bluuebunny/crossref_metadata_2025 huggingface dataset:
Working with people with learning disabilities in varying degrees of security: nurses' perceptions of competencies
Authors: Lovell Andrew , Bailey Jan , Kingdon Anne , Gentile Domenica
Published: February 2014

Aim

To identify and discuss the competencies required by learning disability nurses to work effectively with people with an offending background in low, medium, high secure and community settings.

Background

Research into the competencies required by nurses working with individuals with an offending background, particularly those with a learning disability, is limited. There is some uncertainty as to whether there should be differentiation according to specific setting.

Design

A qualitative study addressing the perceptions of nurses on the knowledge, skills and competencies required to effectively work with people with learning disabilities and an offending background in different settings.

Methods

Seven focus groups were conducted across the four settings to inform the construction of the semi‐structured interview schedule. Thirty‐nine interviews were subsequently undertaken with nurses across settings to develop a fuller understanding of the competencies and ascertain if these were influenced by the specific setting where the nurses worked. Data were collected over 1‐year in 2010 and analysed using a structured thematic analysis supported by the software package MAXqda.

Findings

The thematic analysis produced four over‐arching competencies: knowledge assimilation and application; team working; communication skills; and decision‐making. A further competency around personal attributes constitutes the basis of a future paper.

Conclusion

The first three competencies combine well to inform the work of nurses and appear transferable across settings, but the fourth appears more complicated, specifically in terms of the role of risk in supporting or detracting from decision‐making capacity.
Radiation of the Drosophila nannoptera species group in Mexico
Authors: Lang M. , Polihronakis Richmond M. , Acurio A. E. , Markow T. A. , Orgogozo V.
Published: February 2014

The Drosophila nannoptera species group, a taxon of Mexican cactophilic flies, is an excellent model system to study the influence of abiotic and biotic factors on speciation, the genetic causes of ecological specialization and the evolution of unusual reproductive characters. However, the phylogenetic relationships in the nannoptera species group and its position within the virilis‐repleta phylogeny have not been thoroughly investigated. Using a multilocus data set of gene coding regions of eight nuclear and three mitochondrial genes, we found that the four described nannoptera group species diverged rapidly, with very short internodes between divergence events. Phylogenetic analysis of repleta group lineages revealed that D. inca and D. canalinea are sister to all other repleta group species, whereas the annulimana species D. aracataca and D. pseudotalamancana are sister to the nannoptera and bromeliae species groups. Our divergence time estimates suggest that the nannoptera species group radiated following important geological events in Central America. Our results indicate that a single evolutionary transition to asymmetric genitalia and to unusual sperm storage may have occurred during evolution of the nannoptera group.
When a clonal genome finds its way back to a sexual species: evidence from ongoing but rare introgression in the hybridogenetic water frog complex
Authors: Mikulíček P. , Kautman M. , Demovič B. , Janko K.
Published: February 2014

Besides several exceptions, asexual metazoans are usually viewed as ephemeral sinks for genomes, which become ‘frozen’ in clonal lineages after their emergence from ancestral sexual species. Here, we investigated whether and at what rate the asexuals are able to introgress their genomes back into the parental sexual population, thus more or less importantly affecting the gene pools of sexual species. We focused on hybridogenetic hybrids of western Palaearctic water frogs (Pelophylax esculentus), which originate through hybridization betweenP. ridibundusandP. lessonae,but transmit only clonalridibundusgenome into their gametes. Although usually mating withP. lessonae,P. esculentusmay upon mating withP. ridibundusor another hybrid produce sexually reproducingP. ridibundusoffspring with the introgressed ex‐clonal genome. We compared the rate of nuclear amplified fragment length polymorphism (AFLP) and mitochondrial introgression in two types of populations, that is, those whereP. ridibundusoccurs in isolation and those where it lives with the hybridogens. Although significant differentiation (Φpt) between sexual and clonalridibundusgenomes suggested limited gene flow between sexuals and hybridogens, a non‐negligible (~5%) proportion ofP. ridibundusbore introgressed mtDNAandAFLPmarkers. Whereas transfer of mtDNAwas exclusively unidirectional, introgression of nuclear markers was bidirectional. The proportion of introgressedP. ridibunduswas highest in syntopic populations withP. esculentus, proving an ongoing and site‐specific interspecific genetic transfer mediated by hybridogenetic hybrids. It turns out that asexual hybrids are not just a sink for genes of sexual species, but may significantly influence the genetic architecture of their sexual counterparts.
Comparison of anesthesia protocols for intravenous glucose tolerance testing in rhesus monkeys
Authors: Vaughan Kelli L. , Szarowicz Mark D. , Herbert Richard L. , Mattison Julie A.
Published: February 2014

Background

Drugs commonly used to sedate non‐human primates for physiological sample collection can affect the metabolic system and alter rates of glucose metabolism. This study was designed to compare the physiological and metabolic effects of ketamine/diazepam, telazol, and ketamine/dexmedetomidine.

Methods

Seven female rhesus monkeys underwent intravenous glucose tolerance testing under each of three anesthesia conditions. Blood glucose, insulin, physiological parameters, and sedation characteristics were measured and recorded.

Results

Glucose and insulin values were both significantly impacted by ketamine/dexmedetomidine sedation while remaining consistent during ketamine and telazol sedation. Heart rate was also significantly lowered during ketamine/dexmedetomidine anesthesia. Though, ketamine/dexmedetomidine resulted in a longer time between induction of anesthesia and need for a supplemental dose of anesthesia drug.

Conclusions

Telazol and ketamine have minimal cardiorespiratory and metabolic effects compared to ketamine/dexmedetomidine. Although practicably interchangeable, telazol appears to be the most efficient for intravenous glucose tolerance testings with non‐human primates.
In vivo brain macromolecule signals in healthy and glioblastoma mouse models: 1H magnetic resonance spectroscopy, post‐processing and metabolite quantification at 14.1 T
Authors: Craveiro Mélanie , Clément‐Schatlo Virginie , Marino Denis , Gruetter Rolf , Cudalbu Cristina
Published: February 2014

In 1H magnetic resonance spectroscopy, macromolecule signals underlay metabolite signals, and knowing their contribution is necessary for reliable metabolite quantification. When macromolecule signals are measured using an inversion‐recovery pulse sequence, special care needs to be taken to correctly remove residual metabolite signals to obtain a pure macromolecule spectrum. Furthermore, since a single spectrum is commonly used for quantification in multiple experiments, the impact of potential macromolecule signal variability, because of regional differences or pathologies, on metabolite quantification has to be assessed. In this study, we introduced a novel method to post‐process measured macromolecule signals that offers a flexible and robust way of removing residual metabolite signals. This method was applied to investigate regional differences in the mouse brain macromolecule signals that may affect metabolite quantification when not taken into account. However, since no significant differences in metabolite quantification were detected, it was concluded that a single macromolecule spectrum can be generally used for the quantification of healthy mouse brain spectra. Alternatively, the study of a mouse model of human glioma showed several alterations of the macromolecule spectrum, including, but not limited to, increased mobile lipid signals, which had to be taken into account to avoid significant metabolite quantification errors.
Induction of phosphorylated c‐Jun in neonatal spinal motoneurons after axonal injury is coincident with both motoneuron death and regeneration
Authors: Yuan Qiuju , Su Huanxing , Guo Jiasong , Wu Wutian , Lin Zhi‐Xiu
Published: February 2014

c‐Jun activation has been implicated not only in neuronal degeneration, but also in survival and regeneration. Here, we investigated c‐Jun activation in injured motoneurons by using a nerve crush model in neonatal rats. We identified two distinct subpopulations of motoneurons: about 60% underwent degeneration following injury whereas the remaining 40% survived and induced a regeneration response at 3 weeks post injury. However, all motoneurons examined expressed phosphorylated‐c‐Jun‐immunoreactivity (p‐c‐Jun‐IR) at the early stage of 3 days following injury. These results suggest that active c‐Jun was induced in all neonatal motoneurons following nerve crush injury, regardless of whether they were destined to degenerate or undergo successful regeneration at a later stage. Our findings therefore support the hypothesis that active c‐Jun is involved in both neuronal degeneration and regeneration.
Physiological Responses of Rice Plants Supplied with Silicon to Monographella albescens Infection
Authors: Tatagiba Sandro D. , Rodrigues Fabrício A. , Filippi Marta Cristina C. , Silva Gisele B. , Silva Leandro C.
Published: February 2014

This study investigated the effect of silicon (Si) on the resistance of rice plants of the cv. ‘Primavera’ cultivar that were grown in a nutrient solution with 0 (−Si) or 2 mm (+Si) Si to leaf scald, which is caused by Monographella albescens. The leaf Si concentration increased in the +Si plants (4.8 decag/kg) compared to the −Si plants (0.9 decag/kg), contributing to a reduced expansion of the leaf scald lesions. The extent of the cellular damage that was caused by the oxidative burst in response to the infection by M. albescens was reduced in the +Si plants, as evidenced by the reduced concentration of malondialdehyde. Higher concentrations of total soluble phenolics and lignin‐thioglycolic acid derivatives and greater activities of peroxidases (POX), polyphenoloxidases (PPO), phenylalanine ammonia‐lyases (PAL) and lipoxygenases (LOX) in the leaves of the +Si plants also contributed to the increased rice resistance to leaf scald. In contrast, the activities of chitinases and β‐1,3‐glucanases were higher in the leaves of the −Si plants probably due to the unlimited M. albescens growth in the leaf tissues, as indicated by the larger lesions. The results of this study highlight the potential of Si in decreasing the expansion of the leaf scald lesions concomitantly with the potentiation of phenolic and lignin production, and the greater activities of POX, PPO, PAL and LOX rather than simply acting only as a physical barrier to avoid M. albescens penetration.
Climate, physiological tolerance and sex‐biased dispersal shape genetic structure of Neotropical orchid bees
Authors: López‐Uribe Margarita M. , Zamudio Kelly R. , Cardoso Carolina F. , Danforth Bryan N.
Published: February 2014

Understanding the impact of past climatic events on the demographic history of extant species is critical for predicting species' responses to future climate change. Palaeoclimatic instability is a major mechanism of lineage diversification in taxa with low dispersal and small geographical ranges in tropical ecosystems. However, the impact of these climatic events remains questionable for the diversification of species with high levels of gene flow and large geographical distributions. In this study, we investigate the impact of Pleistocene climate change on three Neotropical orchid bee species (Eulaema bombiformis, E. meriana and E. cingulata) with transcontinental distributions and different physiological tolerances. We first generated ecological niche models to identify species‐specific climatically stable areas during Pleistocene climatic oscillations. Using a combination of mitochondrial and nuclear markers, we inferred calibrated phylogenies and estimated historical demographic parameters to reconstruct the phylogeographical history of each species. Our results indicate species with narrower physiological tolerance experienced less suitable habitat during glaciations and currently exhibit strong population structure in the mitochondrial genome. However, nuclear markers with low and high mutation rates show lack of association with geography. These results combined with lower migration rate estimates from the mitochondrial than the nuclear genome suggest male‐biased dispersal. We conclude that despite large effective population sizes and capacity for long‐distance dispersal, climatic instability is an important mechanism of maternal lineage diversification in orchid bees. Thus, these Neotropical pollinators are susceptible to disruption of genetic connectivity in the event of large‐scale climatic changes.
Microwave Radiation Injures Microvasculature Through Inducing Endoplasmic Reticulum Stress
Authors: Li Yuzhen , Qu Xiaoling , Wang Xiaoreng , Liu Mi , Wang Chen , Lv Zhenrong , Li Weihong , Tao Tianqi , Song Dandan , Liu Xiuhua
Published: February 2014

Objective

The study aimed to investigate the effect of microwave radiation on microvasculature as well as the underlying mechanisms.

Methods

Sprague Dawley rats were exposed to microwave radiation. Microvascular diameters, flow velocity, blood perfusion, and permeability were measured. Cultured endothelial cells from microvessels were subjected to microwave radiation. Cytoskeleton, apoptosis, protein synthesis, and the markers of endoplasmic reticulum stress including 78‐kDa glucose‐regulated protein and calreticulin in endothelial cells were examined.

Results

Microwave radiation decreased microvascular diameters and blood perfusion, and increased the permeability of microvessles. And microwave radiation induced the formation of stress fibers, apoptosis, and LDH leakage from microvascular endothelial cells. Also, when microvascular endothelial cells were exposed to microwaves, protein synthesis was significantly elevated. We found that upon microwave radiation, the expression of 78‐kDa glucose‐regulated protein and calreticulin were greatly upregulated in microvascular endothelial cells. We also investigated possible signaling pathways for endoplasmic reticulum stress‐initiated apoptosis. C/EBP homologous protein (CHOP) pathway was activated in microvascular endothelial cells exposed to microwaves.

Conclusions

Microwave radiation induces microvascular injury by triggering the apoptotic pathway of endoplasmic reticulum stress.
Human prokinetic drugs promote gastrointestinal motility in zebrafish
Authors: Zhou J. , Guo S.‐Y. , Zhang Y. , Li C.‐Q.
Published: February 2014

Background

Gastrointestinal (GI) motility disorders are highly prevalent in populations worldwide and the development of effective and safe drug treatments for GI motility disorders has proven challenging. In this study, taking advantage of the transparency of larval zebrafish, we developed a novel zebrafish GI motility model for drug screening and efficacy assessment.

Methods

Zebrafish at 5 days postfertilization were fed 10 μg/L Nile red for 16 h, followed by drug treatment for 6 h. Tested drugs were delivered into the zebrafish by direct soaking. Drug effect on zebrafish GI motility was quantitatively assessed using GI tract fluorescent image‐based morphometric analysis. During all the periods of the experiments, the zebrafish were not fed any food.

Key Results

All four human prokinetic drugs (domperidone, metoclopramide, mosapride, and magnesium sulfate) increased zebrafish GI motility, whereas two drugs that inhibit human GI movement (atropine and anisodamine) and two negative control drugs (glucose and vitamin C) did not show statistically significant effect on zebrafish GI motility.

Conclusions & Inferences

These results suggest that larval zebrafish motility model developed here is a useful tool for whole‐animal in vivo GI transit studies and for assessing prokinetic drugs.
Detection of Tomato yellow leaf curl virus in imported tomato fruit in northern Europe
Authors: Just K. , Leke W. N. , Sattar M. N. , Luik A. , Kvarnheden A.
Published: February 2014

Imported tomato fruits infected with Tomato yellow leaf curl virus (TYLCV) were identified on the market in northern Europe using paper‐based FTA Classic Cards (Whatman), polymerase chain reaction (PCR) and partial DNA sequence analysis. Trade tomatoes originating from southern Europe, Africa and the Middle East were sampled in Estonia and Sweden, and tested for infection with begomoviruses. Out of 100 batches analysed with five fruits sampled in each batch (58 batches from Estonia and 42 from Sweden), 20 batches were positive (16 from Estonia and four from Sweden). Rolling circle amplification (RCA) and full‐length genome sequence analysis of one isolate collected in Estonia and one isolate in Sweden, revealed highest nucleotide sequence identity at 99% to TYLCV‐IL for the Estonian isolate and at 97% to TYLCV‐Mld for the Swedish isolate. In this study, TYLCV was identified for the first time in imported tomato fruits on the market in northern Europe. FTA cards proved to be an effective means to collect, extract and store begomovirus DNA from tomato fruits and the subsequent molecular analysis.
Efficacy of Vapam fumigant against clubroot (Plasmodiophora brassicae) of canola
Authors: Hwang S. F. , Ahmed H. U. , Zhou Q. , Strelkov S. E. , Gossen B. D. , Peng G. , Turnbull G. D.
Published: February 2014

Clubroot, caused by Plasmodiophora brassicae, has become a serious threat to canola (Brassica napus) production in western Canada. Experiments were conducted under greenhouse and field conditions to assess the effect of Vapam fumigant (dithiocarbamate; sodium N‐methyldithiocarbamate) on primary and secondary infection by P. brassicae, clubroot severity, and growth parameters in canola. Preliminary trials showed a 12–16‐fold reduction in primary and secondary infection and clubroot severity at all of the Vapam application rates (0·4–1·6 mL L−1 soil) assessed. Vapam was also found to be effective in reducing clubroot severity and improving seed yield of canola under field conditions. Application of Vapam at soil moisture levels in the range of 10–30% (v:v) had a large effect on both disease severity and infection rates and plant growth parameters. The results suggest that Vapam can effectively reduce clubroot severity and may be useful for the treatment of transplant propagation beds in brassica vegetable production, and for the containment of small, localized clubroot infestations in commercial canola crops.
Ultrafast Diffusion of a Fluorescent Cholesterol Analog in Compartmentalized Plasma Membranes
Authors: Hiramoto‐Yamaki Nao , Tanaka Kenji A. K. , Suzuki Kenichi G. N. , Hirosawa Koichiro M. , Miyahara Manami S. H. , Kalay Ziya , Tanaka Koichiro , Kasai Rinshi S. , Kusumi Akihiro , Fujiwara Takahiro K.
Published: February 2014

Cholesterol distribution and dynamics in the plasma membrane (PM) are poorly understood. The recent development of Bodipy488‐conjugated cholesterol molecule (Bdp‐Chol) allowed us to study cholesterol behavior in the PM, using single fluorescent‐molecule imaging. Surprisingly, in the intact PM, Bdp‐Chol diffused at the fastest rate ever found for any molecules in the PM, with a median diffusion coefficient (D) of 3.4 µm2/second, which was ∼10 times greater than that of non‐raft phospholipid molecules (0.33 µm2/second), despite Bdp‐Chol's probable association with raft domains. Furthermore, Bdp‐Chol exhibited no sign of entrapment in time scales longer than 0.5 milliseconds. In the blebbed PM, where actin filaments were largely depleted, Bdp‐Chol and Cy3‐conjugated dioleoylphosphatidylethanolamine (Cy3‐DOPE) diffused at comparable Ds (medians = 5.8 and 6.2 µm2/second, respectively), indicating that the actin‐based membrane skeleton reduces the D of Bdp‐Chol only by a factor of ∼2 from that in the blebbed PM, whereas it reduces the D of Cy3‐DOPE by a factor of ∼20. These results are consistent with the previously proposed model, in which the PM is compartmentalized by the actin‐based membrane‐skeleton fence and its associated transmembrane picket proteins for the macroscopic diffusion of all of the membrane molecules, and suggest that the probability of Bdp‐Chol passing through the compartment boundaries, once it enters the boundary, is ∼10× greater than that of Cy3‐DOPE. Since the compartment sizes are greater than those of the putative raft domains, we conclude that raft domains coexist with membrane‐skeleton‐induced compartments and are contained within them.
Analysis of Main Steam Line Break Accident at Hot Shutdown State Using a Coupled Method
Authors: Cui Dawei , Leng Jinzhen , Chen Jun
Published: February 2014

This paper describes the analysis of main steam line break at hot shutdown state performed using a new developed method where a 3D core neutronics code, a core thermal-hydraulics code and a plant simulation computer code are fully coupled. Models, main hypothesis applied and calculation results of the main steam line break (MSLB) accident analysis are presented. To cover as many as states points a new parameter named Transient Reactivity Variation (TRV) is introduced, the conservatism of this parameter when doing safety analysis are evaluated also. The study shows that the coupled method using some best estimate parameters can get more margins compared with the traditional analysis method, and the TRV can be used as a key parameter to determine which core configuration is the most penalizing case.
Modeling the Irradiation Swelling of UO2 at the Fuel Pellet Rim
Authors: Gao Lijun , Chen Bingde , Xiao Zhong , Jiang Shengyao , Yu Jiyang
Published: February 2014

Irradiation swelling of UO2 at the fuel pellet rim was modeled based on the published theory and data of HBS (High Burnup Structure) formation. Fuel swelling was divided into two parts: fuel matrix swelling and porosity growth. Both solid fission products and fission gas contribute to the fuel matrix swelling prior to HBS transformation, resulting in relatively stable matrix swelling rate of around 1.0% per 10 GWd/tU, but the transformation accompanied by Xe depletion reduces the matrix swelling rate to approximately 0.3% per 10 GWd/tU, only attributed to solid fission products. Considering the direct impact of Xe depletion on the drop of matrix swelling rate, the exponential law of Xe depletion was applied to model the reduction of matrix swelling rate. Pore size and pore density evolution are the two main aspects of porosity growth. Pore size takes the form of lognormal distribution, whose parameters are obtained through fitting the experimental data. Pore density increases in the transformation process but goes down as a result of pore coarsening thereafter. Published data of three pellets were used to verify the correlations modeling pore growth, which were proven generally consistent with each other. The results of this work are ready to be incorporated into fuel performance modeling code as an option for detailed calculation of fuel swelling.
Bypass Flows in Control Rod Channels of the HTR-PM
Authors: Sun Jun , Zheng Yanhua , Li Fu
Published: February 2014

A large amount of graphite blocks were served as the construction material, the neutron reflectors and also shaped as several helium flow paths in the HTR-PM reactor core. A majority of helium flowed through the pebble bed to bring out the huge fission heat, while a minority might flow in varieties of gaps between graphite blocks without being heated enough. In our previous papers, the method of combined flow network and CFD was established to analyze several bypass flows in HTR-PM. In current paper, we focused on bypass flows in control rod channels by introducing the flow network there and several CFD simulations of complicated flow paths. The inlet and outlet of the control rod channels were discussed for with various sizes to clarify their effect on bypass flow rate. Besides, horizontal gap flows between piles of graphite reflectors were also considered as one kind of bypass flow paths influencing the flow rate in control rod channels. The size distributions of these horizontal bypass flow paths were assumed to be consistent from top to bottom. With the existence of the horizontal flows, the flow rate in the control rod channels was also affected.
Stationarity Issues in Monte Carlo Simulation for Neutron Transport
Authors: Koreshi Zafar Ullah
Published: February 2014

Monte Carlo (MC) simulation, especially suitable for large and complex nuclear systems, can become computationally expensive due to the large number of neutrons which must be simulated for statistically accurate and precise estimates. It is generally understood that a sample estimate will converge to the population mean when a ‘large’ sample size is taken. The term ‘large’ is usually based on a guess and hence MC simulation is understood to be both an art and a science. Considerable work has been done to analyze convergence of MC results and develop posterior diagnostic tools. This paper addresses the convergence of MC simulation for two problems viz (i) a fixed-source non-multiplying system, and (ii) a critical system represented by Godiva. A traditional approach is used in the first part of the work while a ‘new’ approach essentially following Signals and Systems techniques from Digital Signal Processing gives ‘orginality’ to the analysis as it provides insight into the convergence of didactic problems in neutron transport simulation. The methods used are (i) comparison of MC flux with exact transport and diffusion solutions and relative entropy, with the Kullback-Leibler (KL) divergence, to quantify the convergence of estimates for flux as a function of sample size in Monte Carlo simulations, (ii) the effect of ‘skip cycles’ on the keff estimate, and (iii) a system identification approach based on the ARX (Auto Regressive Exogenous Source) method to determine the correlation between generations. The latter can be incorporated in Monte Carlo codes leading to a priori rather than to a posteriori diagnostic tools for establishment of convergence. The main findings of this work for simple one-group problems are that a Kullback Leibler ε∼10−3 can be specified a priori for the convergence criteria of a fixed source problem while a system-identification approach for a simple Godiva simulation would need a large number of data points to build an accurate ARX model and hence would be more difficult to include as an a priori tool; so it would essentially serve a purpose similar to the FOM which gives a quality metric only after the simulation is completed.
Transient and Safety Analysis Code for TP-1 Sodium Cooled TWR
Authors: Cong Tenglong , Wei Hongyang , Tian Wenxi , Su Guanghui , Qiu Suizheng
Published: February 2014

As a new concept of reactor, traveling wave reactor (TWR) is under fundamental research. In this paper, we modeled the main parts of primary loop of TP-1 sodium cooled traveling wave reactor, which was designed by TerrraPower Co., and developed a Transient and safety Analysis code for Sodium cooled TWR (TAST) with Fortran program. We first performed a steady analysis based on this code to evaluate the accuracy of this code. The calculated results agreed well with design parameters. After this, this program was used to simulate the loss of flow accident and reactivity insertion accident separately. The transient safety analysis indicated that TWR can work safely under these two accident conditions.
Nuclear Quadrupole Resonance Technology Applied in the Field of Explosives Detection
Authors: He Gaokui , Zhang Xiangyang , Wang Guobao , Wan Yuqing , Tian Huayang
Published: February 2014

There are a number of detection techniques for the detection of explosives, 14N nuclear quadrupole resonance (NQR) is a very promising technique owing to its unambiguous detection and identification of explosives. with this unique advantage, NQR technique gets more and more attentions around the world. Almost all of the explosives contain nitrogen element, the 14N nucleus is a non-spherically symmetric nucleus and has a quadrupole moment, the same 14N nuclei in different substances have different NQR frequencies, therefore, each substance is characterized by its own NQR frequency. So far, there have been more than 30 NQR probe nuclei, more than 10 thousands of substances have been investigated by the NQR technique and no identical NQR frequencies have been found. China Institute of Atomic Energy (CIAE) has investigated the concealed explosives detection by NQR for many years, this paper introduces the principle of 14N NQR detection, the structure of NQR detection system, and the application of NQR for the detection of explosives, mainly reviews the research activities of NQR at CIAE.
Developing of China Nuclear Emergency Response Ability Post Fukushima Accident
Authors: Zhang Jiangang , Tang Rongyao , Xu Xiaoxiao , Yang Yapeng
Published: February 2014

After Fukushima nuclear accidents, China timely started national nuclear emergency coordination mechanism, and the national nuclear emergency organizations carried out effective response, strengthened communication with IAEA, widely collected all kinds of related information, carried out the monitoring on the land, sea, air, and ocean, predicted the accident consequence, and increased public communication. On all kinds of nuclear facilities, governments required the urgent circular-self safety assessments by each operators, and organized safety inspection groups to comprehensive on-site safety supervision and inspection. Safety inspection thought China overall nuclear safety condition was controllable, and safety was guaranteed. Meanwhile, safety improvements of NPPs considered the external disaster warning and operational, waterproof ability evaluations and improvements of important buildings, etc. China reported China radiation monitoring data to IAEA emergency center, and organized Chinese nuclear emergency expert delegation to develop technical exchanges with Japanese experts. From fukushima nuclear accident response experiences, China national nuclear emergency response ability should continue to increase according to the national nuclear energy scale: (1) Nuclear emergency response professional capacity needs to increase and professional quantity also need to increase. (2) Nuclear emergency response technique and ability needs to emphasize, and the practicability, systematic and integration of nuclear emergency response system also need to emphasize. (3) The operation mechanism and guarantee conditions of national nuclear emergency response system should be further to take attention and should be continuous to improve.
Study on Application of Decoupling Circuit to I&C System of Nuclear Power Plant
Authors: Zheng Tian , Zhang Longqiang , Peng Huaqing
Published: February 2014

Electrical isolation is required for signal exchanging between redundant I&C divisions. Relay and isolation amplifier are often used as the isolation device for binary and analog signal transmission. Simple isolation device is not enough to make the electrical isolation. Decoupling circuit which is the combination of isolation devices and an independent power supply can totally compensate the insufficiency of simple isolation device and prevent the electrical fault propagating along the signal exchanging circuit.
Design of the Essential Material Test Equipment for the Pebble Bed Effective Thermal Conductivity Measurement Experiment
Authors: Ren Cheng , Yang Xing-Tuan , Li Cong-Xin , Liu Zhi-Yong , Jiang Sheng-Yao
Published: February 2014

High Temperature Gas-cooled Reactor (HTGR) is a typical representation of Generation IV nuclear power system for its advantages like inherent safety, high efficiency, widely application as high-temperature heat source. The first two 250-MWt high temperature reactor pebble bed modules (HTR-PM) have be installing at the Shidaowan plant in Shandong Province, China, which have the cylindrical core structure with thousands of spherical fuel elements randomly packed inside. The values of the effective thermal conductivity of the pebble bed core under different temperatures are essential parameters for the design of HTGR, which are needed to analyze the maximum fuel temperature, temperature distribution and residual heat releasing ability in reactor core. For this purpose, Tsinghua University in China has proposed a full-scale heat transfer experiment to conduct comprehensive thermal transfer tests in packed pebble bed and to determine the effective thermal conductivity through the pebble bed under vacuum condition and helium environment with temperature up to 1600°C.

An essential material test equipment is built in advance to provide reliable materials and technical support for the design of the final experimental device aimed at measuring the effective thermal conductivity of pebble bed type reactor core of the high temperature gas-cooled reactor. The design of the essential material test equipment is introduced in detail, including the heat element, the insulation structure, the temperature detector, cooling water system, vacuum system, hydraulic lifting system, data acquisition system and so on. Several key technologies in design are described in detail. Test temperature in the equipment was elevated up to 1600°C, which covers the whole temperature range of the normal operation and accident condition of HTGR and could fully meet the test requirements of materials used in the reactor. The construction and commissioning of the test equipment shows that the test equipment has met the design requirements and verified the feasibility of the related materials and structures.
AP1000 Plant Typical Operational Transient Analysis
Authors: Liu Lixin , Zheng Limin
Published: February 2014

According to advanced light water reactor (ALWR) Utility Requirement Document (URD), plant control systems should be designed to meet the specified design requirements for an advanced 1000 MWe class PWR nuclear power plant (NPP).

As per the plant design requirements, AP1000 control systems were simulated, and plant thermal-hydraulic performance analysis have been performed with RELAP5 thermal-hydraulic computer code under five typical operational transients, i.e. (a) a step load increase from 15% FP to 25%FP, (b) a step load decrease from 100% FP to 90%FP, (c) +5%/min ramp load increase, (d) large load rejection to house load at full power, (e) normal reactor trip at full power. Based on a preliminary plant performance analysis, it indicates that plant design requirements could be satisfied for AP1000 control systems.
Fast On-Line Source Term Estimation of Non-Constant Releases in Nuclear Accident Scenario Using Extended Kalman Filter
Authors: Tricard Pierre , Fang Sheng , Wang Jianlong , Li Hong , Qu Jingyuan , Tong Jiejuan , Fang Dong
Published: February 2014

In nuclear accidents, source estimation methods can be used to assess the amount and status of radioactive materials emission, which is important for nuclear emergency response. Current studies primarily focus on source estimation of a constant release mode, which may not match real nuclear accident scenario.

To solve this problem, a fast on-line source term estimation method for non-constant release mode was proposed in this study. Based on the well-established RIMPUFF dispersion model, the extended Kalman filter algorithm was utilized to perform an online estimation of the total amount and height of the release source simultaneously. To simulate the accidental radioactive release mode, a non-constant function was used as the state description of the release source. Both air dispersion model error and measurement error were considered. To demonstrate the feasibility of the proposed method, twin experiments were performed with release profiles. A sensitivity study was also performed to assess the robustness of the algorithm.

The experiment results demonstrate that the proposed method can provide robust source term estimation for both constant and non-constant release. The estimation accuracy depends on the steepness of the curve in the growth of the release mode and the distribution of simulated monitors.
Hydrogen Permeability of Rubber Gaskets
Authors: Nakano Mitsuyuki , Sasaki Haruko , Watanabe Tomokazu , Maezawa Ayumi
Published: February 2014

At Fukushima Dai-ichi nuclear power plant zircaloy that was used for cladding tube was exposed to high temperature steam and Hydrogen was produced by rapid oxidation. Essentially produced oxygen had to be sealed in containment vessel and released to the air by venting. However Hydrogen released from containment vessel were stored in reactor building and exploded at the NPP.

From the experience engineers recognized that countermeasure to prevent Hydrogen leak from containment vessel was required. Unfortunately there are few studies relevant to Hydrogen permeability at high temperature and demanded Hydrogen permeability coefficient of sealing material in the case of high temperature exposure.

In this study tests were conducted to predict Hydrogen permeability through rubber gasket at ACCIDENT. Experimental conditions were 1) deteriorated by heat, 2) deteriorated by heat and steam, 3) at high temperature.

Tests were conducted for Silicone rubber, EPDM, NBR and Fluoro-rubber and we found that there was no significant difference between the rubbers Hydrogen permeability coefficient under conditions from 1) to 3) without the case of losing its elasticity.

Currently we can present basic data to predict Hydrogen leak volume from containment vessel to reactor building at ACCIDENT. Based on the data we calculated Hydrogen leak volume from containment vessel through top flange of Fukushima Dai-ichi nuclear power plant in the case that zircaloy was melted completely as example.
A Design Proposal and Assessment of In-Vessel Retention Strategy for 2nd Generation PWR
Authors: Li Yabing , Tong Lili , Cao Xuewu
Published: February 2014

In order to satisfy the higher safety requirements after the Fukushima Accident, in-vessel retention (IVR) strategy is suggested to be a measure for the improvement for the operating 2nd generation Pressurized Water Reactor (PWR). In this paper, a design of passive cavity flooding system isproposed for the 2nd generation modified PWR with reference to the design of in-containment refueling water storage tank (IRWST)for AP1000, and the IVR assessmentis evaluated with the risk oriented accident analysis methodology (ROAAM). Seven representational accident sequences are selected for the IVR assessment and analyzed by lumped-parameter safety analysis computer code. Accident analysis focuses on four key parameters forthe assessment, that is, decay power, zirconium oxidation fraction, and both the mass of oxidic pool and metal layer. The values of them are obtained through analysis and used for the assessment. The probability density distributions of those parameters are determined by combining the analysis results and engineering judgment. The success probability of IVR from the viewpoint of thermal failure is predicted using a program written by the Matlab code. Furthermore, some sensitivity analysis and parametric studies are investigated to support the assessment. The assessment result shows that the success probability of the cavity injection system is higher than 99%. Detail analysis about system reliability and feasibility is needed for further work.
Scaling Assessment for the Integral Effect Tests: 2 — Open System Depressurization
Authors: Cai Xiaoyu
Published: February 2014

In this paper a method is described for using NOTRUMP models to corroborate the Hierarchical Two-Tiered Scaling (H2TS) methodology that has been used for design of the APEX and SPES-2 test facilities. These facilities were built for the Westinghouse Electric Corporation to obtain data on the performance of the passive safety systems of the advanced pressurized water reactors.

Similarity between the prototype system and the scaled test facilities is investigated for the open system depressurization phenomena in the postulated small break loss of coolant accident transient. The objective of this analysis is to provide a basis that an integral test for the passive safety system will provide valid experimental data for the high-ranked phenomena that may occur during the hypothetical SBLOCA transients. In this way, the experiment will capture the phenomena that would be expected to occur in the plant, and hence provide data that can be used to validate computer code.
The Status on Design Collaboration in ITER Chinese Domestic Agency
Authors: Wu Shuqin , Song Yuntao , Xing Chao , Luo Delong
Published: February 2014

Being an international cooperative engineering project, integration and compatibility of ITER design from numbers of different contributors worldwide is one of the crucial challenges. In order to fully integrate analysis, design, integration, and simulation of mechanical and plant design, and minimize interfaces between tools and methodologies, ITER Project developed a Computer Assisted Design (CAD) collaborative Platform for ITER Organization (IO) and all the parties to implement design collaborations. And also, ITER project standardized design activity via mandatory rules and recommendations for the design lifecycle and tool selections which are documented in the CAD Manual and other related supporting satellite documents.

ITER Chinese Domestic Agency (CN DA) as one of seven parties of ITER Project, undertakes twelve Procurement Packages to design and manufacture several ITER TOKAMAK Machine components and systems, including Magnet Support, Corrective Coils, Magnet Feeders, AC/DC Converters, Diagnostic Systems, Gas Injection System, Glow Discharge Cleaning and so on. Most of them comprise plenty of design work with different design maturities.CN DA accepts ITER design rules and standards, and performs proper deign collaboration schemes according to corresponding PA Design Collaboration Implementation Forms (DCIF).

This paper will present the status of CN DA design collaboration with IO and other DAs. It will include an overall description of design collaboration strategy and infrastructure in CN DA; the introduction of design tasks CN DA involved; and the associated organization and implementation of design collaboration schemes in specific PAs.
Hollow-Fiber Membrane Based Micro-Filtration Technology for the Treatment of Low Level Nuclear Laundry Waste and Floor Drain Water
Authors: Zhang Lei , Farooq Khalid , Liao Zhiyuan , Pang Kewen
Published: February 2014

A commonly used treatment for laundry waste and floor drain water in a nuclear power plant (NPP) in China involves filtration, followed by passing through a mixed ion exchange bed or evaporator. Due to the presence of foam and suspended solid in the laundry waste, the treatment systems require frequent maintenance and have a short filter service life. Pall ARIA™ platform, a hollow-fiber membrane based Micro-Filtration (MF) technology, was recently used at a German nuclear power plant to upgrade the low level radioactive laundry waste treatment system. The MF system with 0.1 μm average pore size and totally automated backwashable design was able to successfully concentrate the low level radioactive waste before it was sent to the evaporator.

An 18-month long pilot test of the MF system, with a flow capacity of 3–6 m3/hr, using 3 modules, was performed at the 1300 MW, Pressurized Water Reactor (PWR) nuclear power plant, at Phillipsburg, Germany, to substitute its legacy centrifuge separators in waste water treatment system. During the long pilot testing, the MF technology amply demonstrated its capability for consistent high particulate removal efficiency, safe & reliable operation and high availability with average recovery rate of 95%. An average activity of 17900 Bq/m3 was reported in the filtrate. The 20X concentrated stream from the MF system was processed by the evaporator. The paper discusses the current liquid radwaste treatment practices in China, and the details of 18-month long trial of the MF system at Phillipsburg NPP.
State of the Art Study for the Basis of Pipe Wall Thinning Management in Japan
Authors: Inada Fumio , Watanabe Yutaka , Ohira Taku , Nakamura Akira
Published: February 2014

Main committee of Power Generation Facility Code (MCPGFC) of Japan Society of Mechanical Engineers (JSME) established rules to manage pipe wall thinning on 2005–2006, and they also made a roadmap in 2007 to enhance pipe wall thinning management rules. Research Committee on Application of New Findings and Technology to Improve Pipe-Wall-Thinning Management, which was conducted from April 2010 to March 2012 summarized the new draft technical knowledge of the major phenomena of pipe wall thinning, that is, flow accelerated corrosion and liquid droplet impingement erosion as well as new inspection method. In this report, the new technical knowledge is described. The achievement situation of the road map made in 2007 was evaluated, and the studies required in future were considered.
Conservative Front-Tracking Method for 2-Dimensional Deformable Drops
Authors: Chang Lei , Yang Yanning
Published: February 2014

Here we present an unsteady two-dimensional numerical study on drops migrating in a matrix fluid. A computer code is developed to simulate the temperature distribution and velocity field both inside and outside drops. The governing momentum and energy equations are solved by finite-difference method and the deformable interface of drops is captured by front-tracking technique. The moving interface advection in front-tracking method is improved and mass conservation is maintained during the entire course of drop migration. Simulation results show that our improved model is consistent with previous numerical work on this subject. With the numerical model, two-dimensional thermocapillary motion of drops is studied.
Thermal–Hydraulic Performance Analysis for AP1000 Passive Containment Cooling System
Authors: Yu Yu , Wang Shengfei , Niu Fenglei
Published: February 2014

In order to improve the safety of new generation nuclear power plant, passive containment cooling system is innovatively used in AP1000 reactor design. However, since the system operation is based on natural circulation, physical process failure — natural circulation cannot establish or be maintained — becomes one of the important failure modes. Uncertainties in the physical parameters such as heat and cold source temperature and in the structure parameters have important effect on the system reliability. In this paper, thermal–hydraulic model is established for passive containment cooling system in AP1000 and the thermal–hydraulic performance is studied, the effect of factors such as air temperature and reactor power on the system reliability are analyzed.
Scaling Analysis of Mixing and Thermal Stratification in Passive Containment
Authors: Cai Junchi , Wang Shengfei , Niu Fenglei , Shi Pengyu , Liu Xin , Zhao Ruichang
Published: February 2014

The passive containment cooling system (PCCS) is one of typical passive systems of AP1000, which is a passive condenser system, designed to remove energy from the containment for long term cooling period after a postulated reactor accident, like LOCA or MSLB. One of the key phenomena of PCCS is mixing and thermal stratification inside the containment. In order to establish empirical correlations and develop model of this phenomenon, the experimental study is essential. Because it is difficult to use prototype system for research, so a scaling analysis is needed to design an experimental facility with smaller scale and accelerated time to simulate the prototype system. In this paper, a scaling method for mixing and thermal stratification is given and gets the governing equations and scaling criterions. In final, a group of primary parameters of the experiment, such as mixing time and volume rate of flow, is given in the form of geometric scaling ratio which is chosen by the designer.