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CFD aided investigation of single droplet coalescence

Chinese Journal of Chemical Engineering 2016年第2期24卷 249-252页

作者： Felix Gebauer Mark W.Hlawitschka Hans-Jorg bart Chair of Separation Science and Technology University of KaiserslauternKaiserslautern 67653Germany Center for Computational and Mathematical Modelling(CIVY) University of KaiserslauternKaisersloutern 67653Germany

This article describes the development of a coalescence model using various CFD work packages,and is validated using as toluene water model *** studies were performed to describe droplet interactions in liquid–liquid test *** models use adjustable parameters to describe these *** research in the past decades led to different correlations to model coalescence and breakage depending on the chemical system and the apparatus *** the complexity of droplet coalescence requires a detailed investigation of local phenomena during the droplet *** fluid dynamics(CFD) studies of single droplet interactions were performed and validated with experimental results to improve the understanding of the local hydrodynamics and film drainage during *** CFD simulations were performed for the interaction of two differently sized droplets at industrial relevant impact *** experimental verification and validation of the numerical results were done with standardized high-speed imaging studies by using a special test cell with a pendant and a free rising *** experimental based algorithm was implemented in the open source code OpenF OAM to account for the contact time and the dimple *** standard European Federation of Chemical Engineering(EFCE) test system toluene/water was used for the numerical studies and the experimental investigations as *** results of the CFD simulations are in good accordance with the observed coalescence behavior in the experimental *** addition,a detailed description of local phenomena,like film rupture,velocity gradients,pressures and micro-droplet entrainment could be obtained.

关键词：数值模拟单液滴计算流体力学模拟计算流体动力学模型系统相互作用合并测试系统

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Mesomorphism of Lanthanide(Ⅲ) 4-Hexyloxybenzoates

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Journal of Rare Earths 2004年第2期22卷 193-196页

作者： Liesbet Jongen bart Goderis Igor P Dolbnya Koen Binnemans Katholieke Universiteit Leuven Department of Chemistry Celestijnenlaan 200F B-3001 Leuven BelgiumKatholieke Universiteit Leuven Department of Chemistry Celestijnenlaan 200F B-3001 Leuven BelgiumDUBBLE-CRG/ESRF Rue des Martyrs 156 B.P. 220 F-38043 Grenoble Cedex FranceKatholieke Universiteit Leuven Department of Chemistry Celestijnenlaan 200F B-3001 Leuven Belgium

The 4-alkoxybenzoic acids are well-known liquid crystals showing several mesophases (nematic, smectic C phase or both) depending on the alkoxy chain length and whereby the rigid core of the mesogen is formed by intermolecular hydrogen bonds. In this paper it is shown that the thermal behaviour of lanthanide salts of 4-hexyloxybenzoic acids depends on the lanthanide ion (Ln=La, Pr, Nd, Sm, Eu). The lanthanum(Ⅲ) and praseodymium(Ⅲ) 4-hexyloxybenzoates exhibit a smectic A mesophase. No mesophase is found for the corresponding compounds of heavier lanthanides. The thermal properties of the lanthanide(Ⅲ) 4-hexyloxybenzoates were investigated by differential scanning calorimetry (DSC), polarising thermo-optical microscopy and synchrotron X-ray radiation.

关键词： lanthanides 4-alkoxybenzoates thermal behaviour synchrotron measurements metallomesogens rare earths

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Air quality improvement in Los Angeles Perspectives for developing cities

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Frontiers of Environmental Science & Engineering 2016年第5期10卷 69-81页

作者： David D. Parrish Jin Xu bart Croes Min Shao Cooperative Institute for Research in Environmental Sciences University of Colorado Boulder CO 80305 USA NOAA Earth System Research Laboratory 325 Broadway R/CSD7 Boulder CO 80305 USA California Air Resources Board 1001 1 Street P.O. Box 2815 Sacramento CA 95814 USA College of Environmental Sciences and Engineering Peking University Beijing 100871 China

Air quality improvement in Los Angeles, California is reviewed with an emphasis on aspects that may inform air quality policy formulation in developing cities. In the mid-twentieth century the air quality in Los Angeles was degraded to an extent comparable to the worst found in developing cities today; ozone exceeded 600 ppb and annual average particulate matter 〈 10 μm reached -150 μg.m -3. Today＇s air quality is much better due to very effective emission controls; e.g., modem automobilcs emit about 1% of the hydrocarbons and carbon monoxide emitted by vehicles of 50 years ago. An overview is given of the emission control efforts in Los Angeles and their impact on anabient concentrations of primary and secondary pollutants： the costs and health benefits of these controls arc briefly summarized, Today＇s developing cities have new challenges that are discussed： the effects of regional pollution transport are much greater in countries with very high population densities： often very large current populations must be supplied with goods and services even while economic development and air quality concerns are addressed; and many of currently developing cities arc located in or close to the tropics where photochemical processing of pollution is expected to be more rapid than at higher latitudes. The air quality issues of Beijing are briefly compared and contrasted with those of Los Angeles, and the opportunities for co-benefits for climate and air quality improvement are pointed out.

关键词： Air pollution Ozone Particulate matter Control technology

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Application of a k-ε Model to Heat Transfer in Impinging Flows

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Journal of Thermal Science 2004年第1期13卷 62-66页

作者： bart Merci Chris De Langhe Koen Lodefier Erik Dick Ghent University Dept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgiumGhent UniversityDept.of FlowHeat and Combustion MechanicsSint-Pietersnieuwstraat 41B-9000 GentBelgium

Local heat transfer is predicted in turbulent axisymmetric jets, impinging onto a flat plate. A non-linear k-e model is used, in which both the constitutive law for the turbulent stresses and the transport equation for the turbulent dissipation rate e have an important contribution in the improved heat transfer predictions. The shape of the Nusselt number profiles, expressing dimensionless heat transfer, as well as the stagnation point value, are well predicted for different distances between the nozzle exit and the plate. Accurate flow field predictions are the basis for good heat transfer predictions. For a fixed Reynolds number, the influence of the nozzle-plate distance is well captured. For a fixed distance, the influence of the Reynolds number is correctly reproduced. Comparisons are made to a low-Reynolds standard k-e model and the v2-f model. A thorough discussion is found in [4]. Only a summary of those results is discussed here, while some new results are also presented.

关键词： local heat transfer impinging jets non-linear k-ε model.

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Comparison of the Reynolds-averaged Turbulence Models on Single Phase Flow Simulation in Agitated Extraction Columns

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Chinese Journal of Chemical Engineering 2003年第3期11卷 362-366页

作者：尤学一 H.J.bart School of Environmental Science and Engineering Tianjin UniversityTianjin 300072China Lehrstuhl

The flow field of liquid phase (water) of agitated extraction columns is simulated with the help of computational fluid dynamics (CFD). Four kinds of Reynolds-averaged turbulence models, i.e. the standard k-ε model, the RNG (renormaiization group) k-ε model, the realizable k-ε model and the Reynolds stress model, are compared in detail in order to judge which is the best model in terms of the accuracy, less CPU time and memory required. The performance of the realizable k-ε model is obviously improved by reducing the model constant from c2 = 1.90 to c2 = 1.61. It is concluded that the improved realizable k-ε model is the optimal model.

关键词：搅拌萃取塔液相混合物分离雷诺平均湍流模型流体动力学模拟单相流动模拟

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Scoping review on health-related physical fitness in patients with inflammatory bowel disease:Assessment,interventions,and future directions

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World Journal of Gastroenterology 2023年第38期29卷 5406-5427页

作者： Karlijn Demers Michiel T J Bak bart C Bongers Annemarie C de Vries Daisy M A E Jonkers Marieke J Pierik Laurents P S Stassen Department of Surgery Maastricht University Medical Center+Maastricht 6229 HXNetherlands Department of Internal Medicine Division of Gastroenterology-HepatologyMaastricht University Medical Center+Maastricht 6229 HXNetherlands Department of Internal Medicine Division of Gastroenterology-HepatologySchool of Nutrition and Translational Research in MetabolismMaastricht UniversityMaastricht 6229 ERNetherlands Stassen Department of SurgerySchool of Nutrition and Translational Research in MetabolismMaastricht UniversityMaastricht 6229 ERNetherlands Department of Gastroenterology and Hepatology Erasmus University Medical Center RotterdamRotterdam 3015 GDNetherlands Department of Nutrition and Movement Sciences School of Nutrition and Translational Research in MetabolismMaastricht UniversityMaastricht 6229 ERNetherlands

BACKGROUND Reaching the Selecting Therapeutic Targets in Inflammatory Bowel Disease-II(STRIDE-II)therapeutic targets for inflammatory bowel disease(IBD)requires an interdisciplinary *** interventions focusing on enhancing and preserving health-related physical fitness(HRPF)may aid in improving subjective health,decreasing disability,or even controlling ***,ambiguity remains about the status and impact of HRPF(*** composition,cardiorespiratory fitness,muscular strength,muscular endurance,and flexibility)in IBD patients,hindering the development of physical activity and physical exercise training *** To review HRPF components in IBD patients and the impact of physical activity and physical exercise training interventions on *** A systematic search in multiple databases was conducted for original studies that included patients with IBD,assessed one or more HRPF components,and/or evaluated physical activity or physical exercise training *** Sixty-eight articles were *** study examined the complete concept of HRPF,and considerable heterogeneity existed in assessment methods,with frequent use of non-validated *** to studies that used gold standard tests,cardiorespiratory fitness seemed to be reduced,but findings on muscular strength and endurance were inconsistent.A limited number of studies that evaluated physical activity or physical exercise training interventions reported effects on HRPF,overall showing a positive *** We performed a scoping review using a systematic and iterative approach to identify and synthesize an emerging body of literature on health-related physical fitness in patients with IBD,highlighting several research gaps and opportunities for future *** of this review revealed a gap in the literature regarding the accurate assessment of HRPF in patients with IBD and highlighted important methodological limitations of studies that eva

关键词： Inflammatory bowel disease Physical fitness Assessment Intervention Physical activity Exercise

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Parameter Ecology for Feedback Vertex Set

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Tsinghua Science and Technology 2014年第4期19卷 387-409页

作者： bart M.P.Jansen Venkatesh Raman Martin Vatshelle the Department of Informatics University of Bergen 5005 Bergen Norway the Institute of Mathematical Sciences Chennai India

This paper deals with the FEEDBACK VERTEX SET problem on undirected graphs, which asks for the existence of a vertex set of bounded size that intersects all cycles. Due it is theoretical and practical importance,the problem has been the subject of intensive study. Motivated by the parameter ecology program we attempt to classify the parameterized and kernelization complexity of FEEDBACK VERTEX SET for a wide range of *** survey known results and present several new complexity classifications. For example, we prove that FEEDBACK VERTEX SET is fixed-parameter tractable parameterized by the vertex-deletion distance to a chordal graph. We also prove that the problem admits a polynomial kernel when parameterized by the vertex-deletion distance to a pseudo forest, a graph in which every connected component has at most one cycle. In contrast, we prove that a slightly smaller parameterization does not allow for a polynomial kernel unless NP coNP=poly and the polynomial-time hierarchy collapses.

关键词： feedback vertex set parameterized complexity parameter ecology program structural parameterizations kernelization

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Optimizing the oxide support composition in Pr-doped CeO_(2) towards highly active and selective Ni-based CO_(2) methanation catalysts

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Journal of Energy Chemistry 2022年第8期31卷 547-561,I0015页

作者： Anastasios I.Tsiotsias Nikolaos D.Charisiou Ayesha AlKhoori Safa Gaber Vlad Stolojan Victor Sebastian bart van der Linden Atul Bansode Steven J.Hinder Mark A.Baker Kyriaki Polychronopoulou Maria A.Goula Laboratory of Alternative Fuels and Environmental Catalysis(LAFEC) Department of Chemical EngineeringUniversity of Western MacedoniaGR-50100Greece Department of Mechanical Engineering Khalifa University of Science and TechnologyAbu DhabiP.O.Box 127788United Arab Emirates Center for Catalysis and Separations Khalifa University of Science and TechnologyAbu DhabiP.O.Box 127788United Arab Emirates Advanced Technology Institute Department of Electrical and Electronic EngineeringUniversity of SurreyGuildford GU24DLUK Department of Chemical Engineering and Environmental Technology Universidad de ZaragozaCampus Río Ebro-Edificio I+D50018 ZaragozaSpain Instituto de Nanociencia y Materiales de Aragón(INMA) Universidad de Zaragoza-CSICc/María de Luna 350018 ZaragozaSpain Networking Research Center on Bioengineering Biomaterials and NanomedicineCIBERBBN28029 MadridSpain Department of Chemical Engineering Delft University of TechnologyVan der Massweg 92629 HZ DelftThe Netherlands The Surface Analysis Laboratory Faculty of Engineering and Physical SciencesUniversity of SurreyGuildford GU24DLUK

In this study,Ni catalysts supported on Pr-doped Ce O_(2) are studied for the CO_(2) methanation reaction and the effect of Pr doping on the physicochemical properties and the catalytic performance is thoroughly *** is shown,that Pr^(3+)ions can substitute Ce^(4+)ones in the support lattice,thereby introducing a high population of oxygen vacancies,which act as active sites for CO_(2) *** doping can also act to reduce the crystallite size of metallic Ni,thus promoting the active metal *** performance evaluation evidences the promoting effect of low Pr loadings(5 at%and 10 at%)towards a higher catalytic activity and lower CO_(2) activation *** the other hand,higher Pr contents negate the positive effects on the catalytic activity by decreasing the oxygen vacancy population,thereby creating a volcano-type trend towards an optimum amount of aliovalent substitution.

关键词： Power-to-gas CO_(2)methanation Ni-based catalyst Pr-doped CeO_(2) Oxygen vacancy Catalytic activity Activation energy

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Novel Hyperbranched Polyurethane Brushes for Biomedical Applications

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复旦学报（自然科学版） 2007年第5期46卷 612-,616页

作者： Ton Loontjens bart Plum University of Groningen Nijenborgh 4 9747AGGroningen the NetherlandsDSM research Urmonderbaan 22 6160MDGeleen the Neterhlands DSM research Urmonderbaan 22 6160MDGeleen the Neterhlands

1 Results The objective was to make hyperbranched (HB) polyurethane brushes with reactive end groups, to coat biomedical devices and to enable the introduction of various functionalities that are needed to fulfill biomedical *** materials should fulfill at least three requirements: (1) good mechanical properties, (2) good biocompatibility and (3) provided with functionalities to perform the required tasks. Since polyurethanes are able to fulfill the first 2 requirements we focused in this w...

关键词： hyperbranched brushes biomedical blocked isocyanates polyurethanes/urea

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Numerical Approaches for Linear Left-invariant Diffusions on SE(2), their Comparison to Exact Solutions, and their Applications in Retinal Imaging

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Numerical Mathematics(Theory,Methods and Applications) 2016年第1期9卷 1-50页

作者： Jiong Zhang Remco Duits Gonzalo Sanguinetti bart Mter Haar Romeny Department of Biomedical Engineering Biomedical Image Analysis(BMIA) Department of Mathematics and Computer Science Image Science and Technology(IST/e) Eindhoven University of Technology P.O.Box 5135600 MBEindhovenThe Netherlands Northeastern University ShenyangChina

Left-invariant PDE-evolutions on the roto-translation group SE(2)(and their resolvent equations)have been widely studied in the fields of cortical model-ing and image *** include hypo-elliptic diffusion(for contour enhance-ment)proposed by Citti&Sarti,and Petitot,and they include the direction process(for contour completion)proposed by *** paper presents a thorough study and comparison of the many numerical approaches,which,remarkably,are missing in the *** numerical approaches can be classified into 3 categories:Finite difference methods,Fourier based methods(equivalent to SE(2)-Fourier methods),and stochastic methods(Monte Carlo simulations).There are also 3 types of exact solutions to the PDE-evolutions that were derived explicitly(in the spatial Fourier domain)in previous works by Duits and van Almsick in *** we provide an overview of these 3 types of exact solutions and explain how they relate to each of the 3 numerical *** compute relative errors of all nu-merical approaches to the exact solutions,and the Fourier based methods show us the best performance with smallest relative *** also provide an improvement of Mathematica algorithms for evaluating Mathieu-functions,crucial in implemen-tations of the exact ***,we include an asymptotical analysis of the singularities within the kernels and we propose a probabilistic extension of un-derlying stochastic processes that overcomes the singular behavior in the origin of time-integrated ***,we show retinal imaging applications of combining left-invariant PDE-evolutions with invertible orientation scores.

关键词： Brownian motion Euclidean motion group PDE’s on SE(2) Mathieu operators contour completion contour enhancement retinal imaging

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