bluuebunny/crossref_metadata_2025 huggingface dataset:
Good coercion: Patients' moral evaluation of coercion in mental health care
Authors: Lorem Geir F. , Hem Marit H. , Molewijk Bert
Published: November 2014

The use of coercion in mental health care is not self‐evident and requires moral justification. A joint understanding is difficult to achieve, because patients and health professionals often evaluate coercion differently. The present study aims to discuss patients' ‘moral’ evaluation of coercion. We believe that such a focus can form the basis for a better and more differentiated understanding of how we evaluate coercion. This is a qualitative study based on participant observation and interviews with patients. In order to focus specifically on the moral evaluation of coercion, we looked within patients' narratives to examine whether we could differentiate between how they experienced coercion and how they morally evaluated its use, and how they envision/describe good coercion. We found that patients differentiated implicitly between experiences and moral evaluation. The findings have been ordered into three types of reactions: agreeing and accepting, fighting or resisting, and resignation. Further reflection upon patients' positive and negative moral evaluations of coercion resulted in the formulation of different concrete elements at three levels: threshold elements, process elements, and empathic elements. These elements helped us to understand what these patients considered ‘good coercion’. The implications are that good clinical practice cannot be separated from the formal, moral evaluation of coercion. A differentiated moral understanding of coercion can form the basis for better and more sensitive communication about coercion among all those involved. A more respectful dialogue on the moral evaluation of coercion might also raise awareness during both the decision‐making process and the actual practising of coercion.
Early stages of tooth morphogenesis in mouse analyzed by 3D reconstructions
Authors: Lesot Hervé , Peterková Renata , Viriot Laurent , Vonesch Jean Luc , Turecková Jolana , Peterka Miroslav , Ruch Jean Victor
Published: November 2014

Computer‐aided 3D reconstructions were used to investigate early odontogenesis in the ICR mouse, from the dental lamina to the cap stage. The diastemal region of the maxilla was not an empty zone: five transient epithelial rudiments (D1–D5) were found between ED 12.5–13.5. Two further rudiments (R1 and R2) were observed between D5 and the maxillary first molar primordium, whose bud emerged at ED 13.5. These rudiments might be related to vestiges of ancestral teeth. During this period, only an epithelial lamina was observed in front of the bud‐shaped molar epithelium in the cheek region of the mandible. Apoptosis plays an important role in the reduction of antemolar rudiments in the maxilla and in the remodeling of the epithelium anterior to the M1 bud and cap in both jaws: two successive waves of apoptosis were detected in the mandible and in the maxilla. Computer‐aided 3D reconstructions clearly demonstrated that morphologically different developmental stages coexist along the anteroposterior axis of M1 in both jaws.
Freeze‐fracture studies of the distal plasma membrane of rat odontoblasts during their differentiation and polarisation
Authors: Arana‐Chavez V. E. , Katchburian E.
Published: November 2014

We have examined freeze‐fracture replicas of maxillary first molar tooth germs of newborn rats at early stages of dentinogenesis to study the development of tight junctions in the distal plasma membrane of differentiating odontoblasts. In addition, freeze‐fracture was combined with filipin to observe the distribution of cholesterol on the distal plasma membrane of odontoblasts during differentiation. Only gap junctions were present in early differentiating odontoblasts. The distal plasma membrane exhibited low cholesterol content, which might indicate high fluidity. With the beginning of mineral deposition in matrix‐vesicles, the first signs of tight junction formation were observed. Further development revealed increasingly complex focal tight junctions. In later stages, when mineralisation is observed progressing to the fibrillar and non‐fibrillar constituents of the matrix, well developed focal tight junctions were detected. Concomitantly, cholesterol in distal portions of the odontoblast plasma membrane increased, indicating, probably, a higher rigidity. Thus, a distal plasma membrane domain is established, odontoblasts become fully differentiated, and partial compartmentalisation of matrix occurs. At this stage, odontoblasts may be able to secrete specific matrix molecules to ensure the progression of mineralisation.
RNAse protection assay for BMP type I receptors
Authors: Cheifetz Sela
Published: November 2014

Bone morphogenetic proteins (BMPs) signal through a receptor complex comprising two distinct transmembrane serine/threonine kinases referred to as type I and type II receptors. The identification of at least three classes of type I receptors (ALK‐2, ‐3, ‐6) and three classes of type II receptors for the BMPs, raises the possibility of multiple receptor complexes which may have distinct functions. An RNAse protection assay has been established which allows simultaneous analyses of the mRNAs for ALK‐2, ‐3, and ‐6. As a test system, cultures of pluripotent C3H10T1/2 cell line were incubated in the presence or absence of BMP‐7, and the relative levels of the receptor mRNAs were determined. Changes in receptor mRNA levels for ALK‐2 and ‐3 were detected during the proliferation phase and adipogenic differentiation of the pluripotent C3H10T1/2 cell line.
Blood vessels and nerve fibers in rat incisor pulp
Authors: Tabata Shoji , Ozaki Hiroki S. , Nakashima Mitsuo , Uemura Masanori
Published: November 2014

The distribution of nerve fibers with special reference to their positional relationship with blood vessels in the pulp of the rat mandibular incisor was investigated by light and electron microscopic immunohistochemistry using polyclonal anti‐substance P antibody. In the center of the pulp, numerous immunoreactive nerve fibers with varicosities were found along larger blood vessels. In the periphery of the pulp, there were two layers of capillary plexus; an odontoblastic and a subodontoblastic. Many nerve fibers, showing varicosities, were located in the subodontoblastic region, and some revealed a close association with pericytes of capillaries of the subodontoblastic plexus. A few nerve fibers entered the odontoblast layer, but no nerve fibers were seen to be associated with the odontoblastic capillary plexus. The results suggest that the local regulation of blood flow takes place not only in larger blood vessels but also in the capillaries of the rat incisor pulp.
Evolution of the amelogenin gene in toothed and toothless vertebrates
Authors: Girondot Marc , Sire Jean‐Yves
Published: November 2014

Amelogenin proteins constitute the major organic contents in forming enamel, but some previously published data indicate that the amelogenin gene could be present in several species lacking teeth or functional enamel. Therefore, amelogenin could have another, still unknown, function other than contributing to enamel formation. In order to test this hypothesis, the presence of this gene has been searched for in various vertebrates. We first compared the mammalian amelogenin sequences available in the literature to obtain the best chance of a successful detection of this gene in phylogenetically distant species. Using this analysis, we have shown that the occurrence of the amelogenin gene in the Y chromosome of primates and of an artiodactyl species is probably due to two independent duplications from genes on the X chromosome. Primers for PCR have therefore been synthesized and tested in eight species, five possessing teeth (human, two phylogenetically distant lizards, and two phylogenetically distant actinopterygians) and three lacking teeth (chicken and two phylogenetically distant turtles). The amelogenin gene has been detected in all species except those lacking teeth. This result indicates that the unique role of amelogenin in amniotes is to contribute to enamel formation.
Extreme variation in the atrial septation of caecilians (Amphibia: Gymnophiona)
Authors: de Bakker Desiderius M. , Wilkinson Mark , Jensen Bjarke
Published: November 2014

Caecilians (order Gymnophiona) are elongate, limbless, snake‐like amphibians that are the sister‐group (closest relatives) of all other recent amphibians (frogs and salamanders). Little is known of their cardiovascular anatomy and physiology, but one nearly century old study suggests that Hypogeophis (family Indotyphlidae), commonly relied upon as a representative caecilian species, has atrial septation in the frontal plane and more than one septum. In contrast, in other vertebrates there generally is one atrial septum in the sagittal plane. We studied the adult heart of Idiocranium (also Indotyphlidae) using immunohistochemistry and confirm that the interatrial septum is close to the frontal plane. Additionally, a parallel right atrial septum divides three‐fourths of the right atrial cavity of this species. Idiocranium embryos in the Hill collection reveal that atrial septation initiates in the sagittal plane as in other tetrapods. Late developmental stages, however, see a left‐ward shift of visceral organs and a concordant rotation of the atria that reorients the atrial septa towards the frontal plane. The gross anatomies of species from six other caecilian families reveal that (i) the right atrial septum developed early in caecilian evolution (only absent in Rhinatrematidae) and that (ii) rotation of the atria evolved later and its degree varies between families. In most vertebrates a prominent atrial trabeculation associates with the sinuatrial valve, the so‐called septum spurium, and the right atrial septum seems homologous to this trabeculation but much more developed. The right atrial septum does not appear to be a consequence of body elongation because it is absent in some caecilians and in snakes. The interatrial septum of caecilians shares multiple characters with the atrial septum of lungfishes, salamanders and the embryonic septum primum of amniotes. In conclusion, atrial septation in caecilians is based on evolutionarily conserved structures but possibly exhibits greater variation than in any other vertebrate order.
The Border Committee of Women Workers and Its International Activism: From the Protection of Women Workers to the Protection of Workers' Rights
Authors: Quintero Ramírez Cirila
Published: November 2014

This study analyzes the case of the Mexican Border Committee of Women Workers, a women's grassroots organization, situated in Piedras Negras, Coahuila, Mexico, that has been part of international prowomen worker alliances since its formation in the mid‐1980s. It argues that the community‐based work that this organization carries out in the form of in‐house training and grassroots organizing inside factories has played a central role in its international alliances and could be considered the social capital of its transnational alliances and campaigns.
Cloning and characterisation of JAZ gene family in Hevea brasiliensis
Authors: Hong H. , Xiao H. , Yuan H. , Zhai J. , Huang X.
Published: November 2014

Mechanical wounding or treatment with exogenous jasmonates (JA) induces differentiation of the laticifer in Hevea brasiliensis. JA is a key signal for latex biosynthesis and wounding response in the rubber tree. Identification of JAZ (jasmonate ZIM‐domain) family of proteins that repress JA responses has facilitated rapid progress in understanding how this lipid‐derived hormone controls gene expression and related physiological processes in plants. In this work, the full‐length cDNAs of six JAZ genes were cloned from H. brasiliensis (termed HbJAZ). These HbJAZ have different lengths and sequence diversity, but all of them contain Jas and ZIM domains, and two of them contain an ERF‐associated amphiphilic repression (EAR) motif in the N‐terminal. Real‐time RT‐PCR analyses revealed that HbJAZ have different expression patterns and tissue specificity. Four HbJAZ were up‐regulated, one was down‐regulated, while two were less effected by rubber tapping treatment, suggesting that they might play distinct roles in the wounding response. A yeast two‐hybrid assay revealed that HbJAZ proteins interact with each other to form homologous or heterogeneous dimer complexes, indicating that the HbJAZ proteins may expand their function through diverse JAZ–JAZ interactions. This work lays a foundation for identification of the JA signalling pathway and molecular mechanisms of latex biosynthesis in rubber trees.
Electrophysiological dynamics reveal distinct processing of stimulus‐stimulus and stimulus‐response conflicts
Authors: Li Qi , Wang Kai , Nan Weizhi , Zheng Ya , Wu Haiyan , Wang Hongbin , Liu Xun
Published: November 2014

The present study examined electroencephalogram profiles on a novel stimulus‐response compatibility (SRC) task in order to elucidate the distinct brain mechanisms of stimulus‐stimulus (S‐S) and stimulus‐response (S‐R) conflict processing. The results showed that the SRC effects on reaction times (RTs) and N2 amplitudes were additive when both S‐S and S‐R conflicts existed. We also observed that, for both RTs and N2 amplitudes, the conflict adaptation effects—the reduced SRC effect following an incongruent trial versus a congruent trial—were present only when two consecutive trials involved the same type of conflict. Time‐frequency analysis revealed that both S‐S and S‐R conflicts modulated power in the theta band, whereas S‐S conflict additionally modulated power in the alpha and beta bands. In summary, our findings provide insight into the domain‐specific conflict processing and the modular organization of cognitive control.
Time Zone Politics and Challenges of Globalisation
Authors: Benediktsson Karl , Brunn Stanley D.
Published: November 2014

Time zones are an under researched topic in geography. In this paper, their political construction is examined, and the conflicts that can arise between biological temporalities on one hand and the interests of international business and state politics on the other are discussed. A detailed map of major deviations from theoretical time zones in China and Europe is presented. The geographically complex and uneven adoption of daylight saving time is also shown on a map. An extended case study of time zone politics in Iceland is then presented. Its current time zone allocation has been contested from two very different viewpoints, where business concerns and geographical position are in conflict. Finally, new challenges to the global time zone system, arising from the increased economic globalisation and opportunities for social interaction in the new reality of cyberspace, are discussed. The concept of ‘time elasticity’ is proposed for partially grappling with these conditions.
Divergent muscle sympathetic responses to dynamic leg exercise in heart failure and age‐matched healthy subjects
Authors: Notarius Catherine F. , Millar Philip J. , Murai Hisayoshi , Morris Beverley L. , Marzolini Susan , Oh Paul , Floras John S.
Published: November 2014

Key points

People with diminished ventricular contraction who develop heart failure have higher sympathetic nerve firing rates at rest compared with healthy individuals of a similar age and this is associated with less exercise capacity.

During handgrip exercise, sympathetic nerve activity to muscle is higher in patients with heart failure but the response to leg exercise is unknown because its recording requires stillness.

We measured sympathetic activity from one leg while the other leg cycled at a moderate level and observed a decrease in nerve firing rate in healthy subjects but an increase in subjects with heart failure.

Because these nerves release noradrenaline, which can restrict muscle blood flow, this observation helps explain the limited exercise capacity of patients with heart failure.

Lower nerve traffic during exercise was associated with greater peak oxygen uptake, suggesting that if exercise training attenuated sympathetic outflow functional capacity in heart failure would improve.

The reflex fibular muscle sympathetic nerve (MSNA) response to dynamic handgrip exercise is elicited at a lower threshold in heart failure with reduced ejection fraction (HFrEF). The present aim was to test the hypothesis that the contralateral MSNA response to mild to moderate dynamic one‐legged exercise is augmented in HFrEF relative to age‐ and sex‐matched controls. Heart rate (HR), blood pressure and MSNA were recorded in 16 patients with HFrEF (left ventricular ejection fraction = 31 ± 2%; age 62 ± 3 years, mean ± SE) and 13 healthy control subjects (56 ± 2 years) before and during 2 min of upright one‐legged unloaded cycling followed by 2 min at 50% of peak oxygen uptake (). Resting HR and blood pressure were similar between groups whereas MSNA burst frequency was higher (50.0 ± 2.0 vs. 42.3 ± 2.7 bursts min−1, P = 0.03) and lower (18.0 ± 2.0 vs. 32.6 ± 2.8 ml kg−1 min−1, P < 0.001) in HFrEF. Exercise increased HR (P < 0.001) with no group difference (P = 0.1). MSNA burst frequency decreased during mild to moderate dynamic exercise in the healthy controls but increased in HFrEF (−5.5 ± 2.0 vs. 6.9 ± 1.8 bursts min−1, P < 0.001). Exercise capacity correlated inversely with MSNA burst frequency at 50% (n = 29; r = −0.64; P < 0.001). At the same relative workload, one‐legged dynamic exercise elicited a fall in MSNA burst frequency in healthy subjects but sympathoexcitation in HFrEF, a divergence probably reflecting between‐group differences in reflexes engaged by cycling. This finding, coupled with an inverse relationship between MSNA burst frequency during loaded cycling and subjects’ , is consistent with a neurogenic determinant of exercise capacity in HFrEF.
Macro‐micro imaging of cardiac–neural circuits in co‐cultures from normal and diseased hearts
Authors: Bub Gil , Burton Rebecca‐Ann B.
Published: November 2014

The autonomic nervous system plays an important role in the modulation of normal cardiac rhythm, but is also implicated in modulating the heart's susceptibility to re‐entrant ventricular and atrial arrhythmias. The mechanisms by which the autonomic nervous system is pro‐arrhythmic or anti‐arrhythmic is multifaceted and varies for different types of arrhythmia and their cardiac substrates. Despite decades of research in this area, fundamental questions related to how neuron density and spatial organization modulate cardiac wave dynamics remain unanswered. These questions may be ill‐posed in intact tissues where the activity of individual cells is often experimentally inaccessible. Development of simplified biological models that would allow us to better understand the influence of neural activation on cardiac activity can be beneficial. This Symposium Review summarizes the development of in vitro cardiomyocyte cell culture models of re‐entrant activity, as well as challenges associated with extending these models to include the effects of neural activation.
Parametric Sensitivity Tests—European Polymer Electrolyte Membrane Fuel Cell Stack Test Procedures
Authors: Simon Araya Samuel , Juhl Andreasen Søren , Knudsen Kær Søren
Published: November 2014

As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests performed based on test procedures proposed by a European project, StackTest. The sensitivity of a Nafion®-based low temperature PEMFC stack's performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity (RH), temperature, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions.
Dopant Clustering and Correlated Oxygen Migration in Conditionally Stabilized Zirconia Electrolytes
Authors: Miller Steven P. , Dunlap Brett I. , Fleischer Amy S.
Published: November 2014

Molecular dynamics (MD) simulation of yttria/scandia-stabilized zirconia (SSZ) with variably distributed Y/Sc dopant ions shows that energy is minimized when the dopants are uniformly spread apart, provided that the lattice maintains cubic fluorite symmetry. In contrast, highly clustered dopants are found to destabilize the cubic phase due to the presence of large regions of dopant-free zirconia. Computed oxygen diffusion coefficients and conductivity values consistently show that the Haven ratio is always less than one, indicating that correlation effects influence the motion of oxygen ions and vacancies. In addition, it is seen that the conductivity of crystals with noncubic symmetry is markedly anisotropic.
Effects of Entrainment on Incapability of High Intensity Beam Drilling
Authors: Wei P. S. , Wu J. H. , Chao T. C.
Published: November 2014

The effects of entrainment accompanying mass, momentum, and energy transport from the keyhole wall on keyhole collapse during high-power-density laser or electron beam drilling are theoretically and systematically investigated in this study. High intensity beam drilling is widely used in components, packaging and manufacturing technologies, micro-electromechanical-systems (MEMS), rapid prototyping manufacturing, and keyhole welding. This study proposes a quasi-steady, one-dimensional transport model to predict supersonic and subsonic flow behavior of the two-phase, vapor–liquid dispersion in a keyhole and applies the Young–Laplace equation to calculate the keyhole shape. The results show that the keyhole collapse, representing decreased or vanished radius, is susceptible to mass ejection at the base and entrainment from the side wall. Deposition of a mixture of gas and droplets in the keyhole stabilizes deformation of the keyhole. Enhanced energy and decreased axial component of momentum associated with entrainment are also apt to keyhole collapse. The predicted results agree with axial variations of transport variables of a compressible flow through a divergent and convergent nozzle, and their exact analytical solutions in the absence of friction, energy absorption, and entrainment. An understanding of the effects of ejected and entrained mass in the keyhole on drilling efficiency is therefore provided.
Thermal Convection in Porous Media at High Rayleigh Numbers
Authors: Keene Daniel J. , Goldstein R. J.
Published: November 2014

An experimental study of thermal convection in a porous medium investigates the heat transfer across a horizontal layer heated from below at high Rayleigh number. Using a packed bed of polypropylene spheres in a cubic enclosure saturated with compressed argon, the pressure was varied between 5.6 bar and 77 bar to obtain fluid Rayleigh numbers between 1.68 × 109 and 3.86 × 1011, corresponding to Rayleigh–Darcy numbers between 7.47 × 103 and 2.03 × 106. From the present and earlier studies of Rayleigh–Benard convection in both porous media and homogeneous fluid systems, the existence and importance of a thin thermal boundary layer are clearly demonstrated. In addition to identifying the governing role of the thermal boundary layer at high Rayleigh numbers, the successful correlation of data using homogeneous fluid dimensionless groups when the thermal boundary layer thickness becomes smaller than the length scale associated with the pore features is shown.
The ATWS Analysis of One Control Rod Withdrawal Out of the HTR-10GT Core Under the Loss of the System Pressure
Authors: Lang Minggang
Published: November 2014

The 10MW High Temperature Gas Cooled Test Reactor (HTR-10) has been built in Institute of Nuclear and New Energy Technology (INET) and has been operating successfully since the beginning of 2003. The core outlet temperature of HTR-10 is 700°C. To verify the technology of gas-turbine direct cycle, at first INET had a plan to increase its core outlet temperature to 750°C and to use a helium gas turbine instead of the steam generator (then the reactor is called HTR-10GT). Though HTR-10 has good intrinsic safety, the design basis accidents and beyond design basis accidents of HTR10-GT must be analyzed according to China’s nuclear regulations due to changed operation parameters. THERMIX code system is used to study the ATWS accident of one control rod withdrawal out of the core by a mistake under the loss of the system pressure. After a control rod in the side reflector was withdrawn out at a speed of 1 cm/s by a mistake, a positive reactivity was inserted. At the same time, the system pressure was supposed to lose by some reason. Thus the reactor power increased and the temperature of the core increased. And the protection system warns with two scram signal: too high of the negative varying rate of the system pressure and too high of the reactor power, which should induce the reactor to scram. It was supposed that all the control rods in the reflectors had been blocked and the reactor could not scram. Thus the accident went on and the core temperature and the system pressure continued to increase but the reactor shutdown at last because of its natural negative temperature reactivity feedback mechanism. The residual heat would be removed out of the core by the cavity cooling system. During the accident sequence the maximum fuel temperature was 1203.4°C. It was a little bit lower than 1230°C — the fuel temperature limitation of HTR-10 and there is no release of any radioactivity. So the HTR-10GT is safe during the ATWS of one control rod withdrawal out of the core. The paper also compares the analysis result of HTR10-GT to those of HTR-10. The results shows that the HTR-10GT is still safe during the accident though its operating temperature is higher than HTR-10.
Dynamic Behavior Analysis of Touchdown Process in Active Magnetic Bearing System Based on Kalman Filtering
Authors: Sun Zhe , Kang Xiao , Zhao Jingjing , Yang Guojun , Shi Zhengang
Published: November 2014

Magnetic bearings are widely applied in High Temperature Gas-cooled Reactor (HTGR) and auxiliary bearings are important backup and safety components in AMB systems. The dynamic analysis of the AMB rotors touchdown process is an important foundation for designing auxiliary bearings. In this paper, a data-based dynamic analysis of the touchdown process is proposed. The dynamic model of the touchdown process is firstly established and then the nonlinear extended Kalman filtering technique is applied. Based on the dynamic model and Kalman filtering technique, the proposed method can offer estimations of rotor’s displacements, velocities and accelerations from noisy observations. The proposed method is validated by the experiment data from touchdown experiments. The touchdown experiments are performed on an experimental system with a 440kg heavy rotor, the rotational speed in the experiments is 5000RPM and no brake is applied.
To Improve the Accuaracy of Harmonic Synthesis Method by Using More Detectors in Azimuthal Direction in HTR
Authors: Fan Kai , Li Fu , Zhou Xuhua
Published: November 2014

Modular high temperature gas cooled reactor HTR-PM demonstration plant, designed by INET, Tsinghua University, is being built in Shidaowan, Shandong province, China. HTR-PM adopts pebble bed concept. Like other HTR, monitoring the core power distribution of HTR-PM is very important but challenging, as there is no in-core neutron detectors. There are some proposals to reconstruct the power distribution using the readings of ex-core neutron detectors. One method is harmonic synthesis method. In HTR, the neutron detectors are arranging symmetrically; and the power distribution of the core is also symmetrical. So in the before, only one set of detectors were used to reconstruct the power distribution, for considering the readings of different sets were almost same. In this paper, all readings of the neutron detectors were used, and new results were calculated and evaluated. It is showed that using more detector readings has no help to the accuracy of the harmonic synthesis method but improve the robustness of the method obvious. Using more detectors could improve both the robustness and the accuracy to the harmonics’ coefficients polynomial expansion method.
Thermal-Hydraulic Design and Transient Analysis of Helium-Cooled Solid Target for ADS
Authors: Peng Tianji , Zhou Zhiwei , Gu Long
Published: November 2014

The Accelerator Driven System (ADS) is a kind of nuclear reactor which can burn minor actinide waste products from conventional reactors with inherent safety. Because of the characteristics of a sub-critical reaction process, the fission chain reaction is maintained by additional neutrons generated by protons in spallation target. In this paper, a helium-cooled solid target is designed for a 10MW helium-cooled prismatic-type experimental ADS. The spallation material tungsten is modeled into the honeycomb structure, and high pressure helium flow in honeycomb holes remove heat deposited by the proton beam in the target. Since the complexity of geometry, if analysis the target with CFD code the computing time is unacceptable. Thus, a simple mathematical method was developed to solve the heat transfer problem in honeycomb structure, which avoids fine grid and the turbulent simulation, and gets a solution quickly. In order to analyze the transient characteristics of spallation target cooling system, a equivalent RELAP5 model for target and a RELAP5 model for cooling system are established. Results obtained indicate that the peak temperature in the target is lower than the limiting value under operating state and blockage condition as well as three typical transients with protected.
Research About Eddy Effect and Dynamic Force of the Magnetic Thrust Bearing
Authors: Liu Xingnan , Mo Ni , Yang Guojun , Shi Zhengang , Yu Suyuan
Published: November 2014

The eddy effect of the magnetic thrust bearing (MTB) is researched by the finite element analysis (FEA). The active magnetic bearing (AMB) is an advanced bearing, used in HTR-PM. The alternating current in the bearing windings will decrease the electromagnetic force and cause phase lag, especially in the MTB which has no lamination structure. According to the calculation in this paper, simple sinusoidal current has large eddy effect. The force decreases obviously and the phase lag is large. However, the current containing direct part and sinusoidal part, which is closer to actual current, has less eddy effect. That is to say, because of the direct part in the current, the eddy effect of the sinusoidal part decreases.
Power Cycles of Generation III and III+ Nuclear Power Plants
Authors: Dragunov Alexey , Saltanov Eugene , Pioro Igor , Kirillov Pavel , Duffey Romney
Published: November 2014

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be generated by: 1) non-renewable-energy sources such as coal, natural gas, oil, and nuclear; and 2) renewable-energy sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy generation are: 1) thermal - primary coal and secondary natural gas; 2) “large” hydro and 3) nuclear. The rest of the energy sources might have visible impact just in some countries.

Modern advanced thermal power plants have reached very high thermal efficiencies (55–62%). In spite of that they are still the largest emitters of carbon dioxide into atmosphere. Due to that, reliable non-fossil-fuel energy generation, such as nuclear power, becomes more and more attractive. However, current Nuclear Power Plants (NPPs) are way behind by thermal efficiency (30–42%) compared to that of advanced thermal power plants. Therefore, it is important to consider various ways to enhance thermal efficiency of NPPs.

The paper presents comparison of thermodynamic cycles and layouts of modern NPPs and discusses ways to improve their thermal efficiencies.
Separation of Nuclides by Different Types of Zeolites in the Presence of Boric Acid
Authors: Fujita Natsuki , Mimura Hitoshi , Kobayashi Takaaki , Sekino Kazuyuki , Nagamine Kunitaka
Published: November 2014

The development of selective adsorbents has become very important for the effective multi-nuclide decontamination. In this study, the selective adsorption properties of 26 nuclides for different types of zeolites (A, L, natural mordenite (NM), Ag-NM) were examined in the presence of boric acid.

The batch adsorption experiments were carried out using four kinds of test solutions containing boric acid and calcium hydroxide; (1)DW (distilled water) + H3BO4: 3,000 ppm + LiOH: 10 ppb, (2)DW + Ca(OH)2: 500 ppm + H3BO4: 3,000 ppm + LiOH: 10 ppb, (3)Seawater (30% diluted) + H3BO4: 3,000 ppm, (4)Seawater + H3BO4: 3,000ppm. The uptake (%) of Sr2+ for zeolite A (A-51J), Cs+ for natural mordenite (NM, 2460#, Ayashi, Sendai), and I− for Ag-NM was determined under the following conditions; Concentration of Sr2+, Cs+ and I− ions: 10 ppm, V/m = 100 cm3/g, 25°C, 24 h. The uptake (%) of Sr2+, Cs+ and I− ions was estimated to be above 90%, while tended to decrease in the presence of seawater. Especially, the uptake (%) of I− ions for Ag-NM markedly decreased in the presence of seawater.

As for the zeolites A and L, the uptake (%) of 26 elements was determined by using two kinds of test solutions; (1)DW (distilled water) + H3BO4: 3,000 ppm + LiOH: 10 ppb + 26 nuclides: 10 ppm, (2)Seawater (30% diluted) + H3BO4: 3,000 ppm + 26 nuclides: 10 ppm.

Zeolite A has relatively large uptake percentage for Sr, Co, Ni and Zn, and zeolite L has high adsorbability to lanthanoid group of Eu, Ce and Pr. The increase in pH led to the enhancement of uptake (%), while the hydrolysis of metal ions should be also considered. The multi-nuclides separation is thus expected by considering the difference in uptake properties of zeolite A, L and natural mordenite.
Static Structure Analysis of Spallation Target Beam Window at the Initial State for CIADS
Authors: Yang Yongwei , Wu Zhuang , Feng Kun , Sun Zhou
Published: November 2014

The conceptual design and basic engineering of a multipurpose ADS for R&D, named Chinese Initiative Accelerator Driven System (CIADS), have been carried out by Chinese Academy of Science. A lead-bismuth eutectic (LBE) spallation target with beam window is an alternative for the CIADS. In this work, by using the code system ANSYS, the static structure analysis of the spallation target beam window at the initial state was performed parametrically in conjunction with the thermal hydraulics to check the design compliance with the stress and the buckling design criteria. The static structure analysis of the target window was presented under the conditions of different window thicknesses, proton beam intensities and beam spot diameters. The results showed that all the parameters investigated in this work which meet the needs of thermal hydraulics design also compliance with the stress and the buckling design criteria. Also, the results were used to select the thickness of the beam window to maximize the engineering margins. More work will be done in the future for the structural analysis of target operating with certain dosage irradiated by the neutrons and the protons.
Computational Analyses of the Thermal Stress Induced by Coolant Mixing in a T-Joint
Authors: Janssens K. G. F. , Niffenegger M. , Sharabi M.
Published: November 2014

In this paper we report computational fluid dynamics and thermal stress finite element analyses of a T-joint component as used in a Swiss nuclear power plant under realistic loading conditions and simplified boundary conditions. In this report the focus is on the thermal stress analyses, and therefore only those fluid dynamics simulations used for thermal stress analyses are presented. The local stress amplitudes, simulated using elastic finite element simulations, are compared to a regulatory fatigue life curve to estimate the local distribution of low cycle fatigue damage and crack initiation probability in the T-joint. The case studies reported here have been selected with the purpose of analyzing the different ways in which the fluid structure interaction induces thermal stress in the mixing tee. In case I only the thermal stress induced by the mixing turbulence is simulated, i.e. with constant mass flow rate boundary conditions. In case II a peak in the flow rate in the main pipe, typical for transient (startup) plant conditions, is addressed and analyzed in detail. Only in the latter case is low cycle fatigue cracking to be expected in the form of non-propagating (i.e. not throughwall) surface cracks or crazing.
Analysis of the Particulate Debris Bed Quenching During Top and Bottom Flood
Authors: Huang Tao , Tian Wenxi , Zhang Yapei , Qiu Suizheng , Su Guanghui
Published: November 2014

The quenching characteristics of particulate debris bed during bottom and top flood is analyzed in this paper. The top flood model is formulated by dividing the quenching process into downward frontal period and upward frontal period, which are controlled by the counter-current flow limitation (CCFL) condition and effects of the incoming coolant subcooling and steam cooling in dry channels during quenching process. The bottom flood model is based on porous media theory under the assumption that the height of the two phase region is negligible and the particulate debris bed is divided into single phase liquid and single phase vapor region. The results calculated by these models were compared with the experimental data. The influences of porosity, initial debris temperature and other parameters on both the top and bottom quenching process were studied in this paper. During the top flood, the quenching velocity increased with the increase of the porosity and the decrease of the initial debris temperature. The porosity and initial debris temperature had a larger influence on quenching velocity compared with other parameters, such as initial coolant temperature and coolant flow rate. During the bottom flood, the quenching velocity also increased with the increase of the porosity and the decrease of the initial debris temperature. However, the coolant flow rate had a large influence on the quenching velocity unlike that during the top flood. Quenching from bottom may be superior to the quenching from top. The results can be expected to be useful to evaluate the quenching process of the particulate debris bed.
Selective Uptake of Sr and Stable Solidification Using Potassium Titanates
Authors: Kanda Hitoshi , Mimura Hitoshi , Niibori Yuichi , Iwasaki Mamoru , Mori Koichi , Itoi Nobuki , Goto Toshiki
Published: November 2014

The development of selective adsorbents for radioactive Sr ions is one of the most important subjects for the safety decontamination in Fukushima NPP-1[1]. In this study, the selective adsorption properties of Sr, characterization and stable solidification were clarified by using the novel adsorbent of potassium titanates (KT-1).

The adsorption properties of Sr2+ ions for original and calcined specimens were examined by batch method under the following conditions; V/m = 100 cm3/g, Mixed solution: 10,000 ppm Na+, 10 ppm Cs+, 10 ppm Ca2+, 1 ppm Mg2+ and 1 ppm Sr2+, 85Sr tracer: 5,000 cpm/cm3, centrifugation: 2,500 rpm, 25°C, shaking time: 1∼24 h, calcination temp.: 300∼900°C. Relatively large uptake percentage above 90% was obtained for the original and calcined specimens below 800°C, while the Sr uptake for calcined specimens above 900°C was lowered due to the thermal decomposition of K2Ti2O5·xH2O.

The Sr distribution in the column was examined by flowing the mixed solution through the columns packed with KT-1. The Sr distribution profiles were obtained by the measurement of γ-activity in the column at 5 mm intervals. In either case, no breakthrough of Sr was observed. The distribution profile tended to smooth with increasing flow rate; Sr adsorption band and flow rate have a linear relationship.

The leachability of Sr for the solid forms was further examined under the following leaching conditions; leachant: pure water and 1 M HCl; leachant temp.: 25°C and 90°C, leaching period: 4 weeks; calcining temp.: 500∼1,100°C. The leached percentage of Sr in pure water was less than the detection limit of ICP-AES, and that in 0.1 M HCl tended to markedly decrease with calcining temperature; the formation of SrTiO3 phase above 800°C was effective for the lowering of leachability.

The novel adsorbent of KT-1 is thus effective for the selective decontamination and stable solidification of Sr in Fukushima NPP-1.
Numerical Investigation on Heat Removal Capacity of Passive Residual Heat Removal Heat Exchanger
Authors: Zhang Wenwen , Tian Wenxi , Qiu Suizheng , Su Guanghui
Published: November 2014

In the present study, thermal-hydraulics characteristics of AP1000 passive residual heat removal heat exchanger (PRHR-HX) at initial operating stage were analyzed based on the porous media models. The data predicated by RELAP5 under the condition of the station blackout was employed as the inlet flow rate and temperature boundary of CFD calculation. The heat transfer from the primary side coolant to the in-containment refueling water storage tank (IRWST) side fluid was calculated in a three-dimensional geometry during iterations, and the distributed resistances were added into the C-type tube bundle regions. Three-dimensional distributions of velocity and temperature in the IRWST were calculated by the CFD code ANSYS FLUENT. The primary temperature, heat transfer coefficients of two sides and the heat transfer were obtained using the coupled heat transfer between the primary side and the IRWST side. The simulation results indicated that the water temperature rises gradually which leads to a thermal stratification phenomenon in the tank and the heat transfer capability decreases with an increase of water temperature. The present results indicated that the method containing coupled heat transfer from the primary side fluid to IRWST side fluid and porous media model is a suitable approach to study the transient thermal-hydraulics of PRHR/IRWST system.
Validation of a New Method for Solving of CFD Problems in Nuclear Engineering Using Petascale HPC
Authors: Chudanov Vladimir , Aksenova Anna , Goreinov Sergey , Makarevich Artem , Pervichko Valerii
Published: November 2014

This paper deal with validation results for the new method for solving of CFD problem in nuclear engineering using petascale HPC. This method was validated on a series of the well-known tests in a wide range of Rayleigh (106−1016) and Reynolds (103−105). A good coincidence of numerical predictions with experimental data was reached.
Experimental Study of Heat Transfer to Supercritical Pressure Water Flowing in a 2×2 Rod Bundle
Authors: Wang Han , Bi Qincheng , Wang Linchuan , Lv Haicai , Leung Laurence K. H.
Published: November 2014

An experiment has recently been performed at Xi’an Jiaotong University to study the wall temperature and pressure drop at supercritical pressures with upward flow of water inside a 2×2 rod bundle. A fuel-assembly simulator with four heated rods was installed inside a square channel with rounded corner. The outer diameter of each heated rod is 8 mm with an effective heated length of 600 mm. Experimental parameters covered the pressure of 23–28 MPa, mass flux of 350–1000 kg/m2s and heat flux on the rod surface of 200–1000 kW/m2. According to the experimental data, it was found that the circumferential wall temperature distribution of a heated rod is not uniform. The temperature difference between the maximum and the minimum varies with heat flux and/or mass flux. Heat transfer characteristics of supercritical water in bundle were discussed with respect to various heat fluxes. The effect of heat flux on heat transfer in rod bundles is similar with that in tubes or annuli. In addition, flow resistance reflected in the form of pressure loss has also been studied. Experimental results showed that the total pressure drop increases with bulk enthalpy and mass flux. Four heat transfer correlations developed for supercritical pressures water were compared with the present test data. Predictions of Jackson correlation agrees closely with the experimental data.
Decreasing Waste of Laser Cutting by Metal Fume Capturing With Water
Authors: Chida Itaru , Shiihara Katsunori , Nomura Kota , Sumiya Rie , Suganuma Naotaka
Published: November 2014

Decommissioning of aged nuclear reactors is planned, and cutting technologies for thick structure are necessary to reduce storage space of radioactive wastes. Though thermal cutting technology is suitable for cutting thick materials, radioactive fume is one of the problems due to increase the environmental dose. A water jet-guided laser cutting technology is one of the solutions for cutting irradiated materials, because radioactive fume is confined in the water and doze level won’t be increased. However, this technology was developed for precision machining like dicing and slotting of silicon wafers, cutting thick materials by using this process is very diffcult. In this study, cutting technology for thick material with a water jet-guided laser was discussed. Phenomenon during cutting thick stainless steel was observed by using high speed camera and optimum conditions for both water jet and laser cutting were derived. Finally, 50mm thick stainless steel plate was successfully cut by using this technology.
Numerical Analysis of Crust Behavior of Molten Core and Concrete Interaction by Using MPS Method
Authors: Watanabe Takeo , Oka Yoshiaki
Published: November 2014

Moving particle semi-implicit (MPS) method is the particle (girdles) method for incompressible medium. Particles are used for discretization of fluids, and governing equations are transformed to particle interaction models. Phase changes are treated as changing particle dynamics. The interface is treated accurately. In the present study, two-dimensional code is created for molten core concrete interaction (MCCI) by using MPS method. Each particle has enthalpy, and three types of heat transfer are treated. Conductive heat transfer is calculated with Laplacian model of MPS. Nucleate boiling and radiation heat transfer is calculated by removing enthalpy from surface particles. Liquid particles can be changed to solid particles depending on their enthalpy. These particles are fixed to space. Semi-implicit method is used in original MPS method, but in this study, explicit method is introduced in order to increase calculation speed. The SWISS-1 and SWISS-2 experiments are analyzed. Gas release from concrete is ignored, and melting of concrete is treated as disappearing of particles. This generate void between crust bridge and liquid debris in SWISS-2, and crust bridge is heated mainly by radiation heat transfer. Calculated ablation rate of concrete agrees well with experimental results of SWISS-1 and SWISS-2, but calculated heat flux from crust bridge to the water pool of SWISS-2 is lower. It is because the water penetration through the crust is ignored, and the amount of penetrated water is estimated by the difference between calculation and experimental result.