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Modelling erosion of a single rock block using a coupled CFD-DEM approach

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journal of Rock Mechanics and Geotechnical Engineering 2023年第9期15卷 2375-2387页

作者： Penghua Teng Fredrik johansson j.gunnar I.Hellström Division of Fluid and Experimental Mechanics Department of Engineering Sciences and MathematicsLuleåUniversity of TechnologyLuleåSE-97187Sweden Division of Soil and Rock Mechanics KTH Royal Institute of TechnologyStockholmSE-10044Sweden

Rock block removal is the prevalent physical mechanism for rock erosion and could affect the stability of dam foundations and *** this,understanding of block removal is still inadequate because of the complex interactions among block characteristics,hydraulic forces,and erosive processes acting on the ***,based on a previously conducted physical experiment of erosion of a single rock block,the removal processes of two different protruding blocks are represented by a coupled computational fluid dynamics-discrete element model(CFD-DEM)approach under varied flow ***,the blocks could be rotated with respect to the flow direction to consider the effect of the discontinuity orientation on the block removal *** results visualize the entire block removal *** simulations reproduce the effects of the discontinuity orientation on the critical flow velocity inducing block incipient motion and the trajectory of the block motion observed in the physical *** numerical results present a similar tendency of the critical velocities at different discontinuity orientations but have slightly lower *** trajectory of the block in the simulations fits well with the experimental *** relationship between the dimensionless critical shear stress and discontinuity orientation observed from the simulations shows that the effect of block protrusion becomes more dominant on the block incipient motion with the increase of relative protrusion *** our knowledge,this present study is the first attempt to use the coupled finite volume method(FVM)-DEM approach for modelling the interaction behavior between the block and the flowing water so that the block removal process can be reproduced and analyzed.

关键词： Rock erosion Block removal Incipient motion Coupled CFD-DEM Critical shear stress

Tumor mutational burden as a new biomarker for PD-1 antibody treatment in gastric cancer

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Cancer Communications 2019年第1期39卷 632-633页

作者： gunnar Folprecht Medical Department I University Hospital Carl Gustav Carus01307 DresdenGermany

Gastric cancer is the fifth most frequently occurring can-cer *** has the largest gastric cancer pop-ulation and nearly half of the patients are diagnosed as advanced-stage[1].The prognosis of most patients with advanced gastric cancer(AGC)remains dismal even despite the approval of several novel chemotherapy drugs and targeted therapy ***,immune check-point inhibitors(ICIs)such as programmed death-1(PD-1)antibody have shown promising activity in various solid *** PD-1 antibodies,pembrolizumab[2]and nivolumab[3],were approved for AGC patients who had treatment failure with ***,the overall response rate(ORR)and the survival benefits of pembrolizumab(11.6%;OS 5.6 months)and nivolumab(nivolumab vs placebo ORR 11%vs 0%,P<0.0001;OS 5.3 vs 4.1 months,P<0.0001)were moderate.

关键词： chemotherapy drugs treatment

The Norwegian Model in Norway

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journal of Data and Information Science 2018年第4期3卷 3-19页

作者： gunnar Sivertsen Nordic Institute for Studies in Innovation Research and Education

The "Norwegian Model" attempts to comprehensively cover all the peer-reviewed scholarly literatures in all areas of research in one single weighted indicator. Thereby, scientific production is made comparable across departments and faculties within and between research institutions, and the indicator may serve institutional evaluation and funding. This article describes the motivation for creating the model in Norway, how it was designed, organized and implemented, as well as the effects and experiences with the model. The article ends with an overview of a new type of bibliometric studies that are based on the type of comprehensive national publication data that the Norwegian Model provides.

关键词： Scientific production Research information system Performance-based funding Evaluation Bibliometrics Indicators Publications journals Book publishing Research institutions Norwegian model

DNA barcoding-based species delimitation increases species count of Eois （Geometridae） moths in a well-studied tropical mountain forest by up to 50%

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Insect Science 2011年第3期18卷 349-362页

作者： Patrick Strutzenberger gunnar Brehm Konrad Fiedler Department of Animal Biodiversity University of Vienna Rennweg 14 1030 Wien Austria Institut for Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum Friedrich Schiller Universitat Erbertstrasse 1 07743 Jena Germany

The genus Eois comprises an important part of megadiverse assemblages of geometrid moths in mountain rainforests of southern Ecuador. In this study we report：（i） on the construction of a DNA barcode library of Eois for identification purposes; and （ii） the exploration of species diversity through species delimitation by pair-wise distance thresholds. COl barcode sequences were generated from 408 individuals （at least 105 species） collected on a narrow geographic scale （-40 km2） in the Reserva Bioldgica San Francisco. Analyses of barcode sequence divergence showed that species delimitations based solely on external morphology result in broad overlap of intra- and interspecific distances. Species delimitation at a 2% pair-wise distance threshold reveals a clear barcoding gap. Fifty-two previously unrecognized species were identified, 31 of which could only be distinguished by an integrative taxonomy approach. Twelve additional putative species could only be recognized by threshold-based delimitation. Most splits resulted in two or three newly perceived cryptic taxa. The present study increased the number of Eois species recorded from that small area of Andean mountain forest from 102 to 154 （morphology- plus integrative taxonomy-based） or even 166 （sequence-based）, leaving the species accumulation curve still far from reaching an asymptote. Notably, in no case did two or more previously distinguished morphospecies have to be lumped. This barcode inventory can be used to match larvae to known adult samples without rearing, and will therefore be of vital help to extend the currently limited knowledge about food plant relationships and host specialization.

关键词： cryptic species Ecuador integrative taxonomy Larentiinae larvae

Design and development of guide vane cascade for a low speed number Francis turbine

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journal of Hydrodynamics 2016年第4期28卷 676-689页

作者： Biraj Singh THAPA Chirag TRIVEDI Ole gunnar DAHLHAUG Department of Energy and Process Engineering Norwegian University of Science and Technology

Guide vane cascade of a low speed number Francis turbine is developed for the experimental investigations. The test setup is able to produce similar velocity distributions at the runner inlet as that of a reference prototype turbine. Standard analytical methods are used to design the reference turbine. Periodic walls of flow channel between guide vanes are identified as the starting profile for the boundary of the cascade. Two alternative designs with three guide vanes and two guide vanes, without runner, are studied. A new approach, for the hydraulic design and optimization of the cascade test setup layout, is proposed and investigated in details. CFD based optimization methods are used to define the final layout of the test setup. The optimum design is developed as a test setup and experimental validation is done with PIV methods. The optimized design of cascade with one guide vane between two flow channels is found to produce similar flow conditions to that in the runner inlet of a low speed number Francis turbine.

关键词： guide vanes Francis turbine cascade optimization CFD PIV

Distributions with Maximum Spread Subject to Wasserstein Distance Constraints

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journal of the Operations Research Society of China 2019年第1期7卷 69-105页

作者： john gunnar Carlsson Ye Wang University of Southern California Los AngelesCA 90089-4017USA

Recent research on formulating and solving distributionally robust optimization problems has seen many different approaches for describing one’s ambiguity set,such as constraints on first and second moments or *** this paper,we use theWasserstein distance to characterize the ambiguity set of distributions,which allows us to circumvent common overestimation that arises when other procedures are used,such as fixing the center of mass and the covariance matrix of the *** particular,we derive closed-form expressions for distributions that are as“spread out”as possible,and apply our result to a problem in multi-vehicle coordination.

关键词： Distributionally robust optimization Surveillance Districting

Gastric cancer:Animal studies on the risk of hypoacidity and hypergastrinemia

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World journal of Gastroenterology 2008年第11期14卷 1646-1651页

作者： Reidar Fossmark gunnar Qvigstad Helge L Waldum Department of Gastroenterology and Hepatology St.Olav'sHospitalTrondheimNorway Department of Cancer Researchand Molecular Medicine Faculty of MedicineNorwegianUniversity of Science and TechnologyTrondheim 7006Norway Department of Gastroenterology and Hepatology St.Olav’sHospitalTrondheimNorway

Gastric hypoacidity and hypergastrinaemia are seen in several conditions associated with an increased risk of gastric *** and hypergastrinaemia are closely related and their long-term effects are difficult to study separately in *** using animal models can provide valuable information about risk factors and mechanisms in gastric cancer development as the models allow a high degree of intervention when introducing or eliminating factors possibly affecting *** this report,we briefly review findings from relevant animal studies on this *** models of gastric hypoacidity and hypergastrinaemia provide evidence hypergastrinaemia is a common causative factor in many otherwise diverse *** all species where sufficient hypoacidity and hypergastrinaemia have been induced,a proportion of the animals develop malignant lesions in the gastric oxyntic mucosa.

关键词： Gash'in Gastric cancer Proton pump inhibitors Acid secretion Animal model

Responses to faecal microbiota transplantation in female and male patients with irritable bowel syndrome

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World journal of Gastroenterology 2021年第18期27卷 2219-2237页

作者： Magdy El-Salhy Christina Casen jørgen Valeur Trygve Hausken jan gunnar Hatlebakk Department of Medicine Stord Helse-Fonna HospitalStord 5416Norway Department of Clinical Medicine University of BergenBergen 5020Norway National Centre for Functional Gastrointestinal Disorders Department of MedicineHaukeland University HospitalBergen 5020Norway Genetic Analysis AS Oslo 0485Norway Unger-Vetlesen Institute Lovisenberg Diaconal HospitalOslo 0440Norway

BACKGROUND Faecal microbiota transplantation(FMT)seems to be a promising treatment for irritable bowel syndrome(IBS)*** Western countries(United States and Europe),there is a female predominance in IBS.A sex difference in the response to FMT has been reported recently in IBS *** To investigate whether there was a sex difference in the response to FMT in the IBS patients who were included in our previous randomized controlled trial of the efficacy of *** The study included 164 IBS patients who participated in our previous randomized controlled *** patients had moderate-to-severe IBS symptoms belonging to the IBS-D(diarrhoea-predominant),IBS-C(constipation-predominant)and IBSM(mixed)subtypes,and had not responded to the National Institute for Health and Care Excellence(NICE)-modified *** belonged in three groups:placebo(own faeces),and active treated group(30-g or 60-g superdonor faeces).The patients completed the IBS severity scoring system(IBS-SSS),Fatigue Assessment Scale(FAS)and the IBS quality of life scale(IBS-QoL)questionnaires at the baseline and 2 wk,1 mo and 3 mo after *** also provided faecal samples at the baseline and 1 mo after *** faecal bacteria profile and dysbiosis were determined using the 16S rRNA gene polymerase chain reaction DNA amplification covering V3-V9;probe labelling by single nucleotide extension and signal *** levels of short-chain fatty acids(SCFAs)were determined by gas chromatography and flame *** There was no sex difference in the response to FMT either in the placebo group or active treated *** was no difference between females and males in either the placebo group or actively treated groups in the total score on the IBS-SSS,FAS or IBS-QoL,in dysbiosis,or in the faecal bacteria or SCFA ***,the response rate was significantly higher in females with diarrhoea-predominant(IBS-D)than that of males at 1 mo,and 3 mo after ***,IBS-SSS total

关键词： Dysbiosis Fatigue Microbiome Quality of life Short-chain fatty acids Superdonor

Sustainable Care:Care as a Communal Virtue in Early Childhood Education

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ECNU Review of Education 2022年第4期5卷 643-663页

作者： gunnar Magnus Eidsvag Early Childhood Education University of StavangerHagbard Lines husStavanger 4036

Purpose:Care is a core concern for early childhood education and care(ECEC)*** may be understood as a basic form of interaction and a foundational need for human *** these reasons,care also presents challenges for ECEC *** staff must seek practical solutions to problems that philosophers have raised on a theoretical basis concerning ethical traditions,such as the ethics of *** are the problems of justice,parochialism,and ***/Approach/Methods:This article develops a theory concerning the ethics of care in ECEC *** theory is informed by qualitative interviews with ECEC teachers reflecting on their caring *** study is therefore located at the intersection of normative ethics and applied *** seven in-depth interviews,the informants discussed how to create a caring ECEC environment that is fair and possible to maintain over ***:Through analyzing the interviews,I found that caring practices that work toward these ideals can be described as sustainable *** practices take care of all the children and provide the staff with opportunities to regain the strength they need to create a caring and educating setting.

关键词： Care ECEC ethics profession virtue