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A novel method for geometric quality assurance of rock joint replicas in direct shear testing-Part 2:Validation and mechanical replicability

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journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2209-2223页

作者： j.Larsson f.johansson D.Mas Ivars E.johnson M.flansbjer N.W.portal Division of Material and Production Department of Chemistry and Applied MechanicsResearch Institutes of Sweden(RISE)Brinellgatan 4Borås50115Sweden Division of Soil and Rock Mechanics Department of Civil and Architectural EngineeringRoyal Institute of Technology(KTH)Brinellvägen 23Stockholm10044Sweden Swedish Nuclear fuel and Waste Management Co.(SKB) SolnaSweden

Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter ***,a method to acquire knowledge about the ability of the replicas to imitate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is *** this study,a novel method is presented for geometric quality assurance of *** aim is to facilitate generation of high-quality direct shear testing data as a prerequisite for reliable subsequent analyses of the *** Part 1 of this study,two quality assurance parameters,smf and V_(Hp100),are derived and their usefulness for evaluation of geometric deviations,*** reproducibility,is *** Part 2,the parameters are validated by showing a correlation between the parameters and the shear mechanical behavior,which qualifies the parameters for usage in the quality assurance *** results from direct shear tests presenting comparisons between replicas and the rock joint show that replicas fulfilling proposed threshold values of σ_(mf)f the rock joint in all aspects apart from having a slightly lower peak shear *** wear in these replicas,which have similar morphology as the rock joint,is in the same areas as in the rock *** wear is slightly larger in the rock joint and therefore the discrepancy in peak shear strength derives from differences in material properties,possibly from differences in *** is shown by application of the suggested method that the quality assured replicas manufactured following the process employed in this study phenomenologically capture the shear strength characteristics,which makes them useful in parameter studies.

关键词： Three-dimensional(3D)scanning Contact area measurements Direct shear testing Geometric quality assurance Mechanical replicability Replicas Rock joint

Radiotherapy-customized head immobilization masks:from modeling and analysis to 3D printing

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Nuclear Science and Techniques 2019年第9期30卷 103-118页

作者： M.A.R.Loja D.S.Craveiro L.Vieira E.Sousa j.A.Rodrigues R.j.f.portal CIMOSM Centro de Investigacao em Modelacao e Optimizacao de Sistemas Multifuncionais ISEL IPL Instituto Superior de Engenharia de Lisboa Av. Conselheiro Emidio Navarro 1 1959-007 Lisbon Portugal LAETA IDMEC Instituto Superior Teccnico Universidade de Lisboa Av. Rovisco Pais 1 1049-001 Lisbon Portugal Department of Mechanical and Industrial Engineering Faculty of Science and Technology NOVA UNIDEMI Universidade Nova de Lisboa Caparica Portugal H&TRC -Health &Technology Research Center ESTeSL - Escola Superior de Tecnologia da Saude de Lisboa Av. D. Joao II Lote 4.69.01 1990-096 Lisbon Portugal Instituto de Biofisica e Engenharia Biomedica Faculdade de Ciencias da Universidade de Lisboa Lisbon Portugal

Immobilization devices may be a valuable aid to ensure the improved effectiveness of radiotherapy treatments where constraining the movements of specific anatomical segments is crucial. This need is also present in other situations, specifically when the superposition of various medical images is required for fine identification and characterization of some pathologies. Because of their structural characteristics, existing head immobilization systems may be claustrophobic and very uncomfortable for patients, during both the modeling and usage stages. Because of this, it is important to minimize all the discomforts related to the mask to alleviate patients’ distress and to simultaneously guarantee and maximize the restraint effectiveness of the mask. In the present work, various head immobilization mask models are proposed based on geometrical information extracted from computerized tomography images and from 3D laser scanning point clouds. These models also consider the corresponding connection to a radiotherapy table, as this connection is easily altered to accommodate various manufacturers’ solutions. A set of materials used in the radiotherapy field is considered to allow the assessment of the stiffness and strength of the masks when submitted to typical loadings.

关键词： Computed tomography 3D laser scanning Geometric modeling Head immobilization devices Stiffness and strength analyses 3D printing

Anisotropic modelling of Opalinus Clay behaviour: from triaxial tests to gallery excavation application

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journal of Rock Mechanics and Geotechnical Engineering 2017年第3期9卷 53-66页

作者： francois Bertrand frédéric Collin Université de Liège Département ArGEnCo/Géomécanique Allée de la découverte 9 4000 Liège Belgium f.R.I.A Fonds de la Recherche Scientifique e FNRS Brussels Belgium

Deep repository in geological formations is the preferential solution considered in many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by jahns(2013) on cores from borehole Schlattingen SLA-1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a DruckerPrager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependence of the elastic properties and damage are taken into account. finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach.

关键词： Opalinus Clay Schlattingen Constitutive modelling Anisotropy Dilatancy Localisation Tunnel excavation

Impact of zinc and arginine on antioxidant status of weanling piglets raised under commercial conditions

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Animal Nutrition 2019年第3期5卷 227-233页

作者： Nadia Bergeron frédéric Guay Departement des Sciences Animales Université Laval

The effects of dietary zinc and L-arginine supplements on the weight gain,feed efficiency,antioxidant capacity and oxidative status of weanling piglets raised under commercial conditions were examined.A total of 288 piglets aged 21 d were fed for 15 d a diet supplemented or not with 2,500 mg/kg of zinc(provided as zinc oxide)and 1% L-arginine *** 4 treatments were distributed in a randomized complete block design with 6 initial body weight categories(12 animals per pen).Access to feed and water was ad *** were analyzed as a 2 x 2 factorial experiment using the SAS MIXED procedure,with zinc and arginine as the main independent *** collection day(d 8 and 15,samples were collected from the same 2 piglets in each pen before the morning feeding)was included as a third *** zinc supplement increased the average daily gain(ADG)from d 0 to 7.d 8 to 15 and d 0 to 15(0.289 vs.0.217 kg/d).average daily feed intake(ADfR)from d 8 to 15 and d 0 to 15(0.338 vs.0.279 kg/d)and the gain to feed(G:f)ratio from d 0 to 7 and d 0 to 15(0.86 vs.0.77)(Pficantly decreased the malondialdehyde concentration(zinc:4.37 vs.3.91 μmol/L,P= 0.005;arginine:4.38 vs.3.89 μmol/L,P = 0.002).Total antioxidant capacity and reduced glutathione(GSH)increased from d 8 to 15(0.953 vs.1.391 μmol/L,2.22 vs.3.37 μmol/L,Pf dietary *** and oxidized GSH concentrations on d 8 were higher in response to the combined supplements(zinc x arginine interaction.Pfed either Zn-supplemented diet had a lower haptoglobin serum concentration(509 vs.1.417 mg/L;Pformance(ADG and ADfI)and oxidative status(based on malondialdehyde concentration).The arginine supplement had a limited effect on growth performance and oxidative status under these conditions.

关键词： Zinc Arginine Weanling piglets Antioxidant status Growth performance

New insights into inflammatory osteoclast precursors as therapeutic targets for rheumatoid arthritis and periodontitis

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Bone Research 2023年第2期11卷 303-315页

作者： Emilie Hascoet frédéric Blanchard Claudine Blin-Wakkach jérôme Guicheux Philippe Lesclous Alexandra Cloitre Nantes Université OnirisUniv AngersCHU NantesINSERMRegenerative Medicine and SkeletonRMeSUMR1229F-44000 NantesFrance UniversitéCote d'Azur CNRSLP2M NiceFrance

Rheumatoid arthritis(RA)and periodontitis are chronic inflammatory diseases leading to increased bone *** this inflammatory bone resorption is a major health *** diseases share immunopathogenic similarities and a common inflammatory *** autoimmune response or periodontal infection stimulates certain immune actors,leading in both cases to chronic inflammation that perpetuates bone ***,RA and periodontitis have a strong epidemiological association that could be explained by periodontal microbial *** dysbiosis is believed to be involved in the initiation of RA via three mechanisms.(i)The dissemination of periodontal pathogens triggers systemic inflammation.(ii)Periodontal pathogens can induce the generation of citrullinated neoepitopes,leading to the generation of anti-citrullinated peptide autoantibodies.(iii)Intracellular danger-associated molecular patterns accelerate local and systemic ***,periodontal dysbiosis could promote or sustain bone resorption in distant inflamed ***,in inflammatory conditions,the existence of osteoclasts distinct from“classical osteoclasts”has recently been *** have proinflammatory origins and *** populations of osteoclast precursors have been described in RA,such as classical monocytes,a dendritic cell subtype,and arthritis-associated osteoclastogenic *** aim of this review is to synthesize knowledge on osteoclasts and their precursors in inflammatory conditions,especially in RA and *** attention will be given to recent data related to RA that could be of potential value in periodontitis due to the immunopathogenic similarities between the two *** our understanding of these pathogenic mechanisms should lead to the identification of new therapeutic targets involved in the pathological inflammatory bone resorption associated with these diseases.

关键词： inflammatory osteoclast period

Time-dependent behaviour of the Callovo-Oxfordian claystone-concrete interface

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journal of Rock Mechanics and Geotechnical Engineering 2020年第1期12卷 89-101页

作者： Eleni Stavropoulou Matthieu Briffaut frédéric Dufour Guillaume Camps Univ.Grenoble Alpes CNRSGrenoble INP3SRF-38000GrenobleFrance Agence Nationale pour la gestion des Déchets Radioactifs(Andra) Chatenay-MalabryFrance

In the context of the Cigeo project,the french National Radioactive Waste Management Agency(Andra)is studying the behaviour of a deep geological facility for radioactive waste deposit in the CallovoOxfordian(COx)*** assessment of durability of this project requires the prediction of irreversible strain over a large time *** mechanical interaction of the host rock and the concrete support of tunnels must be investigated to ensure the long-term sustainability of the *** instantaneous and time-dependent behaviour of the claystone-concrete interface is experimentally investigated with direct shear tests and long-duration shear tests of a few *** mechanical and structural state of the claystone which is affected after interaction with concrete reflects to the response of the claystone-concrete interface,and thus different types of COx claystone-concrete interfaces are *** delayed deformation of the interface is found to be linked to the level of the normal loading and the loading history while a different response of the interface was observed from the short-and long-duration tests,indicating a possible progressive modification of interface under long-duration loadings.

关键词： Callovo-Oxfordian(COx)claystone Interfaces Time-dependent behaviour

feed supplementation with arginine and zinc on antioxidant status and inflammatory response in challenged weanling piglets

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Animal Nutrition 2017年第3期3卷 236-246页

作者： Nadia Bergeron Claude Robert frédéric Guay Département des sciences animales Université Laval

Although supplementing the diet with zinc oxide and arginine is known to improve growth in weanling piglets, the mechanism of action is not well understood. We measured the antioxidant status and inflammatory response in 48 weanling castrated male piglets fed diets supplemented with or without zinc oxide(2,500 mg Zn oxide per kg) and arginine(1%) starting at the age of 20 days. The animals were injected with lipopolysaccharide(100 μg/kg) on day 5. Half of them received another injection on day *** samples were taken just before and 6, 24 and 48 h after injection and the mucosa lining the ileum was recovered following euthanizing on days 7 and 14. Zinc supplementation increased reduced and total glutathione(GSH)(reduced and total) during days 5 to 7 and arginine decreased oxidized GSH measured on days 5 and 12 and the ratio of total antioxidant capacity to total oxidative status during days12 to 14. Zinc decreased plasma malondialdehyde measured on days 5 and 12 and serum haptoglobin measured on day 12 and increased both metallothionein-1 expression and total antioxidant capacity measured in the ileal mucosa on day 14. Tumour necrosis factor a concentration decreased from days 5 to12(all effects were significant at P flammation during the post-weaning period, while the arginine supplementation had only a limited effect.

关键词： Antioxidant Inflammation Zinc Arginine Piglet Weanling

Optical Nanoimpacts of Dielectric and Metallic Nanoparticles on Gold Surface by Reflectance Microscopy: Adsorption or Bouncing?

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journal of Analysis and Testing 2019年第2期3卷 175-188页

作者： jean-françois Lemineur Talia jane Stockmann jérôme Médard Claire Smadja Catherine Combellas frédéric Kanoufi UniversitéSorbonne Paris Cité UniversitéParis DiderotITODYSCNRS UMR 708615 rue J.A.de Baïf75013 ParisFrance Present Address:Memorial University of Newfoundland Chemistry Department283 Prince Philip Dr.St.John’sNL A1B 3X7Canada faculty of Pharmacy University Paris-SudCNRS UMR 86125 rue J.B.Clément92296 Châtenay-MalabryFrance

Optical modeling coupled to experiments show that a microscope operating in reflection mode allows imaging,through solutions or even a microfluidic cover,various kinds of nanoparticles,NPs,over a(reflecting)sensing surface,here a gold(Au)*** modeling suggests that this configuration enables the interferometric imaging of single NPs which can be characterized individually from local change in the surface *** interferometric detection improves the optical limit of detection compared to classical configurations exploiting only the light scattered by the *** method is then tested experimentally,to monitor in situ and in real time,the collision of single Brownian NPs,or optical nanoimpacts,with an Au-sensing ***,mimicking a microfluidic biosensor platform,the capture of 300 nm feOx maghemite NPs from a convective flow by a surface-functionalized Au surface is dynamically ***,the adsorption or bouncing of individual dielectric(100 nm polystyrene)or metallic(40 and 60 nm silver)NPs is observed directly through the *** influence of the electrolyte on the ability of NPs to repetitively bounce or irreversibly adsorb onto the Au surface is *** such visualization mode of single-NP optical nanoimpacts is insightful for comprehending single-NP electrochemical studies relying on NP collision on an electrode(electrochemical nanoimpacts).

关键词： Reflection microscopy Single nanoparticle Sensor Adsorption Silver Polystyrene

Design methodology of permanent magnet generators for fixed-pitch tidal turbines with overspeed power limitation strategy

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journal of Ocean Engineering and Science 2020年第1期5卷 73-83页

作者： Sofiane Djebarri jean frédéric Charpentier frank Scuiller Mohamed Benbouzid ECAM Lyon LabECAMF69005 LyonFrance french Naval Academy IRENav EA 363429240 BrestFrance University of Brest UMR CNRS 6027 IRDL29238 BrestFrance Shanghai Maritime University 201306 ShanghaiChina

This paper deals with a design methodology of permanent magnets(PM)generators used for fixed-pitch tidal turbines in a marine renewable energy *** the case of underwater turbines,fixed-pitch tidal turbines could be very attractive and interesting to reduce maintenance operation by avoiding using such a complex electromechanical system for *** this technological case,one of the main control challenges is to ensure power limitation at high tidal current *** control mode can be achieved using the generator *** this context,this paper proposes an original and systemic design methodology to optimize the generator design taking into account the tidal turbine power limitation for high tidal currents velocities.

关键词： Tidal turbine fixed-pitch turbine Direct-drive PM generator Design methodology flux-weakening power limitation.