with Biomass and Waste Fired Bottoming Cycle - a Literature Study

Energy Technology Data Exchange (ETDEWEB)

Petrov, Miroslav P.

2002-02-01

Biomass is one of the main natural resources in Sweden. The present low-CO{sub 2} emission characteristics of the Swedish electricity production system (hydro and nuclear) can be retained only by expansion of biofuel applications for energy purposes. Domestic Swedish biomass resources are vast and renewable, but not infinite. They must be utilized as efficiently as possible, in order to make sure that they meet the conditions for sustainability in the future. Application of efficient power generation cycles at low costs is essential for meeting this challenge. This applies also to municipal solid waste incineration with energy extraction, which should be preferred to its dumping in landfills. Hybrid dual-fuel combined cycle units are a simple and affordable way to increase the electric efficiency of biofuel energy utilization, without big investments, uncertainties or loss of reliability arising from complicated technologies. Configurations of such power cycles are very flexible and reliable. Their potential for high electric efficiency in condensing mode, high total efficiency in combined heat and power mode and unrivalled load flexibility is explored in this project. The present report is a literature study that concentrates on certain biomass utilization technologies, in particular the design and performance of hybrid combined cycle power units of various configurations, with gas turbines and internal combustion engines as topping cycles. An overview of published literature and general development trends on the relevant topic is presented. The study is extended to encompass a short overview of biomass utilization as an energy source (focusing on Sweden), history of combined cycles development with reference especially to combined cycles with supplementary firing and coal-fired hybrid combined cycles, repowering of old steam units into hybrid ones and combined cycles for internal combustion engines. The hybrid combined cycle concept for municipal solid waste

High-intensity cycle interval training improves cycling and running performance in triathletes.

Science.gov (United States)

Etxebarria, Naroa; Anson, Judith M; Pyne, David B; Ferguson, Richard A

2014-01-01

Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.

Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part A

DEFF Research Database (Denmark)

Meroni, Andrea; La Seta, Angelo; Andreasen, Jesper Graa

2016-01-01

Axial-flow turbines represent a well-established technology for a wide variety of power generation systems. Compactness, flexibility, reliability and high efficiency have been key factors for the extensive use of axial turbines in conventional power plants and, in the last decades, in organic...... Rankine cycle power systems. In this two-part paper, an overall cycle model and a model of an axial turbine were combined in order to provide a comprehensive preliminary design of the organic Rankine cycle unit, taking into account both cycle and turbine optimal designs. Part A presents the preliminary...

Menstrual cycle pattern and fertility

DEFF Research Database (Denmark)

Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik

1999-01-01

To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss.......To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss....

Spatio-temporal structure and cycle to cycle variations of an in-cylinder tumbling flow

Science.gov (United States)

Voisine, M.; Thomas, L.; Borée, J.; Rey, P.

2011-05-01

The aim of this paper is to make use of PIV and high-speed PIV in a research engine of moderate tumbling ratio in order to analyze both the spatial structure of the flow and its temporal evolution during series of consecutive cycles. Appropriate analyzing tools are introduced, and four different points are addressed: (1) the chain of events driving the generation of the three-dimensional mean tumbling motion is investigated; (2) a Lagrangian analysis of the roll-up of the tumbling jet in individual cycles demonstrates a strong cycle to cycle variation during the compression phase (the rms of the position of the jet front being approximately 10% of the piston stroke); (3) focussing on the "breakdown" phase, phase invariant proper orthogonal decomposition enables us to distinguish cycles according to their structure near top dead center (TDC). We show that when the coherent energy of the flow is conserved, there is no increase in the fluctuating kinetic energy; (4) finally, the phase-averaged Reynolds stresses is decomposed into a contribution of the in-cycle coherence and the turbulence carried by the flow states. Approximately 30% of the fluctuating kinetic energy is due to cycle to cycle fluctuations in this chamber near TDC.

Nutrient cycling strategies.

NARCIS (Netherlands)

Breemen, van N.

1995-01-01

This paper briefly reviews pathways by which plants can influence the nutrient cycle, and thereby the nutrient supply of themselves and of their competitors. Higher or lower internal nutrient use efficiency positively feeds back into the nutrient cycle, and helps to increase or decrease soil

Universal cycle periods

NARCIS (Netherlands)

Groot, de E.A. (Bert); Franses, P.H.P.H.

2009-01-01

We present a meta-analysis of cycles in historical economic data. The literature on stochastic and deterministic cycles in variables such as the consumer price index, employment, interest rates, commodity prices, and GDP is huge and scattered, but our meta-analysis reveals various communalities. Our

Predicting the start and maximum amplitude of solar cycle 24 using similar phases and a cycle grouping

International Nuclear Information System (INIS)

Wang Jialong; Zong Weiguo; Le Guiming; Zhao Haijuan; Tang Yunqiu; Zhang Yang

2009-01-01

We find that the solar cycles 9, 11, and 20 are similar to cycle 23 in their respective descending phases. Using this similarity and the observed data of smoothed monthly mean sunspot numbers (SMSNs) available for the descending phase of cycle 23, we make a date calibration for the average time sequence made of the three descending phases of the three cycles, and predict the start of March or April 2008 for cycle 24. For the three cycles, we also find a linear correlation of the length of the descending phase of a cycle with the difference between the maximum epoch of this cycle and that of its next cycle. Using this relationship along with the known relationship between the rise-time and the maximum amplitude of a slowly rising solar cycle, we predict the maximum SMSN of cycle 24 of 100.2 ± 7.5 to appear during the period from May to October 2012. (letters)

Is there a relationship between mood disorders and dysmenorrhea?

Science.gov (United States)

Balık, Gülşah; Ustüner, Işık; Kağıtcı, Mehmet; Sahin, Figen Kır

2014-12-01

Menstrual problems are common among adolescent females. Mood changes are related to menstrual problems (menorrhagia, dysmenorrhea, and abnormal menstrual cycle length). The aim of this study was to determine the relationship between depressive symptoms, anxiety, and premenstrual syndrome (PMS) with dysmenorrhea in adolescent girls. A total of 159 adolescent girls (aged 13-19 y) with regular menstrual cycles presenting to the gynecology clinic with any complaints were included in the study during April-May 2013. All of the participants filled up the sociodemographic data collection form, FACES Pain Rating Scale, Beck anxiety inventory (BAI), Beck depression inventory (BDI), and a questionnaire form on criteria for PMS. Mann-Whitney U and chi-square tests were used to analyze the data. The prevalence of dysmenorrhea was 67.9%. The mean BAI and BDI scores of the patients were 13.64 ± 12.81 and 11.88 ± 10.83, respectively. Statistically significant differences were observed between patients and control groups on the BAI and BDI scoring (P dysmenorrhea have an increased risk of depression and anxiety. These results of our study are significant in emphasizing the importance of a multidisciplinary approach to primary dysmenorrhea follow-up and treatment. Copyright © 2014 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Associations between urban form and cycling

DEFF Research Database (Denmark)

Nielsen, Thomas Alexander Sick; Olafsson, Anton Stahl; Carstensen, Trine Agervig

of National Travel Survey data indicated that established walkability factors such as density, connectivity and diversity are related to cycling, and that access to retail concentrations/centres, public transportation level-of-service, as well as competition between walking and cycling depending...... of cycling and the distance cycled. A high probability of cycling generally implies short cycling distances, which leads to non-uniform, non-monotonous relations between environmental indicators such as walkability and total cycling. Further analysis of primary data allowing a consideration of attitudes...

Characterizing cycle-to-cycle variations of the shedding cycle in the turbulent wake of a normal flat plate using generalized phase averages

Science.gov (United States)

Martinuzzi, Robert

2016-11-01

Quasi-periodic vortex shedding in the turbulent wake of a thin-flat plate placed normal to a uniform stream at Reynolds number of 6700 is investigated based on Particle Image Velocimetry experiments. The wake structure and vortex formation are characterized using a generalized phase average (GPA), a refinement of the triple decomposition of Reynolds and Hussain (1970) incorporating elements of mean-field theory (Stuart, 1958). The resulting analysis highlights the importance of cycle-to-cycle variations in characterizing vortex formation, wake topology and the residual turbulent Reynolds Stresses. For example, it is shown that during high-amplitude cycles vorticity is strongly concentrated within the well-organized shed vortices, whereas during low-amplitude cycles the shed vortices are highly distorted resulting in significant modulation of the shedding frequency. It is found that high-amplitude cycles contribute more to the coherent Reynolds stress field while the low-amplitude cycles contribute to the residual stress field. It is further shown that traditional phase-averaging techniques lead to an over-estimation of the residual stress field. Natural Sciences and Engineering Research Council of Canada.

Stability through cycles

NARCIS (Netherlands)

E.A. de Groot (Bert); Ph.H.B.F. Franses (Philip Hans)

2006-01-01

textabstractEconomic variables like GDP growth, employment, interest rates and consumption show signs of cyclical behavior. Many variables display multiple cycles, with lengths ranging in between 5 to even up to 100 years. We argue that multiple cycles can be associated with long-run stability of

Economics analysis of fuel cycle cost of fusion–fission hybrid reactors based on different fuel cycle strategies

Energy Technology Data Exchange (ETDEWEB)

Zu, Tiejun, E-mail: tiejun@mail.xjtu.edu.cn; Wu, Hongchun; Zheng, Youqi; Cao, Liangzhi

2015-01-15

Highlights: • Economics analysis of fuel cycle cost of FFHRs is carried out. • The mass flows of different fuel cycle strategies are established based on the equilibrium fuel cycle model. • The levelized fuel cycle costs of different fuel cycle strategies are calculated, and compared with current once-through fuel cycle. - Abstract: The economics analysis of fuel cycle cost of fusion–fission hybrid reactors has been performed to compare four fuel cycle strategies: light water cooled blanket burning natural uranium (Strategy A) or spent nuclear fuel (Strategy B), sodium cooled blanket burning transuranics (Strategy C) or minor actinides (Strategy D). The levelized fuel cycle costs (LFCC) which does not include the capital cost, operation and maintenance cost have been calculated based on the equilibrium mass flows. The current once-through (OT) cycle strategy has also been analyzed to serve as the reference fuel cycle for comparisons. It is found that Strategy A and Strategy B have lower LFCCs than OT cycle; although the LFCC of Strategy C is higher than that of OT cycle when the uranium price is at its nominal value, it would become comparable to that of OT cycle when the uranium price reaches its historical peak value level; Strategy D shows the highest LFCC, because it needs to reprocess huge mass of spent nuclear fuel; LFCC is sensitive to the discharge burnup of the nuclear fuel.

HTGR fuel and fuel cycle technology

International Nuclear Information System (INIS)

Lotts, A.L.; Coobs, J.H.

1976-08-01

The status of fuel and fuel cycle technology for high-temperature gas-cooled reactors (HTGRs) is reviewed. The all-ceramic core of the HTGRs permits high temperatures compared with other reactors. Core outlet temperatures of 740 0 C are now available for the steam cycle. For advanced HTGRs such as are required for direct-cycle power generation and for high-temperature process heat, coolant temperatures as high as 1000 0 C may be expected. The paper discusses the variations of HTGR fuel designs that meet the performance requirements and the requirements of the isotopes to be used in the fuel cycle. Also discussed are the fuel cycle possibilities, which include the low-enrichment cycle, the Th- 233 U cycle, and plutonium utilization in either cycle. The status of fuel and fuel cycle development is summarized

Cell cycle phases in the unequal mother/daughter cell cycles of Saccharomyces cerevisiae.

Science.gov (United States)

Brewer, B J; Chlebowicz-Sledziewska, E; Fangman, W L

1984-11-01

During cell division in the yeast Saccharomyces cerevisiae mother cells produce buds (daughter cells) which are smaller and have longer cell cycles. We performed experiments to compare the lengths of cell cycle phases in mothers and daughters. As anticipated from earlier indirect observations, the longer cell cycle time of daughter cells is accounted for by a longer G1 interval. The S-phase and the G2-phase are of the same duration in mother and daughter cells. An analysis of five isogenic strains shows that cell cycle phase lengths are independent of cell ploidy and mating type.

On acyclicity of games with cycles

DEFF Research Database (Denmark)

Andersson, Klas Olof Daniel; Hansen, Thomas Dueholm; Gurvich, Vladimir

2010-01-01

We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (di-graphs) that may contain directed cycles (di-cycles). We assume that all these di-cycles form one outcome c, for example, a draw. We obtain criteria...

An integrated life cycle inventory for demolition processes in the context of life cycle sustainability assessment

DEFF Research Database (Denmark)

Bozhilova-Kisheva, Kossara Petrova; Hu, Mingming; van Roekel, Eric

2012-01-01

According to the Life Cycle Assessment in Building and Construction: State-of-the-Art Report (2003), the dismantling and demolition stage of the building life cycle is only sometimes included in the Life Cycle Inventory (LCI) when doing Life Cycle Assessments (LCA). The reason that it is less...... inventoried in a traditional LCA maybe because this stage is expected to have a negligible environmental impact comparing to other stages in the life cycle of the buildings. When doing a life cycle sustainability assessment considering not only environmental but also economic and social impacts, the impacts...

A comparison of advanced heat recovery power cycles in a combined cycle for large ships

DEFF Research Database (Denmark)

Larsen, Ulrik; Sigthorsson, Oskar; Haglind, Fredrik

2014-01-01

Strong motivation exists within the marine sector to reduce fuel expenses and to comply with ever stricter emission regulations. Heat recovery can address both of these issues. The ORC (organic Rankine cycle), the Kalina cycle and the steam Rankine cycle have received the majority of the focus...... fluids possess high global warming potentials and hazard levels. It is concluded that the ORC has the greatest potential for increasing the fuel efficiency, and the combined cycle offers very high thermal efficiency. While being less efficient, the steam cycle has the advantages of being well proven...

CANDU fuel-cycle vision

International Nuclear Information System (INIS)

Boczar, P.G.

1999-01-01

The fuel-cycle path chosen by a particular country will depend on a range of local and global factors. The CANDU reactor provides the fuel-cycle flexibility to enable any country to optimize its fuel-cycle strategy to suit its own needs. AECL has developed the CANFLEX fuel bundle as the near-term carrier of advanced fuel cycles. A demonstration irradiation of 24 CANFLEX bundles in the Point Lepreau power station, and a full-scale critical heat flux (CHF) test in water are planned in 1998, before commercial implementation of CANFLEX fuelling. CANFLEX fuel provides a reduction in peak linear element ratings, and a significant enhancement in thermalhydraulic performance. Whereas natural uranium fuel provides many advantages, the use of slightly enriched uranium (SEU) in CANDU reactors offers even lower fuel-cycle costs and other benefits, such as uprating capability through flattening the channel power distribution across the core. Recycled uranium (RU) from reprocessing spent PWR fuel is a subset of SEU that has significant economic promise. AECL views the use of SEU/RU in the CANFLEX bundle as the first logical step from natural uranium. High neutron economy enables the use of low-fissile fuel in CANDU reactors, which opens up a spectrum of unique fuel-cycle opportunities that exploit the synergism between CANDU reactors and LWRs. At one end of this spectrum is the use of materials from conventional reprocessing: CANDU reactors can utilize the RU directly without re-enrichment, the plutonium as conventional Mixed-oxide (MOX) fuel, and the actinide waste mixed with plutonium in an inert-matrix carrier. At the other end of the spectrum is the DUPIC cycle, employing only thermal-mechanical processes to convert spent LWR fuel into CANDU fuel, with no purposeful separation of isotopes from the fuel, and possessing a high degree of proliferation resistance. Between these two extremes are other advanced recycling options that offer particular advantages in exploiting the

CANDU fuel-cycle vision

International Nuclear Information System (INIS)

Boczar, P.G

1998-05-01

The fuel-cycle path chosen by a particular country will depend on a range of local and global factors. The CANDU reactor provides the fuel-cycle flexibility to enable any country to optimize its fuel-cycle strategy to suit its own needs. AECL has developed the CANFLEX fuel bundle as the near-term carrier of advanced fuel cycles. A demonstration irradiation of 24 CANFLEX bundles in the Point Lepreau power station, and a full-scale critical heat flux (CHF) test in water are planned in 1998, before commercial implementation of CANFLEX fuelling. CANFLEX fuel provides a reduction in peak linear element ratings, and a significant enhancement in thermalhydraulic performance. Whereas natural uranium fuel provides many advantages, the use of slightly enriched uranium (SEU) in CANDU reactors offers even lower fuel-cycle costs and other benefits, such as uprating capability through flattening the channel power distribution across the core. Recycled uranium (RU) from reprocessing spent PWR fuel is a subset of SEU that has significant economic promise. AECL views the use of SEU/RU in the CANFLEX bundle as the first logical step from natural uranium. High neutron economy enables the use of low-fissile fuel in CANDU reactors, which opens up a spectrum of unique fuel-cycle opportunities that exploit the synergism between CANDU reactors and LWRs. At one end of this spectrum is the use of materials from conventional reprocessing: CANDU reactors can utilize the RU directly without reenrichment, the plutonium as conventional mixed-oxide (MOX) fuel, and the actinide waste mixed with plutonium in an inert-matrix carrier. At the other end of the spectrum is the DUPIC cycle, employing only thermal-mechanical processes to convert spent LWR fuel into CANDU fuel, with no purposeful separation of isotopes from the fuel, and possessing a high degree of proliferation resistance. Between these two extremes are other advanced recycling options that offer particular advantages in exploiting the

Verifiable Fuel Cycle Simulation Model (VISION): A Tool for Analyzing Nuclear Fuel Cycle Futures

International Nuclear Information System (INIS)

Jacobson, Jacob J.; Piet, Steven J.; Matthern, Gretchen E.; Shropshire, David E.; Jeffers, Robert F.; Yacout, A.M.; Schweitzer, Tyler

2010-01-01

The nuclear fuel cycle consists of a set of complex components that are intended to work together. To support the nuclear renaissance, it is necessary to understand the impacts of changes and timing of events in any part of the fuel cycle system such as how the system would respond to each technological change, a series of which moves the fuel cycle from where it is to a postulated future state. The system analysis working group of the United States research program on advanced fuel cycles (formerly called the Advanced Fuel Cycle Initiative) is developing a dynamic simulation model, VISION, to capture the relationships, timing, and changes in and among the fuel cycle components to help develop an understanding of how the overall fuel cycle works. This paper is an overview of the philosophy and development strategy behind VISION. The paper includes some descriptions of the model components and some examples of how to use VISION. For example, VISION users can now change yearly the selection of separation or reactor technologies, the performance characteristics of those technologies, and/or the routing of material among separation and reactor types - with the model still operating on a PC in <5 min.

Part 5. Fuel cycle options

International Nuclear Information System (INIS)

Lineberry, M.J.; McFarlane, H.F.; Amundson, P.I.; Goin, R.W.; Webster, D.S.

1980-01-01

The results of the FBR fuel cycle study that supported US contributions to the INFCE are presented. Fuel cycle technology is reviewed from both generic and historical standpoints. Technology requirements are developed within the framework of three deployment scenarios: the reference international, the secured area, and the integral cycle. Reprocessing, fabrication, waste handling, transportation, and safeguards are discussed for each deployment scenario. Fuel cycle modifications designed to increase proliferation defenses are described and assessed for effectiveness and technology feasibility. The present status of fuel cycle technology is reviewed and key issues that require resolution are identified

Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

Science.gov (United States)

Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

2010-01-01

Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

Fast breeder fuel cycle

International Nuclear Information System (INIS)

1978-09-01

Basic elements of the ex-reactor part of the fuel cycle (reprocessing, fabrication, waste handling and transportation) are described. Possible technical and proliferation measures are evaluated, including current methods of accountability, surveillance and protection. The reference oxide based cycle and advanced cycles based on carbide and metallic fuels are considered utilizing conventional processes; advanced nonaqueous reprocessing is also considered. This contribution provides a comprehensive data base for evaluation of proliferation risks

Advanced fuel cycles: a rationale and strategy for adopting the low-enriched-uranium fuel cycle

International Nuclear Information System (INIS)

James, R.A.

1980-01-01

A two-year study of alternatives to the natural uranium fuel cycle in CANDU reactors is summarized. The possible advanced cycles are briefly described. Selection criteria for choosing a cycle for development include resource utilization, economics, ease of implementaton, and social acceptability. It is recommended that a detailed study should be made with a view to the early implementation of the low-enriched uranium cycle. (LL)

Cell Cycle Control by PTEN.

Science.gov (United States)

Brandmaier, Andrew; Hou, Sheng-Qi; Shen, Wen H

2017-07-21

Continuous and error-free chromosome inheritance through the cell cycle is essential for genomic stability and tumor suppression. However, accumulation of aberrant genetic materials often causes the cell cycle to go awry, leading to malignant transformation. In response to genotoxic stress, cells employ diverse adaptive mechanisms to halt or exit the cell cycle temporarily or permanently. The intrinsic machinery of cycling, resting, and exiting shapes the cellular response to extrinsic stimuli, whereas prevalent disruption of the cell cycle machinery in tumor cells often confers resistance to anticancer therapy. Phosphatase and tensin homolog (PTEN) is a tumor suppressor and a guardian of the genome that is frequently mutated or deleted in human cancer. Moreover, it is increasingly evident that PTEN deficiency disrupts the fundamental processes of genetic transmission. Cells lacking PTEN exhibit cell cycle deregulation and cell fate reprogramming. Here, we review the role of PTEN in regulating the key processes in and out of cell cycle to optimize genomic integrity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Menstrual cycle pattern and fertility

DEFF Research Database (Denmark)

Kolstad, Henrik A.; Bonde, Jens Peter; Hjøllund, Niels Henrik

1999-01-01

OBJECTIVE: To characterize how the menstrual cycle pattern relates to fertility regardless of potential biases caused by inappropriate coital timing during the menstrual cycle or early embryonal loss. DESIGN: Prospective follow-up study. SETTING: Healthy couples recruited throughout Denmark....... PATIENT(S): Two hundred ninety-five couples who were planning their first pregnancy were followed up from the discontinuation of birth control until a pregnancy was recognized within six menstrual cycles. Early embryonal losses were detected by changes in urinary hCG levels. INTERVENTION(S): None. MAIN...... OUTCOME MEASURE(S): The probability of pregnancy occurring within one menstrual cycle (fecundity). RESULT(S): In women who had a cycle length that differed by >10 days from the usual cycle length, fecundity was approximately 25% that of women who had no variation (odds ratio 0.25, 95% confidence interval...

National Policy on Nuclear Fuel Cycle

International Nuclear Information System (INIS)

Soedyartomo, S.

1996-01-01

National policy on nuclear fuel cycle is aimed at attaining the expected condition, i.e. being able to support optimality the national energy policy and other related Government policies taking into account current domestic nuclear fuel cycle condition and the trend of international nuclear fuel cycle development, the national strength, weakness, thread and opportunity in the field of energy. This policy has to be followed by the strategy to accomplish covering the optimization of domestic efforts, cooperation with other countries, and or purchasing licences. These policy and strategy have to be broken down into various nuclear fuel cycle programmes covering basically assesment of the whole cycle, performing research and development of the whole cycle without enrichment and reprocessing being able for weapon, as well as programmes for industrialization of the fuel cycle stepwisery commencing with the middle part of the cycle and ending with the edge of the back-end of the cycle

Rock Cycle Roulette.

Science.gov (United States)

Schmidt, Stan M.; Palmer, Courtney

2000-01-01

Introduces an activity on the rock cycle. Sets 11 stages representing the transitions of an earth material in the rock cycle. Builds six-sided die for each station, and students move to the stations depending on the rolling side of the die. Evaluates students by discussing several questions in the classroom. Provides instructional information for…

[Effects and mechanism of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem].

Science.gov (United States)

Wang, Li-qin; Qi, Yu-chun; Dong, Yun-she; Peng, Qin; Guo, Shu-fang; He, Yun-long; Yan, Zhong-qing

2015-11-01

As a widespread natural phenomenon in the soil of middle and high latitude as well as high altitude, freeze-thawing cycles have a great influence on the nitrogen cycle of terrestrial ecosystem in non-growing season. Freeze-thawing cycles can alter the physicochemical and biological properties of the soil, which thereby affect the migration and transformation of soil nitrogen. The impacts of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem found in available studies remain inconsistent, the mechanism is still not clear, and the research methods also need to be further explored and innovated. So it is necessary to sum up and analyze the existing achievements in order to better understand the processes of soil nitrogen cycle subjected to freeze-thawing cycles. This paper reviewed the research progress in China and abroad about the effects and mechanisms of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem, including mineralization, immobilization, nitrification and denitrification, N leakage and gaseous loss, and analyzed the deficiencies of extant research. The possible key research topics that should be urgently paid more attention to in the future were also discussed.

Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk

DEFF Research Database (Denmark)

Rasmussen, Martin G; Grøntved, Anders; Blond, Kim

2016-01-01

BACKGROUND: Cycling is a recreational activity and mode of commuting with substantial potential to improve public health in many countries around the world. The aim of this study was to examine prospective associations between recreational and commuter cycling, changes in cycling habits, and risk.......83 (0.69, 1.00), and 0.70 (0.57, 0.85) (p for trend = 150 min/wk to work, respectively. The main limitation of the current study is the use of self-reported physical activity. CONCLUSIONS: Commuter and recreational cycling was consistently associated with lower...

Transportation life cycle assessment (LCA) synthesis : life cycle assessment learning module series.

Science.gov (United States)

2015-03-12

The Life Cycle Assessment Learning Module Series is a set of narrated, self-advancing slideshows on : various topics related to environmental life cycle assessment (LCA). This research project produced the first 27 of such modules, which : are freely...

Large-scale fuel cycle centres

International Nuclear Information System (INIS)

Smiley, S.H.; Black, K.M.

1977-01-01

The US Nuclear Regulatory Commission (NRC) has considered the nuclear energy centre concept for fuel cycle plants in the Nuclear Energy Centre Site Survey 1975 (NECSS-75) Rep. No. NUREG-0001, an important study mandated by the US Congress in the Energy Reorganization Act of 1974 which created the NRC. For this study, the NRC defined fuel cycle centres as consisting of fuel reprocessing and mixed-oxide fuel fabrication plants, and optional high-level waste and transuranic waste management facilities. A range of fuel cycle centre sizes corresponded to the fuel throughput of power plants with a total capacity of 50,000-300,000MW(e). The types of fuel cycle facilities located at the fuel cycle centre permit the assessment of the role of fuel cycle centres in enhancing the safeguard of strategic special nuclear materials - plutonium and mixed oxides. Siting fuel cycle centres presents a smaller problem than siting reactors. A single reprocessing plant of the scale projected for use in the USA (1500-2000t/a) can reprocess fuel from reactors producing 50,000-65,000MW(e). Only two or three fuel cycle centres of the upper limit size considered in the NECSS-75 would be required in the USA by the year 2000. The NECSS-75 fuel cycle centre evaluation showed that large-scale fuel cycle centres present no real technical siting difficulties from a radiological effluent and safety standpoint. Some construction economies may be achievable with fuel cycle centres, which offer opportunities to improve waste-management systems. Combined centres consisting of reactors and fuel reprocessing and mixed-oxide fuel fabrication plants were also studied in the NECSS. Such centres can eliminate shipment not only of Pu but also mixed-oxide fuel. Increased fuel cycle costs result from implementation of combined centres unless the fuel reprocessing plants are commercial-sized. Development of Pu-burning reactors could reduce any economic penalties of combined centres. The need for effective fissile

Economic comparison of fusion fuel cycles

International Nuclear Information System (INIS)

Brereton, S.J.; Kazimi, M.S.

1987-01-01

The economics of the DT, DD, and DHe fusion fuel cycles are evaluated by comparison on a consistent basis. The designs for the comparison employ HT-9 structure and helium coolant; liquid lithium is used as the tritium breeding material for the DT fuel cycle. The reactors are pulsed, superconducting tokamaks, producing 1200 MW of electric power. The DT and DD designs scan a range of values of plasma beta, assuming first stability scaling laws. The results indicate that on a purely economic basis, the DT fuel cycle is superior to both of the advanced fuel cycles. Geometric factors, materials limitations, and plasma beta were seen to have an impact on the Cost of Electricity (COE). The economics for the DD fuel cycle are more strongly affected by these parameters than is the DT fuel cycle. Fuel costs are a major factor in determining the COE for the DHe fuel cycle. Based on costs directly attributable to the fuel cycle, the DT fuel cycle appears most attractive. Technological advances, improved understanding of physics, or strides in advanced energy conversion schemes may result in altering the economic ranking of the fuel cycles indicated here. 7 refs., 6 figs., 2 tabs

Cycle layout studies of S-CO2 cycle for the next generation nuclear system application

International Nuclear Information System (INIS)

Ahn, Yoonhan; Bae, Seong Jun; Kim, Minseok; Cho, Seong Kuk; Baik, Seungjoon; Lee, Jeong Ik; Cha, Jae Eun

2014-01-01

According to the second law of thermodynamics, the next generation nuclear reactor system efficiency can potentially be increased with higher operating temperature. Fig.1 shows several power conversion system efficiencies and heat sources with respect to the system top operating temperature. As shown in Fig.1, the steam Rankine and gas Brayton cycles have been considered as the major power conversion systems more than several decades. In the next generation reactor operating temperature region (450 - 900 .deg. C), the steam Rankine and gas Brayton cycles have limits due to material problems and low efficiency, respectively. Among the future power conversion systems, S-CO 2 cycle is receiving interests due to several benefits including high efficiency under the mild turbine inlet temperature range (450-650 .deg. C), compact turbomachinery and simple layout compared to the steam Rankine cycle. S-CO 2 cycle can show relatively high efficiency under the mild turbine inlet temperature range (450-600 .deg. C) compared to other power conversion systems. The recompression cycle shows the best efficiency among other layouts and it is suitable for the application to advanced nuclear reactor systems. As S-CO 2 cycle performance can vary depending on the layout configuration, further studies on the layouts are required to design a better performing cycle

The Life Cycle of Centrioles

OpenAIRE

Hatch, E.; Stearns, T.

2010-01-01

Centrioles organize the centrosome and nucleate the ciliary axoneme, and the centriole life cycle has many parallels to the chromosome cycle. The centriole cycle in animals begins at fertilization with the contribution of two centrioles by the male gamete. In the ensuing cell cycles, the duplication of centrioles is controlled temporally, spatially, and numerically. As a consequence of the duplication mechanism, the two centrioles in a typical interphase cell are of different ages and have di...

Gas fired combined cycle plant in Singapore: energy use, GWP and cost-a life cycle approach

International Nuclear Information System (INIS)

Kannan, R.; Leong, K.C.; Osman, Ramli; Ho, H.K.; Tso, C.P.

2005-01-01

A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency have been established

In anticipation of cycle 24

Science.gov (United States)

Kunches, Joseph; van der Linden, Ronald; Lundstedt, Henrik

Anxious eyes are watching for the beginnings of new solar cycle 24. The watchers are many; scientists, engineers, academics, forecasters, end users. Their needs however vary, from the attraction of a better understanding of our nearest star, to how its increase in luminosity will affect particular aspects such as satellite orbits or the strength of the episodic storms that are most likely to occur during the height of the cycle. The first sign, however fleeting, occurred in January, 2008, when an ephemeral new cycle spot was numbered by NOAA as 10981. It was gone quickly but did mark the possible beginning of the new cycle. There has been great debate among solar physicists on how strong cycle 24 will be; and when it will start, reach maximum, and decline. This talk will give the status of the efforts to predict cycle 24, and the most recent projections.

The economics of thorium fuel cycles

International Nuclear Information System (INIS)

James, R.A.

1978-01-01

The individual cost components and the total fuel cycle costs for natural uranium and thorium fuel cycles are discussed. The thorium cycles are initiated by using either enriched uranium or plutonium. Subsequent thorium cycles utilize recycled uranium-233 and, where necessary, either uranium-235 or plutonium as topping. A calculation is performed to establish the economic conditions under which thorium cycles are economically attractive. (auth)

Limit cycles in quantum systems

Energy Technology Data Exchange (ETDEWEB)

Niemann, Patrick

2015-04-27

In this thesis we investigate Limit Cycles in Quantum Systems. Limit cycles are a renormalization group (RG) topology. When degrees of freedom are integrated out, the coupling constants flow periodically in a closed curve. The presence of limit cycles is restricted by the necessary condition of discrete scale invariance. A signature of discrete scale invariance and limit cycles is log-periodic behavior. The first part of this thesis is concerned with the study of limit cycles with the similarity renormalization group (SRG). Limit cycles are mainly investigated within conventional renormalization group frameworks, where degrees of freedom, which are larger than a given cutoff, are integrated out. In contrast, in the SRG potentials are unitarily transformed and thereby obtain a band-diagonal structure. The width of the band structure can be regarded as an effective cutoff. We investigate the appearance of limit cycles in the SRG evolution. Our aim is to extract signatures as well as the scaling factor of the limit cycle. We consider the 1/R{sup 2}-potential in a two-body system and a three-body system with large scattering lengths. Both systems display a limit cycle. Besides the frequently used kinetic energy generator we apply the exponential and the inverse generator. In the second part of this thesis, Limit Cycles at Finite Density, we examine the pole structure of the scattering amplitude for distinguishable fermions at zero temperature in the medium. Unequal masses and a filled Fermi sphere for each fermion species are considered. We focus on negative scattering lengths and the unitary limit. The properties of the three-body spectrum in the medium and implications for the phase structure of ultracold Fermi gases are discussed.

The nuclear fuel cycle versus the carbon cycle

International Nuclear Information System (INIS)

Ewing, R.C.

2005-01-01

Nuclear power provides approximately 17% of the world's electricity, which is equivalent to a reduction in carbon emissions of ∼0.5 gigatonnes (Gt) of C/yr. This is a modest reduction as compared with global emissions of carbon, ∼7 Gt C/yr. Most analyses suggest that in order to have a significant and timely impact on carbon emissions, carbon-free sources, such as nuclear power, would have to expand total production of energy by factors of three to ten by 2050. A three-fold increase in nuclear power capacity would result in a projected reduction in carbon emissions of 1 to 2 Gt C/yr, depending on the type of carbon-based energy source that is displaced. This three-fold increase utilizing present nuclear technologies would result in 25,000 metric tonnes (t) of spent nuclear fuel (SNF) per year, containing over 200 t of plutonium. This is compared to a present global inventory of approximately 280,000 t of SNF and >1,700 t of Pu. A nuclear weapon can be fashioned from as little as 5 kg of 239 Pu. However, there is considerable technological flexibility in the nuclear fuel cycle. There are three types of nuclear fuel cycles that might be utilized for the increased production of energy: open, closed, or a symbiotic combination of different types of reactor (such as, thermal and fast neutron reactors). The neutron energy spectrum has a significant effect on the fission product yield, and the consumption of long-lived actinides, by fission, is best achieved by fast neutrons. Within each cycle, the volume and composition of the high-level nuclear waste and fissile material depend on the type of nuclear fuel, the amount of burn-up, the extent of radionuclide separation during reprocessing, and the types of materials used to immobilize different radionuclides. As an example, a 232 Th-based fuel cycle can be used to breed fissile 233 U with minimum production of Pu. In this paper, I will contrast the production of excess carbon in the form of CO 2 from fossil fuels with

Measuring Business Cycle Time.

OpenAIRE

Stock, James H

1987-01-01

The business cycle analysis of Arthur F. Burns and Wesley C. Mitchell and the National Bureau of Economic Research presumed that aggregate economic variables evolve on a time scale defined by business cycle turning points rather than by months or quarters. Do macroeconomic variables appear to evolve on an economic rather than a calendar time scale? Evidence presented here suggests that they do. However, the estimated economic time scales are only weakly related to business cycle time scales, ...

Power generation from a 7700C heat source by means of a main steam cycle, a topping closed gas cycle and a ammonia bottoming cycle

International Nuclear Information System (INIS)

Tilliette, Z.P.

1981-03-01

For power generation, steam cycles make an efficient use of medium temperature heat sources. They can be adapted to dry cooling, higher power ratings and output increase in winter by addition of an ammonia bottoming cycle. Active development is carried out in this field by 'Electricite de France'. As far as heat sources at higher temperatures are concerned, particularly related to coal-fired or nuclear power plants, a more efficient way of converting energy is at first to expand a hot working fluid through a gas turbine. It is shown in this paper that a satisfactory result, for heat sources of about 770 0 C, is obtained with a topping closed gas cycle of moderate power rating, rejecting its waste heat into the main steam cycle. Attention has to be paid to this gas cycle waste heat recovery and to the coupling of the gas and steam cycles. This concept drastically reduces the importance of new technology components. The use and the significance of an ammonia bottoming cycle in this case are investigated

Entrepreneurship and the Business Cycle

NARCIS (Netherlands)

Ph.D. Koellinger (Philipp); A.R. Thurik (Roy)

2011-01-01

textabstractWe find new empirical regularities in the business cycle in a cross-country panel of 22 OECD countries for the period 1972-2007; entrepreneurship Granger-causes the cycles of the world economy. Furthermore, the entrepreneurial cycle is positively affected by the national unemployment

Quadratic reactivity fuel cycle model

International Nuclear Information System (INIS)

Lewins, J.D.

1985-01-01

For educational purposes it is highly desirable to provide simple yet realistic models for fuel cycle and fuel economy. In particular, a lumped model without recourse to detailed spatial calculations would be very helpful in providing the student with a proper understanding of the purposes of fuel cycle calculations. A teaching model for fuel cycle studies based on a lumped model assuming the summability of partial reactivities with a linear dependence of reactivity usefully illustrates fuel utilization concepts. The linear burnup model does not satisfactorily represent natural enrichment reactors. A better model, showing the trend of initial plutonium production before subsequent fuel burnup and fission product generation, is a quadratic fit. The study of M-batch cycles, reloading 1/Mth of the core at end of cycle, is now complicated by nonlinear equations. A complete account of the asymptotic cycle for any order of M-batch refueling can be given and compared with the linear model. A complete account of the transient cycle can be obtained readily in the two-batch model and this exact solution would be useful in verifying numerical marching models. It is convenient to treat the parabolic fit rho = 1 - tau 2 as a special case of the general quadratic fit rho = 1 - C/sub tau/ - (1 - C)tau 2 in suitably normalized reactivity and cycle time units. The parabolic results are given in this paper

Historicising the Hydrosocial Cycle

Directory of Open Access Journals (Sweden)

Jeremy J. Schmidt

2014-02-01

Full Text Available This paper examines the historical claims made in support of the hydrosocial cycle. In particular, it considers how arguments advancing the hydrosocial cycle make historical claims regarding modernist conceptions of what water is (i.e. H2O and its fit with society. The paper gives special emphasis to the society/nature dualism and to the notion of agency as key sites of contest in arguments regarding the hydrosocial cycle. It finds that, while several versions of the hydrosocial cycle seek to advance a political ecology more sensitive to non-human actions, these same accounts often do not address the robust account of non-human agency in the historical record. Evidence is presented regarding water’s agency amongst late 19th and early 20th century architects of key water management norms in the United States. This evidence troubles accounts of the hydrosocial cycle that critique the US experience and suggests new directions for rethinking the role of historical and institutional norms in water policy.

Combined rankine and vapor compression cycles

Science.gov (United States)

Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

2005-04-19

An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

Life cycle assessment (LCA)

DEFF Research Database (Denmark)

Thrane, Mikkel; Schmidt, Jannick Andresen

2004-01-01

The chapter introduces Life Cycle Assessment (LCA) and its application according to the ISO 1404043 standards.......The chapter introduces Life Cycle Assessment (LCA) and its application according to the ISO 1404043 standards....

Cycling biomechanics: a literature review.

Science.gov (United States)

Wozniak Timmer, C A

1991-01-01

Submitted in partial fulfillment for a Master of Science degree at the University of Pittsburgh, School of Health Related Professions, Pittsburgh, PA 1.5213 This review of current literature on cycling biomechanics emphasizes lower extremity muscle actions and joint excursions, seat height, pedal position, pedaling rate, force application, and pedaling symmetry. Guidelines are discussed for optimal seat height, pedal position, and pedaling rate. Force application in the power and recovery phases of cycling and the relationship of force application to pedaling symmetry are discussed. The need for a biomechanical approach to cycling exists since a great deal of the literature is primarily physiologic in nature. The purpose of this review is to make cyclists and their advisors aware of the biomechanics of cycling and guidelines to follow. This approach is also important because cycling is a very common form of exercise prescribed by physical therapists for clinic or home programs. Biomechanical aspects of cycling should be considered by cyclists at any level of participation and by physical therapists in order for goal-oriented, efficient cycling to occur. J Orthop Sports Phys Ther 1991;14(3):106-113.

Thorium fuel cycle analysis

Energy Technology Data Exchange (ETDEWEB)

Yamaji, K [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

1980-07-01

Systems analysis of the thorium cycle, a nuclear fuel cycle accomplished by using thorium, is reported in this paper. Following a brief review on the history of the thorium cycle development, analysis is made on the three functions of the thorium cycle; (1) auxiliary system of U-Pu cycle to save uranium consumption, (2) thermal breeder system to exert full capacity of the thorium resource, (3) symbiotic system to utilize special features of /sup 233/U and neutron sources. The effects of the thorium loading in LWR (Light Water Reactor), HWR (Heavy Water Reactor) and HTGR (High Temperature Gas-cooled Reactor) are considered for the function of auxiliary system of U-Pu cycle. Analysis is made to find how much uranium is saved by /sup 233/U recycling and how the decrease in Pu production influences the introduction of FBR (Fast Breeder Reactor). Study on thermal breeder system is carried out in the case of MSBR (Molten Salt Breeder Reactor). Under a certain amount of fissile material supply, the potential system expansion rate of MSBR, which is determined by fissile material balance, is superior to that of FBR because of the smaller specific fissile inventory of MSBR. For symbiotic system, three cases are treated; i) nuclear heat supply system using HTGR, ii) denatured fuel supply system for nonproliferation purpose, and iii) hybrid system utilizing neutron sources other than fission reactor.

International Business Cycle Accounting

OpenAIRE

Keisuke Otsu

2009-01-01

In this paper, I extend the business cycle accounting method a la Chari, Kehoe and McGrattan (2007) to a two-country international business cycle model and quantify the effect of the disturbances in relevant markets on the business cycle correlation between Japan and the US over the 1980-2008 period. This paper finds that disturbances in the labor market and production efficiency are important in accounting for the recent increase in the cross-country output correlation. If international fina...

Optimal Life Cycle Portfolio Choice with Housing Market Cycles

DEFF Research Database (Denmark)

Fischer, Marcel; Stamos, Michael Z.

2013-01-01

income, and pre-existing housing wealth but also the state of the housing market significantly affect household decisions. Consistently with the data, the model predicts that in good states of housing market cycles (1) homeownership rates increase, (2) households buying homes invest a larger share......In recent decades U.S. households have experienced residential house prices moving persistently, that is, returns being positively serially correlated. We set up a realistically calibrated life cycle model with slow-moving time variation in expected housing returns, showing that not only age, labor...

Large-scale fuel cycle centers

International Nuclear Information System (INIS)

Smiley, S.H.; Black, K.M.

1977-01-01

The United States Nuclear Regulatory Commission (NRC) has considered the nuclear energy center concept for fuel cycle plants in the Nuclear Energy Center Site Survey - 1975 (NECSS-75) -- an important study mandated by the U.S. Congress in the Energy Reorganization Act of 1974 which created the NRC. For the study, NRC defined fuel cycle centers to consist of fuel reprocessing and mixed oxide fuel fabrication plants, and optional high-level waste and transuranic waste management facilities. A range of fuel cycle center sizes corresponded to the fuel throughput of power plants with a total capacity of 50,000 - 300,000 MWe. The types of fuel cycle facilities located at the fuel cycle center permit the assessment of the role of fuel cycle centers in enhancing safeguarding of strategic special nuclear materials -- plutonium and mixed oxides. Siting of fuel cycle centers presents a considerably smaller problem than the siting of reactors. A single reprocessing plant of the scale projected for use in the United States (1500-2000 MT/yr) can reprocess the fuel from reactors producing 50,000-65,000 MWe. Only two or three fuel cycle centers of the upper limit size considered in the NECSS-75 would be required in the United States by the year 2000 . The NECSS-75 fuel cycle center evaluations showed that large scale fuel cycle centers present no real technical difficulties in siting from a radiological effluent and safety standpoint. Some construction economies may be attainable with fuel cycle centers; such centers offer opportunities for improved waste management systems. Combined centers consisting of reactors and fuel reprocessing and mixed oxide fuel fabrication plants were also studied in the NECSS. Such centers can eliminate not only shipment of plutonium, but also mixed oxide fuel. Increased fuel cycle costs result from implementation of combined centers unless the fuel reprocessing plants are commercial-sized. Development of plutonium-burning reactors could reduce any

Fuel cycle optimization in PWR'S

International Nuclear Information System (INIS)

Castro Lobo, P.D. de; Amorim, E.S. do.

1979-08-01

Neutronics aspects of a reactor core throughout its cycle were investigated in a search for increasing in-core utilization of the residual fissile isotopes content in the cycle discharged disposal. The effects due to design modifications introduced at burnup levels near the end-of-cycle, in an equilibrium cycle condition, have indicated the possibility of a better in-core utilization of the residual fissile isotopes existing in the cycle discharged disposal. The potential benefits are significant to warranty an examination of the mechanical and thermal hydraulic involved. At convenient burnup levels, change in H 2 O/UO 2 volume ratio were introduced allowing an intense depletion of the residual fissile isotopes existing in assemblies with high exposures levels. (Author) [pt

Gender differences in recreational and transport cycling: a cross-sectional mixed-methods comparison of cycling patterns, motivators, and constraints.

Science.gov (United States)

Heesch, Kristiann C; Sahlqvist, Shannon; Garrard, Jan

2012-09-08

Gender differences in cycling are well-documented. However, most analyses of gender differences make broad comparisons, with few studies modeling male and female cycling patterns separately for recreational and transport cycling. This modeling is important, in order to improve our efforts to promote cycling to women and men in countries like Australia with low rates of transport cycling. The main aim of this study was to examine gender differences in cycling patterns and in motivators and constraints to cycling, separately for recreational and transport cycling. Adult members of a Queensland, Australia, community bicycling organization completed an online survey about their cycling patterns; cycling purposes; and personal, social and perceived environmental motivators and constraints (47% response rate). Closed and open-end questions were completed. Using the quantitative data, multivariable linear, logistic and ordinal regression models were used to examine associations between gender and cycling patterns, motivators and constraints. The qualitative data were thematically analyzed to expand upon the quantitative findings. In this sample of 1862 bicyclists, men were more likely than women to cycle for recreation and for transport, and they cycled for longer. Most transport cycling was for commuting, with men more likely than women to commute by bicycle. Men were more likely to cycle on-road, and women off-road. However, most men and women did not prefer to cycle on-road without designed bicycle lanes, and qualitative data indicated a strong preference by men and women for bicycle-only off-road paths. Both genders reported personal factors (health and enjoyment related) as motivators for cycling, although women were more likely to agree that other personal, social and environmental factors were also motivating. The main constraints for both genders and both cycling purposes were perceived environmental factors related to traffic conditions, motorist aggression and

Cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with EGR

Energy Technology Data Exchange (ETDEWEB)

Huang, Bin; Hu, Erjiang; Huang, Zuohua; Zheng, Jianjun; Liu, Bing; Jiang, Deming [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, 710049 Xi' an (China)

2009-10-15

Study of cycle-by-cycle variations in a spark ignition engine fueled with natural gas-hydrogen blends combined with exhaust gas recirculation (EGR) was conducted. The effects of EGR ratio and hydrogen fraction on engine cycle-by-cycle variations are analyzed. The results show that the cylinder peak pressure, the maximum rate of pressure rise and the indicated mean effective pressure decrease and cycle-by-cycle variations increase with the increase of EGR ratio. Interdependency between the above parameters and their corresponding crank angles of cylinder peak pressure is decreased with the increase of EGR ratio. For a given EGR ratio, combustion stability is promoted and cycle-by-cycle variations are decreased with the increase of hydrogen fraction in the fuel blends. Non-linear relationship is presented between the indicated mean effective pressure and EGR ratio. Slight influence of EGR ratio on indicated mean effective pressure is observed at low EGR ratios while large influence of EGR ratio on indicated mean effective pressure is demonstrated at high EGR ratios. The high test engine speed has lower cycle-by-cycle variations due to the enhancement of air flow turbulence and swirls in the cylinder. Increasing hydrogen fraction can maintain low cycle-by-cycle variations at high EGR ratios. (author)

Interventions to promote cycling: systematic review.

Science.gov (United States)

Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J; Ogilvie, David

2010-10-18

To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Systematic review. Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled "before and after" experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of "environmentally friendly" modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Community-wide promotional activities and improving infrastructure for cycling have the potential to increase cycling by modest amounts, but further controlled

Effect of irreversible processes on the thermodynamic performance of open-cycle desiccant cooling cycles

International Nuclear Information System (INIS)

La, Dong; Li, Yong; Dai, Yanjun; Ge, Tianshu; Wang, Ruzhu

2013-01-01

Highlights: ► Effects of irreversible processes on the performance of desiccant cooling cycle are identified. ► The exergy destructions involved are classified by the properties of the individual processes. ► Appropriate indexes for thermodynamic evaluation are proposed based on thermodynamic analyses. - Abstract: Thermodynamic analyses of desiccant cooling cycle usually focus on the overall cycle performance in previous study. In this paper, the effects of the individual irreversible processes in each component on thermodynamic performance are analyzed in detail. The objective of this paper is to reveal the elemental features of the individual components, and to show their effects on the thermodynamic performance of the whole cycle in a fundamental way. Appropriate indexes for thermodynamic evaluation are derived based on the first and second law analyses. A generalized model independent of the connection of components is developed. The results indicate that as the effectiveness of the desiccant wheel increases, the cycle performance is increased principally due to the significant reduction in exergy carried out by exhaust air. The corresponding exergy destruction coefficient of the cycle with moderate performance desiccant wheel is decreased greatly to 3.9%, which is more than 50% lower than that of the cycle with low performance desiccant wheel. The effect of the heat source is similar. As the temperature of the heat source increases from 60 °C to 90 °C, the percentage of exergy destruction raised by exhaust air increases sharply from 5.3% to 21.8%. High heat exchanger effectiveness improves the cycle performance mainly by lowering the irreversibility of the heat exchanger, using less regeneration heat and pre-cooling the process air effectively

Life Cycle Sustainability Dashboard

DEFF Research Database (Denmark)

Traverso, Marzia; Finkbeiner, Matthias; Jørgensen, Andreas

2012-01-01

One method to assess the sustainability performance of products is life cycle sustainability assessment (LCSA), which assesses product performance considering the environmental,economic, and social dimensions of the life cycle. The results of LCSA can be used to compare different products...... of sustainability is the communicability of the results by means of a graphical representation (a cartogram), characterized by a suitable chromatic scale and ranking score. The integration of LCSA and the dashboard of sustainability into a so-called Life Cycle Sustainability Dashboard (LCSD) is described here...

Assessing the impact of road traffic on cycling for leisure and cycling to work

Directory of Open Access Journals (Sweden)

Wareham Nicholas J

2011-06-01

Full Text Available Abstract Background To explore the relationship between leisure and commuter cycling with objectively measured levels of road traffic and whether any relationship was affected by traffic levels directly outside of home or in local neighbourhood. Findings We conducted a secondary analysis of data from the UK European Prospective Investigation of Cancer (EPIC Norfolk cohort in 2009. We used a geographical information system (GIS and gender specific multivariate models to relate 13 927 participants' reported levels of cycling with an index of road traffic volume (Road Traffic Volume Index Score - RTVIS. RTVIS were calculated around each participants home, using four distance based buffers, (0.5 km, 1 km, 2 km and 3.2 km. Models were adjusted for age, social status, education, car access and deprivation. Both genders had similar decreases in leisure cycling as traffic volumes increased at greater distances from home (OR 0.42, (95% CI 0.32-0.52, p Conclusions Traffic volumes appear to have greater impact on leisure cycling than commuter cycling. Future research should investigate the importance of traffic on different types of cycling and include psychosocial correlates.

Frozen-Thawed Embryo Transfer Cycles Have a Lower Incidence of Ectopic Pregnancy Compared With Fresh Embryo Transfer Cycles.

Science.gov (United States)

Zhang, Xinyu; Ma, Caihong; Wu, Zhangxin; Tao, Liyuan; Li, Rong; Liu, Ping; Qiao, Jie

2017-01-01

To evaluate the risk of ectopic pregnancy of embryo transfer. A retrospective cohort study on the incidence of ectopic pregnancy in fresh and frozen-thawed embryo transfer cycles from January 1 st , 2010, to January 1 st , 2015. Infertile women undergoing frozen-thawed transfer cycles or fresh transfer cycles. In-vitro fertilization, fresh embryo transfer, frozen-thawed embryo transfer, ectopic pregnancy. Ectopic pregnancy rate and clinical pregnancy rate. A total of 69 756 in vitro fertilization-embryo transfer cycles from 2010 to 2015 were analyzed, including 45 960 (65.9%) fresh and 23 796 (34.1%) frozen-thawed embryo transfer cycles. The clinical pregnancy rate per embryo transfer was slightly lower in fresh embryo transfer cycles compared with frozen-thawed embryo transfer cycles (40.8% vs 43.1%, P cycles, blastocyst transfer shows a significantly lower incidence of ectopic pregnancy (0.8% vs 1.8%, P = .002) in comparison with day 3 cleavage embryo transfer. The risk of ectopic pregnancy is lower in frozen-thawed embryo transfer cycles than fresh embryo transfer cycles, and blastocyst transfer could further decrease the ectopic pregnancy rate in frozen-thawed embryo transfer cycles.

Research on Correlation between Vehicle Cycle and Engine Cycle in Heavy-duty commercial vehicle

Science.gov (United States)

lin, Chen; Zhong, Wang; Shuai, Liu

2017-12-01

In order to study the correlation between vehicle cycle and engine cycle in heavy commercial vehicles, the conversion model of vehicle cycle to engine cycle is constructed based on the vehicle power system theory and shift strategy, which considers the verification on diesel truck. The results show that the model has high rationality and reliability in engine operation. In the acceleration process of high speed, the difference of model gear selection leads to the actual deviation. Compared with the drum test, the engine speed distribution obtained by the model deviates to right, which fits to the lower grade. The grade selection has high influence on the model.

Thorium fuel cycle management

International Nuclear Information System (INIS)

Zajac, R.; Darilek, P.; Breza, J.; Necas, V.

2010-01-01

In this presentation author deals with the thorium fuel cycle management. Description of the thorium fuels and thorium fuel cycle benefits and challenges as well as thorium fuel calculations performed by the computer code HELIOS are presented.

Thermodynamic Modeling for Open Combined Regenerative Brayton and Inverse Brayton Cycles with Regeneration before the Inverse Cycle

Directory of Open Access Journals (Sweden)

Lingen Chen

2012-01-01

Full Text Available A thermodynamic model of an open combined regenerative Brayton and inverse Brayton cycles with regeneration before the inverse cycle is established in this paper by using thermodynamic optimization theory. The flow processes of the working fluid with the pressure drops and the size constraint of the real power plant are modeled. There are 13 flow resistances encountered by the working fluid stream for the cycle model. Four of these, the friction through the blades and vanes of the compressors and the turbines, are related to the isentropic efficiencies. The remaining nine flow resistances are always present because of the changes in flow cross-section at the compressor inlet of the top cycle, regenerator inlet and outlet, combustion chamber inlet and outlet, turbine outlet of the top cycle, turbine outlet of the bottom cycle, heat exchanger inlet, and compressor inlet of the bottom cycle. These resistances associated with the flow through various cross-sectional areas are derived as functions of the compressor inlet relative pressure drop of the top cycle, and control the air flow rate, the net power output and the thermal efficiency. The analytical formulae about the power output, efficiency and other coefficients are derived with 13 pressure drop losses. It is found that the combined cycle with regenerator can reach higher thermal efficiency but smaller power output than those of the base combined cycle at small compressor inlet relative pressure drop of the top cycle.

Nitrogen Cycle Evaluation (NiCE) Chip for the Simultaneous Analysis of Multiple N-Cycle Associated Genes.

Science.gov (United States)

Oshiki, Mamoru; Segawa, Takahiro; Ishii, Satoshi

2018-02-02

Various microorganisms play key roles in the Nitrogen (N) cycle. Quantitative PCR (qPCR) and PCR-amplicon sequencing of the N cycle functional genes allow us to analyze the abundance and diversity of microbes responsible in the N transforming reactions in various environmental samples. However, analysis of multiple target genes can be cumbersome and expensive. PCR-independent analysis, such as metagenomics and metatranscriptomics, is useful but expensive especially when we analyze multiple samples and try to detect N cycle functional genes present at relatively low abundance. Here, we present the application of microfluidic qPCR chip technology to simultaneously quantify and prepare amplicon sequence libraries for multiple N cycle functional genes as well as taxon-specific 16S rRNA gene markers for many samples. This approach, named as N cycle evaluation (NiCE) chip, was evaluated by using DNA from pure and artificially mixed bacterial cultures and by comparing the results with those obtained by conventional qPCR and amplicon sequencing methods. Quantitative results obtained by the NiCE chip were comparable to those obtained by conventional qPCR. In addition, the NiCE chip was successfully applied to examine abundance and diversity of N cycle functional genes in wastewater samples. Although non-specific amplification was detected on the NiCE chip, this could be overcome by optimizing the primer sequences in the future. As the NiCE chip can provide high-throughput format to quantify and prepare sequence libraries for multiple N cycle functional genes, this tool should advance our ability to explore N cycling in various samples. Importance. We report a novel approach, namely Nitrogen Cycle Evaluation (NiCE) chip by using microfluidic qPCR chip technology. By sequencing the amplicons recovered from the NiCE chip, we can assess diversities of the N cycle functional genes. The NiCE chip technology is applicable to analyze the temporal dynamics of the N cycle gene

Sensitivity study on nitrogen Brayton cycle coupled with a small ultra-long cycle fast reactor

International Nuclear Information System (INIS)

Seo, Seok Bin; Seo, Han; Bang, In Cheol

2014-01-01

The main characteristics of UCFR are constant neutron flux and power density. They move their positions every moment at constant speed along with axial position of fuel rod for 60 years. Simultaneously with the development of the reactors, a new power conversion system has been considered. To solve existing issues of vigorous sodium-water reaction in SFR with steam power cycle, many researchers suggested a closed Brayton cycle as an alternative technique for SFR power conversion system. Many inactive gases are selected as a working fluid in Brayton power cycle, mainly supercritical CO 2 (S-CO 2 ). However, S-CO 2 still has potential for reaction with sodium. CO 2 -sodium reaction produces solid product, which has possibility to have an auto ignition reaction around 600 .deg. C. Thus, instead of S-CO 2 , CEA in France has developed nitrogen power cycle for ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration). In addition to inactive characteristic of nitrogen with sodium, its thermal and physical similarity with air enables to easily adopt to existing air Brayton cycle technology. In this study, for an optimized power conversion system for UCFR, a nitrogen Brayton cycle was analyzed in thermodynamic aspect. Based on subchannel analysis data of UCFR-100, a parametric study for thermal performance of nitrogen Brayton cycle was achieved. The system maximum pressure significantly affects to the overall efficiency of cycle, while other parameters show little effects. Little differences of the overall efficiencies for all cases between three stages (BOC, MOC, EOC) indicate that the power cycle of UCFR-100 maintains its performance during the operation

Multiparameter Cell Cycle Analysis.

Science.gov (United States)

Jacobberger, James W; Sramkoski, R Michael; Stefan, Tammy; Woost, Philip G

2018-01-01

Cell cycle cytometry and analysis are essential tools for studying cells of model organisms and natural populations (e.g., bone marrow). Methods have not changed much for many years. The simplest and most common protocol is DNA content analysis, which is extensively published and reviewed. The next most common protocol, 5-bromo-2-deoxyuridine S phase labeling detected by specific antibodies, is also well published and reviewed. More recently, S phase labeling using 5'-ethynyl-2'-deoxyuridine incorporation and a chemical reaction to label substituted DNA has been established as a basic, reliable protocol. Multiple antibody labeling to detect epitopes on cell cycle regulated proteins, which is what this chapter is about, is the most complex of these cytometric cell cycle assays, requiring knowledge of the chemistry of fixation, the biochemistry of antibody-antigen reactions, and spectral compensation. However, because this knowledge is relatively well presented methodologically in many papers and reviews, this chapter will present a minimal Methods section for one mammalian cell type and an extended Notes section, focusing on aspects that are problematic or not well described in the literature. Most of the presented work involves how to segment the data to produce a complete, progressive, and compartmentalized cell cycle analysis from early G1 to late mitosis (telophase). A more recent development, using fluorescent proteins fused with proteins or peptides that are degraded by ubiquitination during specific periods of the cell cycle, termed "Fucci" (fluorescent, ubiquitination-based cell cycle indicators) provide an analysis similar in concept to multiple antibody labeling, except in this case cells can be analyzed while living and transgenic organisms can be created to perform cell cycle analysis ex or in vivo (Sakaue-Sawano et al., Cell 132:487-498, 2007). This technology will not be discussed.

Evaluation method for regional water cycle health based on nature-society water cycle theory

Science.gov (United States)

Zhang, Shanghong; Fan, Weiwei; Yi, Yujun; Zhao, Yong; Liu, Jiahong

2017-08-01

Regional water cycles increasingly reflect the dual influences of natural and social processes, and are affected by global climate change and expanding human activities. Understanding how to maintain a healthy state of the water cycle has become an important proposition for sustainable development of human society. In this paper, natural-social attributes of the water cycle are synthesized and 19 evaluation indices are selected from four dimensions, i.e., water-based ecosystem integrity, water quality, water resource abundance and water resource use. A hierarchical water-cycle health evaluation system is established. An analytic hierarchy process is used to set the weight of the criteria layer and index layer, and the health threshold for each index is defined. Finally, a water-cycle health composite-index assessment model and fuzzy recognition model are constructed based on the comprehensive index method and fuzzy mathematics theory. The model is used to evaluate the state of health of the water cycle in Beijing during 2010-2014 and in the planning year (late 2014), considering the transfer of 1 billion m3 of water by the South-to-North Water Diversion Project (SNWDP). The results show health scores for Beijing of 2.87, 3.10, 3.38, 3.11 and 3.02 during 2010-2014. The results of fuzzy recognition show that the sub-healthy grade accounted for 54%, 49%, 61% and 49% of the total score, and all years had a sub-healthy state. Results of the criteria layer analysis show that water ecosystem function, water quality and water use were all at the sub-healthy level and that water abundance was at the lowest, or sick, level. With the water transfer from the SNWDP, the health score of the water cycle in Beijing reached 4.04. The healthy grade accounted for 60% of the total score, and the water cycle system was generally in a healthy state. Beijing's water cycle health level is expected to further improve with increasing water diversion from the SNWDP and industrial

Parametric Investigation and Thermoeconomic Optimization of a Combined Cycle for Recovering the Waste Heat from Nuclear Closed Brayton Cycle

Directory of Open Access Journals (Sweden)

Lihuang Luo

2016-01-01

Full Text Available A combined cycle that combines AWM cycle with a nuclear closed Brayton cycle is proposed to recover the waste heat rejected from the precooler of a nuclear closed Brayton cycle in this paper. The detailed thermodynamic and economic analyses are carried out for the combined cycle. The effects of several important parameters, such as the absorber pressure, the turbine inlet pressure, the turbine inlet temperature, the ammonia mass fraction, and the ambient temperature, are investigated. The combined cycle performance is also optimized based on a multiobjective function. Compared with the closed Brayton cycle, the optimized power output and overall efficiency of the combined cycle are higher by 2.41% and 2.43%, respectively. The optimized LEC of the combined cycle is 0.73% lower than that of the closed Brayton cycle.

Political Budget Cycles

DEFF Research Database (Denmark)

Aaskoven, Lasse; Lassen, David Dreyer

2017-01-01

The political budget cycle—how elections affect government fiscal policy—is one of the most studied subjects in political economy and political science. The key theoretical question is whether incumbent governments can time or structure public finances in ways that improve their chances of reelec......The political budget cycle—how elections affect government fiscal policy—is one of the most studied subjects in political economy and political science. The key theoretical question is whether incumbent governments can time or structure public finances in ways that improve their chances...... on political budget cycles have recently focused on conditions under which such cycles are likely to obtain. Much recent research focuses on subnational settings, allowing comparisons of governments in similar institutional environments, and a consensus on the presences of cycles in public finances...

Fuel cycle economics of HTRs

Energy Technology Data Exchange (ETDEWEB)

Hansen, U.

1975-06-15

The High Temperature Reactor commands a unique fuel cycle flexibility and alternative options are open to the utilities. The reference thorium reactor operating in the U-233 recycle mode is 10 to 20% cheaper than the low-enriched reactor; however, the thorium cycle depends on the supply of 93% enriched uranium and the availability of reprocessing and refabrication facilities to utilize its bred fissile material. The economic landscape towards the end of the 20th Century will presumably be dominated by pronounced increases in the costs of natural resources. In the case of nuclear energy, resource considerations are reflected in the price of uranium, which is expected Lo have reached 50 $/lbm U3O8 in the early 1990s and around 100 $/lbm U3O8 around 2010. In this economic environment the fuel cycle advantage of the thorium system amounts to some 20% and is capable of absorbing substantial expenses in bringing about the closing of the out-of-pile cycle. A most attractive aspect of the HTR fuel cycle flexibility is for the utility to start operating the reactor on the low enriched uranium cycle and at a later date switch over to the thorium cycle as this becomes economically more and more attractive. The incentive amounts to some 50 M$ in terms of present worth money at the time of decision making, assumed to take place 10 years after start-up. The closing of the thorium cycle is of paramount importance and a step to realize this objective lies in simplifying the head-end reprocessing technology by abandoning the segregation concept of feed and breed coated particles in the reference cycle. A one-coated-particle scheme in which all discharged uranium isotopes are recycled in mixed oxide particles is feasible and suffers a very minor economic penalty only.

Cycle bases to the rescue

Science.gov (United States)

Tóbiás, Roland; Furtenbacher, Tibor; Császár, Attila G.

2017-12-01

Cycle bases of graph theory are introduced for the analysis of transition data deposited in line-by-line rovibronic spectroscopic databases. The principal advantage of using cycle bases is that outlier transitions -almost always present in spectroscopic databases built from experimental data originating from many different sources- can be detected and identified straightforwardly and automatically. The data available for six water isotopologues, H216O, H217O, H218O, HD16O, HD17O, and HD18O, in the HITRAN2012 and GEISA2015 databases are used to demonstrate the utility of cycle-basis-based outlier-detection approaches. The spectroscopic databases appear to be sufficiently complete so that the great majority of the entries of the minimum cycle basis have the minimum possible length of four. More than 2000 transition conflicts have been identified for the isotopologue H216O in the HITRAN2012 database, the seven common conflict types are discussed. It is recommended to employ cycle bases, and especially a minimum cycle basis, for the analysis of transitions deposited in high-resolution spectroscopic databases.

Optimization of the fuel cycle

International Nuclear Information System (INIS)

Kidd, S.W.; Balu, K.; Boczar, P.G.; Krebs, W.D.

1999-01-01

The nuclear fuel cycle can be optimized subject to a wide range of criteria. Prime amongst these are economics, sustainability of resources, environmental aspects, and proliferation-resistance of the fuel cycle. Other specific national objectives will also be important. These criteria, and their relative importance, will vary from country to country, and with time. There is no single fuel cycle strategy that is optimal for all countries. Within the short term, the industry is attached to dominant thermal reactor technologies, which themselves have two main variants, a cycle closed by reprocessing of spent fuel and subsequent recycling and a once through one where spent fuel is stored in advance of geological disposal. However, even with current technologies, much can be done to optimize the fuel cycles to meet the relevant criteria. In the long term, resource sustainability can be assured for centuries through the use of fast breeder reactors, supporting high-conversion thermal reactors, possibly also utilizing the thorium cycle. These must, however, meet the other key criteria by being both economic and safe. (author)

Gender differences in recreational and transport cycling: a cross-sectional mixed-methods comparison of cycling patterns, motivators, and constraints

Directory of Open Access Journals (Sweden)

Heesch Kristiann C

2012-09-01

Full Text Available Abstract Background Gender differences in cycling are well-documented. However, most analyses of gender differences make broad comparisons, with few studies modeling male and female cycling patterns separately for recreational and transport cycling. This modeling is important, in order to improve our efforts to promote cycling to women and men in countries like Australia with low rates of transport cycling. The main aim of this study was to examine gender differences in cycling patterns and in motivators and constraints to cycling, separately for recreational and transport cycling. Methods Adult members of a Queensland, Australia, community bicycling organization completed an online survey about their cycling patterns; cycling purposes; and personal, social and perceived environmental motivators and constraints (47% response rate. Closed and open-end questions were completed. Using the quantitative data, multivariable linear, logistic and ordinal regression models were used to examine associations between gender and cycling patterns, motivators and constraints. The qualitative data were thematically analyzed to expand upon the quantitative findings. Results In this sample of 1862 bicyclists, men were more likely than women to cycle for recreation and for transport, and they cycled for longer. Most transport cycling was for commuting, with men more likely than women to commute by bicycle. Men were more likely to cycle on-road, and women off-road. However, most men and women did not prefer to cycle on-road without designed bicycle lanes, and qualitative data indicated a strong preference by men and women for bicycle-only off-road paths. Both genders reported personal factors (health and enjoyment related as motivators for cycling, although women were more likely to agree that other personal, social and environmental factors were also motivating. The main constraints for both genders and both cycling purposes were perceived environmental factors

Associations Between Selenium Content in Hair and Kashin-Beck Disease/Keshan Disease in Children in Northwestern China: a Prospective Cohort Study.

Science.gov (United States)

Liu, Huan; Yu, Fangfang; Shao, Wanzhen; Ding, Dexiu; Yu, Zhidao; Chen, Fengshi; Geng, Dong; Tan, Xiwang; Lammi, Mikko J; Guo, Xiong

2018-07-01

The objective of this study was to investigate the relationship between selenium content in hair and the incidence of Kashin-Beck disease (KBD) and Keshan disease (KD) in China. A prospective cohort study was conducted among children aged 5-12 years with different levels of low-selenium (group 1, Se ≤ 110 ng/g; group 2, 110  200 ng/g) exposure. A person-years approach was used to calculate the incidence and rate of positive clinical signs. Relative risk (RR), attributable risk, and etiologic fraction were used to determine the strength of association between selenium and disease incidence. Seven new KBD cases were diagnosed during 3-year follow-up. Positive clinical signs of KBD were found in 17.78 (95% confidence interval [CI] 14.27-21.29) cases per 100 person-years in group 1, 13.28 (9.82-16.74) in group 2, 12.95 (9.34-16.56) in group 3, and 8.18 (5.50-10.85) in group 4. Compared with group 4, the RR (95% CI) of groups 1, 2, and 3 were 2.17 (1.48-3.19), 1.62 (1.07-2.47), and 1.58 (1.03-2.43), respectively. Positive clinical signs of KD were 25.90 (18.62-33.18) cases per 100 person-years in group 1, 5.66 (1.26-10.06) in group 2, 4.60 (0.20-9.00) in group 3, and 14.62 (8.54-20.69) in group 4. Compared with group 4, the RR (95% CI) were 1.77 (1.07-2.93), 0.39 (0.16-0.93), and 0.31 (0.11-0.89), respectively. In children, the onset of KBD was negatively correlated with selenium content within a certain range. However, there may be a U-shaped association between selenium content and KD in children.

Sometimes "Newton's Method" Always "Cycles"

Science.gov (United States)

Latulippe, Joe; Switkes, Jennifer

2012-01-01

Are there functions for which Newton's method cycles for all non-trivial initial guesses? We construct and solve a differential equation whose solution is a real-valued function that two-cycles under Newton iteration. Higher-order cycles of Newton's method iterates are explored in the complex plane using complex powers of "x." We find a class of…

Accounting for the biogeochemical cycle of nitrogen in input-output life cycle assessment.

Science.gov (United States)

Singh, Shweta; Bakshi, Bhavik R

2013-08-20

Nitrogen is indispensable for sustaining human activities through its role in the production of food, animal feed, and synthetic chemicals. This has encouraged significant anthropogenic mobilization of reactive nitrogen and its emissions into the environment resulting in severe disruption of the nitrogen cycle. This paper incorporates the biogeochemical cycle of nitrogen into the 2002 input-output model of the U.S. economy. Due to the complexity of this cycle, this work proposes a unique classification of nitrogen flows to facilitate understanding of the interaction between economic activities and various flows in the nitrogen cycle. The classification scheme distinguishes between the mobilization of inert nitrogen into its reactive form, use of nitrogen in various products, and nitrogen losses to the environment. The resulting inventory and model of the US economy can help quantify the direct and indirect impacts or dependence of economic sectors on the nitrogen cycle. This paper emphasizes the need for methods to manage the N cycle that focus not just on N losses, which has been the norm until now, but also include other N flows for a more comprehensive view and balanced decisions. Insight into the N profile of various sectors of the 2002 U.S. economy is presented, and the inventory can also be used for LCA or Hybrid LCA of various products. The resulting model is incorporated in the approach of Ecologically-Based LCA and available online.

Fuel cycle modelling of open cycle thorium-fuelled nuclear energy systems

International Nuclear Information System (INIS)

Ashley, S.F.; Lindley, B.A.; Parks, G.T.; Nuttall, W.J.; Gregg, R.; Hesketh, K.W.; Kannan, U.; Krishnani, P.D.; Singh, B.; Thakur, A.; Cowper, M.; Talamo, A.

2014-01-01

Highlights: • We study three open cycle Th–U-fuelled nuclear energy systems. • Comparison of these systems is made to a reference U-fuelled EPR. • Fuel cycle modelling is performed with UK NNL code “ORION”. • U-fuelled system is economically favourable and needs least separative work per kWh. • Th–U-fuelled systems offer negligible waste and proliferation resistance advantages. - Abstract: In this study, we have sought to determine the advantages, disadvantages, and viability of open cycle thorium–uranium-fuelled (Th–U-fuelled) nuclear energy systems. This has been done by assessing three such systems, each of which requires uranium enriched to ∼20% 235 U, in comparison to a reference uranium-fuelled (U-fuelled) system over various performance indicators, spanning material flows, waste composition, economics, and proliferation resistance. The values of these indicators were determined using the UK National Nuclear Laboratory’s fuel cycle modelling code ORION. This code required the results of lattice-physics calculations to model the neutronics of each nuclear energy system, and these were obtained using various nuclear reactor physics codes and burn-up routines. In summary, all three Th–U-fuelled nuclear energy systems required more separative work capacity than the equivalent benchmark U-fuelled system, with larger levelised fuel cycle costs and larger levelised cost of electricity. Although a reduction of ∼6% in the required uranium ore per kWh was seen for one of the Th–U-fuelled systems compared to the reference U-fuelled system, the other two Th–U-fuelled systems required more uranium ore per kWh than the reference. Negligible advantages and disadvantages were observed for the amount and the properties of the spent nuclear fuel (SNF) generated by the systems considered. Two of the Th–U-fuelled systems showed some benefit in terms of proliferation resistance of the SNF generated. Overall, it appears that there is little

The life cycle of centrioles.

Science.gov (United States)

Hatch, E; Stearns, T

2010-01-01

Centrioles organize the centrosome and nucleate the ciliary axoneme, and the centriole life cycle has many parallels to the chromosome cycle. The centriole cycle in animals begins at fertilization with the contribution of two centrioles by the male gamete. In the ensuing cell cycles, the duplication of centrioles is controlled temporally, spatially, and numerically. As a consequence of the duplication mechanism, the two centrioles in a typical interphase cell are of different ages and have different functions. Here, we discuss how new centrioles are assembled, what mechanisms limit centriole number, and the consequences of the inherent asymmetry of centriole duplication and segregation.

Pseudo-simple heteroclinic cycles in R4

Science.gov (United States)

Chossat, Pascal; Lohse, Alexander; Podvigina, Olga

2018-06-01

We study pseudo-simple heteroclinic cycles for a Γ-equivariant system in R4 with finite Γ ⊂ O(4) , and their nearby dynamics. In particular, in a first step towards a full classification - analogous to that which exists already for the class of simple cycles - we identify all finite subgroups of O(4) admitting pseudo-simple cycles. To this end we introduce a constructive method to build equivariant dynamical systems possessing a robust heteroclinic cycle. Extending a previous study we also investigate the existence of periodic orbits close to a pseudo-simple cycle, which depends on the symmetry groups of equilibria in the cycle. Moreover, we identify subgroups Γ ⊂ O(4) , Γ ⊄ SO(4) , admitting fragmentarily asymptotically stable pseudo-simple heteroclinic cycles. (It has been previously shown that for Γ ⊂ SO(4) pseudo-simple cycles generically are completely unstable.) Finally, we study a generalized heteroclinic cycle, which involves a pseudo-simple cycle as a subset.

Not all counterclockwise thermodynamic cycles are refrigerators

Science.gov (United States)

Dickerson, R. H.; Mottmann, J.

2016-06-01

Clockwise cycles on PV diagrams always represent heat engines. It is therefore tempting to assume that counterclockwise cycles always represent refrigerators. This common assumption is incorrect: most counterclockwise cycles cannot be refrigerators. This surprising result is explored here for quasi-static ideal gas cycles, and the necessary conditions for refrigeration cycles are clarified. Three logically self-consistent criteria can be used to determine if a counterclockwise cycle is a refrigerator. The most fundamental test compares the counterclockwise cycle with a correctly determined corresponding Carnot cycle. Other criteria we employ include a widely accepted description of the functional behavior of refrigerators, and a corollary to the second law that limits a refrigerator's coefficient of performance.

Extended fuel cycle length

International Nuclear Information System (INIS)

Bruyere, M.; Vallee, A.; Collette, C.

1986-09-01

Extended fuel cycle length and burnup are currently offered by Framatome and Fragema in order to satisfy the needs of the utilities in terms of fuel cycle cost and of overall systems cost optimization. We intend to point out the consequences of an increased fuel cycle length and burnup on reactor safety, in order to determine whether the bounding safety analyses presented in the Safety Analysis Report are applicable and to evaluate the effect on plant licensing. This paper presents the results of this examination. The first part indicates the consequences of increased fuel cycle length and burnup on the nuclear data used in the bounding accident analyses. In the second part of this paper, the required safety reanalyses are presented and the impact on the safety margins of different fuel management strategies is examined. In addition, systems modifications which can be required are indicated

Detonation Jet Engine. Part 1--Thermodynamic Cycle

Science.gov (United States)

Bulat, Pavel V.; Volkov, Konstantin N.

2016-01-01

We present the most relevant works on jet engine design that utilize thermodynamic cycle of detonative combustion. The efficiency advantages of thermodynamic detonative combustion cycle over Humphrey combustion cycle at constant volume and Brayton combustion cycle at constant pressure were demonstrated. An ideal Ficket-Jacobs detonation cycle, and…

ITER fuel cycle

International Nuclear Information System (INIS)

Leger, D.; Dinner, P.; Yoshida, H.

1991-01-01

Resulting from the Conceptual Design Activities (1988-1990) by the parties involved in the International Thermonuclear Experimental Reactor (ITER) project, this document summarizes the design requirements and the Conceptual Design Descriptions for each of the principal subsystems and design options of the ITER Fuel Cycle conceptual design. The ITER Fuel Cycle system provides for the handling of all tritiated water and gas mixtures on ITER. The system is subdivided into subsystems for fuelling, primary (torus) vacuum pumping, fuel processing, blanket tritium recovery, and common processes (including isotopic separation, fuel management and storage, and processes for detritiation of solid, liquid, and gaseous wastes). After an introduction describing system function and conceptual design procedure, a summary of the design is presented including a discussion of scope and main parameters, and the fuel design options for fuelling, plasma chamber vacuum pumping, fuel cleanup, blanket tritium recovery, and auxiliary and common processes. Design requirements are defined and design descriptions are given for the various subsystems (fuelling, plasma vacuum pumping, fuel cleanup, blanket tritium recovery, and auxiliary/common processes). The document ends with sections on fuel cycle design integration, fuel cycle building layout, safety considerations, a summary of the research and development programme, costing, and conclusions. Refs, figs and tabs

Quantifying the Adaptive Cycle.

Directory of Open Access Journals (Sweden)

David G Angeler

Full Text Available The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011 data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

The effectiveness of community-based cycling promotion: findings from the Cycling Connecting Communities project in Sydney, Australia

Directory of Open Access Journals (Sweden)

Merom Dafna

2010-01-01

Full Text Available Abstract Background Encouraging cycling is an important way to increase physical activity in the community. The Cycling Connecting Communities (CCC Project is a community-based cycling promotion program that included a range of community engagement and social marketing activities, such as organised bike rides and events, cycling skills courses, the distribution of cycling maps of the area and coverage in the local press. The aim of the study was to assess the effectiveness of this program designed to encourage the use of newly completed off-road cycle paths through south west Sydney, Australia. Methods The evaluation used a quasi-experimental design that consisted of a pre- and post-intervention telephone survey (24 months apart of a cohort of residents (n = 909 in the intervention area (n = 520 (Fairfield and Liverpool and a socio-demographically similar comparison area (n = 389 (Bankstown. Both areas had similar bicycle infrastructure. Four bicycle counters were placed on the main bicycle paths in the intervention and comparison areas to monitor daily bicycle use before and after the intervention. Results The telephone survey results showed significantly greater awareness of the Cycling Connecting Communities project (13.5% vs 8.0%, p Conclusion Despite relatively modest resources, the Cycling Connecting Communities project achieved significant increases in bicycle path use, and increased cycling in some sub-groups. However, this community based intervention with limited funding had very limited reach into the community and did not increase population cycling levels.

The spatial dimension of cycle logistics

Directory of Open Access Journals (Sweden)

Luca Staricco

2016-08-01

Full Text Available Cycle logistics is emerging as a promising alternative in urban freight transport. Compared to fossil fuelled vans, the use of cycles for delivering goods within urban areas offers advantages in terms of environmental friendliness, economic efficiency, flexibility, and liveability of urban neighbourhood. At the same time, cycle logistics has to face limits in terms of weight and volume of goods that can be delivered, distances that can be covered, and spatial urban structures that can be served. This latter issue has till now received less attention in the scientific literature: it is generally recognized that cycle logistics performs at its best in inner urban areas, but no systematic study has been realized to identify specific spatial requisites for the effectiveness of cycle logistics. This paper provides a brief review of the main issues that emerge from the literature over cycle logistics, and contributes to stimulate the debate over the spatial dimension of cycle logistics: it presents a classification of cycle logistics schemes, on the basis of their integration with other urban logistic facilities and of the spatial structure of delivery operations. A three-level classification is proposed, depending on the type of goods consolidation: only distribution without consolidation, consolidation in a fixed urban consolidation centre, or consolidation in a mobile depot; for each level, operational examples and case studies are provided. This systematizing typology could support both public and private operators in decisions about the organization of cycle logistics facilities, such as the location of urban consolidation centres or the composition of cycle fleets.

Economic evaluation of fast reactor fuel cycling

International Nuclear Information System (INIS)

Hu Ping; Zhao Fuyu; Yan Zhou; Li Chong

2012-01-01

Economic calculation and analysis of two kinds of nuclear fuel cycle are conducted by check off method, based on the nuclear fuel cycling process and model for fast reactor power plant, and comparison is carried out for the economy of fast reactor fuel cycle and PWR once-through fuel cycle. Calculated based on the current price level, the economy of PWR one-through fuel cycle is better than that of the fast reactor fuel cycle. However, in the long term considering the rising of the natural uranium's price and the development of the post treatment technology for nuclear fuels, the cost of the fast reactor fuel cycle is expected to match or lower than that of the PWR once-through fuel cycle. (authors)

Analysis of possible fuel cycles

International Nuclear Information System (INIS)

Boehm, H.; Kessler, G.; Engelmann, P.; Maerkl, H.; Stoll, W.

1978-01-01

A brief survey is presented of the most important fuel cycles. A rough analysis of fuel cycles is attempted under the aspects of proliferation, status of technical feasibility, resource conservation and waste management and the most important criteria for such an analysis are discussed. Among the multitude of potential combinations of fuel cycles and types of reactors only a few have reached a level of technical feasibility which would make them eligible for commercial implementation within the next decade. However, if, for instance, the higher proliferation resistance of a specific fuel cycle is to be utilized to diminish the worldwide proliferation hazard, that cycle would first of all have to be introduced on an industrial scale as quickly as possible. The analysis shows that the reduction of the bazard of worldwide proliferation will continue to be the objective primarily of international agreements and measures taken in the political realm. (orig.) [de

Advanced Fuel Cycle Economic Sensitivity Analysis

Energy Technology Data Exchange (ETDEWEB)

David Shropshire; Kent Williams; J.D. Smith; Brent Boore

2006-12-01

A fuel cycle economic analysis was performed on four fuel cycles to provide a baseline for initial cost comparison using the Gen IV Economic Modeling Work Group G4 ECON spreadsheet model, Decision Programming Language software, the 2006 Advanced Fuel Cycle Cost Basis report, industry cost data, international papers, the nuclear power related cost study from MIT, Harvard, and the University of Chicago. The analysis developed and compared the fuel cycle cost component of the total cost of energy for a wide range of fuel cycles including: once through, thermal with fast recycle, continuous fast recycle, and thermal recycle.

Polity age and political budget cycles

DEFF Research Database (Denmark)

Aaskoven, Lasse

2018-01-01

Incumbent incentive for competence-signaling and lack of voter information are generally thought to be factors that increase the prevalence of political budget cycles. These mechanisms should be more prevalent in new political units. Since the creation of new political units is rarely exogenous......-experimental to study whether political budget cycles are larger in new political units. Contrary to theoretical predictions, political budget cycles seem to be of a smaller scale in the new municipalities, but only regarding budget cycles in budgetary overruns. The findings are of wider interest for discussions about...... the mechanisms behind context-conditional political budget cycles....

The thorium fuel cycle

International Nuclear Information System (INIS)

Merz, E.R.

1977-01-01

The utilization of the thorium fuel cycle has long since been considered attractive owing to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Rapidly increasing uranium prices, public reluctance for widespread Pu recycling and expected delays for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, problems associated with reprocessing and waste handling, particularly with re-fabrication by remote handling of 233 U, are certainly not appreciably more difficult than for Pu recycling. To divert from uranium as a nuclear energy source it seems worth while intensifying future efforts for closing the Th/ 233 U fuel cycle. HTGRs are particularly promising for economic application. However, further research and development activities should not concentrate on this reactor type alone. Light- and heavy-water-moderated reactors, and even future fast breeders, may just as well take advantage of a demonstrated thorium fuel cycle. (author)

Understanding Solar Cycle Variability

Energy Technology Data Exchange (ETDEWEB)

Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

2017-07-10

The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

Out-of-core nuclear fuel cycle economic optimization for nonequilibrium cycles

International Nuclear Information System (INIS)

Comes, S.A.

1987-01-01

A methodology and associated computer code was developed to determine near-optimum out-of-core fuel management strategies. The code, named OCEON (Out-of-Core Economic OptimizationN), identified feed-region sizes and enrichments, and partially burned fuel-reload strategies for each cycle of a multi-cycle planning horizon, subject to cycle-energy requirements and constraints on feed enrichments, discharge burnups, and the moderator temperature coefficient. A zero-dimensional reactor physics model, enhanced by a linear reactivity model to provide batch power shares, performs the initial feed enrichment, burnup and constraint evaluations, while a two-dimensional, nodal code is used to refine the calculations for the final solutions. The economic calculations are performed rapidly using an annuity-factor-based model. Use of Monte Carlo integer programming to select the optimum solutions allows for the determination of a family of near-optimum solutions, from which engineering judgment may be used to select an appropriate strategy. Results from various nonequilibrium cycle energy requirement cases typically show a large number of low-cost solutions near the optimum. This confirms that the Monte Carlo integer programming approach of generating a family of solutions will be most useful for selecting optimum strategies when other considerations, such as incore loading pattern concerns, must be addressed

Parametric-based thermodynamic analysis of organic Rankine cycle as bottoming cycle for combined-cycle power plant

International Nuclear Information System (INIS)

Qureshi, S.; Memon, A.G.; Abbasi, A.F.

2017-01-01

In Pakistan, the thermal efficiency of the power plants is low because of a huge share of fuel energy is dumped into the atmosphere as waste heat. The ORC (Organic Rankine Cycle) has been revealed as one of the promising technologies to recover waste heat to enhance the thermal efficiency of the power plant. In current work, ORC is proposed as a second bottoming cycle for existing CCPP (Combined Cycle Power Plant). In order to assess the efficiency of the plant, a thermodynamic model is developed in the ESS (Engineering Equation Solver) software. The developed model is used for parametric analysis to assess the effects of various operating parameters on the system performance. The analysis of results shows that the integration of ORC system with existing CCPP system enhances the overall power output in the range of 150.5-154.58 MW with 0.24-5% enhancement in the efficiency depending on the operating conditions. During the parametric analysis of ORC, it is observed that inlet pressure of the turbine shows a significant effect on the performance of the system as compared to other operating parameters. (author)

BUSINESS CYCLES, ELECTORAL CYCLES. TOWARD A THEORETICAL FRAME OF INTERACTION

Directory of Open Access Journals (Sweden)

BOGDAN-LUCIAN DOSPINESCU

2015-06-01

Full Text Available The idea of cyclical movement of a system: be it political, economic, institutional, is one of the constants of critical thinking. In this sense, there is a natural cyclic movement that cannot be avoided (only amplified or diminished and is connected with the nature of these systems. The economy follows a cyclical movement; a period of growth follows a period of decline, and so on. So does popularity for political parties or leaders. In this paper, I explore the links between the business cycles and electoral cycles. For this purpose, I introduce the concept of electoral perception cycles. My hypothesis is that popularity of political parties and leaders follow a cyclical evolution, both on short and long term. I show how perception cycles can impact the “political business cycle theory”. There is great interest in political science literature for the factors that influence the fluctuations in Presidents’ popularity, especially from United States. However, very little has been said about Romania’s case. I investigate the hypothesis of electoral perception cycles looking at the popularity of former president Traian Basescu, over his two terms. The variable used to measure popularity is favorability, measured in national surveys, done face to face, on representative samplez, of around 1000 subjects. I’ve correlated the fluctuations in favorability over time, with key public events or political decisions taken by Traian Băsescu. The main findings are as follows. Firstly, there are significant short term fluctuations (short term perception cycles and they are correlated with major events on the agenda. I would point the following key moments: 1. The referendum for dismissal of the President in May 2007 – Traian Băsescu’s favorability increased by 7 percentage points; 2. The referendum for unicameral Parliament with 300 MPs in the fall of 2009. Coupled with victory in the presidential election, it lead to an increase of 10 percentage

Gender differences in recreational and transport cycling: a cross-sectional mixed-methods comparison of cycling patterns, motivators, and constraints

OpenAIRE

Heesch, Kristiann C; Sahlqvist, Shannon; Garrard, Jan

2012-01-01

Abstract Background Gender differences in cycling are well-documented. However, most analyses of gender differences make broad comparisons, with few studies modeling male and female cycling patterns separately for recreational and transport cycling. This modeling is important, in order to improve our efforts to promote cycling to women and men in countries like Australia with low rates of transport cycling. The main aim of this study was to examine gender differences in cycling patterns and i...

IFR fuel cycle demonstration in the EBR-II Fuel Cycle Facility

International Nuclear Information System (INIS)

Lineberry, M.J.; Phipps, R.D.; Rigg, R.H.; Benedict, R.W.; Carnes, M.D.; Herceg, J.E.; Holtz, R.E.

1991-01-01

The next major milestone of the IFR (Integral Fast Reactor) program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase which includes completion of facility modifications, and installation and cold checkout of process equipment. This paper reviews the design and construction of the facility, the design and fabrication of the process equipment, and the schedule and initial plan for its operation. (author)

IFR fuel cycle demonstration in the EBR-II Fuel Cycle Facility

International Nuclear Information System (INIS)

Lineberry, M.J.; Phipps, R.D.; Rigg, R.H.; Benedict, R.W.; Carnes, M.D.; Herceg, J.E.; Holtz, R.E.

1991-01-01

The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase which includes completion of facility modifications, and installation and cold checkout of process equipment. This paper reviews the design and construction of the facility, the design and fabrication of the process equipment, and the schedule and initial plan for its operation. 5 refs., 4 figs

IFR fuel cycle

International Nuclear Information System (INIS)

Battles, J.E.; Miller, W.E.; Lineberry, M.J.; Phipps, R.D.

1992-01-01

The next major milestone of the IFR program is engineering-scale demonstration of the pyroprocess fuel cycle. The EBR-II Fuel Cycle Facility has just entered a startup phase, which includes completion of facility modifications and installation and cold checkout of process equipment. This paper reviews the development of the electrorefining pyroprocess, the design and construction of the facility for the hot demonstration, the design and fabrication of the equipment, and the schedule and initial plan for its operation

Life Cycle Impact Assessment

DEFF Research Database (Denmark)

Rosenbaum, Ralph K.; Hauschild, Michael Zwicky; Boulay, Anne-Marie

2018-01-01

This chapter is dedicated to the third phase of an LCA study, the Life Cycle Impact Assessment (LCIA) where the life cycle inventory’s information on elementary flows is translated into environmental impact scores. In contrast to the three other LCA phases, LCIA is in practice largely automated...

Management Cycle: from Planning to Evaluation

OpenAIRE

Kova?i?, Luka; Jakši?, Želimir

2008-01-01

The planning process in health care known as management cycle or cycle of organization and management is described. The cycle is divided in four main elements: planning, organization, implementation and evaluation. Each element is defined and described.

Cycling environmental perception in Beijing – A study of residents' attitudes towards future cycling and car purchasing

DEFF Research Database (Denmark)

Zhao, Chunli; Nielsen, Thomas Alexander Sick; Olafsson, Anton Stahl

2018-01-01

distances up to 2 km are positively linked to future cycling prospects. Non-car owners' attitude to future car ownership is strongly linked to socio-demographic status - low education and low income level groups seems to be most unlikely to take up driving in the future. To encourage people to cycle more...... and drive less, policy should direct efforts to promoting the clarity of cycling space on the street and strengthen pro-cycling policies. Attention should also be given to stabilizing the current travel modes of non-car users, including promoting the image of cycling, improving the service of walking...

The thorium fuel cycle

International Nuclear Information System (INIS)

Merz, E.R.

1977-01-01

The utilization of the thorium fuel cycle has long since been considered attractive due to the excellent neutronic characteristics of 233 U, and the widespread and cheap thorium resources. Although the uranium ore as well as the separative work requirements are usually lower for any thorium-based fuel cycle in comparison to present uranium-plutonium fuel cycles of thermal water reactors, interest by nuclear industry has hitherto been marginal. Fast increasing uranium prices, public reluctance against widespread Pu-recycling and expected retardations for the market penetration of fast breeders have led to a reconsideration of the thorium fuel cycle merits. In addition, it could be learned in the meantime that problems associated with reprocessing and waste handling, but particularly with a remote refabrication of 233 U are certainly not appreciably more difficult than for Pu-recycling. This may not only be due to psychological constraints but be based upon technological as well as economical facts, which have been mostly neglected up till now. In order to diversify from uranium as a nuclear energy source it seems to be worthwhile to greatly intensify efforts in the future for closing the Th/ 233 U fuel cycle. HTGR's are particularly promising for economic application. However, further R and D activites should not be solely focussed on this reactor type alone. Light and heavy-water moderated reactors, as well as even fast breeders later on, may just as well take advantage of a demonstrated thorium fuel cycle. A summary is presented of the state-of-the-art of Th/ 233 U-recycling technology and the efforts still necessary to demonstrate this technology all the way through to its industrial application

Advanced fuel cycles in CANDU reactors

International Nuclear Information System (INIS)

Green, R.E.; Boczar, P.G.

1990-04-01

This paper re-examines the rationale for advanced nuclear fuel cycles in general, and for CANDU advanced fuel cycles in particular. The traditional resource-related arguments for more uranium nuclear fuel cycles are currently clouded by record-low prices for uranium. However, the total known conventional uranium resources can support projected uranium requirements for only another 50 years or so, less if a major revival of the nuclear option occurs as part of the solution to the world's environmental problems. While the extent of the uranium resource in the earth's crust and oceans is very large, uncertainty in the availability and price of uranium is the prime resource-related motivation for advanced fuel cycles. There are other important reasons for pursuing advanced fuel cycles. The three R's of the environmental movement, reduce, recycle, reuse, can be achieved in nuclear energy production through the employment of advanced fuel cycles. The adoption of more uranium-conserving fuel cycles would reduce the amount of uranium which needs to be mined, and the environmental impact of that mining. Environmental concerns over the back end of the fuel cycle can be mitigated as well. Higher fuel burnup reduces the volume of spent fuels which needs to be disposed of. The transmutation of actinides and long-lived fission products into short-lived fission products would reduce the radiological hazard of the waste from thousands to hundreds of years. Recycling of uranium and/or plutonium in spent fuel reuses valuable fissile material, leaving only true waste to be disposed of. Advanced fuel cycles have an economical benefit as well, enabling a ceiling to be put on fuel cycle costs, which are

Life-cycle assessment of semiconductors

CERN Document Server

Boyd, Sarah B

2012-01-01

Life-Cycle Assessment of Semiconductors presents the first and thus far only available transparent and complete life cycle assessment of semiconductor devices. A lack of reliable semiconductor LCA data has been a major challenge to evaluation of the potential environmental benefits of information technologies (IT). The analysis and results presented in this book will allow a higher degree of confidence and certainty in decisions concerning the use of IT in efforts to reduce climate change and other environmental effects. Coverage includes but is not limited to semiconductor manufacturing trends by product type and geography, unique coverage of life-cycle assessment, with a focus on uncertainty and sensitivity analysis of energy and global warming missions for CMOS logic devices, life cycle assessment of flash memory and life cycle assessment of DRAM. The information and conclusions discussed here will be highly relevant and useful to individuals and institutions. The book also: Provides a detailed, complete a...

Comparative analysis of thermodynamic performance and optimization of organic flash cycle (OFC) and organic Rankine cycle (ORC)

International Nuclear Information System (INIS)

Lee, Ho Yong; Park, Sang Hee; Kim, Kyoung Hoon

2016-01-01

A comparative thermodynamic performance and optimization analysis of basic organic flash cycle (OFCB), organic flash cycle with two-phase expander (OFCT), and organic Rankine cycle (ORC) activated by low-temperature sensible energy is carried out in the subcritical pressure regions. The three substances of R245fa, R123, and o-xylene are considered as the working fluids. Effects of cycle type, working fluid, and evaporation and source temperatures are systemically investigated on the system performance such as net power production, thermal and exergy efficiencies, and exergy destruction ratios at each component of the systems. Results show that the cycle type or working fluid which shows optimum performance depends on the source temperature, and organic flash cycle shows a potential for efficient recovery of low grade energy source.

Practical introduction of thorium fuel cycles

International Nuclear Information System (INIS)

Kasten, P.R.

1982-01-01

The pracitcal introduction of throrium fuel cycles implies that thorium fuel cycles compete economically with uranium fuel cycles in economic nuclear power plants. In this study the reactor types under consideration are light water reactors (LWRs), heavy water reactors (HWRs), high-temperature gas-cooled reactors (HTGRs), and fast breeder reactors (FBRs). On the basis that once-through fuel cycles will be used almost exclusively for the next 20 or 25 years, introduction of economic thorium fuel cycles appears best accomplished by commercial introduction of HTGRs. As the price of natural uranium increases, along with commercialization of fuel recycle, there will be increasing incentive to utilize thorium fuel cycles in heavy water reactors and light water reactors as well as in HTGRs. After FBRs and fuel recycle are commercialized, use of thorium fuel cycles in the blanket of FBRs appears advantageous when fast breeder reactors and thermal reactors operate in a symbiosis mode (i.e., where 233 U bred in the blanket of a fast breeder reactor is utilized as fissile fuel in thermal converter reactors)

Thermal cycling in multifilamentary superconducting composites

International Nuclear Information System (INIS)

Aragao, E.E.A. de.

1984-01-01

NbTi-Cu multifilamentary superconducting composites were embedded, polished, characterized by microscopic techniques, and analyzed in a qualitative and semiquantitative way by energy dispersion technique. The superconductors were submitted to thermal cycling between the ambient temperature and the boiling point of helium (4.2K), for different number of cycles. The aims were to study the correlation between the possible microstructural damages due to thermal stresses arising in the composite during cycling and the variation of properties of the material with the number of cycles as well as to verify the validity of an elastic model for thermal stresses for low temperature cycles. (author)

Understanding the petrochemical cycle: Part 1

International Nuclear Information System (INIS)

Sedriks, W.

1994-01-01

Fitness in the hydrocarbon processing industry (HPI) arena involves understanding and coping with business cycles: supply and demand. This becomes increasingly more important as the industry globalizes and matures. Competitive-edge thinking needs to look hard at the forces that influence business cycles. Recognition of potential pitfalls is very important when considering: future capacity expansion, mergers and acquisitions, market departure, plant closure, potential product substitution, etc. Understanding pricing mechanisms and the workings of hockey-stick profitability profiles help HPI operators endure cycle downturns and prepare plants to maximize profits for the next upswing. The paper discusses characteristic trends, cycles in the hydrocarbon processing industry, current conditions, and mitigating cycle effects

Life cycle management (LCM)

DEFF Research Database (Denmark)

Remmen, Arne; Thrane, Mikkel

2004-01-01

The chapter gives an introduction to Life Cycle Management (LCM) and shows how LCM can be practiced in different contexts and at different ambition levels.......The chapter gives an introduction to Life Cycle Management (LCM) and shows how LCM can be practiced in different contexts and at different ambition levels....

Kriisi fataalne oht / Ulrich Beck

Index Scriptorium Estoniae

Beck, Ulrich

2009-01-01

Sotsioloogi arvates peitub praeguses majanduskriisis võimalus tuua Euroopa Liit uutele alustele, võttes aluseks printsiibi, et poliitika on rahvuslikul tasemel seda edukam, mida euroopalikum, kosmopoliitlikum ta on

En kommentar til Becks model

DEFF Research Database (Denmark)

Philipps, Morten; Andersen, Thomas Dyreborg

2014-01-01

Flipped classroom – en trend vi må forholde os til Online læringsressourcer har de sidste par år fået mange til at indse at teknologien har noget radikalt andet at byde på, og dette har skabt en populær didaktik kaldet flipped classroom som vi både ser vinde indpas i folkeskolen og på...... Professionshøjskolen Metropol hvor vi er ansat. Kommentaren her retter sig mod en tidligere bragt artikel i MONA, “Det virtuelle læringsrums topologi” af Claus Jessen. Vi argumenterer for at den didaktiske model flipped classrooms brug af video, frem for tavleundervisning, kan frigøre undervisningstid til at arbejde...

The NEWS Water Cycle Climatology

Science.gov (United States)

Rodell, M.; Beaudoing, H. K.; L'Ecuyer, T.; Olson, W. S.

2012-12-01

NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the first phase of the NEWS Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project was a multi-institutional collaboration with more than 20 active contributors. This presentation will describe the results of the water cycle component of the first phase of the project, which include seasonal (monthly) climatologies of water fluxes over land, ocean, and atmosphere at continental and ocean basin scales. The requirement of closure of the water budget (i.e., mass conservation) at various scales was exploited to constrain the flux estimates via an optimization approach that will also be described. Further, error assessments were included with the input datasets, and we examine these in relation to inferred uncertainty in the optimized flux estimates in order to gauge our current ability to close the water budget within an expected uncertainty range.

The NEWS Water Cycle Climatology

Science.gov (United States)

Rodell, Matthew; Beaudoing, Hiroko Kato; L'Ecuyer, Tristan; William, Olson

2012-01-01

NASA's Energy and Water Cycle Study (NEWS) program fosters collaborative research towards improved quantification and prediction of water and energy cycle consequences of climate change. In order to measure change, it is first necessary to describe current conditions. The goal of the first phase of the NEWS Water and Energy Cycle Climatology project was to develop "state of the global water cycle" and "state of the global energy cycle" assessments based on data from modern ground and space based observing systems and data integrating models. The project was a multi-institutional collaboration with more than 20 active contributors. This presentation will describe the results of the water cycle component of the first phase of the project, which include seasonal (monthly) climatologies of water fluxes over land, ocean, and atmosphere at continental and ocean basin scales. The requirement of closure of the water budget (i.e., mass conservation) at various scales was exploited to constrain the flux estimates via an optimization approach that will also be described. Further, error assessments were included with the input datasets, and we examine these in relation to inferred uncertainty in the optimized flux estimates in order to gauge our current ability to close the water budget within an expected uncertainty range.

Energy and exergy analysis of a closed Brayton cycle-based combined cycle for solar power tower plants

International Nuclear Information System (INIS)

Zare, V.; Hasanzadeh, M.

2016-01-01

Highlights: • A novel combined cycle is proposed for solar power tower plants. • The effects of solar subsystem and power cycle parameters are examined. • The proposed combined cycle yields exergy efficiencies of higher than 70%. • For the overall power plant exergy efficiencies of higher than 30% is achievable. - Abstract: Concentrating Solar Power (CSP) technology offers an interesting potential for future power generation and research on CSP systems of all types, particularly those with central receiver system (CRS) has been attracting a lot of attention recently. Today, these power plants cannot compete with the conventional power generation systems in terms of Levelized Cost of Electricity (LCOE) and if a competitive LCOE is to be reached, employing an efficient thermodynamic power cycle is deemed essential. In the present work, a novel combined cycle is proposed for power generation from solar power towers. The proposed system consists of a closed Brayton cycle, which uses helium as the working fluid, and two organic Rankine cycles which are employed to recover the waste heat of the Brayton cycle. The system is thermodynamically assessed from both the first and second law viewpoints. A parametric study is conducted to examine the effects of key operating parameters (including solar subsystem and power cycle parameters) on the overall power plant performance. The results indicate that exergy efficiencies of higher than 30% are achieved for the overall power plant. Also, according to the results, the power cycle proposed in this work has a better performance than the other investigated Rankine and supercritical CO_2 systems operating under similar conditions, for these types of solar power plants.

Automatic control of clock duty cycle

Science.gov (United States)

Feng, Xiaoxin (Inventor); Roper, Weston (Inventor); Seefeldt, James D. (Inventor)

2010-01-01

In general, this disclosure is directed to a duty cycle correction (DCC) circuit that adjusts a falling edge of a clock signal to achieve a desired duty cycle. In some examples, the DCC circuit may generate a pulse in response to a falling edge of an input clock signal, delay the pulse based on a control voltage, adjust the falling edge of the input clock signal based on the delayed pulse to produce an output clock signal, and adjust the control voltage based on the difference between a duty cycle of the output clock signal and a desired duty cycle. Since the DCC circuit adjusts the falling edge of the clock cycle to achieve a desired duty cycle, the DCC may be incorporated into existing PLL control loops that adjust the rising edge of a clock signal without interfering with the operation of such PLL control loops.

Multidimensional evaluation on FR cycle systems

International Nuclear Information System (INIS)

Nakai, Ryodai; Fujii, Sumio; Takakuma, Katsuyuki; Katoh, Atsushi; Ono, Kiyoshi; Ohtaki, Akira; Shiotani, Hiroki

2004-01-01

This report explains some results of the multidimensional evaluation on various fast reactor cycle system concepts from an interim report of the 2nd phase of ''Feasibility Study on Commercialized FR Cycle System''. This method is designed to give more objective and more quantitative evaluations to clarify commercialized system candidate concepts. Here we brief current evaluation method from the five viewpoints of safety, economy, environment, resource and non-proliferation, with some trial evaluation results for some cycles consist of promising technologies in reactor, core and fuel, reprocessing and fuel manufacture. Moreover, we describe FR cycle deployment scenarios which describe advantages and disadvantages of the cycles from the viewpoints of uranium resource and radioactive waste based on long-term nuclear material mass flow analyses and advantages of the deployment of FR cycle itself from the viewpoints of the comparison with alternative power supplies as well as cost and benefit. (author)

IAEA activities on nuclear fuel cycle 1997

Energy Technology Data Exchange (ETDEWEB)

Oi, N [International Atomic Energy Agency, Vienna (Austria). Nuclear Fuel Cycle and Materials Section

1997-12-01

The presentation discussing the IAEA activities on nuclear fuel cycle reviews the following issues: organizational charts of IAEA, division of nuclear power and the fuel cycle, nuclear fuel cycle and materials section; 1997 budget estimates; budget trends; the nuclear fuel cycle programme.

IAEA activities on nuclear fuel cycle 1997

International Nuclear Information System (INIS)

Oi, N.

1997-01-01

The presentation discussing the IAEA activities on nuclear fuel cycle reviews the following issues: organizational charts of IAEA, division of nuclear power and the fuel cycle, nuclear fuel cycle and materials section; 1997 budget estimates; budget trends; the nuclear fuel cycle programme

Fuel cycle related parametric study considering long lived actinide production, decay heat and fuel cycle performances

International Nuclear Information System (INIS)

Raepsaet, X.; Damian, F.; Lenain, R.; Lecomte, M.

2001-01-01

One of the very attractive HTGR reactor characteristics is its highly versatile and flexible core that can fulfil a wide range of diverse fuel cycles. Based on a GTMHR-600 MWth reactor, analyses of several fuel cycles were carried out without taking into account common fuel particle performance limits (burnup, fast fluence, temperature). These values are, however, indicated in each case. Fuel derived from uranium, thorium and a wide variety of plutonium grades has been considered. Long-lived actinide production and total residual decay heat were evaluated for the various types of fuel. The results presented in this papers provide a comparison of the potential and limits of each fuel cycle and allow to define specific cycles offering lowest actinide production and residual heat associated with a long life cycle. (author)

CO2 cycle

Science.gov (United States)

Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.

2017-01-01

This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

International Business Cycle

Directory of Open Access Journals (Sweden)

Marek Lubiński

2007-04-01

Full Text Available Prime stylized facts of international business cycle theory refer to positive correlation in the cyclical components of important macroeconomic variables across countries. However a number of indicators of business cycle synchronization do not point to clear trends. It can be ascribed to the fact that different forces influence level of business cycle correlation. When investigating into the forces behind the commonness in aggregate fluctuations economic research seems to have pointed in two directions. One strand of the literature examines the idea of common exogenous shocks that affect economies simultaneously. In addition to that economic interdependencies such as trade in goods and services or capital account transactions may serve as the channels through which disturbances spill over across countries.The observed degree of output co movement reflects both the nature of the shocks that have occurred and the degree of economic interdependence. In the periods when common shocks prevail level of synchronization is usually higher than in times of transmission dominance.

Fast Cycled Superconducting Magnet - Connecting hydraulically the Fast Cycled magnet to the cryogenic feed box.

CERN Multimedia

Maximilien Brice

2012-01-01

Photo 1 : Connecting hydraulically the Fast Cycled magnet to the cryogenic feed box. Patrck Viret and Guy Deferne technicians of TE-MSC-TF in SM18. - Photo 2 : Installation of the Fast Cycled Superconducting Magnet (FCM) to the new cold feed box in Sm18. - Photo 3 : Connecting the powering cables of the FCM to the feed box. - Photo 5/6 : The connections of the Fast Cycled Magnet. Intermediate pieces. - Photo 7 : Hydraulic connections of the Fast Cycle Magnet cable to allow the cooling of the magnet’s conductor ( Cable in conduit type) with supercritical helium. - Photo 8 : Verification of the connection: design versus reality. Guy Deferne and Frederick Rougemont, technicians of TE-MSC-TE in SM18.

[Physiological differences between cycling and running].

Science.gov (United States)

Millet, Grégoire

2009-08-05

This review compares the differences in systemic responses (VO2max, anaerobic threshold, heart rate and economy) and in underlying mechanisms of adaptation (ventilatory and hemodynamic and neuromuscular responses) between cycling and running. VO2max is specific to the exercise modality. Overall, there is more physiological training transfer from running to cycling than vice-versa. Several other physiological differences between cycling and running are discussed: HR is different between the two activities both for maximal and sub-maximal intensities. The delta efficiency is higher in running. Ventilation is more impaired in cycling than running due to mechanical constraints. Central fatigue and decrease in maximal strength are more important after prolonged exercise in running than in cycling.

Metabolic Interaction between Urea Cycle and Citric Acid Cycle Shunt: A Guided Approach

Science.gov (United States)

Pesi, Rossana; Balestri, Francesco; Ipata, Piero L.

2018-01-01

This article is a guided pedagogical approach, devoted to postgraduate students specializing in biochemistry, aimed at presenting all single reactions and overall equations leading to the metabolic interaction between ureagenesis and citric acid cycle to be incorporated into a two-three lecture series about the interaction of urea cycle with other…

On Acyclicity of Games with Cycles

DEFF Research Database (Denmark)

Andersson, Daniel; Gurvich, Vladimir; Hansen, Thomas Dueholm

2009-01-01

We study restricted improvement cycles (ri-cycles) in finite positional n-person games with perfect information modeled by directed graphs (digraphs) that may contain cycles. We obtain criteria of restricted improvement acyclicity (ri-acyclicity) in two cases: for n = 2 and for acyclic digraphs. We...

New insight into regenerated air heat pump cycle

International Nuclear Information System (INIS)

Zhang, Chun-Lu; Yuan, Han; Cao, Xiang

2015-01-01

Regenerated air (reverse Brayton) cycle has unique potentials in heat pump applications compared to conventional vapor-compression cycles. To better understand the regenerated air heat pump cycle characteristics, a thermodynamic model with new equivalent parameters was developed in this paper. Equivalent temperature ratio and equivalent isentropic efficiency of expander were introduced to represent the effect of regenerator, which made the regenerated air cycle in the same mathematical expressions as the basic air cycle and created an easy way to prove some important features that regenerated air cycle inherits from the basic one. Moreover, we proved in theory that the regenerator does not always improve the air cycle efficiency. Larger temperature ratio and lower effectiveness of regenerator could make the regenerated air cycle even worse than the basic air cycle. Lastly, we found that only under certain conditions the cycle could get remarkable benefits from a well-sized regenerator. These results would enable further study of the regenerated air cycle from a different perspective. - Highlights: • A thermodynamic model for regenerated air heat pump cycle was developed. • Equivalent temperature ratio and equivalent expander efficiency were introduced. • We proved regenerated air cycle can make heating capacity in line with heating load. • We proved the regenerator does not always improve the air cycle efficiency.

Fuel cycle oriented approach

International Nuclear Information System (INIS)

Petit, A.

1987-01-01

The term fuel cycle oriented approach is currently used to designate two quite different things: the attempt to consider all or part of a national fuel cycle as one material balance area (MBA) or to consider individual MBAs existing in a state while designing a unique safeguards approach for each and applying the principle of nondiscrimination to fuel cycles as a whole, rather than to individual facilities. The merits of such an approach are acceptability by the industry and comparison with the contemplated establishment of long-term criteria. The following points concern the acceptability by the industry: (1) The main interest of the industry is to keep an open international market and therefore, to have effective and efficient safeguards. (2) The main concerns of the industry regarding international safeguards are economic burden, intrusiveness, and discrimination. Answers to these legitimate concerns, which retain the benefits of a fuel cycle oriented approach, are needed. More specifically, the problem of reimbursing the operator the costs that he has incurred for the safeguards must be considered

Empirical solar/stellar cycle simulations

Directory of Open Access Journals (Sweden)

Santos Ângela R. G.

2015-01-01

Full Text Available As a result of the magnetic cycle, the properties of the solar oscillations vary periodically. With the recent discovery of manifestations of activity cycles in the seismic data of other stars, the understanding of the different contributions to such variations becomes even more important. With this in mind, we built an empirical parameterised model able to reproduce the properties of the sunspot cycle. The resulting simulations can be used to estimate the magnetic-induced frequency shifts.

The nuclear fuel cycle

International Nuclear Information System (INIS)

Jones, P.M.S.

1987-01-01

This chapter explains the distinction between fissile and fertile materials, examines briefly the processes involved in fuel manufacture and management, describes the alternative nuclear fuel cycles and considers their advantages and disadvantages. Fuel management is usually divided into three stages; the front end stage of production and fabrication, the back end stage which deals with the fuel after it is removed from the reactor (including reprocessing and waste treatment) and the stage in between when the fuel is actually in the reactor. These stages are illustrated and explained in detail. The plutonium fuel cycle and thorium-uranium-233 fuel cycle are explained. The differences between fuels for thermal reactors and fast reactors are explained. (U.K.)

Dynamic Simulations of Advanced Fuel Cycles

International Nuclear Information System (INIS)

Piet, Steven J.; Dixon, Brent W.; Jacobson, Jacob J.; Matthern, Gretchen E.; Shropshire, David E.

2011-01-01

Years of performing dynamic simulations of advanced nuclear fuel cycle options provide insights into how they could work and how one might transition from the current once-through fuel cycle. This paper summarizes those insights from the context of the 2005 objectives and goals of the U.S. Advanced Fuel Cycle Initiative (AFCI). Our intent is not to compare options, assess options versus those objectives and goals, nor recommend changes to those objectives and goals. Rather, we organize what we have learned from dynamic simulations in the context of the AFCI objectives for waste management, proliferation resistance, uranium utilization, and economics. Thus, we do not merely describe 'lessons learned' from dynamic simulations but attempt to answer the 'so what' question by using this context. The analyses have been performed using the Verifiable Fuel Cycle Simulation of Nuclear Fuel Cycle Dynamics (VISION). We observe that the 2005 objectives and goals do not address many of the inherently dynamic discriminators among advanced fuel cycle options and transitions thereof.

The status of nuclear fuel cycle system analysis for the development of advanced nuclear fuel cycles

Energy Technology Data Exchange (ETDEWEB)

Ko, Won Il; Kim, Seong Ki; Lee, Hyo Jik; Chang, Hong Rae; Kwon, Eun Ha; Lee, Yoon Hee; Gao, Fanxing [KAERI, Daejeon (Korea, Republic of)

2011-11-15

The system analysis has been used with different system and objectives in various fields. In the nuclear field, the system can be applied from uranium mining to spent fuel reprocessing or disposal which is called the nuclear fuel cycle. The analysis of nuclear fuel cycle can be guideline for development of advanced fuel cycle through integrating and evaluating the technologies. For this purpose, objective approach is essential and modeling and simulation can be useful. In this report, several methods which can be applicable for development of advanced nuclear fuel cycle, such as TRL, simulation and trade analysis were explained with case study

Answering Key Fuel Cycle Questions

International Nuclear Information System (INIS)

Piet, S.J.; Dixon, B.W.; Bennett, R.G.; Smith, J.D.; Hill, R.N.

2004-01-01

Given the range of fuel cycle goals and criteria, and the wide range of fuel cycle options, how can the set of options eventually be narrowed in a transparent and justifiable fashion? It is impractical to develop all options. We suggest an approach that starts by considering a range of goals for the Advanced Fuel Cycle Initiative (AFCI) and then posits seven questions, such as whether Cs and Sr isotopes should be separated from spent fuel and, if so, what should be done with them. For each question, we consider which of the goals may be relevant to eventually providing answers. The AFCI program has both ''outcome'' and ''process'' goals because it must address both waste already accumulating as well as completing the fuel cycle in connection with advanced nuclear power plant concepts. The outcome objectives are waste geologic repository capacity and cost, energy security and sustainability, proliferation resistance, fuel cycle economics, and safety. The process objectives are rea diness to proceed and adaptability and robustness in the face of uncertainties

Primary water chemistry optimization for extended fuel cycle operation. Results of the 'Duo experimentation' after three cycles

International Nuclear Information System (INIS)

Viricel, L.; Andrieu, C.; Segura, J.C.; Rocher, A.; Thomazet, J.; Clinard, M.H.; Dacquait, F.

2002-01-01

The primary coolant conditioning in French nuclear power plants is essentially based on the boron-lithium coordinated chemistry, with a target pH of 7.2 at 300 C and a maximum lithium concentration of 2.2 mg/kg. In 1996, EDF 1300 MWe units began operating 18-month fuel cycles, increasing boron concentrations at the beginning of the cycles. Since today the maximum lithium concentration in normal operation is 2.2 mg/kg, extended cycle operation results in a decrease in the pH at the beginning of the cycles, which may possibly lead to deposits in RCS, and particularly on the fuel cladding, and increased dose rates. It has to be noted that today, the fuel assemblies maximum burnup is set at 52 GWd/tU. One solution is to adjust the pH by increasing the lithium content at the beginning of the cycles, which is easy to implement and does not require any modification on the units. Hence, EDF is testing a ''modified'' chemistry regime in the > during 4 fuel cycles, with a maximum authorized lithium content of 3.5 mg/kg at the beginning of the cycles in the Cattenom 2 pilot unit. The Golfech 1 reference unit implements a standard boron-lithium coordination pH 300 7.2. The major goal of the experimentation is to assess the impact of elevated lithium concentrations at the beginning of the cycles on fuel cladding oxide behavior, mass transport and dose rates. This paper presents the results of the first three cycles of the Duo experimentation. (author)

Rapsodie: A closed fuel cycle

International Nuclear Information System (INIS)

Levallet, E.H.; Costa, L.; Mougniot, J.C.; Robin, J.

1977-01-01

The Fortissimo Version of the core of the RAPSODIE fast reactor produces 40 MWTh. Since its start up in May 1970 in the CEN-CADARACHE its availability has stayed around 85%. Some of the mixed oxyde fuel pins UO 2 - 30% PuO 2 have already reached 150.000 MWd/t. The reprocessing is done in the pilot plant located in the La Hague Center and the plutonium obtained has already been re-used in the reactor. The Rapsodie-Fortissimo cycle is therefore now a closed cycle. This cycle is quite representative of fast reactor cycle characteristics and thus provides a remarkable research and development tool for the study of fabrication, in-reactor performances, transport, storage and reprocessing. These studies concern in particular the evolution of fission products and heavy isotopes content in fuel which controls both reprocessing schemes and intensity of emitted radiations. A program for the analysis of irradiated fuel has been developed either using samples collected all along the cycle, or following the actual reprocessing subassemblies. A set of basic data and calculation models has been established with two objectives: to give a better interpretation of the experimental program on one hand, and to extrapolate these results to the fuel cycle of fast reactors in general on the other hand. The first results have been quite encouraging up to now [fr

Exergy optimization for a novel combination of organic Rankine cycles, Stirling cycle and direct expander turbines

Science.gov (United States)

Moghimi, Mahdi; Khosravian, Mohammadreza

2018-06-01

In this paper, a novel combination of organic Rankine cycles (ORCs), Stirling cycle and direct expander turbines is modeled and optimized using the genetic algorithm. The Exergy efficiency is considered as an objective function in the genetic algorithm. High efficiency is the main advantage of Stirling cycle, however, it needs nearly isothermal compressor and turbine. Therefore, an argon ORC and a R14 ORC are placed before and after the Striling cycle along with two expander turbines at the end of the line. Each component and cycle of the proposed plant in this article is verified by the previous works available in the literature and good agreement is achieved. The obtained results reveal that 27.98%, 20.86% and 12.90% of the total cold exergy are used by argon ORC, Stirling cycle and R14 ORC, respectively. Therefore, utilization of the Stirling cycle is a good idea for the LNG line cold exergy. The maximum exergy destruction occurs in the heat exchanger after the argon ORC (85.786 kJ/s per one kg/s LNG) due to the wasted cold exergy, which can be used for air conditioning systems in the plant. Finally, it would be shown that the maximum efficiency of the proposed plant is 54.25% and the maximum output power is 355.72 kW.

Exergy optimization for a novel combination of organic Rankine cycles, Stirling cycle and direct expander turbines

Science.gov (United States)

Moghimi, Mahdi; Khosravian, Mohammadreza

2018-01-01

In this paper, a novel combination of organic Rankine cycles (ORCs), Stirling cycle and direct expander turbines is modeled and optimized using the genetic algorithm. The Exergy efficiency is considered as an objective function in the genetic algorithm. High efficiency is the main advantage of Stirling cycle, however, it needs nearly isothermal compressor and turbine. Therefore, an argon ORC and a R14 ORC are placed before and after the Striling cycle along with two expander turbines at the end of the line. Each component and cycle of the proposed plant in this article is verified by the previous works available in the literature and good agreement is achieved. The obtained results reveal that 27.98%, 20.86% and 12.90% of the total cold exergy are used by argon ORC, Stirling cycle and R14 ORC, respectively. Therefore, utilization of the Stirling cycle is a good idea for the LNG line cold exergy. The maximum exergy destruction occurs in the heat exchanger after the argon ORC (85.786 kJ/s per one kg/s LNG) due to the wasted cold exergy, which can be used for air conditioning systems in the plant. Finally, it would be shown that the maximum efficiency of the proposed plant is 54.25% and the maximum output power is 355.72 kW.

Policy paper no. 1 : Pedestrians and cycling

Energy Technology Data Exchange (ETDEWEB)

Zbogar, H. [City of Brampton, ON (Canada)

2004-06-01

The City of Brampton's Transportation and Transit Master Plan includes a workable plan to promote walking and cycling facilities in the area. This paper reviewed existing policies, programs and practices in the City of Brampton that pertain to cycling and walking. Walking and cycling issues and trends were also reviewed with reference to the principles that improve the pedestrian and cycling environment, such as safety, security, convenience, continuity, comfort, coherence and attractiveness. The recreation, health and fitness benefits of walking and cycling were also outlined along with transportation, environmental, and economic benefits. The official plan for the city was included with reference to walking and cycling sections in the city. It was noted that effective pathways should be customer driven and respond to the needs of residents. They should also accommodate all uses, including walking, jogging, cycling and in-line skating. Experience of other jurisdictions in Ontario in providing walking and cycling facilities were also reviewed. It was noted that walking and cycling are significant elements of an intermodal transportation system and have a strong bearing on a city's vision for urban street design. 11 refs., 2 tabs., 3 figs.

Exploring cycle crash characteristics in Malaysia

Directory of Open Access Journals (Sweden)

Hamzah A.

2017-01-01

Full Text Available This paper explains the cycle road crash trend, characteristics and injuries in Malaysia. It analyses the in-depth road crash investigation data collected by the Royal Malaysian Police which was made available to MIROS crash database. Fatality data was utilized due to its consistency. Cycle casualties reflected a continual downward pattern for year 2009 to 2014 in which the number of cycle crash involvement reduced by 49% and fatalities dropped by 42%. Among the prevalent factors of cycle fatalities are >60 age group, federal and state roads and straight road sections, rural and small towns, evening peak hours, and mainly involving cars and motorcycles. It is hoped that all these information would spark interests to improve cycle safety in Malaysia.

Fuel cycle centres

International Nuclear Information System (INIS)

Hagen, M.

1977-01-01

The concept of co-locating and integrating fuel cycle facilities at one site is discussed. This concept offers considerable advantages, especially in minimizing the amount of radioactive material to be transported on public roads. Safeguards and physical protection as relating to such an integrated system of facilities are analysed in detail, also industrial and commercial questions. An overall risk-benefit evaluation turns out to be in favour of fuel cycle centres. These centres seem to be specifically attractive with regard to the back end of the fuel cycle, including on-site disposal of radioactive wastes. The respective German approach is presented as an example. Special emphasis is given to the site selection procedures in this case. Time scale and cost for the implementation of this concept are important factors to be looked at. Since participation of governmental institutions in these centres seems to be indispensable their respective roles as compared to industry must be clearly defined. The idea of adjusting fuel cycle centres to regional rather than national use might be an attractive option, depending on the specific parameters in the region, though results of existing multinational ventures are inconclusive in this respect. Major difficulties might be expected e.g. because of different national safety regulations and standards as well as commercial conditions among partner countries. Public acceptance in the host country seems to be another stumbling block for the realization of this type of multinational facilities

Role of the seasonal cycle in coupling climate and carbon cycling in subanartic zone

CSIR Research Space (South Africa)

Monteiro, PMS

2010-08-01

Full Text Available There is increasing evidence in the Southern Ocean that mesoscales and seasonal scales play an important role in the coupling of ocean carbon cycling and climate. The seasonal cycle is one of the strongest modes of variability in different...

Measuring business cycles in The Netherlands, 1815-1913: a comparison of business cycle dating methods

OpenAIRE

Bonenkamp, Jan; Jacobs, Jan; Kuper, Gerard H.

2001-01-01

This paper compares different business cycle dating methods both on theoretical and practical grounds. Weighing the pros and cons of these methods, and based on a new data set for The Netherlands in the nineteenth century, we finally recommend two preferred methods for doing further business cycle research on the economy of the Netherlands. With respect to the methods for finding turning points in the level of economic activity, the classical cycle definition, we prefer the Bry-Boschan algori...

Vitamin D Supplementation Affects the Beck Depression Inventory, Insulin Resistance, and Biomarkers of Oxidative Stress in Patients with Major Depressive Disorder: A Randomized, Controlled Clinical Trial.

Science.gov (United States)

Sepehrmanesh, Zahra; Kolahdooz, Fariba; Abedi, Fatemeh; Mazroii, Navid; Assarian, Amin; Asemi, Zatollah; Esmaillzadeh, Ahmad

2016-02-01

Vitamin D may decrease depression symptoms through its beneficial effects on neurotransmitters, metabolic profiles, biomarkers of inflammation, and oxidative stress. This study was designed to assess whether vitamin D supplementation can reduce symptoms of depression, metabolic profiles, serum high-sensitivity C-reactive protein (hs-CRP), and biomarkers of oxidative stress in patients with major depressive disorder (MDD). This randomized, double-blind, placebo-controlled clinical trial was performed in 40 patients between 18 and 65 y of age with a diagnosis of MDD based on criteria from the Diagnostic and Statistical Manual of Mental Disorders. Patients were randomly assigned to receive either a single capsule of 50 kIU vitamin D/wk (n = 20) or placebo (n = 20) for 8 wk. Fasting blood samples were taken at baseline and postintervention to quantify relevant variables. The primary [Beck Depression Inventory (BDI), which examines depressive symptoms] and secondary (glucose homeostasis variables, lipid profiles, hs-CRP, and biomarkers of oxidative stress) outcomes were assessed. Baseline concentrations of mean serum 25-hydroxyvitamin D were significantly different between the 2 groups (9.2 ± 6.0 and 13.6 ± 7.9 μg/L in the placebo and control groups, respectively, P = 0.02). After 8 wk of intervention, changes in serum 25-hydroxyvitamin D concentrations were significantly greater in the vitamin D group (+20.4 μg/L) than in the placebo group (-0.9 μg/L, P stress. This trial was registered at www.irct.ir as IRCT201412065623N29. © 2016 American Society for Nutrition.

Introducing advanced nuclear fuel cycles in Canada

International Nuclear Information System (INIS)

Duret, M.F.

1978-05-01

The ability of several different advanced fuel cycles to provide energy for a range of energy growth scenarios has been examined for a few special situations of interest in Canada. Plutonium generated from the CANDU-PHW operating on natural uranium is used to initiate advanced fuel cycles in the year 2000. The four fuel cycles compared are: 1) natural uranium in the CANDU-PHW; 2) high burnup thorium cycle in the CANDU-PHW; 3) self-sufficient thorium cycle in the CANDU-PHW; 4) plutonium-uranium cycle in a fast breeder reactor. The general features of the results are quite clear. While any plutonium generated prior to the introduction of the advanced fuel cycle remains, system requirements for natural uranium for each of the advanced fuel cycles are the same and are governed by the rate at which plants operating on natural uranium can be retired. When the accumulated plutonium inventory has been entirely used, natural uranium is again required to provide inventory for the advanced fuel cycle reactors. The time interval during which no uranium is required varies only from about 25 to 40 years for both thorium cycles, depending primarily on the energy growth rate. The breeder does not require the entire plutonium inventory produced and so would call for less processing of fuel from the PHW reactors. (author)

40 CFR 94.105 - Duty cycles.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Duty cycles. 94.105 Section 94.105... EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES Test Procedures § 94.105 Duty cycles. (a) Overview. For....8(e), engines shall be tested using the appropriate duty cycles described in this section. (b...

When Product Life Cycle Meets Customer Activity Cycle

DEFF Research Database (Denmark)

Tan, Adrian Ronald

2007-01-01

Manufacturing companies have traditionally focused their efforts on designing, developing and producing products to offer on the market. Today global competition and demands for greater company responsibility of products throughout their entire life cycle are driving manufacturing companies to sh...

Carbon cycle makeover

DEFF Research Database (Denmark)

Canfield, Donald Eugene; Kump, Lee R.

2013-01-01

remaining in sediments after respiration leave a residual of oxygen in the atmosphere. The source of oxygen to the atmosphere represented by organic matter burial is balanced by oxygen sinks associated with rock weathering and chemical reaction with volcanic gases. This is the long-term carbon and oxygen...... geochemical cycle. But Earth is an old planet, and oxygen levels have changed through time (2). On page 540 of this issue, Schrag et al. (3) challenge the most commonly used geochemical approach to assess long-term changes in the coupled oxygen and carbon cycles....

High performance integrated solar combined cycles with minimum modifications to the combined cycle power plant design

International Nuclear Information System (INIS)

Manente, Giovanni

2016-01-01

Highlights: • Off-design model of a 390 MW_e three pressure combined cycle developed and validated. • The off-design model is used to evaluate different hybridization schemes with solar. • Power boosting and fuel saving with different design modifications are considered. • Maximum solar share of total electricity is only 1% with the existing equipment. • The maximum incremental solar radiation-to-electrical efficiency approaches 29%. - Abstract: The integration of solar energy into natural gas combined cycles has been successfully demonstrated in several integrated solar combined cycles since the beginning of this decade in many countries. There are many motivations that drive investments on integrated solar combined cycles which are primarily the repowering of existing power plants, the compliance with more severe environmental laws on emissions and the mitigation of risks associated with large solar projects. Integrated solar combined cycles are usually developed as brownfield facilities by retrofitting existing natural gas combined cycles and keeping the existing equipment to minimize costs. In this work a detailed off-design model of a 390 MW_e three pressure level natural gas combined cycle is built to evaluate different integration schemes of solar energy which either keep the equipment of the combined cycle unchanged or include new equipment (steam turbine, heat recovery steam generator). Both power boosting and fuel saving operation strategies are analyzed in the search for the highest annual efficiency and solar share. Results show that the maximum incremental power output from solar at design solar irradiance is limited to 19 MW_e without modifications to the existing equipment. Higher values are attainable only including a larger steam turbine. High solar radiation-to-electrical efficiencies in the range 24–29% can be achieved in the integrated solar combined cycle depending on solar share and extension of tube banks in the heat recovery

Actinide production in different HTR-fuel cycle concepts

International Nuclear Information System (INIS)

Filges, D.; Hecker, R.; Mirza, N.; Rueckert, M.

1978-01-01

At the 'Institut fuer Reaktorentwicklung der Kernforschungsanlage Juelich' the production of α-activities in the following HTR-OTTO cycle concepts were studied: 1. standard HTR cycle (U-Th); 2. low enriched HTR cycle (U-Pu); 3. near breeder HTR cycle (U-Th); 4. combined system (conventional and near breeder HTR). The production of α-activity in HTR Uranium-Thorium fuel cycles has been investigated and compared with the standard LWR cycles. The production of α-activity in HTR Uranium-Thorium fuel cycles has been investigated and compared with the standard LWR cycles. The calculations were performed by the short depletion code KASCO and the well-known ORIGEN program

Efficacy of Adjunctive Sleep Interventions for PTSD

Science.gov (United States)

2009-03-01

MURI; BAA 08-019: Topic #1; PI: M. Hall, University of Pittsburgh). This multidisciplinary translational project focuses on investigating sleep...rate variability (high & low frequency) CAPS Part 2 PTSD symptom checklist (civilian version) Beck Depression Inventory Beck Anxiety...be completed by a CNRC RN) PTSD symptom checklist (civilian version) Beck Depression Inventory Beck Anxiety Inventory Inventory of

Dual Pressure versus Hybrid Recuperation in an Integrated Solid Oxide Fuel Cell Cycle – Steam Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2014-01-01

A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...... other to reveal the most superior concept with respect to plant efficiency and power. It was found that in order to increase the plant efficiency considerably, it was enough to use a single pressure with a hybrid recuperator instead of a dual pressure Rankine cycle....

Cell cycle gene expression under clinorotation

Science.gov (United States)

Artemenko, Olga

2016-07-01

Cyclins and cyclin-dependent kinase (CDK) are main regulators of the cell cycle of eukaryotes. It's assumes a significant change of their level in cells under microgravity conditions and by other physical factors actions. The clinorotation use enables to determine the influence of gravity on simulated events in the cell during the cell cycle - exit from the state of quiet stage and promotion presynthetic phase (G1) and DNA synthesis phase (S) of the cell cycle. For the clinorotation effect study on cell proliferation activity is the necessary studies of molecular mechanisms of cell cycle regulation and development of plants under altered gravity condition. The activity of cyclin D, which is responsible for the events of the cell cycle in presynthetic phase can be controlled by the action of endogenous as well as exogenous factors, but clinorotation is one of the factors that influence on genes expression that regulate the cell cycle.These data can be used as a model for further research of cyclin - CDK complex for study of molecular mechanisms regulation of growth and proliferation. In this investigation we tried to summarize and analyze known literature and own data we obtained relatively the main regulators of the cell cycle in altered gravity condition.

Teaching the Rock Cycle with Ease.

Science.gov (United States)

Bereki, Debra

2000-01-01

Describes a hands-on lesson for teaching high school students the concept of the rock cycle using sedimentary, metamorphic, and igneous rocks. Students use a rock cycle diagram to identify pairs of rocks. From the rock cycle, students explain on paper how their first rock became the second rock and vice versa. (PVD)

Reversible and irreversible heat engine and refrigerator cycles

Science.gov (United States)

Leff, Harvey S.

2018-05-01

Although no reversible thermodynamic cycles exist in nature, nearly all cycles covered in textbooks are reversible. This is a review, clarification, and extension of results and concepts for quasistatic, reversible and irreversible processes and cycles, intended primarily for teachers and students. Distinctions between the latter process types are explained, with emphasis on clockwise (CW) and counterclockwise (CCW) cycles. Specific examples of each are examined, including Carnot, Kelvin and Stirling cycles. For the Stirling cycle, potentially useful task-specific efficiency measures are proposed and illustrated. Whether a cycle behaves as a traditional refrigerator or heat engine can depend on whether it is reversible or irreversible. Reversible and irreversible-quasistatic CW cycles both satisfy Carnot's inequality for thermal efficiency, η ≤ η C a r n o t . Irreversible CCW cycles with two reservoirs satisfy the coefficient of performance inequality K ≤ K C a r n o t . However, an arbitrary reversible cycle satisfies K ≥ K C a r n o t when compared with a reversible Carnot cycle operating between its maximum and minimum temperatures, a potentially counterintuitive result.

10 CFR 436.19 - Life cycle costs.

Science.gov (United States)

2010-01-01

... operation and maintenance costs: (c) Replacement costs less salvage costs of replaced building systems; and... 10 Energy 3 2010-01-01 2010-01-01 false Life cycle costs. 436.19 Section 436.19 Energy DEPARTMENT... Procedures for Life Cycle Cost Analyses § 436.19 Life cycle costs. Life cycle costs are the sum of the...

Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

DEFF Research Database (Denmark)

Rokni, Masoud

2010-01-01

Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization unit...

Nature's third cycle a story of sunspots

CERN Document Server

Choudhuri, Arnab Rai

2015-01-01

The cycle of day and night and the cycle of seasons are two familiar natural cycles around which many human activities are organized. But is there a third natural cycle of importance for us humans? On 13 March 1989, six million people in Canada went without electricity for many hours: a large explosion on the sun was discovered as the cause of this blackout. Such explosions occur above sunspots, dark features on the surface of the Sun that have been observed through telescopes since the time of Galileo. The number of sunspots has been found to wax and wane over a period of 11 years. Although this cycle was discovered less than two centuries ago, it is becoming increasingly important for us as human society becomes more dependent on technology. For nearly a century after its discovery, the cause of the sunspot cycle remained completely shrouded in mystery. The 1908 discovery of strong magnetic fields in sunspots made it clear that the 11-year cycle is the magnetic cycle of the sun. It is only during the last ...

Solar cycles and climate variations

International Nuclear Information System (INIS)

Chistyakov, V.F.

1990-01-01

Climate oscillations with 100-, 200- and 300-year periods are positively correlated with solar activity oscillations: the higher is solar activity the warmer is climate. According to geological data (varved clays) it is determined, that length of cycles has decreased from 23.4 up to 11 years during latter 2.5 billion years. 12-year cycles occurred during the great glaciation periods, while 10-year cycles occurred during interglaciation periods. It is suggested, that these oscillations are related with variations of the solar activity and luminescence

40 CFR 89.410 - Engine test cycle.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine test cycle. 89.410 Section 89... Procedures § 89.410 Engine test cycle. (a) Emissions shall be measured using one of the test cycles specified...) through (a)(4) of this section. These cycles shall be used to test engines on a dynamometer. (1) The 8...

CHOOSING DRIVING CYCLE OF HYBRID VEHICLE

Directory of Open Access Journals (Sweden)

A. Vorona

2011-01-01

Full Text Available The analysis of existing driving cycles was performed. After comparing some of the cycles, one specific driving cycle was selected for the hybrid vehicle as the most reliable in representing the real moving of the vehicle in operating conditions and which may be reproduced at experimental tests at the modeling roller stand.

Round and Round the Water Cycle

Science.gov (United States)

Bradley, Barbara A.

2017-01-01

Children enjoy water play, and kindergarten children can learn about the water cycle. Teachers are already introducing elements of the water cycle when discussing weather and bodies of water. The water cycle also can be a springboard for teaching children about plants and animals and the importance of water for sustaining life and shaping our…

Investigation of the structural, electronic and optical properties of the cubic RbMF{sub 3} perovskites (M = Be, Mg, Ca, Sr and Ba) using modified Becke-Johnson exchange potential

Energy Technology Data Exchange (ETDEWEB)

Sandeep, E-mail: sndp.chettri@gmail.com [Department of Physics, Mizoram University, Aizawl, 796004 (India); Rai, D.P. [Department of Physics, Pachhunga University College, Mizoram University, 796001 (India); Shankar, A. [Department of Physics, University of North Bengal, Darjeeling, 734013 (India); Ghimire, M.P. [Condensed Matter Physics Research Center, Butwal-13, Rupandehi, Lumbini (Nepal); IFW-Dresden, Helmholtzstraße 20, D-01069, Dresden (Germany); Khenata, R. [Laboratoire de Physique Quantique de la Mati´ere et de Modélisation Mathématique LPQ3M, Université de Mascara, Mascara, 29000 (Algeria); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P. O. Box 2455, Riyadh, 11451 (Saudi Arabia); Syrotyuk, S.V. [Semiconductor Electronics Department, Lviv Polytechnic National University, Lviv, 79013 (Ukraine); Thapa, R.K. [Department of Physics, Mizoram University, Aizawl, 796004 (India)

2017-05-01

The structural, electronic and optical properties of the cubic RbMF{sub 3} perovskites (M = Be, Mg, Ca, Sr, Ba) have been investigated using the full-potential linearized augmented plane wave (FP-LAPW) method. The exchange and correlation potential was applied using the generalized gradient approximation for calculating the structural properties In addition, the modified Becke-Johnson (TB-mBJ) potential was used for calculating the electronic and optical properties. It was found that the lattice constant increases while the bulk modulus decreases with the change of cation (M) in going from Be to Ba in the RbMF{sub 3} perovskites (M = Be, Mg, Ca, Sr, Ba). The reflectivity and absorption properties were also studied using the mBJ method to understand the inter-band transitions and their possible applications in absorption devices in the UV-region. - Highlights: • Closer estimate of the band-gaps of RbMF{sub 3} with experimental results using GGA and mBJ results predicting them to be absorption devices and substrates for thin film growth. • The RbMF{sub 3} were also found to be potential candidate for in absorption devices in UV-region which were correlated to their calculated optical properties. • The materials are transparent, so may be used as substrates for thin film growth, for the optoelectric applications.

The uranium-plutonium breeder reactor fuel cycle

International Nuclear Information System (INIS)

Salmon, A.; Allardice, R.H.

1979-01-01

All power-producing systems have an associated fuel cycle covering the history of the fuel from its source to its eventual sink. Most, if not all, of the processes of extraction, preparation, generation, reprocessing, waste treatment and transportation are involved. With thermal nuclear reactors more than one fuel cycle is possible, however it is probable that the uranium-plutonium fuel cycle will become predominant; in this cycle the fuel is mined, usually enriched, fabricated, used and then reprocessed. The useful components of the fuel, the uranium and the plutonium, are then available for further use, the waste products are treated and disposed of safely. This particular thermal reactor fuel cycle is essential if the fast breeder reactor (FBR) using plutonium as its major fuel is to be used in a power-producing system, because it provides the necessary initial plutonium to get the system started. In this paper the authors only consider the FBR using plutonium as its major fuel, at present it is the type envisaged in all, current national plans for FBR power systems. The corresponding fuel cycle, the uranium-plutonium breeder reactor fuel cycle, is basically the same as the thermal reactor fuel cycle - the fuel is used and then reprocessed to separate the useful components from the waste products, the useful uranium and plutonium are used again and the waste disposed of safely. However the details of the cycle are significantly different from those of the thermal reactor cycle. (Auth.)

Cycle-by-cycle exhaust temperature monitoring for detection of misfiring and combustion instability in reciprocating natural gas engines

Energy Technology Data Exchange (ETDEWEB)

Gardiner, D.P. [Nexum Research Corp., Kingston, ON (Canada); Bardon, M.F. [Royal Military Coll. of Canada, Kingston, ON (Canada). Dept. of Mechanical Engineering

2007-07-01

The effectiveness of a cycle-by-cycle exhaust temperature monitoring system on engines operating at or near their fully rate load capacity was examined. Tests were conducted on stationary industrial natural gas engines. The study evaluated the monitoring system's ability to detect isolated single misfires, as well as combustion instability during misfire-free operations when the air/fuel ratio of the engine was adjusted to progressively lower settings. The combustion instability level of the engines was quantified by determining the relative variability of the groups of consecutive cycles. The coefficient of variation of indicated mean effective pressure (COV of IMEP) was used to examine cyclic variability. A combustion instability index was used to quantify cyclic variability with cycle-by-cycle exhaust temperature monitoring. Two engines were tested, notably a Cummins QSK 19G turbocharged natural gas engine; and a Waukesha VHP L5790G industrial natural gas engine. The tests demonstrated that cycle-by-cycle exhaust temperature monitoring system was capable of detecting misfiring and combustion instabilities in natural gas engines. 6 refs., 9 figs.

Origins of the supercontinent cycle

Directory of Open Access Journals (Sweden)

R. Damian Nance

2013-07-01

Full Text Available The supercontinent cycle, by which Earth history is seen as having been punctuated by the episodic assembly and breakup of supercontinents, has influenced the rock record more than any other geologic phenomena, and its recognition is arguably the most important advance in Earth Science since plate tectonics. It documents fundamental aspects of the planet's interior dynamics and has charted the course of Earth's tectonic, climatic and biogeochemical evolution for billions of years. But while the widespread realization of the importance of supercontinents in Earth history is a relatively recent development, the supercontinent cycle was first proposed thirty years ago and episodicity in tectonic processes was recognized long before plate tectonics provided a potential explanation for its occurrence. With interest in the supercontinent cycle gaining momentum and the literature expanding rapidly, it is instructive to recall the historical context from which the concept developed. Here we examine the supercontinent cycle from this perspective by tracing its development from the early recognition of long-term episodicity in tectonic processes, through the identification of tectonic cycles following the advent of plate tectonics, to the first realization that these phenomena were the manifestation of episodic supercontinent assembly and breakup.

Fuel cycles

International Nuclear Information System (INIS)

Hawley, N.J.

1983-05-01

AECL publications, from the open literature, on fuels and fuel cycles used in CANDU reactors are listed in this bibliography. The accompanying index is by subject. The bibliography will be brought up to date periodically

Reporting in vitro fertilization cycles to the Society for Assisted Reproductive Technology database: where have all the cycles gone?

Science.gov (United States)

Kulak, David; Jindal, Sangita K; Oh, Cheongeun; Morelli, Sara S; Kratka, Scott; McGovern, Peter G

2016-04-01

To assess the relationship between live birth rates (LBRs) and the incidence of under-reported cycles by IVF clinics. Cohort study. Not applicable. All patients undergoing IVF cycles in the aforementioned clinics. Not applicable. The reporting percentage (RP), defined as number of cycles with reported pregnancy rates divided by total cycles performed. Results from cryopreservation cycles are only presented by SART if an embryo transfer occurs. Thus, RP decreases as incidence of embryo or oocyte banking cycles increases. The LBRs in women aged cycles than the median. In clinics with very low RP, the cycles that are reported have higher success rates. Regardless of intent, the reduction of reported data to SART makes it increasingly difficult for clinicians and patients to accurately assess a clinic's success rates. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

The glutamate/GABA-glutamine cycle

DEFF Research Database (Denmark)

Bak, Lasse K; Schousboe, Arne; Waagepetersen, Helle S

2006-01-01

Neurons are metabolically handicapped in the sense that they are not able to perform de novo synthesis of neurotransmitter glutamate and gamma-aminobutyric acid (GABA) from glucose. A metabolite shuttle known as the glutamate/GABA-glutamine cycle describes the release of neurotransmitter glutamate...... or GABA from neurons and subsequent uptake into astrocytes. In return, astrocytes release glutamine to be taken up into neurons for use as neurotransmitter precursor. In this review, the basic properties of the glutamate/GABA-glutamine cycle will be discussed, including aspects of transport and metabolism...... of intercellular transfer of ammonia produced in neurons (when glutamine is deamidated to glutamate) and utilized in astrocytes (for amidation of glutamate) when the glutamate/GABA-glutamine cycle is operating. A main objective of this review is to endorse the view that the glutamate/GABA-glutamine cycle must...

Nitrogen Cycle Ninja, A Teaching Exercise.

Science.gov (United States)

Raun, William R.; And Others

1997-01-01

Assesses the effectiveness of using pop quizzes and rewards to improve student retention of the nitrogen cycle. Students able to diagram the N cycle on pop quizzes were rewarded with special cards that included the N cycle. These cards could then be used on subsequent tests in place of memory alone. Six of 11 students tested three months later…

Does It Have a Life Cycle?

Science.gov (United States)

Keeley, Page

2010-01-01

If life continues from generation to generation, then all plants and animals must go through a life cycle, even though it may be different from organism to organism. Is this what students have "learned," or do they have their own private conceptions about life cycles? The formative assessment probe "Does It Have a Life Cycle?" reveals some…

Introducing Life Cycle Impact Assessment

DEFF Research Database (Denmark)

Hauschild, Michael Zwicky; Huijbregts, Mark AJ

2015-01-01

This chapter serves as an introduction to the presentation of the many aspects of life cycle impact assessment (LCIA) in this volume of the book series ‘LCA Compendium’. It starts with a brief historical overview of the development of life cycle impact assessment driven by numerous national LCIA...... methodology projects and presents the international scientific discussions and methodological consensus attempts in consecutive working groups under the auspices of the Society of Environmental Toxicology and Chemistry (SETAC) as well as the UNEP/ SETAC Life Cycle Initiative, and the (almost) parallel...

Plutonium re-cycle in HTR

Energy Technology Data Exchange (ETDEWEB)

Desoisa, J. A.

1974-03-15

The study of plutonium cycles in HTRs using reprocessed plutonium from Magnox and AGR fuel cycles has shown that full core plutonium/uranium loadings are in general not feasible, burn-up is limited due the need for lower loadings of plutonium to meet reload core reactivity limits, on-line refueling is not practicable due to the need for higher burnable poison loadings, and low conversion rates in the plutonium-uranium cycles cannot be mitigated by axial loading schemes so that fissile make-up is needed if HTR plutonium recycle is desired.

40 CFR 90.410 - Engine test cycle.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine test cycle. 90.410 Section 90... Procedures § 90.410 Engine test cycle. (a) Follow the appropriate 6-mode test cycle for Class I, I-B and II engines and 2-mode test cycle for Class I-A, III, IV, and V engines when testing spark-ignition engines...

The relevance of food composition data for nutrition surveys in rural Tibet: pilot study in the context of Kashin-Beck Disease

Directory of Open Access Journals (Sweden)

Dermience, M.

2013-01-01

Full Text Available Kashin-Beck disease (KBD is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People's Republic of China. The etiology of the disease remains obscure although environmental factors are assumed to be involved. Diet, in particular, differentiates the rural community, affected by KBD, from the other communities (nomads and city-dwellers, who remain unaffected. In anticipation of a nutrition survey, this study aimed to measure the mineral content (Ca, P, Mg, Fe, Zn, Mn, Cu, Ni, Se, Al, Sr, Mo, Cd, As, Pb, Hg, Cr, and Co of eight Tibetan staple foods and to compare the results against two food composition tables (FCTs. Foods were sampled in twenty households selected from both an endemic and a non-endemic area of rural Tibet. Ten minerals involved in bone metabolism were measured using atomic and molecular spectrometric methods. Results revealed that a very limited number of food/constituent pairs showed a variation in mineral composition during a single year of testing for a given region. In addition, results showed significant differences in mineral content between the endemic and the non-endemic area, especially for wheat flour. Following our analysis of the mineral content of the Tibetan food samples, results were statistically compared with similar foods listed in two food composition tables: the USDA National Nutrient Database (USDA Food Search for Windows, Version 1.0, database version SR23, and the China Food Composition Table (book 1, 2nd edition. More than 50 to 60% of p-values < 0.05 were highlighted, suggesting the inappropriateness of using FCTs as a reference for nutrition surveys in rural Tibet, and emphasizing the need for analysis of traditional foods. Differences were found to be more or less marked depending on the element considered, and calcium content seemed to show the greatest difference. Although it is obviously too early for definite

Aromatase inhibitors in stimulated IVF cycles

DEFF Research Database (Denmark)

Papanikolaou, Evangelos G; Polyzos, Nikolaos P; Al Humaidan, Peter Samir Heskjær

2011-01-01

are available regarding their efficacy in IVF stimulated cycles. Current available evidence support that letrozole may have a promising role in stimulated IVF cycles, either when administered during the follicular phase for ovarian stimulation. Especially for women with poor ovarian response, letrozole appears...... to have the potential to increase clinical pregnancy rates when combined with gonadotropins, whereas at the same time reduces the total gonadotropin dose required for ovarian stimulation. However, given that in all of the trials letrozole has been administered in GnRH antagonist cycles, it is intriguing...... to test in the future how it may perform when used in GnRH agonist cycles. Finally administration of letrozole during luteal phase in IVF cycles offers another treatment modality for patients at high risk for OHSS taking into account that it drastically reduces estradiol levels....

Supermarket Defrost Cycles As Flexible Reserve

DEFF Research Database (Denmark)

Pedersen, Rasmus; Sloth, Christoffer; Wisniewski, Rafal

2015-01-01

This work analyses how supermarket defrost cycles can be used as flexible reserve in a smart grid context. The consumption flexibility originates from being able to shift defrost cycles in time, while adhering to the underlying refrigeration systems constraints. It is shown how this time...... constrained behavior can be modeled and used by a defrost planner to optimally schedule defrost start times for several defrost cycles, according to electricity price. Because the defrost planning problem is a boolean programming problem a method of relaxing it is proposed. While the relaxed problem requires...... less computational effort, convexity is dependent on properties of the price signal. Simulation study show that the optimal planning strategy can reduce cost of defrost cycles with 31.7%, compared to a current strategy of executing all defrost cycles at the same time each day. Copyright ©2015 by IEEE...

Plutonium in an enduring fuel cycle

International Nuclear Information System (INIS)

Pillay, K.K.S.

1998-05-01

Nuclear fuel cycles evolved over the past five decades have allowed many nations of the world to enjoy the benefits of nuclear energy, while contributing to the sustainable consumption of the world's energy resources. The nuclear fuel cycle for energy production suffered many traumas since the 1970s because of perceived risks of proliferation of nuclear weapons. However, the experience of the past five decades has shown that the world community is committed to safeguarding all fissile materials and continuing the use of nuclear energy resources. Decisions of a few nations to discard spent nuclear fuels in geologic formations are contrary to the goals of an enduring nuclear fuel cycle and sustainable development being pursued by the world community. The maintenance of an enduring nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including spent fuels

Emissions from photovoltaic life cycles

NARCIS (Netherlands)

Fthenakis, V.M.; Kim, H.C.; Alsema, E.A.|info:eu-repo/dai/nl/073416258

2008-01-01

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004–2006, this study presents the life-cycle

National Urea Cycle Disorders Foundation

Science.gov (United States)

... urea cycle disorders. Donate Now To End Urea Cycle Disorders © 2005-2017 NUCDF. All rights reserved. This site may be freely linked to but not copied or duplicated in any fashion without the Foundation's consent. Make A Donation in ...

Nuclear-fuel-cycle optimization: methods and modelling techniques

International Nuclear Information System (INIS)

Silvennoinen, P.

1982-01-01

This book present methods applicable to analyzing fuel-cycle logistics and optimization as well as in evaluating the economics of different reactor strategies. After an introduction to the phases of a fuel cycle, uranium cost trends are assessed in a global perspective. Subsequent chapters deal with the fuel-cycle problems faced by a power utility. The fuel-cycle models cover the entire cycle from the supply of uranium to the disposition of spent fuel. The chapter headings are: Nuclear Fuel Cycle, Uranium Supply and Demand, Basic Model of the LWR (light water reactor) Fuel Cycle, Resolution of Uncertainties, Assessment of Proliferation Risks, Multigoal Optimization, Generalized Fuel-Cycle Models, Reactor Strategy Calculations, and Interface with Energy Strategies. 47 references, 34 figures, 25 tables

Optimum heat power cycles for specified boundary conditions

International Nuclear Information System (INIS)

Ibrahim, O.M.; Klein, S.A.; Mitchell, J.W.

1991-01-01

In this paper optimization of the power output of Carnot and closed Brayton cycles is considered for both finite and infinite thermal capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures that yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at maximum power are obtained. A comparison of the maximum power from the two cycles for the same boundary conditions, i.e., the same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances, shows that the Brayton cycle can produce more power than the Carnot cycle. This comparison illustrates that cycles exist that can produce more power than the Carnot cycle. The optimum heat power cycle, which will provide the upper limit of power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger conductances is considered. The optimum heat power cycle is identified by optimizing the sum of the power output from a sequence of Carnot cycles. The shape of the optimum heat power cycle, the power output, and corresponding efficiency are presented. The efficiency at maximum power of all cycles investigated in this study is found to be equal to (or well approximated by) η = 1 - sq. root T L.in /φT H.in where φ is a factor relating the entropy changes during heat rejection and heat addition

Efficiency of an air-cooled thermodynamic cycle

International Nuclear Information System (INIS)

Bezborodov, Yu.A.; Bubnov, V.P.; Nesterenko, V.B.

1979-01-01

The application of air, nitrogen, helium and the chemically reacting N 2 O 4 reversible 2NO 2 reversible 2NO + O 2 system as working agents and coolants for a low capacity nuclear power plant is investigated. The above system due to its physico-chemical and thermo-physical properties allows both a gaseous cycle and a cycle with condensation. The analysis has shown that a thermodynamic air-cooled cycle with the dissociating nitrogen tetroxide in the temperature range from 500 to 600 deg C has an advantage over cycles with air and nitrogen. To identify the chemical reaction kinetics in the thermodynamic processes, thermodynamic calculations of the gas-liquid cycle with N 2 O 4 both with simple and intermediate heat regeneration at different pressures over hot side were performed. At gas pressures lower than 12 - 15 atm, the cycle with a simple regeneration is more effective, and at pressure increase, the cycle with an intermediate regeneration is preferable

The Geologic Nitrogen Cycle

Science.gov (United States)

Johnson, B. W.; Goldblatt, C.

2013-12-01

N2 is the dominant gas in Earth's atmosphere, and has been so through the majority of the planet's history. Originally thought to only be cycled in significant amounts through the biosphere, it is becoming increasingly clear that a large degree of geologic cycling can occur as well. N is present in crustal rocks at 10s to 100s of ppm and in the mantle at 1s to perhaps 10s of ppm. In light of new data, we present an Earth-system perspective of the modern N cycle, an updated N budget for the silicate Earth, and venture to explain the evolution of the N cycle over time. In an fashion similar to C, N has a fast, biologically mediated cycle and a slower cycle driven by plate tectonics. Bacteria fix N2 from the atmosphere into bioavailable forms. N is then cycled through the food chain, either by direct consumption of N-fixing bacteria, as NH4+ (the primary waste form), or NO3- (the most common inorganic species in the modern ocean). Some organic material settles as sediment on the ocean floor. In anoxic sediments, NH4+ dominates; due to similar ionic radii, it can readily substitute for K+ in mineral lattices, both in sedimentary rocks and in oceanic lithosphere. Once it enters a subduction zone, N may either be volatilized and returned to the atmosphere at arc volcanoes as N2 or N2O, sequestered into intrusive igneous rocks (as NH4+?), or subducted deep into the mantle, likely as NH4+. Mounting evidence indicates that a significant amount of N may be sequestered into the solid Earth, where it may remain for long periods (100s m.y.) before being returned to the atmosphere/biosphere by volcanism or weathering. The magnitude fluxes into the solid Earth and size of geologic N reservoirs are poorly constrained. The size of the N reservoirs contained in the solid Earth directly affects the evolution of Earth's atmosphere. It is possible that N now sequestered in the solid Earth was once in the atmosphere, which would have resulted in a higher atmospheric pressure, and

Fuel cycle based safeguards

International Nuclear Information System (INIS)

De Montmollin, J.M.; Higinbotham, W.A.; Gupta, D.

1985-07-01

In NPT safeguards the same model approach and absolute-quantity inspection goals are applied at present to all similar facilities, irrespective of the State's fuel cycle. There is a continuing interest and activity on the part of the IAEA in new NPT safeguards approaches that more directly address a State's nuclear activities as a whole. This fuel cycle based safeguards system is expected to a) provide a statement of findings for the entire State rather than only for individual facilities; b) allocate inspection efforts so as to reflect more realistically the different categories of nuclear materials in the different parts of the fuel cycle and c) provide more timely and better coordinated information on the inputs, outputs and inventories of nuclear materials in a State. (orig./RF) [de

Alternative fuel cycles and non-proliferation aspects

International Nuclear Information System (INIS)

Kessler, G.

1980-10-01

The most important physical characteristics of the U/Pu and the Th/U fuel cycles and the technical data of the most significant converter reactors operating with Th/U fuel are outlined in the report. Near breeders as well as breeders with a thermal neutron spectrum are briefly discussed, and the potential of breeders with fast neutron spectra in the Th/U fuel is outlined. The essential criteria for the comparison of the alternative fuel cycles with the reference Pu/U cycle are the consumption of natural uranium, the numbers of U-233 producing and U-233 consuming converter reactors and the amounts of fission material transported and handled within the fuel cycle (reprocessing, refabrication). Although the alternative U/Th fuel cycles are feasible with some advantages and some disadvantages as compared to the reference U/Pu cycle, not much experience has so far been gathered with pilot plants of the fuel cycle. The respective status in reprocessing, refabrication and waste disposal is briefly discussed. Finally, a comparison of the risk potential inherent in secular storage is presented and questions of resistance to proliferation and of safeguards of the U/Th cycle are discussed

50 AÑOS DE LOS INVENTARIOS DE DEPRESIÓN DE BECK: CONSEJOS PARA LA UTILIZACIÓN DE LA ADAPTACIÓN ESPAÑOLA DEL BDI-II EN LA PRÁCTICA CLÍNICA

Directory of Open Access Journals (Sweden)

Jesús Sanz

2013-09-01

Full Text Available En 2011 se publicó la primera adaptación española del Inventario de Depresión de Beck-II (BDI-II, justo cuando se cumplía el 50º aniversario de la publicación de su primera edición. En este tiempo, el BDI se ha convertido en el cuestionario autoaplicado más utilizado en España y en el mundo para evaluar la gravedad de la depresión. En este trabajo se presentan las características básicas del BDI-II en relación con sus versiones anteriores (BDI-I y BDI-IA y el proceso de su adaptación a la población española, se resumen las propiedades psicométricas de dicha adaptación y se discute su utilización en la práctica clínica, proponiéndose pautas y puntuaciones de corte para la evaluación de la gravedad de la depresión, la evaluación de la significación clínica de los cambios terapéuticos, el cribado de personas con depresión y la ayuda en el diagnóstico diferencial de los trastornos depresivos.

Cycle accurate and cycle reproducible memory for an FPGA based hardware accelerator

Science.gov (United States)

Asaad, Sameh W.; Kapur, Mohit

2016-03-15

A method, system and computer program product are disclosed for using a Field Programmable Gate Array (FPGA) to simulate operations of a device under test (DUT). The DUT includes a device memory having a number of input ports, and the FPGA is associated with a target memory having a second number of input ports, the second number being less than the first number. In one embodiment, a given set of inputs is applied to the device memory at a frequency Fd and in a defined cycle of time, and the given set of inputs is applied to the target memory at a frequency Ft. Ft is greater than Fd and cycle accuracy is maintained between the device memory and the target memory. In an embodiment, a cycle accurate model of the DUT memory is created by separating the DUT memory interface protocol from the target memory storage array.

Steam turbine cycle

International Nuclear Information System (INIS)

Okuzumi, Naoaki.

1994-01-01

In a steam turbine cycle, steams exhausted from the turbine are extracted, and they are connected to a steam sucking pipe of a steam injector, and a discharge pipe of the steam injector is connected to an inlet of a water turbine. High pressure discharge water is obtained from low pressure steams by utilizing a pressurizing performance of the steam injector and the water turbine is rotated by the high pressure water to generate electric power. This recover and reutilize discharged heat of the steam turbine effectively, thereby enabling to improve heat efficiency of the steam turbine cycle. (T.M.)

Global water cycle

Science.gov (United States)

Robertson, Franklin; Goodman, Steven J.; Christy, John R.; Fitzjarrald, Daniel E.; Chou, Shi-Hung; Crosson, William; Wang, Shouping; Ramirez, Jorge

1993-01-01

This research is the MSFC component of a joint MSFC/Pennsylvania State University Eos Interdisciplinary Investigation on the global water cycle extension across the earth sciences. The primary long-term objective of this investigation is to determine the scope and interactions of the global water cycle with all components of the Earth system and to understand how it stimulates and regulates change on both global and regional scales. Significant accomplishments in the past year are presented and include the following: (1) water vapor variability; (2) multi-phase water analysis; (3) global modeling; and (4) optimal precipitation and stream flow analysis and hydrologic processes.

Coordination cycles

Czech Academy of Sciences Publication Activity Database

Steiner, Jakub

-, č. 274 (2005), s. 1-26 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : coordination * crises * cycles and fluctuations Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp274.pdf

Low cycle fatigue: high cycle fatigue damage accumulation in a 304L austenitic stainless steel

International Nuclear Information System (INIS)

Lehericy, Y.

2007-05-01

The aim of this study was to evaluate the consequences of a Low Cycle Fatigue pre-damage on the subsequent fatigue limit of a 304L stainless steel. The effects of hardening and severe roughness (grinding) have also been investigated. In a first set of tests, the evolution of the surface damage induced by the different LCF pre-cycling was characterized. This has permitted to identify mechanisms and kinetics of damage in the plastic domain for different surface conditions. Then, pre-damaged samples were tested in the High Cycle Fatigue domain in order to establish the fatigue limits associated with each level of pre-damage. Results evidence that, in the case of polished samples, an important number of cycles is required to initiate surface cracks ant then to affect the fatigue limit of the material but, in the case of ground samples, a few number of cycles is sufficient to initiate cracks and to critically decrease the fatigue limit. The fatigue limit of pre-damaged samples can be estimated using the stress intensity factor threshold. Moreover, this detrimental effect of severe surface conditions is enhanced when fatigue tests are performed under a positive mean stress (author)

Nonlinear solar cycle forecasting: theory and perspectives

Science.gov (United States)

Baranovski, A. L.; Clette, F.; Nollau, V.

2008-02-01

In this paper we develop a modern approach to solar cycle forecasting, based on the mathematical theory of nonlinear dynamics. We start from the design of a static curve fitting model for the experimental yearly sunspot number series, over a time scale of 306 years, starting from year 1700 and we establish a least-squares optimal pulse shape of a solar cycle. The cycle-to-cycle evolution of the parameters of the cycle shape displays different patterns, such as a Gleissberg cycle and a strong anomaly in the cycle evolution during the Dalton minimum. In a second step, we extract a chaotic mapping for the successive values of one of the key model parameters - the rate of the exponential growth-decrease of the solar activity during the n-th cycle. We examine piece-wise linear techniques for the approximation of the derived mapping and we provide its probabilistic analysis: calculation of the invariant distribution and autocorrelation function. We find analytical relationships for the sunspot maxima and minima, as well as their occurrence times, as functions of chaotic values of the above parameter. Based on a Lyapunov spectrum analysis of the embedded mapping, we finally establish a horizon of predictability for the method, which allows us to give the most probable forecasting of the upcoming solar cycle 24, with an expected peak height of 93±21 occurring in 2011/2012.

NICMOS Cycles 13 and 14 Calibration Plans

Science.gov (United States)

Arribas, Santiago; Bergeron, Eddie; de Jong, Roeof; Malhotra, Sangeeta; Mobasher, Bahram; Noll, Keith; Schultz, Al; Wiklind, Tommy; Xu, Chun

2005-11-01

This document summarizes the NICMOS Calibration Plans for Cycles 13 and 14. These plans complement the SMOV3b, the Cycle 10 (interim), and the Cycles 11 and 12 (regular) calibration programs executed after the installation of the NICMOS Cooling System (NCS).. These previous programs have shown that the instrument is very stable, which has motivated a further reduction in the frequency of the monitoring programs for Cycle 13. In addition, for Cycle 14 some of these programs were slightly modified to account for 2 Gyro HST operations. The special calibrations on Cycle 13 were focussed on a follow up of the spectroscopic recalibration initiated in Cycle 12. This program led to the discovery of a possible count rate non-linearity, which has triggered a special program for Cycle 13 and a number of subsequent tests and calibrations during Cycle 14. At the time of writing this is a very active area of research. We also briefly comment on other calibrations defined to address other specific issues like: the autoreset test, the SPAR sequences tests, and the low-frequency flat residual for NIC1. The calibration programs for the 2-Gyro campaigns are not included here, since they have been described somewhere else. Further details and updates on specific programs can be found via the NICMOS web site.

Effectiveness of psycho-education on depression, hopelessness ...

African Journals Online (AJOL)

... hopelessness, suicidality, anxiety and substance use among basic diploma students at ... questionnaires were used to collect data: the researcher-designed social ... Beck's Hopelessness Scale, Beck's Suicide Ideation Scale, Beck's Anxiety ...

Pyroelectric Energy Harvesting: With Thermodynamic-Based Cycles

OpenAIRE

Saber Mohammadi; Akram Khodayari

2012-01-01

This work deals with energy harvesting from temperature variations using ferroelectric materials as a microgenerator. The previous researches show that direct pyroelectric energy harvesting is not effective, whereas thermodynamic-based cycles give higher energy. Also, at different temperatures some thermodynamic cycles exhibit different behaviours. In this paper pyroelectric energy harvesting using Lenoir and Ericsson thermodynamic cycles has been studied numerically and the two cycles were c...

Comparative energy analysis on a new regenerative Brayton cycle

International Nuclear Information System (INIS)

Goodarzi, M.

2016-01-01

Highlights: • New regenerative Brayton cycle has been introduced. • New cycle has higher thermal efficiency and lower exhausted heat per output power. • Regenerator may remain useful in the new cycle even at high pressure ratio. • New regenerative Brayton cycle is suggested for low pressure ratio operations. - Abstract: Gas turbines are frequently used for power generation. Brayton cycle is the basis for gas turbine operation and developing the alternative cycles. Regenerative Brayton cycle is a developed cycle for basic Brayton cycle with higher thermal efficiency at low to moderate pressure ratios. A new regenerative Brayton cycle has been introduced in the present study. Energy analysis has been conducted on ideal cycles to compare them from the first law of thermodynamics viewpoint. Comparative analyses showed that the new regenerative Brayton cycle has higher thermal efficiency than the original one at the same pressure ratio, and also lower heat absorption and exhausted heat per unite output power. Computed results show that new cycle improves thermal efficiency from 12% to 26% relative to the original regenerative Brayton cycle in the range of studied pressure ratios. Contrary to the original regenerative Brayton cycle, regenerator remains useful in the new regenerative Brayton cycle even at higher pressure ratio.

Naturalistic drive cycle synthesis for pickup trucks.

Science.gov (United States)

Liu, Zifan; Ivanco, Andrej; Filipi, Zoran

2015-09-01

Future pick-up trucks are meeting much stricter fuel economy and exhaust emission standards. Design tradeoffs will have to be carefully evaluated to satisfy consumer expectations within the regulatory and cost constraints. Boundary conditions will obviously be critical for decision making: thus, the understanding of how customers are driving in naturalistic settings is indispensable. Federal driving schedules, while critical for certification, do not capture the richness of naturalistic cycles, particularly the aggressive maneuvers that often shape consumer perception of performance. While there are databases with large number of drive cycles, applying all of them directly in the design process is impractical. Therefore, representative drive cycles that capture the essence of the naturalistic driving should be synthesized from naturalistic driving data. Naturalistic drive cycles are firstly categorized by investigating their micro-trip components, defined as driving activities between successive stops. Micro-trips are expected to characterize underlying local traffic conditions, and separate different driving patterns. Next, the transitions from one vehicle state to another vehicle state in each cycle category are captured with Transition Probability Matrix (TPM). Candidate drive cycles can subsequently be synthesized using Markov Chain based on TPMs for each category. Finally, representative synthetic drive cycles are selected through assessment of significant cycle metrics to identify the ones with smallest errors. This paper provides a framework for synthesis of representative drive cycles from naturalistic driving data, which can subsequently be used for efficient optimization of design or control of pick-up truck powertrains. Manufacturers will benefit from representative drive cycles in several aspects, including quick assessments of vehicle performance and energy consumption in simulations, component sizing and design, optimization of control strategies, and

Human chorionic gonadotropin-administered natural cycle versus spontaneous ovulatory cycle in patients undergoing two pronuclear zygote frozen-thawed embryo transfer.

Science.gov (United States)

Lee, You-Jung; Kim, Chung-Hoon; Kim, Do-Young; Ahn, Jun-Woo; Kim, Sung-Hoon; Chae, Hee-Dong; Kang, Byung-Moon

2018-03-01

To compare human chorionic gonadotropin (HCG)-administered natural cycle with spontaneous ovulatory cycle in patients undergoing frozen-thawed embryo transfer (FTET) in natural cycles. In this retrospective cohort study, we analyzed the clinical outcome of a total of 166 consecutive FTET cycles that were performed in either natural cycle controlled by HCG for ovulation triggering (HCG group, n=110) or natural cycle with spontaneous ovulation (control group, n=56) in 166 infertile patients between January 2009 and November 2013. There were no differences in patients' characteristics between the 2 groups. The numbers of oocytes retrieved, mature oocytes, fertilized oocytes, grade I or II embryos and frozen embryos in the previous in vitro fertilization (IVF) cycle in which embryos were frozen were comparable between the HCG and control groups. Significant differences were not also observed between the 2 groups in clinical pregnancy rate (CPR), embryo implantation rate, miscarriage rate, live birth rate and multiple CPR. However, the number of hospital visits for follicular monitoring was significantly fewer in the HCG group than in the control group ( P cycle reduces the number of hospital visits for follicular monitoring without any detrimental effect on FTET outcome when compared with spontaneous ovulatory cycles in infertile patients undergoing FTET in natural ovulatory cycles.

Drought and ecosystem carbon cycling

NARCIS (Netherlands)

Molen, M.K. van der; Dolman, A.J.; Ciais, P.; Eglin, T.; Gobron, N.; Law, B.E.; Meir, P.; Peters, P.; Philips, O.L.; Reichstein, M.; Chen, T.; Dekker, S.C.; Doubkova, M.; Friedl, M.A.; Jung, M.; Hurk, B.J.J.M. van den; Jeu, R.A.M. de; Kruijt, B.; Ohta, T.; Rebel, K.T.; Plummer, S.; Seneviratne, S.I.; Sitch, S.; Teuling, A.J.; Werf, G.R. van der; Wang, G.

2011-01-01

Drought as an intermittent disturbance of the water cycle interacts with the carbon cycle differently than the ‘gradual’ climate change. During drought plants respond physiologically and structurally to prevent excessive water loss according to species-specific water use strategies. This has

Coordination cycles

Czech Academy of Sciences Publication Activity Database

Steiner, Jakub

2008-01-01

Roč. 63, č. 1 (2008), s. 308-327 ISSN 0899-8256 Institutional research plan: CEZ:AV0Z70850503 Keywords : global games * coordination * crises * cycles and fluctuations Subject RIV: AH - Economics Impact factor: 1.333, year: 2008

Homogeneous Thorium Fuel Cycles in Candu Reactors

Energy Technology Data Exchange (ETDEWEB)

Hyland, B.; Dyck, G.R.; Edwards, G.W.R.; Magill, M. [Chalk River Laboratories, Atomic Energy of Canada Limited (Canada)

2009-06-15

The CANDU{sup R} reactor has an unsurpassed degree of fuel-cycle flexibility, as a consequence of its fuel-channel design, excellent neutron economy, on-power refueling, and simple fuel bundle [1]. These features facilitate the introduction and full exploitation of thorium fuel cycles in Candu reactors in an evolutionary fashion. Because thorium itself does not contain a fissile isotope, neutrons must be provided by adding a fissile material, either within or outside of the thorium-based fuel. Those same Candu features that provide fuel-cycle flexibility also make possible many thorium fuel-cycle options. Various thorium fuel cycles can be categorized by the type and geometry of the added fissile material. The simplest of these fuel cycles are based on homogeneous thorium fuel designs, where the fissile material is mixed uniformly with the fertile thorium. These fuel cycles can be competitive in resource utilization with the best uranium-based fuel cycles, while building up a 'mine' of U-233 in the spent fuel, for possible recycle in thermal reactors. When U-233 is recycled from the spent fuel, thorium-based fuel cycles in Candu reactors can provide substantial improvements in the efficiency of energy production from existing fissile resources. The fissile component driving the initial fuel could be enriched uranium, plutonium, or uranium-233. Many different thorium fuel cycle options have been studied at AECL [2,3]. This paper presents the results of recent homogeneous thorium fuel cycle calculations using plutonium and enriched uranium as driver fuels, with and without U-233 recycle. High and low burnup cases have been investigated for both the once-through and U-233 recycle cases. CANDU{sup R} is a registered trademark of Atomic Energy of Canada Limited (AECL). 1. Boczar, P.G. 'Candu Fuel-Cycle Vision', Presented at IAEA Technical Committee Meeting on 'Fuel Cycle Options for LWRs and HWRs', 1998 April 28 - May 01, also Atomic Energy

Endogenous, Imperfectly Competitive Business Cycles

DEFF Research Database (Denmark)

Whitta-Jacobsen, Hans Jørgen

We investigate how imperfect competition affects the occurrence and the properties of endogenous, rational expectations business cycles in an overlapping generations model with constant returns to scale in production. The model has explicit product and labor markets all characterized...... by monopolistic competition. An implicit assumption of barriers to entry justifies that the number of firms is fixed even when positive profits occur. It turns out that both market power of firms on the product markets and market power of unions on the labor markets make the occurrence of cycles more likely....... In particular, imperfect competition on the product markets and the positive profits associated with it may have the effect that there is a cycle even if the labor supply curve is increasing in the real-wage rate. For competitive cycles is required not only a decreasing labor supply curve, but a wage elasticity...

Comparison of rapid-cycling and non-rapid-cycling bipolar disorder based on prospective mood ratings in 539 outpatients

NARCIS (Netherlands)

Kupka, RW; Luckenbaugh, DA; Post, RM; Suppes, T; Altshuler, LL; Keck, PE; Frye, MA; Denicoff, KD; Grunze, H; Leverich, GS; McElroy, SL; Walden, J; Nolen, WA

Objective: To detect risk factors for rapid cycling in bipolar disorder, the authors compared characteristics of rapid-cycling and non-rapid-cycling patients both from a categorical and a dimensional perspective. Method: Outpatients with bipolar I disorder (N = 419), bipolar II disorder (N = 104),

Nuclear fuel cycles : description, demand and supply estimates

International Nuclear Information System (INIS)

Gadallah, A.A.; Abou Zahra, A.A.; Hammad, F.H.

1985-01-01

This report deals with various nuclear fuel cycles description as well as the world demand and supply estimates of materials and services. Estimates of world nuclear fuel cycle requirements: nuclear fuel, heavy water and other fuel cycle services as well as the availability and production capabilities of these requirements, are discussed for several reactor fuel cycle strategies, different operating and under construction fuel cycle facilities in some industrialized and developed countries are surveyed. Various uncertainties and bottlenecks which are recently facing the development of some fuel cycle components are also discussed, as well as various proposals concerning fuel cycle back-end concepts. finally, the nuclear fuel cycles activities in some developing countries are reviewed with emphasis on the egyptian plans to introduce nuclear power in the country. 11 fig., 16 tab

Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

DEFF Research Database (Denmark)

Haglind, Fredrik

2011-01-01

The part-load performance of combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry gas turbines on the part-load efficiency for combined...... cycles used for ship propulsion. Moreover, the paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within combined cycle power plants. Two different gas turbine configurations are studied, a two-shaft aero......-derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

Role of expanders in helium liquefaction cycles: Parametric studies using Collins cycle

International Nuclear Information System (INIS)

Thomas, Rijo Jacob; Ghosh, Parthasarathi; Chowdhury, Kanchan

2011-01-01

Large scale helium liquefaction/refrigeration plant is a key subsystem of fusion devices. Performance of these plants is dependent on a number of geometric and operating parameters of its constituting components such as compressors, heat exchangers, expanders, valves, etc. Expander has been chosen as the subject matter of analyses in the present study. As the sensible cold of helium vapor is lost in liquefiers, the expanders in liquefaction cycles have to provide more refrigeration than those in refrigeration cycles. The expander parameters such as rate of mass flow, operating pressure, inlet temperature, etc. are inter-dependent, and hence, it is difficult to predict the system behavior with variation of a particular parameter. This necessitates the use of process simulators. Parametric studies have been performed on Collins helium liquefaction cycle using Aspen HYSYS. Collins cycle has all the basic characteristics of a large-scale helium liquefier and the results of this study may be extrapolated to understand the behavior of large scale helium liquefiers. The study shows that the maximum liquid production is obtained when 80% of the compressor flow is diverted through the expanders and it is equally distributed between the two expanders. The relationships between the liquid production and the isentropic efficiency of expanders are almost linear and both the higher and lower temperature expanders exhibit similar trends.

Role of expanders in helium liquefaction cycles: Parametric studies using Collins cycle

Energy Technology Data Exchange (ETDEWEB)

Thomas, Rijo Jacob, E-mail: rijojthomas@gmail.com [Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Ghosh, Parthasarathi; Chowdhury, Kanchan [Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)

2011-06-15

Large scale helium liquefaction/refrigeration plant is a key subsystem of fusion devices. Performance of these plants is dependent on a number of geometric and operating parameters of its constituting components such as compressors, heat exchangers, expanders, valves, etc. Expander has been chosen as the subject matter of analyses in the present study. As the sensible cold of helium vapor is lost in liquefiers, the expanders in liquefaction cycles have to provide more refrigeration than those in refrigeration cycles. The expander parameters such as rate of mass flow, operating pressure, inlet temperature, etc. are inter-dependent, and hence, it is difficult to predict the system behavior with variation of a particular parameter. This necessitates the use of process simulators. Parametric studies have been performed on Collins helium liquefaction cycle using Aspen HYSYS. Collins cycle has all the basic characteristics of a large-scale helium liquefier and the results of this study may be extrapolated to understand the behavior of large scale helium liquefiers. The study shows that the maximum liquid production is obtained when 80% of the compressor flow is diverted through the expanders and it is equally distributed between the two expanders. The relationships between the liquid production and the isentropic efficiency of expanders are almost linear and both the higher and lower temperature expanders exhibit similar trends.

Analysis of Refrigeration Cycle Performance with an Ejector

Directory of Open Access Journals (Sweden)

Wani J. R.

2016-01-01

Full Text Available A conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses during the expansion process. A refrigeration cycle with ejector is a promising modification to improve the performance of conventional refrigeration cycle. The ejector is used to recover some of the available work so that the compressor suction pressure increases. To investigate the enhancement a model with R134a refrigerant was developed. To solve the set of equations and simulate the cycle performance a subroutine was written on engineering equation solver (EES environment. At specific conditions, the refrigerant properties are obtained from EES. At the design conditions the ejector refrigeration cycle achieved 5.141 COP compared to 4.609 COP of the conventional refrigeration cycle. This means that ejector refrigeration cycle offers better COP with 10.35% improvement compared to conventional refrigeration cycle. Parametric analysis of ejector refrigeration cycle indicated that COP was influenced significantly by evaporator and condenser temperatures, entrainment ratio and diffuser efficiency.

The global carbon cycle

International Nuclear Information System (INIS)

Maier-Reimer, E.

1991-01-01

Basic concepts of the global carbon cycle on earth are described; by careful analyses of isotopic ratios, emission history and oceanic ventilation rates are derived, which provide crucial tests for constraining and calibrating models. Effects of deforestation, fertilizing, fossil fuel burning, soil erosion, etc. are quantified and compared, and the oceanic carbon process is evaluated. Oceanic and terrestrial biosphere modifications are discussed and a carbon cycle model is proposed

International Real Business Cycles

OpenAIRE

Mario J. Crucini

2006-01-01

This paper is a non-technical review of research developments in the international real business cycle literature. International business cycle facts are summarize with particular attention to the sources of output variance from the expenditure side of the NIPA and the production side, using a familiar neoclassical production function. Theoretical developments focus on the how consumption smoothing and investment dynamics shape the current account; the search for sources and propagation mecha...

Hat cycle dynamic simulation

International Nuclear Information System (INIS)

Trucco, A.; Corallo, C.; Pini Prato, A.; Porro, S.

1999-01-01

Among the innovative cycle recently proposed in literature, the Humid Air Turbine Cycle - Hat better seems to fulfil the main energy market requirements of today: High efficiency in a large power ranger, low pollution, low specific capital cost. The previous results of an analysis at partial load and transient conditions are here presented, where the Hat plant has been simulated using the original model implemented in LEGO environment [it

The Sphinx's Riddle: Life and Career Cycles.

Science.gov (United States)

Burack, Elmer H.

1984-01-01

Career cycles should be considered apart from life cycles, even though the two are interrelated. This essay examines five theories about life and career cycles, and offers insights into their limitations and potential uses. (JB)

Evaporative cycles - in theory and in practise

Energy Technology Data Exchange (ETDEWEB)

Rosen, P.M.

2000-08-01

The thesis is based on applied research, rather closed to industrial development. The developed simulation model, for pre-design of evaporative gas turbine cycles, has been validated in a 600 kW pilot plant and in rebuilt turbo-charged diesel engines. Besides of the work with the thesis including theoretical modelling and hardware development concerning wet cycles, the work has also resulted in three patents dealing with the technique studied. The main feature of the evaporative cycles is the way the integration between the gas and liquid flows is executed, combined with using low-level heat gathered into the liquid phase which is later used to evaporate the liquid itself in a humidification tower. In this tower, the mass- and heat transfer take place under stable physical laws, and if the tower is properly designed, the distilling effect in the tower will also be high. Today the combined cycle has the best thermal efficiency to generate electricity from fuels. Every new power cycle, including the evaporative cycles, will therefore be compared with power stations based on combined cycles. In evaporative cycles, the steam bottoming cycle of the combined cycles has been eliminated. Instead the 'steam' cycle is integrated into the gas cycle. This action has a favourable effect on thermal efficiency and on NO{sub x} formation in the combustion zone. The major part of this thesis is about the EvGT-project. At Lund University, the major objective of this project was to develop, design, erect and operate the world's first evaporative gas turbine unit. The objective was accomplished in 1999, and in the process of reaching the objective, rather large modelling errors, both thermodynamic and dimensioning of the humidification tower, have been detected in the open literature. It seems as if the pressure dependency of the humidification process has been underestimated in the models used today. The EvGT-pilot plant at Lund University was built and taken into

Fuel cycles using adulterated plutonium

International Nuclear Information System (INIS)

Brooksbank, R.E.; Bigelow, J.E.; Campbell, D.O.; Kitts, F.G.; Lindauer, R.B.

1978-01-01

Adjustments in the U-Pu fuel cycle necessitated by decisions made to improve the nonproliferation objectives of the US are examined. The uranium-based fuel cycle, using bred plutonium to provide the fissile enrichment, is the fuel system with the highest degree of commercial development at the present time. However, because purified plutonium can be used in weapons, this fuel cycle is potentially vulnerable to diversion of that plutonium. It does appear that there are technologically sound ways in which the plutonium might be adulterated by admixture with 238 U and/or radioisotopes, and maintained in that state throughout the fuel cycle, so that the likelihood of a successful diversion is small. Adulteration of the plutonium in this manner would have relatively little effect on the operations of existing or planned reactors. Studies now in progress should show within a year or two whether the less expensive coprocessing scheme would provide adequate protection (coupled perhaps with elaborate conventional safeguards procedures) or if the more expensive spiked fuel cycle is needed as in the proposed civex pocess. If the latter is the case, it will be further necessary to determine the optimum spiking level, which could vary as much as a factor of a billion. A very basic question hangs on these determinations: What is to be the nature of the recycle fuel fabrication facilities. If the hot, fully remote fuel fabrication is required, then a great deal of further development work will be required to make the full cycle fully commercial

Thermodynamic efficiency analysis and cycle optimization of deeply precooled combined cycle engine in the air-breathing mode

Science.gov (United States)

Zhang, Jianqiang; Wang, Zhenguo; Li, Qinglian

2017-09-01

The efficiency calculation and cycle optimization were carried out for the Synergistic Air-Breathing Rocket Engine (SABRE) with deeply precooled combined cycle. A component-level model was developed for the engine, and exergy efficiency analysis based on the model was carried out. The methods to improve cycle efficiency have been proposed. The results indicate cycle efficiency of SABRE is between 29.7% and 41.7% along the flight trajectory, and most of the wasted exergy is occupied by the unburned hydrogen in exit gas. Exergy loss exists in each engine component, and the sum losses of main combustion chamber(CC), pre-burner(PB), precooler(PC) and 3# heat exchanger(HX3) are greater than 71.3% of the total loss. Equivalence ratio is the main influencing factor of cycle, and it can be regulated by adjusting parameters of helium loop. Increase the maximum helium outlet temperature of PC by 50 K, the total assumption of hydrogen will be saved by 4.8%, and the cycle efficiency is advanced by 3% averagely in the trajectory. Helium recirculation scheme introduces a helium recirculation loop to increase local helium flow rate of PC. It turns out the total assumption of hydrogen will be saved by 9%, that's about 1740 kg, and the cycle efficiency is advanced by 5.6% averagely.

Rotary Stirling-Cycle Engine And Generator

Science.gov (United States)

Chandler, Joseph A.

1990-01-01

Proposed electric-power generator comprises three motor generators coordinated by microprocessor and driven by rotary Stirling-cycle heat engine. Combination offers thermodynamic efficiency of Stirling cycle, relatively low vibration, and automatic adjustment of operating parameters to suit changing load on generator. Rotary Stirling cycle engine converts heat to power via compression and expansion of working gas between three pairs of rotary pistons on three concentric shafts in phased motion. Three motor/generators each connected to one of concentric shafts, can alternately move and be moved by pistons. Microprocessor coordinates their operation, including switching between motor and generator modes at appropriate times during each cycle.

Life Cycle Assessment for Biofuels

Science.gov (United States)

A presentation based on life cycle assessment (LCA) for biofuels is given. The presentation focuses on energy and biofuels, interesting environmental aspects of biofuels, and how to do a life cycle assessment with some examples related to biofuel systems. The stages of a (biofuel...

TryCYCLE: A Prospective Study of the Safety and Feasibility of Early In-Bed Cycling in Mechanically Ventilated Patients.

Directory of Open Access Journals (Sweden)

Michelle E Kho

Full Text Available The objective of this study was to assess the safety and feasibility of in-bed cycling started within the first 4 days of mechanical ventilation (MV to inform a future randomized clinical trial.We conducted a 33-patient prospective cohort study in a 21-bed adult academic medical-surgical intensive care unit (ICU in Hamilton, ON, Canada. We included adult patients (≥ 18 years receiving MV who walked independently pre-ICU. Our intervention was 30 minutes of in-bed supine cycling 6 days/week in the ICU. Our primary outcome was Safety (termination, measured as events prompting cycling termination; secondary Safety (disconnection or dislodgement outcomes included catheter/tube dislodgements. Feasibility was measured as consent rate and fidelity to intervention. For our primary outcome, we calculated the binary proportion and 95% confidence interval (CI.From 10/2013-8/2014, we obtained consent from 34 of 37 patients approached (91.9%, 33 of whom received in-bed cycling. Of those who cycled, 16(48.4% were female, the mean (SD age was 65.8(12.2 years, and APACHE II score was 24.3(6.7; 29(87.9% had medical admitting diagnoses. Cycling termination was infrequent (2.0%, 95% CI: 0.8%-4.9% and no device dislodgements occurred. Cycling began a median [IQR] of 3 [2, 4] days after ICU admission; patients received 5 [3, 8] cycling sessions with a median duration of 30.7 [21.6, 30.8] minutes per session. During 205 total cycling sessions, patients were receiving invasive MV (150 [73.1%], vasopressors (6 [2.9%], sedative or analgesic infusions (77 [37.6%] and dialysis (4 [2.0%].Early cycling within the first 4 days of MV among hemodynamically stable patients is safe and feasible. Research to evaluate the effect of early cycling on patient function is warranted.Clinicaltrials.gov: NCT01885442.

The evolving nuclear fuel cycle

International Nuclear Information System (INIS)

Gale, J.D.; Hanson, G.E.; Coleman, T.A.

1993-01-01

Various economics and political pressures have shaped the evolution of nuclear fuel cycles over the past 10 to 15 yr. Future trends will no doubt be similarly driven. This paper discusses the influences that long cycles, high discharge burnups, fuel reliability, and costs will have on the future nuclear cycle. Maintaining the economic viability of nuclear generation is a key issue facing many utilities. Nuclear fuel has been a tremendous bargain for utilities, helping to offset major increases in operation and maintenance (O ampersand M) expenses. An important factor in reducing O ampersand M costs is increasing capacity factor by eliminating outages

The fuel cycle scoping system

International Nuclear Information System (INIS)

Dooley, G.D.; Malone, J.P.

1986-01-01

The Fuel Cycle Scoping System (FCSS) was created to fill the need for a scoping tool which provides the utilities with the ability to quickly evaluate alternative fuel management strategies, tails assay choices, fuel fabrication quotes, fuel financing alternatives, fuel cycle schedules, and other fuel cycle perturbations. The FCSS was specifically designed for PC's that support dBASE-III(TM), a relational data base software system by Ashton-Tate. However, knowledge of dBASE-III is not necessary in order to utilize the FCSS. The FCSS is menu driven and can be utilized as a teaching tool as well as a scoping tool

Digital daily cycles of individuals

DEFF Research Database (Denmark)

Aledavood, Talayeh; Jørgensen, Sune Lehmann; Saramäki, Jari

2015-01-01

Humans, like almost all animals, are phase-locked to the diurnal cycle. Most of us sleep at night and are active through the day. Because we have evolved to function with this cycle, the circadian rhythm is deeply ingrained and even detectable at the biochemical level. However, within the broader...... day-night pattern, there are individual differences: e.g., some of us are intrinsically morning-active, while others prefer evenings. In this article, we look at digital daily cycles: circadian patterns of activity viewed through the lens of auto-recorded data of communication and online activity. We...

Fuel cycle parameters for strategy studies

International Nuclear Information System (INIS)

Archinoff, G.H.

1979-05-01

This report summarizes seven fuel cycle parameters (efficiency, specific power, burnup, equilibrium net fissile feed, equilibrium net fissile surplus, first charge fissile content, and whether or not fuel reprocessing is required) to be used in long-term strategy analyses of fuel cycles based on natural UO 2 , low enriched uranium, mixed oxides, plutonium topped thorium, uranium topped thorium, and the fast breeder oxide cycle. (LL)

Synergistic fuel cycles of the future

International Nuclear Information System (INIS)

Meneley, D.A.; Dastur, A.R.

1997-01-01

Good neutron economy is the basis of the fuel cycle flexibility in the CANDU reactor. This paper describes the fuel cycle options available to the CANDU owner with special emphasis on resource conservation and waste management. CANDU fuel cycles with low initial fissile content operate with relatively high conversion ratio. The natural uranium cycle provides over 55 % of energy from the plutonium that is created during fuel life. Resource utilization is over 7 MWd/kg NU. This can be improved by slight enrichment (between 0.9 and 1.2 wt % U235) of the fuel. Resource utilization increases to 11 MWd/kg NU with the Slightly Enriched Uranium cycle. Thorium based cycles in CANDU operate at near-breeder efficiency. Obey provide attractive options when used with natural uranium or separated (reactor grade and weapons grade) plutonium as driver fuels. In the latter case, the energy from the U233 plus the initial plutonium content amounts to 3.4 GW(th).d/kg Pu-fissile. The same utilization is expected from the use of FBR plutonium in a CANDU thorium cycle. Extension of natural resource is achieved by the use of spent fuels in CANDU. The LWR/CANDU Tandem cycle leads to an additional 77 % of energy through the use of reprocessed LWR fuel (which has a fissile content of 1.6 wt %) in CANDU. Dry reprocessing of LWR fuel with the OREOX process (a more safeguardable alternative to the PUREX process) provides an additional 50 % energy. Uranium recovered (RU) from separation of plutonium contained in spent LWR fuel provides an additional 15 MWd/kg RU. CANDU's low fissile requirement provides the possibility, through the use of non-fertile targets, of extracting energy from the minor actinides contained in spent fuel. In addition to the resource utilization advantage described above, there is a corresponding reduction in waste arisings with such cycles. This is especially significant when separated plutonium is available as a fissile resource. (author)

Exergy Losses in the Szewalski Binary Vapor Cycle

Directory of Open Access Journals (Sweden)

Tomasz Kowalczyk

2015-10-01

Full Text Available In this publication, we present an energy and exergy analysis of the Szewalski binary vapor cycle based on a model of a supercritical steam power plant. We used energy analysis to conduct a preliminary optimization of the cycle. Exergy loss analysis was employed to perform a comparison of heat-transfer processes, which are essential for hierarchical cycles. The Szewalski binary vapor cycle consists of a steam cycle bottomed with an organic Rankine cycle installation. This coupling has a negative influence on the thermal efficiency of the cycle. However, the primary aim of this modification is to reduce the size of the power unit by decreasing the low-pressure steam turbine cylinder and the steam condenser. The reduction of the “cold end” of the turbine is desirable from economic and technical standpoints. We present the Szewalski binary vapor cycle in addition to a mathematical model of the chosen power plant’s thermodynamic cycle. We elaborate on the procedure of the Szewalski cycle design and its optimization in order to attain an optimal size reduction of the power unit and limit exergy loss.

Advanced nuclear fuel cycles and radioactive waste management

International Nuclear Information System (INIS)

2006-01-01

This study analyses a range of advanced nuclear fuel cycle options from the perspective of their effect on radioactive waste management policies. It presents various fuel cycle options which illustrate differences between alternative technologies, but does not purport to cover all foreseeable future fuel cycles. The analysis extends the work carried out in previous studies, assesses the fuel cycles as a whole, including all radioactive waste generated at each step of the cycles, and covers high-level waste repository performance for the different fuel cycles considered. The estimates of quantities and types of waste arising from advanced fuel cycles are based on best available data and experts' judgement. The effects of various advanced fuel cycles on the management of radioactive waste are assessed relative to current technologies and options, using tools such as repository performance analysis and cost studies. (author)

Fatigue diminishes motoneuronal excitability during cycling exercise.

Science.gov (United States)

Weavil, Joshua C; Sidhu, Simranjit K; Mangum, Tyler S; Richardson, Russell S; Amann, Markus

2016-10-01

Exercise-induced fatigue influences the excitability of the motor pathway during single-joint isometric contractions. This study sought to investigate the influence of fatigue on corticospinal excitability during cycling exercise. Eight men performed fatiguing constant-load (80% W peak ; 241 ± 13 W) cycling to exhaustion during which the percent increase in quadriceps electromyography (ΔEMG; vastus lateralis and rectus femoris) was quantified. During a separate trial, subjects performed two brief (∼45 s) nonfatiguing cycling bouts (244 ± 15 and 331 ± 23W) individually chosen to match the ΔEMG across bouts to that observed during fatiguing cycling. Corticospinal excitability during exercise was quantified by transcranial magnetic, electric transmastoid, and femoral nerve stimulation to elicit motor-evoked potentials (MEP), cervicomedullary evoked potentials (CMEP), and M waves in the quadriceps. Peripheral and central fatigue were expressed as pre- to postexercise reductions in quadriceps twitch force (ΔQ tw ) and voluntary quadriceps activation (ΔVA). Whereas nonfatiguing cycling caused no measureable fatigue, fatiguing cycling resulted in significant peripheral (ΔQ tw : 42 ± 6%) and central (ΔVA: 4 ± 1%) fatigue. During nonfatiguing cycling, the area of MEPs and CMEPs, normalized to M waves, similarly increased in the quadriceps (∼40%; P fatiguing cycling. As a consequence, the ratio of MEP to CMEP was unchanged during both trials (P > 0.5). Therefore, although increases in muscle activation promote corticospinal excitability via motoneuronal facilitation during nonfatiguing cycling, this effect is abolished during fatigue. We conclude that the unaltered excitability of the corticospinal pathway from start of intense cycling exercise to exhaustion is, in part, determined by inhibitory influences on spinal motoneurons obscuring the facilitating effects of muscle activation.

Introduction to nuclear supply chain management. In the context of fuel cycle strategy from LWR cycle system to FR cycle system

International Nuclear Information System (INIS)

Shiotani, Hiroki; Ono, Kiyoshi; Namba, Takashi; Yasumatsu, Naoto; Heta, Masanori

2011-01-01

Supply chain management (SCM) is an important technique to maintain supply and demand balance and to achieve total optimization from upstream to downstream in manufacturers' management. One of the major reasons why SCM receives much attention recently is the trend in production and sales systems from 'Push type' to 'Pull type'. 'Push type' can be restated as 'Make to Stock' (MTS). MTS is a type of supply chain in which the production is not connected to actual demand. On the contrary, 'Pull type' can be restated as 'Make to Order' (MTO) in which the production is connected to actual demand. In this paper, the terminologies and ideas of SCM was introduced into the scenario study to give a fresh perspective for considering LWR cycle to FR cycle transition strategies in Japan. Then, an analytical tool (SCM tool) which has been developed by the authors is used to survey Japanese nuclear energy system in transition with the SCM terminologies and viewpoints. When some of the Japanese nuclear fuel cycle strategies and tools are thought back with the framework of SCM, they tend to treat nuclear fuel cycle system as 'Push type' supply chain in their simulations. For example, a reprocessing plant separates SFs (spent fuels) without considering the actual Pu demand. However, because future reprocessing plants and fuel fabrication plants will act as Pu suppliers (front-end facility) to FR as well as back-end facilities of LWRs, the reasonable plant operation principle can be 'Pull type'. The analysis was conducted by the SCM tool to simulate the behaviors of both MTS and MTO type facilities during the LWR to FR transition period. If there are large uncertainties in the Pu demand or the load factor, etc. of future reprocessing plants, SCM framework is beneficial. Furthermore, the realization of MTO type operation by SCM can reduce the recovered Pu stock in spite of the increase of the SF interim storage. As the result of the investigation on the boundary location of 'Push type

Nonlinear solar cycle forecasting: theory and perspectives

Directory of Open Access Journals (Sweden)

A. L. Baranovski

2008-02-01

Full Text Available In this paper we develop a modern approach to solar cycle forecasting, based on the mathematical theory of nonlinear dynamics. We start from the design of a static curve fitting model for the experimental yearly sunspot number series, over a time scale of 306 years, starting from year 1700 and we establish a least-squares optimal pulse shape of a solar cycle. The cycle-to-cycle evolution of the parameters of the cycle shape displays different patterns, such as a Gleissberg cycle and a strong anomaly in the cycle evolution during the Dalton minimum. In a second step, we extract a chaotic mapping for the successive values of one of the key model parameters – the rate of the exponential growth-decrease of the solar activity during the n-th cycle. We examine piece-wise linear techniques for the approximation of the derived mapping and we provide its probabilistic analysis: calculation of the invariant distribution and autocorrelation function. We find analytical relationships for the sunspot maxima and minima, as well as their occurrence times, as functions of chaotic values of the above parameter. Based on a Lyapunov spectrum analysis of the embedded mapping, we finally establish a horizon of predictability for the method, which allows us to give the most probable forecasting of the upcoming solar cycle 24, with an expected peak height of 93±21 occurring in 2011/2012.

Economic aspects of Dukovany NPP fuel cycle

International Nuclear Information System (INIS)

Vesely, P.; Borovicka, M.

2001-01-01

The paper discusses some aspects of high burnup program implementation at Dukovany NPP and its influence on the fuel cycle costs. Dukovany internal fuel cycle is originally designed as a three years cycle of the Out-In-In fuel reloading patterns. These reloads are not only uneconomical but they additionally increased the radiation load of the reactor pressure vessel due to high neutron leakage typical for Out-In-In loading pattern. To avoid the high neutron leakage from the core a transition to 4-year fuel cycle is started in 1987. The neutron leakage from the core is sequentially decreased by insertion of older fuel assemblies at the core periphery. Other developments in fuel cycle are: 1) increasing of enrichment in control assemblies (3.6% of U-235); 2) improvement in fuel assembly design (reduce the assembly shroud thickness from 2.1 to 1.6 mm); 3) introduction of Zr spacer grid instead of stainless steel; 4) introduction of new type of assembly with profiled enrichment with average value of 3.82%. Due to increased reactivity of the new assemblies the transition to the partial 5-year fuel cycle is required. Typical fuel loading pattern for 3, 3.5, 4 and 5-year cycles are shown in the presented paper. An evaluation of fuel cost is also discussed by using comparative analysis of different fuel cycle options. The analysis shows that introduction of the high burnup program has decrease relative fuel cycle costs

INTERNAL-CYCLE VARIATION OF SOLAR DIFFERENTIAL ROTATION

International Nuclear Information System (INIS)

Li, K. J.; Xie, J. L.; Shi, X. J.

2013-01-01

The latitudinal distributions of the yearly mean rotation rates measured by Suzuki in 1998 and 2012 and Pulkkinen and Tuominen in 1998 are utilized to investigate internal-cycle variation of solar differential rotation. The rotation rate at the solar equator seems to have decreased since cycle 10 onward. The coefficient B of solar differential rotation, which represents the latitudinal gradient of rotation, is found to be smaller in the several years after the minimum of a solar cycle than in the several years after the maximum time of the cycle, and it peaks several years after the maximum time of the solar cycle. The internal-cycle variation of the solar rotation rates looks similar in profile to that of the coefficient B. A new explanation is proposed to address such a solar-cycle-related variation of the solar rotation rates. Weak magnetic fields may more effectively reflect differentiation at low latitudes with high rotation rates than at high latitudes with low rotation rates, and strong magnetic fields may more effectively repress differentiation at relatively low latitudes than at high latitudes. The internal-cycle variation is inferred as the result of both the latitudinal migration of the surface torsional pattern and the repression of strong magnetic activity in differentiation.

Theory of limit cycles

CERN Document Server

Ye, Yan-Qian; Lo, Chi Y

1986-01-01

Over the past two decades the theory of limit cycles, especially for quadratic differential systems, has progressed dramatically in China as well as in other countries. This monograph, updating the 1964 first edition, includes these recent developments, as revised by eight of the author's colleagues in their own areas of expertise. The first part of the book deals with limit cycles of general plane stationary systems, including their existence, nonexistence, stability, and uniqueness. The second section discusses the global topological structure of limit cycles and phase-portraits of quadratic systems. Finally, the last section collects important results that could not be included under the subject matter of the previous two sections or that have appeared in the literature very recently. The book as a whole serves as a reference for college seniors, graduate students, and researchers in mathematics and physics.

Back end of an enduring fuel cycle

International Nuclear Information System (INIS)

Pillay, K.K.S.

1998-03-01

An enduring nuclear fuel cycle is an essential part of sustainable consumption, the process whereby world's riches are consumed in a responsible manner so that future generations can continue to enjoy at least some of them. In many countries, the goal of sustainable development has focused attention on the benefits of nuclear technologies. However, sustenance of the nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including energy, spent fuels, and all of its side streams. The nuclear fuel cycle for energy production has suffered many traumas since the mid seventies. The common basis of technologies producing nuclear explosives and consumable nuclear energy has been a preoccupation for some, predicament for others, and a perception problem for many. It is essential to reestablish a reliable back end of the nuclear fuel cycle that can sustain the resource requirements of an enduring full cycle. This paper identifies some pragmatic steps necessary to reverse the trend and to maintain a necessary fuel cycle option for the future

Study of cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends

Energy Technology Data Exchange (ETDEWEB)

Wang, Jinhua; Chen, Hao; Liu, Bing; Huang, Zuohua [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

2008-09-15

Cycle-by-cycle variations of a spark ignition engine fueled with natural gas-hydrogen blends with hydrogen volumetric fraction of 0%, 12%, 23%, 30% and 40% were studied. The effect of hydrogen addition on cycle-by-cycle variations of the natural gas engine was analyzed. The results showed that the peak cylinder pressure, the maximum rate of pressure rise and the indicated mean effective pressure increased and their corresponding cycle-by-cycle variations decreased with the increase of hydrogen fraction at lean mixture operation. The interdependency between the combustion parameters and the corresponding crank angle tended to be strongly correlated with the increase of hydrogen fraction under lean mixture operation. Coefficient of variation of the indicated mean effective pressure gave a low level and is slightly influenced by hydrogen addition under the stoichiometric and relatively rich mixture operation while it decreased remarkably with the increase of hydrogen fraction under the lean mixture operation. The excessive air ratio at CoV{sub imep} = 10% extended to the leaner mixture side with the increase of hydrogen fraction and this indicated that the engine lean operating limit could be extended with hydrogen addition. (author)

Credit cycles and macro fundamentals

NARCIS (Netherlands)

Koopman, S.J.; Kraeussl, R.G.W.; Lucas, A.; Monteiro, A.

2009-01-01

We use an intensity-based framework to study the relation between macroeconomic fundamentals and cycles in defaults and rating activity. Using Standard and Poor's U.S. corporate rating transition and default data over the period 1980-2005, we directly estimate the default and rating cycle from micro

Is the beck anxiety inventory a good tool to assess the severity of anxiety? A primary care study in The Netherlands study of depression and anxiety (NESDA

Directory of Open Access Journals (Sweden)

van der Feltz-Cornelis Christina M

2011-07-01

Full Text Available Abstract Background Appropriate management of anxiety disorders in primary care requires clinical assessment and monitoring of the severity of the anxiety. This study focuses on the Beck Anxiety Inventory (BAI as a severity indicator for anxiety in primary care patients with different anxiety disorders (social phobia, panic disorder with or without agoraphobia, agoraphobia or generalized anxiety disorder, depressive disorders or no disorder (controls. Methods Participants were 1601 primary care patients participating in the Netherlands Study of Depression and Anxiety (NESDA. Regression analyses were used to compare the mean BAI scores of the different diagnostic groups and to correct for age and gender. Results Patients with any anxiety disorder had a significantly higher mean score than the controls. A significantly higher score was found for patients with panic disorder and agoraphobia compared to patients with agoraphobia only or social phobia only. BAI scores in patients with an anxiety disorder with a co-morbid anxiety disorder and in patients with an anxiety disorder with a co-morbid depressive disorder were significantly higher than BAI scores in patients with an anxiety disorder alone or patients with a depressive disorder alone. Depressed and anxious patients did not differ significantly in their mean scores. Conclusions The results suggest that the BAI may be used as a severity indicator of anxiety in primary care patients with different anxiety disorders. However, because the instrument seems to reflect the severity of depression as well, it is not a suitable instrument to discriminate between anxiety and depression in a primary care population.

Towards Life Cycle Sustainability Assessment

Directory of Open Access Journals (Sweden)

Marzia Traverso

2010-10-01

Full Text Available Sustainability is nowadays accepted by all stakeholders as a guiding principle for both public policy making and corporate strategies. However, the biggest challenge for most organizations remains in the real and substantial implementation of the sustainability concept. The core of the implementation challenge is the question, how sustainability performance can be measured, especially for products and processes. This paper explores the current status of Life Cycle Sustainability Assessment (LCSA for products and processes. For the environmental dimension well established tools like Life Cycle Assessment are available. For the economic and social dimension, there is still need for consistent and robust indicators and methods. In addition to measuring the individual sustainability dimensions, another challenge is a comprehensive, yet understandable presentation of the results. The “Life Cycle Sustainability Dashboard” and the “Life Cycle Sustainability Triangle” are presented as examples for communication tools for both experts and non expert stakeholders.

Ammonium generation during SRAT cycle

International Nuclear Information System (INIS)

Hsu, C.W.

1992-01-01

During the IDMS noble-metal demonstration runs ammonium nitrate deposition was found in the vessel vent system of the feed preparation area. In the bench-scale experiments of studying the hydrogen generation during the sludge treatment cycle, ammonium ion production was also monitored. It was found that: During a simulation of the DWPF Cold Chemical Runs SRAT cycle no detectable amount of ammonium ions was generated when treating a non-noble-metal containing sludge simulant according to the nitric acid flowsheet. Ammonium ions were generated during the SRAT-SME cycle when treating the noble-metal containing sludge with either formic acid or nitric acid/late-washing PHA. This is due to the reaction between formic acid and nitrate catalyzed by the noble metals in the sludge simulant. Ammonium ion production closely followed the hydrogen evolution from the catalytic decomposition of formic acid. This report summarizes the results of the production of ammonia during the SRAT cycle

Electrofishing power requirements in relation to duty cycle

Science.gov (United States)

Miranda, L.E.; Dolan, C.R.

2004-01-01

Under controlled laboratory conditions we measured the electrical peak power required to immobilize (i.e., narcotize or tetanize) fish of various species and sizes with duty cycles (i.e., percentage of time a field is energized) ranging from 1.5% to 100%. Electrofishing effectiveness was closely associated with duty cycle. Duty cycles of 10-50% required the least peak power to immobilize fish; peak power requirements increased gradually above 50% duty cycle and sharply below 10%. Small duty cycles can increase field strength by making possible higher instantaneous peak voltages that allow the threshold power needed to immobilize fish to radiate farther away from the electrodes. Therefore, operating within the 10-50% range of duty cycles would allow a larger radius of immobilization action than operating with higher duty cycles. This 10-50% range of duty cycles also coincided with some of the highest margins of difference between the electrical power required to narcotize and that required to tetanize fish. This observation is worthy of note because proper use of duty cycle could help reduce the mortality associated with tetany documented by some authors. Although electrofishing with intermediate duty cycles can potentially increase effectiveness of electrofishing, our results suggest that immobilization response is not fully accounted for by duty cycle because of a potential interaction between pulse frequency and duration that requires further investigation.

Fast power cycle for fusion reactors

International Nuclear Information System (INIS)

Powell, J.; Fillo, J.; Makowitz, H.

1978-01-01

The unique, deep penetration capability of 14 MeV neutrons produced in DT fusion reactions allows the generation of very high temperature working fluid temperatures in a thermal power cycle. In the FAST (Fusion Augmented Steam Turbine) power cycle steam is directly superheated by the high temperature ceramic refractory interior of the blanket, after being generated by heat extracted from the relatively cool blanket structure. The steam is then passed to a high temperature gas turbine for power generation. Cycle studies have been carried out for a range of turbine inlet temperatures [1600 0 F to 3000 0 F (870 to 1650 0 C)], number of reheats, turbine mechanical efficiency, recuperator effectiveness, and system pressure losses. Gross cycle efficiency is projected to be in the range of 55 to 60%, (fusion energy to electric power), depending on parameters selected. Turbine inlet temperatures above 2000 0 F, while they do increase efficiency somewhat, are not necessarily for high cycle efficiency

Universality, marginal operators, and limit cycles

International Nuclear Information System (INIS)

Glazek, Stanislaw D.; Wilson, Kenneth G.

2004-01-01

The universality of renormalization-group limit-cycle behavior is illustrated with a simple discrete Hamiltonian model. A nonperturbative renormalization-group equation for the model is soluble analytically at criticality and exhibits one marginal operator (made necessary by the limit cycle) and an infinite set of irrelevant operators. Relevant operators are absent. The model exhibits an infinite series of bound-state energy eigenvalues. This infinite series approaches an exact geometric series as the eigenvalues approach zero--also a consequence of the limit cycle. Wegner's eigenvalues for irrelevant operators are calculated generically for all choices of parameters in the model. We show that Wegner's eigenvalues are independent of location on the limit cycle, in contrast with Wegner's operators themselves, which vary depending on their location on the limit cycle. An example is then used to illustrate numerically how one can tune the initial Hamiltonian to eliminate the first two irrelevant operators. After tuning, the Hamiltonian's bound-state eigenvalues converge much more quickly than otherwise to an exact geometric series

Income inequality and the business cycle

Directory of Open Access Journals (Sweden)

Shahee Mostafa

2015-01-01

Full Text Available This paper first examines the relationship between ordinary least squares estimators of consumption and investment for 36 selected countries with their respective Gini indices. The analysis shows that income inequality is consistent with a smaller estimator of consumption and a greater estimator of investment. Second, the cycles of GDP, consumption and investment are dated separately to determine how the deepness and duration of cycles of those variables are correlated with the Gini indices of countries. The results show that income inequality leads to a deeper and longer decline of GDP, which causes a greater cumulative income loss of GDP during recession, and a somewhat faster speed of recovery during expansion. Likewise, the result of a correlation between Gini indices and the number of cycles in consumption, investment and GDP indicate that income inequality is associated with a greater number of cycles in consumption and GDP and a lower number of cycles in investment.

A hybrid mammalian cell cycle model

Directory of Open Access Journals (Sweden)

Vincent Noël

2013-08-01

Full Text Available Hybrid modeling provides an effective solution to cope with multiple time scales dynamics in systems biology. Among the applications of this method, one of the most important is the cell cycle regulation. The machinery of the cell cycle, leading to cell division and proliferation, combines slow growth, spatio-temporal re-organisation of the cell, and rapid changes of regulatory proteins concentrations induced by post-translational modifications. The advancement through the cell cycle comprises a well defined sequence of stages, separated by checkpoint transitions. The combination of continuous and discrete changes justifies hybrid modelling approaches to cell cycle dynamics. We present a piecewise-smooth version of a mammalian cell cycle model, obtained by hybridization from a smooth biochemical model. The approximate hybridization scheme, leading to simplified reaction rates and binary event location functions, is based on learning from a training set of trajectories of the smooth model. We discuss several learning strategies for the parameters of the hybrid model.

Study of wurtzite and zincblende GaN/InN based solar cells alloys: First-principles investigation within the improved modified Becke-Johnson potential

KAUST Repository

Ul Haq, Bakhtiar

2014-09-01

Wurtzite GaInN alloys with flexible energy gaps are pronounced for their potential applications in optoelectronics and solar cell technology. Recently the unwanted built-in fields caused by spontaneous polarization and piezoelectric effects in wurtzite (WZ) GaInN, has turned the focus towards zinc-blende (ZB) GaInN alloys. To comprehend merits and demerits of GaInN alloys in WZ and ZB structures, we performed a comparative study of the structural, electronic and optical properties of Ga1-xInxN alloys with different In concentration using first-principles methodology with density function theory with generalized gradient approximations (GGA) and modified Becke-Johnson (mBJ) potential. Investigations pertaining to total energy of GaInN for the both phases, demonstrate a marginal difference, reflecting nearly equivalent stability of the ZB-GaInN to WZ-GaInN. The larger ionic radii of indium (In), result in larger values of lattice parameters of Ga1-xInxN with higher In concentration. For In deficient Ga1-xInxN, at first, the formation enthalpies increase rapidly as the In content approaches to 45% in WZ and 47% in ZB, and then decreases with the further increase in In concentration. ZB-Ga1-xInxN alloys exhibit comparatively narrower energy gaps than WZ, and get smaller with increase in In contents. The smaller values of effective masses of free carriers, in WZ phase, than ZB phase, reflect higher carrier mobility and electrical conductivity of WZ-Ga1-xInxN. Moreover wide energy gap of WZ-Ga1-xInxN results in large values of the absorption coefficients comparatively and smaller static refractive indices compared to ZB-Ga1-xInxN. Comparable electronic and optical characteristics of the ZB-Ga1-xInxN to WZ-Ga1-xInxN endorses it a material of choice for optoelectronics and solar cell applications besides the WZ-Ga1-xInxN. © 2014 Elsevier Ltd.

Study of wurtzite and zincblende GaN/InN based solar cells alloys: First-principles investigation within the improved modified Becke-Johnson potential

KAUST Repository

Ul Haq, Bakhtiar; Ahmed, Rashid; Shaari, Amiruddin; El Haj Hassan, Fouad; Kanoun, Mohammed; Goumri-Said, Souraya

2014-01-01

Wurtzite GaInN alloys with flexible energy gaps are pronounced for their potential applications in optoelectronics and solar cell technology. Recently the unwanted built-in fields caused by spontaneous polarization and piezoelectric effects in wurtzite (WZ) GaInN, has turned the focus towards zinc-blende (ZB) GaInN alloys. To comprehend merits and demerits of GaInN alloys in WZ and ZB structures, we performed a comparative study of the structural, electronic and optical properties of Ga1-xInxN alloys with different In concentration using first-principles methodology with density function theory with generalized gradient approximations (GGA) and modified Becke-Johnson (mBJ) potential. Investigations pertaining to total energy of GaInN for the both phases, demonstrate a marginal difference, reflecting nearly equivalent stability of the ZB-GaInN to WZ-GaInN. The larger ionic radii of indium (In), result in larger values of lattice parameters of Ga1-xInxN with higher In concentration. For In deficient Ga1-xInxN, at first, the formation enthalpies increase rapidly as the In content approaches to 45% in WZ and 47% in ZB, and then decreases with the further increase in In concentration. ZB-Ga1-xInxN alloys exhibit comparatively narrower energy gaps than WZ, and get smaller with increase in In contents. The smaller values of effective masses of free carriers, in WZ phase, than ZB phase, reflect higher carrier mobility and electrical conductivity of WZ-Ga1-xInxN. Moreover wide energy gap of WZ-Ga1-xInxN results in large values of the absorption coefficients comparatively and smaller static refractive indices compared to ZB-Ga1-xInxN. Comparable electronic and optical characteristics of the ZB-Ga1-xInxN to WZ-Ga1-xInxN endorses it a material of choice for optoelectronics and solar cell applications besides the WZ-Ga1-xInxN. © 2014 Elsevier Ltd.

Feasibility study on tandem fuel cycle

International Nuclear Information System (INIS)

Han, P.S.; Suh, I.S.; Rim, C.S.; Kim, B.K.; Suh, K.S.; Ro, S.K.; Juhn, P.I.; Kim, S.Y.

1983-01-01

The objective of this feasibility study is to review and assess the current state of technology concerning the tandem fuel cycle. Based on the results from this study, a long-term development plan suitable for Korea has been proposed for this cycle, i.e., the PWR → CANDU tandem fuel cycle which used plutonium and uranium, recovered from spent PWR fuel by co-processing, as fuel material for CANDU reactors. (Author)

Utilization of Indonesia's Hot Spring Sources for Electricity using Kalina Cycle and Organic Rankine Cycle

Science.gov (United States)

Prabumukti, Grano; Purwanto; Widodo, Wahyu

2018-02-01

Indonesia posses 40% of the world's geothermal energy sources. The existence of hydrothermal sources is usually characterized by their surface manifestations such as hot springs, geysers and fumarole. Hot spring has a potential to be used as a heat source to generate electricity especially in a rural and isolated area. Hot springs can be converted into electricity by binary thermodynamic cycles such as Kalina cycle and ORC. The aim of this study is to obtain the best performances of cycle configuration and the potential power capacity. Simulation is conducted using UNISIM software with working fluid and its operating condition as the decision variables. The simulation result shows that R1234yf and propene with simple ORC as desired working fluid and cycle configuration. It reaches a maximum thermal efficiency up to 9.6% with a specific turbine inlet pressure. Higher temperature heat source will result a higher thermal efficiency‥ Cycle thermal efficiency varies from 4.7% to 9.6% depends on source of hot spring temperature. Power capacity that can be generated using Indonesia's hot spring is ranged from 2 kWe to 61.2 kWe. The highest capacity located in Kawah Sirung and the least located in Kaendi.

Quantifying fluctuations in reversible enzymatic cycles and clocks

Science.gov (United States)

Wierenga, Harmen; ten Wolde, Pieter Rein; Becker, Nils B.

2018-04-01

Biochemical reactions are fundamentally noisy at a molecular scale. This limits the precision of reaction networks, but it also allows fluctuation measurements that may reveal the structure and dynamics of the underlying biochemical network. Here, we study nonequilibrium reaction cycles, such as the mechanochemical cycle of molecular motors, the phosphorylation cycle of circadian clock proteins, or the transition state cycle of enzymes. Fluctuations in such cycles may be measured using either of two classical definitions of the randomness parameter, which we show to be equivalent in general microscopically reversible cycles. We define a stochastic period for reversible cycles and present analytical solutions for its moments. Furthermore, we associate the two forms of the randomness parameter with the thermodynamic uncertainty relation, which sets limits on the timing precision of the cycle in terms of thermodynamic quantities. Our results should prove useful also for the study of temporal fluctuations in more general networks.

Economic growth and business cycles

NARCIS (Netherlands)

Canton, E.J.F.

1997-01-01

This thesis contains five essays on economic growth and business cycles. The main focus is on the interaction between economic growth and the cycle: is cyclical variability good or bad for the long-run rate of economic growth? The introduction aims to provide some empirical evidence for an

Nuclear fuel cycle risk assessment: survey and computer compilation of risk-related literature. [Once-through Cycle and Plutonium Recycle

Energy Technology Data Exchange (ETDEWEB)

Yates, K.R.; Schreiber, A.M.; Rudolph, A.W.

1982-10-01

The US Nuclear Regulatory Commission has initiated the Fuel Cycle Risk Assessment Program to provide risk assessment methods for assistance in the regulatory process for nuclear fuel cycle facilities other than reactors. Both the once-through cycle and plutonium recycle are being considered. A previous report generated by this program defines and describes fuel cycle facilities, or elements, considered in the program. This report, the second from the program, describes the survey and computer compilation of fuel cycle risk-related literature. Sources of available information on the design, safety, and risk associated with the defined set of fuel cycle elements were searched and documents obtained were catalogued and characterized with respect to fuel cycle elements and specific risk/safety information. Both US and foreign surveys were conducted. Battelle's computer-based BASIS information management system was used to facilitate the establishment of the literature compilation. A complete listing of the literature compilation and several useful indexes are included. Future updates of the literature compilation will be published periodically. 760 annotated citations are included.

Increase of carbon cycle feedback with climate sensitivity: results from a coupled climate and carbon cycle model

International Nuclear Information System (INIS)

Govindasamy, B.; Thompson, S.; Mirin, A.; Wickett, M.; Caldeira, K.; Delire, C.

2005-01-01

Coupled climate and carbon cycle modelling studies have shown that the feedback between global warming and the carbon cycle, in particular the terrestrial carbon cycle, could accelerate climate change and result in greater warming. In this paper we investigate the sensitivity of this feedback for year 2100 global warming in the range of 0 to 8 K. Differing climate sensitivities to increased CO 2 content are imposed on the carbon cycle models for the same emissions. Emissions from the SRES A2 scenario are used. We use a fully coupled climate and carbon cycle model, the INtegrated Climate and CArbon model (INCCA), the NCAR/DOE Parallel Climate Model coupled to the IBIS terrestrial biosphere model and a modified OCMIP ocean biogeochemistry model. In our integrated model, for scenarios with year 2100 global warming increasing from 0 to 8 K, land uptake decreases from 47% to 29% of total CO 2 emissions. Due to competing effects, ocean uptake (16%) shows almost no change at all. Atmospheric CO 2 concentration increases are 48% higher in the run with 8 K global climate warming than in the case with no warming. Our results indicate that carbon cycle amplification of climate warming will be greater if there is higher climate sensitivity to increased atmospheric CO 2 content; the carbon cycle feedback factor increases from 1.13 to 1.48 when global warming increases from 3.2 to 8 K

Estrogen receptor alpha is cell cycle-regulated and regulates the cell cycle in a ligand-dependent fashion.

Science.gov (United States)

JavanMoghadam, Sonia; Weihua, Zhang; Hunt, Kelly K; Keyomarsi, Khandan

2016-06-17

Estrogen receptor alpha (ERα) has been implicated in several cell cycle regulatory events and is an important predictive marker of disease outcome in breast cancer patients. Here, we aimed to elucidate the mechanism through which ERα influences proliferation in breast cancer cells. Our results show that ERα protein is cell cycle-regulated in human breast cancer cells and that the presence of 17-β-estradiol (E2) in the culture medium shortened the cell cycle significantly (by 4.5 hours, P cycle duration were observed in the S and G2/M phases, whereas the G1 phase was indistinguishable under liganded and unliganded conditions. In addition, ERα knockdown in MCF-7 cells accelerated mitotic exit, whereas transfection of ERα-negative MDA-MB-231 cells with exogenous ERα significantly shortened the S and G2/M phases (by 9.1 hours, P cycle progression through the S and G2/M phases than fulvestrant does, presumably because of the destabilizing effect of fulvestrant on ERα protein. Together, these results show that ERα modulates breast cancer cell proliferation by regulating events during the S and G2/M phases of the cell cycle in a ligand-dependent fashion. These results provide the rationale for an effective treatment strategy that includes a cell cycle inhibitor in combination with a drug that lowers estrogen levels, such as an aromatase inhibitor, and an antiestrogen that does not result in the degradation of ERα, such as tamoxifen.

Do donor oocyte cycles comply with ASRM/SART embryo transfer guidelines? An analysis of 13,393 donor cycles from the SART registry.

Science.gov (United States)

Acharya, Kelly S; Keyhan, Sanaz; Acharya, Chaitanya R; Yeh, Jason S; Provost, Meredith P; Goldfarb, James M; Muasher, Suheil J

2016-09-01

To analyze donor oocyte cycles in the Society for Assisted Reproductive Technology (SART) registry to determine: 1) how many cycles complied with the 2009 American Society for Reproductive Medicine/SART embryo transfer guidelines; and 2) cycle outcomes according to the number of embryos transferred. For donor oocyte IVF with donor age cycles from 2011 to 2012. Embryos transferred in donor IVF cycles. Percentage of compliant cycles, multiple pregnancy rate. There were 3,157 donor cleavage-stage transfers and 10,236 donor blastocyst transfers. In the cleavage-stage cycles, 88% met compliance criteria. The multiple pregnancy rate (MPR) was significantly higher in the noncompliant cycles. In a subanalysis of compliant cleavage-stage cycles, 91% transferred two embryos and only 9% single embryos. In those patients transferring two embryos, the MPR was significantly higher (33% vs. 1%). In blastocyst transfers, only 28% of the cycles met compliance criteria. The MPR was significantly higher in the noncompliant blastocyst cohort at 53% (compared with 2% in compliant cycles). The majority of donor cleavage-stage transfers are compliant with current guidelines, but the transfer of two embryos results in a significantly higher MPR compared with single-embryo transfer. The majority of donor blastocyst cycles are noncompliant, which appears to be driving an unacceptably high MPR in these cycles. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Seasonal variation in assisted conception cycles and the influence of photoperiodism on outcome in in vitro fertilization cycles.

Science.gov (United States)

Wood, Simon; Quinn, Alison; Troupe, Stephen; Kingsland, Charles; Lewis-Jones, Iwan

2006-12-01

The effect of seasonality and daylight length on mammalian reproduction leading to spring births has been well established, and is known as photoperiodism. In assisted reproduction there is much greater uncertainty as to the effect of seasonality. This was a 4-year retrospective analysis of 2709 standardised cycles of IVF/ICSI. Data was analysed with regard to the 1642 cycles occurring during the months of extended daylight (Apr-Sept) and those 1067 cycles during winter months of restricted light length (Oct-Mar). The results showed that there was significant improvement in assisted conception outcomes in cycles performed in summer (lighter) months with more efficient ovarian stimulation 766iu v880iu/per oocyte retrieved (p=0.006). There was similarly a significantly improved implantation rate per embryo transferred 11.42% vs 9.35% (p=0.011) and greater clinical pregnancy rate 20% vs 15% (p=0.0033) during summer cycles. This study appears to demonstrate a significant benefit of increased daylight length on outcomes of IVF/ICSI cycles. Whilst the exact mechanism of this is unclear, it would seem probable that melatonin may have actions at multiple sites and on multiple levels of the reproductive tract, and may exert a more profound effect on outcomes of assisted conception cycles than has been previously considered.

Combined Turbine and Cycle Optimization for Organic Rankine Cycle Power Systems—Part B