bluuebunny/crossref_metadata_2025 huggingface dataset:
Pubic Hair Preferences, Reasons for Removal, and Associated Genital Symptoms: Comparisons Between Men and Women
Authors: Butler Scott M. , Smith Nicole K. , Collazo Erika , Caltabiano Lucia , Herbenick Debby
Published: November 2014

Introduction

Pubic hair grooming and removal are common behaviors among men and women. However, little is known about the reasons for grooming, preferred pubic hairstyle of sexual partners, and symptoms associated with regular grooming.

Aims

This study aims to assess pubic hair removal/grooming practices, pubic hairstyle preferences, and genital outcomes associated with pubic hair removal among men and women in a college sample.

Methods

Data were gathered from 1,110 participants (671 women and 439 men) at a large public Midwestern university and a small Southern public university.

Main Outcome Measures

Items assessed demographics, pubic hair grooming and removal practices in the past 4 weeks, reasons for pubic hair status, preference for pubic hairstyle of sexual partners, and symptoms associated with removal and grooming.

Results

Most (95%) participants had removed their pubic hair on at least one occasion in the past 4 weeks with shaving being the most commonly reported hair removal technique by women (82%) and men (49%). Women were significantly more likely to report their typical status as hair-free (50% vs. 19%; χ2 = 165.528, P < 0.001) and men were significantly more likely to prefer a hair-free sexual partner (60% vs. 24%; χ2 = 211.712, P < 0.001). Genital itching was experienced on at least one occasion by 80.3% of pubic hair groomers and was the most commonly reported side effect.

Conclusion

Genital grooming and pubic hair removal are common practices among both men and women of college-age. Women are likely to report stronger associations with feelings of cleanliness, comfort, sex appeal, social norms of their peer group, and affordability as reasons for their chosen pubic hair style. Women also report more experiences with genital side effects of pubic hair removal, an expected result as women are removing pubic hair more frequently and more completely than their male counterparts.
Transnational Sisterhood? Brazilian Feminisms Facing Prostitution
Authors: Piscitelli Adriana
Published: November 2014

During the 1980s, the sex wars concerning feminism and prostitution had little effect on Brazilian feminisms. Although prostitution was far from central in this “second wave” of feminism in Brazil, which was organized around fighting the military regime, struggling for democracy and amnesty, and confronting specific struggles against male domination, it provoked curiosity, and a certain proximity grew between feminists and prostitutes. During the decades of 2000 and 2010, networks and coalitions of Brazilian feminists with transnational articulations have increasingly adopted an abolitionist position, denying the differences between prostitution and sex trafficking and refusing to listen to the voices of organized prostitutes. In this article I analyze this complex process, based on research conducted between 2004 and 2011 with an anthropological approach on transnational sex markets and sex trafficking, in which I interviewed Brazilian prostitutes in this country and abroad, feminists, and agents in different positions of the Brazilian state.
Peasant Women in Latin America: Transnational Networking for Food Sovereignty as an Empowerment Tool
Authors: Pinheiro Machado Brochner Gabriela
Published: November 2014

Inside La Via Campesina, a transnational network of social movements, it is possible to identify women networks through specific struggles. This article aims to analyze how women have built their networking for food sovereignty as a cornerstone of labor within La Via Campesina using a multiscale perspective. The objectives are to identify how peasant women networks use the claim of food sovereignty and how they use the boomerang mechanism at different spatial levels. It further attempts to identify how food sovereignty is linked to other gender claims, such as combating gender violence, to become a tool of emancipation and empowerment of rural women in Latin America. It will consider how transnational networking operates to empower them.
Petrography, stable isotope compositions, microRaman spectroscopy, and presolar components of Roberts Massif 04133: A reduced CV3 carbonaceous chondrite
Authors: Davidson Jemma , Schrader Devin L. , Alexander Conel M. O'D. , Lauretta Dante S. , Busemann Henner , Franchi Ian A. , Greenwood Richard C. , Connolly Harold C. , Domanik Kenneth J. , Verchovsky Alexander
Published: November 2014

Here, we report the mineralogy, petrography, C‐N‐O‐stable isotope compositions, degree of disorder of organic matter, and abundances of presolar components of the chondrite Roberts Massif (RBT) 04133 using a coordinated, multitechnique approach. The results of this study are inconsistent with its initial classification as a Renazzo‐like carbonaceous chondrite, and strongly support RBT 04133 being a brecciated, reduced petrologic type >3.3 Vigarano‐like carbonaceous (CV) chondrite. RBT 04133 shows no evidence for aqueous alteration. However, it is mildly thermally altered (up to approximately 440 °C); which is apparent in its whole‐rock C and N isotopic compositions, the degree of disorder of C in insoluble organic matter, low presolar grain abundances, minor element compositions of Fe,Ni metal, chromite compositions and morphologies, and the presence of unequilibrated silicates. Sulfides within type I chondrules from RBT 04133 appear to be pre‐accretionary (i.e., did not form via aqueous alteration), providing further evidence that some sulfide minerals formed prior to accretion of the CV chondrite parent body. The thin section studied contains two reduced CV3 lithologies, one of which appears to be more thermally metamorphosed, indicating that RBT 04133, like several other CV chondrites, is a breccia and thus experienced impact processing. Linear foliation of chondrules was not observed implying that RBT 04133 did not experience high velocity impacts that could lead to extensive thermal metamorphism. Presolar silicates are still present in RBT 04133, although presolar SiC grain abundances are very low, indicating that the progressive destruction or modification of presolar SiC grains begins before presolar silicate grains are completely unidentifiable.
Extracellular ATP: a potential regulator of plant cell death
Authors: Feng Hanqing , Guan Dongdong , Bai Jingyue , Sun Kun , Jia Lingyun
Published: November 2014

Adenosine 5′‐triphosphate (ATP) has been regarded as an intracellular energy currency molecule for many years. In recent decades, it has been determined that ATP is released into the extracellular milieu by animal, plant and microbial cells. In animal cells, this extracellular ATP (eATP) functions as a signalling compound to mediate many cellular processes through its interaction with membrane‐associated receptor proteins. It has also been reported that eATP is a signalling molecule required for the regulation of plant growth, development and responses to environmental stimuli. Recently, the first plant receptor for eATP was identified in Arabidopsis thaliana. Interestingly, some studies have shown that eATP is of particular importance in the control of plant cell death. In this review article, we summarize and discuss the theoretical and experimental advances that have been made with regard to the roles and mechanisms of eATP in plant cell death. We also make an attempt to address some speculative aspects to help develop and expand future research in this area.
Net endogenous acid production and mortality in NHANES III
Authors: Huston Hunter K , Abramowitz Matthew K , Zhang Yingying , Greene Tom , Raphael Kalani L
Published: November 2014

Aim

Low serum bicarbonate is a strong mortality risk factor in people with low estimated glomerular filtration rate (eGFR). It may also raise mortality risk in people with normal eGFR. This study investigated whether higher net endogenous acid production (NEAP), an estimate of net dietary acid intake and a risk factor for chronic kidney disease (CKD) progression, associates with higher mortality in people with and without low eGFR.

Methods

NEAP was calculated among adult participants in the Third National Health and Nutrition Examination Survey as −10.2 + 54.5 x (protein intake in grams per day/potassium intake in milliequivalent per day). Cox models were performed in the (i) total population and (ii) low eGFR and (iii) normal eGFR subgroups using the lowest NEAP quartile as the reference.

Results

Sixteen thousand nine hundred six participants were included in the analysis. The mortality hazard ratios (95% confidence interval) for the highest NEAP quartile (72–145 mEq/day) were: (i) 0.75 (0.62–0.90) in the total population; (ii) 0.77 (0.51–1.17) in the low eGFR subgroup; and (iii) 0.75 (0.61–0.93) in the normal eGFR subgroup after adjusting for demographics, serum bicarbonate, eGFR, albuminuria and comorbidities. The mortality hazard ratios in the second and third NEAP quartiles were similar to the lowest (reference) NEAP quartile in the total population and low and normal eGFR subgroups.

Conclusions

Higher NEAP is not associated with higher mortality in people with low or normal eGFR. Future studies should consider the effect of modifying dietary acid and alkali intake on mortality and CKD progression in people with reduced eGFR.
What carers and family said about music therapy on behaviours of older people with dementia in residential aged care
Authors: Tuckett Anthony G. , Hodgkinson Brent , Rouillon Lisa , Balil‐Lozoya Tania , Parker Deborah
Published: November 2014

Aim

This study sought to evaluate the effectiveness of group music therapy (MT) intervention on behaviours of older people with dementia.

Method

Reported here are qualitative data from five, semi‐structured focus groups; two comprising a total of seven family members and three comprising a total of 23 staff members.

Results

A number of core themes emerged: temporality, effect and policy with a number of subthemes. The MT effect is tempered by the temporality of (i) the older person's dementia state, (ii) the session and (iii) the psychosomatic effect on the older person. Music therapy is perceived to (i) evoke memories and facilitate reminiscence, (ii) act as a diversion (has an instrumental value) and it is contentious to discount the (iii) dichotomy between music and therapist in terms of the overall effect. Finally, policymakers need to know that MT is (i) highly prized and more, not less, MT is recommended.

Conclusion

Findings from this study illustrate that the timing of the MT session has consequences for the workflow in the residential aged care facility; MT has a psychosomatic effect and participants here evaluate this as temporal. Care providers and family members acknowledge the instrumental value of MT and its helping with cognition and exercise. They have mixed views about the effects of the music and the effect on the older person by the therapist but most definitely want policymakers to ensure more, not less, planned and better funded MT is part of ongoing care in the residential aged care context. Areas for future research and policy are also highlighted.

Implications for practice

These views on group MT in residential aged care can initiate critical reflection on current practices and systems. Research is needed exploring the timing and scheduling of MT sessions at different times in the day for older person with dementia exhibiting negative behaviours.
Automatically Analyzing Large Texts in aGISEnvironment: The Registrar General's Reports and Cholera in the 19th Century
Authors: Murrieta‐Flores Patricia , Baron Alistair , Gregory Ian , Hardie Andrew , Rayson Paul
Published: November 2014

The aim of this article is to present new research showcasing how Geographic Information Systems in combination with Natural Language Processing and Corpus Linguistics methods can offer innovative venues of research to analyze large textual collections in the Humanities, particularly in historical research. Using as examples parts of the collection of the Registrar General's Reports that contain more than 200,000 pages of descriptions, census data and vital statistics for theUK, we introduce newly developed automated textual tools and well known spatial analyses used in combination to investigate a case study of the references made to cholera and other diseases in these historical sources, and their relationship to place‐names during Victorian times. The integration of such techniques has allowed us to explore, in an automatic way, this historical source containing millions of words, to examine the geographies depicted in it, and to identify textual and geographic patterns in the corpus.
Georeferencing Animal Specimen Datasets
Authors: van Erp Marieke , Hensel Robert , Ceolin Davide , van der Meij Marian
Published: November 2014

For biodiversity research, the field of study that is concerned with the richness of species of our planet, it is of the utmost importance that the location of an animal specimen find is known with high precision. Due to specimens often having been collected over the course of many years, their accompanying geographical data is often ambiguous or may be very imprecise. In this article, we detail an approach that utilizes reasoning and external sources to improve the geographical information of animal finds. Our main contribution is to show that adding external domain knowledge improves the ability to georeference locations over traditional methods that focus solely on analyzing geographical information. Additionally, our system is able to output the confidence it has in its decisions through a confidence measure based on the difficulty of the instance and the steps undertaken to disambiguate it. Our results show that adding domain knowledge to the georeferencing process increases the accuracy @5km from 38.9% to 61.7% and from 47.0% to 74.5% @25km. Furthermore, we reduce the mean distance by more than half, from 251.1km to 114.5km, and decrease the number of records for which no reference can be found from 26.2% to 7.4%.
Intraoperative platelet transfusion is associated with increased postoperative sternal wound infections among type A aortic dissection patients after total arch replacement
Authors: Wu B. , Wang Y. , Wang C. , Cheng Y. , Rong R.
Published: November 2014

SUMMARY

Background

Blood transfusion and its impact upon clinical outcomes of cardiac surgery have been extensively discussed, especially in the post‐aprotinin era. This study compared clinical outcomes and perioperative blood utilisation among acute type A aortic dissection (AAD) patients with or without intraoperative platelet transfusion during total arch replacement, thus intending to investigate prognostic value of platelet transfusion during major aortic surgeries.

Materials and Methods

Acute AAD patients undergoing total arch replacement and stented elephant trunk procedure under hypothermic circulatory arrest with and without intraoperative platelet transfusion at our institute from January 2008 to December 2012 were retrospectively included. Patients were categorised into PLT (n = 74) and non‐PLT (n = 85) groups to compare the in‐hospital mortality and complications, as well as blood components utilisation.

Results

Baseline characteristics and operational features were all comparable between two groups. In PLT group, in‐hospital survival was not improved and intraoperative utilisation of red blood cell RBC, fresh frozen plasma (FFP) and cryoprecipitate was not reduced. Postoperative RBC transfusion [2·0(0–4·0) vs 0(0–4·0) U, p = 0·026; 64·9 vs 43·5%, p = 0·007] was significantly increased in PLT group, parallel with the prolonged postoperative hospitalisation time [(24·0 ± 12·7) vs (20·8 ± 10·9) days, p = 0·093] and elevated incidence of sternal wound infections (16·2 vs 5·9%, p = 0·035). Intraoperative platelet transfusion [odds ratio (OR): 3·10, 95% confidence interval (CI): 1·04–9·25, p = 0·043] was identified as independent risk factor of postoperative sternal wound infections by multivariate logistic regression analysis.

Conclusion

Intraoperative platelet transfusion did not improve in‐hospital prognosis among AAD patients after total arch replacement. The incidence of postoperative sternal wound infections increased among those who received intraoperative platelet transfusion.
Virtual leak channels modulate firing dynamics and synaptic integration in rat sympathetic neurons: implications for ganglionic transmission in vivo
Authors: Springer Mitchell G. , Kullmann Paul H. M. , Horn John P.
Published: November 2014

Key points

The synaptic organization of paravertebral sympathetic ganglia enables them to relay activity from the spinal cord to the periphery and thereby control autonomic functions, including blood pressure and body temperature.

The present experiments were done to reconcile conflicting observations in tissue culture, intact isolated ganglia and living animals. By recording intracellularly from dissociated neurons and intact ganglia, we found that when electrode damage makes cells leaky it could profoundly distort cellular excitability and the integration of synaptic potentials.

The experiments relied on the dynamic clamp method, which allows the creation of virtual ion channels by injecting current into a cell based upon a mathematical model and using rapid feedback between the model and cell.

The results support the hypothesis that sympathetic ganglia can produce a 2.4‐fold amplification of presynaptic activity. This could aid understanding of the neural hyperactivity that is believed to drive high blood pressure in some patients.

The excitability of rat sympathetic neurons and integration of nicotinic EPSPs were compared in primary cell culture and in the acutely isolated intact superior cervical ganglion using whole cell patch electrode recordings. When repetitive firing was classified by Hodgkin's criteria in cultured cells, 18% displayed tonic class 1 excitability, 36% displayed adapting class 2 excitability and 46% displayed phasic class 3 excitability. In the intact ganglion, 71% of cells were class 1 and 29% were class 2. This diverges from microelectrode reports that nearly 100% of superior cervical ganglion neurons show phasic class 3 firing. The hypothesis that the disparity between patch and microelectrode data arises from a shunt conductance was tested using the dynamic clamp in cell culture. Non‐depolarizing shunts of 3–10 nS converted cells from classes 1 and 2 to class 3 dynamics with current–voltage relations that replicated microelectrode data. Primary and secondary EPSPs recorded from the intact superior cervical ganglion were modelled as virtual synapses in cell culture using the dynamic clamp. Stimulating sympathetic neurons with virtual synaptic activity, designed to replicate in vivo recordings of EPSPs in muscle vasoconstrictor neurons, produced a 2.4‐fold amplification of presynaptic activity. This gain in postsynaptic output did not differ between neurons displaying the three classes of excitability. Mimicry of microelectrode damage by virtual leak channels reduced and eventually obliterated synaptic gain by inhibiting summation of subthreshold EPSPs. These results provide a framework for interpreting sympathetic activity recorded from intact animals and support the hypothesis that paravertebral ganglia function as activity‐dependent amplifiers of spinal output from preganglionic circuitry.
Characteristics of Droplet Formation During Spout Process of Water Ingress Accident
Authors: Zheng Yanhua , Sun Jun , Chen Zhipeng , Shi Lei
Published: November 2014

Water ingress is one of the peculiar accidents of high temperature gas-cooled reactors (HTR). Since the pressure of the secondary circuit is higher than that of the primary circuit, when the break of heating tubes of the SG occurs, liquid water and steam will enter the primary circuit from the secondary side, and then enter the reactor core together with the helium coolant. This will result in introduction of a certain positive reactivity, rising of the primary pressure and corrosion of the in-core fuel elements and graphite components. Therefore, water ingress is a complex physical processes involving water spout, flash evaporation, multi-phase flow, heat transfer and other phenomena, and in-depth research of this accident will benefit further understanding of the characteristics of HTRs.

Based on the preliminary design of the Chinese high temperature gas-cooled reactor pebble-bed modular (HTR-PM), assuming that the break of steam generator (SG) heating tube can be considered as a round pressure nozzle, the characteristics of the flow line at breaks with different diameters, as well as the property of the droplet spectrum are studied. According to the analysis of droplet properties of flow and evaporation in the primary circuit, the preliminary result shows that under the design basis accidents of water ingress, the water will enters the reactor core in the form of steam. This analysis result can provide a basis for the further research of water ingress of HTR in the future.
Materials and Stress Analysis of Fuel-Channel of a Generic 1200-MWel Pressure-Channel Reactor With Nuclear Steam Reheat
Authors: Abdullah Rand , Baldock Matthew , Vincze Andrei , Sidawi Khalil , Pioro Igor
Published: November 2014

The objective of this paper is to modify the current existing CANFLEX® fuel-bundle design to examine its ability to withstand high-temperature conditions of a proposed generic reactor with nuclear steam reheat. One of this reactor’s characteristics is having Super-Heated Steam (SHS) channels in addition to Pressurized-Water (PW) channels in order to increase the thermal efficiency of the plant by about 7–12%. This increase may be attained by raising the outlet temperature of the SHS-channels coolant to about 550°C. Operating at the higher temperatures will definitely have an effect on the mechanical and neutronic properties of fuel-channel materials, specifically on fuel-sheath and pressure-tube materials.

This paper compares Inconel-600 and SS-304 in order to determine the most suitable material for SHS-channel’s sheath and pressure tube. This is achieved by comparing strength of materials by performing stress- and displacement-analysis simulation using NX8.5 software (NX8.5, 2009).

The analysis in this paper can also be applied to other Nuclear-Power Plants (NPPs) that require operating at higher temperatures such as Super-Critical Water-cooled Reactors (SCWRs).
Numerical Simulations on Supercritical Water Flow Instability
Authors: Li Jingjing , Zhou Tao , Song Mingqiang , Huang Yanping
Published: November 2014

3-D simulation of supercritical water flow instability in parallel channels and a natural circulation loop are presented. Results are obtained for various heating powers. The results show that, in the natural circulation loop the steady state mass flow will firstly increase with the heating power and then decrease. And mass flow grows with the growing of the inlet temperature, decreases with the growing of system pressure. Under a large heat flux, the parallel channels will experience the flow instability of out phase mass flow oscillation. And the oscillation amplitude will grow with the growing of heating power. At last, the numerical simulations are validated by B.T. Swapnalee’s experience formula.
Studies on Maintainability and Repairability for Japan Sodium-Cooled Fast Reactor (JSFR)
Authors: Isono Kenichi , Kubo Shigenobu , Chikazawa Yoshitaka , Dozaki Koji , Oya Takeaki , Yui Masahiro
Published: November 2014

Aiming at enabling maintenance and repair of almost all components in JSFR demonstration reactor to a level equivalent to that attained for the light water reactors, we identified a number of parts which have difficulty in maintenance and repair in main components of the reactor structure and the primary/secondary main coolant system. And we defined the criteria for design improvement and then provided candidates of improvement measures for the identified parts.

Furthermore, we made a modification of the plant design in a consistent manner integrating the improvements investigated for each major component. A series of evaluations were conducted to check the feasibility as a power plant. As the result, we found that the concept could be adopted not only to the demonstration reactor (750MWe) but to the commercial one (1500MWe).
Experimental Study of the Characteristics of Heat Transfer and HLMC Cross-Flow Around Tubes
Authors: Chernysh Aleksei , Iarmonov Mikhail , Makhov Kirill , Beznosov A. V.
Published: November 2014

The process of heat transfer in a heavy liquid-metal coolant (HLMC) cross-flow around heat-transfer tubes is not yet thoroughly studied. Therefore, it is of great interest to carry out experimental studies for determining the heat transfer characteristics in a lead coolant cross-flow around tubes. It is also interesting to explore the velocity and temperature fields in a HLMC flow.

To achieve this goal, experts of the R.E. Alekseev Nizhny Novgorod State Technical University performed the work aimed at the experimental determination of the temperature and velocity fields in high-temperature lead coolant cross-flows around a tube bundle.

The experimental studies were carried out in a specially designed high-temperature liquid-metal facility. The experimental facility is a combination of two high-temperature liquid-metal setups, i.e., FT-2 with a lead coolant and FT-1 with a lead-bismuth coolant, united by an experimental site.

The experimental site is a model of the steam generator of the BREST reactor facility. The heat-transfer surface is an in-line tube bank of a diameter of 17×3.5 mm, which is made of 10H9NSMFB ferritic-martensitic steel. The temperature of the heat-transfer surface is measured with thermocouples of a diameter of 1 mm being installed in the walls of heat-transfer tubes. The velocity and temperature fields in a high-temperature HLMC flow are measured with special sensors installed in the flow cross section between the rows of heat-transfer tubes.

The characteristics of heat transfer and velocity fields in a lead coolant flow were studied in different directions of the coolant flow: the vertical (“top-down” and “bottom-up” [1]) and the horizontal ones. The studies were conducted under the following operating conditions: the temperature of lead was t=450–500°C, the thermodynamic activity of oxygen was a=10−5−100, and the lead flow through the experimental site was Q = 3–6 m3/h, which corresponds to coolant velocities of V = 0.4–0.8 m/s.

Comprehensive experimental studies of the characteristics of heat transfer in a lead coolant cross-flow around tubes have been carried out for the first time and the dependences NU = f(Pe) for a controlled and regulated content of the thermodynamically active oxygen impurity and sediments of impurities have been obtained.

The effect of the oxygen impurity content in the coolant and characteristics of protective oxide coatings on the temperature and velocity fields in a lead coolant flow is revealed. This is because the presence of oxygen in the coolant and oxide coatings on the surface, which restrict the liquid-metal flow, leads to a change in the characteristics of the wall-adjacent region.

The obtained experimental data on the distribution of the velocity and temperature fields in a HLMC flow permit studying the heat-transfer processes and, on this basis, creating program codes for engineering calculations of HLMC flows around heat-transfer surfaces.
Experimental Study on Resistance Characteristics in a 3 × 3 Rod Bundle
Authors: Yan Chaoxing , Yan Changqi , Sun Licheng , Wang Yang
Published: November 2014

Experimental study on resistance of air-water two-phase flow in a vertical 3 × 3 rod bundle was carried out under normal temperature and pressure. The rod diameter and pitch were 8 mm and 11 mm, respectively. The ranges of gas and liquid superficial velocity were 0.013∼3.763 m/s and 0.076∼1.792 m/s, respectively. The result indicated that the existing correlations for calculating frictional coefficient in the rod bundle and local resistance coefficient could not give favorable predictions on the single-phase experimental data. For the case of two-phase flow, eight correlations for calculating two-phase equivalent viscosity poorly predicted the frictional pressure drop, with the mean absolute errors around 60%. Meanwhile, the eight classical two-phase viscosity formulae were evaluated against the local pressure drop at spacer grid. It is shown that Dukler model predicted the experimental data well in the range of Rel<9000 while McAdams correlation was the best for Rel⩾9000. For all the experimental data, Dukler model provided the best prediction with MRE of 29.03%. Furthermore, approaches to calculate two-phase frictional pressure drop and local resistance were proposed by considering mass quality, two-phase Reynolds number and densities in homogenous flow model, resulting in a good agreement with the experimental data.
Investigating the Natural Convection Behavior in the Transportable Storage Canister of Dry Storage Systems Through CFD Simulation
Authors: Tseng Yung-Shin , Chen Chun-Yu , Ferng Yuh-Ming , Shih Chunkuan
Published: November 2014

The dry storage system (DSS) is a major interim storage method for the spent nuclear fuel (SNF). The passive cooling concept and sealed fuel canister design provide the better safety and retrievability capability for SNF management. However, the sealed design of DSS causes that the internal status of transportable storage canister (TSC) is difficult to monitor for operation requirement. The issue means that many kinds of safety events, such as the re-filling gas leakage issue of TSC, half-blockage and fully-blockage cannot be early detected by present measurement method. In this study, a validated CFD simulation methodology has been employed to investigate the relationship between the natural convection behavior of DSS and shell temperature distribution of the TSC. All possible accidents (e.g., re-filling gas leakage, half-blockage, and fully-blockage) are considered in this investigation. The results show that those accidents will influence the convection behavior and further change the temperature profile of the TSC shell. The quantified comparison also shows that the minimum deviation of temperature is large enough to measured and will increased with heat load increasing. This results implying that the change of status of DSS can be determined by the temperature values and profile of TSC. Finally, a two measure point method has been purposed and proofed in this study. It proof that the major accident of DSS, such as the re-filling gas leakage, half-blockage and full blockage for a DSS can be confirmed through the purposed measured method.
Experience Gained From the Living PSA Project for Dukovany NPP
Authors: Hust’ák Stanislav
Published: November 2014

PSA specialists in ÚJV Řež, a. s. maintain a Living Probabilistic Safety Assessment (Living PSA) program for Dukovany Nuclear Power Plant (NPP), a four-unit VVER-440 plant type, which is operated in the Czech Republic. This project has been established as a broad framework for all plant activities related to risk assessment and as a support for risk-informed decision making carried out at this plant. In addition to recommendations for design and operation measures in order to increase the plant safety, it provides a basis and platform for all PSA applications at Dukovany NPP.

The Living PSA model for Dukovany NPP is an integrated model representing the complete scope of Level 1 and Level 2 PSA for all plant operational modes. It produces the unit specific outputs for any Dukovany NPP unit. The RiskSpectrum® PSA software has been used for development and quantification of the PSA model. It is continuously updated and extensively used for various PSA applications at Dukovany NPP (e.g. risk monitoring, evaluation of plant Technical Specification changes, support for procedure development and training process, event analysis, etc.).

The paper focuses on the important features of the Living PSA project for Dukovany NPP. It also discusses the broad experience gained during model development and update as well as possible future enhancements.
HT9 Strain Modeling for Fuel Pin Deformation
Authors: Hackett Micah , Latta Ryan , Miller Sam , Xu Cheng
Published: November 2014

The TerraPower Traveling Wave Reactor (TWR) is a sodium-cooled fast reactor design that utilizes a high-burnup metallic uranium fuel cycle. The fuel system depends on a cladding material with demonstrated swelling resistance to high doses as well as adequate thermal creep strength. HT9 steel is a leading cladding candidate for the first TWR, having demonstrated excellent swelling and strain performance to doses > 200 dpa. A strain model was developed as a design tool to predict fuel pin deformation as a function of irradiation dose, stress, and temperature. The sources of strain deformation will be described along with the uncertainties in utilizing existing data to build a mechanistic model. The strain model is then incorporated into a fuel performance code to provide new insight in deformation behavior of HT9 fuel pins.
Subchannel Analysis of Large Power PWR
Authors: Xie Fei
Published: November 2014

Researches of steady-state thermal hydraulic performance of a large power PWR had been made using the COBRA III C/MIT-2 code. The basic thermal hydraulic parameters and characteristics of the core channels were studied. The results showed that the hottest channel and the maximum enthalpy rise hot channel were not boiling. The result will lay the foundation for further studies in the thermal-hydraulic design of a large advanced PWR.
Visualization Investigation of Secondary Flow on Heat Transfer Deterioration in Horizontal Heat Tube
Authors: Wu Chao , Li Hui-xiong , Zhang Qian
Published: November 2014

Mixed convection heat transfer in heated tubes has been studied extensively in the past decades, which is widely used in various industrial fields such as cooling of a nuclear reactor core. The secondary flow, which is induced by buoyancy force, has been found in previous research to have profound influence on the heat transfer difference on circumferential position and occurrence of heat transfer deterioration in horizontal heated channel. Therefore, understanding the secondary flow velocity field has important implications to prevent heat transfer deterioration and ensure the safe operation of nuclear power plants. Numerical methods have been adopted in literature to analyze the complex interaction between secondary flow and heat transfer deterioration. However, to the knowledge of the author, experimental measurement of secondary flow in the radial cross-section of a horizontal tube does not exist.

In this paper, a novel measurement method, which combines the transparent heating and PIV (Particle Image Velocimetry) technology, has been adopted to experimentally investigate the secondary flow velocity field on the radial cross-section in a horizontal heated tube. The heat transfer deterioration mechanism is revealed through analysis of the distribution of secondary flow along circumference direction at low mass flow rates and high heat flux conditions. We found that the buoyancy force lead the hot fluid to rise along the tube wall from bottom to top. While the secondary flow is most intensive near the middle of the interface, the secondary velocities are high at the bottom of the cross-section, where the tube wall is well cooled by cold fluid descends from the central part of the cross-section. Near the top of the tube wall, the secondary velocities are very small and the thermal acceleration effect makes the fluid rise. As a result, the mixed convection of top and center part of cross-section is weak and heat is primarily transferred by conduction, which leads the occurrence of thermal stratification of fluid. Consequently, the thermal accumulation of fluid in the top leads to heat transfer deterioration. Moreover, thermal properties differences between Freon (FC-72) and water, especially the Prandtl number (Pr), make the occurrence of heat transfer deterioration much easier for FC-72 than water with same working conditions.
The Controllability of the Point Reactor Neutron Kinetics Equations
Authors: Liu Dong , Luan Xiuchun , Yu Tao , Zhao Weining , Liu Lei
Published: November 2014

In this paper, the conditions to ensure the controllability of the point reactor neutron kinetics equations are studied. In a nuclear reactor, due to the delayed neutron precursor concentration and the internal reactivity, the kinetics equations of the nuclear reactor are nonlinear. To solve the problem of the pole placement, the controllability of the point kinetics equations must be guaranteed. Then, a new method to analysis of the controllability conditions of the point kinetics equations of a reactor is carried out here. The method is based on the controllability matrix directly denoted by relevant symbols, and a formula used for controllability analysis is showed with symbols by calculating the determinant of the matrix. First, with using the linearization technique, the equations are linearized with respect to any possible equilibrium point. Subsequently, an analysis of the controllability of the general linear model that includes only one group delayed neutron precursor is performed, obtaining the interesting result that the controllability of the equations are controllable except when the effective precursor radioactive decay constant and the reciprocal of the fuel-to-coolant heat transfer mean time have the same value, which does not occur in practice. Thus, with the same method, the other analysis obtained the conditions to guarantee the controllability of the point kinetics equations with different groups delayed neutron precursor, which includes two-group, three-group and six-group models. Then, the results are compared with that of the numerical controllability matrix, obtaining the final conclusion that the results of the new analysis method give the closer results to the actual situation and list the restrictions that guarantee the controllability of the point reactor neutron kinetics equations.
Diffusion Coefficients of Metallic Impurities in High Temperature Lead-Bismuth Eutectic
Authors: Gao Yun , Takahashi Minoru , Nomura Masao
Published: November 2014

One of the most crucial issues in development of the lead-bismuth cooled fast reactors (LFR), and the accelerator-driven system (ADS) is the compatibility of structural steels with liquid lead-bismuth eutectic (LBE) at high temperature range from 500°C to 650°C. In the primary circuit of LBE, metallic impurities such as Fe, Cr and Ni dissolve from structural steels into LBE at high temperature region, are transported to low temperature region, and precipitate as solid metals on channel wall. In this circulation, the data bases of diffusion coefficients of the metallic impurities are required for the estimate of mass transfer rates. In order to investigate the characteristics of diffusion of metallic impurities, the measurement of diffusion coefficients of Ni and Fe in liquid LBE was carried out using a capillary method. The concentrations of the diffusing species in LBE were determined by means of the inductively coupled plasma mass spectrometry (ICP-MS). From the measured axial distribution of Ni and Fe concentration in the LBE, the diffusion coefficient of Ni and Fe were obtained. The results are expressed by DNi=1.7×10-3exp⁡-3.63×10-4/RT500°C≤T≤650°Ccm2/sDFe=3.5×10-3exp⁡-4.15×10-4/RT550°C≤T≤650°Ccm2/s It was found that the value of diffusion coefficient of Ni is similar to the diffusion coefficient of Fe in liquid LBE.
Heat Transfer Characteristics of Subcooled Flowing Boiling in Circular Tubes With and Without Swirl Tapes Under High Heat Fluxes
Authors: Yan Jianguo , Bi Qincheng , Zhu Ge , Lv Haicai , Guo Yajun
Published: November 2014

Experiments of heat transfer and flow characteristics of subcooled water flowing in circular tubes, with and without swirl tapes, at high heat fluxes (ITER levels) were carried out at Xi’an Jiaotong University. Test sections of vertical tubes with an inner diameter of 9.0mm were electrically heated and water flow upwards. Two types swirl tapes were used with twist ratios of 2 and 4. Wall temperature distributions, critical heat fluxes and pressure drops were obtained during the experiment. The main attentions were paid to the effects of swirl tapes on enhancing the heat transfer and postponing the departure from nucleate boiling (DNB). The test parameters were as follows, heat flux (q)=10, 15MW/m2, pressure (P)=3, 4.2, 5MPa, mass flow rates (G)=6000, 8000kg/m2s, bulk temperature (Tb)=25–247 °C. Compared with the smooth tube, the experimental results showed that the swirl tapes can improve the heat transfer performance slightly while the pressure drops increase greatly. However, the DNB can be remarkably postponed with the swirl tapes, which is of vital practical significance to ITER. In addition, it was interesting to find that harsh boiling noise, which could be caused by microbubble emission boiling (MEB), and some inner surface of the tube was damaged, looks like cavitation erosion.
3D Flow Field Analysis for a Traditional II+ PWR Containment Under Normal Condition
Authors: Tian Maolin , Tian Wenxi , Su Guanghui , Qiu Suizheng
Published: November 2014

Flow field analysis is a foundation to many thermal-dynamic phenomena in the nuclear containment. There are several ventilation systems under normal condition to assure the proper environment for staff and facilities, and the two main ventilation systems are the Reactor Pit Ventilation system (EVC) and the Containment Continuous Ventilation system (EVR). The fans of the ventilation systems recycle the air in the containment to various rooms, and cooling coils are cooled by the Nuclear Island Chilled Water system (DEG). In this paper, we simulated the 3D flow field in a Chinese traditional generation II+ PWR reactor containment under normal conditions with a commercial CFD software ANSYS FLUENT.

According the actual geometry data of the reactor plant, we built the geometry model, including the EVC and EVR system, and they were checked by plant experts to assure authenticity. Proper maximum mesh sizes were set for different parts at the ICEM CFD, and the grid number was about ten millions. We used the fan model in the ANSYS FLUENT to simulate fans in the ventilations. The calculated values of flow rate in ventilation systems were in good agreement with the design values.
Design, Optimization and Performance Testing of Self-Healing Tritium Permeation Barriers
Authors: Liu Dawei , Zhou Tong , Wang Yan , Suo Jinping
Published: November 2014

Tritium permeation barriers (TPBs) are essential to reduce the tritium permeation through blanket structural materials and cooling tubes. The pores and cracks are the most important problem of thermally sprayed TPBs. Irradiation swelling is another serious problem in NiAl which used as adhesive layer in traditional Al2O3 coatings. A self-healing coating TiC+mixture (TiC/Al2O3)+Al2O3 without NiAl had been designed and manufactured by our group. It can cure 90% porosity after a certain heat treatment under normal atmosphere. The adhesive strength is as good as the traditional coating NiAl+Al2O3. The thermal shock cycles were 300, 210 and 123 at 600°C, 700°C and 800°C respectively. On the basis, the self-healing treatment parameters were explored further, and a more effective and efficient treatment was found. Structural design and component design were also researched. The thermal shock results showed that the thicknesses of TiC layer and mixture (TiC/Al2O3) layer both had a significant effect while the Al2O3 layer hadn’t. The interface of TiC and mixture (TiC/Al2O3) was most easily damaged, so other proportion of TiC and Al2O3 was applied, and several kinds of new coatings were designed, manufactured and tested. A better coating has been found, and it will probably be a good candidate for TPBs in fusion reactors.
Numerical Investigation on Thermal Striping Phenomena in a T-Junction Piping System
Authors: Tanaka Masaaki , Miyake Yasuhiro
Published: November 2014

Thermal striping phenomena caused by mixing of fluids at different temperature is one of the most important issues in design of Fast Breeder Reactors (FBRs), because it may cause high-cycle thermal fatigue in structure and affect the structural integrity. A numerical simulation code MUGTHES has been developed to investigate thermal striping phenomena and to estimate high cycle thermal fatigue in FBRs. In this study, numerical simulation for the WATLON experiment which was the water experiment of a T-junction piping system (T-pipe) conducted in JAEA was carried out to validate the MUGTHES and to investigate the relation between the mechanism of temperature fluctuation generation and the unsteady motion of large eddy structures. In the numerical simulation, the large eddy simulation (LES) approach with standard Smagorinsky model was employed as eddy viscosity model to simulate large-scale eddy motion in the T-pipe. The mesh as the same with the previous study as reference, the finer mesh and the coarser mesh arrangements were employed to estimate the Grid Convergence Index (GCI) for uncertainty quantification in the validation process. The modified method of the GCI estimation based on the least squire version could successfully quantify uncertainty. Through the numerical simulations, it was indicated that the fine mesh arrangement could improve the temperature distribution in the wake. It could be found that the thermal mixing phenomena in the T-pipe were caused by the mutual interaction of the necklace-shaped vortex around the wake from in the front of the branch jet, the horseshoe-shaped vortex and the Karman’s vortex motions in the wake.
Experimental Study on Sodium Fire Combustion in a Columnar Flow
Authors: Guo Ming , Zhang Zhi-Gang , Tang Ye-Xin , Sun Shu-Bin
Published: November 2014

In the operation of the sodium-cooled fast reactor, the accident caused by the leakage and combustion of liquid sodium is common and frequent in sodium-related facilities. In this paper, an experimental study of sodium fire in a columnar flow was carried out to focus on the burning characteristics by analyzing the temperature fields in the burner. The injection of 250 °C liquid sodium was poured into a 7.9m3 volume stainless steel cylindrical burner to shape a sodium fire, the data of temperature fields in the burner have been collected by dozens of thermocouples which are laid in the combustion space and sodium collection plate. These results show that the sodium fire in a columnar flow is composed of the foregoing spray fire, subsequent centered columnar fire and pool fire on the collection plate. The temperature in the combustion space close to the burning sodium flow could maximally reaches up to 828 °C. The radial temperatures apart from the sodium flow are relatively low and generally about 175–330 °C. The maximum temperature of the burning sodium dropping on the collection plate rises in the position of Td10, about 579°C. This study is promising to evaluate the combustion characteristics, formation process and composing forms of the sodium fire in the sodium-related facilities.
A Prediction of the Leakage Through Cracks for Leak Before Break
Authors: Zhang Jing , Wu Yingwei , Ding Lei , Qiao Hongwei , Li Pengzhou , Su Guanghui , Qiu Suizheng , Tian Wenxi
Published: November 2014

A code was developed in this study to predict the leakage of the leak before break (LBB). Various stagnation conditions were considered, including the subcooled water, the two-phase fluid and the overheated steam. Moreover, both the critical and noncritical flow was studied. The Henry-Fauske critical flow model was revised by a new phase transition point and the pressure drop due to friction and turns were modified. The code was verified by the comparison with the experimental data on the leakage of conventional pipes, artificial cracks and naturally occurring cracks, which shows a good agreement and this code has a higher precision than the existing codes. The influence of crack morphologies on LBB leakage was discussed, including the local roughness, the global roughness, the crack open displacement (COD) and the number of the corners. Besides, the dependence of the LBB leakage on stagnation enthalpy and back pressure was also investigated.