bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of an Euler-Bernoulli Beam Model Coupled to CFD in Order to Perform Fluid-Structure Simulations
Authors: Vivaldi Daniele , Ricciardi Guillaume 
Published: November 2022

Abstract
Fluid-structure interactions (FSI) are a safety and operation concern in nuclear power plants. Numerical simulation can represent a useful approach to investigate and predict such mechanisms. Nevertheless, the very high computational resources required by FSI simulations can represent a significant limitation in terms of industrial applications. From this point of view, simplified modelling approaches, when physically applicable, can represent an interesting compromise. This can be the case of slender structures (tubes, pins, rods, etc.) often encountered in nuclear power plants. In this paper, a 1D Euler-Bernoulli beam finite element model was implemented inside the CFD code code Saturne. The resulting fluid-structure coupled model is able to calculate the vibration response of a cantilever beam (a cylinder, for example) under a fluid flow, avoiding the necessity of CFD-FEM code coupling. The first part of the paper describes the model and its implementation: it allows to perform 2-way explicit fluid-structure coupling, using the Arbitrary Lagrangian-Eulerian approach in order to take into account the structure deformations. Validation test cases are presented in the second part of the paper, for a cylinder in static air and water and submitted to water cross-flow: frequency, damping, fluid forces and cylinder vibrations in the drag and the lift directions are analysed and compared to reference data.
Direct Analysis of Elastic-Plastic Strain Ranges and Accumulated Strains Considering Stress Stiffening
Authors: Vollrath Bastian , Hübel Hartwig 
Published: November 2022

Abstract
Many pressure vessel and piping components have to withstand high internal pressures and are therefore thick-walled so that geometric effects such as stress stiffening need not be accounted for. However, thin-walled, or moderately thick structures may be sensitive to these effects. Design Codes such as the ASME Boiler and Pressure Vessel Code usually provide little guidance on when they are to be accounted for. In general, the effects of stress stiffening are difficult to estimate even for experienced engineers and can only be estimated by detailed finite element analyses. In the opinion of the authors, this effect deserves more attention. This is particularly true for simplified elastic-plastic methods for fatigue and ratcheting assessment of structures subjected to cyclic loading.
Cyclic loading may cause elastic-plastic strains to accumulate if a ratcheting mechanism is present. After a number of cycles, strain accumulation may cease so that a state of either elastic or plastic shakedown is reached. Determination of accumulated strains, strain ranges and other quantities in the state of shakedown (post-shakedown quantities) by means of incremental analyses is costly, in particular if geometric effects such as stress stiffening play a role. Direct methods aim at providing estimates of the post-shakedown quantities, bypassing cycle-by-cycle analyses. These methods claim to deliver the post-shakedown quantities with high accuracy and low computational effort.
The Simplified Theory of Plastic Zones can account for the combination of plasticity and stress stiffening. The theory is described and illustrated by examples. The Simplified Theory of Plastic Zones (STPZ) has proven itself for estimating the post-shakedown quantities in the state of elastic and plastic shakedown within the framework of the 1st order theory, i.e. if the equilibrium conditions are satisfied for the undeformed structure.
In this paper, the results of elbows subjected to various loading parameters are compared, considering and neglecting stress stiffening. Thus, the results show the influence 2nd order effects can generate. It is further shown that the STPZ can capture 2nd order effects introduced by the equilibrium of the deformed structure. Some examples are used to demonstrate its applicability and the quality of the results, e.g. for a pipe bend subjected to cyclic in-plane bending.
Platform Life Extension – Assessment Methodology for Pressure Vessel and Piping
Authors: Oubella Khaled 
Published: November 2022

Abstract
With global energy demand expected to increase substantially in the next few decades, the world will continue to need oil and gas developments. At the same time, new developments are difficult to sanction in the current market, and platforms life extension is an excellent way to meet increased demand. There are new fields to be exploited where an existing platform from another field could be reused economically. With the squeeze on capital expenditures, there is now incentive to find economical ways to extend the life of existing production facilities. In addition, the industry is being increasingly challenged with lowering the carbon footprint of barrel produced. Selection of the most suitable strategy among a wide range of potential options to extend the lifetime of equipment remains a challenging task. In order to tackle this challenge, it is crucial to develop analytical tools and methods capable to anticipate actions and costs required to keep the equipment operational at an adequate level of integrity for the expected life time of the asset. This paper presents systematic approach for the life extension assessment of the pressure vessels and piping of an ageing offshore asset. The potential of the proposed methodology is demonstrated through a case study involving an offshore asset which was constructed in the mid-1980s.
Study on Post-Buckling Behaviors of Lower Heads for Fracture Control of Reactor Vessels Under BDBE
Authors: Kasahara Naoto , Murohara Masato , Sato Takuya 
Published: November 2022

Abstract
As a lesson learned from the Fukushima nuclear power plant accident, the industry recognized the importance of mitigating accident consequences after Beyond Design Basis Events (BDBE). We propose the concept of applying fracture control to mitigate failure consequences of nuclear components under BDBE. This paper studies post-buckling behaviors of lower heads for fracture control of reactor vessels under BDBE.
In the case of a reactor vessel that supports the weight of the vessel at the top, such as a fast reactor, if a loss of cooling accident occurs, the cylindrical body may rupture with large creep deformation due to extremely high temperature. In order to cope with this event, application of fracture control concept is proposed. As a concrete example of the countermeasure, it is considered that reactor vessel lower heads can contact the floor or other structures to relieve the load on the cylindrical body and avoid catastrophic failure of the cylindrical body. In order to achieve this, it is necessary that even if a lower head in contact with the floor or other structures buckles, the subsequent post-buckling behavior is stable to maintain the load carrying capacity, and there is a strength margin before the failure of the lower head.
Buckling experiments and analyses were conducted on spherical shells with central cylindrical bodies and smooth spherical shells in contact with a rigid floor. The post-buckling behavior of all the above spherical shells was stable to maintain the load carrying capacity, and they did not fail immediately after buckling occurs.
From above results that the load carrying capacity of the lower head is sufficiently maintained after buckling, it was shown that the rupture of the cylindrical body of reactor vessel can be controlled by redistributing the load on the cylindrical body, which is expected to rupture due to extremely high temperature at a loss of cooling function.re.
Optimization and Property Analysis of the Sealing Structure of Type IV Cylinder for High-Pressure Hydrogen Storage
Authors: Tao Jiahui , Fan Zhichao , Xu Peng , Wang Lu , Xue Jilin 
Published: November 2022

Abstract
Composite overwrapped pressure cylinders with plastic liner (type IV) have a broad application prospect in high-pressure gaseous hydrogen storage due to their excellent properties, such as lightweight, corrosion resistance, fatigue resistance and low cost. Heterogeneous materials sealing is an important issue during the connection structure design between the plastic liner and the metal valve, where a rubber O-ring was often set for the sealing of hydrogen with high pressure. In this work, a finite element model (FEM) of the bottle mouth structure of composite overwrapped pressure cylinder composed of a plastic liner and a metal boss was established using the ABAQUS software, and the influences of boss shape and thickness of liner on the deformation and contact stress of rubber O-ring were analyzed. As a result, the shape and sizes of the metal boss and the liner were optimized and the connection structure between the liner and metal boss was determined. Based on the optimization, the effects of compression ratio, hydrogen pressure, backup ring and the temperature variation during the filling of composite overwrapped pressure vessel on the sealing performance of rubber O-ring were determined. The results of this work can provide guidance for the tightness analysis and lightweight design of composite overwrapped pressure vessels with plastic liners.
The Influence of Hydrogen on the Elastic Modulus of 316L and XM-19 Austenitic Stainless Steels
Authors: Scott Kevin , Mendez Patricio , Seetharaman Sridhar 
Published: November 2022

Abstract
Elastic modulus of 316L and XM-19 austenitic stainless steel was characterized before and after hydrogen charging using impulse excitation. Four coupons of each alloy were subsequently charged at 300 C and 138 MPa for 13 days with gaseous hydrogen to ensure an equilibrium concentration of hydrogen was achieved. Elastic modulus was re-characterized after charging. In 316L, the elastic modulus increased by 0.28% (0.546 GPa) on average on three of the samples, while one sample did not show a significant change. In XM-19, the elastic modulus increased by 0.38% (0.734 GPa) on average. The increase in both XM-19 test coupons and three 316L test coupons was statistically significant, while the increase in the other 316L test coupon was not.
High-Temperature Design of 700°C Heat Exchanger in a Large Scale High-Temperature Thermal Energy Storage Performance Test Facility
Authors: Lee Hyeong-Yeon , Yoon Jung , Lee Jewhan , Eoh Jaehyuk 
Published: November 2022

Abstract
High-temperature design evaluations of 700°C (1292°F) heat exchanger was conducted that would be installed in a large-scale high-temperature thermal energy storage performance test facility under development at KAERI site. The helical tube type sodium-to-air heat exchanger, AHX with 125kWt capacity of Type 316L austenitic stainless steel would be subjected to high-temperature operation at 700°C. Case studies in elevated temperature designs were conducted for the two materials of Type 316L and Type 316L(N) stainless steel codified in French high-temperature design rules of RCC-MRx. Because some significant material properties are not available up to 700°C in RCC-MRx, the lack material properties and design coefficients were determined through high-temperature material tests and relevant determination procedures. Another case studies on design temperatures with 700°C and 650°C (1202°F) in sodium coolant were conducted due to the availability of material properties in the design rules, and comparisons were made among the four cases of the two materials (316L and 316L(N)) and two design temperatures (700°C and 650°C).
Gutsy memory T cells stand their ground against pathogens
Authors: Jensen Isaac J. , Farber Donna L. 
Published: November 2022

Elegant fate-mapping models to label intestinal tissue-resident memory CD8
+
T (T
RM
) cells demonstrate retention and lack of expansion of CD103
+
T
RM
cells, whereas intestinal CD103
−
memory cells expand, forming both new tissue-localized CD103
+
and CD103
−
T
RM
cells (see related Research Articles by Fung
et al.
and von Hoesslin
et al.
).
The North American Cordillera during the Mesozoic to Paleogene: Selected questions and controversies
Authors: Busby C.J. , Pavlis T.L. , Roeske S.M. , Tikoff B. 
Published: November 2022

ABSTRACT
The North American Cordillera experienced significant and varied tectonism during the Triassic to Paleogene time interval. Herein, we highlight selected questions and controversies that remain at this time. First, we describe two tectonic processes that have hindered interpretations of the evolution of the orogen: (1) strike-slip systems with poorly resolved displacement; and (2) the closing of ocean basins of uncertain size, origin, and mechanism of closure. Next, we divide the orogen into southern, central, and northern segments to discuss selected controversies relevant to each area. Controversies/questions from the southern segment include: What is the origin of cryptic transform faults (Mojave-Sonora megashear vs. California Coahuila transform fault)? Is the Nazas an arc or a continental rift province? What is the Arperos basin (Guerrero terrane), and did its closure produce the Mexican fold-and-thrust belt? How may inherited basement control patterns of deformation during subduction? Controversies/questions from the central segment include: Can steeply dipping mantle anomalies be reconciled with geology? What caused high-flux events in the Sierra Nevada batholith? What is the origin of the North American Cordilleran anatectic belt? How does the Idaho segment of the orogen connect to the north and south? Controversies/questions from the northern segment include: How do we solve the Baja–British Columbia problem? How big and what kind of basin was the Early Cretaceous lost ocean basin? What connections can be found between Arctic geology and Cordilleran geology in Alaska? How do the Cretaceous tectonic events in the Arctic and northern Alaska connect with the Cordilleran Cretaceous events? What caused the Eocene tectonic transitions seen throughout the northern Cordillera? By addressing these questions along the length of the Cordillera, we hope to highlight common problems and facilitate productive discussion on the development of these features.
Climatic influence on the expression of strike-slip faulting
Authors: Reitman Nadine G. , Klinger Yann , Briggs Richard W. , Gold Ryan D. 
Published: November 2022

Abstract
Earthquakes on strike-slip faults are preserved in the geomorphic record by offset land-forms that span a range of displacements, from small offsets created in the most recent earthquake (MRE) to large offsets that record cumulative slip from multiple prior events. An exponential decay in the number of large cumulative offsets has been observed on many faults, and a leading hypothesis is that climate controls the rate of decay. We present offset measurements compiled from 31 studies of strike-slip faults with evidence of multiple paleoearthquakes and corresponding climatic and tectonic information to test this hypothesis. Both the global compilation and numerical landscape evolution modeling reveal that the decay rate in large offsets is negatively correlated with mean annual precipitation. Faults in dry regions with high drainage density more commonly preserve small MRE offsets, and faults in wet regions with lower drainage density more commonly preserve a mix of small MRE and large cumulative offsets. Geomorphology of faults in different climates supports this result and illustrates precipitation's effect on the development and preservation of off-set channels. Our findings imply that current and past climate affect how displacement on strike-slip faults is recorded and interpreted to inform earthquake history.
Spindle cell sarcomatoid tumour of the trachea: a rare primary malignant tumour
Authors: Moore Emily , Khosla Shivun , Jogai Sanjay , Derbyshire Stephen 
Published: November 2022

Spindle cell carcinoma is a subtype of sarcomatoid carcinoma, which has previously been described in various anatomical locations, though rarely in the trachea.We present the case of a woman in her 70s who presented with a sore throat and stridor. Fibreoptic nasendoscopy demonstrated a tracheal mass occupying 80% of the airway from the cricoid cartilage to the third tracheal ring, infiltrating the thyroid gland. Subsequent CT demonstrated pulmonary emboli and vertebral metastasis. Biopsy of the infiltrated thyroid confirmed the diagnosis of spindle cell carcinoma. The length of the tumour and metastasis at presentation made this surgically unresectable, and she was referred for a palliative stent but died after an acute deterioration.This pathology has been reported only five times previously in the literature, with management strategies varying greatly between patients. Primary tracheal tumours are difficult to manage as, due to their rarity, there are no clear guidelines.
Protecting the stars of tomorrow: do international cardiovascular preparticipation screening policies account for the paediatric athlete? A systematic review and quality appraisal
Authors: Riding Nathan R , Dorobantu Dan-Mihai , Williams Craig A , Stuart Graham , Fritsch Peter , Wilson Mathew G , Mossialos Elias , Pieles Guido 
Published: November 2022

Objective(1) Identify and review current policies for the cardiovascular screening of athletes to assess their applicability to the paediatric population and (2) evaluate the quality of these policy documents using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) tool.DesignSystematic review and quality appraisal of policy documents.Data sourcesA systematic search of PubMed, MEDLINE, Scopus, Web of Science, SportDiscus and CINAHL.Eligibility criteria for selecting studiesAn article was included if it was a policy/position statement/guideline/consensus or recommendation paper relating to athletes and cardiovascular preparticipation screening.Results and summaryOf the 1630 articles screened, 13 met the inclusion criteria. Relevance to paediatric athletes was found to be high in 3 (23%), moderate in 6 (46%) and low in 4 (31%), and only 2 provide tailored guidance for the athlete aged 12–18 years. A median 5 related citations per policy investigated solely paediatric athletes, with study designs most commonly being retrospective (72%). AGREEII overall quality scores ranged from 25% to 92%, with a median of 75%. The lowest scoring domains were rigour of development; (median 32%) stakeholder involvement (median 47%) and Applicability (median 52%).ConclusionCardiac screening policies for athletes predominantly focus on adults, with few providing specific recommendations for paediatric athletes. The overall quality of the policies was moderate, with more recent documents scoring higher. Future research is needed in paediatric athletes to inform and develop cardiac screening guidelines, to improve the cardiac care of youth athletes.
Phase III, randomised, double-blind, placebo-controlled trial of Neuroaspis plp10 as an adjuvant treatment for relapsing multiple sclerosis: the MINERAL Study
Authors: Pantzaris Marios C , Bakirtzis Christos , Grigoriadis Nikolaos , Hadjigeorgiou Georgios , Dardiotis Efthimos , Loucaides George , Ntzani Evangelia , Markozannes Georgios , Omorfos Savvas , Valsasina Paola , Messina Roberta , Preziosa Paolo , Rocca Maria A , Patrikios Ioannis 
Published: November 2022

ObjectivesTo assess the effectiveness of Neuroaspis plp10 nutritional supplement when added to interferon (IFN)-β treatment in patients with relapsing-remitting multiple sclerosis (RRMS).DesignA 30-month phase III multicentre, randomised, double-blind, placebo-controlled trial. Randomisation stratified by centre using a computer-generated procedure with Neuroaspis plp10 versus placebo in 1:1 ratio. The first 6 months were used as both the pre-entry and normalisation period.Setting3 teaching hospitals in Greece and 1 Neurology Institute in Cyprus.Participants61 patients with RRMS on IFN-β were randomly assigned to receive Neuroaspis plp10 (n=32) or placebo (n=29), 20 mL, orally, once daily, for 30 months.InterventionNeuroaspis plp10, a cocktail mixture, containing specific PUFA (12 150 mg) and γ-tocopherol (760 mg) versus virgin olive oil (placebo).Main outcome measureThe primary end point was the annual relapse rate (ARR) whereas the secondary ones were the rate of sustained progression of disability, as measured by the Expanded Disability Status Scale (EDSS) and the brain T2 and gadolinium-enhancing lesions, at 2 years.ResultsFor the intention-to-treat analyses Neuroaspis plp10 significantly reduced the ARR by 80%, (RRR, 0.20; 95% CI: 0.09 to 0.45; p=0.0001) and the risk of sustained progression of disability by 73% (HR, 0.27; 95% CI: 0.09 to 0.83; p=0.022) versus placebo, at 2 years. The number of T1 gadolinium-enhancing lesions and the number of new/enlarged T2-hyperintense lesions were significantly reduced (p=0.01 and p<0.0001, respectively). Both T1-enhancing and new/enlarging T2-hyperintense lesions were significantly reduced (p=0.05 and p<0.0001, respectively). No significant adverse events were reported.ConclusionsNeuroaspis plp10 added to IFN-β was significantly more effective than IFN-β alone in patients with RRMS.Trial registration numberISRCTN06166891.
Mer-tyrosine kinase: a novel susceptibility gene for SLE related end-stage renal disease
Authors: Yavuz Sule , Pucholt Pascal , Sandling Johanna K , Bianchi Matteo , Leonard Dag , Bolin Karin , Imgenberg-Kreuz Juliana , Eloranta Maija-Leena , Kozyrev Sergey V , Lanata Cristina M , Jönsen Andreas , Bengtsson Anders A , Sjöwall Christopher , Svenungsson Elisabet , Gunnarsson Iva , Rantapää-Dahlqvist Solbritt ,   ImmunoArray Development Consortium,   DISSECT Consortium, Nititham Joanne , Criswell Lindsey A , Lindblad-Toh Kerstin , Rönnblom Lars 
Published: November 2022

ObjectiveLupus nephritis (LN) is a common and severe manifestation of SLE. The genetic risk for nephritis and progression to end-stage renal disease (ESRD) in patients with LN remains unclear. Herein, we aimed to identify novel genetic associations with LN, focusing on subphenotypes and ESRD.MethodsWe analysed genomic data on 958 patients with SLE (discovery cohort: LN=338) with targeted sequencing data from 1832 immunological pathway genes. We used an independent multiethnic cohort comprising 1226 patients with SLE (LN=603) as a replication dataset. Detailed functional annotation and functional epigenomic enrichment analyses were applied to predict functional effects of the candidate variants.ResultsA genetic variant (rs56097910) within theMERTKgene was associated with ESRD in both cohorts, meta-analysis OR=5.4 (2.8 to 10.6); p=1.0×10-6. We observed decreased methylation levels in peripheral blood cells from SLE patients with ESRD, compared with patients without renal SLE (p=2.7×10-4), at one CpG site (cg16333401) in close vicinity to the transcription start site ofMERTKand located in a DNAse hypersensitivity region in T and B cells. Rs56097910 is linked to alteredMERTKexpression in kidney tissue in public eQTL databases. Two loci were replicated for association with proliferative LN:PRDM1(rs6924535, pmeta=1.6×10-5, OR=0.58) andAPOA1BP(NAXE) (rs942960, pmeta=1.2×10-5, OR=2.64).ConclusionWe identified a novel genetic risk locus,MERTK, associated with SLE-ESRD using the data from two large SLE cohorts. Through DNA methylation analysis and functional annotation, we showed that the risk could be mediated through regulation of gene expression. Our results suggest that variants in theMERTKgene are important for the risk of developing SLE-ESRD and suggest a role forPRDM1andAPOA1BPin proliferative LN.