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B-Spline Gaussian Collocation Software for Two-Dimensional Parabolic PDEs

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Advances in Applied Mathematics and Mechanics 2013年第4期5卷 528-547页

作者： Zhi Li paul Muir Mathematics and Computing Science Saint Mary’s UniversityHalifaxNova ScotiaCanada B3H 3C3

In this paper we describe new B-spline Gaussian collocation software for solving two-dimensional parabolic partial differential equations(PDEs)defined over a rectangular *** numerical solution is represented as a bi-variate piecewise polynomial(using a tensor product B-spline basis)with time-dependent unknown *** coefficients are determined by imposing collocation conditions:the numerical solution is required to satisfy the PDE and boundary conditions at images of the Gauss points mapped onto certain subregions of the spatial *** leads to a large system of time-dependent differential algebraic equations(DAEs)which is solved using the DAE solver,*** provide numerical results in which we use the new software,called BACOL2D,to solve three test problems.

关键词： Collocation B-splines two-dimensional partial differential equations differentialalgebraic equations

Integrated adsorption and absorption process for post-combustion CO_(2) capture

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Frontiers of Chemical Science and Engineering 2021年第3期15卷 483-492页

作者： Gongkui Xiao Penny Xiao Andrew Hoadley paul Webley Department of Chemical Engineering The University of Western AustraliaPerth WA 6009Australia Department of Chemical Engineering University of MelbourneVictoria 3010Australia Department of Chemical Engineering Monash UniversityVictoria 3800Australia

This study explored the feasibility of integrating an adsorption and solvent scrubbing process for postcombustion CO_(2) capture from a coal-fired power *** integrated process has two stages:the first is a vacuum swing adsorption(VSA)process using activated carbon as the adsorbent,and the second stage is a solvent scrubber/stripper system using monoethanolamine (30 wt-%) as the *** results showed that the adsorption process could enrich CO_(2) in the flue gas from 12 to 50 mol-% with a CO_(2) recovery of >90%,and the concentrated CO_(2) stream fed to the solvent scrubber had a significantly lower volumetric *** increased CO_(2) concentration and reduced feed flow to the absorption section resulted in significant reduction in the diameter of the solvent absorber,bringing the size of the absorber from uneconomically large to readily achievable *** addition,the VSA process could also remove most of the oxygen initially existed in the feed gas,alleviating the downstream corrosion and degradation problems in the absorption *** findings in this work will reduce the technical risks associated with the state-of-the art solvent absorption technology for CO_(2) capture and thus accelerate the deployment of such technologies to reduce carbon emissions.

关键词： vacuum swing adsorption monoethanolamine post-combustion CO_(2)capture integrated process

Multi-axial unsplit frequency-shifted perfectly matched layer for displacement-based anisotropic wave simulation in infinite domain

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 407-421页

作者： Xie Zhinan Zheng Yonglu paul Cristini Zhang Xubin Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China Aix Marseille University CNRSCentrale MarseilleLMAMarseille F-13353France

Multi-axial perfectly matched layer(M-PML),known to have lost the perfect-matching property owing to multi-axial coordinate stretching,has been numerically validated to be long-time stable and it is thus used extensively in linear anisotropic wave simulation and in isotropic cases where the PML becomes *** are concerned with the construction of the M-PML for anisotropic wave simulation based on a second order wave equation implemented with the displacement-based numerical *** address the benefit of the incorrect chain rule,which is implicitly adopted in the previous derivation of the *** show that using the frequency-shifted stretching function improves the absorbing efficiency of the M-PML for near-grazing incident ***,through multi-axial complex-coordinate stretching the second order anisotropic wave equation in a weak form,we derive a time-domain multi-axial unsplit frequency-shifted PML(M-UFSPML)using the frequency-shifted stretching function and the incorrect chain rule.A new approach is provided to reduce the number of memory variables needed for computing convolution terms in the *** obtained M-UFSPML is well suited for implementation with a finite element or the spectral element *** providing several typical examples,we numerically verify the accuracy and long-time stability of the implementation of our M-UFSPML by utilizing the Legendre spectral element method.

关键词： computational seismology seismic anisotropy wave propagation elastodynamics

Tribological mechanisms of slurry abrasive wear

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Friction 2023年第6期11卷 1079-1093页

作者： Yulong LI paul SCHREIBER Johannes SCHNEIDER Christian GREINER Institute for Applied Material(IAM) Karlsruhe Institute of Technology(KIT)Karlsruhe76131Germany KIT IAM-ZM MicroTribology Center(μTC) Karlsruhe76131Germany

Abrasive wear mechanisms—including two-body and three-body abrasion—dominate the performance and lifespan of tribological systems in many engineering fields,even of those operating in lubricated *** steel(100Cr6)pins and discs in a flat-on-flat contact were utilized in experiments together with 5 and 13 μm Al_(2)O_(3)-based slurries as interfacial media to shed light on the acting *** results indicate that a speed-induced hydrodynamic effect occurred and significantly altered the systems'frictional behavior in tests that were performed using the 5 μm *** experiments revealed that a speed-dependent hydrodynamic effect can lead to a 14% increase in film thickness and a decrease in friction of around 2/3,accompanied by a transition from two-body abrasion to three-body abrasion and a change in wear mechanism from microcutting and microploughing to fatigue ***,no correlation could be found between the total amount of wear and the operating state of the system during the experiment;however,the wear distribution over pin and disc was observed to change *** paper studies the influence of the hydrodynamic effect on the tribological mechanism of lubricated abrasive wear and also highlights the importance to not only consider a tribological systems'global amount of wear.

关键词： abrasive wear two-body abrasion three-body abrasion hydrodynamic effect steel

Equal Sex Ratios of a Marine Green Alga, Bryopsis plumosa

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Journal of Integrative Plant Biology 2008年第6期50卷 648-652页

作者： Tatsuya Togashi paul Alan Cox Marine Biosystems Research Center Chiba University Institute for Ethnomedicine Box 3464 Jackson Hole Wyoming 83001 USA Institute for Ethnomedicine Box 3464 Jackson Hole

By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa （Hudson） C. Agardh. In this study, we focused on the primary and secondary sex ratios （i.e. at inception and maturity） using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli＇s enriched seawater （PES） medium under a 14：10 h light： dark cycle at 14 ℃. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PES medium under a 14：10 h light ： nbsp;dark cycle at 18℃. Then they were transferred into Schreiber medium and cultured under a 10：14 h light： dark cycle at 22℃. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1：1. Synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature.

关键词： algal culture Bryopsis green algae life history sex ratio.

On the unipolarity of charge transport in methanofullerene diodes

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npj Flexible Electronics 2017年第1期1卷 100-105页

作者： Ardalan Armin Safa Shoaee Qianqian Lin paul L Burn paul Meredith Centre for Organic Photonics&Electronics The University of QueenslandSt Lucia CampusBrisbaneQLD 4072Australia Centre for Engineered Quantum Systems School of Mathematics and PhysicsThe University of QueenslandSt Lucia CampusBrisbaneQLD 4072Australia Institute of Physics and Astronomy University of PotsdamKarl-Liebknecht-Straße 24-25Potsdam-Golm D-14476Germany Clarendon Laboratory Department of PhysicsThe University of OxfordParks Road OxfordOxfordOX13PUUK Department of Physics Swansea UniversitySingleton ParkSwanseaWales SA28PPUK

Fullerenes are electron transporting organic semiconductors with a wide range of *** particular,methanofullerenes have been the preferred choice for solution-processed solar cells and *** wide applicability of fullerenes as both‘ntype’transport materials and electron acceptors is ***,what is still a matter of debate is whether the fullerenes can also support efficient transport of holes,particularly in diode *** this letter,we utilize a number of recently developed experimental methods for selective electron and hole mobility *** show for the two most widely used solution processable fullerenes,PC70-and-PC60BM,that whilst both exhibit electron mobilities as high as 10^(−3)cm^(2)/Vs,their hole mobilities are<10^(−9)cm^(2)/*** charge transport in these fullerenes can be considered predominantly unipolar in diode configurations.

关键词： charge utilize polarity

Experiments on thermo-hydro-mechanical behaviour of Opalinus Clay at Mont Terri rock laboratory, Switzerland

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第3期9卷 120-128页

作者： paul Bossart David Jaeggi Christophe Nussbaum Swiss Geological Survey at swisstopo Wabern Switzerland

Repositories for deep geological disposal of radioactive waste rely on multi-barrier systems to isolate waste from the biosphere.A multi-barrier system typically comprises the natural geological barrier provided by the repository host rock e in our case the Opalinus Clay e and an engineered barrier system(EBS).The Swiss repository concept for spent fuel and vitrified high-level waste(HLW)consists of waste canisters,which are emplaced horizontally in the middle of an emplacement gallery and are separated from the gallery wall by granular backfill material(GBM).We describe here a selection of five in-situ experiments where characteristic hydro-mechanical(HM)and thermo-hydro-mechanical(THM)processes have been *** first example is a coupled HM and mine-by test where the evolution of the excavation damaged zone(EDZ)was monitored around a gallery in the Opalinus Clay(ED-B experiment).Measurements of pore-water pressures and convergences due to stress redistribution during excavation highlighted the HM *** same measurements were subsequently carried out in a heater test(HE-D)where we were able to characterise the Opalinus Clay in terms of its THM *** yielded detailed data to better understand the THM behaviours of the granular backfill and the natural host *** a presentation of the Swiss concept for HLW storage,we designed three demonstration experiments that were subsequently implemented in the Mont Terri rock laboratory:(1)the engineered barrier(EB)experiment,(2)the in-situ heater test on key-THM processes and parameters(HE-E)experiment,and(3)the full-scale emplacement(FE)*** first demonstration experiment has been dismantled,but the last two ones are on-going.

关键词： Deep geological disposal Radioactive waste Demonstration experiments Engineered barrier system(EBS) Granular backfill material(GBM) Bentonite Thermo-hydro-mechanical(THM) behaviour

The unique structural and functional features of CXCL12

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Cellular & Molecular Immunology 2018年第4期15卷 299-311页

作者： Rik Janssens Sofie Struyf paul Proost Department of Microbiology and Immunology Rega Institute for Medical ResearchLaboratory of Molecular ImmunologyKU LeuvenUniversity of LeuvenLeuven B-3000Belgium

The CXC chemokine CXCL12 is an important factor in physiological and pathological processes, includingembryogenesis, hematopoiesis, angiogenesis and inflammation, because it activates and/or induces migration ofhematopoietic progenitor and stem cells, endothelial cells and most leukocytes. Therefore, CXCL12 activity istightly regulated at multiple levels. CXCL12 has the unique property of existing in six splice variants in humans,each having a specific tissue distribution and in vivo activity. Controlled splice variant transcription and mRNAstability determine the CXCL12 expression profile. CXCL12 fulfills its functions in homeostatic and pathologicalconditions by interacting with its receptors CXC chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3(ACKR3) and by binding to glycosaminoglycans (GAGs) in tissues and on the endothelium to allow a properpresentation to passing leukocytes. Homodimerizaton and heterodimerization of CXCL12 and its receptors can altertheir signaling activity, as exemplified by the synergy between CXCL12 and other chemokines in leukocyte migrationassays. Receptor binding may also initiate CXCL12 internalization and its subsequent removal from theenvironment. Furthermore, CXCL12 activity is regulated by posttranslational modifications. Proteolytic removal ofNH2- or COOH-terminal amino acids, citrullination of arginine residues by peptidyl arginine deiminases or nitrationof tyrosine residues reduce CXCL12 activity. This review summarizes the interactions of CXCL12 with the cellularenvironment and discusses the different levels of CXCL12 activity regulation.

关键词： ACKR3 chemokine CXCL12 CXCR4 regulation

Effects of wood species and retention levels on removal of copper,chromium,and arsenic from CCA-treated wood using sodium hypochlorite

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Journal of Forestry Research 2016年第2期27卷 433-442页

作者： Engin Derya Gezer paul A.Cooper Department of Forest Industry Engineering Karadeniz Technical University61080 TrabzonTurkey Faculty of Forestry University of Toronto33 Willcocks St.TorontoON M5S 3B3Canada

Chemical extraction, bioremediation, and electrodialytic processes have been extensively studied for removal of copper, chromium, and arsenic from wood treated with chromated copper arsenate （CCA）. However, one problem has not been addressed： the effects of wood species and retention levels on remediation efficiency. The objectives of this study were to investigate the effects of wood species and retention levels on removal of copper, chromium, and arsenic from CCA-treated wood samples using sodium hypochlorite. Our results showed that sodium hypochlorite （NaOC1） was very effective for removal of copper, chromium, and arsenic from CCA-C treated milled wood samples for all three species used in this study. The Cu, Cr, and As extraction efficiencies for red pine were 95 % Cu, 97 % Cr and 94 % As, for maple were 95 % Cu, 97 % Cr, and 98 % As at 4.0 kg m-3 retention levels, and for aspen were 95 % Cu, 92% Cr, and 91% As at 9.6 kg m-3 retention level, respectively. However, the results showed that wood species and initial retention levels of CCA-treated wood products played very impor- tant roles in terms of removal of Cu, Cr, and As.

关键词： Chromated copper arsenate (CCA) Remediation Remediation efficiency Wood species Retention level