bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benchmark of Elastic Plastic Seismic Response Analysis and Fatigue Evaluation for Piping
Authors: Otoyo Teruyoshi , Otani Akihito 
Published: November 2015

This paper shows a benchmark result regarding elastic-plastic seismic response analysis and fatigue evaluation for of piping model excitation test. National Research Institute for Earth Science and Disaster Prevention (NIED) has a lot of experimental results of shaking table test of piping. To propose advance seismic evaluation method for piping under severe seismic event, a task in JSME Code committee performs benchmark activity for elastic plastic seismic response analysis and evaluation for piping by using NIED’s experimental results [1].
Authors are taking part in the task and have been performed a benchmark of seismic response analysis and seismic evaluation by comparing with the experimental results. For fatigue evaluation, the strain ranges and the cycles of each range obtained from strain time history were evaluated. The response acceleration and displacement was evaluated for plastic collapse.
Benchmarking of Pressurized Water Reactor Blowdown Analysis Using RELAP5 and ANSYS
Authors: Luke Olivia , Xu Heqin , Liszkai Tamas 
Published: November 2015

Mechanical design bases for pressurized water reactors typically include various transients involving line breaches or valve actuations in high energy pressure boundaries. Due to the rapidly changing thermal hydraulic conditions and the resulting dynamic mechanical loads caused by the depressurization wave, blowdown events require special treatment from a mechanical analysis standpoint in order to meet the requirements of 10 CFR 50 Appendix A, General Design Criteria 4 and 14. Specifically, the fluid-structure interaction (FSI) is important for accurate prediction of dynamic mechanical loads, and must be evaluated to ensure that a reasonably bounding loading profile can be assured for all components, reactor vessel internals, and supports subject to the blowdown event.
This paper proposes a methodology to evaluate dynamic responses during blowdown events for mechanical design, using the code RELAP5-3D to simulate the thermal hydraulic conditions and subsequently the code ANSYS to simulate the FSI and resulting dynamic mechanical loads. Results from the German Heissdampf Reactor (HDR) blowdown experiments are used for methodology benchmarking. HDR benchmarking cases are studied to demonstrate that the capabilities of the thermal-hydraulic code RELAP5-3D and the multi-physics code ANSYS are sufficient to analyze high energy pressure boundary breaches. Thermal hydraulic boundary conditions are generated first using a RELAP5-3D model of the HDR break location for the selected study cases. The resulting time history data from RELAP5-3D are utilized in the ANSYS model, which is comprised of structural and acoustic elements. The use of essential, natural and acoustic impedance boundary conditions is investigated to determine the optimal method for simulating the fluid-structure interaction. Simulated displacements, strains, and differential pressure on the reactor vessel and reactor vessel internals are in excellent agreement with the experimental data for the time period of interest.
Core Mechanical Dynamics Experiment in the Phénix Reactor
Authors: Broc Daniel , Cardolaccia Jérome , Martin Laurent , Portier Jean Louis 
Published: November 2015

ASTRID is a project for an industrial prototype of a 600 MWe sodium cooled Fast Reactor, led by CEA. A consequent program is in progress for the development and the validation of numerical tools for the simulation of the dynamic mechanical behavior of the Fast Reactor cores, with both experimental and numerical parts. The cores are constituted of Fuel Assemblies (or FA) and Neutronic Shields (or NS) immersed in the primary coolant (sodium), which circulates inside the Fluid Assemblies. The FA and the NS are slender structures, which may be considered as beams, from a mechanical point of view.
The dynamic behavior of this system has to be understood, for design and safety studies. Two main movements have to be considered: global horizontal movements under the effect of a seismic excitation, and a radial opening of the core. The fluid presence leads to complex interactions between the structures at a distance. The dynamic behavior of the core is strongly influenced by contacts between the beams and by the interactions with the sodium, which both limit their relative displacements. Numerical methods and models are built to describe and simulate this dynamic behavior. The validation of the numerical tools is based on the results of different experimental programs, already performed or in progress.
The paper presents the interpretation of tests performed in 2013 in the Phénix reactor. The French Phénix reactor was definitively shutdown in 2009 and is currently at an early stage of the decommissioning process. Before unloading the core, it has been decided to perform one last experimental campaign aimed at testing the mechanical dynamic behavior of the core. The interpretation of the tests highly contributes to the validation of the simulation methods. Relatively good comparisons have been obtained between the theoretical and experimental results, for the static excitation (stiffness of the bundle) and for the dynamic response (characteristic times). The tests confirm that the fluid leads to a significant decrease of the frequencies. Uncertainties remain on the significant damping which seems to be present, and may be due to the fluid or to the structures.
Development and Use of the Risk-Based Joint Integrity (RBJI) Assessment Methodology
Authors: Brown Warren 
Published: November 2015

The ability to determine, using a uniform approach, which joints in a unit, plant or company represent the highest level of risk of leakage is extremely useful. Similarly to Risk-Based Inspection (RBI), Risk Based Joint Integrity (RBJI) allows the identification and allocation of resources to the joints that pose the greatest risk of failure. This ensures that the appropriate level of effort is placed in the most appropriate locations.
This paper outlines a quantitative methodology for assessing the probability of failure for any given pressure boundary bolted joint. It allows rapid calculation across a range of joints without resorting to the typical qualitative, reactive, experienced-based methods commonly employed to assess risk of joint leakage (i.e.: waiting for the joint to leak in order for it to be labelled a bad actor). This methodology has been successfully employed in a number of applications over the past three years, such as justification of heat exchanger replacement (demonstrating the expected improvement in joint integrity) and assessment of residual risk associated with historic joint assembly practices. Future applications include assessment of risk and definition of acceptable residual risk during the project design phase in order to eliminate problematic joints prior to fabrication and using the methodology to reduce the time associated with leak-testing of piping systems during maintenance turn-around activities.
Calibrating Phase Transformation and Grain Growth Models and Measuring Phase Dependent Material Properties for Use in FE Simulations of Welds
Authors: O’Meara Nicholas , Smith Simon D. , Francis John A. 
Published: November 2015

Computer modelling methods are being used to determine the residual stresses in nuclear reactor pressure vessel welds. It has been found that such models need to simulate the effects of solid state phase transformations. Transformations have an associated transformation strain which can significantly influence the evolution of residual stress. The predicted distribution of phases enables structural simulations to account for the distribution of mechanical properties throughout a weld. Factors such as heating or cooling rate and prior austenite grain size must be considered in order to accurately predict the distribution of phases during a transient thermal cycle since they influence transformation kinetics.
In this paper, a model to predict the prior austenite grain size and its effects on phase transformation kinetics is presented and calibrated using free dilatometry data. Validation experiments are conducted using a Gleeble thermo-mechanical simulator and are modelled in a commercial FE package to assess the accuracy of a phase transformation model. Samples have been heat treated to possess specific microstructures and have been tested at different temperatures to establish the properties of the phases that can form during weld thermal cycles.
Experimental Consideration of the Detonation Expansion Wave Limit
Authors: Ligon Thomas C. , Pellman Abby M. , Minichiello John C. 
Published: November 2015

The pressure time-history associated with a propagating detonation within a pipe can be reasonably well described using a one-dimensional model. These models describe the advancement of the detonation front and the expansion wave behind the detonation front, over which the pressure decays. The length of the expansion wave, and the corresponding pressure decay period, is a function of the distance the detonation wave has traveled. One-dimensional detonation models typically assume an isentropic expansion behind the detonation front. The consequence of this assumption is that the expansion wave will grow infinitively long in an infinitely long pipe. The loss of energy due to heat transfer, however, has been observed to result in a natural limit in the length of the expansion wave, and corresponding pressure decay.
The implication of this limit on piping design for gaseous detonations is that there is a limit on the pressure-impulse that is applied to the system. When a detonation propagates through a piping system, the detonation pressure produces unbalanced loads at the bends, tees, reducers, and closed-ends. These transient loads are a function of both the peak pressure and the details of the pressure decay. In long piping systems, the decay period of the expansion wave can become sufficiently long that very high loads are imposed on the system. Crediting a natural limit of these loads may have significant implications for the design of the pipe and its supports.
Although the existence of an expansion wave limit has been previously observed, consensus on its length does not currently exist in the literature. This paper describes detonation tests that were performed in both 2-inch and 4-inch 36.6m long pipes using mixtures of hydrogen and nitrous oxide. Pressure transducers were installed at periodic locations along the pipe. The slope of the initial pressure decay of the detonation was used to characterize its shape. The slope of the initial pressure decay was found to exponentially approach a limiting steady state value, and this limiting value was achieved after the detonation had propagated approximately 120 pipe diameters.
Are Retirement Villages Promoting Active Aging?
Authors: Holt Annie , Lee Andy H. , Jancey Jonine , Kerr Deborah , Howat Peter 
Published: November 2015

Purpose:This study investigated physical activity (PA) facilities of retirement villages (RVs) and neighborhood PA barriers identified by RV residents in Perth, Australia.Methods:An environmental audit of PA facilities was undertaken on 50 RV with 50+ independent living units, using the Audit of Physical Activity Resources for Seniors. Telephone interviews with 200 RV residents were conducted to identify neighborhood barriers to walking, and to obtain information on utilization of facilities and attendance of PA programs.Results:Larger size RV appeared to provide significantly more PA facilities and programs. Utilization of PA facilities and program attendance were low (≈ 50%) and not associated with the RV environment (size, age, and facilities). Neighborhood barriers to walking were unsafe streets and hills.Discussion:RV offers an attractive residential option with facilities that support active aging, but it is important to understand the barriers and enablers to use such facilities and attend programs offered.
Lymphocyte Perturbations in Malawian Children with Severe and Uncomplicated Malaria
Authors: Mandala Wilson L. , Msefula Chisomo L. , Gondwe Esther N. , Gilchrist James J. , Graham Stephen M. , Pensulo Paul , Mwimaniwa Grace , Banda Meraby , Taylor Terrie E. , Molyneux Elizabeth E. , Drayson Mark T. , Ward Steven A. , Molyneux Malcolm E. , MacLennan Calman A. 
Published: November 2015

ABSTRACT

Lymphocytes are implicated in immunity and pathogenesis of severe malaria. Since lymphocyte subsets vary with age, assessment of their contribution to different etiologies can be difficult. We immunophenotyped peripheral blood from Malawian children presenting with cerebral malaria, severe malarial anemia, and uncomplicated malaria (
n
= 113) and healthy aparasitemic children (
n
= 42) in Blantyre, Malawi, and investigated lymphocyte subset counts, activation, and memory status. Children with cerebral malaria were older than those with severe malarial anemia. We found panlymphopenia in children presenting with cerebral malaria (median lymphocyte count, 2,100/μl) and uncomplicated malaria (3,700/μl), which was corrected in convalescence and was absent in severe malarial anemia (5,950/μl). Median percentages of activated CD69
+
NK (73%) and γδ T (60%) cells were higher in cerebral malaria than in other malaria types. Median ratios of memory to naive CD4
+
lymphocytes were higher in cerebral malaria than in uncomplicated malaria and low in severe malarial anemia. The polarized lymphocyte subset profiles of different forms of severe malaria are independent of age. In conclusion, among Malawian children cerebral malaria is characterized by lymphocyte activation and increased memory cells, consistent with immune priming. In contrast, there are reduced memory cells and less activation in severe malaria anemia. Further studies are required to understand whether these immunological profiles indicate predisposition of some children to one or another form of severe malaria.
Characterization of Samples Identified as Hepatitis C Virus Genotype 1 without Subtype by Abbott RealTi
m
e HCV Genotype II Assay Using the New Abbott HCV Genotype
Plus
RUO Test
Authors: Mokhtari Camelia , Ebel Anne , Reinhardt Birgit , Merlin Sandra , Proust Stéphanie , Roque-Afonso Anne-Marie 
Published: November 2015

ABSTRACT

Hepatitis C virus (HCV) genotyping continues to be relevant for therapeutic strategies. Some samples are reported as genotype 1 (gt 1) without subtype by the Abbott RealTi
m
e HCV Genotype II (GT II) test. To characterize such samples further, the Abbott HCV Genotype
Plus
RUO (Plus) assay, which targets the core region for gt 1a, gt 1b, and gt 6 detection, was evaluated as a reflex test in reference to NS5B or 5′-untranslated region (UTR)/core region sequencing. Of 3,626 routine samples, results of gt 1 without subtype were received for 171 samples (4.7%), accounting for 11.5% of gt 1 specimens. The Plus assay and sequencing were applied to 98 of those samples. NS5B or 5′-UTR/core region sequencing was successful for 91/98 specimens (92.9%). Plus assay and sequencing results were concordant for 87.9% of specimens (80/91 samples). Sequencing confirmed Plus assay results for 82.6%, 85.7%, 100%, and 89.3% of gt 1a, gt 1b, gt 6, and non-gt 1a/1b/6 results, respectively. Notably, 12 gt 6 samples that had been identified previously as gt 1 without subtype were assigned correctly here; for 25/28 samples reported as “not detected” by the Plus assay, sequencing identified the samples as gt 1 with subtypes other than 1a/1b. The genetic variability of HCV continues to present challenges for the current genotyping platforms regardless of the applied methodology. Samples identified by the GT II assay as gt 1 without subtype can be further resolved and reliably characterized by the new Plus assay.
Multicenter Evaluation of MRSASelectII Chromogenic Agar for Identification of Methicillin-Resistant Staphylococcus aureus from Wound and Nasal Specimens
Authors: Hernandez Diana R. , Newton Duane W. , Ledeboer Nathan A. , Buchan Blake , Young Carol , Clark Andrew E. , Connoly Jessica , Wolk Donna M. 
Published: November 2015

ABSTRACTHospitals strive to reduce methicillin-resistantStaphylococcus aureus(MRSA) prevalence via active surveillance of inpatient populations. Rapid and inexpensive screening methods are utilized when molecular methods are not operationally feasible. In this multisite clinical trial, the utility of Bio-Rad's MRSASelectII was evaluated for MRSA identification from remnant nares and wound swabs. The prevalence of MRSA was 11.1% (n= 1,384) from nares samples and 18.1% (n= 842) from wound samples. MRSASelectII had an overall concordance of 95.4% (confidence interval [CI] = 94.5% to 96.2%) compared to a broth-enriched reference standard. Comparisons between results, stratified by examination times, exhibited a nonsignificant trend toward increased positivity at prolonged incubation times. Cefoxitin screening of colonies directly from MRSASelectII was 96.7% (95.8% to 97.3%) concordant compared to testing of colonies following broth enrichment. A comparison of MRSASelectand MRSASelectII revealed no statistical differences; however, the latter exhibited earlier positivity, greater selectivity, and more intense indicator staining, which resulted in facilitated differentiation of positive results. MRSASelectII agar is a simple, rapid, and robust method to routinely screen patients for MRSA colonization without the need for additional testing.
Enhanced Tracking of Nosocomial Transmission of Endemic Sequence Type 22 Methicillin-Resistant Staphylococcus aureus Type IV Isolates among Patients and Environmental Sites by Use of Whole-Genome Sequencing
Authors: Kinnevey Peter M. , Shore Anna C. , Mac Aogáin Micheál , Creamer Eilish , Brennan Gráinne I. , Humphreys Hilary , Rogers Thomas R. , O'Connell Brian , Coleman David C. 
Published: November 2015

ABSTRACT

Whole-genome sequencing (WGS) of 41 patient and environmental sequence type 22 methicillin-resistant
Staphylococcus aureus
staphylococcal cassette chromosome
mec
type IV (ST22-MRSA-IV) isolates recovered over 6 weeks in one acute hospital ward in Dublin, Ireland, where ST22-MRSA IV is endemic, revealed 228 pairwise combinations differing by <40 single nucleotide variants corresponding to potential cross-transmission events (CTEs). In contrast, 15 pairwise combinations of isolates representing five CTEs were previously identified by conventional molecular epidemiological typing. WGS enhanced ST22-MRSA-IV tracking and highlighted potential transmission of MRSA via the hospital environment.
Mechanism of Cell Culture Adaptation of an Enteric Calicivirus, the Porcine Sapovirus Cowden Strain
Authors: Lu Zhongyan , Yokoyama Masaru , Chen Ning , Oka Tomoichiro , Jung Kwonil , Chang Kyeong-Ok , Annamalai Thavamathi , Wang Qiuhong , Saif Linda J. 
Published: November 2015

ABSTRACT

The porcine sapovirus (SaV) (PoSaV) Cowden strain is one of only a few culturable enteric caliciviruses. Compared to the wild-type (WT) PoSaV Cowden strain, tissue culture-adapted (TC) PoSaV has two conserved amino acid substitutions in the RNA-dependent RNA polymerase (RdRp) and six in the capsid protein (VP1). By using the reverse-genetics system, we identified that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328), but not the substitutions in the RdRp region, were critical for the cell culture adaptation of the PoSaV Cowden strain. The other two substitutions in VP1 (residues 291 and 295) reduced virus replication
in vitro
. Three-dimensional (3D) structural analysis of VP1 showed that residue 178 was located near the dimer-dimer interface, which may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 were located at protruding subdomain 2 (P2) of VP1, which may influence virus binding to cellular receptors; and residue 295 was located at the interface of two monomeric VP1 proteins, which may influence VP1 dimerization. Although reversion of the mutation at residue 291 or 295 from that of the TC strain to that of the WT reduced virus replication
in vitro
, it enhanced virus replication
in vivo
, and the revertants induced higher-level serum and mucosal antibody responses than those induced by the TC PoSaV Cowden strain. Our findings reveal the molecular basis for PoSaV adaptation to cell culture. These findings may provide new, critical information for the cell culture adaptation of other PoSaV strains and human SaVs or noroviruses.

IMPORTANCE
The tissue culture-adapted porcine sapovirus Cowden strain is one of only a few culturable enteric caliciviruses. We discovered that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328) were critical for its adaptation to LLC-PK cells. Two substitutions in VP1 (residues 291 and 295) reduced virus replication
in vitro
but enhanced virus replication and induced higher-level serum and mucosal antibody responses in gnotobiotic pigs than those induced by the tissue culture-adapted strain. Structural modeling analysis of VP1 suggested that residue 178 may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 may influence virus binding to cellular receptors; and residue 295 may influence VP1 dimerization. Our findings will provide new information for the cell culture adaptation of other sapoviruses and possibly noroviruses.