bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case Study of Seismic Response for Shell Key Gasification Equipment Based on Transient Dynamic Analysis
Authors: Shen Jun , Wu Yunlong , Peng Heng , Liu Yinghua 
Published: December 2016

Coal gasification is a key technology for clean coal conversion with high efficiency. During the past decade, more than twenty Shell Key Gasification Equipments (SKGE) used in the Shell Coal Gasification Process (SCGP) have been built in coal-to-chemicals industry in China. SKGE is composed of Gasifier and Syngas cooler which are connected by Transfer duct. The support skirt of the Gasifier base is fixed, while the Syngas cooler side is supported by a constant hanger (floating support).
In this paper, a FE model of the largest 2000-ton SKGE system in China is established by using ANSYS. The global dynamic response under the seismic load is simulated. In order to verify the correction of the calculation, the results are also compared with that by using ABAQUS.
Compared to the traditional static analysis, it can be found that the deformation and stress distribution, the force and moment on several specified cross sections of SKGE change over time under seismic load based on the transient dynamic analysis.
As the result of the seismic analysis is the prerequisite and foundation for accurate calculation of each key part (e.g. connection between Transfer duct and Gas reversal chamber), the seismic analysis is one of the most important analyses in the Gasification design, which will ensure the essential safety of SKGE system.
Material Properties of Reactor Pressure Vessel Shells Affected by Hydrogen Flaking
Authors: Gérard Robert , De Smet Michel , Chaouadi Rachid 
Published: December 2016

During the summer outages of 2012, large numbers of nearly-laminar indications were found in the core shells of the Doel 3 and Tihange 2 reactor pressure vessels (RPV). As a consequence, both units remained in cold shutdown with their core unloaded. A series of examinations, tests and inspections were performed leading to the conclusion that the indications are hydrogen flakes and that they do not affect the structural integrity of the RPV, regardless of the operating mode, transient or accident condition. All this was documented in the Safety Case reports issued in December 2012 and in the Safety Case Addenda issued in April 2013 [1]. Based on those reports, the Belgian Federal Agency for Nuclear Control (FANC) authorized the restart of both units which went back on-line in June 2013.
A key input required for this Safety Case was the definition of the appropriate material properties, in particular fracture toughness, for the RPV shells affected by hydrogen flakes. A material testing program on non-irradiated materials evaluated aspects like the possible effects of macro-segregations and local segregations (ghost lines) and of specimen orientation on the fracture toughness. The irradiation embrittlement sensitivity of the zone of macro-segregation in which the flakes are located was evaluated on the basis of the maximum enrichment in Cu, P and Ni in macro-segregations based on literature data. This was the basis of the trend curve of RTNDT evolution vs. fluence used in the Safety Cases submitted in 2012–2013.
The restart authorization in 2013 was accompanied by a number of “mid-term” requirements, to be completed during the first operating cycle after the restart. One of these requirements was the mechanical testing of irradiated specimens containing hydrogen flakes, in order to confirm the conservativeness of the RTNDT trend curve used for the structural integrity analyses.
After a first irradiation campaign of a material containing hydrogen flakes in the BR2 reactor of the Belgian Nuclear Research Center SCK.CEN, atypical results were obtained and the utility decided to shut down the units in March 2014. Detailed investigations involving three additional irradiation campaigns in BR2 including other reference materials, among which another material affected by hydrogen flakes, were performed in order to characterize this atypical behaviour and to derive a new conservative RTNDT trend curve. The resulting trend curve was accepted by the FANC and was used in the 2015 Safety Cases [1]. An overview of the Doel 3 and Tihange 2 safety cases is given in [6].
The paper summarizes the results of the material investigations on non-irradiated and irradiated materials and the process leading to the definition of this conservative RTNDT trend curve.
Technical Basis for Code Case N-853: A600 Branch Connection Weld Repair for SCC Mitigation
Authors: Waskey David , McCracken Steven 
Published: December 2016

The NRC Issued a Regulatory Issue Summary (RIS 15-10) which was an inquiry to the ASME Code Committee to review the in-service inspection requirements for Alloy 600 full penetration branch connections. This NRC request resulted in the initiation of two PWROG projects, PA-MSC-1283 and 1294.
PA-MSC-1283 is a Fracture Analysis to evaluate the crack growth rate of the various existing A600 configurations, heat treat conditions and operating loads. The results from this study would provide the technical basis for in-service inspection method and frequency.
PA-MSC-1294 is a project to consider contingency repair techniques and provide a bounding analysis for all nozzle configurations of the selected repair technique. The selected repair approach to be analyzed was a weld buildup referred as a Branch Connection Weld Metal Buildup (BCWMB) in the ASME Code Case (N-853) developed to provide the rules for design, implementation and inspection. Included in this project was a proof-of-principle phase to demonstrate that the repair methodology is implementable and assist in establishing the potential on component repair duration and anticipated dose.
Leak-Before-Break Assessment of a Cracked Reactor Vessel Nozzle Using 3D Crack Meshes
Authors: Thorwald Greg , Parietti Lucie 
Published: December 2016

A postulated surface crack near a reactor pressure vessel nozzle is evaluated using finite element analysis (FEA) to compute the fatigue crack growth rate, evaluate crack stability, and examine the possibility of a leak-before-break (LBB) condition. For a pressurized vessel with cyclic loading, determining if the crack may have a LBB condition is desirable to allow for the possibility of leak detection leading to corrective action before catastrophic failure.
A fatigue crack growth analysis is used to determine how the surface crack dimensions develop before re-categorizing the surface crack as a through thickness crack and evaluating its stability for LBB. To evaluate if a particular crack is unstable and may cause a structural failure, the Failure Assessment Diagram (FAD) method provides an evaluation using two ratios: brittle fracture and plastic collapse. The FAD method is described in the engineering best practice standard API 579-1/ASME FFS-1. The FAD curve and assessment ratios can be obtained from crack front J-integral values, which are computed using 3D crack meshes and elastic and elastic-plastic FEA. Computing custom crack solutions is beneficial when structural component geometries do not have an available stress intensity or reference stress solution.
Hardened Enclosure Design for High Pressure Extreme Temperature Pneumatic Seal Test Fixture
Authors: Wesevich James W. , Dunn Peter E. , Hansen Eric J. , Gage Eric N. 
Published: December 2016

This paper discusses the design of a hardened enclosure for high pressure extreme temperature (HPET) pneumatic testing of seals. The seal test fixture is located within a blast-fragment barrier (BFB) in case of a failure of the test fixture. The BFB is located within a hardened test room since the BFB has a 1-in annulus air gap to allow for cabling access to the test fixture, through which shock and gas pressure can propagate out into the room. A 30.5in3 (0.51) volume charged with 15,000psi (1034bar) of compressed nitrogen under a temperature range of −50°F to 400°F was used to produce the worst-case energy release in the event of a catastrophic failure of the seal fixture.
In order to assess the structural capacities of the BFB and test room, an equivalent axisymmetric computational fluid dynamics (CFD) model of the test fixture, BFB, and test room was used to estimate the fragment velocity and applied blast load time histories to the BFB and test room. The BFB was assessed using non-linear dynamic finite element analysis. All of the materials are modeled using a plasticity-based piecewise linear hardening constitutive model, with rate dependency and softening, fit to each material yield, tensile, and elongation limit. The seal fixture generated fragment interactions with the interior surfaces of the BFB model using slideline and pinball contact algorithms.
Uncertainty Sampling of Weld Residual Stress Fields in Probabilistic Analysis: Part II — Examples
Authors: Kurth Robert E. , Sallaberry Cédric J. , Brust Frederick W. , Kurth Elizabeth A. , Benson Michael L. , Rudland David L. 
Published: December 2016

NRC Standard Review Plan (SRP) 3.6.3 describes Leak-Before-Break (LBB) assessment procedures that can be used to assess compliance with the 10CFR50 Appendix A, GDC-4 requirement that primary system pressure piping exhibit an extremely low probability of rupture. SRP 3.6.3 does not allow for assessment of piping systems with active degradation mechanisms, such as Primary Water Stress Corrosion Cracking (PWSCC) which is currently occurring in systems that have been granted LBB approvals.
US NRC staff, working cooperatively with the Electric Power Research Institute through a memorandum of understanding, conducted a multi-year project that focused on the development of a viable method and approach to address the effects of PWSCC in primary piping systems approved for LBB. This project, called eXtremely Low Probability of Rupture (xLPR) [1], defined the requirements necessary for a modular-based probabilistic fracture mechanics assessment tool to directly assess compliance with the regulations.
Using the lessons learned from the pilot study, the production version of this code, designated as Version 2.0, focused on those primary piping systems previously approved for LBB. In this version the appropriate fracture mechanics-based models are employed to model the physical cracking behavior and a variety of computational options are provided to characterize, categorize and propagate problem uncertainties.
One of the most influential uncertainty on risk in the xLPR code is the one associated with weld residual stresses (WRS). WRS plays a key role in both crack initiation and crack growth. PWSCC is mainly driven by tensile stresses, whose major contributors are the tensile weld residual stresses that develop during fabrication of the piping system.
Handling the uncertainty involved with WRS within a probabilistic framework is quite challenging. A companion paper presents the selected approach to represent uncertainty within the framework of the xLPR code while respecting a set of requirements in term of smoothness of profile, efficiency of (potential) importance sampling and (for axial WRS) equilibrium. This paper illustrate with examples the implementation of the described methods into xLPR v2.0.
Experimentally-Benchmarked Computational Fluid Dynamics Simulations of an Array of Heated Rods Within a Square-Cross-Section Helium-Filled Pressure Vessel
Authors: Maharjan Dilesh , Hadj-Nacer Mustafa , Chalasani Narayana R. , Greiner Miles 
Published: December 2016

An experimental apparatus was constructed, consisting of an 8×8 array of electrically-heated rods held in a square array by stainless-steel spacer plates near their ends. The rod/plate assembly was enclosed within a square-cross-section helium-filled aluminum pressure vessel and the rods were oriented vertically. The apparatus simulates the region between two consecutive spacer plates of a used nuclear fuel assembly within a vertical dry storage canister. Rod, spacer plate, and enclosure wall temperatures were measured using thermocouples in a matrix of nine experiments with total rod heat generation rates of 100, 300, and 500 W, and nominal helium pressures of 1, 2, and 3 atm.
Steady-state simulations representing the experiment were performed, which include heat generation within the rods, conduction within the solid elements, as well as buoyancy-induced motion within, and natural convection and radiation heat transfer across, helium-filled regions. These were compared to the experimental results to assess the accuracy of the computational model for a range of boundary conditions.
The comparison between the simulated and measured data showed that the simulations systematically under predict the hotter rod temperatures and over predict the cooler ones. Linear regression showed that 95% of the simulated temperatures are within 4.26°C of the correlation values.
Dynamic Analysis of NPP Piping Systems and Components With Viscoelastic Dampers Subjected to Severe Earthquake Motions
Authors: Tamura Ichiro , Kuramasu Masashi , Barutzki Frank , Fischer Daniel , Kostarev Victor , Berkovskiy Alexey , Vasiliev Peter , Inoue Takuma , Okita Shunsuke , Namita Yoshio 
Published: December 2016

In Shimane nuclear power plant of Chugoku Electric Power Co., a number of safety improvements are planned to be implemented aiming for the highest level of safety in the world to be achieved. One of the new safety measures is the application of viscoelastic dampers for seismic protection of safety related piping system and components.
High performance of viscoelastic dampers has been confirmed by direct testing of the piping natural scale model at the shaking table subjected to severe seismic accelerations up to 20 m/s2.
However, viscoelastic dampers as a dynamic protection device have frequency-dependent dynamic characteristics, which are difficult to reproduce in the frame of conventional seismic analysis based typically on the use of response spectrum method.
For example, the dynamic properties of viscoelastic dampers exhibit nonlinear dependence on dissipation energy, shear rate of viscous fluid, and temperature.
Method for Seismic analysis of systems with viscoelastic dampers (SAVD-Method) is one of the analytical approaches capable of considering the dynamic properties and nonlinear behavior of viscoelastic dampers.
The SAVD-Method is a comparatively simple but reliable approach for dynamic analysis of a piping system and components with viscoelastic dampers.
Frequency-dependent dynamic characteristics of the viscoelastic dampers are able to be modeled by a four-parameter Maxwell model.
To consider the nonlinearity of the dynamic properties of viscoelastic dampers, the Maxwell model parameters were determined for different usage conditions in conjunction with the adjustment dependent on the energy dissipation criteria.
Direct comparison of the shaking table measurements and analysis according to SAVD-method shows good matching of results for all controlled parameters and levels of seismic excitation.
The Linear Ubiquitin Assembly Complex Modulates Latent Membrane Protein 1 Activation of NF-κB and Interferon Regulatory Factor 7
Authors: Wang Ling , Wang Yujia , Zhao Juan , Ren Junping , Hall Kenton H. , Moorman Jonathan P. , Yao Zhi Q. , Ning Shunbin 
Published: December 2016

ABSTRACT
Recently, linear ubiquitin assembly complex (LUBAC)-mediated linear ubiquitination has come into focus due to its emerging role in activation of NF-κB in different biological contexts. However, the role of LUBAC in LMP1 signaling leading to NF-κB and interferon regulatory factor 7 (IRF7) activation has not been investigated. We show here that RNF31, the key component of LUBAC, interacts with LMP1 and IRF7 in Epstein-Barr virus (EBV)-transformed cells and that LUBAC stimulates linear ubiquitination of NEMO and IRF7. Consequently, LUBAC is required for LMP1 signaling to full activation of NF-κB but inhibits LMP1-stimulated IRF7 transcriptional activity. The protein levels of RNF31 and LMP1 are correlated in EBV-transformed cells. Knockdown of RNF31 in EBV-transformed IB4 cells by RNA interference negatively regulates the expression of the genes downstream of LMP1 signaling and results in a decrease of cell proliferation. These lines of evidence indicate that LUBAC-mediated linear ubiquitination plays crucial roles in regulating LMP1 signaling and functions.

IMPORTANCE
We show here that LUBAC-mediated linear ubiquitination is required for LMP1 activation of NF-κB but inhibits LMP1-mediated IRF7 activation. Our findings provide novel mechanisms underlying EBV-mediated oncogenesis and may have a broad impact on IRF7-mediated immune responses.
A Protective Role for Interleukin-1 Signaling during Mouse Adenovirus Type 1-Induced Encephalitis
Authors: Castro-Jorge Luiza A. , Pretto Carla D. , Smith Asa B. , Foreman Oded , Carnahan Kelly E. , Spindler Katherine R. 
Published: December 2016

ABSTRACTInterleukin-1β (IL-1β), an inflammatory cytokine and IL-1 receptor ligand, has diverse activities in the brain. We examined whether IL-1 signaling contributes to the encephalitis observed in mouse adenovirus type 1 (MAV-1) infection, using mice lacking the IL-1 receptor (Il1r1−/−mice).Il1r1−/−mice demonstrated reduced survival, greater disruption of the blood-brain barrier (BBB), higher brain viral loads, and higher brain inflammatory cytokine and chemokine levels than control C57BL/6J mice. We also examined infections of mice defective in IL-1β production (Pycard−/−mice) and mice defective in trafficking of Toll-like receptors to the endosome (Unc93b1−/−mice).Pycard−/−andUnc93b1−/−mice showed lower survival (similar toIl1r1−/−mice) than control mice but, unlikeIl1r1−/−mice, did not have increased brain viral loads or BBB disruption. Based on the brain cytokine levels, MAV-1-infectedUnc93b1−/−mice had a very different inflammatory profile from infectedIl1r1−/−andPycard−/−mice. Histological examination demonstrated pathological findings consistent with encephalitis in control and knockout mice; however, intranuclear viral inclusions were seen only inIl1r1−/−mice. A time course of infection of control andIl1r1−/−mice evaluating the kinetics of viral replication and cytokine production revealed differences between the mouse strains primarily at 7 to 8 days after infection, when mice began succumbing to MAV-1 infection. In the absence of IL-1 signaling, we noted an increase in the transcription of type I interferon (IFN)-stimulated genes. Together, these results indicate that IL-1 signaling is important during MAV-1 infection and suggest that, in its absence, increased IFN-β signaling may result in increased neuroinflammation.IMPORTANCEThe investigation of encephalitis pathogenesis produced by different viruses is needed to characterize virus and host-specific factors that contribute to disease. MAV-1 produces viral encephalitis in its natural host, providing a good model for studying factors involved in encephalitis development. We investigated the role of IL-1 signaling during MAV-1-induced encephalitis. Unexpectedly, the lack of IL-1 signaling increased the mortality and inflammation in mice infected with MAV-1. Also, there was an increase in the transcription of type I IFN-stimulated genes that correlated with the observed increased mortality and inflammation. The findings highlight the complex nature of encephalitis and suggests that IL-1 has a protective effect for the development of MAV-1-induced encephalitis.
Contribution of the long-term care insurance certificate for predicting 1-year all-cause readmission compared with validated risk scores in elderly patients with heart failure
Authors: Takahashi Kayo , Saito Makoto , Inaba Shinji , Morofuji Toru , Aisu Hiroe , Sumimoto Takumi , Ogimoto Akiyoshi , Ikeda Shuntaro , Higaki Jitsuo 
Published: December 2016

ObjectivesReadmission is a common and serious problem associated with heart failure (HF). Unfortunately, conventional risk models have limited predictive value for predicting readmission. The recipients of long-term care insurance (LTCI) are frail and have mental and physical impairments. We hypothesised that adjustment of the conventional risk score with an LTCI certificate enables a more accurate appreciation of readmission for HF.MethodsWe investigated 452 patients with HF who were followed up for 1 year to determine all-cause readmission. We obtained their clinical and socioeconomic data, including LTCI. The three clinical risk scores used in our evaluation were Keenan (2008), Krumholz (2000) and Charlson (1994). We used net reclassification improvement (NRI) to assess the incremental benefit.ResultsPatients with LTCI were significantly older, and had a higher prevalence of cerebrovascular disease and dementia than those without LTCI. One-year all-cause readmission (n=193, 43%) was significantly associated with all risk scores, receiving LTCI and the category of LTCI. Receiving LTCI was associated with readmission independent of all risk scores (HR, 1.59 to 1.63; all p<0.01). Adding LTCI to all risk scores led to a significantly improved reclassification, which was observed in the subgroup of patients with HF with preserved ejection fraction (≥50%) but not in the subgroup with reduced ejection fraction (<50%).ConclusionsPossession of an LTCI certificate was independently associated with 1-year all-cause readmission after adjusting for validated clinical risk scores in patients with HF. Adding LTCI status significantly improved the model performance for readmission risk, particularly in patients with HF and preserved ejection fraction.
Diboson excess and Z′-predictions via left–right nonlinear Higgs
Authors: Shu Jing , Yepes Juan 
Published: December 2016

The excess events reported by the ATLAS collaboration in the WZ-final state, and by the CMS collaboration in the e[Formula: see text]e[Formula: see text]jj, Wh and jj-final states, may be induced by the decays of a heavy boson W[Formula: see text] in the 1.8–2 TeV mass range, here modeled via the larger local group SU(2)L × SU(2)R × U(1)[Formula: see text] in a nonlinear dynamical Higgs scenario. The W[Formula: see text]-production cross-section at the 13 TeV LHC is around 700–1200 fb. This framework also predicts a heavy Z[Formula: see text] boson with a mass of 2.5–4 TeV, and some decay channels testable in the LHC Run II. We determine the cross-section times branching fractions for the dijet, dilepton and top-pair Z[Formula: see text]-decay channels at the 13 TeV LHC around 2.3, 7.1, 70.2 fb, respectively, for M[Formula: see text] = 2.5 TeV, while one/two orders of magnitude smaller for the dijet/dilepton and top-pair modes at M[Formula: see text] = 4 TeV. Nonzero contributions from the effective operators, and the underlying Higgs sector of the model, will induce sizeable enhancement in the W[Formula: see text]W[Formula: see text] and Zh-final states that could be probed in the future LHC Run II.