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Prediction of dispersed phase holdup in pulsed disc and doughnut solvent extraction columns under different mass transfer conditions

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Chinese Journal of Chemical Engineering 2016年第2期24卷 226-231页

作者： Yong wang Kathryn H.smith Kathryn Mumford Teobaldo F.Grabin Zheng Li Geoffrey w.Stevens Particulate Fluids Processing Centre Department of Chemical and Biomolecular EngineeringThe University of Melbourne

Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla- tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns （PDDC） have been used for a range of important applications such as ura- nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis- persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland lind. Eng. Chem. Res.,27 （1988）,131-138] which did not consider the effect of col- umn geometry. In order to incorporate the characteristic length of the PDDC （i.e. the plate spacing）, the unified cor- relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 （1995） 3925-3940] was refitted to the PDDC data. New constants have been presented for each hold- up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of onerating conditions and nhwical nronerties and consider the direction of mass transfer.

关键词： Solvent extraction Liquid extraction Pulsed disc and doughnut columns Solvent extraction column design Holdup Dispersed phase holdup Hydrodynamics of extraction columns

Real-Time Mesoscale Forecast Support During the CLAMS Field Campaign

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Advances in Atmospheric Sciences 2007年第4期24卷 599-605页

作者：王东海 P. MINNIS T. P. CHARLOCK D. K. ZHOU F. G. ROSE w. L. smith w. L. smith Jr L. NGUYEN State Key Laboratory of Severe weather Chinese Academy of Meteorological Sciences Beijing 100081 Center for Atmospheric Sciences Hampton University Hampton Virginia Langley Research Center National Aeronautics and Space Administration Hampton Virginia Analytical Services ＆ Materials Inc. Hampton Virginia

This paper reports the use of a specialized, mesoscale, numerical weather prediction （NwP） system and a satellite imaging and prediction system that were set up to support the CLAMS （Chesapeake Lighthouse and Aircraft Measurements for Satellites） field campaign during the summer of 2001. The primary objective of CLAMS was to validate satellite-based retrievals of aerosol properties and vertical profiles of the radiative flux, temperature and water vapor. Six research aircraft were deployed to make detailed coincident measurements of the atmosphere and ocean surface with the research satellites that orbited overhead. The mesoscale weather modeling system runs in real-time to provide high spatial and temporal resolution for forecasts that are delivered via the world wide web along with a variety of satellite imagery and satellite location predictions. This system is a multi-purpose modeling system capable of both data analysis/assimilation and multi-scale NwP ranging from cloud-scale to larger than regional scale. This is a three-dimensional, non-hydrostatic compressible model in a terrain-following coordinate. The model employs advanced numerical techniques and contains detailed interactive physical processes. The utility of the forecasting system is illustrated throughout the discussion on the impact of the surface-wind forecast on BRDF （Bidirectional Reflectance Distribution Function） and the description of the cloud/moisture forecast versus the aircraft measurement.

关键词： CLAMS field campaign mesoscale numerical weather prediction forecast support

Inherent Complexities of a Multi-stakeholder Approach to Building Community Resilience

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International Journal of Disaster Risk Science 2020年第1期11卷 32-45页

作者： Josephine Adekola Denis Fischabcher-smith Moira Fischabcher-smith Finance Accounting and RiskGlasgow Caledonian UniversityGlasgow G40BAScotlandUK College of Social Sciences University of GlasgowGlasgow G128QQScotlandUK

Enhancing community resilience has increasingly involved national and regional governments adopting a multi-stakeholder approach because of the potential interagency benefits. This has led to questions about how best to involve stakeholder groups in translating community resilience policies into practice. This exploratory study contributes to this discussion by addressing two key areas that are fundamental in the concerted effort to build community resilience to natural hazards:(1) stakeholder understanding of community resilience as a concept;and(2) the difficulties associated with the processes of risk assessment and preparedness that stakeholders face locally in building community resilience. Data were collected through semistructured interviews with 25 practitioners and experts within Scotland’s resilience community, and were analyzed through an inductive approach to thematic analysis. These data show how the interpretation of community resilience differs across stakeholder groups. Analysis of the data reveals challenges around the nature of the risk assessment and its role in shaping risk perception and communication. Significant complications occur in communicating about low probability-high consequence events, perceived territoriality, competing risk prioritizations, and the challenges of managing hazards within a context of limited resources. The implications of these issues for policy and practice are also discussed.

关键词： Community disaster preparedness Community resilience Multi-stakeholder approach Natural hazards Risk assessment

Novel Heat Transfer Issues Associated with the Design and Safe Operation of the MEGAPIE Spallation Source Target

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Journal of Thermal Science 2007年第1期16卷 63-78页

作者： Brian L.smith Thermal Hydraulics Laboratory Paul Scherrer InstituteSwitzerland

Critical heat transfer problems are discussed in the context of the operation of a spallation source target, which represents a first demonstration of the feasibility of an innovative concept for generating energy using a particle accelerator. within the framework of the umbrella project MEGAPIE, an R＆D support group was organized to take responsibility for target cooling. This involved the use of advanced numerical methods - Computational Fluid Dynamics （CFD） and Finite Element Method （FEM） - validated against suitable experimental data, and by means of appropriate benchmarking exercises. The design studies using CFD resulted in an optimum flow configuration being defined for the coolant circulation. Flow visualization tests were undertaken using a glass/water test section, with the velocity field mapped using optical and ultrasonic measuring techniques. These were followed by heat transfer tests, using the actual target materials （lead-bismuth-eutectic coolant and steel confinement）. Further CFD/FEM work to analyze operational transients and accident sequences was also carded out, and is described in the paper.

关键词： computational fluid dynamics finite element method liquid-metal coolant spallation source target

The Analysis of Zirconium (Ⅳ) Oxide (ZrO_(2)) Nanoparticles for Peroxidase Activity

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Journal of Analysis and Testing 2019年第3期3卷 246-252页

作者： Christopher w.smith Yu-Sheng Chen Nidhi Nandu Mahera Kachwala Mehmet V.Yigit Department of Chemistry University at AlbanyState University of New York1400 Washington AvenueAlbanyNY 12222USA The RNA Institute University at AlbanyState University of New York1400 Washington AvenueAlbanyNY 12222USA

In this study,the peroxidase-like activity of zirconium(Ⅳ)oxide nanoparticles(nZr)is *** catalyze the oxidation of their substrate in the presence of peroxide species.3,3′,5,5′-tetramethylbenzidine(TMB)is a peroxidase substrate,and we have demonstrated that nZr oxidizes the TMB in the presence of hydrogen peroxide resulting in a colored(TMBox)*** reaction was tested in various buffers,and sodium acetate with pH 4 was observed to be an ideal buffer for the enzymatic reaction and the dispersity of the nZr in the *** nanozyme behavior was studied systematically at three different temperatures(25,35 and 45℃)and a wide range of H_(2)O_(2) *** dependence of the enzymatic reaction on temperature,nZr content and H_(2)O_(2) concentration was *** enzymatic reaction was tested in different protein solutions and no noticeable interference was observed with these ***,we demonstrate that nZr,which is often used for industrial applications,mimics peroxidase enzyme and catalyzes oxidation of its substrate in the presence of peroxide species.

关键词： Artificial enzyme Nanozyme Peroxidase Sensor Zirconium(Ⅳ)oxide(ZrO_(2))

A machine learning enabled hybrid optimization framework for efficient coarse-graining of a model polymer

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npj Computational Materials 2022年第1期8卷 2128-2138页

作者： Zakiya Shireen Hansani weeratunge Adrian Menzel Andrew w.Phillips Ronald G.Larson Kate smith-Miles Elnaz Hajizadeh Department of Mechanical Engineering Faculty of Engineering and Information TechnologyThe University of MelbourneMelbourneAustralia Platforms Division Defence Science and Technology GroupMelbourneAustralia Department of Chemical Engineering University of MichiganAnn ArborMIUSA School of Mathematics and Statistics The University of MelbourneMelbourneAustralia

This work presents a framework governing the development of an efficient,accurate,and transferable coarse-grained(CG)model of a polyether *** framework combines bottom-up and top-down approaches of coarse-grained model parameters by integrating machine learning(ML)with optimization *** the bottom-up approach,bonded interactions of the CG model are optimized using deep neural networks(DNN),where atomistic bonded distributions are *** the top-down approach,optimization of nonbonded parameters is accomplished by reproducing the temperature-dependent experimental *** demonstrate that developed framework addresses the thermodynamic consistency and transferability issues associated with the classical coarse-graining *** efficiency and transferability of the CG model is demonstrated through accurate predictions of chain statistics,the limiting behavior of the glass transition temperature,diffusion,and stress relaxation,where none were included in the parametrization *** accuracy of the predicted properties are evaluated in context of molecular theories and available experimental data.

关键词： optimization grain integrating

Carbon dioxide capture by solvent absorption using amino acids: A review

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Chinese Journal of Chemical Engineering 2018年第11期26卷 2229-2237页

作者： Guoping Hu Kathryn H.smith Yue wu Kathryn A.Mumford Sandra E.Kentish Geoffrey w.Stevens Peter Cook Centre for Carbon Capture and Storage Research (PCC) Particulate Fluids Processing Centre (PFPC)Department of Chemical EngineeringThe University of Melbourne

The emission of large amounts of carbon dioxide is of major concern with regard to increasing the risk of climate change. Carbon capture, utilisation and storage (CCUS) has been proposed as an important pathway for slowing the rate of these emissions. Solvent absorption of CO_2 using amino acid solvents has drawn much attention over the last few years due to advantages including their ionic nature, low evaporation rate, low toxicity, high absorption rate and high biodegradation potential, compared to traditional amine solvents. In this review, recent progress on the absorption kinetics of amino acids is summarised, and the engineering potential of using amino acids as carbon capture solvents is discussed. The reaction orders between amino acids and carbon dioxide are typ- ically between 1 and 2. Glycine exhibits a reaction order of 1, whilst, by comparison, lysine, proline and sarcosine have the largest reaction constants with carbon dioxide which is much larger than that of the benchmark solvent monoethanolamine (MEA). Ionic strength, p H and cations such as sodium and potassium have been shown to be important factors influencing the reactivity of amino acids. Corrosivity and reactivity with impurities such as SOx and NOxare not considered to be significant problems for amino acids solvents. The precipitation of CO_2 loaded amino acid salts is thought to be a good pathway for increasing CO_2loading capacity and cutting desorption energy costs if well-controlled. It is recommended that more detailed research on amino acid degradation and overall process energy costs is conducted. Overall, amino acid solvents are recognised as promising potential solvents for car- bon dioxide capture.

关键词： Amino acids Carbon capture Absorption Solvents

Evolving carbon dioxide emission rate intensities of coal-fired power plant on U.S. electricity operating systems

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Journal of Modern Power Systems and Clean Energy 2018年第6期6卷 1103-1112页

作者： Robert Kennedy smith U.S. Department of Energy Office of Fossil Energy

For many years, coal-fired power plant generation comprised the largest share of electricity in the *** sector. while natural gas plants now constitute a greater portion of the total, coal is projected to remain a shrinking but significant component of U.S. electricity production. Natural gas-fired technologies are dispatchable and versatile generation sources, but the recent and anticipated growth of wind and solar technologies will add nondispatchable, intermittent power generation sources to *** grids. Numerous emissions-related benefits arise from the deployment of these technologies, but they must coexist with coal plants, many of which run most efficiently under baseload operating procedures. Historical monthly emissions data has been analyzed on a sample of coal plants to show how modified coal operations have affected plant emission rates, as measured by carbon dioxide emitted per unit of electricity output. Statistically significant correlations between plant capacity factors and emission rate intensity have been observed by the majority of the sample, showing a worsening under more sporadic operations. Since nearly all of the coal plants in the sample are generating less electricity, determining the emission impact of operational decisions will assist policymakers as they seek to minimize total system emissions without severe disruptions to electricity cost and service reliability.

关键词： Coal Emission intensity Renewable generation Baseload power generation

Response of saproxylic insect communities to logging history, tree species, stage of decay, and wood posture in the central Nearctic boreal forest

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Journal of Forestry Research 2018年第5期29卷 1365-1377页

作者： R.w.James Dennis Jay R.Malcolm Sandy M.smith M.Isabel Bellocq Faculty of Forestry University of Toronto 33 Willcocks St.Toronto ON M5S 3B3 Canada Departamento de Ecología Genética y EvoluciónFacultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires and IEGEBA (CONICET)Buenos Aires Argentina

Saproxylic insect assemblages are essential functional components of forest ecosystems that can be affected by forest *** used a split-plot ANOVA design to analyze differences in selected saproxylic insects（all arthropod orders and dipteran and parasitic hymenopteran families） emerging from dead wood of sites with different logging histories（horse-logged,mechanically-logged and unlogged）,tree species（Populus and Picea）,stage of decay（early-and late-decay stages） and posture（standing and downed logs） in the boreal forest of central *** clear effects of logging history were seen for the studied taxa; however,interaction between logging history and other dead wood features was *** consistently emerged more from Populus than from Picea dead *** of the studied saproxylic families were more abundant in late-decay than in early-decay *** of the Cecidomyiidae,Ceratopogonidae,Empididae,Mycetophilidae and Sciaridae families,and hymenopterans of the Diapriidae and Ichneumonidae families were significantly more abundant in downed than in standing dead *** contrast,Mymaridae was most abundant in standing dead *** study provides evidence that some insects at high taxonomic levels respond differently to dead wood quality,and this could inform future management strategies in the boreal forest for the conservation of saproxylic fauna and their ecological functions.

关键词： Boreal forest Dead wood quality Forest harvesting High-level taxa Saproxylic insects