bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modélisation de la cinétique morphologique en corrosion générale et en corrosion localisée
Authors: Santarini Gérard 
Published: March 2009

AbstractDeux méthodes théoriques d'étude de l'évolution de la forme des interfaces sont présentées. La première permet de relier les différents types d'évolution morphologique globale (aplanissement et augmentation de rugosité) et les intensités des forces motrices de ces évolutions à la nature des processus physico‐chimiques qui se déroulent à l'interface et à son voisinage. La deuxième méthode concerne la caractérisation quantitative des évolutions morphologiques locales, plus particulièrement en corrosion sous contrainte. Elle permet la détermination, à partir des informations morphologiques portées par des éprouvettes, des cinétiques d'amorçage et de propagation des fissures.
The kinetics of carbochlorination of titania slag
Authors: Sohn Hong Yong , Zhou Ling 
Published: March 2009

AbstractThe kinetics of the carbochlorination of titania slag with chlorine gas and petroleum coke were determined. The porosity created, when easily chlorinated components of the slag such as iron oxide are rapidly reacted, had a significant effect on the chlorination of the slag. The effects of temperature, chlorine partial pressure, and initial particle size were determined, and a rate equation that incorporates these effects in the ranges of experimental conditions used in this work was developed. The results of this work show that the chlorination kinetics of titania slag are quite different from those of rutile with which most previous studies were concerned.
The ignition temperature of lignite char in a fluidized bed combustor
Authors: Van Puyvelde Dennis , Stubington John 
Published: March 2009

AbstractThis paper summarises the experimental and modelling work carried out for the variation of bed ignition temperature of a fluidized bed combustor with the char particle diameter and the fluidizing velocity. A lignite char was used and its reactivity was represented using data from Field (1967) and Turnbull and Davidson (1984). The modelling involved solving the steady state heat balance around the fluidized bed combustor at the ignition temperature. A correlation of the total area of char ignited per unit bed mass was determined as a function of the char particle diameter and the fluidizing velocity. This correlation was used to determine the ignition temperature of the fluidized bed combustor operating at different conditions. The fluidized bed combustor heat balance was then solved for the bed ignition temperature which was influenced by both the rate of heat loss from the bed and the reactivity of the char. A sensitivity analysis suggests that the chemical rate reaction coefficient is the most prominent variable when determining the ignition temperature of a fluidized bed combustor.
Inlet plenum pressure drop calculation for a cross‐flow module
Authors: Darcovich Ken , Toll Floyd N. , Paynot François , PÉlerin Erick 
Published: March 2009

AbstractOutlined here is a method for applying a model of discharge flow through a series of sharp‐edged orifices from an inlet plenum, to accurately predict the total pressure drop across the flow distribution geometry. This particular case relates to a cross‐flow filtration membrane module, but is applicable for any flow distribution system of a similar format.
Modélisation de nanofiltration/osmose inverse en tenant compte du facteur de séparations minimale et maximale
Authors: Xu Yazhen , Lebrun Rémi E. 
Published: March 2009

AbstractBased on theorical analysis of existing models and on experimental observations, a model that allows us to connect the permeate flux tothe intrinsic separation factor takingaccount of the termsof the minimal and maximalseparation factors, was established. The experiments covering a large range of permeate flux (from several 10−9 μL/m 2.s) to several 10.3 mL/(m 2.s)) permit us todetermine the values of maximal seaparation and minimal separation, as well as the solute transport parameterr for the solutions of sodiumchloride and sodium sulfate.
Mass transfer modeling during cross‐flow filtration of non‐newtonian fluids
Authors: Carrère Héléne , René Frédéric , Lorizzo Antonio 
Published: March 2009

AbstractThe film theory was used to determine the mass transfer coefficient for the cross‐flow filtration of guar gum solutions. We investigated their variation with cross‐flow velocity and concentration. Comparing the experimental results with the Sherwood correlation generalized for power law fluids and with two models found in the literature led to the evaluation of an effective diffusion coefficient for each model. This parameter was shown to depend on cross‐flow velocity and concentration.
Decrement estimation of the heat transfer coefficient in mixture boiling
Authors: Gu Junjie , Bartf Hans‐jörg 
Published: March 2009

AbstractBased on the analysis of the principles of heat and mass transfer from the liquid bulk to bubble surface during nucleation, a new theoretical method to predict the heat transfer of the nucleate pool boiling in binary mixtures is proposed in this paper by using the heat and mass transfer analogy (Colburn analogy) at the bubble surface transfer layers. With use of Thome's concept of boiling range, an approximate method is derived to realize the calculation. The predicted results by this method are in good agreement with the experimental data from different sources. This hypothesis can also be applied to electrolyte solutions. This method is restricted to developed boiling cases, fortunately, which occur in most industrial applications.
Radial liquid velocity distribution in an external‐loop airlift column with a tapered riser
Authors: Wagoe Mikio Ka , Yoshida Shohei , Ishii Yukimasa , Naoe Kazvmitsu 
Published: March 2009

AbstractRadial and axial liquid velocity distributions in the tapered riser were investigated theoretically and experimentally. The liquid velocity distributions were computed by solving the Navier‐Stokes equation numerically based on a modified mixing‐length theory. Both radial and axial components of liquid velocity were taken into account. As a result, we found that the radial velocity component was much smaller than the axial velocity component. For a cylindrical column, which means no tapered section, a simplified solution was obtained. The simplified solution was found to agree well with the rigorous numerical solution even in the tapered riser. To confirm the validity of the present hydrodynamic model, the velocity distributions in the tapered riser were measured by an electric probe method using KCl solution as a tracer. The measured velocity distributions agreed with the computed ones, except in the vicinity of the bottom of the tapered riser at high gas flow rates.
The effect of a perfluorochemical emulsion on enzyme reaction stability
Authors: Warrington James C. , Savillex Bradley A. 
Published: March 2009

AbstractA reaction system consisting of (oxygen‐consuming) tyrosinase immersed within a perfluorochemical emulsion was investigated by comparing the activity and stability of the enzyme within the emulsion to that within pure buffer. The perfluorochemical emulsion contained 30 v/v% perfluorooctane, 70 v/v% aqueous buffer and pluronic‐F68 as a surfactant. The catecholase activity of soluble mushroom tyrosinase was chosen for study and catechol was used as a substrate. A turnover parameter of 0.50 absorbance units and an inactivation rate constant of 0.012 s−1 were found in the presence of a perfluorochemical emulsion and a turnover parameter of 0.53 absorbance units and an inactivation rate constant of 0.012 s−1 were found in the absence of perfluorochemicals (pure buffer). The enzyme demonstrated no appreciable loss in performance within the perfluorochemical emulsion relative to its behaviour within aqueous buffer. This implies that the local concentrations of oxygen are the same under both systems and that under conditions when oxygen is limited in an aqueous system, tyrosinase performance would be improved within the perfluorochemical medium.
Processing efficiency of immobilized non‐growing bacteria: Biocatalytic modeling and experimental analysis
Authors: Kim Jin‐Woo , Engler Cady R. , Wild James R. , Rainina Evguenia I. 
Published: March 2009

AbstractModeling methods used to optimize the biocatalytic efficiency of freely suspended cells have been applied to non‐growing microbial cells entrapped within a macro‐porous carrier. The catalytic rate, which is dependent on cell concentration inside the biocatalyst beads, coincided with catalytic parameters for freely suspended cells. Immobilized non‐growing cell systems could be optimized utilizing the characteristics of freely suspended cells without requiring extensive experimentation to define catalytic behaviour inside the biocatalyst. A dynamic diffusion–reaction model was developed and validated using experimental data for thiodiglycol degradation by Alcaligenes xylosoxidans subsp. xylosoxidans immobilized within macro‐porous poly(vinyl alcohol) cryogel in a completely mixed batch bioreactor.
Design and experimental study of immobilized soil bioreactor for in‐well biodegradation of pentach rophenol in groundwater
Authors: Karamanev Dimitre G. , Ramsay Bruce A. , Hassan Marie‐Claire 
Published: March 2009

AbstractA novel system for in‐situ biological treatment of pentachlorophenol in groundwater is proposed in this work. It is based on the concept of soil immobilization, which has already been shown to be very efficient when applied to bioreactor engineering. For this paper, we used immobilized soil to develop a bioreactor system for an in‐situ (in‐well) biodegradation of pentachlorophenol (PCP). The process was carried out at 9dGC, a temperature typical for groundwater. The volumetric PCP degradation efficiency in the new system was very high – up to 400 mg/(L.h). The effect of some physicochemical parameters (temperature, substrate concentration) on the biodegradation kinetics was studied. The results obtained show that the application of soil immobilization to the in‐situ biodegradation of groundwater contaminated with PCP is very promising.
The potential of L‐form bacteria in biotechnology
Authors: Grichko Varvara P. , Glick Bernard R. 
Published: March 2009

AbstractL‐form bacteria include both stable and unstable cell wall‐less variants of native walled bacteria. These organisms have been implicated as etiologic agents in both plant and animal diseases. L‐form bacteria may also be used to protect plants or animals against disease‐causing organisms, or to act as a host bacterium for the production and secretion to the growth medium of recombinant proteins. This article summarizes the fundamental biology of these unusual bacteria and discusses their potential uses.
Liquid wall friction in two‐phase turbulent gas laminar liquid stratified pipe flow
Authors: Biberg Dag 
Published: March 2009

AbstractThe main result of the present work is an analytic expression for the mean liquid wall shear stress in two‐phase turbulent gas/laminar liquid stratified pipe flow. The Navier‐Stokes equations are solved assuming a flat fluid‐fluid interface subject to a constant interfacial shear — approximating the interfacial drag exerted by the gas. The effect of a pipe inclination is accounted for, thereby retaining the interesting two‐phase phenomenon of backflow in upwardly inclined pipes. The corresponding expression for the wall shear stress distribution is obtained by formal differentiation. Its limiting behaviour in the triple points, where the fluid‐fluid interface meets the pipe wall, is determined by residue calculus. The expression for the mean wall shear stress is given by integration. It is found to be a linear combination of two terms. The first term accounts for the free surface liquid flow in the absence of the gas. The corresponding approximate hydraulic diameter model is found to be in surprisingly good agreement with this term. The second term represents the shear flow associated with the interfacial drag exerted by the gas (not accounted for by the hydraulic diameter approximation). The shear flow increases the flow rate near the interface on behalf of the flow rate near the pipe wall, thus reducing the wall shear stress below the free surface flow value. Expedient evaluation of the expression for the mean wall shear stress, suitable for use in a 1‐D multiphase pipe flow simulator, is facilitated by replacing certain one‐parameter integrals with highly accurate rational approximations.
Kinetic study of reaction of hexachlorocyclophosphazene with phenol by triphase catalysis
Authors: Wu Ho‐Shing , Meng Shang‐Shin 
Published: March 2009

AbstractThe kinetics of the substitution reaction of hexachlorocyclotriphosphazene, (NPCl2)3, with phenol to synthesize the partially substituted (phenoxy) chlorocyclotriphosphazene was investigated by using triphase catalysis in an organic phase/alkaline solution. The relative reaction‐rate constants and the corresponding energies, enthalpies, and entropies of activation of the sequential substitution were also estimated. The diffusional limitations involve both ion diffusion in the aqueous phase and organic reactant diffusion in the organic phase within the catalyst pellet. The particle diffusion and intrinsic reactivity limit the substitution reaction in the organic phase. The diffusion of the aqueous phase in the ion‐exchange step is the main rate‐limiting factor.
Parameters of the epoxidation of 1‐octene by t‐butyl hydroperoxide
Authors: Lewandowski Grzegorz , Milchert Eugeniusz 
Published: March 2009

AbstractThe epoxidation of 1‐octene with t‐butyl hydroperoxide in the presence of Mo(CO)6 has been studied. The influence of the crucial parameters on the yield of 1,2‐epoxyoctane in relation to hydroperoxide, on the hydroperoxide conversion, on the selectivity of the transformation of 1‐octene to epoxy compound and on the yield of 1,2‐epoxyoctane in relation to 1‐octene has been described by the use of regression functions in the form of a second order polynomial. The optimal values of parameters: reaction time, temperature, olefin to hydroperoxide mol ratio, Mo(CO)6 to hydroperoxide mol ratio, ensuring the maximum values of these functions have been determined.
Electrodialysis for bleach effluent recycling in kraft pulp production: Simultaneous control of chloride and other non‐process elements
Authors: Pfromm Peter H. , Tsai Shih‐Perng , Henry Michael P. 
Published: March 2009

AbstractIn the United States, more than 50 million tons of kraft pulp are produced per year. A strong effort by kraft pulp producers has been under way for several years to reduce water use. The in‐process recycling of the acidic bleach effluent carrying metals, transition metals, calcium, and often large amounts of chloride is still a significant challenge. The simultaneous selective removal of chloride, and detrimental cations from the acidic bleach effluent of bleached kraft pulp mills by electrodialysis was investigated. The laboratory results with actual effluents show that very good removal levels can be achieved in an economical process. The chloride removal from acidic bleach effluent will aid significantly in keeping chloride levels acceptable in the recovery cycle.
Suspension of solid particles in multi‐impeller three‐phase stirred tank reactors
Authors: Dohi Naoki , Matsuda Yukimasa , Itano Norihiro , Minekawa Kimio , Takahashi Takanori , Kawase Yoshinori 
Published: March 2009

AbstractSolids suspension characteristics in gas—liquid–solid three‐phase stirred tanks with multi‐impellers were experimentally examined. Minimum impeller speeds for ultimately homogeneous solid suspension have been measured stirred tank reactors. Three impellers were installed: two four‐pitched blade downflow disk turbines and one Pfaudler type impeller chosen to provide good gas dispersion and to accomplish off‐bottom suspension of solid particles, respectively. Gas dispersion causes an increase in particle sedimentation associated with a decrease in power consumption and as a result, minimum impeller speeds for ultimately homogeneous solid suspension increase with increasing gas flow rates. A correlation was developed to predict minimum impeller speeds for ultimately homogeneous solid suspension. The proposed correlation, which agrees satisfactorily with the experimental results, is expected to be useful in design and scale‐up.
Effect of gravity forces on oil recovery in a Hele‐Shaw cell
Authors: Camirand Martin , Jahoda Milan , Hornof Vladimir 
Published: March 2009

AbstractThe effect of gravity on oil recovery was studied in a Hele‐Shaw cell. An immiscible two fluid system consisting of light paraffin oil as the displaced phase and distilled water as the displacing phase was used. Oil recovery at breakthrough was found to be almost linearly dependent on the Bond number. Maximum recovery was obtained in the case of upward flooding with the cell positioned vertically. The minimum oil recovery occurred when flooding was performed in the downward direction with the cell also placed in the vertical position. The recovery results obtained for the experiments carried out at a 45 degree incline and in the horizontal position were situated between these extremes.
Coronary Sarcoidosis Presenting as Acute Coronary Syndrome
Authors: Lam Carolyn S. P. , Tolep Kenneth A. , Metke Michael P. , Glockner James , Cooper Leslie T. 
Published: March 2009

AbstractSarcoidosis is a systemic disorder of uncertain etiology characterized by noncaseating granulomatous inflammation. The disease often involves the heart on autopsy, but the antemortem diagnosis of cardiac sarcoidosis is frequently missed. Cardiac involvement usually includes granulomatous inflammation or fibrosis of the myocardium, conduction system, or pericardium. We now describe a case of epicardial coronary involvement by sarcoidosis, where the diagnosis was made by surgical biopsy of the coronary artery in an African American man presenting with acute coronary syndrome and recurrent symptomatic restenosis following coronary intervention. The case extends the spectrum of common cardiac syndromes that cardiac sarcoidosis can masquerade as and highlights the importance of maintaining a high index of suspicion for early recognition and instituting specific treatment that might improve prognosis. A review of the literature also suggests the need for improvement in diagnostic approaches and prospective clinical trials to establish the best management strategy for this disease. Copyright © 2009 Wiley Periodicals, Inc.
Strategic corporate environmental management within the South African automotive industry: motivations, benefits, hurdles
Authors: Kehbila Anderson Gwanyebit , Ertel Jürgen , Brent Alan Colin 
Published: March 2009

AbstractThis paper conveys the experiences of the South African automotive industry as it attempted to implement the ISO 14001 standard. Through a questionnaire‐based survey, small and medium‐sized enterprises (SMEs) as well as larger companies were asked about the key motivations for engaging in environmental change, the benefits accrued and the barriers that prevented them from doing so. This paper analyzes the variation in adoption rates in order to establish different relationships between them. The results reveal substantial differences and some similarities with regard to the hurdles, benefits and motivations behind the implementation of environmental management systems (EMSs) that are hidden behind corporate rhetoric and commitment to sustainability. This paper concludes by prescribing robust recommendations that would set off the pace for government officials to incorporate effective and realistic incentives into future policy to better encourage environmental compliance and improved performance while minimizing costs both to businesses and to the Government. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Effects of caffeine in chewing gum on mood and attention
Authors: Smith Andrew 
Published: March 2009

AbstractRationaleRecent research has shown that even small doses (<40mg) of caffeine can improve alertness and increase performance efficiency on attention tasks. Previous studies have given the caffeine in a variety of beverages or in capsules and it was of interest to see whether similar effects could be observed when the caffeine was given in gum. In addition, chewing gum has been shown to have behavioural effects and the present study extended our knowledge of this topic.ObjectivesTo compare the effects of caffeinated gum (40 mg), placebo gum and no gum conditions on mood and attention.MethodsA double blind placebo controlled study was conducted with volunteers being randomly assigned to one of the three conditions. Baseline measures of mood and attention were taken prior to chewing and a test session was then conducted. One hundred and eighteen young adults participated in the study.ResultsCaffeinated gum was associated with a more positive mood and better performance on tasks requiring sustained attention. The caffeine improved the speed of encoding of new information which is consistent with previous findings. Chewing placebo gum was also found to be associated with more positive mood, both shortly after chewing and at the end of the study.ConclusionsThe implications of the present study are that chewing caffeinated gum has been shown to improve performance efficiency and mood by its alerting and energising effects. The profile of caffeine effects is what one would predict from the existing caffeine literature and such effects may be extremely beneficial in real‐life situations. Prior chewing of placebo gum was associated with a more positive mood and this also confirms previous findings. Copyright © 2009 John Wiley & Sons, Ltd.
Development of a fungal pre‐treatment process for reduction of organic matter in contaminated soil
Authors: Winquist Erika , Valentin Lara , Moilanen Ulla , Leisola Matti , Hatakka Annele , Tuomela Marja , Steffen Kari T. 
Published: March 2009

AbstractBACKGROUND:Combustion at high temperature is a common treatment method for heavily contaminated soils. The capacity of the combustion process is negatively correlated with organic matter content of the soil. Thus, by reducing the amount of soil organic matter, batch size could be increased and the combustion process improved. In this study, the possibility to pre‐treat soil containing high levels of organic matter with white‐rot and litter‐decomposing fungi was examined and scaled up.RESULTS:Calculations based on the CO2production in laboratory experiments indicated that 20% of the soil organic carbon would have been degraded in 6 months when treated withSphaerobolus stellatusand 10% when treated withStropharia rugosoannulata. In a pilot‐scale experiment withS. rugosoannulatamass loss due to degradation of soil organic matter accounted for 10% of the total weight of the soil in 6 months.CONCLUSION:A fungal pre‐treatment process for contaminated soils with high organic matter content was developed. Good results were obtained withS. stellatusandS. rugosoannulataand the process was successfully scaled up to 300 kg scale. Copyright © 2009 Society of Chemical Industry
Effect of Topology on the Properties of Poly(N‐isopropylacrylamide) in Water and in Bulk
Authors: Qiu Xing‐Ping , Winnik Françoise M. 
Published: March 2009

AbstractThree macrocyclic poly(N‐isopropylacrylamide)s (PNIPAM) with molecular weight (MW) ranging from 6 to 19 kg/mol were synthesized by ‘click’ ring closure of the corresponding α‐azido ω‐propargyl telechelic linear PNIPAMs, themselves prepared by reversible addition fragmentation chain transfer (RAFT) polymerization of N‐isopropylacrylamide. Differential scanning calorimetry (DSC) studies revealed that both the thermal phase separation in water and the glass transition in bulk of PNIPAM were affected by polymer topology. In aqueous solution, the cyclic polymers exhibit a higher phase separation temperature and broader phase transition range than the corresponding linear counterparts. In bulk, the cyclic polymers display a higher glass transition temperature of lesser molecular weight dependence, as compared to their linear precursors.