bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research Progress on Irradiation Effects of RPV Materials
Authors: Feng Mingquan , Mo Huajun , Li Guoyun , Tong Mingyan , Liu Xiaosong 
Published: February 2014

Reactor pressure vessel (RPV) is an important safety component which holds reactor core and keep on high temperature and high pressure coolant. The irradiated region of RPV is subjected to neutron damage so that the fracture toughness decrease and RTNDT of materials with neutron fluence increase. According to fracture toughness requirements based on the rule, RPV beltline materials must have Charpy upper-shelf energy of no less than 102J initially and must maintain upper-shelf energy throughout the life of the vessel of no less than 68J.
Chinese manufactures (China First Heavy Industries, China National Erzhong Group Co. and Dongfang Electric Corporation, Shanghai Electric Corporation) have supplied A508-3 steel forging and fabricated RPV for many constructing NPP in China. Nuclear Power Institute of China (NPIC) has being put into practice a program about the irradiation tests and irradiation brettling research of Chinese A508-3 steel from these manufactures. This paper introduces the program and progressing briefly. Specimen, irradiation test parameters, irradiation facility and post irradiation mechanical tests are also described.
Research on Negative Pressure Control Technology in NPP Reactor Building and its Application
Authors: Xie Jianghong 
Published: February 2014

The paper mainly elaborates the negative pressure control technology and commissioning approaches for double-wall containment of Russian WWER-1000 nuclear power units. It also carries out an analysis and research on the layered negative pressure technology in the containment. It mainly includes the following three parts:
A Russian WWER-1000 nuclear power unit adopts the structure of double-wall containment for its Reactor building, with independent negative pressure systems for the containment and the annular space between the two walls. The paper mainly elaborates the control methods and limits requirements for the negative pressure in the containment and the annular space under the normal operation condition and in case of design basis accidents, with analysis and argumentation on the design function and operation requirements of the negative pressure system for the containment and the annular space.
In the paper, the design philosophy of layered negative pressure and its feasibility study are analyzed from the aspects of radiated partition, air distribution of the negative pressure system and containment separator for layered negative pressure.
The commissioning methods and technical requirements of negative pressure system in the Reactor building are described in the paper. Problems encountered during commissioning are also addressed and analyzed.
Operations practices prove that the negative pressure control technology for double-wall containment of WWER-1000 nuclear power unit is advanced and reliable, which meets the requirements on nuclear air decontamination emission and radiation protection, and is worthy of study, research and reference.
Analysis of Fluid-Induced Excitation Forces in Triangular Tube Arrays Based on the LES Method
Authors: Jiang Qing-lei , Zhou Ji-yun , Wang Xian-yuan 
Published: February 2014

The turbulence-induced excitation and periodic wake shedding are two important flow-induced vibration mechanisms of tube arrays in steam generators and were normally considered to be random excitation and periodic excitation respectively. Recent findings show that the turbulence-induced excitation is actually the quasi-periodic excitation, which is similar to periodic excitation. Since the turbulence-induced excitation generally occurs in the small pitch-diameter ratio (P/D ratio) tube arrays and the periodic excitation occurs only at large pitch-diameter ratios, the turbulence-induced excitation mechanism seems essentially another form of the periodic excitation at small P/D ratios.
To verify this hypothesize and figure out the transition procedure from periodic excitation to quasi-periodic excitation, Numerical simulations were conducted on triangle tube arrays with P/D ratios of 1.47 to 4.0 based on the LES method. Numerical results were compared with experiments results to verify the reliability of numerical models. The lift forces and the force spectra at indifferent P/D ratios were obtained to study the evolution mechanism between turbulence-induced excitation and periodic excitation. The results show that the turbulence-induced excitation and quasi-periodic excitation in tube arrays are essentially other forms of the periodic excitation. The lift forces changed from periodic excitation to quasi-periodic excitation when the P/D ratio was between 2.5 and 3.0, and the lift force nearly complete random excitation when P/D ratios below 1.5. The frequency range of the random excitation is 0 to 50Hz. The peak frequencies of the quasi-periodic excitation were greater than that of periodic excitation and decreased with the increase of P/D ratios.
RCC-M and RSE-M: A Set of Consistent Codes for PWR Design and Operation
Authors: Faidy Claude 
Published: February 2014

Inside the French Association for Design, Construction and Surveillance Rules of Nuclear Power Plant Components (AFCEN), RCC-M is dedicated to Design, Material Selection, Fabrication and welding, Examination and RSE-M In-Sercice-Inspection, Surveillance, Monitoring, Maintenance and flaw evaluations.
In a first part, this paper will shortly presents the Code contents and organization of each of them.
In a second part, how they are consistent and flexible to be adapted to international requirements.
And finally in a third part, a short comparison with ASME Corresponding Codes: BPV Section III and XI. The conclusion of the paper will present the major objectives and topics of development of these Codes for new international projects in connection with Code Harmonization by Regulators (MDEP), Standard Development Organization board (SDO) and Industry Association (CORDEL).
Fatigue of Stainless Steel Components: Toward Codified Rules Improvements
Authors: Faidy Claude 
Published: February 2014

During the past 30 years many fatigue tests and fatigue analysis improvements have been developed in France in order to improve Codified Fatigue Rules of RCC-M, RSE-M and RCC-MRx.
This paper will present comments and proposals for development of these rules associated to Gaps and Needs in order to finalize and justify the AFCEN Codes new rules.
Recently 3 new international R&D results confirm possible un-conservative fatigue material data:
- High cycle fatigue in air for stainless steel,
- Environmental effects on fatigue S-N curve for all materials, and in particular stainless steels,
- Fatigue Crack Growth law under PWR environment for stainless steel.
In front of these new results, AFCEN is working on a 1st set of rules based on existing knowledge:
- Air fatigue curve
- PWR Environmental effects
A periodic up-dating of AFCEN proposed rules will be done using French and International R&D programs with a particular attention on harmonization with other Code rules developed in USA, Japan and Germany, in particular.
On Efficient Passive Cooling of Control Rod Drivers
Authors: Gershuni A. N. , Nishchik A. P. , Razumovskiy V. G. , Pioro I. L. 
Published: February 2014

Experimental research of natural convection and the ways of its suppression in an annular vertical channel to simulate the conditions of cooling the control rod drivers of the reactor protection system (RPS) in its so-called wet design, where the drivers are cooled by primary circuit water supplied due to the system that includes branched pipelines, valves, pump, heat exchanger, etc., is reported. Reliability of the drivers depends upon their temperature ensured by operation of an active multi-element cooling system. Its replacement by an available passive cooling system is possible only under significant suppression of natural convection in control rod channel filled with primary coolant. The methods of suppression of natural convection proposed in the work have demonstrated the possibility both of minimization of axial heat transfer and of almost complete elimination of temperature non-uniformity and oscillation inside the channel under the conditions of free travel of moving element (control rod) in it.
The obtained results widen the possibilities of substitution of the active systems of cooling the RPS drivers by reliable passive systems, such as high-performance heat-transfer systems of evaporation-condensation type with heat pipes or two-phase thermosyphons as heat-transferring elements.
Countermeasures to Improve LWR Safety Level in Design and Operation by Accident Analyses at Fukushima Daiichi Nuclear Power Plants
Authors: Shimizu Kazumasa , Hamada Yuhei , Sakashita Hiroto , Mori Michitsugu 
Published: February 2014

The 2011 off the Pacific coast of Tohoku Earthquake occurred on March 11. The earthquake attacked the Fukushima Daiichi nuclear power station with six boiling water reactors (BWRs), three out of which, units 1 through 3 in rated operation except for three reactors of units 4 through 6 in scheduled periodic inspection, automatically shut down in response to the intense seismic motion. Emergency diesel generators started to pump water to cool reactors, and an hour later, the back-up generators lost their all functions by the station blackout resulting from tsunami flooding. In this situation at the unit 1, the isolation condenser system (IC) should have made a critical role to keep the reactor pressure and water level to be safety by removing the decay heat by natural circulation. In fact at the unit 1 during the accident, IC valves were closed by fail-safe and could not have shown the ability of the designed function.
An accident report gave general descriptions of the causes and results of accidents, but not the quantitative data indicative of details; therefore, it seems difficult to identify the specific problems in plant operations. Even in this case, if an appropriate analysis code is available for reproducing events based on the reports, it will be possible to determine individual data quantitatively and identify problems in plant operations.
In our work, we used the nuclear reactor thermal-hydraulic code RETRAN-3D/MOD4, which has been approved and licensed by U.S. Nuclear Regulatory Commission, to model light water reactors (LWRs) and reproduce the circumstances of the 2011 Fukushima Daiichi nuclear accident as the simulation code. Here, we subjected transition analyses of the process on the core-meltdown accident, and put forward the system to prevent the accident, where the accident analysis report was employed to simulate conditions of the accident. It could enable us to suggest adequate operation procedures suitable for LWR to avoid the severe accident, and to propose countermeasures to improve LWR safety level in design and operation.
Development of Co-Reduced Valve Seat for Nuclear Power Plants
Authors: Tazawa Toshiyuki , Saito Masahiro , Kojima Nobuo 
Published: February 2014

The overlaying of Co-based alloy (e.g. “Stellite”) has been applied to valve seats in power plants to improve wear and abrasion resistance. However, using of the Co-based alloy should be avoided to valves which involve with reactor water in nuclear power plant because of activating to Co-60, and increment of radiation dose. Therefore, the alternative material to Co-based alloy has been required for these valves.
Hardfacing is usually applied to improve abrasion resistance. Several high hardness materials without Co element were investigated, and it was found a Fe-based alloy as an alternative to Co-based alloy for the overlaying of valve seats.
Mechanical tests of this Fe-based alloy formed by Plasma Transfer Arc (PTA) welding were carried out. Obtained values of tensile strength, Vickers hardness and Charpy impact value of the Fe-based alloy were almost equivalent to Co-based alloy. In addition, mock-up valve specimen was prepared, and sliding test was performed in simulated BWR plants environment. As a result, the amount of leakage was little enough when the Fe-based alloy is overlaid on one side seat part, and the radiation exposure from the valve seat can be reduced by 78 percent compared with the case of using the Co-based alloy for both side of overlaying.
Note: Product names mentioned herein may be trademarks of their respective companies.
Surface Expression of ω-Transaminase in Escherichia coli
Authors: Gustavsson Martin , Muraleedharan Madhu Nair , Larsson Gen 
Published: February 2014

ABSTRACT

Chiral amines are important for the chemical and pharmaceutical industries, and there is rapidly growing interest to use transaminases for their synthesis. Since the cost of the enzyme is an important factor for process economy, the use of whole-cell biocatalysts is attractive, since expensive purification and immobilization steps can be avoided. Display of the protein on the cell surface provides a possible way to reduce the mass transfer limitations of such biocatalysts. However, transaminases need to dimerize in order to become active, and furthermore, they require the cofactor pyridoxal phosphate; consequently, successful transaminase surface expression has not been reported thus far. In this work, we produced an
Arthrobacter citreus
ω-transaminase in
Escherichia coli
using a surface display vector based on the autotransporter
a
dhesin
i
nvolved in
d
iffuse
a
dherence (AIDA-I), which has previously been used for display of dimeric proteins. The correct localization of the transaminase in the
E. coli
outer membrane and its orientation toward the cell exterior were verified. Furthermore, transaminase activity was detected exclusively in the outer membrane protein fraction, showing that successful dimerization had occurred. The transaminase was found to be present in both full-length and proteolytically degraded forms. The removal of this proteolysis is considered to be the main obstacle to achieving sufficient whole-cell transaminase activity.
Ste18p Is a Positive Control Element in the Mating Process of Candida albicans
Authors: Lu Hui , Sun Yuan , Jiang Yuan-Ying , Whiteway Malcolm 
Published: February 2014

ABSTRACT

Heterotrimeric G proteins are an important class of eukaryotic signaling molecules that have been identified as central elements in the pheromone response pathways of many fungi. In the fungal pathogen
Candida albicans
, the
STE18
gene (
ORF19.6551.1
) encodes a potential γ subunit of a heterotrimeric G protein; this protein contains the C-terminal CAAX box characteristic of γ subunits and has sequence similarity to γ subunits implicated in the mating pathways of a variety of fungi. Disruption of this gene was shown to cause sterility of
MTL
a
mating cells and to block pheromone-induced gene expression and shmoo formation; deletion of just the CAAX box residues is sufficient to inactivate Ste18 function in the mating process. Intriguingly, ectopic expression behind the strong
ACT1
promoter of either the Gα or the Gβ subunit of the heterotrimeric G protein is able to suppress the mating defect caused by deletion of the Gγ subunit and restore both pheromone-induced gene expression and morphology changes.
Draft Genome Sequence of Petroleum Hydrocarbon-Degrading Pseudomonas aeruginosa Strain PK6, Isolated from the Saurashtra Region of Gujarat, India
Authors: Patel P. A. , Kothari V. V. , Kothari C. R. , Faldu P. R. , Domadia K. K. , Rawal C. M. , Bhimani H. D. , Parmar N. R. , Nathani N. M. , Koringa P. G. , Joshi C. G. , Kothari R. K. 
Published: February 2014

ABSTRACT

Pseudomonas aeruginosa
strain PK6, a potential petroleum hydrocarbon-degrading soil bacterium, was isolated from a site contaminated by a petroleum hydrocarbon spill from an automobile service station in Junagadh, Gujarat, India. Here, we provide the 6.04-Mb draft genome sequence of strain PK6, which has genes encoding enzymes for potential and related metabolic pathways of the strain.
A cross-sectional study ofMycoplasma genitaliuminfection and correlates in women undergoing population-based screening or clinic-based testing forChlamydiainfection in London
Authors: Svenstrup H F , Dave S S , Carder C , Grant P , Morris-Jones S , Kidd M , Stephenson J M 
Published: February 2014

ObjectiveTo determineMycoplasma genitaliuminfection and correlates among young women undergoing population-based screening or clinic-based testing forChlamydiainfection.DesignCross-sectional study.SettingNational Chlamydia Screening Programme (NCSP) and two London sexually transmitted infection (STI) clinics.Participants2441 women aged 15–64 years who participated in the NCSP and 2172 women who attended two London STI clinics over a 4-month period in 2009.Outcome measures(1)M genitaliumprevalence in defined populations (%). (2) Age-adjusted ORs (aORs) for correlates ofM genitaliuminfection.ResultsThe overall frequency ofM genitaliumandChlamydia trachomatiswas 3% and 5.4%, respectively. Co-infection was relatively uncommon (0.5% of all women); however 9% of women withC trachomatisalso hadM genitaliuminfection.M genitaliumwas more frequently detected in swab than urine samples (3.9 vs 1.3%, p<0.001) with a significantly higher mean bacterial load (p ≤ 0.001). Among NCSP participants,M genitaliumwas significantly more likely to be diagnosed in women of black/black British ethnicity (aOR 2.3, 95% CI 1.2 to 4.5, p=0.01).M genitaliumandC trachomatisand were both significantly associated with multiple sexual partners in the past year (aOR 2.4, 95% CI 1.3 to 4.4, p=0.01 and aOR 2.0, 95% CI 1.4 to 2.8, p<0.01). Among STI clinic attendees,M genitaliumwas more common in women who were less than 25 years in age.ConclusionsM genitaliumis a relatively common infection among young women in London. It is significantly more likely to be detected in vulvovaginal swabs than in urine samples. Co-infection withChlamydiais uncommon. The clinical effectiveness of testing and treatment strategies forM genitaliumneeds further investigation.
ELECTROSTATICS STUDY OF A SINGLE-STRANDED DNA: A PROSPECTIVE FOR SINGLE MOLECULE SEQUENCING
Authors: SAUDE MOHAMMAD J. I. A. , MORSHED BASHIR I. 
Published: February 2014

Single molecule DNA sequencing requires new approaches to identify nucleotide bases. Using molecular dynamics simulations, we investigate the intrinsic electrostatics of single-stranded DNA by solving the nonlinear Poisson–Boltzmann equation. The results show variations of the molecular electrostatic potential (MEP) within 3 nm from the center of the sugar backbone, with suitably differentiable variations at 1.4 nm distance. MEP variations among four nucleotide bases are the most significant near ~ 33.7° and ~ 326.3° angular orientation, while the influences of the neighboring bases on MEPs become insignificant after the 3rd-nearest neighbors. This analysis shows potential for direct electronic sequencing of individual DNA molecules. [Formula: see text]Special Issue Comment: This paper about DNA sequencing based on molecular electrostatic potential maps of the DNA in the channel is related to the Special Issue articles about: measuring enzymes,32 and solving single molecules' trajectories with the RDF approach33 and with the QuB software.34
Iceberg-rafted tephra as a potential tool for the reconstruction of ice-sheet processes and ocean surface circulation in the glacial North Atlantic
Authors: Kuhs Marion , Austin William E. N. , Abbott Peter M. , Hodell David A. 
Published: February 2014

Abstract
Ice-rafted tephra deposits, of Marine Isotope Stage 6 (MIS 6) age, from Site U 1304 on the Gardar Drift, North Atlantic were examined for their shard size distribution and major element composition. The heterogeneous composition, large shard sizes and association with ice-rafted debris (IRD) indicate that these late MIS 6 deposits were transported by iceberg-rafting from Iceland to Site U 1304. Comparison of individual shard geochemistry with the geochemistry of Holocene volcanic systems from Iceland allows the identification of different potential volcanic source regions. This detailed geochemical analysis, when combined with Icelandic Ice Sheet (IIS) flow models for the Last Glacial Maximum (LGM), suggests that the IIS had calving margins to both the north and south during the late MIS 6 and that icebergs could have been transported to the Site U 1304 by following surface ocean circulation patterns similar to those that prevailed during the LGM. We demonstrate that the descriptive concept of Icelandic glass in the characterization of tephra components within North Atlantic IRD can be significantly improved through quantitative characterization and that such data hold the potential to help constrain surface ocean circulation models, while also potentially yielding new information about the IIS during earlier glacial periods.

Supplementary material:

Statistical tests, major element concentrations of analysed shards, primary and secondary standards are available at
http://www.geolsoc.org.uk/SUP18716
Cross-talk between EphA2 and BRaf/CRaf Is a Key Determinant of Response to Dasatinib
Authors: Huang Jie , Hu Wei , Bottsford-Miller Justin , Liu Tao , Han Hee Dong , Zand Behrouz , Pradeep Sunila , Roh Ju-Won , Thanapprapasr Duangmani , Dalton Heather J. , Pecot Chad V. , Rupaimoole Rajesh , Lu Chunhua , Fellman Bryan , Urbauer Diana , Kang Yu , Jennings Nicholas B. , Huang Li , Deavers Michael T. , Broaddus Russell , Coleman Robert L. , Sood Anil K. 
Published: February 2014

Abstract
Purpose: EphA2 is an attractive therapeutic target because of its diverse roles in cancer growth and progression. Dasatinib is a multikinase inhibitor that targets EphA2 and other kinases. However, reliable predictive markers and a better understanding of the mechanisms of response to this agent are needed.
Experimental design: The effects of dasatinib on human uterine cancer cell lines were examined using a series of in vitro experiments, including MTT, Western blot analysis, and plasmid transfection. In vivo, an orthotopic mouse model of uterine cancer was utilized to identify the biologic effects of dasatinib. Molecular markers for response prediction and the mechanisms relevant to response to dasatinib were identified by using reverse phase protein array (RPPA), immunoprecipitation, and double immunofluorescence staining.
Results: We show that high levels of CAV-1, EphA2 phosphorylation at S897, and the status of PTEN are key determinants of dasatinib response in uterine carcinoma. A set of markers essential for dasatinib response was also identified and includes CRaf, pCRafS338, pMAPKT202/Y204 (mitogen-activated protein kinase [MAPK] pathway), pS6S240/244, p70S6kT389 (mTOR pathway), and pAKTS473. A novel mechanism for response was discovered whereby high expression level of CAV-1 at the plasma membrane disrupts the BRaf/CRaf heterodimer and thus inhibits the activation of MAPK pathway during dasatinib treatment.
Conclusions: Our in vitro and in vivo results provide a new understanding of EphA2 targeting by dasatinib and identify key predictors of therapeutic response. These findings have implications for ongoing dasatinib-based clinical trials. Clin Cancer Res; 20(7); 1846–55. ©2014 AACR.