bluuebunny/crossref_metadata_2025 huggingface dataset:
Trends in Endoscopic Retrograde Cholangiopancreatography in Children Within the United States, 2000–2009
Authors: Pant Chaitanya , Sferra Thomas J. , Barth Bradley A. , Deshpande Abhishek , Minocha Anil , Qureshi Waqar A. , Olyaee Mojtaba , Anderson Michael P.
Published: February 2014

We investigated the volume of endoscopic retrograde cholangiopancreatographies (ERCPs) performed in hospitalized children in the United States using a nationwide healthcare administrative database for the years 2000 to 2009. A total of 22,153 cases of ERCP were identified: 6372 diagnostic and 17,314 therapeutic (1533 cases were recorded as undergoing both types during a single hospitalization). The number of ERCPs increased from 5337 to 6733 per year; diagnostic ERCPs decreased 43% and therapeutic increased 69% (significant decreasing trends for diagnostic and increasing for therapeutic ERCPs, P < 0.001 for each analysis). Our results define a recent increase in the use of therapeutic ERCPs in hospitalized children.
Association and prediction of amniotic fluid measurements for adverse pregnancy outcome: systematic review and meta‐analysis
Authors: Morris RK , Meller CH , Tamblyn J , Malin GM , Riley RD , Kilby MD , Robson SC , Khan KS
Published: February 2014

Background

Measurements of amniotic fluid volume are used for pregnancy surveillance despite a lack of evidence for their predictive ability.

Objective

To evaluate the association and predictive value of ultrasound measurements of amniotic fluid volume for adverse pregnancy outcome.

Search strategy

Electronic databases (inception to October 2011), reference lists, hand searching of journals, contact with experts.

Selection criteria

Studies comparing measurements of amniotic fluid volume with adverse outcome, excluding pre‐labour ruptured membranes or congenital/structural anomalies.

Data collection

Data on study characteristics, design, quality. Random effects meta‐analysis to estimate summary odds ratios (prognostic association) and summary sensitivity, specificity and likelihood ratios (predictive ability).

Main results

Forty‐three studies (244 493 fetuses) were included demonstrating a strong association between oligohydramnios (varying definitions) and birthweight <10th centile (summary odds ratio [OR] 6.31, 95% confidence interval [95% CI] 4.15–9.58; high‐risk population [author definition] n = 6 studies, 28 510 fetuses), and mortality (neonatal death any population summary OR 8.72, 95% CI 2.43–31.26; n = 6 studies, 55 735 fetuses; and perinatal mortality high‐risk population summary OR 11.54, 95% CI 4.05–32.9; n = 2 studies, 27 891 fetuses). There was a strong association between polyhydramnios (maximum pool depth >8 cm or amniotic fluid index ≥25 cm) and birthweight >90th centile (OR 11.41, 95% CI 7.09–18.36; n = 1 study, 3960 fetuses). Despite strong associations, predictive accuracy for perinatal outcome was poor.

Author's conclusion

Current evidence suggests that oligohydramnios is strongly associated with being small for gestational age and mortality, and polyhydramnios with birthweight >90th centile. Despite strong associations with poor outcome, they do not accurately predict outcome risk for individuals.
Longer anogenital distance is associated with higher testosterone levels in women: a cross‐sectional study
Authors: Mira‐Escolano MP , Mendiola J , Mínguez‐Alarcón L , Melgarejo M , Cutillas‐Tolín A , Roca M , López‐Espín JJ , Noguera‐Velasco JA , Torres‐Cantero AM
Published: February 2014

Objective

Animal models have suggested that anogenital distance (AGD) at birth reflects androgen levels during in utero development and predicts adult AGD. A recent study showed an association between perineal length and androgen levels in men, suggesting that serum testosterone levels in adulthood will depend on factors involved during the fetal period. The aim of this study is to assess the relationship between AGD measures and reproductive hormone levels in women.

Design

Cross‐sectional study conducted between February and November 2011.

Setting

University‐affiliated fertility clinics.

Population

100 young college students.

Methods

Physical and gynaecological examinations were conducted on university students. All participants provided a blood sample for determination of reproductive hormones and completed an epidemiological questionnaire on lifestyles and gynaecological history. We used multiple linear regression analysis to examine the associations between perineal length measurements [anus‐fourchette (AGDAF) and anus‐clitoris (AGDAC)] and reproductive hormone levels.

Main outcome measures

Anogenital distance measurements and reproductive hormone levels.

Results

In the multiple linear regression analyses, AGDAF was positively associated with serum testosterone levels. Serum testosterone increased 0.06 ng/ml (95%CI 0.01, 0.10; P = 0.02) for each 1‐cm increase in AGDAF. None of the measurements was associated with other reproductive hormones.

Conclusions

Anogenital distance may predict normal reproductive development in women, and may be a new tool of potential clinical interest to evaluate ovarian function. Our results suggest that serum testosterone levels in adulthood may depend on factors operating in the prenatal period.
Physicochemical and Thermal Properties of Phaseolus vulgaris L. var. Great Northern Bean Starch
Authors: Wang Hui , Ratnayake Wajira S.
Published: February 2014

The compositions and properties of 5 Great Northern bean cultivars (Beryl‐R, Coyne, Gemini, Marquis, and Orion) were investigated. Starch was isolated from each cultivar by a wet milling process. Isolated, unmodified starches were characterized for granular, molecular, thermal, and rheological properties. Smooth surfaces and essentially similar granule sizes and shapes were observed among all cultivars. Amylose contents were in the range 21.0% to 22.6%. Amylose and amylopectin molecular weights were approximately 105 and 109 Da, respectively. Typical C‐type X‐ray pattern was observed in all cultivars. Significant differences were observed among cultivars in percentage relative crystallinities, which were in the range 18.2% to 23.8%. The relative crystallinity was independent of amylose proportion and molecular weight. The 5 Great Northern bean cultivars differed in their thermal and rheological properties. Coyne and Gemini had low gelatinization enthalpies. In pasting profile analysis, Coyne had the lowest peak and final viscosities. Granule size, polymer proportion, and molecular weights had major influences on gelatinization and pasting properties of Great Northern bean starches.

Practical Application

Great Northern bean is one of the major varieties of dry‐edible beans produced worldwide. Starch is the major component in Great Northern beans, which accounts for approximately 40% of its composition. Although most legume starches have been studied in detail, physicochemical and functional properties of Great Northern bean starch are largely unknown. This study investigated the properties and thermal behaviors of 5 Great Northern bean cultivars. The new information reported in this article, on starch properties, would pave ways to find new ingredient and product applications for Great Northern beans in food processing.
Diagnostic validity of comorbid bipolar disorder and obsessive–compulsive disorder: a systematic review
Authors: Amerio A. , Odone A. , Liapis C. C. , Ghaemi S. N.
Published: February 2014

Objective

At least 50% of bipolar disorder (BD) patients have an additional diagnosis, one of the most difficult to manage being obsessive–compulsive disorder (OCD). Defining the nosology of BD‐OCD comorbidity has important clinical implications, given that treatments for OCD can worsen BD outcomes.

Method

A systematic review was conducted on: i) BD‐OCD comorbidity lifetime prevalence and ii) on standard diagnostic validators: phenomenology, course of illness, heredity, biological markers, and treatment response. Relevant papers published through March 30th 2013 were identified searching the electronic databases MEDLINE, Embase, PsycINFO, and the Cochrane Library.

Results

Sixty‐four articles met inclusion criteria. Lifetime comorbidity prevalence was 11–21% in BD patients and 6–10% in OCD patients. Compared to non‐comorbid subjects, BD‐OCD has a more episodic course of OC symptoms (up to 75% vs. 3%), typically with worsening during depression (78%) and improvement during mania/hypomania (64%), as well as a higher total mean number of depressive episodes (8.9 ± 4.2 vs. 4.1 ± 2.7) and perhaps more antidepressant‐induced mania/hypomania (39% vs. 9%).

Conclusion

In this first systematic review of BD‐OCD comorbidity, it appears that OC symptoms are usually secondary to BD, rather than representing a separate disease.
Chemerin‐Derived Peptide C‐20 Suppressed Gonadal Steroidogenesis
Authors: Li Lei , Huang Chen , Zhang Xu , Wang Jiangbo , Ma Ping , Liu Yongjun , Xiao Tianxia , Zabel Brian A. , Zhang Jian V.
Published: February 2014

Problem

Chemerin is a novel chemo‐attractant and adipokine involved in leukocyte recruitment, inflammation, adipogenesis, lipid/carbohydrate metabolism, and reproduction. Based on the bioinformatic search for putative small peptides in the conserved region of pre‐pro‐chemerin, an evolutionary conserved region flanked by potential convertase cleavage sites was identified and we named it as C‐20. The binding capacity of C‐20 to chemerin receptors and its potential bioactivities were investigated in this study.

Method of study

Radioligand binding assay, receptor internalization assay, and early response gene C‐FOS simulation, cAMP assay were carried out in chemokine‐like receptor 1 (CMKLR1)/HEK293 transfectants and G protein‐coupled receptor 1 (GPR1)/HEK293 transfectants. In vitro transwell chemotaxis assay in CMKLR1/L1.2 transfectants, primary Leydig cell culture, and antral follicle culture was explored to investigate the bioactivity of C‐20.

Results

C‐20 bound to chemerin receptors CMKLR1 and GPR1 with high affinity triggered CMKLR1 internalization and stimulated subsequent signal C‐FOS expression and cAMP production. C‐20, such as chemerin, showed CMKLR1‐dependent chemotactic property. Furthermore, in primary Leydig cells and antral follicles, C‐20 showed similar but less potent suppressive effect on human chorionic gonadotropin‐stimulated testosterone production and progesterone production, compared with chemerin.

Conclusion

The novel chemerin‐derived C‐20 peptide binds to chemerin receptors CMKLR1 and GPR1 and showed similar but less potent bioactivity in chemotaxis and the suppression of gonadal steroidogenesis, suggesting that after optimization, C‐20 is possible to be a useful experimental tool for the understanding of the biological functions of chemerin/CMKLR1 and chemerin/GPR1 signaling.
Children with Chronic Renal Disease Undergoing Dialysis or Conservative Treatment–Differences in Structural and Functional Echocardiographic Parameters
Authors: Scavarda Valeska Tavares , Pinheiro Aurélio Carvalho , Costa Symône Damasceno , de Andrade Zélia Maria , Carvalhaes João Tomás de Abreu , Campos Orlando , Carvalho Antonio Carlos , Moises Valdir Ambrosio
Published: February 2014

Cardiac disease frequently occurs in children with chronic kidney disease (CKD) undergoing dialysis (DI), but it is not well studied in patients undergoing conservative treatment (CT). The aim of our study was to use echocardiography to analyze and compare the cardiac involvement of children with CKD undergoing DI or CT.

Methods

Seventy‐one children with CKD were included; 41 undergoing DI and 30 undergoing CT. There were 33 controls. Measurements of arterial pressure and structural and functional echocardiographic variables were obtained; the children were followed up for 18 months. Tests of comparison and multiple regression were used; significant if P < 0.05.

Results

Arterial hypertension (AH) was present in 37 of 71 (52%) children with CKD: 27 (65.8%) in DI and 10 (33.3%) in CT (X2 = 8.7; P = 0.003). An abnormal left ventricular geometric pattern was present in 37/41 (90.3%) undergoing DI, 33 had left ventricular hypertrophy (LVH), and in 14/30 (46.7%) undergoing CT, 5 had LVH. Ejection fraction was normal in all groups; diastolic function alteration (DFA) occurred in 28/41 (68.3%) children on DI and in 10/30 (33.3%) on CT (X2 = 9.2; P = 0.002). For children with CKD, DI (P = 0.002) and hypertension (P = 0.04) were associated with LVH; among those on DI, only AH was associated with LVH (P = 0.02). During the follow‐up, 18 (43.9%) children undergoing DI had at least one cardiovascular event.

Conclusion

Children with CKD undergoing CT had less cardiac involvement than those undergoing DI. LVH was associated with DI and AH in all children with CKD and with AH in those on DI.
Transthoracic Echocardiographic Assessment of Spindle Cell Sarcoma of the Pulmonary Artery in a Child
Authors: Garg Ashok , Mooney John , Amado Escañuela Maximiliano German , Mathur Alok , Goyal Vikram , Nanda Navin C.
Published: February 2014

In this report, we present a case of spindle cell sarcoma of the pulmonary artery diagnosed by transthoracic echocardiography. To the best of our knowledge, this case is the youngest reported case of pulmonary artery sarcoma (PAS) to date. PAS is frequently confused for pulmonary embolism; in this case, echocardiographic findings allowed for differentiation between pulmonary embolism and solid tumor.
Reference Values of the Mitral Annular Peak Systolic Velocity (Sm) in 690 Healthy Pediatric Patients, Calculation of Z‐Score Values, and Comparison to the Mitral Annular Plane Systolic Excursion (MAPSE)
Authors: Koestenberger Martin , Nagel Bert , Ravekes William , Avian Alexander , Cvirn Gerhard , Rehak Thomas , Gamillscheg Andreas
Published: February 2014

Background

The mitral annular peak systolic velocity (Sm) is an echocardiographic measurement using tissue Doppler imaging to assess longitudinal left ventricular (LV) systolic function in children and adults. We determined growth‐related changes in Sm to establish reference values for the entire pediatric age group.

Methods and Results

A prospective study was conducted in a group of 690 healthy pediatric patients (age: 1 day–18 years). We determined the effects of age, sex, and body surface area (BSA) on the Sm values. Regression analysis was used to estimate Sm from age, BSA, and sex. In addition, a correlation of normal Sm with normal age‐matched values of the M‐mode parameter mitral annular plane systolic excursion (MAPSE) was measured. The Sm ranged from a mean of 5.8 cm/sec (Z‐score ±2: 3.6–8.0 cm/sec) in the newborn to 11.8 cm/sec (Z‐score ±2: 8.5–15.1 cm/sec) in the 18‐year‐old adolescent. The Sm values showed a positive correlation with age and BSA with a nonlinear course. There was no significant difference in Sm values between females and males. A significant correlation was found between Sm and MAPSE values.

Conclusion

Z‐scores of Sm values were calculated and percentile charts were established to serve as reference data in patients with congenital heart diseases.
Controlled intramyocardial release of engineered chemokines by biodegradable hydrogels as a treatment approach of myocardial infarction
Authors: Projahn Delia , Simsekyilmaz Sakine , Singh Smriti , Kanzler Isabella , Kramp Birgit K. , Langer Marcella , Burlacu Alexandrina , Bernhagen Jürgen , Klee Doris , Zernecke Alma , Hackeng Tilman M. , Groll Jürgen , Weber Christian , Liehn Elisa A. , Koenen Rory R.
Published: February 2014

Myocardial infarction (MI) induces a complex inflammatory immune response, followed by the remodelling of the heart muscle and scar formation. The rapid regeneration of the blood vessel network system by the attraction of hematopoietic stem cells is beneficial for heart function. Despite the important role of chemokines in these processes, their use in clinical practice has so far been limited by their limited availability over a long time‐span in vivo. Here, a method is presented to increase physiological availability of chemokines at the site of injury over a defined time‐span and simultaneously control their release using biodegradable hydrogels. Two different biodegradable hydrogels were implemented, a fast degradable hydrogel (FDH) for delivering Met‐CCL5 over 24 hrs and a slow degradable hydrogel (SDH) for a gradual release of protease‐resistant CXCL12 (S4V) over 4 weeks. We demonstrate that the time‐controlled release using Met‐CCL5‐FDH and CXCL12 (S4V)‐SDH suppressed initial neutrophil infiltration, promoted neovascularization and reduced apoptosis in the infarcted myocardium. Thus, we were able to significantly preserve the cardiac function after MI. This study demonstrates that time‐controlled, biopolymer‐mediated delivery of chemokines represents a novel and feasible strategy to support the endogenous reparatory mechanisms after MI and may compliment cell‐based therapies.
The presence, function and regulation of IL‐17 and Th17 cells in periodontitis
Authors: Cheng Wan‐Chien , Hughes Francis J. , Taams Leonie S.
Published: February 2014

Periodontitis (PD) is a chronic inflammatory disease characterised by tissue inflammation and destruction of the associated alveolar bone. It is caused by the colonisation of the bacterial plaque biofilm and the resultant host immune responses in the surrounding periodontal tissues. The pro‐inflammatory cytokine IL‐17, and IL‐17 producing CD4+ T cells (also called Th17 cells) have been shown to play an important role in many inflammatory diseases. There is increasing evidence of the presence of IL‐17 and Th17 cells in human PD lesions and this may be associated with disease severity. Moreover, several animal studies indicate the potential role of IL‐17 and Th17 cells in gingival inflammation and the resultant bone destruction in PD. Here we review recent findings regarding the presence, function and regulation of IL‐17 and Th17 cells in PD, and we highlight potential areas of future research interest.
Diagnostic accuracy of three biopsy techniques in 117 dogs with intra‐nasal neoplasia
Authors: Harris B. J. , Lourenço B. N. , Dobson J. M. , Herrtage M. E.
Published: February 2014

OBJECTIVES

To determine if nasal biopsies taken at rhinoscopy are more accurate for diagnosing neoplasia than biopsies taken blindly or using advanced imaging for guidance.

METHODS

A retrospective study of 117 dogs with nasal mass lesions that were divided into three groups according to the method of nasal biopsy collection; advanced imaging‐guided, rhinoscopy‐guided and blind biopsy. Signalment, imaging and rhinoscopic findings, and histopathological diagnosis were compared between groups. The proportion of first attempt biopsies confirming neoplasia were determined for each group.

RESULTS

There were no statistically significant differences in the proportion of biopsies that confirmed neoplasia obtained via advanced imaging‐guided, rhinoscopy‐guided or blind biopsy techniques.

CLINICAL SIGNIFICANCE

In dogs with a high index of suspicion of nasal neoplasia, blind biopsy may be as diagnostic as rhinoscopy‐guided biopsy. Repeated biopsies are frequently required for definitive diagnosis.
Deforming God: Why Nothing Really Matters A Lacanian Reading of Thomas Aquinas
Authors: Beattie Tina
Published: February 2014

This paper takes its cue from studies that point to the influence of Thomas Aquinas on the psychoanalytical theory of Jacques Lacan and explores key Lacanian themes of language, desire, God/the real, embodiment and gender from the perspective of the Summa Theologiae. To illustrate how a Lacanian perspective opens new interpretative possibilities with regard to the Summa, it focuses on language and desire, on the doctrines of creation ex nihilo and the incarnation, and on Thomas's attempt to incorporate gendered Aristotelian concepts of form and matter into Christian theology. It argues that it is possible to resist Lacan's nihilism, while allowing his psychoanalytical approach to language to bring about a deconstructive reading of Aristotelian philosophy from the perspective of Christian theology. This allows the reconciling paradox of the incarnation to challenge the dualism of form and matter inherent in philosophical cosmologies, to offer a more dynamic understanding of the significance of material creation and its incorporation into God by way of the resurrected body of Christ. A Lacanian approach brings to light hidden and neglected dimensions of Thomas's theology, making possible a postmodern Thomism, which offers a viable theological response to some of the most challenging questions facing theology today, around questions of language, desire, gender and creation.
The Early Aquinas on the Question of Universal Salvation, or How a Knight May Choose Not to Ride His Horse
Authors: Harkins Franklin T.
Published: February 2014

This article considers how the young Thomas Aquinas treats the question of universal salvation by examining his reading of 1 Timothy 2.4, God wills that all humans should be saved, in two of his early works, the Scriptum on the Sentences of Peter Lombard and the sixth Disputed Question on Truth, both dated to the period 1252–1257. Drawing on John Damascene's distinction between God's antecedent and consequent will, Thomas here teaches that whereas God wills antecedently in a unimodal way that all humans should be saved, He wills consequently in a bimodal way based on foreknown merits. Though foreknown merits are not a cause of predestination itself, they are a cause of glory, one of predestination's temporal effects. On Thomas's account, then, reading 1 Tim 2.4 as a straightforward statement of what God has done eternally—namely, predestine or save every individual human—would undermine the freedom of the human will that is necessary in order to attain to beatitude.
Faith before Hope and Love
Authors: O'Donovan Oliver
Published: February 2014

Thomas’ Compendium was composed in imitation of Augustine's Enchiridion, and with the intention of correcting features which struck Thomas, as they have struck other readers, as strange. The treatment of faith was the principal focus of Thomas’ discontent. In place of Augustine's wandering history of the engagement of divine goodness with the world, Thomas emphasised the cognitive aspect of faith and its concern with being. The two approaches differ in the extent to which they can allow a distinction of the cognitive from the voluntative in virtue. Augustine's insistence on keeping them together has definite strengths in resisting voluntarism, but Thomas’ emphasis imposes constraints on the moralising reduction of faith to action.
Why Do We Still Need Aquinas?
Authors: Ryan Fáinche
Published: February 2014

This paper seeks to demonstrate the enduring importance of the teachings and methodologies of Thomas Aquinas to the theological project. The paper has three parts. The first part emphasises the importance of Aquinas’ clarity in dealing with the question of God, emphasising how God is radically transcendent and yet sovereignly present to, and active in, creation. The second part addresses Thomas Aquinas’ thought on human relatedness to God, especially in the area of prayer. The third part focuses on Aquinas’ account of human flourishing as virtuous living. A no less goal of this paper is to demonstrate that, even if Aquinas had not said anything about a particular issue as perhaps the question we seek to address is of of our time, much is to be gleaned from his precise and clear, analytical and argumentative approach to all questions.
Aquinas and Augustine on Creation and God as “Eternal Being”
Authors: Soskice Janet
Published: February 2014

This paper considers the centrality of the doctrine of creation ex nihilo to both Augustine and Aquinas, especially as these pertain to knowing and naming God. It argues that too much has been ceded to Augustine's purported debt to neo-Platonism, and too little to the doctrine of creation as found in the Christian (and Jewish) middle-Platonists. In these thinkers God's self-disclosure from the burning bush was of signal importance, the ‘I AM WHO I AM’ glossed in terms of God's creative and redemptive power. The theme is traced through Augustine and Aquinas before returning the Christology of the Book of Revelation.
The Impact of Religion on Voting Behaviour – A Multilevel Approach for Switzerland
Authors: Goldberg Andreas C.
Published: February 2014

Abstract

The traditional cleavages like social class or religion are often reported to have lost explanatory power for the voting decision. Regarding the religious cleavage, the evidence is ambiguous depending on the choice of cases and indicators used. The present study tests the impact of religion for the preference to vote the Christian Democratic Party of Switzerland (CVP) using data from the 2007 and 2011 Swiss national elections. Additional to the inclusion of individual variables, a special focus lies on contextual effects. The estimated hierarchical linear models confirm a prevailing influence of the simple individual factors and the presence of a significant contextual effect. Statistical evidence is also presented for some of the supposed interaction effects between individual and contextual religious variables.
Research and Application Status of the Modular Technology in Nuclear Power Engineering of CGNPC
Authors: Lu Qinwu
Published: February 2014

Modular design and construction is one of the distinctive features of the 3rd generation nuclear power technology. In order to promote the technological innovations in nuclear power engineering design and construction and develop the self-owned modular technology, China Guangdong Nuclear Power Holding Co., Ltd (hereafter referred as to CGNPC) has carried out the R&D and application of the modular technology based on the CPR1000-type nuclear power plants, and has made the national-level achievements in the establishment of modular design technology system, development of 3D modular design system and application of modular construction of containment steel liner in the demonstration projects.
Determination of Preventive Maintenance Cycle for Ageing Equipment in Nuclear Power Plant Based on Economic Analysis
Authors: Shi Jie , Deng Fan , Lu Yong-fang
Published: February 2014

An approach for determining the preventive maintenance cycle for ageing equipment was proposed in consideration of lifetime, optimal cost and economy. Two parameters Weibull distribution was used to assess the lifetime of the ageing equipment. The block replacement model and age replacement model were built with the objective of optimal cost, and the preventive replacement cycle was accounted. After that eight options for preventive replacement cycle were proposed. Finally, the economic analysis model was applied to assess those options and the optimal options were confirmed.
Opportunity and Challenge of MOX Fuel Application in China
Authors: Li Rui , Zhou Yuemin
Published: February 2014

In this paper, the opportunity and challenge for application of MOX fuel in China are discussed. With the great demand of energy to develop economy of China, the government plans to achieve 58GW installed capacity and 30GW installing capacity in nuclear power before 2020. China needs about 81,306t～102,613t nature Uranium to support the nuclear power developing project at that time. For the obvious reason, China should insist on closed fuel cycle to recover the fissionable materials in the spent fuel. China will build its first spent fuel reprocessing factory to supply MOX fuel to PWRs and FRs. Both government and nuclear companies put more and more enthusiasm into the application of MOX fuel.

However, China is also suffered from great challenges of MOX fuel application, such as the spent fuel reprocessing technique roadmap, the manufacture technology of MOX fuel, the modification of PWRs to accommodate the MOX fuel, and the recalculation of nuclear parameters by design procedure. The economic effect of applying MOX fuel is also considered. At last, the prospect of MOX fuel application is predicted in this paper.
Development and Validation of Two-Way Fluid-Particle Coupling in Turbulent Flows for a CFD Code
Authors: Xiao Jianjun , Svishchev Anatoly , Jordan Thomas
Published: February 2014

A Lagrangian approach was used in CFD code GASFLOW to describe particle dispersion in turbulent flows. One-way coupling between fluid and particle is often used due to its simplicity of implementation. However, in case of higher particle volume fraction or mass loading in the continuous phase, one-way coupling is not sufficient to simulate the interaction between fluid and particles. For instance, the liquid droplets released by a spray nozzle in the nuclear power plant will lead to a strong gas entrainment, and consequently impact the gas flow field. When the volume fraction of the discrete phase is not negligible compared to the continuous phase, the interaction between the continuous fluid and dispersed phase becomes significant. Two-way momentum coupling between fluid and solid particles was developed in CFD code GASFLOW. The dynamics of the discrete particles was solved by an implicit algorithm to ensure the numerical stability. The contribution of all particles to a fluid cell was treated as the source term to the continuous phase which was solved with Arbitrary-Lagrangian-Eulerian (ALE) methodology. In order to verify and validate the code, the calculation results were then compared to theoretical results, predictions of other CFD codes and experimental data. Predictions compared favorably with the experimental data. It indicates that the effect of two-way coupling is significant when the volume fraction of discrete phase is not negligible. Two-way coupling of mass, energy and turbulence will be implemented in the future development of the GASFLOW code.
Wall-Thinning Analysis of the Pipelines in the Secondary Section of NPP
Authors: Ma Na , Wang Li , Qin Jinguang
Published: February 2014

Wall-thinning investigation of three carbon steel pipe samples from secondary section of nuclear power plants has been carried out in this paper. The operating conditions of the three pipe samples are quite different, which leads to the different wall-thinning reasons and characteristics of the pipes. The chemical compositions of the steel materials, the stereomicroscope examinations, SEM examinations, as well as the XRD analysis are performed. The results show that: The wall-thinning of No.1 elbow was caused by erosion corrosion; the wall-thinning of No.2 elbow was caused by flow accelerated corrosion; the wall-thinning and crevasse of No.3 orifice plate was caused by cavitations. Measures to solve the wall-thinning problems of different pipes are also given in this paper.
Design Development of a Nuclear Standard Bidirectional Solenoid Valve to Enable PWR Fluid System Simplification
Authors: Mann Chris
Published: February 2014

Rolls-Royce has designed and manufactured Pressurised Water Reactors (PWRs) for over 50 years. This paper describes the design development of a nuclear standard bidirectional solenoid valve that can be used to simplify a valve actuating system for a PWR. In PWRs, hydraulic actuation systems to operate key plant valves can be complex, often comprising of a combination of electrical and pneumatically actuated valves. A typical arrangement uses solenoid-controlled pneumatic valves to operate hydraulically actuated valves.

A bidirectional solenoid valve was developed to eliminate the requirement for pneumatic control valves and their associated infrastructure, allowing direct solenoid valve control of the actuating water. The elimination of the pneumatic system affords benefits in terms of cost and maintenance. The solenoid valve design was developed from an existing design with proven history in the petrochemical industry. The concept design was chosen for its simplicity, but required significant development in order to meet the requirements for a PWR application.

This paper highlights some of the key developments and gives an overview of the verification and validation activities undertaken to demonstrate the functional viability of the concept design.
Experimental Analyses by SIMMER-III on Duct-Wall Failure and Fuel Discharge/Relocation Behavior
Authors: Yamano Hidemasa , Tobita Yoshiharu
Published: February 2014

This paper describes experimental analyses using SIMMER-III/IV, which are two/three-dimensional multi-component multi-phase Eulerian fluid-dynamics codes, for the purpose of the code validation. Two topics of key phenomena in core disruptive accidents were presented in this paper: duct-wall failure and fuel discharge/relocation behavior. To analyze the duct-wall failure behavior, the SCARABEE BE+3 in-pile experiments were selected. The SIMMER-III calculation was in good agreement with the overall event progression; which was characterized by coolant boiling, clad melting, fuel failure, molten pool formation, duct-wall failure, etc.; observed in the experiment. The CAMEL C6 experiment investigated the fuel discharge and relocation behavior through a simulated control rod guide tube, which is important in evaluating the neutronic reactivity. SIMMER-IV well simulated fuel-coolant interaction, sodium voiding, fuel relocation behavior observed in the experiment. These experimental analyses indicated the validity of the SIMMER-III/IV computer code for the duct wall failure and fuel discharge/relocation behavior.
Study on the SBO Coping Capability for Qinshan Phase II Unit 3
Authors: Deng Jian , Chen Bin , Deng Chunrui , Zhang Ming
Published: February 2014

The accident in Japan on March 2011 was caused by a natural event (i.e., earthquake, and the induced tsunami) which was far more severe than the design basis for the Fukushima Dai-ichi nuclear power plant. The reactor cores of Dai-ichi unit 1 through 3 have been degraded due to the long term station blackout (SBO). Actually, a nuclear power plant is able to prevent the core damage despite the SBO event occurs, called “coping capability” or “coping time”.

In this paper, the SBO coping capability is assessed for Qinshan II unit 3 based on the following: 1) reactor coolant inventory, 2) condensate inventory for decay heat removal, 3) class 1E battery capacity, 4) compressed air, 5) effects of loss of ventilation, 6) containment isolation. As a result, the SBO event tree is suggested to be updated and a few vulnerabilities have been identified and some modifications are proposed.
Characterization of Hot Deformation Behavior of Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr Using Processing Map
Authors: Luan B. F. , Qiu R. S. , Zhou Z. , Murty K. L. , Zhou J. , Liu Q.
Published: February 2014

Hot deformation characteristics of forged and β-quenched Zr-1.0Sn-0.3Nb-0.3Fe-0.1Cr (N18 alloy) in the temperature range 625–950°C and in the strain rate range 0.005–5 s−1 have been studied by uniaxial compression testing of Gleeble 3500. For this study, the approach of processing maps has been adopted and their interpretation done using the Dynamic Materials Model (DMM). Based on a series of true stress-true strain curves on various temperatures and strain rates, the flow stress has been summarized and both the strain rate sensitivity index (m) and deformation activation energy (Q) have been calculated by the constitutive equations that flow stress and the relationship of Z parameter and flow stress have been established subsequently. Furthermore, the efficiency of power dissipation (⬜) given by [2m/(m+1)] and improved by Murty has been plotted as a function of temperature and strain rate to obtain different processing maps at different true strain rates ranging from 0.1–0.7. Subsequently, the microstructures of the specimens after compression testing were characterized by electron channeling contrast (ECC) imaging techniques used an FEI Nova 400 field emission gun scanning electron microscopy (FEG-SEM). The results showed that: (i) The hyperbolic sine constitutive equation can describe the flow stress behavior of zirconium alloy, and the deformation activation energy and flow stress equation were calculated under the different temperature stages which insists that the deformation mechanism is not dynamic recovery. (ii) The hot processing maps and its validation were analyzed, which indicated that the DMM theory was reliable and could be adopted as useful tool for optimizing hot workability of Zr. The optimum parameters for extrusion and hammer forging were revealed on the processing maps of 830–950°C, 0.048–2.141 s−1 and 916–950°C, 2.465–5 s−1. (iii) The microstructure of the ingot exhibits a typical lamellar Widmanstatten structure. Under the different strain rates, the grains formed by dynamic recrystallization existed normally in the central zone of the compression samples while the no uniformity of grain size increased with the increasing of strain rate. Meanwhile, due to the dynamic recrystallization as a thermal activation process, the grains size and uniformity increased with the increasing of temperature. In brief, microstructure analysis showed that continuous dynamic recrystallization and geometric dynamic recrystallization operated concurrently during the isothermal compressive deformation.
Development and Application of Single-Phase CFD Methodology for Estimating Flow Field in Rod Bundles
Authors: Gan Fujun , Zhu Libing , Liu Jiazheng , Zheng Yixiong , Tong Xing
Published: February 2014

Computational Fluid Dynamics (CFD) simulation has been increasingly used in Nuclear Reactor Safety (NRS) analysis to describe safety–relevant phenomena occurring in the reactor coolant system in greater detail. In this paper, the work about single-phase CFD simulation of rod bundles conducted in Shanghai Nuclear Engineering Research & Design Institute (SNERDI) is introduced. A single-phase methodology based on commercial software STAR-CCM+ is developed to simulate the flow field and temperature distribution in fuel rod bundles. Solid model is simply introduced at first. Mesh types, including tetrahedral, polyhedral and trimmer, are compared in order to select the most best one with both good accuracy and less cost. Several turbulence models available in STAR-CCM+, including standard k-epsilon model, realizable k-epsilon model (RKE), shear stress transport k-omega model (SST k-omega), and Reynolds stress model (RSM) are investigated. Trimmed mesh and RKE turbulence model with two-layer all y+ model are finally employed for following calculations. Vortex structures downstream of mixing vanes is qualitatively compared with Particle Image Velocity (PIV) results, and good agreement is achieved. The present method will be further refined in order to play significant role in future optimal design of fuel assembly (FA) grid.
Numerical Simulation of Quasi Periodic Large Scale Vortices in Rod Bundles With Non-Uniform Wall Roughness
Authors: Hu Gaojie , Yu Lei , Zhang Yangwei , Yan Binghuo
Published: February 2014

The flow and heat transfer in rod bundles are of vital importance in the reactor design. Studies on the turbulent flow in tight lattice have presented the quasi periodic large scale vortex structure is highly accounted for the local flow and heat transfer and turbulent mixing in rod bundles.

In this work, the Unsteady Reynolds Averaged Navier–Stokes (URANS) simulation with the Reynolds Stress Model (RSM) is adopted to simulate the flow and vortex structure in rod bundles. The vortex structure in sparse lattice with nonuniform wall roughness is also investigated and compared with that in tight lattice. The results indicate that the quasi periodic large scale vortex structure and flow pulsation are available in both tight lattice and the sparse lattice with non-uniform wall roughness. Due to the existence of the vortex structure, the heat transfer in spare lattice is enhanced.
Analysis of the Thermal Hydraulic Phenomena Caused by Steam Jets in AP1000 Containment
Authors: Hu Yingqiu , Yu Yu , Niu Fenglei , Liu Xin , Zhao Ruichang
Published: February 2014

In order to get a better analysis of the thermal hydraulic phenomena related to steam jets in AP1000 containment, a model based on the actual AP1000 containment size has been used to simulate the steam jet injection at different positions with different velocities of the containment. ANSYS CFX is used to get the temperature profiles of the ambient fluid. From the results of the simulation, stratification can be expected in the gas spaces of the containment, because the temperature only changes along with the vertical height, due to the heat or mass transfer processes between the air and the steam jets. It can be predicted that the hot air rises and eventually stratification forms, with lighter air overlying the heavier air. In this paper, strong and weak steam jet injections have been both simulated by ANSYS CFX, however, it turned out that stable stratification phenomena can only be found in weak steam jet injections, strong injections can’t form obvious stratification. This is very important for the design and operation of AP1000 containment, and can help us to study the long-term containment behavior during LOCAs.
The Influence of Non-Uniform Heating on Two-Phase Flow Instability in Parallel Channels
Authors: Lu Xiaodong , Zhou Linglan , Zhang Hong , Wu Yingwei , Su Guanghui , Qiu Suizheng
Published: February 2014

The two-phase flow instability in parallel channels heated by uniform and non-uniform heat flux has been theoretically studied in this paper. Based on the homogeneous flow model in two-phase region, the system control equations of parallel channels were established. Semi-implicit finite-difference method and staggered mesh method were used to discretize the system control equations and the difference equations were solved with a chasing method. The cosine profile and uniform constant heat flux represent the non-uniform and uniform heating condition, respectively. The marginal stability boundaries (MSB) of parallel channels and the three-dimensional instability spaces (or instability reefs) of different heat flux models were obtained. For cosine profile heating, the stability of parallel channels increases with the increase of the system pressure and inlet resistant coefficient. In high inlet subcooling region, cosine heat flux can strengthen the system stability. However, in low inlet subcooling region, the negative effect to system stability will be caused by non-uniform heating. The increase of inlet resistant coefficient will move the turning point of the MSB to high inlet subcooling number.
A Conceptual Design of a Small Modular Natural-Circulation Liquid Metal Fast Reactor With AMTEC Units
Authors: Zhang Xun , Lu Daogang
Published: February 2014

A conceptual design of a low power liquid metal fast reactor with Alkali-metal thermal-to-electric conversion (AMTEC) units is presented. The small modular reactor (SMR) can operate in remote locations as a distributed energy system. This paper provides the layout of the main components of the plant and main design parameters. The reactor core power of 2MW (t) may be completely removed by natural circulation, thus there is no need for primary pumps. Passive heat removal system (PHRS) is adopted to remove the decay heat. In addition, it could also be activated when part of the energy conversion units are disabled. AMTEC unit is a good candidate for converting the reactor power to electricity. An expanded AMTEC tube bundle system and the layout of power conversion system are both presented. The converters are coupled to the primary loop through six independent secondary loops. Liquid-liquid intermediate heat exchangers (IHXs) would be used to connect the primary loop and secondary loops as well as power conversion system and secondary loops. The design objectives for SMR-AMTEC system are to provide a greatly simplified power system with respect to design, construction, operation and maintenance.
Response Functions of a Cs2LiYCl6 Scintillator to Neutron and Gamma Radiation
Authors: Khan Nafisah , Machrafi Rachid , Kovaltchouk Vitali
Published: February 2014

A new scintillator, CLYC, has been investigated for possible use in neutron spectrometry. This sensor provides neutron detection for both thermal and fast neutrons from the reactions 6Li(n,α) and 35Cl(n,p), respectively. This work primarily focuses on the detection of fast neutrons since there is currently no sensor that can accurately and efficiently provide information about their incident neutron energy. Conventional methods of fast neutron detection have been based on utilizing materials that use the elastic scattering process of neutrons on 1H to create recoil protons or by thermalizing and capturing these neutrons at thermal energies. Both approaches have drawbacks and are complex in deriving the energy spectrum through the unfolding process. The CLYC scintillator uses a distinct proton peak, whereby the position on the spectrum is proportional to the energy of the incident neutron.

The response function of this detector has been simulated using Monte Carlo N-Particle eXtended code (MCNPX) for gamma-rays and neutrons of different energies. The obtained data has been discussed and analyzed.
Discussing the Modification of Dedicated Lines Used for Severe Accident Depressurization
Authors: Zhang Bo , Liu Jing , Liu Xichao , Gao Yafu , Gong Aicheng
Published: February 2014

A barrier that limits the development of the nuclear power plants is the problem of the depressurization for severe accidents. The present work addresses this issue by adding the dedicated severe accident depressurization system that is placed on the top of the pressurizer. This design enables the excessive heat to be directly pumped into the atmosphere to lower the pressure in the containment. The theoretical and numerical results indicated that the addition of the dedicated severe accident depressurization system does not affect the performance of the second generation of PWRs. More importantly, this design not only significantly reduces the LERF value but also facilitates the modification of the present structure.
Assessment of Subchannel Code ASSERT-PV for Flow-Distribution Predictions
Authors: Nava-Dominguez A. , Rao Y. F. , Waddington G. M.
Published: February 2014

The recently released ASSERT-PV 3.2 code version provides improvements in the predictions of flow distribution, critical heat flux (CHF) and dryout power, and post-dryout (PDO) fuel sheath temperatures. This paper summarizes the flow distribution prediction improvements achieved with the new code version, by comparing code predictions against subchannel measurements from four experiments.
Experimental Study on Adsorption of Carbon Dioxide on 13X Molecular Sieve for Coolant Helium Purification
Authors: Chang Hua , Ma Tao , Liu Ling , Yin Hua-Qiang , He Xue-Dong
Published: February 2014

The adsorption capability of carbon dioxide on 13X molecular sieve (13XMS) was investigated in a fixed-bed apparatus with two-road gas mixing system by dynamic column breakthrough method with helium as carrier gas at helium purification conditions of high-temperature gas-cooled reactor (HTGR). Experiments were performed at temperatures of 5°C ∼35 °C and low carbon dioxide partial pressure range of 10∼150Pa. By analyzing the breakthrough curve, both equilibrium adsorption capacity and kinetic adsorption capacity at breakthrough point were determined. Based on mass-transfer zone model, the experimental breakthrough curves at different operation conditions were analyzed. The carbon dioxide isotherm on 13XMS was fitted well by Langmuir model and the enthalpy of adsorption of carbon dioxide was estimated.