bluuebunny/crossref_metadata_2025 huggingface dataset:
Emotional Intelligence and Criminal Behavior
Authors: Megreya Ahmed M.
Published: November 2014

A large body of research links criminality to cognitive intelligence and personality traits. This study examined the link between emotional intelligence (EI) and criminal behavior. One hundred Egyptian adult male offenders who have been sentenced for theft, drug dealing or murder and 100 nonoffenders were administered the Bar‐On Emotional Quotient Inventory (EQ‐i). The offenders had lower levels of EI than the nonoffenders. In addition, EI varied as a function of the types of offenses. Namely, it decreased in magnitude with crime severity (lowest for murder, higher for drug dealing, and highest for theft). These results converged with the direct/ indirect aggression theory suggesting that indirect aggression requires more social intelligence than physical aggression. Forensic intervention programs should therefore include EI training, especially when violence is involved.
Microscopic Saw Mark Analysis: An Empirical Approach
Authors: Love Jennifer C. , Derrick Sharon M. , Wiersema Jason M. , Peters Charles
Published: November 2014

Microscopic saw mark analysis is a well published and generally accepted qualitative analytical method. However, little research has focused on identifying and mitigating potential sources of error associated with the method. The presented study proposes the use of classification trees and random forest classifiers as an optimal, statistically sound approach to mitigate the potential for error of variability and outcome error in microscopic saw mark analysis. The statistical model was applied to 58 experimental saw marks created with four types of saws. The saw marks were made in fresh human femurs obtained through anatomical gift and were analyzed using a Keyence digital microscope. The statistical approach weighed the variables based on discriminatory value and produced decision trees with an associated outcome error rate of 8.62–17.82%.
A Sensitive and Selective Fluorimetric Method of Quick Determination of Sialic Acids in Egg Products by Lectin‐CdTe Quantum Dots as Nanoprobe
Authors: Wang Qi , Wang Beibei , Ma Meihu , Cai Zhaoxia
Published: November 2014

Sialic acids (SA) are widely found as components of oligosaccharide units in mucins, glycoproteins and other microbial polymers in nature food. The aim of this study is to create a new fluorimetric detection method applied for determinating SA in egg products by using a sensitive lectin‐CdTe quantum dots (QDs) nanoprobe. Water‐soluble and high luminescent CdTe QDs were conjugated with sambucus nigra bark lectin (SNA) as probe for SA detection. As a result of specific interaction between SA and SNA‐CdTe QDs, the conjugations finally lead to the change of a fluorescent signal. Under optimal conditions, fluorescence intensity increase linearly with the increase of the concentration of SA ranging from 12 to 680 ng/mL. The low detection limit is 0.67 ng/mL. This quick and selective analysis method for SA detection has been used in synthetic samples and egg products with recovery between 97.92% and 110.42%, which demonstrates the application of this assay is feasible and practical.
Synopsis on the Linkage of Alzheimer's and Parkinson's Disease with Chronic Diseases
Authors: Jabir Nasimudeen R. , Firoz Chelapram K. , Baeesa Saleh S. , Ashraf Ghulam Md , Akhtar Suhail , Kamal Warda , Kamal Mohammad A. , Tabrez Shams
Published: November 2014

Neurodegeneration is the progressive loss of neuronal structure and function, which ultimately leads to neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis, and Huntington's disease. Even after the recent significant advances in neurobiology, the above‐mentioned disorders continue to haunt the global population. Several studies have suggested the role of specific environmental and genetic risk factors associated with these disorders. However, the exact mechanism associated with the progression of these disorders still needs to be elucidated. In the recent years, sophisticated research has revealed interesting association of prominent neurodegenerative disorders such as AD and PD with chronic diseases such as cancer, diabetes, and cardiovascular diseases. Several common molecular mechanisms such as generation of free radicals, oxidative DNA damage, aberrations in mitochondrial DNA, and dysregulation of apoptosis have been highlighted as possible points of connection. The present review summarizes the possible mechanism of coexistence of AD and PD with other chronic diseases.
Overview of the 3rd isirv‐Antiviral Group Conference – advances in clinical management
Authors: Hurt Aeron C. , Hui David S. , Hay Alan , Hayden Frederick G.
Published: November 2014

This review highlights the main points which emerged from the presentations and discussions at the 3rd isirv‐Antiviral Group Conference ‐ advances in clinical management. The conference covered emerging and potentially pandemic influenza viruses and discussed novel/pre‐licensure therapeutics and currently approved antivirals and vaccines for the control of influenza. Current data on approved and novel treatments for non‐influenza respiratory viruses such as MERS‐CoV, respiratory syncytial virus (RSV) and rhinoviruses and the challenges of treating immunocompromised patients with respiratory infections was highlighted.
A Kinect‐Based System for 3D Reconstruction of Sewer Manholes
Authors: Bellés Cristóbal , Pla* Filiberto
Published: November 2014

A system for automatic 3D modeling of sewer manholes using two Microsoft Kinect sensors is presented. The hardware design is based on a hand‐held scanner that includes two Kinect sensors, a mini‐PC and LED‐based illumination bars. The scanning and reconstruction software has been implemented using open‐source software toolkits. The information from the two Kinect sensors is merged into a single 3D model. Reconstruction is performed by adapting an existing RGB‐D SLAM‐based algorithm by filtering out nonconsistent correspondences and an alternative graph‐based optimization, which results in reconstruction errors of the order of 1 cm. The final result obtained is a complete system with a hand‐held scanner and management software which is highly competitive with respect to present commercial systems, using much cheaper technology and open‐source toolkits with low reconstruction errors.
Effects of Polychlorinated Biphenyls 28, 30 and 118 on Bovine Spermatozoa In Vitro
Authors: Yurdakok B , Tekin K , Daskin A , Filazi A
Published: November 2014

Contents

Decline of semen quality due to endocrine‐disrupting chemicals is of concern globally. Among endocrine disrupting chemicals (EDC), Polychlorinated biphenyls (PCB) are associated with reduced semen quality in various epidemiological studies. In this study, we evaluated the direct effects of selected PCBs (28, 30 and 118) on fresh spermatozoa of Simmetial bulls aged 2–4 years were evaluated in vitro by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and computer assisted semen analysis (CASA) (SCA; Microptics) analysis. IC50 values were found as 8.45, 5.45 and 9.55 ng/ml for PCB 28, 30 and 118, respectively. Total motility, progressive motility and viability decreased dependent on dose and duration of exposure (0, 2, 4 h). Total motility at IC50 doses decreased the most in PCB 28 (72.24%) followed by 30 (60.75%) and 118 (64.77%) at 2nd hour following exposure. Motility results were found to be in accordance with the vitality and morphology data where total abnormalities (especially reacted acrosome rate) were found to have increased.
Selective carotid body ablation in experimental heart failure: a new therapeutic tool to improve cardiorespiratory control
Authors: Del Rio Rodrigo , Andrade David C. , Marcus Noah J. , Schultz Harold D.
Published: November 2014

New Findings

What is the topic of this review?

This review summarizes the physiological role played by the carotid body in the autonomic dysregulation and breathing disturbances during the progression of chronic heart failure and the therapeutic potential of carotid body ablation to control cardiorespiratory imbalance and improve survival in heart failure.

What advances does it highlight?

Carotid body ablation markedly improves breathing stability and normalizes autonomic function in chronic heart failure. More importantly, if carotid body ablation is performed early during the progression of the disease it significantly improves animal survival.

Chronic heart failure (CHF) is a leading medical problem worldwide. Common hallmarks of CHF include autonomic imbalance and breathing disorders, both of which are closely related to the progression of the disease and strongly predict mortality in CHF patients. The role played by the carotid body (CB) chemoreceptors in the progression of CHF has received attention because enhanced carotid chemoreflex drive is thought to contribute to autonomic dysfunction, abnormal breathing patterns and increased mortality in CHF. Therefore, therapeutic tools intended to normalize CB‐mediated chemoreflex drive could have the potential to improve quality of life and decrease mortality of CHF patients. In experimental CHF, an enhancement of the CB chemoreflex drive, elevated sympathetic outflow, increased resting breathing variability, increased incidence of apnoea and desensitization of the baroreflex have been shown. Notably, selective elimination of the CB reduced central presympathetic neuronal activation, normalized sympathetic outflow and baroreflex sensitivity and stabilized breathing function in CHF. More remarkably, CB ablation has been shown to be a valuable therapeutic tool that significantly reduced aberrant cardiac remodelling, improved left ventriclular ejection fraction and reduced cardiac arrhythmogenesis. Most importantly, animals with CHF that underwent CB ablation showed a marked improvement in survival rate. Interestingly, a case report from a heart failure patient in whom unilateral CB ablation was performed showed promising results, with significant improvement in autonomic balance and breathing variability. Together, the CHF data from experimental animals as well as humans unveil a major role for the CB chemoreceptors in the progression of heart failure and support the notion that CB ablation could represent a novel therapeutic strategy to reduce cardiorespiratory dysfunction and improve survival during heart failure.
Leptin differentially increases sympathetic nerve activity and its baroreflex regulation in female rats: role of oestrogen
Authors: Shi Zhigang , Brooks Virginia L.
Published: November 2014

Key points

Leptin increases sympathetic nerve activity (SNA) in males, which contributes to obesity‐induced hypertension; however, whether leptin is equally effective in females is unknown.

We report that leptin does increase SNA and heart rate in female rats; however, for lumbar and renal SNA, this action is only evident in pro‐oestrus and in oestrogen‐treated ovariectomized rats, but not in ovariectomized or dioestrus rats.

Leptin increases SNA and heart rate similarly in male and pro‐oestrus female rats; however, leptin increases arterial pressure only in males.

Blockade of MC3/4 receptors in the paraventricular nucleus (PVN) with SHU9119 decreases SNA in leptin‐treated pro‐oestrus rats, suggesting that leptin increases SNA in part by increasing α‐melanocyte‐stimulating hormone drive of PVN presympathetic neurons.

Our data establish sex differences in leptin's effects to increase SNA and arterial pressure, which emphasizes the need for enhanced recognition and investigation of sex differences in obesity‐induced sympathoexcitation and hypertension.

Obesity and hypertension are commonly associated, and activation of the sympathetic nervous system is considered to be a major contributor, at least in part due to the central actions of leptin. However, while leptin increases sympathetic nerve activity (SNA) in males, whether leptin is equally effective in females is unknown. Here, we show that intracerebroventricular (i.c.v.) leptin increases lumbar (LSNA) and renal (RSNA) SNA and baroreflex control of LSNA and RSNA in α‐chloralose anaesthetized female rats, but only during pro‐oestrus. In contrast, i.c.v. leptin increased basal and baroreflex control of splanchnic SNA (SSNA) and heart rate (HR) in rats in both the pro‐oestrus and dioestrus states. The effects of leptin on basal LSNA, RSNA, SSNA and HR were similar in males and pro‐oestrus females; however, i.c.v. leptin increased mean arterial pressure (MAP) only in males. Leptin did not alter LSNA or HR in ovariectomized rats, but its effects were normalized with 4 days of oestrogen treatment. Bilateral nanoinjection of SHU9119 into the paraventricular nucleus of the hypothalamus (PVN), to block α‐melanocyte‐stimulating hormone (α‐MSH) type 3 and 4 receptors, decreased LSNA in leptin‐treated pro‐oestrus but not dioestrus rats. Unlike leptin, i.c.v. insulin infusion increased basal and baroreflex control of LSNA and HR similarly in pro‐oestrus and dioestrus rats; these responses did not differ from those in male rats. We conclude that, in female rats, leptin's stimulatory effects on SNA are differentially enhanced by oestrogen, at least in part via an increase in α‐MSH activity in the PVN. These data further suggest that the actions of leptin and insulin to increase the activity of various sympathetic nerves occur via different neuronal pathways or cellular mechanisms. These results may explain the poor correlation in females of SNA with adiposity, or of MAP with leptin.
Study on Neutronics and Thermalhydraulics Characteristics of 1200-MWel Pressure-Channel Supercritical Water-Cooled Reactor
Authors: Miletic Marija , Peiman Wargha , Farah Amjad , Samuel Jeffrey , Dragunov Alexey , Pioro Igor
Published: November 2014

Nuclear power becomes more and more important in many countries worldwide as a basis for current and future electrical energy generation. The largest group of operating nuclear power plants (NPPs) equipped with water-cooled reactors (96% of all NPPs) has gross thermal efficiencies ranging from 30–36%. Such relatively low values of thermal efficiencies are due to lower pressures/temperatures at the inlet to a turbine (4.5–7.8  MPa/257–293°C). However, modern combined-cycle power plants (Brayton gas-turbine cycle and subcritical-pressure steam Rankine cycle, fueled by natural gas) and supercritical-pressure coal-fired power plants have reached gross thermal efficiencies of 62% and 55%, respectively. Therefore, next generation or Generation IV NPPs with water-cooled reactors should have thermal efficiencies as close as possible to those of modern thermal power plants. A significant increase in thermal efficiencies of water-cooled NPPs can be possible only due to increasing turbine inlet parameters above the critical point of water, i.e., supercritical water-cooled reactors (SCWRs) have to be designed. This path of increasing thermal efficiency is considered as a conventional way that coal-fired power plants followed more than 50 years ago. Therefore, an objective of the current paper is a study on neutronics and thermalhydraulics characteristics of a generic 1200-MWel pressure-channel (PCh) SCWR. Standard neutronics codes DRAGON and DONJON have been coupled with a new thermalhydraulics code developed based on the latest empirical heat-transfer correlation, which allowed for more accurate estimation of basic characteristics of a PCh SCWR. In addition, the computational fluid dynamics (CFD) Fluent code has been used for better understanding of the specifics of heat transfer in supercritical water. Future studies will be dedicated to materials and fuels testing in an in-pile supercritical water loop and developing passive safety systems.
Computational Fluid Dynamics Analysis for Asymmetric Power Generation
in a Prismatic Fuel Block of Fluoride-Salt-Cooled High-Temperature Test
Reactor
Authors: Cheng Wen-Chi , Sun Kaichao , Hu Lin-Wen , Chieng Ching-Chang
Published: November 2014

The fluoride-salt-cooled high-temperature reactor (FHR) is an advanced reactor concept that uses tristructural isotropic (TRISO) high-temperature fuel and low-pressure liquid salt coolant. A 20-MWth test reactor, as the key step in demonstrating the technical feasibility, is currently under design at Massachusetts Institute of Technology. This study focuses on the coupled conduction and convection heat transfer adopting a three-dimensional unit-cell model with one coolant channel and six one-third fuel compacts. The laminar, transitional, and turbulent flows are investigated with the use of computational fluid dynamic (CFD) software, CD-adapco STARCCM+. The model is validated against theory for developing laminar flow in the benchmark study with excellent agreement. The model is also benchmarked for transitional and turbulent flows by Hausen, Gnielinski, Dittus-Boelter, and Sieder-Tate correlations. Azimuthal distributions of temperature, heat flux, and heat transfer coefficient along the coolant-graphite interface were obtained for the asymmetric heat source, graphite materials, and two different types of salt coolant. The results show that the asymmetric power generation has little impact on peak fuel temperature, interface temperature, and heat transfer coefficient for a unit-cell module in laminar flow regime due to effective thermal conduction of the graphite matrix. In the turbulent flow regime, the effect on the azimuthal heat flux and heat transfer coefficient is more pronounced.
Application of the System Based Code Concept to the Determination of In-Service Inspection Requirements
Authors: Takaya Shigeru , Asayama Tai , Kamishima Yoshio , Machida Hideo , Watanabe Daigo , Nakai Satoru , Morishita Masaki
Published: November 2014

A new process for determination of in-service inspection (ISI) requirements was proposed on the basis of the system based code concept to realize effective and rational ISI by properly taking into account plant-specific features. The proposed process consists of two complementary evaluations, one focusing on structural integrity and the other one on detectability of defects before they would grow to an unacceptable size in light of plant safety. If defect detection was not feasible, structural integrity evaluation would be required under sufficiently conservative hypothesis. The applicability of the proposed process was illustrated through an application to the existing prototype fast breeder reactor, Monju.
RANS and LES Analyses on a Density Stratified Layer Behavior of Multicomponent Gas by Buoyant Jet in a Small Vessel
Authors: Abe Satoshi , Ishigaki Masahiro , Sibamoto Yasuteru , Yonomoto Taisuke
Published: November 2014

The analysis on a density stratified layer consisting of multiple gases in the reactor containment vessel is important for the safety assessment of sever accidents. Computational Fluid Dynamics (CFD) code has a potential to clarify detailed stratification phenomena in the containment vessel. In this paper, CFD analyses were carried out in order to investigate the erosion of the stratified layer by a vertical buoyant jet injected from the bottom of a small vessel. Although the Reynolds-Averaged Navier-Stokes (RANS) model is commonly used in industrial applications, it is known that the RANS analyses tend to overpredict effects of turbulent mixing and stratification erosion for these phenomena. This study carried out the RANS and Large-Eddy simulations (LES) in order to understand the detailed phenomena of the stratification erosion in a containment vessel, and clarify the problems of the RANS analysis from the comparison. As a result, although both the RANS and LES models calculated the erosion, the erosion rates calculated by the RANS models were faster than that by the LES model. The calculated erosion behavior was qualitatively different: the LES analyses showed the vertical helium turbulent transport was enhanced only in the radial region directly affected by the impinging jet, while the RANS analyses indicated the occurrences of such transportation at all the radial locations. Although more detailed validation is required using appropriate experimental data, this difference among the calculated cases suggests the importance of the improvement of the turbulence models in order to accurately predict turbulence damping in the stratification layer.
Single-Channel Thermal Analysis of Fully Ceramic Microencapsulated Fuel via Two-Temperature Homogenized Model
Authors: Lee Yoonhee , Cho Nam Zin , Chung Sun Kyo
Published: November 2014

The fully ceramic microencapsulated (FCM) fuel, one of the accident tolerant fuel (ATF) concepts, consists of TRISO particles randomly dispersed in SiC matrix. This high heterogeneity in compositions leads to difficulty in explicit thermal calculation of such a fuel. For thermal analysis of a fuel element in very high temperature reactors (VHTRs) which has a similar configuration to the FCM fuel, a two-temperature homogenized model was proposed by the authors. The model was developed using particle transport Monte Carlo method for heat conduction problems. It gives more realistic temperature profiles and provides the fuel-kernel and graphite temperatures separately.

In this paper, we apply the two-temperature homogenized model to single-channel thermal analysis of the FCM fuel element for steady- and transient-states using 2-D FEM/1-D FDM hybrid method. The results of analyses are compared to those of conventional UO2 fuel having the same geometric dimension and operating conditions.
A Numerical Analysis on Graphite Dust Deposition and Resuspension in HTR-10 Steam Generator
Authors: Peng Wei , Zhang Tian-qi , Zhen Ya-nan , Yu Su-yuan
Published: November 2014

The behavior of graphite dust is important to the safety analysis of High-Temperature Gas-cooled Reactor (HTGR). The fission products released by fuel elements would enter the primary loop and combine with dust, resulting in that the dust has a high load capacity of cesium, strontium, iodine and tritium. It would bring difficulty and inconvenience to the maintenance and repair of steam generator. Therefore, the behavior of graphite dust in the steam generator is essential to the safety of High Temperature Gas-cooled Reactors. The present study focused on the deposition and resuspension of graphite dust in steam generator of HTR by numerical method. The results show that the graphite dust in steam generator deposits on the surface of heat transfer tube through turbulent deposition, thermophoretic deposition, and other depositional mechanisms, of which thermophoretic deposition is the main mechanism for the particles with the diameter of 2.2μm in the present study. The preliminary calculation result shows that about 6760mg/m2 of graphite dust tends to load on the tube surface.
The FEM Calculation of Iron Loss in the Active Magnetic Bearing
Authors: Wu Peicai , Liu Xingnan , Yang Guojun , Shi Zhengang
Published: November 2014

The active magnetic bearing (AMB) is a new kind of high-performance bearing which suspends the rotor with controlled electromagnetic force. It was chosen to support the rotor of the helium blower in HTR-PM instead of conventional bearings. The power losses in the active magnetic bearings compose of three components: copper loss, iron loss and windage loss. In this paper, the iron loss, which composes of the eddy current loss and the hysteresis loss, is researched. The power loss of silicon steel lamination (35H300) was measured. Experimental data was taken over a range of 50Hz to 25,000Hz (sinusoidal current) for several magnetic field intensities. According to the experimental data, the eddy current loss and hysteresis loss increase with the frequency. And the hysteresis loss in the silicon steel lamination occupies the major part when the frequency of current is low, however the growth rate of eddy current is much faster than that of the hysteresis loss. And the FEM calculation of power loss in the magnetic bearing, which rotor and stator are made from silicon steel lamination (35H300), is also presented. The result shows the core loss of magnetic bearing also follow the separation theory. We can separate the core loss of magnetic bearing into two parts: hysteresis loss and eddy current loss. It will be very useful to calculate the power loss in the magnetic bearing.
Application of Heat Balance Integral Method in Freezing Process of Overheated Melt on Cold Structure
Authors: Zhuohua Zhang , Shinian Peng , Junchong Yu
Published: November 2014

Relocation process of molten materiel in core assembled with plate-type fuel is a significant process during severe accident which determines sequences of core degradation. Recently, HBI methods used in system codes for severe accident are generally applied in freezing problems with two plates structure. Actually, there are three plates existing during freezing process and the former methods are not quite available. Different temperature profiles will be compared in this paper for choosing the best suitable profile which has the least errors compared with exact solution of freezing process. A new HBI method combining quasi-steady method and numerical method is developed in this paper which can solve freezing problems with three plates structure, and comparing results between my HBI method and numerical method, equilibrium method and experimental results indicate the applicability of my method.
Study on Specifics of Forced-Convective Heat Transfer in Supercritical Carbon Dioxide
Authors: Saltanov Eugene , Pioro Igor , Mann David , Gupta Sahil , Mokry Sarah , Harvel Glenn
Published: November 2014

The appropriate description of heat-transfer to coolants at supercritical state is limited by the current understanding. Thus, poses one of the main challenges in development of supercritical-fluids applications for the Generation–IV reactors. The objective of the paper is, therefore, to discuss the basis for comparison of relatively recent experimental data on supercritical carbon dioxide (CO2) obtained at facilities of the Korea Atomic Energy Research Institute (KAERI) and Chalk River Laboratories (CRL) of Atomic Energy of Canada Limited (AECL). Based on the available instrumental error, a thorough analysis of experimental errors in wall- and bulk-fluid temperatures, and heat transfer coefficient is conducted. It is shown that rarely published data on instrumental errors tend to underpredict significantly actual experimental errors. A revised heat-transfer correlation for the CRL data is presented. A preliminary heat-transfer correlation for joint CRL and KAERI datasets is developed.
Analysis of Thermophysical Properties for Selected Supercritical Fluids
Authors: Jouvin Juan Carlos , Samuel Jeffrey , Pioro Igor
Published: November 2014

Currently, there are six Generation IV reactor systems under development worldwide: 1) Very-High-Temperature Reactor (VHTR); 2) Sodium-cooled Fast Reactor (SFR); 3) SuperCritical Water-cooled Reactor (SCWR), 4) Gas-cooled Fast Reactor (GFR), 5) Lead-cooled Fast Reactor (LFR); and 6) Molten Salt Reactor (MSR). Of these six systems, Canada has decided to pursue the SCWR as its choice for a Generation IV reactor, with some research being conducted on the VHTR. One main objective of SCWRs is to increase the thermal efficiency of current nuclear power plants from the 30–35% range to approximately 45–50%. In order to accomplish this, SCWRs are being designed to operate well above the critical point of water at pressures of 25 MPa and reactor outlet temperatures up to 625°C. These operating conditions also make the SCWR, along with the VHTR and other Generation IV systems, suitable candidates to support thermochemical hydrogen cogeneration.

The design and operation of a facility capable of accurately and safely conducting experiments in supercritical water is a very expensive task. In order to facilitate our understanding of supercritical heat-transfer phenomena, modeling fluids such as carbon dioxide, refrigerants, ammonia and helium can be used to complement our knowledge of supercritical fluids. Some of these fluids, namely helium and carbon dioxide, have also been considered as potential working fluids in some special designs of reactors and power cycles.

The objective of this paper is to investigate the feasibility of using alternative working fluids such as helium and Refrigerant-134a (R-134a) by comparing the fluid and transport properties with those of water. Operating conditions of SCWRs are scaled into those of the modeling fluid, R-134a, in order to provide proper SCWR-equivalent conditions. The equivalent properties for helium, which is one possible coolant for the VHTR, are also discussed. The thermophysical properties for selected working fluids are obtained from NIST REFPROP software. The results indicate that the thermophysical properties of the fluids undergo significant changes within the critical and pseudocritical regions similar to that of supercritical water. A sensitivity analysis for the effect of temperature on selected thermophysical properties at various supercritical pressures was performed.
Analysis of Heterogeneous Cores Using SN Code With Discontinuity Factor
Authors: Zhao Jing , Liu Zhihong , Wei Chunlin , Hu Yongming
Published: November 2014

Solving diffusion equations with the equivalence homogenization theory is the common method in reactor neutronics. But for some case, as for stronger absorbers, the diffusion equations will bring great errors and the transport method will be more suitable. The discontinuity factor theory has been successfully used in core diffusion computation programs and effectively reduced the homogenization error. The method of using the discontinuity factor in the transport method were studied. The result shows that higher accuracy was obtained from the discrete ordinates core transport computation program with discontinued factor.
Thermal-Hydraulic Analysis for Experimental Device of Supercritical Water Reactor-Fuel Qualification Test
Authors: Liu Liang , Zhou Tao , Li Yu , Cheng Wanxu , Chen Juan , Huang Shanfang , Huang Yanping
Published: November 2014

The China EU cooperation project SCWR-FQT small experimental reactor is selected as the research object. The new SCWR-FQT calculation code is made. Thermal performance of four channels are analyzed. The results show that: During normal condition, the coolant temperature increases gradually and pressure reduces gradually. The highest temperature of the coolant does not exceed 450°C working limit, meets the design safety requirement. When transient of entrance temperature occurs, lateral two channels are affected significantly. The inside channel has maximum temperature stability because of the minimum affection. The increasing of the entrance temperature will shorten the time of the relative inner two channels to reach stable. When transient of entrance flow occurs, the inside channel has the maximum affection. The decreasing of the entrance flow will increase the time of the inside channel to reach stable. The entrance flow should not lower than 49.2% of the normal operating mode.
Physical Analysis of LBE Spallation Target Coupled With the Reactor for CIADS
Authors: Zhang Lu , Yang Yongwei , Gao Yucui
Published: November 2014

For the project of the Chinese Initiative Accelerator Driven Sub-critical system (CIADS), the Lead-Bismuth-Eutectic (LBE) spallation target is one of the two alternatives, which has high good thermal performance, mature technology, and other advantages. The physical design of the spallation target determines the neutron yield and the utilization of the neuron source, as well as the performance of the sub-critical reactor and other key issues. Based on the Monte Carlo program MCNPX, we did the preliminary design of spallation target coupled with the reactor with a keff about 0.95. The energy deposition density distribution of the target and the window were calculated. In the mean time, the neutron flux density, the neutron energy spectrum, and the power amplification factors were calculated. By changing the positions of the target, the radii of the beam pipe and the thickness of target, we studied the variation of the neutronic parameters mainly mentioned above. The energy deposition density distribution was used as the heat source of the thermal-hydraulics analyses. From the neutronic parameters, we found that to get the maximum power amplification factor, the target window should be put at the positions 11.4 cm above the center of the core. Actually, when the target was put above the center of the core, from 0cm to 22cm, the maximum differences of the power amplification factor is less than 4.0%, which means the position will have little influences in this range. When the target window was put at the center, increasing of the window’s thickness will lead the decreasing of the power amplification factor. The enlargement of the beam pipe radii will decrease the maximum that the amplification factors can reach. Meanwhile, the increasing of the beam radii will enlarge the power amplification factor slightly. The physics analysis of the LBE target coupled with the reactor can give more information to the optimization of the target structure and the sub-critical reactor for CIADS.
ROSA/LSTF Experiment on a PWR Station Blackout Transient With AM Measures and RELAP5 Post-Test Analysis
Authors: Takeda Takeshi , Ohtsu Iwao , Yonomoto Taisuke
Published: November 2014

An experiment on a PWR station blackout transient with the TMLB’ scenario and accident management (AM) measures was conducted using the ROSA/large scale test facility (LSTF) at Japan Atomic Energy Agency under an assumption of non-condensable gas inflow to the primary system from accumulator (ACC) tanks. The AM measures proposed in this study are steam generator (SG) secondary-side depressurization by fully opening the safety valves in both SGs with the start of core uncovery and coolant injection into the secondary-side of both SGs at low pressures. The LSTF test revealed the primary pressure started to decrease when the SG primary-to-secondary heat removal resumed soon after the coolant injection into the SG secondary-side. The primary depressurization worsened due to the gas accumulation in the SG U-tubes after the completion of ACC coolant injection. The RELAP5 code predicted well the overall trend of the major phenomena observed in the LSTF test, and indicated remaining problems in the predictions of SG U-tube collapsed liquid level and primary mass flow rate after the gas ingress. The SG coolant injection flow rate was found to affect significantly the peak cladding temperature and the ACC actuation time through the RELAP5 sensitivity analyses.
Structural Analysis for Assembly by Integrating Parts
Authors: Nakajima Norihiro , Nishida Akemi , Kawakami Yoshiaki , Okada Tatsuo , Tsuruta Osamu , Sawa Kazuhiro , Iigaki Kazuhiko
Published: November 2014

Almost all industrial products are assembled from multiple parts, and this is true for all sizes of products. As an example, a nuclear facility is a large structure consisting of more than 10 million components. This paper discusses a method to analyze an assembly by gathering data on its component parts. Gathered data on component may identify ill conditioned meshes for connecting surfaces between components. These ill meshes are typified by nodal point disagreement in finite element discretization. A technique to resolve inconsistencies in data among the components is developed. By using this technique, structural analysis for an assembly can be carried out, and results can be obtained by the use of supercomputers, such as the K computer. Numerical results are discussed for components of the High Temperature Engineering Test Reactor of the Japan Atomic Energy Agency.
Experimental Study of the Wall Boundary Layer “Heavy Liquid-Metal Coolant – Constructional Material” as Applied to Fast Reactors
Authors: Makhov Kirill , Beznosov Aleksander V. , Bokova Tatyana , Shumilkov Artem , Chernysh Aleksei , Knyazev Alexander Vladimirovich
Published: November 2014

The specific feature of heavy liquid-metal coolants (HLMC) is the possibility to form solid-phase impurity particles, which requires a deep study of characteristics of the wall boundary layer enriched with impurity particles. This is necessary for a fundamental understanding of the processes occurring on contact surfaces and triboprocesses to validate the use of materials for developing fast reactors with these coolants. The paper deals with results of experimental studies of structures and characteristics of the wall boundary layer. The use of the thermal shock technique enabled us to experimentally determine the wall boundary structure typical of circuits with heavy liquid-metal coolants (lead or lead-bismuth alloy). It has been experimentally demonstrated that the wall boundary region is a multicomponent structure:

1 – steel;

2 – oxide coating;

3 – layer of loose deposits weakly adhering to oxide coating;

4 – gas phase (due to unwettability of oxide surface by coolant);

5 – impurity-rich diffusion layer of boundary turbulent layer;

6 – boundary turbulent layer;

7 – impurity particles in coolant flow close to wall boundary region, which do not adhere to layers 3 and 5.

It is found that long-term HLMC circulation in channels leads to an increase in the surface roughness of constructional materials due to the deposition of solid-phase impurities, which should be taken into account in tribological studies.

The experimental results have also shown that the microhardness of structures of the wall boundary layer is an order different from the microhardness of both steel and solidified lead ingot (HVsteel = 245, HVwall boundary layer = 60, HVlead = 6), which permits to assume that the wall boundary layer is a rheological fluid.

Also the chemical analysis of deposits on construction material surfaces is presented. The chemical analysis included X-Ray method and elemental analysis.
Predictions of Heat Transfer Coefficients and Pressure Drops to Supercritical Pressure HCFC22 Flowing in a Small Tube
Authors: Zhao Chen-Ru , Jiang Pei-Xue , Bo Han-Liang
Published: November 2014

In this paper, experimental flow and heat transfer data of supercritical pressure HCFC22 flowing in a uniformly heated smooth tube with inner diameter of 1.004 mm at p/pc=1.1 obtained by the authors are analyzed accounting for the influence of the thermophysical properties variation, the buoyancy effect, as well as the flow acceleration effect due to thermal expansion. These analyses indicate that both of the sharp thermophysical properties variation in the fluid adjacent to the wall with low density, low specific heat and low thermal conductivity and the flow acceleration effect due to thermal expansion have significant negative effects on the heat transfer under the present study conditions for HCFC22, while for the friction factor, the thermophysical properties variation is the predominant factor. The buoyancy effect on the flow and heat transfer is negligible.

A new semi-empirical local heat transfer correlation accounting for the thermophysical properties variation and the flow acceleration effect due to thermal expansion for supercritical pressure fluids flowing through a vertical small tube during heating is proposed. The predicted values agree with 95% of the measured data within ±25%. In addition, a flow correlation with thermophysical properties variation correction terms to predict the friction factors for supercritical pressure fluids is proposed which predicts the measured friction factors within ±25%.
Dynamic Stability Analysis of Cans in Reactor Coolant Pump Subjected to Axial Flow
Authors: Ning Wenbo , Wang Dezhong
Published: November 2014

The stator and rotor cans in canned motor reactor coolant pump are assumed to be elastic coaxial cylindrical shells due to their particular geometric structures in present study. Thin shell structures such as cans are prone to buckling instabilities. Furthermore, a lot of accidents were caused by losing stability. The dynamic behavior of coaxial circular cylindrical shells subjected to axial fluid flow in the annular gap between two shells is investigated in this paper. The outer shell is stiffened by ring-ribs because of its instability easily. The shell is modeled based on Donnell’s shallow theory. The “smeared stiffeners” approach is used for ring-stiffeners. The fluid is assumed to be an incompressible ideal fluid and the potential flow theory is employed to describe shell-fluid interaction. Numerical analyses are conducted by means of energy variation to obtain the critical flow velocity of losing stability with aid of Hamilton principle. This study shows effects of geometrical parameters on stability of shells. The size and number of ring-stiffeners on dynamic stability are examined. It is found that stiffeners can vary modes instability and enhance the stability of shells. The flow velocities of losing stability with different boundary conductions can be calculated and compared. The results show clamped shells are more stable than simply supported shells. The results presented are in reasonable agreement with those available in the literature.
Development of a Fast Simulation Program for AP1000 Reactor With Application of Mechanical Shim (MSHIM) Control Strategy and Nodal Method
Authors: Wang Pengfei , Fang Huawei , Wang Zhao , Yan Shoujun , Wan Jiashuang , Zhao Fuyu
Published: November 2014

The Mechanical Shim (MSHIM) core control strategy makes use of two independently controlled rod groups to provide fine control of both core reactivity and axial power distribution. This paper presents a reactor core fast simulation program (RCFSP) for AP1000 using MATLAB/SIMULINK. A nodal core model including xenon iodine dynamics is used to describe the core thermal power transient with the two group neutron diffusion equation for neutron kinetics modeling and an integral method for thermal-hydraulic calculation. Two closed loop rod controllers with implementation of the MSHIM core control strategy are developed to modulate the insertion of control rods. Based on the developed RCFSP, the MSHIM load follow operations with the original and revised MSHIM control strategies and two typical MSHIM load regulation operations with ten-percent step load change and five-percent per minute ramp load change are simulated. Results of these MSHIM operations demonstrate that the core reactivity and axial power distribution can be well-controlled via automatic rod control only. It has also been demonstrated that the MSHIM capabilities provided by the original MSHIM strategy are not diminished by the revised one. Moreover, the M-bank insertion for the original strategy is much deeper than that for the revised one. Thus, the power distribution perturbations associate with the M-bank movement for the revised strategy are not as pronounced as those for the original one during load change transients, which helps to alleviated peaking factor concerns associated with the control rod insertion. In view of its accuracy, simplicity and fast computation speed, the developed RCFSP can be used for dynamic simulations and control studies of the AP1000 reactor with application of MSHIM control strategy. With the adoption of modular programming techniques, the RCFSP code can be easily modified and applied to other pressurized water nuclear reactors that employs separate, independent control rod banks for respectively controlling core reactivity and axial offset within corresponding deadbands.
Effect of Lath Width and Dislocation Density on Resistance to Irradiation of Warmly Deformed SCRAM Steel
Authors: Mou Yang , Xue Lihong , Zhou Qilai , Lu Caixuan , Suo Jinping , Yan Youwei , Guo Liping
Published: November 2014

The martensitic lath width (0.83 ± 0.45μm ∼ 0.48 ± 0.14 μm) and dislocation density (1.3 ± 0.3 × 1015 m−2 ∼ 6.4 ± 1.6 ×1015 m−2) change of Super-clean Reduced Activation Martensitic (SCRAM) steel caused by warm deformation on Gleeble-3500 thermo-simulation machine have been examined. The irradiation-induced helium bubbles and hardening were observed in all the specimens after helium implantation to 1e + 17/cm2 at 723 K. The helium bubbles became smaller and more numerous while the distribution was more homogeneous when the lath width decrease and dislocation density increase. The nano-indentation hardness indicated that the sample, the martensitic lath width is 0.83 ± 0.45μm and the dislocation density is 1.3 ± 0.3 × 1015 m−2, exhibited the maximum nano-indentation variation (ΔH) and the ΔH decreased with the lath width decreasing and dislocation density increasing. The hardening occurred in all helium implanted samples can mainly be ascribed to helium bubbles.
Modeling and Control Strategy of the China LBE Cooled Fast Reactor
Authors: Yan Shoujun , Wang Zhao , Wang Pengfei , Wan Jiashuang , Fang Huawei , Zhao Fuyu
Published: November 2014

China lead bismuth eutectic (LBE) cooled fast reactor comprises of the primary system with lead bismuth eutectic (LBE) as the coolant, the secondary circuit with sub-cooled water as the coolant and the associated air cooling system for an effective rejection of thermal power to the environment as a final heat sink. The dynamic characteristics of LBE cooled fast reactor are different from the traditional Pressurized Water Reactors (PWRs) because of the variances in coolant properties as well as major differences due to the operation in the fast versus the thermal neutron spectrum. To investigate the dynamic characteristics of the CLEAR-IA reactor for control system design and simulation, a model for the main components of the reactor and the most relevant interactions among them is developed. Since all the coefficients in the models are functions of temperature, the models in this paper are not described by ordinary differential equation. These models are realized by using the S-function builder of SIMULINK. The steady state calculation result based on the thermal-hydraulic models show agreement with the design value. To show the proposed models could be used for the simulation, the transient process of parameter change is compared with Relap5 simulation code, which shows agreement. A Proportional-Integral (PI) controller is designed to keep the power following the set value as quickly as possible. To keep the inlet temperature of core coolant constant, a control strategy based on a simultaneous feed-forward and feedback scheme has been adopted. The feed-back control system is a PI controller and it can achieve a real time and no error control, but it has time delay. The feed-forward control can realize the control in advance before the LBE temperature at inlet of the core has been changed to reduce the overshoot. So the feed-forward can realize an advance and rough control, the feedback can realize a no error and accurate control. Based on the developed model and control strategy, dynamic simulations of the whole system in case of step changes of reactivity and set power are performed. The simulation results show that the proposed model is accurate enough to describe the dynamic behaviors of the plant in spite of its simplicity. It has also been demonstrated that the developed controllers for the CLEAR-IA can provide superior reactor control due to the efficiency of the control strategy adopted.
Preliminary Core Design of the Long Life S-CO2 Cooled Fast Reactor With 300WMth
Authors: Liu Baolin , Wu Hongchun , Zheng Youqi , Cao Liangzhi , Yuan Xianbao
Published: November 2014

Gas cooled fast reactors are one of the Generation 4 nuclear power plants with hard neutron spectrum and high conversion ratio. In the study a long life Supercritical CO2 (S-CO2) cooled fast reactor core design with 300 MWth is presented. Physical calculation was carried out based on Dragon and CITATION, and thermal hydraulic analysis was performed based on the single channel code. The MOX fuel was utilized in the core design, and the tube-in-duct (TID) assembly was chosen for its excellent characteristics. According to the physical and thermal hydraulic coupling calculation, the reactor in the study can be operated with 300MWth for 20Ys without shuffling or refueling. Through the core life power peaking was kept relatively low, and the fuel temperature was kept below the 1800 degree centigrade.