bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aggregation Behaviour of Gibbsite Crystals in Supersaturated Sodium and Potassium Aluminate Liquors
Authors: Addai‐Mensah Jonas , Li Jun , Prestidge Clive A. 
Published: August 2010

AbstractThe aggregation behaviour of colloidal size gibbsite crystals in synthetic supersaturated caustic aluminate liquors has been investigated as a function of solution alkali metal ion type and Al(III) relative supersaturation in crystallization studies. The results indicate that alkali metal ions (Na+ versus K+) and supersaturation play an influential role in the particle aggregation mechanism. The initial particle aggregation rate is linearly dependent upon Al(III) relative supersaturation, and is significantly greater in Na+ rather than in K+ based suspensions. The study demonstrates that the initial orthokinetic aggregation and subsequent cementation both lead to faster agglomeration in sodium than in potassium aluminate liquors
An Experimental Study of Combustion Characteristics of Petroleum Coke
Authors: Mi T. , Wu Z.S. , Shen B.X. , Liu D.C. , Chen H.P. 
Published: August 2010

AbstractThe combustion characteristics of petroleum coke have been analyzed by the TGA method. The same tests have also been performed to determine the combustion characteristics of 3 types of coals for comparison. The combustion tests and measurement of the pollutant emissions for petroleum coke and a mixture of petroleum coke and coal have been performed in a bench‐scale CFB rig by limestone addition. The pollutant emissions have been measured by an on‐line analyzer. The results show that the index of combustion characteristics of the petroleum coke is higher than that of anthracite, and lower than that of soft coal, and close to lean coal. During the 72‐hour combustion tests, agglomeration and slagging were not observed. The combustion is stable and the pollutant emissions are within the environmental standards.
Some Dynamic Features of Fluidised Bed Reactors for Partial Oxidation of o‐Xylene.
Authors: Abashar M.E.E. 
Published: August 2010

AbstractA dynamic analysis of fluidised bed reactors for the partial oxidation of o‐xylene to phthalic anhydride is presented. The theory of bifurcation, continuation and Poincareé techniques play key roles in the analysis. A new type of period‐adding bifurcation of Poincaré return points is observed and is shown to generate a complex dynamic behaviour. The period adding is classified as a second kind of period adding according to the classification of Holden and Fan [15]. It is found that relaxation oscillations develop through distortion of limit cycles, which have fast and slow motion in the different regions of the phase space.
Transport Process in Electrolytic Membrane Flow Reactor for Producing Strong Acid Water
Authors: Kanki Tatsuo , Katayama Shigeyuki , Sano Noriaki , Tatsumi Yoshiki , Hasegawa Kazuhiko 
Published: August 2010

AbstractIn order to establish the optimum condition for designing an electrolytic membrane flow reactor for producing strong acid water, a test reactor was developed. The pH, concentration of residual chlorine and oxidation reduction potential of the electrolytic acid water produced by the reactor were measured against applied voltage by changing the sodium chloride concentration and feed rate of water. Mass transport accompanied by electrolytic reaction of hydrogen, hydroxide, and the other related ions in the reactor was formulated and the analytical solutions to local concentrations of the related ions were presented. The relevant transport coefficients and physicochemical constants included in the model equations were determined and compared with the experimental data. It was shown that pH, residual chlorine concentration and oxidation reduction potential of the acid water can be accurately estimated from the present analytical solutions with the empirical physicochemical constants.
Effect of Alloying Elements on the Rate of Growth of Individual Pits on Stainless Steels
Authors: Marinovich Y. , Fukutsuka T. , Matsuo Y. , Sugie Y. 
Published: August 2010

AbstractPotentiodynamic polarization curves of five different commercially available stainless steels (SS) were measured in air‐saturated 0.5 M NaCl (25d̀C, pH = 5.2). This data gave useful information on the corrosion behavior of the alloys in this system. It was found that the potential at which pitting begins becomes more positive with increasing Cr and Ni content. A strong relationship between the magnitude of the cathodic current density and the electrode surface area was also observed, and a reason for this observation was suggested. Potentiostatic pitting experiments were performed in order to determine the effect of Cr, Ni, Ti and Mo concentrations on the growth rate of a single pit. However, quantitative data was not obtained since it proved difficult to form a single pit on the SS microelectrode. Instead, many pits formed over the surface thus making quantitative analysis of the current transients impossible. The reason for this phenomenon is still unclear. With 316 SS, both ideal hemispherical and irregularly shaped pits were observed to occur together. From Electron Probe Micro Analysis (EPMA) mapping it was shown that sulfide inclusions were probably not responsible for producing pit nucleation sites on 316 SS.
The Use of Aqueous‐based Emulsion Polymers as Moisture Barrier Coatings for Carton Boards
Authors: Ryan N. M. , Mcnally G. M. , Welsh J. 
Published: August 2010

AbstractThe rate of moisture permeation through paper carton boards can be critical in high peformance packaging applications. Moisture barrier paperboards have been developed using aqueous‐based emulsion polymers, and the results obtained with these materials are presented. These polymers include polyethylene terephthalate (PET), polyvinylidene chloride (PVdC), and styrene‐based emulsions. A range of these coated carton boards were prepared using a hand coater to achieve a controlled range of barrier layer thickness (6–100 microns). Water vapour transmission rate (WVTR) analysis was carried out on these coated boards over a range of temperatures and relative humidities. In addition, some boards were precoated with a primer coat before the application of the barrier topcoat in order to investigate the effect of carton board topography on the moisture barrier properties. Low WVTRs in the range of 3–10 g/(m2 day) were achieved using several of the emulsion polymers. It is clearly shown that pre‐coating the surface of a board with aprimer before applying a barrier coat can lower the WVTR further even with a thinner overall layer of coating. Analysis also illustrated that boards coated on one side exhibited anisotropic characteristics, with lower WVTRs always being achieved when the coated side of the board is adjacent to the higher humidity.
The Effect of Rapid High Temperature Excursions on the Moisture Absorption and Dynamic Mechanical Properties of Carbon Fibre Epoxy Composite Materials
Authors: Mcnally G. M. , Mccourt M. P. , Spedding P. L. 
Published: August 2010

AbstractThe effect of elevated temperature excursions (thermal spiking) on the moisture absorption characteristics and dynamic mechanical properties of Cycom 8 HS carbon fibre epoxy laminates was investigated. Cured laminate samples were preconditioned (65d̀C, 95%R.H.) and these samples were exposed to various thermal spiking (150d̀C/2min) programmes. Dynamic mechanical thermal analysis (DMTA) techniques measured the changes in glass transition temperature (Tg) storage modulus (log E') and damping (Tan δ max) of the laminates as a result of exposure to these environments. The thermal spiking programme was shown to cause an increase in both the amount and rate of moisture absorption of the laminates. These increments were accompanied by a significant decrease in Tg, log E', and Tan δ max. Scanning Electron Microscopy (SEM) analysis also showed the progressive growth of both interlaminar and translaminar micro‐cracks as a result of thermal spiking.
Simulating the Heat Transfer Process of Horizontal Anode Baking Furnace
Authors: Zhang Liqi , Zheng Chuguang , Xu Minghou 
Published: August 2010

AbstractA transient two‐dimensional mathematical model of a horizontal baking furnace is presented. The model combines complicated thermal phenomena in the baking process such as air infiltration, evolution and combustion of volatile matter; combustion of packing coke, and heat losses. The predicted results are in good agreement with measured data. Furthermore, the processes are simulated under different operating conditions such as firing cycle time, airflow and air infiltration. The simulated results indicate that the fuel consumption decreases as the firing cycle time decreases, it is also found that reducing the airflow and air infiltration will assist fuel efficiency. The model has proved to be a useful tool in the process optimization of the baking furnace in the aluminum industry.
Organic Carbon Mineralisation in a Subtropical River
Authors: Pollard P. C. 
Published: August 2010

AbstractMicroorganisms mediate the many biochemical transformations of aquatic ecosystems. Heterotrophic bacteria mineralise most of the total carbon of freshwater and marine ecosystems via the dissolved organic carbon (DOC) fraction. This paper describes the relationship between primary and heterotrophic microbial production in a major subtropical river in South East Queensland, Australia, in dry weather. Stormwater was not the major external source of organic carbon in dry weather. The rate of heterotrophic bacterial production was 4 g C m−2 d−1. The bacteria were decomposing over four times more organic carbon per day than the daily primary production (1.1 g C m−2 d−1). There was not sufficient organic carbon generated through photosynthesis to support the heterotrophic bacterial growth. The river ecosystem was net heterotrophic. However, the concentration of the DOC in the water column remained relatively constant. The bacteria mineralised the DOC pool every few days. This suggests that organic carbon was constantly being supplied to this aquatic ecosystem from a terrestrial source that was readily degradable. The organic carbon pollution was likely due to non‐point sources related to human activities in the catchment.
Explicit Calculation of the Friction Factor for Non‐Newtonian Fluids Using Artificial Neural Networks
Authors: Shayya W. H. , Sablani S. S. , Campo A. 
Published: August 2010

AbstractAn explicit procedure based on artificial neural networks (ANN) was developed for calculating the friction factor (f) for Herschel‐Bulkley fluids under laminar and turbulent flow conditions in closed pipes. The Regula‐Falsi method was used as an iterative procedure to estimate the f values for a range of flow behavior indexes (n), Reynolds numbers (Re), and Hedstrom numbers (He). In developing the ANN model, the input parameters Re and He and the output parameter f were transformed using a logarithmic scale to the base 10, while the input parameter n was taken on a linear scale. An ANN configuration with 16 neurons in each of two hidden layers was found to be optimal. However, a simpler ANN model with eight neurons in one hidden layer also produced reasonably good predictions. These values were in close agreement with those obtained using the numerical technique. The developed ANN model may offer significant advantages when dealing with flow problems that involve repetitive calculations of the friction factor such as those encountered in the hydraulic analysis of viscous non‐Newtonian fluids in pipe networks.
Preliminary Investigation of the Applicability of a Simulated Set‐up to Assess Membrane Fouling by Residence Time Distribution Studies
Authors: Hardin M. T. , Chen X. D. , Rochilly B. , Patel P. 
Published: August 2010

AbstractFouling of membrane systems represents significant cost in time, maintenance and quality in the food and dairy industry. While gross methods of fouling determination such as flux decline and changes in transmembrane pressure are adequate to determine the overall extent of fouling, finer tools are necessary to properly diagnose fouling and to properly assess the effectiveness of cleaning regimes. This study investigates the effect of simulated and actual fouling on the residence time distribution of a single pulse through a single membrane sheet. The differences in residence time distribution observed allow an assessment of the degree and spatial position of fouling material without any need to disrupt the operation of the membrane. This method can be used to assess the need for cleaning and maintenance as well as the effectiveness of cleaning regimes.
Experimental Investigation into Wall Deposition of Milk Powder in Spray Dryers
Authors: Ozmen L. , Langrish T.A.G. 
Published: August 2010

AbstractThe effect of varying the inlet air swirl, inlet air temperature and liquid feed flowrate on the wall deposition flux of skim milk powder has been investigated in a small‐scale, co‐current spray dryer. The spray dyer was a cylinder‐on‐cone unit with diameter 0.8 m and height 2 m, fitted with adjustable swirl vanes surrounding a Delavan GAI two‐fluid atomizer. In this work, swirl vane angles of 0d̀, 25d̀, and 30d̀, inlet air temperatures of 170d̀C, 200d̀C, and 230d̀C, and feed flowrates of 1.4 kg h.−1, 1.6 kg h−1′ and 1.8 kg h−1 were used. The wall deposition flux was found to be significantly influenced by inlet air swirl, with the highest swirl vane angle of 30d̀ giving rise to the highest wall deposition flux of 13 g m−2 h−1. For the skim milk powder, the difference between the particle temperature and sticky‐point temperature was also found to be important in influencing the wall deposition flux. When the outlet particle temperature was furthest above the sticky‐point temperature and the inlet air temperature was lowest ( 170d̀C), then the wall deposition flux was the highest at 16 g m−2 h−1. It is likely that cohesion is the critical process in the wall deposition of milk powder. The effect of grounding the dryer on the deposition flux did not appear to be very significant. The measured deposition rates appear to be representative of those in industrial equipment.
Fractionation of Proteins Using Ultrafiltration: Developments and Challenges
Authors: Wan Y. , Cui Z. , Ghosh R. 
Published: August 2010

AbstractIn recent years ultrafiltration has attracted significant interest as a potential technology for fractionating proteins. Although traditionally thought to be suitable for size‐based separation with high‐throughput but relatively low‐resolution, recent research has demonstrated that it is possible to significantly increase the selectivity in protein fractionation using ultrafiltration while still maintaining its inherent high‐throughput. This paper reviews recent developments in the area of protein fractionation using ultrafiltration, with focus on strategies employed to improve selectivity of separation. Several new techniques, technological developments, and their applications for selective ultrafiltration of proteins are also briefly introduced.
Mathematical Modelling of Non‐Linear Solvent‐Gradient Simulated Moving Bed Chromatographic Separation Processes
Authors: Lu J.‐G. , Sun Y.‐X. 
Published: August 2010

AbstractThe solvent‐gradient operation mode exploited within simulated moving bed (SMB) chromatographic separation processes can be used to improve the efficiency of separations. A detailed model that takes into account non‐linear isotherms, solvent gradient, mass transfer resistance, and the discrete event of port periodic switching, was developed in order to simulate the complex dynamics. All design parameters (number, configuration, length and diameter of columns, particle size) and operating parameters (switching period, flow rates of feed, raffinate, desorbent, extract and recycling flow, feed concentrations, different volume fraction of the weak solvent in desorbent and feed) can be chosen correctly by numerical simulation. This model can facilitate the design, operation, optimization, control and scale‐up of the non‐linear solvent‐gradient SMB (SG‐SMB) units.
Soft Sensor Based on Relevance Vector Machines for Microbiological Fermentation
Authors: Sun Zonghai , Sun Youxian 
Published: August 2010

AbstractMicrobiological fermentation is a type of complicated butch process that is severely nonlinear and time variant system. Many process parameters are required to be monitored and controlled in order to make the microbiological fermentation process successful. Therefore, it is particularly important to measure the process variables, however the instrumentation and sensors available for fermentation control do not cover all the desirable or necessary measurements. In fermentation processes, many important internal variables cannot be measured. Soft sensor has become an indispensable method that measures internal variables in fermentation processes. In this paper, the relevance vector machine has been shown to provide an effective method for constructing a soft sensor for microbiological fermentation. The results obtained have demonstrated that the relevance vector machine soft sensor can estimate the internal variables in fermentation process.
Real‐time Optimization of Acetaldehyde Production Process
Authors: Zhijiang Shao , Jinlin Wang , Jixin Qian 
Published: August 2010

AbstractA real‐time optimization (RTO) system of an acetaldehyde production process is presented in this paper. Data reconciliation with steady state detection and gross error detection, soft sensoring of coarse acetaldehyde concentration, formulation and implementation of yield optimization are discussed in detail. The effect of the RTO system described was validated in an industrial chemical plant, with an average 2.68% increase in yield promotion obtained, which confirms the effectiveness and practicability of the proposed technique.
Electrolyte Inventory Control in a Senate Leach Plant
Authors: Folet M.W. , Christie C.R. , Julien R.H. 
Published: August 2010

AbstractThe regulation of electrolyte inventory in a zinc leaching plant is a challenging process control problem. This paper presents a simple plant‐wide control strategy to maintain level in the Electrolytic and Meeting (E&M) feed tank at the operator‐specified upper limit. Electrolyte production is thereby maximized while ensuring that the outlet temperature of the Hot Stage Purification heat exchanger remains greater than its lower limit, and that levels in the other vessels are kept in their desired ranges. The basic principle underlying this approach is to set throughput at a value which will consume spare capacity in the E&M tank over the next M hours of operation. To tune to strategy, the user must choose the prediction horizon M, as well as maximum allowable rate‐of‐change in plant throughput at a value which will consume spare capacity in the E&M tank over the next M hours of operation. To tune the strategy, the user must in choose the prediction horizon M, as well as a maximum allowable rate‐of‐change in plant throughput. The algorithm is easily programmed using standard DCS functions and does not require the purchase of third‐party optimization software. Simulation results are included which demonstrate that proposed method provides high‐performance control of electrolyte inventory in response to typical plant disturbances, such as reduction in steam header pressure and step changes in E&M feedrate.
A Variable Structure Control Scheme Based on Combined Switching Surfaces for Discrete‐Time Systems
Authors: Zhang Yi‐Bo , Pi Dao‐Ying , Sun You‐Xian 
Published: August 2010

AbstractA scheme based on combined switching surface is introduced. Based on the characters of shifting switching surface (SSS) and conventional switching surface (CSS), a modified exponent reaching law is adopted. The state of system is designed initially staying at the SSS, and then moving to the stable point. As soon as the state moves into the converge range of the CSS, the parameters of the CSS will be determined by the state, and the state will turn to stay at the CSS and move to zero state. By using the scheme of combined switching surfaces, the state always stays on the switching surfaces, and so robustness of systems is guaranteed. Moreover, this scheme could be used in high‐order systems. Simulation results show that the scheme is effective.
A Robust Control Real‐Time Scheduling Design
Authors: Du Bing , Levy David C. 
Published: August 2010

AbstractToday's real‐time systems need to be operated under tighter performance specifications, and require more and more constraints to be satisfied. These specifications can only be met when system nonlinearities and constraints are explicitly considered. The paper presents a new H∞‐nonlinear model predictive control scheduling method to regulate the deadline miss ratio and CPU utilization, and to satisfy the performance specifications. It is difficult to accurately model a real‐time multimedia system. H∞ control theory addresses the issue of worst‐case controller design for linear plants subjects to unknown additive disturbances and plant uncertainties. Model predictive methodology is extended to H∞ controllers for nonlinear systems. A scheduling architecture that includes model uncertainty is proposed. We firstly integrate H∞ robust optimal control and scheduling theory in order to satisfy trade‐offs between control performance and computing resource utilization. Performance evaluation results are demonstrated by simulated examples, and earliest‐deadline first (EDF) scheduling results are compared.
The Effects of Solid Sorbents on Heavy Metal Emission under Various Combustion
Authors: Han J. , Xu M.H. , Zeng H. , Zhang Z. , Yi F. 
Published: August 2010

AbstractExperimental studies on heavy metals captured by solid sorbents were carried out in a downflow reactor. The effects of various sorbents on heavy metal emissions under different combustion conditions were investigated. The operating parameters evaluated included: (1) different ratios of sorbent/coal (2%, 4% and 6%); (2) elevated temperatures (950 d̀C, 1100d̀C and 1250d̀C); (3) un‐staged and staged combustion. The experimental results indicated that the best metal capture efficiency occurs when the ratio of bauxite/coal is 2%, and 4% for both limestone/coal and calcium sulfate/coal systems. It was found that increasing temperature has a negative effect on heavy metal capture by sorbents. The experimental results also showed that the staged combustion has no effect on heavy metal removal, although it is effective in the control of NOx emissions. The leaching tests indicated that the mechanisms of heavy metal capture by solid sorbents include both physical adsorption and chemical reaction.
Issues in Plant Cell Culture Engineering for Enhancement of Productivity
Authors: Abdullah Mohd A. , Ali Abdul M. , Lajis Nordin H. , Marziah M. , Sinskey Anthony J. , Rha Chokyun 
Published: August 2010

AbstractPlant cell culture is seen as an alternative source to whole plants for the production of useful compounds, such as dyes, pharmaceuticals, perfumes and insecticides. Despite intensive research for the last 30 years, only a few products have reached commercial production in bioreactors, and the number is far less than those commercialized for bacterial and animal cells. Several biological challenges including slow cell growth, low productivity, compartmentation, metabolite channelling and poor metabolite secretion have hampered the realization of commercialization of plant cell products. Other engineering and technological problems include cell aggregation, plant cell shear sensitivity, foaming and lack of automation. Several strategies are being explored to improve productivity including medium optimization and cultural conditions, and the understanding of biochemical and signal transduction pathways. In plant cell culture process development, there is a great need to explore a more rational approach through metabolic and genetic engineering by making use of advanced technologies in genomic, transcriptomic, proteomic and metabolomic analyses. These should be integrated with developments in bioprocess and systems engineering.