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Numerical Solution of the Upper-Convected maxwell model for Three-Dimensional Free Surface Flows

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Communications in Computational Physics 2009年第7期6卷 367-395页

作者： murilo F.Tome Renato A.P.Silva Cassio m.Oishi sean mcKee Departamento de matematica Aplicada e Estatıstica Instituto de Ciencias Matematicas e de Computa¸caoUniversidade de Sao PauloSao CarlosBrazil Department of mathematics University of StrathclydeGlasgowUK

This work presents a finite difference technique for simulating three-dimensional free surface flows governed by the Upper-Convected maxwell(UCm)constitutive equation.A marker-and-Cell approach is employed to represent the fluid free surface and formulations for calculating the non-Newtonian stress tensor on solid boundaries are *** complete free surface stress conditions are *** momentum equation is solved by an implicit technique while the UCm constitutive equation is integrated by the explicit Euler *** resulting equations are solved by the finite difference method on a 3D-staggered *** using an exact solution for fully developed flow inside a pipe,validation and convergence results are *** results include the simulation of the transient extrudate swell and the comparison between jet buckling of UCm and Newtonian fluids.

关键词： Viscoelastic flow Upper-Convected maxwell finite difference free surface implicit techniques marker-and-Cell

High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution reactions

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Frontiers in Energy 2024年第3期18卷 265-290页

作者： Simiao SHA Riyue GE Ying LI Julie m.CAIRNEY Rongkun ZHENG sean LI Bin LIU Jiujun ZHANG Wenxian LI School of materials Science and Engineering Shanghai UniversityShanghai 200444China School of Chemical and Environmental Engineering Anhui Polytechnic UniversityWuhu 241000China Australian Centre for microscopy and microanalysis School of AerospaceMechanical and Mechatronic EngineeringThe University of SydneySydney NSW 2006Australia School of Physics The University of SydneySydney NSW 2006Australia School of materials Science and Engineering UNSW Materials&Manufacturing Futures InstituteUniversity of New South WalesSydney NSW 2052Australia College of materials Science and Engineering Fuzhou UniversityFuzhou 350108China

High entropy materials (HEms) have developed rapidly in the field of electrocatalytic water-electrolysis for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to their unique properties. In particular, HEm catalysts are composed of many elements. Therefore, they have rich active sites and enhanced entropy stability relative to single atoms. In this paper, the preparation strategies and applications of HEm catalysts in electrochemical water-electrolysis are reviewed to explore the stabilization of HEms and their catalytic mechanisms as well as their application in support green hydrogen production. First, the concept and four characteristics of HEms are introduced based on entropy and composition. Then, synthetic strategies of HEm catalysts are systematically reviewed in terms of the categories of bottom-up and top-down. The application of HEms as catalysts for electrochemical water-electrolysis in recent years is emphatically discussed, and the mechanisms of improving the performance of electrocatalysis is expounded by combining theoretical calculation technology and ex-situ/in situ characterization experiments. Finally, the application prospect of HEms is proposed to conquer the challenges in HEm catalyst fabrications and applications.

关键词： high-entropy electrocatalysis synthetic methods water-electrolysis hydrogen and oxygen evolutions

Review of current reconstructive approaches for pan-brachial plexus injuries

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Plastic and Aesthetic Research 2023年第1期10卷 258-269页

作者： sean m.mitchell Justin W.Zumsteg Karan A.Desai Department of Hand&Upper Extremity Surgery Orlando Health Jewett Orthopedic InstituteOrlandoFL 32806USA

Pan-brachial plexus injuries present a challenging clinical problem,resulting in severe impairment of motor and sensory function in the upper *** current literature has outlined several promising methodologies for treatment,a consensus has yet to be *** this review,we present three general approaches for reconstructing the upper extremity in these complex cases.

关键词： Pan-brachial plexus injuries brachial plexus reconstructive techniques

NRG COSIA Carbon XPRIZE: carbon-dioxide mineralization in recycled concrete wash water

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Clean Energy 2021年第4期5卷 553-574页

作者： sean monkman Travis Janke Alex Hanmore CarbonCure Technologies 42 Payzant AveDartmouthNSB3B 1Z6Canada

Wash water is generated as a waste stream from ready-mixed-concrete *** of the water as mixture water is limited,in practice,by the negative material performance impacts associated with the water chemistry and properties;the effects are intensified with increasing content of suspended solids and ***,this waste material can be used as a beneficial additive to concrete by profiting from the cementitious properties of the suspended solids,if variability can be reduced.A method of stabilizing this material is through CO_(2) *** added CO_(2) is mineralized through a reaction with the calcium from the cement *** provides a calcium-carbonate coating that prevents further cement hydration,making the material *** has been shown to alleviate concerns with set acceleration and inconsistencies in compressive strength.A method of CO_(2) treatment was tested as part of the NRG COSIA Carbon XPRIZE at a site in Calgary,*** slurry for the treatment was provided by a local concrete plant and had a specific gravity of *** simulated wash water was treated in 1000-L quantities with each treatment mineralizing an average of 40 kg of CO_(2).The system ran for 1600 hours of operation over 127 treatment cycles and converted 14.5 tonnes of CO_(2) at an average mineralization efficiency of 80%.The treated slurry was used as an additive in>300 batches of concrete where the concrete met the necessary requirements for fresh properties and setting time,while achieving a strength *** of 5%and 10%of batch water with treated slurry(9.4 and 18.8 kg slurry/m^(3) concrete)showed a strength benefit of 3%and 6%compared to a *** technology was selected as the winner of the NRG COSIA Carbon XPRIZE(Track B:Natural Gas)in April 2021.

关键词： CCUS CO_(2)conversion CO_(2)utilization Carbon XPRIZE CO_(2)mineralization

A Facile and Template-Free One-Pot Synthesis of mn_3O_4 Nanostructures as Electrochemical Supercapacitors

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Nano-micro Letters 2016年第2期8卷 165-173页

作者： Zhenjun Qi Adnan Younis Dewei Chu sean Li School of materials Science and Engineering University of New South Wales

In this paper, we report an effective, simple, and cost-effective strategy of electrochemical deposition to prepare hausmannite mn_3O_4 thin films for the applications of supercapacitors. Various precursor concentrations and deposition durations were manipulated to tailor the surface morphologies of mn_3O_4 nanostructures and to optimize their electrochemical performances. The mn_3O_4 samples prepared at 0.05 m mn(NO3)2solution for 30 min delivered a large gravimetric specific capacitance of 210 F g-1at a current density of 0.5 A g-1, and a good rate capability over other samples. This superior electrochemical performance may be attributed to the improved electrode conductivity with increased accessible area for electrolytes ions. Furthermore, a nanocomposite film based on mn_3O_4/carbon foam was fabricated by utilizing the developed optimized conditions. The mn_3O_4/carbon foam films exhibit an excellent specific capacitance with negligible degradation in retaining specific capacitance values up to 4000 cycles. These findings could further broaden the applications of hausmannite mn_3O_4 in electrochemical energy storage electrodes.

关键词： Electrochemical deposition Supercapacitors Charge storage

The Changing Cold Regions Network:Observation,diagnosis and prediction of environmental change in the Saskatchewan and mackenzie River Basins,Canada

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Science China Earth Sciences 2015年第1期58卷 46-60页

作者： Chris m DEBEER Howard S WHEATER William L QUINTON sean K CAREY Ronald E STEWART murray D mACKAY Philip mARSH Global Institute for Water Security University of SaskatchewanNational Hydrology Research Centre Cold Regions Research Centre Wilfrid Laurier University School of Geography and Earth Sciences Mc Master University Department of Environment and Geography University of Manitoba Science and Technology Branch Environment Canada

Climate change is causing rapid and severe changes to many Earth systems and processes,with widespread cryospheric,ecological,and hydrological impacts globally,and especially in high northern *** is of major societal concern and there is an urgent need for improved understanding and predictive tools for environmental *** Changing Cold Regions Network(CCRN)is a Canadian research consortium with a focus to integrate existing and new experimental data with modelling and remote sensing products to understand,diagnose,and predict changing land,water,and climate,and their interactions and feedbacks over the geographic domain of the mackenzie and Saskatchewan River Basins in *** network operates a set of 14 unique and focused Water,Ecosystem,Cryosphere and Climate(WECC)observatories within this region,which provide opportunities to observe and understand processes and their interaction,as well as develop and test numerical simulation models,and provide validation data for remote sensing *** paper describes this network and its observational,experimental,and modelling *** overview of many of the recent Earth system changes observed across the study region is provided,and some local insights from WECC observatories that may partly explain regional patterns and trends are *** of the model products being developed are discussed,and linkages with the local to international user community are reviewed—In particular,the use of WECC data towards model and remote sensing product calibration and validation is *** future activities and prospects for the network are also presented at the end of the paper.

关键词： climate change cryosphere hydrology atmospheric science ecology modelling Canada

Tornado effects on damage,resprouting and spatial heterogeneity in the Cross Timbers ecotone of Oklahoma,USA

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Journal of Plant Ecology 2010年第3期3卷 157-163页

作者： randall W.myster michael P.malahy Biology Department Oklahoma State UniversityOklahoma CityOK 73107USA Botany Department Oklahoma State UniversityStillwaterOK 74078USA

Aims In order to better understand how tornados structure the ecotone between eastern deciduous forest and tallgrass prairie,we sampled trees in a recent tornado blowdown area and in the adjacent undisturbed *** are part of the Cross Timbers ecotone of Osage County,Northeastern Oklahoma,*** We set up a 1-ha square plot in each area and sampled all tree stems at least 50 cm tall where stems were identified to species and measured for size and spatial location in both *** the stems in the blowdown plot,we also scored damage and *** then used the spatial location data to compute the spatial heterogeneity and degree of clumping in both *** Findings Significant clumping was observed in the control forest at the small spatial scale of 1–8 m and at the medium spatial scale of 30–36 *** blowdown area:showed domination by post oak(Quercus stellata)with small stems,branch damage and stem resprouting above 1 m most common;had no trees that either lost their leaves without branch or stem damage or lived without some sort of resprouting,had a significant negative correlation between damage and resprouting and clumped only at small spatial scales for stems of medium size,for stems with branch damage and for stems that resprouted at or below 1 m *** conclude that in addition to largely eliminating a forest’s spatial heterogeneity,tornados may also structure this ecotone by increasing tree persistence through resprouting。

关键词： eastern deciduous forest landscape patches O-ring analysis post oak tallgrass prairie

Synchronous colorectal liver metastases:therapeutic considerations

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Hepatobiliary Surgery and Nutrition 2021年第5期10卷 711-713页

作者： michael R.Driedger sean P.Cleary David m.Nagorney Division of Hepatobiliary and Pancreatic Surgery Atrium HealthCharlotteNCUSA Division of Hepatobiliary and Pancreatic Surgery Mayo ClinicRochesterMNUSA

more than 50%of patients will develop colorectal cancer(CRC)liver metastases(CRCLm)during the course of their disease,while 15-25%of patients will have metastatic disease present at the time of initial *** of CRCLm is possible in approximately one-in-four patients and 5-year overall survival(OS)rates have improved to nearly 60%in selected patients who undergo resection.

关键词： colorectal metastases patients

management of stage Ⅳ rectal cancer: Palliative options

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World Journal of Gastroenterology 2011年第7期17卷 835-847页

作者： sean m Ronnekleiv-Kelly Gregory D Kennedy Department of Surgery Section of Colon and Rectal Surgery University of Wisconsin School of Medicine and Public Health 600 HighlandAvenue G4/701A CSC Madison WI 53792 United States

Approximately 30% of patients with rectal cancer present with metastatic disease. many of these patients have symptoms of bleeding or obstruction. Several treatment options are available to deal with the various complications that may afflict these patients. Endorectal stenting, laser ablation, and operative resection are a few of the options available to the patient with a malignant large bowel obstruction. A thorough understanding of treatment options will ensure the patient is offered the most effective therapy with the least amount of associated morbidity. In this review, we describe various options for palliation of symptoms in patients with metastatic rectal cancer. Additionally, we briefly discuss treatment for asymptomatic patients with metastatic disease.

关键词： Palliative therapy Rectal cancer malignant bleeding malignant obstruction Endorectal stenting Laser ablation