bluuebunny/crossref_metadata_2025_split huggingface dataset:
Injectable Sacrificial Material System to Contain Ex-Vessel Molten Corium in Nuclear Accidents
Authors: Louie David L. Y. , Wang Yifeng , Rao Rekha , Kucala Alec , Kruichak Jessica 
Published: October 2018

An ongoing Sandia National Laboratories’ (SNL) research study is evaluating a potential design of an injectable sacrificial material (SM) system that could contain and cool corium ejected from a reactor vessel lower head failure during a potential severe accident involving melting fuel at a commercial light water nuclear reactor (LWR). An injectable system could be installed at any existing LWR, without significant modification to the cavity or to the drywell pedestal region of the plant. The conceptual design under consideration is a passive system. The SM is being optimized to quickly cool the corium mixture while creating gas to form porosity in the solid, such that subsequent water flooding can penetrate the structure and provide additional cooling. The SM would form a barrier and limit corium-concrete interactions.
This three-year project takes a joint experimental and computational approach. In this paper, we will first discuss the success of our small-scale experiments conducted on the interactions between the surrogate corium material (SCM) and SM, used to evaluate the injectable concept. A larger experimental study, currently underway, will further validate the injectable concept, with a focus on accurately measuring interactions. This paper details the modeling study and its progress, including modeling the experiments on a surrogate system and extending the model to bench-scale corium flow from validation experiments. The project’s modeling studies will use the SNL engineering code suite SIERRA Mechanics to understand the interaction of injectable SM and molten corium and predict corium spreading. Spreading is modeled using a level set method to track the front in conjunction with a pressure-stabilized finite element method on the fully three-dimensional mass, momentum, and energy conservation equations. Using this diffuse-interface method, the corium spreading front can be tracked and an appropriate pseudo-solidification viscosity models can be implemented to accurately model the corium spreading physics. Finally, an injectable SM delivery system is discussed along with its deployment to the six-common commercial LWR designs currently operating in the United States.
At the end of this project, a simplified model based on SIERRA simulations will be developed for implementation into MELCOR, a severe reactor analysis code, developed at SNL for the U.S. Nuclear Regulatory Commission. This will allow us to demonstrate the ability of the injectable SM system to mitigate the ex-vessel corium spreading, provide containment and negate the release of radionuclides.
Assessment of RELAP/SCDAPSIM for Turbine Trip Transient in NuScale-SMR
Authors: Skolik Katarzyna , Trivedi Anuj , Perez-Ferragut Marina , Allison Chris 
Published: October 2018

The NuScale Small Modular Reactor (SMR) is an integrated Pressurized Water Reactor (iPWR) with the coolant flow based on the natural circulation. The reactor core consists of 37 fuel assemblies similar to those used in typical PWRs, but only half of their length to generate 160MW thermal power (50 MWe).
Current study involves the development of a NuScale-SMR model based on its Design Certification Application (DCA) data (from NRC) using RELAP/SCDAPSIM. The turbine trip transient (TTT) was simulated and analysed. The objective was to assess this version of the code for natural circulation system modeling capabilities and also to verify the input model against the publicly available TTT results obtained using NRELAP5. This successful benchmark confirms the reliability of the thermal hydraulic model and allows authors to use it for further safety and severe accident analyses.
The reactor core channels, pressurizer, riser and downcomer pipes as well as the secondary steam generator tubes and the containment were modeled with RELAP5 components. SCDAP core and control components were used for the fuel elements in the core. The final input deck achieved the steady state with the operating conditions comparable to those reported in the DCA. RELAP/SCDAPSIM predictions are found to be satisfactory and comparable to the reference study. It confirms the code code capabilities for natural circulation system transients.
“Begging the Question” in Licensing Basis Accident Analyses
Authors: Miranda Samuel 
Published: October 2018

“Begging the question” describes a situation in which the statement under examination is assumed to be true (i.e., the statement is used to support itself). Examples of this can be found in analysis reports that were prepared by analysts who are not mindful (or maybe uninformed) of the analysis criteria they’re required to fulfill.
This is generally seen in analyses of anticipated operational occurrences (AOOs). AOOs are defined in Appendix A of 10 CFR §50 [1], and in ANS-N18.2-1973 [2], where they’re also known as American Nuclear Society (ANS) Condition II events. This standard [2] also defines more serious, Condition III and IV events. Analyses of AOOs, or ANS Condition II events are required to show that:
(1) reactor coolant system (RCS) pressure will not exceed its safety limit, and
(2) no fuel damage will be incurred, and
(3) a more serious accident will not develop, unless there is a simultaneous occurrence of another, independent fault.
The three requirements are often demonstrated by three different analyses, each of which is designed to yield conservative results with respect to one of the requirements. Accident analyses that are performed to demonstrate compliance with the first two requirements are relatively straightforward. They rely mostly upon the design of safety valves and the timing of reactor trips.
“Begging the question” is seen in analyses that are designed to demonstrate compliance with the third requirement. This paper will describe how this logical fallacy has been applied in licensees’ accident analyses, and accepted by the NRC staff.
Acceleration of Plume Dispersion Simulation Using Locally Mesh-Refined Lattice Boltzmann Method
Authors: Onodera Naoyuki , Idomura Yasuhiro 
Published: October 2018

A large-scale simulation of the environmental dynamics of radioactive substances is very important from the viewpoint of nuclear security. Recently, GPU has been emerging as one of high performance devices to realize a large-scale simulation with less power consumption. We design a plume dispersion simulation to achieve high performance on the GPU. Lattice Boltzmann method (LBM) is a class of CFD method which is based on a weak compressible formulation. Since the LBM has a simple algorithm with continuous memory accesses, it is suitable for large-scale computation. We apply an adaptive mesh refinement (AMR) method to the LBM. The AMR method arranges fine grids in a necessary region, so that we can realize a multi-scale analysis at high-resolution.
We measure the performance of the LBM code on the GPU-rich supercomputer TSUBAME 3.0 at Tokyo Tech. Good weak scaling from 4 GPUs to 144 GPUs, and 30 times higher node performance is achieved compared with CPUs. The code is validated against a wind tunnel test which was released from the National Institute of Advanced Industrial Science and Technology (AIST). The computational grids are subdivided by the AMR method, and the total number of grid points is reduced to less than 10% compared to the finest meshes. In spite of the fewer grid points, the turbulent statistics and plume dispersion are in good agreement with the experiment data. From these results, it is shown that the present scheme is promising for large-scale local air flow simulations on future exascale supercomputers.
Development of Boron Dilution Model in COBRA-EN
Authors: Yu Hao , Wang Mingjun , Qiu Suizheng , Tian Wenxi , Su G. H. 
Published: October 2018

The dilution characteristic of concentrated boron in reactor core is very important for reactivity control during the Small Break Loss of Coolant Accident (SB-LOCA). Nonuniform distribution of the boron concentration may increase the risk of reactivity accidents. However, tracking the boron concentration inside the primary coolant system meets lots of challenges. Hence the development of a thermal-hydraulic code with accurate boron tracking model is necessary.
This paper presents a multidimensional boron transport model based on subchannel software COBRA-EN. The original model gives a poor prediction in tracking the boron concentration of high Re, since it only considers the mass exchange caused by pressure difference and ignores the mass exchange put forward by the turbulent diffusion. In this paper, a new tracking model was proposed and implemented in the COBRA-EN code, in which the turbulent diffusion was considered. Then a 3 × 3 fuel bundle model was adopted to verify the proposed model. The CFD study was also conducted to investigate the feasibility of the new tracking model. The results indicate: (1) the modified boron tracking model are more close to the actual than the original model; (2) the modified model was verified by FLUENT; (3) the model shows defects at low Re due to the ignorance of molecule diffusion.
Lifestyles and mindsets of Olympic, Paralympic and world champions: is an integrated approach the key to elite performance?
Authors: Burns Lauren , Weissensteiner Juanita Ruth , Cohen Marc 
Published: October 2018

ObjectivesThe holy grail of any nation in the global sporting race is to better understand, replicate and sustain podium winning performances on the world stage. International sporting bodies advocate a holistic approach to the athletic profile and environmental and system-level factors required for world-class sporting performance, yet key lifestyle, relational, training and performance practices are commonly overlooked. We aimed to explore the contribution, interplay, and impact of lifestyle and psychological factors among a sample of world-class, champion athletes.MethodsOpen-ended, semistructured face-to-face interviews were conducted with 10 World, Olympic and Paralympic Champion athletes that covered their sporting development and athletic profile including their mindset, training and competition practices, along with lifestyle and other key factors to which they attributed their success. A thematic approach guided by grounded theory principles, was employed to source and analyse their perspectives and experiences and determine common themes.ResultsFour dominant and overlapping themes emerged: psychological attributes, interpersonal relationships, performance strategies and lifestyle practices. All athletes attributed their success to psychological rather than physical factors, and the vast majority relied on mental rehearsal skills and recovery practices.ConclusionThe athletic profile and support required to reach and sustain podium-level performance is multidimensional, integrated and individualised and psychological factors are paramount. Championship performance is likely to occur at the intersection of psychological prowess, interpersonal support, effective performance strategies and lifestyle. An integrated approach inclusive of these dimensions can be used to guide athlete development and support at both an individual level and a collective level.
Vanishing racial disparities in drowning in Florida
Authors: Gorsuch Marina Mileo , Myers Jr. Samuel L , Lai Yufeng , Steward Devan , Motachwa Rachel 
Published: October 2018

ObjectivesTo examine the change in the racial disparity in drowning in Florida from 1970 to 2015 and to analyse the contextual factors associated with white, black and Hispanic drowning rates in Florida from 2007 to 2015.MethodsOur outcome variable is county-level annual drowning rates by race, ethnicity, sex and age group. We computed county-level contextual data, including emergency weather events, temperature, extreme weather, number of pools, quality of pools, coastline, swimming participation rates and prominent black competitive swim teams.ResultsBetween 1970 and 1990, the disparity in drowning rates between white and black males in Florida decreased dramatically. By 2005, the overall age-adjusted drowning rates converged. This convergence was most striking for those aged 10–34 and 35–64. While the gap has declined dramatically, there remains a racial disparity in drownings among those aged 10–34.ConclusionsOverall, racial disparities in drowning have disappeared in Florida. However, some disparities remain. There is a persistent disparity in drownings among those aged 10–34.
2PAC
Authors: Tonneau Steve , Fernbach Pierre , Prete Andrea Del , Pettré Julien , Mansard Nicolas 
Published: October 2018

Synthesizing motions for legged characters in arbitrary environments is a long-standing problem that has recently received a lot of attention from the computer graphics community. We tackle this problem with a procedural approach that is generic, fully automatic, and independent from motion capture data. The main contribution of this article is a point-mass-model-based method to synthesize Center Of Mass trajectories. These trajectories are then used to generate the whole-body motion of the character.
The use of a point mass model results in physically inconsistent motions and joint limit violations when mapped back to a full- body motion. We mitigate these issues through the use of a novel formulation of the kinematic constraints that allows us to generate a quasi-static Center Of Mass trajectory in a way that is both user-friendly and computationally efficient. We also show that the quasi-static constraint can be relaxed to generate motions usable for computer animation at the cost of a moderate violation of the dynamic constraints.
Our method was integrated in our open-source contact planner and tested with different scenarios—some never addressed before—featuring legged characters performing non-gaited motions in cluttered environments. The computational efficiency of our trajectory generation algorithm (under one ms to compute one second of trajectory) enables us to synthesize motions in a few seconds, one order of magnitude faster than state-of-the-art methods. Although our method is empirically able to synthesize collision-free motions, the formal handling of environmental constraints is not part of the proposed method and left for future work.
Polymer Thin Film–Induced Tumor Spheroids Acquire Cancer Stem Cell–like Properties
Authors: Choi Minsuk , Yu Seung J. , Choi Yoonjung , Lee Hak R. , Lee Eunbeol , Lee Eunjung , Lee Yumi , Song Junhyuk , Son Jin G. , Lee Tae G. , Kim Jin Y. , Kang Sukmo , Baek Jieung , Lee Daeyoup , Im Sung G. , Jon Sangyong 
Published: October 2018

Abstract

Although cancer stem cells (CSC) are thought to be responsible for tumor recurrence and resistance to chemotherapy, CSC-related research and drug development have been hampered by the limited supply of diverse, patient-derived CSC. Here, we present a functional polymer thin film (PTF) platform that promotes conversion of cancer cells to highly tumorigenic three-dimensional (3D) spheroids without the use of biochemical or genetic manipulations. Culturing various human cancer cells on the specific PTF, poly(2,4,6,8-tetravinyl-2,4,6,8-tetramethyl cyclotetrasiloxane) (pV4D4), gave rise to numerous multicellular tumor spheroids within 24 hours with high efficiency and reproducibility. Cancer cells in the resulting spheroids showed a significant increase in the expression of CSC-associated genes and acquired increased drug resistance compared with two-dimensional monolayer-cultured controls. These spheroids also exhibited enhanced xenograft tumor-forming ability and metastatic capacity in nude mice. By enabling the generation of tumorigenic spheroids from diverse cancer cells, the surface platform described here harbors the potential to contribute to CSC-related basic research and drug development.

Significance:
A new cell culture technology enables highly tumorigenic 3D spheroids to be easily generated from various cancer cell sources in the common laboratory.
Cancer Risk and Prognosis after a Hospital Contact for an Elevated Erythrocyte Sedimentation Rate
Authors: Kornum Jette B. , Farkas Dóra K. , Sværke Claus , Severinsen Marianne T. , Thomsen Reimar W. , Sørensen Henrik T. 
Published: October 2018

Abstract

Background:
An elevated erythrocyte sedimentation rate (ESR) may be a marker of occult cancer.

Methods:
We linked Danish medical databases to examine cancer incidence in patients with a first-time hospital contact for elevated ESR during 1980 to 2013. We calculated standardized incidence ratios (SIR) of cancer compared with the general population, and comorbidity-adjusted HRs (aHR) versus matched population comparisons without elevated ESR. We also compared survival among patients with cancer with elevated ESR with that among patients with cancer without elevated ESR.

Results:
During median follow-up of 4.9 years, we observed 3,926 cancers among 18,540 patients with a first-time hospital contact for elevated ESR. The risk for any cancer diagnosed during the first year following the contact for elevated ESR was 8.5% [95% confidence interval (CI), 8.1%–8.9%]. The overall 1-year cancer incidence was markedly elevated [SIR 5.3 (95% CI, 5.1–5.6); aHR 5.8 (95% CI, 5.4–6.3)] and was more than 3-fold elevated for most hematologic cancers and for cancers of the peritoneum and connective tissue in the abdominal wall, kidney, and adrenal glands. After the first year, patients were at increased risk of developing especially hematologic cancers. Patients diagnosed with cancer within 1 year after a contact for elevated ESR had poorer survival compared with matched cancer comparisons [adjusted mortality rate ratio 1.2 (95% CI, 1.1–1.3)].

Conclusions:
Elevated ESR is a strong marker of undiagnosed cancer and is associated with poorer survival.

Impact:
Our findings may help clinicians in assessing absolute risk, common sites, and prognosis of cancers discovered after hospital contact with elevated ERS.
DNA Sequencing of Small Bowel Adenocarcinomas Identifies Targetable Recurrent Mutations in the ERBB2 Signaling Pathway
Authors: Adam Liana , San Lucas F. Anthony , Fowler Richard , Yu Yao , Wu Wenhui , Liu Yulun , Wang Huamin , Menter David , Tetzlaff Michael T. , Ensor Joe , Manyam Ganiraju , Arold Stefan T. , Huff Chad , Kopetz Scott , Scheet Paul , Overman Michael J. 
Published: October 2018

Abstract

Purpose:
Little is known about the genetic alterations characteristic of small bowel adenocarcinoma (SBA). Our purpose was to identify targetable alterations and develop experimental models of this disease.
Experimental Design: Whole-exome sequencing (WES) was completed on 17 SBA patient samples and targeted-exome sequencing (TES) on 27 samples to confirm relevant driver mutations. Two SBA models with ERBB2 kinase activating mutations were tested for sensitivity to anti-ERBB2 agents in vivo and in vitro. Biochemical changes were measured by reverse-phase protein arrays.

Results:
WES identified somatic mutations in 4 canonical pathways (WNT, ERBB2, STAT3, and chromatin remodeling), which were validated in the TES cohort. Although APC mutations were present in only 23% of samples, additional WNT-related alterations were seen in 12%. ERBB2 mutations and amplifications were present in 23% of samples. Patients with alterations in the ERBB2 signaling cascade (64%) demonstrated worse clinical outcomes (median survival 70.3 months vs. 109 months; log-rank HR = 2.4, P = 0.03). Two ERBB2-mutated (V842I and Y803H) cell lines were generated from SBA patient samples. Both demonstrated high sensitivity to ERBB2 inhibitor dacomitinib (IC50 &lt; 2.5 nmol/L). In xenografts derived from these samples, treatment with dacomitinib reduced tumor growth by 39% and 59%, respectively, whereas it had no effect in an SBA wild-type ERBB2 model.

Conclusions:
The in vitro and in vivo models of SBA developed here provide a valuable resource for understanding targetable mutations in this disease. Our findings support clinical efforts to target activating ERBB2 mutations in patients with SBA that harbor these alterations.
Therapeutic Potential of Focal Adhesion Kinase Inhibition in Small Cell Lung Cancer
Authors: Aboubakar Nana Frank , Lecocq Marylène , Ladjemi Maha Zohra , Detry Bruno , Dupasquier Sébastien , Feron Olivier , Massion Pierre P. , Sibille Yves , Pilette Charles , Ocak Sebahat 
Published: October 2018

Abstract
Small cell lung cancer (SCLC) has a poor prognosis. Focal adhesion kinase (FAK) is a non–receptor tyrosine kinase regulating cell proliferation, survival, migration, and invasion, which is overexpressed and/or activated in several cancers, including SCLC. We wanted to determine whether FAK contributes to SCLC aggressive behavior. We first evaluated the effect of FAK small-molecule inhibitor PF-573,228 in NCI-H82, NCI-H146, NCI-H196, and NCI-H446 SCLC cell lines. PF-573,228 (0.1–5 μmol/L) inhibited FAK activity by decreasing phospho-FAK (Tyr397), without modifying total FAK expression. PF-573,228 decreased proliferation, decreased DNA synthesis, induced cell-cycle arrest in G2–M phases, and increased apoptosis in all cell lines. PF-573,228 also decreased motility in adherent cell lines. To make sure that these effects were not off-target, we then used a genetic method to inhibit FAK in NCI-H82 and NCI-H446, namely stable transduction with FAK shRNA and/or FAK-related nonkinase (FRNK), a splice variant lacking the N-terminal and kinase domains. Although FAK shRNA transduction decreased total and phospho-FAK (Tyr397) expression, it did not affect proliferation, DNA synthesis, or progression through cell cycle. However, restoration of FAK-targeting (FAT) domain (attached to focal adhesion complex where it inhibits pro-proliferative proteins such as Rac-1) by FRNK transduction inhibited proliferation, DNA synthesis, and induced apoptosis. Moreover, although FAK shRNA transduction increased active Rac1 level, FRNK reexpression in cells previously transduced with FAK shRNA decreased it. Therefore, FAK appears important in SCLC biology and targeting its kinase domain may have a therapeutic potential, while targeting its FAT domain should be avoided to prevent Rac1-mediated protumoral activity.