bluuebunny/crossref_metadata_2025_split huggingface dataset:
Co‐combustion of Municipal Solid Waste and Coal in a Circulating Fluidized Bed
Authors: Dong Changqing , Jin Baosheng , Lan Jixiang 
Published: August 2010

AbstractExperiments on the co‐combustion of municipal solid waste (MSW) and coal were performed in a 0.2 MWth circulating fluidized bed and focused on the emissions of NO, N2O, HCl and SO2. The results show that the addition of MSW leads to lower NO, N2O, and SO2 emissions. However, hydrogen chloride concentrations increase with the amount of waste added. A feedforward neural network model was proposed to predict the variation of NO emission with the mixture composition.
Blood Flow Characteristics in a Femoral Artery Bypass Graft
Authors: Cole J.S. , Watterson J.K. , O'Reilly M.J.G. 
Published: August 2010

AbstractThe development of disease at sites where a bypass graft is attached to an artery is a major cause of graft failure. Localisation of this disease suggests that it may be promoted by the local disturbed flow field.Computational Fluid Dynamics (CFD) simulations of the pulsatile, non‐Newtonian flow of blood through a life‐like femoral artery bypass configuration have been performed in order to further the understanding of bypass flows, and to identify aspects of the flow which encourage the progression of disease. It may then be possible to develop more effective bypass systems.The graft/artery junction flow is characterised by extensive recirculation, flow separation and reversal, complicated flow paths, elevated fluid particle residence times, and an unusual wall shear stress distribution. It is believed that the occurrence of disease is related to high particle residence times and the unnatural shear stresses acting on the artery wall.
A Universal Flow Regime Map for Horizontal Two‐Phase Flow in Pipes
Authors: Spedding P.L. , Cooper R.K. , Mcbride W.J. 
Published: August 2010

AbstractA new universal flow regime map has been developed for two‐phase co‐current pipe flow for the condition that the liquid viscosity μL < 0.02 kg m−1 s−1. The map has been successfully tested against a wide variety of data. Three flow regime transitions suggested by various other workers have been shown to be useful in prediction of regime transitions.Six new models are proposed for certain transitions, namely the smooth stratified to stratified ripple and inertial wave; the stratified ripple to roll wave; the stratified roll wave to film plus droplet; the film plus droplet to annular type flows; the blow through slug to slug; and the slug to bubble flow regime changes.
Effect of Pigment Type and Concentration on the Rheological Properties of Polypropylene
Authors: Marks A.F. , Orr P. , Mcnally G.M. , Murphy W.R. 
Published: August 2010

AbstractThe rheological characteristics of a range of pigmented isotactic polypropylene (iPP) was investigated using dual capillary rheometry techniques, over the temperature range 190d̀C to 230d̀C and shear rate range of s−1 to 800 s−1. The iPP was compounded with pigment masterbatch concentrations ranging from 0.2% to 3.0%, using a 38 mm Killion compounding line. The pigment masterbatches investigated were iron oxide, titanium dioxide and phthalocyanine blue. The rheological data, showed that there were considerable increases in apparent viscosity of pigmented iPP even at relatively low pigment loadings. The increase in apparent viscosity was particularly from the rheological data showed large increases in Ea for pigmented iPP especially at lower shear rates, suggesting crystallization of the iPP melt.
The Effect of Cure Conditions on the Performance of Styrene Butadiene Rubber for Industrial Conveying Applications
Authors: Mcnally G. M. , Clarke J. L. , Small C. M. , Skelton W. J. , Mccall J. 
Published: August 2010

AbstractA range of samples were prepared from a commercial styrene butadiene rubber (SBR), over a range of cure temperatures (140d̀C‐170d̀C) and cure times (30–120 min), using a high temperature moulding press held at a constant pressure of 5000 psi. Mechanical analysis of the various samples showed considerable increase in modulus, shore hardness and break strength with progressive increase in cure temperature, especially at lower cure times. Dynamic frictional analysis under different loadings, of the SBR samples with High Molecular Weight Polyethylene (HMWPE) and 90 Shore A Polyurethane (PU), showed a progressive decrease in frictional force with increase in SBR cure temperature and time. Some reversion of the SBR was shown to occur at higher temperatures and longer cure time
Urea From Underground Coal Gas
Authors: Williamson C.J. 
Published: August 2010

AbstractNew Zealand has a dwindling supply of natural gas currently used as both a petrochemical feedstock and as a fuel for thermal power stations. However, the country has large reserves of coal, much of it at depths that make it difficult to mine using conventional methods. It is possible to gasify the coal underground and produce a gaseous mixture of hydrogen, carbon dioxide, carbon monoxide and water that can be used as a replacement for natural gas as a feedstock or fuel. This paper describes a design study on the production of urea from underground coal gas in New Zealand.
Agglomeration of Fine‐Grained Petroleum Coke
Authors: Aly I.H.M. , Magdy Y.H. , Barakat N.A.M. , Madany A.B. 
Published: August 2010

AbstractFine‐grained petroleum coke cannot be used for industrial purposes, therefore pelletizing of fine petroleum coke (less than 200 μm) was achieved with addition of bentonite as inorganic binder. The effect of moisture content, inclination angle, residence time and bentonite percent on the crushing strength, as well as the average diameters produced were studied. From the experimental results obtained it was found that the optium working conditions were: inclination angle of 60d̀, moisture content of 32.5%, and residence time of 15 minutes. Several mathematical models were created using the experimental results. They were developed as two computer programs to calculate the crushing strength and the average pellet diameter of the produced pellets when bentonite was as binder. The validity of these programs was examined and acceptable results were obtained.
Deformation and Disintegration Behaviour of Single Water Drops in an Oil Phase in an Electric Field
Authors: Maruyama Morito , Ishii Hiroki , Yamaguchi Manabu 
Published: August 2010

AbstractDeformation and disintegration behavior for single water drops in an oil phase in electric fields were studied experimentally. The experimental degree of deformation of the drops and their maximum degree just before their disintegration agreed approximately with the theoretical value proposed by Taylor. Two types of electrical disintegration for the drops were observed depending on the size of the drops: a small deformed drop was disintegrated by ejecting a series of smaller drops at its sharp pointed ends; while a large drop was elongated as a rod‐like shape and immediately disintegrated into several small drops.
Control of Polymorphism in Crystallization of Amino Acid
Authors: Kitamura Mitsutaka 
Published: August 2010

AbstractThe crystallization mechanism and the controlling factors in the crystallization of amino acid polymorphs were investigated. It was demonstrated that the effect of supersaturation (Ostwald's step rule) was not observed for systems of either L‐Glutamic acid (α, β) or L‐Histidine (A, B). The intensive effect of temperature was shown in the crystallization of L‐Glutamic acid (L‐Glu) polymorphs, however, no temperature effect was observed in the case of L‐Histidine (L‐Hist)polymorphs. It was suggested that such a difference could be related to the difference of the molecular conformation between the polymorphs, and the contribution of the conformers in the solutions to the nucleation process of L‐Glu polymorphs. The growth of both L‐Glu polymorphs (α and β) appeared to be due to the nuclei‐above‐nuclei mechanism. With these results, temperature and supersaturation appeared to be the basic important controlling factors (the primary factors) of polymorphism. Solvents and additives (the secondary factors) also have an influence on polymorphism. The influence of ethanol compositions on the crystallization of L‐His polymorphs (A and B) was observed, and demonstrated that the solvent effect is very kinetic, i.e. the nucleation and growth rate of the A form are suppressed with an increase in the ethanol composition. The effects of L‐Phenylalanine as an additive on the crystallization and transformation rates were shown in batch crystallization. The effect of L‐phenylalanine on the growth rate and morphology of L‐Glu polymorphs was also examined using the single crystal method in a flow system. The relationship between the additive concentration and the growth rate of each polymorph was expressed by the proposed equation. The importance of the kinetics of the crystallization for control of the polymorphic crystallization was demonstrated. The supersaturation needed for control of the selective crystallization of the polymorph was also calculated. From these results the controlling factors for the crystallization of polymorphs have been classified in order to clarify their complex interrelationship.
A Comparative Study of Numerical Methods for Solving Continuous Population Balance Models for Aggregation Processes
Authors: Balliu N.E. , Cameron I.T. , Newell R. 
Published: August 2010

AbstractIn this paper two discretization methods—Hounslow's fixed discretization method and Ramkrishna's adjustable discretization method—will be applied to population balance models in order to compare their performance under various modelling and simulation scenarios. The methods will be tested using an integrated dynamic modelling and simulation system for analysis of particulate processes in the case of agglomeration in a continuous granulation unit where the fresh feed and the recycle have different particle size distributions. In this comparison we will consider the accuracy of the results, the computational time required and the modelling effort.The results show that Hounslow's method is able to give satisfactory predictions for small to medium particle size ranges but the quality of predictions for large size ranges is poor. The method of Kumar and Ramkrishna is slightly more complex than Hounslow 's method but is able to give good predictions for all particle size ranges. Both methods requires similar computational time when a geometrical grid with a size ratio equal to 2 is used while Kumar and Ramkrishna's technique requires more time to be implemented and solved for finer grids.
Catalytic Partial Oxidation of Propylene to Acrolein: The Activity of Bismuth Molybdate Catalysts under Oxygen‐Rich Conditions
Authors: Fansuri H. , Pham G.H. , Wibawanta S. , Radford R.D. , Zhang D.K. 
Published: August 2010

AbstractThe effect of Bi/Mo ratio, which varied between 1:3 and 2:1, on the activity of bismuth molybdate catalysts prepared by precipitation method for partial oxidation of propylene has been investigated. X‐ray diffraction analysis revealed that the catalysts contained a mixture of α‐Bi2Mo3O12 and molybdite (MoO3) for BI/Mo = 1:3, pure α‐Bi2Mo3O12, for Bi/Mo = 2:3, a mixture of β‐Bi2Mo2O9 and α‐Bi2Mo3O12 for Bi/Mo = ]:I, and pure γ.Bi2MoO6 for Bi/Mo = 2:l. The catalytic activity tests show that the catalysts achieved up to 56% conversion of C3H6, with up to 91% selectivity towards C3H40 production. The relative reactivity of the catalysts follow the order of Bi/Mo 2:3 = Bi/Mo 2:1> Bi/Mo 1.3 Bi/Mo 1:1.
Flocculation of silica by High Molecular Weight Polysaccharides
Authors: Foong K. K. , Amal R. , Doherty W. O. S. , Edye L. A. 
Published: August 2010

AbstractFlocculation of colloidal silica particles by naturally occurring polysaccharides is of interest to soft drink and beer manufacturers. Compounds found in floc include polysaccharides, proteins, lipids, waxes and silica. These compounds may originate from the water, sugar, yeast, other beverage ingredients or additives used in the beverage manufacture. In this paper, the flocculation of silica particles by polysaccharide extracts of cane sugar was investigated. The change in the particle size with time was monitored by small angle light scattering. Studies were performed under both static and agitated conditions. Under static conditions, it was observed that faster flocculation kinetics were obtained at higher polysaccharide loadings as the time taken to form the floc network was reduced. Higher silica concentrations resulted in larger and denser flocs. The time lapse prior to the appearance of visible cottonball floc was reduced substantially when the solutions were agitated
Constructed Wetlands for Water Pollution Control ‐ Processes, Parameters and Performance
Authors: Greenway M. 
Published: August 2010

Abstractconstructed wetlands are now recognised as an ecologically sustainable option for water pollution control. Natural wetlands are biologically diverse ecosystem. They provide an array of physical, biological and chemical processes to facilitate the removal, recycling, transformation or immobilisation of sediment and nutrients. Most of these processes are facilitated by the wetland vegetation, associated biofilms and micro‐organisms. Wetland ecosystems are complex and the interactions between abiotic and biotic components are fundamental to an understanding of the treatment processes. Constructed wetlands must therefore be designed to have the attributes of natural wetland ecosystems.The treatment efficiency of a wetland system requires a balance between pollutant loading rate and hydraulic retention time, which is also affected by the water quality and quantity of wastewater effluent or stormwater runoff: The size of a wetland will depend upon the volume of runoff, pollutant characteristics, desired level of treatment and the extent to which the wetland is expected to function as a flood retention basin. Water depth and extent of inundation will determine the types and species of aquatic plants. A combination of emergent, submerged and floating species should be selected.Pretreatment and detention times are crucial parameters to maximise pollutant removal efficiency. Sedimentation ponds are important in stormwater wetlands to remove particulates, but dense vegetated macrophyte zones are essential to enhance the removal of suspended solids and nutrients.Ecologists and engineers need to work together to maximise the treatment efficiency of constructed wetlands. Planners and landscape architects' must become involved to ensure that stormwater wetlands have a multi‐functional role in the urban setting.Constructed wetlands offer the ideal challenge to environmental engineers allowing for the integration of engineering and ecological principles to find the technical solution to fit both nature and society.
Kinetic Model for the Water Oxidation Method for Treating Wastewater Sludges
Authors: Imteaz M.A. , Shanableh A. 
Published: August 2010

AbstractA generalized kinetic model for the hydrothermal oxidation of organic matter in biological wastewater treatment sludge was developed using a simplified first‐order reaction scheme. The model was based on a series of experimental results obtained using a continuous‐flow hydrothermal reactor system used to destroy the organic component of the sludge. Forty‐eight hydrothermal treatment experiments using three sets of inflow conditions were performed. Using excess oxygen, the treatment involved sludge destruction under subcritical (<374d̀C) and supercritical (>374d̀C) water oxidation temperatures. The chemical oxygen demand (COD) was used to measure the organic content and progress of the oxidation reaction. The Arrhenius equation was used to model the reaction rate constant. In the Arrhenius equation, the pre‐exponential factor was fixed and the activation energy was found to vav with temperature. The activation energy increased up to approximately 263d̀C then stabilised at temperatures above 263d̀C. The variation of the activation energy with temperature reflected the complexity of the composition of the organic content of the sludge, which generally consists of proteins, lipids, carbohydrates and fibres. In hydrothermal oxidation, the various organic compounds oxidize at different rates, with the easily oxidized matter being removed first. As such, the activation energy reflected the changing composition of the remaining organic matter with the progress of the oxidation reaction. Above about 263d̀C, the activation energy became virtually independent of temperature. A functional relationship was established between activation energy and average temperature of the reactor. A mathematical model for the destruction of COD in the presence of excess oxygen was set using a kinetic equation having an average pre‐exponential constant and temperature dependent activation energy. With the new equation and known influent COD, efluent COD was simulated for the entire set of experiments and was compared with the actual measured effluent COD.
A Method for Measuring the Strength of Scale Deposits on Heat Transfer Surfaces
Authors: Chew J. Y. M. , Paterson W. R. , Wilson D. I. , Höufling V. , Augustin W. 
Published: August 2010

AbstractThe technique of fluid dynamic gauging has been successfully applied to assess the adhesion characteristics of thin (< 1 mm) layers of calcium sulphate deposits serving as mimics of mineral scales often found on heat transfer surfaces. The shear strength of the scale layers increased on ageing; layers aged for more than 14 hours could not be removed by the gauging fluid flow. The shear stresses imposed by the gauging flow have been shown to be reliably estimated by an analytical result, provided that the flow rate is measured.
Absorption Rate of Carbon Dioxide by K2CO3‐KHCO3 DEA Aqueous Solution
Authors: Takahshi K. , Nii S. , Kawaizumi F. 
Published: August 2010

AbstractGas absorption rates of carbon dioxide from CO2‐air mixtures into K2CO3, K2CO3‐KHCO3, DEA and K2CO3‐KHCO3‐DEA solutions have been measured by using a wetted wall column. The method to determine the enhancement factor of chemical absorption is confirmed by the absorption of carbon dioxide in NaOH solution. The enhancement factor was correlated with the potassium concentration [K+] (= 2[K2CO3 + [KHCO3]), the DEA concentration, and the CO2‐loading ratio of the absorbent. The chemical reaction for CO2, absorption has been expressed by an (m,n)th order irreversible‐reaction model, where the reaction orders are m = 1 for CO2, n = 1.35 for DEA, n = 0.6 for K2CO3, and n = 0.6 and 1.35 for K2CO3 and DEA respectively. Experimental values of the enhancement factor were successfully reproduced by the calculations, where the reaction rate constants reflected the effect of loading ratio of the absorbent with carbon dioxide.
A Soft Sensor Based on Orthogonal Nonlinear Principal Component Analysis
Authors: Zhao Yuhong 
Published: August 2010

AbstractAn accurate on‐line measurement of quality variables is essential for the successful monitoring and control tasks in chemical process operations. A soft sensor is developed based on orthogonal nonlinear principal component analysis, due to its ability to capture the linear and nonlinear features of the data. An orthogonal nonlinear principal component analysis network is utilized to retain a compact representation of the data optimally. Then the linear relationship between the scores and estimated variable is gained by robust linear regression based on M‐estimation. The proposed method is applied on an industrial crude oil atmospheric distillation tower, and illustrated by comparison with other familiar methods. The results have shown that the proposed method gives a better performance over the conventional PCA method and neural networks method.
A Dioid Linear Algebraic Model for a Class of Hybrid Event Graphs
Authors: Zhang Duan , Dai Huaping , Sun Youxian 
Published: August 2010

AbstractHybrid Event Graphs (HEGs), a subclass of Hybrid Petri Nets, are extensions of Timed Event Graphs and Timed Event Multi‐graphs. A set of dioid linear algebraic equations will be inferred as a novel method of analysis a special class of HEG, if we treat the numbers of firings for discrete transitions and the cumulated amount of consumed token for continuous transitions as state‐variables. As a new modelling approach, it clearly illustrates characteristics of both discrete events and continuous events. Based on the algebraic model, the analyses and controls of HEG are more convenient. An example of optimal control is demonstrated.
Removal of SO2 and NOx from Flue Gas by Pulsed Corona Discharges
Authors: Ning C. , Zheng C. G. , Li J. 
Published: August 2010

AbstractA pulsed power supply set and a plasma reactor were designed to investigate the process of removal of SO2 and NO using pulsed corona discharge. It is shown that positive pulsed corona is more effective than negative pulsed in removing both SO2 and NO. Using positive pulsed corona, the energy yields for SO2 and NO removed are 64.3 SO2/kWh and 9.9 gNO/kWh, respectively. The amounts of SO2 or NO removed are independent of the initial concentration and primarily determined by the energy absorbed by flue gas. Removal efficiency of 95% of SO2 can be achieved only by ammonia addition (without pulsed voltage). The removal effectiveness and thermal stability of reaction products can be enhanced when exerting a pulsed voltage. Ammonia is critical to SO2 removal and pulsed corona discharge plays a decisive role in NO removal. Ash itself can only remove a small amount of SO2, but the presence of ash in the flue gas reduced the effectiveness of pulsed corona discharge in SO2 removal. Our results indicate that pulsed corona discharges should be operated at temperatures below 80 d̀C.
Modelling and Simulation of Enzymatic Membrane Reactor for Hydrolysis of Ibuprofen Ester: Separation of Products
Authors: Long Wei Sing , Kamaruddin Azlina Harun , Bhatia Subhash 
Published: August 2010

AbstractThe enzymatic hydrolysis of racemic ibuprofen ester by lipase from Candida rugosa using a hollow‐fiber membrane reactor was studied. The modeling and simulation of an enzymatic membrane reactor was based on the diffusion of (S)‐ibuprofen acid product which leaves the reactor from the lumen side of the capillary fibers. The mathematical model containing a set of nonlinear partial differential equations was solved using orthogonal collocation technique. Orthogonal collocation technique is a weighted residual method based on Jacobi polynomials incorporating orthogonal trial functions. This paper presents a numerical technique of high efficiency, based on the orthogonal collocation of weighted residuals in solving the nonlinear partial differential equations of product diffusion in the capillary fibers. The modelling simulation study provided a better understanding of the process dynamics and product separation in the integrated enzymatic membrane reactor. The simulation study shows that noticeable product diffusion and transport occurred throughout the region of the fiber length, with 63.0% of product concentration (solute concentration) obtained at the exit of the fiber. The input parameters investigated were Peclet number and weighing function parameters, α and β. The best simulation results were achieved at the optimal 10 collocation points.