Aeolian sediments on the Tibetan Plateau

Abstract HKT-ISTP 2013 B

Advanced Multiphysics Modeling of Solar Tower Receivers Using Object-oriented Software and High Performance Computing Platforms

AbstractThis paper presents an advanced methodology for the detailed modeling of the heat transfer and fluid dynamics phenomena in solar tower receivers. It has been carried out in the framework of a more ambitious enterprise which aims at modeling all the complex heat transfer and fluid dynamics phenomena present in central solar receivers. The global model is composed of 4 sub-models (heat conduction, two-phase flow, solar and thermal radiation and natural convection) which are described. Results of the numerical model obtained so far are also presented and discusse

Landscape and Lake-System Response to Late Quaternary Monsoon Dynamics on the Tibetan Plateau - Northern Transect

Abstract HKT-ISTP 2013 B

LES-based Study of the Roughness Effects on the Wake of a Circular Cylinder from Subcritical to Transcritical Reynolds Numbers

This paper investigates the effects of surface roughness on the flow past a circular cylinder at subcritical to transcritical Reynolds numbers. Large eddy simulations of the flow for sand grain roughness of size k/D = 0.02 are performed (D is the cylinder diameter). Results show that surface roughness triggers the transition to turbulence in the boundary layer at all Reynolds numbers, thus leading to an early separation caused by the increased momentum deficit, especially at transcritical Reynolds numbers. Even at subcritical Reynolds numbers, boundary layer instabilities are triggered in the roughness sublayer and eventually lead to the transition to turbulence. The early separation at transcritical Reynolds numbers leads to a wake topology similar to that of the subcritical regime, resulting in an increased drag coefficient and lower Strouhal number. Turbulent statistics in the wake are also affected by roughness; the Reynolds stresses are larger due to the increased turbulent kinetic energy production in the boundary layer and separated shear layers close to the cylinder shoulders.We acknowledge “Red Española de Surpercomputación” (RES) for awarding us access to the MareNostrum III machine based in Barcelona, Spain (Ref. FI-2015-2-0026 and FI-2015-3-0011). We also acknowledge PRACE for awarding us access to Fermi and Marconi Supercomputers at Cineca, Italy (Ref. 2015133120). Oriol Lehmkuhl acknowledges a PDJ 2014 Grant by AGAUR (Generalitat de Catalunya). Ugo Piomelli acknowledges the support of the Natural Sciences and Engineering Research Council (NSERC) of Canada under the Discovery Grant Programme (Grant No. RGPIN-2016-04391). Ricard Borrell acknowledges a Juan de la Cierva postdoctoral grant (IJCI-2014-21034). Ivette Rodriguez, Oriol Lehmkuhl, Ricard Borrell and Assensi Oliva acknowledge Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain (ref. ENE2014-60577-R).Peer ReviewedPostprint (author's final draft

Heterogeneous CPU/GPU co-execution of CFD simulations on the POWER9 architecture: Application to airplane aerodynamics

High fidelity Computational Fluid Dynamics simulations are generally associated with large computing requirements, which are progressively acute with each new generation of supercomputers. However, significant research efforts are required to unlock the computing power of leading-edge systems, currently referred to as pre-Exascale systems, based on increasingly complex architectures. In this paper, we present the approach implemented in the computational mechanics code Alya. We describe in detail the parallelization strategy implemented to fully exploit the different levels of parallelism, together with a novel co-execution method for the efficient utilization of heterogeneous CPU/GPU architectures. The latter is based on a multi-code co-execution approach with a dynamic load balancing mechanism. The assessment of the performance of all the proposed strategies has been carried out for airplane simulations on the POWER9 architecture accelerated with NVIDIA Volta V100 GPUs

Surface modification of structural materials by low-energy high-current pulsed electron beam treatment

Microstructure formation in surface layers of pure titanium and ferritic-martensitic steel subjected to electron beam treatment is studied. It is shown that low energy high-current pulsed electron beam irradiation leads to the martensite structure within the surface layer of pure titanium. Contrary, the columnar ferrite grains grow during solidification of ferritic-martensitic steel. The effect of electron beam energy density on the surface morphology and microstructure of the irradiated metals is demonstrated

Emotional abuse interacts with borderline personality in adolescent inpatients with binge-purging eating disorders

Purpose Childhood abuse is associated with an increased risk of developing eating disorders (EDs) as well as personality disorders (PDs). However, their interaction is still uncertain, particularly in adolescents. This study investigates the correlations between childhood emotional neglect (CEN), childhood emotional abuse (CEA), and obsessive-compulsive and borderline personality styles in female adolescent inpatients with eating disorders (EDs). Methods One hundred and twenty-eight inpatients (ages 14-18) were assessed, 54 were diagnosed with restricting-type anorexia nervosa (AN-R) and 33 with a binge-purging ED [BP-ED; comprising patients with binge-purging type anorexia nervosa (AN-BP), n = 15, and bulimia nervosa (BN), n = 18]. Fifty healthy participants made up the control group (CG). CEN and CEA were assessed with the Childhood Trauma Questionnaire, while the Personality Style and Disorder Inventory was implemented to determine personality styles. Results A MANOVA revealed a significant main effect of CEA on spontaneous-borderline personality style [F(8,119) = 17.1, p < 0.001, η2 = 0.126], as well as a main effect of ED group on spontaneous-borderline [F(2,119) = 3.1, p = 0.048, η2 = 0.050]. A significant interaction between ED group, CEA, and spontaneous-borderline was found [F(2,119) = 3.5, p = 0.034, η2 = 0.055] with BP-ED showing significantly higher scores in CEA (9.3 ± 4.0) and in spontaneous-borderline (14.2 ± 6.2). Conclusions Considering CEA and borderline personality style in adolescent inpatients with BN or AN-BP may help improve the understanding of the etiology and maintenance of BP-ED and provide more effective treatment targets. Level of evidence Level III, case–control analytic study

Ante-mortem detection of chronic wasting disease in recto-anal mucosa-associated lymphoid tissues from elk (\u3ci\u3eCervus elaphus nelsoni\u3c/i\u3e) using real-time quaking-induced conversion (RT-QuIC) assay: A blinded collaborative study

Prion diseases are transmissible spongiform encephalopathies (TSEs) characterized by fatal, progressive neurologic diseases with prolonged incubation periods and an accumulation of infectious misfolded prion proteins. Antemortem diagnosis is often difficult due to a long asymptomatic incubation period, differences in the pathogenesis of different prions, and the presence of very low levels of infectious prion in easily accessible samples. Chronic wasting disease (CWD) is a TSE affecting both wild and captive populations of cervids, including mule deer, white-tailed deer, elk, moose, muntjac, and most recently, wild reindeer. This study represents a well-controlled evaluation of a newly developed real-time quaking-induced conversion (RT-QuIC) assay as a potential CWD diagnostic screening test using rectal biopsy sections from a depopulated elk herd. We evaluated 69 blinded samples of recto-anal mucosa-associated lymphoid tissue (RAMALT) obtained from USDA Veterinary Services. The results were later un-blinded and statistically compared to immunohistochemical (IHC) results from the USDA National Veterinary Services Laboratories (NVSL) for RAMALT, obex, and medial retropharyngeal lymph node (MRPLN). Comparison of RAMALT RT-QuIC assay results with the IHC results of RAMALT revealed 92% relative sensitivity (95% confidence limits: 61.52–99.8%) and 95% relative specificity (95% confidence limits: 85.13– 99%). Collectively, our results show a potential utility of the RT-QuIC assay to advance the development of a rapid, sensitive, and specific prion diagnostic assay for CWD prions